1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 
  22 /*
  23  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Copyright (c) 2013, Joyent, Inc. All rights reserved.
  25  * Copyright (c) 2012 by Delphix. All rights reserved.
  26  */
  27 
  28 /*
  29  * DTrace - Dynamic Tracing for Solaris
  30  *
  31  * This is the implementation of the Solaris Dynamic Tracing framework
  32  * (DTrace).  The user-visible interface to DTrace is described at length in
  33  * the "Solaris Dynamic Tracing Guide".  The interfaces between the libdtrace
  34  * library, the in-kernel DTrace framework, and the DTrace providers are
  35  * described in the block comments in the <sys/dtrace.h> header file.  The
  36  * internal architecture of DTrace is described in the block comments in the
  37  * <sys/dtrace_impl.h> header file.  The comments contained within the DTrace
  38  * implementation very much assume mastery of all of these sources; if one has
  39  * an unanswered question about the implementation, one should consult them
  40  * first.
  41  *
  42  * The functions here are ordered roughly as follows:
  43  *
  44  *   - Probe context functions
  45  *   - Probe hashing functions
  46  *   - Non-probe context utility functions
  47  *   - Matching functions
  48  *   - Provider-to-Framework API functions
  49  *   - Probe management functions
  50  *   - DIF object functions
  51  *   - Format functions
  52  *   - Predicate functions
  53  *   - ECB functions
  54  *   - Buffer functions
  55  *   - Enabling functions
  56  *   - DOF functions
  57  *   - Anonymous enabling functions
  58  *   - Consumer state functions
  59  *   - Helper functions
  60  *   - Hook functions
  61  *   - Driver cookbook functions
  62  *
  63  * Each group of functions begins with a block comment labelled the "DTrace
  64  * [Group] Functions", allowing one to find each block by searching forward
  65  * on capital-f functions.
  66  */
  67 #include <sys/errno.h>
  68 #include <sys/stat.h>
  69 #include <sys/modctl.h>
  70 #include <sys/conf.h>
  71 #include <sys/systm.h>
  72 #include <sys/ddi.h>
  73 #include <sys/sunddi.h>
  74 #include <sys/cpuvar.h>
  75 #include <sys/kmem.h>
  76 #include <sys/strsubr.h>
  77 #include <sys/sysmacros.h>
  78 #include <sys/dtrace_impl.h>
  79 #include <sys/atomic.h>
  80 #include <sys/cmn_err.h>
  81 #include <sys/mutex_impl.h>
  82 #include <sys/rwlock_impl.h>
  83 #include <sys/ctf_api.h>
  84 #include <sys/panic.h>
  85 #include <sys/priv_impl.h>
  86 #include <sys/policy.h>
  87 #include <sys/cred_impl.h>
  88 #include <sys/procfs_isa.h>
  89 #include <sys/taskq.h>
  90 #include <sys/mkdev.h>
  91 #include <sys/kdi.h>
  92 #include <sys/zone.h>
  93 #include <sys/socket.h>
  94 #include <netinet/in.h>
  95 
  96 /*
  97  * DTrace Tunable Variables
  98  *
  99  * The following variables may be tuned by adding a line to /etc/system that
 100  * includes both the name of the DTrace module ("dtrace") and the name of the
 101  * variable.  For example:
 102  *
 103  *   set dtrace:dtrace_destructive_disallow = 1
 104  *
 105  * In general, the only variables that one should be tuning this way are those
 106  * that affect system-wide DTrace behavior, and for which the default behavior
 107  * is undesirable.  Most of these variables are tunable on a per-consumer
 108  * basis using DTrace options, and need not be tuned on a system-wide basis.
 109  * When tuning these variables, avoid pathological values; while some attempt
 110  * is made to verify the integrity of these variables, they are not considered
 111  * part of the supported interface to DTrace, and they are therefore not
 112  * checked comprehensively.  Further, these variables should not be tuned
 113  * dynamically via "mdb -kw" or other means; they should only be tuned via
 114  * /etc/system.
 115  */
 116 int             dtrace_destructive_disallow = 0;
 117 dtrace_optval_t dtrace_nonroot_maxsize = (16 * 1024 * 1024);
 118 size_t          dtrace_difo_maxsize = (256 * 1024);
 119 dtrace_optval_t dtrace_dof_maxsize = (256 * 1024);
 120 size_t          dtrace_global_maxsize = (16 * 1024);
 121 size_t          dtrace_actions_max = (16 * 1024);
 122 size_t          dtrace_retain_max = 1024;
 123 dtrace_optval_t dtrace_helper_actions_max = 1024;
 124 dtrace_optval_t dtrace_helper_providers_max = 32;
 125 dtrace_optval_t dtrace_dstate_defsize = (1 * 1024 * 1024);
 126 size_t          dtrace_strsize_default = 256;
 127 dtrace_optval_t dtrace_cleanrate_default = 9900990;             /* 101 hz */
 128 dtrace_optval_t dtrace_cleanrate_min = 200000;                  /* 5000 hz */
 129 dtrace_optval_t dtrace_cleanrate_max = (uint64_t)60 * NANOSEC;  /* 1/minute */
 130 dtrace_optval_t dtrace_aggrate_default = NANOSEC;               /* 1 hz */
 131 dtrace_optval_t dtrace_statusrate_default = NANOSEC;            /* 1 hz */
 132 dtrace_optval_t dtrace_statusrate_max = (hrtime_t)10 * NANOSEC;  /* 6/minute */
 133 dtrace_optval_t dtrace_switchrate_default = NANOSEC;            /* 1 hz */
 134 dtrace_optval_t dtrace_nspec_default = 1;
 135 dtrace_optval_t dtrace_specsize_default = 32 * 1024;
 136 dtrace_optval_t dtrace_stackframes_default = 20;
 137 dtrace_optval_t dtrace_ustackframes_default = 20;
 138 dtrace_optval_t dtrace_jstackframes_default = 50;
 139 dtrace_optval_t dtrace_jstackstrsize_default = 512;
 140 int             dtrace_msgdsize_max = 128;
 141 hrtime_t        dtrace_chill_max = 500 * (NANOSEC / MILLISEC);  /* 500 ms */
 142 hrtime_t        dtrace_chill_interval = NANOSEC;                /* 1000 ms */
 143 int             dtrace_devdepth_max = 32;
 144 int             dtrace_err_verbose;
 145 hrtime_t        dtrace_deadman_interval = NANOSEC;
 146 hrtime_t        dtrace_deadman_timeout = (hrtime_t)10 * NANOSEC;
 147 hrtime_t        dtrace_deadman_user = (hrtime_t)30 * NANOSEC;
 148 hrtime_t        dtrace_unregister_defunct_reap = (hrtime_t)60 * NANOSEC;
 149 
 150 /*
 151  * DTrace External Variables
 152  *
 153  * As dtrace(7D) is a kernel module, any DTrace variables are obviously
 154  * available to DTrace consumers via the backtick (`) syntax.  One of these,
 155  * dtrace_zero, is made deliberately so:  it is provided as a source of
 156  * well-known, zero-filled memory.  While this variable is not documented,
 157  * it is used by some translators as an implementation detail.
 158  */
 159 const char      dtrace_zero[256] = { 0 };       /* zero-filled memory */
 160 
 161 /*
 162  * DTrace Internal Variables
 163  */
 164 static dev_info_t       *dtrace_devi;           /* device info */
 165 static vmem_t           *dtrace_arena;          /* probe ID arena */
 166 static vmem_t           *dtrace_minor;          /* minor number arena */
 167 static taskq_t          *dtrace_taskq;          /* task queue */
 168 static dtrace_probe_t   **dtrace_probes;        /* array of all probes */
 169 static int              dtrace_nprobes;         /* number of probes */
 170 static dtrace_provider_t *dtrace_provider;      /* provider list */
 171 static dtrace_meta_t    *dtrace_meta_pid;       /* user-land meta provider */
 172 static int              dtrace_opens;           /* number of opens */
 173 static int              dtrace_helpers;         /* number of helpers */
 174 static int              dtrace_getf;            /* number of unpriv getf()s */
 175 static void             *dtrace_softstate;      /* softstate pointer */
 176 static dtrace_hash_t    *dtrace_bymod;          /* probes hashed by module */
 177 static dtrace_hash_t    *dtrace_byfunc;         /* probes hashed by function */
 178 static dtrace_hash_t    *dtrace_byname;         /* probes hashed by name */
 179 static dtrace_toxrange_t *dtrace_toxrange;      /* toxic range array */
 180 static int              dtrace_toxranges;       /* number of toxic ranges */
 181 static int              dtrace_toxranges_max;   /* size of toxic range array */
 182 static dtrace_anon_t    dtrace_anon;            /* anonymous enabling */
 183 static kmem_cache_t     *dtrace_state_cache;    /* cache for dynamic state */
 184 static uint64_t         dtrace_vtime_references; /* number of vtimestamp refs */
 185 static kthread_t        *dtrace_panicked;       /* panicking thread */
 186 static dtrace_ecb_t     *dtrace_ecb_create_cache; /* cached created ECB */
 187 static dtrace_genid_t   dtrace_probegen;        /* current probe generation */
 188 static dtrace_helpers_t *dtrace_deferred_pid;   /* deferred helper list */
 189 static dtrace_enabling_t *dtrace_retained;      /* list of retained enablings */
 190 static dtrace_genid_t   dtrace_retained_gen;    /* current retained enab gen */
 191 static dtrace_dynvar_t  dtrace_dynhash_sink;    /* end of dynamic hash chains */
 192 static int              dtrace_dynvar_failclean; /* dynvars failed to clean */
 193 
 194 /*
 195  * DTrace Locking
 196  * DTrace is protected by three (relatively coarse-grained) locks:
 197  *
 198  * (1) dtrace_lock is required to manipulate essentially any DTrace state,
 199  *     including enabling state, probes, ECBs, consumer state, helper state,
 200  *     etc.  Importantly, dtrace_lock is _not_ required when in probe context;
 201  *     probe context is lock-free -- synchronization is handled via the
 202  *     dtrace_sync() cross call mechanism.
 203  *
 204  * (2) dtrace_provider_lock is required when manipulating provider state, or
 205  *     when provider state must be held constant.
 206  *
 207  * (3) dtrace_meta_lock is required when manipulating meta provider state, or
 208  *     when meta provider state must be held constant.
 209  *
 210  * The lock ordering between these three locks is dtrace_meta_lock before
 211  * dtrace_provider_lock before dtrace_lock.  (In particular, there are
 212  * several places where dtrace_provider_lock is held by the framework as it
 213  * calls into the providers -- which then call back into the framework,
 214  * grabbing dtrace_lock.)
 215  *
 216  * There are two other locks in the mix:  mod_lock and cpu_lock.  With respect
 217  * to dtrace_provider_lock and dtrace_lock, cpu_lock continues its historical
 218  * role as a coarse-grained lock; it is acquired before both of these locks.
 219  * With respect to dtrace_meta_lock, its behavior is stranger:  cpu_lock must
 220  * be acquired _between_ dtrace_meta_lock and any other DTrace locks.
 221  * mod_lock is similar with respect to dtrace_provider_lock in that it must be
 222  * acquired _between_ dtrace_provider_lock and dtrace_lock.
 223  */
 224 static kmutex_t         dtrace_lock;            /* probe state lock */
 225 static kmutex_t         dtrace_provider_lock;   /* provider state lock */
 226 static kmutex_t         dtrace_meta_lock;       /* meta-provider state lock */
 227 
 228 /*
 229  * DTrace Provider Variables
 230  *
 231  * These are the variables relating to DTrace as a provider (that is, the
 232  * provider of the BEGIN, END, and ERROR probes).
 233  */
 234 static dtrace_pattr_t   dtrace_provider_attr = {
 235 { DTRACE_STABILITY_STABLE, DTRACE_STABILITY_STABLE, DTRACE_CLASS_COMMON },
 236 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
 237 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
 238 { DTRACE_STABILITY_STABLE, DTRACE_STABILITY_STABLE, DTRACE_CLASS_COMMON },
 239 { DTRACE_STABILITY_STABLE, DTRACE_STABILITY_STABLE, DTRACE_CLASS_COMMON },
 240 };
 241 
 242 static void
 243 dtrace_nullop(void)
 244 {}
 245 
 246 static int
 247 dtrace_enable_nullop(void)
 248 {
 249         return (0);
 250 }
 251 
 252 static dtrace_pops_t    dtrace_provider_ops = {
 253         (void (*)(void *, const dtrace_probedesc_t *))dtrace_nullop,
 254         (void (*)(void *, struct modctl *))dtrace_nullop,
 255         (int (*)(void *, dtrace_id_t, void *))dtrace_enable_nullop,
 256         (void (*)(void *, dtrace_id_t, void *))dtrace_nullop,
 257         (void (*)(void *, dtrace_id_t, void *))dtrace_nullop,
 258         (void (*)(void *, dtrace_id_t, void *))dtrace_nullop,
 259         NULL,
 260         NULL,
 261         NULL,
 262         (void (*)(void *, dtrace_id_t, void *))dtrace_nullop
 263 };
 264 
 265 static dtrace_id_t      dtrace_probeid_begin;   /* special BEGIN probe */
 266 static dtrace_id_t      dtrace_probeid_end;     /* special END probe */
 267 dtrace_id_t             dtrace_probeid_error;   /* special ERROR probe */
 268 
 269 /*
 270  * DTrace Helper Tracing Variables
 271  */
 272 uint32_t dtrace_helptrace_next = 0;
 273 uint32_t dtrace_helptrace_nlocals;
 274 char    *dtrace_helptrace_buffer;
 275 int     dtrace_helptrace_bufsize = 512 * 1024;
 276 
 277 #ifdef DEBUG
 278 int     dtrace_helptrace_enabled = 1;
 279 #else
 280 int     dtrace_helptrace_enabled = 0;
 281 #endif
 282 
 283 /*
 284  * DTrace Error Hashing
 285  *
 286  * On DEBUG kernels, DTrace will track the errors that has seen in a hash
 287  * table.  This is very useful for checking coverage of tests that are
 288  * expected to induce DIF or DOF processing errors, and may be useful for
 289  * debugging problems in the DIF code generator or in DOF generation .  The
 290  * error hash may be examined with the ::dtrace_errhash MDB dcmd.
 291  */
 292 #ifdef DEBUG
 293 static dtrace_errhash_t dtrace_errhash[DTRACE_ERRHASHSZ];
 294 static const char *dtrace_errlast;
 295 static kthread_t *dtrace_errthread;
 296 static kmutex_t dtrace_errlock;
 297 #endif
 298 
 299 /*
 300  * DTrace Macros and Constants
 301  *
 302  * These are various macros that are useful in various spots in the
 303  * implementation, along with a few random constants that have no meaning
 304  * outside of the implementation.  There is no real structure to this cpp
 305  * mishmash -- but is there ever?
 306  */
 307 #define DTRACE_HASHSTR(hash, probe)     \
 308         dtrace_hash_str(*((char **)((uintptr_t)(probe) + (hash)->dth_stroffs)))
 309 
 310 #define DTRACE_HASHNEXT(hash, probe)    \
 311         (dtrace_probe_t **)((uintptr_t)(probe) + (hash)->dth_nextoffs)
 312 
 313 #define DTRACE_HASHPREV(hash, probe)    \
 314         (dtrace_probe_t **)((uintptr_t)(probe) + (hash)->dth_prevoffs)
 315 
 316 #define DTRACE_HASHEQ(hash, lhs, rhs)   \
 317         (strcmp(*((char **)((uintptr_t)(lhs) + (hash)->dth_stroffs)), \
 318             *((char **)((uintptr_t)(rhs) + (hash)->dth_stroffs))) == 0)
 319 
 320 #define DTRACE_AGGHASHSIZE_SLEW         17
 321 
 322 #define DTRACE_V4MAPPED_OFFSET          (sizeof (uint32_t) * 3)
 323 
 324 /*
 325  * The key for a thread-local variable consists of the lower 61 bits of the
 326  * t_did, plus the 3 bits of the highest active interrupt above LOCK_LEVEL.
 327  * We add DIF_VARIABLE_MAX to t_did to assure that the thread key is never
 328  * equal to a variable identifier.  This is necessary (but not sufficient) to
 329  * assure that global associative arrays never collide with thread-local
 330  * variables.  To guarantee that they cannot collide, we must also define the
 331  * order for keying dynamic variables.  That order is:
 332  *
 333  *   [ key0 ] ... [ keyn ] [ variable-key ] [ tls-key ]
 334  *
 335  * Because the variable-key and the tls-key are in orthogonal spaces, there is
 336  * no way for a global variable key signature to match a thread-local key
 337  * signature.
 338  */
 339 #define DTRACE_TLS_THRKEY(where) { \
 340         uint_t intr = 0; \
 341         uint_t actv = CPU->cpu_intr_actv >> (LOCK_LEVEL + 1); \
 342         for (; actv; actv >>= 1) \
 343                 intr++; \
 344         ASSERT(intr < (1 << 3)); \
 345         (where) = ((curthread->t_did + DIF_VARIABLE_MAX) & \
 346             (((uint64_t)1 << 61) - 1)) | ((uint64_t)intr << 61); \
 347 }
 348 
 349 #define DT_BSWAP_8(x)   ((x) & 0xff)
 350 #define DT_BSWAP_16(x)  ((DT_BSWAP_8(x) << 8) | DT_BSWAP_8((x) >> 8))
 351 #define DT_BSWAP_32(x)  ((DT_BSWAP_16(x) << 16) | DT_BSWAP_16((x) >> 16))
 352 #define DT_BSWAP_64(x)  ((DT_BSWAP_32(x) << 32) | DT_BSWAP_32((x) >> 32))
 353 
 354 #define DT_MASK_LO 0x00000000FFFFFFFFULL
 355 
 356 #define DTRACE_STORE(type, tomax, offset, what) \
 357         *((type *)((uintptr_t)(tomax) + (uintptr_t)offset)) = (type)(what);
 358 
 359 #ifndef __x86
 360 #define DTRACE_ALIGNCHECK(addr, size, flags)                            \
 361         if (addr & (size - 1)) {                                    \
 362                 *flags |= CPU_DTRACE_BADALIGN;                          \
 363                 cpu_core[CPU->cpu_id].cpuc_dtrace_illval = addr;     \
 364                 return (0);                                             \
 365         }
 366 #else
 367 #define DTRACE_ALIGNCHECK(addr, size, flags)
 368 #endif
 369 
 370 /*
 371  * Test whether a range of memory starting at testaddr of size testsz falls
 372  * within the range of memory described by addr, sz.  We take care to avoid
 373  * problems with overflow and underflow of the unsigned quantities, and
 374  * disallow all negative sizes.  Ranges of size 0 are allowed.
 375  */
 376 #define DTRACE_INRANGE(testaddr, testsz, baseaddr, basesz) \
 377         ((testaddr) - (uintptr_t)(baseaddr) < (basesz) && \
 378         (testaddr) + (testsz) - (uintptr_t)(baseaddr) <= (basesz) && \
 379         (testaddr) + (testsz) >= (testaddr))
 380 
 381 /*
 382  * Test whether alloc_sz bytes will fit in the scratch region.  We isolate
 383  * alloc_sz on the righthand side of the comparison in order to avoid overflow
 384  * or underflow in the comparison with it.  This is simpler than the INRANGE
 385  * check above, because we know that the dtms_scratch_ptr is valid in the
 386  * range.  Allocations of size zero are allowed.
 387  */
 388 #define DTRACE_INSCRATCH(mstate, alloc_sz) \
 389         ((mstate)->dtms_scratch_base + (mstate)->dtms_scratch_size - \
 390         (mstate)->dtms_scratch_ptr >= (alloc_sz))
 391 
 392 #define DTRACE_LOADFUNC(bits)                                           \
 393 /*CSTYLED*/                                                             \
 394 uint##bits##_t                                                          \
 395 dtrace_load##bits(uintptr_t addr)                                       \
 396 {                                                                       \
 397         size_t size = bits / NBBY;                                      \
 398         /*CSTYLED*/                                                     \
 399         uint##bits##_t rval;                                            \
 400         int i;                                                          \
 401         volatile uint16_t *flags = (volatile uint16_t *)                \
 402             &cpu_core[CPU->cpu_id].cpuc_dtrace_flags;                    \
 403                                                                         \
 404         DTRACE_ALIGNCHECK(addr, size, flags);                           \
 405                                                                         \
 406         for (i = 0; i < dtrace_toxranges; i++) {                     \
 407                 if (addr >= dtrace_toxrange[i].dtt_limit)            \
 408                         continue;                                       \
 409                                                                         \
 410                 if (addr + size <= dtrace_toxrange[i].dtt_base)              \
 411                         continue;                                       \
 412                                                                         \
 413                 /*                                                      \
 414                  * This address falls within a toxic region; return 0.  \
 415                  */                                                     \
 416                 *flags |= CPU_DTRACE_BADADDR;                           \
 417                 cpu_core[CPU->cpu_id].cpuc_dtrace_illval = addr;     \
 418                 return (0);                                             \
 419         }                                                               \
 420                                                                         \
 421         *flags |= CPU_DTRACE_NOFAULT;                                   \
 422         /*CSTYLED*/                                                     \
 423         rval = *((volatile uint##bits##_t *)addr);                      \
 424         *flags &= ~CPU_DTRACE_NOFAULT;                                      \
 425                                                                         \
 426         return (!(*flags & CPU_DTRACE_FAULT) ? rval : 0);           \
 427 }
 428 
 429 #ifdef _LP64
 430 #define dtrace_loadptr  dtrace_load64
 431 #else
 432 #define dtrace_loadptr  dtrace_load32
 433 #endif
 434 
 435 #define DTRACE_DYNHASH_FREE     0
 436 #define DTRACE_DYNHASH_SINK     1
 437 #define DTRACE_DYNHASH_VALID    2
 438 
 439 #define DTRACE_MATCH_FAIL       -1
 440 #define DTRACE_MATCH_NEXT       0
 441 #define DTRACE_MATCH_DONE       1
 442 #define DTRACE_ANCHORED(probe)  ((probe)->dtpr_func[0] != '\0')
 443 #define DTRACE_STATE_ALIGN      64
 444 
 445 #define DTRACE_FLAGS2FLT(flags)                                         \
 446         (((flags) & CPU_DTRACE_BADADDR) ? DTRACEFLT_BADADDR :               \
 447         ((flags) & CPU_DTRACE_ILLOP) ? DTRACEFLT_ILLOP :            \
 448         ((flags) & CPU_DTRACE_DIVZERO) ? DTRACEFLT_DIVZERO :                \
 449         ((flags) & CPU_DTRACE_KPRIV) ? DTRACEFLT_KPRIV :            \
 450         ((flags) & CPU_DTRACE_UPRIV) ? DTRACEFLT_UPRIV :            \
 451         ((flags) & CPU_DTRACE_TUPOFLOW) ?  DTRACEFLT_TUPOFLOW :             \
 452         ((flags) & CPU_DTRACE_BADALIGN) ?  DTRACEFLT_BADALIGN :             \
 453         ((flags) & CPU_DTRACE_NOSCRATCH) ?  DTRACEFLT_NOSCRATCH :   \
 454         ((flags) & CPU_DTRACE_BADSTACK) ?  DTRACEFLT_BADSTACK :             \
 455         DTRACEFLT_UNKNOWN)
 456 
 457 #define DTRACEACT_ISSTRING(act)                                         \
 458         ((act)->dta_kind == DTRACEACT_DIFEXPR &&                     \
 459         (act)->dta_difo->dtdo_rtype.dtdt_kind == DIF_TYPE_STRING)
 460 
 461 static size_t dtrace_strlen(const char *, size_t);
 462 static dtrace_probe_t *dtrace_probe_lookup_id(dtrace_id_t id);
 463 static void dtrace_enabling_provide(dtrace_provider_t *);
 464 static int dtrace_enabling_match(dtrace_enabling_t *, int *);
 465 static void dtrace_enabling_matchall(void);
 466 static void dtrace_enabling_reap(void);
 467 static dtrace_state_t *dtrace_anon_grab(void);
 468 static uint64_t dtrace_helper(int, dtrace_mstate_t *,
 469     dtrace_state_t *, uint64_t, uint64_t);
 470 static dtrace_helpers_t *dtrace_helpers_create(proc_t *);
 471 static void dtrace_buffer_drop(dtrace_buffer_t *);
 472 static int dtrace_buffer_consumed(dtrace_buffer_t *, hrtime_t when);
 473 static intptr_t dtrace_buffer_reserve(dtrace_buffer_t *, size_t, size_t,
 474     dtrace_state_t *, dtrace_mstate_t *);
 475 static int dtrace_state_option(dtrace_state_t *, dtrace_optid_t,
 476     dtrace_optval_t);
 477 static int dtrace_ecb_create_enable(dtrace_probe_t *, void *);
 478 static void dtrace_helper_provider_destroy(dtrace_helper_provider_t *);
 479 static int dtrace_priv_proc(dtrace_state_t *, dtrace_mstate_t *);
 480 static void dtrace_getf_barrier(void);
 481 
 482 /*
 483  * DTrace Probe Context Functions
 484  *
 485  * These functions are called from probe context.  Because probe context is
 486  * any context in which C may be called, arbitrarily locks may be held,
 487  * interrupts may be disabled, we may be in arbitrary dispatched state, etc.
 488  * As a result, functions called from probe context may only call other DTrace
 489  * support functions -- they may not interact at all with the system at large.
 490  * (Note that the ASSERT macro is made probe-context safe by redefining it in
 491  * terms of dtrace_assfail(), a probe-context safe function.) If arbitrary
 492  * loads are to be performed from probe context, they _must_ be in terms of
 493  * the safe dtrace_load*() variants.
 494  *
 495  * Some functions in this block are not actually called from probe context;
 496  * for these functions, there will be a comment above the function reading
 497  * "Note:  not called from probe context."
 498  */
 499 void
 500 dtrace_panic(const char *format, ...)
 501 {
 502         va_list alist;
 503 
 504         va_start(alist, format);
 505         dtrace_vpanic(format, alist);
 506         va_end(alist);
 507 }
 508 
 509 int
 510 dtrace_assfail(const char *a, const char *f, int l)
 511 {
 512         dtrace_panic("assertion failed: %s, file: %s, line: %d", a, f, l);
 513 
 514         /*
 515          * We just need something here that even the most clever compiler
 516          * cannot optimize away.
 517          */
 518         return (a[(uintptr_t)f]);
 519 }
 520 
 521 /*
 522  * Atomically increment a specified error counter from probe context.
 523  */
 524 static void
 525 dtrace_error(uint32_t *counter)
 526 {
 527         /*
 528          * Most counters stored to in probe context are per-CPU counters.
 529          * However, there are some error conditions that are sufficiently
 530          * arcane that they don't merit per-CPU storage.  If these counters
 531          * are incremented concurrently on different CPUs, scalability will be
 532          * adversely affected -- but we don't expect them to be white-hot in a
 533          * correctly constructed enabling...
 534          */
 535         uint32_t oval, nval;
 536 
 537         do {
 538                 oval = *counter;
 539 
 540                 if ((nval = oval + 1) == 0) {
 541                         /*
 542                          * If the counter would wrap, set it to 1 -- assuring
 543                          * that the counter is never zero when we have seen
 544                          * errors.  (The counter must be 32-bits because we
 545                          * aren't guaranteed a 64-bit compare&swap operation.)
 546                          * To save this code both the infamy of being fingered
 547                          * by a priggish news story and the indignity of being
 548                          * the target of a neo-puritan witch trial, we're
 549                          * carefully avoiding any colorful description of the
 550                          * likelihood of this condition -- but suffice it to
 551                          * say that it is only slightly more likely than the
 552                          * overflow of predicate cache IDs, as discussed in
 553                          * dtrace_predicate_create().
 554                          */
 555                         nval = 1;
 556                 }
 557         } while (dtrace_cas32(counter, oval, nval) != oval);
 558 }
 559 
 560 /*
 561  * Use the DTRACE_LOADFUNC macro to define functions for each of loading a
 562  * uint8_t, a uint16_t, a uint32_t and a uint64_t.
 563  */
 564 DTRACE_LOADFUNC(8)
 565 DTRACE_LOADFUNC(16)
 566 DTRACE_LOADFUNC(32)
 567 DTRACE_LOADFUNC(64)
 568 
 569 static int
 570 dtrace_inscratch(uintptr_t dest, size_t size, dtrace_mstate_t *mstate)
 571 {
 572         if (dest < mstate->dtms_scratch_base)
 573                 return (0);
 574 
 575         if (dest + size < dest)
 576                 return (0);
 577 
 578         if (dest + size > mstate->dtms_scratch_ptr)
 579                 return (0);
 580 
 581         return (1);
 582 }
 583 
 584 static int
 585 dtrace_canstore_statvar(uint64_t addr, size_t sz,
 586     dtrace_statvar_t **svars, int nsvars)
 587 {
 588         int i;
 589 
 590         for (i = 0; i < nsvars; i++) {
 591                 dtrace_statvar_t *svar = svars[i];
 592 
 593                 if (svar == NULL || svar->dtsv_size == 0)
 594                         continue;
 595 
 596                 if (DTRACE_INRANGE(addr, sz, svar->dtsv_data, svar->dtsv_size))
 597                         return (1);
 598         }
 599 
 600         return (0);
 601 }
 602 
 603 /*
 604  * Check to see if the address is within a memory region to which a store may
 605  * be issued.  This includes the DTrace scratch areas, and any DTrace variable
 606  * region.  The caller of dtrace_canstore() is responsible for performing any
 607  * alignment checks that are needed before stores are actually executed.
 608  */
 609 static int
 610 dtrace_canstore(uint64_t addr, size_t sz, dtrace_mstate_t *mstate,
 611     dtrace_vstate_t *vstate)
 612 {
 613         /*
 614          * First, check to see if the address is in scratch space...
 615          */
 616         if (DTRACE_INRANGE(addr, sz, mstate->dtms_scratch_base,
 617             mstate->dtms_scratch_size))
 618                 return (1);
 619 
 620         /*
 621          * Now check to see if it's a dynamic variable.  This check will pick
 622          * up both thread-local variables and any global dynamically-allocated
 623          * variables.
 624          */
 625         if (DTRACE_INRANGE(addr, sz, vstate->dtvs_dynvars.dtds_base,
 626             vstate->dtvs_dynvars.dtds_size)) {
 627                 dtrace_dstate_t *dstate = &vstate->dtvs_dynvars;
 628                 uintptr_t base = (uintptr_t)dstate->dtds_base +
 629                     (dstate->dtds_hashsize * sizeof (dtrace_dynhash_t));
 630                 uintptr_t chunkoffs;
 631 
 632                 /*
 633                  * Before we assume that we can store here, we need to make
 634                  * sure that it isn't in our metadata -- storing to our
 635                  * dynamic variable metadata would corrupt our state.  For
 636                  * the range to not include any dynamic variable metadata,
 637                  * it must:
 638                  *
 639                  *      (1) Start above the hash table that is at the base of
 640                  *      the dynamic variable space
 641                  *
 642                  *      (2) Have a starting chunk offset that is beyond the
 643                  *      dtrace_dynvar_t that is at the base of every chunk
 644                  *
 645                  *      (3) Not span a chunk boundary
 646                  *
 647                  */
 648                 if (addr < base)
 649                         return (0);
 650 
 651                 chunkoffs = (addr - base) % dstate->dtds_chunksize;
 652 
 653                 if (chunkoffs < sizeof (dtrace_dynvar_t))
 654                         return (0);
 655 
 656                 if (chunkoffs + sz > dstate->dtds_chunksize)
 657                         return (0);
 658 
 659                 return (1);
 660         }
 661 
 662         /*
 663          * Finally, check the static local and global variables.  These checks
 664          * take the longest, so we perform them last.
 665          */
 666         if (dtrace_canstore_statvar(addr, sz,
 667             vstate->dtvs_locals, vstate->dtvs_nlocals))
 668                 return (1);
 669 
 670         if (dtrace_canstore_statvar(addr, sz,
 671             vstate->dtvs_globals, vstate->dtvs_nglobals))
 672                 return (1);
 673 
 674         return (0);
 675 }
 676 
 677 
 678 /*
 679  * Convenience routine to check to see if the address is within a memory
 680  * region in which a load may be issued given the user's privilege level;
 681  * if not, it sets the appropriate error flags and loads 'addr' into the
 682  * illegal value slot.
 683  *
 684  * DTrace subroutines (DIF_SUBR_*) should use this helper to implement
 685  * appropriate memory access protection.
 686  */
 687 static int
 688 dtrace_canload(uint64_t addr, size_t sz, dtrace_mstate_t *mstate,
 689     dtrace_vstate_t *vstate)
 690 {
 691         volatile uintptr_t *illval = &cpu_core[CPU->cpu_id].cpuc_dtrace_illval;
 692         file_t *fp;
 693 
 694         /*
 695          * If we hold the privilege to read from kernel memory, then
 696          * everything is readable.
 697          */
 698         if ((mstate->dtms_access & DTRACE_ACCESS_KERNEL) != 0)
 699                 return (1);
 700 
 701         /*
 702          * You can obviously read that which you can store.
 703          */
 704         if (dtrace_canstore(addr, sz, mstate, vstate))
 705                 return (1);
 706 
 707         /*
 708          * We're allowed to read from our own string table.
 709          */
 710         if (DTRACE_INRANGE(addr, sz, mstate->dtms_difo->dtdo_strtab,
 711             mstate->dtms_difo->dtdo_strlen))
 712                 return (1);
 713 
 714         if (vstate->dtvs_state != NULL &&
 715             dtrace_priv_proc(vstate->dtvs_state, mstate)) {
 716                 proc_t *p;
 717 
 718                 /*
 719                  * When we have privileges to the current process, there are
 720                  * several context-related kernel structures that are safe to
 721                  * read, even absent the privilege to read from kernel memory.
 722                  * These reads are safe because these structures contain only
 723                  * state that (1) we're permitted to read, (2) is harmless or
 724                  * (3) contains pointers to additional kernel state that we're
 725                  * not permitted to read (and as such, do not present an
 726                  * opportunity for privilege escalation).  Finally (and
 727                  * critically), because of the nature of their relation with
 728                  * the current thread context, the memory associated with these
 729                  * structures cannot change over the duration of probe context,
 730                  * and it is therefore impossible for this memory to be
 731                  * deallocated and reallocated as something else while it's
 732                  * being operated upon.
 733                  */
 734                 if (DTRACE_INRANGE(addr, sz, curthread, sizeof (kthread_t)))
 735                         return (1);
 736 
 737                 if ((p = curthread->t_procp) != NULL && DTRACE_INRANGE(addr,
 738                     sz, curthread->t_procp, sizeof (proc_t))) {
 739                         return (1);
 740                 }
 741 
 742                 if (curthread->t_cred != NULL && DTRACE_INRANGE(addr, sz,
 743                     curthread->t_cred, sizeof (cred_t))) {
 744                         return (1);
 745                 }
 746 
 747                 if (p != NULL && p->p_pidp != NULL && DTRACE_INRANGE(addr, sz,
 748                     &(p->p_pidp->pid_id), sizeof (pid_t))) {
 749                         return (1);
 750                 }
 751 
 752                 if (curthread->t_cpu != NULL && DTRACE_INRANGE(addr, sz,
 753                     curthread->t_cpu, offsetof(cpu_t, cpu_pause_thread))) {
 754                         return (1);
 755                 }
 756         }
 757 
 758         if ((fp = mstate->dtms_getf) != NULL) {
 759                 uintptr_t psz = sizeof (void *);
 760                 vnode_t *vp;
 761                 vnodeops_t *op;
 762 
 763                 /*
 764                  * When getf() returns a file_t, the enabling is implicitly
 765                  * granted the (transient) right to read the returned file_t
 766                  * as well as the v_path and v_op->vnop_name of the underlying
 767                  * vnode.  These accesses are allowed after a successful
 768                  * getf() because the members that they refer to cannot change
 769                  * once set -- and the barrier logic in the kernel's closef()
 770                  * path assures that the file_t and its referenced vode_t
 771                  * cannot themselves be stale (that is, it impossible for
 772                  * either dtms_getf itself or its f_vnode member to reference
 773                  * freed memory).
 774                  */
 775                 if (DTRACE_INRANGE(addr, sz, fp, sizeof (file_t)))
 776                         return (1);
 777 
 778                 if ((vp = fp->f_vnode) != NULL) {
 779                         if (DTRACE_INRANGE(addr, sz, &vp->v_path, psz))
 780                                 return (1);
 781 
 782                         if (vp->v_path != NULL && DTRACE_INRANGE(addr, sz,
 783                             vp->v_path, strlen(vp->v_path) + 1)) {
 784                                 return (1);
 785                         }
 786 
 787                         if (DTRACE_INRANGE(addr, sz, &vp->v_op, psz))
 788                                 return (1);
 789 
 790                         if ((op = vp->v_op) != NULL &&
 791                             DTRACE_INRANGE(addr, sz, &op->vnop_name, psz)) {
 792                                 return (1);
 793                         }
 794 
 795                         if (op != NULL && op->vnop_name != NULL &&
 796                             DTRACE_INRANGE(addr, sz, op->vnop_name,
 797                             strlen(op->vnop_name) + 1)) {
 798                                 return (1);
 799                         }
 800                 }
 801         }
 802 
 803         DTRACE_CPUFLAG_SET(CPU_DTRACE_KPRIV);
 804         *illval = addr;
 805         return (0);
 806 }
 807 
 808 /*
 809  * Convenience routine to check to see if a given string is within a memory
 810  * region in which a load may be issued given the user's privilege level;
 811  * this exists so that we don't need to issue unnecessary dtrace_strlen()
 812  * calls in the event that the user has all privileges.
 813  */
 814 static int
 815 dtrace_strcanload(uint64_t addr, size_t sz, dtrace_mstate_t *mstate,
 816     dtrace_vstate_t *vstate)
 817 {
 818         size_t strsz;
 819 
 820         /*
 821          * If we hold the privilege to read from kernel memory, then
 822          * everything is readable.
 823          */
 824         if ((mstate->dtms_access & DTRACE_ACCESS_KERNEL) != 0)
 825                 return (1);
 826 
 827         strsz = 1 + dtrace_strlen((char *)(uintptr_t)addr, sz);
 828         if (dtrace_canload(addr, strsz, mstate, vstate))
 829                 return (1);
 830 
 831         return (0);
 832 }
 833 
 834 /*
 835  * Convenience routine to check to see if a given variable is within a memory
 836  * region in which a load may be issued given the user's privilege level.
 837  */
 838 static int
 839 dtrace_vcanload(void *src, dtrace_diftype_t *type, dtrace_mstate_t *mstate,
 840     dtrace_vstate_t *vstate)
 841 {
 842         size_t sz;
 843         ASSERT(type->dtdt_flags & DIF_TF_BYREF);
 844 
 845         /*
 846          * If we hold the privilege to read from kernel memory, then
 847          * everything is readable.
 848          */
 849         if ((mstate->dtms_access & DTRACE_ACCESS_KERNEL) != 0)
 850                 return (1);
 851 
 852         if (type->dtdt_kind == DIF_TYPE_STRING)
 853                 sz = dtrace_strlen(src,
 854                     vstate->dtvs_state->dts_options[DTRACEOPT_STRSIZE]) + 1;
 855         else
 856                 sz = type->dtdt_size;
 857 
 858         return (dtrace_canload((uintptr_t)src, sz, mstate, vstate));
 859 }
 860 
 861 /*
 862  * Compare two strings using safe loads.
 863  */
 864 static int
 865 dtrace_strncmp(char *s1, char *s2, size_t limit)
 866 {
 867         uint8_t c1, c2;
 868         volatile uint16_t *flags;
 869 
 870         if (s1 == s2 || limit == 0)
 871                 return (0);
 872 
 873         flags = (volatile uint16_t *)&cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
 874 
 875         do {
 876                 if (s1 == NULL) {
 877                         c1 = '\0';
 878                 } else {
 879                         c1 = dtrace_load8((uintptr_t)s1++);
 880                 }
 881 
 882                 if (s2 == NULL) {
 883                         c2 = '\0';
 884                 } else {
 885                         c2 = dtrace_load8((uintptr_t)s2++);
 886                 }
 887 
 888                 if (c1 != c2)
 889                         return (c1 - c2);
 890         } while (--limit && c1 != '\0' && !(*flags & CPU_DTRACE_FAULT));
 891 
 892         return (0);
 893 }
 894 
 895 /*
 896  * Compute strlen(s) for a string using safe memory accesses.  The additional
 897  * len parameter is used to specify a maximum length to ensure completion.
 898  */
 899 static size_t
 900 dtrace_strlen(const char *s, size_t lim)
 901 {
 902         uint_t len;
 903 
 904         for (len = 0; len != lim; len++) {
 905                 if (dtrace_load8((uintptr_t)s++) == '\0')
 906                         break;
 907         }
 908 
 909         return (len);
 910 }
 911 
 912 /*
 913  * Check if an address falls within a toxic region.
 914  */
 915 static int
 916 dtrace_istoxic(uintptr_t kaddr, size_t size)
 917 {
 918         uintptr_t taddr, tsize;
 919         int i;
 920 
 921         for (i = 0; i < dtrace_toxranges; i++) {
 922                 taddr = dtrace_toxrange[i].dtt_base;
 923                 tsize = dtrace_toxrange[i].dtt_limit - taddr;
 924 
 925                 if (kaddr - taddr < tsize) {
 926                         DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
 927                         cpu_core[CPU->cpu_id].cpuc_dtrace_illval = kaddr;
 928                         return (1);
 929                 }
 930 
 931                 if (taddr - kaddr < size) {
 932                         DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
 933                         cpu_core[CPU->cpu_id].cpuc_dtrace_illval = taddr;
 934                         return (1);
 935                 }
 936         }
 937 
 938         return (0);
 939 }
 940 
 941 /*
 942  * Copy src to dst using safe memory accesses.  The src is assumed to be unsafe
 943  * memory specified by the DIF program.  The dst is assumed to be safe memory
 944  * that we can store to directly because it is managed by DTrace.  As with
 945  * standard bcopy, overlapping copies are handled properly.
 946  */
 947 static void
 948 dtrace_bcopy(const void *src, void *dst, size_t len)
 949 {
 950         if (len != 0) {
 951                 uint8_t *s1 = dst;
 952                 const uint8_t *s2 = src;
 953 
 954                 if (s1 <= s2) {
 955                         do {
 956                                 *s1++ = dtrace_load8((uintptr_t)s2++);
 957                         } while (--len != 0);
 958                 } else {
 959                         s2 += len;
 960                         s1 += len;
 961 
 962                         do {
 963                                 *--s1 = dtrace_load8((uintptr_t)--s2);
 964                         } while (--len != 0);
 965                 }
 966         }
 967 }
 968 
 969 /*
 970  * Copy src to dst using safe memory accesses, up to either the specified
 971  * length, or the point that a nul byte is encountered.  The src is assumed to
 972  * be unsafe memory specified by the DIF program.  The dst is assumed to be
 973  * safe memory that we can store to directly because it is managed by DTrace.
 974  * Unlike dtrace_bcopy(), overlapping regions are not handled.
 975  */
 976 static void
 977 dtrace_strcpy(const void *src, void *dst, size_t len)
 978 {
 979         if (len != 0) {
 980                 uint8_t *s1 = dst, c;
 981                 const uint8_t *s2 = src;
 982 
 983                 do {
 984                         *s1++ = c = dtrace_load8((uintptr_t)s2++);
 985                 } while (--len != 0 && c != '\0');
 986         }
 987 }
 988 
 989 /*
 990  * Copy src to dst, deriving the size and type from the specified (BYREF)
 991  * variable type.  The src is assumed to be unsafe memory specified by the DIF
 992  * program.  The dst is assumed to be DTrace variable memory that is of the
 993  * specified type; we assume that we can store to directly.
 994  */
 995 static void
 996 dtrace_vcopy(void *src, void *dst, dtrace_diftype_t *type)
 997 {
 998         ASSERT(type->dtdt_flags & DIF_TF_BYREF);
 999 
1000         if (type->dtdt_kind == DIF_TYPE_STRING) {
1001                 dtrace_strcpy(src, dst, type->dtdt_size);
1002         } else {
1003                 dtrace_bcopy(src, dst, type->dtdt_size);
1004         }
1005 }
1006 
1007 /*
1008  * Compare s1 to s2 using safe memory accesses.  The s1 data is assumed to be
1009  * unsafe memory specified by the DIF program.  The s2 data is assumed to be
1010  * safe memory that we can access directly because it is managed by DTrace.
1011  */
1012 static int
1013 dtrace_bcmp(const void *s1, const void *s2, size_t len)
1014 {
1015         volatile uint16_t *flags;
1016 
1017         flags = (volatile uint16_t *)&cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
1018 
1019         if (s1 == s2)
1020                 return (0);
1021 
1022         if (s1 == NULL || s2 == NULL)
1023                 return (1);
1024 
1025         if (s1 != s2 && len != 0) {
1026                 const uint8_t *ps1 = s1;
1027                 const uint8_t *ps2 = s2;
1028 
1029                 do {
1030                         if (dtrace_load8((uintptr_t)ps1++) != *ps2++)
1031                                 return (1);
1032                 } while (--len != 0 && !(*flags & CPU_DTRACE_FAULT));
1033         }
1034         return (0);
1035 }
1036 
1037 /*
1038  * Zero the specified region using a simple byte-by-byte loop.  Note that this
1039  * is for safe DTrace-managed memory only.
1040  */
1041 static void
1042 dtrace_bzero(void *dst, size_t len)
1043 {
1044         uchar_t *cp;
1045 
1046         for (cp = dst; len != 0; len--)
1047                 *cp++ = 0;
1048 }
1049 
1050 static void
1051 dtrace_add_128(uint64_t *addend1, uint64_t *addend2, uint64_t *sum)
1052 {
1053         uint64_t result[2];
1054 
1055         result[0] = addend1[0] + addend2[0];
1056         result[1] = addend1[1] + addend2[1] +
1057             (result[0] < addend1[0] || result[0] < addend2[0] ? 1 : 0);
1058 
1059         sum[0] = result[0];
1060         sum[1] = result[1];
1061 }
1062 
1063 /*
1064  * Shift the 128-bit value in a by b. If b is positive, shift left.
1065  * If b is negative, shift right.
1066  */
1067 static void
1068 dtrace_shift_128(uint64_t *a, int b)
1069 {
1070         uint64_t mask;
1071 
1072         if (b == 0)
1073                 return;
1074 
1075         if (b < 0) {
1076                 b = -b;
1077                 if (b >= 64) {
1078                         a[0] = a[1] >> (b - 64);
1079                         a[1] = 0;
1080                 } else {
1081                         a[0] >>= b;
1082                         mask = 1LL << (64 - b);
1083                         mask -= 1;
1084                         a[0] |= ((a[1] & mask) << (64 - b));
1085                         a[1] >>= b;
1086                 }
1087         } else {
1088                 if (b >= 64) {
1089                         a[1] = a[0] << (b - 64);
1090                         a[0] = 0;
1091                 } else {
1092                         a[1] <<= b;
1093                         mask = a[0] >> (64 - b);
1094                         a[1] |= mask;
1095                         a[0] <<= b;
1096                 }
1097         }
1098 }
1099 
1100 /*
1101  * The basic idea is to break the 2 64-bit values into 4 32-bit values,
1102  * use native multiplication on those, and then re-combine into the
1103  * resulting 128-bit value.
1104  *
1105  * (hi1 << 32 + lo1) * (hi2 << 32 + lo2) =
1106  *     hi1 * hi2 << 64 +
1107  *     hi1 * lo2 << 32 +
1108  *     hi2 * lo1 << 32 +
1109  *     lo1 * lo2
1110  */
1111 static void
1112 dtrace_multiply_128(uint64_t factor1, uint64_t factor2, uint64_t *product)
1113 {
1114         uint64_t hi1, hi2, lo1, lo2;
1115         uint64_t tmp[2];
1116 
1117         hi1 = factor1 >> 32;
1118         hi2 = factor2 >> 32;
1119 
1120         lo1 = factor1 & DT_MASK_LO;
1121         lo2 = factor2 & DT_MASK_LO;
1122 
1123         product[0] = lo1 * lo2;
1124         product[1] = hi1 * hi2;
1125 
1126         tmp[0] = hi1 * lo2;
1127         tmp[1] = 0;
1128         dtrace_shift_128(tmp, 32);
1129         dtrace_add_128(product, tmp, product);
1130 
1131         tmp[0] = hi2 * lo1;
1132         tmp[1] = 0;
1133         dtrace_shift_128(tmp, 32);
1134         dtrace_add_128(product, tmp, product);
1135 }
1136 
1137 /*
1138  * This privilege check should be used by actions and subroutines to
1139  * verify that the user credentials of the process that enabled the
1140  * invoking ECB match the target credentials
1141  */
1142 static int
1143 dtrace_priv_proc_common_user(dtrace_state_t *state)
1144 {
1145         cred_t *cr, *s_cr = state->dts_cred.dcr_cred;
1146 
1147         /*
1148          * We should always have a non-NULL state cred here, since if cred
1149          * is null (anonymous tracing), we fast-path bypass this routine.
1150          */
1151         ASSERT(s_cr != NULL);
1152 
1153         if ((cr = CRED()) != NULL &&
1154             s_cr->cr_uid == cr->cr_uid &&
1155             s_cr->cr_uid == cr->cr_ruid &&
1156             s_cr->cr_uid == cr->cr_suid &&
1157             s_cr->cr_gid == cr->cr_gid &&
1158             s_cr->cr_gid == cr->cr_rgid &&
1159             s_cr->cr_gid == cr->cr_sgid)
1160                 return (1);
1161 
1162         return (0);
1163 }
1164 
1165 /*
1166  * This privilege check should be used by actions and subroutines to
1167  * verify that the zone of the process that enabled the invoking ECB
1168  * matches the target credentials
1169  */
1170 static int
1171 dtrace_priv_proc_common_zone(dtrace_state_t *state)
1172 {
1173         cred_t *cr, *s_cr = state->dts_cred.dcr_cred;
1174 
1175         /*
1176          * We should always have a non-NULL state cred here, since if cred
1177          * is null (anonymous tracing), we fast-path bypass this routine.
1178          */
1179         ASSERT(s_cr != NULL);
1180 
1181         if ((cr = CRED()) != NULL && s_cr->cr_zone == cr->cr_zone)
1182                 return (1);
1183 
1184         return (0);
1185 }
1186 
1187 /*
1188  * This privilege check should be used by actions and subroutines to
1189  * verify that the process has not setuid or changed credentials.
1190  */
1191 static int
1192 dtrace_priv_proc_common_nocd()
1193 {
1194         proc_t *proc;
1195 
1196         if ((proc = ttoproc(curthread)) != NULL &&
1197             !(proc->p_flag & SNOCD))
1198                 return (1);
1199 
1200         return (0);
1201 }
1202 
1203 static int
1204 dtrace_priv_proc_destructive(dtrace_state_t *state, dtrace_mstate_t *mstate)
1205 {
1206         int action = state->dts_cred.dcr_action;
1207 
1208         if (!(mstate->dtms_access & DTRACE_ACCESS_PROC))
1209                 goto bad;
1210 
1211         if (((action & DTRACE_CRA_PROC_DESTRUCTIVE_ALLZONE) == 0) &&
1212             dtrace_priv_proc_common_zone(state) == 0)
1213                 goto bad;
1214 
1215         if (((action & DTRACE_CRA_PROC_DESTRUCTIVE_ALLUSER) == 0) &&
1216             dtrace_priv_proc_common_user(state) == 0)
1217                 goto bad;
1218 
1219         if (((action & DTRACE_CRA_PROC_DESTRUCTIVE_CREDCHG) == 0) &&
1220             dtrace_priv_proc_common_nocd() == 0)
1221                 goto bad;
1222 
1223         return (1);
1224 
1225 bad:
1226         cpu_core[CPU->cpu_id].cpuc_dtrace_flags |= CPU_DTRACE_UPRIV;
1227 
1228         return (0);
1229 }
1230 
1231 static int
1232 dtrace_priv_proc_control(dtrace_state_t *state, dtrace_mstate_t *mstate)
1233 {
1234         if (mstate->dtms_access & DTRACE_ACCESS_PROC) {
1235                 if (state->dts_cred.dcr_action & DTRACE_CRA_PROC_CONTROL)
1236                         return (1);
1237 
1238                 if (dtrace_priv_proc_common_zone(state) &&
1239                     dtrace_priv_proc_common_user(state) &&
1240                     dtrace_priv_proc_common_nocd())
1241                         return (1);
1242         }
1243 
1244         cpu_core[CPU->cpu_id].cpuc_dtrace_flags |= CPU_DTRACE_UPRIV;
1245 
1246         return (0);
1247 }
1248 
1249 static int
1250 dtrace_priv_proc(dtrace_state_t *state, dtrace_mstate_t *mstate)
1251 {
1252         if ((mstate->dtms_access & DTRACE_ACCESS_PROC) &&
1253             (state->dts_cred.dcr_action & DTRACE_CRA_PROC))
1254                 return (1);
1255 
1256         cpu_core[CPU->cpu_id].cpuc_dtrace_flags |= CPU_DTRACE_UPRIV;
1257 
1258         return (0);
1259 }
1260 
1261 static int
1262 dtrace_priv_kernel(dtrace_state_t *state)
1263 {
1264         if (state->dts_cred.dcr_action & DTRACE_CRA_KERNEL)
1265                 return (1);
1266 
1267         cpu_core[CPU->cpu_id].cpuc_dtrace_flags |= CPU_DTRACE_KPRIV;
1268 
1269         return (0);
1270 }
1271 
1272 static int
1273 dtrace_priv_kernel_destructive(dtrace_state_t *state)
1274 {
1275         if (state->dts_cred.dcr_action & DTRACE_CRA_KERNEL_DESTRUCTIVE)
1276                 return (1);
1277 
1278         cpu_core[CPU->cpu_id].cpuc_dtrace_flags |= CPU_DTRACE_KPRIV;
1279 
1280         return (0);
1281 }
1282 
1283 /*
1284  * Determine if the dte_cond of the specified ECB allows for processing of
1285  * the current probe to continue.  Note that this routine may allow continued
1286  * processing, but with access(es) stripped from the mstate's dtms_access
1287  * field.
1288  */
1289 static int
1290 dtrace_priv_probe(dtrace_state_t *state, dtrace_mstate_t *mstate,
1291     dtrace_ecb_t *ecb)
1292 {
1293         dtrace_probe_t *probe = ecb->dte_probe;
1294         dtrace_provider_t *prov = probe->dtpr_provider;
1295         dtrace_pops_t *pops = &prov->dtpv_pops;
1296         int mode = DTRACE_MODE_NOPRIV_DROP;
1297 
1298         ASSERT(ecb->dte_cond);
1299 
1300         if (pops->dtps_mode != NULL) {
1301                 mode = pops->dtps_mode(prov->dtpv_arg,
1302                     probe->dtpr_id, probe->dtpr_arg);
1303 
1304                 ASSERT(mode & (DTRACE_MODE_USER | DTRACE_MODE_KERNEL));
1305                 ASSERT(mode & (DTRACE_MODE_NOPRIV_RESTRICT |
1306                     DTRACE_MODE_NOPRIV_DROP));
1307         }
1308 
1309         /*
1310          * If the dte_cond bits indicate that this consumer is only allowed to
1311          * see user-mode firings of this probe, check that the probe was fired
1312          * while in a user context.  If that's not the case, use the policy
1313          * specified by the provider to determine if we drop the probe or
1314          * merely restrict operation.
1315          */
1316         if (ecb->dte_cond & DTRACE_COND_USERMODE) {
1317                 ASSERT(mode != DTRACE_MODE_NOPRIV_DROP);
1318 
1319                 if (!(mode & DTRACE_MODE_USER)) {
1320                         if (mode & DTRACE_MODE_NOPRIV_DROP)
1321                                 return (0);
1322 
1323                         mstate->dtms_access &= ~DTRACE_ACCESS_ARGS;
1324                 }
1325         }
1326 
1327         /*
1328          * This is more subtle than it looks. We have to be absolutely certain
1329          * that CRED() isn't going to change out from under us so it's only
1330          * legit to examine that structure if we're in constrained situations.
1331          * Currently, the only times we'll this check is if a non-super-user
1332          * has enabled the profile or syscall providers -- providers that
1333          * allow visibility of all processes. For the profile case, the check
1334          * above will ensure that we're examining a user context.
1335          */
1336         if (ecb->dte_cond & DTRACE_COND_OWNER) {
1337                 cred_t *cr;
1338                 cred_t *s_cr = state->dts_cred.dcr_cred;
1339                 proc_t *proc;
1340 
1341                 ASSERT(s_cr != NULL);
1342 
1343                 if ((cr = CRED()) == NULL ||
1344                     s_cr->cr_uid != cr->cr_uid ||
1345                     s_cr->cr_uid != cr->cr_ruid ||
1346                     s_cr->cr_uid != cr->cr_suid ||
1347                     s_cr->cr_gid != cr->cr_gid ||
1348                     s_cr->cr_gid != cr->cr_rgid ||
1349                     s_cr->cr_gid != cr->cr_sgid ||
1350                     (proc = ttoproc(curthread)) == NULL ||
1351                     (proc->p_flag & SNOCD)) {
1352                         if (mode & DTRACE_MODE_NOPRIV_DROP)
1353                                 return (0);
1354 
1355                         mstate->dtms_access &= ~DTRACE_ACCESS_PROC;
1356                 }
1357         }
1358 
1359         /*
1360          * If our dte_cond is set to DTRACE_COND_ZONEOWNER and we are not
1361          * in our zone, check to see if our mode policy is to restrict rather
1362          * than to drop; if to restrict, strip away both DTRACE_ACCESS_PROC
1363          * and DTRACE_ACCESS_ARGS
1364          */
1365         if (ecb->dte_cond & DTRACE_COND_ZONEOWNER) {
1366                 cred_t *cr;
1367                 cred_t *s_cr = state->dts_cred.dcr_cred;
1368 
1369                 ASSERT(s_cr != NULL);
1370 
1371                 if ((cr = CRED()) == NULL ||
1372                     s_cr->cr_zone->zone_id != cr->cr_zone->zone_id) {
1373                         if (mode & DTRACE_MODE_NOPRIV_DROP)
1374                                 return (0);
1375 
1376                         mstate->dtms_access &=
1377                             ~(DTRACE_ACCESS_PROC | DTRACE_ACCESS_ARGS);
1378                 }
1379         }
1380 
1381         /*
1382          * By merits of being in this code path at all, we have limited
1383          * privileges.  If the provider has indicated that limited privileges
1384          * are to denote restricted operation, strip off the ability to access
1385          * arguments.
1386          */
1387         if (mode & DTRACE_MODE_LIMITEDPRIV_RESTRICT)
1388                 mstate->dtms_access &= ~DTRACE_ACCESS_ARGS;
1389 
1390         return (1);
1391 }
1392 
1393 /*
1394  * Note:  not called from probe context.  This function is called
1395  * asynchronously (and at a regular interval) from outside of probe context to
1396  * clean the dirty dynamic variable lists on all CPUs.  Dynamic variable
1397  * cleaning is explained in detail in <sys/dtrace_impl.h>.
1398  */
1399 void
1400 dtrace_dynvar_clean(dtrace_dstate_t *dstate)
1401 {
1402         dtrace_dynvar_t *dirty;
1403         dtrace_dstate_percpu_t *dcpu;
1404         dtrace_dynvar_t **rinsep;
1405         int i, j, work = 0;
1406 
1407         for (i = 0; i < NCPU; i++) {
1408                 dcpu = &dstate->dtds_percpu[i];
1409                 rinsep = &dcpu->dtdsc_rinsing;
1410 
1411                 /*
1412                  * If the dirty list is NULL, there is no dirty work to do.
1413                  */
1414                 if (dcpu->dtdsc_dirty == NULL)
1415                         continue;
1416 
1417                 if (dcpu->dtdsc_rinsing != NULL) {
1418                         /*
1419                          * If the rinsing list is non-NULL, then it is because
1420                          * this CPU was selected to accept another CPU's
1421                          * dirty list -- and since that time, dirty buffers
1422                          * have accumulated.  This is a highly unlikely
1423                          * condition, but we choose to ignore the dirty
1424                          * buffers -- they'll be picked up a future cleanse.
1425                          */
1426                         continue;
1427                 }
1428 
1429                 if (dcpu->dtdsc_clean != NULL) {
1430                         /*
1431                          * If the clean list is non-NULL, then we're in a
1432                          * situation where a CPU has done deallocations (we
1433                          * have a non-NULL dirty list) but no allocations (we
1434                          * also have a non-NULL clean list).  We can't simply
1435                          * move the dirty list into the clean list on this
1436                          * CPU, yet we also don't want to allow this condition
1437                          * to persist, lest a short clean list prevent a
1438                          * massive dirty list from being cleaned (which in
1439                          * turn could lead to otherwise avoidable dynamic
1440                          * drops).  To deal with this, we look for some CPU
1441                          * with a NULL clean list, NULL dirty list, and NULL
1442                          * rinsing list -- and then we borrow this CPU to
1443                          * rinse our dirty list.
1444                          */
1445                         for (j = 0; j < NCPU; j++) {
1446                                 dtrace_dstate_percpu_t *rinser;
1447 
1448                                 rinser = &dstate->dtds_percpu[j];
1449 
1450                                 if (rinser->dtdsc_rinsing != NULL)
1451                                         continue;
1452 
1453                                 if (rinser->dtdsc_dirty != NULL)
1454                                         continue;
1455 
1456                                 if (rinser->dtdsc_clean != NULL)
1457                                         continue;
1458 
1459                                 rinsep = &rinser->dtdsc_rinsing;
1460                                 break;
1461                         }
1462 
1463                         if (j == NCPU) {
1464                                 /*
1465                                  * We were unable to find another CPU that
1466                                  * could accept this dirty list -- we are
1467                                  * therefore unable to clean it now.
1468                                  */
1469                                 dtrace_dynvar_failclean++;
1470                                 continue;
1471                         }
1472                 }
1473 
1474                 work = 1;
1475 
1476                 /*
1477                  * Atomically move the dirty list aside.
1478                  */
1479                 do {
1480                         dirty = dcpu->dtdsc_dirty;
1481 
1482                         /*
1483                          * Before we zap the dirty list, set the rinsing list.
1484                          * (This allows for a potential assertion in
1485                          * dtrace_dynvar():  if a free dynamic variable appears
1486                          * on a hash chain, either the dirty list or the
1487                          * rinsing list for some CPU must be non-NULL.)
1488                          */
1489                         *rinsep = dirty;
1490                         dtrace_membar_producer();
1491                 } while (dtrace_casptr(&dcpu->dtdsc_dirty,
1492                     dirty, NULL) != dirty);
1493         }
1494 
1495         if (!work) {
1496                 /*
1497                  * We have no work to do; we can simply return.
1498                  */
1499                 return;
1500         }
1501 
1502         dtrace_sync();
1503 
1504         for (i = 0; i < NCPU; i++) {
1505                 dcpu = &dstate->dtds_percpu[i];
1506 
1507                 if (dcpu->dtdsc_rinsing == NULL)
1508                         continue;
1509 
1510                 /*
1511                  * We are now guaranteed that no hash chain contains a pointer
1512                  * into this dirty list; we can make it clean.
1513                  */
1514                 ASSERT(dcpu->dtdsc_clean == NULL);
1515                 dcpu->dtdsc_clean = dcpu->dtdsc_rinsing;
1516                 dcpu->dtdsc_rinsing = NULL;
1517         }
1518 
1519         /*
1520          * Before we actually set the state to be DTRACE_DSTATE_CLEAN, make
1521          * sure that all CPUs have seen all of the dtdsc_clean pointers.
1522          * This prevents a race whereby a CPU incorrectly decides that
1523          * the state should be something other than DTRACE_DSTATE_CLEAN
1524          * after dtrace_dynvar_clean() has completed.
1525          */
1526         dtrace_sync();
1527 
1528         dstate->dtds_state = DTRACE_DSTATE_CLEAN;
1529 }
1530 
1531 /*
1532  * Depending on the value of the op parameter, this function looks-up,
1533  * allocates or deallocates an arbitrarily-keyed dynamic variable.  If an
1534  * allocation is requested, this function will return a pointer to a
1535  * dtrace_dynvar_t corresponding to the allocated variable -- or NULL if no
1536  * variable can be allocated.  If NULL is returned, the appropriate counter
1537  * will be incremented.
1538  */
1539 dtrace_dynvar_t *
1540 dtrace_dynvar(dtrace_dstate_t *dstate, uint_t nkeys,
1541     dtrace_key_t *key, size_t dsize, dtrace_dynvar_op_t op,
1542     dtrace_mstate_t *mstate, dtrace_vstate_t *vstate)
1543 {
1544         uint64_t hashval = DTRACE_DYNHASH_VALID;
1545         dtrace_dynhash_t *hash = dstate->dtds_hash;
1546         dtrace_dynvar_t *free, *new_free, *next, *dvar, *start, *prev = NULL;
1547         processorid_t me = CPU->cpu_id, cpu = me;
1548         dtrace_dstate_percpu_t *dcpu = &dstate->dtds_percpu[me];
1549         size_t bucket, ksize;
1550         size_t chunksize = dstate->dtds_chunksize;
1551         uintptr_t kdata, lock, nstate;
1552         uint_t i;
1553 
1554         ASSERT(nkeys != 0);
1555 
1556         /*
1557          * Hash the key.  As with aggregations, we use Jenkins' "One-at-a-time"
1558          * algorithm.  For the by-value portions, we perform the algorithm in
1559          * 16-bit chunks (as opposed to 8-bit chunks).  This speeds things up a
1560          * bit, and seems to have only a minute effect on distribution.  For
1561          * the by-reference data, we perform "One-at-a-time" iterating (safely)
1562          * over each referenced byte.  It's painful to do this, but it's much
1563          * better than pathological hash distribution.  The efficacy of the
1564          * hashing algorithm (and a comparison with other algorithms) may be
1565          * found by running the ::dtrace_dynstat MDB dcmd.
1566          */
1567         for (i = 0; i < nkeys; i++) {
1568                 if (key[i].dttk_size == 0) {
1569                         uint64_t val = key[i].dttk_value;
1570 
1571                         hashval += (val >> 48) & 0xffff;
1572                         hashval += (hashval << 10);
1573                         hashval ^= (hashval >> 6);
1574 
1575                         hashval += (val >> 32) & 0xffff;
1576                         hashval += (hashval << 10);
1577                         hashval ^= (hashval >> 6);
1578 
1579                         hashval += (val >> 16) & 0xffff;
1580                         hashval += (hashval << 10);
1581                         hashval ^= (hashval >> 6);
1582 
1583                         hashval += val & 0xffff;
1584                         hashval += (hashval << 10);
1585                         hashval ^= (hashval >> 6);
1586                 } else {
1587                         /*
1588                          * This is incredibly painful, but it beats the hell
1589                          * out of the alternative.
1590                          */
1591                         uint64_t j, size = key[i].dttk_size;
1592                         uintptr_t base = (uintptr_t)key[i].dttk_value;
1593 
1594                         if (!dtrace_canload(base, size, mstate, vstate))
1595                                 break;
1596 
1597                         for (j = 0; j < size; j++) {
1598                                 hashval += dtrace_load8(base + j);
1599                                 hashval += (hashval << 10);
1600                                 hashval ^= (hashval >> 6);
1601                         }
1602                 }
1603         }
1604 
1605         if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_FAULT))
1606                 return (NULL);
1607 
1608         hashval += (hashval << 3);
1609         hashval ^= (hashval >> 11);
1610         hashval += (hashval << 15);
1611 
1612         /*
1613          * There is a remote chance (ideally, 1 in 2^31) that our hashval
1614          * comes out to be one of our two sentinel hash values.  If this
1615          * actually happens, we set the hashval to be a value known to be a
1616          * non-sentinel value.
1617          */
1618         if (hashval == DTRACE_DYNHASH_FREE || hashval == DTRACE_DYNHASH_SINK)
1619                 hashval = DTRACE_DYNHASH_VALID;
1620 
1621         /*
1622          * Yes, it's painful to do a divide here.  If the cycle count becomes
1623          * important here, tricks can be pulled to reduce it.  (However, it's
1624          * critical that hash collisions be kept to an absolute minimum;
1625          * they're much more painful than a divide.)  It's better to have a
1626          * solution that generates few collisions and still keeps things
1627          * relatively simple.
1628          */
1629         bucket = hashval % dstate->dtds_hashsize;
1630 
1631         if (op == DTRACE_DYNVAR_DEALLOC) {
1632                 volatile uintptr_t *lockp = &hash[bucket].dtdh_lock;
1633 
1634                 for (;;) {
1635                         while ((lock = *lockp) & 1)
1636                                 continue;
1637 
1638                         if (dtrace_casptr((void *)lockp,
1639                             (void *)lock, (void *)(lock + 1)) == (void *)lock)
1640                                 break;
1641                 }
1642 
1643                 dtrace_membar_producer();
1644         }
1645 
1646 top:
1647         prev = NULL;
1648         lock = hash[bucket].dtdh_lock;
1649 
1650         dtrace_membar_consumer();
1651 
1652         start = hash[bucket].dtdh_chain;
1653         ASSERT(start != NULL && (start->dtdv_hashval == DTRACE_DYNHASH_SINK ||
1654             start->dtdv_hashval != DTRACE_DYNHASH_FREE ||
1655             op != DTRACE_DYNVAR_DEALLOC));
1656 
1657         for (dvar = start; dvar != NULL; dvar = dvar->dtdv_next) {
1658                 dtrace_tuple_t *dtuple = &dvar->dtdv_tuple;
1659                 dtrace_key_t *dkey = &dtuple->dtt_key[0];
1660 
1661                 if (dvar->dtdv_hashval != hashval) {
1662                         if (dvar->dtdv_hashval == DTRACE_DYNHASH_SINK) {
1663                                 /*
1664                                  * We've reached the sink, and therefore the
1665                                  * end of the hash chain; we can kick out of
1666                                  * the loop knowing that we have seen a valid
1667                                  * snapshot of state.
1668                                  */
1669                                 ASSERT(dvar->dtdv_next == NULL);
1670                                 ASSERT(dvar == &dtrace_dynhash_sink);
1671                                 break;
1672                         }
1673 
1674                         if (dvar->dtdv_hashval == DTRACE_DYNHASH_FREE) {
1675                                 /*
1676                                  * We've gone off the rails:  somewhere along
1677                                  * the line, one of the members of this hash
1678                                  * chain was deleted.  Note that we could also
1679                                  * detect this by simply letting this loop run
1680                                  * to completion, as we would eventually hit
1681                                  * the end of the dirty list.  However, we
1682                                  * want to avoid running the length of the
1683                                  * dirty list unnecessarily (it might be quite
1684                                  * long), so we catch this as early as
1685                                  * possible by detecting the hash marker.  In
1686                                  * this case, we simply set dvar to NULL and
1687                                  * break; the conditional after the loop will
1688                                  * send us back to top.
1689                                  */
1690                                 dvar = NULL;
1691                                 break;
1692                         }
1693 
1694                         goto next;
1695                 }
1696 
1697                 if (dtuple->dtt_nkeys != nkeys)
1698                         goto next;
1699 
1700                 for (i = 0; i < nkeys; i++, dkey++) {
1701                         if (dkey->dttk_size != key[i].dttk_size)
1702                                 goto next; /* size or type mismatch */
1703 
1704                         if (dkey->dttk_size != 0) {
1705                                 if (dtrace_bcmp(
1706                                     (void *)(uintptr_t)key[i].dttk_value,
1707                                     (void *)(uintptr_t)dkey->dttk_value,
1708                                     dkey->dttk_size))
1709                                         goto next;
1710                         } else {
1711                                 if (dkey->dttk_value != key[i].dttk_value)
1712                                         goto next;
1713                         }
1714                 }
1715 
1716                 if (op != DTRACE_DYNVAR_DEALLOC)
1717                         return (dvar);
1718 
1719                 ASSERT(dvar->dtdv_next == NULL ||
1720                     dvar->dtdv_next->dtdv_hashval != DTRACE_DYNHASH_FREE);
1721 
1722                 if (prev != NULL) {
1723                         ASSERT(hash[bucket].dtdh_chain != dvar);
1724                         ASSERT(start != dvar);
1725                         ASSERT(prev->dtdv_next == dvar);
1726                         prev->dtdv_next = dvar->dtdv_next;
1727                 } else {
1728                         if (dtrace_casptr(&hash[bucket].dtdh_chain,
1729                             start, dvar->dtdv_next) != start) {
1730                                 /*
1731                                  * We have failed to atomically swing the
1732                                  * hash table head pointer, presumably because
1733                                  * of a conflicting allocation on another CPU.
1734                                  * We need to reread the hash chain and try
1735                                  * again.
1736                                  */
1737                                 goto top;
1738                         }
1739                 }
1740 
1741                 dtrace_membar_producer();
1742 
1743                 /*
1744                  * Now set the hash value to indicate that it's free.
1745                  */
1746                 ASSERT(hash[bucket].dtdh_chain != dvar);
1747                 dvar->dtdv_hashval = DTRACE_DYNHASH_FREE;
1748 
1749                 dtrace_membar_producer();
1750 
1751                 /*
1752                  * Set the next pointer to point at the dirty list, and
1753                  * atomically swing the dirty pointer to the newly freed dvar.
1754                  */
1755                 do {
1756                         next = dcpu->dtdsc_dirty;
1757                         dvar->dtdv_next = next;
1758                 } while (dtrace_casptr(&dcpu->dtdsc_dirty, next, dvar) != next);
1759 
1760                 /*
1761                  * Finally, unlock this hash bucket.
1762                  */
1763                 ASSERT(hash[bucket].dtdh_lock == lock);
1764                 ASSERT(lock & 1);
1765                 hash[bucket].dtdh_lock++;
1766 
1767                 return (NULL);
1768 next:
1769                 prev = dvar;
1770                 continue;
1771         }
1772 
1773         if (dvar == NULL) {
1774                 /*
1775                  * If dvar is NULL, it is because we went off the rails:
1776                  * one of the elements that we traversed in the hash chain
1777                  * was deleted while we were traversing it.  In this case,
1778                  * we assert that we aren't doing a dealloc (deallocs lock
1779                  * the hash bucket to prevent themselves from racing with
1780                  * one another), and retry the hash chain traversal.
1781                  */
1782                 ASSERT(op != DTRACE_DYNVAR_DEALLOC);
1783                 goto top;
1784         }
1785 
1786         if (op != DTRACE_DYNVAR_ALLOC) {
1787                 /*
1788                  * If we are not to allocate a new variable, we want to
1789                  * return NULL now.  Before we return, check that the value
1790                  * of the lock word hasn't changed.  If it has, we may have
1791                  * seen an inconsistent snapshot.
1792                  */
1793                 if (op == DTRACE_DYNVAR_NOALLOC) {
1794                         if (hash[bucket].dtdh_lock != lock)
1795                                 goto top;
1796                 } else {
1797                         ASSERT(op == DTRACE_DYNVAR_DEALLOC);
1798                         ASSERT(hash[bucket].dtdh_lock == lock);
1799                         ASSERT(lock & 1);
1800                         hash[bucket].dtdh_lock++;
1801                 }
1802 
1803                 return (NULL);
1804         }
1805 
1806         /*
1807          * We need to allocate a new dynamic variable.  The size we need is the
1808          * size of dtrace_dynvar plus the size of nkeys dtrace_key_t's plus the
1809          * size of any auxiliary key data (rounded up to 8-byte alignment) plus
1810          * the size of any referred-to data (dsize).  We then round the final
1811          * size up to the chunksize for allocation.
1812          */
1813         for (ksize = 0, i = 0; i < nkeys; i++)
1814                 ksize += P2ROUNDUP(key[i].dttk_size, sizeof (uint64_t));
1815 
1816         /*
1817          * This should be pretty much impossible, but could happen if, say,
1818          * strange DIF specified the tuple.  Ideally, this should be an
1819          * assertion and not an error condition -- but that requires that the
1820          * chunksize calculation in dtrace_difo_chunksize() be absolutely
1821          * bullet-proof.  (That is, it must not be able to be fooled by
1822          * malicious DIF.)  Given the lack of backwards branches in DIF,
1823          * solving this would presumably not amount to solving the Halting
1824          * Problem -- but it still seems awfully hard.
1825          */
1826         if (sizeof (dtrace_dynvar_t) + sizeof (dtrace_key_t) * (nkeys - 1) +
1827             ksize + dsize > chunksize) {
1828                 dcpu->dtdsc_drops++;
1829                 return (NULL);
1830         }
1831 
1832         nstate = DTRACE_DSTATE_EMPTY;
1833 
1834         do {
1835 retry:
1836                 free = dcpu->dtdsc_free;
1837 
1838                 if (free == NULL) {
1839                         dtrace_dynvar_t *clean = dcpu->dtdsc_clean;
1840                         void *rval;
1841 
1842                         if (clean == NULL) {
1843                                 /*
1844                                  * We're out of dynamic variable space on
1845                                  * this CPU.  Unless we have tried all CPUs,
1846                                  * we'll try to allocate from a different
1847                                  * CPU.
1848                                  */
1849                                 switch (dstate->dtds_state) {
1850                                 case DTRACE_DSTATE_CLEAN: {
1851                                         void *sp = &dstate->dtds_state;
1852 
1853                                         if (++cpu >= NCPU)
1854                                                 cpu = 0;
1855 
1856                                         if (dcpu->dtdsc_dirty != NULL &&
1857                                             nstate == DTRACE_DSTATE_EMPTY)
1858                                                 nstate = DTRACE_DSTATE_DIRTY;
1859 
1860                                         if (dcpu->dtdsc_rinsing != NULL)
1861                                                 nstate = DTRACE_DSTATE_RINSING;
1862 
1863                                         dcpu = &dstate->dtds_percpu[cpu];
1864 
1865                                         if (cpu != me)
1866                                                 goto retry;
1867 
1868                                         (void) dtrace_cas32(sp,
1869                                             DTRACE_DSTATE_CLEAN, nstate);
1870 
1871                                         /*
1872                                          * To increment the correct bean
1873                                          * counter, take another lap.
1874                                          */
1875                                         goto retry;
1876                                 }
1877 
1878                                 case DTRACE_DSTATE_DIRTY:
1879                                         dcpu->dtdsc_dirty_drops++;
1880                                         break;
1881 
1882                                 case DTRACE_DSTATE_RINSING:
1883                                         dcpu->dtdsc_rinsing_drops++;
1884                                         break;
1885 
1886                                 case DTRACE_DSTATE_EMPTY:
1887                                         dcpu->dtdsc_drops++;
1888                                         break;
1889                                 }
1890 
1891                                 DTRACE_CPUFLAG_SET(CPU_DTRACE_DROP);
1892                                 return (NULL);
1893                         }
1894 
1895                         /*
1896                          * The clean list appears to be non-empty.  We want to
1897                          * move the clean list to the free list; we start by
1898                          * moving the clean pointer aside.
1899                          */
1900                         if (dtrace_casptr(&dcpu->dtdsc_clean,
1901                             clean, NULL) != clean) {
1902                                 /*
1903                                  * We are in one of two situations:
1904                                  *
1905                                  *  (a) The clean list was switched to the
1906                                  *      free list by another CPU.
1907                                  *
1908                                  *  (b) The clean list was added to by the
1909                                  *      cleansing cyclic.
1910                                  *
1911                                  * In either of these situations, we can
1912                                  * just reattempt the free list allocation.
1913                                  */
1914                                 goto retry;
1915                         }
1916 
1917                         ASSERT(clean->dtdv_hashval == DTRACE_DYNHASH_FREE);
1918 
1919                         /*
1920                          * Now we'll move the clean list to our free list.
1921                          * It's impossible for this to fail:  the only way
1922                          * the free list can be updated is through this
1923                          * code path, and only one CPU can own the clean list.
1924                          * Thus, it would only be possible for this to fail if
1925                          * this code were racing with dtrace_dynvar_clean().
1926                          * (That is, if dtrace_dynvar_clean() updated the clean
1927                          * list, and we ended up racing to update the free
1928                          * list.)  This race is prevented by the dtrace_sync()
1929                          * in dtrace_dynvar_clean() -- which flushes the
1930                          * owners of the clean lists out before resetting
1931                          * the clean lists.
