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) 2012, Joyent, Inc. All rights reserved.
  25  */
  26 
  27 /*
  28  * DTrace - Dynamic Tracing for Solaris
  29  *
  30  * This is the implementation of the Solaris Dynamic Tracing framework
  31  * (DTrace).  The user-visible interface to DTrace is described at length in
  32  * the "Solaris Dynamic Tracing Guide".  The interfaces between the libdtrace
  33  * library, the in-kernel DTrace framework, and the DTrace providers are
  34  * described in the block comments in the <sys/dtrace.h> header file.  The
  35  * internal architecture of DTrace is described in the block comments in the
  36  * <sys/dtrace_impl.h> header file.  The comments contained within the DTrace
  37  * implementation very much assume mastery of all of these sources; if one has
  38  * an unanswered question about the implementation, one should consult them
  39  * first.
  40  *
  41  * The functions here are ordered roughly as follows:
  42  *
  43  *   - Probe context functions
  44  *   - Probe hashing functions
  45  *   - Non-probe context utility functions
  46  *   - Matching functions
  47  *   - Provider-to-Framework API functions
  48  *   - Probe management functions
  49  *   - DIF object functions
  50  *   - Format functions
  51  *   - Predicate functions
  52  *   - ECB functions
  53  *   - Buffer functions
  54  *   - Enabling functions
  55  *   - DOF functions
  56  *   - Anonymous enabling functions
  57  *   - Consumer state functions
  58  *   - Helper functions
  59  *   - Hook functions
  60  *   - Driver cookbook functions
  61  *
  62  * Each group of functions begins with a block comment labelled the "DTrace
  63  * [Group] Functions", allowing one to find each block by searching forward
  64  * on capital-f functions.
  65  */
  66 #include <sys/errno.h>
  67 #include <sys/stat.h>
  68 #include <sys/modctl.h>
  69 #include <sys/conf.h>
  70 #include <sys/systm.h>
  71 #include <sys/ddi.h>
  72 #include <sys/sunddi.h>
  73 #include <sys/cpuvar.h>
  74 #include <sys/kmem.h>
  75 #include <sys/strsubr.h>
  76 #include <sys/sysmacros.h>
  77 #include <sys/dtrace_impl.h>
  78 #include <sys/atomic.h>
  79 #include <sys/cmn_err.h>
  80 #include <sys/mutex_impl.h>
  81 #include <sys/rwlock_impl.h>
  82 #include <sys/ctf_api.h>
  83 #include <sys/panic.h>
  84 #include <sys/priv_impl.h>
  85 #include <sys/policy.h>
  86 #include <sys/cred_impl.h>
  87 #include <sys/procfs_isa.h>
  88 #include <sys/taskq.h>
  89 #include <sys/mkdev.h>
  90 #include <sys/kdi.h>
  91 #include <sys/zone.h>
  92 #include <sys/socket.h>
  93 #include <netinet/in.h>
  94 
  95 /*
  96  * DTrace Tunable Variables
  97  *
  98  * The following variables may be tuned by adding a line to /etc/system that
  99  * includes both the name of the DTrace module ("dtrace") and the name of the
 100  * variable.  For example:
 101  *
 102  *   set dtrace:dtrace_destructive_disallow = 1
 103  *
 104  * In general, the only variables that one should be tuning this way are those
 105  * that affect system-wide DTrace behavior, and for which the default behavior
 106  * is undesirable.  Most of these variables are tunable on a per-consumer
 107  * basis using DTrace options, and need not be tuned on a system-wide basis.
 108  * When tuning these variables, avoid pathological values; while some attempt
 109  * is made to verify the integrity of these variables, they are not considered
 110  * part of the supported interface to DTrace, and they are therefore not
 111  * checked comprehensively.  Further, these variables should not be tuned
 112  * dynamically via "mdb -kw" or other means; they should only be tuned via
 113  * /etc/system.
 114  */
 115 int             dtrace_destructive_disallow = 0;
 116 dtrace_optval_t dtrace_nonroot_maxsize = (16 * 1024 * 1024);
 117 size_t          dtrace_difo_maxsize = (256 * 1024);
 118 dtrace_optval_t dtrace_dof_maxsize = (256 * 1024);
 119 size_t          dtrace_global_maxsize = (16 * 1024);
 120 size_t          dtrace_actions_max = (16 * 1024);
 121 size_t          dtrace_retain_max = 1024;
 122 dtrace_optval_t dtrace_helper_actions_max = 1024;
 123 dtrace_optval_t dtrace_helper_providers_max = 32;
 124 dtrace_optval_t dtrace_dstate_defsize = (1 * 1024 * 1024);
 125 size_t          dtrace_strsize_default = 256;
 126 dtrace_optval_t dtrace_cleanrate_default = 9900990;             /* 101 hz */
 127 dtrace_optval_t dtrace_cleanrate_min = 200000;                  /* 5000 hz */
 128 dtrace_optval_t dtrace_cleanrate_max = (uint64_t)60 * NANOSEC;  /* 1/minute */
 129 dtrace_optval_t dtrace_aggrate_default = NANOSEC;               /* 1 hz */
 130 dtrace_optval_t dtrace_statusrate_default = NANOSEC;            /* 1 hz */
 131 dtrace_optval_t dtrace_statusrate_max = (hrtime_t)10 * NANOSEC;  /* 6/minute */
 132 dtrace_optval_t dtrace_switchrate_default = NANOSEC;            /* 1 hz */
 133 dtrace_optval_t dtrace_nspec_default = 1;
 134 dtrace_optval_t dtrace_specsize_default = 32 * 1024;
 135 dtrace_optval_t dtrace_stackframes_default = 20;
 136 dtrace_optval_t dtrace_ustackframes_default = 20;
 137 dtrace_optval_t dtrace_jstackframes_default = 50;
 138 dtrace_optval_t dtrace_jstackstrsize_default = 512;
 139 int             dtrace_msgdsize_max = 128;
 140 hrtime_t        dtrace_chill_max = 500 * (NANOSEC / MILLISEC);  /* 500 ms */
 141 hrtime_t        dtrace_chill_interval = NANOSEC;                /* 1000 ms */
 142 int             dtrace_devdepth_max = 32;
 143 int             dtrace_err_verbose;
 144 hrtime_t        dtrace_deadman_interval = NANOSEC;
 145 hrtime_t        dtrace_deadman_timeout = (hrtime_t)10 * NANOSEC;
 146 hrtime_t        dtrace_deadman_user = (hrtime_t)30 * NANOSEC;
 147 hrtime_t        dtrace_unregister_defunct_reap = (hrtime_t)60 * NANOSEC;
 148 
 149 /*
 150  * DTrace External Variables
 151  *
 152  * As dtrace(7D) is a kernel module, any DTrace variables are obviously
 153  * available to DTrace consumers via the backtick (`) syntax.  One of these,
 154  * dtrace_zero, is made deliberately so:  it is provided as a source of
 155  * well-known, zero-filled memory.  While this variable is not documented,
 156  * it is used by some translators as an implementation detail.
 157  */
 158 const char      dtrace_zero[256] = { 0 };       /* zero-filled memory */
 159 
 160 /*
 161  * DTrace Internal Variables
 162  */
 163 static dev_info_t       *dtrace_devi;           /* device info */
 164 static vmem_t           *dtrace_arena;          /* probe ID arena */
 165 static vmem_t           *dtrace_minor;          /* minor number arena */
 166 static taskq_t          *dtrace_taskq;          /* task queue */
 167 static dtrace_probe_t   **dtrace_probes;        /* array of all probes */
 168 static int              dtrace_nprobes;         /* number of probes */
 169 static dtrace_provider_t *dtrace_provider;      /* provider list */
 170 static dtrace_meta_t    *dtrace_meta_pid;       /* user-land meta provider */
 171 static int              dtrace_opens;           /* number of opens */
 172 static int              dtrace_helpers;         /* number of helpers */
 173 static int              dtrace_getf;            /* number of unpriv getf()s */
 174 static void             *dtrace_softstate;      /* softstate pointer */
 175 static dtrace_hash_t    *dtrace_bymod;          /* probes hashed by module */
 176 static dtrace_hash_t    *dtrace_byfunc;         /* probes hashed by function */
 177 static dtrace_hash_t    *dtrace_byname;         /* probes hashed by name */
 178 static dtrace_toxrange_t *dtrace_toxrange;      /* toxic range array */
 179 static int              dtrace_toxranges;       /* number of toxic ranges */
 180 static int              dtrace_toxranges_max;   /* size of toxic range array */
 181 static dtrace_anon_t    dtrace_anon;            /* anonymous enabling */
 182 static kmem_cache_t     *dtrace_state_cache;    /* cache for dynamic state */
 183 static uint64_t         dtrace_vtime_references; /* number of vtimestamp refs */
 184 static kthread_t        *dtrace_panicked;       /* panicking thread */
 185 static dtrace_ecb_t     *dtrace_ecb_create_cache; /* cached created ECB */
 186 static dtrace_genid_t   dtrace_probegen;        /* current probe generation */
 187 static dtrace_helpers_t *dtrace_deferred_pid;   /* deferred helper list */
 188 static dtrace_enabling_t *dtrace_retained;      /* list of retained enablings */
 189 static dtrace_genid_t   dtrace_retained_gen;    /* current retained enab gen */
 190 static dtrace_dynvar_t  dtrace_dynhash_sink;    /* end of dynamic hash chains */
 191 static int              dtrace_dynvar_failclean; /* dynvars failed to clean */
 192 
 193 /*
 194  * DTrace Locking
 195  * DTrace is protected by three (relatively coarse-grained) locks:
 196  *
 197  * (1) dtrace_lock is required to manipulate essentially any DTrace state,
 198  *     including enabling state, probes, ECBs, consumer state, helper state,
 199  *     etc.  Importantly, dtrace_lock is _not_ required when in probe context;
 200  *     probe context is lock-free -- synchronization is handled via the
 201  *     dtrace_sync() cross call mechanism.
 202  *
 203  * (2) dtrace_provider_lock is required when manipulating provider state, or
 204  *     when provider state must be held constant.
 205  *
 206  * (3) dtrace_meta_lock is required when manipulating meta provider state, or
 207  *     when meta provider state must be held constant.
 208  *
 209  * The lock ordering between these three locks is dtrace_meta_lock before
 210  * dtrace_provider_lock before dtrace_lock.  (In particular, there are
 211  * several places where dtrace_provider_lock is held by the framework as it
 212  * calls into the providers -- which then call back into the framework,
 213  * grabbing dtrace_lock.)
 214  *
 215  * There are two other locks in the mix:  mod_lock and cpu_lock.  With respect
 216  * to dtrace_provider_lock and dtrace_lock, cpu_lock continues its historical
 217  * role as a coarse-grained lock; it is acquired before both of these locks.
 218  * With respect to dtrace_meta_lock, its behavior is stranger:  cpu_lock must
 219  * be acquired _between_ dtrace_meta_lock and any other DTrace locks.
 220  * mod_lock is similar with respect to dtrace_provider_lock in that it must be
 221  * acquired _between_ dtrace_provider_lock and dtrace_lock.
 222  */
 223 static kmutex_t         dtrace_lock;            /* probe state lock */
 224 static kmutex_t         dtrace_provider_lock;   /* provider state lock */
 225 static kmutex_t         dtrace_meta_lock;       /* meta-provider state lock */
 226 
 227 /*
 228  * DTrace Provider Variables
 229  *
 230  * These are the variables relating to DTrace as a provider (that is, the
 231  * provider of the BEGIN, END, and ERROR probes).
 232  */
 233 static dtrace_pattr_t   dtrace_provider_attr = {
 234 { DTRACE_STABILITY_STABLE, DTRACE_STABILITY_STABLE, DTRACE_CLASS_COMMON },
 235 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
 236 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
 237 { DTRACE_STABILITY_STABLE, DTRACE_STABILITY_STABLE, DTRACE_CLASS_COMMON },
 238 { DTRACE_STABILITY_STABLE, DTRACE_STABILITY_STABLE, DTRACE_CLASS_COMMON },
 239 };
 240 
 241 static void
 242 dtrace_nullop(void)
 243 {}
 244 
 245 static int
 246 dtrace_enable_nullop(void)
 247 {
 248         return (0);
 249 }
 250 
 251 static dtrace_pops_t    dtrace_provider_ops = {
 252         (void (*)(void *, const dtrace_probedesc_t *))dtrace_nullop,
 253         (void (*)(void *, struct modctl *))dtrace_nullop,
 254         (int (*)(void *, dtrace_id_t, void *))dtrace_enable_nullop,
 255         (void (*)(void *, dtrace_id_t, void *))dtrace_nullop,
 256         (void (*)(void *, dtrace_id_t, void *))dtrace_nullop,
 257         (void (*)(void *, dtrace_id_t, void *))dtrace_nullop,
 258         NULL,
 259         NULL,
 260         NULL,
 261         (void (*)(void *, dtrace_id_t, void *))dtrace_nullop
 262 };
 263 
 264 static dtrace_id_t      dtrace_probeid_begin;   /* special BEGIN probe */
 265 static dtrace_id_t      dtrace_probeid_end;     /* special END probe */
 266 dtrace_id_t             dtrace_probeid_error;   /* special ERROR probe */
 267 
 268 /*
 269  * DTrace Helper Tracing Variables
 270  */
 271 uint32_t dtrace_helptrace_next = 0;
 272 uint32_t dtrace_helptrace_nlocals;
 273 char    *dtrace_helptrace_buffer;
 274 int     dtrace_helptrace_bufsize = 512 * 1024;
 275 
 276 #ifdef DEBUG
 277 int     dtrace_helptrace_enabled = 1;
 278 #else
 279 int     dtrace_helptrace_enabled = 0;
 280 #endif
 281 
 282 /*
 283  * DTrace Error Hashing
 284  *
 285  * On DEBUG kernels, DTrace will track the errors that has seen in a hash
 286  * table.  This is very useful for checking coverage of tests that are
 287  * expected to induce DIF or DOF processing errors, and may be useful for
 288  * debugging problems in the DIF code generator or in DOF generation .  The
 289  * error hash may be examined with the ::dtrace_errhash MDB dcmd.
 290  */
 291 #ifdef DEBUG
 292 static dtrace_errhash_t dtrace_errhash[DTRACE_ERRHASHSZ];
 293 static const char *dtrace_errlast;
 294 static kthread_t *dtrace_errthread;
 295 static kmutex_t dtrace_errlock;
 296 #endif
 297 
 298 /*
 299  * DTrace Macros and Constants
 300  *
 301  * These are various macros that are useful in various spots in the
 302  * implementation, along with a few random constants that have no meaning
 303  * outside of the implementation.  There is no real structure to this cpp
 304  * mishmash -- but is there ever?
 305  */
 306 #define DTRACE_HASHSTR(hash, probe)     \
 307         dtrace_hash_str(*((char **)((uintptr_t)(probe) + (hash)->dth_stroffs)))
 308 
 309 #define DTRACE_HASHNEXT(hash, probe)    \
 310         (dtrace_probe_t **)((uintptr_t)(probe) + (hash)->dth_nextoffs)
 311 
 312 #define DTRACE_HASHPREV(hash, probe)    \
 313         (dtrace_probe_t **)((uintptr_t)(probe) + (hash)->dth_prevoffs)
 314 
 315 #define DTRACE_HASHEQ(hash, lhs, rhs)   \
 316         (strcmp(*((char **)((uintptr_t)(lhs) + (hash)->dth_stroffs)), \
 317             *((char **)((uintptr_t)(rhs) + (hash)->dth_stroffs))) == 0)
 318 
 319 #define DTRACE_AGGHASHSIZE_SLEW         17
 320 
 321 #define DTRACE_V4MAPPED_OFFSET          (sizeof (uint32_t) * 3)
 322 
 323 /*
 324  * The key for a thread-local variable consists of the lower 61 bits of the
 325  * t_did, plus the 3 bits of the highest active interrupt above LOCK_LEVEL.
 326  * We add DIF_VARIABLE_MAX to t_did to assure that the thread key is never
 327  * equal to a variable identifier.  This is necessary (but not sufficient) to
 328  * assure that global associative arrays never collide with thread-local
 329  * variables.  To guarantee that they cannot collide, we must also define the
 330  * order for keying dynamic variables.  That order is:
 331  *
 332  *   [ key0 ] ... [ keyn ] [ variable-key ] [ tls-key ]
 333  *
 334  * Because the variable-key and the tls-key are in orthogonal spaces, there is
 335  * no way for a global variable key signature to match a thread-local key
 336  * signature.
 337  */
 338 #define DTRACE_TLS_THRKEY(where) { \
 339         uint_t intr = 0; \
 340         uint_t actv = CPU->cpu_intr_actv >> (LOCK_LEVEL + 1); \
 341         for (; actv; actv >>= 1) \
 342                 intr++; \
 343         ASSERT(intr < (1 << 3)); \
 344         (where) = ((curthread->t_did + DIF_VARIABLE_MAX) & \
 345             (((uint64_t)1 << 61) - 1)) | ((uint64_t)intr << 61); \
 346 }
 347 
 348 #define DT_BSWAP_8(x)   ((x) & 0xff)
 349 #define DT_BSWAP_16(x)  ((DT_BSWAP_8(x) << 8) | DT_BSWAP_8((x) >> 8))
 350 #define DT_BSWAP_32(x)  ((DT_BSWAP_16(x) << 16) | DT_BSWAP_16((x) >> 16))
 351 #define DT_BSWAP_64(x)  ((DT_BSWAP_32(x) << 32) | DT_BSWAP_32((x) >> 32))
 352 
 353 #define DT_MASK_LO 0x00000000FFFFFFFFULL
 354 
 355 #define DTRACE_STORE(type, tomax, offset, what) \
 356         *((type *)((uintptr_t)(tomax) + (uintptr_t)offset)) = (type)(what);
 357 
 358 #ifndef __i386
 359 #define DTRACE_ALIGNCHECK(addr, size, flags)                            \
 360         if (addr & (size - 1)) {                                    \
 361                 *flags |= CPU_DTRACE_BADALIGN;                          \
 362                 cpu_core[CPU->cpu_id].cpuc_dtrace_illval = addr;     \
 363                 return (0);                                             \
 364         }
 365 #else
 366 #define DTRACE_ALIGNCHECK(addr, size, flags)
 367 #endif
 368 
 369 /*
 370  * Test whether a range of memory starting at testaddr of size testsz falls
 371  * within the range of memory described by addr, sz.  We take care to avoid
 372  * problems with overflow and underflow of the unsigned quantities, and
 373  * disallow all negative sizes.  Ranges of size 0 are allowed.
 374  */
 375 #define DTRACE_INRANGE(testaddr, testsz, baseaddr, basesz) \
 376         ((testaddr) - (uintptr_t)(baseaddr) < (basesz) && \
 377         (testaddr) + (testsz) - (uintptr_t)(baseaddr) <= (basesz) && \
 378         (testaddr) + (testsz) >= (testaddr))
 379 
 380 /*
 381  * Test whether alloc_sz bytes will fit in the scratch region.  We isolate
 382  * alloc_sz on the righthand side of the comparison in order to avoid overflow
 383  * or underflow in the comparison with it.  This is simpler than the INRANGE
 384  * check above, because we know that the dtms_scratch_ptr is valid in the
 385  * range.  Allocations of size zero are allowed.
 386  */
 387 #define DTRACE_INSCRATCH(mstate, alloc_sz) \
 388         ((mstate)->dtms_scratch_base + (mstate)->dtms_scratch_size - \
 389         (mstate)->dtms_scratch_ptr >= (alloc_sz))
 390 
 391 #define DTRACE_LOADFUNC(bits)                                           \
 392 /*CSTYLED*/                                                             \
 393 uint##bits##_t                                                          \
 394 dtrace_load##bits(uintptr_t addr)                                       \
 395 {                                                                       \
 396         size_t size = bits / NBBY;                                      \
 397         /*CSTYLED*/                                                     \
 398         uint##bits##_t rval;                                            \
 399         int i;                                                          \
 400         volatile uint16_t *flags = (volatile uint16_t *)                \
 401             &cpu_core[CPU->cpu_id].cpuc_dtrace_flags;                    \
 402                                                                         \
 403         DTRACE_ALIGNCHECK(addr, size, flags);                           \
 404                                                                         \
 405         for (i = 0; i < dtrace_toxranges; i++) {                     \
 406                 if (addr >= dtrace_toxrange[i].dtt_limit)            \
 407                         continue;                                       \
 408                                                                         \
 409                 if (addr + size <= dtrace_toxrange[i].dtt_base)              \
 410                         continue;                                       \
 411                                                                         \
 412                 /*                                                      \
 413                  * This address falls within a toxic region; return 0.  \
 414                  */                                                     \
 415                 *flags |= CPU_DTRACE_BADADDR;                           \
 416                 cpu_core[CPU->cpu_id].cpuc_dtrace_illval = addr;     \
 417                 return (0);                                             \
 418         }                                                               \
 419                                                                         \
 420         *flags |= CPU_DTRACE_NOFAULT;                                   \
 421         /*CSTYLED*/                                                     \
 422         rval = *((volatile uint##bits##_t *)addr);                      \
 423         *flags &= ~CPU_DTRACE_NOFAULT;                                      \
 424                                                                         \
 425         return (!(*flags & CPU_DTRACE_FAULT) ? rval : 0);           \
 426 }
 427 
 428 #ifdef _LP64
 429 #define dtrace_loadptr  dtrace_load64
 430 #else
 431 #define dtrace_loadptr  dtrace_load32
 432 #endif
 433 
 434 #define DTRACE_DYNHASH_FREE     0
 435 #define DTRACE_DYNHASH_SINK     1
 436 #define DTRACE_DYNHASH_VALID    2
 437 
 438 #define DTRACE_MATCH_FAIL       -1
 439 #define DTRACE_MATCH_NEXT       0
 440 #define DTRACE_MATCH_DONE       1
 441 #define DTRACE_ANCHORED(probe)  ((probe)->dtpr_func[0] != '\0')
 442 #define DTRACE_STATE_ALIGN      64
 443 
 444 #define DTRACE_FLAGS2FLT(flags)                                         \
 445         (((flags) & CPU_DTRACE_BADADDR) ? DTRACEFLT_BADADDR :               \
 446         ((flags) & CPU_DTRACE_ILLOP) ? DTRACEFLT_ILLOP :            \
 447         ((flags) & CPU_DTRACE_DIVZERO) ? DTRACEFLT_DIVZERO :                \
 448         ((flags) & CPU_DTRACE_KPRIV) ? DTRACEFLT_KPRIV :            \
 449         ((flags) & CPU_DTRACE_UPRIV) ? DTRACEFLT_UPRIV :            \
 450         ((flags) & CPU_DTRACE_TUPOFLOW) ?  DTRACEFLT_TUPOFLOW :             \
 451         ((flags) & CPU_DTRACE_BADALIGN) ?  DTRACEFLT_BADALIGN :             \
 452         ((flags) & CPU_DTRACE_NOSCRATCH) ?  DTRACEFLT_NOSCRATCH :   \
 453         ((flags) & CPU_DTRACE_BADSTACK) ?  DTRACEFLT_BADSTACK :             \
 454         DTRACEFLT_UNKNOWN)
 455 
 456 #define DTRACEACT_ISSTRING(act)                                         \
 457         ((act)->dta_kind == DTRACEACT_DIFEXPR &&                     \
 458         (act)->dta_difo->dtdo_rtype.dtdt_kind == DIF_TYPE_STRING)
 459 
 460 static size_t dtrace_strlen(const char *, size_t);
 461 static dtrace_probe_t *dtrace_probe_lookup_id(dtrace_id_t id);
 462 static void dtrace_enabling_provide(dtrace_provider_t *);
 463 static int dtrace_enabling_match(dtrace_enabling_t *, int *);
 464 static void dtrace_enabling_matchall(void);
 465 static void dtrace_enabling_reap(void);
 466 static dtrace_state_t *dtrace_anon_grab(void);
 467 static uint64_t dtrace_helper(int, dtrace_mstate_t *,
 468     dtrace_state_t *, uint64_t, uint64_t);
 469 static dtrace_helpers_t *dtrace_helpers_create(proc_t *);
 470 static void dtrace_buffer_drop(dtrace_buffer_t *);
 471 static int dtrace_buffer_consumed(dtrace_buffer_t *, hrtime_t when);
 472 static intptr_t dtrace_buffer_reserve(dtrace_buffer_t *, size_t, size_t,
 473     dtrace_state_t *, dtrace_mstate_t *);
 474 static int dtrace_state_option(dtrace_state_t *, dtrace_optid_t,
 475     dtrace_optval_t);
 476 static int dtrace_ecb_create_enable(dtrace_probe_t *, void *);
 477 static void dtrace_helper_provider_destroy(dtrace_helper_provider_t *);
 478 static int dtrace_priv_proc(dtrace_state_t *, dtrace_mstate_t *);
 479 static void dtrace_getf_barrier(void);
 480 
 481 /*
 482  * DTrace Probe Context Functions
 483  *
 484  * These functions are called from probe context.  Because probe context is
 485  * any context in which C may be called, arbitrarily locks may be held,
 486  * interrupts may be disabled, we may be in arbitrary dispatched state, etc.
 487  * As a result, functions called from probe context may only call other DTrace
 488  * support functions -- they may not interact at all with the system at large.
 489  * (Note that the ASSERT macro is made probe-context safe by redefining it in
 490  * terms of dtrace_assfail(), a probe-context safe function.) If arbitrary
 491  * loads are to be performed from probe context, they _must_ be in terms of
 492  * the safe dtrace_load*() variants.
 493  *
 494  * Some functions in this block are not actually called from probe context;
 495  * for these functions, there will be a comment above the function reading
 496  * "Note:  not called from probe context."
 497  */
 498 void
 499 dtrace_panic(const char *format, ...)
 500 {
 501         va_list alist;
 502 
 503         va_start(alist, format);
 504         dtrace_vpanic(format, alist);
 505         va_end(alist);
 506 }
 507 
 508 int
 509 dtrace_assfail(const char *a, const char *f, int l)
 510 {
 511         dtrace_panic("assertion failed: %s, file: %s, line: %d", a, f, l);
 512 
 513         /*
 514          * We just need something here that even the most clever compiler
 515          * cannot optimize away.
 516          */
 517         return (a[(uintptr_t)f]);
 518 }
 519 
 520 /*
 521  * Atomically increment a specified error counter from probe context.
 522  */
 523 static void
 524 dtrace_error(uint32_t *counter)
 525 {
 526         /*
 527          * Most counters stored to in probe context are per-CPU counters.
 528          * However, there are some error conditions that are sufficiently
 529          * arcane that they don't merit per-CPU storage.  If these counters
 530          * are incremented concurrently on different CPUs, scalability will be
 531          * adversely affected -- but we don't expect them to be white-hot in a
 532          * correctly constructed enabling...
 533          */
 534         uint32_t oval, nval;
 535 
 536         do {
 537                 oval = *counter;
 538 
 539                 if ((nval = oval + 1) == 0) {
 540                         /*
 541                          * If the counter would wrap, set it to 1 -- assuring
 542                          * that the counter is never zero when we have seen
 543                          * errors.  (The counter must be 32-bits because we
 544                          * aren't guaranteed a 64-bit compare&swap operation.)
 545                          * To save this code both the infamy of being fingered
 546                          * by a priggish news story and the indignity of being
 547                          * the target of a neo-puritan witch trial, we're
 548                          * carefully avoiding any colorful description of the
 549                          * likelihood of this condition -- but suffice it to
 550                          * say that it is only slightly more likely than the
 551                          * overflow of predicate cache IDs, as discussed in
 552                          * dtrace_predicate_create().
 553                          */
 554                         nval = 1;
 555                 }
 556         } while (dtrace_cas32(counter, oval, nval) != oval);
 557 }
 558 
 559 /*
 560  * Use the DTRACE_LOADFUNC macro to define functions for each of loading a
 561  * uint8_t, a uint16_t, a uint32_t and a uint64_t.
 562  */
 563 DTRACE_LOADFUNC(8)
 564 DTRACE_LOADFUNC(16)
 565 DTRACE_LOADFUNC(32)
 566 DTRACE_LOADFUNC(64)
 567 
 568 static int
 569 dtrace_inscratch(uintptr_t dest, size_t size, dtrace_mstate_t *mstate)
 570 {
 571         if (dest < mstate->dtms_scratch_base)
 572                 return (0);
 573 
 574         if (dest + size < dest)
 575                 return (0);
 576 
 577         if (dest + size > mstate->dtms_scratch_ptr)
 578                 return (0);
 579 
 580         return (1);
 581 }
 582 
 583 static int
 584 dtrace_canstore_statvar(uint64_t addr, size_t sz,
 585     dtrace_statvar_t **svars, int nsvars)
 586 {
 587         int i;
 588 
 589         for (i = 0; i < nsvars; i++) {
 590                 dtrace_statvar_t *svar = svars[i];
 591 
 592                 if (svar == NULL || svar->dtsv_size == 0)
 593                         continue;
 594 
 595                 if (DTRACE_INRANGE(addr, sz, svar->dtsv_data, svar->dtsv_size))
 596                         return (1);
 597         }
 598 
 599         return (0);
 600 }
 601 
 602 /*
 603  * Check to see if the address is within a memory region to which a store may
 604  * be issued.  This includes the DTrace scratch areas, and any DTrace variable
 605  * region.  The caller of dtrace_canstore() is responsible for performing any
 606  * alignment checks that are needed before stores are actually executed.
 607  */
 608 static int
 609 dtrace_canstore(uint64_t addr, size_t sz, dtrace_mstate_t *mstate,
 610     dtrace_vstate_t *vstate)
 611 {
 612         /*
 613          * First, check to see if the address is in scratch space...
 614          */
 615         if (DTRACE_INRANGE(addr, sz, mstate->dtms_scratch_base,
 616             mstate->dtms_scratch_size))
 617                 return (1);
 618 
 619         /*
 620          * Now check to see if it's a dynamic variable.  This check will pick
 621          * up both thread-local variables and any global dynamically-allocated
 622          * variables.
 623          */
 624         if (DTRACE_INRANGE(addr, sz, vstate->dtvs_dynvars.dtds_base,
 625             vstate->dtvs_dynvars.dtds_size)) {
 626                 dtrace_dstate_t *dstate = &vstate->dtvs_dynvars;
 627                 uintptr_t base = (uintptr_t)dstate->dtds_base +
 628                     (dstate->dtds_hashsize * sizeof (dtrace_dynhash_t));
 629                 uintptr_t chunkoffs;
 630 
 631                 /*
 632                  * Before we assume that we can store here, we need to make
 633                  * sure that it isn't in our metadata -- storing to our
 634                  * dynamic variable metadata would corrupt our state.  For
 635                  * the range to not include any dynamic variable metadata,
 636                  * it must:
 637                  *
 638                  *      (1) Start above the hash table that is at the base of
 639                  *      the dynamic variable space
 640                  *
 641                  *      (2) Have a starting chunk offset that is beyond the
 642                  *      dtrace_dynvar_t that is at the base of every chunk
 643                  *
 644                  *      (3) Not span a chunk boundary
 645                  *
 646                  */
 647                 if (addr < base)
 648                         return (0);
 649 
 650                 chunkoffs = (addr - base) % dstate->dtds_chunksize;
 651 
 652                 if (chunkoffs < sizeof (dtrace_dynvar_t))
 653                         return (0);
 654 
 655                 if (chunkoffs + sz > dstate->dtds_chunksize)
 656                         return (0);
 657 
 658                 return (1);
 659         }
 660 
 661         /*
 662          * Finally, check the static local and global variables.  These checks
 663          * take the longest, so we perform them last.
 664          */
 665         if (dtrace_canstore_statvar(addr, sz,
 666             vstate->dtvs_locals, vstate->dtvs_nlocals))
 667                 return (1);
 668 
 669         if (dtrace_canstore_statvar(addr, sz,
 670             vstate->dtvs_globals, vstate->dtvs_nglobals))
 671                 return (1);
 672 
 673         return (0);
 674 }
 675 
 676 
 677 /*
 678  * Convenience routine to check to see if the address is within a memory
 679  * region in which a load may be issued given the user's privilege level;
 680  * if not, it sets the appropriate error flags and loads 'addr' into the
 681  * illegal value slot.
 682  *
 683  * DTrace subroutines (DIF_SUBR_*) should use this helper to implement
 684  * appropriate memory access protection.
 685  */
 686 static int
 687 dtrace_canload(uint64_t addr, size_t sz, dtrace_mstate_t *mstate,
 688     dtrace_vstate_t *vstate)
 689 {
 690         volatile uintptr_t *illval = &cpu_core[CPU->cpu_id].cpuc_dtrace_illval;
 691         file_t *fp;
 692 
 693         /*
 694          * If we hold the privilege to read from kernel memory, then
 695          * everything is readable.
 696          */
 697         if ((mstate->dtms_access & DTRACE_ACCESS_KERNEL) != 0)
 698                 return (1);
 699 
 700         /*
 701          * You can obviously read that which you can store.
 702          */
 703         if (dtrace_canstore(addr, sz, mstate, vstate))
 704                 return (1);
 705 
 706         /*
 707          * We're allowed to read from our own string table.
 708          */
 709         if (DTRACE_INRANGE(addr, sz, mstate->dtms_difo->dtdo_strtab,
 710             mstate->dtms_difo->dtdo_strlen))
 711                 return (1);
 712 
 713         if (vstate->dtvs_state != NULL &&
 714             dtrace_priv_proc(vstate->dtvs_state, mstate)) {
 715                 proc_t *p;
 716 
 717                 /*
 718                  * When we have privileges to the current process, there are
 719                  * several context-related kernel structures that are safe to
 720                  * read, even absent the privilege to read from kernel memory.
 721                  * These reads are safe because these structures contain only
 722                  * state that (1) we're permitted to read, (2) is harmless or
 723                  * (3) contains pointers to additional kernel state that we're
 724                  * not permitted to read (and as such, do not present an
 725                  * opportunity for privilege escalation).  Finally (and
 726                  * critically), because of the nature of their relation with
 727                  * the current thread context, the memory associated with these
 728                  * structures cannot change over the duration of probe context,
 729                  * and it is therefore impossible for this memory to be
 730                  * deallocated and reallocated as something else while it's
 731                  * being operated upon.
 732                  */
 733                 if (DTRACE_INRANGE(addr, sz, curthread, sizeof (kthread_t)))
 734                         return (1);
 735 
 736                 if ((p = curthread->t_procp) != NULL && DTRACE_INRANGE(addr,
 737                     sz, curthread->t_procp, sizeof (proc_t))) {
 738                         return (1);
 739                 }
 740 
 741                 if (curthread->t_cred != NULL && DTRACE_INRANGE(addr, sz,
 742                     curthread->t_cred, sizeof (cred_t))) {
 743                         return (1);
 744                 }
 745 
 746                 if (p != NULL && p->p_pidp != NULL && DTRACE_INRANGE(addr, sz,
 747                     &(p->p_pidp->pid_id), sizeof (pid_t))) {
 748                         return (1);
 749                 }
 750 
 751                 if (curthread->t_cpu != NULL && DTRACE_INRANGE(addr, sz,
 752                     curthread->t_cpu, offsetof(cpu_t, cpu_pause_thread))) {
 753                         return (1);
 754                 }
 755         }
 756 
 757         if ((fp = mstate->dtms_getf) != NULL) {
 758                 uintptr_t psz = sizeof (void *);
 759                 vnode_t *vp;
 760                 vnodeops_t *op;
 761 
 762                 /*
 763                  * When getf() returns a file_t, the enabling is implicitly
 764                  * granted the (transient) right to read the returned file_t
 765                  * as well as the v_path and v_op->vnop_name of the underlying
 766                  * vnode.  These accesses are allowed after a successful
 767                  * getf() because the members that they refer to cannot change
 768                  * once set -- and the barrier logic in the kernel's closef()
 769                  * path assures that the file_t and its referenced vode_t
 770                  * cannot themselves be stale (that is, it impossible for
 771                  * either dtms_getf itself or its f_vnode member to reference
 772                  * freed memory).
 773                  */
 774                 if (DTRACE_INRANGE(addr, sz, fp, sizeof (file_t)))
 775                         return (1);
 776 
 777                 if ((vp = fp->f_vnode) != NULL) {
 778                         if (DTRACE_INRANGE(addr, sz, &vp->v_path, psz))
 779                                 return (1);
 780 
 781                         if (vp->v_path != NULL && DTRACE_INRANGE(addr, sz,
 782                             vp->v_path, strlen(vp->v_path) + 1)) {
 783                                 return (1);
 784                         }
 785 
 786                         if (DTRACE_INRANGE(addr, sz, &vp->v_op, psz))
 787                                 return (1);
 788 
 789                         if ((op = vp->v_op) != NULL &&
 790                             DTRACE_INRANGE(addr, sz, &op->vnop_name, psz)) {
 791                                 return (1);
 792                         }
 793 
 794                         if (op != NULL && op->vnop_name != NULL &&
 795                             DTRACE_INRANGE(addr, sz, op->vnop_name,
 796                             strlen(op->vnop_name) + 1)) {
 797                                 return (1);
 798                         }
 799                 }
 800         }
 801 
 802         DTRACE_CPUFLAG_SET(CPU_DTRACE_KPRIV);
 803         *illval = addr;
 804         return (0);
 805 }
 806 
 807 /*
 808  * Convenience routine to check to see if a given string is within a memory
 809  * region in which a load may be issued given the user's privilege level;
 810  * this exists so that we don't need to issue unnecessary dtrace_strlen()
 811  * calls in the event that the user has all privileges.
 812  */
 813 static int
 814 dtrace_strcanload(uint64_t addr, size_t sz, dtrace_mstate_t *mstate,
 815     dtrace_vstate_t *vstate)
 816 {
 817         size_t strsz;
 818 
 819         /*
 820          * If we hold the privilege to read from kernel memory, then
 821          * everything is readable.
 822          */
 823         if ((mstate->dtms_access & DTRACE_ACCESS_KERNEL) != 0)
 824                 return (1);
 825 
 826         strsz = 1 + dtrace_strlen((char *)(uintptr_t)addr, sz);
 827         if (dtrace_canload(addr, strsz, mstate, vstate))
 828                 return (1);
 829 
 830         return (0);
 831 }
 832 
 833 /*
 834  * Convenience routine to check to see if a given variable is within a memory
 835  * region in which a load may be issued given the user's privilege level.
 836  */
 837 static int
 838 dtrace_vcanload(void *src, dtrace_diftype_t *type, dtrace_mstate_t *mstate,
 839     dtrace_vstate_t *vstate)
 840 {
 841         size_t sz;
 842         ASSERT(type->dtdt_flags & DIF_TF_BYREF);
 843 
 844         /*
 845          * If we hold the privilege to read from kernel memory, then
 846          * everything is readable.
 847          */
 848         if ((mstate->dtms_access & DTRACE_ACCESS_KERNEL) != 0)
 849                 return (1);
 850 
 851         if (type->dtdt_kind == DIF_TYPE_STRING)
 852                 sz = dtrace_strlen(src,
 853                     vstate->dtvs_state->dts_options[DTRACEOPT_STRSIZE]) + 1;
 854         else
 855                 sz = type->dtdt_size;
 856 
 857         return (dtrace_canload((uintptr_t)src, sz, mstate, vstate));
 858 }
 859 
 860 /*
 861  * Compare two strings using safe loads.
 862  */
 863 static int
 864 dtrace_strncmp(char *s1, char *s2, size_t limit)
 865 {
 866         uint8_t c1, c2;
 867         volatile uint16_t *flags;
 868 
 869         if (s1 == s2 || limit == 0)
 870                 return (0);
 871 
 872         flags = (volatile uint16_t *)&cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
 873 
 874         do {
 875                 if (s1 == NULL) {
 876                         c1 = '\0';
 877                 } else {
 878                         c1 = dtrace_load8((uintptr_t)s1++);
 879                 }
 880 
 881                 if (s2 == NULL) {
 882                         c2 = '\0';
 883                 } else {
 884                         c2 = dtrace_load8((uintptr_t)s2++);
 885                 }
 886 
 887                 if (c1 != c2)
 888                         return (c1 - c2);
 889         } while (--limit && c1 != '\0' && !(*flags & CPU_DTRACE_FAULT));
 890 
 891         return (0);
 892 }
 893 
 894 /*
 895  * Compute strlen(s) for a string using safe memory accesses.  The additional
 896  * len parameter is used to specify a maximum length to ensure completion.
 897  */
 898 static size_t
 899 dtrace_strlen(const char *s, size_t lim)
 900 {
 901         uint_t len;
 902 
 903         for (len = 0; len != lim; len++) {
 904                 if (dtrace_load8((uintptr_t)s++) == '\0')
 905                         break;
 906         }
 907 
 908         return (len);
 909 }
 910 
 911 /*
 912  * Check if an address falls within a toxic region.
 913  */
 914 static int
 915 dtrace_istoxic(uintptr_t kaddr, size_t size)
 916 {
 917         uintptr_t taddr, tsize;
 918         int i;
 919 
 920         for (i = 0; i < dtrace_toxranges; i++) {
 921                 taddr = dtrace_toxrange[i].dtt_base;
 922                 tsize = dtrace_toxrange[i].dtt_limit - taddr;
 923 
 924                 if (kaddr - taddr < tsize) {
 925                         DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
 926                         cpu_core[CPU->cpu_id].cpuc_dtrace_illval = kaddr;
 927                         return (1);
 928                 }
 929 
 930                 if (taddr - kaddr < size) {
 931                         DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
 932                         cpu_core[CPU->cpu_id].cpuc_dtrace_illval = taddr;
 933                         return (1);
 934                 }
 935         }
 936 
 937         return (0);
 938 }
 939 
 940 /*
 941  * Copy src to dst using safe memory accesses.  The src is assumed to be unsafe
 942  * memory specified by the DIF program.  The dst is assumed to be safe memory
 943  * that we can store to directly because it is managed by DTrace.  As with
 944  * standard bcopy, overlapping copies are handled properly.
 945  */
 946 static void
 947 dtrace_bcopy(const void *src, void *dst, size_t len)
 948 {
 949         if (len != 0) {
 950                 uint8_t *s1 = dst;
 951                 const uint8_t *s2 = src;
 952 
 953                 if (s1 <= s2) {
 954                         do {
 955                                 *s1++ = dtrace_load8((uintptr_t)s2++);
 956                         } while (--len != 0);
 957                 } else {
 958                         s2 += len;
 959                         s1 += len;
 960 
 961                         do {
 962                                 *--s1 = dtrace_load8((uintptr_t)--s2);
 963                         } while (--len != 0);
 964                 }
 965         }
 966 }
 967 
 968 /*
 969  * Copy src to dst using safe memory accesses, up to either the specified
 970  * length, or the point that a nul byte is encountered.  The src is assumed to
 971  * be unsafe memory specified by the DIF program.  The dst is assumed to be
 972  * safe memory that we can store to directly because it is managed by DTrace.
 973  * Unlike dtrace_bcopy(), overlapping regions are not handled.
 974  */
 975 static void
 976 dtrace_strcpy(const void *src, void *dst, size_t len)
 977 {
 978         if (len != 0) {
 979                 uint8_t *s1 = dst, c;
 980                 const uint8_t *s2 = src;
 981 
 982                 do {
 983                         *s1++ = c = dtrace_load8((uintptr_t)s2++);
 984                 } while (--len != 0 && c != '\0');
 985         }
 986 }
 987 
 988 /*
 989  * Copy src to dst, deriving the size and type from the specified (BYREF)
 990  * variable type.  The src is assumed to be unsafe memory specified by the DIF
 991  * program.  The dst is assumed to be DTrace variable memory that is of the
 992  * specified type; we assume that we can store to directly.
 993  */
 994 static void
 995 dtrace_vcopy(void *src, void *dst, dtrace_diftype_t *type)
 996 {
 997         ASSERT(type->dtdt_flags & DIF_TF_BYREF);
 998 
 999         if (type->dtdt_kind == DIF_TYPE_STRING) {
1000                 dtrace_strcpy(src, dst, type->dtdt_size);
1001         } else {
1002                 dtrace_bcopy(src, dst, type->dtdt_size);
1003         }
1004 }
1005 
1006 /*
1007  * Compare s1 to s2 using safe memory accesses.  The s1 data is assumed to be
1008  * unsafe memory specified by the DIF program.  The s2 data is assumed to be
1009  * safe memory that we can access directly because it is managed by DTrace.
1010  */
1011 static int
1012 dtrace_bcmp(const void *s1, const void *s2, size_t len)
1013 {
1014         volatile uint16_t *flags;
1015 
1016         flags = (volatile uint16_t *)&cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
1017 
1018         if (s1 == s2)
1019                 return (0);
1020 
1021         if (s1 == NULL || s2 == NULL)
1022                 return (1);
1023 
1024         if (s1 != s2 && len != 0) {
1025                 const uint8_t *ps1 = s1;
1026                 const uint8_t *ps2 = s2;
1027 
1028                 do {
1029                         if (dtrace_load8((uintptr_t)ps1++) != *ps2++)
1030                                 return (1);
1031                 } while (--len != 0 && !(*flags & CPU_DTRACE_FAULT));
1032         }
1033         return (0);
1034 }
1035 
1036 /*
1037  * Zero the specified region using a simple byte-by-byte loop.  Note that this
1038  * is for safe DTrace-managed memory only.
1039  */
1040 static void
1041 dtrace_bzero(void *dst, size_t len)
1042 {
1043         uchar_t *cp;
1044 
1045         for (cp = dst; len != 0; len--)
1046                 *cp++ = 0;
1047 }
1048 
1049 static void
1050 dtrace_add_128(uint64_t *addend1, uint64_t *addend2, uint64_t *sum)
1051 {
1052         uint64_t result[2];
1053 
1054         result[0] = addend1[0] + addend2[0];
1055         result[1] = addend1[1] + addend2[1] +
1056             (result[0] < addend1[0] || result[0] < addend2[0] ? 1 : 0);
1057 
1058         sum[0] = result[0];
1059         sum[1] = result[1];
1060 }
1061 
1062 /*
1063  * Shift the 128-bit value in a by b. If b is positive, shift left.
1064  * If b is negative, shift right.
1065  */
1066 static void
1067 dtrace_shift_128(uint64_t *a, int b)
1068 {
1069         uint64_t mask;
1070 
1071         if (b == 0)
1072                 return;
1073 
1074         if (b < 0) {
1075                 b = -b;
1076                 if (b >= 64) {
1077                         a[0] = a[1] >> (b - 64);
1078                         a[1] = 0;
1079                 } else {
1080                         a[0] >>= b;
1081                         mask = 1LL << (64 - b);
1082                         mask -= 1;
1083                         a[0] |= ((a[1] & mask) << (64 - b));
1084                         a[1] >>= b;
1085                 }
1086         } else {
1087                 if (b >= 64) {
1088                         a[1] = a[0] << (b - 64);
1089                         a[0] = 0;
1090                 } else {
1091                         a[1] <<= b;
1092                         mask = a[0] >> (64 - b);
1093                         a[1] |= mask;
1094                         a[0] <<= b;
1095                 }
1096         }
1097 }
1098 
1099 /*
1100  * The basic idea is to break the 2 64-bit values into 4 32-bit values,
1101  * use native multiplication on those, and then re-combine into the
1102  * resulting 128-bit value.
1103  *
1104  * (hi1 << 32 + lo1) * (hi2 << 32 + lo2) =
1105  *     hi1 * hi2 << 64 +
1106  *     hi1 * lo2 << 32 +
1107  *     hi2 * lo1 << 32 +
1108  *     lo1 * lo2
1109  */
1110 static void
1111 dtrace_multiply_128(uint64_t factor1, uint64_t factor2, uint64_t *product)
1112 {
1113         uint64_t hi1, hi2, lo1, lo2;
1114         uint64_t tmp[2];
1115 
1116         hi1 = factor1 >> 32;
1117         hi2 = factor2 >> 32;
1118 
1119         lo1 = factor1 & DT_MASK_LO;
1120         lo2 = factor2 & DT_MASK_LO;
1121 
1122         product[0] = lo1 * lo2;
1123         product[1] = hi1 * hi2;
1124 
1125         tmp[0] = hi1 * lo2;
1126         tmp[1] = 0;
1127         dtrace_shift_128(tmp, 32);
1128         dtrace_add_128(product, tmp, product);
1129 
1130         tmp[0] = hi2 * lo1;
1131         tmp[1] = 0;
1132         dtrace_shift_128(tmp, 32);
1133         dtrace_add_128(product, tmp, product);
1134 }
1135 
1136 /*
1137  * This privilege check should be used by actions and subroutines to
1138  * verify that the user credentials of the process that enabled the
1139  * invoking ECB match the target credentials
1140  */
1141 static int
1142 dtrace_priv_proc_common_user(dtrace_state_t *state)
1143 {
1144         cred_t *cr, *s_cr = state->dts_cred.dcr_cred;
1145 
1146         /*
1147          * We should always have a non-NULL state cred here, since if cred
1148          * is null (anonymous tracing), we fast-path bypass this routine.
1149          */
1150         ASSERT(s_cr != NULL);
1151 
1152         if ((cr = CRED()) != NULL &&
1153             s_cr->cr_uid == cr->cr_uid &&
1154             s_cr->cr_uid == cr->cr_ruid &&
1155             s_cr->cr_uid == cr->cr_suid &&
1156             s_cr->cr_gid == cr->cr_gid &&
1157             s_cr->cr_gid == cr->cr_rgid &&
1158             s_cr->cr_gid == cr->cr_sgid)
1159                 return (1);
1160 
1161         return (0);
1162 }
1163 
1164 /*
1165  * This privilege check should be used by actions and subroutines to
1166  * verify that the zone of the process that enabled the invoking ECB
1167  * matches the target credentials
1168  */
1169 static int
1170 dtrace_priv_proc_common_zone(dtrace_state_t *state)
1171 {
1172         cred_t *cr, *s_cr = state->dts_cred.dcr_cred;
1173 
1174         /*
1175          * We should always have a non-NULL state cred here, since if cred
1176          * is null (anonymous tracing), we fast-path bypass this routine.
1177          */
1178         ASSERT(s_cr != NULL);
1179 
1180         if ((cr = CRED()) != NULL && s_cr->cr_zone == cr->cr_zone)
1181                 return (1);
1182 
1183         return (0);
1184 }
1185 
1186 /*
1187  * This privilege check should be used by actions and subroutines to
1188  * verify that the process has not setuid or changed credentials.
1189  */
1190 static int
1191 dtrace_priv_proc_common_nocd()
1192 {
1193         proc_t *proc;
1194 
1195         if ((proc = ttoproc(curthread)) != NULL &&
1196             !(proc->p_flag & SNOCD))
1197                 return (1);
1198 
1199         return (0);
1200 }
1201 
1202 static int
1203 dtrace_priv_proc_destructive(dtrace_state_t *state, dtrace_mstate_t *mstate)
1204 {
1205         int action = state->dts_cred.dcr_action;
1206 
1207         if (!(mstate->dtms_access & DTRACE_ACCESS_PROC))
1208                 goto bad;
1209 
1210         if (((action & DTRACE_CRA_PROC_DESTRUCTIVE_ALLZONE) == 0) &&
1211             dtrace_priv_proc_common_zone(state) == 0)
1212                 goto bad;
1213 
1214         if (((action & DTRACE_CRA_PROC_DESTRUCTIVE_ALLUSER) == 0) &&
1215             dtrace_priv_proc_common_user(state) == 0)
1216                 goto bad;
1217 
1218         if (((action & DTRACE_CRA_PROC_DESTRUCTIVE_CREDCHG) == 0) &&
1219             dtrace_priv_proc_common_nocd() == 0)
1220                 goto bad;
1221 
1222         return (1);
1223 
1224 bad:
1225         cpu_core[CPU->cpu_id].cpuc_dtrace_flags |= CPU_DTRACE_UPRIV;
1226 
1227         return (0);
1228 }
1229 
1230 static int
1231 dtrace_priv_proc_control(dtrace_state_t *state, dtrace_mstate_t *mstate)
1232 {
1233         if (mstate->dtms_access & DTRACE_ACCESS_PROC) {
1234                 if (state->dts_cred.dcr_action & DTRACE_CRA_PROC_CONTROL)
1235                         return (1);
1236 
1237                 if (dtrace_priv_proc_common_zone(state) &&
1238                     dtrace_priv_proc_common_user(state) &&
1239                     dtrace_priv_proc_common_nocd())
1240                         return (1);
1241         }
1242 
1243         cpu_core[CPU->cpu_id].cpuc_dtrace_flags |= CPU_DTRACE_UPRIV;
1244 
1245         return (0);
1246 }
1247 
1248 static int
1249 dtrace_priv_proc(dtrace_state_t *state, dtrace_mstate_t *mstate)
1250 {
1251         if ((mstate->dtms_access & DTRACE_ACCESS_PROC) &&
1252             (state->dts_cred.dcr_action & DTRACE_CRA_PROC))
1253                 return (1);
1254 
1255         cpu_core[CPU->cpu_id].cpuc_dtrace_flags |= CPU_DTRACE_UPRIV;
1256 
1257         return (0);
1258 }
1259 
1260 static int
1261 dtrace_priv_kernel(dtrace_state_t *state)
1262 {
1263         if (state->dts_cred.dcr_action & DTRACE_CRA_KERNEL)
1264                 return (1);
1265 
1266         cpu_core[CPU->cpu_id].cpuc_dtrace_flags |= CPU_DTRACE_KPRIV;
1267 
1268         return (0);
1269 }
1270 
1271 static int
1272 dtrace_priv_kernel_destructive(dtrace_state_t *state)
1273 {
1274         if (state->dts_cred.dcr_action & DTRACE_CRA_KERNEL_DESTRUCTIVE)
1275                 return (1);
1276 
1277         cpu_core[CPU->cpu_id].cpuc_dtrace_flags |= CPU_DTRACE_KPRIV;
1278 
1279         return (0);
1280 }
1281 
1282 /*
1283  * Determine if the dte_cond of the specified ECB allows for processing of
1284  * the current probe to continue.  Note that this routine may allow continued
1285  * processing, but with access(es) stripped from the mstate's dtms_access
1286  * field.
1287  */
1288 static int
1289 dtrace_priv_probe(dtrace_state_t *state, dtrace_mstate_t *mstate,
1290     dtrace_ecb_t *ecb)
1291 {
1292         dtrace_probe_t *probe = ecb->dte_probe;
1293         dtrace_provider_t *prov = probe->dtpr_provider;
1294         dtrace_pops_t *pops = &prov->dtpv_pops;
1295         int mode = DTRACE_MODE_NOPRIV_DROP;
1296 
1297         ASSERT(ecb->dte_cond);
1298 
1299         if (pops->dtps_mode != NULL) {
1300                 mode = pops->dtps_mode(prov->dtpv_arg,
1301                     probe->dtpr_id, probe->dtpr_arg);
1302 
1303                 ASSERT((mode & DTRACE_MODE_USER) ||
1304                     (mode & DTRACE_MODE_KERNEL));
1305                 ASSERT((mode & DTRACE_MODE_NOPRIV_RESTRICT) ||
1306                     (mode & 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, call the provider's dtps_mode()
1312          * entry point to check that the probe was fired while in a user
1313          * context.  If that's not the case, use the policy specified by the
1314          * provider to determine if we drop the probe or merely restrict
1315          * operation.
1316          */
1317         if (ecb->dte_cond & DTRACE_COND_USERMODE) {
1318                 ASSERT(mode != DTRACE_MODE_NOPRIV_DROP);
1319 
1320                 if (!(mode & DTRACE_MODE_USER)) {
1321                         if (mode & DTRACE_MODE_NOPRIV_DROP)
1322                                 return (0);
1323 
1324                         mstate->dtms_access &= ~DTRACE_ACCESS_ARGS;
1325                 }
1326         }
1327 
1328         /*
1329          * This is more subtle than it looks. We have to be absolutely certain
1330          * that CRED() isn't going to change out from under us so it's only
1331          * legit to examine that structure if we're in constrained situations.
1332          * Currently, the only times we'll this check is if a non-super-user
1333          * has enabled the profile or syscall providers -- providers that
1334          * allow visibility of all processes. For the profile case, the check
1335          * above will ensure that we're examining a user context.
1336          */
1337         if (ecb->dte_cond & DTRACE_COND_OWNER) {
1338                 cred_t *cr;
1339                 cred_t *s_cr = state->dts_cred.dcr_cred;
1340                 proc_t *proc;
1341 
1342                 ASSERT(s_cr != NULL);
1343 
1344                 if ((cr = CRED()) == NULL ||
1345                     s_cr->cr_uid != cr->cr_uid ||
1346                     s_cr->cr_uid != cr->cr_ruid ||
1347                     s_cr->cr_uid != cr->cr_suid ||
1348                     s_cr->cr_gid != cr->cr_gid ||
1349                     s_cr->cr_gid != cr->cr_rgid ||
1350                     s_cr->cr_gid != cr->cr_sgid ||
1351                     (proc = ttoproc(curthread)) == NULL ||
1352                     (proc->p_flag & SNOCD)) {
1353                         if (mode & DTRACE_MODE_NOPRIV_DROP)
1354                                 return (0);
1355 
1356                         mstate->dtms_access &= ~DTRACE_ACCESS_PROC;
1357                 }
1358         }
1359 
1360         /*
1361          * If our dte_cond is set to DTRACE_COND_ZONEOWNER and we are not
1362          * in our zone, check to see if our mode policy is to restrict rather
1363          * than to drop; if to restrict, strip away both DTRACE_ACCESS_PROC
1364          * and DTRACE_ACCESS_ARGS
1365          */
1366         if (ecb->dte_cond & DTRACE_COND_ZONEOWNER) {
1367                 cred_t *cr;
1368                 cred_t *s_cr = state->dts_cred.dcr_cred;
1369 
1370                 ASSERT(s_cr != NULL);
1371 
1372                 if ((cr = CRED()) == NULL ||
1373                     s_cr->cr_zone->zone_id != cr->cr_zone->zone_id) {
1374                         if (mode & DTRACE_MODE_NOPRIV_DROP)
1375                                 return (0);
1376 
1377                         mstate->dtms_access &=
1378                             ~(DTRACE_ACCESS_PROC | DTRACE_ACCESS_ARGS);
1379                 }
1380         }
1381 
1382         return (1);
1383 }
1384 
1385 /*
1386  * Note:  not called from probe context.  This function is called
1387  * asynchronously (and at a regular interval) from outside of probe context to
1388  * clean the dirty dynamic variable lists on all CPUs.  Dynamic variable
1389  * cleaning is explained in detail in <sys/dtrace_impl.h>.
1390  */
1391 void
1392 dtrace_dynvar_clean(dtrace_dstate_t *dstate)
1393 {
1394         dtrace_dynvar_t *dirty;
1395         dtrace_dstate_percpu_t *dcpu;
1396         dtrace_dynvar_t **rinsep;
1397         int i, j, work = 0;
1398 
1399         for (i = 0; i < NCPU; i++) {
1400                 dcpu = &dstate->dtds_percpu[i];
1401                 rinsep = &dcpu->dtdsc_rinsing;
1402 
1403                 /*
1404                  * If the dirty list is NULL, there is no dirty work to do.
1405                  */
1406                 if (dcpu->dtdsc_dirty == NULL)
1407                         continue;
1408 
1409                 if (dcpu->dtdsc_rinsing != NULL) {
1410                         /*
1411                          * If the rinsing list is non-NULL, then it is because
1412                          * this CPU was selected to accept another CPU's
1413                          * dirty list -- and since that time, dirty buffers
1414                          * have accumulated.  This is a highly unlikely
1415                          * condition, but we choose to ignore the dirty
1416                          * buffers -- they'll be picked up a future cleanse.
1417                          */
1418                         continue;
1419                 }
1420 
1421                 if (dcpu->dtdsc_clean != NULL) {
1422                         /*
1423                          * If the clean list is non-NULL, then we're in a
1424                          * situation where a CPU has done deallocations (we
1425                          * have a non-NULL dirty list) but no allocations (we
1426                          * also have a non-NULL clean list).  We can't simply
1427                          * move the dirty list into the clean list on this
1428                          * CPU, yet we also don't want to allow this condition
1429                          * to persist, lest a short clean list prevent a
1430                          * massive dirty list from being cleaned (which in
1431                          * turn could lead to otherwise avoidable dynamic
1432                          * drops).  To deal with this, we look for some CPU
1433                          * with a NULL clean list, NULL dirty list, and NULL
1434                          * rinsing list -- and then we borrow this CPU to
1435                          * rinse our dirty list.
1436                          */
1437                         for (j = 0; j < NCPU; j++) {
1438                                 dtrace_dstate_percpu_t *rinser;
1439 
1440                                 rinser = &dstate->dtds_percpu[j];
1441 
1442                                 if (rinser->dtdsc_rinsing != NULL)
1443                                         continue;
1444 
1445                                 if (rinser->dtdsc_dirty != NULL)
1446                                         continue;
1447 
1448                                 if (rinser->dtdsc_clean != NULL)
1449                                         continue;
1450 
1451                                 rinsep = &rinser->dtdsc_rinsing;
1452                                 break;
1453                         }
1454 
1455                         if (j == NCPU) {
1456                                 /*
1457                                  * We were unable to find another CPU that
1458                                  * could accept this dirty list -- we are
1459                                  * therefore unable to clean it now.
1460                                  */
1461                                 dtrace_dynvar_failclean++;
1462                                 continue;
1463                         }
1464                 }
1465 
1466                 work = 1;
1467 
1468                 /*
1469                  * Atomically move the dirty list aside.
1470                  */
1471                 do {
1472                         dirty = dcpu->dtdsc_dirty;
1473 
1474                         /*
1475                          * Before we zap the dirty list, set the rinsing list.
1476                          * (This allows for a potential assertion in
1477                          * dtrace_dynvar():  if a free dynamic variable appears
1478                          * on a hash chain, either the dirty list or the
1479                          * rinsing list for some CPU must be non-NULL.)
1480                          */
1481                         *rinsep = dirty;
1482                         dtrace_membar_producer();
1483                 } while (dtrace_casptr(&dcpu->dtdsc_dirty,
1484                     dirty, NULL) != dirty);
1485         }
1486 
1487         if (!work) {
1488                 /*
1489                  * We have no work to do; we can simply return.
1490                  */
1491                 return;
1492         }
1493 
1494         dtrace_sync();
1495 
1496         for (i = 0; i < NCPU; i++) {
1497                 dcpu = &dstate->dtds_percpu[i];
1498 
1499                 if (dcpu->dtdsc_rinsing == NULL)
1500                         continue;
1501 
1502                 /*
1503                  * We are now guaranteed that no hash chain contains a pointer
1504                  * into this dirty list; we can make it clean.
1505                  */
1506                 ASSERT(dcpu->dtdsc_clean == NULL);
1507                 dcpu->dtdsc_clean = dcpu->dtdsc_rinsing;
1508                 dcpu->dtdsc_rinsing = NULL;
1509         }
1510 
1511         /*
1512          * Before we actually set the state to be DTRACE_DSTATE_CLEAN, make
1513          * sure that all CPUs have seen all of the dtdsc_clean pointers.
1514          * This prevents a race whereby a CPU incorrectly decides that
1515          * the state should be something other than DTRACE_DSTATE_CLEAN
1516          * after dtrace_dynvar_clean() has completed.
1517          */
1518         dtrace_sync();
1519 
1520         dstate->dtds_state = DTRACE_DSTATE_CLEAN;
1521 }
1522 
1523 /*
1524  * Depending on the value of the op parameter, this function looks-up,
1525  * allocates or deallocates an arbitrarily-keyed dynamic variable.  If an
1526  * allocation is requested, this function will return a pointer to a
1527  * dtrace_dynvar_t corresponding to the allocated variable -- or NULL if no
1528  * variable can be allocated.  If NULL is returned, the appropriate counter
1529  * will be incremented.
1530  */
1531 dtrace_dynvar_t *
1532 dtrace_dynvar(dtrace_dstate_t *dstate, uint_t nkeys,
1533     dtrace_key_t *key, size_t dsize, dtrace_dynvar_op_t op,
1534     dtrace_mstate_t *mstate, dtrace_vstate_t *vstate)
1535 {
1536         uint64_t hashval = DTRACE_DYNHASH_VALID;
1537         dtrace_dynhash_t *hash = dstate->dtds_hash;
1538         dtrace_dynvar_t *free, *new_free, *next, *dvar, *start, *prev = NULL;
1539         processorid_t me = CPU->cpu_id, cpu = me;
1540         dtrace_dstate_percpu_t *dcpu = &dstate->dtds_percpu[me];
1541         size_t bucket, ksize;
1542         size_t chunksize = dstate->dtds_chunksize;
1543         uintptr_t kdata, lock, nstate;
1544         uint_t i;
1545 
1546         ASSERT(nkeys != 0);
1547 
1548         /*
1549          * Hash the key.  As with aggregations, we use Jenkins' "One-at-a-time"
1550          * algorithm.  For the by-value portions, we perform the algorithm in
1551          * 16-bit chunks (as opposed to 8-bit chunks).  This speeds things up a
1552          * bit, and seems to have only a minute effect on distribution.  For
1553          * the by-reference data, we perform "One-at-a-time" iterating (safely)
1554          * over each referenced byte.  It's painful to do this, but it's much
1555          * better than pathological hash distribution.  The efficacy of the
1556          * hashing algorithm (and a comparison with other algorithms) may be
1557          * found by running the ::dtrace_dynstat MDB dcmd.
1558          */
1559         for (i = 0; i < nkeys; i++) {
1560                 if (key[i].dttk_size == 0) {
1561                         uint64_t val = key[i].dttk_value;
1562 
1563                         hashval += (val >> 48) & 0xffff;
1564                         hashval += (hashval << 10);
1565                         hashval ^= (hashval >> 6);
1566 
1567                         hashval += (val >> 32) & 0xffff;
1568                         hashval += (hashval << 10);
1569                         hashval ^= (hashval >> 6);
1570 
1571                         hashval += (val >> 16) & 0xffff;
1572                         hashval += (hashval << 10);
1573                         hashval ^= (hashval >> 6);
1574 
1575                         hashval += val & 0xffff;
1576                         hashval += (hashval << 10);
1577                         hashval ^= (hashval >> 6);
1578                 } else {
1579                         /*
1580                          * This is incredibly painful, but it beats the hell
1581                          * out of the alternative.
1582                          */
1583                         uint64_t j, size = key[i].dttk_size;
1584                         uintptr_t base = (uintptr_t)key[i].dttk_value;
1585 
1586                         if (!dtrace_canload(base, size, mstate, vstate))
1587                                 break;
1588 
1589                         for (j = 0; j < size; j++) {
1590                                 hashval += dtrace_load8(base + j);
1591                                 hashval += (hashval << 10);
1592                                 hashval ^= (hashval >> 6);
1593                         }
1594                 }
1595         }
1596 
1597         if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_FAULT))
1598                 return (NULL);
1599 
1600         hashval += (hashval << 3);
1601         hashval ^= (hashval >> 11);
1602         hashval += (hashval << 15);
1603 
1604         /*
1605          * There is a remote chance (ideally, 1 in 2^31) that our hashval
1606          * comes out to be one of our two sentinel hash values.  If this
1607          * actually happens, we set the hashval to be a value known to be a
1608          * non-sentinel value.
1609          */
1610         if (hashval == DTRACE_DYNHASH_FREE || hashval == DTRACE_DYNHASH_SINK)
1611                 hashval = DTRACE_DYNHASH_VALID;
1612 
1613         /*
1614          * Yes, it's painful to do a divide here.  If the cycle count becomes
1615          * important here, tricks can be pulled to reduce it.  (However, it's
1616          * critical that hash collisions be kept to an absolute minimum;
1617          * they're much more painful than a divide.)  It's better to have a
1618          * solution that generates few collisions and still keeps things
1619          * relatively simple.
1620          */
1621         bucket = hashval % dstate->dtds_hashsize;
1622 
1623         if (op == DTRACE_DYNVAR_DEALLOC) {
1624                 volatile uintptr_t *lockp = &hash[bucket].dtdh_lock;
1625 
1626                 for (;;) {
1627                         while ((lock = *lockp) & 1)
1628                                 continue;
1629 
1630                         if (dtrace_casptr((void *)lockp,
1631                             (void *)lock, (void *)(lock + 1)) == (void *)lock)
1632                                 break;
1633                 }
1634 
1635                 dtrace_membar_producer();
1636         }
1637 
1638 top:
1639         prev = NULL;
1640         lock = hash[bucket].dtdh_lock;
1641 
1642         dtrace_membar_consumer();
1643 
1644         start = hash[bucket].dtdh_chain;
1645         ASSERT(start != NULL && (start->dtdv_hashval == DTRACE_DYNHASH_SINK ||
1646             start->dtdv_hashval != DTRACE_DYNHASH_FREE ||
1647             op != DTRACE_DYNVAR_DEALLOC));
1648 
1649         for (dvar = start; dvar != NULL; dvar = dvar->dtdv_next) {
1650                 dtrace_tuple_t *dtuple = &dvar->dtdv_tuple;
1651                 dtrace_key_t *dkey = &dtuple->dtt_key[0];
1652 
1653                 if (dvar->dtdv_hashval != hashval) {
1654                         if (dvar->dtdv_hashval == DTRACE_DYNHASH_SINK) {
1655                                 /*
1656                                  * We've reached the sink, and therefore the
1657                                  * end of the hash chain; we can kick out of
1658                                  * the loop knowing that we have seen a valid
1659                                  * snapshot of state.
1660                                  */
1661                                 ASSERT(dvar->dtdv_next == NULL);
1662                                 ASSERT(dvar == &dtrace_dynhash_sink);
1663                                 break;
1664                         }
1665 
1666                         if (dvar->dtdv_hashval == DTRACE_DYNHASH_FREE) {
1667                                 /*
1668                                  * We've gone off the rails:  somewhere along
1669                                  * the line, one of the members of this hash
1670                                  * chain was deleted.  Note that we could also
1671                                  * detect this by simply letting this loop run
1672                                  * to completion, as we would eventually hit
1673                                  * the end of the dirty list.  However, we
1674                                  * want to avoid running the length of the
1675                                  * dirty list unnecessarily (it might be quite
1676                                  * long), so we catch this as early as
1677                                  * possible by detecting the hash marker.  In
1678                                  * this case, we simply set dvar to NULL and
1679                                  * break; the conditional after the loop will
1680                                  * send us back to top.
1681                                  */
1682                                 dvar = NULL;
1683                                 break;
1684                         }
1685 
1686                         goto next;
1687                 }
1688 
1689                 if (dtuple->dtt_nkeys != nkeys)
1690                         goto next;
1691 
1692                 for (i = 0; i < nkeys; i++, dkey++) {
1693                         if (dkey->dttk_size != key[i].dttk_size)
1694                                 goto next; /* size or type mismatch */
1695 
1696                         if (dkey->dttk_size != 0) {
1697                                 if (dtrace_bcmp(
1698                                     (void *)(uintptr_t)key[i].dttk_value,
1699                                     (void *)(uintptr_t)dkey->dttk_value,
1700                                     dkey->dttk_size))
1701                                         goto next;
1702                         } else {
1703                                 if (dkey->dttk_value != key[i].dttk_value)
1704                                         goto next;
1705                         }
1706                 }
1707 
1708                 if (op != DTRACE_DYNVAR_DEALLOC)
1709                         return (dvar);
1710 
1711                 ASSERT(dvar->dtdv_next == NULL ||
1712                     dvar->dtdv_next->dtdv_hashval != DTRACE_DYNHASH_FREE);
1713 
1714                 if (prev != NULL) {
1715                         ASSERT(hash[bucket].dtdh_chain != dvar);
1716                         ASSERT(start != dvar);
1717                         ASSERT(prev->dtdv_next == dvar);
1718                         prev->dtdv_next = dvar->dtdv_next;
1719                 } else {
1720                         if (dtrace_casptr(&hash[bucket].dtdh_chain,
1721                             start, dvar->dtdv_next) != start) {
1722                                 /*
1723                                  * We have failed to atomically swing the
1724                                  * hash table head pointer, presumably because
1725                                  * of a conflicting allocation on another CPU.