1932                          */
1933                         dcpu = &dstate->dtds_percpu[me];
1934                         rval = dtrace_casptr(&dcpu->dtdsc_free, NULL, clean);
1935                         ASSERT(rval == NULL);
1936                         goto retry;
1937                 }
1938 
1939                 dvar = free;
1940                 new_free = dvar->dtdv_next;
1941         } while (dtrace_casptr(&dcpu->dtdsc_free, free, new_free) != free);
1942 
1943         /*
1944          * We have now allocated a new chunk.  We copy the tuple keys into the
1945          * tuple array and copy any referenced key data into the data space
1946          * following the tuple array.  As we do this, we relocate dttk_value
1947          * in the final tuple to point to the key data address in the chunk.
1948          */
1949         kdata = (uintptr_t)&dvar->dtdv_tuple.dtt_key[nkeys];
1950         dvar->dtdv_data = (void *)(kdata + ksize);
1951         dvar->dtdv_tuple.dtt_nkeys = nkeys;
1952 
1953         for (i = 0; i < nkeys; i++) {
1954                 dtrace_key_t *dkey = &dvar->dtdv_tuple.dtt_key[i];
1955                 size_t kesize = key[i].dttk_size;
1956 
1957                 if (kesize != 0) {
1958                         dtrace_bcopy(
1959                             (const void *)(uintptr_t)key[i].dttk_value,
1960                             (void *)kdata, kesize);
1961                         dkey->dttk_value = kdata;
1962                         kdata += P2ROUNDUP(kesize, sizeof (uint64_t));
1963                 } else {
1964                         dkey->dttk_value = key[i].dttk_value;
1965                 }
1966 
1967                 dkey->dttk_size = kesize;
1968         }
1969 
1970         ASSERT(dvar->dtdv_hashval == DTRACE_DYNHASH_FREE);
1971         dvar->dtdv_hashval = hashval;
1972         dvar->dtdv_next = start;
1973 
1974         if (dtrace_casptr(&hash[bucket].dtdh_chain, start, dvar) == start)
1975                 return (dvar);
1976 
1977         /*
1978          * The cas has failed.  Either another CPU is adding an element to
1979          * this hash chain, or another CPU is deleting an element from this
1980          * hash chain.  The simplest way to deal with both of these cases
1981          * (though not necessarily the most efficient) is to free our
1982          * allocated block and tail-call ourselves.  Note that the free is
1983          * to the dirty list and _not_ to the free list.  This is to prevent
1984          * races with allocators, above.
1985          */
1986         dvar->dtdv_hashval = DTRACE_DYNHASH_FREE;
1987 
1988         dtrace_membar_producer();
1989 
1990         do {
1991                 free = dcpu->dtdsc_dirty;
1992                 dvar->dtdv_next = free;
1993         } while (dtrace_casptr(&dcpu->dtdsc_dirty, free, dvar) != free);
1994 
1995         return (dtrace_dynvar(dstate, nkeys, key, dsize, op, mstate, vstate));
1996 }
1997 
1998 /*ARGSUSED*/
1999 static void
2000 dtrace_aggregate_min(uint64_t *oval, uint64_t nval, uint64_t arg)
2001 {
2002         if ((int64_t)nval < (int64_t)*oval)
2003                 *oval = nval;
2004 }
2005 
2006 /*ARGSUSED*/
2007 static void
2008 dtrace_aggregate_max(uint64_t *oval, uint64_t nval, uint64_t arg)
2009 {
2010         if ((int64_t)nval > (int64_t)*oval)
2011                 *oval = nval;
2012 }
2013 
2014 static void
2015 dtrace_aggregate_quantize(uint64_t *quanta, uint64_t nval, uint64_t incr)
2016 {
2017         int i, zero = DTRACE_QUANTIZE_ZEROBUCKET;
2018         int64_t val = (int64_t)nval;
2019 
2020         if (val < 0) {
2021                 for (i = 0; i < zero; i++) {
2022                         if (val <= DTRACE_QUANTIZE_BUCKETVAL(i)) {
2023                                 quanta[i] += incr;
2024                                 return;
2025                         }
2026                 }
2027         } else {
2028                 for (i = zero + 1; i < DTRACE_QUANTIZE_NBUCKETS; i++) {
2029                         if (val < DTRACE_QUANTIZE_BUCKETVAL(i)) {
2030                                 quanta[i - 1] += incr;
2031                                 return;
2032                         }
2033                 }
2034 
2035                 quanta[DTRACE_QUANTIZE_NBUCKETS - 1] += incr;
2036                 return;
2037         }
2038 
2039         ASSERT(0);
2040 }
2041 
2042 static void
2043 dtrace_aggregate_lquantize(uint64_t *lquanta, uint64_t nval, uint64_t incr)
2044 {
2045         uint64_t arg = *lquanta++;
2046         int32_t base = DTRACE_LQUANTIZE_BASE(arg);
2047         uint16_t step = DTRACE_LQUANTIZE_STEP(arg);
2048         uint16_t levels = DTRACE_LQUANTIZE_LEVELS(arg);
2049         int32_t val = (int32_t)nval, level;
2050 
2051         ASSERT(step != 0);
2052         ASSERT(levels != 0);
2053 
2054         if (val < base) {
2055                 /*
2056                  * This is an underflow.
2057                  */
2058                 lquanta[0] += incr;
2059                 return;
2060         }
2061 
2062         level = (val - base) / step;
2063 
2064         if (level < levels) {
2065                 lquanta[level + 1] += incr;
2066                 return;
2067         }
2068 
2069         /*
2070          * This is an overflow.
2071          */
2072         lquanta[levels + 1] += incr;
2073 }
2074 
2075 static int
2076 dtrace_aggregate_llquantize_bucket(uint16_t factor, uint16_t low,
2077     uint16_t high, uint16_t nsteps, int64_t value)
2078 {
2079         int64_t this = 1, last, next;
2080         int base = 1, order;
2081 
2082         ASSERT(factor <= nsteps);
2083         ASSERT(nsteps % factor == 0);
2084 
2085         for (order = 0; order < low; order++)
2086                 this *= factor;
2087 
2088         /*
2089          * If our value is less than our factor taken to the power of the
2090          * low order of magnitude, it goes into the zeroth bucket.
2091          */
2092         if (value < (last = this))
2093                 return (0);
2094 
2095         for (this *= factor; order <= high; order++) {
2096                 int nbuckets = this > nsteps ? nsteps : this;
2097 
2098                 if ((next = this * factor) < this) {
2099                         /*
2100                          * We should not generally get log/linear quantizations
2101                          * with a high magnitude that allows 64-bits to
2102                          * overflow, but we nonetheless protect against this
2103                          * by explicitly checking for overflow, and clamping
2104                          * our value accordingly.
2105                          */
2106                         value = this - 1;
2107                 }
2108 
2109                 if (value < this) {
2110                         /*
2111                          * If our value lies within this order of magnitude,
2112                          * determine its position by taking the offset within
2113                          * the order of magnitude, dividing by the bucket
2114                          * width, and adding to our (accumulated) base.
2115                          */
2116                         return (base + (value - last) / (this / nbuckets));
2117                 }
2118 
2119                 base += nbuckets - (nbuckets / factor);
2120                 last = this;
2121                 this = next;
2122         }
2123 
2124         /*
2125          * Our value is greater than or equal to our factor taken to the
2126          * power of one plus the high magnitude -- return the top bucket.
2127          */
2128         return (base);
2129 }
2130 
2131 static void
2132 dtrace_aggregate_llquantize(uint64_t *llquanta, uint64_t nval, uint64_t incr)
2133 {
2134         uint64_t arg = *llquanta++;
2135         uint16_t factor = DTRACE_LLQUANTIZE_FACTOR(arg);
2136         uint16_t low = DTRACE_LLQUANTIZE_LOW(arg);
2137         uint16_t high = DTRACE_LLQUANTIZE_HIGH(arg);
2138         uint16_t nsteps = DTRACE_LLQUANTIZE_NSTEP(arg);
2139 
2140         llquanta[dtrace_aggregate_llquantize_bucket(factor,
2141             low, high, nsteps, nval)] += incr;
2142 }
2143 
2144 /*ARGSUSED*/
2145 static void
2146 dtrace_aggregate_avg(uint64_t *data, uint64_t nval, uint64_t arg)
2147 {
2148         data[0]++;
2149         data[1] += nval;
2150 }
2151 
2152 /*ARGSUSED*/
2153 static void
2154 dtrace_aggregate_stddev(uint64_t *data, uint64_t nval, uint64_t arg)
2155 {
2156         int64_t snval = (int64_t)nval;
2157         uint64_t tmp[2];
2158 
2159         data[0]++;
2160         data[1] += nval;
2161 
2162         /*
2163          * What we want to say here is:
2164          *
2165          * data[2] += nval * nval;
2166          *
2167          * But given that nval is 64-bit, we could easily overflow, so
2168          * we do this as 128-bit arithmetic.
2169          */
2170         if (snval < 0)
2171                 snval = -snval;
2172 
2173         dtrace_multiply_128((uint64_t)snval, (uint64_t)snval, tmp);
2174         dtrace_add_128(data + 2, tmp, data + 2);
2175 }
2176 
2177 /*ARGSUSED*/
2178 static void
2179 dtrace_aggregate_count(uint64_t *oval, uint64_t nval, uint64_t arg)
2180 {
2181         *oval = *oval + 1;
2182 }
2183 
2184 /*ARGSUSED*/
2185 static void
2186 dtrace_aggregate_sum(uint64_t *oval, uint64_t nval, uint64_t arg)
2187 {
2188         *oval += nval;
2189 }
2190 
2191 /*
2192  * Aggregate given the tuple in the principal data buffer, and the aggregating
2193  * action denoted by the specified dtrace_aggregation_t.  The aggregation
2194  * buffer is specified as the buf parameter.  This routine does not return
2195  * failure; if there is no space in the aggregation buffer, the data will be
2196  * dropped, and a corresponding counter incremented.
2197  */
2198 static void
2199 dtrace_aggregate(dtrace_aggregation_t *agg, dtrace_buffer_t *dbuf,
2200     intptr_t offset, dtrace_buffer_t *buf, uint64_t expr, uint64_t arg)
2201 {
2202         dtrace_recdesc_t *rec = &agg->dtag_action.dta_rec;
2203         uint32_t i, ndx, size, fsize;
2204         uint32_t align = sizeof (uint64_t) - 1;
2205         dtrace_aggbuffer_t *agb;
2206         dtrace_aggkey_t *key;
2207         uint32_t hashval = 0, limit, isstr;
2208         caddr_t tomax, data, kdata;
2209         dtrace_actkind_t action;
2210         dtrace_action_t *act;
2211         uintptr_t offs;
2212 
2213         if (buf == NULL)
2214                 return;
2215 
2216         if (!agg->dtag_hasarg) {
2217                 /*
2218                  * Currently, only quantize() and lquantize() take additional
2219                  * arguments, and they have the same semantics:  an increment
2220                  * value that defaults to 1 when not present.  If additional
2221                  * aggregating actions take arguments, the setting of the
2222                  * default argument value will presumably have to become more
2223                  * sophisticated...
2224                  */
2225                 arg = 1;
2226         }
2227 
2228         action = agg->dtag_action.dta_kind - DTRACEACT_AGGREGATION;
2229         size = rec->dtrd_offset - agg->dtag_base;
2230         fsize = size + rec->dtrd_size;
2231 
2232         ASSERT(dbuf->dtb_tomax != NULL);
2233         data = dbuf->dtb_tomax + offset + agg->dtag_base;
2234 
2235         if ((tomax = buf->dtb_tomax) == NULL) {
2236                 dtrace_buffer_drop(buf);
2237                 return;
2238         }
2239 
2240         /*
2241          * The metastructure is always at the bottom of the buffer.
2242          */
2243         agb = (dtrace_aggbuffer_t *)(tomax + buf->dtb_size -
2244             sizeof (dtrace_aggbuffer_t));
2245 
2246         if (buf->dtb_offset == 0) {
2247                 /*
2248                  * We just kludge up approximately 1/8th of the size to be
2249                  * buckets.  If this guess ends up being routinely
2250                  * off-the-mark, we may need to dynamically readjust this
2251                  * based on past performance.
2252                  */
2253                 uintptr_t hashsize = (buf->dtb_size >> 3) / sizeof (uintptr_t);
2254 
2255                 if ((uintptr_t)agb - hashsize * sizeof (dtrace_aggkey_t *) <
2256                     (uintptr_t)tomax || hashsize == 0) {
2257                         /*
2258                          * We've been given a ludicrously small buffer;
2259                          * increment our drop count and leave.
2260                          */
2261                         dtrace_buffer_drop(buf);
2262                         return;
2263                 }
2264 
2265                 /*
2266                  * And now, a pathetic attempt to try to get a an odd (or
2267                  * perchance, a prime) hash size for better hash distribution.
2268                  */
2269                 if (hashsize > (DTRACE_AGGHASHSIZE_SLEW << 3))
2270                         hashsize -= DTRACE_AGGHASHSIZE_SLEW;
2271 
2272                 agb->dtagb_hashsize = hashsize;
2273                 agb->dtagb_hash = (dtrace_aggkey_t **)((uintptr_t)agb -
2274                     agb->dtagb_hashsize * sizeof (dtrace_aggkey_t *));
2275                 agb->dtagb_free = (uintptr_t)agb->dtagb_hash;
2276 
2277                 for (i = 0; i < agb->dtagb_hashsize; i++)
2278                         agb->dtagb_hash[i] = NULL;
2279         }
2280 
2281         ASSERT(agg->dtag_first != NULL);
2282         ASSERT(agg->dtag_first->dta_intuple);
2283 
2284         /*
2285          * Calculate the hash value based on the key.  Note that we _don't_
2286          * include the aggid in the hashing (but we will store it as part of
2287          * the key).  The hashing algorithm is Bob Jenkins' "One-at-a-time"
2288          * algorithm: a simple, quick algorithm that has no known funnels, and
2289          * gets good distribution in practice.  The efficacy of the hashing
2290          * algorithm (and a comparison with other algorithms) may be found by
2291          * running the ::dtrace_aggstat MDB dcmd.
2292          */
2293         for (act = agg->dtag_first; act->dta_intuple; act = act->dta_next) {
2294                 i = act->dta_rec.dtrd_offset - agg->dtag_base;
2295                 limit = i + act->dta_rec.dtrd_size;
2296                 ASSERT(limit <= size);
2297                 isstr = DTRACEACT_ISSTRING(act);
2298 
2299                 for (; i < limit; i++) {
2300                         hashval += data[i];
2301                         hashval += (hashval << 10);
2302                         hashval ^= (hashval >> 6);
2303 
2304                         if (isstr && data[i] == '\0')
2305                                 break;
2306                 }
2307         }
2308 
2309         hashval += (hashval << 3);
2310         hashval ^= (hashval >> 11);
2311         hashval += (hashval << 15);
2312 
2313         /*
2314          * Yes, the divide here is expensive -- but it's generally the least
2315          * of the performance issues given the amount of data that we iterate
2316          * over to compute hash values, compare data, etc.
2317          */
2318         ndx = hashval % agb->dtagb_hashsize;
2319 
2320         for (key = agb->dtagb_hash[ndx]; key != NULL; key = key->dtak_next) {
2321                 ASSERT((caddr_t)key >= tomax);
2322                 ASSERT((caddr_t)key < tomax + buf->dtb_size);
2323 
2324                 if (hashval != key->dtak_hashval || key->dtak_size != size)
2325                         continue;
2326 
2327                 kdata = key->dtak_data;
2328                 ASSERT(kdata >= tomax && kdata < tomax + buf->dtb_size);
2329 
2330                 for (act = agg->dtag_first; act->dta_intuple;
2331                     act = act->dta_next) {
2332                         i = act->dta_rec.dtrd_offset - agg->dtag_base;
2333                         limit = i + act->dta_rec.dtrd_size;
2334                         ASSERT(limit <= size);
2335                         isstr = DTRACEACT_ISSTRING(act);
2336 
2337                         for (; i < limit; i++) {
2338                                 if (kdata[i] != data[i])
2339                                         goto next;
2340 
2341                                 if (isstr && data[i] == '\0')
2342                                         break;
2343                         }
2344                 }
2345 
2346                 if (action != key->dtak_action) {
2347                         /*
2348                          * We are aggregating on the same value in the same
2349                          * aggregation with two different aggregating actions.
2350                          * (This should have been picked up in the compiler,
2351                          * so we may be dealing with errant or devious DIF.)
2352                          * This is an error condition; we indicate as much,
2353                          * and return.
2354                          */
2355                         DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
2356                         return;
2357                 }
2358 
2359                 /*
2360                  * This is a hit:  we need to apply the aggregator to
2361                  * the value at this key.
2362                  */
2363                 agg->dtag_aggregate((uint64_t *)(kdata + size), expr, arg);
2364                 return;
2365 next:
2366                 continue;
2367         }
2368 
2369         /*
2370          * We didn't find it.  We need to allocate some zero-filled space,
2371          * link it into the hash table appropriately, and apply the aggregator
2372          * to the (zero-filled) value.
2373          */
2374         offs = buf->dtb_offset;
2375         while (offs & (align - 1))
2376                 offs += sizeof (uint32_t);
2377 
2378         /*
2379          * If we don't have enough room to both allocate a new key _and_
2380          * its associated data, increment the drop count and return.
2381          */
2382         if ((uintptr_t)tomax + offs + fsize >
2383             agb->dtagb_free - sizeof (dtrace_aggkey_t)) {
2384                 dtrace_buffer_drop(buf);
2385                 return;
2386         }
2387 
2388         /*CONSTCOND*/
2389         ASSERT(!(sizeof (dtrace_aggkey_t) & (sizeof (uintptr_t) - 1)));
2390         key = (dtrace_aggkey_t *)(agb->dtagb_free - sizeof (dtrace_aggkey_t));
2391         agb->dtagb_free -= sizeof (dtrace_aggkey_t);
2392 
2393         key->dtak_data = kdata = tomax + offs;
2394         buf->dtb_offset = offs + fsize;
2395 
2396         /*
2397          * Now copy the data across.
2398          */
2399         *((dtrace_aggid_t *)kdata) = agg->dtag_id;
2400 
2401         for (i = sizeof (dtrace_aggid_t); i < size; i++)
2402                 kdata[i] = data[i];
2403 
2404         /*
2405          * Because strings are not zeroed out by default, we need to iterate
2406          * looking for actions that store strings, and we need to explicitly
2407          * pad these strings out with zeroes.
2408          */
2409         for (act = agg->dtag_first; act->dta_intuple; act = act->dta_next) {
2410                 int nul;
2411 
2412                 if (!DTRACEACT_ISSTRING(act))
2413                         continue;
2414 
2415                 i = act->dta_rec.dtrd_offset - agg->dtag_base;
2416                 limit = i + act->dta_rec.dtrd_size;
2417                 ASSERT(limit <= size);
2418 
2419                 for (nul = 0; i < limit; i++) {
2420                         if (nul) {
2421                                 kdata[i] = '\0';
2422                                 continue;
2423                         }
2424 
2425                         if (data[i] != '\0')
2426                                 continue;
2427 
2428                         nul = 1;
2429                 }
2430         }
2431 
2432         for (i = size; i < fsize; i++)
2433                 kdata[i] = 0;
2434 
2435         key->dtak_hashval = hashval;
2436         key->dtak_size = size;
2437         key->dtak_action = action;
2438         key->dtak_next = agb->dtagb_hash[ndx];
2439         agb->dtagb_hash[ndx] = key;
2440 
2441         /*
2442          * Finally, apply the aggregator.
2443          */
2444         *((uint64_t *)(key->dtak_data + size)) = agg->dtag_initial;
2445         agg->dtag_aggregate((uint64_t *)(key->dtak_data + size), expr, arg);
2446 }
2447 
2448 /*
2449  * Given consumer state, this routine finds a speculation in the INACTIVE
2450  * state and transitions it into the ACTIVE state.  If there is no speculation
2451  * in the INACTIVE state, 0 is returned.  In this case, no error counter is
2452  * incremented -- it is up to the caller to take appropriate action.
2453  */
2454 static int
2455 dtrace_speculation(dtrace_state_t *state)
2456 {
2457         int i = 0;
2458         dtrace_speculation_state_t current;
2459         uint32_t *stat = &state->dts_speculations_unavail, count;
2460 
2461         while (i < state->dts_nspeculations) {
2462                 dtrace_speculation_t *spec = &state->dts_speculations[i];
2463 
2464                 current = spec->dtsp_state;
2465 
2466                 if (current != DTRACESPEC_INACTIVE) {
2467                         if (current == DTRACESPEC_COMMITTINGMANY ||
2468                             current == DTRACESPEC_COMMITTING ||
2469                             current == DTRACESPEC_DISCARDING)
2470                                 stat = &state->dts_speculations_busy;
2471                         i++;
2472                         continue;
2473                 }
2474 
2475                 if (dtrace_cas32((uint32_t *)&spec->dtsp_state,
2476                     current, DTRACESPEC_ACTIVE) == current)
2477                         return (i + 1);
2478         }
2479 
2480         /*
2481          * We couldn't find a speculation.  If we found as much as a single
2482          * busy speculation buffer, we'll attribute this failure as "busy"
2483          * instead of "unavail".
2484          */
2485         do {
2486                 count = *stat;
2487         } while (dtrace_cas32(stat, count, count + 1) != count);
2488 
2489         return (0);
2490 }
2491 
2492 /*
2493  * This routine commits an active speculation.  If the specified speculation
2494  * is not in a valid state to perform a commit(), this routine will silently do
2495  * nothing.  The state of the specified speculation is transitioned according
2496  * to the state transition diagram outlined in <sys/dtrace_impl.h>
2497  */
2498 static void
2499 dtrace_speculation_commit(dtrace_state_t *state, processorid_t cpu,
2500     dtrace_specid_t which)
2501 {
2502         dtrace_speculation_t *spec;
2503         dtrace_buffer_t *src, *dest;
2504         uintptr_t daddr, saddr, dlimit, slimit;
2505         dtrace_speculation_state_t current, new;
2506         intptr_t offs;
2507         uint64_t timestamp;
2508 
2509         if (which == 0)
2510                 return;
2511 
2512         if (which > state->dts_nspeculations) {
2513                 cpu_core[cpu].cpuc_dtrace_flags |= CPU_DTRACE_ILLOP;
2514                 return;
2515         }
2516 
2517         spec = &state->dts_speculations[which - 1];
2518         src = &spec->dtsp_buffer[cpu];
2519         dest = &state->dts_buffer[cpu];
2520 
2521         do {
2522                 current = spec->dtsp_state;
2523 
2524                 if (current == DTRACESPEC_COMMITTINGMANY)
2525                         break;
2526 
2527                 switch (current) {
2528                 case DTRACESPEC_INACTIVE:
2529                 case DTRACESPEC_DISCARDING:
2530                         return;
2531 
2532                 case DTRACESPEC_COMMITTING:
2533                         /*
2534                          * This is only possible if we are (a) commit()'ing
2535                          * without having done a prior speculate() on this CPU
2536                          * and (b) racing with another commit() on a different
2537                          * CPU.  There's nothing to do -- we just assert that
2538                          * our offset is 0.
2539                          */
2540                         ASSERT(src->dtb_offset == 0);
2541                         return;
2542 
2543                 case DTRACESPEC_ACTIVE:
2544                         new = DTRACESPEC_COMMITTING;
2545                         break;
2546 
2547                 case DTRACESPEC_ACTIVEONE:
2548                         /*
2549                          * This speculation is active on one CPU.  If our
2550                          * buffer offset is non-zero, we know that the one CPU
2551                          * must be us.  Otherwise, we are committing on a
2552                          * different CPU from the speculate(), and we must
2553                          * rely on being asynchronously cleaned.
2554                          */
2555                         if (src->dtb_offset != 0) {
2556                                 new = DTRACESPEC_COMMITTING;
2557                                 break;
2558                         }
2559                         /*FALLTHROUGH*/
2560 
2561                 case DTRACESPEC_ACTIVEMANY:
2562                         new = DTRACESPEC_COMMITTINGMANY;
2563                         break;
2564 
2565                 default:
2566                         ASSERT(0);
2567                 }
2568         } while (dtrace_cas32((uint32_t *)&spec->dtsp_state,
2569             current, new) != current);
2570 
2571         /*
2572          * We have set the state to indicate that we are committing this
2573          * speculation.  Now reserve the necessary space in the destination
2574          * buffer.
2575          */
2576         if ((offs = dtrace_buffer_reserve(dest, src->dtb_offset,
2577             sizeof (uint64_t), state, NULL)) < 0) {
2578                 dtrace_buffer_drop(dest);
2579                 goto out;
2580         }
2581 
2582         /*
2583          * We have sufficient space to copy the speculative buffer into the
2584          * primary buffer.  First, modify the speculative buffer, filling
2585          * in the timestamp of all entries with the current time.  The data
2586          * must have the commit() time rather than the time it was traced,
2587          * so that all entries in the primary buffer are in timestamp order.
2588          */
2589         timestamp = dtrace_gethrtime();
2590         saddr = (uintptr_t)src->dtb_tomax;
2591         slimit = saddr + src->dtb_offset;
2592         while (saddr < slimit) {
2593                 size_t size;
2594                 dtrace_rechdr_t *dtrh = (dtrace_rechdr_t *)saddr;
2595 
2596                 if (dtrh->dtrh_epid == DTRACE_EPIDNONE) {
2597                         saddr += sizeof (dtrace_epid_t);
2598                         continue;
2599                 }
2600                 ASSERT3U(dtrh->dtrh_epid, <=, state->dts_necbs);
2601                 size = state->dts_ecbs[dtrh->dtrh_epid - 1]->dte_size;
2602 
2603                 ASSERT3U(saddr + size, <=, slimit);
2604                 ASSERT3U(size, >=, sizeof (dtrace_rechdr_t));
2605                 ASSERT3U(DTRACE_RECORD_LOAD_TIMESTAMP(dtrh), ==, UINT64_MAX);
2606 
2607                 DTRACE_RECORD_STORE_TIMESTAMP(dtrh, timestamp);
2608 
2609                 saddr += size;
2610         }
2611 
2612         /*
2613          * Copy the buffer across.  (Note that this is a
2614          * highly subobtimal bcopy(); in the unlikely event that this becomes
2615          * a serious performance issue, a high-performance DTrace-specific
2616          * bcopy() should obviously be invented.)
2617          */
2618         daddr = (uintptr_t)dest->dtb_tomax + offs;
2619         dlimit = daddr + src->dtb_offset;
2620         saddr = (uintptr_t)src->dtb_tomax;
2621 
2622         /*
2623          * First, the aligned portion.
2624          */
2625         while (dlimit - daddr >= sizeof (uint64_t)) {
2626                 *((uint64_t *)daddr) = *((uint64_t *)saddr);
2627 
2628                 daddr += sizeof (uint64_t);
2629                 saddr += sizeof (uint64_t);
2630         }
2631 
2632         /*
2633          * Now any left-over bit...
2634          */
2635         while (dlimit - daddr)
2636                 *((uint8_t *)daddr++) = *((uint8_t *)saddr++);
2637 
2638         /*
2639          * Finally, commit the reserved space in the destination buffer.
2640          */
2641         dest->dtb_offset = offs + src->dtb_offset;
2642 
2643 out:
2644         /*
2645          * If we're lucky enough to be the only active CPU on this speculation
2646          * buffer, we can just set the state back to DTRACESPEC_INACTIVE.
2647          */
2648         if (current == DTRACESPEC_ACTIVE ||
2649             (current == DTRACESPEC_ACTIVEONE && new == DTRACESPEC_COMMITTING)) {
2650                 uint32_t rval = dtrace_cas32((uint32_t *)&spec->dtsp_state,
2651                     DTRACESPEC_COMMITTING, DTRACESPEC_INACTIVE);
2652 
2653                 ASSERT(rval == DTRACESPEC_COMMITTING);
2654         }
2655 
2656         src->dtb_offset = 0;
2657         src->dtb_xamot_drops += src->dtb_drops;
2658         src->dtb_drops = 0;
2659 }
2660 
2661 /*
2662  * This routine discards an active speculation.  If the specified speculation
2663  * is not in a valid state to perform a discard(), this routine will silently
2664  * do nothing.  The state of the specified speculation is transitioned
2665  * according to the state transition diagram outlined in <sys/dtrace_impl.h>
2666  */
2667 static void
2668 dtrace_speculation_discard(dtrace_state_t *state, processorid_t cpu,
2669     dtrace_specid_t which)
2670 {
2671         dtrace_speculation_t *spec;
2672         dtrace_speculation_state_t current, new;
2673         dtrace_buffer_t *buf;
2674 
2675         if (which == 0)
2676                 return;
2677 
2678         if (which > state->dts_nspeculations) {
2679                 cpu_core[cpu].cpuc_dtrace_flags |= CPU_DTRACE_ILLOP;
2680                 return;
2681         }
2682 
2683         spec = &state->dts_speculations[which - 1];
2684         buf = &spec->dtsp_buffer[cpu];
2685 
2686         do {
2687                 current = spec->dtsp_state;
2688 
2689                 switch (current) {
2690                 case DTRACESPEC_INACTIVE:
2691                 case DTRACESPEC_COMMITTINGMANY:
2692                 case DTRACESPEC_COMMITTING:
2693                 case DTRACESPEC_DISCARDING:
2694                         return;
2695 
2696                 case DTRACESPEC_ACTIVE:
2697                 case DTRACESPEC_ACTIVEMANY:
2698                         new = DTRACESPEC_DISCARDING;
2699                         break;
2700 
2701                 case DTRACESPEC_ACTIVEONE:
2702                         if (buf->dtb_offset != 0) {
2703                                 new = DTRACESPEC_INACTIVE;
2704                         } else {
2705                                 new = DTRACESPEC_DISCARDING;
2706                         }
2707                         break;
2708 
2709                 default:
2710                         ASSERT(0);
2711                 }
2712         } while (dtrace_cas32((uint32_t *)&spec->dtsp_state,
2713             current, new) != current);
2714 
2715         buf->dtb_offset = 0;
2716         buf->dtb_drops = 0;
2717 }
2718 
2719 /*
2720  * Note:  not called from probe context.  This function is called
2721  * asynchronously from cross call context to clean any speculations that are
2722  * in the COMMITTINGMANY or DISCARDING states.  These speculations may not be
2723  * transitioned back to the INACTIVE state until all CPUs have cleaned the
2724  * speculation.
2725  */
2726 static void
2727 dtrace_speculation_clean_here(dtrace_state_t *state)
2728 {
2729         dtrace_icookie_t cookie;
2730         processorid_t cpu = CPU->cpu_id;
2731         dtrace_buffer_t *dest = &state->dts_buffer[cpu];
2732         dtrace_specid_t i;
2733 
2734         cookie = dtrace_interrupt_disable();
2735 
2736         if (dest->dtb_tomax == NULL) {
2737                 dtrace_interrupt_enable(cookie);
2738                 return;
2739         }
2740 
2741         for (i = 0; i < state->dts_nspeculations; i++) {
2742                 dtrace_speculation_t *spec = &state->dts_speculations[i];
2743                 dtrace_buffer_t *src = &spec->dtsp_buffer[cpu];
2744 
2745                 if (src->dtb_tomax == NULL)
2746                         continue;
2747 
2748                 if (spec->dtsp_state == DTRACESPEC_DISCARDING) {
2749                         src->dtb_offset = 0;
2750                         continue;
2751                 }
2752 
2753                 if (spec->dtsp_state != DTRACESPEC_COMMITTINGMANY)
2754                         continue;
2755 
2756                 if (src->dtb_offset == 0)
2757                         continue;
2758 
2759                 dtrace_speculation_commit(state, cpu, i + 1);
2760         }
2761 
2762         dtrace_interrupt_enable(cookie);
2763 }
2764 
2765 /*
2766  * Note:  not called from probe context.  This function is called
2767  * asynchronously (and at a regular interval) to clean any speculations that
2768  * are in the COMMITTINGMANY or DISCARDING states.  If it discovers that there
2769  * is work to be done, it cross calls all CPUs to perform that work;
2770  * COMMITMANY and DISCARDING speculations may not be transitioned back to the
2771  * INACTIVE state until they have been cleaned by all CPUs.
2772  */
2773 static void
2774 dtrace_speculation_clean(dtrace_state_t *state)
2775 {
2776         int work = 0, rv;
2777         dtrace_specid_t i;
2778 
2779         for (i = 0; i < state->dts_nspeculations; i++) {
2780                 dtrace_speculation_t *spec = &state->dts_speculations[i];
2781 
2782                 ASSERT(!spec->dtsp_cleaning);
2783 
2784                 if (spec->dtsp_state != DTRACESPEC_DISCARDING &&
2785                     spec->dtsp_state != DTRACESPEC_COMMITTINGMANY)
2786                         continue;
2787 
2788                 work++;
2789                 spec->dtsp_cleaning = 1;
2790         }
2791 
2792         if (!work)
2793                 return;
2794 
2795         dtrace_xcall(DTRACE_CPUALL,
2796             (dtrace_xcall_t)dtrace_speculation_clean_here, state);
2797 
2798         /*
2799          * We now know that all CPUs have committed or discarded their
2800          * speculation buffers, as appropriate.  We can now set the state
2801          * to inactive.
2802          */
2803         for (i = 0; i < state->dts_nspeculations; i++) {
2804                 dtrace_speculation_t *spec = &state->dts_speculations[i];
2805                 dtrace_speculation_state_t current, new;
2806 
2807                 if (!spec->dtsp_cleaning)
2808                         continue;
2809 
2810                 current = spec->dtsp_state;
2811                 ASSERT(current == DTRACESPEC_DISCARDING ||
2812                     current == DTRACESPEC_COMMITTINGMANY);
2813 
2814                 new = DTRACESPEC_INACTIVE;
2815 
2816                 rv = dtrace_cas32((uint32_t *)&spec->dtsp_state, current, new);
2817                 ASSERT(rv == current);
2818                 spec->dtsp_cleaning = 0;
2819         }
2820 }
2821 
2822 /*
2823  * Called as part of a speculate() to get the speculative buffer associated
2824  * with a given speculation.  Returns NULL if the specified speculation is not
2825  * in an ACTIVE state.  If the speculation is in the ACTIVEONE state -- and
2826  * the active CPU is not the specified CPU -- the speculation will be
2827  * atomically transitioned into the ACTIVEMANY state.
2828  */
2829 static dtrace_buffer_t *
2830 dtrace_speculation_buffer(dtrace_state_t *state, processorid_t cpuid,
2831     dtrace_specid_t which)
2832 {
2833         dtrace_speculation_t *spec;
2834         dtrace_speculation_state_t current, new;
2835         dtrace_buffer_t *buf;
2836 
2837         if (which == 0)
2838                 return (NULL);
2839 
2840         if (which > state->dts_nspeculations) {
2841                 cpu_core[cpuid].cpuc_dtrace_flags |= CPU_DTRACE_ILLOP;
2842                 return (NULL);
2843         }
2844 
2845         spec = &state->dts_speculations[which - 1];
2846         buf = &spec->dtsp_buffer[cpuid];
2847 
2848         do {
2849                 current = spec->dtsp_state;
2850 
2851                 switch (current) {
2852                 case DTRACESPEC_INACTIVE:
2853                 case DTRACESPEC_COMMITTINGMANY:
2854                 case DTRACESPEC_DISCARDING:
2855                         return (NULL);
2856 
2857                 case DTRACESPEC_COMMITTING:
2858                         ASSERT(buf->dtb_offset == 0);
2859                         return (NULL);
2860 
2861                 case DTRACESPEC_ACTIVEONE:
2862                         /*
2863                          * This speculation is currently active on one CPU.
2864                          * Check the offset in the buffer; if it's non-zero,
2865                          * that CPU must be us (and we leave the state alone).
2866                          * If it's zero, assume that we're starting on a new
2867                          * CPU -- and change the state to indicate that the
2868                          * speculation is active on more than one CPU.
2869                          */
2870                         if (buf->dtb_offset != 0)
2871                                 return (buf);
2872 
2873                         new = DTRACESPEC_ACTIVEMANY;
2874                         break;
2875 
2876                 case DTRACESPEC_ACTIVEMANY:
2877                         return (buf);
2878 
2879                 case DTRACESPEC_ACTIVE:
2880                         new = DTRACESPEC_ACTIVEONE;
2881                         break;
2882 
2883                 default:
2884                         ASSERT(0);
2885                 }
2886         } while (dtrace_cas32((uint32_t *)&spec->dtsp_state,
2887             current, new) != current);
2888 
2889         ASSERT(new == DTRACESPEC_ACTIVEONE || new == DTRACESPEC_ACTIVEMANY);
2890         return (buf);
2891 }
2892 
2893 /*
2894  * Return a string.  In the event that the user lacks the privilege to access
2895  * arbitrary kernel memory, we copy the string out to scratch memory so that we
2896  * don't fail access checking.
2897  *
2898  * dtrace_dif_variable() uses this routine as a helper for various
2899  * builtin values such as 'execname' and 'probefunc.'
2900  */
2901 uintptr_t
2902 dtrace_dif_varstr(uintptr_t addr, dtrace_state_t *state,
2903     dtrace_mstate_t *mstate)
2904 {
2905         uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
2906         uintptr_t ret;
2907         size_t strsz;
2908 
2909         /*
2910          * The easy case: this probe is allowed to read all of memory, so
2911          * we can just return this as a vanilla pointer.
2912          */
2913         if ((mstate->dtms_access & DTRACE_ACCESS_KERNEL) != 0)
2914                 return (addr);
2915 
2916         /*
2917          * This is the tougher case: we copy the string in question from
2918          * kernel memory into scratch memory and return it that way: this
2919          * ensures that we won't trip up when access checking tests the
2920          * BYREF return value.
2921          */
2922         strsz = dtrace_strlen((char *)addr, size) + 1;
2923 
2924         if (mstate->dtms_scratch_ptr + strsz >
2925             mstate->dtms_scratch_base + mstate->dtms_scratch_size) {
2926                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
2927                 return (NULL);
2928         }
2929 
2930         dtrace_strcpy((const void *)addr, (void *)mstate->dtms_scratch_ptr,
2931             strsz);
2932         ret = mstate->dtms_scratch_ptr;
2933         mstate->dtms_scratch_ptr += strsz;
2934         return (ret);
2935 }
2936 
2937 /*
2938  * This function implements the DIF emulator's variable lookups.  The emulator
2939  * passes a reserved variable identifier and optional built-in array index.
2940  */
2941 static uint64_t
2942 dtrace_dif_variable(dtrace_mstate_t *mstate, dtrace_state_t *state, uint64_t v,
2943     uint64_t ndx)
2944 {
2945         /*
2946          * If we're accessing one of the uncached arguments, we'll turn this
2947          * into a reference in the args array.
2948          */
2949         if (v >= DIF_VAR_ARG0 && v <= DIF_VAR_ARG9) {
2950                 ndx = v - DIF_VAR_ARG0;
2951                 v = DIF_VAR_ARGS;
2952         }
2953 
2954         switch (v) {
2955         case DIF_VAR_ARGS:
2956                 if (!(mstate->dtms_access & DTRACE_ACCESS_ARGS)) {
2957                         cpu_core[CPU->cpu_id].cpuc_dtrace_flags |=
2958                             CPU_DTRACE_KPRIV;
2959                         return (0);
2960                 }
2961 
2962                 ASSERT(mstate->dtms_present & DTRACE_MSTATE_ARGS);
2963                 if (ndx >= sizeof (mstate->dtms_arg) /
2964                     sizeof (mstate->dtms_arg[0])) {
2965                         int aframes = mstate->dtms_probe->dtpr_aframes + 2;
2966                         dtrace_provider_t *pv;
2967                         uint64_t val;
2968 
2969                         pv = mstate->dtms_probe->dtpr_provider;
2970                         if (pv->dtpv_pops.dtps_getargval != NULL)
2971                                 val = pv->dtpv_pops.dtps_getargval(pv->dtpv_arg,
2972                                     mstate->dtms_probe->dtpr_id,
2973                                     mstate->dtms_probe->dtpr_arg, ndx, aframes);
2974                         else
2975                                 val = dtrace_getarg(ndx, aframes);
2976 
2977                         /*
2978                          * This is regrettably required to keep the compiler
2979                          * from tail-optimizing the call to dtrace_getarg().
2980                          * The condition always evaluates to true, but the
2981                          * compiler has no way of figuring that out a priori.
2982                          * (None of this would be necessary if the compiler
2983                          * could be relied upon to _always_ tail-optimize
2984                          * the call to dtrace_getarg() -- but it can't.)
2985                          */
2986                         if (mstate->dtms_probe != NULL)
2987                                 return (val);
2988 
2989                         ASSERT(0);
2990                 }
2991 
2992                 return (mstate->dtms_arg[ndx]);
2993 
2994         case DIF_VAR_UREGS: {
2995                 klwp_t *lwp;
2996 
2997                 if (!dtrace_priv_proc(state, mstate))
2998                         return (0);
2999 
3000                 if ((lwp = curthread->t_lwp) == NULL) {
3001                         DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
3002                         cpu_core[CPU->cpu_id].cpuc_dtrace_illval = NULL;
3003                         return (0);
3004                 }
3005 
3006                 return (dtrace_getreg(lwp->lwp_regs, ndx));
3007         }
3008 
3009         case DIF_VAR_VMREGS: {
3010                 uint64_t rval;
3011 
3012                 if (!dtrace_priv_kernel(state))
3013                         return (0);
3014 
3015                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
3016 
3017                 rval = dtrace_getvmreg(ndx,
3018                     &cpu_core[CPU->cpu_id].cpuc_dtrace_flags);
3019 
3020                 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
3021 
3022                 return (rval);
3023         }
3024 
3025         case DIF_VAR_CURTHREAD:
3026                 if (!dtrace_priv_proc(state, mstate))
3027                         return (0);
3028                 return ((uint64_t)(uintptr_t)curthread);
3029 
3030         case DIF_VAR_TIMESTAMP:
3031                 if (!(mstate->dtms_present & DTRACE_MSTATE_TIMESTAMP)) {
3032                         mstate->dtms_timestamp = dtrace_gethrtime();
3033                         mstate->dtms_present |= DTRACE_MSTATE_TIMESTAMP;
3034                 }
3035                 return (mstate->dtms_timestamp);
3036 
3037         case DIF_VAR_VTIMESTAMP:
3038                 ASSERT(dtrace_vtime_references != 0);
3039                 return (curthread->t_dtrace_vtime);
3040 
3041         case DIF_VAR_WALLTIMESTAMP:
3042                 if (!(mstate->dtms_present & DTRACE_MSTATE_WALLTIMESTAMP)) {
3043                         mstate->dtms_walltimestamp = dtrace_gethrestime();
3044                         mstate->dtms_present |= DTRACE_MSTATE_WALLTIMESTAMP;
3045                 }
3046                 return (mstate->dtms_walltimestamp);
3047 
3048         case DIF_VAR_IPL:
3049                 if (!dtrace_priv_kernel(state))
3050                         return (0);
3051                 if (!(mstate->dtms_present & DTRACE_MSTATE_IPL)) {
3052                         mstate->dtms_ipl = dtrace_getipl();
3053                         mstate->dtms_present |= DTRACE_MSTATE_IPL;
3054                 }
3055                 return (mstate->dtms_ipl);
3056 
3057         case DIF_VAR_EPID:
3058                 ASSERT(mstate->dtms_present & DTRACE_MSTATE_EPID);
3059                 return (mstate->dtms_epid);
3060 
3061         case DIF_VAR_ID:
3062                 ASSERT(mstate->dtms_present & DTRACE_MSTATE_PROBE);
3063                 return (mstate->dtms_probe->dtpr_id);
3064 
3065         case DIF_VAR_STACKDEPTH:
3066                 if (!dtrace_priv_kernel(state))
3067                         return (0);
3068                 if (!(mstate->dtms_present & DTRACE_MSTATE_STACKDEPTH)) {
3069                         int aframes = mstate->dtms_probe->dtpr_aframes + 2;
3070 
3071                         mstate->dtms_stackdepth = dtrace_getstackdepth(aframes);
3072                         mstate->dtms_present |= DTRACE_MSTATE_STACKDEPTH;
3073                 }
3074                 return (mstate->dtms_stackdepth);
3075 
3076         case DIF_VAR_USTACKDEPTH:
3077                 if (!dtrace_priv_proc(state, mstate))
3078                         return (0);
3079                 if (!(mstate->dtms_present & DTRACE_MSTATE_USTACKDEPTH)) {
3080                         /*
3081                          * See comment in DIF_VAR_PID.
3082                          */
3083                         if (DTRACE_ANCHORED(mstate->dtms_probe) &&
3084                             CPU_ON_INTR(CPU)) {
3085                                 mstate->dtms_ustackdepth = 0;
3086                         } else {
3087                                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
3088                                 mstate->dtms_ustackdepth =
3089                                     dtrace_getustackdepth();
3090                                 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
3091                         }
3092                         mstate->dtms_present |= DTRACE_MSTATE_USTACKDEPTH;
3093                 }
3094                 return (mstate->dtms_ustackdepth);
3095 
3096         case DIF_VAR_CALLER:
3097                 if (!dtrace_priv_kernel(state))
3098                         return (0);
3099                 if (!(mstate->dtms_present & DTRACE_MSTATE_CALLER)) {
3100                         int aframes = mstate->dtms_probe->dtpr_aframes + 2;
3101 
3102                         if (!DTRACE_ANCHORED(mstate->dtms_probe)) {
3103                                 /*
3104                                  * If this is an unanchored probe, we are
3105                                  * required to go through the slow path:
3106                                  * dtrace_caller() only guarantees correct
3107                                  * results for anchored probes.
3108                                  */
3109                                 pc_t caller[2];
3110 
3111                                 dtrace_getpcstack(caller, 2, aframes,
3112                                     (uint32_t *)(uintptr_t)mstate->dtms_arg[0]);
3113                                 mstate->dtms_caller = caller[1];
3114                         } else if ((mstate->dtms_caller =
3115                             dtrace_caller(aframes)) == -1) {
3116                                 /*
3117                                  * We have failed to do this the quick way;
3118                                  * we must resort to the slower approach of
3119                                  * calling dtrace_getpcstack().
3120                                  */
3121                                 pc_t caller;
3122 
3123                                 dtrace_getpcstack(&caller, 1, aframes, NULL);
3124                                 mstate->dtms_caller = caller;
3125                         }
3126 
3127                         mstate->dtms_present |= DTRACE_MSTATE_CALLER;
3128                 }
3129                 return (mstate->dtms_caller);
3130 
3131         case DIF_VAR_UCALLER:
3132                 if (!dtrace_priv_proc(state, mstate))
3133                         return (0);
3134 
3135                 if (!(mstate->dtms_present & DTRACE_MSTATE_UCALLER)) {
3136                         uint64_t ustack[3];
3137 
3138                         /*
3139                          * dtrace_getupcstack() fills in the first uint64_t
3140                          * with the current PID.  The second uint64_t will
3141                          * be the program counter at user-level.  The third
3142                          * uint64_t will contain the caller, which is what
3143                          * we're after.
3144                          */
3145                         ustack[2] = NULL;
3146                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
3147                         dtrace_getupcstack(ustack, 3);
3148                         DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
3149                         mstate->dtms_ucaller = ustack[2];
3150                         mstate->dtms_present |= DTRACE_MSTATE_UCALLER;
3151                 }
3152 
3153                 return (mstate->dtms_ucaller);
3154 
3155         case DIF_VAR_PROBEPROV:
3156                 ASSERT(mstate->dtms_present & DTRACE_MSTATE_PROBE);
3157                 return (dtrace_dif_varstr(
3158                     (uintptr_t)mstate->dtms_probe->dtpr_provider->dtpv_name,
3159                     state, mstate));
3160 
3161         case DIF_VAR_PROBEMOD:
3162                 ASSERT(mstate->dtms_present & DTRACE_MSTATE_PROBE);
3163                 return (dtrace_dif_varstr(
3164                     (uintptr_t)mstate->dtms_probe->dtpr_mod,
3165                     state, mstate));
3166 
3167         case DIF_VAR_PROBEFUNC:
3168                 ASSERT(mstate->dtms_present & DTRACE_MSTATE_PROBE);
3169                 return (dtrace_dif_varstr(
3170                     (uintptr_t)mstate->dtms_probe->dtpr_func,
3171                     state, mstate));
3172 
3173         case DIF_VAR_PROBENAME:
3174                 ASSERT(mstate->dtms_present & DTRACE_MSTATE_PROBE);
3175                 return (dtrace_dif_varstr(
3176                     (uintptr_t)mstate->dtms_probe->dtpr_name,
3177                     state, mstate));
3178 
3179         case DIF_VAR_PID:
3180                 if (!dtrace_priv_proc(state, mstate))
3181                         return (0);
3182 
3183                 /*
3184                  * Note that we are assuming that an unanchored probe is
3185                  * always due to a high-level interrupt.  (And we're assuming
3186                  * that there is only a single high level interrupt.)
3187                  */
3188                 if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
3189                         return (pid0.pid_id);
3190 
3191                 /*
3192                  * It is always safe to dereference one's own t_procp pointer:
3193                  * it always points to a valid, allocated proc structure.
3194                  * Further, it is always safe to dereference the p_pidp member
3195                  * of one's own proc structure.  (These are truisms becuase
3196                  * threads and processes don't clean up their own state --
3197                  * they leave that task to whomever reaps them.)
3198                  */
3199                 return ((uint64_t)curthread->t_procp->p_pidp->pid_id);
3200 
3201         case DIF_VAR_PPID:
3202                 if (!dtrace_priv_proc(state, mstate))
3203                         return (0);
3204 
3205                 /*
3206                  * See comment in DIF_VAR_PID.
3207                  */
3208                 if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
3209                         return (pid0.pid_id);
3210 
3211                 /*
3212                  * It is always safe to dereference one's own t_procp pointer:
3213                  * it always points to a valid, allocated proc structure.
3214                  * (This is true because threads don't clean up their own
3215                  * state -- they leave that task to whomever reaps them.)
3216                  */
3217                 return ((uint64_t)curthread->t_procp->p_ppid);
3218 
3219         case DIF_VAR_TID:
3220                 /*
3221                  * See comment in DIF_VAR_PID.
3222                  */
3223                 if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
3224                         return (0);
3225 
3226                 return ((uint64_t)curthread->t_tid);
3227 
3228         case DIF_VAR_EXECNAME:
3229                 if (!dtrace_priv_proc(state, mstate))
3230                         return (0);
3231 
3232                 /*
3233                  * See comment in DIF_VAR_PID.
3234                  */
3235                 if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
3236                         return ((uint64_t)(uintptr_t)p0.p_user.u_comm);
3237 
3238                 /*
3239                  * It is always safe to dereference one's own t_procp pointer:
3240                  * it always points to a valid, allocated proc structure.
3241                  * (This is true because threads don't clean up their own
3242                  * state -- they leave that task to whomever reaps them.)
3243                  */
3244                 return (dtrace_dif_varstr(
3245                     (uintptr_t)curthread->t_procp->p_user.u_comm,
3246                     state, mstate));
3247 
3248         case DIF_VAR_ZONENAME:
3249                 if (!dtrace_priv_proc(state, mstate))
3250                         return (0);
3251 
3252                 /*
3253                  * See comment in DIF_VAR_PID.
3254                  */
3255                 if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
3256                         return ((uint64_t)(uintptr_t)p0.p_zone->zone_name);
3257 
3258                 /*
3259                  * It is always safe to dereference one's own t_procp pointer:
3260                  * it always points to a valid, allocated proc structure.
3261                  * (This is true because threads don't clean up their own
3262                  * state -- they leave that task to whomever reaps them.)
3263                  */
3264                 return (dtrace_dif_varstr(
3265                     (uintptr_t)curthread->t_procp->p_zone->zone_name,
3266                     state, mstate));
3267 
3268         case DIF_VAR_UID:
3269                 if (!dtrace_priv_proc(state, mstate))
3270                         return (0);
3271 
3272                 /*
3273                  * See comment in DIF_VAR_PID.
3274                  */
3275                 if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
3276                         return ((uint64_t)p0.p_cred->cr_uid);
3277 
3278                 /*
3279                  * It is always safe to dereference one's own t_procp pointer:
3280                  * it always points to a valid, allocated proc structure.
3281                  * (This is true because threads don't clean up their own
3282                  * state -- they leave that task to whomever reaps them.)
3283                  *
3284                  * Additionally, it is safe to dereference one's own process
3285                  * credential, since this is never NULL after process birth.
3286                  */
3287                 return ((uint64_t)curthread->t_procp->p_cred->cr_uid);
3288 
3289         case DIF_VAR_GID:
3290                 if (!dtrace_priv_proc(state, mstate))
3291                         return (0);
3292 
3293                 /*
3294                  * See comment in DIF_VAR_PID.
3295                  */
3296                 if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
3297                         return ((uint64_t)p0.p_cred->cr_gid);
3298 
3299                 /*
3300                  * It is always safe to dereference one's own t_procp pointer:
3301                  * it always points to a valid, allocated proc structure.
3302                  * (This is true because threads don't clean up their own
3303                  * state -- they leave that task to whomever reaps them.)
3304                  *
3305                  * Additionally, it is safe to dereference one's own process
3306                  * credential, since this is never NULL after process birth.
3307                  */
3308                 return ((uint64_t)curthread->t_procp->p_cred->cr_gid);
3309 
3310         case DIF_VAR_ERRNO: {
3311                 klwp_t *lwp;
3312                 if (!dtrace_priv_proc(state, mstate))
3313                         return (0);
3314 
3315                 /*
3316                  * See comment in DIF_VAR_PID.
3317                  */
3318                 if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
3319                         return (0);
3320 
3321                 /*
3322                  * It is always safe to dereference one's own t_lwp pointer in
3323                  * the event that this pointer is non-NULL.  (This is true
3324                  * because threads and lwps don't clean up their own state --
3325                  * they leave that task to whomever reaps them.)
3326                  */
3327                 if ((lwp = curthread->t_lwp) == NULL)
3328                         return (0);
3329 
3330                 return ((uint64_t)lwp->lwp_errno);
3331         }
3332         default:
3333                 DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
3334                 return (0);
3335         }
3336 }
3337 
3338 /*
3339  * Emulate the execution of DTrace ID subroutines invoked by the call opcode.
3340  * Notice that we don't bother validating the proper number of arguments or
3341  * their types in the tuple stack.  This isn't needed because all argument
3342  * interpretation is safe because of our load safety -- the worst that can
3343  * happen is that a bogus program can obtain bogus results.
3344  */
3345 static void
3346 dtrace_dif_subr(uint_t subr, uint_t rd, uint64_t *regs,
3347     dtrace_key_t *tupregs, int nargs,
3348     dtrace_mstate_t *mstate, dtrace_state_t *state)
3349 {
3350         volatile uint16_t *flags = &cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
3351         volatile uintptr_t *illval = &cpu_core[CPU->cpu_id].cpuc_dtrace_illval;
3352         dtrace_vstate_t *vstate = &state->dts_vstate;
3353 
3354         union {
3355                 mutex_impl_t mi;
3356                 uint64_t mx;
3357         } m;
3358 
3359         union {
3360                 krwlock_t ri;
3361                 uintptr_t rw;
3362         } r;
3363 
3364         switch (subr) {
3365         case DIF_SUBR_RAND:
3366                 regs[rd] = (dtrace_gethrtime() * 2416 + 374441) % 1771875;
3367                 break;
3368 
3369         case DIF_SUBR_MUTEX_OWNED:
3370                 if (!dtrace_canload(tupregs[0].dttk_value, sizeof (kmutex_t),
3371                     mstate, vstate)) {
3372                         regs[rd] = NULL;
3373                         break;
3374                 }
3375 
3376                 m.mx = dtrace_load64(tupregs[0].dttk_value);
3377                 if (MUTEX_TYPE_ADAPTIVE(&m.mi))
3378                         regs[rd] = MUTEX_OWNER(&m.mi) != MUTEX_NO_OWNER;
3379                 else
3380                         regs[rd] = LOCK_HELD(&m.mi.m_spin.m_spinlock);
3381                 break;
3382 
3383         case DIF_SUBR_MUTEX_OWNER:
3384                 if (!dtrace_canload(tupregs[0].dttk_value, sizeof (kmutex_t),
3385                     mstate, vstate)) {
3386                         regs[rd] = NULL;
3387                         break;
3388                 }
3389 
3390                 m.mx = dtrace_load64(tupregs[0].dttk_value);
3391                 if (MUTEX_TYPE_ADAPTIVE(&m.mi) &&
3392                     MUTEX_OWNER(&m.mi) != MUTEX_NO_OWNER)
3393                         regs[rd] = (uintptr_t)MUTEX_OWNER(&m.mi);
3394                 else
3395                         regs[rd] = 0;
3396                 break;
3397 
3398         case DIF_SUBR_MUTEX_TYPE_ADAPTIVE:
3399                 if (!dtrace_canload(tupregs[0].dttk_value, sizeof (kmutex_t),
3400                     mstate, vstate)) {
3401                         regs[rd] = NULL;
3402                         break;
3403                 }
3404 
3405                 m.mx = dtrace_load64(tupregs[0].dttk_value);
3406                 regs[rd] = MUTEX_TYPE_ADAPTIVE(&m.mi);
3407                 break;
3408 
3409         case DIF_SUBR_MUTEX_TYPE_SPIN:
3410                 if (!dtrace_canload(tupregs[0].dttk_value, sizeof (kmutex_t),
3411                     mstate, vstate)) {
3412                         regs[rd] = NULL;
3413                         break;
3414                 }
3415 
3416                 m.mx = dtrace_load64(tupregs[0].dttk_value);
3417                 regs[rd] = MUTEX_TYPE_SPIN(&m.mi);
3418                 break;
3419 
3420         case DIF_SUBR_RW_READ_HELD: {
3421                 uintptr_t tmp;
3422 
3423                 if (!dtrace_canload(tupregs[0].dttk_value, sizeof (uintptr_t),
3424                     mstate, vstate)) {
3425                         regs[rd] = NULL;
3426                         break;
3427                 }
3428 
3429                 r.rw = dtrace_loadptr(tupregs[0].dttk_value);
3430                 regs[rd] = _RW_READ_HELD(&r.ri, tmp);
3431                 break;
3432         }
3433 
3434         case DIF_SUBR_RW_WRITE_HELD:
3435                 if (!dtrace_canload(tupregs[0].dttk_value, sizeof (krwlock_t),
3436                     mstate, vstate)) {
3437                         regs[rd] = NULL;
3438                         break;
3439                 }
3440 
3441                 r.rw = dtrace_loadptr(tupregs[0].dttk_value);
3442                 regs[rd] = _RW_WRITE_HELD(&r.ri);
3443                 break;
3444 
3445         case DIF_SUBR_RW_ISWRITER:
3446                 if (!dtrace_canload(tupregs[0].dttk_value, sizeof (krwlock_t),
3447                     mstate, vstate)) {
3448                         regs[rd] = NULL;
3449                         break;
3450                 }
3451 
3452                 r.rw = dtrace_loadptr(tupregs[0].dttk_value);
3453                 regs[rd] = _RW_ISWRITER(&r.ri);
3454                 break;
3455 
3456         case DIF_SUBR_BCOPY: {
3457                 /*
3458                  * We need to be sure that the destination is in the scratch
3459                  * region -- no other region is allowed.
3460                  */
3461                 uintptr_t src = tupregs[0].dttk_value;
3462                 uintptr_t dest = tupregs[1].dttk_value;
3463                 size_t size = tupregs[2].dttk_value;
3464 
3465                 if (!dtrace_inscratch(dest, size, mstate)) {
3466                         *flags |= CPU_DTRACE_BADADDR;
3467                         *illval = regs[rd];
3468                         break;
3469                 }
3470 
3471                 if (!dtrace_canload(src, size, mstate, vstate)) {
3472                         regs[rd] = NULL;
3473                         break;
3474                 }
3475 
3476                 dtrace_bcopy((void *)src, (void *)dest, size);
3477                 break;
3478         }
3479 
3480         case DIF_SUBR_ALLOCA:
3481         case DIF_SUBR_COPYIN: {
3482                 uintptr_t dest = P2ROUNDUP(mstate->dtms_scratch_ptr, 8);
3483                 uint64_t size =
3484                     tupregs[subr == DIF_SUBR_ALLOCA ? 0 : 1].dttk_value;
3485                 size_t scratch_size = (dest - mstate->dtms_scratch_ptr) + size;
3486 
3487                 /*
3488                  * This action doesn't require any credential checks since
3489                  * probes will not activate in user contexts to which the
3490                  * enabling user does not have permissions.
3491                  */
3492 
3493                 /*
3494                  * Rounding up the user allocation size could have overflowed
3495                  * a large, bogus allocation (like -1ULL) to 0.
3496                  */
3497                 if (scratch_size < size ||
3498                     !DTRACE_INSCRATCH(mstate, scratch_size)) {
3499                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
3500                         regs[rd] = NULL;
3501                         break;
3502                 }
3503 
3504                 if (subr == DIF_SUBR_COPYIN) {
3505                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
3506                         dtrace_copyin(tupregs[0].dttk_value, dest, size, flags);
3507                         DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
3508                 }
3509 
3510                 mstate->dtms_scratch_ptr += scratch_size;
3511                 regs[rd] = dest;
3512                 break;
3513         }
3514 
3515         case DIF_SUBR_COPYINTO: {
3516                 uint64_t size = tupregs[1].dttk_value;
3517                 uintptr_t dest = tupregs[2].dttk_value;
3518 
3519                 /*
3520                  * This action doesn't require any credential checks since
3521                  * probes will not activate in user contexts to which the
3522                  * enabling user does not have permissions.
3523                  */
3524                 if (!dtrace_inscratch(dest, size, mstate)) {
3525                         *flags |= CPU_DTRACE_BADADDR;
3526                         *illval = regs[rd];
3527                         break;
3528                 }
3529 
3530                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
3531                 dtrace_copyin(tupregs[0].dttk_value, dest, size, flags);
3532                 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
3533                 break;
3534         }
3535 
3536         case DIF_SUBR_COPYINSTR: {
3537                 uintptr_t dest = mstate->dtms_scratch_ptr;
3538                 uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
3539 
3540                 if (nargs > 1 && tupregs[1].dttk_value < size)
3541                         size = tupregs[1].dttk_value + 1;
3542 
3543                 /*
3544                  * This action doesn't require any credential checks since
3545                  * probes will not activate in user contexts to which the
3546                  * enabling user does not have permissions.
3547                  */
3548                 if (!DTRACE_INSCRATCH(mstate, size)) {
3549                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
3550                         regs[rd] = NULL;
3551                         break;
3552                 }
3553 
3554                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
3555                 dtrace_copyinstr(tupregs[0].dttk_value, dest, size, flags);
3556                 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
3557 
3558                 ((char *)dest)[size - 1] = '\0';
3559                 mstate->dtms_scratch_ptr += size;
3560                 regs[rd] = dest;
3561                 break;
3562         }
3563 
3564         case DIF_SUBR_MSGSIZE:
3565         case DIF_SUBR_MSGDSIZE: {
3566                 uintptr_t baddr = tupregs[0].dttk_value, daddr;
3567                 uintptr_t wptr, rptr;
3568                 size_t count = 0;
3569                 int cont = 0;
3570 
3571                 while (baddr != NULL && !(*flags & CPU_DTRACE_FAULT)) {
3572 
3573                         if (!dtrace_canload(baddr, sizeof (mblk_t), mstate,
3574                             vstate)) {
3575                                 regs[rd] = NULL;
3576                                 break;
3577                         }
3578 
3579                         wptr = dtrace_loadptr(baddr +
3580                             offsetof(mblk_t, b_wptr));
3581 
3582                         rptr = dtrace_loadptr(baddr +
3583                             offsetof(mblk_t, b_rptr));
3584 
3585                         if (wptr < rptr) {
3586                                 *flags |= CPU_DTRACE_BADADDR;
3587                                 *illval = tupregs[0].dttk_value;
3588                                 break;
3589                         }
3590 
3591                         daddr = dtrace_loadptr(baddr +
3592                             offsetof(mblk_t, b_datap));
3593 
3594                         baddr = dtrace_loadptr(baddr +
3595                             offsetof(mblk_t, b_cont));
3596 
3597                         /*
3598                          * We want to prevent against denial-of-service here,
3599                          * so we're only going to search the list for
3600                          * dtrace_msgdsize_max mblks.
3601                          */
3602                         if (cont++ > dtrace_msgdsize_max) {
3603                                 *flags |= CPU_DTRACE_ILLOP;
3604                                 break;
3605                         }
3606 
3607                         if (subr == DIF_SUBR_MSGDSIZE) {
3608                                 if (dtrace_load8(daddr +
3609                                     offsetof(dblk_t, db_type)) != M_DATA)
3610                                         continue;
3611                         }
3612 
3613                         count += wptr - rptr;
3614                 }
3615 
3616                 if (!(*flags & CPU_DTRACE_FAULT))
3617                         regs[rd] = count;
3618 
3619                 break;
3620         }
3621 
3622         case DIF_SUBR_PROGENYOF: {
3623                 pid_t pid = tupregs[0].dttk_value;
3624                 proc_t *p;
3625                 int rval = 0;
3626 
3627                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
3628 
3629                 for (p = curthread->t_procp; p != NULL; p = p->p_parent) {
3630                         if (p->p_pidp->pid_id == pid) {
3631                                 rval = 1;
3632                                 break;
3633                         }
3634                 }
3635 
3636                 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
3637 
3638                 regs[rd] = rval;
3639                 break;
3640         }
3641 
3642         case DIF_SUBR_SPECULATION:
3643                 regs[rd] = dtrace_speculation(state);
3644                 break;
3645 
3646         case DIF_SUBR_COPYOUT: {
3647                 uintptr_t kaddr = tupregs[0].dttk_value;
3648                 uintptr_t uaddr = tupregs[1].dttk_value;
3649                 uint64_t size = tupregs[2].dttk_value;
3650 
3651                 if (!dtrace_destructive_disallow &&
3652                     dtrace_priv_proc_control(state, mstate) &&
3653                     !dtrace_istoxic(kaddr, size)) {
3654                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
3655                         dtrace_copyout(kaddr, uaddr, size, flags);
3656                         DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
3657                 }
3658                 break;
3659         }
3660 
3661         case DIF_SUBR_COPYOUTSTR: {
3662                 uintptr_t kaddr = tupregs[0].dttk_value;
3663                 uintptr_t uaddr = tupregs[1].dttk_value;
3664                 uint64_t size = tupregs[2].dttk_value;
3665 
3666                 if (!dtrace_destructive_disallow &&
3667                     dtrace_priv_proc_control(state, mstate) &&
3668                     !dtrace_istoxic(kaddr, size)) {
3669                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
3670                         dtrace_copyoutstr(kaddr, uaddr, size, flags);
3671                         DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
3672                 }
3673                 break;
3674         }
3675 
3676         case DIF_SUBR_STRLEN: {
3677                 size_t sz;
3678                 uintptr_t addr = (uintptr_t)tupregs[0].dttk_value;
3679                 sz = dtrace_strlen((char *)addr,
3680                     state->dts_options[DTRACEOPT_STRSIZE]);
3681 
3682                 if (!dtrace_canload(addr, sz + 1, mstate, vstate)) {
3683                         regs[rd] = NULL;
3684                         break;
3685                 }
3686 
3687                 regs[rd] = sz;
3688 
3689                 break;
3690         }
3691 
3692         case DIF_SUBR_STRCHR:
3693         case DIF_SUBR_STRRCHR: {
3694                 /*
3695                  * We're going to iterate over the string looking for the
3696                  * specified character.  We will iterate until we have reached
3697                  * the string length or we have found the character.  If this
3698                  * is DIF_SUBR_STRRCHR, we will look for the last occurrence
3699                  * of the specified character instead of the first.
3700                  */
3701                 uintptr_t saddr = tupregs[0].dttk_value;
3702                 uintptr_t addr = tupregs[0].dttk_value;
3703                 uintptr_t limit = addr + state->dts_options[DTRACEOPT_STRSIZE];
3704                 char c, target = (char)tupregs[1].dttk_value;
3705 
3706                 for (regs[rd] = NULL; addr < limit; addr++) {
3707                         if ((c = dtrace_load8(addr)) == target) {
3708                                 regs[rd] = addr;
3709 
3710                                 if (subr == DIF_SUBR_STRCHR)
3711                                         break;
3712                         }
3713 
3714                         if (c == '\0')
3715                                 break;
3716                 }
3717 
3718                 if (!dtrace_canload(saddr, addr - saddr, mstate, vstate)) {
3719                         regs[rd] = NULL;
3720                         break;
3721                 }
3722 
3723                 break;
3724         }
3725 
3726         case DIF_SUBR_STRSTR:
3727         case DIF_SUBR_INDEX:
3728         case DIF_SUBR_RINDEX: {
3729                 /*
3730                  * We're going to iterate over the string looking for the
3731                  * specified string.  We will iterate until we have reached
3732                  * the string length or we have found the string.  (Yes, this
3733                  * is done in the most naive way possible -- but considering
3734                  * that the string we're searching for is likely to be
3735                  * relatively short, the complexity of Rabin-Karp or similar
3736                  * hardly seems merited.)
3737                  */
3738                 char *addr = (char *)(uintptr_t)tupregs[0].dttk_value;
3739                 char *substr = (char *)(uintptr_t)tupregs[1].dttk_value;
3740                 uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
3741                 size_t len = dtrace_strlen(addr, size);
3742                 size_t sublen = dtrace_strlen(substr, size);
3743                 char *limit = addr + len, *orig = addr;
3744                 int notfound = subr == DIF_SUBR_STRSTR ? 0 : -1;
3745                 int inc = 1;
3746 
3747                 regs[rd] = notfound;
3748 
3749                 if (!dtrace_canload((uintptr_t)addr, len + 1, mstate, vstate)) {
3750                         regs[rd] = NULL;
3751                         break;
3752                 }
3753 
3754                 if (!dtrace_canload((uintptr_t)substr, sublen + 1, mstate,
3755                     vstate)) {
3756                         regs[rd] = NULL;
3757                         break;
3758                 }
3759 
3760                 /*
3761                  * strstr() and index()/rindex() have similar semantics if
3762                  * both strings are the empty string: strstr() returns a
3763                  * pointer to the (empty) string, and index() and rindex()
3764                  * both return index 0 (regardless of any position argument).
3765                  */
3766                 if (sublen == 0 && len == 0) {
3767                         if (subr == DIF_SUBR_STRSTR)
3768                                 regs[rd] = (uintptr_t)addr;
3769                         else
3770                                 regs[rd] = 0;
3771                         break;
3772                 }
3773 
3774                 if (subr != DIF_SUBR_STRSTR) {
3775                         if (subr == DIF_SUBR_RINDEX) {
3776                                 limit = orig - 1;
3777                                 addr += len;
3778                                 inc = -1;
3779                         }
3780 
3781                         /*
3782                          * Both index() and rindex() take an optional position
3783                          * argument that denotes the starting position.
3784                          */
3785                         if (nargs == 3) {
3786                                 int64_t pos = (int64_t)tupregs[2].dttk_value;
3787 
3788                                 /*
3789                                  * If the position argument to index() is
3790                                  * negative, Perl implicitly clamps it at
3791                                  * zero.  This semantic is a little surprising
3792                                  * given the special meaning of negative
3793                                  * positions to similar Perl functions like
3794                                  * substr(), but it appears to reflect a
3795                                  * notion that index() can start from a
3796                                  * negative index and increment its way up to
3797                                  * the string.  Given this notion, Perl's
3798                                  * rindex() is at least self-consistent in
3799                                  * that it implicitly clamps positions greater
3800                                  * than the string length to be the string
3801                                  * length.  Where Perl completely loses
3802                                  * coherence, however, is when the specified
3803                                  * substring is the empty string ("").  In
3804                                  * this case, even if the position is
3805                                  * negative, rindex() returns 0 -- and even if
3806                                  * the position is greater than the length,
3807                                  * index() returns the string length.  These
3808                                  * semantics violate the notion that index()
3809                                  * should never return a value less than the
3810                                  * specified position and that rindex() should
3811                                  * never return a value greater than the
3812                                  * specified position.  (One assumes that
3813                                  * these semantics are artifacts of Perl's
3814                                  * implementation and not the results of
3815                                  * deliberate design -- it beggars belief that
3816                                  * even Larry Wall could desire such oddness.)
3817                                  * While in the abstract one would wish for
3818                                  * consistent position semantics across
3819                                  * substr(), index() and rindex() -- or at the
3820                                  * very least self-consistent position
3821                                  * semantics for index() and rindex() -- we
3822                                  * instead opt to keep with the extant Perl
3823                                  * semantics, in all their broken glory.  (Do
3824                                  * we have more desire to maintain Perl's
3825                                  * semantics than Perl does?  Probably.)
3826                                  */
3827                                 if (subr == DIF_SUBR_RINDEX) {
3828                                         if (pos < 0) {
3829                                                 if (sublen == 0)
3830                                                         regs[rd] = 0;
3831                                                 break;
3832                                         }
3833 
3834                                         if (pos > len)
3835                                                 pos = len;
3836                                 } else {
3837                                         if (pos < 0)
3838                                                 pos = 0;
3839 
3840                                         if (pos >= len) {
3841                                                 if (sublen == 0)
3842                                                         regs[rd] = len;
3843                                                 break;
3844                                         }
3845                                 }
3846 
3847                                 addr = orig + pos;
3848                         }
3849                 }
3850 
3851                 for (regs[rd] = notfound; addr != limit; addr += inc) {
3852                         if (dtrace_strncmp(addr, substr, sublen) == 0) {
3853                                 if (subr != DIF_SUBR_STRSTR) {
3854                                         /*
3855                                          * As D index() and rindex() are
3856                                          * modeled on Perl (and not on awk),
3857                                          * we return a zero-based (and not a
3858                                          * one-based) index.  (For you Perl
3859                                          * weenies: no, we're not going to add
3860                                          * $[ -- and shouldn't you be at a con
3861                                          * or something?)
3862                                          */
3863                                         regs[rd] = (uintptr_t)(addr - orig);
3864                                         break;
3865                                 }
3866 
3867                                 ASSERT(subr == DIF_SUBR_STRSTR);
3868                                 regs[rd] = (uintptr_t)addr;
3869                                 break;
3870                         }
3871                 }
3872 
3873                 break;
3874         }
3875 
3876         case DIF_SUBR_STRTOK: {
3877                 uintptr_t addr = tupregs[0].dttk_value;
3878                 uintptr_t tokaddr = tupregs[1].dttk_value;
3879                 uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
3880                 uintptr_t limit, toklimit = tokaddr + size;
3881                 uint8_t c, tokmap[32];   /* 256 / 8 */
3882                 char *dest = (char *)mstate->dtms_scratch_ptr;
3883                 int i;
3884 
3885                 /*
3886                  * Check both the token buffer and (later) the input buffer,
3887                  * since both could be non-scratch addresses.
3888                  */
3889                 if (!dtrace_strcanload(tokaddr, size, mstate, vstate)) {
3890                         regs[rd] = NULL;
3891                         break;
3892                 }
3893 
3894                 if (!DTRACE_INSCRATCH(mstate, size)) {
3895                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
3896                         regs[rd] = NULL;
3897                         break;
3898                 }
3899 
3900                 if (addr == NULL) {
3901                         /*
3902                          * If the address specified is NULL, we use our saved
3903                          * strtok pointer from the mstate.  Note that this
3904                          * means that the saved strtok pointer is _only_
3905                          * valid within multiple enablings of the same probe --
3906                          * it behaves like an implicit clause-local variable.
3907                          */
3908                         addr = mstate->dtms_strtok;
3909                 } else {
3910                         /*
3911                          * If the user-specified address is non-NULL we must
3912                          * access check it.  This is the only time we have
3913                          * a chance to do so, since this address may reside
3914                          * in the string table of this clause-- future calls
3915                          * (when we fetch addr from mstate->dtms_strtok)
3916                          * would fail this access check.
3917                          */
3918                         if (!dtrace_strcanload(addr, size, mstate, vstate)) {
3919                                 regs[rd] = NULL;
3920                                 break;
3921                         }
3922                 }
3923 
3924                 /*
3925                  * First, zero the token map, and then process the token
3926                  * string -- setting a bit in the map for every character
3927                  * found in the token string.
3928                  */
3929                 for (i = 0; i < sizeof (tokmap); i++)
3930                         tokmap[i] = 0;
3931 
3932                 for (; tokaddr < toklimit; tokaddr++) {
3933                         if ((c = dtrace_load8(tokaddr)) == '\0')
3934                                 break;
3935 
3936                         ASSERT((c >> 3) < sizeof (tokmap));
3937                         tokmap[c >> 3] |= (1 << (c & 0x7));
3938                 }
3939 
3940                 for (limit = addr + size; addr < limit; addr++) {
3941                         /*
3942                          * We're looking for a character that is _not_ contained
3943                          * in the token string.
3944                          */
3945                         if ((c = dtrace_load8(addr)) == '\0')
3946                                 break;
3947 
3948                         if (!(tokmap[c >> 3] & (1 << (c & 0x7))))
3949                                 break;
3950                 }
3951 
3952                 if (c == '\0') {
3953                         /*
3954                          * We reached the end of the string without finding
3955                          * any character that was not in the token string.
3956                          * We return NULL in this case, and we set the saved
3957                          * address to NULL as well.
3958                          */
3959                         regs[rd] = NULL;
3960                         mstate->dtms_strtok = NULL;
3961                         break;
3962                 }
3963 
3964                 /*
3965                  * From here on, we're copying into the destination string.
3966                  */
3967                 for (i = 0; addr < limit && i < size - 1; addr++) {
3968                         if ((c = dtrace_load8(addr)) == '\0')
3969                                 break;
3970 
3971                         if (tokmap[c >> 3] & (1 << (c & 0x7)))
3972                                 break;
3973 
3974                         ASSERT(i < size);
3975                         dest[i++] = c;
3976                 }
3977 
3978                 ASSERT(i < size);
3979                 dest[i] = '\0';
3980                 regs[rd] = (uintptr_t)dest;
3981                 mstate->dtms_scratch_ptr += size;
3982                 mstate->dtms_strtok = addr;
3983                 break;
3984         }
3985 
3986         case DIF_SUBR_SUBSTR: {
3987                 uintptr_t s = tupregs[0].dttk_value;
3988                 uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
3989                 char *d = (char *)mstate->dtms_scratch_ptr;
3990                 int64_t index = (int64_t)tupregs[1].dttk_value;
3991                 int64_t remaining = (int64_t)tupregs[2].dttk_value;
3992                 size_t len = dtrace_strlen((char *)s, size);
3993                 int64_t i;
3994 
3995                 if (!dtrace_canload(s, len + 1, mstate, vstate)) {
3996                         regs[rd] = NULL;
3997                         break;
3998                 }
3999 
4000                 if (!DTRACE_INSCRATCH(mstate, size)) {
4001                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4002                         regs[rd] = NULL;
4003                         break;
4004                 }
4005 
4006                 if (nargs <= 2)
4007                         remaining = (int64_t)size;
4008 
4009                 if (index < 0) {
4010                         index += len;
4011 
4012                         if (index < 0 && index + remaining > 0) {
4013                                 remaining += index;
4014                                 index = 0;
4015                         }
4016                 }
4017 
4018                 if (index >= len || index < 0) {
4019                         remaining = 0;
4020                 } else if (remaining < 0) {
4021                         remaining += len - index;
4022                 } else if (index + remaining > size) {
4023                         remaining = size - index;
4024                 }
4025 
4026                 for (i = 0; i < remaining; i++) {
4027                         if ((d[i] = dtrace_load8(s + index + i)) == '\0')
4028                                 break;
4029                 }
4030 
4031                 d[i] = '\0';
4032 
4033                 mstate->dtms_scratch_ptr += size;
4034                 regs[rd] = (uintptr_t)d;
4035                 break;
4036         }
4037 
4038         case DIF_SUBR_TOUPPER:
4039         case DIF_SUBR_TOLOWER: {
4040                 uintptr_t s = tupregs[0].dttk_value;
4041                 uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
4042                 char *dest = (char *)mstate->dtms_scratch_ptr, c;
4043                 size_t len = dtrace_strlen((char *)s, size);
4044                 char lower, upper, convert;
4045                 int64_t i;
4046 
4047                 if (subr == DIF_SUBR_TOUPPER) {
4048                         lower = 'a';
4049                         upper = 'z';
4050                         convert = 'A';
4051                 } else {
4052                         lower = 'A';
4053                         upper = 'Z';
4054                         convert = 'a';
4055                 }
4056 
4057                 if (!dtrace_canload(s, len + 1, mstate, vstate)) {
4058                         regs[rd] = NULL;
4059                         break;
4060                 }
4061 
4062                 if (!DTRACE_INSCRATCH(mstate, size)) {
4063                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4064                         regs[rd] = NULL;
4065                         break;
4066                 }
4067 
4068                 for (i = 0; i < size - 1; i++) {
4069                         if ((c = dtrace_load8(s + i)) == '\0')
4070                                 break;
4071 
4072                         if (c >= lower && c <= upper)
4073                                 c = convert + (c - lower);
4074 
4075                         dest[i] = c;
4076                 }
4077 
4078                 ASSERT(i < size);
4079                 dest[i] = '\0';
4080                 regs[rd] = (uintptr_t)dest;
4081                 mstate->dtms_scratch_ptr += size;
4082                 break;
4083         }
4084 
4085 case DIF_SUBR_GETMAJOR:
4086 #ifdef _LP64
4087                 regs[rd] = (tupregs[0].dttk_value >> NBITSMINOR64) & MAXMAJ64;
4088 #else
4089                 regs[rd] = (tupregs[0].dttk_value >> NBITSMINOR) & MAXMAJ;
4090 #endif
4091                 break;
4092 
4093         case DIF_SUBR_GETMINOR:
4094 #ifdef _LP64
4095                 regs[rd] = tupregs[0].dttk_value & MAXMIN64;
4096 #else
4097                 regs[rd] = tupregs[0].dttk_value & MAXMIN;
4098 #endif
4099                 break;
4100 
4101         case DIF_SUBR_DDI_PATHNAME: {
4102                 /*
4103                  * This one is a galactic mess.  We are going to roughly
4104                  * emulate ddi_pathname(), but it's made more complicated
4105                  * by the fact that we (a) want to include the minor name and
4106                  * (b) must proceed iteratively instead of recursively.