1726                                  * We need to reread the hash chain and try
1727                                  * again.
1728                                  */
1729                                 goto top;
1730                         }
1731                 }
1732 
1733                 dtrace_membar_producer();
1734 
1735                 /*
1736                  * Now set the hash value to indicate that it's free.
1737                  */
1738                 ASSERT(hash[bucket].dtdh_chain != dvar);
1739                 dvar->dtdv_hashval = DTRACE_DYNHASH_FREE;
1740 
1741                 dtrace_membar_producer();
1742 
1743                 /*
1744                  * Set the next pointer to point at the dirty list, and
1745                  * atomically swing the dirty pointer to the newly freed dvar.
1746                  */
1747                 do {
1748                         next = dcpu->dtdsc_dirty;
1749                         dvar->dtdv_next = next;
1750                 } while (dtrace_casptr(&dcpu->dtdsc_dirty, next, dvar) != next);
1751 
1752                 /*
1753                  * Finally, unlock this hash bucket.
1754                  */
1755                 ASSERT(hash[bucket].dtdh_lock == lock);
1756                 ASSERT(lock & 1);
1757                 hash[bucket].dtdh_lock++;
1758 
1759                 return (NULL);
1760 next:
1761                 prev = dvar;
1762                 continue;
1763         }
1764 
1765         if (dvar == NULL) {
1766                 /*
1767                  * If dvar is NULL, it is because we went off the rails:
1768                  * one of the elements that we traversed in the hash chain
1769                  * was deleted while we were traversing it.  In this case,
1770                  * we assert that we aren't doing a dealloc (deallocs lock
1771                  * the hash bucket to prevent themselves from racing with
1772                  * one another), and retry the hash chain traversal.
1773                  */
1774                 ASSERT(op != DTRACE_DYNVAR_DEALLOC);
1775                 goto top;
1776         }
1777 
1778         if (op != DTRACE_DYNVAR_ALLOC) {
1779                 /*
1780                  * If we are not to allocate a new variable, we want to
1781                  * return NULL now.  Before we return, check that the value
1782                  * of the lock word hasn't changed.  If it has, we may have
1783                  * seen an inconsistent snapshot.
1784                  */
1785                 if (op == DTRACE_DYNVAR_NOALLOC) {
1786                         if (hash[bucket].dtdh_lock != lock)
1787                                 goto top;
1788                 } else {
1789                         ASSERT(op == DTRACE_DYNVAR_DEALLOC);
1790                         ASSERT(hash[bucket].dtdh_lock == lock);
1791                         ASSERT(lock & 1);
1792                         hash[bucket].dtdh_lock++;
1793                 }
1794 
1795                 return (NULL);
1796         }
1797 
1798         /*
1799          * We need to allocate a new dynamic variable.  The size we need is the
1800          * size of dtrace_dynvar plus the size of nkeys dtrace_key_t's plus the
1801          * size of any auxiliary key data (rounded up to 8-byte alignment) plus
1802          * the size of any referred-to data (dsize).  We then round the final
1803          * size up to the chunksize for allocation.
1804          */
1805         for (ksize = 0, i = 0; i < nkeys; i++)
1806                 ksize += P2ROUNDUP(key[i].dttk_size, sizeof (uint64_t));
1807 
1808         /*
1809          * This should be pretty much impossible, but could happen if, say,
1810          * strange DIF specified the tuple.  Ideally, this should be an
1811          * assertion and not an error condition -- but that requires that the
1812          * chunksize calculation in dtrace_difo_chunksize() be absolutely
1813          * bullet-proof.  (That is, it must not be able to be fooled by
1814          * malicious DIF.)  Given the lack of backwards branches in DIF,
1815          * solving this would presumably not amount to solving the Halting
1816          * Problem -- but it still seems awfully hard.
1817          */
1818         if (sizeof (dtrace_dynvar_t) + sizeof (dtrace_key_t) * (nkeys - 1) +
1819             ksize + dsize > chunksize) {
1820                 dcpu->dtdsc_drops++;
1821                 return (NULL);
1822         }
1823 
1824         nstate = DTRACE_DSTATE_EMPTY;
1825 
1826         do {
1827 retry:
1828                 free = dcpu->dtdsc_free;
1829 
1830                 if (free == NULL) {
1831                         dtrace_dynvar_t *clean = dcpu->dtdsc_clean;
1832                         void *rval;
1833 
1834                         if (clean == NULL) {
1835                                 /*
1836                                  * We're out of dynamic variable space on
1837                                  * this CPU.  Unless we have tried all CPUs,
1838                                  * we'll try to allocate from a different
1839                                  * CPU.
1840                                  */
1841                                 switch (dstate->dtds_state) {
1842                                 case DTRACE_DSTATE_CLEAN: {
1843                                         void *sp = &dstate->dtds_state;
1844 
1845                                         if (++cpu >= NCPU)
1846                                                 cpu = 0;
1847 
1848                                         if (dcpu->dtdsc_dirty != NULL &&
1849                                             nstate == DTRACE_DSTATE_EMPTY)
1850                                                 nstate = DTRACE_DSTATE_DIRTY;
1851 
1852                                         if (dcpu->dtdsc_rinsing != NULL)
1853                                                 nstate = DTRACE_DSTATE_RINSING;
1854 
1855                                         dcpu = &dstate->dtds_percpu[cpu];
1856 
1857                                         if (cpu != me)
1858                                                 goto retry;
1859 
1860                                         (void) dtrace_cas32(sp,
1861                                             DTRACE_DSTATE_CLEAN, nstate);
1862 
1863                                         /*
1864                                          * To increment the correct bean
1865                                          * counter, take another lap.
1866                                          */
1867                                         goto retry;
1868                                 }
1869 
1870                                 case DTRACE_DSTATE_DIRTY:
1871                                         dcpu->dtdsc_dirty_drops++;
1872                                         break;
1873 
1874                                 case DTRACE_DSTATE_RINSING:
1875                                         dcpu->dtdsc_rinsing_drops++;
1876                                         break;
1877 
1878                                 case DTRACE_DSTATE_EMPTY:
1879                                         dcpu->dtdsc_drops++;
1880                                         break;
1881                                 }
1882 
1883                                 DTRACE_CPUFLAG_SET(CPU_DTRACE_DROP);
1884                                 return (NULL);
1885                         }
1886 
1887                         /*
1888                          * The clean list appears to be non-empty.  We want to
1889                          * move the clean list to the free list; we start by
1890                          * moving the clean pointer aside.
1891                          */
1892                         if (dtrace_casptr(&dcpu->dtdsc_clean,
1893                             clean, NULL) != clean) {
1894                                 /*
1895                                  * We are in one of two situations:
1896                                  *
1897                                  *  (a) The clean list was switched to the
1898                                  *      free list by another CPU.
1899                                  *
1900                                  *  (b) The clean list was added to by the
1901                                  *      cleansing cyclic.
1902                                  *
1903                                  * In either of these situations, we can
1904                                  * just reattempt the free list allocation.
1905                                  */
1906                                 goto retry;
1907                         }
1908 
1909                         ASSERT(clean->dtdv_hashval == DTRACE_DYNHASH_FREE);
1910 
1911                         /*
1912                          * Now we'll move the clean list to our free list.
1913                          * It's impossible for this to fail:  the only way
1914                          * the free list can be updated is through this
1915                          * code path, and only one CPU can own the clean list.
1916                          * Thus, it would only be possible for this to fail if
1917                          * this code were racing with dtrace_dynvar_clean().
1918                          * (That is, if dtrace_dynvar_clean() updated the clean
1919                          * list, and we ended up racing to update the free
1920                          * list.)  This race is prevented by the dtrace_sync()
1921                          * in dtrace_dynvar_clean() -- which flushes the
1922                          * owners of the clean lists out before resetting
1923                          * the clean lists.
1924                          */
1925                         dcpu = &dstate->dtds_percpu[me];
1926                         rval = dtrace_casptr(&dcpu->dtdsc_free, NULL, clean);
1927                         ASSERT(rval == NULL);
1928                         goto retry;
1929                 }
1930 
1931                 dvar = free;
1932                 new_free = dvar->dtdv_next;
1933         } while (dtrace_casptr(&dcpu->dtdsc_free, free, new_free) != free);
1934 
1935         /*
1936          * We have now allocated a new chunk.  We copy the tuple keys into the
1937          * tuple array and copy any referenced key data into the data space
1938          * following the tuple array.  As we do this, we relocate dttk_value
1939          * in the final tuple to point to the key data address in the chunk.
1940          */
1941         kdata = (uintptr_t)&dvar->dtdv_tuple.dtt_key[nkeys];
1942         dvar->dtdv_data = (void *)(kdata + ksize);
1943         dvar->dtdv_tuple.dtt_nkeys = nkeys;
1944 
1945         for (i = 0; i < nkeys; i++) {
1946                 dtrace_key_t *dkey = &dvar->dtdv_tuple.dtt_key[i];
1947                 size_t kesize = key[i].dttk_size;
1948 
1949                 if (kesize != 0) {
1950                         dtrace_bcopy(
1951                             (const void *)(uintptr_t)key[i].dttk_value,
1952                             (void *)kdata, kesize);
1953                         dkey->dttk_value = kdata;
1954                         kdata += P2ROUNDUP(kesize, sizeof (uint64_t));
1955                 } else {
1956                         dkey->dttk_value = key[i].dttk_value;
1957                 }
1958 
1959                 dkey->dttk_size = kesize;
1960         }
1961 
1962         ASSERT(dvar->dtdv_hashval == DTRACE_DYNHASH_FREE);
1963         dvar->dtdv_hashval = hashval;
1964         dvar->dtdv_next = start;
1965 
1966         if (dtrace_casptr(&hash[bucket].dtdh_chain, start, dvar) == start)
1967                 return (dvar);
1968 
1969         /*
1970          * The cas has failed.  Either another CPU is adding an element to
1971          * this hash chain, or another CPU is deleting an element from this
1972          * hash chain.  The simplest way to deal with both of these cases
1973          * (though not necessarily the most efficient) is to free our
1974          * allocated block and tail-call ourselves.  Note that the free is
1975          * to the dirty list and _not_ to the free list.  This is to prevent
1976          * races with allocators, above.
1977          */
1978         dvar->dtdv_hashval = DTRACE_DYNHASH_FREE;
1979 
1980         dtrace_membar_producer();
1981 
1982         do {
1983                 free = dcpu->dtdsc_dirty;
1984                 dvar->dtdv_next = free;
1985         } while (dtrace_casptr(&dcpu->dtdsc_dirty, free, dvar) != free);
1986 
1987         return (dtrace_dynvar(dstate, nkeys, key, dsize, op, mstate, vstate));
1988 }
1989 
1990 /*ARGSUSED*/
1991 static void
1992 dtrace_aggregate_min(uint64_t *oval, uint64_t nval, uint64_t arg)
1993 {
1994         if ((int64_t)nval < (int64_t)*oval)
1995                 *oval = nval;
1996 }
1997 
1998 /*ARGSUSED*/
1999 static void
2000 dtrace_aggregate_max(uint64_t *oval, uint64_t nval, uint64_t arg)
2001 {
2002         if ((int64_t)nval > (int64_t)*oval)
2003                 *oval = nval;
2004 }
2005 
2006 static void
2007 dtrace_aggregate_quantize(uint64_t *quanta, uint64_t nval, uint64_t incr)
2008 {
2009         int i, zero = DTRACE_QUANTIZE_ZEROBUCKET;
2010         int64_t val = (int64_t)nval;
2011 
2012         if (val < 0) {
2013                 for (i = 0; i < zero; i++) {
2014                         if (val <= DTRACE_QUANTIZE_BUCKETVAL(i)) {
2015                                 quanta[i] += incr;
2016                                 return;
2017                         }
2018                 }
2019         } else {
2020                 for (i = zero + 1; i < DTRACE_QUANTIZE_NBUCKETS; i++) {
2021                         if (val < DTRACE_QUANTIZE_BUCKETVAL(i)) {
2022                                 quanta[i - 1] += incr;
2023                                 return;
2024                         }
2025                 }
2026 
2027                 quanta[DTRACE_QUANTIZE_NBUCKETS - 1] += incr;
2028                 return;
2029         }
2030 
2031         ASSERT(0);
2032 }
2033 
2034 static void
2035 dtrace_aggregate_lquantize(uint64_t *lquanta, uint64_t nval, uint64_t incr)
2036 {
2037         uint64_t arg = *lquanta++;
2038         int32_t base = DTRACE_LQUANTIZE_BASE(arg);
2039         uint16_t step = DTRACE_LQUANTIZE_STEP(arg);
2040         uint16_t levels = DTRACE_LQUANTIZE_LEVELS(arg);
2041         int32_t val = (int32_t)nval, level;
2042 
2043         ASSERT(step != 0);
2044         ASSERT(levels != 0);
2045 
2046         if (val < base) {
2047                 /*
2048                  * This is an underflow.
2049                  */
2050                 lquanta[0] += incr;
2051                 return;
2052         }
2053 
2054         level = (val - base) / step;
2055 
2056         if (level < levels) {
2057                 lquanta[level + 1] += incr;
2058                 return;
2059         }
2060 
2061         /*
2062          * This is an overflow.
2063          */
2064         lquanta[levels + 1] += incr;
2065 }
2066 
2067 static int
2068 dtrace_aggregate_llquantize_bucket(uint16_t factor, uint16_t low,
2069     uint16_t high, uint16_t nsteps, int64_t value)
2070 {
2071         int64_t this = 1, last, next;
2072         int base = 1, order;
2073 
2074         ASSERT(factor <= nsteps);
2075         ASSERT(nsteps % factor == 0);
2076 
2077         for (order = 0; order < low; order++)
2078                 this *= factor;
2079 
2080         /*
2081          * If our value is less than our factor taken to the power of the
2082          * low order of magnitude, it goes into the zeroth bucket.
2083          */
2084         if (value < (last = this))
2085                 return (0);
2086 
2087         for (this *= factor; order <= high; order++) {
2088                 int nbuckets = this > nsteps ? nsteps : this;
2089 
2090                 if ((next = this * factor) < this) {
2091                         /*
2092                          * We should not generally get log/linear quantizations
2093                          * with a high magnitude that allows 64-bits to
2094                          * overflow, but we nonetheless protect against this
2095                          * by explicitly checking for overflow, and clamping
2096                          * our value accordingly.
2097                          */
2098                         value = this - 1;
2099                 }
2100 
2101                 if (value < this) {
2102                         /*
2103                          * If our value lies within this order of magnitude,
2104                          * determine its position by taking the offset within
2105                          * the order of magnitude, dividing by the bucket
2106                          * width, and adding to our (accumulated) base.
2107                          */
2108                         return (base + (value - last) / (this / nbuckets));
2109                 }
2110 
2111                 base += nbuckets - (nbuckets / factor);
2112                 last = this;
2113                 this = next;
2114         }
2115 
2116         /*
2117          * Our value is greater than or equal to our factor taken to the
2118          * power of one plus the high magnitude -- return the top bucket.
2119          */
2120         return (base);
2121 }
2122 
2123 static void
2124 dtrace_aggregate_llquantize(uint64_t *llquanta, uint64_t nval, uint64_t incr)
2125 {
2126         uint64_t arg = *llquanta++;
2127         uint16_t factor = DTRACE_LLQUANTIZE_FACTOR(arg);
2128         uint16_t low = DTRACE_LLQUANTIZE_LOW(arg);
2129         uint16_t high = DTRACE_LLQUANTIZE_HIGH(arg);
2130         uint16_t nsteps = DTRACE_LLQUANTIZE_NSTEP(arg);
2131 
2132         llquanta[dtrace_aggregate_llquantize_bucket(factor,
2133             low, high, nsteps, nval)] += incr;
2134 }
2135 
2136 /*ARGSUSED*/
2137 static void
2138 dtrace_aggregate_avg(uint64_t *data, uint64_t nval, uint64_t arg)
2139 {
2140         data[0]++;
2141         data[1] += nval;
2142 }
2143 
2144 /*ARGSUSED*/
2145 static void
2146 dtrace_aggregate_stddev(uint64_t *data, uint64_t nval, uint64_t arg)
2147 {
2148         int64_t snval = (int64_t)nval;
2149         uint64_t tmp[2];
2150 
2151         data[0]++;
2152         data[1] += nval;
2153 
2154         /*
2155          * What we want to say here is:
2156          *
2157          * data[2] += nval * nval;
2158          *
2159          * But given that nval is 64-bit, we could easily overflow, so
2160          * we do this as 128-bit arithmetic.
2161          */
2162         if (snval < 0)
2163                 snval = -snval;
2164 
2165         dtrace_multiply_128((uint64_t)snval, (uint64_t)snval, tmp);
2166         dtrace_add_128(data + 2, tmp, data + 2);
2167 }
2168 
2169 /*ARGSUSED*/
2170 static void
2171 dtrace_aggregate_count(uint64_t *oval, uint64_t nval, uint64_t arg)
2172 {
2173         *oval = *oval + 1;
2174 }
2175 
2176 /*ARGSUSED*/
2177 static void
2178 dtrace_aggregate_sum(uint64_t *oval, uint64_t nval, uint64_t arg)
2179 {
2180         *oval += nval;
2181 }
2182 
2183 /*
2184  * Aggregate given the tuple in the principal data buffer, and the aggregating
2185  * action denoted by the specified dtrace_aggregation_t.  The aggregation
2186  * buffer is specified as the buf parameter.  This routine does not return
2187  * failure; if there is no space in the aggregation buffer, the data will be
2188  * dropped, and a corresponding counter incremented.
2189  */
2190 static void
2191 dtrace_aggregate(dtrace_aggregation_t *agg, dtrace_buffer_t *dbuf,
2192     intptr_t offset, dtrace_buffer_t *buf, uint64_t expr, uint64_t arg)
2193 {
2194         dtrace_recdesc_t *rec = &agg->dtag_action.dta_rec;
2195         uint32_t i, ndx, size, fsize;
2196         uint32_t align = sizeof (uint64_t) - 1;
2197         dtrace_aggbuffer_t *agb;
2198         dtrace_aggkey_t *key;
2199         uint32_t hashval = 0, limit, isstr;
2200         caddr_t tomax, data, kdata;
2201         dtrace_actkind_t action;
2202         dtrace_action_t *act;
2203         uintptr_t offs;
2204 
2205         if (buf == NULL)
2206                 return;
2207 
2208         if (!agg->dtag_hasarg) {
2209                 /*
2210                  * Currently, only quantize() and lquantize() take additional
2211                  * arguments, and they have the same semantics:  an increment
2212                  * value that defaults to 1 when not present.  If additional
2213                  * aggregating actions take arguments, the setting of the
2214                  * default argument value will presumably have to become more
2215                  * sophisticated...
2216                  */
2217                 arg = 1;
2218         }
2219 
2220         action = agg->dtag_action.dta_kind - DTRACEACT_AGGREGATION;
2221         size = rec->dtrd_offset - agg->dtag_base;
2222         fsize = size + rec->dtrd_size;
2223 
2224         ASSERT(dbuf->dtb_tomax != NULL);
2225         data = dbuf->dtb_tomax + offset + agg->dtag_base;
2226 
2227         if ((tomax = buf->dtb_tomax) == NULL) {
2228                 dtrace_buffer_drop(buf);
2229                 return;
2230         }
2231 
2232         /*
2233          * The metastructure is always at the bottom of the buffer.
2234          */
2235         agb = (dtrace_aggbuffer_t *)(tomax + buf->dtb_size -
2236             sizeof (dtrace_aggbuffer_t));
2237 
2238         if (buf->dtb_offset == 0) {
2239                 /*
2240                  * We just kludge up approximately 1/8th of the size to be
2241                  * buckets.  If this guess ends up being routinely
2242                  * off-the-mark, we may need to dynamically readjust this
2243                  * based on past performance.
2244                  */
2245                 uintptr_t hashsize = (buf->dtb_size >> 3) / sizeof (uintptr_t);
2246 
2247                 if ((uintptr_t)agb - hashsize * sizeof (dtrace_aggkey_t *) <
2248                     (uintptr_t)tomax || hashsize == 0) {
2249                         /*
2250                          * We've been given a ludicrously small buffer;
2251                          * increment our drop count and leave.
2252                          */
2253                         dtrace_buffer_drop(buf);
2254                         return;
2255                 }
2256 
2257                 /*
2258                  * And now, a pathetic attempt to try to get a an odd (or
2259                  * perchance, a prime) hash size for better hash distribution.
2260                  */
2261                 if (hashsize > (DTRACE_AGGHASHSIZE_SLEW << 3))
2262                         hashsize -= DTRACE_AGGHASHSIZE_SLEW;
2263 
2264                 agb->dtagb_hashsize = hashsize;
2265                 agb->dtagb_hash = (dtrace_aggkey_t **)((uintptr_t)agb -
2266                     agb->dtagb_hashsize * sizeof (dtrace_aggkey_t *));
2267                 agb->dtagb_free = (uintptr_t)agb->dtagb_hash;
2268 
2269                 for (i = 0; i < agb->dtagb_hashsize; i++)
2270                         agb->dtagb_hash[i] = NULL;
2271         }
2272 
2273         ASSERT(agg->dtag_first != NULL);
2274         ASSERT(agg->dtag_first->dta_intuple);
2275 
2276         /*
2277          * Calculate the hash value based on the key.  Note that we _don't_
2278          * include the aggid in the hashing (but we will store it as part of
2279          * the key).  The hashing algorithm is Bob Jenkins' "One-at-a-time"
2280          * algorithm: a simple, quick algorithm that has no known funnels, and
2281          * gets good distribution in practice.  The efficacy of the hashing
2282          * algorithm (and a comparison with other algorithms) may be found by
2283          * running the ::dtrace_aggstat MDB dcmd.
2284          */
2285         for (act = agg->dtag_first; act->dta_intuple; act = act->dta_next) {
2286                 i = act->dta_rec.dtrd_offset - agg->dtag_base;
2287                 limit = i + act->dta_rec.dtrd_size;
2288                 ASSERT(limit <= size);
2289                 isstr = DTRACEACT_ISSTRING(act);
2290 
2291                 for (; i < limit; i++) {
2292                         hashval += data[i];
2293                         hashval += (hashval << 10);
2294                         hashval ^= (hashval >> 6);
2295 
2296                         if (isstr && data[i] == '\0')
2297                                 break;
2298                 }
2299         }
2300 
2301         hashval += (hashval << 3);
2302         hashval ^= (hashval >> 11);
2303         hashval += (hashval << 15);
2304 
2305         /*
2306          * Yes, the divide here is expensive -- but it's generally the least
2307          * of the performance issues given the amount of data that we iterate
2308          * over to compute hash values, compare data, etc.
2309          */
2310         ndx = hashval % agb->dtagb_hashsize;
2311 
2312         for (key = agb->dtagb_hash[ndx]; key != NULL; key = key->dtak_next) {
2313                 ASSERT((caddr_t)key >= tomax);
2314                 ASSERT((caddr_t)key < tomax + buf->dtb_size);
2315 
2316                 if (hashval != key->dtak_hashval || key->dtak_size != size)
2317                         continue;
2318 
2319                 kdata = key->dtak_data;
2320                 ASSERT(kdata >= tomax && kdata < tomax + buf->dtb_size);
2321 
2322                 for (act = agg->dtag_first; act->dta_intuple;
2323                     act = act->dta_next) {
2324                         i = act->dta_rec.dtrd_offset - agg->dtag_base;
2325                         limit = i + act->dta_rec.dtrd_size;
2326                         ASSERT(limit <= size);
2327                         isstr = DTRACEACT_ISSTRING(act);
2328 
2329                         for (; i < limit; i++) {
2330                                 if (kdata[i] != data[i])
2331                                         goto next;
2332 
2333                                 if (isstr && data[i] == '\0')
2334                                         break;
2335                         }
2336                 }
2337 
2338                 if (action != key->dtak_action) {
2339                         /*
2340                          * We are aggregating on the same value in the same
2341                          * aggregation with two different aggregating actions.
2342                          * (This should have been picked up in the compiler,
2343                          * so we may be dealing with errant or devious DIF.)
2344                          * This is an error condition; we indicate as much,
2345                          * and return.
2346                          */
2347                         DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
2348                         return;
2349                 }
2350 
2351                 /*
2352                  * This is a hit:  we need to apply the aggregator to
2353                  * the value at this key.
2354                  */
2355                 agg->dtag_aggregate((uint64_t *)(kdata + size), expr, arg);
2356                 return;
2357 next:
2358                 continue;
2359         }
2360 
2361         /*
2362          * We didn't find it.  We need to allocate some zero-filled space,
2363          * link it into the hash table appropriately, and apply the aggregator
2364          * to the (zero-filled) value.
2365          */
2366         offs = buf->dtb_offset;
2367         while (offs & (align - 1))
2368                 offs += sizeof (uint32_t);
2369 
2370         /*
2371          * If we don't have enough room to both allocate a new key _and_
2372          * its associated data, increment the drop count and return.
2373          */
2374         if ((uintptr_t)tomax + offs + fsize >
2375             agb->dtagb_free - sizeof (dtrace_aggkey_t)) {
2376                 dtrace_buffer_drop(buf);
2377                 return;
2378         }
2379 
2380         /*CONSTCOND*/
2381         ASSERT(!(sizeof (dtrace_aggkey_t) & (sizeof (uintptr_t) - 1)));
2382         key = (dtrace_aggkey_t *)(agb->dtagb_free - sizeof (dtrace_aggkey_t));
2383         agb->dtagb_free -= sizeof (dtrace_aggkey_t);
2384 
2385         key->dtak_data = kdata = tomax + offs;
2386         buf->dtb_offset = offs + fsize;
2387 
2388         /*
2389          * Now copy the data across.
2390          */
2391         *((dtrace_aggid_t *)kdata) = agg->dtag_id;
2392 
2393         for (i = sizeof (dtrace_aggid_t); i < size; i++)
2394                 kdata[i] = data[i];
2395 
2396         /*
2397          * Because strings are not zeroed out by default, we need to iterate
2398          * looking for actions that store strings, and we need to explicitly
2399          * pad these strings out with zeroes.
2400          */
2401         for (act = agg->dtag_first; act->dta_intuple; act = act->dta_next) {
2402                 int nul;
2403 
2404                 if (!DTRACEACT_ISSTRING(act))
2405                         continue;
2406 
2407                 i = act->dta_rec.dtrd_offset - agg->dtag_base;
2408                 limit = i + act->dta_rec.dtrd_size;
2409                 ASSERT(limit <= size);
2410 
2411                 for (nul = 0; i < limit; i++) {
2412                         if (nul) {
2413                                 kdata[i] = '\0';
2414                                 continue;
2415                         }
2416 
2417                         if (data[i] != '\0')
2418                                 continue;
2419 
2420                         nul = 1;
2421                 }
2422         }
2423 
2424         for (i = size; i < fsize; i++)
2425                 kdata[i] = 0;
2426 
2427         key->dtak_hashval = hashval;
2428         key->dtak_size = size;
2429         key->dtak_action = action;
2430         key->dtak_next = agb->dtagb_hash[ndx];
2431         agb->dtagb_hash[ndx] = key;
2432 
2433         /*
2434          * Finally, apply the aggregator.
2435          */
2436         *((uint64_t *)(key->dtak_data + size)) = agg->dtag_initial;
2437         agg->dtag_aggregate((uint64_t *)(key->dtak_data + size), expr, arg);
2438 }
2439 
2440 /*
2441  * Given consumer state, this routine finds a speculation in the INACTIVE
2442  * state and transitions it into the ACTIVE state.  If there is no speculation
2443  * in the INACTIVE state, 0 is returned.  In this case, no error counter is
2444  * incremented -- it is up to the caller to take appropriate action.
2445  */
2446 static int
2447 dtrace_speculation(dtrace_state_t *state)
2448 {
2449         int i = 0;
2450         dtrace_speculation_state_t current;
2451         uint32_t *stat = &state->dts_speculations_unavail, count;
2452 
2453         while (i < state->dts_nspeculations) {
2454                 dtrace_speculation_t *spec = &state->dts_speculations[i];
2455 
2456                 current = spec->dtsp_state;
2457 
2458                 if (current != DTRACESPEC_INACTIVE) {
2459                         if (current == DTRACESPEC_COMMITTINGMANY ||
2460                             current == DTRACESPEC_COMMITTING ||
2461                             current == DTRACESPEC_DISCARDING)
2462                                 stat = &state->dts_speculations_busy;
2463                         i++;
2464                         continue;
2465                 }
2466 
2467                 if (dtrace_cas32((uint32_t *)&spec->dtsp_state,
2468                     current, DTRACESPEC_ACTIVE) == current)
2469                         return (i + 1);
2470         }
2471 
2472         /*
2473          * We couldn't find a speculation.  If we found as much as a single
2474          * busy speculation buffer, we'll attribute this failure as "busy"
2475          * instead of "unavail".
2476          */
2477         do {
2478                 count = *stat;
2479         } while (dtrace_cas32(stat, count, count + 1) != count);
2480 
2481         return (0);
2482 }
2483 
2484 /*
2485  * This routine commits an active speculation.  If the specified speculation
2486  * is not in a valid state to perform a commit(), this routine will silently do
2487  * nothing.  The state of the specified speculation is transitioned according
2488  * to the state transition diagram outlined in <sys/dtrace_impl.h>
2489  */
2490 static void
2491 dtrace_speculation_commit(dtrace_state_t *state, processorid_t cpu,
2492     dtrace_specid_t which)
2493 {
2494         dtrace_speculation_t *spec;
2495         dtrace_buffer_t *src, *dest;
2496         uintptr_t daddr, saddr, dlimit;
2497         dtrace_speculation_state_t current, new;
2498         intptr_t offs;
2499 
2500         if (which == 0)
2501                 return;
2502 
2503         if (which > state->dts_nspeculations) {
2504                 cpu_core[cpu].cpuc_dtrace_flags |= CPU_DTRACE_ILLOP;
2505                 return;
2506         }
2507 
2508         spec = &state->dts_speculations[which - 1];
2509         src = &spec->dtsp_buffer[cpu];
2510         dest = &state->dts_buffer[cpu];
2511 
2512         do {
2513                 current = spec->dtsp_state;
2514 
2515                 if (current == DTRACESPEC_COMMITTINGMANY)
2516                         break;
2517 
2518                 switch (current) {
2519                 case DTRACESPEC_INACTIVE:
2520                 case DTRACESPEC_DISCARDING:
2521                         return;
2522 
2523                 case DTRACESPEC_COMMITTING:
2524                         /*
2525                          * This is only possible if we are (a) commit()'ing
2526                          * without having done a prior speculate() on this CPU
2527                          * and (b) racing with another commit() on a different
2528                          * CPU.  There's nothing to do -- we just assert that
2529                          * our offset is 0.
2530                          */
2531                         ASSERT(src->dtb_offset == 0);
2532                         return;
2533 
2534                 case DTRACESPEC_ACTIVE:
2535                         new = DTRACESPEC_COMMITTING;
2536                         break;
2537 
2538                 case DTRACESPEC_ACTIVEONE:
2539                         /*
2540                          * This speculation is active on one CPU.  If our
2541                          * buffer offset is non-zero, we know that the one CPU
2542                          * must be us.  Otherwise, we are committing on a
2543                          * different CPU from the speculate(), and we must
2544                          * rely on being asynchronously cleaned.
2545                          */
2546                         if (src->dtb_offset != 0) {
2547                                 new = DTRACESPEC_COMMITTING;
2548                                 break;
2549                         }
2550                         /*FALLTHROUGH*/
2551 
2552                 case DTRACESPEC_ACTIVEMANY:
2553                         new = DTRACESPEC_COMMITTINGMANY;
2554                         break;
2555 
2556                 default:
2557                         ASSERT(0);
2558                 }
2559         } while (dtrace_cas32((uint32_t *)&spec->dtsp_state,
2560             current, new) != current);
2561 
2562         /*
2563          * We have set the state to indicate that we are committing this
2564          * speculation.  Now reserve the necessary space in the destination
2565          * buffer.
2566          */
2567         if ((offs = dtrace_buffer_reserve(dest, src->dtb_offset,
2568             sizeof (uint64_t), state, NULL)) < 0) {
2569                 dtrace_buffer_drop(dest);
2570                 goto out;
2571         }
2572 
2573         /*
2574          * We have the space; copy the buffer across.  (Note that this is a
2575          * highly subobtimal bcopy(); in the unlikely event that this becomes
2576          * a serious performance issue, a high-performance DTrace-specific
2577          * bcopy() should obviously be invented.)
2578          */
2579         daddr = (uintptr_t)dest->dtb_tomax + offs;
2580         dlimit = daddr + src->dtb_offset;
2581         saddr = (uintptr_t)src->dtb_tomax;
2582 
2583         /*
2584          * First, the aligned portion.
2585          */
2586         while (dlimit - daddr >= sizeof (uint64_t)) {
2587                 *((uint64_t *)daddr) = *((uint64_t *)saddr);
2588 
2589                 daddr += sizeof (uint64_t);
2590                 saddr += sizeof (uint64_t);
2591         }
2592 
2593         /*
2594          * Now any left-over bit...
2595          */
2596         while (dlimit - daddr)
2597                 *((uint8_t *)daddr++) = *((uint8_t *)saddr++);
2598 
2599         /*
2600          * Finally, commit the reserved space in the destination buffer.
2601          */
2602         dest->dtb_offset = offs + src->dtb_offset;
2603 
2604 out:
2605         /*
2606          * If we're lucky enough to be the only active CPU on this speculation
2607          * buffer, we can just set the state back to DTRACESPEC_INACTIVE.
2608          */
2609         if (current == DTRACESPEC_ACTIVE ||
2610             (current == DTRACESPEC_ACTIVEONE && new == DTRACESPEC_COMMITTING)) {
2611                 uint32_t rval = dtrace_cas32((uint32_t *)&spec->dtsp_state,
2612                     DTRACESPEC_COMMITTING, DTRACESPEC_INACTIVE);
2613 
2614                 ASSERT(rval == DTRACESPEC_COMMITTING);
2615         }
2616 
2617         src->dtb_offset = 0;
2618         src->dtb_xamot_drops += src->dtb_drops;
2619         src->dtb_drops = 0;
2620 }
2621 
2622 /*
2623  * This routine discards an active speculation.  If the specified speculation
2624  * is not in a valid state to perform a discard(), this routine will silently
2625  * do nothing.  The state of the specified speculation is transitioned
2626  * according to the state transition diagram outlined in <sys/dtrace_impl.h>
2627  */
2628 static void
2629 dtrace_speculation_discard(dtrace_state_t *state, processorid_t cpu,
2630     dtrace_specid_t which)
2631 {
2632         dtrace_speculation_t *spec;
2633         dtrace_speculation_state_t current, new;
2634         dtrace_buffer_t *buf;
2635 
2636         if (which == 0)
2637                 return;
2638 
2639         if (which > state->dts_nspeculations) {
2640                 cpu_core[cpu].cpuc_dtrace_flags |= CPU_DTRACE_ILLOP;
2641                 return;
2642         }
2643 
2644         spec = &state->dts_speculations[which - 1];
2645         buf = &spec->dtsp_buffer[cpu];
2646 
2647         do {
2648                 current = spec->dtsp_state;
2649 
2650                 switch (current) {
2651                 case DTRACESPEC_INACTIVE:
2652                 case DTRACESPEC_COMMITTINGMANY:
2653                 case DTRACESPEC_COMMITTING:
2654                 case DTRACESPEC_DISCARDING:
2655                         return;
2656 
2657                 case DTRACESPEC_ACTIVE:
2658                 case DTRACESPEC_ACTIVEMANY:
2659                         new = DTRACESPEC_DISCARDING;
2660                         break;
2661 
2662                 case DTRACESPEC_ACTIVEONE:
2663                         if (buf->dtb_offset != 0) {
2664                                 new = DTRACESPEC_INACTIVE;
2665                         } else {
2666                                 new = DTRACESPEC_DISCARDING;
2667                         }
2668                         break;
2669 
2670                 default:
2671                         ASSERT(0);
2672                 }
2673         } while (dtrace_cas32((uint32_t *)&spec->dtsp_state,
2674             current, new) != current);
2675 
2676         buf->dtb_offset = 0;
2677         buf->dtb_drops = 0;
2678 }
2679 
2680 /*
2681  * Note:  not called from probe context.  This function is called
2682  * asynchronously from cross call context to clean any speculations that are
2683  * in the COMMITTINGMANY or DISCARDING states.  These speculations may not be
2684  * transitioned back to the INACTIVE state until all CPUs have cleaned the
2685  * speculation.
2686  */
2687 static void
2688 dtrace_speculation_clean_here(dtrace_state_t *state)
2689 {
2690         dtrace_icookie_t cookie;
2691         processorid_t cpu = CPU->cpu_id;
2692         dtrace_buffer_t *dest = &state->dts_buffer[cpu];
2693         dtrace_specid_t i;
2694 
2695         cookie = dtrace_interrupt_disable();
2696 
2697         if (dest->dtb_tomax == NULL) {
2698                 dtrace_interrupt_enable(cookie);
2699                 return;
2700         }
2701 
2702         for (i = 0; i < state->dts_nspeculations; i++) {
2703                 dtrace_speculation_t *spec = &state->dts_speculations[i];
2704                 dtrace_buffer_t *src = &spec->dtsp_buffer[cpu];
2705 
2706                 if (src->dtb_tomax == NULL)
2707                         continue;
2708 
2709                 if (spec->dtsp_state == DTRACESPEC_DISCARDING) {
2710                         src->dtb_offset = 0;
2711                         continue;
2712                 }
2713 
2714                 if (spec->dtsp_state != DTRACESPEC_COMMITTINGMANY)
2715                         continue;
2716 
2717                 if (src->dtb_offset == 0)
2718                         continue;
2719 
2720                 dtrace_speculation_commit(state, cpu, i + 1);
2721         }
2722 
2723         dtrace_interrupt_enable(cookie);
2724 }
2725 
2726 /*
2727  * Note:  not called from probe context.  This function is called
2728  * asynchronously (and at a regular interval) to clean any speculations that
2729  * are in the COMMITTINGMANY or DISCARDING states.  If it discovers that there
2730  * is work to be done, it cross calls all CPUs to perform that work;
2731  * COMMITMANY and DISCARDING speculations may not be transitioned back to the
2732  * INACTIVE state until they have been cleaned by all CPUs.
2733  */
2734 static void
2735 dtrace_speculation_clean(dtrace_state_t *state)
2736 {
2737         int work = 0, rv;
2738         dtrace_specid_t i;
2739 
2740         for (i = 0; i < state->dts_nspeculations; i++) {
2741                 dtrace_speculation_t *spec = &state->dts_speculations[i];
2742 
2743                 ASSERT(!spec->dtsp_cleaning);
2744 
2745                 if (spec->dtsp_state != DTRACESPEC_DISCARDING &&
2746                     spec->dtsp_state != DTRACESPEC_COMMITTINGMANY)
2747                         continue;
2748 
2749                 work++;
2750                 spec->dtsp_cleaning = 1;
2751         }
2752 
2753         if (!work)
2754                 return;
2755 
2756         dtrace_xcall(DTRACE_CPUALL,
2757             (dtrace_xcall_t)dtrace_speculation_clean_here, state);
2758 
2759         /*
2760          * We now know that all CPUs have committed or discarded their
2761          * speculation buffers, as appropriate.  We can now set the state
2762          * to inactive.
2763          */
2764         for (i = 0; i < state->dts_nspeculations; i++) {
2765                 dtrace_speculation_t *spec = &state->dts_speculations[i];
2766                 dtrace_speculation_state_t current, new;
2767 
2768                 if (!spec->dtsp_cleaning)
2769                         continue;
2770 
2771                 current = spec->dtsp_state;
2772                 ASSERT(current == DTRACESPEC_DISCARDING ||
2773                     current == DTRACESPEC_COMMITTINGMANY);
2774 
2775                 new = DTRACESPEC_INACTIVE;
2776 
2777                 rv = dtrace_cas32((uint32_t *)&spec->dtsp_state, current, new);
2778                 ASSERT(rv == current);
2779                 spec->dtsp_cleaning = 0;
2780         }
2781 }
2782 
2783 /*
2784  * Called as part of a speculate() to get the speculative buffer associated
2785  * with a given speculation.  Returns NULL if the specified speculation is not
2786  * in an ACTIVE state.  If the speculation is in the ACTIVEONE state -- and
2787  * the active CPU is not the specified CPU -- the speculation will be
2788  * atomically transitioned into the ACTIVEMANY state.
2789  */
2790 static dtrace_buffer_t *
2791 dtrace_speculation_buffer(dtrace_state_t *state, processorid_t cpuid,
2792     dtrace_specid_t which)
2793 {
2794         dtrace_speculation_t *spec;
2795         dtrace_speculation_state_t current, new;
2796         dtrace_buffer_t *buf;
2797 
2798         if (which == 0)
2799                 return (NULL);
2800 
2801         if (which > state->dts_nspeculations) {
2802                 cpu_core[cpuid].cpuc_dtrace_flags |= CPU_DTRACE_ILLOP;
2803                 return (NULL);
2804         }
2805 
2806         spec = &state->dts_speculations[which - 1];
2807         buf = &spec->dtsp_buffer[cpuid];
2808 
2809         do {
2810                 current = spec->dtsp_state;
2811 
2812                 switch (current) {
2813                 case DTRACESPEC_INACTIVE:
2814                 case DTRACESPEC_COMMITTINGMANY:
2815                 case DTRACESPEC_DISCARDING:
2816                         return (NULL);
2817 
2818                 case DTRACESPEC_COMMITTING:
2819                         ASSERT(buf->dtb_offset == 0);
2820                         return (NULL);
2821 
2822                 case DTRACESPEC_ACTIVEONE:
2823                         /*
2824                          * This speculation is currently active on one CPU.
2825                          * Check the offset in the buffer; if it's non-zero,
2826                          * that CPU must be us (and we leave the state alone).
2827                          * If it's zero, assume that we're starting on a new
2828                          * CPU -- and change the state to indicate that the
2829                          * speculation is active on more than one CPU.
2830                          */
2831                         if (buf->dtb_offset != 0)
2832                                 return (buf);
2833 
2834                         new = DTRACESPEC_ACTIVEMANY;
2835                         break;
2836 
2837                 case DTRACESPEC_ACTIVEMANY:
2838                         return (buf);
2839 
2840                 case DTRACESPEC_ACTIVE:
2841                         new = DTRACESPEC_ACTIVEONE;
2842                         break;
2843 
2844                 default:
2845                         ASSERT(0);
2846                 }
2847         } while (dtrace_cas32((uint32_t *)&spec->dtsp_state,
2848             current, new) != current);
2849 
2850         ASSERT(new == DTRACESPEC_ACTIVEONE || new == DTRACESPEC_ACTIVEMANY);
2851         return (buf);
2852 }
2853 
2854 /*
2855  * Return a string.  In the event that the user lacks the privilege to access
2856  * arbitrary kernel memory, we copy the string out to scratch memory so that we
2857  * don't fail access checking.
2858  *
2859  * dtrace_dif_variable() uses this routine as a helper for various
2860  * builtin values such as 'execname' and 'probefunc.'
2861  */
2862 uintptr_t
2863 dtrace_dif_varstr(uintptr_t addr, dtrace_state_t *state,
2864     dtrace_mstate_t *mstate)
2865 {
2866         uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
2867         uintptr_t ret;
2868         size_t strsz;
2869 
2870         /*
2871          * The easy case: this probe is allowed to read all of memory, so
2872          * we can just return this as a vanilla pointer.
2873          */
2874         if ((mstate->dtms_access & DTRACE_ACCESS_KERNEL) != 0)
2875                 return (addr);
2876 
2877         /*
2878          * This is the tougher case: we copy the string in question from
2879          * kernel memory into scratch memory and return it that way: this
2880          * ensures that we won't trip up when access checking tests the
2881          * BYREF return value.
2882          */
2883         strsz = dtrace_strlen((char *)addr, size) + 1;
2884 
2885         if (mstate->dtms_scratch_ptr + strsz >
2886             mstate->dtms_scratch_base + mstate->dtms_scratch_size) {
2887                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
2888                 return (NULL);
2889         }
2890 
2891         dtrace_strcpy((const void *)addr, (void *)mstate->dtms_scratch_ptr,
2892             strsz);
2893         ret = mstate->dtms_scratch_ptr;
2894         mstate->dtms_scratch_ptr += strsz;
2895         return (ret);
2896 }
2897 
2898 /*
2899  * This function implements the DIF emulator's variable lookups.  The emulator
2900  * passes a reserved variable identifier and optional built-in array index.
2901  */
2902 static uint64_t
2903 dtrace_dif_variable(dtrace_mstate_t *mstate, dtrace_state_t *state, uint64_t v,
2904     uint64_t ndx)
2905 {
2906         /*
2907          * If we're accessing one of the uncached arguments, we'll turn this
2908          * into a reference in the args array.
2909          */
2910         if (v >= DIF_VAR_ARG0 && v <= DIF_VAR_ARG9) {
2911                 ndx = v - DIF_VAR_ARG0;
2912                 v = DIF_VAR_ARGS;
2913         }
2914 
2915         switch (v) {
2916         case DIF_VAR_ARGS:
2917                 if (!(mstate->dtms_access & DTRACE_ACCESS_ARGS)) {
2918                         cpu_core[CPU->cpu_id].cpuc_dtrace_flags |=
2919                             CPU_DTRACE_KPRIV;
2920                         return (0);
2921                 }
2922 
2923                 ASSERT(mstate->dtms_present & DTRACE_MSTATE_ARGS);
2924                 if (ndx >= sizeof (mstate->dtms_arg) /
2925                     sizeof (mstate->dtms_arg[0])) {
2926                         int aframes = mstate->dtms_probe->dtpr_aframes + 2;
2927                         dtrace_provider_t *pv;
2928                         uint64_t val;
2929 
2930                         pv = mstate->dtms_probe->dtpr_provider;
2931                         if (pv->dtpv_pops.dtps_getargval != NULL)
2932                                 val = pv->dtpv_pops.dtps_getargval(pv->dtpv_arg,
2933                                     mstate->dtms_probe->dtpr_id,
2934                                     mstate->dtms_probe->dtpr_arg, ndx, aframes);
2935                         else
2936                                 val = dtrace_getarg(ndx, aframes);
2937 
2938                         /*
2939                          * This is regrettably required to keep the compiler
2940                          * from tail-optimizing the call to dtrace_getarg().
2941                          * The condition always evaluates to true, but the
2942                          * compiler has no way of figuring that out a priori.
2943                          * (None of this would be necessary if the compiler
2944                          * could be relied upon to _always_ tail-optimize
2945                          * the call to dtrace_getarg() -- but it can't.)
2946                          */
2947                         if (mstate->dtms_probe != NULL)
2948                                 return (val);
2949 
2950                         ASSERT(0);
2951                 }
2952 
2953                 return (mstate->dtms_arg[ndx]);
2954 
2955         case DIF_VAR_UREGS: {
2956                 klwp_t *lwp;
2957 
2958                 if (!dtrace_priv_proc(state, mstate))
2959                         return (0);
2960 
2961                 if ((lwp = curthread->t_lwp) == NULL) {
2962                         DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
2963                         cpu_core[CPU->cpu_id].cpuc_dtrace_illval = NULL;
2964                         return (0);
2965                 }
2966 
2967                 return (dtrace_getreg(lwp->lwp_regs, ndx));
2968         }
2969 
2970         case DIF_VAR_VMREGS: {
2971                 uint64_t rval;
2972 
2973                 if (!dtrace_priv_kernel(state))
2974                         return (0);
2975 
2976                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
2977 
2978                 rval = dtrace_getvmreg(ndx,
2979                     &cpu_core[CPU->cpu_id].cpuc_dtrace_flags);
2980 
2981                 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
2982 
2983                 return (rval);
2984         }
2985 
2986         case DIF_VAR_CURTHREAD:
2987                 if (!dtrace_priv_proc(state, mstate))
2988                         return (0);
2989                 return ((uint64_t)(uintptr_t)curthread);
2990 
2991         case DIF_VAR_TIMESTAMP:
2992                 if (!(mstate->dtms_present & DTRACE_MSTATE_TIMESTAMP)) {
2993                         mstate->dtms_timestamp = dtrace_gethrtime();
2994                         mstate->dtms_present |= DTRACE_MSTATE_TIMESTAMP;
2995                 }
2996                 return (mstate->dtms_timestamp);
2997 
2998         case DIF_VAR_VTIMESTAMP:
2999                 ASSERT(dtrace_vtime_references != 0);
3000                 return (curthread->t_dtrace_vtime);
3001 
3002         case DIF_VAR_WALLTIMESTAMP:
3003                 if (!(mstate->dtms_present & DTRACE_MSTATE_WALLTIMESTAMP)) {
3004                         mstate->dtms_walltimestamp = dtrace_gethrestime();
3005                         mstate->dtms_present |= DTRACE_MSTATE_WALLTIMESTAMP;
3006                 }
3007                 return (mstate->dtms_walltimestamp);
3008 
3009         case DIF_VAR_IPL:
3010                 if (!dtrace_priv_kernel(state))
3011                         return (0);
3012                 if (!(mstate->dtms_present & DTRACE_MSTATE_IPL)) {
3013                         mstate->dtms_ipl = dtrace_getipl();
3014                         mstate->dtms_present |= DTRACE_MSTATE_IPL;
3015                 }
3016                 return (mstate->dtms_ipl);
3017 
3018         case DIF_VAR_EPID:
3019                 ASSERT(mstate->dtms_present & DTRACE_MSTATE_EPID);
3020                 return (mstate->dtms_epid);
3021 
3022         case DIF_VAR_ID:
3023                 ASSERT(mstate->dtms_present & DTRACE_MSTATE_PROBE);
3024                 return (mstate->dtms_probe->dtpr_id);
3025 
3026         case DIF_VAR_STACKDEPTH:
3027                 if (!dtrace_priv_kernel(state))
3028                         return (0);
3029                 if (!(mstate->dtms_present & DTRACE_MSTATE_STACKDEPTH)) {
3030                         int aframes = mstate->dtms_probe->dtpr_aframes + 2;
3031 
3032                         mstate->dtms_stackdepth = dtrace_getstackdepth(aframes);
3033                         mstate->dtms_present |= DTRACE_MSTATE_STACKDEPTH;
3034                 }
3035                 return (mstate->dtms_stackdepth);
3036 
3037         case DIF_VAR_USTACKDEPTH:
3038                 if (!dtrace_priv_proc(state, mstate))
3039                         return (0);
3040                 if (!(mstate->dtms_present & DTRACE_MSTATE_USTACKDEPTH)) {
3041                         /*
3042                          * See comment in DIF_VAR_PID.
3043                          */
3044                         if (DTRACE_ANCHORED(mstate->dtms_probe) &&
3045                             CPU_ON_INTR(CPU)) {
3046                                 mstate->dtms_ustackdepth = 0;
3047                         } else {
3048                                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
3049                                 mstate->dtms_ustackdepth =
3050                                     dtrace_getustackdepth();
3051                                 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
3052                         }
3053                         mstate->dtms_present |= DTRACE_MSTATE_USTACKDEPTH;
3054                 }
3055                 return (mstate->dtms_ustackdepth);
3056 
3057         case DIF_VAR_CALLER:
3058                 if (!dtrace_priv_kernel(state))
3059                         return (0);
3060                 if (!(mstate->dtms_present & DTRACE_MSTATE_CALLER)) {
3061                         int aframes = mstate->dtms_probe->dtpr_aframes + 2;
3062 
3063                         if (!DTRACE_ANCHORED(mstate->dtms_probe)) {
3064                                 /*
3065                                  * If this is an unanchored probe, we are
3066                                  * required to go through the slow path:
3067                                  * dtrace_caller() only guarantees correct
3068                                  * results for anchored probes.
3069                                  */
3070                                 pc_t caller[2];
3071 
3072                                 dtrace_getpcstack(caller, 2, aframes,
3073                                     (uint32_t *)(uintptr_t)mstate->dtms_arg[0]);
3074                                 mstate->dtms_caller = caller[1];
3075                         } else if ((mstate->dtms_caller =
3076                             dtrace_caller(aframes)) == -1) {
3077                                 /*
3078                                  * We have failed to do this the quick way;
3079                                  * we must resort to the slower approach of
3080                                  * calling dtrace_getpcstack().
3081                                  */
3082                                 pc_t caller;
3083 
3084                                 dtrace_getpcstack(&caller, 1, aframes, NULL);
3085                                 mstate->dtms_caller = caller;
3086                         }
3087 
3088                         mstate->dtms_present |= DTRACE_MSTATE_CALLER;
3089                 }
3090                 return (mstate->dtms_caller);
3091 
3092         case DIF_VAR_UCALLER:
3093                 if (!dtrace_priv_proc(state, mstate))
3094                         return (0);
3095 
3096                 if (!(mstate->dtms_present & DTRACE_MSTATE_UCALLER)) {
3097                         uint64_t ustack[3];
3098 
3099                         /*
3100                          * dtrace_getupcstack() fills in the first uint64_t
3101                          * with the current PID.  The second uint64_t will
3102                          * be the program counter at user-level.  The third
3103                          * uint64_t will contain the caller, which is what
3104                          * we're after.
3105                          */
3106                         ustack[2] = NULL;
3107                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
3108                         dtrace_getupcstack(ustack, 3);
3109                         DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
3110                         mstate->dtms_ucaller = ustack[2];
3111                         mstate->dtms_present |= DTRACE_MSTATE_UCALLER;
3112                 }
3113 
3114                 return (mstate->dtms_ucaller);
3115 
3116         case DIF_VAR_PROBEPROV:
3117                 ASSERT(mstate->dtms_present & DTRACE_MSTATE_PROBE);
3118                 return (dtrace_dif_varstr(
3119                     (uintptr_t)mstate->dtms_probe->dtpr_provider->dtpv_name,
3120                     state, mstate));
3121 
3122         case DIF_VAR_PROBEMOD:
3123                 ASSERT(mstate->dtms_present & DTRACE_MSTATE_PROBE);
3124                 return (dtrace_dif_varstr(
3125                     (uintptr_t)mstate->dtms_probe->dtpr_mod,
3126                     state, mstate));
3127 
3128         case DIF_VAR_PROBEFUNC:
3129                 ASSERT(mstate->dtms_present & DTRACE_MSTATE_PROBE);
3130                 return (dtrace_dif_varstr(
3131                     (uintptr_t)mstate->dtms_probe->dtpr_func,
3132                     state, mstate));
3133 
3134         case DIF_VAR_PROBENAME:
3135                 ASSERT(mstate->dtms_present & DTRACE_MSTATE_PROBE);
3136                 return (dtrace_dif_varstr(
3137                     (uintptr_t)mstate->dtms_probe->dtpr_name,
3138                     state, mstate));
3139 
3140         case DIF_VAR_PID:
3141                 if (!dtrace_priv_proc(state, mstate))
3142                         return (0);
3143 
3144                 /*
3145                  * Note that we are assuming that an unanchored probe is
3146                  * always due to a high-level interrupt.  (And we're assuming
3147                  * that there is only a single high level interrupt.)
3148                  */
3149                 if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
3150                         return (pid0.pid_id);
3151 
3152                 /*
3153                  * It is always safe to dereference one's own t_procp pointer:
3154                  * it always points to a valid, allocated proc structure.
3155                  * Further, it is always safe to dereference the p_pidp member
3156                  * of one's own proc structure.  (These are truisms becuase
3157                  * threads and processes don't clean up their own state --
3158                  * they leave that task to whomever reaps them.)
3159                  */
3160                 return ((uint64_t)curthread->t_procp->p_pidp->pid_id);
3161 
3162         case DIF_VAR_PPID:
3163                 if (!dtrace_priv_proc(state, mstate))
3164                         return (0);
3165 
3166                 /*
3167                  * See comment in DIF_VAR_PID.
3168                  */
3169                 if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
3170                         return (pid0.pid_id);
3171 
3172                 /*
3173                  * It is always safe to dereference one's own t_procp pointer:
3174                  * it always points to a valid, allocated proc structure.
3175                  * (This is true because threads don't clean up their own
3176                  * state -- they leave that task to whomever reaps them.)
3177                  */
3178                 return ((uint64_t)curthread->t_procp->p_ppid);
3179 
3180         case DIF_VAR_TID:
3181                 /*
3182                  * See comment in DIF_VAR_PID.
3183                  */
3184                 if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
3185                         return (0);
3186 
3187                 return ((uint64_t)curthread->t_tid);
3188 
3189         case DIF_VAR_EXECNAME:
3190                 if (!dtrace_priv_proc(state, mstate))
3191                         return (0);
3192 
3193                 /*
3194                  * See comment in DIF_VAR_PID.
3195                  */
3196                 if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
3197                         return ((uint64_t)(uintptr_t)p0.p_user.u_comm);
3198 
3199                 /*
3200                  * It is always safe to dereference one's own t_procp pointer:
3201                  * it always points to a valid, allocated proc structure.
3202                  * (This is true because threads don't clean up their own
3203                  * state -- they leave that task to whomever reaps them.)
3204                  */
3205                 return (dtrace_dif_varstr(
3206                     (uintptr_t)curthread->t_procp->p_user.u_comm,
3207                     state, mstate));
3208 
3209         case DIF_VAR_ZONENAME:
3210                 if (!dtrace_priv_proc(state, mstate))
3211                         return (0);
3212 
3213                 /*
3214                  * See comment in DIF_VAR_PID.
3215                  */
3216                 if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
3217                         return ((uint64_t)(uintptr_t)p0.p_zone->zone_name);
3218 
3219                 /*
3220                  * It is always safe to dereference one's own t_procp pointer:
3221                  * it always points to a valid, allocated proc structure.
3222                  * (This is true because threads don't clean up their own
3223                  * state -- they leave that task to whomever reaps them.)
3224                  */
3225                 return (dtrace_dif_varstr(
3226                     (uintptr_t)curthread->t_procp->p_zone->zone_name,
3227                     state, mstate));
3228 
3229         case DIF_VAR_UID:
3230                 if (!dtrace_priv_proc(state, mstate))
3231                         return (0);
3232 
3233                 /*
3234                  * See comment in DIF_VAR_PID.
3235                  */
3236                 if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
3237                         return ((uint64_t)p0.p_cred->cr_uid);
3238 
3239                 /*
3240                  * It is always safe to dereference one's own t_procp pointer:
3241                  * it always points to a valid, allocated proc structure.
3242                  * (This is true because threads don't clean up their own
3243                  * state -- they leave that task to whomever reaps them.)
3244                  *
3245                  * Additionally, it is safe to dereference one's own process
3246                  * credential, since this is never NULL after process birth.
3247                  */
3248                 return ((uint64_t)curthread->t_procp->p_cred->cr_uid);
3249 
3250         case DIF_VAR_GID:
3251                 if (!dtrace_priv_proc(state, mstate))
3252                         return (0);
3253 
3254                 /*
3255                  * See comment in DIF_VAR_PID.
3256                  */
3257                 if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
3258                         return ((uint64_t)p0.p_cred->cr_gid);
3259 
3260                 /*
3261                  * It is always safe to dereference one's own t_procp pointer:
3262                  * it always points to a valid, allocated proc structure.
3263                  * (This is true because threads don't clean up their own
3264                  * state -- they leave that task to whomever reaps them.)
3265                  *
3266                  * Additionally, it is safe to dereference one's own process
3267                  * credential, since this is never NULL after process birth.
3268                  */
3269                 return ((uint64_t)curthread->t_procp->p_cred->cr_gid);
3270 
3271         case DIF_VAR_ERRNO: {
3272                 klwp_t *lwp;
3273                 if (!dtrace_priv_proc(state, mstate))
3274                         return (0);
3275 
3276                 /*
3277                  * See comment in DIF_VAR_PID.
3278                  */
3279                 if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
3280                         return (0);
3281 
3282                 /*
3283                  * It is always safe to dereference one's own t_lwp pointer in
3284                  * the event that this pointer is non-NULL.  (This is true
3285                  * because threads and lwps don't clean up their own state --
3286                  * they leave that task to whomever reaps them.)
3287                  */
3288                 if ((lwp = curthread->t_lwp) == NULL)
3289                         return (0);
3290 
3291                 return ((uint64_t)lwp->lwp_errno);
3292         }
3293         default:
3294                 DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
3295                 return (0);
3296         }
3297 }
3298 
3299 /*
3300  * Emulate the execution of DTrace ID subroutines invoked by the call opcode.
3301  * Notice that we don't bother validating the proper number of arguments or
3302  * their types in the tuple stack.  This isn't needed because all argument
3303  * interpretation is safe because of our load safety -- the worst that can
3304  * happen is that a bogus program can obtain bogus results.
3305  */
3306 static void
3307 dtrace_dif_subr(uint_t subr, uint_t rd, uint64_t *regs,
3308     dtrace_key_t *tupregs, int nargs,
3309     dtrace_mstate_t *mstate, dtrace_state_t *state)
3310 {
3311         volatile uint16_t *flags = &cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
3312         volatile uintptr_t *illval = &cpu_core[CPU->cpu_id].cpuc_dtrace_illval;
3313         dtrace_vstate_t *vstate = &state->dts_vstate;
3314 
3315         union {
3316                 mutex_impl_t mi;
3317                 uint64_t mx;
3318         } m;
3319 
3320         union {
3321                 krwlock_t ri;
3322                 uintptr_t rw;
3323         } r;
3324 
3325         switch (subr) {
3326         case DIF_SUBR_RAND:
3327                 regs[rd] = (dtrace_gethrtime() * 2416 + 374441) % 1771875;
3328                 break;
3329 
3330         case DIF_SUBR_MUTEX_OWNED:
3331                 if (!dtrace_canload(tupregs[0].dttk_value, sizeof (kmutex_t),
3332                     mstate, vstate)) {
3333                         regs[rd] = NULL;
3334                         break;
3335                 }
3336 
3337                 m.mx = dtrace_load64(tupregs[0].dttk_value);
3338                 if (MUTEX_TYPE_ADAPTIVE(&m.mi))
3339                         regs[rd] = MUTEX_OWNER(&m.mi) != MUTEX_NO_OWNER;
3340                 else
3341                         regs[rd] = LOCK_HELD(&m.mi.m_spin.m_spinlock);
3342                 break;
3343 
3344         case DIF_SUBR_MUTEX_OWNER:
3345                 if (!dtrace_canload(tupregs[0].dttk_value, sizeof (kmutex_t),
3346                     mstate, vstate)) {
3347                         regs[rd] = NULL;
3348                         break;
3349                 }
3350 
3351                 m.mx = dtrace_load64(tupregs[0].dttk_value);
3352                 if (MUTEX_TYPE_ADAPTIVE(&m.mi) &&
3353                     MUTEX_OWNER(&m.mi) != MUTEX_NO_OWNER)
3354                         regs[rd] = (uintptr_t)MUTEX_OWNER(&m.mi);
3355                 else
3356                         regs[rd] = 0;
3357                 break;
3358 
3359         case DIF_SUBR_MUTEX_TYPE_ADAPTIVE:
3360                 if (!dtrace_canload(tupregs[0].dttk_value, sizeof (kmutex_t),
3361                     mstate, vstate)) {
3362                         regs[rd] = NULL;
3363                         break;
3364                 }
3365 
3366                 m.mx = dtrace_load64(tupregs[0].dttk_value);
3367                 regs[rd] = MUTEX_TYPE_ADAPTIVE(&m.mi);
3368                 break;
3369 
3370         case DIF_SUBR_MUTEX_TYPE_SPIN:
3371                 if (!dtrace_canload(tupregs[0].dttk_value, sizeof (kmutex_t),
3372                     mstate, vstate)) {
3373                         regs[rd] = NULL;
3374                         break;
3375                 }
3376 
3377                 m.mx = dtrace_load64(tupregs[0].dttk_value);
3378                 regs[rd] = MUTEX_TYPE_SPIN(&m.mi);
3379                 break;
3380 
3381         case DIF_SUBR_RW_READ_HELD: {
3382                 uintptr_t tmp;
3383 
3384                 if (!dtrace_canload(tupregs[0].dttk_value, sizeof (uintptr_t),
3385                     mstate, vstate)) {
3386                         regs[rd] = NULL;
3387                         break;
3388                 }
3389 
3390                 r.rw = dtrace_loadptr(tupregs[0].dttk_value);
3391                 regs[rd] = _RW_READ_HELD(&r.ri, tmp);
3392                 break;
3393         }
3394 
3395         case DIF_SUBR_RW_WRITE_HELD:
3396                 if (!dtrace_canload(tupregs[0].dttk_value, sizeof (krwlock_t),
3397                     mstate, vstate)) {
3398                         regs[rd] = NULL;
3399                         break;
3400                 }
3401 
3402                 r.rw = dtrace_loadptr(tupregs[0].dttk_value);
3403                 regs[rd] = _RW_WRITE_HELD(&r.ri);
3404                 break;
3405 
3406         case DIF_SUBR_RW_ISWRITER:
3407                 if (!dtrace_canload(tupregs[0].dttk_value, sizeof (krwlock_t),
3408                     mstate, vstate)) {
3409                         regs[rd] = NULL;
3410                         break;
3411                 }
3412 
3413                 r.rw = dtrace_loadptr(tupregs[0].dttk_value);
3414                 regs[rd] = _RW_ISWRITER(&r.ri);
3415                 break;
3416 
3417         case DIF_SUBR_BCOPY: {
3418                 /*
3419                  * We need to be sure that the destination is in the scratch
3420                  * region -- no other region is allowed.
3421                  */
3422                 uintptr_t src = tupregs[0].dttk_value;
3423                 uintptr_t dest = tupregs[1].dttk_value;
3424                 size_t size = tupregs[2].dttk_value;
3425 
3426                 if (!dtrace_inscratch(dest, size, mstate)) {
3427                         *flags |= CPU_DTRACE_BADADDR;
3428                         *illval = regs[rd];
3429                         break;
3430                 }
3431 
3432                 if (!dtrace_canload(src, size, mstate, vstate)) {
3433                         regs[rd] = NULL;
3434                         break;
3435                 }
3436 
3437                 dtrace_bcopy((void *)src, (void *)dest, size);
3438                 break;
3439         }
3440 
3441         case DIF_SUBR_ALLOCA:
3442         case DIF_SUBR_COPYIN: {
3443                 uintptr_t dest = P2ROUNDUP(mstate->dtms_scratch_ptr, 8);
3444                 uint64_t size =
3445                     tupregs[subr == DIF_SUBR_ALLOCA ? 0 : 1].dttk_value;
3446                 size_t scratch_size = (dest - mstate->dtms_scratch_ptr) + size;
3447 
3448                 /*
3449                  * This action doesn't require any credential checks since
3450                  * probes will not activate in user contexts to which the
3451                  * enabling user does not have permissions.
3452                  */
3453 
3454                 /*
3455                  * Rounding up the user allocation size could have overflowed
3456                  * a large, bogus allocation (like -1ULL) to 0.
3457                  */
3458                 if (scratch_size < size ||
3459                     !DTRACE_INSCRATCH(mstate, scratch_size)) {
3460                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
3461                         regs[rd] = NULL;
3462                         break;
3463                 }
3464 
3465                 if (subr == DIF_SUBR_COPYIN) {
3466                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
3467                         dtrace_copyin(tupregs[0].dttk_value, dest, size, flags);
3468                         DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
3469                 }
3470 
3471                 mstate->dtms_scratch_ptr += scratch_size;
3472                 regs[rd] = dest;
3473                 break;
3474         }
3475 
3476         case DIF_SUBR_COPYINTO: {
3477                 uint64_t size = tupregs[1].dttk_value;
3478                 uintptr_t dest = tupregs[2].dttk_value;
3479 
3480                 /*
3481                  * This action doesn't require any credential checks since
3482                  * probes will not activate in user contexts to which the
3483                  * enabling user does not have permissions.
3484                  */
3485                 if (!dtrace_inscratch(dest, size, mstate)) {
3486                         *flags |= CPU_DTRACE_BADADDR;
3487                         *illval = regs[rd];
3488                         break;
3489                 }
3490 
3491                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
3492                 dtrace_copyin(tupregs[0].dttk_value, dest, size, flags);
3493                 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
3494                 break;
3495         }
3496 
3497         case DIF_SUBR_COPYINSTR: {
3498                 uintptr_t dest = mstate->dtms_scratch_ptr;
3499                 uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
3500 
3501                 if (nargs > 1 && tupregs[1].dttk_value < size)
3502                         size = tupregs[1].dttk_value + 1;
3503 
3504                 /*
3505                  * This action doesn't require any credential checks since
3506                  * probes will not activate in user contexts to which the
3507                  * enabling user does not have permissions.
3508                  */
3509                 if (!DTRACE_INSCRATCH(mstate, size)) {
3510                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
3511                         regs[rd] = NULL;
3512                         break;
3513                 }
3514 
3515                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
3516                 dtrace_copyinstr(tupregs[0].dttk_value, dest, size, flags);
3517                 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
3518 
3519                 ((char *)dest)[size - 1] = '\0';
3520                 mstate->dtms_scratch_ptr += size;
3521                 regs[rd] = dest;
3522                 break;
3523         }
3524 
3525         case DIF_SUBR_MSGSIZE:
3526         case DIF_SUBR_MSGDSIZE: {
3527                 uintptr_t baddr = tupregs[0].dttk_value, daddr;
3528                 uintptr_t wptr, rptr;
3529                 size_t count = 0;
3530                 int cont = 0;
3531 
3532                 while (baddr != NULL && !(*flags & CPU_DTRACE_FAULT)) {
3533 
3534                         if (!dtrace_canload(baddr, sizeof (mblk_t), mstate,
3535                             vstate)) {
3536                                 regs[rd] = NULL;
3537                                 break;
3538                         }
3539 
3540                         wptr = dtrace_loadptr(baddr +
3541                             offsetof(mblk_t, b_wptr));
3542 
3543                         rptr = dtrace_loadptr(baddr +
3544                             offsetof(mblk_t, b_rptr));
3545 
3546                         if (wptr < rptr) {
3547                                 *flags |= CPU_DTRACE_BADADDR;
3548                                 *illval = tupregs[0].dttk_value;
3549                                 break;
3550                         }
3551 
3552                         daddr = dtrace_loadptr(baddr +
3553                             offsetof(mblk_t, b_datap));
3554 
3555                         baddr = dtrace_loadptr(baddr +
3556                             offsetof(mblk_t, b_cont));
3557 
3558                         /*
3559                          * We want to prevent against denial-of-service here,
3560                          * so we're only going to search the list for
3561                          * dtrace_msgdsize_max mblks.