4107                  */
4108                 uintptr_t dest = mstate->dtms_scratch_ptr;
4109                 uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
4110                 char *start = (char *)dest, *end = start + size - 1;
4111                 uintptr_t daddr = tupregs[0].dttk_value;
4112                 int64_t minor = (int64_t)tupregs[1].dttk_value;
4113                 char *s;
4114                 int i, len, depth = 0;
4115 
4116                 /*
4117                  * Due to all the pointer jumping we do and context we must
4118                  * rely upon, we just mandate that the user must have kernel
4119                  * read privileges to use this routine.
4120                  */
4121                 if ((mstate->dtms_access & DTRACE_ACCESS_KERNEL) == 0) {
4122                         *flags |= CPU_DTRACE_KPRIV;
4123                         *illval = daddr;
4124                         regs[rd] = NULL;
4125                 }
4126 
4127                 if (!DTRACE_INSCRATCH(mstate, size)) {
4128                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4129                         regs[rd] = NULL;
4130                         break;
4131                 }
4132 
4133                 *end = '\0';
4134 
4135                 /*
4136                  * We want to have a name for the minor.  In order to do this,
4137                  * we need to walk the minor list from the devinfo.  We want
4138                  * to be sure that we don't infinitely walk a circular list,
4139                  * so we check for circularity by sending a scout pointer
4140                  * ahead two elements for every element that we iterate over;
4141                  * if the list is circular, these will ultimately point to the
4142                  * same element.  You may recognize this little trick as the
4143                  * answer to a stupid interview question -- one that always
4144                  * seems to be asked by those who had to have it laboriously
4145                  * explained to them, and who can't even concisely describe
4146                  * the conditions under which one would be forced to resort to
4147                  * this technique.  Needless to say, those conditions are
4148                  * found here -- and probably only here.  Is this the only use
4149                  * of this infamous trick in shipping, production code?  If it
4150                  * isn't, it probably should be...
4151                  */
4152                 if (minor != -1) {
4153                         uintptr_t maddr = dtrace_loadptr(daddr +
4154                             offsetof(struct dev_info, devi_minor));
4155 
4156                         uintptr_t next = offsetof(struct ddi_minor_data, next);
4157                         uintptr_t name = offsetof(struct ddi_minor_data,
4158                             d_minor) + offsetof(struct ddi_minor, name);
4159                         uintptr_t dev = offsetof(struct ddi_minor_data,
4160                             d_minor) + offsetof(struct ddi_minor, dev);
4161                         uintptr_t scout;
4162 
4163                         if (maddr != NULL)
4164                                 scout = dtrace_loadptr(maddr + next);
4165 
4166                         while (maddr != NULL && !(*flags & CPU_DTRACE_FAULT)) {
4167                                 uint64_t m;
4168 #ifdef _LP64
4169                                 m = dtrace_load64(maddr + dev) & MAXMIN64;
4170 #else
4171                                 m = dtrace_load32(maddr + dev) & MAXMIN;
4172 #endif
4173                                 if (m != minor) {
4174                                         maddr = dtrace_loadptr(maddr + next);
4175 
4176                                         if (scout == NULL)
4177                                                 continue;
4178 
4179                                         scout = dtrace_loadptr(scout + next);
4180 
4181                                         if (scout == NULL)
4182                                                 continue;
4183 
4184                                         scout = dtrace_loadptr(scout + next);
4185 
4186                                         if (scout == NULL)
4187                                                 continue;
4188 
4189                                         if (scout == maddr) {
4190                                                 *flags |= CPU_DTRACE_ILLOP;
4191                                                 break;
4192                                         }
4193 
4194                                         continue;
4195                                 }
4196 
4197                                 /*
4198                                  * We have the minor data.  Now we need to
4199                                  * copy the minor's name into the end of the
4200                                  * pathname.
4201                                  */
4202                                 s = (char *)dtrace_loadptr(maddr + name);
4203                                 len = dtrace_strlen(s, size);
4204 
4205                                 if (*flags & CPU_DTRACE_FAULT)
4206                                         break;
4207 
4208                                 if (len != 0) {
4209                                         if ((end -= (len + 1)) < start)
4210                                                 break;
4211 
4212                                         *end = ':';
4213                                 }
4214 
4215                                 for (i = 1; i <= len; i++)
4216                                         end[i] = dtrace_load8((uintptr_t)s++);
4217                                 break;
4218                         }
4219                 }
4220 
4221                 while (daddr != NULL && !(*flags & CPU_DTRACE_FAULT)) {
4222                         ddi_node_state_t devi_state;
4223 
4224                         devi_state = dtrace_load32(daddr +
4225                             offsetof(struct dev_info, devi_node_state));
4226 
4227                         if (*flags & CPU_DTRACE_FAULT)
4228                                 break;
4229 
4230                         if (devi_state >= DS_INITIALIZED) {
4231                                 s = (char *)dtrace_loadptr(daddr +
4232                                     offsetof(struct dev_info, devi_addr));
4233                                 len = dtrace_strlen(s, size);
4234 
4235                                 if (*flags & CPU_DTRACE_FAULT)
4236                                         break;
4237 
4238                                 if (len != 0) {
4239                                         if ((end -= (len + 1)) < start)
4240                                                 break;
4241 
4242                                         *end = '@';
4243                                 }
4244 
4245                                 for (i = 1; i <= len; i++)
4246                                         end[i] = dtrace_load8((uintptr_t)s++);
4247                         }
4248 
4249                         /*
4250                          * Now for the node name...
4251                          */
4252                         s = (char *)dtrace_loadptr(daddr +
4253                             offsetof(struct dev_info, devi_node_name));
4254 
4255                         daddr = dtrace_loadptr(daddr +
4256                             offsetof(struct dev_info, devi_parent));
4257 
4258                         /*
4259                          * If our parent is NULL (that is, if we're the root
4260                          * node), we're going to use the special path
4261                          * "devices".
4262                          */
4263                         if (daddr == NULL)
4264                                 s = "devices";
4265 
4266                         len = dtrace_strlen(s, size);
4267                         if (*flags & CPU_DTRACE_FAULT)
4268                                 break;
4269 
4270                         if ((end -= (len + 1)) < start)
4271                                 break;
4272 
4273                         for (i = 1; i <= len; i++)
4274                                 end[i] = dtrace_load8((uintptr_t)s++);
4275                         *end = '/';
4276 
4277                         if (depth++ > dtrace_devdepth_max) {
4278                                 *flags |= CPU_DTRACE_ILLOP;
4279                                 break;
4280                         }
4281                 }
4282 
4283                 if (end < start)
4284                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4285 
4286                 if (daddr == NULL) {
4287                         regs[rd] = (uintptr_t)end;
4288                         mstate->dtms_scratch_ptr += size;
4289                 }
4290 
4291                 break;
4292         }
4293 
4294         case DIF_SUBR_STRJOIN: {
4295                 char *d = (char *)mstate->dtms_scratch_ptr;
4296                 uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
4297                 uintptr_t s1 = tupregs[0].dttk_value;
4298                 uintptr_t s2 = tupregs[1].dttk_value;
4299                 int i = 0;
4300 
4301                 if (!dtrace_strcanload(s1, size, mstate, vstate) ||
4302                     !dtrace_strcanload(s2, size, mstate, vstate)) {
4303                         regs[rd] = NULL;
4304                         break;
4305                 }
4306 
4307                 if (!DTRACE_INSCRATCH(mstate, size)) {
4308                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4309                         regs[rd] = NULL;
4310                         break;
4311                 }
4312 
4313                 for (;;) {
4314                         if (i >= size) {
4315                                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4316                                 regs[rd] = NULL;
4317                                 break;
4318                         }
4319 
4320                         if ((d[i++] = dtrace_load8(s1++)) == '\0') {
4321                                 i--;
4322                                 break;
4323                         }
4324                 }
4325 
4326                 for (;;) {
4327                         if (i >= size) {
4328                                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4329                                 regs[rd] = NULL;
4330                                 break;
4331                         }
4332 
4333                         if ((d[i++] = dtrace_load8(s2++)) == '\0')
4334                                 break;
4335                 }
4336 
4337                 if (i < size) {
4338                         mstate->dtms_scratch_ptr += i;
4339                         regs[rd] = (uintptr_t)d;
4340                 }
4341 
4342                 break;
4343         }
4344 
4345         case DIF_SUBR_LLTOSTR: {
4346                 int64_t i = (int64_t)tupregs[0].dttk_value;
4347                 uint64_t val, digit;
4348                 uint64_t size = 65;     /* enough room for 2^64 in binary */
4349                 char *end = (char *)mstate->dtms_scratch_ptr + size - 1;
4350                 int base = 10;
4351 
4352                 if (nargs > 1) {
4353                         if ((base = tupregs[1].dttk_value) <= 1 ||
4354                             base > ('z' - 'a' + 1) + ('9' - '0' + 1)) {
4355                                 *flags |= CPU_DTRACE_ILLOP;
4356                                 break;
4357                         }
4358                 }
4359 
4360                 val = (base == 10 && i < 0) ? i * -1 : i;
4361 
4362                 if (!DTRACE_INSCRATCH(mstate, size)) {
4363                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4364                         regs[rd] = NULL;
4365                         break;
4366                 }
4367 
4368                 for (*end-- = '\0'; val; val /= base) {
4369                         if ((digit = val % base) <= '9' - '0') {
4370                                 *end-- = '0' + digit;
4371                         } else {
4372                                 *end-- = 'a' + (digit - ('9' - '0') - 1);
4373                         }
4374                 }
4375 
4376                 if (i == 0 && base == 16)
4377                         *end-- = '0';
4378 
4379                 if (base == 16)
4380                         *end-- = 'x';
4381 
4382                 if (i == 0 || base == 8 || base == 16)
4383                         *end-- = '0';
4384 
4385                 if (i < 0 && base == 10)
4386                         *end-- = '-';
4387 
4388                 regs[rd] = (uintptr_t)end + 1;
4389                 mstate->dtms_scratch_ptr += size;
4390                 break;
4391         }
4392 
4393         case DIF_SUBR_HTONS:
4394         case DIF_SUBR_NTOHS:
4395 #ifdef _BIG_ENDIAN
4396                 regs[rd] = (uint16_t)tupregs[0].dttk_value;
4397 #else
4398                 regs[rd] = DT_BSWAP_16((uint16_t)tupregs[0].dttk_value);
4399 #endif
4400                 break;
4401 
4402 
4403         case DIF_SUBR_HTONL:
4404         case DIF_SUBR_NTOHL:
4405 #ifdef _BIG_ENDIAN
4406                 regs[rd] = (uint32_t)tupregs[0].dttk_value;
4407 #else
4408                 regs[rd] = DT_BSWAP_32((uint32_t)tupregs[0].dttk_value);
4409 #endif
4410                 break;
4411 
4412 
4413         case DIF_SUBR_HTONLL:
4414         case DIF_SUBR_NTOHLL:
4415 #ifdef _BIG_ENDIAN
4416                 regs[rd] = (uint64_t)tupregs[0].dttk_value;
4417 #else
4418                 regs[rd] = DT_BSWAP_64((uint64_t)tupregs[0].dttk_value);
4419 #endif
4420                 break;
4421 
4422 
4423         case DIF_SUBR_DIRNAME:
4424         case DIF_SUBR_BASENAME: {
4425                 char *dest = (char *)mstate->dtms_scratch_ptr;
4426                 uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
4427                 uintptr_t src = tupregs[0].dttk_value;
4428                 int i, j, len = dtrace_strlen((char *)src, size);
4429                 int lastbase = -1, firstbase = -1, lastdir = -1;
4430                 int start, end;
4431 
4432                 if (!dtrace_canload(src, len + 1, mstate, vstate)) {
4433                         regs[rd] = NULL;
4434                         break;
4435                 }
4436 
4437                 if (!DTRACE_INSCRATCH(mstate, size)) {
4438                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4439                         regs[rd] = NULL;
4440                         break;
4441                 }
4442 
4443                 /*
4444                  * The basename and dirname for a zero-length string is
4445                  * defined to be "."
4446                  */
4447                 if (len == 0) {
4448                         len = 1;
4449                         src = (uintptr_t)".";
4450                 }
4451 
4452                 /*
4453                  * Start from the back of the string, moving back toward the
4454                  * front until we see a character that isn't a slash.  That
4455                  * character is the last character in the basename.
4456                  */
4457                 for (i = len - 1; i >= 0; i--) {
4458                         if (dtrace_load8(src + i) != '/')
4459                                 break;
4460                 }
4461 
4462                 if (i >= 0)
4463                         lastbase = i;
4464 
4465                 /*
4466                  * Starting from the last character in the basename, move
4467                  * towards the front until we find a slash.  The character
4468                  * that we processed immediately before that is the first
4469                  * character in the basename.
4470                  */
4471                 for (; i >= 0; i--) {
4472                         if (dtrace_load8(src + i) == '/')
4473                                 break;
4474                 }
4475 
4476                 if (i >= 0)
4477                         firstbase = i + 1;
4478 
4479                 /*
4480                  * Now keep going until we find a non-slash character.  That
4481                  * character is the last character in the dirname.
4482                  */
4483                 for (; i >= 0; i--) {
4484                         if (dtrace_load8(src + i) != '/')
4485                                 break;
4486                 }
4487 
4488                 if (i >= 0)
4489                         lastdir = i;
4490 
4491                 ASSERT(!(lastbase == -1 && firstbase != -1));
4492                 ASSERT(!(firstbase == -1 && lastdir != -1));
4493 
4494                 if (lastbase == -1) {
4495                         /*
4496                          * We didn't find a non-slash character.  We know that
4497                          * the length is non-zero, so the whole string must be
4498                          * slashes.  In either the dirname or the basename
4499                          * case, we return '/'.
4500                          */
4501                         ASSERT(firstbase == -1);
4502                         firstbase = lastbase = lastdir = 0;
4503                 }
4504 
4505                 if (firstbase == -1) {
4506                         /*
4507                          * The entire string consists only of a basename
4508                          * component.  If we're looking for dirname, we need
4509                          * to change our string to be just "."; if we're
4510                          * looking for a basename, we'll just set the first
4511                          * character of the basename to be 0.
4512                          */
4513                         if (subr == DIF_SUBR_DIRNAME) {
4514                                 ASSERT(lastdir == -1);
4515                                 src = (uintptr_t)".";
4516                                 lastdir = 0;
4517                         } else {
4518                                 firstbase = 0;
4519                         }
4520                 }
4521 
4522                 if (subr == DIF_SUBR_DIRNAME) {
4523                         if (lastdir == -1) {
4524                                 /*
4525                                  * We know that we have a slash in the name --
4526                                  * or lastdir would be set to 0, above.  And
4527                                  * because lastdir is -1, we know that this
4528                                  * slash must be the first character.  (That
4529                                  * is, the full string must be of the form
4530                                  * "/basename".)  In this case, the last
4531                                  * character of the directory name is 0.
4532                                  */
4533                                 lastdir = 0;
4534                         }
4535 
4536                         start = 0;
4537                         end = lastdir;
4538                 } else {
4539                         ASSERT(subr == DIF_SUBR_BASENAME);
4540                         ASSERT(firstbase != -1 && lastbase != -1);
4541                         start = firstbase;
4542                         end = lastbase;
4543                 }
4544 
4545                 for (i = start, j = 0; i <= end && j < size - 1; i++, j++)
4546                         dest[j] = dtrace_load8(src + i);
4547 
4548                 dest[j] = '\0';
4549                 regs[rd] = (uintptr_t)dest;
4550                 mstate->dtms_scratch_ptr += size;
4551                 break;
4552         }
4553 
4554         case DIF_SUBR_GETF: {
4555                 uintptr_t fd = tupregs[0].dttk_value;
4556                 uf_info_t *finfo = &curthread->t_procp->p_user.u_finfo;
4557                 file_t *fp;
4558 
4559                 if (!dtrace_priv_proc(state, mstate)) {
4560                         regs[rd] = NULL;
4561                         break;
4562                 }
4563 
4564                 /*
4565                  * This is safe because fi_nfiles only increases, and the
4566                  * fi_list array is not freed when the array size doubles.
4567                  * (See the comment in flist_grow() for details on the
4568                  * management of the u_finfo structure.)
4569                  */
4570                 fp = fd < finfo->fi_nfiles ? finfo->fi_list[fd].uf_file : NULL;
4571 
4572                 mstate->dtms_getf = fp;
4573                 regs[rd] = (uintptr_t)fp;
4574                 break;
4575         }
4576 
4577         case DIF_SUBR_CLEANPATH: {
4578                 char *dest = (char *)mstate->dtms_scratch_ptr, c;
4579                 uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
4580                 uintptr_t src = tupregs[0].dttk_value;
4581                 int i = 0, j = 0;
4582                 zone_t *z;
4583 
4584                 if (!dtrace_strcanload(src, size, mstate, vstate)) {
4585                         regs[rd] = NULL;
4586                         break;
4587                 }
4588 
4589                 if (!DTRACE_INSCRATCH(mstate, size)) {
4590                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4591                         regs[rd] = NULL;
4592                         break;
4593                 }
4594 
4595                 /*
4596                  * Move forward, loading each character.
4597                  */
4598                 do {
4599                         c = dtrace_load8(src + i++);
4600 next:
4601                         if (j + 5 >= size)   /* 5 = strlen("/..c\0") */
4602                                 break;
4603 
4604                         if (c != '/') {
4605                                 dest[j++] = c;
4606                                 continue;
4607                         }
4608 
4609                         c = dtrace_load8(src + i++);
4610 
4611                         if (c == '/') {
4612                                 /*
4613                                  * We have two slashes -- we can just advance
4614                                  * to the next character.
4615                                  */
4616                                 goto next;
4617                         }
4618 
4619                         if (c != '.') {
4620                                 /*
4621                                  * This is not "." and it's not ".." -- we can
4622                                  * just store the "/" and this character and
4623                                  * drive on.
4624                                  */
4625                                 dest[j++] = '/';
4626                                 dest[j++] = c;
4627                                 continue;
4628                         }
4629 
4630                         c = dtrace_load8(src + i++);
4631 
4632                         if (c == '/') {
4633                                 /*
4634                                  * This is a "/./" component.  We're not going
4635                                  * to store anything in the destination buffer;
4636                                  * we're just going to go to the next component.
4637                                  */
4638                                 goto next;
4639                         }
4640 
4641                         if (c != '.') {
4642                                 /*
4643                                  * This is not ".." -- we can just store the
4644                                  * "/." and this character and continue
4645                                  * processing.
4646                                  */
4647                                 dest[j++] = '/';
4648                                 dest[j++] = '.';
4649                                 dest[j++] = c;
4650                                 continue;
4651                         }
4652 
4653                         c = dtrace_load8(src + i++);
4654 
4655                         if (c != '/' && c != '\0') {
4656                                 /*
4657                                  * This is not ".." -- it's "..[mumble]".
4658                                  * We'll store the "/.." and this character
4659                                  * and continue processing.
4660                                  */
4661                                 dest[j++] = '/';
4662                                 dest[j++] = '.';
4663                                 dest[j++] = '.';
4664                                 dest[j++] = c;
4665                                 continue;
4666                         }
4667 
4668                         /*
4669                          * This is "/../" or "/..\0".  We need to back up
4670                          * our destination pointer until we find a "/".
4671                          */
4672                         i--;
4673                         while (j != 0 && dest[--j] != '/')
4674                                 continue;
4675 
4676                         if (c == '\0')
4677                                 dest[++j] = '/';
4678                 } while (c != '\0');
4679 
4680                 dest[j] = '\0';
4681 
4682                 if (mstate->dtms_getf != NULL &&
4683                     !(mstate->dtms_access & DTRACE_ACCESS_KERNEL) &&
4684                     (z = state->dts_cred.dcr_cred->cr_zone) != kcred->cr_zone) {
4685                         /*
4686                          * If we've done a getf() as a part of this ECB and we
4687                          * don't have kernel access (and we're not in the global
4688                          * zone), check if the path we cleaned up begins with
4689                          * the zone's root path, and trim it off if so.  Note
4690                          * that this is an output cleanliness issue, not a
4691                          * security issue: knowing one's zone root path does
4692                          * not enable privilege escalation.
4693                          */
4694                         if (strstr(dest, z->zone_rootpath) == dest)
4695                                 dest += strlen(z->zone_rootpath) - 1;
4696                 }
4697 
4698                 regs[rd] = (uintptr_t)dest;
4699                 mstate->dtms_scratch_ptr += size;
4700                 break;
4701         }
4702 
4703         case DIF_SUBR_INET_NTOA:
4704         case DIF_SUBR_INET_NTOA6:
4705         case DIF_SUBR_INET_NTOP: {
4706                 size_t size;
4707                 int af, argi, i;
4708                 char *base, *end;
4709 
4710                 if (subr == DIF_SUBR_INET_NTOP) {
4711                         af = (int)tupregs[0].dttk_value;
4712                         argi = 1;
4713                 } else {
4714                         af = subr == DIF_SUBR_INET_NTOA ? AF_INET: AF_INET6;
4715                         argi = 0;
4716                 }
4717 
4718                 if (af == AF_INET) {
4719                         ipaddr_t ip4;
4720                         uint8_t *ptr8, val;
4721 
4722                         /*
4723                          * Safely load the IPv4 address.
4724                          */
4725                         ip4 = dtrace_load32(tupregs[argi].dttk_value);
4726 
4727                         /*
4728                          * Check an IPv4 string will fit in scratch.
4729                          */
4730                         size = INET_ADDRSTRLEN;
4731                         if (!DTRACE_INSCRATCH(mstate, size)) {
4732                                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4733                                 regs[rd] = NULL;
4734                                 break;
4735                         }
4736                         base = (char *)mstate->dtms_scratch_ptr;
4737                         end = (char *)mstate->dtms_scratch_ptr + size - 1;
4738 
4739                         /*
4740                          * Stringify as a dotted decimal quad.
4741                          */
4742                         *end-- = '\0';
4743                         ptr8 = (uint8_t *)&ip4;
4744                         for (i = 3; i >= 0; i--) {
4745                                 val = ptr8[i];
4746 
4747                                 if (val == 0) {
4748                                         *end-- = '0';
4749                                 } else {
4750                                         for (; val; val /= 10) {
4751                                                 *end-- = '0' + (val % 10);
4752                                         }
4753                                 }
4754 
4755                                 if (i > 0)
4756                                         *end-- = '.';
4757                         }
4758                         ASSERT(end + 1 >= base);
4759 
4760                 } else if (af == AF_INET6) {
4761                         struct in6_addr ip6;
4762                         int firstzero, tryzero, numzero, v6end;
4763                         uint16_t val;
4764                         const char digits[] = "0123456789abcdef";
4765 
4766                         /*
4767                          * Stringify using RFC 1884 convention 2 - 16 bit
4768                          * hexadecimal values with a zero-run compression.
4769                          * Lower case hexadecimal digits are used.
4770                          *      eg, fe80::214:4fff:fe0b:76c8.
4771                          * The IPv4 embedded form is returned for inet_ntop,
4772                          * just the IPv4 string is returned for inet_ntoa6.
4773                          */
4774 
4775                         /*
4776                          * Safely load the IPv6 address.
4777                          */
4778                         dtrace_bcopy(
4779                             (void *)(uintptr_t)tupregs[argi].dttk_value,
4780                             (void *)(uintptr_t)&ip6, sizeof (struct in6_addr));
4781 
4782                         /*
4783                          * Check an IPv6 string will fit in scratch.
4784                          */
4785                         size = INET6_ADDRSTRLEN;
4786                         if (!DTRACE_INSCRATCH(mstate, size)) {
4787                                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4788                                 regs[rd] = NULL;
4789                                 break;
4790                         }
4791                         base = (char *)mstate->dtms_scratch_ptr;
4792                         end = (char *)mstate->dtms_scratch_ptr + size - 1;
4793                         *end-- = '\0';
4794 
4795                         /*
4796                          * Find the longest run of 16 bit zero values
4797                          * for the single allowed zero compression - "::".
4798                          */
4799                         firstzero = -1;
4800                         tryzero = -1;
4801                         numzero = 1;
4802                         for (i = 0; i < sizeof (struct in6_addr); i++) {
4803                                 if (ip6._S6_un._S6_u8[i] == 0 &&
4804                                     tryzero == -1 && i % 2 == 0) {
4805                                         tryzero = i;
4806                                         continue;
4807                                 }
4808 
4809                                 if (tryzero != -1 &&
4810                                     (ip6._S6_un._S6_u8[i] != 0 ||
4811                                     i == sizeof (struct in6_addr) - 1)) {
4812 
4813                                         if (i - tryzero <= numzero) {
4814                                                 tryzero = -1;
4815                                                 continue;
4816                                         }
4817 
4818                                         firstzero = tryzero;
4819                                         numzero = i - i % 2 - tryzero;
4820                                         tryzero = -1;
4821 
4822                                         if (ip6._S6_un._S6_u8[i] == 0 &&
4823                                             i == sizeof (struct in6_addr) - 1)
4824                                                 numzero += 2;
4825                                 }
4826                         }
4827                         ASSERT(firstzero + numzero <= sizeof (struct in6_addr));
4828 
4829                         /*
4830                          * Check for an IPv4 embedded address.
4831                          */
4832                         v6end = sizeof (struct in6_addr) - 2;
4833                         if (IN6_IS_ADDR_V4MAPPED(&ip6) ||
4834                             IN6_IS_ADDR_V4COMPAT(&ip6)) {
4835                                 for (i = sizeof (struct in6_addr) - 1;
4836                                     i >= DTRACE_V4MAPPED_OFFSET; i--) {
4837                                         ASSERT(end >= base);
4838 
4839                                         val = ip6._S6_un._S6_u8[i];
4840 
4841                                         if (val == 0) {
4842                                                 *end-- = '0';
4843                                         } else {
4844                                                 for (; val; val /= 10) {
4845                                                         *end-- = '0' + val % 10;
4846                                                 }
4847                                         }
4848 
4849                                         if (i > DTRACE_V4MAPPED_OFFSET)
4850                                                 *end-- = '.';
4851                                 }
4852 
4853                                 if (subr == DIF_SUBR_INET_NTOA6)
4854                                         goto inetout;
4855 
4856                                 /*
4857                                  * Set v6end to skip the IPv4 address that
4858                                  * we have already stringified.
4859                                  */
4860                                 v6end = 10;
4861                         }
4862 
4863                         /*
4864                          * Build the IPv6 string by working through the
4865                          * address in reverse.
4866                          */
4867                         for (i = v6end; i >= 0; i -= 2) {
4868                                 ASSERT(end >= base);
4869 
4870                                 if (i == firstzero + numzero - 2) {
4871                                         *end-- = ':';
4872                                         *end-- = ':';
4873                                         i -= numzero - 2;
4874                                         continue;
4875                                 }
4876 
4877                                 if (i < 14 && i != firstzero - 2)
4878                                         *end-- = ':';
4879 
4880                                 val = (ip6._S6_un._S6_u8[i] << 8) +
4881                                     ip6._S6_un._S6_u8[i + 1];
4882 
4883                                 if (val == 0) {
4884                                         *end-- = '0';
4885                                 } else {
4886                                         for (; val; val /= 16) {
4887                                                 *end-- = digits[val % 16];
4888                                         }
4889                                 }
4890                         }
4891                         ASSERT(end + 1 >= base);
4892 
4893                 } else {
4894                         /*
4895                          * The user didn't use AH_INET or AH_INET6.
4896                          */
4897                         DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
4898                         regs[rd] = NULL;
4899                         break;
4900                 }
4901 
4902 inetout:        regs[rd] = (uintptr_t)end + 1;
4903                 mstate->dtms_scratch_ptr += size;
4904                 break;
4905         }
4906 
4907         }
4908 }
4909 
4910 /*
4911  * Emulate the execution of DTrace IR instructions specified by the given
4912  * DIF object.  This function is deliberately void of assertions as all of
4913  * the necessary checks are handled by a call to dtrace_difo_validate().
4914  */
4915 static uint64_t
4916 dtrace_dif_emulate(dtrace_difo_t *difo, dtrace_mstate_t *mstate,
4917     dtrace_vstate_t *vstate, dtrace_state_t *state)
4918 {
4919         const dif_instr_t *text = difo->dtdo_buf;
4920         const uint_t textlen = difo->dtdo_len;
4921         const char *strtab = difo->dtdo_strtab;
4922         const uint64_t *inttab = difo->dtdo_inttab;
4923 
4924         uint64_t rval = 0;
4925         dtrace_statvar_t *svar;
4926         dtrace_dstate_t *dstate = &vstate->dtvs_dynvars;
4927         dtrace_difv_t *v;
4928         volatile uint16_t *flags = &cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
4929         volatile uintptr_t *illval = &cpu_core[CPU->cpu_id].cpuc_dtrace_illval;
4930 
4931         dtrace_key_t tupregs[DIF_DTR_NREGS + 2]; /* +2 for thread and id */
4932         uint64_t regs[DIF_DIR_NREGS];
4933         uint64_t *tmp;
4934 
4935         uint8_t cc_n = 0, cc_z = 0, cc_v = 0, cc_c = 0;
4936         int64_t cc_r;
4937         uint_t pc = 0, id, opc;
4938         uint8_t ttop = 0;
4939         dif_instr_t instr;
4940         uint_t r1, r2, rd;
4941 
4942         /*
4943          * We stash the current DIF object into the machine state: we need it
4944          * for subsequent access checking.
4945          */
4946         mstate->dtms_difo = difo;
4947 
4948         regs[DIF_REG_R0] = 0;           /* %r0 is fixed at zero */
4949 
4950         while (pc < textlen && !(*flags & CPU_DTRACE_FAULT)) {
4951                 opc = pc;
4952 
4953                 instr = text[pc++];
4954                 r1 = DIF_INSTR_R1(instr);
4955                 r2 = DIF_INSTR_R2(instr);
4956                 rd = DIF_INSTR_RD(instr);
4957 
4958                 switch (DIF_INSTR_OP(instr)) {
4959                 case DIF_OP_OR:
4960                         regs[rd] = regs[r1] | regs[r2];
4961                         break;
4962                 case DIF_OP_XOR:
4963                         regs[rd] = regs[r1] ^ regs[r2];
4964                         break;
4965                 case DIF_OP_AND:
4966                         regs[rd] = regs[r1] & regs[r2];
4967                         break;
4968                 case DIF_OP_SLL:
4969                         regs[rd] = regs[r1] << regs[r2];
4970                         break;
4971                 case DIF_OP_SRL:
4972                         regs[rd] = regs[r1] >> regs[r2];
4973                         break;
4974                 case DIF_OP_SUB:
4975                         regs[rd] = regs[r1] - regs[r2];
4976                         break;
4977                 case DIF_OP_ADD:
4978                         regs[rd] = regs[r1] + regs[r2];
4979                         break;
4980                 case DIF_OP_MUL:
4981                         regs[rd] = regs[r1] * regs[r2];
4982                         break;
4983                 case DIF_OP_SDIV:
4984                         if (regs[r2] == 0) {
4985                                 regs[rd] = 0;
4986                                 *flags |= CPU_DTRACE_DIVZERO;
4987                         } else {
4988                                 regs[rd] = (int64_t)regs[r1] /
4989                                     (int64_t)regs[r2];
4990                         }
4991                         break;
4992 
4993                 case DIF_OP_UDIV:
4994                         if (regs[r2] == 0) {
4995                                 regs[rd] = 0;
4996                                 *flags |= CPU_DTRACE_DIVZERO;
4997                         } else {
4998                                 regs[rd] = regs[r1] / regs[r2];
4999                         }
5000                         break;
5001 
5002                 case DIF_OP_SREM:
5003                         if (regs[r2] == 0) {
5004                                 regs[rd] = 0;
5005                                 *flags |= CPU_DTRACE_DIVZERO;
5006                         } else {
5007                                 regs[rd] = (int64_t)regs[r1] %
5008                                     (int64_t)regs[r2];
5009                         }
5010                         break;
5011 
5012                 case DIF_OP_UREM:
5013                         if (regs[r2] == 0) {
5014                                 regs[rd] = 0;
5015                                 *flags |= CPU_DTRACE_DIVZERO;
5016                         } else {
5017                                 regs[rd] = regs[r1] % regs[r2];
5018                         }
5019                         break;
5020 
5021                 case DIF_OP_NOT:
5022                         regs[rd] = ~regs[r1];
5023                         break;
5024                 case DIF_OP_MOV:
5025                         regs[rd] = regs[r1];
5026                         break;
5027                 case DIF_OP_CMP:
5028                         cc_r = regs[r1] - regs[r2];
5029                         cc_n = cc_r < 0;
5030                         cc_z = cc_r == 0;
5031                         cc_v = 0;
5032                         cc_c = regs[r1] < regs[r2];
5033                         break;
5034                 case DIF_OP_TST:
5035                         cc_n = cc_v = cc_c = 0;
5036                         cc_z = regs[r1] == 0;
5037                         break;
5038                 case DIF_OP_BA:
5039                         pc = DIF_INSTR_LABEL(instr);
5040                         break;
5041                 case DIF_OP_BE:
5042                         if (cc_z)
5043                                 pc = DIF_INSTR_LABEL(instr);
5044                         break;
5045                 case DIF_OP_BNE:
5046                         if (cc_z == 0)
5047                                 pc = DIF_INSTR_LABEL(instr);
5048                         break;
5049                 case DIF_OP_BG:
5050                         if ((cc_z | (cc_n ^ cc_v)) == 0)
5051                                 pc = DIF_INSTR_LABEL(instr);
5052                         break;
5053                 case DIF_OP_BGU:
5054                         if ((cc_c | cc_z) == 0)
5055                                 pc = DIF_INSTR_LABEL(instr);
5056                         break;
5057                 case DIF_OP_BGE:
5058                         if ((cc_n ^ cc_v) == 0)
5059                                 pc = DIF_INSTR_LABEL(instr);
5060                         break;
5061                 case DIF_OP_BGEU:
5062                         if (cc_c == 0)
5063                                 pc = DIF_INSTR_LABEL(instr);
5064                         break;
5065                 case DIF_OP_BL:
5066                         if (cc_n ^ cc_v)
5067                                 pc = DIF_INSTR_LABEL(instr);
5068                         break;
5069                 case DIF_OP_BLU:
5070                         if (cc_c)
5071                                 pc = DIF_INSTR_LABEL(instr);
5072                         break;
5073                 case DIF_OP_BLE:
5074                         if (cc_z | (cc_n ^ cc_v))
5075                                 pc = DIF_INSTR_LABEL(instr);
5076                         break;
5077                 case DIF_OP_BLEU:
5078                         if (cc_c | cc_z)
5079                                 pc = DIF_INSTR_LABEL(instr);
5080                         break;
5081                 case DIF_OP_RLDSB:
5082                         if (!dtrace_canload(regs[r1], 1, mstate, vstate))
5083                                 break;
5084                         /*FALLTHROUGH*/
5085                 case DIF_OP_LDSB:
5086                         regs[rd] = (int8_t)dtrace_load8(regs[r1]);
5087                         break;
5088                 case DIF_OP_RLDSH:
5089                         if (!dtrace_canload(regs[r1], 2, mstate, vstate))
5090                                 break;
5091                         /*FALLTHROUGH*/
5092                 case DIF_OP_LDSH:
5093                         regs[rd] = (int16_t)dtrace_load16(regs[r1]);
5094                         break;
5095                 case DIF_OP_RLDSW:
5096                         if (!dtrace_canload(regs[r1], 4, mstate, vstate))
5097                                 break;
5098                         /*FALLTHROUGH*/
5099                 case DIF_OP_LDSW:
5100                         regs[rd] = (int32_t)dtrace_load32(regs[r1]);
5101                         break;
5102                 case DIF_OP_RLDUB:
5103                         if (!dtrace_canload(regs[r1], 1, mstate, vstate))
5104                                 break;
5105                         /*FALLTHROUGH*/
5106                 case DIF_OP_LDUB:
5107                         regs[rd] = dtrace_load8(regs[r1]);
5108                         break;
5109                 case DIF_OP_RLDUH:
5110                         if (!dtrace_canload(regs[r1], 2, mstate, vstate))
5111                                 break;
5112                         /*FALLTHROUGH*/
5113                 case DIF_OP_LDUH:
5114                         regs[rd] = dtrace_load16(regs[r1]);
5115                         break;
5116                 case DIF_OP_RLDUW:
5117                         if (!dtrace_canload(regs[r1], 4, mstate, vstate))
5118                                 break;
5119                         /*FALLTHROUGH*/
5120                 case DIF_OP_LDUW:
5121                         regs[rd] = dtrace_load32(regs[r1]);
5122                         break;
5123                 case DIF_OP_RLDX:
5124                         if (!dtrace_canload(regs[r1], 8, mstate, vstate))
5125                                 break;
5126                         /*FALLTHROUGH*/
5127                 case DIF_OP_LDX:
5128                         regs[rd] = dtrace_load64(regs[r1]);
5129                         break;
5130                 case DIF_OP_ULDSB:
5131                         regs[rd] = (int8_t)
5132                             dtrace_fuword8((void *)(uintptr_t)regs[r1]);
5133                         break;
5134                 case DIF_OP_ULDSH:
5135                         regs[rd] = (int16_t)
5136                             dtrace_fuword16((void *)(uintptr_t)regs[r1]);
5137                         break;
5138                 case DIF_OP_ULDSW:
5139                         regs[rd] = (int32_t)
5140                             dtrace_fuword32((void *)(uintptr_t)regs[r1]);
5141                         break;
5142                 case DIF_OP_ULDUB:
5143                         regs[rd] =
5144                             dtrace_fuword8((void *)(uintptr_t)regs[r1]);
5145                         break;
5146                 case DIF_OP_ULDUH:
5147                         regs[rd] =
5148                             dtrace_fuword16((void *)(uintptr_t)regs[r1]);
5149                         break;
5150                 case DIF_OP_ULDUW:
5151                         regs[rd] =
5152                             dtrace_fuword32((void *)(uintptr_t)regs[r1]);
5153                         break;
5154                 case DIF_OP_ULDX:
5155                         regs[rd] =
5156                             dtrace_fuword64((void *)(uintptr_t)regs[r1]);
5157                         break;
5158                 case DIF_OP_RET:
5159                         rval = regs[rd];
5160                         pc = textlen;
5161                         break;
5162                 case DIF_OP_NOP:
5163                         break;
5164                 case DIF_OP_SETX:
5165                         regs[rd] = inttab[DIF_INSTR_INTEGER(instr)];
5166                         break;
5167                 case DIF_OP_SETS:
5168                         regs[rd] = (uint64_t)(uintptr_t)
5169                             (strtab + DIF_INSTR_STRING(instr));
5170                         break;
5171                 case DIF_OP_SCMP: {
5172                         size_t sz = state->dts_options[DTRACEOPT_STRSIZE];
5173                         uintptr_t s1 = regs[r1];
5174                         uintptr_t s2 = regs[r2];
5175 
5176                         if (s1 != NULL &&
5177                             !dtrace_strcanload(s1, sz, mstate, vstate))
5178                                 break;
5179                         if (s2 != NULL &&
5180                             !dtrace_strcanload(s2, sz, mstate, vstate))
5181                                 break;
5182 
5183                         cc_r = dtrace_strncmp((char *)s1, (char *)s2, sz);
5184 
5185                         cc_n = cc_r < 0;
5186                         cc_z = cc_r == 0;
5187                         cc_v = cc_c = 0;
5188                         break;
5189                 }
5190                 case DIF_OP_LDGA:
5191                         regs[rd] = dtrace_dif_variable(mstate, state,
5192                             r1, regs[r2]);
5193                         break;
5194                 case DIF_OP_LDGS:
5195                         id = DIF_INSTR_VAR(instr);
5196 
5197                         if (id >= DIF_VAR_OTHER_UBASE) {
5198                                 uintptr_t a;
5199 
5200                                 id -= DIF_VAR_OTHER_UBASE;
5201                                 svar = vstate->dtvs_globals[id];
5202                                 ASSERT(svar != NULL);
5203                                 v = &svar->dtsv_var;
5204 
5205                                 if (!(v->dtdv_type.dtdt_flags & DIF_TF_BYREF)) {
5206                                         regs[rd] = svar->dtsv_data;
5207                                         break;
5208                                 }
5209 
5210                                 a = (uintptr_t)svar->dtsv_data;
5211 
5212                                 if (*(uint8_t *)a == UINT8_MAX) {
5213                                         /*
5214                                          * If the 0th byte is set to UINT8_MAX
5215                                          * then this is to be treated as a
5216                                          * reference to a NULL variable.
5217                                          */
5218                                         regs[rd] = NULL;
5219                                 } else {
5220                                         regs[rd] = a + sizeof (uint64_t);
5221                                 }
5222 
5223                                 break;
5224                         }
5225 
5226                         regs[rd] = dtrace_dif_variable(mstate, state, id, 0);
5227                         break;
5228 
5229                 case DIF_OP_STGS:
5230                         id = DIF_INSTR_VAR(instr);
5231 
5232                         ASSERT(id >= DIF_VAR_OTHER_UBASE);
5233                         id -= DIF_VAR_OTHER_UBASE;
5234 
5235                         svar = vstate->dtvs_globals[id];
5236                         ASSERT(svar != NULL);
5237                         v = &svar->dtsv_var;
5238 
5239                         if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
5240                                 uintptr_t a = (uintptr_t)svar->dtsv_data;
5241 
5242                                 ASSERT(a != NULL);
5243                                 ASSERT(svar->dtsv_size != 0);
5244 
5245                                 if (regs[rd] == NULL) {
5246                                         *(uint8_t *)a = UINT8_MAX;
5247                                         break;
5248                                 } else {
5249                                         *(uint8_t *)a = 0;
5250                                         a += sizeof (uint64_t);
5251                                 }
5252                                 if (!dtrace_vcanload(
5253                                     (void *)(uintptr_t)regs[rd], &v->dtdv_type,
5254                                     mstate, vstate))
5255                                         break;
5256 
5257                                 dtrace_vcopy((void *)(uintptr_t)regs[rd],
5258                                     (void *)a, &v->dtdv_type);
5259                                 break;
5260                         }
5261 
5262                         svar->dtsv_data = regs[rd];
5263                         break;
5264 
5265                 case DIF_OP_LDTA:
5266                         /*
5267                          * There are no DTrace built-in thread-local arrays at
5268                          * present.  This opcode is saved for future work.
5269                          */
5270                         *flags |= CPU_DTRACE_ILLOP;
5271                         regs[rd] = 0;
5272                         break;
5273 
5274                 case DIF_OP_LDLS:
5275                         id = DIF_INSTR_VAR(instr);
5276 
5277                         if (id < DIF_VAR_OTHER_UBASE) {
5278                                 /*
5279                                  * For now, this has no meaning.
5280                                  */
5281                                 regs[rd] = 0;
5282                                 break;
5283                         }
5284 
5285                         id -= DIF_VAR_OTHER_UBASE;
5286 
5287                         ASSERT(id < vstate->dtvs_nlocals);
5288                         ASSERT(vstate->dtvs_locals != NULL);
5289 
5290                         svar = vstate->dtvs_locals[id];
5291                         ASSERT(svar != NULL);
5292                         v = &svar->dtsv_var;
5293 
5294                         if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
5295                                 uintptr_t a = (uintptr_t)svar->dtsv_data;
5296                                 size_t sz = v->dtdv_type.dtdt_size;
5297 
5298                                 sz += sizeof (uint64_t);
5299                                 ASSERT(svar->dtsv_size == NCPU * sz);
5300                                 a += CPU->cpu_id * sz;
5301 
5302                                 if (*(uint8_t *)a == UINT8_MAX) {
5303                                         /*
5304                                          * If the 0th byte is set to UINT8_MAX
5305                                          * then this is to be treated as a
5306                                          * reference to a NULL variable.
5307                                          */
5308                                         regs[rd] = NULL;
5309                                 } else {
5310                                         regs[rd] = a + sizeof (uint64_t);
5311                                 }
5312 
5313                                 break;
5314                         }
5315 
5316                         ASSERT(svar->dtsv_size == NCPU * sizeof (uint64_t));
5317                         tmp = (uint64_t *)(uintptr_t)svar->dtsv_data;
5318                         regs[rd] = tmp[CPU->cpu_id];
5319                         break;
5320 
5321                 case DIF_OP_STLS:
5322                         id = DIF_INSTR_VAR(instr);
5323 
5324                         ASSERT(id >= DIF_VAR_OTHER_UBASE);
5325                         id -= DIF_VAR_OTHER_UBASE;
5326                         ASSERT(id < vstate->dtvs_nlocals);
5327 
5328                         ASSERT(vstate->dtvs_locals != NULL);
5329                         svar = vstate->dtvs_locals[id];
5330                         ASSERT(svar != NULL);
5331                         v = &svar->dtsv_var;
5332 
5333                         if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
5334                                 uintptr_t a = (uintptr_t)svar->dtsv_data;
5335                                 size_t sz = v->dtdv_type.dtdt_size;
5336 
5337                                 sz += sizeof (uint64_t);
5338                                 ASSERT(svar->dtsv_size == NCPU * sz);
5339                                 a += CPU->cpu_id * sz;
5340 
5341                                 if (regs[rd] == NULL) {
5342                                         *(uint8_t *)a = UINT8_MAX;
5343                                         break;
5344                                 } else {
5345                                         *(uint8_t *)a = 0;
5346                                         a += sizeof (uint64_t);
5347                                 }
5348 
5349                                 if (!dtrace_vcanload(
5350                                     (void *)(uintptr_t)regs[rd], &v->dtdv_type,
5351                                     mstate, vstate))
5352                                         break;
5353 
5354                                 dtrace_vcopy((void *)(uintptr_t)regs[rd],
5355                                     (void *)a, &v->dtdv_type);
5356                                 break;
5357                         }
5358 
5359                         ASSERT(svar->dtsv_size == NCPU * sizeof (uint64_t));
5360                         tmp = (uint64_t *)(uintptr_t)svar->dtsv_data;
5361                         tmp[CPU->cpu_id] = regs[rd];
5362                         break;
5363 
5364                 case DIF_OP_LDTS: {
5365                         dtrace_dynvar_t *dvar;
5366                         dtrace_key_t *key;
5367 
5368                         id = DIF_INSTR_VAR(instr);
5369                         ASSERT(id >= DIF_VAR_OTHER_UBASE);
5370                         id -= DIF_VAR_OTHER_UBASE;
5371                         v = &vstate->dtvs_tlocals[id];
5372 
5373                         key = &tupregs[DIF_DTR_NREGS];
5374                         key[0].dttk_value = (uint64_t)id;
5375                         key[0].dttk_size = 0;
5376                         DTRACE_TLS_THRKEY(key[1].dttk_value);
5377                         key[1].dttk_size = 0;
5378 
5379                         dvar = dtrace_dynvar(dstate, 2, key,
5380                             sizeof (uint64_t), DTRACE_DYNVAR_NOALLOC,
5381                             mstate, vstate);
5382 
5383                         if (dvar == NULL) {
5384                                 regs[rd] = 0;
5385                                 break;
5386                         }
5387 
5388                         if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
5389                                 regs[rd] = (uint64_t)(uintptr_t)dvar->dtdv_data;
5390                         } else {
5391                                 regs[rd] = *((uint64_t *)dvar->dtdv_data);
5392                         }
5393 
5394                         break;
5395                 }
5396 
5397                 case DIF_OP_STTS: {
5398                         dtrace_dynvar_t *dvar;
5399                         dtrace_key_t *key;
5400 
5401                         id = DIF_INSTR_VAR(instr);
5402                         ASSERT(id >= DIF_VAR_OTHER_UBASE);
5403                         id -= DIF_VAR_OTHER_UBASE;
5404 
5405                         key = &tupregs[DIF_DTR_NREGS];
5406                         key[0].dttk_value = (uint64_t)id;
5407                         key[0].dttk_size = 0;
5408                         DTRACE_TLS_THRKEY(key[1].dttk_value);
5409                         key[1].dttk_size = 0;
5410                         v = &vstate->dtvs_tlocals[id];
5411 
5412                         dvar = dtrace_dynvar(dstate, 2, key,
5413                             v->dtdv_type.dtdt_size > sizeof (uint64_t) ?
5414                             v->dtdv_type.dtdt_size : sizeof (uint64_t),
5415                             regs[rd] ? DTRACE_DYNVAR_ALLOC :
5416                             DTRACE_DYNVAR_DEALLOC, mstate, vstate);
5417 
5418                         /*
5419                          * Given that we're storing to thread-local data,
5420                          * we need to flush our predicate cache.
5421                          */
5422                         curthread->t_predcache = NULL;
5423 
5424                         if (dvar == NULL)
5425                                 break;
5426 
5427                         if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
5428                                 if (!dtrace_vcanload(
5429                                     (void *)(uintptr_t)regs[rd],
5430                                     &v->dtdv_type, mstate, vstate))
5431                                         break;
5432 
5433                                 dtrace_vcopy((void *)(uintptr_t)regs[rd],
5434                                     dvar->dtdv_data, &v->dtdv_type);
5435                         } else {
5436                                 *((uint64_t *)dvar->dtdv_data) = regs[rd];
5437                         }
5438 
5439                         break;
5440                 }
5441 
5442                 case DIF_OP_SRA:
5443                         regs[rd] = (int64_t)regs[r1] >> regs[r2];
5444                         break;
5445 
5446                 case DIF_OP_CALL:
5447                         dtrace_dif_subr(DIF_INSTR_SUBR(instr), rd,
5448                             regs, tupregs, ttop, mstate, state);
5449                         break;
5450 
5451                 case DIF_OP_PUSHTR:
5452                         if (ttop == DIF_DTR_NREGS) {
5453                                 *flags |= CPU_DTRACE_TUPOFLOW;
5454                                 break;
5455                         }
5456 
5457                         if (r1 == DIF_TYPE_STRING) {
5458                                 /*
5459                                  * If this is a string type and the size is 0,
5460                                  * we'll use the system-wide default string
5461                                  * size.  Note that we are _not_ looking at
5462                                  * the value of the DTRACEOPT_STRSIZE option;
5463                                  * had this been set, we would expect to have
5464                                  * a non-zero size value in the "pushtr".
5465                                  */
5466                                 tupregs[ttop].dttk_size =
5467                                     dtrace_strlen((char *)(uintptr_t)regs[rd],
5468                                     regs[r2] ? regs[r2] :
5469                                     dtrace_strsize_default) + 1;
5470                         } else {
5471                                 tupregs[ttop].dttk_size = regs[r2];
5472                         }
5473 
5474                         tupregs[ttop++].dttk_value = regs[rd];
5475                         break;
5476 
5477                 case DIF_OP_PUSHTV:
5478                         if (ttop == DIF_DTR_NREGS) {
5479                                 *flags |= CPU_DTRACE_TUPOFLOW;
5480                                 break;
5481                         }
5482 
5483                         tupregs[ttop].dttk_value = regs[rd];
5484                         tupregs[ttop++].dttk_size = 0;
5485                         break;
5486 
5487                 case DIF_OP_POPTS:
5488                         if (ttop != 0)
5489                                 ttop--;
5490                         break;
5491 
5492                 case DIF_OP_FLUSHTS:
5493                         ttop = 0;
5494                         break;
5495 
5496                 case DIF_OP_LDGAA:
5497                 case DIF_OP_LDTAA: {
5498                         dtrace_dynvar_t *dvar;
5499                         dtrace_key_t *key = tupregs;
5500                         uint_t nkeys = ttop;
5501 
5502                         id = DIF_INSTR_VAR(instr);
5503                         ASSERT(id >= DIF_VAR_OTHER_UBASE);
5504                         id -= DIF_VAR_OTHER_UBASE;
5505 
5506                         key[nkeys].dttk_value = (uint64_t)id;
5507                         key[nkeys++].dttk_size = 0;
5508 
5509                         if (DIF_INSTR_OP(instr) == DIF_OP_LDTAA) {
5510                                 DTRACE_TLS_THRKEY(key[nkeys].dttk_value);
5511                                 key[nkeys++].dttk_size = 0;
5512                                 v = &vstate->dtvs_tlocals[id];
5513                         } else {
5514                                 v = &vstate->dtvs_globals[id]->dtsv_var;
5515                         }
5516 
5517                         dvar = dtrace_dynvar(dstate, nkeys, key,
5518                             v->dtdv_type.dtdt_size > sizeof (uint64_t) ?
5519                             v->dtdv_type.dtdt_size : sizeof (uint64_t),
5520                             DTRACE_DYNVAR_NOALLOC, mstate, vstate);
5521 
5522                         if (dvar == NULL) {
5523                                 regs[rd] = 0;
5524                                 break;
5525                         }
5526 
5527                         if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
5528                                 regs[rd] = (uint64_t)(uintptr_t)dvar->dtdv_data;
5529                         } else {
5530                                 regs[rd] = *((uint64_t *)dvar->dtdv_data);
5531                         }
5532 
5533                         break;
5534                 }
5535 
5536                 case DIF_OP_STGAA:
5537                 case DIF_OP_STTAA: {
5538                         dtrace_dynvar_t *dvar;
5539                         dtrace_key_t *key = tupregs;
5540                         uint_t nkeys = ttop;
5541 
5542                         id = DIF_INSTR_VAR(instr);
5543                         ASSERT(id >= DIF_VAR_OTHER_UBASE);
5544                         id -= DIF_VAR_OTHER_UBASE;
5545 
5546                         key[nkeys].dttk_value = (uint64_t)id;
5547                         key[nkeys++].dttk_size = 0;
5548 
5549                         if (DIF_INSTR_OP(instr) == DIF_OP_STTAA) {
5550                                 DTRACE_TLS_THRKEY(key[nkeys].dttk_value);
5551                                 key[nkeys++].dttk_size = 0;
5552                                 v = &vstate->dtvs_tlocals[id];
5553                         } else {
5554                                 v = &vstate->dtvs_globals[id]->dtsv_var;
5555                         }
5556 
5557                         dvar = dtrace_dynvar(dstate, nkeys, key,
5558                             v->dtdv_type.dtdt_size > sizeof (uint64_t) ?
5559                             v->dtdv_type.dtdt_size : sizeof (uint64_t),
5560                             regs[rd] ? DTRACE_DYNVAR_ALLOC :
5561                             DTRACE_DYNVAR_DEALLOC, mstate, vstate);
5562 
5563                         if (dvar == NULL)
5564                                 break;
5565 
5566                         if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
5567                                 if (!dtrace_vcanload(
5568                                     (void *)(uintptr_t)regs[rd], &v->dtdv_type,
5569                                     mstate, vstate))
5570                                         break;
5571 
5572                                 dtrace_vcopy((void *)(uintptr_t)regs[rd],
5573                                     dvar->dtdv_data, &v->dtdv_type);
5574                         } else {
5575                                 *((uint64_t *)dvar->dtdv_data) = regs[rd];
5576                         }
5577 
5578                         break;
5579                 }
5580 
5581                 case DIF_OP_ALLOCS: {
5582                         uintptr_t ptr = P2ROUNDUP(mstate->dtms_scratch_ptr, 8);
5583                         size_t size = ptr - mstate->dtms_scratch_ptr + regs[r1];
5584 
5585                         /*
5586                          * Rounding up the user allocation size could have
5587                          * overflowed large, bogus allocations (like -1ULL) to
5588                          * 0.
5589                          */
5590                         if (size < regs[r1] ||
5591                             !DTRACE_INSCRATCH(mstate, size)) {
5592                                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
5593                                 regs[rd] = NULL;
5594                                 break;
5595                         }
5596 
5597                         dtrace_bzero((void *) mstate->dtms_scratch_ptr, size);
5598                         mstate->dtms_scratch_ptr += size;
5599                         regs[rd] = ptr;
5600                         break;
5601                 }
5602 
5603                 case DIF_OP_COPYS:
5604                         if (!dtrace_canstore(regs[rd], regs[r2],
5605                             mstate, vstate)) {
5606                                 *flags |= CPU_DTRACE_BADADDR;
5607                                 *illval = regs[rd];
5608                                 break;
5609                         }
5610 
5611                         if (!dtrace_canload(regs[r1], regs[r2], mstate, vstate))
5612                                 break;
5613 
5614                         dtrace_bcopy((void *)(uintptr_t)regs[r1],
5615                             (void *)(uintptr_t)regs[rd], (size_t)regs[r2]);
5616                         break;
5617 
5618                 case DIF_OP_STB:
5619                         if (!dtrace_canstore(regs[rd], 1, mstate, vstate)) {
5620                                 *flags |= CPU_DTRACE_BADADDR;
5621                                 *illval = regs[rd];
5622                                 break;
5623                         }
5624                         *((uint8_t *)(uintptr_t)regs[rd]) = (uint8_t)regs[r1];
5625                         break;
5626 
5627                 case DIF_OP_STH:
5628                         if (!dtrace_canstore(regs[rd], 2, mstate, vstate)) {
5629                                 *flags |= CPU_DTRACE_BADADDR;
5630                                 *illval = regs[rd];
5631                                 break;
5632                         }
5633                         if (regs[rd] & 1) {
5634                                 *flags |= CPU_DTRACE_BADALIGN;
5635                                 *illval = regs[rd];
5636                                 break;
5637                         }
5638                         *((uint16_t *)(uintptr_t)regs[rd]) = (uint16_t)regs[r1];
5639                         break;
5640 
5641                 case DIF_OP_STW:
5642                         if (!dtrace_canstore(regs[rd], 4, mstate, vstate)) {
5643                                 *flags |= CPU_DTRACE_BADADDR;
5644                                 *illval = regs[rd];
5645                                 break;
5646                         }
5647                         if (regs[rd] & 3) {
5648                                 *flags |= CPU_DTRACE_BADALIGN;
5649                                 *illval = regs[rd];
5650                                 break;
5651                         }
5652                         *((uint32_t *)(uintptr_t)regs[rd]) = (uint32_t)regs[r1];
5653                         break;
5654 
5655                 case DIF_OP_STX:
5656                         if (!dtrace_canstore(regs[rd], 8, mstate, vstate)) {
5657                                 *flags |= CPU_DTRACE_BADADDR;
5658                                 *illval = regs[rd];
5659                                 break;
5660                         }
5661                         if (regs[rd] & 7) {
5662                                 *flags |= CPU_DTRACE_BADALIGN;
5663                                 *illval = regs[rd];
5664                                 break;
5665                         }
5666                         *((uint64_t *)(uintptr_t)regs[rd]) = regs[r1];
5667                         break;
5668                 }
5669         }
5670 
5671         if (!(*flags & CPU_DTRACE_FAULT))
5672                 return (rval);
5673 
5674         mstate->dtms_fltoffs = opc * sizeof (dif_instr_t);
5675         mstate->dtms_present |= DTRACE_MSTATE_FLTOFFS;
5676 
5677         return (0);
5678 }
5679 
5680 static void
5681 dtrace_action_breakpoint(dtrace_ecb_t *ecb)
5682 {
5683         dtrace_probe_t *probe = ecb->dte_probe;
5684         dtrace_provider_t *prov = probe->dtpr_provider;
5685         char c[DTRACE_FULLNAMELEN + 80], *str;
5686         char *msg = "dtrace: breakpoint action at probe ";
5687         char *ecbmsg = " (ecb ";
5688         uintptr_t mask = (0xf << (sizeof (uintptr_t) * NBBY / 4));
5689         uintptr_t val = (uintptr_t)ecb;
5690         int shift = (sizeof (uintptr_t) * NBBY) - 4, i = 0;
5691 
5692         if (dtrace_destructive_disallow)
5693                 return;
5694 
5695         /*
5696          * It's impossible to be taking action on the NULL probe.
5697          */
5698         ASSERT(probe != NULL);
5699 
5700         /*
5701          * This is a poor man's (destitute man's?) sprintf():  we want to
5702          * print the provider name, module name, function name and name of
5703          * the probe, along with the hex address of the ECB with the breakpoint
5704          * action -- all of which we must place in the character buffer by
5705          * hand.
5706          */
5707         while (*msg != '\0')
5708                 c[i++] = *msg++;
5709 
5710         for (str = prov->dtpv_name; *str != '\0'; str++)
5711                 c[i++] = *str;
5712         c[i++] = ':';
5713 
5714         for (str = probe->dtpr_mod; *str != '\0'; str++)
5715                 c[i++] = *str;
5716         c[i++] = ':';
5717 
5718         for (str = probe->dtpr_func; *str != '\0'; str++)
5719                 c[i++] = *str;
5720         c[i++] = ':';
5721 
5722         for (str = probe->dtpr_name; *str != '\0'; str++)
5723                 c[i++] = *str;
5724 
5725         while (*ecbmsg != '\0')
5726                 c[i++] = *ecbmsg++;
5727 
5728         while (shift >= 0) {
5729                 mask = (uintptr_t)0xf << shift;
5730 
5731                 if (val >= ((uintptr_t)1 << shift))
5732                         c[i++] = "0123456789abcdef"[(val & mask) >> shift];
5733                 shift -= 4;
5734         }
5735 
5736         c[i++] = ')';
5737         c[i] = '\0';
5738 
5739         debug_enter(c);
5740 }
5741 
5742 static void
5743 dtrace_action_panic(dtrace_ecb_t *ecb)
5744 {
5745         dtrace_probe_t *probe = ecb->dte_probe;
5746 
5747         /*
5748          * It's impossible to be taking action on the NULL probe.
5749          */
5750         ASSERT(probe != NULL);
5751 
5752         if (dtrace_destructive_disallow)
5753                 return;
5754 
5755         if (dtrace_panicked != NULL)
5756                 return;
5757 
5758         if (dtrace_casptr(&dtrace_panicked, NULL, curthread) != NULL)
5759                 return;
5760 
5761         /*
5762          * We won the right to panic.  (We want to be sure that only one
5763          * thread calls panic() from dtrace_probe(), and that panic() is
5764          * called exactly once.)
5765          */
5766         dtrace_panic("dtrace: panic action at probe %s:%s:%s:%s (ecb %p)",
5767             probe->dtpr_provider->dtpv_name, probe->dtpr_mod,
5768             probe->dtpr_func, probe->dtpr_name, (void *)ecb);
5769 }
5770 
5771 static void
5772 dtrace_action_raise(uint64_t sig)
5773 {
5774         if (dtrace_destructive_disallow)
5775                 return;
5776 
5777         if (sig >= NSIG) {
5778                 DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
5779                 return;
5780         }
5781 
5782         /*
5783          * raise() has a queue depth of 1 -- we ignore all subsequent
5784          * invocations of the raise() action.
5785          */
5786         if (curthread->t_dtrace_sig == 0)
5787                 curthread->t_dtrace_sig = (uint8_t)sig;
5788 
5789         curthread->t_sig_check = 1;
5790         aston(curthread);
5791 }
5792 
5793 static void
5794 dtrace_action_stop(void)
5795 {
5796         if (dtrace_destructive_disallow)
5797                 return;
5798 
5799         if (!curthread->t_dtrace_stop) {
5800                 curthread->t_dtrace_stop = 1;
5801                 curthread->t_sig_check = 1;
5802                 aston(curthread);
5803         }
5804 }
5805 
5806 static void
5807 dtrace_action_chill(dtrace_mstate_t *mstate, hrtime_t val)
5808 {
5809         hrtime_t now;
5810         volatile uint16_t *flags;
5811         cpu_t *cpu = CPU;
5812 
5813         if (dtrace_destructive_disallow)
5814                 return;
5815 
5816         flags = (volatile uint16_t *)&cpu_core[cpu->cpu_id].cpuc_dtrace_flags;
5817 
5818         now = dtrace_gethrtime();
5819 
5820         if (now - cpu->cpu_dtrace_chillmark > dtrace_chill_interval) {
5821                 /*
5822                  * We need to advance the mark to the current time.
5823                  */
5824                 cpu->cpu_dtrace_chillmark = now;
5825                 cpu->cpu_dtrace_chilled = 0;
5826         }
5827 
5828         /*
5829          * Now check to see if the requested chill time would take us over
5830          * the maximum amount of time allowed in the chill interval.  (Or
5831          * worse, if the calculation itself induces overflow.)
5832          */
5833         if (cpu->cpu_dtrace_chilled + val > dtrace_chill_max ||
5834             cpu->cpu_dtrace_chilled + val < cpu->cpu_dtrace_chilled) {
5835                 *flags |= CPU_DTRACE_ILLOP;
5836                 return;
5837         }
5838 
5839         while (dtrace_gethrtime() - now < val)
5840                 continue;
5841 
5842         /*
5843          * Normally, we assure that the value of the variable "timestamp" does
5844          * not change within an ECB.  The presence of chill() represents an
5845          * exception to this rule, however.
5846          */
5847         mstate->dtms_present &= ~DTRACE_MSTATE_TIMESTAMP;
5848         cpu->cpu_dtrace_chilled += val;
5849 }
5850 
5851 static void
5852 dtrace_action_ustack(dtrace_mstate_t *mstate, dtrace_state_t *state,
5853     uint64_t *buf, uint64_t arg)
5854 {
5855         int nframes = DTRACE_USTACK_NFRAMES(arg);
5856         int strsize = DTRACE_USTACK_STRSIZE(arg);
5857         uint64_t *pcs = &buf[1], *fps;
5858         char *str = (char *)&pcs[nframes];
5859         int size, offs = 0, i, j;
5860         uintptr_t old = mstate->dtms_scratch_ptr, saved;
5861         uint16_t *flags = &cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
5862         char *sym;
5863 
5864         /*
5865          * Should be taking a faster path if string space has not been
5866          * allocated.
5867          */
5868         ASSERT(strsize != 0);
5869 
5870         /*
5871          * We will first allocate some temporary space for the frame pointers.
5872          */
5873         fps = (uint64_t *)P2ROUNDUP(mstate->dtms_scratch_ptr, 8);
5874         size = (uintptr_t)fps - mstate->dtms_scratch_ptr +
5875             (nframes * sizeof (uint64_t));
5876 
5877         if (!DTRACE_INSCRATCH(mstate, size)) {
5878                 /*
5879                  * Not enough room for our frame pointers -- need to indicate
5880                  * that we ran out of scratch space.
5881                  */
5882                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
5883                 return;
5884         }
5885 
5886         mstate->dtms_scratch_ptr += size;
5887         saved = mstate->dtms_scratch_ptr;
5888 
5889         /*
5890          * Now get a stack with both program counters and frame pointers.
5891          */
5892         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
5893         dtrace_getufpstack(buf, fps, nframes + 1);
5894         DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
5895 
5896         /*
5897          * If that faulted, we're cooked.
5898          */
5899         if (*flags & CPU_DTRACE_FAULT)
5900                 goto out;
5901 
5902         /*
5903          * Now we want to walk up the stack, calling the USTACK helper.  For
5904          * each iteration, we restore the scratch pointer.
5905          */
5906         for (i = 0; i < nframes; i++) {
5907                 mstate->dtms_scratch_ptr = saved;
5908 
5909                 if (offs >= strsize)
5910                         break;
5911 
5912                 sym = (char *)(uintptr_t)dtrace_helper(
5913                     DTRACE_HELPER_ACTION_USTACK,
5914                     mstate, state, pcs[i], fps[i]);
5915 
5916                 /*
5917                  * If we faulted while running the helper, we're going to
5918                  * clear the fault and null out the corresponding string.
5919                  */
5920                 if (*flags & CPU_DTRACE_FAULT) {
5921                         *flags &= ~CPU_DTRACE_FAULT;
5922                         str[offs++] = '\0';
5923                         continue;
5924                 }
5925 
5926                 if (sym == NULL) {
5927                         str[offs++] = '\0';
5928                         continue;
5929                 }
5930 
5931                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
5932 
5933                 /*
5934                  * Now copy in the string that the helper returned to us.
5935                  */
5936                 for (j = 0; offs + j < strsize; j++) {
5937                         if ((str[offs + j] = sym[j]) == '\0')
5938                                 break;
5939                 }
5940 
5941                 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
5942 
5943                 offs += j + 1;
5944         }
5945 
5946         if (offs >= strsize) {
5947                 /*
5948                  * If we didn't have room for all of the strings, we don't
5949                  * abort processing -- this needn't be a fatal error -- but we
5950                  * still want to increment a counter (dts_stkstroverflows) to
5951                  * allow this condition to be warned about.  (If this is from
5952                  * a jstack() action, it is easily tuned via jstackstrsize.)
5953                  */
5954                 dtrace_error(&state->dts_stkstroverflows);
5955         }
5956 
5957         while (offs < strsize)
5958                 str[offs++] = '\0';
5959 
5960 out:
5961         mstate->dtms_scratch_ptr = old;
5962 }
5963 
5964 /*
5965  * If you're looking for the epicenter of DTrace, you just found it.  This
5966  * is the function called by the provider to fire a probe -- from which all
5967  * subsequent probe-context DTrace activity emanates.
5968  */
5969 void
5970 dtrace_probe(dtrace_id_t id, uintptr_t arg0, uintptr_t arg1,
5971     uintptr_t arg2, uintptr_t arg3, uintptr_t arg4)
5972 {
5973         processorid_t cpuid;
5974         dtrace_icookie_t cookie;
5975         dtrace_probe_t *probe;
5976         dtrace_mstate_t mstate;
5977         dtrace_ecb_t *ecb;
5978         dtrace_action_t *act;
5979         intptr_t offs;
5980         size_t size;
5981         int vtime, onintr;
5982         volatile uint16_t *flags;
5983         hrtime_t now, end;
5984 
5985         /*
5986          * Kick out immediately if this CPU is still being born (in which case
5987          * curthread will be set to -1) or the current thread can't allow
5988          * probes in its current context.
5989          */
5990         if (((uintptr_t)curthread & 1) || (curthread->t_flag & T_DONTDTRACE))
5991                 return;
5992 
5993         cookie = dtrace_interrupt_disable();
5994         probe = dtrace_probes[id - 1];
5995         cpuid = CPU->cpu_id;
5996         onintr = CPU_ON_INTR(CPU);
5997 
5998         CPU->cpu_dtrace_probes++;
5999 
6000         if (!onintr && probe->dtpr_predcache != DTRACE_CACHEIDNONE &&
6001             probe->dtpr_predcache == curthread->t_predcache) {
6002                 /*
6003                  * We have hit in the predicate cache; we know that
6004                  * this predicate would evaluate to be false.
6005                  */
6006                 dtrace_interrupt_enable(cookie);
6007                 return;
6008         }
6009 
6010         if (panic_quiesce) {
6011                 /*
6012                  * We don't trace anything if we're panicking.
6013                  */
6014                 dtrace_interrupt_enable(cookie);
6015                 return;
6016         }
6017 
6018         now = dtrace_gethrtime();
6019         vtime = dtrace_vtime_references != 0;
6020 
6021         if (vtime && curthread->t_dtrace_start)
6022                 curthread->t_dtrace_vtime += now - curthread->t_dtrace_start;
6023 
6024         mstate.dtms_difo = NULL;
6025         mstate.dtms_probe = probe;
6026         mstate.dtms_strtok = NULL;
6027         mstate.dtms_arg[0] = arg0;
6028         mstate.dtms_arg[1] = arg1;
6029         mstate.dtms_arg[2] = arg2;
6030         mstate.dtms_arg[3] = arg3;
6031         mstate.dtms_arg[4] = arg4;
6032 
6033         flags = (volatile uint16_t *)&cpu_core[cpuid].cpuc_dtrace_flags;
6034 
6035         for (ecb = probe->dtpr_ecb; ecb != NULL; ecb = ecb->dte_next) {
6036                 dtrace_predicate_t *pred = ecb->dte_predicate;
6037                 dtrace_state_t *state = ecb->dte_state;
6038                 dtrace_buffer_t *buf = &state->dts_buffer[cpuid];
6039                 dtrace_buffer_t *aggbuf = &state->dts_aggbuffer[cpuid];
6040                 dtrace_vstate_t *vstate = &state->dts_vstate;
6041                 dtrace_provider_t *prov = probe->dtpr_provider;
6042                 uint64_t tracememsize = 0;
6043                 int committed = 0;
6044                 caddr_t tomax;
6045 
6046                 /*
6047                  * A little subtlety with the following (seemingly innocuous)
6048                  * declaration of the automatic 'val':  by looking at the
6049                  * code, you might think that it could be declared in the
6050                  * action processing loop, below.  (That is, it's only used in
6051                  * the action processing loop.)  However, it must be declared
6052                  * out of that scope because in the case of DIF expression
6053                  * arguments to aggregating actions, one iteration of the
6054                  * action loop will use the last iteration's value.
6055                  */
6056 #ifdef lint
6057                 uint64_t val = 0;
6058 #else
6059                 uint64_t val;
6060 #endif
6061 
6062                 mstate.dtms_present = DTRACE_MSTATE_ARGS | DTRACE_MSTATE_PROBE;
6063                 mstate.dtms_access = DTRACE_ACCESS_ARGS | DTRACE_ACCESS_PROC;
6064                 mstate.dtms_getf = NULL;
6065 
6066                 *flags &= ~CPU_DTRACE_ERROR;
6067 
6068                 if (prov == dtrace_provider) {
6069                         /*
6070                          * If dtrace itself is the provider of this probe,
6071                          * we're only going to continue processing the ECB if
6072                          * arg0 (the dtrace_state_t) is equal to the ECB's
6073                          * creating state.  (This prevents disjoint consumers
6074                          * from seeing one another's metaprobes.)
6075                          */
6076                         if (arg0 != (uint64_t)(uintptr_t)state)
6077                                 continue;
6078                 }
6079 
6080                 if (state->dts_activity != DTRACE_ACTIVITY_ACTIVE) {
6081                         /*
6082                          * We're not currently active.  If our provider isn't
6083                          * the dtrace pseudo provider, we're not interested.
6084                          */
6085                         if (prov != dtrace_provider)
6086                                 continue;
6087 
6088                         /*
6089                          * Now we must further check if we are in the BEGIN
6090                          * probe.  If we are, we will only continue processing
6091                          * if we're still in WARMUP -- if one BEGIN enabling
6092                          * has invoked the exit() action, we don't want to
6093                          * evaluate subsequent BEGIN enablings.
6094                          */
6095                         if (probe->dtpr_id == dtrace_probeid_begin &&
6096                             state->dts_activity != DTRACE_ACTIVITY_WARMUP) {
6097                                 ASSERT(state->dts_activity ==
6098                                     DTRACE_ACTIVITY_DRAINING);
6099                                 continue;
6100                         }
6101                 }
6102 
6103                 if (ecb->dte_cond && !dtrace_priv_probe(state, &mstate, ecb))
6104                         continue;
6105 
6106                 if (now - state->dts_alive > dtrace_deadman_timeout) {
6107                         /*
6108                          * We seem to be dead.  Unless we (a) have kernel
6109                          * destructive permissions (b) have explicitly enabled
6110                          * destructive actions and (c) destructive actions have
6111                          * not been disabled, we're going to transition into
6112                          * the KILLED state, from which no further processing
6113                          * on this state will be performed.
6114                          */
6115                         if (!dtrace_priv_kernel_destructive(state) ||
6116                             !state->dts_cred.dcr_destructive ||
6117                             dtrace_destructive_disallow) {
6118                                 void *activity = &state->dts_activity;
6119                                 dtrace_activity_t current;
6120 
6121                                 do {
6122                                         current = state->dts_activity;
6123                                 } while (dtrace_cas32(activity, current,
6124                                     DTRACE_ACTIVITY_KILLED) != current);
6125 
6126                                 continue;
6127                         }
6128                 }
6129 
6130                 if ((offs = dtrace_buffer_reserve(buf, ecb->dte_needed,
6131                     ecb->dte_alignment, state, &mstate)) < 0)
6132                         continue;
6133 
6134                 tomax = buf->dtb_tomax;
6135                 ASSERT(tomax != NULL);
6136 
6137                 if (ecb->dte_size != 0) {
6138                         dtrace_rechdr_t dtrh;
6139                         if (!(mstate.dtms_present & DTRACE_MSTATE_TIMESTAMP)) {
6140                                 mstate.dtms_timestamp = dtrace_gethrtime();
6141                                 mstate.dtms_present |= DTRACE_MSTATE_TIMESTAMP;
6142                         }
6143                         ASSERT3U(ecb->dte_size, >=, sizeof (dtrace_rechdr_t));
6144                         dtrh.dtrh_epid = ecb->dte_epid;
6145                         DTRACE_RECORD_STORE_TIMESTAMP(&dtrh,
6146                             mstate.dtms_timestamp);
6147                         *((dtrace_rechdr_t *)(tomax + offs)) = dtrh;
6148                 }
6149 
6150                 mstate.dtms_epid = ecb->dte_epid;
6151                 mstate.dtms_present |= DTRACE_MSTATE_EPID;
6152 
6153                 if (state->dts_cred.dcr_visible & DTRACE_CRV_KERNEL)
6154                         mstate.dtms_access |= DTRACE_ACCESS_KERNEL;
6155 
6156                 if (pred != NULL) {
6157                         dtrace_difo_t *dp = pred->dtp_difo;
6158                         int rval;
6159 
6160                         rval = dtrace_dif_emulate(dp, &mstate, vstate, state);
6161 
6162                         if (!(*flags & CPU_DTRACE_ERROR) && !rval) {
6163                                 dtrace_cacheid_t cid = probe->dtpr_predcache;
6164 
6165                                 if (cid != DTRACE_CACHEIDNONE && !onintr) {
6166                                         /*
6167                                          * Update the predicate cache...
6168                                          */
6169                                         ASSERT(cid == pred->dtp_cacheid);
6170                                         curthread->t_predcache = cid;
6171                                 }
6172 
6173                                 continue;
6174                         }
6175                 }
6176 
6177                 for (act = ecb->dte_action; !(*flags & CPU_DTRACE_ERROR) &&
6178                     act != NULL; act = act->dta_next) {
6179                         size_t valoffs;
6180                         dtrace_difo_t *dp;
6181                         dtrace_recdesc_t *rec = &act->dta_rec;
6182 
6183                         size = rec->dtrd_size;
6184                         valoffs = offs + rec->dtrd_offset;
6185 
6186                         if (DTRACEACT_ISAGG(act->dta_kind)) {
6187                                 uint64_t v = 0xbad;
6188                                 dtrace_aggregation_t *agg;
6189 
6190                                 agg = (dtrace_aggregation_t *)act;
6191 
6192                                 if ((dp = act->dta_difo) != NULL)
6193                                         v = dtrace_dif_emulate(dp,
6194                                             &mstate, vstate, state);
6195 
6196                                 if (*flags & CPU_DTRACE_ERROR)
6197                                         continue;
6198 
6199                                 /*
6200                                  * Note that we always pass the expression
6201                                  * value from the previous iteration of the
6202                                  * action loop.  This value will only be used
6203                                  * if there is an expression argument to the
6204                                  * aggregating action, denoted by the
6205                                  * dtag_hasarg field.
6206                                  */
6207                                 dtrace_aggregate(agg, buf,
6208                                     offs, aggbuf, v, val);
6209                                 continue;
6210                         }
6211 
6212                         switch (act->dta_kind) {
6213                         case DTRACEACT_STOP:
6214                                 if (dtrace_priv_proc_destructive(state,
6215                                     &mstate))
6216                                         dtrace_action_stop();
6217                                 continue;
6218 
6219                         case DTRACEACT_BREAKPOINT:
6220                                 if (dtrace_priv_kernel_destructive(state))
6221                                         dtrace_action_breakpoint(ecb);
6222                                 continue;
6223 
6224                         case DTRACEACT_PANIC:
6225                                 if (dtrace_priv_kernel_destructive(state))
6226                                         dtrace_action_panic(ecb);
6227                                 continue;
6228 
6229                         case DTRACEACT_STACK:
6230                                 if (!dtrace_priv_kernel(state))
6231                                         continue;
6232 
6233                                 dtrace_getpcstack((pc_t *)(tomax + valoffs),
6234                                     size / sizeof (pc_t), probe->dtpr_aframes,
6235                                     DTRACE_ANCHORED(probe) ? NULL :
6236                                     (uint32_t *)arg0);
6237 
6238                                 continue;
6239 
6240                         case DTRACEACT_JSTACK:
6241                         case DTRACEACT_USTACK:
6242                                 if (!dtrace_priv_proc(state, &mstate))
6243                                         continue;
6244 
6245                                 /*
6246                                  * See comment in DIF_VAR_PID.
6247                                  */
6248                                 if (DTRACE_ANCHORED(mstate.dtms_probe) &&
6249                                     CPU_ON_INTR(CPU)) {
6250                                         int depth = DTRACE_USTACK_NFRAMES(
6251                                             rec->dtrd_arg) + 1;
6252 
6253                                         dtrace_bzero((void *)(tomax + valoffs),
6254                                             DTRACE_USTACK_STRSIZE(rec->dtrd_arg)
6255                                             + depth * sizeof (uint64_t));
6256 
6257                                         continue;
6258                                 }
6259 
6260                                 if (DTRACE_USTACK_STRSIZE(rec->dtrd_arg) != 0 &&
6261                                     curproc->p_dtrace_helpers != NULL) {
6262                                         /*
6263                                          * This is the slow path -- we have
6264                                          * allocated string space, and we're
6265                                          * getting the stack of a process that
6266                                          * has helpers.  Call into a separate
6267                                          * routine to perform this processing.
6268                                          */
6269                                         dtrace_action_ustack(&mstate, state,
6270                                             (uint64_t *)(tomax + valoffs),
6271                                             rec->dtrd_arg);
6272                                         continue;
6273                                 }
6274 
6275                                 /*
6276                                  * Clear the string space, since there's no
6277                                  * helper to do it for us.
6278                                  */
6279                                 if (DTRACE_USTACK_STRSIZE(rec->dtrd_arg) != 0) {
6280                                         int depth = DTRACE_USTACK_NFRAMES(
6281                                             rec->dtrd_arg);
6282                                         size_t strsize = DTRACE_USTACK_STRSIZE(
6283                                             rec->dtrd_arg);
6284                                         uint64_t *buf = (uint64_t *)(tomax +
6285                                             valoffs);
6286                                         void *strspace = &buf[depth + 1];
6287 
6288                                         dtrace_bzero(strspace,
6289                                             MIN(depth, strsize));
6290                                 }
6291 
6292                                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
6293                                 dtrace_getupcstack((uint64_t *)
6294                                     (tomax + valoffs),
6295                                     DTRACE_USTACK_NFRAMES(rec->dtrd_arg) + 1);
6296                                 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
6297                                 continue;
6298 
6299                         default:
6300                                 break;
6301                         }
6302 
6303                         dp = act->dta_difo;
6304                         ASSERT(dp != NULL);
6305 
6306                         val = dtrace_dif_emulate(dp, &mstate, vstate, state);
6307 
6308                         if (*flags & CPU_DTRACE_ERROR)
6309                                 continue;
6310 
6311                         switch (act->dta_kind) {
6312                         case DTRACEACT_SPECULATE: {
6313                                 dtrace_rechdr_t *dtrh;
6314 
6315                                 ASSERT(buf == &state->dts_buffer[cpuid]);
6316                                 buf = dtrace_speculation_buffer(state,
6317                                     cpuid, val);
6318 
6319                                 if (buf == NULL) {
6320                                         *flags |= CPU_DTRACE_DROP;
6321                                         continue;
6322                                 }
6323 
6324                                 offs = dtrace_buffer_reserve(buf,
6325                                     ecb->dte_needed, ecb->dte_alignment,
6326                                     state, NULL);
6327 
6328                                 if (offs < 0) {
6329                                         *flags |= CPU_DTRACE_DROP;
6330                                         continue;
6331                                 }
6332 
6333                                 tomax = buf->dtb_tomax;
6334                                 ASSERT(tomax != NULL);
6335 
6336                                 if (ecb->dte_size == 0)
6337                                         continue;
6338 
6339                                 ASSERT3U(ecb->dte_size, >=,
6340                                     sizeof (dtrace_rechdr_t));
6341                                 dtrh = ((void *)(tomax + offs));
6342                                 dtrh->dtrh_epid = ecb->dte_epid;
6343                                 /*
6344                                  * When the speculation is committed, all of
6345                                  * the records in the speculative buffer will
6346                                  * have their timestamps set to the commit
6347                                  * time.  Until then, it is set to a sentinel
6348                                  * value, for debugability.
6349                                  */
6350                                 DTRACE_RECORD_STORE_TIMESTAMP(dtrh, UINT64_MAX);
6351                                 continue;
6352                         }
6353 
6354                         case DTRACEACT_CHILL:
6355                                 if (dtrace_priv_kernel_destructive(state))
6356                                         dtrace_action_chill(&mstate, val);
6357                                 continue;
6358 
6359                         case DTRACEACT_RAISE:
6360                                 if (dtrace_priv_proc_destructive(state,
6361                                     &mstate))
6362                                         dtrace_action_raise(val);
6363                                 continue;
6364 
6365                         case DTRACEACT_COMMIT:
6366                                 ASSERT(!committed);
6367 
6368                                 /*
6369                                  * We need to commit our buffer state.
6370                                  */
6371                                 if (ecb->dte_size)
6372                                         buf->dtb_offset = offs + ecb->dte_size;
6373                                 buf = &state->dts_buffer[cpuid];
6374                                 dtrace_speculation_commit(state, cpuid, val);
6375                                 committed = 1;
6376                                 continue;
6377 
6378                         case DTRACEACT_DISCARD:
6379                                 dtrace_speculation_discard(state, cpuid, val);
6380                                 continue;
6381 
6382                         case DTRACEACT_DIFEXPR:
6383                         case DTRACEACT_LIBACT:
6384                         case DTRACEACT_PRINTF:
6385                         case DTRACEACT_PRINTA:
6386                         case DTRACEACT_SYSTEM:
6387                         case DTRACEACT_FREOPEN:
6388                         case DTRACEACT_TRACEMEM:
6389                                 break;
6390 
6391                         case DTRACEACT_TRACEMEM_DYNSIZE:
6392                                 tracememsize = val;
6393                                 break;
6394 
6395                         case DTRACEACT_SYM:
6396                         case DTRACEACT_MOD:
6397                                 if (!dtrace_priv_kernel(state))
6398                                         continue;
6399                                 break;
6400 
6401                         case DTRACEACT_USYM:
6402                         case DTRACEACT_UMOD:
6403                         case DTRACEACT_UADDR: {
6404                                 struct pid *pid = curthread->t_procp->p_pidp;
6405 
6406                                 if (!dtrace_priv_proc(state, &mstate))
6407                                         continue;
6408 
6409                                 DTRACE_STORE(uint64_t, tomax,
6410                                     valoffs, (uint64_t)pid->pid_id);
6411                                 DTRACE_STORE(uint64_t, tomax,
6412                                     valoffs + sizeof (uint64_t), val);
6413 
6414                                 continue;
6415                         }
6416 
6417                         case DTRACEACT_EXIT: {
6418                                 /*
6419                                  * For the exit action, we are going to attempt
6420                                  * to atomically set our activity to be
6421                                  * draining.  If this fails (either because
6422                                  * another CPU has beat us to the exit action,
6423                                  * or because our current activity is something
6424                                  * other than ACTIVE or WARMUP), we will
6425                                  * continue.  This assures that the exit action
6426                                  * can be successfully recorded at most once
6427                                  * when we're in the ACTIVE state.  If we're
6428                                  * encountering the exit() action while in
6429                                  * COOLDOWN, however, we want to honor the new
6430                                  * status code.  (We know that we're the only
6431                                  * thread in COOLDOWN, so there is no race.)
6432                                  */
6433                                 void *activity = &state->dts_activity;
6434                                 dtrace_activity_t current = state->dts_activity;
6435 
6436                                 if (current == DTRACE_ACTIVITY_COOLDOWN)
6437                                         break;
6438 
6439                                 if (current != DTRACE_ACTIVITY_WARMUP)
6440                                         current = DTRACE_ACTIVITY_ACTIVE;
6441 
6442                                 if (dtrace_cas32(activity, current,
6443                                     DTRACE_ACTIVITY_DRAINING) != current) {
6444                                         *flags |= CPU_DTRACE_DROP;
6445                                         continue;
6446                                 }
6447 
6448                                 break;
6449                         }
6450 
6451                         default:
6452                                 ASSERT(0);
6453                         }
6454 
6455                         if (dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF) {
6456                                 uintptr_t end = valoffs + size;
6457 
6458                                 if (tracememsize != 0 &&
6459                                     valoffs + tracememsize < end) {
6460                                         end = valoffs + tracememsize;
6461                                         tracememsize = 0;
6462                                 }
6463 
6464                                 if (!dtrace_vcanload((void *)(uintptr_t)val,
6465                                     &dp->dtdo_rtype, &mstate, vstate))
6466                                         continue;
6467 
6468                                 /*
6469                                  * If this is a string, we're going to only
6470                                  * load until we find the zero byte -- after
6471                                  * which we'll store zero bytes.
6472                                  */
6473                                 if (dp->dtdo_rtype.dtdt_kind ==
6474                                     DIF_TYPE_STRING) {
6475                                         char c = '\0' + 1;
6476                                         int intuple = act->dta_intuple;
6477                                         size_t s;
6478 
6479                                         for (s = 0; s < size; s++) {
6480                                                 if (c != '\0')
6481                                                         c = dtrace_load8(val++);
6482 
6483                                                 DTRACE_STORE(uint8_t, tomax,
6484                                                     valoffs++, c);
6485 
6486                                                 if (c == '\0' && intuple)
6487                                                         break;
6488                                         }
6489 
6490                                         continue;
6491                                 }
6492 
6493                                 while (valoffs < end) {
6494                                         DTRACE_STORE(uint8_t, tomax, valoffs++,
6495                                             dtrace_load8(val++));
6496                                 }
6497 
6498                                 continue;
6499                         }
6500 
6501                         switch (size) {
6502                         case 0:
6503                                 break;
6504 
6505                         case sizeof (uint8_t):
6506                                 DTRACE_STORE(uint8_t, tomax, valoffs, val);
6507                                 break;
6508                         case sizeof (uint16_t):
6509                                 DTRACE_STORE(uint16_t, tomax, valoffs, val);
6510                                 break;
6511                         case sizeof (uint32_t):
6512                                 DTRACE_STORE(uint32_t, tomax, valoffs, val);
6513                                 break;
6514                         case sizeof (uint64_t):
6515                                 DTRACE_STORE(uint64_t, tomax, valoffs, val);
6516                                 break;
6517                         default:
6518                                 /*
6519                                  * Any other size should have been returned by
6520                                  * reference, not by value.
6521                                  */
6522                                 ASSERT(0);
6523                                 break;
6524                         }
6525                 }
6526 
6527                 if (*flags & CPU_DTRACE_DROP)
6528                         continue;
6529 
6530                 if (*flags & CPU_DTRACE_FAULT) {
6531                         int ndx;
6532                         dtrace_action_t *err;
6533 
6534                         buf->dtb_errors++;
6535 
6536                         if (probe->dtpr_id == dtrace_probeid_error) {
6537                                 /*
6538                                  * There's nothing we can do -- we had an
6539                                  * error on the error probe.  We bump an
6540                                  * error counter to at least indicate that
6541                                  * this condition happened.
6542                                  */
6543                                 dtrace_error(&state->dts_dblerrors);
6544                                 continue;
6545                         }
6546 
6547                         if (vtime) {
6548                                 /*
6549                                  * Before recursing on dtrace_probe(), we
6550                                  * need to explicitly clear out our start
6551                                  * time to prevent it from being accumulated
6552                                  * into t_dtrace_vtime.
6553                                  */
6554                                 curthread->t_dtrace_start = 0;
6555                         }
6556 
6557                         /*
6558                          * Iterate over the actions to figure out which action
6559                          * we were processing when we experienced the error.
6560                          * Note that act points _past_ the faulting action; if
6561                          * act is ecb->dte_action, the fault was in the
6562                          * predicate, if it's ecb->dte_action->dta_next it's
6563                          * in action #1, and so on.
6564                          */
6565                         for (err = ecb->dte_action, ndx = 0;
6566                             err != act; err = err->dta_next, ndx++)
6567                                 continue;
6568 
6569                         dtrace_probe_error(state, ecb->dte_epid, ndx,
6570                             (mstate.dtms_present & DTRACE_MSTATE_FLTOFFS) ?
6571                             mstate.dtms_fltoffs : -1, DTRACE_FLAGS2FLT(*flags),
6572                             cpu_core[cpuid].cpuc_dtrace_illval);
6573 
6574                         continue;
6575                 }
6576 
6577                 if (!committed)
6578                         buf->dtb_offset = offs + ecb->dte_size;
6579         }
6580 
6581         end = dtrace_gethrtime();
6582         if (vtime)
6583                 curthread->t_dtrace_start = end;
6584 
6585         CPU->cpu_dtrace_nsec += end - now;
6586 
6587         dtrace_interrupt_enable(cookie);
6588 }
6589 
6590 /*
6591  * DTrace Probe Hashing Functions
6592  *
6593  * The functions in this section (and indeed, the functions in remaining
6594  * sections) are not _called_ from probe context.  (Any exceptions to this are
6595  * marked with a "Note:".)  Rather, they are called from elsewhere in the
6596  * DTrace framework to look-up probes in, add probes to and remove probes from
6597  * the DTrace probe hashes.  (Each probe is hashed by each element of the
6598  * probe tuple -- allowing for fast lookups, regardless of what was
6599  * specified.)
6600  */
6601 static uint_t
6602 dtrace_hash_str(char *p)
6603 {
6604         unsigned int g;
6605         uint_t hval = 0;
6606 
6607         while (*p) {
6608                 hval = (hval << 4) + *p++;
6609                 if ((g = (hval & 0xf0000000)) != 0)
6610                         hval ^= g >> 24;
6611                 hval &= ~g;
6612         }
6613         return (hval);
6614 }
6615 
6616 static dtrace_hash_t *
6617 dtrace_hash_create(uintptr_t stroffs, uintptr_t nextoffs, uintptr_t prevoffs)
6618 {
6619         dtrace_hash_t *hash = kmem_zalloc(sizeof (dtrace_hash_t), KM_SLEEP);
6620 
6621         hash->dth_stroffs = stroffs;
6622         hash->dth_nextoffs = nextoffs;
6623         hash->dth_prevoffs = prevoffs;
6624 
6625         hash->dth_size = 1;
6626         hash->dth_mask = hash->dth_size - 1;
6627 
6628         hash->dth_tab = kmem_zalloc(hash->dth_size *
6629             sizeof (dtrace_hashbucket_t *), KM_SLEEP);
6630 
6631         return (hash);
6632 }
6633 
6634 static void
6635 dtrace_hash_destroy(dtrace_hash_t *hash)
6636 {
6637 #ifdef DEBUG
6638         int i;
6639 
6640         for (i = 0; i < hash->dth_size; i++)
6641                 ASSERT(hash->dth_tab[i] == NULL);
6642 #endif
6643 
6644         kmem_free(hash->dth_tab,
6645             hash->dth_size * sizeof (dtrace_hashbucket_t *));
6646         kmem_free(hash, sizeof (dtrace_hash_t));
6647 }
6648 
6649 static void
6650 dtrace_hash_resize(dtrace_hash_t *hash)
6651 {
6652         int size = hash->dth_size, i, ndx;
6653         int new_size = hash->dth_size << 1;
6654         int new_mask = new_size - 1;
6655         dtrace_hashbucket_t **new_tab, *bucket, *next;
6656 
6657         ASSERT((new_size & new_mask) == 0);
6658 
6659         new_tab = kmem_zalloc(new_size * sizeof (void *), KM_SLEEP);
6660 
6661         for (i = 0; i < size; i++) {
6662                 for (bucket = hash->dth_tab[i]; bucket != NULL; bucket = next) {
6663                         dtrace_probe_t *probe = bucket->dthb_chain;
6664 
6665                         ASSERT(probe != NULL);
6666                         ndx = DTRACE_HASHSTR(hash, probe) & new_mask;
6667 
6668                         next = bucket->dthb_next;
6669                         bucket->dthb_next = new_tab[ndx];
6670                         new_tab[ndx] = bucket;
6671                 }
6672         }
6673 
6674         kmem_free(hash->dth_tab, hash->dth_size * sizeof (void *));
6675         hash->dth_tab = new_tab;
6676         hash->dth_size = new_size;
6677         hash->dth_mask = new_mask;
6678 }
6679 
6680 static void
6681 dtrace_hash_add(dtrace_hash_t *hash, dtrace_probe_t *new)
6682 {
6683         int hashval = DTRACE_HASHSTR(hash, new);
6684         int ndx = hashval & hash->dth_mask;
6685         dtrace_hashbucket_t *bucket = hash->dth_tab[ndx];
6686         dtrace_probe_t **nextp, **prevp;
6687 
6688         for (; bucket != NULL; bucket = bucket->dthb_next) {
6689                 if (DTRACE_HASHEQ(hash, bucket->dthb_chain, new))
6690                         goto add;
6691         }
6692 
6693         if ((hash->dth_nbuckets >> 1) > hash->dth_size) {
6694                 dtrace_hash_resize(hash);
6695                 dtrace_hash_add(hash, new);
6696                 return;
6697         }
6698 
6699         bucket = kmem_zalloc(sizeof (dtrace_hashbucket_t), KM_SLEEP);
6700         bucket->dthb_next = hash->dth_tab[ndx];
6701         hash->dth_tab[ndx] = bucket;
6702         hash->dth_nbuckets++;
6703 
6704 add:
6705         nextp = DTRACE_HASHNEXT(hash, new);
6706         ASSERT(*nextp == NULL && *(DTRACE_HASHPREV(hash, new)) == NULL);
6707         *nextp = bucket->dthb_chain;
6708 
6709         if (bucket->dthb_chain != NULL) {
6710                 prevp = DTRACE_HASHPREV(hash, bucket->dthb_chain);
6711                 ASSERT(*prevp == NULL);
6712                 *prevp = new;
6713         }
6714 
6715         bucket->dthb_chain = new;
6716         bucket->dthb_len++;
6717 }
6718 
6719 static dtrace_probe_t *
6720 dtrace_hash_lookup(dtrace_hash_t *hash, dtrace_probe_t *template)
6721 {
6722         int hashval = DTRACE_HASHSTR(hash, template);
6723         int ndx = hashval & hash->dth_mask;
6724         dtrace_hashbucket_t *bucket = hash->dth_tab[ndx];
6725 
6726         for (; bucket != NULL; bucket = bucket->dthb_next) {
6727                 if (DTRACE_HASHEQ(hash, bucket->dthb_chain, template))
6728                         return (bucket->dthb_chain);
6729         }
6730 
6731         return (NULL);
6732 }
6733 
6734 static int
6735 dtrace_hash_collisions(dtrace_hash_t *hash, dtrace_probe_t *template)
6736 {
6737         int hashval = DTRACE_HASHSTR(hash, template);
6738         int ndx = hashval & hash->dth_mask;
6739         dtrace_hashbucket_t *bucket = hash->dth_tab[ndx];
6740 
6741         for (; bucket != NULL; bucket = bucket->dthb_next) {
6742                 if (DTRACE_HASHEQ(hash, bucket->dthb_chain, template))
6743                         return (bucket->dthb_len);
6744         }
6745 
6746         return (NULL);
6747 }
6748 
6749 static void
6750 dtrace_hash_remove(dtrace_hash_t *hash, dtrace_probe_t *probe)
6751 {
6752         int ndx = DTRACE_HASHSTR(hash, probe) & hash->dth_mask;
6753         dtrace_hashbucket_t *bucket = hash->dth_tab[ndx];
6754 
6755         dtrace_probe_t **prevp = DTRACE_HASHPREV(hash, probe);
6756         dtrace_probe_t **nextp = DTRACE_HASHNEXT(hash, probe);
6757 
6758         /*
6759          * Find the bucket that we're removing this probe from.
6760          */
6761         for (; bucket != NULL; bucket = bucket->dthb_next) {
6762                 if (DTRACE_HASHEQ(hash, bucket->dthb_chain, probe))
6763                         break;
6764         }
6765 
6766         ASSERT(bucket != NULL);
6767 
6768         if (*prevp == NULL) {
6769                 if (*nextp == NULL) {
6770                         /*
6771                          * The removed probe was the only probe on this
6772                          * bucket; we need to remove the bucket.
6773                          */
6774                         dtrace_hashbucket_t *b = hash->dth_tab[ndx];
6775 
6776                         ASSERT(bucket->dthb_chain == probe);
6777                         ASSERT(b != NULL);
6778 
6779                         if (b == bucket) {
6780                                 hash->dth_tab[ndx] = bucket->dthb_next;
6781                         } else {
6782                                 while (b->dthb_next != bucket)
6783                                         b = b->dthb_next;
6784                                 b->dthb_next = bucket->dthb_next;
6785                         }
6786 
6787                         ASSERT(hash->dth_nbuckets > 0);
6788                         hash->dth_nbuckets--;
6789                         kmem_free(bucket, sizeof (dtrace_hashbucket_t));
6790                         return;
6791                 }
6792 
6793                 bucket->dthb_chain = *nextp;
6794         } else {
6795                 *(DTRACE_HASHNEXT(hash, *prevp)) = *nextp;
6796         }
6797 
6798         if (*nextp != NULL)
6799                 *(DTRACE_HASHPREV(hash, *nextp)) = *prevp;
6800 }
6801 
6802 /*
6803  * DTrace Utility Functions
6804  *
6805  * These are random utility functions that are _not_ called from probe context.
6806  */
6807 static int
6808 dtrace_badattr(const dtrace_attribute_t *a)
6809 {
6810         return (a->dtat_name > DTRACE_STABILITY_MAX ||
6811             a->dtat_data > DTRACE_STABILITY_MAX ||
6812             a->dtat_class > DTRACE_CLASS_MAX);
6813 }
6814 
6815 /*
6816  * Return a duplicate copy of a string.  If the specified string is NULL,
6817  * this function returns a zero-length string.
6818  */
6819 static char *
6820 dtrace_strdup(const char *str)
6821 {
6822         char *new = kmem_zalloc((str != NULL ? strlen(str) : 0) + 1, KM_SLEEP);
6823 
6824         if (str != NULL)
6825                 (void) strcpy(new, str);
6826 
6827         return (new);
6828 }
6829 
6830 #define DTRACE_ISALPHA(c)       \
6831         (((c) >= 'a' && (c) <= 'z') || ((c) >= 'A' && (c) <= 'Z'))
6832 
6833 static int
6834 dtrace_badname(const char *s)
6835 {
6836         char c;
6837 
6838         if (s == NULL || (c = *s++) == '\0')
6839                 return (0);
6840 
6841         if (!DTRACE_ISALPHA(c) && c != '-' && c != '_' && c != '.')
6842                 return (1);
6843 
6844         while ((c = *s++) != '\0') {
6845                 if (!DTRACE_ISALPHA(c) && (c < '0' || c > '9') &&
6846                     c != '-' && c != '_' && c != '.' && c != '`')
6847                         return (1);
6848         }
6849 
6850         return (0);
6851 }
6852 
6853 static void
6854 dtrace_cred2priv(cred_t *cr, uint32_t *privp, uid_t *uidp, zoneid_t *zoneidp)
6855 {
6856         uint32_t priv;
6857 
6858         if (cr == NULL || PRIV_POLICY_ONLY(cr, PRIV_ALL, B_FALSE)) {
6859                 /*
6860                  * For DTRACE_PRIV_ALL, the uid and zoneid don't matter.
6861                  */
6862                 priv = DTRACE_PRIV_ALL;
6863         } else {
6864                 *uidp = crgetuid(cr);
6865                 *zoneidp = crgetzoneid(cr);
6866 
6867                 priv = 0;
6868                 if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_KERNEL, B_FALSE))
6869                         priv |= DTRACE_PRIV_KERNEL | DTRACE_PRIV_USER;
6870                 else if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_USER, B_FALSE))
6871                         priv |= DTRACE_PRIV_USER;
6872                 if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_PROC, B_FALSE))
6873                         priv |= DTRACE_PRIV_PROC;
6874                 if (PRIV_POLICY_ONLY(cr, PRIV_PROC_OWNER, B_FALSE))
6875                         priv |= DTRACE_PRIV_OWNER;
6876                 if (PRIV_POLICY_ONLY(cr, PRIV_PROC_ZONE, B_FALSE))
6877                         priv |= DTRACE_PRIV_ZONEOWNER;
6878         }
6879 
6880         *privp = priv;
6881 }
6882 
6883 #ifdef DTRACE_ERRDEBUG
6884 static void
6885 dtrace_errdebug(const char *str)
6886 {
6887         int hval = dtrace_hash_str((char *)str) % DTRACE_ERRHASHSZ;
6888         int occupied = 0;
6889 
6890         mutex_enter(&dtrace_errlock);
6891         dtrace_errlast = str;
6892         dtrace_errthread = curthread;
6893 
6894         while (occupied++ < DTRACE_ERRHASHSZ) {
6895                 if (dtrace_errhash[hval].dter_msg == str) {
6896                         dtrace_errhash[hval].dter_count++;
6897                         goto out;
6898                 }
6899 
6900                 if (dtrace_errhash[hval].dter_msg != NULL) {
6901                         hval = (hval + 1) % DTRACE_ERRHASHSZ;
6902                         continue;
6903                 }
6904 
6905                 dtrace_errhash[hval].dter_msg = str;
6906                 dtrace_errhash[hval].dter_count = 1;
6907                 goto out;
6908         }
6909 
6910         panic("dtrace: undersized error hash");
6911 out:
6912         mutex_exit(&dtrace_errlock);
6913 }
6914 #endif
6915 
6916 /*
6917  * DTrace Matching Functions
6918  *
6919  * These functions are used to match groups of probes, given some elements of
6920  * a probe tuple, or some globbed expressions for elements of a probe tuple.
6921  */
6922 static int
6923 dtrace_match_priv(const dtrace_probe_t *prp, uint32_t priv, uid_t uid,
6924     zoneid_t zoneid)
6925 {
6926         if (priv != DTRACE_PRIV_ALL) {
6927                 uint32_t ppriv = prp->dtpr_provider->dtpv_priv.dtpp_flags;
6928                 uint32_t match = priv & ppriv;
6929 
6930                 /*
6931                  * No PRIV_DTRACE_* privileges...
6932                  */
6933                 if ((priv & (DTRACE_PRIV_PROC | DTRACE_PRIV_USER |
6934                     DTRACE_PRIV_KERNEL)) == 0)
6935                         return (0);
6936 
6937                 /*
6938                  * No matching bits, but there were bits to match...
6939                  */
6940                 if (match == 0 && ppriv != 0)
6941                         return (0);
6942 
6943                 /*
6944                  * Need to have permissions to the process, but don't...
6945                  */
6946                 if (((ppriv & ~match) & DTRACE_PRIV_OWNER) != 0 &&
6947                     uid != prp->dtpr_provider->dtpv_priv.dtpp_uid) {
6948                         return (0);
6949                 }
6950 
6951                 /*
6952                  * Need to be in the same zone unless we possess the
6953                  * privilege to examine all zones.
6954                  */
6955                 if (((ppriv & ~match) & DTRACE_PRIV_ZONEOWNER) != 0 &&
6956                     zoneid != prp->dtpr_provider->dtpv_priv.dtpp_zoneid) {
6957                         return (0);
6958                 }
6959         }
6960 
6961         return (1);
6962 }
6963 
6964 /*
6965  * dtrace_match_probe compares a dtrace_probe_t to a pre-compiled key, which
6966  * consists of input pattern strings and an ops-vector to evaluate them.
6967  * This function returns >0 for match, 0 for no match, and <0 for error.
6968  */
6969 static int
6970 dtrace_match_probe(const dtrace_probe_t *prp, const dtrace_probekey_t *pkp,
6971     uint32_t priv, uid_t uid, zoneid_t zoneid)
6972 {
6973         dtrace_provider_t *pvp = prp->dtpr_provider;
6974         int rv;
6975 
6976         if (pvp->dtpv_defunct)
6977                 return (0);
6978 
6979         if ((rv = pkp->dtpk_pmatch(pvp->dtpv_name, pkp->dtpk_prov, 0)) <= 0)
6980                 return (rv);
6981 
6982         if ((rv = pkp->dtpk_mmatch(prp->dtpr_mod, pkp->dtpk_mod, 0)) <= 0)
6983                 return (rv);
6984 
6985         if ((rv = pkp->dtpk_fmatch(prp->dtpr_func, pkp->dtpk_func, 0)) <= 0)
6986                 return (rv);
6987 
6988         if ((rv = pkp->dtpk_nmatch(prp->dtpr_name, pkp->dtpk_name, 0)) <= 0)
6989                 return (rv);
6990 
6991         if (dtrace_match_priv(prp, priv, uid, zoneid) == 0)
6992                 return (0);
6993 
6994         return (rv);
6995 }
6996 
6997 /*
6998  * dtrace_match_glob() is a safe kernel implementation of the gmatch(3GEN)
6999  * interface for matching a glob pattern 'p' to an input string 's'.  Unlike
7000  * libc's version, the kernel version only applies to 8-bit ASCII strings.
7001  * In addition, all of the recursion cases except for '*' matching have been
7002  * unwound.  For '*', we still implement recursive evaluation, but a depth
7003  * counter is maintained and matching is aborted if we recurse too deep.
7004  * The function returns 0 if no match, >0 if match, and <0 if recursion error.
7005  */
7006 static int
7007 dtrace_match_glob(const char *s, const char *p, int depth)
7008 {
7009         const char *olds;
7010         char s1, c;
7011         int gs;
7012 
7013         if (depth > DTRACE_PROBEKEY_MAXDEPTH)
7014                 return (-1);
7015 
7016         if (s == NULL)
7017                 s = ""; /* treat NULL as empty string */
7018 
7019 top:
7020         olds = s;
7021         s1 = *s++;
7022 
7023         if (p == NULL)
7024                 return (0);
7025 
7026         if ((c = *p++) == '\0')
7027                 return (s1 == '\0');
7028 
7029         switch (c) {
7030         case '[': {
7031                 int ok = 0, notflag = 0;
7032                 char lc = '\0';
7033 
7034                 if (s1 == '\0')
7035                         return (0);
7036 
7037                 if (*p == '!') {
7038                         notflag = 1;
7039                         p++;
7040                 }
7041 
7042                 if ((c = *p++) == '\0')
7043                         return (0);
7044 
7045                 do {
7046                         if (c == '-' && lc != '\0' && *p != ']') {
7047                                 if ((c = *p++) == '\0')
7048                                         return (0);
7049                                 if (c == '\\' && (c = *p++) == '\0')
7050                                         return (0);
7051 
7052                                 if (notflag) {
7053                                         if (s1 < lc || s1 > c)
7054                                                 ok++;
7055                                         else
7056                                                 return (0);
7057                                 } else if (lc <= s1 && s1 <= c)
7058                                         ok++;
7059 
7060                         } else if (c == '\\' && (c = *p++) == '\0')
7061                                 return (0);
7062 
7063                         lc = c; /* save left-hand 'c' for next iteration */
7064 
7065                         if (notflag) {
7066                                 if (s1 != c)
7067                                         ok++;
7068                                 else
7069                                         return (0);
7070                         } else if (s1 == c)
7071                                 ok++;
7072 
7073                         if ((c = *p++) == '\0')
7074                                 return (0);
7075 
7076                 } while (c != ']');
7077 
7078                 if (ok)
7079                         goto top;
7080 
7081                 return (0);
7082         }
7083 
7084         case '\\':
7085                 if ((c = *p++) == '\0')
7086                         return (0);
7087                 /*FALLTHRU*/
7088 
7089         default:
7090                 if (c != s1)
7091                         return (0);
7092                 /*FALLTHRU*/
7093 
7094         case '?':
7095                 if (s1 != '\0')
7096                         goto top;
7097                 return (0);
7098 
7099         case '*':
7100                 while (*p == '*')
7101                         p++; /* consecutive *'s are identical to a single one */
7102 
7103                 if (*p == '\0')
7104                         return (1);
7105 
7106                 for (s = olds; *s != '\0'; s++) {
7107                         if ((gs = dtrace_match_glob(s, p, depth + 1)) != 0)
7108                                 return (gs);
7109                 }
7110 
7111                 return (0);
7112         }
7113 }
7114 
7115 /*ARGSUSED*/
7116 static int
7117 dtrace_match_string(const char *s, const char *p, int depth)
7118 {
7119         return (s != NULL && strcmp(s, p) == 0);
7120 }
7121 
7122 /*ARGSUSED*/
7123 static int
7124 dtrace_match_nul(const char *s, const char *p, int depth)
7125 {
7126         return (1); /* always match the empty pattern */
7127 }
7128 
7129 /*ARGSUSED*/
7130 static int
7131 dtrace_match_nonzero(const char *s, const char *p, int depth)
7132 {
7133         return (s != NULL && s[0] != '\0');
7134 }
7135 
7136 static int
7137 dtrace_match(const dtrace_probekey_t *pkp, uint32_t priv, uid_t uid,
7138     zoneid_t zoneid, int (*matched)(dtrace_probe_t *, void *), void *arg)
7139 {
7140         dtrace_probe_t template, *probe;
7141         dtrace_hash_t *hash = NULL;
7142         int len, rc, best = INT_MAX, nmatched = 0;
7143         dtrace_id_t i;
7144 
7145         ASSERT(MUTEX_HELD(&dtrace_lock));
7146 
7147         /*
7148          * If the probe ID is specified in the key, just lookup by ID and
7149          * invoke the match callback once if a matching probe is found.
7150          */
7151         if (pkp->dtpk_id != DTRACE_IDNONE) {
7152                 if ((probe = dtrace_probe_lookup_id(pkp->dtpk_id)) != NULL &&
7153                     dtrace_match_probe(probe, pkp, priv, uid, zoneid) > 0) {
7154                         if ((*matched)(probe, arg) == DTRACE_MATCH_FAIL)
7155                                 return (DTRACE_MATCH_FAIL);
7156                         nmatched++;
7157                 }
7158                 return (nmatched);
7159         }
7160 
7161         template.dtpr_mod = (char *)pkp->dtpk_mod;
7162         template.dtpr_func = (char *)pkp->dtpk_func;
7163         template.dtpr_name = (char *)pkp->dtpk_name;
7164 
7165         /*
7166          * We want to find the most distinct of the module name, function
7167          * name, and name.  So for each one that is not a glob pattern or
7168          * empty string, we perform a lookup in the corresponding hash and
7169          * use the hash table with the fewest collisions to do our search.
7170          */
7171         if (pkp->dtpk_mmatch == &dtrace_match_string &&
7172             (len = dtrace_hash_collisions(dtrace_bymod, &template)) < best) {
7173                 best = len;
7174                 hash = dtrace_bymod;
7175         }
7176 
7177         if (pkp->dtpk_fmatch == &dtrace_match_string &&
7178             (len = dtrace_hash_collisions(dtrace_byfunc, &template)) < best) {
7179                 best = len;
7180                 hash = dtrace_byfunc;
7181         }
7182 
7183         if (pkp->dtpk_nmatch == &dtrace_match_string &&
7184             (len = dtrace_hash_collisions(dtrace_byname, &template)) < best) {
7185                 best = len;
7186                 hash = dtrace_byname;
7187         }
7188 
7189         /*
7190          * If we did not select a hash table, iterate over every probe and
7191          * invoke our callback for each one that matches our input probe key.
7192          */
7193         if (hash == NULL) {
7194                 for (i = 0; i < dtrace_nprobes; i++) {
7195                         if ((probe = dtrace_probes[i]) == NULL ||
7196                             dtrace_match_probe(probe, pkp, priv, uid,
7197                             zoneid) <= 0)
7198                                 continue;
7199 
7200                         nmatched++;
7201 
7202                         if ((rc = (*matched)(probe, arg)) !=
7203                             DTRACE_MATCH_NEXT) {
7204                                 if (rc == DTRACE_MATCH_FAIL)
7205                                         return (DTRACE_MATCH_FAIL);
7206                                 break;
7207                         }
7208                 }
7209 
7210                 return (nmatched);
7211         }
7212 
7213         /*
7214          * If we selected a hash table, iterate over each probe of the same key
7215          * name and invoke the callback for every probe that matches the other
7216          * attributes of our input probe key.
7217          */
7218         for (probe = dtrace_hash_lookup(hash, &template); probe != NULL;
7219             probe = *(DTRACE_HASHNEXT(hash, probe))) {
7220 
7221                 if (dtrace_match_probe(probe, pkp, priv, uid, zoneid) <= 0)
7222                         continue;
7223 
7224                 nmatched++;
7225 
7226                 if ((rc = (*matched)(probe, arg)) != DTRACE_MATCH_NEXT) {
7227                         if (rc == DTRACE_MATCH_FAIL)
7228                                 return (DTRACE_MATCH_FAIL);
7229                         break;
7230                 }
7231         }
7232 
7233         return (nmatched);
7234 }
7235 
7236 /*
7237  * Return the function pointer dtrace_probecmp() should use to compare the
7238  * specified pattern with a string.  For NULL or empty patterns, we select
7239  * dtrace_match_nul().  For glob pattern strings, we use dtrace_match_glob().
7240  * For non-empty non-glob strings, we use dtrace_match_string().
7241  */
7242 static dtrace_probekey_f *
7243 dtrace_probekey_func(const char *p)
7244 {
7245         char c;
7246 
7247         if (p == NULL || *p == '\0')
7248                 return (&dtrace_match_nul);
7249 
7250         while ((c = *p++) != '\0') {
7251                 if (c == '[' || c == '?' || c == '*' || c == '\\')
7252                         return (&dtrace_match_glob);
7253         }
7254 
7255         return (&dtrace_match_string);
7256 }
7257 
7258 /*
7259  * Build a probe comparison key for use with dtrace_match_probe() from the
7260  * given probe description.  By convention, a null key only matches anchored
7261  * probes: if each field is the empty string, reset dtpk_fmatch to
7262  * dtrace_match_nonzero().
7263  */
7264 static void
7265 dtrace_probekey(const dtrace_probedesc_t *pdp, dtrace_probekey_t *pkp)
7266 {
7267         pkp->dtpk_prov = pdp->dtpd_provider;
7268         pkp->dtpk_pmatch = dtrace_probekey_func(pdp->dtpd_provider);
7269 
7270         pkp->dtpk_mod = pdp->dtpd_mod;
7271         pkp->dtpk_mmatch = dtrace_probekey_func(pdp->dtpd_mod);
7272 
7273         pkp->dtpk_func = pdp->dtpd_func;
7274         pkp->dtpk_fmatch = dtrace_probekey_func(pdp->dtpd_func);
7275 
7276         pkp->dtpk_name = pdp->dtpd_name;
7277         pkp->dtpk_nmatch = dtrace_probekey_func(pdp->dtpd_name);
7278 
7279         pkp->dtpk_id = pdp->dtpd_id;
7280 
7281         if (pkp->dtpk_id == DTRACE_IDNONE &&
7282             pkp->dtpk_pmatch == &dtrace_match_nul &&
7283             pkp->dtpk_mmatch == &dtrace_match_nul &&
7284             pkp->dtpk_fmatch == &dtrace_match_nul &&
7285             pkp->dtpk_nmatch == &dtrace_match_nul)
7286                 pkp->dtpk_fmatch = &dtrace_match_nonzero;
7287 }
7288 
7289 /*
7290  * DTrace Provider-to-Framework API Functions
7291  *
7292  * These functions implement much of the Provider-to-Framework API, as
7293  * described in <sys/dtrace.h>.  The parts of the API not in this section are
7294  * the functions in the API for probe management (found below), and
7295  * dtrace_probe() itself (found above).
7296  */
7297 
7298 /*
7299  * Register the calling provider with the DTrace framework.  This should
7300  * generally be called by DTrace providers in their attach(9E) entry point.
7301  */
7302 int
7303 dtrace_register(const char *name, const dtrace_pattr_t *pap, uint32_t priv,
7304     cred_t *cr, const dtrace_pops_t *pops, void *arg, dtrace_provider_id_t *idp)
7305 {
7306         dtrace_provider_t *provider;
7307 
7308         if (name == NULL || pap == NULL || pops == NULL || idp == NULL) {
7309                 cmn_err(CE_WARN, "failed to register provider '%s': invalid "
7310                     "arguments", name ? name : "<NULL>");
7311                 return (EINVAL);
7312         }
7313 
7314         if (name[0] == '\0' || dtrace_badname(name)) {
7315                 cmn_err(CE_WARN, "failed to register provider '%s': invalid "
7316                     "provider name", name);
7317                 return (EINVAL);
7318         }
7319 
7320         if ((pops->dtps_provide == NULL && pops->dtps_provide_module == NULL) ||
7321             pops->dtps_enable == NULL || pops->dtps_disable == NULL ||
7322             pops->dtps_destroy == NULL ||
7323             ((pops->dtps_resume == NULL) != (pops->dtps_suspend == NULL))) {
7324                 cmn_err(CE_WARN, "failed to register provider '%s': invalid "
7325                     "provider ops", name);
7326                 return (EINVAL);
7327         }
7328 
7329         if (dtrace_badattr(&pap->dtpa_provider) ||
7330             dtrace_badattr(&pap->dtpa_mod) ||
7331             dtrace_badattr(&pap->dtpa_func) ||
7332             dtrace_badattr(&pap->dtpa_name) ||
7333             dtrace_badattr(&pap->dtpa_args)) {
7334                 cmn_err(CE_WARN, "failed to register provider '%s': invalid "
7335                     "provider attributes", name);
7336                 return (EINVAL);
7337         }
7338 
7339         if (priv & ~DTRACE_PRIV_ALL) {
7340                 cmn_err(CE_WARN, "failed to register provider '%s': invalid "
7341                     "privilege attributes", name);
7342                 return (EINVAL);
7343         }
7344 
7345         if ((priv & DTRACE_PRIV_KERNEL) &&
7346             (priv & (DTRACE_PRIV_USER | DTRACE_PRIV_OWNER)) &&
7347             pops->dtps_mode == NULL) {
7348                 cmn_err(CE_WARN, "failed to register provider '%s': need "
7349                     "dtps_mode() op for given privilege attributes", name);
7350                 return (EINVAL);
7351         }
7352 
7353         provider = kmem_zalloc(sizeof (dtrace_provider_t), KM_SLEEP);
7354         provider->dtpv_name = kmem_alloc(strlen(name) + 1, KM_SLEEP);
7355         (void) strcpy(provider->dtpv_name, name);
7356 
7357         provider->dtpv_attr = *pap;
7358         provider->dtpv_priv.dtpp_flags = priv;
7359         if (cr != NULL) {
7360                 provider->dtpv_priv.dtpp_uid = crgetuid(cr);
7361                 provider->dtpv_priv.dtpp_zoneid = crgetzoneid(cr);
7362         }
7363         provider->dtpv_pops = *pops;
7364 
7365         if (pops->dtps_provide == NULL) {
7366                 ASSERT(pops->dtps_provide_module != NULL);
7367                 provider->dtpv_pops.dtps_provide =
7368                     (void (*)(void *, const dtrace_probedesc_t *))dtrace_nullop;
7369         }
7370 
7371         if (pops->dtps_provide_module == NULL) {
7372                 ASSERT(pops->dtps_provide != NULL);
7373                 provider->dtpv_pops.dtps_provide_module =
7374                     (void (*)(void *, struct modctl *))dtrace_nullop;
7375         }
7376 
7377         if (pops->dtps_suspend == NULL) {
7378                 ASSERT(pops->dtps_resume == NULL);
7379                 provider->dtpv_pops.dtps_suspend =
7380                     (void (*)(void *, dtrace_id_t, void *))dtrace_nullop;
7381                 provider->dtpv_pops.dtps_resume =
7382                     (void (*)(void *, dtrace_id_t, void *))dtrace_nullop;
7383         }
7384 
7385         provider->dtpv_arg = arg;
7386         *idp = (dtrace_provider_id_t)provider;
7387 
7388         if (pops == &dtrace_provider_ops) {
7389                 ASSERT(MUTEX_HELD(&dtrace_provider_lock));
7390                 ASSERT(MUTEX_HELD(&dtrace_lock));
7391                 ASSERT(dtrace_anon.dta_enabling == NULL);
7392 
7393                 /*
7394                  * We make sure that the DTrace provider is at the head of
7395                  * the provider chain.
7396                  */
7397                 provider->dtpv_next = dtrace_provider;
7398                 dtrace_provider = provider;
7399                 return (0);
7400         }
7401 
7402         mutex_enter(&dtrace_provider_lock);
7403         mutex_enter(&dtrace_lock);
7404 
7405         /*
7406          * If there is at least one provider registered, we'll add this
7407          * provider after the first provider.
7408          */
7409         if (dtrace_provider != NULL) {
7410                 provider->dtpv_next = dtrace_provider->dtpv_next;
7411                 dtrace_provider->dtpv_next = provider;
7412         } else {
7413                 dtrace_provider = provider;
7414         }
7415 
7416         if (dtrace_retained != NULL) {
7417                 dtrace_enabling_provide(provider);
7418 
7419                 /*
7420                  * Now we need to call dtrace_enabling_matchall() -- which
7421                  * will acquire cpu_lock and dtrace_lock.  We therefore need
7422                  * to drop all of our locks before calling into it...
7423                  */
7424                 mutex_exit(&dtrace_lock);
7425                 mutex_exit(&dtrace_provider_lock);
7426                 dtrace_enabling_matchall();
7427 
7428                 return (0);
7429         }
7430 
7431         mutex_exit(&dtrace_lock);
7432         mutex_exit(&dtrace_provider_lock);
7433 
7434         return (0);
7435 }
7436 
7437 /*
7438  * Unregister the specified provider from the DTrace framework.  This should
7439  * generally be called by DTrace providers in their detach(9E) entry point.
7440  */
7441 int
7442 dtrace_unregister(dtrace_provider_id_t id)
7443 {
7444         dtrace_provider_t *old = (dtrace_provider_t *)id;
7445         dtrace_provider_t *prev = NULL;
7446         int i, self = 0, noreap = 0;
7447         dtrace_probe_t *probe, *first = NULL;
7448 
7449         if (old->dtpv_pops.dtps_enable ==
7450             (int (*)(void *, dtrace_id_t, void *))dtrace_enable_nullop) {
7451                 /*
7452                  * If DTrace itself is the provider, we're called with locks
7453                  * already held.
7454                  */
7455                 ASSERT(old == dtrace_provider);
7456                 ASSERT(dtrace_devi != NULL);
7457                 ASSERT(MUTEX_HELD(&dtrace_provider_lock));
7458                 ASSERT(MUTEX_HELD(&dtrace_lock));
7459                 self = 1;
7460 
7461                 if (dtrace_provider->dtpv_next != NULL) {
7462                         /*
7463                          * There's another provider here; return failure.
7464                          */
7465                         return (EBUSY);
7466                 }
7467         } else {
7468                 mutex_enter(&dtrace_provider_lock);
7469                 mutex_enter(&mod_lock);
7470                 mutex_enter(&dtrace_lock);
7471         }
7472 
7473         /*
7474          * If anyone has /dev/dtrace open, or if there are anonymous enabled
7475          * probes, we refuse to let providers slither away, unless this
7476          * provider has already been explicitly invalidated.
7477          */
7478         if (!old->dtpv_defunct &&
7479             (dtrace_opens || (dtrace_anon.dta_state != NULL &&
7480             dtrace_anon.dta_state->dts_necbs > 0))) {
7481                 if (!self) {
7482                         mutex_exit(&dtrace_lock);
7483                         mutex_exit(&mod_lock);
7484                         mutex_exit(&dtrace_provider_lock);
7485                 }
7486                 return (EBUSY);
7487         }
7488 
7489         /*
7490          * Attempt to destroy the probes associated with this provider.
7491          */
7492         for (i = 0; i < dtrace_nprobes; i++) {
7493                 if ((probe = dtrace_probes[i]) == NULL)
7494                         continue;
7495 
7496                 if (probe->dtpr_provider != old)
7497                         continue;
7498 
7499                 if (probe->dtpr_ecb == NULL)
7500                         continue;
7501 
7502                 /*
7503                  * If we are trying to unregister a defunct provider, and the
7504                  * provider was made defunct within the interval dictated by
7505                  * dtrace_unregister_defunct_reap, we'll (asynchronously)
7506                  * attempt to reap our enablings.  To denote that the provider
7507                  * should reattempt to unregister itself at some point in the
7508                  * future, we will return a differentiable error code (EAGAIN
7509                  * instead of EBUSY) in this case.
7510                  */
7511                 if (dtrace_gethrtime() - old->dtpv_defunct >
7512                     dtrace_unregister_defunct_reap)
7513                         noreap = 1;
7514 
7515                 if (!self) {
7516                         mutex_exit(&dtrace_lock);
7517                         mutex_exit(&mod_lock);
7518                         mutex_exit(&dtrace_provider_lock);
7519                 }
7520 
7521                 if (noreap)
7522                         return (EBUSY);
7523 
7524                 (void) taskq_dispatch(dtrace_taskq,
7525                     (task_func_t *)dtrace_enabling_reap, NULL, TQ_SLEEP);
7526 
7527                 return (EAGAIN);
7528         }
7529 
7530         /*
7531          * All of the probes for this provider are disabled; we can safely
7532          * remove all of them from their hash chains and from the probe array.
7533          */
7534         for (i = 0; i < dtrace_nprobes; i++) {
7535                 if ((probe = dtrace_probes[i]) == NULL)
7536                         continue;
7537 
7538                 if (probe->dtpr_provider != old)
7539                         continue;
7540 
7541                 dtrace_probes[i] = NULL;
7542 
7543                 dtrace_hash_remove(dtrace_bymod, probe);
7544                 dtrace_hash_remove(dtrace_byfunc, probe);
7545                 dtrace_hash_remove(dtrace_byname, probe);
7546 
7547                 if (first == NULL) {
7548                         first = probe;
7549                         probe->dtpr_nextmod = NULL;
7550                 } else {
7551                         probe->dtpr_nextmod = first;
7552                         first = probe;
7553                 }
7554         }
7555 
7556         /*
7557          * The provider's probes have been removed from the hash chains and
7558          * from the probe array.  Now issue a dtrace_sync() to be sure that
7559          * everyone has cleared out from any probe array processing.
7560          */
7561         dtrace_sync();
7562 
7563         for (probe = first; probe != NULL; probe = first) {
7564                 first = probe->dtpr_nextmod;
7565 
7566                 old->dtpv_pops.dtps_destroy(old->dtpv_arg, probe->dtpr_id,
7567                     probe->dtpr_arg);
7568                 kmem_free(probe->dtpr_mod, strlen(probe->dtpr_mod) + 1);
7569                 kmem_free(probe->dtpr_func, strlen(probe->dtpr_func) + 1);
7570                 kmem_free(probe->dtpr_name, strlen(probe->dtpr_name) + 1);
7571                 vmem_free(dtrace_arena, (void *)(uintptr_t)(probe->dtpr_id), 1);
7572                 kmem_free(probe, sizeof (dtrace_probe_t));
7573         }
7574 
7575         if ((prev = dtrace_provider) == old) {
7576                 ASSERT(self || dtrace_devi == NULL);
7577                 ASSERT(old->dtpv_next == NULL || dtrace_devi == NULL);
7578                 dtrace_provider = old->dtpv_next;
7579         } else {
7580                 while (prev != NULL && prev->dtpv_next != old)
7581                         prev = prev->dtpv_next;
7582 
7583                 if (prev == NULL) {
7584                         panic("attempt to unregister non-existent "
7585                             "dtrace provider %p\n", (void *)id);
7586                 }
7587 
7588                 prev->dtpv_next = old->dtpv_next;
7589         }
7590 
7591         if (!self) {
7592                 mutex_exit(&dtrace_lock);
7593                 mutex_exit(&mod_lock);
7594                 mutex_exit(&dtrace_provider_lock);
7595         }
7596 
7597         kmem_free(old->dtpv_name, strlen(old->dtpv_name) + 1);
7598         kmem_free(old, sizeof (dtrace_provider_t));
7599 
7600         return (0);
7601 }
7602 
7603 /*
7604  * Invalidate the specified provider.  All subsequent probe lookups for the
7605  * specified provider will fail, but its probes will not be removed.
7606  */
7607 void
7608 dtrace_invalidate(dtrace_provider_id_t id)
7609 {
7610         dtrace_provider_t *pvp = (dtrace_provider_t *)id;
7611 
7612         ASSERT(pvp->dtpv_pops.dtps_enable !=
7613             (int (*)(void *, dtrace_id_t, void *))dtrace_enable_nullop);
7614 
7615         mutex_enter(&dtrace_provider_lock);
7616         mutex_enter(&dtrace_lock);
7617 
7618         pvp->dtpv_defunct = dtrace_gethrtime();
7619 
7620         mutex_exit(&dtrace_lock);
7621         mutex_exit(&dtrace_provider_lock);
7622 }
7623 
7624 /*
7625  * Indicate whether or not DTrace has attached.
7626  */
7627 int
7628 dtrace_attached(void)
7629 {
7630         /*
7631          * dtrace_provider will be non-NULL iff the DTrace driver has
7632          * attached.  (It's non-NULL because DTrace is always itself a
7633          * provider.)
7634          */
7635         return (dtrace_provider != NULL);
7636 }
7637 
7638 /*
7639  * Remove all the unenabled probes for the given provider.  This function is
7640  * not unlike dtrace_unregister(), except that it doesn't remove the provider
7641  * -- just as many of its associated probes as it can.
7642  */
7643 int
7644 dtrace_condense(dtrace_provider_id_t id)
7645 {
7646         dtrace_provider_t *prov = (dtrace_provider_t *)id;
7647         int i;
7648         dtrace_probe_t *probe;
7649 
7650         /*
7651          * Make sure this isn't the dtrace provider itself.
7652          */
7653         ASSERT(prov->dtpv_pops.dtps_enable !=
7654             (int (*)(void *, dtrace_id_t, void *))dtrace_enable_nullop);
7655 
7656         mutex_enter(&dtrace_provider_lock);
7657         mutex_enter(&dtrace_lock);
7658 
7659         /*
7660          * Attempt to destroy the probes associated with this provider.
7661          */
7662         for (i = 0; i < dtrace_nprobes; i++) {
7663                 if ((probe = dtrace_probes[i]) == NULL)
7664                         continue;
7665 
7666                 if (probe->dtpr_provider != prov)
7667                         continue;
7668 
7669                 if (probe->dtpr_ecb != NULL)
7670                         continue;
7671 
7672                 dtrace_probes[i] = NULL;
7673 
7674                 dtrace_hash_remove(dtrace_bymod, probe);
7675                 dtrace_hash_remove(dtrace_byfunc, probe);
7676                 dtrace_hash_remove(dtrace_byname, probe);
7677 
7678                 prov->dtpv_pops.dtps_destroy(prov->dtpv_arg, i + 1,
7679                     probe->dtpr_arg);
7680                 kmem_free(probe->dtpr_mod, strlen(probe->dtpr_mod) + 1);
7681                 kmem_free(probe->dtpr_func, strlen(probe->dtpr_func) + 1);
7682                 kmem_free(probe->dtpr_name, strlen(probe->dtpr_name) + 1);
7683                 kmem_free(probe, sizeof (dtrace_probe_t));
7684                 vmem_free(dtrace_arena, (void *)((uintptr_t)i + 1), 1);
7685         }
7686 
7687         mutex_exit(&dtrace_lock);
7688         mutex_exit(&dtrace_provider_lock);
7689 
7690         return (0);
7691 }
7692 
7693 /*
7694  * DTrace Probe Management Functions
7695  *
7696  * The functions in this section perform the DTrace probe management,
7697  * including functions to create probes, look-up probes, and call into the
7698  * providers to request that probes be provided.  Some of these functions are
7699  * in the Provider-to-Framework API; these functions can be identified by the
7700  * fact that they are not declared "static".
7701  */
7702 
7703 /*
7704  * Create a probe with the specified module name, function name, and name.
7705  */
7706 dtrace_id_t
7707 dtrace_probe_create(dtrace_provider_id_t prov, const char *mod,
7708     const char *func, const char *name, int aframes, void *arg)
7709 {
7710         dtrace_probe_t *probe, **probes;
7711         dtrace_provider_t *provider = (dtrace_provider_t *)prov;
7712         dtrace_id_t id;
7713 
7714         if (provider == dtrace_provider) {
7715                 ASSERT(MUTEX_HELD(&dtrace_lock));
7716         } else {
7717                 mutex_enter(&dtrace_lock);
7718         }
7719 
7720         id = (dtrace_id_t)(uintptr_t)vmem_alloc(dtrace_arena, 1,
7721             VM_BESTFIT | VM_SLEEP);
7722         probe = kmem_zalloc(sizeof (dtrace_probe_t), KM_SLEEP);
7723 
7724         probe->dtpr_id = id;
7725         probe->dtpr_gen = dtrace_probegen++;
7726         probe->dtpr_mod = dtrace_strdup(mod);
7727         probe->dtpr_func = dtrace_strdup(func);
7728         probe->dtpr_name = dtrace_strdup(name);
7729         probe->dtpr_arg = arg;
7730         probe->dtpr_aframes = aframes;
7731         probe->dtpr_provider = provider;
7732 
7733         dtrace_hash_add(dtrace_bymod, probe);
7734         dtrace_hash_add(dtrace_byfunc, probe);
7735         dtrace_hash_add(dtrace_byname, probe);
7736 
7737         if (id - 1 >= dtrace_nprobes) {
7738                 size_t osize = dtrace_nprobes * sizeof (dtrace_probe_t *);
7739                 size_t nsize = osize << 1;
7740 
7741                 if (nsize == 0) {
7742                         ASSERT(osize == 0);
7743                         ASSERT(dtrace_probes == NULL);
7744                         nsize = sizeof (dtrace_probe_t *);
7745                 }
7746 
7747                 probes = kmem_zalloc(nsize, KM_SLEEP);
7748 
7749                 if (dtrace_probes == NULL) {
7750                         ASSERT(osize == 0);
7751                         dtrace_probes = probes;
7752                         dtrace_nprobes = 1;
7753                 } else {
7754                         dtrace_probe_t **oprobes = dtrace_probes;
7755 
7756                         bcopy(oprobes, probes, osize);
7757                         dtrace_membar_producer();
7758                         dtrace_probes = probes;
7759 
7760                         dtrace_sync();
7761 
7762                         /*
7763                          * All CPUs are now seeing the new probes array; we can
7764                          * safely free the old array.
7765                          */
7766                         kmem_free(oprobes, osize);
7767                         dtrace_nprobes <<= 1;
7768                 }
7769 
7770                 ASSERT(id - 1 < dtrace_nprobes);
7771         }
7772 
7773         ASSERT(dtrace_probes[id - 1] == NULL);
7774         dtrace_probes[id - 1] = probe;
7775 
7776         if (provider != dtrace_provider)
7777                 mutex_exit(&dtrace_lock);
7778 
7779         return (id);
7780 }
7781 
7782 static dtrace_probe_t *
7783 dtrace_probe_lookup_id(dtrace_id_t id)
7784 {
7785         ASSERT(MUTEX_HELD(&dtrace_lock));
7786 
7787         if (id == 0 || id > dtrace_nprobes)
7788                 return (NULL);
7789 
7790         return (dtrace_probes[id - 1]);
7791 }
7792 
7793 static int
7794 dtrace_probe_lookup_match(dtrace_probe_t *probe, void *arg)
7795 {
7796         *((dtrace_id_t *)arg) = probe->dtpr_id;
7797 
7798         return (DTRACE_MATCH_DONE);
7799 }
7800 
7801 /*
7802  * Look up a probe based on provider and one or more of module name, function
7803  * name and probe name.
7804  */
7805 dtrace_id_t
7806 dtrace_probe_lookup(dtrace_provider_id_t prid, const char *mod,
7807     const char *func, const char *name)
7808 {
7809         dtrace_probekey_t pkey;
7810         dtrace_id_t id;
7811         int match;
7812 
7813         pkey.dtpk_prov = ((dtrace_provider_t *)prid)->dtpv_name;
7814         pkey.dtpk_pmatch = &dtrace_match_string;
7815         pkey.dtpk_mod = mod;
7816         pkey.dtpk_mmatch = mod ? &dtrace_match_string : &dtrace_match_nul;
7817         pkey.dtpk_func = func;
7818         pkey.dtpk_fmatch = func ? &dtrace_match_string : &dtrace_match_nul;
7819         pkey.dtpk_name = name;
7820         pkey.dtpk_nmatch = name ? &dtrace_match_string : &dtrace_match_nul;
7821         pkey.dtpk_id = DTRACE_IDNONE;
7822 
7823         mutex_enter(&dtrace_lock);
7824         match = dtrace_match(&pkey, DTRACE_PRIV_ALL, 0, 0,
7825             dtrace_probe_lookup_match, &id);
7826         mutex_exit(&dtrace_lock);
7827 
7828         ASSERT(match == 1 || match == 0);
7829         return (match ? id : 0);
7830 }
7831 
7832 /*
7833  * Returns the probe argument associated with the specified probe.
7834  */
7835 void *
7836 dtrace_probe_arg(dtrace_provider_id_t id, dtrace_id_t pid)
7837 {
7838         dtrace_probe_t *probe;
7839         void *rval = NULL;
7840 
7841         mutex_enter(&dtrace_lock);
7842 
7843         if ((probe = dtrace_probe_lookup_id(pid)) != NULL &&
7844             probe->dtpr_provider == (dtrace_provider_t *)id)
7845                 rval = probe->dtpr_arg;
7846 
7847         mutex_exit(&dtrace_lock);
7848 
7849         return (rval);
7850 }
7851 
7852 /*
7853  * Copy a probe into a probe description.
7854  */
7855 static void
7856 dtrace_probe_description(const dtrace_probe_t *prp, dtrace_probedesc_t *pdp)
7857 {
7858         bzero(pdp, sizeof (dtrace_probedesc_t));
7859         pdp->dtpd_id = prp->dtpr_id;
7860 
7861         (void) strncpy(pdp->dtpd_provider,
7862             prp->dtpr_provider->dtpv_name, DTRACE_PROVNAMELEN - 1);
7863 
7864         (void) strncpy(pdp->dtpd_mod, prp->dtpr_mod, DTRACE_MODNAMELEN - 1);
7865         (void) strncpy(pdp->dtpd_func, prp->dtpr_func, DTRACE_FUNCNAMELEN - 1);
7866         (void) strncpy(pdp->dtpd_name, prp->dtpr_name, DTRACE_NAMELEN - 1);
7867 }
7868 
7869 /*
7870  * Called to indicate that a probe -- or probes -- should be provided by a
7871  * specfied provider.  If the specified description is NULL, the provider will
7872  * be told to provide all of its probes.  (This is done whenever a new
7873  * consumer comes along, or whenever a retained enabling is to be matched.) If
7874  * the specified description is non-NULL, the provider is given the
7875  * opportunity to dynamically provide the specified probe, allowing providers
7876  * to support the creation of probes on-the-fly.  (So-called _autocreated_
7877  * probes.)  If the provider is NULL, the operations will be applied to all
7878  * providers; if the provider is non-NULL the operations will only be applied
7879  * to the specified provider.  The dtrace_provider_lock must be held, and the
7880  * dtrace_lock must _not_ be held -- the provider's dtps_provide() operation
7881  * will need to grab the dtrace_lock when it reenters the framework through
7882  * dtrace_probe_lookup(), dtrace_probe_create(), etc.
7883  */
7884 static void
7885 dtrace_probe_provide(dtrace_probedesc_t *desc, dtrace_provider_t *prv)
7886 {
7887         struct modctl *ctl;
7888         int all = 0;
7889 
7890         ASSERT(MUTEX_HELD(&dtrace_provider_lock));
7891 
7892         if (prv == NULL) {
7893                 all = 1;
7894                 prv = dtrace_provider;
7895         }
7896 
7897         do {
7898                 /*
7899                  * First, call the blanket provide operation.
7900                  */
7901                 prv->dtpv_pops.dtps_provide(prv->dtpv_arg, desc);
7902 
7903                 /*
7904                  * Now call the per-module provide operation.  We will grab
7905                  * mod_lock to prevent the list from being modified.  Note
7906                  * that this also prevents the mod_busy bits from changing.
7907                  * (mod_busy can only be changed with mod_lock held.)
7908                  */
7909                 mutex_enter(&mod_lock);
7910 
7911                 ctl = &modules;
7912                 do {
7913                         if (ctl->mod_busy || ctl->mod_mp == NULL)
7914                                 continue;
7915 
7916                         prv->dtpv_pops.dtps_provide_module(prv->dtpv_arg, ctl);
7917 
7918                 } while ((ctl = ctl->mod_next) != &modules);
7919 
7920                 mutex_exit(&mod_lock);
7921         } while (all && (prv = prv->dtpv_next) != NULL);
7922 }
7923 
7924 /*
7925  * Iterate over each probe, and call the Framework-to-Provider API function
7926  * denoted by offs.
7927  */
7928 static void
7929 dtrace_probe_foreach(uintptr_t offs)
7930 {
7931         dtrace_provider_t *prov;
7932         void (*func)(void *, dtrace_id_t, void *);
7933         dtrace_probe_t *probe;
7934         dtrace_icookie_t cookie;
7935         int i;
7936 
7937         /*
7938          * We disable interrupts to walk through the probe array.  This is
7939          * safe -- the dtrace_sync() in dtrace_unregister() assures that we
7940          * won't see stale data.
7941          */
7942         cookie = dtrace_interrupt_disable();
7943 
7944         for (i = 0; i < dtrace_nprobes; i++) {
7945                 if ((probe = dtrace_probes[i]) == NULL)
7946                         continue;
7947 
7948                 if (probe->dtpr_ecb == NULL) {
7949                         /*
7950                          * This probe isn't enabled -- don't call the function.
7951                          */
7952                         continue;
7953                 }
7954 
7955                 prov = probe->dtpr_provider;
7956                 func = *((void(**)(void *, dtrace_id_t, void *))
7957                     ((uintptr_t)&prov->dtpv_pops + offs));
7958 
7959                 func(prov->dtpv_arg, i + 1, probe->dtpr_arg);
7960         }
7961 
7962         dtrace_interrupt_enable(cookie);
7963 }
7964 
7965 static int
7966 dtrace_probe_enable(const dtrace_probedesc_t *desc, dtrace_enabling_t *enab)
7967 {
7968         dtrace_probekey_t pkey;
7969         uint32_t priv;
7970         uid_t uid;
7971         zoneid_t zoneid;
7972 
7973         ASSERT(MUTEX_HELD(&dtrace_lock));
7974         dtrace_ecb_create_cache = NULL;
7975 
7976         if (desc == NULL) {
7977                 /*
7978                  * If we're passed a NULL description, we're being asked to
7979                  * create an ECB with a NULL probe.
7980                  */
7981                 (void) dtrace_ecb_create_enable(NULL, enab);
7982                 return (0);
7983         }
7984 
7985         dtrace_probekey(desc, &pkey);
7986         dtrace_cred2priv(enab->dten_vstate->dtvs_state->dts_cred.dcr_cred,
7987             &priv, &uid, &zoneid);
7988 
7989         return (dtrace_match(&pkey, priv, uid, zoneid, dtrace_ecb_create_enable,
7990             enab));
7991 }
7992 
7993 /*
7994  * DTrace Helper Provider Functions
7995  */
7996 static void
7997 dtrace_dofattr2attr(dtrace_attribute_t *attr, const dof_attr_t dofattr)
7998 {
7999         attr->dtat_name = DOF_ATTR_NAME(dofattr);
8000         attr->dtat_data = DOF_ATTR_DATA(dofattr);
8001         attr->dtat_class = DOF_ATTR_CLASS(dofattr);
8002 }
8003 
8004 static void
8005 dtrace_dofprov2hprov(dtrace_helper_provdesc_t *hprov,
8006     const dof_provider_t *dofprov, char *strtab)
8007 {
8008         hprov->dthpv_provname = strtab + dofprov->dofpv_name;
8009         dtrace_dofattr2attr(&hprov->dthpv_pattr.dtpa_provider,
8010             dofprov->dofpv_provattr);
8011         dtrace_dofattr2attr(&hprov->dthpv_pattr.dtpa_mod,
8012             dofprov->dofpv_modattr);
8013         dtrace_dofattr2attr(&hprov->dthpv_pattr.dtpa_func,
8014             dofprov->dofpv_funcattr);
8015         dtrace_dofattr2attr(&hprov->dthpv_pattr.dtpa_name,
8016             dofprov->dofpv_nameattr);
8017         dtrace_dofattr2attr(&hprov->dthpv_pattr.dtpa_args,
8018             dofprov->dofpv_argsattr);
8019 }
8020 
8021 static void
8022 dtrace_helper_provide_one(dof_helper_t *dhp, dof_sec_t *sec, pid_t pid)
8023 {
8024         uintptr_t daddr = (uintptr_t)dhp->dofhp_dof;
8025         dof_hdr_t *dof = (dof_hdr_t *)daddr;
8026         dof_sec_t *str_sec, *prb_sec, *arg_sec, *off_sec, *enoff_sec;
8027         dof_provider_t *provider;
8028         dof_probe_t *probe;
8029         uint32_t *off, *enoff;
8030         uint8_t *arg;
8031         char *strtab;
8032         uint_t i, nprobes;
8033         dtrace_helper_provdesc_t dhpv;
8034         dtrace_helper_probedesc_t dhpb;
8035         dtrace_meta_t *meta = dtrace_meta_pid;
8036         dtrace_mops_t *mops = &meta->dtm_mops;
8037         void *parg;
8038 
8039         provider = (dof_provider_t *)(uintptr_t)(daddr + sec->dofs_offset);
8040         str_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
8041             provider->dofpv_strtab * dof->dofh_secsize);
8042         prb_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
8043             provider->dofpv_probes * dof->dofh_secsize);
8044         arg_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
8045             provider->dofpv_prargs * dof->dofh_secsize);
8046         off_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
8047             provider->dofpv_proffs * dof->dofh_secsize);
8048 
8049         strtab = (char *)(uintptr_t)(daddr + str_sec->dofs_offset);
8050         off = (uint32_t *)(uintptr_t)(daddr + off_sec->dofs_offset);
8051         arg = (uint8_t *)(uintptr_t)(daddr + arg_sec->dofs_offset);
8052         enoff = NULL;
8053 
8054         /*
8055          * See dtrace_helper_provider_validate().
8056          */
8057         if (dof->dofh_ident[DOF_ID_VERSION] != DOF_VERSION_1 &&
8058             provider->dofpv_prenoffs != DOF_SECT_NONE) {
8059                 enoff_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
8060                     provider->dofpv_prenoffs * dof->dofh_secsize);
8061                 enoff = (uint32_t *)(uintptr_t)(daddr + enoff_sec->dofs_offset);
8062         }
8063 
8064         nprobes = prb_sec->dofs_size / prb_sec->dofs_entsize;
8065 
8066         /*
8067          * Create the provider.
8068          */
8069         dtrace_dofprov2hprov(&dhpv, provider, strtab);
8070 
8071         if ((parg = mops->dtms_provide_pid(meta->dtm_arg, &dhpv, pid)) == NULL)
8072                 return;
8073 
8074         meta->dtm_count++;
8075 
8076         /*
8077          * Create the probes.
8078          */
8079         for (i = 0; i < nprobes; i++) {
8080                 probe = (dof_probe_t *)(uintptr_t)(daddr +
8081                     prb_sec->dofs_offset + i * prb_sec->dofs_entsize);
8082 
8083                 dhpb.dthpb_mod = dhp->dofhp_mod;
8084                 dhpb.dthpb_func = strtab + probe->dofpr_func;
8085                 dhpb.dthpb_name = strtab + probe->dofpr_name;
8086                 dhpb.dthpb_base = probe->dofpr_addr;
8087                 dhpb.dthpb_offs = off + probe->dofpr_offidx;
8088                 dhpb.dthpb_noffs = probe->dofpr_noffs;
8089                 if (enoff != NULL) {
8090                         dhpb.dthpb_enoffs = enoff + probe->dofpr_enoffidx;
8091                         dhpb.dthpb_nenoffs = probe->dofpr_nenoffs;
8092                 } else {
8093                         dhpb.dthpb_enoffs = NULL;
8094                         dhpb.dthpb_nenoffs = 0;
8095                 }
8096                 dhpb.dthpb_args = arg + probe->dofpr_argidx;
8097                 dhpb.dthpb_nargc = probe->dofpr_nargc;
8098                 dhpb.dthpb_xargc = probe->dofpr_xargc;
8099                 dhpb.dthpb_ntypes = strtab + probe->dofpr_nargv;
8100                 dhpb.dthpb_xtypes = strtab + probe->dofpr_xargv;
8101 
8102                 mops->dtms_create_probe(meta->dtm_arg, parg, &dhpb);
8103         }
8104 }
8105 
8106 static void
8107 dtrace_helper_provide(dof_helper_t *dhp, pid_t pid)
8108 {
8109         uintptr_t daddr = (uintptr_t)dhp->dofhp_dof;
8110         dof_hdr_t *dof = (dof_hdr_t *)daddr;
8111         int i;
8112 
8113         ASSERT(MUTEX_HELD(&dtrace_meta_lock));
8114 
8115         for (i = 0; i < dof->dofh_secnum; i++) {
8116                 dof_sec_t *sec = (dof_sec_t *)(uintptr_t)(daddr +
8117                     dof->dofh_secoff + i * dof->dofh_secsize);
8118 
8119                 if (sec->dofs_type != DOF_SECT_PROVIDER)
8120                         continue;
8121 
8122                 dtrace_helper_provide_one(dhp, sec, pid);
8123         }
8124 
8125         /*
8126          * We may have just created probes, so we must now rematch against
8127          * any retained enablings.  Note that this call will acquire both
8128          * cpu_lock and dtrace_lock; the fact that we are holding
8129          * dtrace_meta_lock now is what defines the ordering with respect to
8130          * these three locks.
8131          */
8132         dtrace_enabling_matchall();
8133 }
8134 
8135 static void
8136 dtrace_helper_provider_remove_one(dof_helper_t *dhp, dof_sec_t *sec, pid_t pid)
8137 {
8138         uintptr_t daddr = (uintptr_t)dhp->dofhp_dof;
8139         dof_hdr_t *dof = (dof_hdr_t *)daddr;
8140         dof_sec_t *str_sec;
8141         dof_provider_t *provider;
8142         char *strtab;
8143         dtrace_helper_provdesc_t dhpv;
8144         dtrace_meta_t *meta = dtrace_meta_pid;
8145         dtrace_mops_t *mops = &meta->dtm_mops;
8146 
8147         provider = (dof_provider_t *)(uintptr_t)(daddr + sec->dofs_offset);
8148         str_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
8149             provider->dofpv_strtab * dof->dofh_secsize);
8150 
8151         strtab = (char *)(uintptr_t)(daddr + str_sec->dofs_offset);
8152 
8153         /*
8154          * Create the provider.
8155          */
8156         dtrace_dofprov2hprov(&dhpv, provider, strtab);
8157 
8158         mops->dtms_remove_pid(meta->dtm_arg, &dhpv, pid);
8159 
8160         meta->dtm_count--;
8161 }
8162 
8163 static void
8164 dtrace_helper_provider_remove(dof_helper_t *dhp, pid_t pid)
8165 {
8166         uintptr_t daddr = (uintptr_t)dhp->dofhp_dof;
8167         dof_hdr_t *dof = (dof_hdr_t *)daddr;
8168         int i;
8169 
8170         ASSERT(MUTEX_HELD(&dtrace_meta_lock));
8171 
8172         for (i = 0; i < dof->dofh_secnum; i++) {
8173                 dof_sec_t *sec = (dof_sec_t *)(uintptr_t)(daddr +
8174                     dof->dofh_secoff + i * dof->dofh_secsize);
8175 
8176                 if (sec->dofs_type != DOF_SECT_PROVIDER)
8177                         continue;
8178 
8179                 dtrace_helper_provider_remove_one(dhp, sec, pid);
8180         }
8181 }
8182 
8183 /*
8184  * DTrace Meta Provider-to-Framework API Functions
8185  *
8186  * These functions implement the Meta Provider-to-Framework API, as described
8187  * in <sys/dtrace.h>.
8188  */
8189 int
8190 dtrace_meta_register(const char *name, const dtrace_mops_t *mops, void *arg,
8191     dtrace_meta_provider_id_t *idp)
8192 {
8193         dtrace_meta_t *meta;
8194         dtrace_helpers_t *help, *next;
8195         int i;
8196 
8197         *idp = DTRACE_METAPROVNONE;
8198 
8199         /*
8200          * We strictly don't need the name, but we hold onto it for
8201          * debuggability. All hail error queues!
8202          */
8203         if (name == NULL) {
8204                 cmn_err(CE_WARN, "failed to register meta-provider: "
8205                     "invalid name");
8206                 return (EINVAL);
8207         }
8208 
8209         if (mops == NULL ||
8210             mops->dtms_create_probe == NULL ||
8211             mops->dtms_provide_pid == NULL ||
8212             mops->dtms_remove_pid == NULL) {
8213                 cmn_err(CE_WARN, "failed to register meta-register %s: "
8214                     "invalid ops", name);
8215                 return (EINVAL);
8216         }
8217 
8218         meta = kmem_zalloc(sizeof (dtrace_meta_t), KM_SLEEP);
8219         meta->dtm_mops = *mops;
8220         meta->dtm_name = kmem_alloc(strlen(name) + 1, KM_SLEEP);
8221         (void) strcpy(meta->dtm_name, name);
8222         meta->dtm_arg = arg;
8223 
8224         mutex_enter(&dtrace_meta_lock);
8225         mutex_enter(&dtrace_lock);
8226 
8227         if (dtrace_meta_pid != NULL) {
8228                 mutex_exit(&dtrace_lock);
8229                 mutex_exit(&dtrace_meta_lock);
8230                 cmn_err(CE_WARN, "failed to register meta-register %s: "
8231                     "user-land meta-provider exists", name);
8232                 kmem_free(meta->dtm_name, strlen(meta->dtm_name) + 1);
8233                 kmem_free(meta, sizeof (dtrace_meta_t));
8234                 return (EINVAL);
8235         }
8236 
8237         dtrace_meta_pid = meta;
8238         *idp = (dtrace_meta_provider_id_t)meta;
8239 
8240         /*
8241          * If there are providers and probes ready to go, pass them
8242          * off to the new meta provider now.