3562                          */
3563                         if (cont++ > dtrace_msgdsize_max) {
3564                                 *flags |= CPU_DTRACE_ILLOP;
3565                                 break;
3566                         }
3567 
3568                         if (subr == DIF_SUBR_MSGDSIZE) {
3569                                 if (dtrace_load8(daddr +
3570                                     offsetof(dblk_t, db_type)) != M_DATA)
3571                                         continue;
3572                         }
3573 
3574                         count += wptr - rptr;
3575                 }
3576 
3577                 if (!(*flags & CPU_DTRACE_FAULT))
3578                         regs[rd] = count;
3579 
3580                 break;
3581         }
3582 
3583         case DIF_SUBR_PROGENYOF: {
3584                 pid_t pid = tupregs[0].dttk_value;
3585                 proc_t *p;
3586                 int rval = 0;
3587 
3588                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
3589 
3590                 for (p = curthread->t_procp; p != NULL; p = p->p_parent) {
3591                         if (p->p_pidp->pid_id == pid) {
3592                                 rval = 1;
3593                                 break;
3594                         }
3595                 }
3596 
3597                 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
3598 
3599                 regs[rd] = rval;
3600                 break;
3601         }
3602 
3603         case DIF_SUBR_SPECULATION:
3604                 regs[rd] = dtrace_speculation(state);
3605                 break;
3606 
3607         case DIF_SUBR_COPYOUT: {
3608                 uintptr_t kaddr = tupregs[0].dttk_value;
3609                 uintptr_t uaddr = tupregs[1].dttk_value;
3610                 uint64_t size = tupregs[2].dttk_value;
3611 
3612                 if (!dtrace_destructive_disallow &&
3613                     dtrace_priv_proc_control(state, mstate) &&
3614                     !dtrace_istoxic(kaddr, size)) {
3615                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
3616                         dtrace_copyout(kaddr, uaddr, size, flags);
3617                         DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
3618                 }
3619                 break;
3620         }
3621 
3622         case DIF_SUBR_COPYOUTSTR: {
3623                 uintptr_t kaddr = tupregs[0].dttk_value;
3624                 uintptr_t uaddr = tupregs[1].dttk_value;
3625                 uint64_t size = tupregs[2].dttk_value;
3626 
3627                 if (!dtrace_destructive_disallow &&
3628                     dtrace_priv_proc_control(state, mstate) &&
3629                     !dtrace_istoxic(kaddr, size)) {
3630                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
3631                         dtrace_copyoutstr(kaddr, uaddr, size, flags);
3632                         DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
3633                 }
3634                 break;
3635         }
3636 
3637         case DIF_SUBR_STRLEN: {
3638                 size_t sz;
3639                 uintptr_t addr = (uintptr_t)tupregs[0].dttk_value;
3640                 sz = dtrace_strlen((char *)addr,
3641                     state->dts_options[DTRACEOPT_STRSIZE]);
3642 
3643                 if (!dtrace_canload(addr, sz + 1, mstate, vstate)) {
3644                         regs[rd] = NULL;
3645                         break;
3646                 }
3647 
3648                 regs[rd] = sz;
3649 
3650                 break;
3651         }
3652 
3653         case DIF_SUBR_STRCHR:
3654         case DIF_SUBR_STRRCHR: {
3655                 /*
3656                  * We're going to iterate over the string looking for the
3657                  * specified character.  We will iterate until we have reached
3658                  * the string length or we have found the character.  If this
3659                  * is DIF_SUBR_STRRCHR, we will look for the last occurrence
3660                  * of the specified character instead of the first.
3661                  */
3662                 uintptr_t saddr = tupregs[0].dttk_value;
3663                 uintptr_t addr = tupregs[0].dttk_value;
3664                 uintptr_t limit = addr + state->dts_options[DTRACEOPT_STRSIZE];
3665                 char c, target = (char)tupregs[1].dttk_value;
3666 
3667                 for (regs[rd] = NULL; addr < limit; addr++) {
3668                         if ((c = dtrace_load8(addr)) == target) {
3669                                 regs[rd] = addr;
3670 
3671                                 if (subr == DIF_SUBR_STRCHR)
3672                                         break;
3673                         }
3674 
3675                         if (c == '\0')
3676                                 break;
3677                 }
3678 
3679                 if (!dtrace_canload(saddr, addr - saddr, mstate, vstate)) {
3680                         regs[rd] = NULL;
3681                         break;
3682                 }
3683 
3684                 break;
3685         }
3686 
3687         case DIF_SUBR_STRSTR:
3688         case DIF_SUBR_INDEX:
3689         case DIF_SUBR_RINDEX: {
3690                 /*
3691                  * We're going to iterate over the string looking for the
3692                  * specified string.  We will iterate until we have reached
3693                  * the string length or we have found the string.  (Yes, this
3694                  * is done in the most naive way possible -- but considering
3695                  * that the string we're searching for is likely to be
3696                  * relatively short, the complexity of Rabin-Karp or similar
3697                  * hardly seems merited.)
3698                  */
3699                 char *addr = (char *)(uintptr_t)tupregs[0].dttk_value;
3700                 char *substr = (char *)(uintptr_t)tupregs[1].dttk_value;
3701                 uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
3702                 size_t len = dtrace_strlen(addr, size);
3703                 size_t sublen = dtrace_strlen(substr, size);
3704                 char *limit = addr + len, *orig = addr;
3705                 int notfound = subr == DIF_SUBR_STRSTR ? 0 : -1;
3706                 int inc = 1;
3707 
3708                 regs[rd] = notfound;
3709 
3710                 if (!dtrace_canload((uintptr_t)addr, len + 1, mstate, vstate)) {
3711                         regs[rd] = NULL;
3712                         break;
3713                 }
3714 
3715                 if (!dtrace_canload((uintptr_t)substr, sublen + 1, mstate,
3716                     vstate)) {
3717                         regs[rd] = NULL;
3718                         break;
3719                 }
3720 
3721                 /*
3722                  * strstr() and index()/rindex() have similar semantics if
3723                  * both strings are the empty string: strstr() returns a
3724                  * pointer to the (empty) string, and index() and rindex()
3725                  * both return index 0 (regardless of any position argument).
3726                  */
3727                 if (sublen == 0 && len == 0) {
3728                         if (subr == DIF_SUBR_STRSTR)
3729                                 regs[rd] = (uintptr_t)addr;
3730                         else
3731                                 regs[rd] = 0;
3732                         break;
3733                 }
3734 
3735                 if (subr != DIF_SUBR_STRSTR) {
3736                         if (subr == DIF_SUBR_RINDEX) {
3737                                 limit = orig - 1;
3738                                 addr += len;
3739                                 inc = -1;
3740                         }
3741 
3742                         /*
3743                          * Both index() and rindex() take an optional position
3744                          * argument that denotes the starting position.
3745                          */
3746                         if (nargs == 3) {
3747                                 int64_t pos = (int64_t)tupregs[2].dttk_value;
3748 
3749                                 /*
3750                                  * If the position argument to index() is
3751                                  * negative, Perl implicitly clamps it at
3752                                  * zero.  This semantic is a little surprising
3753                                  * given the special meaning of negative
3754                                  * positions to similar Perl functions like
3755                                  * substr(), but it appears to reflect a
3756                                  * notion that index() can start from a
3757                                  * negative index and increment its way up to
3758                                  * the string.  Given this notion, Perl's
3759                                  * rindex() is at least self-consistent in
3760                                  * that it implicitly clamps positions greater
3761                                  * than the string length to be the string
3762                                  * length.  Where Perl completely loses
3763                                  * coherence, however, is when the specified
3764                                  * substring is the empty string ("").  In
3765                                  * this case, even if the position is
3766                                  * negative, rindex() returns 0 -- and even if
3767                                  * the position is greater than the length,
3768                                  * index() returns the string length.  These
3769                                  * semantics violate the notion that index()
3770                                  * should never return a value less than the
3771                                  * specified position and that rindex() should
3772                                  * never return a value greater than the
3773                                  * specified position.  (One assumes that
3774                                  * these semantics are artifacts of Perl's
3775                                  * implementation and not the results of
3776                                  * deliberate design -- it beggars belief that
3777                                  * even Larry Wall could desire such oddness.)
3778                                  * While in the abstract one would wish for
3779                                  * consistent position semantics across
3780                                  * substr(), index() and rindex() -- or at the
3781                                  * very least self-consistent position
3782                                  * semantics for index() and rindex() -- we
3783                                  * instead opt to keep with the extant Perl
3784                                  * semantics, in all their broken glory.  (Do
3785                                  * we have more desire to maintain Perl's
3786                                  * semantics than Perl does?  Probably.)
3787                                  */
3788                                 if (subr == DIF_SUBR_RINDEX) {
3789                                         if (pos < 0) {
3790                                                 if (sublen == 0)
3791                                                         regs[rd] = 0;
3792                                                 break;
3793                                         }
3794 
3795                                         if (pos > len)
3796                                                 pos = len;
3797                                 } else {
3798                                         if (pos < 0)
3799                                                 pos = 0;
3800 
3801                                         if (pos >= len) {
3802                                                 if (sublen == 0)
3803                                                         regs[rd] = len;
3804                                                 break;
3805                                         }
3806                                 }
3807 
3808                                 addr = orig + pos;
3809                         }
3810                 }
3811 
3812                 for (regs[rd] = notfound; addr != limit; addr += inc) {
3813                         if (dtrace_strncmp(addr, substr, sublen) == 0) {
3814                                 if (subr != DIF_SUBR_STRSTR) {
3815                                         /*
3816                                          * As D index() and rindex() are
3817                                          * modeled on Perl (and not on awk),
3818                                          * we return a zero-based (and not a
3819                                          * one-based) index.  (For you Perl
3820                                          * weenies: no, we're not going to add
3821                                          * $[ -- and shouldn't you be at a con
3822                                          * or something?)
3823                                          */
3824                                         regs[rd] = (uintptr_t)(addr - orig);
3825                                         break;
3826                                 }
3827 
3828                                 ASSERT(subr == DIF_SUBR_STRSTR);
3829                                 regs[rd] = (uintptr_t)addr;
3830                                 break;
3831                         }
3832                 }
3833 
3834                 break;
3835         }
3836 
3837         case DIF_SUBR_STRTOK: {
3838                 uintptr_t addr = tupregs[0].dttk_value;
3839                 uintptr_t tokaddr = tupregs[1].dttk_value;
3840                 uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
3841                 uintptr_t limit, toklimit = tokaddr + size;
3842                 uint8_t c, tokmap[32];   /* 256 / 8 */
3843                 char *dest = (char *)mstate->dtms_scratch_ptr;
3844                 int i;
3845 
3846                 /*
3847                  * Check both the token buffer and (later) the input buffer,
3848                  * since both could be non-scratch addresses.
3849                  */
3850                 if (!dtrace_strcanload(tokaddr, size, mstate, vstate)) {
3851                         regs[rd] = NULL;
3852                         break;
3853                 }
3854 
3855                 if (!DTRACE_INSCRATCH(mstate, size)) {
3856                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
3857                         regs[rd] = NULL;
3858                         break;
3859                 }
3860 
3861                 if (addr == NULL) {
3862                         /*
3863                          * If the address specified is NULL, we use our saved
3864                          * strtok pointer from the mstate.  Note that this
3865                          * means that the saved strtok pointer is _only_
3866                          * valid within multiple enablings of the same probe --
3867                          * it behaves like an implicit clause-local variable.
3868                          */
3869                         addr = mstate->dtms_strtok;
3870                 } else {
3871                         /*
3872                          * If the user-specified address is non-NULL we must
3873                          * access check it.  This is the only time we have
3874                          * a chance to do so, since this address may reside
3875                          * in the string table of this clause-- future calls
3876                          * (when we fetch addr from mstate->dtms_strtok)
3877                          * would fail this access check.
3878                          */
3879                         if (!dtrace_strcanload(addr, size, mstate, vstate)) {
3880                                 regs[rd] = NULL;
3881                                 break;
3882                         }
3883                 }
3884 
3885                 /*
3886                  * First, zero the token map, and then process the token
3887                  * string -- setting a bit in the map for every character
3888                  * found in the token string.
3889                  */
3890                 for (i = 0; i < sizeof (tokmap); i++)
3891                         tokmap[i] = 0;
3892 
3893                 for (; tokaddr < toklimit; tokaddr++) {
3894                         if ((c = dtrace_load8(tokaddr)) == '\0')
3895                                 break;
3896 
3897                         ASSERT((c >> 3) < sizeof (tokmap));
3898                         tokmap[c >> 3] |= (1 << (c & 0x7));
3899                 }
3900 
3901                 for (limit = addr + size; addr < limit; addr++) {
3902                         /*
3903                          * We're looking for a character that is _not_ contained
3904                          * in the token string.
3905                          */
3906                         if ((c = dtrace_load8(addr)) == '\0')
3907                                 break;
3908 
3909                         if (!(tokmap[c >> 3] & (1 << (c & 0x7))))
3910                                 break;
3911                 }
3912 
3913                 if (c == '\0') {
3914                         /*
3915                          * We reached the end of the string without finding
3916                          * any character that was not in the token string.
3917                          * We return NULL in this case, and we set the saved
3918                          * address to NULL as well.
3919                          */
3920                         regs[rd] = NULL;
3921                         mstate->dtms_strtok = NULL;
3922                         break;
3923                 }
3924 
3925                 /*
3926                  * From here on, we're copying into the destination string.
3927                  */
3928                 for (i = 0; addr < limit && i < size - 1; addr++) {
3929                         if ((c = dtrace_load8(addr)) == '\0')
3930                                 break;
3931 
3932                         if (tokmap[c >> 3] & (1 << (c & 0x7)))
3933                                 break;
3934 
3935                         ASSERT(i < size);
3936                         dest[i++] = c;
3937                 }
3938 
3939                 ASSERT(i < size);
3940                 dest[i] = '\0';
3941                 regs[rd] = (uintptr_t)dest;
3942                 mstate->dtms_scratch_ptr += size;
3943                 mstate->dtms_strtok = addr;
3944                 break;
3945         }
3946 
3947         case DIF_SUBR_SUBSTR: {
3948                 uintptr_t s = tupregs[0].dttk_value;
3949                 uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
3950                 char *d = (char *)mstate->dtms_scratch_ptr;
3951                 int64_t index = (int64_t)tupregs[1].dttk_value;
3952                 int64_t remaining = (int64_t)tupregs[2].dttk_value;
3953                 size_t len = dtrace_strlen((char *)s, size);
3954                 int64_t i;
3955 
3956                 if (!dtrace_canload(s, len + 1, mstate, vstate)) {
3957                         regs[rd] = NULL;
3958                         break;
3959                 }
3960 
3961                 if (!DTRACE_INSCRATCH(mstate, size)) {
3962                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
3963                         regs[rd] = NULL;
3964                         break;
3965                 }
3966 
3967                 if (nargs <= 2)
3968                         remaining = (int64_t)size;
3969 
3970                 if (index < 0) {
3971                         index += len;
3972 
3973                         if (index < 0 && index + remaining > 0) {
3974                                 remaining += index;
3975                                 index = 0;
3976                         }
3977                 }
3978 
3979                 if (index >= len || index < 0) {
3980                         remaining = 0;
3981                 } else if (remaining < 0) {
3982                         remaining += len - index;
3983                 } else if (index + remaining > size) {
3984                         remaining = size - index;
3985                 }
3986 
3987                 for (i = 0; i < remaining; i++) {
3988                         if ((d[i] = dtrace_load8(s + index + i)) == '\0')
3989                                 break;
3990                 }
3991 
3992                 d[i] = '\0';
3993 
3994                 mstate->dtms_scratch_ptr += size;
3995                 regs[rd] = (uintptr_t)d;
3996                 break;
3997         }
3998 
3999         case DIF_SUBR_TOUPPER:
4000         case DIF_SUBR_TOLOWER: {
4001                 uintptr_t s = tupregs[0].dttk_value;
4002                 uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
4003                 char *dest = (char *)mstate->dtms_scratch_ptr, c;
4004                 size_t len = dtrace_strlen((char *)s, size);
4005                 char lower, upper, convert;
4006                 int64_t i;
4007 
4008                 if (subr == DIF_SUBR_TOUPPER) {
4009                         lower = 'a';
4010                         upper = 'z';
4011                         convert = 'A';
4012                 } else {
4013                         lower = 'A';
4014                         upper = 'Z';
4015                         convert = 'a';
4016                 }
4017 
4018                 if (!dtrace_canload(s, len + 1, mstate, vstate)) {
4019                         regs[rd] = NULL;
4020                         break;
4021                 }
4022 
4023                 if (!DTRACE_INSCRATCH(mstate, size)) {
4024                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4025                         regs[rd] = NULL;
4026                         break;
4027                 }
4028 
4029                 for (i = 0; i < size - 1; i++) {
4030                         if ((c = dtrace_load8(s + i)) == '\0')
4031                                 break;
4032 
4033                         if (c >= lower && c <= upper)
4034                                 c = convert + (c - lower);
4035 
4036                         dest[i] = c;
4037                 }
4038 
4039                 ASSERT(i < size);
4040                 dest[i] = '\0';
4041                 regs[rd] = (uintptr_t)dest;
4042                 mstate->dtms_scratch_ptr += size;
4043                 break;
4044         }
4045 
4046 case DIF_SUBR_GETMAJOR:
4047 #ifdef _LP64
4048                 regs[rd] = (tupregs[0].dttk_value >> NBITSMINOR64) & MAXMAJ64;
4049 #else
4050                 regs[rd] = (tupregs[0].dttk_value >> NBITSMINOR) & MAXMAJ;
4051 #endif
4052                 break;
4053 
4054         case DIF_SUBR_GETMINOR:
4055 #ifdef _LP64
4056                 regs[rd] = tupregs[0].dttk_value & MAXMIN64;
4057 #else
4058                 regs[rd] = tupregs[0].dttk_value & MAXMIN;
4059 #endif
4060                 break;
4061 
4062         case DIF_SUBR_DDI_PATHNAME: {
4063                 /*
4064                  * This one is a galactic mess.  We are going to roughly
4065                  * emulate ddi_pathname(), but it's made more complicated
4066                  * by the fact that we (a) want to include the minor name and
4067                  * (b) must proceed iteratively instead of recursively.
4068                  */
4069                 uintptr_t dest = mstate->dtms_scratch_ptr;
4070                 uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
4071                 char *start = (char *)dest, *end = start + size - 1;
4072                 uintptr_t daddr = tupregs[0].dttk_value;
4073                 int64_t minor = (int64_t)tupregs[1].dttk_value;
4074                 char *s;
4075                 int i, len, depth = 0;
4076 
4077                 /*
4078                  * Due to all the pointer jumping we do and context we must
4079                  * rely upon, we just mandate that the user must have kernel
4080                  * read privileges to use this routine.
4081                  */
4082                 if ((mstate->dtms_access & DTRACE_ACCESS_KERNEL) == 0) {
4083                         *flags |= CPU_DTRACE_KPRIV;
4084                         *illval = daddr;
4085                         regs[rd] = NULL;
4086                 }
4087 
4088                 if (!DTRACE_INSCRATCH(mstate, size)) {
4089                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4090                         regs[rd] = NULL;
4091                         break;
4092                 }
4093 
4094                 *end = '\0';
4095 
4096                 /*
4097                  * We want to have a name for the minor.  In order to do this,
4098                  * we need to walk the minor list from the devinfo.  We want
4099                  * to be sure that we don't infinitely walk a circular list,
4100                  * so we check for circularity by sending a scout pointer
4101                  * ahead two elements for every element that we iterate over;
4102                  * if the list is circular, these will ultimately point to the
4103                  * same element.  You may recognize this little trick as the
4104                  * answer to a stupid interview question -- one that always
4105                  * seems to be asked by those who had to have it laboriously
4106                  * explained to them, and who can't even concisely describe
4107                  * the conditions under which one would be forced to resort to
4108                  * this technique.  Needless to say, those conditions are
4109                  * found here -- and probably only here.  Is this the only use
4110                  * of this infamous trick in shipping, production code?  If it
4111                  * isn't, it probably should be...
4112                  */
4113                 if (minor != -1) {
4114                         uintptr_t maddr = dtrace_loadptr(daddr +
4115                             offsetof(struct dev_info, devi_minor));
4116 
4117                         uintptr_t next = offsetof(struct ddi_minor_data, next);
4118                         uintptr_t name = offsetof(struct ddi_minor_data,
4119                             d_minor) + offsetof(struct ddi_minor, name);
4120                         uintptr_t dev = offsetof(struct ddi_minor_data,
4121                             d_minor) + offsetof(struct ddi_minor, dev);
4122                         uintptr_t scout;
4123 
4124                         if (maddr != NULL)
4125                                 scout = dtrace_loadptr(maddr + next);
4126 
4127                         while (maddr != NULL && !(*flags & CPU_DTRACE_FAULT)) {
4128                                 uint64_t m;
4129 #ifdef _LP64
4130                                 m = dtrace_load64(maddr + dev) & MAXMIN64;
4131 #else
4132                                 m = dtrace_load32(maddr + dev) & MAXMIN;
4133 #endif
4134                                 if (m != minor) {
4135                                         maddr = dtrace_loadptr(maddr + next);
4136 
4137                                         if (scout == NULL)
4138                                                 continue;
4139 
4140                                         scout = dtrace_loadptr(scout + next);
4141 
4142                                         if (scout == NULL)
4143                                                 continue;
4144 
4145                                         scout = dtrace_loadptr(scout + next);
4146 
4147                                         if (scout == NULL)
4148                                                 continue;
4149 
4150                                         if (scout == maddr) {
4151                                                 *flags |= CPU_DTRACE_ILLOP;
4152                                                 break;
4153                                         }
4154 
4155                                         continue;
4156                                 }
4157 
4158                                 /*
4159                                  * We have the minor data.  Now we need to
4160                                  * copy the minor's name into the end of the
4161                                  * pathname.
4162                                  */
4163                                 s = (char *)dtrace_loadptr(maddr + name);
4164                                 len = dtrace_strlen(s, size);
4165 
4166                                 if (*flags & CPU_DTRACE_FAULT)
4167                                         break;
4168 
4169                                 if (len != 0) {
4170                                         if ((end -= (len + 1)) < start)
4171                                                 break;
4172 
4173                                         *end = ':';
4174                                 }
4175 
4176                                 for (i = 1; i <= len; i++)
4177                                         end[i] = dtrace_load8((uintptr_t)s++);
4178                                 break;
4179                         }
4180                 }
4181 
4182                 while (daddr != NULL && !(*flags & CPU_DTRACE_FAULT)) {
4183                         ddi_node_state_t devi_state;
4184 
4185                         devi_state = dtrace_load32(daddr +
4186                             offsetof(struct dev_info, devi_node_state));
4187 
4188                         if (*flags & CPU_DTRACE_FAULT)
4189                                 break;
4190 
4191                         if (devi_state >= DS_INITIALIZED) {
4192                                 s = (char *)dtrace_loadptr(daddr +
4193                                     offsetof(struct dev_info, devi_addr));
4194                                 len = dtrace_strlen(s, size);
4195 
4196                                 if (*flags & CPU_DTRACE_FAULT)
4197                                         break;
4198 
4199                                 if (len != 0) {
4200                                         if ((end -= (len + 1)) < start)
4201                                                 break;
4202 
4203                                         *end = '@';
4204                                 }
4205 
4206                                 for (i = 1; i <= len; i++)
4207                                         end[i] = dtrace_load8((uintptr_t)s++);
4208                         }
4209 
4210                         /*
4211                          * Now for the node name...
4212                          */
4213                         s = (char *)dtrace_loadptr(daddr +
4214                             offsetof(struct dev_info, devi_node_name));
4215 
4216                         daddr = dtrace_loadptr(daddr +
4217                             offsetof(struct dev_info, devi_parent));
4218 
4219                         /*
4220                          * If our parent is NULL (that is, if we're the root
4221                          * node), we're going to use the special path
4222                          * "devices".
4223                          */
4224                         if (daddr == NULL)
4225                                 s = "devices";
4226 
4227                         len = dtrace_strlen(s, size);
4228                         if (*flags & CPU_DTRACE_FAULT)
4229                                 break;
4230 
4231                         if ((end -= (len + 1)) < start)
4232                                 break;
4233 
4234                         for (i = 1; i <= len; i++)
4235                                 end[i] = dtrace_load8((uintptr_t)s++);
4236                         *end = '/';
4237 
4238                         if (depth++ > dtrace_devdepth_max) {
4239                                 *flags |= CPU_DTRACE_ILLOP;
4240                                 break;
4241                         }
4242                 }
4243 
4244                 if (end < start)
4245                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4246 
4247                 if (daddr == NULL) {
4248                         regs[rd] = (uintptr_t)end;
4249                         mstate->dtms_scratch_ptr += size;
4250                 }
4251 
4252                 break;
4253         }
4254 
4255         case DIF_SUBR_STRJOIN: {
4256                 char *d = (char *)mstate->dtms_scratch_ptr;
4257                 uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
4258                 uintptr_t s1 = tupregs[0].dttk_value;
4259                 uintptr_t s2 = tupregs[1].dttk_value;
4260                 int i = 0;
4261 
4262                 if (!dtrace_strcanload(s1, size, mstate, vstate) ||
4263                     !dtrace_strcanload(s2, size, mstate, vstate)) {
4264                         regs[rd] = NULL;
4265                         break;
4266                 }
4267 
4268                 if (!DTRACE_INSCRATCH(mstate, size)) {
4269                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4270                         regs[rd] = NULL;
4271                         break;
4272                 }
4273 
4274                 for (;;) {
4275                         if (i >= size) {
4276                                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4277                                 regs[rd] = NULL;
4278                                 break;
4279                         }
4280 
4281                         if ((d[i++] = dtrace_load8(s1++)) == '\0') {
4282                                 i--;
4283                                 break;
4284                         }
4285                 }
4286 
4287                 for (;;) {
4288                         if (i >= size) {
4289                                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4290                                 regs[rd] = NULL;
4291                                 break;
4292                         }
4293 
4294                         if ((d[i++] = dtrace_load8(s2++)) == '\0')
4295                                 break;
4296                 }
4297 
4298                 if (i < size) {
4299                         mstate->dtms_scratch_ptr += i;
4300                         regs[rd] = (uintptr_t)d;
4301                 }
4302 
4303                 break;
4304         }
4305 
4306         case DIF_SUBR_LLTOSTR: {
4307                 int64_t i = (int64_t)tupregs[0].dttk_value;
4308                 uint64_t val, digit;
4309                 uint64_t size = 65;     /* enough room for 2^64 in binary */
4310                 char *end = (char *)mstate->dtms_scratch_ptr + size - 1;
4311                 int base = 10;
4312 
4313                 if (nargs > 1) {
4314                         if ((base = tupregs[1].dttk_value) <= 1 ||
4315                             base > ('z' - 'a' + 1) + ('9' - '0' + 1)) {
4316                                 *flags |= CPU_DTRACE_ILLOP;
4317                                 break;
4318                         }
4319                 }
4320 
4321                 val = (base == 10 && i < 0) ? i * -1 : i;
4322 
4323                 if (!DTRACE_INSCRATCH(mstate, size)) {
4324                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4325                         regs[rd] = NULL;
4326                         break;
4327                 }
4328 
4329                 for (*end-- = '\0'; val; val /= base) {
4330                         if ((digit = val % base) <= '9' - '0') {
4331                                 *end-- = '0' + digit;
4332                         } else {
4333                                 *end-- = 'a' + (digit - ('9' - '0') - 1);
4334                         }
4335                 }
4336 
4337                 if (i == 0 && base == 16)
4338                         *end-- = '0';
4339 
4340                 if (base == 16)
4341                         *end-- = 'x';
4342 
4343                 if (i == 0 || base == 8 || base == 16)
4344                         *end-- = '0';
4345 
4346                 if (i < 0 && base == 10)
4347                         *end-- = '-';
4348 
4349                 regs[rd] = (uintptr_t)end + 1;
4350                 mstate->dtms_scratch_ptr += size;
4351                 break;
4352         }
4353 
4354         case DIF_SUBR_HTONS:
4355         case DIF_SUBR_NTOHS:
4356 #ifdef _BIG_ENDIAN
4357                 regs[rd] = (uint16_t)tupregs[0].dttk_value;
4358 #else
4359                 regs[rd] = DT_BSWAP_16((uint16_t)tupregs[0].dttk_value);
4360 #endif
4361                 break;
4362 
4363 
4364         case DIF_SUBR_HTONL:
4365         case DIF_SUBR_NTOHL:
4366 #ifdef _BIG_ENDIAN
4367                 regs[rd] = (uint32_t)tupregs[0].dttk_value;
4368 #else
4369                 regs[rd] = DT_BSWAP_32((uint32_t)tupregs[0].dttk_value);
4370 #endif
4371                 break;
4372 
4373 
4374         case DIF_SUBR_HTONLL:
4375         case DIF_SUBR_NTOHLL:
4376 #ifdef _BIG_ENDIAN
4377                 regs[rd] = (uint64_t)tupregs[0].dttk_value;
4378 #else
4379                 regs[rd] = DT_BSWAP_64((uint64_t)tupregs[0].dttk_value);
4380 #endif
4381                 break;
4382 
4383 
4384         case DIF_SUBR_DIRNAME:
4385         case DIF_SUBR_BASENAME: {
4386                 char *dest = (char *)mstate->dtms_scratch_ptr;
4387                 uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
4388                 uintptr_t src = tupregs[0].dttk_value;
4389                 int i, j, len = dtrace_strlen((char *)src, size);
4390                 int lastbase = -1, firstbase = -1, lastdir = -1;
4391                 int start, end;
4392 
4393                 if (!dtrace_canload(src, len + 1, mstate, vstate)) {
4394                         regs[rd] = NULL;
4395                         break;
4396                 }
4397 
4398                 if (!DTRACE_INSCRATCH(mstate, size)) {
4399                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4400                         regs[rd] = NULL;
4401                         break;
4402                 }
4403 
4404                 /*
4405                  * The basename and dirname for a zero-length string is
4406                  * defined to be "."
4407                  */
4408                 if (len == 0) {
4409                         len = 1;
4410                         src = (uintptr_t)".";
4411                 }
4412 
4413                 /*
4414                  * Start from the back of the string, moving back toward the
4415                  * front until we see a character that isn't a slash.  That
4416                  * character is the last character in the basename.
4417                  */
4418                 for (i = len - 1; i >= 0; i--) {
4419                         if (dtrace_load8(src + i) != '/')
4420                                 break;
4421                 }
4422 
4423                 if (i >= 0)
4424                         lastbase = i;
4425 
4426                 /*
4427                  * Starting from the last character in the basename, move
4428                  * towards the front until we find a slash.  The character
4429                  * that we processed immediately before that is the first
4430                  * character in the basename.
4431                  */
4432                 for (; i >= 0; i--) {
4433                         if (dtrace_load8(src + i) == '/')
4434                                 break;
4435                 }
4436 
4437                 if (i >= 0)
4438                         firstbase = i + 1;
4439 
4440                 /*
4441                  * Now keep going until we find a non-slash character.  That
4442                  * character is the last character in the dirname.
4443                  */
4444                 for (; i >= 0; i--) {
4445                         if (dtrace_load8(src + i) != '/')
4446                                 break;
4447                 }
4448 
4449                 if (i >= 0)
4450                         lastdir = i;
4451 
4452                 ASSERT(!(lastbase == -1 && firstbase != -1));
4453                 ASSERT(!(firstbase == -1 && lastdir != -1));
4454 
4455                 if (lastbase == -1) {
4456                         /*
4457                          * We didn't find a non-slash character.  We know that
4458                          * the length is non-zero, so the whole string must be
4459                          * slashes.  In either the dirname or the basename
4460                          * case, we return '/'.
4461                          */
4462                         ASSERT(firstbase == -1);
4463                         firstbase = lastbase = lastdir = 0;
4464                 }
4465 
4466                 if (firstbase == -1) {
4467                         /*
4468                          * The entire string consists only of a basename
4469                          * component.  If we're looking for dirname, we need
4470                          * to change our string to be just "."; if we're
4471                          * looking for a basename, we'll just set the first
4472                          * character of the basename to be 0.
4473                          */
4474                         if (subr == DIF_SUBR_DIRNAME) {
4475                                 ASSERT(lastdir == -1);
4476                                 src = (uintptr_t)".";
4477                                 lastdir = 0;
4478                         } else {
4479                                 firstbase = 0;
4480                         }
4481                 }
4482 
4483                 if (subr == DIF_SUBR_DIRNAME) {
4484                         if (lastdir == -1) {
4485                                 /*
4486                                  * We know that we have a slash in the name --
4487                                  * or lastdir would be set to 0, above.  And
4488                                  * because lastdir is -1, we know that this
4489                                  * slash must be the first character.  (That
4490                                  * is, the full string must be of the form
4491                                  * "/basename".)  In this case, the last
4492                                  * character of the directory name is 0.
4493                                  */
4494                                 lastdir = 0;
4495                         }
4496 
4497                         start = 0;
4498                         end = lastdir;
4499                 } else {
4500                         ASSERT(subr == DIF_SUBR_BASENAME);
4501                         ASSERT(firstbase != -1 && lastbase != -1);
4502                         start = firstbase;
4503                         end = lastbase;
4504                 }
4505 
4506                 for (i = start, j = 0; i <= end && j < size - 1; i++, j++)
4507                         dest[j] = dtrace_load8(src + i);
4508 
4509                 dest[j] = '\0';
4510                 regs[rd] = (uintptr_t)dest;
4511                 mstate->dtms_scratch_ptr += size;
4512                 break;
4513         }
4514 
4515         case DIF_SUBR_GETF: {
4516                 uintptr_t fd = tupregs[0].dttk_value;
4517                 uf_info_t *finfo = &curthread->t_procp->p_user.u_finfo;
4518                 file_t *fp;
4519 
4520                 if (!dtrace_priv_proc(state, mstate)) {
4521                         regs[rd] = NULL;
4522                         break;
4523                 }
4524 
4525                 /*
4526                  * This is safe because fi_nfiles only increases, and the
4527                  * fi_list array is not freed when the array size doubles.
4528                  * (See the comment in flist_grow() for details on the
4529                  * management of the u_finfo structure.)
4530                  */
4531                 fp = fd < finfo->fi_nfiles ? finfo->fi_list[fd].uf_file : NULL;
4532 
4533                 mstate->dtms_getf = fp;
4534                 regs[rd] = (uintptr_t)fp;
4535                 break;
4536         }
4537 
4538         case DIF_SUBR_CLEANPATH: {
4539                 char *dest = (char *)mstate->dtms_scratch_ptr, c;
4540                 uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
4541                 uintptr_t src = tupregs[0].dttk_value;
4542                 int i = 0, j = 0;
4543                 zone_t *z;
4544 
4545                 if (!dtrace_strcanload(src, size, mstate, vstate)) {
4546                         regs[rd] = NULL;
4547                         break;
4548                 }
4549 
4550                 if (!DTRACE_INSCRATCH(mstate, size)) {
4551                         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4552                         regs[rd] = NULL;
4553                         break;
4554                 }
4555 
4556                 /*
4557                  * Move forward, loading each character.
4558                  */
4559                 do {
4560                         c = dtrace_load8(src + i++);
4561 next:
4562                         if (j + 5 >= size)   /* 5 = strlen("/..c\0") */
4563                                 break;
4564 
4565                         if (c != '/') {
4566                                 dest[j++] = c;
4567                                 continue;
4568                         }
4569 
4570                         c = dtrace_load8(src + i++);
4571 
4572                         if (c == '/') {
4573                                 /*
4574                                  * We have two slashes -- we can just advance
4575                                  * to the next character.
4576                                  */
4577                                 goto next;
4578                         }
4579 
4580                         if (c != '.') {
4581                                 /*
4582                                  * This is not "." and it's not ".." -- we can
4583                                  * just store the "/" and this character and
4584                                  * drive on.
4585                                  */
4586                                 dest[j++] = '/';
4587                                 dest[j++] = c;
4588                                 continue;
4589                         }
4590 
4591                         c = dtrace_load8(src + i++);
4592 
4593                         if (c == '/') {
4594                                 /*
4595                                  * This is a "/./" component.  We're not going
4596                                  * to store anything in the destination buffer;
4597                                  * we're just going to go to the next component.