8243          */
8244 
8245         help = dtrace_deferred_pid;
8246         dtrace_deferred_pid = NULL;
8247 
8248         mutex_exit(&dtrace_lock);
8249 
8250         while (help != NULL) {
8251                 for (i = 0; i < help->dthps_nprovs; i++) {
8252                         dtrace_helper_provide(&help->dthps_provs[i]->dthp_prov,
8253                             help->dthps_pid);
8254                 }
8255 
8256                 next = help->dthps_next;
8257                 help->dthps_next = NULL;
8258                 help->dthps_prev = NULL;
8259                 help->dthps_deferred = 0;
8260                 help = next;
8261         }
8262 
8263         mutex_exit(&dtrace_meta_lock);
8264 
8265         return (0);
8266 }
8267 
8268 int
8269 dtrace_meta_unregister(dtrace_meta_provider_id_t id)
8270 {
8271         dtrace_meta_t **pp, *old = (dtrace_meta_t *)id;
8272 
8273         mutex_enter(&dtrace_meta_lock);
8274         mutex_enter(&dtrace_lock);
8275 
8276         if (old == dtrace_meta_pid) {
8277                 pp = &dtrace_meta_pid;
8278         } else {
8279                 panic("attempt to unregister non-existent "
8280                     "dtrace meta-provider %p\n", (void *)old);
8281         }
8282 
8283         if (old->dtm_count != 0) {
8284                 mutex_exit(&dtrace_lock);
8285                 mutex_exit(&dtrace_meta_lock);
8286                 return (EBUSY);
8287         }
8288 
8289         *pp = NULL;
8290 
8291         mutex_exit(&dtrace_lock);
8292         mutex_exit(&dtrace_meta_lock);
8293 
8294         kmem_free(old->dtm_name, strlen(old->dtm_name) + 1);
8295         kmem_free(old, sizeof (dtrace_meta_t));
8296 
8297         return (0);
8298 }
8299 
8300 
8301 /*
8302  * DTrace DIF Object Functions
8303  */
8304 static int
8305 dtrace_difo_err(uint_t pc, const char *format, ...)
8306 {
8307         if (dtrace_err_verbose) {
8308                 va_list alist;
8309 
8310                 (void) uprintf("dtrace DIF object error: [%u]: ", pc);
8311                 va_start(alist, format);
8312                 (void) vuprintf(format, alist);
8313                 va_end(alist);
8314         }
8315 
8316 #ifdef DTRACE_ERRDEBUG
8317         dtrace_errdebug(format);
8318 #endif
8319         return (1);
8320 }
8321 
8322 /*
8323  * Validate a DTrace DIF object by checking the IR instructions.  The following
8324  * rules are currently enforced by dtrace_difo_validate():
8325  *
8326  * 1. Each instruction must have a valid opcode
8327  * 2. Each register, string, variable, or subroutine reference must be valid
8328  * 3. No instruction can modify register %r0 (must be zero)
8329  * 4. All instruction reserved bits must be set to zero
8330  * 5. The last instruction must be a "ret" instruction
8331  * 6. All branch targets must reference a valid instruction _after_ the branch
8332  */
8333 static int
8334 dtrace_difo_validate(dtrace_difo_t *dp, dtrace_vstate_t *vstate, uint_t nregs,
8335     cred_t *cr)
8336 {
8337         int err = 0, i;
8338         int (*efunc)(uint_t pc, const char *, ...) = dtrace_difo_err;
8339         int kcheckload;
8340         uint_t pc;
8341 
8342         kcheckload = cr == NULL ||
8343             (vstate->dtvs_state->dts_cred.dcr_visible & DTRACE_CRV_KERNEL) == 0;
8344 
8345         dp->dtdo_destructive = 0;
8346 
8347         for (pc = 0; pc < dp->dtdo_len && err == 0; pc++) {
8348                 dif_instr_t instr = dp->dtdo_buf[pc];
8349 
8350                 uint_t r1 = DIF_INSTR_R1(instr);
8351                 uint_t r2 = DIF_INSTR_R2(instr);
8352                 uint_t rd = DIF_INSTR_RD(instr);
8353                 uint_t rs = DIF_INSTR_RS(instr);
8354                 uint_t label = DIF_INSTR_LABEL(instr);
8355                 uint_t v = DIF_INSTR_VAR(instr);
8356                 uint_t subr = DIF_INSTR_SUBR(instr);
8357                 uint_t type = DIF_INSTR_TYPE(instr);
8358                 uint_t op = DIF_INSTR_OP(instr);
8359 
8360                 switch (op) {
8361                 case DIF_OP_OR:
8362                 case DIF_OP_XOR:
8363                 case DIF_OP_AND:
8364                 case DIF_OP_SLL:
8365                 case DIF_OP_SRL:
8366                 case DIF_OP_SRA:
8367                 case DIF_OP_SUB:
8368                 case DIF_OP_ADD:
8369                 case DIF_OP_MUL:
8370                 case DIF_OP_SDIV:
8371                 case DIF_OP_UDIV:
8372                 case DIF_OP_SREM:
8373                 case DIF_OP_UREM:
8374                 case DIF_OP_COPYS:
8375                         if (r1 >= nregs)
8376                                 err += efunc(pc, "invalid register %u\n", r1);
8377                         if (r2 >= nregs)
8378                                 err += efunc(pc, "invalid register %u\n", r2);
8379                         if (rd >= nregs)
8380                                 err += efunc(pc, "invalid register %u\n", rd);
8381                         if (rd == 0)
8382                                 err += efunc(pc, "cannot write to %r0\n");
8383                         break;
8384                 case DIF_OP_NOT:
8385                 case DIF_OP_MOV:
8386                 case DIF_OP_ALLOCS:
8387                         if (r1 >= nregs)
8388                                 err += efunc(pc, "invalid register %u\n", r1);
8389                         if (r2 != 0)
8390                                 err += efunc(pc, "non-zero reserved bits\n");
8391                         if (rd >= nregs)
8392                                 err += efunc(pc, "invalid register %u\n", rd);
8393                         if (rd == 0)
8394                                 err += efunc(pc, "cannot write to %r0\n");
8395                         break;
8396                 case DIF_OP_LDSB:
8397                 case DIF_OP_LDSH:
8398                 case DIF_OP_LDSW:
8399                 case DIF_OP_LDUB:
8400                 case DIF_OP_LDUH:
8401                 case DIF_OP_LDUW:
8402                 case DIF_OP_LDX:
8403                         if (r1 >= nregs)
8404                                 err += efunc(pc, "invalid register %u\n", r1);
8405                         if (r2 != 0)
8406                                 err += efunc(pc, "non-zero reserved bits\n");
8407                         if (rd >= nregs)
8408                                 err += efunc(pc, "invalid register %u\n", rd);
8409                         if (rd == 0)
8410                                 err += efunc(pc, "cannot write to %r0\n");
8411                         if (kcheckload)
8412                                 dp->dtdo_buf[pc] = DIF_INSTR_LOAD(op +
8413                                     DIF_OP_RLDSB - DIF_OP_LDSB, r1, rd);
8414                         break;
8415                 case DIF_OP_RLDSB:
8416                 case DIF_OP_RLDSH:
8417                 case DIF_OP_RLDSW:
8418                 case DIF_OP_RLDUB:
8419                 case DIF_OP_RLDUH:
8420                 case DIF_OP_RLDUW:
8421                 case DIF_OP_RLDX:
8422                         if (r1 >= nregs)
8423                                 err += efunc(pc, "invalid register %u\n", r1);
8424                         if (r2 != 0)
8425                                 err += efunc(pc, "non-zero reserved bits\n");
8426                         if (rd >= nregs)
8427                                 err += efunc(pc, "invalid register %u\n", rd);
8428                         if (rd == 0)
8429                                 err += efunc(pc, "cannot write to %r0\n");
8430                         break;
8431                 case DIF_OP_ULDSB:
8432                 case DIF_OP_ULDSH:
8433                 case DIF_OP_ULDSW:
8434                 case DIF_OP_ULDUB:
8435                 case DIF_OP_ULDUH:
8436                 case DIF_OP_ULDUW:
8437                 case DIF_OP_ULDX:
8438                         if (r1 >= nregs)
8439                                 err += efunc(pc, "invalid register %u\n", r1);
8440                         if (r2 != 0)
8441                                 err += efunc(pc, "non-zero reserved bits\n");
8442                         if (rd >= nregs)
8443                                 err += efunc(pc, "invalid register %u\n", rd);
8444                         if (rd == 0)
8445                                 err += efunc(pc, "cannot write to %r0\n");
8446                         break;
8447                 case DIF_OP_STB:
8448                 case DIF_OP_STH:
8449                 case DIF_OP_STW:
8450                 case DIF_OP_STX:
8451                         if (r1 >= nregs)
8452                                 err += efunc(pc, "invalid register %u\n", r1);
8453                         if (r2 != 0)
8454                                 err += efunc(pc, "non-zero reserved bits\n");
8455                         if (rd >= nregs)
8456                                 err += efunc(pc, "invalid register %u\n", rd);
8457                         if (rd == 0)
8458                                 err += efunc(pc, "cannot write to 0 address\n");
8459                         break;
8460                 case DIF_OP_CMP:
8461                 case DIF_OP_SCMP:
8462                         if (r1 >= nregs)
8463                                 err += efunc(pc, "invalid register %u\n", r1);
8464                         if (r2 >= nregs)
8465                                 err += efunc(pc, "invalid register %u\n", r2);
8466                         if (rd != 0)
8467                                 err += efunc(pc, "non-zero reserved bits\n");
8468                         break;
8469                 case DIF_OP_TST:
8470                         if (r1 >= nregs)
8471                                 err += efunc(pc, "invalid register %u\n", r1);
8472                         if (r2 != 0 || rd != 0)
8473                                 err += efunc(pc, "non-zero reserved bits\n");
8474                         break;
8475                 case DIF_OP_BA:
8476                 case DIF_OP_BE:
8477                 case DIF_OP_BNE:
8478                 case DIF_OP_BG:
8479                 case DIF_OP_BGU:
8480                 case DIF_OP_BGE:
8481                 case DIF_OP_BGEU:
8482                 case DIF_OP_BL:
8483                 case DIF_OP_BLU:
8484                 case DIF_OP_BLE:
8485                 case DIF_OP_BLEU:
8486                         if (label >= dp->dtdo_len) {
8487                                 err += efunc(pc, "invalid branch target %u\n",
8488                                     label);
8489                         }
8490                         if (label <= pc) {
8491                                 err += efunc(pc, "backward branch to %u\n",
8492                                     label);
8493                         }
8494                         break;
8495                 case DIF_OP_RET:
8496                         if (r1 != 0 || r2 != 0)
8497                                 err += efunc(pc, "non-zero reserved bits\n");
8498                         if (rd >= nregs)
8499                                 err += efunc(pc, "invalid register %u\n", rd);
8500                         break;
8501                 case DIF_OP_NOP:
8502                 case DIF_OP_POPTS:
8503                 case DIF_OP_FLUSHTS:
8504                         if (r1 != 0 || r2 != 0 || rd != 0)
8505                                 err += efunc(pc, "non-zero reserved bits\n");
8506                         break;
8507                 case DIF_OP_SETX:
8508                         if (DIF_INSTR_INTEGER(instr) >= dp->dtdo_intlen) {
8509                                 err += efunc(pc, "invalid integer ref %u\n",
8510                                     DIF_INSTR_INTEGER(instr));
8511                         }
8512                         if (rd >= nregs)
8513                                 err += efunc(pc, "invalid register %u\n", rd);
8514                         if (rd == 0)
8515                                 err += efunc(pc, "cannot write to %r0\n");
8516                         break;
8517                 case DIF_OP_SETS:
8518                         if (DIF_INSTR_STRING(instr) >= dp->dtdo_strlen) {
8519                                 err += efunc(pc, "invalid string ref %u\n",
8520                                     DIF_INSTR_STRING(instr));
8521                         }
8522                         if (rd >= nregs)
8523                                 err += efunc(pc, "invalid register %u\n", rd);
8524                         if (rd == 0)
8525                                 err += efunc(pc, "cannot write to %r0\n");
8526                         break;
8527                 case DIF_OP_LDGA:
8528                 case DIF_OP_LDTA:
8529                         if (r1 > DIF_VAR_ARRAY_MAX)
8530                                 err += efunc(pc, "invalid array %u\n", r1);
8531                         if (r2 >= nregs)
8532                                 err += efunc(pc, "invalid register %u\n", r2);
8533                         if (rd >= nregs)
8534                                 err += efunc(pc, "invalid register %u\n", rd);
8535                         if (rd == 0)
8536                                 err += efunc(pc, "cannot write to %r0\n");
8537                         break;
8538                 case DIF_OP_LDGS:
8539                 case DIF_OP_LDTS:
8540                 case DIF_OP_LDLS:
8541                 case DIF_OP_LDGAA:
8542                 case DIF_OP_LDTAA:
8543                         if (v < DIF_VAR_OTHER_MIN || v > DIF_VAR_OTHER_MAX)
8544                                 err += efunc(pc, "invalid variable %u\n", v);
8545                         if (rd >= nregs)
8546                                 err += efunc(pc, "invalid register %u\n", rd);
8547                         if (rd == 0)
8548                                 err += efunc(pc, "cannot write to %r0\n");
8549                         break;
8550                 case DIF_OP_STGS:
8551                 case DIF_OP_STTS:
8552                 case DIF_OP_STLS:
8553                 case DIF_OP_STGAA:
8554                 case DIF_OP_STTAA:
8555                         if (v < DIF_VAR_OTHER_UBASE || v > DIF_VAR_OTHER_MAX)
8556                                 err += efunc(pc, "invalid variable %u\n", v);
8557                         if (rs >= nregs)
8558                                 err += efunc(pc, "invalid register %u\n", rd);
8559                         break;
8560                 case DIF_OP_CALL:
8561                         if (subr > DIF_SUBR_MAX)
8562                                 err += efunc(pc, "invalid subr %u\n", subr);
8563                         if (rd >= nregs)
8564                                 err += efunc(pc, "invalid register %u\n", rd);
8565                         if (rd == 0)
8566                                 err += efunc(pc, "cannot write to %r0\n");
8567 
8568                         if (subr == DIF_SUBR_COPYOUT ||
8569                             subr == DIF_SUBR_COPYOUTSTR) {
8570                                 dp->dtdo_destructive = 1;
8571                         }
8572 
8573                         if (subr == DIF_SUBR_GETF) {
8574                                 /*
8575                                  * If we have a getf() we need to record that
8576                                  * in our state.  Note that our state can be
8577                                  * NULL if this is a helper -- but in that
8578                                  * case, the call to getf() is itself illegal,
8579                                  * and will be caught (slightly later) when
8580                                  * the helper is validated.
8581                                  */
8582                                 if (vstate->dtvs_state != NULL)
8583                                         vstate->dtvs_state->dts_getf++;
8584                         }
8585 
8586                         break;
8587                 case DIF_OP_PUSHTR:
8588                         if (type != DIF_TYPE_STRING && type != DIF_TYPE_CTF)
8589                                 err += efunc(pc, "invalid ref type %u\n", type);
8590                         if (r2 >= nregs)
8591                                 err += efunc(pc, "invalid register %u\n", r2);
8592                         if (rs >= nregs)
8593                                 err += efunc(pc, "invalid register %u\n", rs);
8594                         break;
8595                 case DIF_OP_PUSHTV:
8596                         if (type != DIF_TYPE_CTF)
8597                                 err += efunc(pc, "invalid val type %u\n", type);
8598                         if (r2 >= nregs)
8599                                 err += efunc(pc, "invalid register %u\n", r2);
8600                         if (rs >= nregs)
8601                                 err += efunc(pc, "invalid register %u\n", rs);
8602                         break;
8603                 default:
8604                         err += efunc(pc, "invalid opcode %u\n",
8605                             DIF_INSTR_OP(instr));
8606                 }
8607         }
8608 
8609         if (dp->dtdo_len != 0 &&
8610             DIF_INSTR_OP(dp->dtdo_buf[dp->dtdo_len - 1]) != DIF_OP_RET) {
8611                 err += efunc(dp->dtdo_len - 1,
8612                     "expected 'ret' as last DIF instruction\n");
8613         }
8614 
8615         if (!(dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF)) {
8616                 /*
8617                  * If we're not returning by reference, the size must be either
8618                  * 0 or the size of one of the base types.
8619                  */
8620                 switch (dp->dtdo_rtype.dtdt_size) {
8621                 case 0:
8622                 case sizeof (uint8_t):
8623                 case sizeof (uint16_t):
8624                 case sizeof (uint32_t):
8625                 case sizeof (uint64_t):
8626                         break;
8627 
8628                 default:
8629                         err += efunc(dp->dtdo_len - 1, "bad return size\n");
8630                 }
8631         }
8632 
8633         for (i = 0; i < dp->dtdo_varlen && err == 0; i++) {
8634                 dtrace_difv_t *v = &dp->dtdo_vartab[i], *existing = NULL;
8635                 dtrace_diftype_t *vt, *et;
8636                 uint_t id, ndx;
8637 
8638                 if (v->dtdv_scope != DIFV_SCOPE_GLOBAL &&
8639                     v->dtdv_scope != DIFV_SCOPE_THREAD &&
8640                     v->dtdv_scope != DIFV_SCOPE_LOCAL) {
8641                         err += efunc(i, "unrecognized variable scope %d\n",
8642                             v->dtdv_scope);
8643                         break;
8644                 }
8645 
8646                 if (v->dtdv_kind != DIFV_KIND_ARRAY &&
8647                     v->dtdv_kind != DIFV_KIND_SCALAR) {
8648                         err += efunc(i, "unrecognized variable type %d\n",
8649                             v->dtdv_kind);
8650                         break;
8651                 }
8652 
8653                 if ((id = v->dtdv_id) > DIF_VARIABLE_MAX) {
8654                         err += efunc(i, "%d exceeds variable id limit\n", id);
8655                         break;
8656                 }
8657 
8658                 if (id < DIF_VAR_OTHER_UBASE)
8659                         continue;
8660 
8661                 /*
8662                  * For user-defined variables, we need to check that this
8663                  * definition is identical to any previous definition that we
8664                  * encountered.
8665                  */
8666                 ndx = id - DIF_VAR_OTHER_UBASE;
8667 
8668                 switch (v->dtdv_scope) {
8669                 case DIFV_SCOPE_GLOBAL:
8670                         if (ndx < vstate->dtvs_nglobals) {
8671                                 dtrace_statvar_t *svar;
8672 
8673                                 if ((svar = vstate->dtvs_globals[ndx]) != NULL)
8674                                         existing = &svar->dtsv_var;
8675                         }
8676 
8677                         break;
8678 
8679                 case DIFV_SCOPE_THREAD:
8680                         if (ndx < vstate->dtvs_ntlocals)
8681                                 existing = &vstate->dtvs_tlocals[ndx];
8682                         break;
8683 
8684                 case DIFV_SCOPE_LOCAL:
8685                         if (ndx < vstate->dtvs_nlocals) {
8686                                 dtrace_statvar_t *svar;
8687 
8688                                 if ((svar = vstate->dtvs_locals[ndx]) != NULL)
8689                                         existing = &svar->dtsv_var;
8690                         }
8691 
8692                         break;
8693                 }
8694 
8695                 vt = &v->dtdv_type;
8696 
8697                 if (vt->dtdt_flags & DIF_TF_BYREF) {
8698                         if (vt->dtdt_size == 0) {
8699                                 err += efunc(i, "zero-sized variable\n");
8700                                 break;
8701                         }
8702 
8703                         if (v->dtdv_scope == DIFV_SCOPE_GLOBAL &&
8704                             vt->dtdt_size > dtrace_global_maxsize) {
8705                                 err += efunc(i, "oversized by-ref global\n");
8706                                 break;
8707                         }
8708                 }
8709 
8710                 if (existing == NULL || existing->dtdv_id == 0)
8711                         continue;
8712 
8713                 ASSERT(existing->dtdv_id == v->dtdv_id);
8714                 ASSERT(existing->dtdv_scope == v->dtdv_scope);
8715 
8716                 if (existing->dtdv_kind != v->dtdv_kind)
8717                         err += efunc(i, "%d changed variable kind\n", id);
8718 
8719                 et = &existing->dtdv_type;
8720 
8721                 if (vt->dtdt_flags != et->dtdt_flags) {
8722                         err += efunc(i, "%d changed variable type flags\n", id);
8723                         break;
8724                 }
8725 
8726                 if (vt->dtdt_size != 0 && vt->dtdt_size != et->dtdt_size) {
8727                         err += efunc(i, "%d changed variable type size\n", id);
8728                         break;
8729                 }
8730         }
8731 
8732         return (err);
8733 }
8734 
8735 /*
8736  * Validate a DTrace DIF object that it is to be used as a helper.  Helpers
8737  * are much more constrained than normal DIFOs.  Specifically, they may
8738  * not:
8739  *
8740  * 1. Make calls to subroutines other than copyin(), copyinstr() or
8741  *    miscellaneous string routines
8742  * 2. Access DTrace variables other than the args[] array, and the
8743  *    curthread, pid, ppid, tid, execname, zonename, uid and gid variables.
8744  * 3. Have thread-local variables.
8745  * 4. Have dynamic variables.
8746  */
8747 static int
8748 dtrace_difo_validate_helper(dtrace_difo_t *dp)
8749 {
8750         int (*efunc)(uint_t pc, const char *, ...) = dtrace_difo_err;
8751         int err = 0;
8752         uint_t pc;
8753 
8754         for (pc = 0; pc < dp->dtdo_len; pc++) {
8755                 dif_instr_t instr = dp->dtdo_buf[pc];
8756 
8757                 uint_t v = DIF_INSTR_VAR(instr);
8758                 uint_t subr = DIF_INSTR_SUBR(instr);
8759                 uint_t op = DIF_INSTR_OP(instr);
8760 
8761                 switch (op) {
8762                 case DIF_OP_OR:
8763                 case DIF_OP_XOR:
8764                 case DIF_OP_AND:
8765                 case DIF_OP_SLL:
8766                 case DIF_OP_SRL:
8767                 case DIF_OP_SRA:
8768                 case DIF_OP_SUB:
8769                 case DIF_OP_ADD:
8770                 case DIF_OP_MUL:
8771                 case DIF_OP_SDIV:
8772                 case DIF_OP_UDIV:
8773                 case DIF_OP_SREM:
8774                 case DIF_OP_UREM:
8775                 case DIF_OP_COPYS:
8776                 case DIF_OP_NOT:
8777                 case DIF_OP_MOV:
8778                 case DIF_OP_RLDSB:
8779                 case DIF_OP_RLDSH:
8780                 case DIF_OP_RLDSW:
8781                 case DIF_OP_RLDUB:
8782                 case DIF_OP_RLDUH:
8783                 case DIF_OP_RLDUW:
8784                 case DIF_OP_RLDX:
8785                 case DIF_OP_ULDSB:
8786                 case DIF_OP_ULDSH:
8787                 case DIF_OP_ULDSW:
8788                 case DIF_OP_ULDUB:
8789                 case DIF_OP_ULDUH:
8790                 case DIF_OP_ULDUW:
8791                 case DIF_OP_ULDX:
8792                 case DIF_OP_STB:
8793                 case DIF_OP_STH:
8794                 case DIF_OP_STW:
8795                 case DIF_OP_STX:
8796                 case DIF_OP_ALLOCS:
8797                 case DIF_OP_CMP:
8798                 case DIF_OP_SCMP:
8799                 case DIF_OP_TST:
8800                 case DIF_OP_BA:
8801                 case DIF_OP_BE:
8802                 case DIF_OP_BNE:
8803                 case DIF_OP_BG:
8804                 case DIF_OP_BGU:
8805                 case DIF_OP_BGE:
8806                 case DIF_OP_BGEU:
8807                 case DIF_OP_BL:
8808                 case DIF_OP_BLU:
8809                 case DIF_OP_BLE:
8810                 case DIF_OP_BLEU:
8811                 case DIF_OP_RET:
8812                 case DIF_OP_NOP:
8813                 case DIF_OP_POPTS:
8814                 case DIF_OP_FLUSHTS:
8815                 case DIF_OP_SETX:
8816                 case DIF_OP_SETS:
8817                 case DIF_OP_LDGA:
8818                 case DIF_OP_LDLS:
8819                 case DIF_OP_STGS:
8820                 case DIF_OP_STLS:
8821                 case DIF_OP_PUSHTR:
8822                 case DIF_OP_PUSHTV:
8823                         break;
8824 
8825                 case DIF_OP_LDGS:
8826                         if (v >= DIF_VAR_OTHER_UBASE)
8827                                 break;
8828 
8829                         if (v >= DIF_VAR_ARG0 && v <= DIF_VAR_ARG9)
8830                                 break;
8831 
8832                         if (v == DIF_VAR_CURTHREAD || v == DIF_VAR_PID ||
8833                             v == DIF_VAR_PPID || v == DIF_VAR_TID ||
8834                             v == DIF_VAR_EXECNAME || v == DIF_VAR_ZONENAME ||
8835                             v == DIF_VAR_UID || v == DIF_VAR_GID)
8836                                 break;
8837 
8838                         err += efunc(pc, "illegal variable %u\n", v);
8839                         break;
8840 
8841                 case DIF_OP_LDTA:
8842                 case DIF_OP_LDTS:
8843                 case DIF_OP_LDGAA:
8844                 case DIF_OP_LDTAA:
8845                         err += efunc(pc, "illegal dynamic variable load\n");
8846                         break;
8847 
8848                 case DIF_OP_STTS:
8849                 case DIF_OP_STGAA:
8850                 case DIF_OP_STTAA:
8851                         err += efunc(pc, "illegal dynamic variable store\n");
8852                         break;
8853 
8854                 case DIF_OP_CALL:
8855                         if (subr == DIF_SUBR_ALLOCA ||
8856                             subr == DIF_SUBR_BCOPY ||
8857                             subr == DIF_SUBR_COPYIN ||
8858                             subr == DIF_SUBR_COPYINTO ||
8859                             subr == DIF_SUBR_COPYINSTR ||
8860                             subr == DIF_SUBR_INDEX ||
8861                             subr == DIF_SUBR_INET_NTOA ||
8862                             subr == DIF_SUBR_INET_NTOA6 ||
8863                             subr == DIF_SUBR_INET_NTOP ||
8864                             subr == DIF_SUBR_LLTOSTR ||
8865                             subr == DIF_SUBR_RINDEX ||
8866                             subr == DIF_SUBR_STRCHR ||
8867                             subr == DIF_SUBR_STRJOIN ||
8868                             subr == DIF_SUBR_STRRCHR ||
8869                             subr == DIF_SUBR_STRSTR ||
8870                             subr == DIF_SUBR_HTONS ||
8871                             subr == DIF_SUBR_HTONL ||
8872                             subr == DIF_SUBR_HTONLL ||
8873                             subr == DIF_SUBR_NTOHS ||
8874                             subr == DIF_SUBR_NTOHL ||
8875                             subr == DIF_SUBR_NTOHLL)
8876                                 break;
8877 
8878                         err += efunc(pc, "invalid subr %u\n", subr);
8879                         break;
8880 
8881                 default:
8882                         err += efunc(pc, "invalid opcode %u\n",
8883                             DIF_INSTR_OP(instr));
8884                 }
8885         }
8886 
8887         return (err);
8888 }
8889 
8890 /*
8891  * Returns 1 if the expression in the DIF object can be cached on a per-thread
8892  * basis; 0 if not.
8893  */
8894 static int
8895 dtrace_difo_cacheable(dtrace_difo_t *dp)
8896 {
8897         int i;
8898 
8899         if (dp == NULL)
8900                 return (0);
8901 
8902         for (i = 0; i < dp->dtdo_varlen; i++) {
8903                 dtrace_difv_t *v = &dp->dtdo_vartab[i];
8904 
8905                 if (v->dtdv_scope != DIFV_SCOPE_GLOBAL)
8906                         continue;
8907 
8908                 switch (v->dtdv_id) {
8909                 case DIF_VAR_CURTHREAD:
8910                 case DIF_VAR_PID:
8911                 case DIF_VAR_TID:
8912                 case DIF_VAR_EXECNAME:
8913                 case DIF_VAR_ZONENAME:
8914                         break;
8915 
8916                 default:
8917                         return (0);
8918                 }
8919         }
8920 
8921         /*
8922          * This DIF object may be cacheable.  Now we need to look for any
8923          * array loading instructions, any memory loading instructions, or
8924          * any stores to thread-local variables.
8925          */
8926         for (i = 0; i < dp->dtdo_len; i++) {
8927                 uint_t op = DIF_INSTR_OP(dp->dtdo_buf[i]);
8928 
8929                 if ((op >= DIF_OP_LDSB && op <= DIF_OP_LDX) ||
8930                     (op >= DIF_OP_ULDSB && op <= DIF_OP_ULDX) ||
8931                     (op >= DIF_OP_RLDSB && op <= DIF_OP_RLDX) ||
8932                     op == DIF_OP_LDGA || op == DIF_OP_STTS)
8933                         return (0);
8934         }
8935 
8936         return (1);
8937 }
8938 
8939 static void
8940 dtrace_difo_hold(dtrace_difo_t *dp)
8941 {
8942         int i;
8943 
8944         ASSERT(MUTEX_HELD(&dtrace_lock));
8945 
8946         dp->dtdo_refcnt++;
8947         ASSERT(dp->dtdo_refcnt != 0);
8948 
8949         /*
8950          * We need to check this DIF object for references to the variable
8951          * DIF_VAR_VTIMESTAMP.
8952          */
8953         for (i = 0; i < dp->dtdo_varlen; i++) {
8954                 dtrace_difv_t *v = &dp->dtdo_vartab[i];
8955 
8956                 if (v->dtdv_id != DIF_VAR_VTIMESTAMP)
8957                         continue;
8958 
8959                 if (dtrace_vtime_references++ == 0)
8960                         dtrace_vtime_enable();
8961         }
8962 }
8963 
8964 /*
8965  * This routine calculates the dynamic variable chunksize for a given DIF
8966  * object.  The calculation is not fool-proof, and can probably be tricked by
8967  * malicious DIF -- but it works for all compiler-generated DIF.  Because this
8968  * calculation is likely imperfect, dtrace_dynvar() is able to gracefully fail
8969  * if a dynamic variable size exceeds the chunksize.
8970  */
8971 static void
8972 dtrace_difo_chunksize(dtrace_difo_t *dp, dtrace_vstate_t *vstate)
8973 {
8974         uint64_t sval;
8975         dtrace_key_t tupregs[DIF_DTR_NREGS + 2]; /* +2 for thread and id */
8976         const dif_instr_t *text = dp->dtdo_buf;
8977         uint_t pc, srd = 0;
8978         uint_t ttop = 0;
8979         size_t size, ksize;
8980         uint_t id, i;
8981 
8982         for (pc = 0; pc < dp->dtdo_len; pc++) {
8983                 dif_instr_t instr = text[pc];
8984                 uint_t op = DIF_INSTR_OP(instr);
8985                 uint_t rd = DIF_INSTR_RD(instr);
8986                 uint_t r1 = DIF_INSTR_R1(instr);
8987                 uint_t nkeys = 0;
8988                 uchar_t scope;
8989 
8990                 dtrace_key_t *key = tupregs;
8991 
8992                 switch (op) {
8993                 case DIF_OP_SETX:
8994                         sval = dp->dtdo_inttab[DIF_INSTR_INTEGER(instr)];
8995                         srd = rd;
8996                         continue;
8997 
8998                 case DIF_OP_STTS:
8999                         key = &tupregs[DIF_DTR_NREGS];
9000                         key[0].dttk_size = 0;
9001                         key[1].dttk_size = 0;
9002                         nkeys = 2;
9003                         scope = DIFV_SCOPE_THREAD;
9004                         break;
9005 
9006                 case DIF_OP_STGAA:
9007                 case DIF_OP_STTAA:
9008                         nkeys = ttop;
9009 
9010                         if (DIF_INSTR_OP(instr) == DIF_OP_STTAA)
9011                                 key[nkeys++].dttk_size = 0;
9012 
9013                         key[nkeys++].dttk_size = 0;
9014 
9015                         if (op == DIF_OP_STTAA) {
9016                                 scope = DIFV_SCOPE_THREAD;
9017                         } else {
9018                                 scope = DIFV_SCOPE_GLOBAL;
9019                         }
9020 
9021                         break;
9022 
9023                 case DIF_OP_PUSHTR:
9024                         if (ttop == DIF_DTR_NREGS)
9025                                 return;
9026 
9027                         if ((srd == 0 || sval == 0) && r1 == DIF_TYPE_STRING) {
9028                                 /*
9029                                  * If the register for the size of the "pushtr"
9030                                  * is %r0 (or the value is 0) and the type is
9031                                  * a string, we'll use the system-wide default
9032                                  * string size.
9033                                  */
9034                                 tupregs[ttop++].dttk_size =
9035                                     dtrace_strsize_default;
9036                         } else {
9037                                 if (srd == 0)
9038                                         return;
9039 
9040                                 tupregs[ttop++].dttk_size = sval;
9041                         }
9042 
9043                         break;
9044 
9045                 case DIF_OP_PUSHTV:
9046                         if (ttop == DIF_DTR_NREGS)
9047                                 return;
9048 
9049                         tupregs[ttop++].dttk_size = 0;
9050                         break;
9051 
9052                 case DIF_OP_FLUSHTS:
9053                         ttop = 0;
9054                         break;
9055 
9056                 case DIF_OP_POPTS:
9057                         if (ttop != 0)
9058                                 ttop--;
9059                         break;
9060                 }
9061 
9062                 sval = 0;
9063                 srd = 0;
9064 
9065                 if (nkeys == 0)
9066                         continue;
9067 
9068                 /*
9069                  * We have a dynamic variable allocation; calculate its size.
9070                  */
9071                 for (ksize = 0, i = 0; i < nkeys; i++)
9072                         ksize += P2ROUNDUP(key[i].dttk_size, sizeof (uint64_t));
9073 
9074                 size = sizeof (dtrace_dynvar_t);
9075                 size += sizeof (dtrace_key_t) * (nkeys - 1);
9076                 size += ksize;
9077 
9078                 /*
9079                  * Now we need to determine the size of the stored data.
9080                  */
9081                 id = DIF_INSTR_VAR(instr);
9082 
9083                 for (i = 0; i < dp->dtdo_varlen; i++) {
9084                         dtrace_difv_t *v = &dp->dtdo_vartab[i];
9085 
9086                         if (v->dtdv_id == id && v->dtdv_scope == scope) {
9087                                 size += v->dtdv_type.dtdt_size;
9088                                 break;
9089                         }
9090                 }
9091 
9092                 if (i == dp->dtdo_varlen)
9093                         return;
9094 
9095                 /*
9096                  * We have the size.  If this is larger than the chunk size
9097                  * for our dynamic variable state, reset the chunk size.
9098                  */
9099                 size = P2ROUNDUP(size, sizeof (uint64_t));
9100 
9101                 if (size > vstate->dtvs_dynvars.dtds_chunksize)
9102                         vstate->dtvs_dynvars.dtds_chunksize = size;
9103         }
9104 }
9105 
9106 static void
9107 dtrace_difo_init(dtrace_difo_t *dp, dtrace_vstate_t *vstate)
9108 {
9109         int i, oldsvars, osz, nsz, otlocals, ntlocals;
9110         uint_t id;
9111 
9112         ASSERT(MUTEX_HELD(&dtrace_lock));
9113         ASSERT(dp->dtdo_buf != NULL && dp->dtdo_len != 0);
9114 
9115         for (i = 0; i < dp->dtdo_varlen; i++) {
9116                 dtrace_difv_t *v = &dp->dtdo_vartab[i];
9117                 dtrace_statvar_t *svar, ***svarp;
9118                 size_t dsize = 0;
9119                 uint8_t scope = v->dtdv_scope;
9120                 int *np;
9121 
9122                 if ((id = v->dtdv_id) < DIF_VAR_OTHER_UBASE)
9123                         continue;
9124 
9125                 id -= DIF_VAR_OTHER_UBASE;
9126 
9127                 switch (scope) {
9128                 case DIFV_SCOPE_THREAD:
9129                         while (id >= (otlocals = vstate->dtvs_ntlocals)) {
9130                                 dtrace_difv_t *tlocals;
9131 
9132                                 if ((ntlocals = (otlocals << 1)) == 0)
9133                                         ntlocals = 1;
9134 
9135                                 osz = otlocals * sizeof (dtrace_difv_t);
9136                                 nsz = ntlocals * sizeof (dtrace_difv_t);
9137 
9138                                 tlocals = kmem_zalloc(nsz, KM_SLEEP);
9139 
9140                                 if (osz != 0) {
9141                                         bcopy(vstate->dtvs_tlocals,
9142                                             tlocals, osz);
9143                                         kmem_free(vstate->dtvs_tlocals, osz);
9144                                 }
9145 
9146                                 vstate->dtvs_tlocals = tlocals;
9147                                 vstate->dtvs_ntlocals = ntlocals;
9148                         }
9149 
9150                         vstate->dtvs_tlocals[id] = *v;
9151                         continue;
9152 
9153                 case DIFV_SCOPE_LOCAL:
9154                         np = &vstate->dtvs_nlocals;
9155                         svarp = &vstate->dtvs_locals;
9156 
9157                         if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF)
9158                                 dsize = NCPU * (v->dtdv_type.dtdt_size +
9159                                     sizeof (uint64_t));
9160                         else
9161                                 dsize = NCPU * sizeof (uint64_t);
9162 
9163                         break;
9164 
9165                 case DIFV_SCOPE_GLOBAL:
9166                         np = &vstate->dtvs_nglobals;
9167                         svarp = &vstate->dtvs_globals;
9168 
9169                         if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF)
9170                                 dsize = v->dtdv_type.dtdt_size +
9171                                     sizeof (uint64_t);
9172 
9173                         break;
9174 
9175                 default:
9176                         ASSERT(0);
9177                 }
9178 
9179                 while (id >= (oldsvars = *np)) {
9180                         dtrace_statvar_t **statics;
9181                         int newsvars, oldsize, newsize;
9182 
9183                         if ((newsvars = (oldsvars << 1)) == 0)
9184                                 newsvars = 1;
9185 
9186                         oldsize = oldsvars * sizeof (dtrace_statvar_t *);
9187                         newsize = newsvars * sizeof (dtrace_statvar_t *);
9188 
9189                         statics = kmem_zalloc(newsize, KM_SLEEP);
9190 
9191                         if (oldsize != 0) {
9192                                 bcopy(*svarp, statics, oldsize);
9193                                 kmem_free(*svarp, oldsize);
9194                         }
9195 
9196                         *svarp = statics;
9197                         *np = newsvars;
9198                 }
9199 
9200                 if ((svar = (*svarp)[id]) == NULL) {
9201                         svar = kmem_zalloc(sizeof (dtrace_statvar_t), KM_SLEEP);
9202                         svar->dtsv_var = *v;
9203 
9204                         if ((svar->dtsv_size = dsize) != 0) {
9205                                 svar->dtsv_data = (uint64_t)(uintptr_t)
9206                                     kmem_zalloc(dsize, KM_SLEEP);
9207                         }
9208 
9209                         (*svarp)[id] = svar;
9210                 }
9211 
9212                 svar->dtsv_refcnt++;
9213         }
9214 
9215         dtrace_difo_chunksize(dp, vstate);
9216         dtrace_difo_hold(dp);
9217 }
9218 
9219 static dtrace_difo_t *
9220 dtrace_difo_duplicate(dtrace_difo_t *dp, dtrace_vstate_t *vstate)
9221 {
9222         dtrace_difo_t *new;
9223         size_t sz;
9224 
9225         ASSERT(dp->dtdo_buf != NULL);
9226         ASSERT(dp->dtdo_refcnt != 0);
9227 
9228         new = kmem_zalloc(sizeof (dtrace_difo_t), KM_SLEEP);
9229 
9230         ASSERT(dp->dtdo_buf != NULL);
9231         sz = dp->dtdo_len * sizeof (dif_instr_t);
9232         new->dtdo_buf = kmem_alloc(sz, KM_SLEEP);
9233         bcopy(dp->dtdo_buf, new->dtdo_buf, sz);
9234         new->dtdo_len = dp->dtdo_len;
9235 
9236         if (dp->dtdo_strtab != NULL) {
9237                 ASSERT(dp->dtdo_strlen != 0);
9238                 new->dtdo_strtab = kmem_alloc(dp->dtdo_strlen, KM_SLEEP);
9239                 bcopy(dp->dtdo_strtab, new->dtdo_strtab, dp->dtdo_strlen);
9240                 new->dtdo_strlen = dp->dtdo_strlen;
9241         }
9242 
9243         if (dp->dtdo_inttab != NULL) {
9244                 ASSERT(dp->dtdo_intlen != 0);
9245                 sz = dp->dtdo_intlen * sizeof (uint64_t);
9246                 new->dtdo_inttab = kmem_alloc(sz, KM_SLEEP);
9247                 bcopy(dp->dtdo_inttab, new->dtdo_inttab, sz);
9248                 new->dtdo_intlen = dp->dtdo_intlen;
9249         }
9250 
9251         if (dp->dtdo_vartab != NULL) {
9252                 ASSERT(dp->dtdo_varlen != 0);
9253                 sz = dp->dtdo_varlen * sizeof (dtrace_difv_t);
9254                 new->dtdo_vartab = kmem_alloc(sz, KM_SLEEP);
9255                 bcopy(dp->dtdo_vartab, new->dtdo_vartab, sz);
9256                 new->dtdo_varlen = dp->dtdo_varlen;
9257         }
9258 
9259         dtrace_difo_init(new, vstate);
9260         return (new);
9261 }
9262 
9263 static void
9264 dtrace_difo_destroy(dtrace_difo_t *dp, dtrace_vstate_t *vstate)
9265 {
9266         int i;
9267 
9268         ASSERT(dp->dtdo_refcnt == 0);
9269 
9270         for (i = 0; i < dp->dtdo_varlen; i++) {
9271                 dtrace_difv_t *v = &dp->dtdo_vartab[i];
9272                 dtrace_statvar_t *svar, **svarp;
9273                 uint_t id;
9274                 uint8_t scope = v->dtdv_scope;
9275                 int *np;
9276 
9277                 switch (scope) {
9278                 case DIFV_SCOPE_THREAD:
9279                         continue;
9280 
9281                 case DIFV_SCOPE_LOCAL:
9282                         np = &vstate->dtvs_nlocals;
9283                         svarp = vstate->dtvs_locals;
9284                         break;
9285 
9286                 case DIFV_SCOPE_GLOBAL:
9287                         np = &vstate->dtvs_nglobals;
9288                         svarp = vstate->dtvs_globals;
9289                         break;
9290 
9291                 default:
9292                         ASSERT(0);
9293                 }
9294 
9295                 if ((id = v->dtdv_id) < DIF_VAR_OTHER_UBASE)
9296                         continue;
9297 
9298                 id -= DIF_VAR_OTHER_UBASE;
9299                 ASSERT(id < *np);
9300 
9301                 svar = svarp[id];
9302                 ASSERT(svar != NULL);
9303                 ASSERT(svar->dtsv_refcnt > 0);
9304 
9305                 if (--svar->dtsv_refcnt > 0)
9306                         continue;
9307 
9308                 if (svar->dtsv_size != 0) {
9309                         ASSERT(svar->dtsv_data != NULL);
9310                         kmem_free((void *)(uintptr_t)svar->dtsv_data,
9311                             svar->dtsv_size);
9312                 }
9313 
9314                 kmem_free(svar, sizeof (dtrace_statvar_t));
9315                 svarp[id] = NULL;
9316         }
9317 
9318         kmem_free(dp->dtdo_buf, dp->dtdo_len * sizeof (dif_instr_t));
9319         kmem_free(dp->dtdo_inttab, dp->dtdo_intlen * sizeof (uint64_t));
9320         kmem_free(dp->dtdo_strtab, dp->dtdo_strlen);
9321         kmem_free(dp->dtdo_vartab, dp->dtdo_varlen * sizeof (dtrace_difv_t));
9322 
9323         kmem_free(dp, sizeof (dtrace_difo_t));
9324 }
9325 
9326 static void
9327 dtrace_difo_release(dtrace_difo_t *dp, dtrace_vstate_t *vstate)
9328 {
9329         int i;
9330 
9331         ASSERT(MUTEX_HELD(&dtrace_lock));
9332         ASSERT(dp->dtdo_refcnt != 0);
9333 
9334         for (i = 0; i < dp->dtdo_varlen; i++) {
9335                 dtrace_difv_t *v = &dp->dtdo_vartab[i];
9336 
9337                 if (v->dtdv_id != DIF_VAR_VTIMESTAMP)
9338                         continue;
9339 
9340                 ASSERT(dtrace_vtime_references > 0);
9341                 if (--dtrace_vtime_references == 0)
9342                         dtrace_vtime_disable();
9343         }
9344 
9345         if (--dp->dtdo_refcnt == 0)
9346                 dtrace_difo_destroy(dp, vstate);
9347 }
9348 
9349 /*
9350  * DTrace Format Functions
9351  */
9352 static uint16_t
9353 dtrace_format_add(dtrace_state_t *state, char *str)
9354 {
9355         char *fmt, **new;
9356         uint16_t ndx, len = strlen(str) + 1;
9357 
9358         fmt = kmem_zalloc(len, KM_SLEEP);
9359         bcopy(str, fmt, len);
9360 
9361         for (ndx = 0; ndx < state->dts_nformats; ndx++) {
9362                 if (state->dts_formats[ndx] == NULL) {
9363                         state->dts_formats[ndx] = fmt;
9364                         return (ndx + 1);
9365                 }
9366         }
9367 
9368         if (state->dts_nformats == USHRT_MAX) {
9369                 /*
9370                  * This is only likely if a denial-of-service attack is being
9371                  * attempted.  As such, it's okay to fail silently here.
9372                  */
9373                 kmem_free(fmt, len);
9374                 return (0);
9375         }
9376 
9377         /*
9378          * For simplicity, we always resize the formats array to be exactly the
9379          * number of formats.
9380          */
9381         ndx = state->dts_nformats++;
9382         new = kmem_alloc((ndx + 1) * sizeof (char *), KM_SLEEP);
9383 
9384         if (state->dts_formats != NULL) {
9385                 ASSERT(ndx != 0);
9386                 bcopy(state->dts_formats, new, ndx * sizeof (char *));
9387                 kmem_free(state->dts_formats, ndx * sizeof (char *));
9388         }
9389 
9390         state->dts_formats = new;
9391         state->dts_formats[ndx] = fmt;
9392 
9393         return (ndx + 1);
9394 }
9395 
9396 static void
9397 dtrace_format_remove(dtrace_state_t *state, uint16_t format)
9398 {
9399         char *fmt;
9400 
9401         ASSERT(state->dts_formats != NULL);
9402         ASSERT(format <= state->dts_nformats);
9403         ASSERT(state->dts_formats[format - 1] != NULL);
9404 
9405         fmt = state->dts_formats[format - 1];
9406         kmem_free(fmt, strlen(fmt) + 1);
9407         state->dts_formats[format - 1] = NULL;
9408 }
9409 
9410 static void
9411 dtrace_format_destroy(dtrace_state_t *state)
9412 {
9413         int i;
9414 
9415         if (state->dts_nformats == 0) {
9416                 ASSERT(state->dts_formats == NULL);
9417                 return;
9418         }
9419 
9420         ASSERT(state->dts_formats != NULL);
9421 
9422         for (i = 0; i < state->dts_nformats; i++) {
9423                 char *fmt = state->dts_formats[i];
9424 
9425                 if (fmt == NULL)
9426                         continue;
9427 
9428                 kmem_free(fmt, strlen(fmt) + 1);
9429         }
9430 
9431         kmem_free(state->dts_formats, state->dts_nformats * sizeof (char *));
9432         state->dts_nformats = 0;
9433         state->dts_formats = NULL;
9434 }
9435 
9436 /*
9437  * DTrace Predicate Functions
9438  */
9439 static dtrace_predicate_t *
9440 dtrace_predicate_create(dtrace_difo_t *dp)
9441 {
9442         dtrace_predicate_t *pred;
9443 
9444         ASSERT(MUTEX_HELD(&dtrace_lock));
9445         ASSERT(dp->dtdo_refcnt != 0);
9446 
9447         pred = kmem_zalloc(sizeof (dtrace_predicate_t), KM_SLEEP);
9448         pred->dtp_difo = dp;
9449         pred->dtp_refcnt = 1;
9450 
9451         if (!dtrace_difo_cacheable(dp))
9452                 return (pred);
9453 
9454         if (dtrace_predcache_id == DTRACE_CACHEIDNONE) {
9455                 /*
9456                  * This is only theoretically possible -- we have had 2^32
9457                  * cacheable predicates on this machine.  We cannot allow any
9458                  * more predicates to become cacheable:  as unlikely as it is,
9459                  * there may be a thread caching a (now stale) predicate cache
9460                  * ID. (N.B.: the temptation is being successfully resisted to
9461                  * have this cmn_err() "Holy shit -- we executed this code!")
9462                  */
9463                 return (pred);
9464         }
9465 
9466         pred->dtp_cacheid = dtrace_predcache_id++;
9467 
9468         return (pred);
9469 }
9470 
9471 static void
9472 dtrace_predicate_hold(dtrace_predicate_t *pred)
9473 {
9474         ASSERT(MUTEX_HELD(&dtrace_lock));
9475         ASSERT(pred->dtp_difo != NULL && pred->dtp_difo->dtdo_refcnt != 0);
9476         ASSERT(pred->dtp_refcnt > 0);
9477 
9478         pred->dtp_refcnt++;
9479 }
9480 
9481 static void
9482 dtrace_predicate_release(dtrace_predicate_t *pred, dtrace_vstate_t *vstate)
9483 {
9484         dtrace_difo_t *dp = pred->dtp_difo;
9485 
9486         ASSERT(MUTEX_HELD(&dtrace_lock));
9487         ASSERT(dp != NULL && dp->dtdo_refcnt != 0);
9488         ASSERT(pred->dtp_refcnt > 0);
9489 
9490         if (--pred->dtp_refcnt == 0) {
9491                 dtrace_difo_release(pred->dtp_difo, vstate);
9492                 kmem_free(pred, sizeof (dtrace_predicate_t));
9493         }
9494 }
9495 
9496 /*
9497  * DTrace Action Description Functions
9498  */
9499 static dtrace_actdesc_t *
9500 dtrace_actdesc_create(dtrace_actkind_t kind, uint32_t ntuple,
9501     uint64_t uarg, uint64_t arg)
9502 {
9503         dtrace_actdesc_t *act;
9504 
9505         ASSERT(!DTRACEACT_ISPRINTFLIKE(kind) || (arg != NULL &&
9506             arg >= KERNELBASE) || (arg == NULL && kind == DTRACEACT_PRINTA));
9507 
9508         act = kmem_zalloc(sizeof (dtrace_actdesc_t), KM_SLEEP);
9509         act->dtad_kind = kind;
9510         act->dtad_ntuple = ntuple;
9511         act->dtad_uarg = uarg;
9512         act->dtad_arg = arg;
9513         act->dtad_refcnt = 1;
9514 
9515         return (act);
9516 }
9517 
9518 static void
9519 dtrace_actdesc_hold(dtrace_actdesc_t *act)
9520 {
9521         ASSERT(act->dtad_refcnt >= 1);
9522         act->dtad_refcnt++;
9523 }
9524 
9525 static void
9526 dtrace_actdesc_release(dtrace_actdesc_t *act, dtrace_vstate_t *vstate)
9527 {
9528         dtrace_actkind_t kind = act->dtad_kind;
9529         dtrace_difo_t *dp;
9530 
9531         ASSERT(act->dtad_refcnt >= 1);
9532 
9533         if (--act->dtad_refcnt != 0)
9534                 return;
9535 
9536         if ((dp = act->dtad_difo) != NULL)
9537                 dtrace_difo_release(dp, vstate);
9538 
9539         if (DTRACEACT_ISPRINTFLIKE(kind)) {
9540                 char *str = (char *)(uintptr_t)act->dtad_arg;
9541 
9542                 ASSERT((str != NULL && (uintptr_t)str >= KERNELBASE) ||
9543                     (str == NULL && act->dtad_kind == DTRACEACT_PRINTA));
9544 
9545                 if (str != NULL)
9546                         kmem_free(str, strlen(str) + 1);
9547         }
9548 
9549         kmem_free(act, sizeof (dtrace_actdesc_t));
9550 }
9551 
9552 /*
9553  * DTrace ECB Functions
9554  */
9555 static dtrace_ecb_t *
9556 dtrace_ecb_add(dtrace_state_t *state, dtrace_probe_t *probe)
9557 {
9558         dtrace_ecb_t *ecb;
9559         dtrace_epid_t epid;
9560 
9561         ASSERT(MUTEX_HELD(&dtrace_lock));
9562 
9563         ecb = kmem_zalloc(sizeof (dtrace_ecb_t), KM_SLEEP);
9564         ecb->dte_predicate = NULL;
9565         ecb->dte_probe = probe;
9566 
9567         /*
9568          * The default size is the size of the default action: recording
9569          * the header.
9570          */
9571         ecb->dte_size = ecb->dte_needed = sizeof (dtrace_rechdr_t);
9572         ecb->dte_alignment = sizeof (dtrace_epid_t);
9573 
9574         epid = state->dts_epid++;
9575 
9576         if (epid - 1 >= state->dts_necbs) {
9577                 dtrace_ecb_t **oecbs = state->dts_ecbs, **ecbs;
9578                 int necbs = state->dts_necbs << 1;
9579 
9580                 ASSERT(epid == state->dts_necbs + 1);
9581 
9582                 if (necbs == 0) {
9583                         ASSERT(oecbs == NULL);
9584                         necbs = 1;
9585                 }
9586 
9587                 ecbs = kmem_zalloc(necbs * sizeof (*ecbs), KM_SLEEP);
9588 
9589                 if (oecbs != NULL)
9590                         bcopy(oecbs, ecbs, state->dts_necbs * sizeof (*ecbs));
9591 
9592                 dtrace_membar_producer();
9593                 state->dts_ecbs = ecbs;
9594 
9595                 if (oecbs != NULL) {
9596                         /*
9597                          * If this state is active, we must dtrace_sync()
9598                          * before we can free the old dts_ecbs array:  we're
9599                          * coming in hot, and there may be active ring
9600                          * buffer processing (which indexes into the dts_ecbs
9601                          * array) on another CPU.
9602                          */
9603                         if (state->dts_activity != DTRACE_ACTIVITY_INACTIVE)
9604                                 dtrace_sync();
9605 
9606                         kmem_free(oecbs, state->dts_necbs * sizeof (*ecbs));
9607                 }
9608 
9609                 dtrace_membar_producer();
9610                 state->dts_necbs = necbs;
9611         }
9612 
9613         ecb->dte_state = state;
9614 
9615         ASSERT(state->dts_ecbs[epid - 1] == NULL);
9616         dtrace_membar_producer();
9617         state->dts_ecbs[(ecb->dte_epid = epid) - 1] = ecb;
9618 
9619         return (ecb);
9620 }
9621 
9622 static int
9623 dtrace_ecb_enable(dtrace_ecb_t *ecb)
9624 {
9625         dtrace_probe_t *probe = ecb->dte_probe;
9626 
9627         ASSERT(MUTEX_HELD(&cpu_lock));
9628         ASSERT(MUTEX_HELD(&dtrace_lock));
9629         ASSERT(ecb->dte_next == NULL);
9630 
9631         if (probe == NULL) {
9632                 /*
9633                  * This is the NULL probe -- there's nothing to do.
9634                  */
9635                 return (0);
9636         }
9637 
9638         if (probe->dtpr_ecb == NULL) {
9639                 dtrace_provider_t *prov = probe->dtpr_provider;
9640 
9641                 /*
9642                  * We're the first ECB on this probe.
9643                  */
9644                 probe->dtpr_ecb = probe->dtpr_ecb_last = ecb;
9645 
9646                 if (ecb->dte_predicate != NULL)
9647                         probe->dtpr_predcache = ecb->dte_predicate->dtp_cacheid;
9648 
9649                 return (prov->dtpv_pops.dtps_enable(prov->dtpv_arg,
9650                     probe->dtpr_id, probe->dtpr_arg));
9651         } else {
9652                 /*
9653                  * This probe is already active.  Swing the last pointer to
9654                  * point to the new ECB, and issue a dtrace_sync() to assure
9655                  * that all CPUs have seen the change.
9656                  */
9657                 ASSERT(probe->dtpr_ecb_last != NULL);
9658                 probe->dtpr_ecb_last->dte_next = ecb;
9659                 probe->dtpr_ecb_last = ecb;
9660                 probe->dtpr_predcache = 0;
9661 
9662                 dtrace_sync();
9663                 return (0);
9664         }
9665 }
9666 
9667 static void
9668 dtrace_ecb_resize(dtrace_ecb_t *ecb)
9669 {
9670         dtrace_action_t *act;
9671         uint32_t curneeded = UINT32_MAX;
9672         uint32_t aggbase = UINT32_MAX;
9673 
9674         /*
9675          * If we record anything, we always record the dtrace_rechdr_t.  (And
9676          * we always record it first.)
9677          */
9678         ecb->dte_size = sizeof (dtrace_rechdr_t);
9679         ecb->dte_alignment = sizeof (dtrace_epid_t);
9680 
9681         for (act = ecb->dte_action; act != NULL; act = act->dta_next) {
9682                 dtrace_recdesc_t *rec = &act->dta_rec;
9683                 ASSERT(rec->dtrd_size > 0 || rec->dtrd_alignment == 1);
9684 
9685                 ecb->dte_alignment = MAX(ecb->dte_alignment,
9686                     rec->dtrd_alignment);
9687 
9688                 if (DTRACEACT_ISAGG(act->dta_kind)) {
9689                         dtrace_aggregation_t *agg = (dtrace_aggregation_t *)act;
9690 
9691                         ASSERT(rec->dtrd_size != 0);
9692                         ASSERT(agg->dtag_first != NULL);
9693                         ASSERT(act->dta_prev->dta_intuple);
9694                         ASSERT(aggbase != UINT32_MAX);
9695                         ASSERT(curneeded != UINT32_MAX);
9696 
9697                         agg->dtag_base = aggbase;
9698 
9699                         curneeded = P2ROUNDUP(curneeded, rec->dtrd_alignment);
9700                         rec->dtrd_offset = curneeded;
9701                         curneeded += rec->dtrd_size;
9702                         ecb->dte_needed = MAX(ecb->dte_needed, curneeded);
9703 
9704                         aggbase = UINT32_MAX;
9705                         curneeded = UINT32_MAX;
9706                 } else if (act->dta_intuple) {
9707                         if (curneeded == UINT32_MAX) {
9708                                 /*
9709                                  * This is the first record in a tuple.  Align
9710                                  * curneeded to be at offset 4 in an 8-byte
9711                                  * aligned block.
9712                                  */
9713                                 ASSERT(act->dta_prev == NULL ||
9714                                     !act->dta_prev->dta_intuple);
9715                                 ASSERT3U(aggbase, ==, UINT32_MAX);
9716                                 curneeded = P2PHASEUP(ecb->dte_size,
9717                                     sizeof (uint64_t), sizeof (dtrace_aggid_t));
9718 
9719                                 aggbase = curneeded - sizeof (dtrace_aggid_t);
9720                                 ASSERT(IS_P2ALIGNED(aggbase,
9721                                     sizeof (uint64_t)));
9722                         }
9723                         curneeded = P2ROUNDUP(curneeded, rec->dtrd_alignment);
9724                         rec->dtrd_offset = curneeded;
9725                         curneeded += rec->dtrd_size;
9726                 } else {
9727                         /* tuples must be followed by an aggregation */
9728                         ASSERT(act->dta_prev == NULL ||
9729                             !act->dta_prev->dta_intuple);
9730 
9731                         ecb->dte_size = P2ROUNDUP(ecb->dte_size,
9732                             rec->dtrd_alignment);
9733                         rec->dtrd_offset = ecb->dte_size;
9734                         ecb->dte_size += rec->dtrd_size;
9735                         ecb->dte_needed = MAX(ecb->dte_needed, ecb->dte_size);
9736                 }
9737         }
9738 
9739         if ((act = ecb->dte_action) != NULL &&
9740             !(act->dta_kind == DTRACEACT_SPECULATE && act->dta_next == NULL) &&
9741             ecb->dte_size == sizeof (dtrace_rechdr_t)) {
9742                 /*
9743                  * If the size is still sizeof (dtrace_rechdr_t), then all
9744                  * actions store no data; set the size to 0.
9745                  */
9746                 ecb->dte_size = 0;
9747         }
9748 
9749         ecb->dte_size = P2ROUNDUP(ecb->dte_size, sizeof (dtrace_epid_t));
9750         ecb->dte_needed = P2ROUNDUP(ecb->dte_needed, (sizeof (dtrace_epid_t)));
9751         ecb->dte_state->dts_needed = MAX(ecb->dte_state->dts_needed,
9752             ecb->dte_needed);
9753 }
9754 
9755 static dtrace_action_t *
9756 dtrace_ecb_aggregation_create(dtrace_ecb_t *ecb, dtrace_actdesc_t *desc)
9757 {
9758         dtrace_aggregation_t *agg;
9759         size_t size = sizeof (uint64_t);
9760         int ntuple = desc->dtad_ntuple;
9761         dtrace_action_t *act;
9762         dtrace_recdesc_t *frec;
9763         dtrace_aggid_t aggid;
9764         dtrace_state_t *state = ecb->dte_state;
9765 
9766         agg = kmem_zalloc(sizeof (dtrace_aggregation_t), KM_SLEEP);
9767         agg->dtag_ecb = ecb;
9768 
9769         ASSERT(DTRACEACT_ISAGG(desc->dtad_kind));
9770 
9771         switch (desc->dtad_kind) {
9772         case DTRACEAGG_MIN:
9773                 agg->dtag_initial = INT64_MAX;
9774                 agg->dtag_aggregate = dtrace_aggregate_min;
9775                 break;
9776 
9777         case DTRACEAGG_MAX:
9778                 agg->dtag_initial = INT64_MIN;
9779                 agg->dtag_aggregate = dtrace_aggregate_max;
9780                 break;
9781 
9782         case DTRACEAGG_COUNT:
9783                 agg->dtag_aggregate = dtrace_aggregate_count;
9784                 break;
9785 
9786         case DTRACEAGG_QUANTIZE:
9787                 agg->dtag_aggregate = dtrace_aggregate_quantize;
9788                 size = (((sizeof (uint64_t) * NBBY) - 1) * 2 + 1) *
9789                     sizeof (uint64_t);
9790                 break;
9791 
9792         case DTRACEAGG_LQUANTIZE: {
9793                 uint16_t step = DTRACE_LQUANTIZE_STEP(desc->dtad_arg);
9794                 uint16_t levels = DTRACE_LQUANTIZE_LEVELS(desc->dtad_arg);
9795 
9796                 agg->dtag_initial = desc->dtad_arg;
9797                 agg->dtag_aggregate = dtrace_aggregate_lquantize;
9798 
9799                 if (step == 0 || levels == 0)
9800                         goto err;
9801 
9802                 size = levels * sizeof (uint64_t) + 3 * sizeof (uint64_t);
9803                 break;
9804         }
9805 
9806         case DTRACEAGG_LLQUANTIZE: {
9807                 uint16_t factor = DTRACE_LLQUANTIZE_FACTOR(desc->dtad_arg);
9808                 uint16_t low = DTRACE_LLQUANTIZE_LOW(desc->dtad_arg);
9809                 uint16_t high = DTRACE_LLQUANTIZE_HIGH(desc->dtad_arg);
9810                 uint16_t nsteps = DTRACE_LLQUANTIZE_NSTEP(desc->dtad_arg);
9811                 int64_t v;
9812 
9813                 agg->dtag_initial = desc->dtad_arg;
9814                 agg->dtag_aggregate = dtrace_aggregate_llquantize;
9815 
9816                 if (factor < 2 || low >= high || nsteps < factor)
9817                         goto err;
9818 
9819                 /*
9820                  * Now check that the number of steps evenly divides a power
9821                  * of the factor.  (This assures both integer bucket size and
9822                  * linearity within each magnitude.)
9823                  */
9824                 for (v = factor; v < nsteps; v *= factor)
9825                         continue;
9826 
9827                 if ((v % nsteps) || (nsteps % factor))
9828                         goto err;
9829 
9830                 size = (dtrace_aggregate_llquantize_bucket(factor,
9831                     low, high, nsteps, INT64_MAX) + 2) * sizeof (uint64_t);
9832                 break;
9833         }
9834 
9835         case DTRACEAGG_AVG:
9836                 agg->dtag_aggregate = dtrace_aggregate_avg;
9837                 size = sizeof (uint64_t) * 2;
9838                 break;
9839 
9840         case DTRACEAGG_STDDEV:
9841                 agg->dtag_aggregate = dtrace_aggregate_stddev;
9842                 size = sizeof (uint64_t) * 4;
9843                 break;
9844 
9845         case DTRACEAGG_SUM:
9846                 agg->dtag_aggregate = dtrace_aggregate_sum;
9847                 break;
9848 
9849         default:
9850                 goto err;
9851         }
9852 
9853         agg->dtag_action.dta_rec.dtrd_size = size;
9854 
9855         if (ntuple == 0)
9856                 goto err;
9857 
9858         /*
9859          * We must make sure that we have enough actions for the n-tuple.
9860          */
9861         for (act = ecb->dte_action_last; act != NULL; act = act->dta_prev) {
9862                 if (DTRACEACT_ISAGG(act->dta_kind))
9863                         break;
9864 
9865                 if (--ntuple == 0) {
9866                         /*
9867                          * This is the action with which our n-tuple begins.
9868                          */
9869                         agg->dtag_first = act;
9870                         goto success;
9871                 }
9872         }
9873 
9874         /*
9875          * This n-tuple is short by ntuple elements.  Return failure.
9876          */
9877         ASSERT(ntuple != 0);
9878 err:
9879         kmem_free(agg, sizeof (dtrace_aggregation_t));
9880         return (NULL);
9881 
9882 success:
9883         /*
9884          * If the last action in the tuple has a size of zero, it's actually
9885          * an expression argument for the aggregating action.
9886          */
9887         ASSERT(ecb->dte_action_last != NULL);
9888         act = ecb->dte_action_last;
9889 
9890         if (act->dta_kind == DTRACEACT_DIFEXPR) {
9891                 ASSERT(act->dta_difo != NULL);
9892 
9893                 if (act->dta_difo->dtdo_rtype.dtdt_size == 0)
9894                         agg->dtag_hasarg = 1;
9895         }
9896 
9897         /*
9898          * We need to allocate an id for this aggregation.
9899          */
9900         aggid = (dtrace_aggid_t)(uintptr_t)vmem_alloc(state->dts_aggid_arena, 1,
9901             VM_BESTFIT | VM_SLEEP);
9902 
9903         if (aggid - 1 >= state->dts_naggregations) {
9904                 dtrace_aggregation_t **oaggs = state->dts_aggregations;
9905                 dtrace_aggregation_t **aggs;
9906                 int naggs = state->dts_naggregations << 1;
9907                 int onaggs = state->dts_naggregations;
9908 
9909                 ASSERT(aggid == state->dts_naggregations + 1);
9910 
9911                 if (naggs == 0) {
9912                         ASSERT(oaggs == NULL);
9913                         naggs = 1;
9914                 }
9915 
9916                 aggs = kmem_zalloc(naggs * sizeof (*aggs), KM_SLEEP);
9917 
9918                 if (oaggs != NULL) {
9919                         bcopy(oaggs, aggs, onaggs * sizeof (*aggs));
9920                         kmem_free(oaggs, onaggs * sizeof (*aggs));
9921                 }
9922 
9923                 state->dts_aggregations = aggs;
9924                 state->dts_naggregations = naggs;
9925         }
9926 
9927         ASSERT(state->dts_aggregations[aggid - 1] == NULL);
9928         state->dts_aggregations[(agg->dtag_id = aggid) - 1] = agg;
9929 
9930         frec = &agg->dtag_first->dta_rec;
9931         if (frec->dtrd_alignment < sizeof (dtrace_aggid_t))
9932                 frec->dtrd_alignment = sizeof (dtrace_aggid_t);
9933 
9934         for (act = agg->dtag_first; act != NULL; act = act->dta_next) {
9935                 ASSERT(!act->dta_intuple);
9936                 act->dta_intuple = 1;
9937         }
9938 
9939         return (&agg->dtag_action);
9940 }
9941 
9942 static void
9943 dtrace_ecb_aggregation_destroy(dtrace_ecb_t *ecb, dtrace_action_t *act)
9944 {
9945         dtrace_aggregation_t *agg = (dtrace_aggregation_t *)act;
9946         dtrace_state_t *state = ecb->dte_state;
9947         dtrace_aggid_t aggid = agg->dtag_id;
9948 
9949         ASSERT(DTRACEACT_ISAGG(act->dta_kind));
9950         vmem_free(state->dts_aggid_arena, (void *)(uintptr_t)aggid, 1);
9951 
9952         ASSERT(state->dts_aggregations[aggid - 1] == agg);
9953         state->dts_aggregations[aggid - 1] = NULL;
9954 
9955         kmem_free(agg, sizeof (dtrace_aggregation_t));
9956 }
9957 
9958 static int
9959 dtrace_ecb_action_add(dtrace_ecb_t *ecb, dtrace_actdesc_t *desc)
9960 {
9961         dtrace_action_t *action, *last;
9962         dtrace_difo_t *dp = desc->dtad_difo;
9963         uint32_t size = 0, align = sizeof (uint8_t), mask;
9964         uint16_t format = 0;
9965         dtrace_recdesc_t *rec;
9966         dtrace_state_t *state = ecb->dte_state;
9967         dtrace_optval_t *opt = state->dts_options, nframes, strsize;
9968         uint64_t arg = desc->dtad_arg;
9969 
9970         ASSERT(MUTEX_HELD(&dtrace_lock));
9971         ASSERT(ecb->dte_action == NULL || ecb->dte_action->dta_refcnt == 1);
9972 
9973         if (DTRACEACT_ISAGG(desc->dtad_kind)) {
9974                 /*
9975                  * If this is an aggregating action, there must be neither
9976                  * a speculate nor a commit on the action chain.
9977                  */
9978                 dtrace_action_t *act;
9979 
9980                 for (act = ecb->dte_action; act != NULL; act = act->dta_next) {
9981                         if (act->dta_kind == DTRACEACT_COMMIT)
9982                                 return (EINVAL);
9983 
9984                         if (act->dta_kind == DTRACEACT_SPECULATE)
9985                                 return (EINVAL);
9986                 }
9987 
9988                 action = dtrace_ecb_aggregation_create(ecb, desc);
9989 
9990                 if (action == NULL)
9991                         return (EINVAL);
9992         } else {
9993                 if (DTRACEACT_ISDESTRUCTIVE(desc->dtad_kind) ||
9994                     (desc->dtad_kind == DTRACEACT_DIFEXPR &&
9995                     dp != NULL && dp->dtdo_destructive)) {
9996                         state->dts_destructive = 1;
9997                 }
9998 
9999                 switch (desc->dtad_kind) {
10000                 case DTRACEACT_PRINTF:
10001                 case DTRACEACT_PRINTA:
10002                 case DTRACEACT_SYSTEM:
10003                 case DTRACEACT_FREOPEN:
10004                 case DTRACEACT_DIFEXPR:
10005                         /*
10006                          * We know that our arg is a string -- turn it into a
10007                          * format.
10008                          */
10009                         if (arg == NULL) {
10010                                 ASSERT(desc->dtad_kind == DTRACEACT_PRINTA ||
10011                                     desc->dtad_kind == DTRACEACT_DIFEXPR);
10012                                 format = 0;
10013                         } else {
10014                                 ASSERT(arg != NULL);
10015                                 ASSERT(arg > KERNELBASE);
10016                                 format = dtrace_format_add(state,
10017                                     (char *)(uintptr_t)arg);
10018                         }
10019 
10020                         /*FALLTHROUGH*/
10021                 case DTRACEACT_LIBACT:
10022                 case DTRACEACT_TRACEMEM:
10023                 case DTRACEACT_TRACEMEM_DYNSIZE:
10024                         if (dp == NULL)
10025                                 return (EINVAL);
10026 
10027                         if ((size = dp->dtdo_rtype.dtdt_size) != 0)
10028                                 break;
10029 
10030                         if (dp->dtdo_rtype.dtdt_kind == DIF_TYPE_STRING) {
10031                                 if (!(dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF))
10032                                         return (EINVAL);
10033 
10034                                 size = opt[DTRACEOPT_STRSIZE];
10035                         }
10036 
10037                         break;
10038 
10039                 case DTRACEACT_STACK:
10040                         if ((nframes = arg) == 0) {
10041                                 nframes = opt[DTRACEOPT_STACKFRAMES];
10042                                 ASSERT(nframes > 0);
10043                                 arg = nframes;
10044                         }
10045 
10046                         size = nframes * sizeof (pc_t);
10047                         break;
10048 
10049                 case DTRACEACT_JSTACK:
10050                         if ((strsize = DTRACE_USTACK_STRSIZE(arg)) == 0)
10051                                 strsize = opt[DTRACEOPT_JSTACKSTRSIZE];
10052 
10053                         if ((nframes = DTRACE_USTACK_NFRAMES(arg)) == 0)
10054                                 nframes = opt[DTRACEOPT_JSTACKFRAMES];
10055 
10056                         arg = DTRACE_USTACK_ARG(nframes, strsize);
10057 
10058                         /*FALLTHROUGH*/
10059                 case DTRACEACT_USTACK:
10060                         if (desc->dtad_kind != DTRACEACT_JSTACK &&
10061                             (nframes = DTRACE_USTACK_NFRAMES(arg)) == 0) {
10062                                 strsize = DTRACE_USTACK_STRSIZE(arg);
10063                                 nframes = opt[DTRACEOPT_USTACKFRAMES];
10064                                 ASSERT(nframes > 0);
10065                                 arg = DTRACE_USTACK_ARG(nframes, strsize);
10066                         }
10067 
10068                         /*
10069                          * Save a slot for the pid.
10070                          */
10071                         size = (nframes + 1) * sizeof (uint64_t);
10072                         size += DTRACE_USTACK_STRSIZE(arg);
10073                         size = P2ROUNDUP(size, (uint32_t)(sizeof (uintptr_t)));
10074 
10075                         break;
10076 
10077                 case DTRACEACT_SYM:
10078                 case DTRACEACT_MOD:
10079                         if (dp == NULL || ((size = dp->dtdo_rtype.dtdt_size) !=
10080                             sizeof (uint64_t)) ||
10081                             (dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF))
10082                                 return (EINVAL);
10083                         break;
10084 
10085                 case DTRACEACT_USYM:
10086                 case DTRACEACT_UMOD:
10087                 case DTRACEACT_UADDR:
10088                         if (dp == NULL ||
10089                             (dp->dtdo_rtype.dtdt_size != sizeof (uint64_t)) ||
10090                             (dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF))
10091                                 return (EINVAL);
10092 
10093                         /*
10094                          * We have a slot for the pid, plus a slot for the
10095                          * argument.  To keep things simple (aligned with
10096                          * bitness-neutral sizing), we store each as a 64-bit
10097                          * quantity.
10098                          */
10099                         size = 2 * sizeof (uint64_t);
10100                         break;
10101 
10102                 case DTRACEACT_STOP:
10103                 case DTRACEACT_BREAKPOINT:
10104                 case DTRACEACT_PANIC:
10105                         break;
10106 
10107                 case DTRACEACT_CHILL:
10108                 case DTRACEACT_DISCARD:
10109                 case DTRACEACT_RAISE:
10110                         if (dp == NULL)
10111                                 return (EINVAL);
10112                         break;
10113 
10114                 case DTRACEACT_EXIT:
10115                         if (dp == NULL ||
10116                             (size = dp->dtdo_rtype.dtdt_size) != sizeof (int) ||
10117                             (dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF))
10118                                 return (EINVAL);
10119                         break;
10120 
10121                 case DTRACEACT_SPECULATE:
10122                         if (ecb->dte_size > sizeof (dtrace_rechdr_t))
10123                                 return (EINVAL);
10124 
10125                         if (dp == NULL)
10126                                 return (EINVAL);
10127 
10128                         state->dts_speculates = 1;
10129                         break;
10130 
10131                 case DTRACEACT_COMMIT: {
10132                         dtrace_action_t *act = ecb->dte_action;
10133 
10134                         for (; act != NULL; act = act->dta_next) {
10135                                 if (act->dta_kind == DTRACEACT_COMMIT)
10136                                         return (EINVAL);
10137                         }
10138 
10139                         if (dp == NULL)
10140                                 return (EINVAL);
10141                         break;
10142                 }
10143 
10144                 default:
10145                         return (EINVAL);
10146                 }
10147 
10148                 if (size != 0 || desc->dtad_kind == DTRACEACT_SPECULATE) {
10149                         /*
10150                          * If this is a data-storing action or a speculate,
10151                          * we must be sure that there isn't a commit on the
10152                          * action chain.
10153                          */
10154                         dtrace_action_t *act = ecb->dte_action;
10155 
10156                         for (; act != NULL; act = act->dta_next) {
10157                                 if (act->dta_kind == DTRACEACT_COMMIT)
10158                                         return (EINVAL);
10159                         }
10160                 }
10161 
10162                 action = kmem_zalloc(sizeof (dtrace_action_t), KM_SLEEP);
10163                 action->dta_rec.dtrd_size = size;
10164         }
10165 
10166         action->dta_refcnt = 1;
10167         rec = &action->dta_rec;
10168         size = rec->dtrd_size;
10169 
10170         for (mask = sizeof (uint64_t) - 1; size != 0 && mask > 0; mask >>= 1) {
10171                 if (!(size & mask)) {
10172                         align = mask + 1;
10173                         break;
10174                 }
10175         }
10176 
10177         action->dta_kind = desc->dtad_kind;
10178 
10179         if ((action->dta_difo = dp) != NULL)
10180                 dtrace_difo_hold(dp);
10181 
10182         rec->dtrd_action = action->dta_kind;
10183         rec->dtrd_arg = arg;
10184         rec->dtrd_uarg = desc->dtad_uarg;
10185         rec->dtrd_alignment = (uint16_t)align;
10186         rec->dtrd_format = format;
10187 
10188         if ((last = ecb->dte_action_last) != NULL) {
10189                 ASSERT(ecb->dte_action != NULL);
10190                 action->dta_prev = last;
10191                 last->dta_next = action;
10192         } else {
10193                 ASSERT(ecb->dte_action == NULL);
10194                 ecb->dte_action = action;
10195         }
10196 
10197         ecb->dte_action_last = action;
10198 
10199         return (0);
10200 }
10201 
10202 static void
10203 dtrace_ecb_action_remove(dtrace_ecb_t *ecb)
10204 {
10205         dtrace_action_t *act = ecb->dte_action, *next;
10206         dtrace_vstate_t *vstate = &ecb->dte_state->dts_vstate;
10207         dtrace_difo_t *dp;
10208         uint16_t format;
10209 
10210         if (act != NULL && act->dta_refcnt > 1) {
10211                 ASSERT(act->dta_next == NULL || act->dta_next->dta_refcnt == 1);
10212                 act->dta_refcnt--;
10213         } else {
10214                 for (; act != NULL; act = next) {
10215                         next = act->dta_next;
10216                         ASSERT(next != NULL || act == ecb->dte_action_last);
10217                         ASSERT(act->dta_refcnt == 1);
10218 
10219                         if ((format = act->dta_rec.dtrd_format) != 0)
10220                                 dtrace_format_remove(ecb->dte_state, format);
10221 
10222                         if ((dp = act->dta_difo) != NULL)
10223                                 dtrace_difo_release(dp, vstate);
10224 
10225                         if (DTRACEACT_ISAGG(act->dta_kind)) {
10226                                 dtrace_ecb_aggregation_destroy(ecb, act);
10227                         } else {
10228                                 kmem_free(act, sizeof (dtrace_action_t));
10229                         }
10230                 }
10231         }
10232 
10233         ecb->dte_action = NULL;
10234         ecb->dte_action_last = NULL;
10235         ecb->dte_size = 0;
10236 }
10237 
10238 static void
10239 dtrace_ecb_disable(dtrace_ecb_t *ecb)
10240 {
10241         /*
10242          * We disable the ECB by removing it from its probe.
10243          */
10244         dtrace_ecb_t *pecb, *prev = NULL;
10245         dtrace_probe_t *probe = ecb->dte_probe;
10246 
10247         ASSERT(MUTEX_HELD(&dtrace_lock));
10248 
10249         if (probe == NULL) {
10250                 /*
10251                  * This is the NULL probe; there is nothing to disable.
10252                  */
10253                 return;
10254         }
10255 
10256         for (pecb = probe->dtpr_ecb; pecb != NULL; pecb = pecb->dte_next) {
10257                 if (pecb == ecb)
10258                         break;
10259                 prev = pecb;
10260         }
10261 
10262         ASSERT(pecb != NULL);
10263 
10264         if (prev == NULL) {
10265                 probe->dtpr_ecb = ecb->dte_next;
10266         } else {
10267                 prev->dte_next = ecb->dte_next;
10268         }
10269 
10270         if (ecb == probe->dtpr_ecb_last) {
10271                 ASSERT(ecb->dte_next == NULL);
10272                 probe->dtpr_ecb_last = prev;
10273         }
10274 
10275         /*
10276          * The ECB has been disconnected from the probe; now sync to assure
10277          * that all CPUs have seen the change before returning.
10278          */
10279         dtrace_sync();
10280 
10281         if (probe->dtpr_ecb == NULL) {
10282                 /*
10283                  * That was the last ECB on the probe; clear the predicate
10284                  * cache ID for the probe, disable it and sync one more time
10285                  * to assure that we'll never hit it again.
10286                  */
10287                 dtrace_provider_t *prov = probe->dtpr_provider;
10288 
10289                 ASSERT(ecb->dte_next == NULL);
10290                 ASSERT(probe->dtpr_ecb_last == NULL);
10291                 probe->dtpr_predcache = DTRACE_CACHEIDNONE;
10292                 prov->dtpv_pops.dtps_disable(prov->dtpv_arg,
10293                     probe->dtpr_id, probe->dtpr_arg);
10294                 dtrace_sync();
10295         } else {
10296                 /*
10297                  * There is at least one ECB remaining on the probe.  If there
10298                  * is _exactly_ one, set the probe's predicate cache ID to be
10299                  * the predicate cache ID of the remaining ECB.
10300                  */
10301                 ASSERT(probe->dtpr_ecb_last != NULL);
10302                 ASSERT(probe->dtpr_predcache == DTRACE_CACHEIDNONE);
10303 
10304                 if (probe->dtpr_ecb == probe->dtpr_ecb_last) {
10305                         dtrace_predicate_t *p = probe->dtpr_ecb->dte_predicate;
10306 
10307                         ASSERT(probe->dtpr_ecb->dte_next == NULL);
10308 
10309                         if (p != NULL)
10310                                 probe->dtpr_predcache = p->dtp_cacheid;
10311                 }
10312 
10313                 ecb->dte_next = NULL;
10314         }
10315 }
10316 
10317 static void
10318 dtrace_ecb_destroy(dtrace_ecb_t *ecb)
10319 {
10320         dtrace_state_t *state = ecb->dte_state;
10321         dtrace_vstate_t *vstate = &state->dts_vstate;
10322         dtrace_predicate_t *pred;
10323         dtrace_epid_t epid = ecb->dte_epid;
10324 
10325         ASSERT(MUTEX_HELD(&dtrace_lock));
10326         ASSERT(ecb->dte_next == NULL);
10327         ASSERT(ecb->dte_probe == NULL || ecb->dte_probe->dtpr_ecb != ecb);
10328 
10329         if ((pred = ecb->dte_predicate) != NULL)
10330                 dtrace_predicate_release(pred, vstate);
10331 
10332         dtrace_ecb_action_remove(ecb);
10333 
10334         ASSERT(state->dts_ecbs[epid - 1] == ecb);
10335         state->dts_ecbs[epid - 1] = NULL;
10336 
10337         kmem_free(ecb, sizeof (dtrace_ecb_t));
10338 }
10339 
10340 static dtrace_ecb_t *
10341 dtrace_ecb_create(dtrace_state_t *state, dtrace_probe_t *probe,
10342     dtrace_enabling_t *enab)
10343 {
10344         dtrace_ecb_t *ecb;
10345         dtrace_predicate_t *pred;
10346         dtrace_actdesc_t *act;
10347         dtrace_provider_t *prov;
10348         dtrace_ecbdesc_t *desc = enab->dten_current;
10349 
10350         ASSERT(MUTEX_HELD(&dtrace_lock));
10351         ASSERT(state != NULL);
10352 
10353         ecb = dtrace_ecb_add(state, probe);
10354         ecb->dte_uarg = desc->dted_uarg;
10355 
10356         if ((pred = desc->dted_pred.dtpdd_predicate) != NULL) {
10357                 dtrace_predicate_hold(pred);
10358                 ecb->dte_predicate = pred;
10359         }
10360 
10361         if (probe != NULL) {
10362                 /*
10363                  * If the provider shows more leg than the consumer is old
10364                  * enough to see, we need to enable the appropriate implicit
10365                  * predicate bits to prevent the ecb from activating at
10366                  * revealing times.
10367                  *
10368                  * Providers specifying DTRACE_PRIV_USER at register time
10369                  * are stating that they need the /proc-style privilege
10370                  * model to be enforced, and this is what DTRACE_COND_OWNER
10371                  * and DTRACE_COND_ZONEOWNER will then do at probe time.
10372                  */
10373                 prov = probe->dtpr_provider;
10374                 if (!(state->dts_cred.dcr_visible & DTRACE_CRV_ALLPROC) &&
10375                     (prov->dtpv_priv.dtpp_flags & DTRACE_PRIV_USER))
10376                         ecb->dte_cond |= DTRACE_COND_OWNER;
10377 
10378                 if (!(state->dts_cred.dcr_visible & DTRACE_CRV_ALLZONE) &&
10379                     (prov->dtpv_priv.dtpp_flags & DTRACE_PRIV_USER))
10380                         ecb->dte_cond |= DTRACE_COND_ZONEOWNER;
10381 
10382                 /*
10383                  * If the provider shows us kernel innards and the user
10384                  * is lacking sufficient privilege, enable the
10385                  * DTRACE_COND_USERMODE implicit predicate.
10386                  */
10387                 if (!(state->dts_cred.dcr_visible & DTRACE_CRV_KERNEL) &&
10388                     (prov->dtpv_priv.dtpp_flags & DTRACE_PRIV_KERNEL))
10389                         ecb->dte_cond |= DTRACE_COND_USERMODE;
10390         }
10391 
10392         if (dtrace_ecb_create_cache != NULL) {
10393                 /*
10394                  * If we have a cached ecb, we'll use its action list instead
10395                  * of creating our own (saving both time and space).
10396                  */
10397                 dtrace_ecb_t *cached = dtrace_ecb_create_cache;
10398                 dtrace_action_t *act = cached->dte_action;
10399 
10400                 if (act != NULL) {
10401                         ASSERT(act->dta_refcnt > 0);
10402                         act->dta_refcnt++;
10403                         ecb->dte_action = act;
10404                         ecb->dte_action_last = cached->dte_action_last;
10405                         ecb->dte_needed = cached->dte_needed;
10406                         ecb->dte_size = cached->dte_size;
10407                         ecb->dte_alignment = cached->dte_alignment;
10408                 }
10409 
10410                 return (ecb);
10411         }
10412 
10413         for (act = desc->dted_action; act != NULL; act = act->dtad_next) {
10414                 if ((enab->dten_error = dtrace_ecb_action_add(ecb, act)) != 0) {
10415                         dtrace_ecb_destroy(ecb);
10416                         return (NULL);
10417                 }
10418         }
10419 
10420         dtrace_ecb_resize(ecb);
10421 
10422         return (dtrace_ecb_create_cache = ecb);
10423 }
10424 
10425 static int
10426 dtrace_ecb_create_enable(dtrace_probe_t *probe, void *arg)
10427 {
10428         dtrace_ecb_t *ecb;
10429         dtrace_enabling_t *enab = arg;
10430         dtrace_state_t *state = enab->dten_vstate->dtvs_state;
10431 
10432         ASSERT(state != NULL);
10433 
10434         if (probe != NULL && probe->dtpr_gen < enab->dten_probegen) {
10435                 /*
10436                  * This probe was created in a generation for which this
10437                  * enabling has previously created ECBs; we don't want to
10438                  * enable it again, so just kick out.
10439                  */
10440                 return (DTRACE_MATCH_NEXT);
10441         }
10442 
10443         if ((ecb = dtrace_ecb_create(state, probe, enab)) == NULL)
10444                 return (DTRACE_MATCH_DONE);
10445 
10446         if (dtrace_ecb_enable(ecb) < 0)
10447                 return (DTRACE_MATCH_FAIL);
10448 
10449         return (DTRACE_MATCH_NEXT);
10450 }
10451 
10452 static dtrace_ecb_t *
10453 dtrace_epid2ecb(dtrace_state_t *state, dtrace_epid_t id)
10454 {
10455         dtrace_ecb_t *ecb;
10456 
10457         ASSERT(MUTEX_HELD(&dtrace_lock));
10458 
10459         if (id == 0 || id > state->dts_necbs)
10460                 return (NULL);
10461 
10462         ASSERT(state->dts_necbs > 0 && state->dts_ecbs != NULL);
10463         ASSERT((ecb = state->dts_ecbs[id - 1]) == NULL || ecb->dte_epid == id);
10464 
10465         return (state->dts_ecbs[id - 1]);
10466 }
10467 
10468 static dtrace_aggregation_t *
10469 dtrace_aggid2agg(dtrace_state_t *state, dtrace_aggid_t id)
10470 {
10471         dtrace_aggregation_t *agg;
10472 
10473         ASSERT(MUTEX_HELD(&dtrace_lock));
10474 
10475         if (id == 0 || id > state->dts_naggregations)
10476                 return (NULL);
10477 
10478         ASSERT(state->dts_naggregations > 0 && state->dts_aggregations != NULL);
10479         ASSERT((agg = state->dts_aggregations[id - 1]) == NULL ||
10480             agg->dtag_id == id);
10481 
10482         return (state->dts_aggregations[id - 1]);
10483 }
10484 
10485 /*
10486  * DTrace Buffer Functions
10487  *
10488  * The following functions manipulate DTrace buffers.  Most of these functions
10489  * are called in the context of establishing or processing consumer state;
10490  * exceptions are explicitly noted.
10491  */
10492 
10493 /*
10494  * Note:  called from cross call context.  This function switches the two
10495  * buffers on a given CPU.  The atomicity of this operation is assured by
10496  * disabling interrupts while the actual switch takes place; the disabling of
10497  * interrupts serializes the execution with any execution of dtrace_probe() on
10498  * the same CPU.
10499  */
10500 static void
10501 dtrace_buffer_switch(dtrace_buffer_t *buf)
10502 {
10503         caddr_t tomax = buf->dtb_tomax;
10504         caddr_t xamot = buf->dtb_xamot;
10505         dtrace_icookie_t cookie;
10506         hrtime_t now;
10507 
10508         ASSERT(!(buf->dtb_flags & DTRACEBUF_NOSWITCH));
10509         ASSERT(!(buf->dtb_flags & DTRACEBUF_RING));
10510 
10511         cookie = dtrace_interrupt_disable();
10512         now = dtrace_gethrtime();
10513         buf->dtb_tomax = xamot;
10514         buf->dtb_xamot = tomax;
10515         buf->dtb_xamot_drops = buf->dtb_drops;
10516         buf->dtb_xamot_offset = buf->dtb_offset;
10517         buf->dtb_xamot_errors = buf->dtb_errors;
10518         buf->dtb_xamot_flags = buf->dtb_flags;
10519         buf->dtb_offset = 0;
10520         buf->dtb_drops = 0;
10521         buf->dtb_errors = 0;
10522         buf->dtb_flags &= ~(DTRACEBUF_ERROR | DTRACEBUF_DROPPED);
10523         buf->dtb_interval = now - buf->dtb_switched;
10524         buf->dtb_switched = now;
10525         dtrace_interrupt_enable(cookie);
10526 }
10527 
10528 /*
10529  * Note:  called from cross call context.  This function activates a buffer
10530  * on a CPU.  As with dtrace_buffer_switch(), the atomicity of the operation
10531  * is guaranteed by the disabling of interrupts.
10532  */
10533 static void
10534 dtrace_buffer_activate(dtrace_state_t *state)
10535 {
10536         dtrace_buffer_t *buf;
10537         dtrace_icookie_t cookie = dtrace_interrupt_disable();
10538 
10539         buf = &state->dts_buffer[CPU->cpu_id];
10540 
10541         if (buf->dtb_tomax != NULL) {
10542                 /*
10543                  * We might like to assert that the buffer is marked inactive,
10544                  * but this isn't necessarily true:  the buffer for the CPU
10545                  * that processes the BEGIN probe has its buffer activated
10546                  * manually.  In this case, we take the (harmless) action
10547                  * re-clearing the bit INACTIVE bit.
10548                  */
10549                 buf->dtb_flags &= ~DTRACEBUF_INACTIVE;
10550         }
10551 
10552         dtrace_interrupt_enable(cookie);
10553 }
10554 
10555 static int
10556 dtrace_buffer_alloc(dtrace_buffer_t *bufs, size_t size, int flags,
10557     processorid_t cpu, int *factor)
10558 {
10559         cpu_t *cp;
10560         dtrace_buffer_t *buf;
10561         int allocated = 0, desired = 0;
10562 
10563         ASSERT(MUTEX_HELD(&cpu_lock));
10564         ASSERT(MUTEX_HELD(&dtrace_lock));
10565 
10566         *factor = 1;
10567 
10568         if (size > dtrace_nonroot_maxsize &&
10569             !PRIV_POLICY_CHOICE(CRED(), PRIV_ALL, B_FALSE))
10570                 return (EFBIG);
10571 
10572         cp = cpu_list;
10573 
10574         do {
10575                 if (cpu != DTRACE_CPUALL && cpu != cp->cpu_id)
10576                         continue;
10577 
10578                 buf = &bufs[cp->cpu_id];
10579 
10580                 /*
10581                  * If there is already a buffer allocated for this CPU, it
10582                  * is only possible that this is a DR event.  In this case,
10583                  * the buffer size must match our specified size.
10584                  */
10585                 if (buf->dtb_tomax != NULL) {
10586                         ASSERT(buf->dtb_size == size);
10587                         continue;
10588                 }
10589 
10590                 ASSERT(buf->dtb_xamot == NULL);
10591 
10592                 if ((buf->dtb_tomax = kmem_zalloc(size,
10593                     KM_NOSLEEP | KM_NORMALPRI)) == NULL)
10594                         goto err;
10595 
10596                 buf->dtb_size = size;
10597                 buf->dtb_flags = flags;
10598                 buf->dtb_offset = 0;
10599                 buf->dtb_drops = 0;
10600 
10601                 if (flags & DTRACEBUF_NOSWITCH)
10602                         continue;
10603 
10604                 if ((buf->dtb_xamot = kmem_zalloc(size,
10605                     KM_NOSLEEP | KM_NORMALPRI)) == NULL)
10606                         goto err;
10607         } while ((cp = cp->cpu_next) != cpu_list);
10608 
10609         return (0);
10610 
10611 err:
10612         cp = cpu_list;
10613 
10614         do {
10615                 if (cpu != DTRACE_CPUALL && cpu != cp->cpu_id)
10616                         continue;
10617 
10618                 buf = &bufs[cp->cpu_id];
10619                 desired += 2;
10620 
10621                 if (buf->dtb_xamot != NULL) {
10622                         ASSERT(buf->dtb_tomax != NULL);
10623                         ASSERT(buf->dtb_size == size);
10624                         kmem_free(buf->dtb_xamot, size);
10625                         allocated++;
10626                 }
10627 
10628                 if (buf->dtb_tomax != NULL) {
10629                         ASSERT(buf->dtb_size == size);
10630                         kmem_free(buf->dtb_tomax, size);
10631                         allocated++;
10632                 }
10633 
10634                 buf->dtb_tomax = NULL;
10635                 buf->dtb_xamot = NULL;
10636                 buf->dtb_size = 0;
10637         } while ((cp = cp->cpu_next) != cpu_list);
10638 
10639         *factor = desired / (allocated > 0 ? allocated : 1);
10640 
10641         return (ENOMEM);
10642 }
10643 
10644 /*
10645  * Note:  called from probe context.  This function just increments the drop
10646  * count on a buffer.  It has been made a function to allow for the
10647  * possibility of understanding the source of mysterious drop counts.  (A
10648  * problem for which one may be particularly disappointed that DTrace cannot
10649  * be used to understand DTrace.)
10650  */
10651 static void
10652 dtrace_buffer_drop(dtrace_buffer_t *buf)
10653 {
10654         buf->dtb_drops++;
10655 }
10656 
10657 /*
10658  * Note:  called from probe context.  This function is called to reserve space
10659  * in a buffer.  If mstate is non-NULL, sets the scratch base and size in the
10660  * mstate.  Returns the new offset in the buffer, or a negative value if an
10661  * error has occurred.
10662  */
10663 static intptr_t
10664 dtrace_buffer_reserve(dtrace_buffer_t *buf, size_t needed, size_t align,
10665     dtrace_state_t *state, dtrace_mstate_t *mstate)
10666 {
10667         intptr_t offs = buf->dtb_offset, soffs;
10668         intptr_t woffs;
10669         caddr_t tomax;
10670         size_t total;
10671 
10672         if (buf->dtb_flags & DTRACEBUF_INACTIVE)
10673                 return (-1);
10674 
10675         if ((tomax = buf->dtb_tomax) == NULL) {
10676                 dtrace_buffer_drop(buf);
10677                 return (-1);
10678         }
10679 
10680         if (!(buf->dtb_flags & (DTRACEBUF_RING | DTRACEBUF_FILL))) {
10681                 while (offs & (align - 1)) {
10682                         /*
10683                          * Assert that our alignment is off by a number which
10684                          * is itself sizeof (uint32_t) aligned.
10685                          */
10686                         ASSERT(!((align - (offs & (align - 1))) &
10687                             (sizeof (uint32_t) - 1)));
10688                         DTRACE_STORE(uint32_t, tomax, offs, DTRACE_EPIDNONE);
10689                         offs += sizeof (uint32_t);
10690                 }
10691 
10692                 if ((soffs = offs + needed) > buf->dtb_size) {
10693                         dtrace_buffer_drop(buf);
10694                         return (-1);
10695                 }
10696 
10697                 if (mstate == NULL)
10698                         return (offs);
10699 
10700                 mstate->dtms_scratch_base = (uintptr_t)tomax + soffs;
10701                 mstate->dtms_scratch_size = buf->dtb_size - soffs;
10702                 mstate->dtms_scratch_ptr = mstate->dtms_scratch_base;
10703 
10704                 return (offs);
10705         }
10706 
10707         if (buf->dtb_flags & DTRACEBUF_FILL) {
10708                 if (state->dts_activity != DTRACE_ACTIVITY_COOLDOWN &&
10709                     (buf->dtb_flags & DTRACEBUF_FULL))
10710                         return (-1);
10711                 goto out;
10712         }
10713 
10714         total = needed + (offs & (align - 1));
10715 
10716         /*
10717          * For a ring buffer, life is quite a bit more complicated.  Before
10718          * we can store any padding, we need to adjust our wrapping offset.
10719          * (If we've never before wrapped or we're not about to, no adjustment
10720          * is required.)
10721          */
10722         if ((buf->dtb_flags & DTRACEBUF_WRAPPED) ||
10723             offs + total > buf->dtb_size) {
10724                 woffs = buf->dtb_xamot_offset;
10725 
10726                 if (offs + total > buf->dtb_size) {
10727                         /*
10728                          * We can't fit in the end of the buffer.  First, a
10729                          * sanity check that we can fit in the buffer at all.
10730                          */
10731                         if (total > buf->dtb_size) {
10732                                 dtrace_buffer_drop(buf);
10733                                 return (-1);
10734                         }
10735 
10736                         /*
10737                          * We're going to be storing at the top of the buffer,
10738                          * so now we need to deal with the wrapped offset.  We
10739                          * only reset our wrapped offset to 0 if it is
10740                          * currently greater than the current offset.  If it
10741                          * is less than the current offset, it is because a
10742                          * previous allocation induced a wrap -- but the
10743                          * allocation didn't subsequently take the space due
10744                          * to an error or false predicate evaluation.  In this
10745                          * case, we'll just leave the wrapped offset alone: if
10746                          * the wrapped offset hasn't been advanced far enough
10747                          * for this allocation, it will be adjusted in the
10748                          * lower loop.
10749                          */
10750                         if (buf->dtb_flags & DTRACEBUF_WRAPPED) {
10751                                 if (woffs >= offs)
10752                                         woffs = 0;
10753                         } else {
10754                                 woffs = 0;
10755                         }
10756 
10757                         /*
10758                          * Now we know that we're going to be storing to the
10759                          * top of the buffer and that there is room for us
10760                          * there.  We need to clear the buffer from the current
10761                          * offset to the end (there may be old gunk there).
10762                          */
10763                         while (offs < buf->dtb_size)
10764                                 tomax[offs++] = 0;
10765 
10766                         /*
10767                          * We need to set our offset to zero.  And because we
10768                          * are wrapping, we need to set the bit indicating as
10769                          * much.  We can also adjust our needed space back
10770                          * down to the space required by the ECB -- we know
10771                          * that the top of the buffer is aligned.
10772                          */
10773                         offs = 0;
10774                         total = needed;
10775                         buf->dtb_flags |= DTRACEBUF_WRAPPED;
10776                 } else {
10777                         /*
10778                          * There is room for us in the buffer, so we simply
10779                          * need to check the wrapped offset.
10780                          */
10781                         if (woffs < offs) {
10782                                 /*
10783                                  * The wrapped offset is less than the offset.
10784                                  * This can happen if we allocated buffer space
10785                                  * that induced a wrap, but then we didn't
10786                                  * subsequently take the space due to an error
10787                                  * or false predicate evaluation.  This is
10788                                  * okay; we know that _this_ allocation isn't
10789                                  * going to induce a wrap.  We still can't
10790                                  * reset the wrapped offset to be zero,
10791                                  * however: the space may have been trashed in
10792                                  * the previous failed probe attempt.  But at
10793                                  * least the wrapped offset doesn't need to
10794                                  * be adjusted at all...
10795                                  */
10796                                 goto out;
10797                         }
10798                 }
10799 
10800                 while (offs + total > woffs) {
10801                         dtrace_epid_t epid = *(uint32_t *)(tomax + woffs);
10802                         size_t size;
10803 
10804                         if (epid == DTRACE_EPIDNONE) {
10805                                 size = sizeof (uint32_t);
10806                         } else {
10807                                 ASSERT3U(epid, <=, state->dts_necbs);
10808                                 ASSERT(state->dts_ecbs[epid - 1] != NULL);
10809 
10810                                 size = state->dts_ecbs[epid - 1]->dte_size;
10811                         }
10812 
10813                         ASSERT(woffs + size <= buf->dtb_size);
10814                         ASSERT(size != 0);
10815 
10816                         if (woffs + size == buf->dtb_size) {
10817                                 /*
10818                                  * We've reached the end of the buffer; we want
10819                                  * to set the wrapped offset to 0 and break
10820                                  * out.  However, if the offs is 0, then we're
10821                                  * in a strange edge-condition:  the amount of
10822                                  * space that we want to reserve plus the size
10823                                  * of the record that we're overwriting is
10824                                  * greater than the size of the buffer.  This
10825                                  * is problematic because if we reserve the
10826                                  * space but subsequently don't consume it (due
10827                                  * to a failed predicate or error) the wrapped
10828                                  * offset will be 0 -- yet the EPID at offset 0
10829                                  * will not be committed.  This situation is
10830                                  * relatively easy to deal with:  if we're in
10831                                  * this case, the buffer is indistinguishable
10832                                  * from one that hasn't wrapped; we need only
10833                                  * finish the job by clearing the wrapped bit,
10834                                  * explicitly setting the offset to be 0, and
10835                                  * zero'ing out the old data in the buffer.
10836                                  */
10837                                 if (offs == 0) {
10838                                         buf->dtb_flags &= ~DTRACEBUF_WRAPPED;
10839                                         buf->dtb_offset = 0;
10840                                         woffs = total;
10841 
10842                                         while (woffs < buf->dtb_size)
10843                                                 tomax[woffs++] = 0;
10844                                 }
10845 
10846                                 woffs = 0;
10847                                 break;
10848                         }
10849 
10850                         woffs += size;
10851                 }
10852 
10853                 /*
10854                  * We have a wrapped offset.  It may be that the wrapped offset
10855                  * has become zero -- that's okay.
10856                  */
10857                 buf->dtb_xamot_offset = woffs;
10858         }
10859 
10860 out:
10861         /*
10862          * Now we can plow the buffer with any necessary padding.
10863          */
10864         while (offs & (align - 1)) {
10865                 /*
10866                  * Assert that our alignment is off by a number which
10867                  * is itself sizeof (uint32_t) aligned.
10868                  */
10869                 ASSERT(!((align - (offs & (align - 1))) &
10870                     (sizeof (uint32_t) - 1)));
10871                 DTRACE_STORE(uint32_t, tomax, offs, DTRACE_EPIDNONE);
10872                 offs += sizeof (uint32_t);
10873         }
10874 
10875         if (buf->dtb_flags & DTRACEBUF_FILL) {
10876                 if (offs + needed > buf->dtb_size - state->dts_reserve) {
10877                         buf->dtb_flags |= DTRACEBUF_FULL;
10878                         return (-1);
10879                 }
10880         }
10881 
10882         if (mstate == NULL)
10883                 return (offs);
10884 
10885         /*
10886          * For ring buffers and fill buffers, the scratch space is always
10887          * the inactive buffer.
10888          */
10889         mstate->dtms_scratch_base = (uintptr_t)buf->dtb_xamot;
10890         mstate->dtms_scratch_size = buf->dtb_size;
10891         mstate->dtms_scratch_ptr = mstate->dtms_scratch_base;
10892 
10893         return (offs);
10894 }
10895 
10896 static void
10897 dtrace_buffer_polish(dtrace_buffer_t *buf)
10898 {
10899         ASSERT(buf->dtb_flags & DTRACEBUF_RING);
10900         ASSERT(MUTEX_HELD(&dtrace_lock));
10901 
10902         if (!(buf->dtb_flags & DTRACEBUF_WRAPPED))
10903                 return;
10904 
10905         /*
10906          * We need to polish the ring buffer.  There are three cases:
10907          *
10908          * - The first (and presumably most common) is that there is no gap
10909          *   between the buffer offset and the wrapped offset.  In this case,
10910          *   there is nothing in the buffer that isn't valid data; we can
10911          *   mark the buffer as polished and return.
10912          *
10913          * - The second (less common than the first but still more common
10914          *   than the third) is that there is a gap between the buffer offset
10915          *   and the wrapped offset, and the wrapped offset is larger than the
10916          *   buffer offset.  This can happen because of an alignment issue, or
10917          *   can happen because of a call to dtrace_buffer_reserve() that
10918          *   didn't subsequently consume the buffer space.  In this case,
10919          *   we need to zero the data from the buffer offset to the wrapped
10920          *   offset.
10921          *
10922          * - The third (and least common) is that there is a gap between the
10923          *   buffer offset and the wrapped offset, but the wrapped offset is
10924          *   _less_ than the buffer offset.  This can only happen because a
10925          *   call to dtrace_buffer_reserve() induced a wrap, but the space
10926          *   was not subsequently consumed.  In this case, we need to zero the
10927          *   space from the offset to the end of the buffer _and_ from the
10928          *   top of the buffer to the wrapped offset.
10929          */
10930         if (buf->dtb_offset < buf->dtb_xamot_offset) {
10931                 bzero(buf->dtb_tomax + buf->dtb_offset,
10932                     buf->dtb_xamot_offset - buf->dtb_offset);
10933         }
10934 
10935         if (buf->dtb_offset > buf->dtb_xamot_offset) {
10936                 bzero(buf->dtb_tomax + buf->dtb_offset,
10937                     buf->dtb_size - buf->dtb_offset);
10938                 bzero(buf->dtb_tomax, buf->dtb_xamot_offset);
10939         }
10940 }
10941 
10942 /*
10943  * This routine determines if data generated at the specified time has likely
10944  * been entirely consumed at user-level.  This routine is called to determine
10945  * if an ECB on a defunct probe (but for an active enabling) can be safely
10946  * disabled and destroyed.
10947  */
10948 static int
10949 dtrace_buffer_consumed(dtrace_buffer_t *bufs, hrtime_t when)
10950 {
10951         int i;
10952 
10953         for (i = 0; i < NCPU; i++) {
10954                 dtrace_buffer_t *buf = &bufs[i];
10955 
10956                 if (buf->dtb_size == 0)
10957                         continue;
10958 
10959                 if (buf->dtb_flags & DTRACEBUF_RING)
10960                         return (0);
10961 
10962                 if (!buf->dtb_switched && buf->dtb_offset != 0)
10963                         return (0);
10964 
10965                 if (buf->dtb_switched - buf->dtb_interval < when)
10966                         return (0);
10967         }
10968 
10969         return (1);
10970 }
10971 
10972 static void
10973 dtrace_buffer_free(dtrace_buffer_t *bufs)
10974 {
10975         int i;
10976 
10977         for (i = 0; i < NCPU; i++) {
10978                 dtrace_buffer_t *buf = &bufs[i];
10979 
10980                 if (buf->dtb_tomax == NULL) {
10981                         ASSERT(buf->dtb_xamot == NULL);
10982                         ASSERT(buf->dtb_size == 0);
10983                         continue;
10984                 }
10985 
10986                 if (buf->dtb_xamot != NULL) {
10987                         ASSERT(!(buf->dtb_flags & DTRACEBUF_NOSWITCH));
10988                         kmem_free(buf->dtb_xamot, buf->dtb_size);
10989                 }
10990 
10991                 kmem_free(buf->dtb_tomax, buf->dtb_size);
10992                 buf->dtb_size = 0;
10993                 buf->dtb_tomax = NULL;
10994                 buf->dtb_xamot = NULL;
10995         }
10996 }
10997 
10998 /*
10999  * DTrace Enabling Functions
11000  */
11001 static dtrace_enabling_t *
11002 dtrace_enabling_create(dtrace_vstate_t *vstate)
11003 {
11004         dtrace_enabling_t *enab;
11005 
11006         enab = kmem_zalloc(sizeof (dtrace_enabling_t), KM_SLEEP);
11007         enab->dten_vstate = vstate;
11008 
11009         return (enab);
11010 }
11011 
11012 static void
11013 dtrace_enabling_add(dtrace_enabling_t *enab, dtrace_ecbdesc_t *ecb)
11014 {
11015         dtrace_ecbdesc_t **ndesc;
11016         size_t osize, nsize;
11017 
11018         /*
11019          * We can't add to enablings after we've enabled them, or after we've
11020          * retained them.
11021          */
11022         ASSERT(enab->dten_probegen == 0);
11023         ASSERT(enab->dten_next == NULL && enab->dten_prev == NULL);
11024 
11025         if (enab->dten_ndesc < enab->dten_maxdesc) {
11026                 enab->dten_desc[enab->dten_ndesc++] = ecb;
11027                 return;
11028         }
11029 
11030         osize = enab->dten_maxdesc * sizeof (dtrace_enabling_t *);
11031 
11032         if (enab->dten_maxdesc == 0) {
11033                 enab->dten_maxdesc = 1;
11034         } else {
11035                 enab->dten_maxdesc <<= 1;
11036         }
11037 
11038         ASSERT(enab->dten_ndesc < enab->dten_maxdesc);
11039 
11040         nsize = enab->dten_maxdesc * sizeof (dtrace_enabling_t *);
11041         ndesc = kmem_zalloc(nsize, KM_SLEEP);
11042         bcopy(enab->dten_desc, ndesc, osize);
11043         kmem_free(enab->dten_desc, osize);
11044 
11045         enab->dten_desc = ndesc;
11046         enab->dten_desc[enab->dten_ndesc++] = ecb;
11047 }
11048 
11049 static void
11050 dtrace_enabling_addlike(dtrace_enabling_t *enab, dtrace_ecbdesc_t *ecb,
11051     dtrace_probedesc_t *pd)
11052 {
11053         dtrace_ecbdesc_t *new;
11054         dtrace_predicate_t *pred;
11055         dtrace_actdesc_t *act;
11056 
11057         /*
11058          * We're going to create a new ECB description that matches the
11059          * specified ECB in every way, but has the specified probe description.
11060          */
11061         new = kmem_zalloc(sizeof (dtrace_ecbdesc_t), KM_SLEEP);
11062 
11063         if ((pred = ecb->dted_pred.dtpdd_predicate) != NULL)
11064                 dtrace_predicate_hold(pred);
11065 
11066         for (act = ecb->dted_action; act != NULL; act = act->dtad_next)
11067                 dtrace_actdesc_hold(act);
11068 
11069         new->dted_action = ecb->dted_action;
11070         new->dted_pred = ecb->dted_pred;
11071         new->dted_probe = *pd;
11072         new->dted_uarg = ecb->dted_uarg;
11073 
11074         dtrace_enabling_add(enab, new);
11075 }
11076 
11077 static void
11078 dtrace_enabling_dump(dtrace_enabling_t *enab)
11079 {
11080         int i;
11081 
11082         for (i = 0; i < enab->dten_ndesc; i++) {
11083                 dtrace_probedesc_t *desc = &enab->dten_desc[i]->dted_probe;
11084 
11085                 cmn_err(CE_NOTE, "enabling probe %d (%s:%s:%s:%s)", i,
11086                     desc->dtpd_provider, desc->dtpd_mod,
11087                     desc->dtpd_func, desc->dtpd_name);
11088         }
11089 }
11090 
11091 static void
11092 dtrace_enabling_destroy(dtrace_enabling_t *enab)
11093 {
11094         int i;
11095         dtrace_ecbdesc_t *ep;
11096         dtrace_vstate_t *vstate = enab->dten_vstate;
11097 
11098         ASSERT(MUTEX_HELD(&dtrace_lock));
11099 
11100         for (i = 0; i < enab->dten_ndesc; i++) {
11101                 dtrace_actdesc_t *act, *next;
11102                 dtrace_predicate_t *pred;
11103 
11104                 ep = enab->dten_desc[i];
11105 
11106                 if ((pred = ep->dted_pred.dtpdd_predicate) != NULL)
11107                         dtrace_predicate_release(pred, vstate);
11108 
11109                 for (act = ep->dted_action; act != NULL; act = next) {
11110                         next = act->dtad_next;
11111                         dtrace_actdesc_release(act, vstate);
11112                 }
11113 
11114                 kmem_free(ep, sizeof (dtrace_ecbdesc_t));
11115         }
11116 
11117         kmem_free(enab->dten_desc,
11118             enab->dten_maxdesc * sizeof (dtrace_enabling_t *));
11119 
11120         /*
11121          * If this was a retained enabling, decrement the dts_nretained count
11122          * and take it off of the dtrace_retained list.
11123          */
11124         if (enab->dten_prev != NULL || enab->dten_next != NULL ||
11125             dtrace_retained == enab) {
11126                 ASSERT(enab->dten_vstate->dtvs_state != NULL);
11127                 ASSERT(enab->dten_vstate->dtvs_state->dts_nretained > 0);
11128                 enab->dten_vstate->dtvs_state->dts_nretained--;
11129                 dtrace_retained_gen++;
11130         }
11131 
11132         if (enab->dten_prev == NULL) {
11133                 if (dtrace_retained == enab) {
11134                         dtrace_retained = enab->dten_next;
11135 
11136                         if (dtrace_retained != NULL)
11137                                 dtrace_retained->dten_prev = NULL;
11138                 }
11139         } else {
11140                 ASSERT(enab != dtrace_retained);
11141                 ASSERT(dtrace_retained != NULL);
11142                 enab->dten_prev->dten_next = enab->dten_next;
11143         }
11144 
11145         if (enab->dten_next != NULL) {
11146                 ASSERT(dtrace_retained != NULL);
11147                 enab->dten_next->dten_prev = enab->dten_prev;
11148         }
11149 
11150         kmem_free(enab, sizeof (dtrace_enabling_t));
11151 }
11152 
11153 static int
11154 dtrace_enabling_retain(dtrace_enabling_t *enab)
11155 {
11156         dtrace_state_t *state;
11157 
11158         ASSERT(MUTEX_HELD(&dtrace_lock));
11159         ASSERT(enab->dten_next == NULL && enab->dten_prev == NULL);
11160         ASSERT(enab->dten_vstate != NULL);
11161 
11162         state = enab->dten_vstate->dtvs_state;
11163         ASSERT(state != NULL);
11164 
11165         /*
11166          * We only allow each state to retain dtrace_retain_max enablings.
11167          */
11168         if (state->dts_nretained >= dtrace_retain_max)
11169                 return (ENOSPC);
11170 
11171         state->dts_nretained++;
11172         dtrace_retained_gen++;
11173 
11174         if (dtrace_retained == NULL) {
11175                 dtrace_retained = enab;
11176                 return (0);
11177         }
11178 
11179         enab->dten_next = dtrace_retained;
11180         dtrace_retained->dten_prev = enab;
11181         dtrace_retained = enab;
11182 
11183         return (0);
11184 }
11185 
11186 static int
11187 dtrace_enabling_replicate(dtrace_state_t *state, dtrace_probedesc_t *match,
11188     dtrace_probedesc_t *create)
11189 {
11190         dtrace_enabling_t *new, *enab;
11191         int found = 0, err = ENOENT;
11192 
11193         ASSERT(MUTEX_HELD(&dtrace_lock));
11194         ASSERT(strlen(match->dtpd_provider) < DTRACE_PROVNAMELEN);
11195         ASSERT(strlen(match->dtpd_mod) < DTRACE_MODNAMELEN);
11196         ASSERT(strlen(match->dtpd_func) < DTRACE_FUNCNAMELEN);
11197         ASSERT(strlen(match->dtpd_name) < DTRACE_NAMELEN);
11198 
11199         new = dtrace_enabling_create(&state->dts_vstate);
11200 
11201         /*
11202          * Iterate over all retained enablings, looking for enablings that
11203          * match the specified state.
11204          */
11205         for (enab = dtrace_retained; enab != NULL; enab = enab->dten_next) {
11206                 int i;
11207 
11208                 /*
11209                  * dtvs_state can only be NULL for helper enablings -- and
11210                  * helper enablings can't be retained.
11211                  */
11212                 ASSERT(enab->dten_vstate->dtvs_state != NULL);
11213 
11214                 if (enab->dten_vstate->dtvs_state != state)
11215                         continue;
11216 
11217                 /*
11218                  * Now iterate over each probe description; we're looking for
11219                  * an exact match to the specified probe description.
11220                  */
11221                 for (i = 0; i < enab->dten_ndesc; i++) {
11222                         dtrace_ecbdesc_t *ep = enab->dten_desc[i];
11223                         dtrace_probedesc_t *pd = &ep->dted_probe;
11224 
11225                         if (strcmp(pd->dtpd_provider, match->dtpd_provider))
11226                                 continue;
11227 
11228                         if (strcmp(pd->dtpd_mod, match->dtpd_mod))
11229                                 continue;
11230 
11231                         if (strcmp(pd->dtpd_func, match->dtpd_func))
11232                                 continue;
11233 
11234                         if (strcmp(pd->dtpd_name, match->dtpd_name))
11235                                 continue;
11236 
11237                         /*
11238                          * We have a winning probe!  Add it to our growing
11239                          * enabling.
11240                          */
11241                         found = 1;
11242                         dtrace_enabling_addlike(new, ep, create);
11243                 }
11244         }
11245 
11246         if (!found || (err = dtrace_enabling_retain(new)) != 0) {
11247                 dtrace_enabling_destroy(new);
11248                 return (err);
11249         }
11250 
11251         return (0);
11252 }
11253 
11254 static void
11255 dtrace_enabling_retract(dtrace_state_t *state)
11256 {
11257         dtrace_enabling_t *enab, *next;
11258 
11259         ASSERT(MUTEX_HELD(&dtrace_lock));
11260 
11261         /*
11262          * Iterate over all retained enablings, destroy the enablings retained
11263          * for the specified state.
11264          */
11265         for (enab = dtrace_retained; enab != NULL; enab = next) {
11266                 next = enab->dten_next;
11267 
11268                 /*
11269                  * dtvs_state can only be NULL for helper enablings -- and
11270                  * helper enablings can't be retained.
11271                  */
11272                 ASSERT(enab->dten_vstate->dtvs_state != NULL);
11273 
11274                 if (enab->dten_vstate->dtvs_state == state) {
11275                         ASSERT(state->dts_nretained > 0);
11276                         dtrace_enabling_destroy(enab);
11277                 }
11278         }
11279 
11280         ASSERT(state->dts_nretained == 0);
11281 }
11282 
11283 static int
11284 dtrace_enabling_match(dtrace_enabling_t *enab, int *nmatched)
11285 {
11286         int i = 0;
11287         int total_matched = 0, matched = 0;
11288 
11289         ASSERT(MUTEX_HELD(&cpu_lock));
11290         ASSERT(MUTEX_HELD(&dtrace_lock));
11291 
11292         for (i = 0; i < enab->dten_ndesc; i++) {
11293                 dtrace_ecbdesc_t *ep = enab->dten_desc[i];
11294 
11295                 enab->dten_current = ep;
11296                 enab->dten_error = 0;
11297 
11298                 /*
11299                  * If a provider failed to enable a probe then get out and
11300                  * let the consumer know we failed.
11301                  */
11302                 if ((matched = dtrace_probe_enable(&ep->dted_probe, enab)) < 0)
11303                         return (EBUSY);
11304 
11305                 total_matched += matched;
11306 
11307                 if (enab->dten_error != 0) {
11308                         /*
11309                          * If we get an error half-way through enabling the
11310                          * probes, we kick out -- perhaps with some number of
11311                          * them enabled.  Leaving enabled probes enabled may
11312                          * be slightly confusing for user-level, but we expect
11313                          * that no one will attempt to actually drive on in
11314                          * the face of such errors.  If this is an anonymous
11315                          * enabling (indicated with a NULL nmatched pointer),
11316                          * we cmn_err() a message.  We aren't expecting to
11317                          * get such an error -- such as it can exist at all,
11318                          * it would be a result of corrupted DOF in the driver
11319                          * properties.
11320                          */
11321                         if (nmatched == NULL) {
11322                                 cmn_err(CE_WARN, "dtrace_enabling_match() "
11323                                     "error on %p: %d", (void *)ep,
11324                                     enab->dten_error);
11325                         }
11326 
11327                         return (enab->dten_error);
11328                 }
11329         }
11330 
11331         enab->dten_probegen = dtrace_probegen;
11332         if (nmatched != NULL)
11333                 *nmatched = total_matched;
11334 
11335         return (0);
11336 }
11337 
11338 static void
11339 dtrace_enabling_matchall(void)
11340 {
11341         dtrace_enabling_t *enab;
11342 
11343         mutex_enter(&cpu_lock);
11344         mutex_enter(&dtrace_lock);
11345 
11346         /*
11347          * Iterate over all retained enablings to see if any probes match
11348          * against them.  We only perform this operation on enablings for which
11349          * we have sufficient permissions by virtue of being in the global zone
11350          * or in the same zone as the DTrace client.  Because we can be called
11351          * after dtrace_detach() has been called, we cannot assert that there
11352          * are retained enablings.  We can safely load from dtrace_retained,
11353          * however:  the taskq_destroy() at the end of dtrace_detach() will
11354          * block pending our completion.
11355          */
11356         for (enab = dtrace_retained; enab != NULL; enab = enab->dten_next) {
11357                 dtrace_cred_t *dcr = &enab->dten_vstate->dtvs_state->dts_cred;
11358                 cred_t *cr = dcr->dcr_cred;
11359                 zoneid_t zone = cr != NULL ? crgetzoneid(cr) : 0;
11360 
11361                 if ((dcr->dcr_visible & DTRACE_CRV_ALLZONE) || (cr != NULL &&
11362                     (zone == GLOBAL_ZONEID || getzoneid() == zone)))
11363                         (void) dtrace_enabling_match(enab, NULL);
11364         }
11365 
11366         mutex_exit(&dtrace_lock);
11367         mutex_exit(&cpu_lock);
11368 }
11369 
11370 /*
11371  * If an enabling is to be enabled without having matched probes (that is, if
11372  * dtrace_state_go() is to be called on the underlying dtrace_state_t), the
11373  * enabling must be _primed_ by creating an ECB for every ECB description.
11374  * This must be done to assure that we know the number of speculations, the
11375  * number of aggregations, the minimum buffer size needed, etc. before we
11376  * transition out of DTRACE_ACTIVITY_INACTIVE.  To do this without actually
11377  * enabling any probes, we create ECBs for every ECB decription, but with a
11378  * NULL probe -- which is exactly what this function does.
11379  */
11380 static void
11381 dtrace_enabling_prime(dtrace_state_t *state)
11382 {
11383         dtrace_enabling_t *enab;
11384         int i;
11385 
11386         for (enab = dtrace_retained; enab != NULL; enab = enab->dten_next) {
11387                 ASSERT(enab->dten_vstate->dtvs_state != NULL);
11388 
11389                 if (enab->dten_vstate->dtvs_state != state)
11390                         continue;
11391 
11392                 /*
11393                  * We don't want to prime an enabling more than once, lest
11394                  * we allow a malicious user to induce resource exhaustion.
11395                  * (The ECBs that result from priming an enabling aren't
11396                  * leaked -- but they also aren't deallocated until the
11397                  * consumer state is destroyed.)
11398                  */
11399                 if (enab->dten_primed)
11400                         continue;
11401 
11402                 for (i = 0; i < enab->dten_ndesc; i++) {
11403                         enab->dten_current = enab->dten_desc[i];
11404                         (void) dtrace_probe_enable(NULL, enab);
11405                 }
11406 
11407                 enab->dten_primed = 1;
11408         }
11409 }
11410 
11411 /*
11412  * Called to indicate that probes should be provided due to retained
11413  * enablings.  This is implemented in terms of dtrace_probe_provide(), but it
11414  * must take an initial lap through the enabling calling the dtps_provide()
11415  * entry point explicitly to allow for autocreated probes.
11416  */
11417 static void
11418 dtrace_enabling_provide(dtrace_provider_t *prv)
11419 {
11420         int i, all = 0;
11421         dtrace_probedesc_t desc;
11422         dtrace_genid_t gen;
11423 
11424         ASSERT(MUTEX_HELD(&dtrace_lock));
11425         ASSERT(MUTEX_HELD(&dtrace_provider_lock));
11426 
11427         if (prv == NULL) {
11428                 all = 1;
11429                 prv = dtrace_provider;
11430         }
11431 
11432         do {
11433                 dtrace_enabling_t *enab;
11434                 void *parg = prv->dtpv_arg;
11435 
11436 retry:
11437                 gen = dtrace_retained_gen;
11438                 for (enab = dtrace_retained; enab != NULL;
11439                     enab = enab->dten_next) {
11440                         for (i = 0; i < enab->dten_ndesc; i++) {
11441                                 desc = enab->dten_desc[i]->dted_probe;
11442                                 mutex_exit(&dtrace_lock);
11443                                 prv->dtpv_pops.dtps_provide(parg, &desc);
11444                                 mutex_enter(&dtrace_lock);
11445                                 /*
11446                                  * Process the retained enablings again if
11447                                  * they have changed while we weren't holding
11448                                  * dtrace_lock.
11449                                  */
11450                                 if (gen != dtrace_retained_gen)
11451                                         goto retry;
11452                         }
11453                 }
11454         } while (all && (prv = prv->dtpv_next) != NULL);
11455 
11456         mutex_exit(&dtrace_lock);
11457         dtrace_probe_provide(NULL, all ? NULL : prv);
11458         mutex_enter(&dtrace_lock);
11459 }
11460 
11461 /*
11462  * Called to reap ECBs that are attached to probes from defunct providers.
11463  */
11464 static void
11465 dtrace_enabling_reap(void)
11466 {
11467         dtrace_provider_t *prov;
11468         dtrace_probe_t *probe;
11469         dtrace_ecb_t *ecb;
11470         hrtime_t when;
11471         int i;
11472 
11473         mutex_enter(&cpu_lock);
11474         mutex_enter(&dtrace_lock);
11475 
11476         for (i = 0; i < dtrace_nprobes; i++) {
11477                 if ((probe = dtrace_probes[i]) == NULL)
11478                         continue;
11479 
11480                 if (probe->dtpr_ecb == NULL)
11481                         continue;
11482 
11483                 prov = probe->dtpr_provider;
11484 
11485                 if ((when = prov->dtpv_defunct) == 0)
11486                         continue;
11487 
11488                 /*
11489                  * We have ECBs on a defunct provider:  we want to reap these
11490                  * ECBs to allow the provider to unregister.  The destruction
11491                  * of these ECBs must be done carefully:  if we destroy the ECB
11492                  * and the consumer later wishes to consume an EPID that
11493                  * corresponds to the destroyed ECB (and if the EPID metadata
11494                  * has not been previously consumed), the consumer will abort
11495                  * processing on the unknown EPID.  To reduce (but not, sadly,
11496                  * eliminate) the possibility of this, we will only destroy an
11497                  * ECB for a defunct provider if, for the state that
11498                  * corresponds to the ECB:
11499                  *
11500                  *  (a) There is no speculative tracing (which can effectively
11501                  *      cache an EPID for an arbitrary amount of time).
11502                  *
11503                  *  (b) The principal buffers have been switched twice since the
11504                  *      provider became defunct.
11505                  *
11506                  *  (c) The aggregation buffers are of zero size or have been
11507                  *      switched twice since the provider became defunct.
11508                  *
11509                  * We use dts_speculates to determine (a) and call a function
11510                  * (dtrace_buffer_consumed()) to determine (b) and (c).  Note
11511                  * that as soon as we've been unable to destroy one of the ECBs
11512                  * associated with the probe, we quit trying -- reaping is only
11513                  * fruitful in as much as we can destroy all ECBs associated
11514                  * with the defunct provider's probes.
11515                  */
11516                 while ((ecb = probe->dtpr_ecb) != NULL) {
11517                         dtrace_state_t *state = ecb->dte_state;
11518                         dtrace_buffer_t *buf = state->dts_buffer;
11519                         dtrace_buffer_t *aggbuf = state->dts_aggbuffer;
11520 
11521                         if (state->dts_speculates)
11522                                 break;
11523 
11524                         if (!dtrace_buffer_consumed(buf, when))
11525                                 break;
11526 
11527                         if (!dtrace_buffer_consumed(aggbuf, when))
11528                                 break;
11529 
11530                         dtrace_ecb_disable(ecb);
11531                         ASSERT(probe->dtpr_ecb != ecb);
11532                         dtrace_ecb_destroy(ecb);
11533                 }
11534         }
11535 
11536         mutex_exit(&dtrace_lock);
11537         mutex_exit(&cpu_lock);
11538 }
11539 
11540 /*
11541  * DTrace DOF Functions
11542  */
11543 /*ARGSUSED*/
11544 static void
11545 dtrace_dof_error(dof_hdr_t *dof, const char *str)
11546 {
11547         if (dtrace_err_verbose)
11548                 cmn_err(CE_WARN, "failed to process DOF: %s", str);
11549 
11550 #ifdef DTRACE_ERRDEBUG
11551         dtrace_errdebug(str);
11552 #endif
11553 }
11554 
11555 /*
11556  * Create DOF out of a currently enabled state.  Right now, we only create
11557  * DOF containing the run-time options -- but this could be expanded to create
11558  * complete DOF representing the enabled state.
11559  */
11560 static dof_hdr_t *
11561 dtrace_dof_create(dtrace_state_t *state)
11562 {
11563         dof_hdr_t *dof;
11564         dof_sec_t *sec;
11565         dof_optdesc_t *opt;
11566         int i, len = sizeof (dof_hdr_t) +
11567             roundup(sizeof (dof_sec_t), sizeof (uint64_t)) +
11568             sizeof (dof_optdesc_t) * DTRACEOPT_MAX;
11569 
11570         ASSERT(MUTEX_HELD(&dtrace_lock));
11571 
11572         dof = kmem_zalloc(len, KM_SLEEP);
11573         dof->dofh_ident[DOF_ID_MAG0] = DOF_MAG_MAG0;
11574         dof->dofh_ident[DOF_ID_MAG1] = DOF_MAG_MAG1;
11575         dof->dofh_ident[DOF_ID_MAG2] = DOF_MAG_MAG2;
11576         dof->dofh_ident[DOF_ID_MAG3] = DOF_MAG_MAG3;
11577 
11578         dof->dofh_ident[DOF_ID_MODEL] = DOF_MODEL_NATIVE;
11579         dof->dofh_ident[DOF_ID_ENCODING] = DOF_ENCODE_NATIVE;
11580         dof->dofh_ident[DOF_ID_VERSION] = DOF_VERSION;
11581         dof->dofh_ident[DOF_ID_DIFVERS] = DIF_VERSION;
11582         dof->dofh_ident[DOF_ID_DIFIREG] = DIF_DIR_NREGS;
11583         dof->dofh_ident[DOF_ID_DIFTREG] = DIF_DTR_NREGS;
11584 
11585         dof->dofh_flags = 0;
11586         dof->dofh_hdrsize = sizeof (dof_hdr_t);
11587         dof->dofh_secsize = sizeof (dof_sec_t);
11588         dof->dofh_secnum = 1;        /* only DOF_SECT_OPTDESC */
11589         dof->dofh_secoff = sizeof (dof_hdr_t);
11590         dof->dofh_loadsz = len;
11591         dof->dofh_filesz = len;
11592         dof->dofh_pad = 0;
11593 
11594         /*
11595          * Fill in the option section header...
11596          */
11597         sec = (dof_sec_t *)((uintptr_t)dof + sizeof (dof_hdr_t));
11598         sec->dofs_type = DOF_SECT_OPTDESC;
11599         sec->dofs_align = sizeof (uint64_t);
11600         sec->dofs_flags = DOF_SECF_LOAD;
11601         sec->dofs_entsize = sizeof (dof_optdesc_t);
11602 
11603         opt = (dof_optdesc_t *)((uintptr_t)sec +
11604             roundup(sizeof (dof_sec_t), sizeof (uint64_t)));
11605 
11606         sec->dofs_offset = (uintptr_t)opt - (uintptr_t)dof;
11607         sec->dofs_size = sizeof (dof_optdesc_t) * DTRACEOPT_MAX;
11608 
11609         for (i = 0; i < DTRACEOPT_MAX; i++) {
11610                 opt[i].dofo_option = i;
11611                 opt[i].dofo_strtab = DOF_SECIDX_NONE;
11612                 opt[i].dofo_value = state->dts_options[i];
11613         }
11614 
11615         return (dof);
11616 }
11617 
11618 static dof_hdr_t *
11619 dtrace_dof_copyin(uintptr_t uarg, int *errp)
11620 {
11621         dof_hdr_t hdr, *dof;
11622 
11623         ASSERT(!MUTEX_HELD(&dtrace_lock));
11624 
11625         /*
11626          * First, we're going to copyin() the sizeof (dof_hdr_t).
11627          */
11628         if (copyin((void *)uarg, &hdr, sizeof (hdr)) != 0) {
11629                 dtrace_dof_error(NULL, "failed to copyin DOF header");
11630                 *errp = EFAULT;
11631                 return (NULL);
11632         }
11633 
11634         /*
11635          * Now we'll allocate the entire DOF and copy it in -- provided
11636          * that the length isn't outrageous.
11637          */
11638         if (hdr.dofh_loadsz >= dtrace_dof_maxsize) {
11639                 dtrace_dof_error(&hdr, "load size exceeds maximum");
11640                 *errp = E2BIG;
11641                 return (NULL);
11642         }
11643 
11644         if (hdr.dofh_loadsz < sizeof (hdr)) {
11645                 dtrace_dof_error(&hdr, "invalid load size");
11646                 *errp = EINVAL;
11647                 return (NULL);
11648         }
11649 
11650         dof = kmem_alloc(hdr.dofh_loadsz, KM_SLEEP);
11651 
11652         if (copyin((void *)uarg, dof, hdr.dofh_loadsz) != 0 ||
11653             dof->dofh_loadsz != hdr.dofh_loadsz) {
11654                 kmem_free(dof, hdr.dofh_loadsz);
11655                 *errp = EFAULT;
11656                 return (NULL);
11657         }
11658 
11659         return (dof);
11660 }
11661 
11662 static dof_hdr_t *
11663 dtrace_dof_property(const char *name)
11664 {
11665         uchar_t *buf;
11666         uint64_t loadsz;
11667         unsigned int len, i;
11668         dof_hdr_t *dof;
11669 
11670         /*
11671          * Unfortunately, array of values in .conf files are always (and
11672          * only) interpreted to be integer arrays.  We must read our DOF
11673          * as an integer array, and then squeeze it into a byte array.
11674          */
11675         if (ddi_prop_lookup_int_array(DDI_DEV_T_ANY, dtrace_devi, 0,
11676             (char *)name, (int **)&buf, &len) != DDI_PROP_SUCCESS)
11677                 return (NULL);
11678 
11679         for (i = 0; i < len; i++)
11680                 buf[i] = (uchar_t)(((int *)buf)[i]);
11681 
11682         if (len < sizeof (dof_hdr_t)) {
11683                 ddi_prop_free(buf);
11684                 dtrace_dof_error(NULL, "truncated header");
11685                 return (NULL);
11686         }
11687 
11688         if (len < (loadsz = ((dof_hdr_t *)buf)->dofh_loadsz)) {
11689                 ddi_prop_free(buf);
11690                 dtrace_dof_error(NULL, "truncated DOF");
11691                 return (NULL);
11692         }
11693 
11694         if (loadsz >= dtrace_dof_maxsize) {
11695                 ddi_prop_free(buf);
11696                 dtrace_dof_error(NULL, "oversized DOF");
11697                 return (NULL);
11698         }
11699 
11700         dof = kmem_alloc(loadsz, KM_SLEEP);
11701         bcopy(buf, dof, loadsz);
11702         ddi_prop_free(buf);
11703 
11704         return (dof);
11705 }
11706 
11707 static void
11708 dtrace_dof_destroy(dof_hdr_t *dof)
11709 {
11710         kmem_free(dof, dof->dofh_loadsz);
11711 }
11712 
11713 /*
11714  * Return the dof_sec_t pointer corresponding to a given section index.  If the
11715  * index is not valid, dtrace_dof_error() is called and NULL is returned.  If
11716  * a type other than DOF_SECT_NONE is specified, the header is checked against
11717  * this type and NULL is returned if the types do not match.
11718  */
11719 static dof_sec_t *
11720 dtrace_dof_sect(dof_hdr_t *dof, uint32_t type, dof_secidx_t i)
11721 {
11722         dof_sec_t *sec = (dof_sec_t *)(uintptr_t)
11723             ((uintptr_t)dof + dof->dofh_secoff + i * dof->dofh_secsize);
11724 
11725         if (i >= dof->dofh_secnum) {
11726                 dtrace_dof_error(dof, "referenced section index is invalid");
11727                 return (NULL);
11728         }
11729 
11730         if (!(sec->dofs_flags & DOF_SECF_LOAD)) {
11731                 dtrace_dof_error(dof, "referenced section is not loadable");
11732                 return (NULL);
11733         }
11734 
11735         if (type != DOF_SECT_NONE && type != sec->dofs_type) {
11736                 dtrace_dof_error(dof, "referenced section is the wrong type");
11737                 return (NULL);
11738         }
11739 
11740         return (sec);
11741 }
11742 
11743 static dtrace_probedesc_t *
11744 dtrace_dof_probedesc(dof_hdr_t *dof, dof_sec_t *sec, dtrace_probedesc_t *desc)
11745 {
11746         dof_probedesc_t *probe;
11747         dof_sec_t *strtab;
11748         uintptr_t daddr = (uintptr_t)dof;
11749         uintptr_t str;
11750         size_t size;
11751 
11752         if (sec->dofs_type != DOF_SECT_PROBEDESC) {
11753                 dtrace_dof_error(dof, "invalid probe section");
11754                 return (NULL);
11755         }
11756 
11757         if (sec->dofs_align != sizeof (dof_secidx_t)) {
11758                 dtrace_dof_error(dof, "bad alignment in probe description");
11759                 return (NULL);
11760         }
11761 
11762         if (sec->dofs_offset + sizeof (dof_probedesc_t) > dof->dofh_loadsz) {
11763                 dtrace_dof_error(dof, "truncated probe description");
11764                 return (NULL);
11765         }
11766 
11767         probe = (dof_probedesc_t *)(uintptr_t)(daddr + sec->dofs_offset);
11768         strtab = dtrace_dof_sect(dof, DOF_SECT_STRTAB, probe->dofp_strtab);
11769 
11770         if (strtab == NULL)
11771                 return (NULL);
11772 
11773         str = daddr + strtab->dofs_offset;
11774         size = strtab->dofs_size;
11775 
11776         if (probe->dofp_provider >= strtab->dofs_size) {
11777                 dtrace_dof_error(dof, "corrupt probe provider");
11778                 return (NULL);
11779         }
11780 
11781         (void) strncpy(desc->dtpd_provider,
11782             (char *)(str + probe->dofp_provider),
11783             MIN(DTRACE_PROVNAMELEN - 1, size - probe->dofp_provider));
11784 
11785         if (probe->dofp_mod >= strtab->dofs_size) {
11786                 dtrace_dof_error(dof, "corrupt probe module");
11787                 return (NULL);
11788         }
11789 
11790         (void) strncpy(desc->dtpd_mod, (char *)(str + probe->dofp_mod),
11791             MIN(DTRACE_MODNAMELEN - 1, size - probe->dofp_mod));
11792 
11793         if (probe->dofp_func >= strtab->dofs_size) {
11794                 dtrace_dof_error(dof, "corrupt probe function");
11795                 return (NULL);
11796         }
11797 
11798         (void) strncpy(desc->dtpd_func, (char *)(str + probe->dofp_func),
11799             MIN(DTRACE_FUNCNAMELEN - 1, size - probe->dofp_func));
11800 
11801         if (probe->dofp_name >= strtab->dofs_size) {
11802                 dtrace_dof_error(dof, "corrupt probe name");
11803                 return (NULL);
11804         }
11805 
11806         (void) strncpy(desc->dtpd_name, (char *)(str + probe->dofp_name),
11807             MIN(DTRACE_NAMELEN - 1, size - probe->dofp_name));
11808 
11809         return (desc);
11810 }
11811 
11812 static dtrace_difo_t *
11813 dtrace_dof_difo(dof_hdr_t *dof, dof_sec_t *sec, dtrace_vstate_t *vstate,
11814     cred_t *cr)
11815 {
11816         dtrace_difo_t *dp;
11817         size_t ttl = 0;
11818         dof_difohdr_t *dofd;
11819         uintptr_t daddr = (uintptr_t)dof;
11820         size_t max = dtrace_difo_maxsize;
11821         int i, l, n;
11822 
11823         static const struct {
11824                 int section;
11825                 int bufoffs;
11826                 int lenoffs;
11827                 int entsize;
11828                 int align;
11829                 const char *msg;
11830         } difo[] = {
11831                 { DOF_SECT_DIF, offsetof(dtrace_difo_t, dtdo_buf),
11832                 offsetof(dtrace_difo_t, dtdo_len), sizeof (dif_instr_t),
11833                 sizeof (dif_instr_t), "multiple DIF sections" },
11834 
11835                 { DOF_SECT_INTTAB, offsetof(dtrace_difo_t, dtdo_inttab),
11836                 offsetof(dtrace_difo_t, dtdo_intlen), sizeof (uint64_t),
11837                 sizeof (uint64_t), "multiple integer tables" },
11838 
11839                 { DOF_SECT_STRTAB, offsetof(dtrace_difo_t, dtdo_strtab),
11840                 offsetof(dtrace_difo_t, dtdo_strlen), 0,
11841                 sizeof (char), "multiple string tables" },
11842 
11843                 { DOF_SECT_VARTAB, offsetof(dtrace_difo_t, dtdo_vartab),
11844                 offsetof(dtrace_difo_t, dtdo_varlen), sizeof (dtrace_difv_t),
11845                 sizeof (uint_t), "multiple variable tables" },
11846 
11847                 { DOF_SECT_NONE, 0, 0, 0, NULL }
11848         };
11849 
11850         if (sec->dofs_type != DOF_SECT_DIFOHDR) {
11851                 dtrace_dof_error(dof, "invalid DIFO header section");
11852                 return (NULL);
11853         }
11854 
11855         if (sec->dofs_align != sizeof (dof_secidx_t)) {
11856                 dtrace_dof_error(dof, "bad alignment in DIFO header");
11857                 return (NULL);
11858         }
11859 
11860         if (sec->dofs_size < sizeof (dof_difohdr_t) ||
11861             sec->dofs_size % sizeof (dof_secidx_t)) {
11862                 dtrace_dof_error(dof, "bad size in DIFO header");
11863                 return (NULL);
11864         }
11865 
11866         dofd = (dof_difohdr_t *)(uintptr_t)(daddr + sec->dofs_offset);
11867         n = (sec->dofs_size - sizeof (*dofd)) / sizeof (dof_secidx_t) + 1;
11868 
11869         dp = kmem_zalloc(sizeof (dtrace_difo_t), KM_SLEEP);
11870         dp->dtdo_rtype = dofd->dofd_rtype;
11871 
11872         for (l = 0; l < n; l++) {
11873                 dof_sec_t *subsec;
11874                 void **bufp;
11875                 uint32_t *lenp;
11876 
11877                 if ((subsec = dtrace_dof_sect(dof, DOF_SECT_NONE,
11878                     dofd->dofd_links[l])) == NULL)
11879                         goto err; /* invalid section link */
11880 
11881                 if (ttl + subsec->dofs_size > max) {
11882                         dtrace_dof_error(dof, "exceeds maximum size");
11883                         goto err;
11884                 }
11885 
11886                 ttl += subsec->dofs_size;
11887 
11888                 for (i = 0; difo[i].section != DOF_SECT_NONE; i++) {
11889                         if (subsec->dofs_type != difo[i].section)
11890                                 continue;
11891 
11892                         if (!(subsec->dofs_flags & DOF_SECF_LOAD)) {
11893                                 dtrace_dof_error(dof, "section not loaded");
11894                                 goto err;
11895                         }
11896 
11897                         if (subsec->dofs_align != difo[i].align) {
11898                                 dtrace_dof_error(dof, "bad alignment");
11899                                 goto err;
11900                         }
11901 
11902                         bufp = (void **)((uintptr_t)dp + difo[i].bufoffs);
11903                         lenp = (uint32_t *)((uintptr_t)dp + difo[i].lenoffs);
11904 
11905                         if (*bufp != NULL) {
11906                                 dtrace_dof_error(dof, difo[i].msg);
11907                                 goto err;
11908                         }
11909 
11910                         if (difo[i].entsize != subsec->dofs_entsize) {
11911                                 dtrace_dof_error(dof, "entry size mismatch");
11912                                 goto err;
11913                         }
11914 
11915                         if (subsec->dofs_entsize != 0 &&
11916                             (subsec->dofs_size % subsec->dofs_entsize) != 0) {
11917                                 dtrace_dof_error(dof, "corrupt entry size");
11918                                 goto err;
11919                         }
11920 
11921                         *lenp = subsec->dofs_size;
11922                         *bufp = kmem_alloc(subsec->dofs_size, KM_SLEEP);
11923                         bcopy((char *)(uintptr_t)(daddr + subsec->dofs_offset),
11924                             *bufp, subsec->dofs_size);
11925 
11926                         if (subsec->dofs_entsize != 0)
11927                                 *lenp /= subsec->dofs_entsize;
11928 
11929                         break;
11930                 }
11931 
11932                 /*
11933                  * If we encounter a loadable DIFO sub-section that is not
11934                  * known to us, assume this is a broken program and fail.
11935                  */
11936                 if (difo[i].section == DOF_SECT_NONE &&
11937                     (subsec->dofs_flags & DOF_SECF_LOAD)) {
11938                         dtrace_dof_error(dof, "unrecognized DIFO subsection");
11939                         goto err;
11940                 }
11941         }
11942 
11943         if (dp->dtdo_buf == NULL) {
11944                 /*
11945                  * We can't have a DIF object without DIF text.
11946                  */
11947                 dtrace_dof_error(dof, "missing DIF text");
11948                 goto err;
11949         }
11950 
11951         /*
11952          * Before we validate the DIF object, run through the variable table
11953          * looking for the strings -- if any of their size are under, we'll set
11954          * their size to be the system-wide default string size.  Note that
11955          * this should _not_ happen if the "strsize" option has been set --
11956          * in this case, the compiler should have set the size to reflect the
11957          * setting of the option.
11958          */
11959         for (i = 0; i < dp->dtdo_varlen; i++) {
11960                 dtrace_difv_t *v = &dp->dtdo_vartab[i];
11961                 dtrace_diftype_t *t = &v->dtdv_type;
11962 
11963                 if (v->dtdv_id < DIF_VAR_OTHER_UBASE)
11964                         continue;
11965 
11966                 if (t->dtdt_kind == DIF_TYPE_STRING && t->dtdt_size == 0)
11967                         t->dtdt_size = dtrace_strsize_default;
11968         }
11969 
11970         if (dtrace_difo_validate(dp, vstate, DIF_DIR_NREGS, cr) != 0)
11971                 goto err;
11972 
11973         dtrace_difo_init(dp, vstate);
11974         return (dp);
11975 
11976 err:
11977         kmem_free(dp->dtdo_buf, dp->dtdo_len * sizeof (dif_instr_t));
11978         kmem_free(dp->dtdo_inttab, dp->dtdo_intlen * sizeof (uint64_t));
11979         kmem_free(dp->dtdo_strtab, dp->dtdo_strlen);
11980         kmem_free(dp->dtdo_vartab, dp->dtdo_varlen * sizeof (dtrace_difv_t));
11981 
11982         kmem_free(dp, sizeof (dtrace_difo_t));
11983         return (NULL);
11984 }
11985 
11986 static dtrace_predicate_t *
11987 dtrace_dof_predicate(dof_hdr_t *dof, dof_sec_t *sec, dtrace_vstate_t *vstate,
11988     cred_t *cr)
11989 {
11990         dtrace_difo_t *dp;
11991 
11992         if ((dp = dtrace_dof_difo(dof, sec, vstate, cr)) == NULL)
11993                 return (NULL);
11994 
11995         return (dtrace_predicate_create(dp));
11996 }
11997 
11998 static dtrace_actdesc_t *
11999 dtrace_dof_actdesc(dof_hdr_t *dof, dof_sec_t *sec, dtrace_vstate_t *vstate,
12000     cred_t *cr)
12001 {
12002         dtrace_actdesc_t *act, *first = NULL, *last = NULL, *next;
12003         dof_actdesc_t *desc;
12004         dof_sec_t *difosec;
12005         size_t offs;
12006         uintptr_t daddr = (uintptr_t)dof;
12007         uint64_t arg;
12008         dtrace_actkind_t kind;
12009 
12010         if (sec->dofs_type != DOF_SECT_ACTDESC) {
12011                 dtrace_dof_error(dof, "invalid action section");
12012                 return (NULL);
12013         }
12014 
12015         if (sec->dofs_offset + sizeof (dof_actdesc_t) > dof->dofh_loadsz) {
12016                 dtrace_dof_error(dof, "truncated action description");
12017                 return (NULL);
12018         }
12019 
12020         if (sec->dofs_align != sizeof (uint64_t)) {
12021                 dtrace_dof_error(dof, "bad alignment in action description");
12022                 return (NULL);
12023         }
12024 
12025         if (sec->dofs_size < sec->dofs_entsize) {
12026                 dtrace_dof_error(dof, "section entry size exceeds total size");
12027                 return (NULL);
12028         }
12029 
12030         if (sec->dofs_entsize != sizeof (dof_actdesc_t)) {
12031                 dtrace_dof_error(dof, "bad entry size in action description");
12032                 return (NULL);
12033         }
12034 
12035         if (sec->dofs_size / sec->dofs_entsize > dtrace_actions_max) {
12036                 dtrace_dof_error(dof, "actions exceed dtrace_actions_max");
12037                 return (NULL);
12038         }
12039 
12040         for (offs = 0; offs < sec->dofs_size; offs += sec->dofs_entsize) {
12041                 desc = (dof_actdesc_t *)(daddr +
12042                     (uintptr_t)sec->dofs_offset + offs);
12043                 kind = (dtrace_actkind_t)desc->dofa_kind;
12044 
12045                 if ((DTRACEACT_ISPRINTFLIKE(kind) &&
12046                     (kind != DTRACEACT_PRINTA ||
12047                     desc->dofa_strtab != DOF_SECIDX_NONE)) ||
12048                     (kind == DTRACEACT_DIFEXPR &&
12049                     desc->dofa_strtab != DOF_SECIDX_NONE)) {
12050                         dof_sec_t *strtab;
12051                         char *str, *fmt;
12052                         uint64_t i;
12053 
12054                         /*
12055                          * The argument to these actions is an index into the
12056                          * DOF string table.  For printf()-like actions, this
12057                          * is the format string.  For print(), this is the
12058                          * CTF type of the expression result.
12059                          */
12060                         if ((strtab = dtrace_dof_sect(dof,
12061                             DOF_SECT_STRTAB, desc->dofa_strtab)) == NULL)
12062                                 goto err;
12063 
12064                         str = (char *)((uintptr_t)dof +
12065                             (uintptr_t)strtab->dofs_offset);
12066 
12067                         for (i = desc->dofa_arg; i < strtab->dofs_size; i++) {
12068                                 if (str[i] == '\0')
12069                                         break;
12070                         }
12071 
12072                         if (i >= strtab->dofs_size) {
12073                                 dtrace_dof_error(dof, "bogus format string");
12074                                 goto err;
12075                         }
12076 
12077                         if (i == desc->dofa_arg) {
12078                                 dtrace_dof_error(dof, "empty format string");
12079                                 goto err;
12080                         }
12081 
12082                         i -= desc->dofa_arg;
12083                         fmt = kmem_alloc(i + 1, KM_SLEEP);
12084                         bcopy(&str[desc->dofa_arg], fmt, i + 1);
12085                         arg = (uint64_t)(uintptr_t)fmt;
12086                 } else {
12087                         if (kind == DTRACEACT_PRINTA) {
12088                                 ASSERT(desc->dofa_strtab == DOF_SECIDX_NONE);
12089                                 arg = 0;
12090                         } else {
12091                                 arg = desc->dofa_arg;
12092                         }
12093                 }
12094 
12095                 act = dtrace_actdesc_create(kind, desc->dofa_ntuple,
12096                     desc->dofa_uarg, arg);
12097 
12098                 if (last != NULL) {
12099                         last->dtad_next = act;
12100                 } else {
12101                         first = act;
12102                 }
12103 
12104                 last = act;
12105 
12106                 if (desc->dofa_difo == DOF_SECIDX_NONE)
12107                         continue;
12108 
12109                 if ((difosec = dtrace_dof_sect(dof,
12110                     DOF_SECT_DIFOHDR, desc->dofa_difo)) == NULL)
12111                         goto err;
12112 
12113                 act->dtad_difo = dtrace_dof_difo(dof, difosec, vstate, cr);
12114 
12115                 if (act->dtad_difo == NULL)
12116                         goto err;
12117         }
12118 
12119         ASSERT(first != NULL);
12120         return (first);
12121 
12122 err:
12123         for (act = first; act != NULL; act = next) {
12124                 next = act->dtad_next;
12125                 dtrace_actdesc_release(act, vstate);
12126         }
12127 
12128         return (NULL);
12129 }
12130 
12131 static dtrace_ecbdesc_t *
12132 dtrace_dof_ecbdesc(dof_hdr_t *dof, dof_sec_t *sec, dtrace_vstate_t *vstate,
12133     cred_t *cr)
12134 {
12135         dtrace_ecbdesc_t *ep;
12136         dof_ecbdesc_t *ecb;
12137         dtrace_probedesc_t *desc;
12138         dtrace_predicate_t *pred = NULL;
12139 
12140         if (sec->dofs_size < sizeof (dof_ecbdesc_t)) {
12141                 dtrace_dof_error(dof, "truncated ECB description");
12142                 return (NULL);
12143         }
12144 
12145         if (sec->dofs_align != sizeof (uint64_t)) {
12146                 dtrace_dof_error(dof, "bad alignment in ECB description");
12147                 return (NULL);
12148         }
12149 
12150         ecb = (dof_ecbdesc_t *)((uintptr_t)dof + (uintptr_t)sec->dofs_offset);
12151         sec = dtrace_dof_sect(dof, DOF_SECT_PROBEDESC, ecb->dofe_probes);
12152 
12153         if (sec == NULL)
12154                 return (NULL);
12155 
12156         ep = kmem_zalloc(sizeof (dtrace_ecbdesc_t), KM_SLEEP);
12157         ep->dted_uarg = ecb->dofe_uarg;
12158         desc = &ep->dted_probe;
12159 
12160         if (dtrace_dof_probedesc(dof, sec, desc) == NULL)
12161                 goto err;
12162 
12163         if (ecb->dofe_pred != DOF_SECIDX_NONE) {
12164                 if ((sec = dtrace_dof_sect(dof,
12165                     DOF_SECT_DIFOHDR, ecb->dofe_pred)) == NULL)
12166                         goto err;
12167 
12168                 if ((pred = dtrace_dof_predicate(dof, sec, vstate, cr)) == NULL)
12169                         goto err;
12170 
12171                 ep->dted_pred.dtpdd_predicate = pred;
12172         }
12173 
12174         if (ecb->dofe_actions != DOF_SECIDX_NONE) {
12175                 if ((sec = dtrace_dof_sect(dof,
12176                     DOF_SECT_ACTDESC, ecb->dofe_actions)) == NULL)
12177                         goto err;
12178 
12179                 ep->dted_action = dtrace_dof_actdesc(dof, sec, vstate, cr);
12180 
12181                 if (ep->dted_action == NULL)
12182                         goto err;
12183         }
12184 
12185         return (ep);
12186 
12187 err:
12188         if (pred != NULL)
12189                 dtrace_predicate_release(pred, vstate);
12190         kmem_free(ep, sizeof (dtrace_ecbdesc_t));
12191         return (NULL);
12192 }
12193 
12194 /*
12195  * Apply the relocations from the specified 'sec' (a DOF_SECT_URELHDR) to the
12196  * specified DOF.  At present, this amounts to simply adding 'ubase' to the
12197  * site of any user SETX relocations to account for load object base address.
12198  * In the future, if we need other relocations, this function can be extended.
12199  */
12200 static int
12201 dtrace_dof_relocate(dof_hdr_t *dof, dof_sec_t *sec, uint64_t ubase)
12202 {
12203         uintptr_t daddr = (uintptr_t)dof;
12204         dof_relohdr_t *dofr =
12205             (dof_relohdr_t *)(uintptr_t)(daddr + sec->dofs_offset);
12206         dof_sec_t *ss, *rs, *ts;
12207         dof_relodesc_t *r;
12208         uint_t i, n;
12209 
12210         if (sec->dofs_size < sizeof (dof_relohdr_t) ||
12211             sec->dofs_align != sizeof (dof_secidx_t)) {
12212                 dtrace_dof_error(dof, "invalid relocation header");
12213                 return (-1);
12214         }
12215 
12216         ss = dtrace_dof_sect(dof, DOF_SECT_STRTAB, dofr->dofr_strtab);
12217         rs = dtrace_dof_sect(dof, DOF_SECT_RELTAB, dofr->dofr_relsec);
12218         ts = dtrace_dof_sect(dof, DOF_SECT_NONE, dofr->dofr_tgtsec);
12219 
12220         if (ss == NULL || rs == NULL || ts == NULL)
12221                 return (-1); /* dtrace_dof_error() has been called already */
12222 
12223         if (rs->dofs_entsize < sizeof (dof_relodesc_t) ||
12224             rs->dofs_align != sizeof (uint64_t)) {
12225                 dtrace_dof_error(dof, "invalid relocation section");
12226                 return (-1);
12227         }
12228 
12229         r = (dof_relodesc_t *)(uintptr_t)(daddr + rs->dofs_offset);
12230         n = rs->dofs_size / rs->dofs_entsize;
12231 
12232         for (i = 0; i < n; i++) {
12233                 uintptr_t taddr = daddr + ts->dofs_offset + r->dofr_offset;
12234 
12235                 switch (r->dofr_type) {
12236                 case DOF_RELO_NONE:
12237                         break;
12238                 case DOF_RELO_SETX:
12239                         if (r->dofr_offset >= ts->dofs_size || r->dofr_offset +
12240                             sizeof (uint64_t) > ts->dofs_size) {
12241                                 dtrace_dof_error(dof, "bad relocation offset");
12242                                 return (-1);
12243                         }
12244 
12245                         if (!IS_P2ALIGNED(taddr, sizeof (uint64_t))) {
12246                                 dtrace_dof_error(dof, "misaligned setx relo");
12247                                 return (-1);
12248                         }
12249 
12250                         *(uint64_t *)taddr += ubase;
12251                         break;
12252                 default:
12253                         dtrace_dof_error(dof, "invalid relocation type");
12254                         return (-1);
12255                 }
12256 
12257                 r = (dof_relodesc_t *)((uintptr_t)r + rs->dofs_entsize);
12258         }
12259 
12260         return (0);
12261 }
12262 
12263 /*
12264  * The dof_hdr_t passed to dtrace_dof_slurp() should be a partially validated
12265  * header:  it should be at the front of a memory region that is at least
12266  * sizeof (dof_hdr_t) in size -- and then at least dof_hdr.dofh_loadsz in
12267  * size.  It need not be validated in any other way.