4598                                  */
4599                                 goto next;
4600                         }
4601 
4602                         if (c != '.') {
4603                                 /*
4604                                  * This is not ".." -- we can just store the
4605                                  * "/." and this character and continue
4606                                  * processing.
4607                                  */
4608                                 dest[j++] = '/';
4609                                 dest[j++] = '.';
4610                                 dest[j++] = c;
4611                                 continue;
4612                         }
4613 
4614                         c = dtrace_load8(src + i++);
4615 
4616                         if (c != '/' && c != '\0') {
4617                                 /*
4618                                  * This is not ".." -- it's "..[mumble]".
4619                                  * We'll store the "/.." and this character
4620                                  * and continue processing.
4621                                  */
4622                                 dest[j++] = '/';
4623                                 dest[j++] = '.';
4624                                 dest[j++] = '.';
4625                                 dest[j++] = c;
4626                                 continue;
4627                         }
4628 
4629                         /*
4630                          * This is "/../" or "/..\0".  We need to back up
4631                          * our destination pointer until we find a "/".
4632                          */
4633                         i--;
4634                         while (j != 0 && dest[--j] != '/')
4635                                 continue;
4636 
4637                         if (c == '\0')
4638                                 dest[++j] = '/';
4639                 } while (c != '\0');
4640 
4641                 dest[j] = '\0';
4642 
4643                 if (mstate->dtms_getf != NULL &&
4644                     !(mstate->dtms_access & DTRACE_ACCESS_KERNEL) &&
4645                     (z = state->dts_cred.dcr_cred->cr_zone) != kcred->cr_zone) {
4646                         /*
4647                          * If we've done a getf() as a part of this ECB and we
4648                          * don't have kernel access (and we're not in the global
4649                          * zone), check if the path we cleaned up begins with
4650                          * the zone's root path, and trim it off if so.  Note
4651                          * that this is an output cleanliness issue, not a
4652                          * security issue: knowing one's zone root path does
4653                          * not enable privilege escalation.
4654                          */
4655                         if (strstr(dest, z->zone_rootpath) == dest)
4656                                 dest += strlen(z->zone_rootpath) - 1;
4657                 }
4658 
4659                 regs[rd] = (uintptr_t)dest;
4660                 mstate->dtms_scratch_ptr += size;
4661                 break;
4662         }
4663 
4664         case DIF_SUBR_INET_NTOA:
4665         case DIF_SUBR_INET_NTOA6:
4666         case DIF_SUBR_INET_NTOP: {
4667                 size_t size;
4668                 int af, argi, i;
4669                 char *base, *end;
4670 
4671                 if (subr == DIF_SUBR_INET_NTOP) {
4672                         af = (int)tupregs[0].dttk_value;
4673                         argi = 1;
4674                 } else {
4675                         af = subr == DIF_SUBR_INET_NTOA ? AF_INET: AF_INET6;
4676                         argi = 0;
4677                 }
4678 
4679                 if (af == AF_INET) {
4680                         ipaddr_t ip4;
4681                         uint8_t *ptr8, val;
4682 
4683                         /*
4684                          * Safely load the IPv4 address.
4685                          */
4686                         ip4 = dtrace_load32(tupregs[argi].dttk_value);
4687 
4688                         /*
4689                          * Check an IPv4 string will fit in scratch.
4690                          */
4691                         size = INET_ADDRSTRLEN;
4692                         if (!DTRACE_INSCRATCH(mstate, size)) {
4693                                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4694                                 regs[rd] = NULL;
4695                                 break;
4696                         }
4697                         base = (char *)mstate->dtms_scratch_ptr;
4698                         end = (char *)mstate->dtms_scratch_ptr + size - 1;
4699 
4700                         /*
4701                          * Stringify as a dotted decimal quad.
4702                          */
4703                         *end-- = '\0';
4704                         ptr8 = (uint8_t *)&ip4;
4705                         for (i = 3; i >= 0; i--) {
4706                                 val = ptr8[i];
4707 
4708                                 if (val == 0) {
4709                                         *end-- = '0';
4710                                 } else {
4711                                         for (; val; val /= 10) {
4712                                                 *end-- = '0' + (val % 10);
4713                                         }
4714                                 }
4715 
4716                                 if (i > 0)
4717                                         *end-- = '.';
4718                         }
4719                         ASSERT(end + 1 >= base);
4720 
4721                 } else if (af == AF_INET6) {
4722                         struct in6_addr ip6;
4723                         int firstzero, tryzero, numzero, v6end;
4724                         uint16_t val;
4725                         const char digits[] = "0123456789abcdef";
4726 
4727                         /*
4728                          * Stringify using RFC 1884 convention 2 - 16 bit
4729                          * hexadecimal values with a zero-run compression.
4730                          * Lower case hexadecimal digits are used.
4731                          *      eg, fe80::214:4fff:fe0b:76c8.
4732                          * The IPv4 embedded form is returned for inet_ntop,
4733                          * just the IPv4 string is returned for inet_ntoa6.
4734                          */
4735 
4736                         /*
4737                          * Safely load the IPv6 address.
4738                          */
4739                         dtrace_bcopy(
4740                             (void *)(uintptr_t)tupregs[argi].dttk_value,
4741                             (void *)(uintptr_t)&ip6, sizeof (struct in6_addr));
4742 
4743                         /*
4744                          * Check an IPv6 string will fit in scratch.
4745                          */
4746                         size = INET6_ADDRSTRLEN;
4747                         if (!DTRACE_INSCRATCH(mstate, size)) {
4748                                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4749                                 regs[rd] = NULL;
4750                                 break;
4751                         }
4752                         base = (char *)mstate->dtms_scratch_ptr;
4753                         end = (char *)mstate->dtms_scratch_ptr + size - 1;
4754                         *end-- = '\0';
4755 
4756                         /*
4757                          * Find the longest run of 16 bit zero values
4758                          * for the single allowed zero compression - "::".
4759                          */
4760                         firstzero = -1;
4761                         tryzero = -1;
4762                         numzero = 1;
4763                         for (i = 0; i < sizeof (struct in6_addr); i++) {
4764                                 if (ip6._S6_un._S6_u8[i] == 0 &&
4765                                     tryzero == -1 && i % 2 == 0) {
4766                                         tryzero = i;
4767                                         continue;
4768                                 }
4769 
4770                                 if (tryzero != -1 &&
4771                                     (ip6._S6_un._S6_u8[i] != 0 ||
4772                                     i == sizeof (struct in6_addr) - 1)) {
4773 
4774                                         if (i - tryzero <= numzero) {
4775                                                 tryzero = -1;
4776                                                 continue;
4777                                         }
4778 
4779                                         firstzero = tryzero;
4780                                         numzero = i - i % 2 - tryzero;
4781                                         tryzero = -1;
4782 
4783                                         if (ip6._S6_un._S6_u8[i] == 0 &&
4784                                             i == sizeof (struct in6_addr) - 1)
4785                                                 numzero += 2;
4786                                 }
4787                         }
4788                         ASSERT(firstzero + numzero <= sizeof (struct in6_addr));
4789 
4790                         /*
4791                          * Check for an IPv4 embedded address.
4792                          */
4793                         v6end = sizeof (struct in6_addr) - 2;
4794                         if (IN6_IS_ADDR_V4MAPPED(&ip6) ||
4795                             IN6_IS_ADDR_V4COMPAT(&ip6)) {
4796                                 for (i = sizeof (struct in6_addr) - 1;
4797                                     i >= DTRACE_V4MAPPED_OFFSET; i--) {
4798                                         ASSERT(end >= base);
4799 
4800                                         val = ip6._S6_un._S6_u8[i];
4801 
4802                                         if (val == 0) {
4803                                                 *end-- = '0';
4804                                         } else {
4805                                                 for (; val; val /= 10) {
4806                                                         *end-- = '0' + val % 10;
4807                                                 }
4808                                         }
4809 
4810                                         if (i > DTRACE_V4MAPPED_OFFSET)
4811                                                 *end-- = '.';
4812                                 }
4813 
4814                                 if (subr == DIF_SUBR_INET_NTOA6)
4815                                         goto inetout;
4816 
4817                                 /*
4818                                  * Set v6end to skip the IPv4 address that
4819                                  * we have already stringified.
4820                                  */
4821                                 v6end = 10;
4822                         }
4823 
4824                         /*
4825                          * Build the IPv6 string by working through the
4826                          * address in reverse.
4827                          */
4828                         for (i = v6end; i >= 0; i -= 2) {
4829                                 ASSERT(end >= base);
4830 
4831                                 if (i == firstzero + numzero - 2) {
4832                                         *end-- = ':';
4833                                         *end-- = ':';
4834                                         i -= numzero - 2;
4835                                         continue;
4836                                 }
4837 
4838                                 if (i < 14 && i != firstzero - 2)
4839                                         *end-- = ':';
4840 
4841                                 val = (ip6._S6_un._S6_u8[i] << 8) +
4842                                     ip6._S6_un._S6_u8[i + 1];
4843 
4844                                 if (val == 0) {
4845                                         *end-- = '0';
4846                                 } else {
4847                                         for (; val; val /= 16) {
4848                                                 *end-- = digits[val % 16];
4849                                         }
4850                                 }
4851                         }
4852                         ASSERT(end + 1 >= base);
4853 
4854                 } else {
4855                         /*
4856                          * The user didn't use AH_INET or AH_INET6.
4857                          */
4858                         DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
4859                         regs[rd] = NULL;
4860                         break;
4861                 }
4862 
4863 inetout:        regs[rd] = (uintptr_t)end + 1;
4864                 mstate->dtms_scratch_ptr += size;
4865                 break;
4866         }
4867 
4868         }
4869 }
4870 
4871 /*
4872  * Emulate the execution of DTrace IR instructions specified by the given
4873  * DIF object.  This function is deliberately void of assertions as all of
4874  * the necessary checks are handled by a call to dtrace_difo_validate().
4875  */
4876 static uint64_t
4877 dtrace_dif_emulate(dtrace_difo_t *difo, dtrace_mstate_t *mstate,
4878     dtrace_vstate_t *vstate, dtrace_state_t *state)
4879 {
4880         const dif_instr_t *text = difo->dtdo_buf;
4881         const uint_t textlen = difo->dtdo_len;
4882         const char *strtab = difo->dtdo_strtab;
4883         const uint64_t *inttab = difo->dtdo_inttab;
4884 
4885         uint64_t rval = 0;
4886         dtrace_statvar_t *svar;
4887         dtrace_dstate_t *dstate = &vstate->dtvs_dynvars;
4888         dtrace_difv_t *v;
4889         volatile uint16_t *flags = &cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
4890         volatile uintptr_t *illval = &cpu_core[CPU->cpu_id].cpuc_dtrace_illval;
4891 
4892         dtrace_key_t tupregs[DIF_DTR_NREGS + 2]; /* +2 for thread and id */
4893         uint64_t regs[DIF_DIR_NREGS];
4894         uint64_t *tmp;
4895 
4896         uint8_t cc_n = 0, cc_z = 0, cc_v = 0, cc_c = 0;
4897         int64_t cc_r;
4898         uint_t pc = 0, id, opc;
4899         uint8_t ttop = 0;
4900         dif_instr_t instr;
4901         uint_t r1, r2, rd;
4902 
4903         /*
4904          * We stash the current DIF object into the machine state: we need it
4905          * for subsequent access checking.
4906          */
4907         mstate->dtms_difo = difo;
4908 
4909         regs[DIF_REG_R0] = 0;           /* %r0 is fixed at zero */
4910 
4911         while (pc < textlen && !(*flags & CPU_DTRACE_FAULT)) {
4912                 opc = pc;
4913 
4914                 instr = text[pc++];
4915                 r1 = DIF_INSTR_R1(instr);
4916                 r2 = DIF_INSTR_R2(instr);
4917                 rd = DIF_INSTR_RD(instr);
4918 
4919                 switch (DIF_INSTR_OP(instr)) {
4920                 case DIF_OP_OR:
4921                         regs[rd] = regs[r1] | regs[r2];
4922                         break;
4923                 case DIF_OP_XOR:
4924                         regs[rd] = regs[r1] ^ regs[r2];
4925                         break;
4926                 case DIF_OP_AND:
4927                         regs[rd] = regs[r1] & regs[r2];
4928                         break;
4929                 case DIF_OP_SLL:
4930                         regs[rd] = regs[r1] << regs[r2];
4931                         break;
4932                 case DIF_OP_SRL:
4933                         regs[rd] = regs[r1] >> regs[r2];
4934                         break;
4935                 case DIF_OP_SUB:
4936                         regs[rd] = regs[r1] - regs[r2];
4937                         break;
4938                 case DIF_OP_ADD:
4939                         regs[rd] = regs[r1] + regs[r2];
4940                         break;
4941                 case DIF_OP_MUL:
4942                         regs[rd] = regs[r1] * regs[r2];
4943                         break;
4944                 case DIF_OP_SDIV:
4945                         if (regs[r2] == 0) {
4946                                 regs[rd] = 0;
4947                                 *flags |= CPU_DTRACE_DIVZERO;
4948                         } else {
4949                                 regs[rd] = (int64_t)regs[r1] /
4950                                     (int64_t)regs[r2];
4951                         }
4952                         break;
4953 
4954                 case DIF_OP_UDIV:
4955                         if (regs[r2] == 0) {
4956                                 regs[rd] = 0;
4957                                 *flags |= CPU_DTRACE_DIVZERO;
4958                         } else {
4959                                 regs[rd] = regs[r1] / regs[r2];
4960                         }
4961                         break;
4962 
4963                 case DIF_OP_SREM:
4964                         if (regs[r2] == 0) {
4965                                 regs[rd] = 0;
4966                                 *flags |= CPU_DTRACE_DIVZERO;
4967                         } else {
4968                                 regs[rd] = (int64_t)regs[r1] %
4969                                     (int64_t)regs[r2];
4970                         }
4971                         break;
4972 
4973                 case DIF_OP_UREM:
4974                         if (regs[r2] == 0) {
4975                                 regs[rd] = 0;
4976                                 *flags |= CPU_DTRACE_DIVZERO;
4977                         } else {
4978                                 regs[rd] = regs[r1] % regs[r2];
4979                         }
4980                         break;
4981 
4982                 case DIF_OP_NOT:
4983                         regs[rd] = ~regs[r1];
4984                         break;
4985                 case DIF_OP_MOV:
4986                         regs[rd] = regs[r1];
4987                         break;
4988                 case DIF_OP_CMP:
4989                         cc_r = regs[r1] - regs[r2];
4990                         cc_n = cc_r < 0;
4991                         cc_z = cc_r == 0;
4992                         cc_v = 0;
4993                         cc_c = regs[r1] < regs[r2];
4994                         break;
4995                 case DIF_OP_TST:
4996                         cc_n = cc_v = cc_c = 0;
4997                         cc_z = regs[r1] == 0;
4998                         break;
4999                 case DIF_OP_BA:
5000                         pc = DIF_INSTR_LABEL(instr);
5001                         break;
5002                 case DIF_OP_BE:
5003                         if (cc_z)
5004                                 pc = DIF_INSTR_LABEL(instr);
5005                         break;
5006                 case DIF_OP_BNE:
5007                         if (cc_z == 0)
5008                                 pc = DIF_INSTR_LABEL(instr);
5009                         break;
5010                 case DIF_OP_BG:
5011                         if ((cc_z | (cc_n ^ cc_v)) == 0)
5012                                 pc = DIF_INSTR_LABEL(instr);
5013                         break;
5014                 case DIF_OP_BGU:
5015                         if ((cc_c | cc_z) == 0)
5016                                 pc = DIF_INSTR_LABEL(instr);
5017                         break;
5018                 case DIF_OP_BGE:
5019                         if ((cc_n ^ cc_v) == 0)
5020                                 pc = DIF_INSTR_LABEL(instr);
5021                         break;
5022                 case DIF_OP_BGEU:
5023                         if (cc_c == 0)
5024                                 pc = DIF_INSTR_LABEL(instr);
5025                         break;
5026                 case DIF_OP_BL:
5027                         if (cc_n ^ cc_v)
5028                                 pc = DIF_INSTR_LABEL(instr);
5029                         break;
5030                 case DIF_OP_BLU:
5031                         if (cc_c)
5032                                 pc = DIF_INSTR_LABEL(instr);
5033                         break;
5034                 case DIF_OP_BLE:
5035                         if (cc_z | (cc_n ^ cc_v))
5036                                 pc = DIF_INSTR_LABEL(instr);
5037                         break;
5038                 case DIF_OP_BLEU:
5039                         if (cc_c | cc_z)
5040                                 pc = DIF_INSTR_LABEL(instr);
5041                         break;
5042                 case DIF_OP_RLDSB:
5043                         if (!dtrace_canload(regs[r1], 1, mstate, vstate))
5044                                 break;
5045                         /*FALLTHROUGH*/
5046                 case DIF_OP_LDSB:
5047                         regs[rd] = (int8_t)dtrace_load8(regs[r1]);
5048                         break;
5049                 case DIF_OP_RLDSH:
5050                         if (!dtrace_canload(regs[r1], 2, mstate, vstate))
5051                                 break;
5052                         /*FALLTHROUGH*/
5053                 case DIF_OP_LDSH:
5054                         regs[rd] = (int16_t)dtrace_load16(regs[r1]);
5055                         break;
5056                 case DIF_OP_RLDSW:
5057                         if (!dtrace_canload(regs[r1], 4, mstate, vstate))
5058                                 break;
5059                         /*FALLTHROUGH*/
5060                 case DIF_OP_LDSW:
5061                         regs[rd] = (int32_t)dtrace_load32(regs[r1]);
5062                         break;
5063                 case DIF_OP_RLDUB:
5064                         if (!dtrace_canload(regs[r1], 1, mstate, vstate))
5065                                 break;
5066                         /*FALLTHROUGH*/
5067                 case DIF_OP_LDUB:
5068                         regs[rd] = dtrace_load8(regs[r1]);
5069                         break;
5070                 case DIF_OP_RLDUH:
5071                         if (!dtrace_canload(regs[r1], 2, mstate, vstate))
5072                                 break;
5073                         /*FALLTHROUGH*/
5074                 case DIF_OP_LDUH:
5075                         regs[rd] = dtrace_load16(regs[r1]);
5076                         break;
5077                 case DIF_OP_RLDUW:
5078                         if (!dtrace_canload(regs[r1], 4, mstate, vstate))
5079                                 break;
5080                         /*FALLTHROUGH*/
5081                 case DIF_OP_LDUW:
5082                         regs[rd] = dtrace_load32(regs[r1]);
5083                         break;
5084                 case DIF_OP_RLDX:
5085                         if (!dtrace_canload(regs[r1], 8, mstate, vstate))
5086                                 break;
5087                         /*FALLTHROUGH*/
5088                 case DIF_OP_LDX:
5089                         regs[rd] = dtrace_load64(regs[r1]);
5090                         break;
5091                 case DIF_OP_ULDSB:
5092                         regs[rd] = (int8_t)
5093                             dtrace_fuword8((void *)(uintptr_t)regs[r1]);
5094                         break;
5095                 case DIF_OP_ULDSH:
5096                         regs[rd] = (int16_t)
5097                             dtrace_fuword16((void *)(uintptr_t)regs[r1]);
5098                         break;
5099                 case DIF_OP_ULDSW:
5100                         regs[rd] = (int32_t)
5101                             dtrace_fuword32((void *)(uintptr_t)regs[r1]);
5102                         break;
5103                 case DIF_OP_ULDUB:
5104                         regs[rd] =
5105                             dtrace_fuword8((void *)(uintptr_t)regs[r1]);
5106                         break;
5107                 case DIF_OP_ULDUH:
5108                         regs[rd] =
5109                             dtrace_fuword16((void *)(uintptr_t)regs[r1]);
5110                         break;
5111                 case DIF_OP_ULDUW:
5112                         regs[rd] =
5113                             dtrace_fuword32((void *)(uintptr_t)regs[r1]);
5114                         break;
5115                 case DIF_OP_ULDX:
5116                         regs[rd] =
5117                             dtrace_fuword64((void *)(uintptr_t)regs[r1]);
5118                         break;
5119                 case DIF_OP_RET:
5120                         rval = regs[rd];
5121                         pc = textlen;
5122                         break;
5123                 case DIF_OP_NOP:
5124                         break;
5125                 case DIF_OP_SETX:
5126                         regs[rd] = inttab[DIF_INSTR_INTEGER(instr)];
5127                         break;
5128                 case DIF_OP_SETS:
5129                         regs[rd] = (uint64_t)(uintptr_t)
5130                             (strtab + DIF_INSTR_STRING(instr));
5131                         break;
5132                 case DIF_OP_SCMP: {
5133                         size_t sz = state->dts_options[DTRACEOPT_STRSIZE];
5134                         uintptr_t s1 = regs[r1];
5135                         uintptr_t s2 = regs[r2];
5136 
5137                         if (s1 != NULL &&
5138                             !dtrace_strcanload(s1, sz, mstate, vstate))
5139                                 break;
5140                         if (s2 != NULL &&
5141                             !dtrace_strcanload(s2, sz, mstate, vstate))
5142                                 break;
5143 
5144                         cc_r = dtrace_strncmp((char *)s1, (char *)s2, sz);
5145 
5146                         cc_n = cc_r < 0;
5147                         cc_z = cc_r == 0;
5148                         cc_v = cc_c = 0;
5149                         break;
5150                 }
5151                 case DIF_OP_LDGA:
5152                         regs[rd] = dtrace_dif_variable(mstate, state,
5153                             r1, regs[r2]);
5154                         break;
5155                 case DIF_OP_LDGS:
5156                         id = DIF_INSTR_VAR(instr);
5157 
5158                         if (id >= DIF_VAR_OTHER_UBASE) {
5159                                 uintptr_t a;
5160 
5161                                 id -= DIF_VAR_OTHER_UBASE;
5162                                 svar = vstate->dtvs_globals[id];
5163                                 ASSERT(svar != NULL);
5164                                 v = &svar->dtsv_var;
5165 
5166                                 if (!(v->dtdv_type.dtdt_flags & DIF_TF_BYREF)) {
5167                                         regs[rd] = svar->dtsv_data;
5168                                         break;
5169                                 }
5170 
5171                                 a = (uintptr_t)svar->dtsv_data;
5172 
5173                                 if (*(uint8_t *)a == UINT8_MAX) {
5174                                         /*
5175                                          * If the 0th byte is set to UINT8_MAX
5176                                          * then this is to be treated as a
5177                                          * reference to a NULL variable.
5178                                          */
5179                                         regs[rd] = NULL;
5180                                 } else {
5181                                         regs[rd] = a + sizeof (uint64_t);
5182                                 }
5183 
5184                                 break;
5185                         }
5186 
5187                         regs[rd] = dtrace_dif_variable(mstate, state, id, 0);
5188                         break;
5189 
5190                 case DIF_OP_STGS:
5191                         id = DIF_INSTR_VAR(instr);
5192 
5193                         ASSERT(id >= DIF_VAR_OTHER_UBASE);
5194                         id -= DIF_VAR_OTHER_UBASE;
5195 
5196                         svar = vstate->dtvs_globals[id];
5197                         ASSERT(svar != NULL);
5198                         v = &svar->dtsv_var;
5199 
5200                         if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
5201                                 uintptr_t a = (uintptr_t)svar->dtsv_data;
5202 
5203                                 ASSERT(a != NULL);
5204                                 ASSERT(svar->dtsv_size != 0);
5205 
5206                                 if (regs[rd] == NULL) {
5207                                         *(uint8_t *)a = UINT8_MAX;
5208                                         break;
5209                                 } else {
5210                                         *(uint8_t *)a = 0;
5211                                         a += sizeof (uint64_t);
5212                                 }
5213                                 if (!dtrace_vcanload(
5214                                     (void *)(uintptr_t)regs[rd], &v->dtdv_type,
5215                                     mstate, vstate))
5216                                         break;
5217 
5218                                 dtrace_vcopy((void *)(uintptr_t)regs[rd],
5219                                     (void *)a, &v->dtdv_type);
5220                                 break;
5221                         }
5222 
5223                         svar->dtsv_data = regs[rd];
5224                         break;
5225 
5226                 case DIF_OP_LDTA:
5227                         /*
5228                          * There are no DTrace built-in thread-local arrays at
5229                          * present.  This opcode is saved for future work.
5230                          */
5231                         *flags |= CPU_DTRACE_ILLOP;
5232                         regs[rd] = 0;
5233                         break;
5234 
5235                 case DIF_OP_LDLS:
5236                         id = DIF_INSTR_VAR(instr);
5237 
5238                         if (id < DIF_VAR_OTHER_UBASE) {
5239                                 /*
5240                                  * For now, this has no meaning.
5241                                  */
5242                                 regs[rd] = 0;
5243                                 break;
5244                         }
5245 
5246                         id -= DIF_VAR_OTHER_UBASE;
5247 
5248                         ASSERT(id < vstate->dtvs_nlocals);
5249                         ASSERT(vstate->dtvs_locals != NULL);
5250 
5251                         svar = vstate->dtvs_locals[id];
5252                         ASSERT(svar != NULL);
5253                         v = &svar->dtsv_var;
5254 
5255                         if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
5256                                 uintptr_t a = (uintptr_t)svar->dtsv_data;
5257                                 size_t sz = v->dtdv_type.dtdt_size;
5258 
5259                                 sz += sizeof (uint64_t);
5260                                 ASSERT(svar->dtsv_size == NCPU * sz);
5261                                 a += CPU->cpu_id * sz;
5262 
5263                                 if (*(uint8_t *)a == UINT8_MAX) {
5264                                         /*
5265                                          * If the 0th byte is set to UINT8_MAX
5266                                          * then this is to be treated as a
5267                                          * reference to a NULL variable.
5268                                          */
5269                                         regs[rd] = NULL;
5270                                 } else {
5271                                         regs[rd] = a + sizeof (uint64_t);
5272                                 }
5273 
5274                                 break;
5275                         }
5276 
5277                         ASSERT(svar->dtsv_size == NCPU * sizeof (uint64_t));
5278                         tmp = (uint64_t *)(uintptr_t)svar->dtsv_data;
5279                         regs[rd] = tmp[CPU->cpu_id];
5280                         break;
5281 
5282                 case DIF_OP_STLS:
5283                         id = DIF_INSTR_VAR(instr);
5284 
5285                         ASSERT(id >= DIF_VAR_OTHER_UBASE);
5286                         id -= DIF_VAR_OTHER_UBASE;
5287                         ASSERT(id < vstate->dtvs_nlocals);
5288 
5289                         ASSERT(vstate->dtvs_locals != NULL);
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 (regs[rd] == NULL) {
5303                                         *(uint8_t *)a = UINT8_MAX;
5304                                         break;
5305                                 } else {
5306                                         *(uint8_t *)a = 0;
5307                                         a += sizeof (uint64_t);
5308                                 }
5309 
5310                                 if (!dtrace_vcanload(
5311                                     (void *)(uintptr_t)regs[rd], &v->dtdv_type,
5312                                     mstate, vstate))
5313                                         break;
5314 
5315                                 dtrace_vcopy((void *)(uintptr_t)regs[rd],
5316                                     (void *)a, &v->dtdv_type);
5317                                 break;
5318                         }
5319 
5320                         ASSERT(svar->dtsv_size == NCPU * sizeof (uint64_t));
5321                         tmp = (uint64_t *)(uintptr_t)svar->dtsv_data;
5322                         tmp[CPU->cpu_id] = regs[rd];
5323                         break;
5324 
5325                 case DIF_OP_LDTS: {
5326                         dtrace_dynvar_t *dvar;
5327                         dtrace_key_t *key;
5328 
5329                         id = DIF_INSTR_VAR(instr);
5330                         ASSERT(id >= DIF_VAR_OTHER_UBASE);
5331                         id -= DIF_VAR_OTHER_UBASE;
5332                         v = &vstate->dtvs_tlocals[id];
5333 
5334                         key = &tupregs[DIF_DTR_NREGS];
5335                         key[0].dttk_value = (uint64_t)id;
5336                         key[0].dttk_size = 0;
5337                         DTRACE_TLS_THRKEY(key[1].dttk_value);
5338                         key[1].dttk_size = 0;
5339 
5340                         dvar = dtrace_dynvar(dstate, 2, key,
5341                             sizeof (uint64_t), DTRACE_DYNVAR_NOALLOC,
5342                             mstate, vstate);
5343 
5344                         if (dvar == NULL) {
5345                                 regs[rd] = 0;
5346                                 break;
5347                         }
5348 
5349                         if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
5350                                 regs[rd] = (uint64_t)(uintptr_t)dvar->dtdv_data;
5351                         } else {
5352                                 regs[rd] = *((uint64_t *)dvar->dtdv_data);
5353                         }
5354 
5355                         break;
5356                 }
5357 
5358                 case DIF_OP_STTS: {
5359                         dtrace_dynvar_t *dvar;
5360                         dtrace_key_t *key;
5361 
5362                         id = DIF_INSTR_VAR(instr);
5363                         ASSERT(id >= DIF_VAR_OTHER_UBASE);
5364                         id -= DIF_VAR_OTHER_UBASE;
5365 
5366                         key = &tupregs[DIF_DTR_NREGS];
5367                         key[0].dttk_value = (uint64_t)id;
5368                         key[0].dttk_size = 0;
5369                         DTRACE_TLS_THRKEY(key[1].dttk_value);
5370                         key[1].dttk_size = 0;
5371                         v = &vstate->dtvs_tlocals[id];
5372 
5373                         dvar = dtrace_dynvar(dstate, 2, key,
5374                             v->dtdv_type.dtdt_size > sizeof (uint64_t) ?
5375                             v->dtdv_type.dtdt_size : sizeof (uint64_t),
5376                             regs[rd] ? DTRACE_DYNVAR_ALLOC :
5377                             DTRACE_DYNVAR_DEALLOC, mstate, vstate);
5378 
5379                         /*
5380                          * Given that we're storing to thread-local data,
5381                          * we need to flush our predicate cache.
5382                          */
5383                         curthread->t_predcache = NULL;
5384 
5385                         if (dvar == NULL)
5386                                 break;
5387 
5388                         if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
5389                                 if (!dtrace_vcanload(
5390                                     (void *)(uintptr_t)regs[rd],
5391                                     &v->dtdv_type, mstate, vstate))
5392                                         break;
5393 
5394                                 dtrace_vcopy((void *)(uintptr_t)regs[rd],
5395                                     dvar->dtdv_data, &v->dtdv_type);
5396                         } else {
5397                                 *((uint64_t *)dvar->dtdv_data) = regs[rd];
5398                         }
5399 
5400                         break;
5401                 }
5402 
5403                 case DIF_OP_SRA:
5404                         regs[rd] = (int64_t)regs[r1] >> regs[r2];
5405                         break;
5406 
5407                 case DIF_OP_CALL:
5408                         dtrace_dif_subr(DIF_INSTR_SUBR(instr), rd,
5409                             regs, tupregs, ttop, mstate, state);
5410                         break;
5411 
5412                 case DIF_OP_PUSHTR:
5413                         if (ttop == DIF_DTR_NREGS) {
5414                                 *flags |= CPU_DTRACE_TUPOFLOW;
5415                                 break;
5416                         }
5417 
5418                         if (r1 == DIF_TYPE_STRING) {
5419                                 /*
5420                                  * If this is a string type and the size is 0,
5421                                  * we'll use the system-wide default string
5422                                  * size.  Note that we are _not_ looking at
5423                                  * the value of the DTRACEOPT_STRSIZE option;
5424                                  * had this been set, we would expect to have
5425                                  * a non-zero size value in the "pushtr".
5426                                  */
5427                                 tupregs[ttop].dttk_size =
5428                                     dtrace_strlen((char *)(uintptr_t)regs[rd],
5429                                     regs[r2] ? regs[r2] :
5430                                     dtrace_strsize_default) + 1;
5431                         } else {
5432                                 tupregs[ttop].dttk_size = regs[r2];
5433                         }
5434 
5435                         tupregs[ttop++].dttk_value = regs[rd];
5436                         break;
5437 
5438                 case DIF_OP_PUSHTV:
5439                         if (ttop == DIF_DTR_NREGS) {
5440                                 *flags |= CPU_DTRACE_TUPOFLOW;
5441                                 break;
5442                         }
5443 
5444                         tupregs[ttop].dttk_value = regs[rd];
5445                         tupregs[ttop++].dttk_size = 0;
5446                         break;
5447 
5448                 case DIF_OP_POPTS:
5449                         if (ttop != 0)
5450                                 ttop--;
5451                         break;
5452 
5453                 case DIF_OP_FLUSHTS:
5454                         ttop = 0;
5455                         break;
5456 
5457                 case DIF_OP_LDGAA:
5458                 case DIF_OP_LDTAA: {
5459                         dtrace_dynvar_t *dvar;
5460                         dtrace_key_t *key = tupregs;
5461                         uint_t nkeys = ttop;
5462 
5463                         id = DIF_INSTR_VAR(instr);
5464                         ASSERT(id >= DIF_VAR_OTHER_UBASE);
5465                         id -= DIF_VAR_OTHER_UBASE;
5466 
5467                         key[nkeys].dttk_value = (uint64_t)id;
5468                         key[nkeys++].dttk_size = 0;
5469 
5470                         if (DIF_INSTR_OP(instr) == DIF_OP_LDTAA) {
5471                                 DTRACE_TLS_THRKEY(key[nkeys].dttk_value);
5472                                 key[nkeys++].dttk_size = 0;
5473                                 v = &vstate->dtvs_tlocals[id];
5474                         } else {
5475                                 v = &vstate->dtvs_globals[id]->dtsv_var;
5476                         }
5477 
5478                         dvar = dtrace_dynvar(dstate, nkeys, key,
5479                             v->dtdv_type.dtdt_size > sizeof (uint64_t) ?
5480                             v->dtdv_type.dtdt_size : sizeof (uint64_t),
5481                             DTRACE_DYNVAR_NOALLOC, mstate, vstate);
5482 
5483                         if (dvar == NULL) {
5484                                 regs[rd] = 0;
5485                                 break;
5486                         }
5487 
5488                         if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
5489                                 regs[rd] = (uint64_t)(uintptr_t)dvar->dtdv_data;
5490                         } else {
5491                                 regs[rd] = *((uint64_t *)dvar->dtdv_data);
5492                         }
5493 
5494                         break;
5495                 }
5496 
5497                 case DIF_OP_STGAA:
5498                 case DIF_OP_STTAA: {
5499                         dtrace_dynvar_t *dvar;
5500                         dtrace_key_t *key = tupregs;
5501                         uint_t nkeys = ttop;
5502 
5503                         id = DIF_INSTR_VAR(instr);
5504                         ASSERT(id >= DIF_VAR_OTHER_UBASE);
5505                         id -= DIF_VAR_OTHER_UBASE;
5506 
5507                         key[nkeys].dttk_value = (uint64_t)id;
5508                         key[nkeys++].dttk_size = 0;
5509 
5510                         if (DIF_INSTR_OP(instr) == DIF_OP_STTAA) {
5511                                 DTRACE_TLS_THRKEY(key[nkeys].dttk_value);
5512                                 key[nkeys++].dttk_size = 0;
5513                                 v = &vstate->dtvs_tlocals[id];
5514                         } else {
5515                                 v = &vstate->dtvs_globals[id]->dtsv_var;
5516                         }
5517 
5518                         dvar = dtrace_dynvar(dstate, nkeys, key,
5519                             v->dtdv_type.dtdt_size > sizeof (uint64_t) ?