12268  */
12269 static int
12270 dtrace_dof_slurp(dof_hdr_t *dof, dtrace_vstate_t *vstate, cred_t *cr,
12271     dtrace_enabling_t **enabp, uint64_t ubase, int noprobes)
12272 {
12273         uint64_t len = dof->dofh_loadsz, seclen;
12274         uintptr_t daddr = (uintptr_t)dof;
12275         dtrace_ecbdesc_t *ep;
12276         dtrace_enabling_t *enab;
12277         uint_t i;
12278 
12279         ASSERT(MUTEX_HELD(&dtrace_lock));
12280         ASSERT(dof->dofh_loadsz >= sizeof (dof_hdr_t));
12281 
12282         /*
12283          * Check the DOF header identification bytes.  In addition to checking
12284          * valid settings, we also verify that unused bits/bytes are zeroed so
12285          * we can use them later without fear of regressing existing binaries.
12286          */
12287         if (bcmp(&dof->dofh_ident[DOF_ID_MAG0],
12288             DOF_MAG_STRING, DOF_MAG_STRLEN) != 0) {
12289                 dtrace_dof_error(dof, "DOF magic string mismatch");
12290                 return (-1);
12291         }
12292 
12293         if (dof->dofh_ident[DOF_ID_MODEL] != DOF_MODEL_ILP32 &&
12294             dof->dofh_ident[DOF_ID_MODEL] != DOF_MODEL_LP64) {
12295                 dtrace_dof_error(dof, "DOF has invalid data model");
12296                 return (-1);
12297         }
12298 
12299         if (dof->dofh_ident[DOF_ID_ENCODING] != DOF_ENCODE_NATIVE) {
12300                 dtrace_dof_error(dof, "DOF encoding mismatch");
12301                 return (-1);
12302         }
12303 
12304         if (dof->dofh_ident[DOF_ID_VERSION] != DOF_VERSION_1 &&
12305             dof->dofh_ident[DOF_ID_VERSION] != DOF_VERSION_2) {
12306                 dtrace_dof_error(dof, "DOF version mismatch");
12307                 return (-1);
12308         }
12309 
12310         if (dof->dofh_ident[DOF_ID_DIFVERS] != DIF_VERSION_2) {
12311                 dtrace_dof_error(dof, "DOF uses unsupported instruction set");
12312                 return (-1);
12313         }
12314 
12315         if (dof->dofh_ident[DOF_ID_DIFIREG] > DIF_DIR_NREGS) {
12316                 dtrace_dof_error(dof, "DOF uses too many integer registers");
12317                 return (-1);
12318         }
12319 
12320         if (dof->dofh_ident[DOF_ID_DIFTREG] > DIF_DTR_NREGS) {
12321                 dtrace_dof_error(dof, "DOF uses too many tuple registers");
12322                 return (-1);
12323         }
12324 
12325         for (i = DOF_ID_PAD; i < DOF_ID_SIZE; i++) {
12326                 if (dof->dofh_ident[i] != 0) {
12327                         dtrace_dof_error(dof, "DOF has invalid ident byte set");
12328                         return (-1);
12329                 }
12330         }
12331 
12332         if (dof->dofh_flags & ~DOF_FL_VALID) {
12333                 dtrace_dof_error(dof, "DOF has invalid flag bits set");
12334                 return (-1);
12335         }
12336 
12337         if (dof->dofh_secsize == 0) {
12338                 dtrace_dof_error(dof, "zero section header size");
12339                 return (-1);
12340         }
12341 
12342         /*
12343          * Check that the section headers don't exceed the amount of DOF
12344          * data.  Note that we cast the section size and number of sections
12345          * to uint64_t's to prevent possible overflow in the multiplication.
12346          */
12347         seclen = (uint64_t)dof->dofh_secnum * (uint64_t)dof->dofh_secsize;
12348 
12349         if (dof->dofh_secoff > len || seclen > len ||
12350             dof->dofh_secoff + seclen > len) {
12351                 dtrace_dof_error(dof, "truncated section headers");
12352                 return (-1);
12353         }
12354 
12355         if (!IS_P2ALIGNED(dof->dofh_secoff, sizeof (uint64_t))) {
12356                 dtrace_dof_error(dof, "misaligned section headers");
12357                 return (-1);
12358         }
12359 
12360         if (!IS_P2ALIGNED(dof->dofh_secsize, sizeof (uint64_t))) {
12361                 dtrace_dof_error(dof, "misaligned section size");
12362                 return (-1);
12363         }
12364 
12365         /*
12366          * Take an initial pass through the section headers to be sure that
12367          * the headers don't have stray offsets.  If the 'noprobes' flag is
12368          * set, do not permit sections relating to providers, probes, or args.
12369          */
12370         for (i = 0; i < dof->dofh_secnum; i++) {
12371                 dof_sec_t *sec = (dof_sec_t *)(daddr +
12372                     (uintptr_t)dof->dofh_secoff + i * dof->dofh_secsize);
12373 
12374                 if (noprobes) {
12375                         switch (sec->dofs_type) {
12376                         case DOF_SECT_PROVIDER:
12377                         case DOF_SECT_PROBES:
12378                         case DOF_SECT_PRARGS:
12379                         case DOF_SECT_PROFFS:
12380                                 dtrace_dof_error(dof, "illegal sections "
12381                                     "for enabling");
12382                                 return (-1);
12383                         }
12384                 }
12385 
12386                 if (DOF_SEC_ISLOADABLE(sec->dofs_type) &&
12387                     !(sec->dofs_flags & DOF_SECF_LOAD)) {
12388                         dtrace_dof_error(dof, "loadable section with load "
12389                             "flag unset");
12390                         return (-1);
12391                 }
12392 
12393                 if (!(sec->dofs_flags & DOF_SECF_LOAD))
12394                         continue; /* just ignore non-loadable sections */
12395 
12396                 if (sec->dofs_align & (sec->dofs_align - 1)) {
12397                         dtrace_dof_error(dof, "bad section alignment");
12398                         return (-1);
12399                 }
12400 
12401                 if (sec->dofs_offset & (sec->dofs_align - 1)) {
12402                         dtrace_dof_error(dof, "misaligned section");
12403                         return (-1);
12404                 }
12405 
12406                 if (sec->dofs_offset > len || sec->dofs_size > len ||
12407                     sec->dofs_offset + sec->dofs_size > len) {
12408                         dtrace_dof_error(dof, "corrupt section header");
12409                         return (-1);
12410                 }
12411 
12412                 if (sec->dofs_type == DOF_SECT_STRTAB && *((char *)daddr +
12413                     sec->dofs_offset + sec->dofs_size - 1) != '\0') {
12414                         dtrace_dof_error(dof, "non-terminating string table");
12415                         return (-1);
12416                 }
12417         }
12418 
12419         /*
12420          * Take a second pass through the sections and locate and perform any
12421          * relocations that are present.  We do this after the first pass to
12422          * be sure that all sections have had their headers validated.
12423          */
12424         for (i = 0; i < dof->dofh_secnum; i++) {
12425                 dof_sec_t *sec = (dof_sec_t *)(daddr +
12426                     (uintptr_t)dof->dofh_secoff + i * dof->dofh_secsize);
12427 
12428                 if (!(sec->dofs_flags & DOF_SECF_LOAD))
12429                         continue; /* skip sections that are not loadable */
12430 
12431                 switch (sec->dofs_type) {
12432                 case DOF_SECT_URELHDR:
12433                         if (dtrace_dof_relocate(dof, sec, ubase) != 0)
12434                                 return (-1);
12435                         break;
12436                 }
12437         }
12438 
12439         if ((enab = *enabp) == NULL)
12440                 enab = *enabp = dtrace_enabling_create(vstate);
12441 
12442         for (i = 0; i < dof->dofh_secnum; i++) {
12443                 dof_sec_t *sec = (dof_sec_t *)(daddr +
12444                     (uintptr_t)dof->dofh_secoff + i * dof->dofh_secsize);
12445 
12446                 if (sec->dofs_type != DOF_SECT_ECBDESC)
12447                         continue;
12448 
12449                 if ((ep = dtrace_dof_ecbdesc(dof, sec, vstate, cr)) == NULL) {
12450                         dtrace_enabling_destroy(enab);
12451                         *enabp = NULL;
12452                         return (-1);
12453                 }
12454 
12455                 dtrace_enabling_add(enab, ep);
12456         }
12457 
12458         return (0);
12459 }
12460 
12461 /*
12462  * Process DOF for any options.  This routine assumes that the DOF has been
12463  * at least processed by dtrace_dof_slurp().
12464  */
12465 static int
12466 dtrace_dof_options(dof_hdr_t *dof, dtrace_state_t *state)
12467 {
12468         int i, rval;
12469         uint32_t entsize;
12470         size_t offs;
12471         dof_optdesc_t *desc;
12472 
12473         for (i = 0; i < dof->dofh_secnum; i++) {
12474                 dof_sec_t *sec = (dof_sec_t *)((uintptr_t)dof +
12475                     (uintptr_t)dof->dofh_secoff + i * dof->dofh_secsize);
12476 
12477                 if (sec->dofs_type != DOF_SECT_OPTDESC)
12478                         continue;
12479 
12480                 if (sec->dofs_align != sizeof (uint64_t)) {
12481                         dtrace_dof_error(dof, "bad alignment in "
12482                             "option description");
12483                         return (EINVAL);
12484                 }
12485 
12486                 if ((entsize = sec->dofs_entsize) == 0) {
12487                         dtrace_dof_error(dof, "zeroed option entry size");
12488                         return (EINVAL);
12489                 }
12490 
12491                 if (entsize < sizeof (dof_optdesc_t)) {
12492                         dtrace_dof_error(dof, "bad option entry size");
12493                         return (EINVAL);
12494                 }
12495 
12496                 for (offs = 0; offs < sec->dofs_size; offs += entsize) {
12497                         desc = (dof_optdesc_t *)((uintptr_t)dof +
12498                             (uintptr_t)sec->dofs_offset + offs);
12499 
12500                         if (desc->dofo_strtab != DOF_SECIDX_NONE) {
12501                                 dtrace_dof_error(dof, "non-zero option string");
12502                                 return (EINVAL);
12503                         }
12504 
12505                         if (desc->dofo_value == DTRACEOPT_UNSET) {
12506                                 dtrace_dof_error(dof, "unset option");
12507                                 return (EINVAL);
12508                         }
12509 
12510                         if ((rval = dtrace_state_option(state,
12511                             desc->dofo_option, desc->dofo_value)) != 0) {
12512                                 dtrace_dof_error(dof, "rejected option");
12513                                 return (rval);
12514                         }
12515                 }
12516         }
12517 
12518         return (0);
12519 }
12520 
12521 /*
12522  * DTrace Consumer State Functions
12523  */
12524 int
12525 dtrace_dstate_init(dtrace_dstate_t *dstate, size_t size)
12526 {
12527         size_t hashsize, maxper, min, chunksize = dstate->dtds_chunksize;
12528         void *base;
12529         uintptr_t limit;
12530         dtrace_dynvar_t *dvar, *next, *start;
12531         int i;
12532 
12533         ASSERT(MUTEX_HELD(&dtrace_lock));
12534         ASSERT(dstate->dtds_base == NULL && dstate->dtds_percpu == NULL);
12535 
12536         bzero(dstate, sizeof (dtrace_dstate_t));
12537 
12538         if ((dstate->dtds_chunksize = chunksize) == 0)
12539                 dstate->dtds_chunksize = DTRACE_DYNVAR_CHUNKSIZE;
12540 
12541         if (size < (min = dstate->dtds_chunksize + sizeof (dtrace_dynhash_t)))
12542                 size = min;
12543 
12544         if ((base = kmem_zalloc(size, KM_NOSLEEP | KM_NORMALPRI)) == NULL)
12545                 return (ENOMEM);
12546 
12547         dstate->dtds_size = size;
12548         dstate->dtds_base = base;
12549         dstate->dtds_percpu = kmem_cache_alloc(dtrace_state_cache, KM_SLEEP);
12550         bzero(dstate->dtds_percpu, NCPU * sizeof (dtrace_dstate_percpu_t));
12551 
12552         hashsize = size / (dstate->dtds_chunksize + sizeof (dtrace_dynhash_t));
12553 
12554         if (hashsize != 1 && (hashsize & 1))
12555                 hashsize--;
12556 
12557         dstate->dtds_hashsize = hashsize;
12558         dstate->dtds_hash = dstate->dtds_base;
12559 
12560         /*
12561          * Set all of our hash buckets to point to the single sink, and (if
12562          * it hasn't already been set), set the sink's hash value to be the
12563          * sink sentinel value.  The sink is needed for dynamic variable
12564          * lookups to know that they have iterated over an entire, valid hash
12565          * chain.
12566          */
12567         for (i = 0; i < hashsize; i++)
12568                 dstate->dtds_hash[i].dtdh_chain = &dtrace_dynhash_sink;
12569 
12570         if (dtrace_dynhash_sink.dtdv_hashval != DTRACE_DYNHASH_SINK)
12571                 dtrace_dynhash_sink.dtdv_hashval = DTRACE_DYNHASH_SINK;
12572 
12573         /*
12574          * Determine number of active CPUs.  Divide free list evenly among
12575          * active CPUs.
12576          */
12577         start = (dtrace_dynvar_t *)
12578             ((uintptr_t)base + hashsize * sizeof (dtrace_dynhash_t));
12579         limit = (uintptr_t)base + size;
12580 
12581         maxper = (limit - (uintptr_t)start) / NCPU;
12582         maxper = (maxper / dstate->dtds_chunksize) * dstate->dtds_chunksize;
12583 
12584         for (i = 0; i < NCPU; i++) {
12585                 dstate->dtds_percpu[i].dtdsc_free = dvar = start;
12586 
12587                 /*
12588                  * If we don't even have enough chunks to make it once through
12589                  * NCPUs, we're just going to allocate everything to the first
12590                  * CPU.  And if we're on the last CPU, we're going to allocate
12591                  * whatever is left over.  In either case, we set the limit to
12592                  * be the limit of the dynamic variable space.
12593                  */
12594                 if (maxper == 0 || i == NCPU - 1) {
12595                         limit = (uintptr_t)base + size;
12596                         start = NULL;
12597                 } else {
12598                         limit = (uintptr_t)start + maxper;
12599                         start = (dtrace_dynvar_t *)limit;
12600                 }
12601 
12602                 ASSERT(limit <= (uintptr_t)base + size);
12603 
12604                 for (;;) {
12605                         next = (dtrace_dynvar_t *)((uintptr_t)dvar +
12606                             dstate->dtds_chunksize);
12607 
12608                         if ((uintptr_t)next + dstate->dtds_chunksize >= limit)
12609                                 break;
12610 
12611                         dvar->dtdv_next = next;
12612                         dvar = next;
12613                 }
12614 
12615                 if (maxper == 0)
12616                         break;
12617         }
12618 
12619         return (0);
12620 }
12621 
12622 void
12623 dtrace_dstate_fini(dtrace_dstate_t *dstate)
12624 {
12625         ASSERT(MUTEX_HELD(&cpu_lock));
12626 
12627         if (dstate->dtds_base == NULL)
12628                 return;
12629 
12630         kmem_free(dstate->dtds_base, dstate->dtds_size);
12631         kmem_cache_free(dtrace_state_cache, dstate->dtds_percpu);
12632 }
12633 
12634 static void
12635 dtrace_vstate_fini(dtrace_vstate_t *vstate)
12636 {
12637         /*
12638          * Logical XOR, where are you?
12639          */
12640         ASSERT((vstate->dtvs_nglobals == 0) ^ (vstate->dtvs_globals != NULL));
12641 
12642         if (vstate->dtvs_nglobals > 0) {
12643                 kmem_free(vstate->dtvs_globals, vstate->dtvs_nglobals *
12644                     sizeof (dtrace_statvar_t *));
12645         }
12646 
12647         if (vstate->dtvs_ntlocals > 0) {
12648                 kmem_free(vstate->dtvs_tlocals, vstate->dtvs_ntlocals *
12649                     sizeof (dtrace_difv_t));
12650         }
12651 
12652         ASSERT((vstate->dtvs_nlocals == 0) ^ (vstate->dtvs_locals != NULL));
12653 
12654         if (vstate->dtvs_nlocals > 0) {
12655                 kmem_free(vstate->dtvs_locals, vstate->dtvs_nlocals *
12656                     sizeof (dtrace_statvar_t *));
12657         }
12658 }
12659 
12660 static void
12661 dtrace_state_clean(dtrace_state_t *state)
12662 {
12663         if (state->dts_activity == DTRACE_ACTIVITY_INACTIVE)
12664                 return;
12665 
12666         dtrace_dynvar_clean(&state->dts_vstate.dtvs_dynvars);
12667         dtrace_speculation_clean(state);
12668 }
12669 
12670 static void
12671 dtrace_state_deadman(dtrace_state_t *state)
12672 {
12673         hrtime_t now;
12674 
12675         dtrace_sync();
12676 
12677         now = dtrace_gethrtime();
12678 
12679         if (state != dtrace_anon.dta_state &&
12680             now - state->dts_laststatus >= dtrace_deadman_user)
12681                 return;
12682 
12683         /*
12684          * We must be sure that dts_alive never appears to be less than the
12685          * value upon entry to dtrace_state_deadman(), and because we lack a
12686          * dtrace_cas64(), we cannot store to it atomically.  We thus instead
12687          * store INT64_MAX to it, followed by a memory barrier, followed by
12688          * the new value.  This assures that dts_alive never appears to be
12689          * less than its true value, regardless of the order in which the
12690          * stores to the underlying storage are issued.
12691          */
12692         state->dts_alive = INT64_MAX;
12693         dtrace_membar_producer();
12694         state->dts_alive = now;
12695 }
12696 
12697 dtrace_state_t *
12698 dtrace_state_create(dev_t *devp, cred_t *cr)
12699 {
12700         minor_t minor;
12701         major_t major;
12702         char c[30];
12703         dtrace_state_t *state;
12704         dtrace_optval_t *opt;
12705         int bufsize = NCPU * sizeof (dtrace_buffer_t), i;
12706 
12707         ASSERT(MUTEX_HELD(&dtrace_lock));
12708         ASSERT(MUTEX_HELD(&cpu_lock));
12709 
12710         minor = (minor_t)(uintptr_t)vmem_alloc(dtrace_minor, 1,
12711             VM_BESTFIT | VM_SLEEP);
12712 
12713         if (ddi_soft_state_zalloc(dtrace_softstate, minor) != DDI_SUCCESS) {
12714                 vmem_free(dtrace_minor, (void *)(uintptr_t)minor, 1);
12715                 return (NULL);
12716         }
12717 
12718         state = ddi_get_soft_state(dtrace_softstate, minor);
12719         state->dts_epid = DTRACE_EPIDNONE + 1;
12720 
12721         (void) snprintf(c, sizeof (c), "dtrace_aggid_%d", minor);
12722         state->dts_aggid_arena = vmem_create(c, (void *)1, UINT32_MAX, 1,
12723             NULL, NULL, NULL, 0, VM_SLEEP | VMC_IDENTIFIER);
12724 
12725         if (devp != NULL) {
12726                 major = getemajor(*devp);
12727         } else {
12728                 major = ddi_driver_major(dtrace_devi);
12729         }
12730 
12731         state->dts_dev = makedevice(major, minor);
12732 
12733         if (devp != NULL)
12734                 *devp = state->dts_dev;
12735 
12736         /*
12737          * We allocate NCPU buffers.  On the one hand, this can be quite
12738          * a bit of memory per instance (nearly 36K on a Starcat).  On the
12739          * other hand, it saves an additional memory reference in the probe
12740          * path.
12741          */
12742         state->dts_buffer = kmem_zalloc(bufsize, KM_SLEEP);
12743         state->dts_aggbuffer = kmem_zalloc(bufsize, KM_SLEEP);
12744         state->dts_cleaner = CYCLIC_NONE;
12745         state->dts_deadman = CYCLIC_NONE;
12746         state->dts_vstate.dtvs_state = state;
12747 
12748         for (i = 0; i < DTRACEOPT_MAX; i++)
12749                 state->dts_options[i] = DTRACEOPT_UNSET;
12750 
12751         /*
12752          * Set the default options.
12753          */
12754         opt = state->dts_options;
12755         opt[DTRACEOPT_BUFPOLICY] = DTRACEOPT_BUFPOLICY_SWITCH;
12756         opt[DTRACEOPT_BUFRESIZE] = DTRACEOPT_BUFRESIZE_AUTO;
12757         opt[DTRACEOPT_NSPEC] = dtrace_nspec_default;
12758         opt[DTRACEOPT_SPECSIZE] = dtrace_specsize_default;
12759         opt[DTRACEOPT_CPU] = (dtrace_optval_t)DTRACE_CPUALL;
12760         opt[DTRACEOPT_STRSIZE] = dtrace_strsize_default;
12761         opt[DTRACEOPT_STACKFRAMES] = dtrace_stackframes_default;
12762         opt[DTRACEOPT_USTACKFRAMES] = dtrace_ustackframes_default;
12763         opt[DTRACEOPT_CLEANRATE] = dtrace_cleanrate_default;
12764         opt[DTRACEOPT_AGGRATE] = dtrace_aggrate_default;
12765         opt[DTRACEOPT_SWITCHRATE] = dtrace_switchrate_default;
12766         opt[DTRACEOPT_STATUSRATE] = dtrace_statusrate_default;
12767         opt[DTRACEOPT_JSTACKFRAMES] = dtrace_jstackframes_default;
12768         opt[DTRACEOPT_JSTACKSTRSIZE] = dtrace_jstackstrsize_default;
12769 
12770         state->dts_activity = DTRACE_ACTIVITY_INACTIVE;
12771 
12772         /*
12773          * Depending on the user credentials, we set flag bits which alter probe
12774          * visibility or the amount of destructiveness allowed.  In the case of
12775          * actual anonymous tracing, or the possession of all privileges, all of
12776          * the normal checks are bypassed.
12777          */
12778         if (cr == NULL || PRIV_POLICY_ONLY(cr, PRIV_ALL, B_FALSE)) {
12779                 state->dts_cred.dcr_visible = DTRACE_CRV_ALL;
12780                 state->dts_cred.dcr_action = DTRACE_CRA_ALL;
12781         } else {
12782                 /*
12783                  * Set up the credentials for this instantiation.  We take a
12784                  * hold on the credential to prevent it from disappearing on
12785                  * us; this in turn prevents the zone_t referenced by this
12786                  * credential from disappearing.  This means that we can
12787                  * examine the credential and the zone from probe context.
12788                  */
12789                 crhold(cr);
12790                 state->dts_cred.dcr_cred = cr;
12791 
12792                 /*
12793                  * CRA_PROC means "we have *some* privilege for dtrace" and
12794                  * unlocks the use of variables like pid, zonename, etc.
12795                  */
12796                 if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_USER, B_FALSE) ||
12797                     PRIV_POLICY_ONLY(cr, PRIV_DTRACE_PROC, B_FALSE)) {
12798                         state->dts_cred.dcr_action |= DTRACE_CRA_PROC;
12799                 }
12800 
12801                 /*
12802                  * dtrace_user allows use of syscall and profile providers.
12803                  * If the user also has proc_owner and/or proc_zone, we
12804                  * extend the scope to include additional visibility and
12805                  * destructive power.
12806                  */
12807                 if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_USER, B_FALSE)) {
12808                         if (PRIV_POLICY_ONLY(cr, PRIV_PROC_OWNER, B_FALSE)) {
12809                                 state->dts_cred.dcr_visible |=
12810                                     DTRACE_CRV_ALLPROC;
12811 
12812                                 state->dts_cred.dcr_action |=
12813                                     DTRACE_CRA_PROC_DESTRUCTIVE_ALLUSER;
12814                         }
12815 
12816                         if (PRIV_POLICY_ONLY(cr, PRIV_PROC_ZONE, B_FALSE)) {
12817                                 state->dts_cred.dcr_visible |=
12818                                     DTRACE_CRV_ALLZONE;
12819 
12820                                 state->dts_cred.dcr_action |=
12821                                     DTRACE_CRA_PROC_DESTRUCTIVE_ALLZONE;
12822                         }
12823 
12824                         /*
12825                          * If we have all privs in whatever zone this is,
12826                          * we can do destructive things to processes which
12827                          * have altered credentials.
12828                          */
12829                         if (priv_isequalset(priv_getset(cr, PRIV_EFFECTIVE),
12830                             cr->cr_zone->zone_privset)) {
12831                                 state->dts_cred.dcr_action |=
12832                                     DTRACE_CRA_PROC_DESTRUCTIVE_CREDCHG;
12833                         }
12834                 }
12835 
12836                 /*
12837                  * Holding the dtrace_kernel privilege also implies that
12838                  * the user has the dtrace_user privilege from a visibility
12839                  * perspective.  But without further privileges, some
12840                  * destructive actions are not available.
12841                  */
12842                 if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_KERNEL, B_FALSE)) {
12843                         /*
12844                          * Make all probes in all zones visible.  However,
12845                          * this doesn't mean that all actions become available
12846                          * to all zones.
12847                          */
12848                         state->dts_cred.dcr_visible |= DTRACE_CRV_KERNEL |
12849                             DTRACE_CRV_ALLPROC | DTRACE_CRV_ALLZONE;
12850 
12851                         state->dts_cred.dcr_action |= DTRACE_CRA_KERNEL |
12852                             DTRACE_CRA_PROC;
12853                         /*
12854                          * Holding proc_owner means that destructive actions
12855                          * for *this* zone are allowed.
12856                          */
12857                         if (PRIV_POLICY_ONLY(cr, PRIV_PROC_OWNER, B_FALSE))
12858                                 state->dts_cred.dcr_action |=
12859                                     DTRACE_CRA_PROC_DESTRUCTIVE_ALLUSER;
12860 
12861                         /*
12862                          * Holding proc_zone means that destructive actions
12863                          * for this user/group ID in all zones is allowed.
12864                          */
12865                         if (PRIV_POLICY_ONLY(cr, PRIV_PROC_ZONE, B_FALSE))
12866                                 state->dts_cred.dcr_action |=
12867                                     DTRACE_CRA_PROC_DESTRUCTIVE_ALLZONE;
12868 
12869                         /*
12870                          * If we have all privs in whatever zone this is,
12871                          * we can do destructive things to processes which
12872                          * have altered credentials.
12873                          */
12874                         if (priv_isequalset(priv_getset(cr, PRIV_EFFECTIVE),
12875                             cr->cr_zone->zone_privset)) {
12876                                 state->dts_cred.dcr_action |=
12877                                     DTRACE_CRA_PROC_DESTRUCTIVE_CREDCHG;
12878                         }
12879                 }
12880 
12881                 /*
12882                  * Holding the dtrace_proc privilege gives control over fasttrap
12883                  * and pid providers.  We need to grant wider destructive
12884                  * privileges in the event that the user has proc_owner and/or
12885                  * proc_zone.
12886                  */
12887                 if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_PROC, B_FALSE)) {
12888                         if (PRIV_POLICY_ONLY(cr, PRIV_PROC_OWNER, B_FALSE))
12889                                 state->dts_cred.dcr_action |=
12890                                     DTRACE_CRA_PROC_DESTRUCTIVE_ALLUSER;
12891 
12892                         if (PRIV_POLICY_ONLY(cr, PRIV_PROC_ZONE, B_FALSE))
12893                                 state->dts_cred.dcr_action |=
12894                                     DTRACE_CRA_PROC_DESTRUCTIVE_ALLZONE;
12895                 }
12896         }
12897 
12898         return (state);
12899 }
12900 
12901 static int
12902 dtrace_state_buffer(dtrace_state_t *state, dtrace_buffer_t *buf, int which)
12903 {
12904         dtrace_optval_t *opt = state->dts_options, size;
12905         processorid_t cpu;
12906         int flags = 0, rval, factor, divisor = 1;
12907 
12908         ASSERT(MUTEX_HELD(&dtrace_lock));
12909         ASSERT(MUTEX_HELD(&cpu_lock));
12910         ASSERT(which < DTRACEOPT_MAX);
12911         ASSERT(state->dts_activity == DTRACE_ACTIVITY_INACTIVE ||
12912             (state == dtrace_anon.dta_state &&
12913             state->dts_activity == DTRACE_ACTIVITY_ACTIVE));
12914 
12915         if (opt[which] == DTRACEOPT_UNSET || opt[which] == 0)
12916                 return (0);
12917 
12918         if (opt[DTRACEOPT_CPU] != DTRACEOPT_UNSET)
12919                 cpu = opt[DTRACEOPT_CPU];
12920 
12921         if (which == DTRACEOPT_SPECSIZE)
12922                 flags |= DTRACEBUF_NOSWITCH;
12923 
12924         if (which == DTRACEOPT_BUFSIZE) {
12925                 if (opt[DTRACEOPT_BUFPOLICY] == DTRACEOPT_BUFPOLICY_RING)
12926                         flags |= DTRACEBUF_RING;
12927 
12928                 if (opt[DTRACEOPT_BUFPOLICY] == DTRACEOPT_BUFPOLICY_FILL)
12929                         flags |= DTRACEBUF_FILL;
12930 
12931                 if (state != dtrace_anon.dta_state ||
12932                     state->dts_activity != DTRACE_ACTIVITY_ACTIVE)
12933                         flags |= DTRACEBUF_INACTIVE;
12934         }
12935 
12936         for (size = opt[which]; size >= sizeof (uint64_t); size /= divisor) {
12937                 /*
12938                  * The size must be 8-byte aligned.  If the size is not 8-byte
12939                  * aligned, drop it down by the difference.
12940                  */
12941                 if (size & (sizeof (uint64_t) - 1))
12942                         size -= size & (sizeof (uint64_t) - 1);
12943 
12944                 if (size < state->dts_reserve) {
12945                         /*
12946                          * Buffers always must be large enough to accommodate
12947                          * their prereserved space.  We return E2BIG instead
12948                          * of ENOMEM in this case to allow for user-level
12949                          * software to differentiate the cases.
12950                          */
12951                         return (E2BIG);
12952                 }
12953 
12954                 rval = dtrace_buffer_alloc(buf, size, flags, cpu, &factor);
12955 
12956                 if (rval != ENOMEM) {
12957                         opt[which] = size;
12958                         return (rval);
12959                 }
12960 
12961                 if (opt[DTRACEOPT_BUFRESIZE] == DTRACEOPT_BUFRESIZE_MANUAL)
12962                         return (rval);
12963 
12964                 for (divisor = 2; divisor < factor; divisor <<= 1)
12965                         continue;
12966         }
12967 
12968         return (ENOMEM);
12969 }
12970 
12971 static int
12972 dtrace_state_buffers(dtrace_state_t *state)
12973 {
12974         dtrace_speculation_t *spec = state->dts_speculations;
12975         int rval, i;
12976 
12977         if ((rval = dtrace_state_buffer(state, state->dts_buffer,
12978             DTRACEOPT_BUFSIZE)) != 0)
12979                 return (rval);
12980 
12981         if ((rval = dtrace_state_buffer(state, state->dts_aggbuffer,
12982             DTRACEOPT_AGGSIZE)) != 0)
12983                 return (rval);
12984 
12985         for (i = 0; i < state->dts_nspeculations; i++) {
12986                 if ((rval = dtrace_state_buffer(state,
12987                     spec[i].dtsp_buffer, DTRACEOPT_SPECSIZE)) != 0)
12988                         return (rval);
12989         }
12990 
12991         return (0);
12992 }
12993 
12994 static void
12995 dtrace_state_prereserve(dtrace_state_t *state)
12996 {
12997         dtrace_ecb_t *ecb;
12998         dtrace_probe_t *probe;
12999 
13000         state->dts_reserve = 0;
13001 
13002         if (state->dts_options[DTRACEOPT_BUFPOLICY] != DTRACEOPT_BUFPOLICY_FILL)
13003                 return;
13004 
13005         /*
13006          * If our buffer policy is a "fill" buffer policy, we need to set the
13007          * prereserved space to be the space required by the END probes.
13008          */
13009         probe = dtrace_probes[dtrace_probeid_end - 1];
13010         ASSERT(probe != NULL);
13011 
13012         for (ecb = probe->dtpr_ecb; ecb != NULL; ecb = ecb->dte_next) {
13013                 if (ecb->dte_state != state)
13014                         continue;
13015 
13016                 state->dts_reserve += ecb->dte_needed + ecb->dte_alignment;
13017         }
13018 }
13019 
13020 static int
13021 dtrace_state_go(dtrace_state_t *state, processorid_t *cpu)
13022 {
13023         dtrace_optval_t *opt = state->dts_options, sz, nspec;
13024         dtrace_speculation_t *spec;
13025         dtrace_buffer_t *buf;
13026         cyc_handler_t hdlr;
13027         cyc_time_t when;
13028         int rval = 0, i, bufsize = NCPU * sizeof (dtrace_buffer_t);
13029         dtrace_icookie_t cookie;
13030 
13031         mutex_enter(&cpu_lock);
13032         mutex_enter(&dtrace_lock);
13033 
13034         if (state->dts_activity != DTRACE_ACTIVITY_INACTIVE) {
13035                 rval = EBUSY;
13036                 goto out;
13037         }
13038 
13039         /*
13040          * Before we can perform any checks, we must prime all of the
13041          * retained enablings that correspond to this state.
13042          */
13043         dtrace_enabling_prime(state);
13044 
13045         if (state->dts_destructive && !state->dts_cred.dcr_destructive) {
13046                 rval = EACCES;
13047                 goto out;
13048         }
13049 
13050         dtrace_state_prereserve(state);
13051 
13052         /*
13053          * Now we want to do is try to allocate our speculations.
13054          * We do not automatically resize the number of speculations; if
13055          * this fails, we will fail the operation.
13056          */
13057         nspec = opt[DTRACEOPT_NSPEC];
13058         ASSERT(nspec != DTRACEOPT_UNSET);
13059 
13060         if (nspec > INT_MAX) {
13061                 rval = ENOMEM;
13062                 goto out;
13063         }
13064 
13065         spec = kmem_zalloc(nspec * sizeof (dtrace_speculation_t),
13066             KM_NOSLEEP | KM_NORMALPRI);
13067 
13068         if (spec == NULL) {
13069                 rval = ENOMEM;
13070                 goto out;
13071         }
13072 
13073         state->dts_speculations = spec;
13074         state->dts_nspeculations = (int)nspec;
13075 
13076         for (i = 0; i < nspec; i++) {
13077                 if ((buf = kmem_zalloc(bufsize,
13078                     KM_NOSLEEP | KM_NORMALPRI)) == NULL) {
13079                         rval = ENOMEM;
13080                         goto err;
13081                 }
13082 
13083                 spec[i].dtsp_buffer = buf;
13084         }
13085 
13086         if (opt[DTRACEOPT_GRABANON] != DTRACEOPT_UNSET) {
13087                 if (dtrace_anon.dta_state == NULL) {
13088                         rval = ENOENT;
13089                         goto out;
13090                 }
13091 
13092                 if (state->dts_necbs != 0) {
13093                         rval = EALREADY;
13094                         goto out;
13095                 }
13096 
13097                 state->dts_anon = dtrace_anon_grab();
13098                 ASSERT(state->dts_anon != NULL);
13099                 state = state->dts_anon;
13100 
13101                 /*
13102                  * We want "grabanon" to be set in the grabbed state, so we'll
13103                  * copy that option value from the grabbing state into the
13104                  * grabbed state.
13105                  */
13106                 state->dts_options[DTRACEOPT_GRABANON] =
13107                     opt[DTRACEOPT_GRABANON];
13108 
13109                 *cpu = dtrace_anon.dta_beganon;
13110 
13111                 /*
13112                  * If the anonymous state is active (as it almost certainly
13113                  * is if the anonymous enabling ultimately matched anything),
13114                  * we don't allow any further option processing -- but we
13115                  * don't return failure.
13116                  */
13117                 if (state->dts_activity != DTRACE_ACTIVITY_INACTIVE)
13118                         goto out;
13119         }
13120 
13121         if (opt[DTRACEOPT_AGGSIZE] != DTRACEOPT_UNSET &&
13122             opt[DTRACEOPT_AGGSIZE] != 0) {
13123                 if (state->dts_aggregations == NULL) {
13124                         /*
13125                          * We're not going to create an aggregation buffer
13126                          * because we don't have any ECBs that contain
13127                          * aggregations -- set this option to 0.
13128                          */
13129                         opt[DTRACEOPT_AGGSIZE] = 0;
13130                 } else {
13131                         /*
13132                          * If we have an aggregation buffer, we must also have
13133                          * a buffer to use as scratch.
13134                          */
13135                         if (opt[DTRACEOPT_BUFSIZE] == DTRACEOPT_UNSET ||
13136                             opt[DTRACEOPT_BUFSIZE] < state->dts_needed) {
13137                                 opt[DTRACEOPT_BUFSIZE] = state->dts_needed;
13138                         }
13139                 }
13140         }
13141 
13142         if (opt[DTRACEOPT_SPECSIZE] != DTRACEOPT_UNSET &&
13143             opt[DTRACEOPT_SPECSIZE] != 0) {
13144                 if (!state->dts_speculates) {
13145                         /*
13146                          * We're not going to create speculation buffers
13147                          * because we don't have any ECBs that actually
13148                          * speculate -- set the speculation size to 0.
13149                          */
13150                         opt[DTRACEOPT_SPECSIZE] = 0;
13151                 }
13152         }
13153 
13154         /*
13155          * The bare minimum size for any buffer that we're actually going to
13156          * do anything to is sizeof (uint64_t).
13157          */
13158         sz = sizeof (uint64_t);
13159 
13160         if ((state->dts_needed != 0 && opt[DTRACEOPT_BUFSIZE] < sz) ||
13161             (state->dts_speculates && opt[DTRACEOPT_SPECSIZE] < sz) ||
13162             (state->dts_aggregations != NULL && opt[DTRACEOPT_AGGSIZE] < sz)) {
13163                 /*
13164                  * A buffer size has been explicitly set to 0 (or to a size
13165                  * that will be adjusted to 0) and we need the space -- we
13166                  * need to return failure.  We return ENOSPC to differentiate
13167                  * it from failing to allocate a buffer due to failure to meet
13168                  * the reserve (for which we return E2BIG).
13169                  */
13170                 rval = ENOSPC;
13171                 goto out;
13172         }
13173 
13174         if ((rval = dtrace_state_buffers(state)) != 0)
13175                 goto err;
13176 
13177         if ((sz = opt[DTRACEOPT_DYNVARSIZE]) == DTRACEOPT_UNSET)
13178                 sz = dtrace_dstate_defsize;
13179 
13180         do {
13181                 rval = dtrace_dstate_init(&state->dts_vstate.dtvs_dynvars, sz);
13182 
13183                 if (rval == 0)
13184                         break;
13185 
13186                 if (opt[DTRACEOPT_BUFRESIZE] == DTRACEOPT_BUFRESIZE_MANUAL)
13187                         goto err;
13188         } while (sz >>= 1);
13189 
13190         opt[DTRACEOPT_DYNVARSIZE] = sz;
13191 
13192         if (rval != 0)
13193                 goto err;
13194 
13195         if (opt[DTRACEOPT_STATUSRATE] > dtrace_statusrate_max)
13196                 opt[DTRACEOPT_STATUSRATE] = dtrace_statusrate_max;
13197 
13198         if (opt[DTRACEOPT_CLEANRATE] == 0)
13199                 opt[DTRACEOPT_CLEANRATE] = dtrace_cleanrate_max;
13200 
13201         if (opt[DTRACEOPT_CLEANRATE] < dtrace_cleanrate_min)
13202                 opt[DTRACEOPT_CLEANRATE] = dtrace_cleanrate_min;
13203 
13204         if (opt[DTRACEOPT_CLEANRATE] > dtrace_cleanrate_max)
13205                 opt[DTRACEOPT_CLEANRATE] = dtrace_cleanrate_max;
13206 
13207         hdlr.cyh_func = (cyc_func_t)dtrace_state_clean;
13208         hdlr.cyh_arg = state;
13209         hdlr.cyh_level = CY_LOW_LEVEL;
13210 
13211         when.cyt_when = 0;
13212         when.cyt_interval = opt[DTRACEOPT_CLEANRATE];
13213 
13214         state->dts_cleaner = cyclic_add(&hdlr, &when);
13215 
13216         hdlr.cyh_func = (cyc_func_t)dtrace_state_deadman;
13217         hdlr.cyh_arg = state;
13218         hdlr.cyh_level = CY_LOW_LEVEL;
13219 
13220         when.cyt_when = 0;
13221         when.cyt_interval = dtrace_deadman_interval;
13222 
13223         state->dts_alive = state->dts_laststatus = dtrace_gethrtime();
13224         state->dts_deadman = cyclic_add(&hdlr, &when);
13225 
13226         state->dts_activity = DTRACE_ACTIVITY_WARMUP;
13227 
13228         if (state->dts_getf != 0 &&
13229             !(state->dts_cred.dcr_visible & DTRACE_CRV_KERNEL)) {
13230                 /*
13231                  * We don't have kernel privs but we have at least one call
13232                  * to getf(); we need to bump our zone's count, and (if
13233                  * this is the first enabling to have an unprivileged call
13234                  * to getf()) we need to hook into closef().
13235                  */
13236                 state->dts_cred.dcr_cred->cr_zone->zone_dtrace_getf++;
13237 
13238                 if (dtrace_getf++ == 0) {
13239                         ASSERT(dtrace_closef == NULL);
13240                         dtrace_closef = dtrace_getf_barrier;
13241                 }
13242         }
13243 
13244         /*
13245          * Now it's time to actually fire the BEGIN probe.  We need to disable
13246          * interrupts here both to record the CPU on which we fired the BEGIN
13247          * probe (the data from this CPU will be processed first at user
13248          * level) and to manually activate the buffer for this CPU.
13249          */
13250         cookie = dtrace_interrupt_disable();
13251         *cpu = CPU->cpu_id;
13252         ASSERT(state->dts_buffer[*cpu].dtb_flags & DTRACEBUF_INACTIVE);
13253         state->dts_buffer[*cpu].dtb_flags &= ~DTRACEBUF_INACTIVE;
13254 
13255         dtrace_probe(dtrace_probeid_begin,
13256             (uint64_t)(uintptr_t)state, 0, 0, 0, 0);
13257         dtrace_interrupt_enable(cookie);
13258         /*
13259          * We may have had an exit action from a BEGIN probe; only change our
13260          * state to ACTIVE if we're still in WARMUP.
13261          */
13262         ASSERT(state->dts_activity == DTRACE_ACTIVITY_WARMUP ||
13263             state->dts_activity == DTRACE_ACTIVITY_DRAINING);
13264 
13265         if (state->dts_activity == DTRACE_ACTIVITY_WARMUP)
13266                 state->dts_activity = DTRACE_ACTIVITY_ACTIVE;
13267 
13268         /*
13269          * Regardless of whether or not now we're in ACTIVE or DRAINING, we
13270          * want each CPU to transition its principal buffer out of the
13271          * INACTIVE state.  Doing this assures that no CPU will suddenly begin
13272          * processing an ECB halfway down a probe's ECB chain; all CPUs will
13273          * atomically transition from processing none of a state's ECBs to
13274          * processing all of them.
13275          */
13276         dtrace_xcall(DTRACE_CPUALL,
13277             (dtrace_xcall_t)dtrace_buffer_activate, state);
13278         goto out;
13279 
13280 err:
13281         dtrace_buffer_free(state->dts_buffer);
13282         dtrace_buffer_free(state->dts_aggbuffer);
13283 
13284         if ((nspec = state->dts_nspeculations) == 0) {
13285                 ASSERT(state->dts_speculations == NULL);
13286                 goto out;
13287         }
13288 
13289         spec = state->dts_speculations;
13290         ASSERT(spec != NULL);
13291 
13292         for (i = 0; i < state->dts_nspeculations; i++) {
13293                 if ((buf = spec[i].dtsp_buffer) == NULL)
13294                         break;
13295 
13296                 dtrace_buffer_free(buf);
13297                 kmem_free(buf, bufsize);
13298         }
13299 
13300         kmem_free(spec, nspec * sizeof (dtrace_speculation_t));
13301         state->dts_nspeculations = 0;
13302         state->dts_speculations = NULL;
13303 
13304 out:
13305         mutex_exit(&dtrace_lock);
13306         mutex_exit(&cpu_lock);
13307 
13308         return (rval);
13309 }
13310 
13311 static int
13312 dtrace_state_stop(dtrace_state_t *state, processorid_t *cpu)
13313 {
13314         dtrace_icookie_t cookie;
13315 
13316         ASSERT(MUTEX_HELD(&dtrace_lock));
13317 
13318         if (state->dts_activity != DTRACE_ACTIVITY_ACTIVE &&
13319             state->dts_activity != DTRACE_ACTIVITY_DRAINING)
13320                 return (EINVAL);
13321 
13322         /*
13323          * We'll set the activity to DTRACE_ACTIVITY_DRAINING, and issue a sync
13324          * to be sure that every CPU has seen it.  See below for the details
13325          * on why this is done.
13326          */
13327         state->dts_activity = DTRACE_ACTIVITY_DRAINING;
13328         dtrace_sync();
13329 
13330         /*
13331          * By this point, it is impossible for any CPU to be still processing
13332          * with DTRACE_ACTIVITY_ACTIVE.  We can thus set our activity to
13333          * DTRACE_ACTIVITY_COOLDOWN and know that we're not racing with any
13334          * other CPU in dtrace_buffer_reserve().  This allows dtrace_probe()
13335          * and callees to know that the activity is DTRACE_ACTIVITY_COOLDOWN
13336          * iff we're in the END probe.
13337          */
13338         state->dts_activity = DTRACE_ACTIVITY_COOLDOWN;
13339         dtrace_sync();
13340         ASSERT(state->dts_activity == DTRACE_ACTIVITY_COOLDOWN);
13341 
13342         /*
13343          * Finally, we can release the reserve and call the END probe.  We
13344          * disable interrupts across calling the END probe to allow us to
13345          * return the CPU on which we actually called the END probe.  This
13346          * allows user-land to be sure that this CPU's principal buffer is
13347          * processed last.
13348          */
13349         state->dts_reserve = 0;
13350 
13351         cookie = dtrace_interrupt_disable();
13352         *cpu = CPU->cpu_id;
13353         dtrace_probe(dtrace_probeid_end,
13354             (uint64_t)(uintptr_t)state, 0, 0, 0, 0);
13355         dtrace_interrupt_enable(cookie);
13356 
13357         state->dts_activity = DTRACE_ACTIVITY_STOPPED;
13358         dtrace_sync();
13359 
13360         if (state->dts_getf != 0 &&
13361             !(state->dts_cred.dcr_visible & DTRACE_CRV_KERNEL)) {
13362                 /*
13363                  * We don't have kernel privs but we have at least one call
13364                  * to getf(); we need to lower our zone's count, and (if
13365                  * this is the last enabling to have an unprivileged call
13366                  * to getf()) we need to clear the closef() hook.
13367                  */
13368                 ASSERT(state->dts_cred.dcr_cred->cr_zone->zone_dtrace_getf > 0);
13369                 ASSERT(dtrace_closef == dtrace_getf_barrier);
13370                 ASSERT(dtrace_getf > 0);
13371 
13372                 state->dts_cred.dcr_cred->cr_zone->zone_dtrace_getf--;
13373 
13374                 if (--dtrace_getf == 0)
13375                         dtrace_closef = NULL;
13376         }
13377 
13378         return (0);
13379 }
13380 
13381 static int
13382 dtrace_state_option(dtrace_state_t *state, dtrace_optid_t option,
13383     dtrace_optval_t val)
13384 {
13385         ASSERT(MUTEX_HELD(&dtrace_lock));
13386 
13387         if (state->dts_activity != DTRACE_ACTIVITY_INACTIVE)
13388                 return (EBUSY);
13389 
13390         if (option >= DTRACEOPT_MAX)
13391                 return (EINVAL);
13392 
13393         if (option != DTRACEOPT_CPU && val < 0)
13394                 return (EINVAL);
13395 
13396         switch (option) {
13397         case DTRACEOPT_DESTRUCTIVE:
13398                 if (dtrace_destructive_disallow)
13399                         return (EACCES);
13400 
13401                 state->dts_cred.dcr_destructive = 1;
13402                 break;
13403 
13404         case DTRACEOPT_BUFSIZE:
13405         case DTRACEOPT_DYNVARSIZE:
13406         case DTRACEOPT_AGGSIZE:
13407         case DTRACEOPT_SPECSIZE:
13408         case DTRACEOPT_STRSIZE:
13409                 if (val < 0)
13410                         return (EINVAL);
13411 
13412                 if (val >= LONG_MAX) {
13413                         /*
13414                          * If this is an otherwise negative value, set it to
13415                          * the highest multiple of 128m less than LONG_MAX.
13416                          * Technically, we're adjusting the size without
13417                          * regard to the buffer resizing policy, but in fact,
13418                          * this has no effect -- if we set the buffer size to
13419                          * ~LONG_MAX and the buffer policy is ultimately set to
13420                          * be "manual", the buffer allocation is guaranteed to
13421                          * fail, if only because the allocation requires two
13422                          * buffers.  (We set the the size to the highest
13423                          * multiple of 128m because it ensures that the size
13424                          * will remain a multiple of a megabyte when
13425                          * repeatedly halved -- all the way down to 15m.)
13426                          */
13427                         val = LONG_MAX - (1 << 27) + 1;
13428                 }
13429         }
13430 
13431         state->dts_options[option] = val;
13432 
13433         return (0);
13434 }
13435 
13436 static void
13437 dtrace_state_destroy(dtrace_state_t *state)
13438 {
13439         dtrace_ecb_t *ecb;
13440         dtrace_vstate_t *vstate = &state->dts_vstate;
13441         minor_t minor = getminor(state->dts_dev);
13442         int i, bufsize = NCPU * sizeof (dtrace_buffer_t);
13443         dtrace_speculation_t *spec = state->dts_speculations;
13444         int nspec = state->dts_nspeculations;
13445         uint32_t match;
13446 
13447         ASSERT(MUTEX_HELD(&dtrace_lock));
13448         ASSERT(MUTEX_HELD(&cpu_lock));
13449 
13450         /*
13451          * First, retract any retained enablings for this state.
13452          */
13453         dtrace_enabling_retract(state);
13454         ASSERT(state->dts_nretained == 0);
13455 
13456         if (state->dts_activity == DTRACE_ACTIVITY_ACTIVE ||
13457             state->dts_activity == DTRACE_ACTIVITY_DRAINING) {
13458                 /*
13459                  * We have managed to come into dtrace_state_destroy() on a
13460                  * hot enabling -- almost certainly because of a disorderly
13461                  * shutdown of a consumer.  (That is, a consumer that is
13462                  * exiting without having called dtrace_stop().) In this case,
13463                  * we're going to set our activity to be KILLED, and then
13464                  * issue a sync to be sure that everyone is out of probe
13465                  * context before we start blowing away ECBs.
13466                  */
13467                 state->dts_activity = DTRACE_ACTIVITY_KILLED;
13468                 dtrace_sync();
13469         }
13470 
13471         /*
13472          * Release the credential hold we took in dtrace_state_create().
13473          */
13474         if (state->dts_cred.dcr_cred != NULL)
13475                 crfree(state->dts_cred.dcr_cred);
13476 
13477         /*
13478          * Now we can safely disable and destroy any enabled probes.  Because
13479          * any DTRACE_PRIV_KERNEL probes may actually be slowing our progress
13480          * (especially if they're all enabled), we take two passes through the
13481          * ECBs:  in the first, we disable just DTRACE_PRIV_KERNEL probes, and
13482          * in the second we disable whatever is left over.
13483          */
13484         for (match = DTRACE_PRIV_KERNEL; ; match = 0) {
13485                 for (i = 0; i < state->dts_necbs; i++) {
13486                         if ((ecb = state->dts_ecbs[i]) == NULL)
13487                                 continue;
13488 
13489                         if (match && ecb->dte_probe != NULL) {
13490                                 dtrace_probe_t *probe = ecb->dte_probe;
13491                                 dtrace_provider_t *prov = probe->dtpr_provider;
13492 
13493                                 if (!(prov->dtpv_priv.dtpp_flags & match))
13494                                         continue;
13495                         }
13496 
13497                         dtrace_ecb_disable(ecb);
13498                         dtrace_ecb_destroy(ecb);
13499                 }
13500 
13501                 if (!match)
13502                         break;
13503         }
13504 
13505         /*
13506          * Before we free the buffers, perform one more sync to assure that
13507          * every CPU is out of probe context.
13508          */
13509         dtrace_sync();
13510 
13511         dtrace_buffer_free(state->dts_buffer);
13512         dtrace_buffer_free(state->dts_aggbuffer);
13513 
13514         for (i = 0; i < nspec; i++)
13515                 dtrace_buffer_free(spec[i].dtsp_buffer);
13516 
13517         if (state->dts_cleaner != CYCLIC_NONE)
13518                 cyclic_remove(state->dts_cleaner);
13519 
13520         if (state->dts_deadman != CYCLIC_NONE)
13521                 cyclic_remove(state->dts_deadman);
13522 
13523         dtrace_dstate_fini(&vstate->dtvs_dynvars);
13524         dtrace_vstate_fini(vstate);
13525         kmem_free(state->dts_ecbs, state->dts_necbs * sizeof (dtrace_ecb_t *));
13526 
13527         if (state->dts_aggregations != NULL) {
13528 #ifdef DEBUG
13529                 for (i = 0; i < state->dts_naggregations; i++)
13530                         ASSERT(state->dts_aggregations[i] == NULL);
13531 #endif
13532                 ASSERT(state->dts_naggregations > 0);
13533                 kmem_free(state->dts_aggregations,
13534                     state->dts_naggregations * sizeof (dtrace_aggregation_t *));
13535         }
13536 
13537         kmem_free(state->dts_buffer, bufsize);
13538         kmem_free(state->dts_aggbuffer, bufsize);
13539 
13540         for (i = 0; i < nspec; i++)
13541                 kmem_free(spec[i].dtsp_buffer, bufsize);
13542 
13543         kmem_free(spec, nspec * sizeof (dtrace_speculation_t));
13544 
13545         dtrace_format_destroy(state);
13546 
13547         vmem_destroy(state->dts_aggid_arena);
13548         ddi_soft_state_free(dtrace_softstate, minor);
13549         vmem_free(dtrace_minor, (void *)(uintptr_t)minor, 1);
13550 }
13551 
13552 /*
13553  * DTrace Anonymous Enabling Functions
13554  */
13555 static dtrace_state_t *
13556 dtrace_anon_grab(void)
13557 {
13558         dtrace_state_t *state;
13559 
13560         ASSERT(MUTEX_HELD(&dtrace_lock));
13561 
13562         if ((state = dtrace_anon.dta_state) == NULL) {
13563                 ASSERT(dtrace_anon.dta_enabling == NULL);
13564                 return (NULL);
13565         }
13566 
13567         ASSERT(dtrace_anon.dta_enabling != NULL);
13568         ASSERT(dtrace_retained != NULL);
13569 
13570         dtrace_enabling_destroy(dtrace_anon.dta_enabling);
13571         dtrace_anon.dta_enabling = NULL;
13572         dtrace_anon.dta_state = NULL;
13573 
13574         return (state);
13575 }
13576 
13577 static void
13578 dtrace_anon_property(void)
13579 {
13580         int i, rv;
13581         dtrace_state_t *state;
13582         dof_hdr_t *dof;
13583         char c[32];             /* enough for "dof-data-" + digits */
13584 
13585         ASSERT(MUTEX_HELD(&dtrace_lock));
13586         ASSERT(MUTEX_HELD(&cpu_lock));
13587 
13588         for (i = 0; ; i++) {
13589                 (void) snprintf(c, sizeof (c), "dof-data-%d", i);
13590 
13591                 dtrace_err_verbose = 1;
13592 
13593                 if ((dof = dtrace_dof_property(c)) == NULL) {
13594                         dtrace_err_verbose = 0;
13595                         break;
13596                 }
13597 
13598                 /*
13599                  * We want to create anonymous state, so we need to transition
13600                  * the kernel debugger to indicate that DTrace is active.  If
13601                  * this fails (e.g. because the debugger has modified text in
13602                  * some way), we won't continue with the processing.
13603                  */
13604                 if (kdi_dtrace_set(KDI_DTSET_DTRACE_ACTIVATE) != 0) {
13605                         cmn_err(CE_NOTE, "kernel debugger active; anonymous "
13606                             "enabling ignored.");
13607                         dtrace_dof_destroy(dof);
13608                         break;
13609                 }
13610 
13611                 /*
13612                  * If we haven't allocated an anonymous state, we'll do so now.
13613                  */
13614                 if ((state = dtrace_anon.dta_state) == NULL) {
13615                         state = dtrace_state_create(NULL, NULL);
13616                         dtrace_anon.dta_state = state;
13617 
13618                         if (state == NULL) {
13619                                 /*
13620                                  * This basically shouldn't happen:  the only
13621                                  * failure mode from dtrace_state_create() is a
13622                                  * failure of ddi_soft_state_zalloc() that
13623                                  * itself should never happen.  Still, the
13624                                  * interface allows for a failure mode, and
13625                                  * we want to fail as gracefully as possible:
13626                                  * we'll emit an error message and cease
13627                                  * processing anonymous state in this case.
13628                                  */
13629                                 cmn_err(CE_WARN, "failed to create "
13630                                     "anonymous state");
13631                                 dtrace_dof_destroy(dof);
13632                                 break;
13633                         }
13634                 }
13635 
13636                 rv = dtrace_dof_slurp(dof, &state->dts_vstate, CRED(),
13637                     &dtrace_anon.dta_enabling, 0, B_TRUE);
13638 
13639                 if (rv == 0)
13640                         rv = dtrace_dof_options(dof, state);
13641 
13642                 dtrace_err_verbose = 0;
13643                 dtrace_dof_destroy(dof);
13644 
13645                 if (rv != 0) {
13646                         /*
13647                          * This is malformed DOF; chuck any anonymous state
13648                          * that we created.
13649                          */
13650                         ASSERT(dtrace_anon.dta_enabling == NULL);
13651                         dtrace_state_destroy(state);
13652                         dtrace_anon.dta_state = NULL;
13653                         break;
13654                 }
13655 
13656                 ASSERT(dtrace_anon.dta_enabling != NULL);
13657         }
13658 
13659         if (dtrace_anon.dta_enabling != NULL) {
13660                 int rval;
13661 
13662                 /*
13663                  * dtrace_enabling_retain() can only fail because we are
13664                  * trying to retain more enablings than are allowed -- but
13665                  * we only have one anonymous enabling, and we are guaranteed
13666                  * to be allowed at least one retained enabling; we assert
13667                  * that dtrace_enabling_retain() returns success.
13668                  */
13669                 rval = dtrace_enabling_retain(dtrace_anon.dta_enabling);
13670                 ASSERT(rval == 0);
13671 
13672                 dtrace_enabling_dump(dtrace_anon.dta_enabling);
13673         }
13674 }
13675 
13676 /*
13677  * DTrace Helper Functions
13678  */
13679 static void
13680 dtrace_helper_trace(dtrace_helper_action_t *helper,
13681     dtrace_mstate_t *mstate, dtrace_vstate_t *vstate, int where)
13682 {
13683         uint32_t size, next, nnext, i;
13684         dtrace_helptrace_t *ent;
13685         uint16_t flags = cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
13686 
13687         if (!dtrace_helptrace_enabled)
13688                 return;
13689 
13690         ASSERT(vstate->dtvs_nlocals <= dtrace_helptrace_nlocals);
13691 
13692         /*
13693          * What would a tracing framework be without its own tracing
13694          * framework?  (Well, a hell of a lot simpler, for starters...)
13695          */
13696         size = sizeof (dtrace_helptrace_t) + dtrace_helptrace_nlocals *
13697             sizeof (uint64_t) - sizeof (uint64_t);
13698 
13699         /*
13700          * Iterate until we can allocate a slot in the trace buffer.
13701          */
13702         do {
13703                 next = dtrace_helptrace_next;
13704 
13705                 if (next + size < dtrace_helptrace_bufsize) {
13706                         nnext = next + size;
13707                 } else {
13708                         nnext = size;
13709                 }
13710         } while (dtrace_cas32(&dtrace_helptrace_next, next, nnext) != next);
13711 
13712         /*
13713          * We have our slot; fill it in.
13714          */
13715         if (nnext == size)
13716                 next = 0;
13717 
13718         ent = (dtrace_helptrace_t *)&dtrace_helptrace_buffer[next];
13719         ent->dtht_helper = helper;
13720         ent->dtht_where = where;
13721         ent->dtht_nlocals = vstate->dtvs_nlocals;
13722 
13723         ent->dtht_fltoffs = (mstate->dtms_present & DTRACE_MSTATE_FLTOFFS) ?
13724             mstate->dtms_fltoffs : -1;
13725         ent->dtht_fault = DTRACE_FLAGS2FLT(flags);
13726         ent->dtht_illval = cpu_core[CPU->cpu_id].cpuc_dtrace_illval;
13727 
13728         for (i = 0; i < vstate->dtvs_nlocals; i++) {
13729                 dtrace_statvar_t *svar;
13730 
13731                 if ((svar = vstate->dtvs_locals[i]) == NULL)
13732                         continue;
13733 
13734                 ASSERT(svar->dtsv_size >= NCPU * sizeof (uint64_t));
13735                 ent->dtht_locals[i] =
13736                     ((uint64_t *)(uintptr_t)svar->dtsv_data)[CPU->cpu_id];
13737         }
13738 }
13739 
13740 static uint64_t
13741 dtrace_helper(int which, dtrace_mstate_t *mstate,
13742     dtrace_state_t *state, uint64_t arg0, uint64_t arg1)
13743 {
13744         uint16_t *flags = &cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
13745         uint64_t sarg0 = mstate->dtms_arg[0];
13746         uint64_t sarg1 = mstate->dtms_arg[1];
13747         uint64_t rval;
13748         dtrace_helpers_t *helpers = curproc->p_dtrace_helpers;
13749         dtrace_helper_action_t *helper;
13750         dtrace_vstate_t *vstate;
13751         dtrace_difo_t *pred;
13752         int i, trace = dtrace_helptrace_enabled;
13753 
13754         ASSERT(which >= 0 && which < DTRACE_NHELPER_ACTIONS);
13755 
13756         if (helpers == NULL)
13757                 return (0);
13758 
13759         if ((helper = helpers->dthps_actions[which]) == NULL)
13760                 return (0);
13761 
13762         vstate = &helpers->dthps_vstate;
13763         mstate->dtms_arg[0] = arg0;
13764         mstate->dtms_arg[1] = arg1;
13765 
13766         /*
13767          * Now iterate over each helper.  If its predicate evaluates to 'true',
13768          * we'll call the corresponding actions.  Note that the below calls
13769          * to dtrace_dif_emulate() may set faults in machine state.  This is
13770          * okay:  our caller (the outer dtrace_dif_emulate()) will simply plow
13771          * the stored DIF offset with its own (which is the desired behavior).
13772          * Also, note the calls to dtrace_dif_emulate() may allocate scratch
13773          * from machine state; this is okay, too.
13774          */
13775         for (; helper != NULL; helper = helper->dtha_next) {
13776                 if ((pred = helper->dtha_predicate) != NULL) {
13777                         if (trace)
13778                                 dtrace_helper_trace(helper, mstate, vstate, 0);
13779 
13780                         if (!dtrace_dif_emulate(pred, mstate, vstate, state))
13781                                 goto next;
13782 
13783                         if (*flags & CPU_DTRACE_FAULT)
13784                                 goto err;
13785                 }
13786 
13787                 for (i = 0; i < helper->dtha_nactions; i++) {
13788                         if (trace)
13789                                 dtrace_helper_trace(helper,
13790                                     mstate, vstate, i + 1);
13791 
13792                         rval = dtrace_dif_emulate(helper->dtha_actions[i],
13793                             mstate, vstate, state);
13794 
13795                         if (*flags & CPU_DTRACE_FAULT)
13796                                 goto err;
13797                 }
13798 
13799 next:
13800                 if (trace)
13801                         dtrace_helper_trace(helper, mstate, vstate,
13802                             DTRACE_HELPTRACE_NEXT);
13803         }
13804 
13805         if (trace)
13806                 dtrace_helper_trace(helper, mstate, vstate,
13807                     DTRACE_HELPTRACE_DONE);
13808 
13809         /*
13810          * Restore the arg0 that we saved upon entry.
13811          */
13812         mstate->dtms_arg[0] = sarg0;
13813         mstate->dtms_arg[1] = sarg1;
13814 
13815         return (rval);
13816 
13817 err:
13818         if (trace)
13819                 dtrace_helper_trace(helper, mstate, vstate,
13820                     DTRACE_HELPTRACE_ERR);
13821 
13822         /*
13823          * Restore the arg0 that we saved upon entry.
13824          */
13825         mstate->dtms_arg[0] = sarg0;
13826         mstate->dtms_arg[1] = sarg1;
13827 
13828         return (NULL);
13829 }
13830 
13831 static void
13832 dtrace_helper_action_destroy(dtrace_helper_action_t *helper,
13833     dtrace_vstate_t *vstate)
13834 {
13835         int i;
13836 
13837         if (helper->dtha_predicate != NULL)
13838                 dtrace_difo_release(helper->dtha_predicate, vstate);
13839 
13840         for (i = 0; i < helper->dtha_nactions; i++) {
13841                 ASSERT(helper->dtha_actions[i] != NULL);
13842                 dtrace_difo_release(helper->dtha_actions[i], vstate);
13843         }
13844 
13845         kmem_free(helper->dtha_actions,
13846             helper->dtha_nactions * sizeof (dtrace_difo_t *));
13847         kmem_free(helper, sizeof (dtrace_helper_action_t));
13848 }
13849 
13850 static int
13851 dtrace_helper_destroygen(int gen)
13852 {
13853         proc_t *p = curproc;
13854         dtrace_helpers_t *help = p->p_dtrace_helpers;
13855         dtrace_vstate_t *vstate;
13856         int i;
13857 
13858         ASSERT(MUTEX_HELD(&dtrace_lock));
13859 
13860         if (help == NULL || gen > help->dthps_generation)
13861                 return (EINVAL);
13862 
13863         vstate = &help->dthps_vstate;
13864 
13865         for (i = 0; i < DTRACE_NHELPER_ACTIONS; i++) {
13866                 dtrace_helper_action_t *last = NULL, *h, *next;
13867 
13868                 for (h = help->dthps_actions[i]; h != NULL; h = next) {
13869                         next = h->dtha_next;
13870 
13871                         if (h->dtha_generation == gen) {
13872                                 if (last != NULL) {
13873                                         last->dtha_next = next;
13874                                 } else {
13875                                         help->dthps_actions[i] = next;
13876                                 }
13877 
13878                                 dtrace_helper_action_destroy(h, vstate);
13879                         } else {
13880                                 last = h;
13881                         }
13882                 }
13883         }
13884 
13885         /*
13886          * Interate until we've cleared out all helper providers with the
13887          * given generation number.
13888          */
13889         for (;;) {
13890                 dtrace_helper_provider_t *prov;
13891 
13892                 /*
13893                  * Look for a helper provider with the right generation. We
13894                  * have to start back at the beginning of the list each time
13895                  * because we drop dtrace_lock. It's unlikely that we'll make
13896                  * more than two passes.
13897                  */
13898                 for (i = 0; i < help->dthps_nprovs; i++) {
13899                         prov = help->dthps_provs[i];
13900 
13901                         if (prov->dthp_generation == gen)
13902                                 break;
13903                 }
13904 
13905                 /*
13906                  * If there were no matches, we're done.
13907                  */
13908                 if (i == help->dthps_nprovs)
13909                         break;
13910 
13911                 /*
13912                  * Move the last helper provider into this slot.
13913                  */
13914                 help->dthps_nprovs--;
13915                 help->dthps_provs[i] = help->dthps_provs[help->dthps_nprovs];
13916                 help->dthps_provs[help->dthps_nprovs] = NULL;
13917 
13918                 mutex_exit(&dtrace_lock);
13919 
13920                 /*
13921                  * If we have a meta provider, remove this helper provider.
13922                  */
13923                 mutex_enter(&dtrace_meta_lock);
13924                 if (dtrace_meta_pid != NULL) {
13925                         ASSERT(dtrace_deferred_pid == NULL);
13926                         dtrace_helper_provider_remove(&prov->dthp_prov,
13927                             p->p_pid);
13928                 }
13929                 mutex_exit(&dtrace_meta_lock);
13930 
13931                 dtrace_helper_provider_destroy(prov);
13932 
13933                 mutex_enter(&dtrace_lock);
13934         }
13935 
13936         return (0);
13937 }
13938 
13939 static int
13940 dtrace_helper_validate(dtrace_helper_action_t *helper)
13941 {
13942         int err = 0, i;
13943         dtrace_difo_t *dp;
13944 
13945         if ((dp = helper->dtha_predicate) != NULL)
13946                 err += dtrace_difo_validate_helper(dp);
13947 
13948         for (i = 0; i < helper->dtha_nactions; i++)
13949                 err += dtrace_difo_validate_helper(helper->dtha_actions[i]);
13950 
13951         return (err == 0);
13952 }
13953 
13954 static int
13955 dtrace_helper_action_add(int which, dtrace_ecbdesc_t *ep)
13956 {
13957         dtrace_helpers_t *help;
13958         dtrace_helper_action_t *helper, *last;
13959         dtrace_actdesc_t *act;
13960         dtrace_vstate_t *vstate;
13961         dtrace_predicate_t *pred;
13962         int count = 0, nactions = 0, i;
13963 
13964         if (which < 0 || which >= DTRACE_NHELPER_ACTIONS)
13965                 return (EINVAL);
13966 
13967         help = curproc->p_dtrace_helpers;
13968         last = help->dthps_actions[which];
13969         vstate = &help->dthps_vstate;
13970 
13971         for (count = 0; last != NULL; last = last->dtha_next) {
13972                 count++;
13973                 if (last->dtha_next == NULL)
13974                         break;
13975         }
13976 
13977         /*
13978          * If we already have dtrace_helper_actions_max helper actions for this
13979          * helper action type, we'll refuse to add a new one.
13980          */
13981         if (count >= dtrace_helper_actions_max)
13982                 return (ENOSPC);
13983 
13984         helper = kmem_zalloc(sizeof (dtrace_helper_action_t), KM_SLEEP);
13985         helper->dtha_generation = help->dthps_generation;
13986 
13987         if ((pred = ep->dted_pred.dtpdd_predicate) != NULL) {
13988                 ASSERT(pred->dtp_difo != NULL);
13989                 dtrace_difo_hold(pred->dtp_difo);
13990                 helper->dtha_predicate = pred->dtp_difo;
13991         }
13992 
13993         for (act = ep->dted_action; act != NULL; act = act->dtad_next) {
13994                 if (act->dtad_kind != DTRACEACT_DIFEXPR)
13995                         goto err;
13996 
13997                 if (act->dtad_difo == NULL)
13998                         goto err;
13999 
14000                 nactions++;
14001         }
14002 
14003         helper->dtha_actions = kmem_zalloc(sizeof (dtrace_difo_t *) *
14004             (helper->dtha_nactions = nactions), KM_SLEEP);
14005 
14006         for (act = ep->dted_action, i = 0; act != NULL; act = act->dtad_next) {
14007                 dtrace_difo_hold(act->dtad_difo);
14008                 helper->dtha_actions[i++] = act->dtad_difo;
14009         }
14010 
14011         if (!dtrace_helper_validate(helper))
14012                 goto err;
14013 
14014         if (last == NULL) {
14015                 help->dthps_actions[which] = helper;
14016         } else {
14017                 last->dtha_next = helper;
14018         }
14019 
14020         if (vstate->dtvs_nlocals > dtrace_helptrace_nlocals) {
14021                 dtrace_helptrace_nlocals = vstate->dtvs_nlocals;
14022                 dtrace_helptrace_next = 0;
14023         }
14024 
14025         return (0);
14026 err:
14027         dtrace_helper_action_destroy(helper, vstate);
14028         return (EINVAL);
14029 }
14030 
14031 static void
14032 dtrace_helper_provider_register(proc_t *p, dtrace_helpers_t *help,
14033     dof_helper_t *dofhp)
14034 {
14035         ASSERT(MUTEX_NOT_HELD(&dtrace_lock));
14036 
14037         mutex_enter(&dtrace_meta_lock);
14038         mutex_enter(&dtrace_lock);
14039 
14040         if (!dtrace_attached() || dtrace_meta_pid == NULL) {
14041                 /*
14042                  * If the dtrace module is loaded but not attached, or if
14043                  * there aren't isn't a meta provider registered to deal with
14044                  * these provider descriptions, we need to postpone creating
14045                  * the actual providers until later.
14046                  */
14047 
14048                 if (help->dthps_next == NULL && help->dthps_prev == NULL &&
14049                     dtrace_deferred_pid != help) {
14050                         help->dthps_deferred = 1;
14051                         help->dthps_pid = p->p_pid;
14052                         help->dthps_next = dtrace_deferred_pid;
14053                         help->dthps_prev = NULL;
14054                         if (dtrace_deferred_pid != NULL)
14055                                 dtrace_deferred_pid->dthps_prev = help;
14056                         dtrace_deferred_pid = help;
14057                 }
14058 
14059                 mutex_exit(&dtrace_lock);
14060 
14061         } else if (dofhp != NULL) {
14062                 /*
14063                  * If the dtrace module is loaded and we have a particular
14064                  * helper provider description, pass that off to the
14065                  * meta provider.
14066                  */
14067 
14068                 mutex_exit(&dtrace_lock);
14069 
14070                 dtrace_helper_provide(dofhp, p->p_pid);
14071 
14072         } else {
14073                 /*
14074                  * Otherwise, just pass all the helper provider descriptions
14075                  * off to the meta provider.
14076                  */
14077 
14078                 int i;
14079                 mutex_exit(&dtrace_lock);
14080 
14081                 for (i = 0; i < help->dthps_nprovs; i++) {
14082                         dtrace_helper_provide(&help->dthps_provs[i]->dthp_prov,
14083                             p->p_pid);
14084                 }
14085         }
14086 
14087         mutex_exit(&dtrace_meta_lock);
14088 }
14089 
14090 static int
14091 dtrace_helper_provider_add(dof_helper_t *dofhp, int gen)
14092 {
14093         dtrace_helpers_t *help;
14094         dtrace_helper_provider_t *hprov, **tmp_provs;
14095         uint_t tmp_maxprovs, i;
14096 
14097         ASSERT(MUTEX_HELD(&dtrace_lock));
14098 
14099         help = curproc->p_dtrace_helpers;
14100         ASSERT(help != NULL);
14101 
14102         /*
14103          * If we already have dtrace_helper_providers_max helper providers,
14104          * we're refuse to add a new one.
14105          */
14106         if (help->dthps_nprovs >= dtrace_helper_providers_max)
14107                 return (ENOSPC);
14108 
14109         /*
14110          * Check to make sure this isn't a duplicate.
14111          */
14112         for (i = 0; i < help->dthps_nprovs; i++) {
14113                 if (dofhp->dofhp_dof ==
14114                     help->dthps_provs[i]->dthp_prov.dofhp_dof)
14115                         return (EALREADY);
14116         }
14117 
14118         hprov = kmem_zalloc(sizeof (dtrace_helper_provider_t), KM_SLEEP);
14119         hprov->dthp_prov = *dofhp;
14120         hprov->dthp_ref = 1;
14121         hprov->dthp_generation = gen;
14122 
14123         /*
14124          * Allocate a bigger table for helper providers if it's already full.
14125          */
14126         if (help->dthps_maxprovs == help->dthps_nprovs) {
14127                 tmp_maxprovs = help->dthps_maxprovs;
14128                 tmp_provs = help->dthps_provs;
14129 
14130                 if (help->dthps_maxprovs == 0)
14131                         help->dthps_maxprovs = 2;
14132                 else
14133                         help->dthps_maxprovs *= 2;
14134                 if (help->dthps_maxprovs > dtrace_helper_providers_max)
14135                         help->dthps_maxprovs = dtrace_helper_providers_max;
14136 
14137                 ASSERT(tmp_maxprovs < help->dthps_maxprovs);
14138 
14139                 help->dthps_provs = kmem_zalloc(help->dthps_maxprovs *
14140                     sizeof (dtrace_helper_provider_t *), KM_SLEEP);
14141 
14142                 if (tmp_provs != NULL) {
14143                         bcopy(tmp_provs, help->dthps_provs, tmp_maxprovs *
14144                             sizeof (dtrace_helper_provider_t *));
14145                         kmem_free(tmp_provs, tmp_maxprovs *
14146                             sizeof (dtrace_helper_provider_t *));
14147                 }
14148         }
14149 
14150         help->dthps_provs[help->dthps_nprovs] = hprov;
14151         help->dthps_nprovs++;
14152 
14153         return (0);
14154 }
14155 
14156 static void
14157 dtrace_helper_provider_destroy(dtrace_helper_provider_t *hprov)
14158 {
14159         mutex_enter(&dtrace_lock);
14160 
14161         if (--hprov->dthp_ref == 0) {
14162                 dof_hdr_t *dof;
14163                 mutex_exit(&dtrace_lock);
14164                 dof = (dof_hdr_t *)(uintptr_t)hprov->dthp_prov.dofhp_dof;
14165                 dtrace_dof_destroy(dof);
14166                 kmem_free(hprov, sizeof (dtrace_helper_provider_t));
14167         } else {
14168                 mutex_exit(&dtrace_lock);
14169         }
14170 }
14171 
14172 static int
14173 dtrace_helper_provider_validate(dof_hdr_t *dof, dof_sec_t *sec)
14174 {
14175         uintptr_t daddr = (uintptr_t)dof;
14176         dof_sec_t *str_sec, *prb_sec, *arg_sec, *off_sec, *enoff_sec;
14177         dof_provider_t *provider;
14178         dof_probe_t *probe;
14179         uint8_t *arg;
14180         char *strtab, *typestr;
14181         dof_stridx_t typeidx;
14182         size_t typesz;
14183         uint_t nprobes, j, k;
14184 
14185         ASSERT(sec->dofs_type == DOF_SECT_PROVIDER);
14186 
14187         if (sec->dofs_offset & (sizeof (uint_t) - 1)) {
14188                 dtrace_dof_error(dof, "misaligned section offset");
14189                 return (-1);
14190         }
14191 
14192         /*
14193          * The section needs to be large enough to contain the DOF provider
14194          * structure appropriate for the given version.
14195          */
14196         if (sec->dofs_size <
14197             ((dof->dofh_ident[DOF_ID_VERSION] == DOF_VERSION_1) ?
14198             offsetof(dof_provider_t, dofpv_prenoffs) :
14199             sizeof (dof_provider_t))) {
14200                 dtrace_dof_error(dof, "provider section too small");
14201                 return (-1);
14202         }
14203 
14204         provider = (dof_provider_t *)(uintptr_t)(daddr + sec->dofs_offset);
14205         str_sec = dtrace_dof_sect(dof, DOF_SECT_STRTAB, provider->dofpv_strtab);
14206         prb_sec = dtrace_dof_sect(dof, DOF_SECT_PROBES, provider->dofpv_probes);
14207         arg_sec = dtrace_dof_sect(dof, DOF_SECT_PRARGS, provider->dofpv_prargs);
14208         off_sec = dtrace_dof_sect(dof, DOF_SECT_PROFFS, provider->dofpv_proffs);
14209 
14210         if (str_sec == NULL || prb_sec == NULL ||
14211             arg_sec == NULL || off_sec == NULL)
14212                 return (-1);
14213 
14214         enoff_sec = NULL;
14215 
14216         if (dof->dofh_ident[DOF_ID_VERSION] != DOF_VERSION_1 &&
14217             provider->dofpv_prenoffs != DOF_SECT_NONE &&
14218             (enoff_sec = dtrace_dof_sect(dof, DOF_SECT_PRENOFFS,
14219             provider->dofpv_prenoffs)) == NULL)
14220                 return (-1);
14221 
14222         strtab = (char *)(uintptr_t)(daddr + str_sec->dofs_offset);
14223 
14224         if (provider->dofpv_name >= str_sec->dofs_size ||
14225             strlen(strtab + provider->dofpv_name) >= DTRACE_PROVNAMELEN) {
14226                 dtrace_dof_error(dof, "invalid provider name");
14227                 return (-1);
14228         }
14229 
14230         if (prb_sec->dofs_entsize == 0 ||
14231             prb_sec->dofs_entsize > prb_sec->dofs_size) {
14232                 dtrace_dof_error(dof, "invalid entry size");
14233                 return (-1);
14234         }
14235 
14236         if (prb_sec->dofs_entsize & (sizeof (uintptr_t) - 1)) {
14237                 dtrace_dof_error(dof, "misaligned entry size");
14238                 return (-1);
14239         }
14240 
14241         if (off_sec->dofs_entsize != sizeof (uint32_t)) {
14242                 dtrace_dof_error(dof, "invalid entry size");
14243                 return (-1);
14244         }
14245 
14246         if (off_sec->dofs_offset & (sizeof (uint32_t) - 1)) {
14247                 dtrace_dof_error(dof, "misaligned section offset");
14248                 return (-1);
14249         }
14250 
14251         if (arg_sec->dofs_entsize != sizeof (uint8_t)) {
14252                 dtrace_dof_error(dof, "invalid entry size");
14253                 return (-1);
14254         }
14255 
14256         arg = (uint8_t *)(uintptr_t)(daddr + arg_sec->dofs_offset);
14257 
14258         nprobes = prb_sec->dofs_size / prb_sec->dofs_entsize;
14259 
14260         /*
14261          * Take a pass through the probes to check for errors.
14262          */
14263         for (j = 0; j < nprobes; j++) {
14264                 probe = (dof_probe_t *)(uintptr_t)(daddr +
14265                     prb_sec->dofs_offset + j * prb_sec->dofs_entsize);
14266 
14267                 if (probe->dofpr_func >= str_sec->dofs_size) {
14268                         dtrace_dof_error(dof, "invalid function name");
14269                         return (-1);
14270                 }
14271 
14272                 if (strlen(strtab + probe->dofpr_func) >= DTRACE_FUNCNAMELEN) {
14273                         dtrace_dof_error(dof, "function name too long");
14274                         return (-1);
14275                 }
14276 
14277                 if (probe->dofpr_name >= str_sec->dofs_size ||
14278                     strlen(strtab + probe->dofpr_name) >= DTRACE_NAMELEN) {
14279                         dtrace_dof_error(dof, "invalid probe name");
14280                         return (-1);
14281                 }
14282 
14283                 /*
14284                  * The offset count must not wrap the index, and the offsets
14285                  * must also not overflow the section's data.
14286                  */
14287                 if (probe->dofpr_offidx + probe->dofpr_noffs <
14288                     probe->dofpr_offidx ||
14289                     (probe->dofpr_offidx + probe->dofpr_noffs) *
14290                     off_sec->dofs_entsize > off_sec->dofs_size) {
14291                         dtrace_dof_error(dof, "invalid probe offset");
14292                         return (-1);
14293                 }
14294 
14295                 if (dof->dofh_ident[DOF_ID_VERSION] != DOF_VERSION_1) {
14296                         /*
14297                          * If there's no is-enabled offset section, make sure
14298                          * there aren't any is-enabled offsets. Otherwise
14299                          * perform the same checks as for probe offsets
14300                          * (immediately above).
14301                          */
14302                         if (enoff_sec == NULL) {
14303                                 if (probe->dofpr_enoffidx != 0 ||
14304                                     probe->dofpr_nenoffs != 0) {
14305                                         dtrace_dof_error(dof, "is-enabled "
14306                                             "offsets with null section");
14307                                         return (-1);
14308                                 }
14309                         } else if (probe->dofpr_enoffidx +
14310                             probe->dofpr_nenoffs < probe->dofpr_enoffidx ||
14311                             (probe->dofpr_enoffidx + probe->dofpr_nenoffs) *
14312                             enoff_sec->dofs_entsize > enoff_sec->dofs_size) {
14313                                 dtrace_dof_error(dof, "invalid is-enabled "
14314                                     "offset");
14315                                 return (-1);
14316                         }
14317 
14318                         if (probe->dofpr_noffs + probe->dofpr_nenoffs == 0) {
14319                                 dtrace_dof_error(dof, "zero probe and "
14320                                     "is-enabled offsets");
14321                                 return (-1);
14322                         }
14323                 } else if (probe->dofpr_noffs == 0) {
14324                         dtrace_dof_error(dof, "zero probe offsets");
14325                         return (-1);
14326                 }
14327 
14328                 if (probe->dofpr_argidx + probe->dofpr_xargc <
14329                     probe->dofpr_argidx ||
14330                     (probe->dofpr_argidx + probe->dofpr_xargc) *
14331                     arg_sec->dofs_entsize > arg_sec->dofs_size) {
14332                         dtrace_dof_error(dof, "invalid args");
14333                         return (-1);
14334                 }
14335 
14336                 typeidx = probe->dofpr_nargv;
14337                 typestr = strtab + probe->dofpr_nargv;
14338                 for (k = 0; k < probe->dofpr_nargc; k++) {
14339                         if (typeidx >= str_sec->dofs_size) {
14340                                 dtrace_dof_error(dof, "bad "
14341                                     "native argument type");
14342                                 return (-1);
14343                         }
14344 
14345                         typesz = strlen(typestr) + 1;
14346                         if (typesz > DTRACE_ARGTYPELEN) {
14347                                 dtrace_dof_error(dof, "native "
14348                                     "argument type too long");
14349                                 return (-1);
14350                         }
14351                         typeidx += typesz;
14352                         typestr += typesz;
14353                 }
14354 
14355                 typeidx = probe->dofpr_xargv;
14356                 typestr = strtab + probe->dofpr_xargv;
14357                 for (k = 0; k < probe->dofpr_xargc; k++) {
14358                         if (arg[probe->dofpr_argidx + k] > probe->dofpr_nargc) {
14359                                 dtrace_dof_error(dof, "bad "
14360                                     "native argument index");
14361                                 return (-1);
14362                         }
14363 
14364                         if (typeidx >= str_sec->dofs_size) {
14365                                 dtrace_dof_error(dof, "bad "
14366                                     "translated argument type");
14367                                 return (-1);
14368                         }
14369 
14370                         typesz = strlen(typestr) + 1;
14371                         if (typesz > DTRACE_ARGTYPELEN) {
14372                                 dtrace_dof_error(dof, "translated argument "
14373                                     "type too long");
14374                                 return (-1);
14375                         }
14376 
14377                         typeidx += typesz;
14378                         typestr += typesz;
14379                 }
14380         }
14381 
14382         return (0);
14383 }
14384 
14385 static int
14386 dtrace_helper_slurp(dof_hdr_t *dof, dof_helper_t *dhp)
14387 {
14388         dtrace_helpers_t *help;
14389         dtrace_vstate_t *vstate;
14390         dtrace_enabling_t *enab = NULL;
14391         int i, gen, rv, nhelpers = 0, nprovs = 0, destroy = 1;
14392         uintptr_t daddr = (uintptr_t)dof;
14393 
14394         ASSERT(MUTEX_HELD(&dtrace_lock));
14395 
14396         if ((help = curproc->p_dtrace_helpers) == NULL)
14397                 help = dtrace_helpers_create(curproc);
14398 
14399         vstate = &help->dthps_vstate;
14400 
14401         if ((rv = dtrace_dof_slurp(dof, vstate, NULL, &enab,
14402             dhp != NULL ? dhp->dofhp_addr : 0, B_FALSE)) != 0) {
14403                 dtrace_dof_destroy(dof);
14404                 return (rv);
14405         }
14406 
14407         /*
14408          * Look for helper providers and validate their descriptions.
14409          */
14410         if (dhp != NULL) {
14411                 for (i = 0; i < dof->dofh_secnum; i++) {
14412                         dof_sec_t *sec = (dof_sec_t *)(uintptr_t)(daddr +
14413                             dof->dofh_secoff + i * dof->dofh_secsize);
14414 
14415                         if (sec->dofs_type != DOF_SECT_PROVIDER)
14416                                 continue;
14417 
14418                         if (dtrace_helper_provider_validate(dof, sec) != 0) {
14419                                 dtrace_enabling_destroy(enab);
14420                                 dtrace_dof_destroy(dof);
14421                                 return (-1);
14422                         }
14423 
14424                         nprovs++;
14425                 }
14426         }
14427 
14428         /*
14429          * Now we need to walk through the ECB descriptions in the enabling.
14430          */
14431         for (i = 0; i < enab->dten_ndesc; i++) {
14432                 dtrace_ecbdesc_t *ep = enab->dten_desc[i];
14433                 dtrace_probedesc_t *desc = &ep->dted_probe;
14434 
14435                 if (strcmp(desc->dtpd_provider, "dtrace") != 0)
14436                         continue;
14437 
14438                 if (strcmp(desc->dtpd_mod, "helper") != 0)
14439                         continue;
14440 
14441                 if (strcmp(desc->dtpd_func, "ustack") != 0)
14442                         continue;
14443 
14444                 if ((rv = dtrace_helper_action_add(DTRACE_HELPER_ACTION_USTACK,
14445                     ep)) != 0) {
14446                         /*
14447                          * Adding this helper action failed -- we are now going
14448                          * to rip out the entire generation and return failure.
14449                          */
14450                         (void) dtrace_helper_destroygen(help->dthps_generation);
14451                         dtrace_enabling_destroy(enab);
14452                         dtrace_dof_destroy(dof);
14453                         return (-1);
14454                 }
14455 
14456                 nhelpers++;
14457         }
14458 
14459         if (nhelpers < enab->dten_ndesc)
14460                 dtrace_dof_error(dof, "unmatched helpers");
14461 
14462         gen = help->dthps_generation++;
14463         dtrace_enabling_destroy(enab);
14464 
14465         if (dhp != NULL && nprovs > 0) {
14466                 dhp->dofhp_dof = (uint64_t)(uintptr_t)dof;
14467                 if (dtrace_helper_provider_add(dhp, gen) == 0) {
14468                         mutex_exit(&dtrace_lock);
14469                         dtrace_helper_provider_register(curproc, help, dhp);
14470                         mutex_enter(&dtrace_lock);
14471 
14472                         destroy = 0;
14473                 }
14474         }
14475 
14476         if (destroy)
14477                 dtrace_dof_destroy(dof);
14478 
14479         return (gen);
14480 }
14481 
14482 static dtrace_helpers_t *
14483 dtrace_helpers_create(proc_t *p)
14484 {
14485         dtrace_helpers_t *help;
14486 
14487         ASSERT(MUTEX_HELD(&dtrace_lock));
14488         ASSERT(p->p_dtrace_helpers == NULL);
14489 
14490         help = kmem_zalloc(sizeof (dtrace_helpers_t), KM_SLEEP);
14491         help->dthps_actions = kmem_zalloc(sizeof (dtrace_helper_action_t *) *
14492             DTRACE_NHELPER_ACTIONS, KM_SLEEP);
14493 
14494         p->p_dtrace_helpers = help;
14495         dtrace_helpers++;
14496 
14497         return (help);
14498 }
14499 
14500 static void
14501 dtrace_helpers_destroy(void)
14502 {
14503         dtrace_helpers_t *help;
14504         dtrace_vstate_t *vstate;
14505         proc_t *p = curproc;
14506         int i;
14507 
14508         mutex_enter(&dtrace_lock);
14509 
14510         ASSERT(p->p_dtrace_helpers != NULL);
14511         ASSERT(dtrace_helpers > 0);
14512 
14513         help = p->p_dtrace_helpers;
14514         vstate = &help->dthps_vstate;
14515 
14516         /*
14517          * We're now going to lose the help from this process.
14518          */
14519         p->p_dtrace_helpers = NULL;
14520         dtrace_sync();
14521 
14522         /*
14523          * Destory the helper actions.
14524          */
14525         for (i = 0; i < DTRACE_NHELPER_ACTIONS; i++) {
14526                 dtrace_helper_action_t *h, *next;
14527 
14528                 for (h = help->dthps_actions[i]; h != NULL; h = next) {
14529                         next = h->dtha_next;
14530                         dtrace_helper_action_destroy(h, vstate);
14531                         h = next;
14532                 }
14533         }
14534 
14535         mutex_exit(&dtrace_lock);
14536 
14537         /*
14538          * Destroy the helper providers.
14539          */
14540         if (help->dthps_maxprovs > 0) {
14541                 mutex_enter(&dtrace_meta_lock);
14542                 if (dtrace_meta_pid != NULL) {
14543                         ASSERT(dtrace_deferred_pid == NULL);
14544 
14545                         for (i = 0; i < help->dthps_nprovs; i++) {
14546                                 dtrace_helper_provider_remove(
14547                                     &help->dthps_provs[i]->dthp_prov, p->p_pid);
14548                         }
14549                 } else {
14550                         mutex_enter(&dtrace_lock);
14551                         ASSERT(help->dthps_deferred == 0 ||
14552                             help->dthps_next != NULL ||
14553                             help->dthps_prev != NULL ||
14554                             help == dtrace_deferred_pid);
14555 
14556                         /*
14557                          * Remove the helper from the deferred list.
14558                          */
14559                         if (help->dthps_next != NULL)
14560                                 help->dthps_next->dthps_prev = help->dthps_prev;
14561                         if (help->dthps_prev != NULL)
14562                                 help->dthps_prev->dthps_next = help->dthps_next;
14563                         if (dtrace_deferred_pid == help) {
14564                                 dtrace_deferred_pid = help->dthps_next;
14565                                 ASSERT(help->dthps_prev == NULL);
14566                         }
14567 
14568                         mutex_exit(&dtrace_lock);
14569                 }
14570 
14571                 mutex_exit(&dtrace_meta_lock);
14572 
14573                 for (i = 0; i < help->dthps_nprovs; i++) {
14574                         dtrace_helper_provider_destroy(help->dthps_provs[i]);
14575                 }
14576 
14577                 kmem_free(help->dthps_provs, help->dthps_maxprovs *
14578                     sizeof (dtrace_helper_provider_t *));
14579         }
14580 
14581         mutex_enter(&dtrace_lock);
14582 
14583         dtrace_vstate_fini(&help->dthps_vstate);
14584         kmem_free(help->dthps_actions,
14585             sizeof (dtrace_helper_action_t *) * DTRACE_NHELPER_ACTIONS);
14586         kmem_free(help, sizeof (dtrace_helpers_t));
14587 
14588         --dtrace_helpers;
14589         mutex_exit(&dtrace_lock);
14590 }
14591 
14592 static void
14593 dtrace_helpers_duplicate(proc_t *from, proc_t *to)
14594 {
14595         dtrace_helpers_t *help, *newhelp;
14596         dtrace_helper_action_t *helper, *new, *last;
14597         dtrace_difo_t *dp;
14598         dtrace_vstate_t *vstate;
14599         int i, j, sz, hasprovs = 0;
14600 
14601         mutex_enter(&dtrace_lock);
14602         ASSERT(from->p_dtrace_helpers != NULL);
14603         ASSERT(dtrace_helpers > 0);
14604 
14605         help = from->p_dtrace_helpers;
14606         newhelp = dtrace_helpers_create(to);
14607         ASSERT(to->p_dtrace_helpers != NULL);
14608 
14609         newhelp->dthps_generation = help->dthps_generation;
14610         vstate = &newhelp->dthps_vstate;
14611 
14612         /*
14613          * Duplicate the helper actions.
14614          */
14615         for (i = 0; i < DTRACE_NHELPER_ACTIONS; i++) {
14616                 if ((helper = help->dthps_actions[i]) == NULL)
14617                         continue;
14618 
14619                 for (last = NULL; helper != NULL; helper = helper->dtha_next) {
14620                         new = kmem_zalloc(sizeof (dtrace_helper_action_t),
14621                             KM_SLEEP);
14622                         new->dtha_generation = helper->dtha_generation;
14623 
14624                         if ((dp = helper->dtha_predicate) != NULL) {
14625                                 dp = dtrace_difo_duplicate(dp, vstate);
14626                                 new->dtha_predicate = dp;
14627                         }
14628 
14629                         new->dtha_nactions = helper->dtha_nactions;
14630                         sz = sizeof (dtrace_difo_t *) * new->dtha_nactions;
14631                         new->dtha_actions = kmem_alloc(sz, KM_SLEEP);
14632 
14633                         for (j = 0; j < new->dtha_nactions; j++) {
14634                                 dtrace_difo_t *dp = helper->dtha_actions[j];
14635 
14636                                 ASSERT(dp != NULL);
14637                                 dp = dtrace_difo_duplicate(dp, vstate);
14638                                 new->dtha_actions[j] = dp;
14639                         }
14640 
14641                         if (last != NULL) {
14642                                 last->dtha_next = new;
14643                         } else {
14644                                 newhelp->dthps_actions[i] = new;
14645                         }
14646 
14647                         last = new;
14648                 }
14649         }
14650 
14651         /*
14652          * Duplicate the helper providers and register them with the
14653          * DTrace framework.
14654          */
14655         if (help->dthps_nprovs > 0) {
14656                 newhelp->dthps_nprovs = help->dthps_nprovs;
14657                 newhelp->dthps_maxprovs = help->dthps_nprovs;
14658                 newhelp->dthps_provs = kmem_alloc(newhelp->dthps_nprovs *
14659                     sizeof (dtrace_helper_provider_t *), KM_SLEEP);
14660                 for (i = 0; i < newhelp->dthps_nprovs; i++) {
14661                         newhelp->dthps_provs[i] = help->dthps_provs[i];
14662                         newhelp->dthps_provs[i]->dthp_ref++;
14663                 }
14664 
14665                 hasprovs = 1;
14666         }
14667 
14668         mutex_exit(&dtrace_lock);
14669 
14670         if (hasprovs)
14671                 dtrace_helper_provider_register(to, newhelp, NULL);
14672 }
14673 
14674 /*
14675  * DTrace Hook Functions
14676  */
14677 static void
14678 dtrace_module_loaded(struct modctl *ctl)
14679 {
14680         dtrace_provider_t *prv;
14681 
14682         mutex_enter(&dtrace_provider_lock);
14683         mutex_enter(&mod_lock);
14684 
14685         ASSERT(ctl->mod_busy);
14686 
14687         /*
14688          * We're going to call each providers per-module provide operation
14689          * specifying only this module.
14690          */
14691         for (prv = dtrace_provider; prv != NULL; prv = prv->dtpv_next)
14692                 prv->dtpv_pops.dtps_provide_module(prv->dtpv_arg, ctl);
14693 
14694         mutex_exit(&mod_lock);
14695         mutex_exit(&dtrace_provider_lock);
14696 
14697         /*
14698          * If we have any retained enablings, we need to match against them.
14699          * Enabling probes requires that cpu_lock be held, and we cannot hold
14700          * cpu_lock here -- it is legal for cpu_lock to be held when loading a
14701          * module.  (In particular, this happens when loading scheduling
14702          * classes.)  So if we have any retained enablings, we need to dispatch
14703          * our task queue to do the match for us.
14704          */
14705         mutex_enter(&dtrace_lock);
14706 
14707         if (dtrace_retained == NULL) {
14708                 mutex_exit(&dtrace_lock);
14709                 return;
14710         }
14711 
14712         (void) taskq_dispatch(dtrace_taskq,
14713             (task_func_t *)dtrace_enabling_matchall, NULL, TQ_SLEEP);
14714 
14715         mutex_exit(&dtrace_lock);
14716 
14717         /*
14718          * And now, for a little heuristic sleaze:  in general, we want to
14719          * match modules as soon as they load.  However, we cannot guarantee
14720          * this, because it would lead us to the lock ordering violation
14721          * outlined above.  The common case, of course, is that cpu_lock is
14722          * _not_ held -- so we delay here for a clock tick, hoping that that's
14723          * long enough for the task queue to do its work.  If it's not, it's
14724          * not a serious problem -- it just means that the module that we
14725          * just loaded may not be immediately instrumentable.
14726          */
14727         delay(1);
14728 }
14729 
14730 static void
14731 dtrace_module_unloaded(struct modctl *ctl)
14732 {
14733         dtrace_probe_t template, *probe, *first, *next;
14734         dtrace_provider_t *prov;
14735 
14736         template.dtpr_mod = ctl->mod_modname;
14737 
14738         mutex_enter(&dtrace_provider_lock);
14739         mutex_enter(&mod_lock);
14740         mutex_enter(&dtrace_lock);
14741 
14742         if (dtrace_bymod == NULL) {
14743                 /*
14744                  * The DTrace module is loaded (obviously) but not attached;
14745                  * we don't have any work to do.
14746                  */
14747                 mutex_exit(&dtrace_provider_lock);
14748                 mutex_exit(&mod_lock);
14749                 mutex_exit(&dtrace_lock);
14750                 return;
14751         }
14752 
14753         for (probe = first = dtrace_hash_lookup(dtrace_bymod, &template);
14754             probe != NULL; probe = probe->dtpr_nextmod) {
14755                 if (probe->dtpr_ecb != NULL) {
14756                         mutex_exit(&dtrace_provider_lock);
14757                         mutex_exit(&mod_lock);
14758                         mutex_exit(&dtrace_lock);
14759 
14760                         /*
14761                          * This shouldn't _actually_ be possible -- we're
14762                          * unloading a module that has an enabled probe in it.
14763                          * (It's normally up to the provider to make sure that
14764                          * this can't happen.)  However, because dtps_enable()
14765                          * doesn't have a failure mode, there can be an
14766                          * enable/unload race.  Upshot:  we don't want to
14767                          * assert, but we're not going to disable the
14768                          * probe, either.
14769                          */
14770                         if (dtrace_err_verbose) {
14771                                 cmn_err(CE_WARN, "unloaded module '%s' had "
14772                                     "enabled probes", ctl->mod_modname);
14773                         }
14774 
14775                         return;
14776                 }
14777         }
14778 
14779         probe = first;
14780 
14781         for (first = NULL; probe != NULL; probe = next) {
14782                 ASSERT(dtrace_probes[probe->dtpr_id - 1] == probe);
14783 
14784                 dtrace_probes[probe->dtpr_id - 1] = NULL;
14785 
14786                 next = probe->dtpr_nextmod;
14787                 dtrace_hash_remove(dtrace_bymod, probe);
14788                 dtrace_hash_remove(dtrace_byfunc, probe);
14789                 dtrace_hash_remove(dtrace_byname, probe);
14790 
14791                 if (first == NULL) {
14792                         first = probe;
14793                         probe->dtpr_nextmod = NULL;
14794                 } else {
14795                         probe->dtpr_nextmod = first;
14796                         first = probe;
14797                 }
14798         }
14799 
14800         /*
14801          * We've removed all of the module's probes from the hash chains and
14802          * from the probe array.  Now issue a dtrace_sync() to be sure that
14803          * everyone has cleared out from any probe array processing.
14804          */
14805         dtrace_sync();
14806 
14807         for (probe = first; probe != NULL; probe = first) {
14808                 first = probe->dtpr_nextmod;
14809                 prov = probe->dtpr_provider;
14810                 prov->dtpv_pops.dtps_destroy(prov->dtpv_arg, probe->dtpr_id,
14811                     probe->dtpr_arg);
14812                 kmem_free(probe->dtpr_mod, strlen(probe->dtpr_mod) + 1);
14813                 kmem_free(probe->dtpr_func, strlen(probe->dtpr_func) + 1);
14814                 kmem_free(probe->dtpr_name, strlen(probe->dtpr_name) + 1);
14815                 vmem_free(dtrace_arena, (void *)(uintptr_t)probe->dtpr_id, 1);
14816                 kmem_free(probe, sizeof (dtrace_probe_t));
14817         }
14818 
14819         mutex_exit(&dtrace_lock);
14820         mutex_exit(&mod_lock);
14821         mutex_exit(&dtrace_provider_lock);
14822 }
14823 
14824 void
14825 dtrace_suspend(void)
14826 {
14827         dtrace_probe_foreach(offsetof(dtrace_pops_t, dtps_suspend));
14828 }
14829 
14830 void
14831 dtrace_resume(void)
14832 {
14833         dtrace_probe_foreach(offsetof(dtrace_pops_t, dtps_resume));
14834 }
14835 
14836 static int
14837 dtrace_cpu_setup(cpu_setup_t what, processorid_t cpu)
14838 {
14839         ASSERT(MUTEX_HELD(&cpu_lock));
14840         mutex_enter(&dtrace_lock);
14841 
14842         switch (what) {
14843         case CPU_CONFIG: {
14844                 dtrace_state_t *state;
14845                 dtrace_optval_t *opt, rs, c;
14846 
14847                 /*
14848                  * For now, we only allocate a new buffer for anonymous state.
14849                  */
14850                 if ((state = dtrace_anon.dta_state) == NULL)
14851                         break;
14852 
14853                 if (state->dts_activity != DTRACE_ACTIVITY_ACTIVE)
14854                         break;
14855 
14856                 opt = state->dts_options;
14857                 c = opt[DTRACEOPT_CPU];
14858 
14859                 if (c != DTRACE_CPUALL && c != DTRACEOPT_UNSET && c != cpu)
14860                         break;
14861 
14862                 /*
14863                  * Regardless of what the actual policy is, we're going to
14864                  * temporarily set our resize policy to be manual.  We're
14865                  * also going to temporarily set our CPU option to denote
14866                  * the newly configured CPU.
14867                  */
14868                 rs = opt[DTRACEOPT_BUFRESIZE];
14869                 opt[DTRACEOPT_BUFRESIZE] = DTRACEOPT_BUFRESIZE_MANUAL;
14870                 opt[DTRACEOPT_CPU] = (dtrace_optval_t)cpu;
14871 
14872                 (void) dtrace_state_buffers(state);
14873 
14874                 opt[DTRACEOPT_BUFRESIZE] = rs;
14875                 opt[DTRACEOPT_CPU] = c;
14876 
14877                 break;
14878         }
14879 
14880         case CPU_UNCONFIG:
14881                 /*
14882                  * We don't free the buffer in the CPU_UNCONFIG case.  (The
14883                  * buffer will be freed when the consumer exits.)
14884                  */
14885                 break;
14886 
14887         default:
14888                 break;
14889         }
14890 
14891         mutex_exit(&dtrace_lock);
14892         return (0);
14893 }
14894 
14895 static void
14896 dtrace_cpu_setup_initial(processorid_t cpu)
14897 {
14898         (void) dtrace_cpu_setup(CPU_CONFIG, cpu);
14899 }
14900 
14901 static void
14902 dtrace_toxrange_add(uintptr_t base, uintptr_t limit)
14903 {
14904         if (dtrace_toxranges >= dtrace_toxranges_max) {
14905                 int osize, nsize;
14906                 dtrace_toxrange_t *range;
14907 
14908                 osize = dtrace_toxranges_max * sizeof (dtrace_toxrange_t);
14909 
14910                 if (osize == 0) {
14911                         ASSERT(dtrace_toxrange == NULL);
14912                         ASSERT(dtrace_toxranges_max == 0);
14913                         dtrace_toxranges_max = 1;
14914                 } else {
14915                         dtrace_toxranges_max <<= 1;
14916                 }
14917 
14918                 nsize = dtrace_toxranges_max * sizeof (dtrace_toxrange_t);
14919                 range = kmem_zalloc(nsize, KM_SLEEP);
14920 
14921                 if (dtrace_toxrange != NULL) {
14922                         ASSERT(osize != 0);
14923                         bcopy(dtrace_toxrange, range, osize);
14924                         kmem_free(dtrace_toxrange, osize);
14925                 }
14926 
14927                 dtrace_toxrange = range;
14928         }
14929 
14930         ASSERT(dtrace_toxrange[dtrace_toxranges].dtt_base == NULL);
14931         ASSERT(dtrace_toxrange[dtrace_toxranges].dtt_limit == NULL);
14932 
14933         dtrace_toxrange[dtrace_toxranges].dtt_base = base;
14934         dtrace_toxrange[dtrace_toxranges].dtt_limit = limit;
14935         dtrace_toxranges++;
14936 }
14937 
14938 static void
14939 dtrace_getf_barrier()
14940 {
14941         /*
14942          * When we have unprivileged (that is, non-DTRACE_CRV_KERNEL) enablings
14943          * that contain calls to getf(), this routine will be called on every
14944          * closef() before either the underlying vnode is released or the
14945          * file_t itself is freed.  By the time we are here, it is essential
14946          * that the file_t can no longer be accessed from a call to getf()
14947          * in probe context -- that assures that a dtrace_sync() can be used
14948          * to clear out any enablings referring to the old structures.
14949          */
14950         if (curthread->t_procp->p_zone->zone_dtrace_getf != 0 ||
14951             kcred->cr_zone->zone_dtrace_getf != 0)
14952                 dtrace_sync();
14953 }
14954 
14955 /*
14956  * DTrace Driver Cookbook Functions
14957  */
14958 /*ARGSUSED*/
14959 static int
14960 dtrace_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
14961 {
14962         dtrace_provider_id_t id;
14963         dtrace_state_t *state = NULL;
14964         dtrace_enabling_t *enab;
14965 
14966         mutex_enter(&cpu_lock);
14967         mutex_enter(&dtrace_provider_lock);
14968         mutex_enter(&dtrace_lock);
14969 
14970         if (ddi_soft_state_init(&dtrace_softstate,
14971             sizeof (dtrace_state_t), 0) != 0) {
14972                 cmn_err(CE_NOTE, "/dev/dtrace failed to initialize soft state");
14973                 mutex_exit(&cpu_lock);
14974                 mutex_exit(&dtrace_provider_lock);
14975                 mutex_exit(&dtrace_lock);
14976                 return (DDI_FAILURE);
14977         }
14978 
14979         if (ddi_create_minor_node(devi, DTRACEMNR_DTRACE, S_IFCHR,
14980             DTRACEMNRN_DTRACE, DDI_PSEUDO, NULL) == DDI_FAILURE ||
14981             ddi_create_minor_node(devi, DTRACEMNR_HELPER, S_IFCHR,
14982             DTRACEMNRN_HELPER, DDI_PSEUDO, NULL) == DDI_FAILURE) {
14983                 cmn_err(CE_NOTE, "/dev/dtrace couldn't create minor nodes");
14984                 ddi_remove_minor_node(devi, NULL);
14985                 ddi_soft_state_fini(&dtrace_softstate);
14986                 mutex_exit(&cpu_lock);
14987                 mutex_exit(&dtrace_provider_lock);
14988                 mutex_exit(&dtrace_lock);
14989                 return (DDI_FAILURE);
14990         }
14991 
14992         ddi_report_dev(devi);
14993         dtrace_devi = devi;
14994 
14995         dtrace_modload = dtrace_module_loaded;
14996         dtrace_modunload = dtrace_module_unloaded;
14997         dtrace_cpu_init = dtrace_cpu_setup_initial;
14998         dtrace_helpers_cleanup = dtrace_helpers_destroy;
14999         dtrace_helpers_fork = dtrace_helpers_duplicate;
15000         dtrace_cpustart_init = dtrace_suspend;
15001         dtrace_cpustart_fini = dtrace_resume;
15002         dtrace_debugger_init = dtrace_suspend;
15003         dtrace_debugger_fini = dtrace_resume;
15004 
15005         register_cpu_setup_func((cpu_setup_func_t *)dtrace_cpu_setup, NULL);
15006 
15007         ASSERT(MUTEX_HELD(&cpu_lock));
15008 
15009         dtrace_arena = vmem_create("dtrace", (void *)1, UINT32_MAX, 1,
15010             NULL, NULL, NULL, 0, VM_SLEEP | VMC_IDENTIFIER);
15011         dtrace_minor = vmem_create("dtrace_minor", (void *)DTRACEMNRN_CLONE,
15012             UINT32_MAX - DTRACEMNRN_CLONE, 1, NULL, NULL, NULL, 0,
15013             VM_SLEEP | VMC_IDENTIFIER);
15014         dtrace_taskq = taskq_create("dtrace_taskq", 1, maxclsyspri,
15015             1, INT_MAX, 0);
15016 
15017         dtrace_state_cache = kmem_cache_create("dtrace_state_cache",
15018             sizeof (dtrace_dstate_percpu_t) * NCPU, DTRACE_STATE_ALIGN,
15019             NULL, NULL, NULL, NULL, NULL, 0);
15020 
15021         ASSERT(MUTEX_HELD(&cpu_lock));
15022         dtrace_bymod = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_mod),
15023             offsetof(dtrace_probe_t, dtpr_nextmod),
15024             offsetof(dtrace_probe_t, dtpr_prevmod));
15025 
15026         dtrace_byfunc = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_func),
15027             offsetof(dtrace_probe_t, dtpr_nextfunc),
15028             offsetof(dtrace_probe_t, dtpr_prevfunc));
15029 
15030         dtrace_byname = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_name),
15031             offsetof(dtrace_probe_t, dtpr_nextname),
15032             offsetof(dtrace_probe_t, dtpr_prevname));
15033 
15034         if (dtrace_retain_max < 1) {
15035                 cmn_err(CE_WARN, "illegal value (%lu) for dtrace_retain_max; "
15036                     "setting to 1", dtrace_retain_max);
15037                 dtrace_retain_max = 1;
15038         }
15039 
15040         /*
15041          * Now discover our toxic ranges.
15042          */
15043         dtrace_toxic_ranges(dtrace_toxrange_add);
15044 
15045         /*
15046          * Before we register ourselves as a provider to our own framework,
15047          * we would like to assert that dtrace_provider is NULL -- but that's
15048          * not true if we were loaded as a dependency of a DTrace provider.
15049          * Once we've registered, we can assert that dtrace_provider is our
15050          * pseudo provider.
15051          */
15052         (void) dtrace_register("dtrace", &dtrace_provider_attr,
15053             DTRACE_PRIV_NONE, 0, &dtrace_provider_ops, NULL, &id);
15054 
15055         ASSERT(dtrace_provider != NULL);
15056         ASSERT((dtrace_provider_id_t)dtrace_provider == id);
15057 
15058         dtrace_probeid_begin = dtrace_probe_create((dtrace_provider_id_t)
15059             dtrace_provider, NULL, NULL, "BEGIN", 0, NULL);
15060         dtrace_probeid_end = dtrace_probe_create((dtrace_provider_id_t)
15061             dtrace_provider, NULL, NULL, "END", 0, NULL);
15062         dtrace_probeid_error = dtrace_probe_create((dtrace_provider_id_t)
15063             dtrace_provider, NULL, NULL, "ERROR", 1, NULL);
15064 
15065         dtrace_anon_property();
15066         mutex_exit(&cpu_lock);
15067 
15068         /*
15069          * If DTrace helper tracing is enabled, we need to allocate the
15070          * trace buffer and initialize the values.
15071          */
15072         if (dtrace_helptrace_enabled) {
15073                 ASSERT(dtrace_helptrace_buffer == NULL);
15074                 dtrace_helptrace_buffer =
15075                     kmem_zalloc(dtrace_helptrace_bufsize, KM_SLEEP);
15076                 dtrace_helptrace_next = 0;
15077         }
15078 
15079         /*
15080          * If there are already providers, we must ask them to provide their
15081          * probes, and then match any anonymous enabling against them.  Note
15082          * that there should be no other retained enablings at this time:
15083          * the only retained enablings at this time should be the anonymous
15084          * enabling.
15085          */
15086         if (dtrace_anon.dta_enabling != NULL) {
15087                 ASSERT(dtrace_retained == dtrace_anon.dta_enabling);
15088 
15089                 dtrace_enabling_provide(NULL);
15090                 state = dtrace_anon.dta_state;
15091 
15092                 /*
15093                  * We couldn't hold cpu_lock across the above call to
15094                  * dtrace_enabling_provide(), but we must hold it to actually
15095                  * enable the probes.  We have to drop all of our locks, pick
15096                  * up cpu_lock, and regain our locks before matching the
15097                  * retained anonymous enabling.
15098                  */
15099                 mutex_exit(&dtrace_lock);
15100                 mutex_exit(&dtrace_provider_lock);
15101 
15102                 mutex_enter(&cpu_lock);
15103                 mutex_enter(&dtrace_provider_lock);
15104                 mutex_enter(&dtrace_lock);
15105 
15106                 if ((enab = dtrace_anon.dta_enabling) != NULL)
15107                         (void) dtrace_enabling_match(enab, NULL);
15108 
15109                 mutex_exit(&cpu_lock);
15110         }
15111 
15112         mutex_exit(&dtrace_lock);
15113         mutex_exit(&dtrace_provider_lock);
15114 
15115         if (state != NULL) {
15116                 /*
15117                  * If we created any anonymous state, set it going now.
15118                  */
15119                 (void) dtrace_state_go(state, &dtrace_anon.dta_beganon);
15120         }
15121 
15122         return (DDI_SUCCESS);
15123 }
15124 
15125 /*ARGSUSED*/
15126 static int
15127 dtrace_open(dev_t *devp, int flag, int otyp, cred_t *cred_p)
15128 {
15129         dtrace_state_t *state;
15130         uint32_t priv;
15131         uid_t uid;
15132         zoneid_t zoneid;
15133 
15134         if (getminor(*devp) == DTRACEMNRN_HELPER)
15135                 return (0);
15136 
15137         /*
15138          * If this wasn't an open with the "helper" minor, then it must be
15139          * the "dtrace" minor.
15140          */
15141         if (getminor(*devp) != DTRACEMNRN_DTRACE)
15142                 return (ENXIO);
15143 
15144         /*
15145          * If no DTRACE_PRIV_* bits are set in the credential, then the
15146          * caller lacks sufficient permission to do anything with DTrace.
15147          */
15148         dtrace_cred2priv(cred_p, &priv, &uid, &zoneid);
15149         if (priv == DTRACE_PRIV_NONE)
15150                 return (EACCES);
15151 
15152         /*
15153          * Ask all providers to provide all their probes.
15154          */
15155         mutex_enter(&dtrace_provider_lock);
15156         dtrace_probe_provide(NULL, NULL);
15157         mutex_exit(&dtrace_provider_lock);
15158 
15159         mutex_enter(&cpu_lock);
15160         mutex_enter(&dtrace_lock);
15161         dtrace_opens++;
15162         dtrace_membar_producer();
15163 
15164         /*
15165          * If the kernel debugger is active (that is, if the kernel debugger
15166          * modified text in some way), we won't allow the open.
15167          */
15168         if (kdi_dtrace_set(KDI_DTSET_DTRACE_ACTIVATE) != 0) {
15169                 dtrace_opens--;
15170                 mutex_exit(&cpu_lock);
15171                 mutex_exit(&dtrace_lock);
15172                 return (EBUSY);
15173         }
15174 
15175         state = dtrace_state_create(devp, cred_p);
15176         mutex_exit(&cpu_lock);
15177 
15178         if (state == NULL) {
15179                 if (--dtrace_opens == 0 && dtrace_anon.dta_enabling == NULL)
15180                         (void) kdi_dtrace_set(KDI_DTSET_DTRACE_DEACTIVATE);
15181                 mutex_exit(&dtrace_lock);
15182                 return (EAGAIN);
15183         }
15184 
15185         mutex_exit(&dtrace_lock);
15186 
15187         return (0);
15188 }
15189 
15190 /*ARGSUSED*/
15191 static int
15192 dtrace_close(dev_t dev, int flag, int otyp, cred_t *cred_p)
15193 {
15194         minor_t minor = getminor(dev);
15195         dtrace_state_t *state;
15196 
15197         if (minor == DTRACEMNRN_HELPER)
15198                 return (0);
15199 
15200         state = ddi_get_soft_state(dtrace_softstate, minor);
15201 
15202         mutex_enter(&cpu_lock);
15203         mutex_enter(&dtrace_lock);
15204 
15205         if (state->dts_anon) {
15206                 /*
15207                  * There is anonymous state. Destroy that first.
15208                  */
15209                 ASSERT(dtrace_anon.dta_state == NULL);
15210                 dtrace_state_destroy(state->dts_anon);
15211         }
15212 
15213         dtrace_state_destroy(state);
15214         ASSERT(dtrace_opens > 0);
15215 
15216         /*
15217          * Only relinquish control of the kernel debugger interface when there
15218          * are no consumers and no anonymous enablings.
15219          */
15220         if (--dtrace_opens == 0 && dtrace_anon.dta_enabling == NULL)
15221                 (void) kdi_dtrace_set(KDI_DTSET_DTRACE_DEACTIVATE);
15222 
15223         mutex_exit(&dtrace_lock);
15224         mutex_exit(&cpu_lock);
15225 
15226         return (0);
15227 }
15228 
15229 /*ARGSUSED*/
15230 static int
15231 dtrace_ioctl_helper(int cmd, intptr_t arg, int *rv)
15232 {
15233         int rval;
15234         dof_helper_t help, *dhp = NULL;
15235 
15236         switch (cmd) {
15237         case DTRACEHIOC_ADDDOF:
15238                 if (copyin((void *)arg, &help, sizeof (help)) != 0) {
15239                         dtrace_dof_error(NULL, "failed to copyin DOF helper");
15240                         return (EFAULT);
15241                 }
15242 
15243                 dhp = &help;
15244                 arg = (intptr_t)help.dofhp_dof;
15245                 /*FALLTHROUGH*/
15246 
15247         case DTRACEHIOC_ADD: {
15248                 dof_hdr_t *dof = dtrace_dof_copyin(arg, &rval);
15249 
15250                 if (dof == NULL)
15251                         return (rval);
15252 
15253                 mutex_enter(&dtrace_lock);
15254 
15255                 /*
15256                  * dtrace_helper_slurp() takes responsibility for the dof --
15257                  * it may free it now or it may save it and free it later.
15258                  */
15259                 if ((rval = dtrace_helper_slurp(dof, dhp)) != -1) {
15260                         *rv = rval;
15261                         rval = 0;
15262                 } else {
15263                         rval = EINVAL;
15264                 }
15265 
15266                 mutex_exit(&dtrace_lock);
15267                 return (rval);
15268         }
15269 
15270         case DTRACEHIOC_REMOVE: {
15271                 mutex_enter(&dtrace_lock);
15272                 rval = dtrace_helper_destroygen(arg);
15273                 mutex_exit(&dtrace_lock);
15274 
15275                 return (rval);
15276         }
15277 
15278         default:
15279                 break;
15280         }
15281 
15282         return (ENOTTY);
15283 }
15284 
15285 /*ARGSUSED*/
15286 static int
15287 dtrace_ioctl(dev_t dev, int cmd, intptr_t arg, int md, cred_t *cr, int *rv)
15288 {
15289         minor_t minor = getminor(dev);
15290         dtrace_state_t *state;
15291         int rval;
15292 
15293         if (minor == DTRACEMNRN_HELPER)
15294                 return (dtrace_ioctl_helper(cmd, arg, rv));
15295 
15296         state = ddi_get_soft_state(dtrace_softstate, minor);
15297 
15298         if (state->dts_anon) {
15299                 ASSERT(dtrace_anon.dta_state == NULL);
15300                 state = state->dts_anon;
15301         }
15302 
15303         switch (cmd) {
15304         case DTRACEIOC_PROVIDER: {
15305                 dtrace_providerdesc_t pvd;
15306                 dtrace_provider_t *pvp;
15307 
15308                 if (copyin((void *)arg, &pvd, sizeof (pvd)) != 0)
15309                         return (EFAULT);
15310 
15311                 pvd.dtvd_name[DTRACE_PROVNAMELEN - 1] = '\0';
15312                 mutex_enter(&dtrace_provider_lock);
15313 
15314                 for (pvp = dtrace_provider; pvp != NULL; pvp = pvp->dtpv_next) {
15315                         if (strcmp(pvp->dtpv_name, pvd.dtvd_name) == 0)
15316                                 break;
15317                 }
15318 
15319                 mutex_exit(&dtrace_provider_lock);
15320 
15321                 if (pvp == NULL)
15322                         return (ESRCH);
15323 
15324                 bcopy(&pvp->dtpv_priv, &pvd.dtvd_priv, sizeof (dtrace_ppriv_t));
15325                 bcopy(&pvp->dtpv_attr, &pvd.dtvd_attr, sizeof (dtrace_pattr_t));
15326                 if (copyout(&pvd, (void *)arg, sizeof (pvd)) != 0)
15327                         return (EFAULT);
15328 
15329                 return (0);
15330         }
15331 
15332         case DTRACEIOC_EPROBE: {
15333                 dtrace_eprobedesc_t epdesc;
15334                 dtrace_ecb_t *ecb;
15335                 dtrace_action_t *act;
15336                 void *buf;
15337                 size_t size;
15338                 uintptr_t dest;
15339                 int nrecs;
15340 
15341                 if (copyin((void *)arg, &epdesc, sizeof (epdesc)) != 0)
15342                         return (EFAULT);
15343 
15344                 mutex_enter(&dtrace_lock);
15345 
15346                 if ((ecb = dtrace_epid2ecb(state, epdesc.dtepd_epid)) == NULL) {
15347                         mutex_exit(&dtrace_lock);
15348                         return (EINVAL);
15349                 }
15350 
15351                 if (ecb->dte_probe == NULL) {
15352                         mutex_exit(&dtrace_lock);
15353                         return (EINVAL);
15354                 }
15355 
15356                 epdesc.dtepd_probeid = ecb->dte_probe->dtpr_id;
15357                 epdesc.dtepd_uarg = ecb->dte_uarg;
15358                 epdesc.dtepd_size = ecb->dte_size;
15359 
15360                 nrecs = epdesc.dtepd_nrecs;
15361                 epdesc.dtepd_nrecs = 0;
15362                 for (act = ecb->dte_action; act != NULL; act = act->dta_next) {
15363                         if (DTRACEACT_ISAGG(act->dta_kind) || act->dta_intuple)
15364                                 continue;
15365 
15366                         epdesc.dtepd_nrecs++;
15367                 }
15368 
15369                 /*
15370                  * Now that we have the size, we need to allocate a temporary
15371                  * buffer in which to store the complete description.  We need
15372                  * the temporary buffer to be able to drop dtrace_lock()
15373                  * across the copyout(), below.
15374                  */
15375                 size = sizeof (dtrace_eprobedesc_t) +
15376                     (epdesc.dtepd_nrecs * sizeof (dtrace_recdesc_t));
15377 
15378                 buf = kmem_alloc(size, KM_SLEEP);
15379                 dest = (uintptr_t)buf;
15380 
15381                 bcopy(&epdesc, (void *)dest, sizeof (epdesc));
15382                 dest += offsetof(dtrace_eprobedesc_t, dtepd_rec[0]);
15383 
15384                 for (act = ecb->dte_action; act != NULL; act = act->dta_next) {
15385                         if (DTRACEACT_ISAGG(act->dta_kind) || act->dta_intuple)
15386                                 continue;
15387 
15388                         if (nrecs-- == 0)
15389                                 break;
15390 
15391                         bcopy(&act->dta_rec, (void *)dest,
15392                             sizeof (dtrace_recdesc_t));
15393                         dest += sizeof (dtrace_recdesc_t);
15394                 }
15395 
15396                 mutex_exit(&dtrace_lock);
15397 
15398                 if (copyout(buf, (void *)arg, dest - (uintptr_t)buf) != 0) {
15399                         kmem_free(buf, size);
15400                         return (EFAULT);
15401                 }
15402 
15403                 kmem_free(buf, size);
15404                 return (0);
15405         }
15406 
15407         case DTRACEIOC_AGGDESC: {
15408                 dtrace_aggdesc_t aggdesc;
15409                 dtrace_action_t *act;
15410                 dtrace_aggregation_t *agg;
15411                 int nrecs;
15412                 uint32_t offs;
15413                 dtrace_recdesc_t *lrec;
15414                 void *buf;
15415                 size_t size;
15416                 uintptr_t dest;
15417 
15418                 if (copyin((void *)arg, &aggdesc, sizeof (aggdesc)) != 0)
15419                         return (EFAULT);
15420 
15421                 mutex_enter(&dtrace_lock);
15422 
15423                 if ((agg = dtrace_aggid2agg(state, aggdesc.dtagd_id)) == NULL) {
15424                         mutex_exit(&dtrace_lock);
15425                         return (EINVAL);
15426                 }
15427 
15428                 aggdesc.dtagd_epid = agg->dtag_ecb->dte_epid;
15429 
15430                 nrecs = aggdesc.dtagd_nrecs;
15431                 aggdesc.dtagd_nrecs = 0;
15432 
15433                 offs = agg->dtag_base;
15434                 lrec = &agg->dtag_action.dta_rec;
15435                 aggdesc.dtagd_size = lrec->dtrd_offset + lrec->dtrd_size - offs;
15436 
15437                 for (act = agg->dtag_first; ; act = act->dta_next) {
15438                         ASSERT(act->dta_intuple ||
15439                             DTRACEACT_ISAGG(act->dta_kind));
15440 
15441                         /*
15442                          * If this action has a record size of zero, it
15443                          * denotes an argument to the aggregating action.
15444                          * Because the presence of this record doesn't (or
15445                          * shouldn't) affect the way the data is interpreted,
15446                          * we don't copy it out to save user-level the
15447                          * confusion of dealing with a zero-length record.
15448                          */
15449                         if (act->dta_rec.dtrd_size == 0) {
15450                                 ASSERT(agg->dtag_hasarg);
15451                                 continue;
15452                         }
15453 
15454                         aggdesc.dtagd_nrecs++;
15455 
15456                         if (act == &agg->dtag_action)
15457                                 break;
15458                 }
15459 
15460                 /*
15461                  * Now that we have the size, we need to allocate a temporary
15462                  * buffer in which to store the complete description.  We need
15463                  * the temporary buffer to be able to drop dtrace_lock()
15464                  * across the copyout(), below.
15465                  */
15466                 size = sizeof (dtrace_aggdesc_t) +
15467                     (aggdesc.dtagd_nrecs * sizeof (dtrace_recdesc_t));
15468 
15469                 buf = kmem_alloc(size, KM_SLEEP);
15470                 dest = (uintptr_t)buf;
15471 
15472                 bcopy(&aggdesc, (void *)dest, sizeof (aggdesc));
15473                 dest += offsetof(dtrace_aggdesc_t, dtagd_rec[0]);
15474 
15475                 for (act = agg->dtag_first; ; act = act->dta_next) {
15476                         dtrace_recdesc_t rec = act->dta_rec;
15477 
15478                         /*
15479                          * See the comment in the above loop for why we pass
15480                          * over zero-length records.
15481                          */
15482                         if (rec.dtrd_size == 0) {
15483                                 ASSERT(agg->dtag_hasarg);
15484                                 continue;
15485                         }
15486 
15487                         if (nrecs-- == 0)
15488                                 break;
15489 
15490                         rec.dtrd_offset -= offs;
15491                         bcopy(&rec, (void *)dest, sizeof (rec));
15492                         dest += sizeof (dtrace_recdesc_t);
15493 
15494                         if (act == &agg->dtag_action)
15495                                 break;
15496                 }
15497 
15498                 mutex_exit(&dtrace_lock);
15499 
15500                 if (copyout(buf, (void *)arg, dest - (uintptr_t)buf) != 0) {
15501                         kmem_free(buf, size);
15502                         return (EFAULT);
15503                 }
15504 
15505                 kmem_free(buf, size);
15506                 return (0);
15507         }
15508 
15509         case DTRACEIOC_ENABLE: {
15510                 dof_hdr_t *dof;
15511                 dtrace_enabling_t *enab = NULL;
15512                 dtrace_vstate_t *vstate;
15513                 int err = 0;
15514 
15515                 *rv = 0;
15516 
15517                 /*
15518                  * If a NULL argument has been passed, we take this as our
15519                  * cue to reevaluate our enablings.
15520                  */
15521                 if (arg == NULL) {
15522                         dtrace_enabling_matchall();
15523 
15524                         return (0);
15525                 }
15526 
15527                 if ((dof = dtrace_dof_copyin(arg, &rval)) == NULL)
15528                         return (rval);
15529 
15530                 mutex_enter(&cpu_lock);
15531                 mutex_enter(&dtrace_lock);
15532                 vstate = &state->dts_vstate;
15533 
15534                 if (state->dts_activity != DTRACE_ACTIVITY_INACTIVE) {
15535                         mutex_exit(&dtrace_lock);
15536                         mutex_exit(&cpu_lock);
15537                         dtrace_dof_destroy(dof);
15538                         return (EBUSY);
15539                 }
15540 
15541                 if (dtrace_dof_slurp(dof, vstate, cr, &enab, 0, B_TRUE) != 0) {
15542                         mutex_exit(&dtrace_lock);
15543                         mutex_exit(&cpu_lock);
15544                         dtrace_dof_destroy(dof);
15545                         return (EINVAL);
15546                 }
15547 
15548                 if ((rval = dtrace_dof_options(dof, state)) != 0) {
15549                         dtrace_enabling_destroy(enab);
15550                         mutex_exit(&dtrace_lock);
15551                         mutex_exit(&cpu_lock);
15552                         dtrace_dof_destroy(dof);
15553                         return (rval);
15554                 }
15555 
15556                 if ((err = dtrace_enabling_match(enab, rv)) == 0) {
15557                         err = dtrace_enabling_retain(enab);
15558                 } else {
15559                         dtrace_enabling_destroy(enab);
15560                 }
15561 
15562                 mutex_exit(&cpu_lock);
15563                 mutex_exit(&dtrace_lock);
15564                 dtrace_dof_destroy(dof);
15565 
15566                 return (err);
15567         }
15568 
15569         case DTRACEIOC_REPLICATE: {
15570                 dtrace_repldesc_t desc;
15571                 dtrace_probedesc_t *match = &desc.dtrpd_match;
15572                 dtrace_probedesc_t *create = &desc.dtrpd_create;
15573                 int err;
15574 
15575                 if (copyin((void *)arg, &desc, sizeof (desc)) != 0)
15576                         return (EFAULT);
15577 
15578                 match->dtpd_provider[DTRACE_PROVNAMELEN - 1] = '\0';
15579                 match->dtpd_mod[DTRACE_MODNAMELEN - 1] = '\0';
15580                 match->dtpd_func[DTRACE_FUNCNAMELEN - 1] = '\0';
15581                 match->dtpd_name[DTRACE_NAMELEN - 1] = '\0';
15582 
15583                 create->dtpd_provider[DTRACE_PROVNAMELEN - 1] = '\0';
15584                 create->dtpd_mod[DTRACE_MODNAMELEN - 1] = '\0';
15585                 create->dtpd_func[DTRACE_FUNCNAMELEN - 1] = '\0';
15586                 create->dtpd_name[DTRACE_NAMELEN - 1] = '\0';
15587 
15588                 mutex_enter(&dtrace_lock);
15589                 err = dtrace_enabling_replicate(state, match, create);
15590                 mutex_exit(&dtrace_lock);
15591 
15592                 return (err);
15593         }
15594 
15595         case DTRACEIOC_PROBEMATCH:
15596         case DTRACEIOC_PROBES: {
15597                 dtrace_probe_t *probe = NULL;
15598                 dtrace_probedesc_t desc;
15599                 dtrace_probekey_t pkey;
15600                 dtrace_id_t i;
15601                 int m = 0;
15602                 uint32_t priv;
15603                 uid_t uid;
15604                 zoneid_t zoneid;
15605 
15606                 if (copyin((void *)arg, &desc, sizeof (desc)) != 0)
15607                         return (EFAULT);
15608 
15609                 desc.dtpd_provider[DTRACE_PROVNAMELEN - 1] = '\0';
15610                 desc.dtpd_mod[DTRACE_MODNAMELEN - 1] = '\0';
15611                 desc.dtpd_func[DTRACE_FUNCNAMELEN - 1] = '\0';
15612                 desc.dtpd_name[DTRACE_NAMELEN - 1] = '\0';
15613 
15614                 /*
15615                  * Before we attempt to match this probe, we want to give
15616                  * all providers the opportunity to provide it.
15617                  */
15618                 if (desc.dtpd_id == DTRACE_IDNONE) {
15619                         mutex_enter(&dtrace_provider_lock);
15620                         dtrace_probe_provide(&desc, NULL);
15621                         mutex_exit(&dtrace_provider_lock);
15622                         desc.dtpd_id++;
15623                 }
15624 
15625                 if (cmd == DTRACEIOC_PROBEMATCH)  {
15626                         dtrace_probekey(&desc, &pkey);
15627                         pkey.dtpk_id = DTRACE_IDNONE;
15628                 }
15629 
15630                 dtrace_cred2priv(cr, &priv, &uid, &zoneid);
15631 
15632                 mutex_enter(&dtrace_lock);
15633 
15634                 if (cmd == DTRACEIOC_PROBEMATCH) {
15635                         for (i = desc.dtpd_id; i <= dtrace_nprobes; i++) {
15636                                 if ((probe = dtrace_probes[i - 1]) != NULL &&
15637                                     (m = dtrace_match_probe(probe, &pkey,
15638                                     priv, uid, zoneid)) != 0)
15639                                         break;
15640                         }
15641 
15642                         if (m < 0) {
15643                                 mutex_exit(&dtrace_lock);
15644                                 return (EINVAL);
15645                         }
15646 
15647                 } else {
15648                         for (i = desc.dtpd_id; i <= dtrace_nprobes; i++) {
15649                                 if ((probe = dtrace_probes[i - 1]) != NULL &&
15650                                     dtrace_match_priv(probe, priv, uid, zoneid))
15651                                         break;
15652                         }
15653                 }
15654 
15655                 if (probe == NULL) {
15656                         mutex_exit(&dtrace_lock);
15657                         return (ESRCH);
15658                 }
15659 
15660                 dtrace_probe_description(probe, &desc);
15661                 mutex_exit(&dtrace_lock);
15662 
15663                 if (copyout(&desc, (void *)arg, sizeof (desc)) != 0)
15664                         return (EFAULT);
15665 
15666                 return (0);
15667         }
15668 
15669         case DTRACEIOC_PROBEARG: {
15670                 dtrace_argdesc_t desc;
15671                 dtrace_probe_t *probe;
15672                 dtrace_provider_t *prov;
15673 
15674                 if (copyin((void *)arg, &desc, sizeof (desc)) != 0)
15675                         return (EFAULT);
15676 
15677                 if (desc.dtargd_id == DTRACE_IDNONE)
15678                         return (EINVAL);
15679 
15680                 if (desc.dtargd_ndx == DTRACE_ARGNONE)
15681                         return (EINVAL);
15682 
15683                 mutex_enter(&dtrace_provider_lock);
15684                 mutex_enter(&mod_lock);
15685                 mutex_enter(&dtrace_lock);
15686 
15687                 if (desc.dtargd_id > dtrace_nprobes) {
15688                         mutex_exit(&dtrace_lock);
15689                         mutex_exit(&mod_lock);
15690                         mutex_exit(&dtrace_provider_lock);
15691                         return (EINVAL);
15692                 }
15693 
15694                 if ((probe = dtrace_probes[desc.dtargd_id - 1]) == NULL) {
15695                         mutex_exit(&dtrace_lock);
15696                         mutex_exit(&mod_lock);
15697                         mutex_exit(&dtrace_provider_lock);
15698                         return (EINVAL);
15699                 }
15700 
15701                 mutex_exit(&dtrace_lock);
15702 
15703                 prov = probe->dtpr_provider;
15704 
15705                 if (prov->dtpv_pops.dtps_getargdesc == NULL) {
15706                         /*
15707                          * There isn't any typed information for this probe.
15708                          * Set the argument number to DTRACE_ARGNONE.
15709                          */
15710                         desc.dtargd_ndx = DTRACE_ARGNONE;
15711                 } else {
15712                         desc.dtargd_native[0] = '\0';
15713                         desc.dtargd_xlate[0] = '\0';
15714                         desc.dtargd_mapping = desc.dtargd_ndx;
15715 
15716                         prov->dtpv_pops.dtps_getargdesc(prov->dtpv_arg,
15717                             probe->dtpr_id, probe->dtpr_arg, &desc);
15718                 }
15719 
15720                 mutex_exit(&mod_lock);
15721                 mutex_exit(&dtrace_provider_lock);
15722 
15723                 if (copyout(&desc, (void *)arg, sizeof (desc)) != 0)
15724                         return (EFAULT);
15725 
15726                 return (0);
15727         }
15728 
15729         case DTRACEIOC_GO: {
15730                 processorid_t cpuid;
15731                 rval = dtrace_state_go(state, &cpuid);
15732 
15733                 if (rval != 0)
15734                         return (rval);
15735 
15736                 if (copyout(&cpuid, (void *)arg, sizeof (cpuid)) != 0)
15737                         return (EFAULT);
15738 
15739                 return (0);
15740         }
15741 
15742         case DTRACEIOC_STOP: {
15743                 processorid_t cpuid;
15744 
15745                 mutex_enter(&dtrace_lock);
15746                 rval = dtrace_state_stop(state, &cpuid);
15747                 mutex_exit(&dtrace_lock);
15748 
15749                 if (rval != 0)
15750                         return (rval);
15751 
15752                 if (copyout(&cpuid, (void *)arg, sizeof (cpuid)) != 0)
15753                         return (EFAULT);
15754 
15755                 return (0);
15756         }
15757 
15758         case DTRACEIOC_DOFGET: {
15759                 dof_hdr_t hdr, *dof;
15760                 uint64_t len;
15761 
15762                 if (copyin((void *)arg, &hdr, sizeof (hdr)) != 0)
15763                         return (EFAULT);
15764 
15765                 mutex_enter(&dtrace_lock);
15766                 dof = dtrace_dof_create(state);
15767                 mutex_exit(&dtrace_lock);
15768 
15769                 len = MIN(hdr.dofh_loadsz, dof->dofh_loadsz);
15770                 rval = copyout(dof, (void *)arg, len);
15771                 dtrace_dof_destroy(dof);
15772 
15773                 return (rval == 0 ? 0 : EFAULT);
15774         }
15775 
15776         case DTRACEIOC_AGGSNAP:
15777         case DTRACEIOC_BUFSNAP: {
15778                 dtrace_bufdesc_t desc;
15779                 caddr_t cached;
15780                 dtrace_buffer_t *buf;
15781 
15782                 if (copyin((void *)arg, &desc, sizeof (desc)) != 0)
15783                         return (EFAULT);
15784 
15785                 if (desc.dtbd_cpu < 0 || desc.dtbd_cpu >= NCPU)
15786                         return (EINVAL);
15787 
15788                 mutex_enter(&dtrace_lock);
15789 
15790                 if (cmd == DTRACEIOC_BUFSNAP) {
15791                         buf = &state->dts_buffer[desc.dtbd_cpu];
15792                 } else {
15793                         buf = &state->dts_aggbuffer[desc.dtbd_cpu];
15794                 }
15795 
15796                 if (buf->dtb_flags & (DTRACEBUF_RING | DTRACEBUF_FILL)) {
15797                         size_t sz = buf->dtb_offset;
15798 
15799                         if (state->dts_activity != DTRACE_ACTIVITY_STOPPED) {
15800                                 mutex_exit(&dtrace_lock);
15801                                 return (EBUSY);
15802                         }
15803 
15804                         /*
15805                          * If this buffer has already been consumed, we're
15806                          * going to indicate that there's nothing left here
15807                          * to consume.
15808                          */
15809                         if (buf->dtb_flags & DTRACEBUF_CONSUMED) {
15810                                 mutex_exit(&dtrace_lock);
15811 
15812                                 desc.dtbd_size = 0;
15813                                 desc.dtbd_drops = 0;
15814                                 desc.dtbd_errors = 0;
15815                                 desc.dtbd_oldest = 0;
15816                                 sz = sizeof (desc);
15817 
15818                                 if (copyout(&desc, (void *)arg, sz) != 0)
15819                                         return (EFAULT);
15820 
15821                                 return (0);
15822                         }
15823 
15824                         /*
15825                          * If this is a ring buffer that has wrapped, we want
15826                          * to copy the whole thing out.
15827                          */
15828                         if (buf->dtb_flags & DTRACEBUF_WRAPPED) {
15829                                 dtrace_buffer_polish(buf);
15830                                 sz = buf->dtb_size;
15831                         }
15832 
15833                         if (copyout(buf->dtb_tomax, desc.dtbd_data, sz) != 0) {
15834                                 mutex_exit(&dtrace_lock);
15835                                 return (EFAULT);
15836                         }
15837 
15838                         desc.dtbd_size = sz;
15839                         desc.dtbd_drops = buf->dtb_drops;
15840                         desc.dtbd_errors = buf->dtb_errors;
15841                         desc.dtbd_oldest = buf->dtb_xamot_offset;
15842                         desc.dtbd_timestamp = dtrace_gethrtime();
15843 
15844                         mutex_exit(&dtrace_lock);
15845 
15846                         if (copyout(&desc, (void *)arg, sizeof (desc)) != 0)
15847                                 return (EFAULT);
15848 
15849                         buf->dtb_flags |= DTRACEBUF_CONSUMED;
15850 
15851                         return (0);
15852                 }
15853 
15854                 if (buf->dtb_tomax == NULL) {
15855                         ASSERT(buf->dtb_xamot == NULL);
15856                         mutex_exit(&dtrace_lock);
15857                         return (ENOENT);
15858                 }
15859 
15860                 cached = buf->dtb_tomax;
15861                 ASSERT(!(buf->dtb_flags & DTRACEBUF_NOSWITCH));
15862 
15863                 dtrace_xcall(desc.dtbd_cpu,
15864                     (dtrace_xcall_t)dtrace_buffer_switch, buf);
15865 
15866                 state->dts_errors += buf->dtb_xamot_errors;
15867 
15868                 /*
15869                  * If the buffers did not actually switch, then the cross call
15870                  * did not take place -- presumably because the given CPU is
15871                  * not in the ready set.  If this is the case, we'll return
15872                  * ENOENT.
15873                  */
15874                 if (buf->dtb_tomax == cached) {
15875                         ASSERT(buf->dtb_xamot != cached);
15876                         mutex_exit(&dtrace_lock);
15877                         return (ENOENT);
15878                 }
15879 
15880                 ASSERT(cached == buf->dtb_xamot);
15881 
15882                 /*
15883                  * We have our snapshot; now copy it out.
15884                  */
15885                 if (copyout(buf->dtb_xamot, desc.dtbd_data,
15886                     buf->dtb_xamot_offset) != 0) {
15887                         mutex_exit(&dtrace_lock);
15888                         return (EFAULT);
15889                 }
15890 
15891                 desc.dtbd_size = buf->dtb_xamot_offset;
15892                 desc.dtbd_drops = buf->dtb_xamot_drops;
15893                 desc.dtbd_errors = buf->dtb_xamot_errors;
15894                 desc.dtbd_oldest = 0;
15895                 desc.dtbd_timestamp = buf->dtb_switched;
15896 
15897                 mutex_exit(&dtrace_lock);
15898 
15899                 /*
15900                  * Finally, copy out the buffer description.
15901                  */
15902                 if (copyout(&desc, (void *)arg, sizeof (desc)) != 0)
15903                         return (EFAULT);
15904 
15905                 return (0);
15906         }
15907 
15908         case DTRACEIOC_CONF: {
15909                 dtrace_conf_t conf;
15910 
15911                 bzero(&conf, sizeof (conf));
15912                 conf.dtc_difversion = DIF_VERSION;
15913                 conf.dtc_difintregs = DIF_DIR_NREGS;
15914                 conf.dtc_diftupregs = DIF_DTR_NREGS;
15915                 conf.dtc_ctfmodel = CTF_MODEL_NATIVE;
15916 
15917                 if (copyout(&conf, (void *)arg, sizeof (conf)) != 0)
15918                         return (EFAULT);
15919 
15920                 return (0);
15921         }
15922 
15923         case DTRACEIOC_STATUS: {
15924                 dtrace_status_t stat;
15925                 dtrace_dstate_t *dstate;
15926                 int i, j;
15927                 uint64_t nerrs;
15928 
15929                 /*
15930                  * See the comment in dtrace_state_deadman() for the reason
15931                  * for setting dts_laststatus to INT64_MAX before setting
15932                  * it to the correct value.
15933                  */
15934                 state->dts_laststatus = INT64_MAX;
15935                 dtrace_membar_producer();
15936                 state->dts_laststatus = dtrace_gethrtime();
15937 
15938                 bzero(&stat, sizeof (stat));
15939 
15940                 mutex_enter(&dtrace_lock);
15941 
15942                 if (state->dts_activity == DTRACE_ACTIVITY_INACTIVE) {
15943                         mutex_exit(&dtrace_lock);
15944                         return (ENOENT);
15945                 }
15946 
15947                 if (state->dts_activity == DTRACE_ACTIVITY_DRAINING)
15948                         stat.dtst_exiting = 1;
15949 
15950                 nerrs = state->dts_errors;
15951                 dstate = &state->dts_vstate.dtvs_dynvars;
15952 
15953                 for (i = 0; i < NCPU; i++) {
15954                         dtrace_dstate_percpu_t *dcpu = &dstate->dtds_percpu[i];
15955 
15956                         stat.dtst_dyndrops += dcpu->dtdsc_drops;
15957                         stat.dtst_dyndrops_dirty += dcpu->dtdsc_dirty_drops;
15958                         stat.dtst_dyndrops_rinsing += dcpu->dtdsc_rinsing_drops;
15959 
15960                         if (state->dts_buffer[i].dtb_flags & DTRACEBUF_FULL)
15961                                 stat.dtst_filled++;
15962 
15963                         nerrs += state->dts_buffer[i].dtb_errors;
15964 
15965                         for (j = 0; j < state->dts_nspeculations; j++) {
15966                                 dtrace_speculation_t *spec;
15967                                 dtrace_buffer_t *buf;
15968 
15969                                 spec = &state->dts_speculations[j];
15970                                 buf = &spec->dtsp_buffer[i];
15971                                 stat.dtst_specdrops += buf->dtb_xamot_drops;
15972                         }
15973                 }
15974 
15975                 stat.dtst_specdrops_busy = state->dts_speculations_busy;
15976                 stat.dtst_specdrops_unavail = state->dts_speculations_unavail;
15977                 stat.dtst_stkstroverflows = state->dts_stkstroverflows;
15978                 stat.dtst_dblerrors = state->dts_dblerrors;
15979                 stat.dtst_killed =
15980                     (state->dts_activity == DTRACE_ACTIVITY_KILLED);
15981                 stat.dtst_errors = nerrs;
15982 
15983                 mutex_exit(&dtrace_lock);
15984 
15985                 if (copyout(&stat, (void *)arg, sizeof (stat)) != 0)
15986                         return (EFAULT);
15987 
15988                 return (0);
15989         }
15990 
15991         case DTRACEIOC_FORMAT: {
15992                 dtrace_fmtdesc_t fmt;
15993                 char *str;
15994                 int len;
15995 
15996                 if (copyin((void *)arg, &fmt, sizeof (fmt)) != 0)
15997                         return (EFAULT);
15998 
15999                 mutex_enter(&dtrace_lock);
16000 
16001                 if (fmt.dtfd_format == 0 ||
16002                     fmt.dtfd_format > state->dts_nformats) {
16003                         mutex_exit(&dtrace_lock);
16004                         return (EINVAL);
16005                 }
16006 
16007                 /*
16008                  * Format strings are allocated contiguously and they are
16009                  * never freed; if a format index is less than the number
16010                  * of formats, we can assert that the format map is non-NULL
16011                  * and that the format for the specified index is non-NULL.
16012                  */
16013                 ASSERT(state->dts_formats != NULL);
16014                 str = state->dts_formats[fmt.dtfd_format - 1];
16015                 ASSERT(str != NULL);
16016 
16017                 len = strlen(str) + 1;
16018 
16019                 if (len > fmt.dtfd_length) {
16020                         fmt.dtfd_length = len;
16021 
16022                         if (copyout(&fmt, (void *)arg, sizeof (fmt)) != 0) {
16023                                 mutex_exit(&dtrace_lock);
16024                                 return (EINVAL);
16025                         }
16026                 } else {
16027                         if (copyout(str, fmt.dtfd_string, len) != 0) {
16028                                 mutex_exit(&dtrace_lock);
16029                                 return (EINVAL);
16030                         }
16031                 }
16032 
16033                 mutex_exit(&dtrace_lock);
16034                 return (0);
16035         }
16036 
16037         default:
16038                 break;
16039         }
16040 
16041         return (ENOTTY);
16042 }
16043 
16044 /*ARGSUSED*/
16045 static int
16046 dtrace_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
16047 {
16048         dtrace_state_t *state;
16049 
16050         switch (cmd) {
16051         case DDI_DETACH:
16052                 break;
16053 
16054         case DDI_SUSPEND:
16055                 return (DDI_SUCCESS);
16056 
16057         default:
16058                 return (DDI_FAILURE);
16059         }
16060 
16061         mutex_enter(&cpu_lock);
16062         mutex_enter(&dtrace_provider_lock);
16063         mutex_enter(&dtrace_lock);
16064 
16065         ASSERT(dtrace_opens == 0);
16066 
16067         if (dtrace_helpers > 0) {
16068                 mutex_exit(&dtrace_provider_lock);
16069                 mutex_exit(&dtrace_lock);
16070                 mutex_exit(&cpu_lock);
16071                 return (DDI_FAILURE);
16072         }
16073 
16074         if (dtrace_unregister((dtrace_provider_id_t)dtrace_provider) != 0) {
16075                 mutex_exit(&dtrace_provider_lock);
16076                 mutex_exit(&dtrace_lock);
16077                 mutex_exit(&cpu_lock);
16078                 return (DDI_FAILURE);
16079         }
16080 
16081         dtrace_provider = NULL;
16082 
16083         if ((state = dtrace_anon_grab()) != NULL) {
16084                 /*
16085                  * If there were ECBs on this state, the provider should
16086                  * have not been allowed to detach; assert that there is
16087                  * none.
16088                  */
16089                 ASSERT(state->dts_necbs == 0);
16090                 dtrace_state_destroy(state);
16091 
16092                 /*
16093                  * If we're being detached with anonymous state, we need to
16094                  * indicate to the kernel debugger that DTrace is now inactive.
16095                  */
16096                 (void) kdi_dtrace_set(KDI_DTSET_DTRACE_DEACTIVATE);
16097         }
16098 
16099         bzero(&dtrace_anon, sizeof (dtrace_anon_t));
16100         unregister_cpu_setup_func((cpu_setup_func_t *)dtrace_cpu_setup, NULL);
16101         dtrace_cpu_init = NULL;
16102         dtrace_helpers_cleanup = NULL;
16103         dtrace_helpers_fork = NULL;
16104         dtrace_cpustart_init = NULL;
16105         dtrace_cpustart_fini = NULL;
16106         dtrace_debugger_init = NULL;
16107         dtrace_debugger_fini = NULL;
16108         dtrace_modload = NULL;
16109         dtrace_modunload = NULL;
16110 
16111         ASSERT(dtrace_getf == 0);
16112         ASSERT(dtrace_closef == NULL);
16113 
16114         mutex_exit(&cpu_lock);
16115 
16116         if (dtrace_helptrace_enabled) {
16117                 kmem_free(dtrace_helptrace_buffer, dtrace_helptrace_bufsize);
16118                 dtrace_helptrace_buffer = NULL;
16119         }
16120 
16121         kmem_free(dtrace_probes, dtrace_nprobes * sizeof (dtrace_probe_t *));
16122         dtrace_probes = NULL;
16123         dtrace_nprobes = 0;
16124 
16125         dtrace_hash_destroy(dtrace_bymod);
16126         dtrace_hash_destroy(dtrace_byfunc);
16127         dtrace_hash_destroy(dtrace_byname);
16128         dtrace_bymod = NULL;
16129         dtrace_byfunc = NULL;
16130         dtrace_byname = NULL;
16131 
16132         kmem_cache_destroy(dtrace_state_cache);
16133         vmem_destroy(dtrace_minor);
16134         vmem_destroy(dtrace_arena);
16135 
16136         if (dtrace_toxrange != NULL) {
16137                 kmem_free(dtrace_toxrange,
16138                     dtrace_toxranges_max * sizeof (dtrace_toxrange_t));
16139                 dtrace_toxrange = NULL;
16140                 dtrace_toxranges = 0;
16141                 dtrace_toxranges_max = 0;
16142         }
16143 
16144         ddi_remove_minor_node(dtrace_devi, NULL);
16145         dtrace_devi = NULL;
16146 
16147         ddi_soft_state_fini(&dtrace_softstate);
16148 
16149         ASSERT(dtrace_vtime_references == 0);
16150         ASSERT(dtrace_opens == 0);
16151         ASSERT(dtrace_retained == NULL);
16152 
16153         mutex_exit(&dtrace_lock);
16154         mutex_exit(&dtrace_provider_lock);
16155 
16156         /*
16157          * We don't destroy the task queue until after we have dropped our
16158          * locks (taskq_destroy() may block on running tasks).  To prevent
16159          * attempting to do work after we have effectively detached but before
16160          * the task queue has been destroyed, all tasks dispatched via the
16161          * task queue must check that DTrace is still attached before
16162          * performing any operation.
16163          */
16164         taskq_destroy(dtrace_taskq);
16165         dtrace_taskq = NULL;
16166 
16167         return (DDI_SUCCESS);
16168 }
16169 
16170 /*ARGSUSED*/
16171 static int
16172 dtrace_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result)
16173 {
16174         int error;
16175 
16176         switch (infocmd) {
16177         case DDI_INFO_DEVT2DEVINFO:
16178                 *result = (void *)dtrace_devi;
16179                 error = DDI_SUCCESS;
16180                 break;
16181         case DDI_INFO_DEVT2INSTANCE:
16182                 *result = (void *)0;
16183                 error = DDI_SUCCESS;
16184                 break;
16185         default:
16186                 error = DDI_FAILURE;
16187         }
16188         return (error);
16189 }
16190 
16191 static struct cb_ops dtrace_cb_ops = {
16192         dtrace_open,            /* open */
16193         dtrace_close,           /* close */
16194         nulldev,                /* strategy */
16195         nulldev,                /* print */
16196         nodev,                  /* dump */
16197         nodev,                  /* read */
16198         nodev,                  /* write */
16199         dtrace_ioctl,           /* ioctl */
16200         nodev,                  /* devmap */
16201         nodev,                  /* mmap */
16202         nodev,                  /* segmap */
16203         nochpoll,               /* poll */
16204         ddi_prop_op,            /* cb_prop_op */
16205         0,                      /* streamtab  */
16206         D_NEW | D_MP            /* Driver compatibility flag */
16207 };
16208 
16209 static struct dev_ops dtrace_ops = {
16210         DEVO_REV,               /* devo_rev */
16211         0,                      /* refcnt */
16212         dtrace_info,            /* get_dev_info */
16213         nulldev,                /* identify */
16214         nulldev,                /* probe */
16215         dtrace_attach,          /* attach */
16216         dtrace_detach,          /* detach */
16217         nodev,                  /* reset */
16218         &dtrace_cb_ops,             /* driver operations */
16219         NULL,                   /* bus operations */
16220         nodev,                  /* dev power */
16221         ddi_quiesce_not_needed,         /* quiesce */
16222 };
16223 
16224 static struct modldrv modldrv = {
16225         &mod_driverops,             /* module type (this is a pseudo driver) */
16226         "Dynamic Tracing",      /* name of module */
16227         &dtrace_ops,                /* driver ops */
16228 };
16229 
16230 static struct modlinkage modlinkage = {
16231         MODREV_1,
16232         (void *)&modldrv,
16233         NULL
16234 };
16235 
16236 int
16237 _init(void)
16238 {
16239         return (mod_install(&modlinkage));
16240 }
16241 
16242 int
16243 _info(struct modinfo *modinfop)
16244 {
16245         return (mod_info(&modlinkage, modinfop));
16246 }
16247 
16248 int
16249 _fini(void)
16250 {
16251         return (mod_remove(&modlinkage));
16252 }