5520                             v->dtdv_type.dtdt_size : sizeof (uint64_t),
5521                             regs[rd] ? DTRACE_DYNVAR_ALLOC :
5522                             DTRACE_DYNVAR_DEALLOC, mstate, vstate);
5523 
5524                         if (dvar == NULL)
5525                                 break;
5526 
5527                         if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
5528                                 if (!dtrace_vcanload(
5529                                     (void *)(uintptr_t)regs[rd], &v->dtdv_type,
5530                                     mstate, vstate))
5531                                         break;
5532 
5533                                 dtrace_vcopy((void *)(uintptr_t)regs[rd],
5534                                     dvar->dtdv_data, &v->dtdv_type);
5535                         } else {
5536                                 *((uint64_t *)dvar->dtdv_data) = regs[rd];
5537                         }
5538 
5539                         break;
5540                 }
5541 
5542                 case DIF_OP_ALLOCS: {
5543                         uintptr_t ptr = P2ROUNDUP(mstate->dtms_scratch_ptr, 8);
5544                         size_t size = ptr - mstate->dtms_scratch_ptr + regs[r1];
5545 
5546                         /*
5547                          * Rounding up the user allocation size could have
5548                          * overflowed large, bogus allocations (like -1ULL) to
5549                          * 0.
5550                          */
5551                         if (size < regs[r1] ||
5552                             !DTRACE_INSCRATCH(mstate, size)) {
5553                                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
5554                                 regs[rd] = NULL;
5555                                 break;
5556                         }
5557 
5558                         dtrace_bzero((void *) mstate->dtms_scratch_ptr, size);
5559                         mstate->dtms_scratch_ptr += size;
5560                         regs[rd] = ptr;
5561                         break;
5562                 }
5563 
5564                 case DIF_OP_COPYS:
5565                         if (!dtrace_canstore(regs[rd], regs[r2],
5566                             mstate, vstate)) {
5567                                 *flags |= CPU_DTRACE_BADADDR;
5568                                 *illval = regs[rd];
5569                                 break;
5570                         }
5571 
5572                         if (!dtrace_canload(regs[r1], regs[r2], mstate, vstate))
5573                                 break;
5574 
5575                         dtrace_bcopy((void *)(uintptr_t)regs[r1],
5576                             (void *)(uintptr_t)regs[rd], (size_t)regs[r2]);
5577                         break;
5578 
5579                 case DIF_OP_STB:
5580                         if (!dtrace_canstore(regs[rd], 1, mstate, vstate)) {
5581                                 *flags |= CPU_DTRACE_BADADDR;
5582                                 *illval = regs[rd];
5583                                 break;
5584                         }
5585                         *((uint8_t *)(uintptr_t)regs[rd]) = (uint8_t)regs[r1];
5586                         break;
5587 
5588                 case DIF_OP_STH:
5589                         if (!dtrace_canstore(regs[rd], 2, mstate, vstate)) {
5590                                 *flags |= CPU_DTRACE_BADADDR;
5591                                 *illval = regs[rd];
5592                                 break;
5593                         }
5594                         if (regs[rd] & 1) {
5595                                 *flags |= CPU_DTRACE_BADALIGN;
5596                                 *illval = regs[rd];
5597                                 break;
5598                         }
5599                         *((uint16_t *)(uintptr_t)regs[rd]) = (uint16_t)regs[r1];
5600                         break;
5601 
5602                 case DIF_OP_STW:
5603                         if (!dtrace_canstore(regs[rd], 4, mstate, vstate)) {
5604                                 *flags |= CPU_DTRACE_BADADDR;
5605                                 *illval = regs[rd];
5606                                 break;
5607                         }
5608                         if (regs[rd] & 3) {
5609                                 *flags |= CPU_DTRACE_BADALIGN;
5610                                 *illval = regs[rd];
5611                                 break;
5612                         }
5613                         *((uint32_t *)(uintptr_t)regs[rd]) = (uint32_t)regs[r1];
5614                         break;
5615 
5616                 case DIF_OP_STX:
5617                         if (!dtrace_canstore(regs[rd], 8, mstate, vstate)) {
5618                                 *flags |= CPU_DTRACE_BADADDR;
5619                                 *illval = regs[rd];
5620                                 break;
5621                         }
5622                         if (regs[rd] & 7) {
5623                                 *flags |= CPU_DTRACE_BADALIGN;
5624                                 *illval = regs[rd];
5625                                 break;
5626                         }
5627                         *((uint64_t *)(uintptr_t)regs[rd]) = regs[r1];
5628                         break;
5629                 }
5630         }
5631 
5632         if (!(*flags & CPU_DTRACE_FAULT))
5633                 return (rval);
5634 
5635         mstate->dtms_fltoffs = opc * sizeof (dif_instr_t);
5636         mstate->dtms_present |= DTRACE_MSTATE_FLTOFFS;
5637 
5638         return (0);
5639 }
5640 
5641 static void
5642 dtrace_action_breakpoint(dtrace_ecb_t *ecb)
5643 {
5644         dtrace_probe_t *probe = ecb->dte_probe;
5645         dtrace_provider_t *prov = probe->dtpr_provider;
5646         char c[DTRACE_FULLNAMELEN + 80], *str;
5647         char *msg = "dtrace: breakpoint action at probe ";
5648         char *ecbmsg = " (ecb ";
5649         uintptr_t mask = (0xf << (sizeof (uintptr_t) * NBBY / 4));
5650         uintptr_t val = (uintptr_t)ecb;
5651         int shift = (sizeof (uintptr_t) * NBBY) - 4, i = 0;
5652 
5653         if (dtrace_destructive_disallow)
5654                 return;
5655 
5656         /*
5657          * It's impossible to be taking action on the NULL probe.
5658          */
5659         ASSERT(probe != NULL);
5660 
5661         /*
5662          * This is a poor man's (destitute man's?) sprintf():  we want to
5663          * print the provider name, module name, function name and name of
5664          * the probe, along with the hex address of the ECB with the breakpoint
5665          * action -- all of which we must place in the character buffer by
5666          * hand.
5667          */
5668         while (*msg != '\0')
5669                 c[i++] = *msg++;
5670 
5671         for (str = prov->dtpv_name; *str != '\0'; str++)
5672                 c[i++] = *str;
5673         c[i++] = ':';
5674 
5675         for (str = probe->dtpr_mod; *str != '\0'; str++)
5676                 c[i++] = *str;
5677         c[i++] = ':';
5678 
5679         for (str = probe->dtpr_func; *str != '\0'; str++)
5680                 c[i++] = *str;
5681         c[i++] = ':';
5682 
5683         for (str = probe->dtpr_name; *str != '\0'; str++)
5684                 c[i++] = *str;
5685 
5686         while (*ecbmsg != '\0')
5687                 c[i++] = *ecbmsg++;
5688 
5689         while (shift >= 0) {
5690                 mask = (uintptr_t)0xf << shift;
5691 
5692                 if (val >= ((uintptr_t)1 << shift))
5693                         c[i++] = "0123456789abcdef"[(val & mask) >> shift];
5694                 shift -= 4;
5695         }
5696 
5697         c[i++] = ')';
5698         c[i] = '\0';
5699 
5700         debug_enter(c);
5701 }
5702 
5703 static void
5704 dtrace_action_panic(dtrace_ecb_t *ecb)
5705 {
5706         dtrace_probe_t *probe = ecb->dte_probe;
5707 
5708         /*
5709          * It's impossible to be taking action on the NULL probe.
5710          */
5711         ASSERT(probe != NULL);
5712 
5713         if (dtrace_destructive_disallow)
5714                 return;
5715 
5716         if (dtrace_panicked != NULL)
5717                 return;
5718 
5719         if (dtrace_casptr(&dtrace_panicked, NULL, curthread) != NULL)
5720                 return;
5721 
5722         /*
5723          * We won the right to panic.  (We want to be sure that only one
5724          * thread calls panic() from dtrace_probe(), and that panic() is
5725          * called exactly once.)
5726          */
5727         dtrace_panic("dtrace: panic action at probe %s:%s:%s:%s (ecb %p)",
5728             probe->dtpr_provider->dtpv_name, probe->dtpr_mod,
5729             probe->dtpr_func, probe->dtpr_name, (void *)ecb);
5730 }
5731 
5732 static void
5733 dtrace_action_raise(uint64_t sig)
5734 {
5735         if (dtrace_destructive_disallow)
5736                 return;
5737 
5738         if (sig >= NSIG) {
5739                 DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
5740                 return;
5741         }
5742 
5743         /*
5744          * raise() has a queue depth of 1 -- we ignore all subsequent
5745          * invocations of the raise() action.
5746          */
5747         if (curthread->t_dtrace_sig == 0)
5748                 curthread->t_dtrace_sig = (uint8_t)sig;
5749 
5750         curthread->t_sig_check = 1;
5751         aston(curthread);
5752 }
5753 
5754 static void
5755 dtrace_action_stop(void)
5756 {
5757         if (dtrace_destructive_disallow)
5758                 return;
5759 
5760         if (!curthread->t_dtrace_stop) {
5761                 curthread->t_dtrace_stop = 1;
5762                 curthread->t_sig_check = 1;
5763                 aston(curthread);
5764         }
5765 }
5766 
5767 static void
5768 dtrace_action_chill(dtrace_mstate_t *mstate, hrtime_t val)
5769 {
5770         hrtime_t now;
5771         volatile uint16_t *flags;
5772         cpu_t *cpu = CPU;
5773 
5774         if (dtrace_destructive_disallow)
5775                 return;
5776 
5777         flags = (volatile uint16_t *)&cpu_core[cpu->cpu_id].cpuc_dtrace_flags;
5778 
5779         now = dtrace_gethrtime();
5780 
5781         if (now - cpu->cpu_dtrace_chillmark > dtrace_chill_interval) {
5782                 /*
5783                  * We need to advance the mark to the current time.
5784                  */
5785                 cpu->cpu_dtrace_chillmark = now;
5786                 cpu->cpu_dtrace_chilled = 0;
5787         }
5788 
5789         /*
5790          * Now check to see if the requested chill time would take us over
5791          * the maximum amount of time allowed in the chill interval.  (Or
5792          * worse, if the calculation itself induces overflow.)
5793          */
5794         if (cpu->cpu_dtrace_chilled + val > dtrace_chill_max ||
5795             cpu->cpu_dtrace_chilled + val < cpu->cpu_dtrace_chilled) {
5796                 *flags |= CPU_DTRACE_ILLOP;
5797                 return;
5798         }
5799 
5800         while (dtrace_gethrtime() - now < val)
5801                 continue;
5802 
5803         /*
5804          * Normally, we assure that the value of the variable "timestamp" does
5805          * not change within an ECB.  The presence of chill() represents an
5806          * exception to this rule, however.
5807          */
5808         mstate->dtms_present &= ~DTRACE_MSTATE_TIMESTAMP;
5809         cpu->cpu_dtrace_chilled += val;
5810 }
5811 
5812 static void
5813 dtrace_action_ustack(dtrace_mstate_t *mstate, dtrace_state_t *state,
5814     uint64_t *buf, uint64_t arg)
5815 {
5816         int nframes = DTRACE_USTACK_NFRAMES(arg);
5817         int strsize = DTRACE_USTACK_STRSIZE(arg);
5818         uint64_t *pcs = &buf[1], *fps;
5819         char *str = (char *)&pcs[nframes];
5820         int size, offs = 0, i, j;
5821         uintptr_t old = mstate->dtms_scratch_ptr, saved;
5822         uint16_t *flags = &cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
5823         char *sym;
5824 
5825         /*
5826          * Should be taking a faster path if string space has not been
5827          * allocated.
5828          */
5829         ASSERT(strsize != 0);
5830 
5831         /*
5832          * We will first allocate some temporary space for the frame pointers.
5833          */
5834         fps = (uint64_t *)P2ROUNDUP(mstate->dtms_scratch_ptr, 8);
5835         size = (uintptr_t)fps - mstate->dtms_scratch_ptr +
5836             (nframes * sizeof (uint64_t));
5837 
5838         if (!DTRACE_INSCRATCH(mstate, size)) {
5839                 /*
5840                  * Not enough room for our frame pointers -- need to indicate
5841                  * that we ran out of scratch space.
5842                  */
5843                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
5844                 return;
5845         }
5846 
5847         mstate->dtms_scratch_ptr += size;
5848         saved = mstate->dtms_scratch_ptr;
5849 
5850         /*
5851          * Now get a stack with both program counters and frame pointers.
5852          */
5853         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
5854         dtrace_getufpstack(buf, fps, nframes + 1);
5855         DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
5856 
5857         /*
5858          * If that faulted, we're cooked.
5859          */
5860         if (*flags & CPU_DTRACE_FAULT)
5861                 goto out;
5862 
5863         /*
5864          * Now we want to walk up the stack, calling the USTACK helper.  For
5865          * each iteration, we restore the scratch pointer.
5866          */
5867         for (i = 0; i < nframes; i++) {
5868                 mstate->dtms_scratch_ptr = saved;
5869 
5870                 if (offs >= strsize)
5871                         break;
5872 
5873                 sym = (char *)(uintptr_t)dtrace_helper(
5874                     DTRACE_HELPER_ACTION_USTACK,
5875                     mstate, state, pcs[i], fps[i]);
5876 
5877                 /*
5878                  * If we faulted while running the helper, we're going to
5879                  * clear the fault and null out the corresponding string.
5880                  */
5881                 if (*flags & CPU_DTRACE_FAULT) {
5882                         *flags &= ~CPU_DTRACE_FAULT;
5883                         str[offs++] = '\0';
5884                         continue;
5885                 }
5886 
5887                 if (sym == NULL) {
5888                         str[offs++] = '\0';
5889                         continue;
5890                 }
5891 
5892                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
5893 
5894                 /*
5895                  * Now copy in the string that the helper returned to us.
5896                  */
5897                 for (j = 0; offs + j < strsize; j++) {
5898                         if ((str[offs + j] = sym[j]) == '\0')
5899                                 break;
5900                 }
5901 
5902                 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
5903 
5904                 offs += j + 1;
5905         }
5906 
5907         if (offs >= strsize) {
5908                 /*
5909                  * If we didn't have room for all of the strings, we don't
5910                  * abort processing -- this needn't be a fatal error -- but we
5911                  * still want to increment a counter (dts_stkstroverflows) to
5912                  * allow this condition to be warned about.  (If this is from
5913                  * a jstack() action, it is easily tuned via jstackstrsize.)
5914                  */
5915                 dtrace_error(&state->dts_stkstroverflows);
5916         }
5917 
5918         while (offs < strsize)
5919                 str[offs++] = '\0';
5920 
5921 out:
5922         mstate->dtms_scratch_ptr = old;
5923 }
5924 
5925 /*
5926  * If you're looking for the epicenter of DTrace, you just found it.  This
5927  * is the function called by the provider to fire a probe -- from which all
5928  * subsequent probe-context DTrace activity emanates.
5929  */
5930 void
5931 dtrace_probe(dtrace_id_t id, uintptr_t arg0, uintptr_t arg1,
5932     uintptr_t arg2, uintptr_t arg3, uintptr_t arg4)
5933 {
5934         processorid_t cpuid;
5935         dtrace_icookie_t cookie;
5936         dtrace_probe_t *probe;
5937         dtrace_mstate_t mstate;
5938         dtrace_ecb_t *ecb;
5939         dtrace_action_t *act;
5940         intptr_t offs;
5941         size_t size;
5942         int vtime, onintr;
5943         volatile uint16_t *flags;
5944         hrtime_t now;
5945 
5946         /*
5947          * Kick out immediately if this CPU is still being born (in which case
5948          * curthread will be set to -1) or the current thread can't allow
5949          * probes in its current context.
5950          */
5951         if (((uintptr_t)curthread & 1) || (curthread->t_flag & T_DONTDTRACE))
5952                 return;
5953 
5954         cookie = dtrace_interrupt_disable();
5955         probe = dtrace_probes[id - 1];
5956         cpuid = CPU->cpu_id;
5957         onintr = CPU_ON_INTR(CPU);
5958 
5959         if (!onintr && probe->dtpr_predcache != DTRACE_CACHEIDNONE &&
5960             probe->dtpr_predcache == curthread->t_predcache) {
5961                 /*
5962                  * We have hit in the predicate cache; we know that
5963                  * this predicate would evaluate to be false.
5964                  */
5965                 dtrace_interrupt_enable(cookie);
5966                 return;
5967         }
5968 
5969         if (panic_quiesce) {
5970                 /*
5971                  * We don't trace anything if we're panicking.
5972                  */
5973                 dtrace_interrupt_enable(cookie);
5974                 return;
5975         }
5976 
5977         now = dtrace_gethrtime();
5978         vtime = dtrace_vtime_references != 0;
5979 
5980         if (vtime && curthread->t_dtrace_start)
5981                 curthread->t_dtrace_vtime += now - curthread->t_dtrace_start;
5982 
5983         mstate.dtms_difo = NULL;
5984         mstate.dtms_probe = probe;
5985         mstate.dtms_strtok = NULL;
5986         mstate.dtms_arg[0] = arg0;
5987         mstate.dtms_arg[1] = arg1;
5988         mstate.dtms_arg[2] = arg2;
5989         mstate.dtms_arg[3] = arg3;
5990         mstate.dtms_arg[4] = arg4;
5991 
5992         flags = (volatile uint16_t *)&cpu_core[cpuid].cpuc_dtrace_flags;
5993 
5994         for (ecb = probe->dtpr_ecb; ecb != NULL; ecb = ecb->dte_next) {
5995                 dtrace_predicate_t *pred = ecb->dte_predicate;
5996                 dtrace_state_t *state = ecb->dte_state;
5997                 dtrace_buffer_t *buf = &state->dts_buffer[cpuid];
5998                 dtrace_buffer_t *aggbuf = &state->dts_aggbuffer[cpuid];
5999                 dtrace_vstate_t *vstate = &state->dts_vstate;
6000                 dtrace_provider_t *prov = probe->dtpr_provider;
6001                 uint64_t tracememsize = 0;
6002                 int committed = 0;
6003                 caddr_t tomax;
6004 
6005                 /*
6006                  * A little subtlety with the following (seemingly innocuous)
6007                  * declaration of the automatic 'val':  by looking at the
6008                  * code, you might think that it could be declared in the
6009                  * action processing loop, below.  (That is, it's only used in
6010                  * the action processing loop.)  However, it must be declared
6011                  * out of that scope because in the case of DIF expression
6012                  * arguments to aggregating actions, one iteration of the
6013                  * action loop will use the last iteration's value.
6014                  */
6015 #ifdef lint
6016                 uint64_t val = 0;
6017 #else
6018                 uint64_t val;
6019 #endif
6020 
6021                 mstate.dtms_present = DTRACE_MSTATE_ARGS | DTRACE_MSTATE_PROBE;
6022                 mstate.dtms_access = DTRACE_ACCESS_ARGS | DTRACE_ACCESS_PROC;
6023                 mstate.dtms_getf = NULL;
6024 
6025                 *flags &= ~CPU_DTRACE_ERROR;
6026 
6027                 if (prov == dtrace_provider) {
6028                         /*
6029                          * If dtrace itself is the provider of this probe,
6030                          * we're only going to continue processing the ECB if
6031                          * arg0 (the dtrace_state_t) is equal to the ECB's
6032                          * creating state.  (This prevents disjoint consumers
6033                          * from seeing one another's metaprobes.)
6034                          */
6035                         if (arg0 != (uint64_t)(uintptr_t)state)
6036                                 continue;
6037                 }
6038 
6039                 if (state->dts_activity != DTRACE_ACTIVITY_ACTIVE) {
6040                         /*
6041                          * We're not currently active.  If our provider isn't
6042                          * the dtrace pseudo provider, we're not interested.
6043                          */
6044                         if (prov != dtrace_provider)
6045                                 continue;
6046 
6047                         /*
6048                          * Now we must further check if we are in the BEGIN
6049                          * probe.  If we are, we will only continue processing
6050                          * if we're still in WARMUP -- if one BEGIN enabling
6051                          * has invoked the exit() action, we don't want to
6052                          * evaluate subsequent BEGIN enablings.
6053                          */
6054                         if (probe->dtpr_id == dtrace_probeid_begin &&
6055                             state->dts_activity != DTRACE_ACTIVITY_WARMUP) {
6056                                 ASSERT(state->dts_activity ==
6057                                     DTRACE_ACTIVITY_DRAINING);
6058                                 continue;
6059                         }
6060                 }
6061 
6062                 if (ecb->dte_cond && !dtrace_priv_probe(state, &mstate, ecb))
6063                         continue;
6064 
6065                 if (now - state->dts_alive > dtrace_deadman_timeout) {
6066                         /*
6067                          * We seem to be dead.  Unless we (a) have kernel
6068                          * destructive permissions (b) have expicitly enabled
6069                          * destructive actions and (c) destructive actions have
6070                          * not been disabled, we're going to transition into
6071                          * the KILLED state, from which no further processing
6072                          * on this state will be performed.
6073                          */
6074                         if (!dtrace_priv_kernel_destructive(state) ||
6075                             !state->dts_cred.dcr_destructive ||
6076                             dtrace_destructive_disallow) {
6077                                 void *activity = &state->dts_activity;
6078                                 dtrace_activity_t current;
6079 
6080                                 do {
6081                                         current = state->dts_activity;
6082                                 } while (dtrace_cas32(activity, current,
6083                                     DTRACE_ACTIVITY_KILLED) != current);
6084 
6085                                 continue;
6086                         }
6087                 }
6088 
6089                 if ((offs = dtrace_buffer_reserve(buf, ecb->dte_needed,
6090                     ecb->dte_alignment, state, &mstate)) < 0)
6091                         continue;
6092 
6093                 tomax = buf->dtb_tomax;
6094                 ASSERT(tomax != NULL);
6095 
6096                 if (ecb->dte_size != 0)
6097                         DTRACE_STORE(uint32_t, tomax, offs, ecb->dte_epid);
6098 
6099                 mstate.dtms_epid = ecb->dte_epid;
6100                 mstate.dtms_present |= DTRACE_MSTATE_EPID;
6101 
6102                 if (state->dts_cred.dcr_visible & DTRACE_CRV_KERNEL)
6103                         mstate.dtms_access |= DTRACE_ACCESS_KERNEL;
6104 
6105                 if (pred != NULL) {
6106                         dtrace_difo_t *dp = pred->dtp_difo;
6107                         int rval;
6108 
6109                         rval = dtrace_dif_emulate(dp, &mstate, vstate, state);
6110 
6111                         if (!(*flags & CPU_DTRACE_ERROR) && !rval) {
6112                                 dtrace_cacheid_t cid = probe->dtpr_predcache;
6113 
6114                                 if (cid != DTRACE_CACHEIDNONE && !onintr) {
6115                                         /*
6116                                          * Update the predicate cache...
6117                                          */
6118                                         ASSERT(cid == pred->dtp_cacheid);
6119                                         curthread->t_predcache = cid;
6120                                 }
6121 
6122                                 continue;
6123                         }
6124                 }
6125 
6126                 for (act = ecb->dte_action; !(*flags & CPU_DTRACE_ERROR) &&
6127                     act != NULL; act = act->dta_next) {
6128                         size_t valoffs;
6129                         dtrace_difo_t *dp;
6130                         dtrace_recdesc_t *rec = &act->dta_rec;
6131 
6132                         size = rec->dtrd_size;
6133                         valoffs = offs + rec->dtrd_offset;
6134 
6135                         if (DTRACEACT_ISAGG(act->dta_kind)) {
6136                                 uint64_t v = 0xbad;
6137                                 dtrace_aggregation_t *agg;
6138 
6139                                 agg = (dtrace_aggregation_t *)act;
6140 
6141                                 if ((dp = act->dta_difo) != NULL)
6142                                         v = dtrace_dif_emulate(dp,
6143                                             &mstate, vstate, state);
6144 
6145                                 if (*flags & CPU_DTRACE_ERROR)
6146                                         continue;
6147 
6148                                 /*
6149                                  * Note that we always pass the expression
6150                                  * value from the previous iteration of the
6151                                  * action loop.  This value will only be used
6152                                  * if there is an expression argument to the
6153                                  * aggregating action, denoted by the
6154                                  * dtag_hasarg field.
6155                                  */
6156                                 dtrace_aggregate(agg, buf,
6157                                     offs, aggbuf, v, val);
6158                                 continue;
6159                         }
6160 
6161                         switch (act->dta_kind) {
6162                         case DTRACEACT_STOP:
6163                                 if (dtrace_priv_proc_destructive(state,
6164                                     &mstate))
6165                                         dtrace_action_stop();
6166                                 continue;
6167 
6168                         case DTRACEACT_BREAKPOINT:
6169                                 if (dtrace_priv_kernel_destructive(state))
6170                                         dtrace_action_breakpoint(ecb);
6171                                 continue;
6172 
6173                         case DTRACEACT_PANIC:
6174                                 if (dtrace_priv_kernel_destructive(state))
6175                                         dtrace_action_panic(ecb);
6176                                 continue;
6177 
6178                         case DTRACEACT_STACK:
6179                                 if (!dtrace_priv_kernel(state))
6180                                         continue;
6181 
6182                                 dtrace_getpcstack((pc_t *)(tomax + valoffs),
6183                                     size / sizeof (pc_t), probe->dtpr_aframes,
6184                                     DTRACE_ANCHORED(probe) ? NULL :
6185                                     (uint32_t *)arg0);
6186 
6187                                 continue;
6188 
6189                         case DTRACEACT_JSTACK:
6190                         case DTRACEACT_USTACK:
6191                                 if (!dtrace_priv_proc(state, &mstate))
6192                                         continue;
6193 
6194                                 /*
6195                                  * See comment in DIF_VAR_PID.
6196                                  */
6197                                 if (DTRACE_ANCHORED(mstate.dtms_probe) &&
6198                                     CPU_ON_INTR(CPU)) {
6199                                         int depth = DTRACE_USTACK_NFRAMES(
6200                                             rec->dtrd_arg) + 1;
6201 
6202                                         dtrace_bzero((void *)(tomax + valoffs),
6203                                             DTRACE_USTACK_STRSIZE(rec->dtrd_arg)
6204                                             + depth * sizeof (uint64_t));
6205 
6206                                         continue;
6207                                 }
6208 
6209                                 if (DTRACE_USTACK_STRSIZE(rec->dtrd_arg) != 0 &&
6210                                     curproc->p_dtrace_helpers != NULL) {
6211                                         /*
6212                                          * This is the slow path -- we have
6213                                          * allocated string space, and we're
6214                                          * getting the stack of a process that
6215                                          * has helpers.  Call into a separate
6216                                          * routine to perform this processing.
6217                                          */
6218                                         dtrace_action_ustack(&mstate, state,
6219                                             (uint64_t *)(tomax + valoffs),
6220                                             rec->dtrd_arg);
6221                                         continue;
6222                                 }
6223 
6224                                 /*
6225                                  * Clear the string space, since there's no
6226                                  * helper to do it for us.
6227                                  */
6228                                 if (DTRACE_USTACK_STRSIZE(rec->dtrd_arg) != 0) {
6229                                         int depth = DTRACE_USTACK_NFRAMES(
6230                                             rec->dtrd_arg);
6231                                         size_t strsize = DTRACE_USTACK_STRSIZE(
6232                                             rec->dtrd_arg);
6233                                         uint64_t *buf = (uint64_t *)(tomax +
6234                                             valoffs);
6235                                         void *strspace = &buf[depth + 1];
6236 
6237                                         dtrace_bzero(strspace,
6238                                             MIN(depth, strsize));
6239                                 }
6240 
6241                                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
6242                                 dtrace_getupcstack((uint64_t *)
6243                                     (tomax + valoffs),
6244                                     DTRACE_USTACK_NFRAMES(rec->dtrd_arg) + 1);
6245                                 DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
6246                                 continue;
6247 
6248                         default:
6249                                 break;
6250                         }
6251 
6252                         dp = act->dta_difo;
6253                         ASSERT(dp != NULL);
6254 
6255                         val = dtrace_dif_emulate(dp, &mstate, vstate, state);
6256 
6257                         if (*flags & CPU_DTRACE_ERROR)
6258                                 continue;
6259 
6260                         switch (act->dta_kind) {
6261                         case DTRACEACT_SPECULATE:
6262                                 ASSERT(buf == &state->dts_buffer[cpuid]);
6263                                 buf = dtrace_speculation_buffer(state,
6264                                     cpuid, val);
6265 
6266                                 if (buf == NULL) {
6267                                         *flags |= CPU_DTRACE_DROP;
6268                                         continue;
6269                                 }
6270 
6271                                 offs = dtrace_buffer_reserve(buf,
6272                                     ecb->dte_needed, ecb->dte_alignment,
6273                                     state, NULL);
6274 
6275                                 if (offs < 0) {
6276                                         *flags |= CPU_DTRACE_DROP;
6277                                         continue;
6278                                 }
6279 
6280                                 tomax = buf->dtb_tomax;
6281                                 ASSERT(tomax != NULL);
6282 
6283                                 if (ecb->dte_size != 0)
6284                                         DTRACE_STORE(uint32_t, tomax, offs,
6285                                             ecb->dte_epid);
6286                                 continue;
6287 
6288                         case DTRACEACT_CHILL:
6289                                 if (dtrace_priv_kernel_destructive(state))
6290                                         dtrace_action_chill(&mstate, val);
6291                                 continue;
6292 
6293                         case DTRACEACT_RAISE:
6294                                 if (dtrace_priv_proc_destructive(state,
6295                                     &mstate))
6296                                         dtrace_action_raise(val);
6297                                 continue;
6298 
6299                         case DTRACEACT_COMMIT:
6300                                 ASSERT(!committed);
6301 
6302                                 /*
6303                                  * We need to commit our buffer state.
6304                                  */
6305                                 if (ecb->dte_size)
6306                                         buf->dtb_offset = offs + ecb->dte_size;
6307                                 buf = &state->dts_buffer[cpuid];
6308                                 dtrace_speculation_commit(state, cpuid, val);
6309                                 committed = 1;
6310                                 continue;
6311 
6312                         case DTRACEACT_DISCARD:
6313                                 dtrace_speculation_discard(state, cpuid, val);
6314                                 continue;
6315 
6316                         case DTRACEACT_DIFEXPR:
6317                         case DTRACEACT_LIBACT:
6318                         case DTRACEACT_PRINTF:
6319                         case DTRACEACT_PRINTA:
6320                         case DTRACEACT_SYSTEM:
6321                         case DTRACEACT_FREOPEN:
6322                         case DTRACEACT_TRACEMEM:
6323                                 break;
6324 
6325                         case DTRACEACT_TRACEMEM_DYNSIZE:
6326                                 tracememsize = val;
6327                                 break;
6328 
6329                         case DTRACEACT_SYM:
6330                         case DTRACEACT_MOD:
6331                                 if (!dtrace_priv_kernel(state))
6332                                         continue;
6333                                 break;
6334 
6335                         case DTRACEACT_USYM:
6336                         case DTRACEACT_UMOD:
6337                         case DTRACEACT_UADDR: {
6338                                 struct pid *pid = curthread->t_procp->p_pidp;
6339 
6340                                 if (!dtrace_priv_proc(state, &mstate))
6341                                         continue;
6342 
6343                                 DTRACE_STORE(uint64_t, tomax,
6344                                     valoffs, (uint64_t)pid->pid_id);
6345                                 DTRACE_STORE(uint64_t, tomax,
6346                                     valoffs + sizeof (uint64_t), val);
6347 
6348                                 continue;
6349                         }
6350 
6351                         case DTRACEACT_EXIT: {
6352                                 /*
6353                                  * For the exit action, we are going to attempt
6354                                  * to atomically set our activity to be
6355                                  * draining.  If this fails (either because
6356                                  * another CPU has beat us to the exit action,
6357                                  * or because our current activity is something
6358                                  * other than ACTIVE or WARMUP), we will
6359                                  * continue.  This assures that the exit action
6360                                  * can be successfully recorded at most once
6361                                  * when we're in the ACTIVE state.  If we're
6362                                  * encountering the exit() action while in
6363                                  * COOLDOWN, however, we want to honor the new
6364                                  * status code.  (We know that we're the only
6365                                  * thread in COOLDOWN, so there is no race.)
6366                                  */
6367                                 void *activity = &state->dts_activity;
6368                                 dtrace_activity_t current = state->dts_activity;
6369 
6370                                 if (current == DTRACE_ACTIVITY_COOLDOWN)
6371                                         break;
6372 
6373                                 if (current != DTRACE_ACTIVITY_WARMUP)
6374                                         current = DTRACE_ACTIVITY_ACTIVE;
6375 
6376                                 if (dtrace_cas32(activity, current,
6377                                     DTRACE_ACTIVITY_DRAINING) != current) {
6378                                         *flags |= CPU_DTRACE_DROP;
6379                                         continue;
6380                                 }
6381 
6382                                 break;
6383                         }
6384 
6385                         default:
6386                                 ASSERT(0);
6387                         }
6388 
6389                         if (dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF) {
6390                                 uintptr_t end = valoffs + size;
6391 
6392                                 if (tracememsize != 0 &&
6393                                     valoffs + tracememsize < end) {
6394                                         end = valoffs + tracememsize;
6395                                         tracememsize = 0;
6396                                 }
6397 
6398                                 if (!dtrace_vcanload((void *)(uintptr_t)val,
6399                                     &dp->dtdo_rtype, &mstate, vstate))
6400                                         continue;
6401 
6402                                 /*
6403                                  * If this is a string, we're going to only
6404                                  * load until we find the zero byte -- after
6405                                  * which we'll store zero bytes.
6406                                  */
6407                                 if (dp->dtdo_rtype.dtdt_kind ==
6408                                     DIF_TYPE_STRING) {
6409                                         char c = '\0' + 1;
6410                                         int intuple = act->dta_intuple;
6411                                         size_t s;
6412 
6413                                         for (s = 0; s < size; s++) {
6414                                                 if (c != '\0')
6415                                                         c = dtrace_load8(val++);
6416 
6417                                                 DTRACE_STORE(uint8_t, tomax,
6418                                                     valoffs++, c);
6419 
6420                                                 if (c == '\0' && intuple)
6421                                                         break;
6422                                         }
6423 
6424                                         continue;
6425                                 }
6426 
6427                                 while (valoffs < end) {
6428                                         DTRACE_STORE(uint8_t, tomax, valoffs++,
6429                                             dtrace_load8(val++));
6430                                 }
6431 
6432                                 continue;
6433                         }
6434 
6435                         switch (size) {
6436                         case 0:
6437                                 break;
6438 
6439                         case sizeof (uint8_t):
6440                                 DTRACE_STORE(uint8_t, tomax, valoffs, val);
6441                                 break;
6442                         case sizeof (uint16_t):
6443                                 DTRACE_STORE(uint16_t, tomax, valoffs, val);
6444                                 break;
6445                         case sizeof (uint32_t):
6446                                 DTRACE_STORE(uint32_t, tomax, valoffs, val);
6447                                 break;
6448                         case sizeof (uint64_t):
6449                                 DTRACE_STORE(uint64_t, tomax, valoffs, val);
6450                                 break;
6451                         default:
6452                                 /*
6453                                  * Any other size should have been returned by
6454                                  * reference, not by value.
6455                                  */
6456                                 ASSERT(0);
6457                                 break;
6458                         }
6459                 }
6460 
6461                 if (*flags & CPU_DTRACE_DROP)
6462                         continue;
6463 
6464                 if (*flags & CPU_DTRACE_FAULT) {
6465                         int ndx;
6466                         dtrace_action_t *err;
6467 
6468                         buf->dtb_errors++;
6469 
6470                         if (probe->dtpr_id == dtrace_probeid_error) {
6471                                 /*
6472                                  * There's nothing we can do -- we had an
6473                                  * error on the error probe.  We bump an
6474                                  * error counter to at least indicate that
6475                                  * this condition happened.
6476                                  */
6477                                 dtrace_error(&state->dts_dblerrors);
6478                                 continue;
6479                         }
6480 
6481                         if (vtime) {
6482                                 /*
6483                                  * Before recursing on dtrace_probe(), we
6484                                  * need to explicitly clear out our start
6485                                  * time to prevent it from being accumulated
6486                                  * into t_dtrace_vtime.
6487                                  */
6488                                 curthread->t_dtrace_start = 0;
6489                         }
6490 
6491                         /*
6492                          * Iterate over the actions to figure out which action
6493                          * we were processing when we experienced the error.
6494                          * Note that act points _past_ the faulting action; if
6495                          * act is ecb->dte_action, the fault was in the
6496                          * predicate, if it's ecb->dte_action->dta_next it's
6497                          * in action #1, and so on.
6498                          */
6499                         for (err = ecb->dte_action, ndx = 0;
6500                             err != act; err = err->dta_next, ndx++)
6501                                 continue;
6502 
6503                         dtrace_probe_error(state, ecb->dte_epid, ndx,
6504                             (mstate.dtms_present & DTRACE_MSTATE_FLTOFFS) ?
6505                             mstate.dtms_fltoffs : -1, DTRACE_FLAGS2FLT(*flags),
6506                             cpu_core[cpuid].cpuc_dtrace_illval);
6507 
6508                         continue;
6509                 }
6510 
6511                 if (!committed)
6512                         buf->dtb_offset = offs + ecb->dte_size;
6513         }
6514 
6515         if (vtime)
6516                 curthread->t_dtrace_start = dtrace_gethrtime();
6517 
6518         dtrace_interrupt_enable(cookie);
6519 }
6520 
6521 /*
6522  * DTrace Probe Hashing Functions
6523  *
6524  * The functions in this section (and indeed, the functions in remaining
6525  * sections) are not _called_ from probe context.  (Any exceptions to this are
6526  * marked with a "Note:".)  Rather, they are called from elsewhere in the
6527  * DTrace framework to look-up probes in, add probes to and remove probes from
6528  * the DTrace probe hashes.  (Each probe is hashed by each element of the
6529  * probe tuple -- allowing for fast lookups, regardless of what was
6530  * specified.)
6531  */
6532 static uint_t
6533 dtrace_hash_str(char *p)
6534 {
6535         unsigned int g;
6536         uint_t hval = 0;
6537 
6538         while (*p) {
6539                 hval = (hval << 4) + *p++;
6540                 if ((g = (hval & 0xf0000000)) != 0)
6541                         hval ^= g >> 24;
6542                 hval &= ~g;
6543         }
6544         return (hval);
6545 }
6546 
6547 static dtrace_hash_t *
6548 dtrace_hash_create(uintptr_t stroffs, uintptr_t nextoffs, uintptr_t prevoffs)
6549 {
6550         dtrace_hash_t *hash = kmem_zalloc(sizeof (dtrace_hash_t), KM_SLEEP);
6551 
6552         hash->dth_stroffs = stroffs;
6553         hash->dth_nextoffs = nextoffs;
6554         hash->dth_prevoffs = prevoffs;
6555 
6556         hash->dth_size = 1;
6557         hash->dth_mask = hash->dth_size - 1;
6558 
6559         hash->dth_tab = kmem_zalloc(hash->dth_size *
6560             sizeof (dtrace_hashbucket_t *), KM_SLEEP);
6561 
6562         return (hash);
6563 }
6564 
6565 static void
6566 dtrace_hash_destroy(dtrace_hash_t *hash)
6567 {
6568 #ifdef DEBUG
6569         int i;
6570 
6571         for (i = 0; i < hash->dth_size; i++)
6572                 ASSERT(hash->dth_tab[i] == NULL);
6573 #endif
6574 
6575         kmem_free(hash->dth_tab,
6576             hash->dth_size * sizeof (dtrace_hashbucket_t *));
6577         kmem_free(hash, sizeof (dtrace_hash_t));
6578 }
6579 
6580 static void
6581 dtrace_hash_resize(dtrace_hash_t *hash)
6582 {
6583         int size = hash->dth_size, i, ndx;
6584         int new_size = hash->dth_size << 1;
6585         int new_mask = new_size - 1;
6586         dtrace_hashbucket_t **new_tab, *bucket, *next;
6587 
6588         ASSERT((new_size & new_mask) == 0);
6589 
6590         new_tab = kmem_zalloc(new_size * sizeof (void *), KM_SLEEP);
6591 
6592         for (i = 0; i < size; i++) {
6593                 for (bucket = hash->dth_tab[i]; bucket != NULL; bucket = next) {
6594                         dtrace_probe_t *probe = bucket->dthb_chain;
6595 
6596                         ASSERT(probe != NULL);
6597                         ndx = DTRACE_HASHSTR(hash, probe) & new_mask;
6598 
6599                         next = bucket->dthb_next;
6600                         bucket->dthb_next = new_tab[ndx];
6601                         new_tab[ndx] = bucket;
6602                 }
6603         }
6604 
6605         kmem_free(hash->dth_tab, hash->dth_size * sizeof (void *));
6606         hash->dth_tab = new_tab;
6607         hash->dth_size = new_size;
6608         hash->dth_mask = new_mask;
6609 }
6610 
6611 static void
6612 dtrace_hash_add(dtrace_hash_t *hash, dtrace_probe_t *new)
6613 {
6614         int hashval = DTRACE_HASHSTR(hash, new);
6615         int ndx = hashval & hash->dth_mask;
6616         dtrace_hashbucket_t *bucket = hash->dth_tab[ndx];
6617         dtrace_probe_t **nextp, **prevp;
6618 
6619         for (; bucket != NULL; bucket = bucket->dthb_next) {
6620                 if (DTRACE_HASHEQ(hash, bucket->dthb_chain, new))
6621                         goto add;
6622         }
6623 
6624         if ((hash->dth_nbuckets >> 1) > hash->dth_size) {
6625                 dtrace_hash_resize(hash);
6626                 dtrace_hash_add(hash, new);
6627                 return;
6628         }
6629 
6630         bucket = kmem_zalloc(sizeof (dtrace_hashbucket_t), KM_SLEEP);
6631         bucket->dthb_next = hash->dth_tab[ndx];
6632         hash->dth_tab[ndx] = bucket;
6633         hash->dth_nbuckets++;
6634 
6635 add:
6636         nextp = DTRACE_HASHNEXT(hash, new);
6637         ASSERT(*nextp == NULL && *(DTRACE_HASHPREV(hash, new)) == NULL);
6638         *nextp = bucket->dthb_chain;
6639 
6640         if (bucket->dthb_chain != NULL) {
6641                 prevp = DTRACE_HASHPREV(hash, bucket->dthb_chain);
6642                 ASSERT(*prevp == NULL);
6643                 *prevp = new;
6644         }
6645 
6646         bucket->dthb_chain = new;
6647         bucket->dthb_len++;
6648 }
6649 
6650 static dtrace_probe_t *
6651 dtrace_hash_lookup(dtrace_hash_t *hash, dtrace_probe_t *template)
6652 {
6653         int hashval = DTRACE_HASHSTR(hash, template);
6654         int ndx = hashval & hash->dth_mask;
6655         dtrace_hashbucket_t *bucket = hash->dth_tab[ndx];
6656 
6657         for (; bucket != NULL; bucket = bucket->dthb_next) {
6658                 if (DTRACE_HASHEQ(hash, bucket->dthb_chain, template))
6659                         return (bucket->dthb_chain);
6660         }
6661 
6662         return (NULL);
6663 }
6664 
6665 static int
6666 dtrace_hash_collisions(dtrace_hash_t *hash, dtrace_probe_t *template)
6667 {
6668         int hashval = DTRACE_HASHSTR(hash, template);
6669         int ndx = hashval & hash->dth_mask;
6670         dtrace_hashbucket_t *bucket = hash->dth_tab[ndx];
6671 
6672         for (; bucket != NULL; bucket = bucket->dthb_next) {
6673                 if (DTRACE_HASHEQ(hash, bucket->dthb_chain, template))
6674                         return (bucket->dthb_len);
6675         }
6676 
6677         return (NULL);
6678 }
6679 
6680 static void
6681 dtrace_hash_remove(dtrace_hash_t *hash, dtrace_probe_t *probe)
6682 {
6683         int ndx = DTRACE_HASHSTR(hash, probe) & hash->dth_mask;
6684         dtrace_hashbucket_t *bucket = hash->dth_tab[ndx];
6685 
6686         dtrace_probe_t **prevp = DTRACE_HASHPREV(hash, probe);
6687         dtrace_probe_t **nextp = DTRACE_HASHNEXT(hash, probe);
6688 
6689         /*
6690          * Find the bucket that we're removing this probe from.
6691          */
6692         for (; bucket != NULL; bucket = bucket->dthb_next) {
6693                 if (DTRACE_HASHEQ(hash, bucket->dthb_chain, probe))
6694                         break;
6695         }
6696 
6697         ASSERT(bucket != NULL);
6698 
6699         if (*prevp == NULL) {
6700                 if (*nextp == NULL) {
6701                         /*
6702                          * The removed probe was the only probe on this
6703                          * bucket; we need to remove the bucket.
6704                          */
6705                         dtrace_hashbucket_t *b = hash->dth_tab[ndx];
6706 
6707                         ASSERT(bucket->dthb_chain == probe);
6708                         ASSERT(b != NULL);
6709 
6710                         if (b == bucket) {
6711                                 hash->dth_tab[ndx] = bucket->dthb_next;
6712                         } else {
6713                                 while (b->dthb_next != bucket)
6714                                         b = b->dthb_next;
6715                                 b->dthb_next = bucket->dthb_next;
6716                         }
6717 
6718                         ASSERT(hash->dth_nbuckets > 0);
6719                         hash->dth_nbuckets--;
6720                         kmem_free(bucket, sizeof (dtrace_hashbucket_t));
6721                         return;
6722                 }
6723 
6724                 bucket->dthb_chain = *nextp;
6725         } else {
6726                 *(DTRACE_HASHNEXT(hash, *prevp)) = *nextp;
6727         }
6728 
6729         if (*nextp != NULL)
6730                 *(DTRACE_HASHPREV(hash, *nextp)) = *prevp;
6731 }
6732 
6733 /*
6734  * DTrace Utility Functions
6735  *
6736  * These are random utility functions that are _not_ called from probe context.
6737  */
6738 static int
6739 dtrace_badattr(const dtrace_attribute_t *a)
6740 {
6741         return (a->dtat_name > DTRACE_STABILITY_MAX ||
6742             a->dtat_data > DTRACE_STABILITY_MAX ||
6743             a->dtat_class > DTRACE_CLASS_MAX);
6744 }
6745 
6746 /*
6747  * Return a duplicate copy of a string.  If the specified string is NULL,
6748  * this function returns a zero-length string.
6749  */
6750 static char *
6751 dtrace_strdup(const char *str)
6752 {
6753         char *new = kmem_zalloc((str != NULL ? strlen(str) : 0) + 1, KM_SLEEP);
6754 
6755         if (str != NULL)
6756                 (void) strcpy(new, str);
6757 
6758         return (new);
6759 }
6760 
6761 #define DTRACE_ISALPHA(c)       \
6762         (((c) >= 'a' && (c) <= 'z') || ((c) >= 'A' && (c) <= 'Z'))
6763 
6764 static int
6765 dtrace_badname(const char *s)
6766 {
6767         char c;
6768 
6769         if (s == NULL || (c = *s++) == '\0')
6770                 return (0);
6771 
6772         if (!DTRACE_ISALPHA(c) && c != '-' && c != '_' && c != '.')
6773                 return (1);
6774 
6775         while ((c = *s++) != '\0') {
6776                 if (!DTRACE_ISALPHA(c) && (c < '0' || c > '9') &&
6777                     c != '-' && c != '_' && c != '.' && c != '`')
6778                         return (1);
6779         }
6780 
6781         return (0);
6782 }
6783 
6784 static void
6785 dtrace_cred2priv(cred_t *cr, uint32_t *privp, uid_t *uidp, zoneid_t *zoneidp)
6786 {
6787         uint32_t priv;
6788 
6789         if (cr == NULL || PRIV_POLICY_ONLY(cr, PRIV_ALL, B_FALSE)) {
6790                 /*
6791                  * For DTRACE_PRIV_ALL, the uid and zoneid don't matter.
6792                  */
6793                 priv = DTRACE_PRIV_ALL;
6794         } else {
6795                 *uidp = crgetuid(cr);
6796                 *zoneidp = crgetzoneid(cr);
6797 
6798                 priv = 0;
6799                 if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_KERNEL, B_FALSE))
6800                         priv |= DTRACE_PRIV_KERNEL | DTRACE_PRIV_USER;
6801                 else if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_USER, B_FALSE))
6802                         priv |= DTRACE_PRIV_USER;
6803                 if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_PROC, B_FALSE))
6804                         priv |= DTRACE_PRIV_PROC;
6805                 if (PRIV_POLICY_ONLY(cr, PRIV_PROC_OWNER, B_FALSE))
6806                         priv |= DTRACE_PRIV_OWNER;
6807                 if (PRIV_POLICY_ONLY(cr, PRIV_PROC_ZONE, B_FALSE))
6808                         priv |= DTRACE_PRIV_ZONEOWNER;
6809         }
6810 
6811         *privp = priv;
6812 }
6813 
6814 #ifdef DTRACE_ERRDEBUG
6815 static void
6816 dtrace_errdebug(const char *str)
6817 {
6818         int hval = dtrace_hash_str((char *)str) % DTRACE_ERRHASHSZ;
6819         int occupied = 0;
6820 
6821         mutex_enter(&dtrace_errlock);
6822         dtrace_errlast = str;
6823         dtrace_errthread = curthread;
6824 
6825         while (occupied++ < DTRACE_ERRHASHSZ) {
6826                 if (dtrace_errhash[hval].dter_msg == str) {
6827                         dtrace_errhash[hval].dter_count++;
6828                         goto out;
6829                 }
6830 
6831                 if (dtrace_errhash[hval].dter_msg != NULL) {
6832                         hval = (hval + 1) % DTRACE_ERRHASHSZ;
6833                         continue;
6834                 }
6835 
6836                 dtrace_errhash[hval].dter_msg = str;
6837                 dtrace_errhash[hval].dter_count = 1;
6838                 goto out;
6839         }
6840 
6841         panic("dtrace: undersized error hash");
6842 out:
6843         mutex_exit(&dtrace_errlock);
6844 }
6845 #endif
6846 
6847 /*
6848  * DTrace Matching Functions
6849  *
6850  * These functions are used to match groups of probes, given some elements of
6851  * a probe tuple, or some globbed expressions for elements of a probe tuple.
6852  */
6853 static int
6854 dtrace_match_priv(const dtrace_probe_t *prp, uint32_t priv, uid_t uid,
6855     zoneid_t zoneid)
6856 {
6857         if (priv != DTRACE_PRIV_ALL) {
6858                 uint32_t ppriv = prp->dtpr_provider->dtpv_priv.dtpp_flags;
6859                 uint32_t match = priv & ppriv;
6860 
6861                 /*
6862                  * No PRIV_DTRACE_* privileges...
6863                  */
6864                 if ((priv & (DTRACE_PRIV_PROC | DTRACE_PRIV_USER |
6865                     DTRACE_PRIV_KERNEL)) == 0)
6866                         return (0);
6867 
6868                 /*
6869                  * No matching bits, but there were bits to match...
6870                  */
6871                 if (match == 0 && ppriv != 0)
6872                         return (0);
6873 
6874                 /*
6875                  * Need to have permissions to the process, but don't...
6876                  */
6877                 if (((ppriv & ~match) & DTRACE_PRIV_OWNER) != 0 &&
6878                     uid != prp->dtpr_provider->dtpv_priv.dtpp_uid) {
6879                         return (0);
6880                 }
6881 
6882                 /*
6883                  * Need to be in the same zone unless we possess the
6884                  * privilege to examine all zones.
6885                  */
6886                 if (((ppriv & ~match) & DTRACE_PRIV_ZONEOWNER) != 0 &&
6887                     zoneid != prp->dtpr_provider->dtpv_priv.dtpp_zoneid) {
6888                         return (0);
6889                 }
6890         }
6891 
6892         return (1);
6893 }
6894 
6895 /*
6896  * dtrace_match_probe compares a dtrace_probe_t to a pre-compiled key, which
6897  * consists of input pattern strings and an ops-vector to evaluate them.
6898  * This function returns >0 for match, 0 for no match, and <0 for error.
6899  */
6900 static int
6901 dtrace_match_probe(const dtrace_probe_t *prp, const dtrace_probekey_t *pkp,
6902     uint32_t priv, uid_t uid, zoneid_t zoneid)
6903 {
6904         dtrace_provider_t *pvp = prp->dtpr_provider;
6905         int rv;
6906 
6907         if (pvp->dtpv_defunct)
6908                 return (0);
6909 
6910         if ((rv = pkp->dtpk_pmatch(pvp->dtpv_name, pkp->dtpk_prov, 0)) <= 0)
6911                 return (rv);
6912 
6913         if ((rv = pkp->dtpk_mmatch(prp->dtpr_mod, pkp->dtpk_mod, 0)) <= 0)
6914                 return (rv);
6915 
6916         if ((rv = pkp->dtpk_fmatch(prp->dtpr_func, pkp->dtpk_func, 0)) <= 0)
6917                 return (rv);
6918 
6919         if ((rv = pkp->dtpk_nmatch(prp->dtpr_name, pkp->dtpk_name, 0)) <= 0)
6920                 return (rv);
6921 
6922         if (dtrace_match_priv(prp, priv, uid, zoneid) == 0)
6923                 return (0);
6924 
6925         return (rv);
6926 }
6927 
6928 /*
6929  * dtrace_match_glob() is a safe kernel implementation of the gmatch(3GEN)
6930  * interface for matching a glob pattern 'p' to an input string 's'.  Unlike
6931  * libc's version, the kernel version only applies to 8-bit ASCII strings.
6932  * In addition, all of the recursion cases except for '*' matching have been
6933  * unwound.  For '*', we still implement recursive evaluation, but a depth
6934  * counter is maintained and matching is aborted if we recurse too deep.
6935  * The function returns 0 if no match, >0 if match, and <0 if recursion error.
6936  */
6937 static int
6938 dtrace_match_glob(const char *s, const char *p, int depth)
6939 {
6940         const char *olds;
6941         char s1, c;
6942         int gs;
6943 
6944         if (depth > DTRACE_PROBEKEY_MAXDEPTH)
6945                 return (-1);
6946 
6947         if (s == NULL)
6948                 s = ""; /* treat NULL as empty string */
6949 
6950 top:
6951         olds = s;
6952         s1 = *s++;
6953 
6954         if (p == NULL)
6955                 return (0);
6956 
6957         if ((c = *p++) == '\0')
6958                 return (s1 == '\0');
6959 
6960         switch (c) {
6961         case '[': {
6962                 int ok = 0, notflag = 0;
6963                 char lc = '\0';
6964 
6965                 if (s1 == '\0')
6966                         return (0);
6967 
6968                 if (*p == '!') {
6969                         notflag = 1;
6970                         p++;
6971                 }
6972 
6973                 if ((c = *p++) == '\0')
6974                         return (0);
6975 
6976                 do {
6977                         if (c == '-' && lc != '\0' && *p != ']') {
6978                                 if ((c = *p++) == '\0')
6979                                         return (0);
6980                                 if (c == '\\' && (c = *p++) == '\0')
6981                                         return (0);
6982 
6983                                 if (notflag) {
6984                                         if (s1 < lc || s1 > c)
6985                                                 ok++;
6986                                         else
6987                                                 return (0);
6988                                 } else if (lc <= s1 && s1 <= c)
6989                                         ok++;
6990 
6991                         } else if (c == '\\' && (c = *p++) == '\0')
6992                                 return (0);
6993 
6994                         lc = c; /* save left-hand 'c' for next iteration */
6995 
6996                         if (notflag) {
6997                                 if (s1 != c)
6998                                         ok++;
6999                                 else
7000                                         return (0);
7001                         } else if (s1 == c)
7002                                 ok++;
7003 
7004                         if ((c = *p++) == '\0')
7005                                 return (0);
7006 
7007                 } while (c != ']');
7008 
7009                 if (ok)
7010                         goto top;
7011 
7012                 return (0);
7013         }
7014 
7015         case '\\':
7016                 if ((c = *p++) == '\0')
7017                         return (0);
7018                 /*FALLTHRU*/
7019 
7020         default:
7021                 if (c != s1)
7022                         return (0);
7023                 /*FALLTHRU*/
7024 
7025         case '?':
7026                 if (s1 != '\0')
7027                         goto top;
7028                 return (0);
7029 
7030         case '*':
7031                 while (*p == '*')
7032                         p++; /* consecutive *'s are identical to a single one */
7033 
7034                 if (*p == '\0')
7035                         return (1);
7036 
7037                 for (s = olds; *s != '\0'; s++) {
7038                         if ((gs = dtrace_match_glob(s, p, depth + 1)) != 0)
7039                                 return (gs);
7040                 }
7041 
7042                 return (0);
7043         }
7044 }
7045 
7046 /*ARGSUSED*/
7047 static int
7048 dtrace_match_string(const char *s, const char *p, int depth)
7049 {
7050         return (s != NULL && strcmp(s, p) == 0);
7051 }
7052 
7053 /*ARGSUSED*/
7054 static int
7055 dtrace_match_nul(const char *s, const char *p, int depth)
7056 {
7057         return (1); /* always match the empty pattern */
7058 }
7059 
7060 /*ARGSUSED*/
7061 static int
7062 dtrace_match_nonzero(const char *s, const char *p, int depth)
7063 {
7064         return (s != NULL && s[0] != '\0');
7065 }
7066 
7067 static int
7068 dtrace_match(const dtrace_probekey_t *pkp, uint32_t priv, uid_t uid,
7069     zoneid_t zoneid, int (*matched)(dtrace_probe_t *, void *), void *arg)
7070 {
7071         dtrace_probe_t template, *probe;
7072         dtrace_hash_t *hash = NULL;
7073         int len, rc, best = INT_MAX, nmatched = 0;
7074         dtrace_id_t i;
7075 
7076         ASSERT(MUTEX_HELD(&dtrace_lock));
7077 
7078         /*
7079          * If the probe ID is specified in the key, just lookup by ID and
7080          * invoke the match callback once if a matching probe is found.
7081          */
7082         if (pkp->dtpk_id != DTRACE_IDNONE) {
7083                 if ((probe = dtrace_probe_lookup_id(pkp->dtpk_id)) != NULL &&
7084                     dtrace_match_probe(probe, pkp, priv, uid, zoneid) > 0) {
7085                         if ((*matched)(probe, arg) == DTRACE_MATCH_FAIL)
7086                                 return (DTRACE_MATCH_FAIL);
7087                         nmatched++;
7088                 }
7089                 return (nmatched);
7090         }
7091 
7092         template.dtpr_mod = (char *)pkp->dtpk_mod;
7093         template.dtpr_func = (char *)pkp->dtpk_func;
7094         template.dtpr_name = (char *)pkp->dtpk_name;
7095 
7096         /*
7097          * We want to find the most distinct of the module name, function
7098          * name, and name.  So for each one that is not a glob pattern or
7099          * empty string, we perform a lookup in the corresponding hash and
7100          * use the hash table with the fewest collisions to do our search.
7101          */
7102         if (pkp->dtpk_mmatch == &dtrace_match_string &&
7103             (len = dtrace_hash_collisions(dtrace_bymod, &template)) < best) {
7104                 best = len;
7105                 hash = dtrace_bymod;
7106         }
7107 
7108         if (pkp->dtpk_fmatch == &dtrace_match_string &&
7109             (len = dtrace_hash_collisions(dtrace_byfunc, &template)) < best) {
7110                 best = len;
7111                 hash = dtrace_byfunc;
7112         }
7113 
7114         if (pkp->dtpk_nmatch == &dtrace_match_string &&
7115             (len = dtrace_hash_collisions(dtrace_byname, &template)) < best) {
7116                 best = len;
7117                 hash = dtrace_byname;
7118         }
7119 
7120         /*
7121          * If we did not select a hash table, iterate over every probe and
7122          * invoke our callback for each one that matches our input probe key.
7123          */
7124         if (hash == NULL) {
7125                 for (i = 0; i < dtrace_nprobes; i++) {
7126                         if ((probe = dtrace_probes[i]) == NULL ||
7127                             dtrace_match_probe(probe, pkp, priv, uid,
7128                             zoneid) <= 0)
7129                                 continue;
7130 
7131                         nmatched++;
7132 
7133                         if ((rc = (*matched)(probe, arg)) !=
7134                             DTRACE_MATCH_NEXT) {
7135                                 if (rc == DTRACE_MATCH_FAIL)
7136                                         return (DTRACE_MATCH_FAIL);
7137                                 break;
7138                         }
7139                 }
7140 
7141                 return (nmatched);
7142         }
7143 
7144         /*
7145          * If we selected a hash table, iterate over each probe of the same key
7146          * name and invoke the callback for every probe that matches the other
7147          * attributes of our input probe key.
7148          */
7149         for (probe = dtrace_hash_lookup(hash, &template); probe != NULL;
7150             probe = *(DTRACE_HASHNEXT(hash, probe))) {
7151 
7152                 if (dtrace_match_probe(probe, pkp, priv, uid, zoneid) <= 0)
7153                         continue;
7154 
7155                 nmatched++;
7156 
7157                 if ((rc = (*matched)(probe, arg)) != DTRACE_MATCH_NEXT) {
7158                         if (rc == DTRACE_MATCH_FAIL)
7159                                 return (DTRACE_MATCH_FAIL);
7160                         break;
7161                 }
7162         }
7163 
7164         return (nmatched);
7165 }
7166 
7167 /*
7168  * Return the function pointer dtrace_probecmp() should use to compare the
7169  * specified pattern with a string.  For NULL or empty patterns, we select
7170  * dtrace_match_nul().  For glob pattern strings, we use dtrace_match_glob().
7171  * For non-empty non-glob strings, we use dtrace_match_string().
7172  */
7173 static dtrace_probekey_f *
7174 dtrace_probekey_func(const char *p)
7175 {
7176         char c;
7177 
7178         if (p == NULL || *p == '\0')
7179                 return (&dtrace_match_nul);
7180 
7181         while ((c = *p++) != '\0') {
7182                 if (c == '[' || c == '?' || c == '*' || c == '\\')
7183                         return (&dtrace_match_glob);
7184         }
7185 
7186         return (&dtrace_match_string);
7187 }
7188 
7189 /*
7190  * Build a probe comparison key for use with dtrace_match_probe() from the
7191  * given probe description.  By convention, a null key only matches anchored
7192  * probes: if each field is the empty string, reset dtpk_fmatch to
7193  * dtrace_match_nonzero().
7194  */
7195 static void
7196 dtrace_probekey(const dtrace_probedesc_t *pdp, dtrace_probekey_t *pkp)
7197 {
7198         pkp->dtpk_prov = pdp->dtpd_provider;
7199         pkp->dtpk_pmatch = dtrace_probekey_func(pdp->dtpd_provider);
7200 
7201         pkp->dtpk_mod = pdp->dtpd_mod;
7202         pkp->dtpk_mmatch = dtrace_probekey_func(pdp->dtpd_mod);
7203 
7204         pkp->dtpk_func = pdp->dtpd_func;
7205         pkp->dtpk_fmatch = dtrace_probekey_func(pdp->dtpd_func);
7206 
7207         pkp->dtpk_name = pdp->dtpd_name;
7208         pkp->dtpk_nmatch = dtrace_probekey_func(pdp->dtpd_name);
7209 
7210         pkp->dtpk_id = pdp->dtpd_id;
7211 
7212         if (pkp->dtpk_id == DTRACE_IDNONE &&
7213             pkp->dtpk_pmatch == &dtrace_match_nul &&
7214             pkp->dtpk_mmatch == &dtrace_match_nul &&
7215             pkp->dtpk_fmatch == &dtrace_match_nul &&
7216             pkp->dtpk_nmatch == &dtrace_match_nul)
7217                 pkp->dtpk_fmatch = &dtrace_match_nonzero;
7218 }
7219 
7220 /*
7221  * DTrace Provider-to-Framework API Functions
7222  *
7223  * These functions implement much of the Provider-to-Framework API, as
7224  * described in <sys/dtrace.h>.  The parts of the API not in this section are
7225  * the functions in the API for probe management (found below), and
7226  * dtrace_probe() itself (found above).
7227  */
7228 
7229 /*
7230  * Register the calling provider with the DTrace framework.  This should
7231  * generally be called by DTrace providers in their attach(9E) entry point.
7232  */
7233 int
7234 dtrace_register(const char *name, const dtrace_pattr_t *pap, uint32_t priv,
7235     cred_t *cr, const dtrace_pops_t *pops, void *arg, dtrace_provider_id_t *idp)
7236 {
7237         dtrace_provider_t *provider;
7238 
7239         if (name == NULL || pap == NULL || pops == NULL || idp == NULL) {
7240                 cmn_err(CE_WARN, "failed to register provider '%s': invalid "
7241                     "arguments", name ? name : "<NULL>");
7242                 return (EINVAL);
7243         }
7244 
7245         if (name[0] == '\0' || dtrace_badname(name)) {
7246                 cmn_err(CE_WARN, "failed to register provider '%s': invalid "
7247                     "provider name", name);
7248                 return (EINVAL);
7249         }
7250 
7251         if ((pops->dtps_provide == NULL && pops->dtps_provide_module == NULL) ||
7252             pops->dtps_enable == NULL || pops->dtps_disable == NULL ||
7253             pops->dtps_destroy == NULL ||
7254             ((pops->dtps_resume == NULL) != (pops->dtps_suspend == NULL))) {
7255                 cmn_err(CE_WARN, "failed to register provider '%s': invalid "
7256                     "provider ops", name);
7257                 return (EINVAL);
7258         }
7259 
7260         if (dtrace_badattr(&pap->dtpa_provider) ||
7261             dtrace_badattr(&pap->dtpa_mod) ||
7262             dtrace_badattr(&pap->dtpa_func) ||
7263             dtrace_badattr(&pap->dtpa_name) ||
7264             dtrace_badattr(&pap->dtpa_args)) {
7265                 cmn_err(CE_WARN, "failed to register provider '%s': invalid "
7266                     "provider attributes", name);
7267                 return (EINVAL);
7268         }
7269 
7270         if (priv & ~DTRACE_PRIV_ALL) {
7271                 cmn_err(CE_WARN, "failed to register provider '%s': invalid "
7272                     "privilege attributes", name);
7273                 return (EINVAL);
7274         }
7275 
7276         if ((priv & DTRACE_PRIV_KERNEL) &&
7277             (priv & (DTRACE_PRIV_USER | DTRACE_PRIV_OWNER)) &&
7278             pops->dtps_mode == NULL) {
7279                 cmn_err(CE_WARN, "failed to register provider '%s': need "
7280                     "dtps_mode() op for given privilege attributes", name);
7281                 return (EINVAL);
7282         }
7283 
7284         provider = kmem_zalloc(sizeof (dtrace_provider_t), KM_SLEEP);
7285         provider->dtpv_name = kmem_alloc(strlen(name) + 1, KM_SLEEP);
7286         (void) strcpy(provider->dtpv_name, name);
7287 
7288         provider->dtpv_attr = *pap;
7289         provider->dtpv_priv.dtpp_flags = priv;
7290         if (cr != NULL) {
7291                 provider->dtpv_priv.dtpp_uid = crgetuid(cr);
7292                 provider->dtpv_priv.dtpp_zoneid = crgetzoneid(cr);
7293         }
7294         provider->dtpv_pops = *pops;
7295 
7296         if (pops->dtps_provide == NULL) {
7297                 ASSERT(pops->dtps_provide_module != NULL);
7298                 provider->dtpv_pops.dtps_provide =
7299                     (void (*)(void *, const dtrace_probedesc_t *))dtrace_nullop;
7300         }
7301 
7302         if (pops->dtps_provide_module == NULL) {
7303                 ASSERT(pops->dtps_provide != NULL);
7304                 provider->dtpv_pops.dtps_provide_module =
7305                     (void (*)(void *, struct modctl *))dtrace_nullop;
7306         }
7307 
7308         if (pops->dtps_suspend == NULL) {
7309                 ASSERT(pops->dtps_resume == NULL);
7310                 provider->dtpv_pops.dtps_suspend =
7311                     (void (*)(void *, dtrace_id_t, void *))dtrace_nullop;
7312                 provider->dtpv_pops.dtps_resume =
7313                     (void (*)(void *, dtrace_id_t, void *))dtrace_nullop;
7314         }
7315 
7316         provider->dtpv_arg = arg;
7317         *idp = (dtrace_provider_id_t)provider;
7318 
7319         if (pops == &dtrace_provider_ops) {
7320                 ASSERT(MUTEX_HELD(&dtrace_provider_lock));
7321                 ASSERT(MUTEX_HELD(&dtrace_lock));
7322                 ASSERT(dtrace_anon.dta_enabling == NULL);
7323 
7324                 /*
7325                  * We make sure that the DTrace provider is at the head of
7326                  * the provider chain.
7327                  */
7328                 provider->dtpv_next = dtrace_provider;
7329                 dtrace_provider = provider;
7330                 return (0);
7331         }
7332 
7333         mutex_enter(&dtrace_provider_lock);
7334         mutex_enter(&dtrace_lock);
7335 
7336         /*
7337          * If there is at least one provider registered, we'll add this
7338          * provider after the first provider.
7339          */
7340         if (dtrace_provider != NULL) {
7341                 provider->dtpv_next = dtrace_provider->dtpv_next;
7342                 dtrace_provider->dtpv_next = provider;
7343         } else {
7344                 dtrace_provider = provider;
7345         }
7346 
7347         if (dtrace_retained != NULL) {
7348                 dtrace_enabling_provide(provider);
7349 
7350                 /*
7351                  * Now we need to call dtrace_enabling_matchall() -- which
7352                  * will acquire cpu_lock and dtrace_lock.  We therefore need
7353                  * to drop all of our locks before calling into it...
7354                  */
7355                 mutex_exit(&dtrace_lock);
7356                 mutex_exit(&dtrace_provider_lock);
7357                 dtrace_enabling_matchall();
7358 
7359                 return (0);
7360         }
7361 
7362         mutex_exit(&dtrace_lock);
7363         mutex_exit(&dtrace_provider_lock);
7364 
7365         return (0);
7366 }
7367 
7368 /*
7369  * Unregister the specified provider from the DTrace framework.  This should
7370  * generally be called by DTrace providers in their detach(9E) entry point.
7371  */
7372 int
7373 dtrace_unregister(dtrace_provider_id_t id)
7374 {
7375         dtrace_provider_t *old = (dtrace_provider_t *)id;
7376         dtrace_provider_t *prev = NULL;
7377         int i, self = 0, noreap = 0;
7378         dtrace_probe_t *probe, *first = NULL;
7379 
7380         if (old->dtpv_pops.dtps_enable ==
7381             (int (*)(void *, dtrace_id_t, void *))dtrace_enable_nullop) {
7382                 /*
7383                  * If DTrace itself is the provider, we're called with locks
7384                  * already held.
7385                  */
7386                 ASSERT(old == dtrace_provider);
7387                 ASSERT(dtrace_devi != NULL);
7388                 ASSERT(MUTEX_HELD(&dtrace_provider_lock));
7389                 ASSERT(MUTEX_HELD(&dtrace_lock));
7390                 self = 1;
7391 
7392                 if (dtrace_provider->dtpv_next != NULL) {
7393                         /*
7394                          * There's another provider here; return failure.
7395                          */
7396                         return (EBUSY);
7397                 }
7398         } else {
7399                 mutex_enter(&dtrace_provider_lock);
7400                 mutex_enter(&mod_lock);
7401                 mutex_enter(&dtrace_lock);
7402         }
7403 
7404         /*
7405          * If anyone has /dev/dtrace open, or if there are anonymous enabled
7406          * probes, we refuse to let providers slither away, unless this
7407          * provider has already been explicitly invalidated.
7408          */
7409         if (!old->dtpv_defunct &&
7410             (dtrace_opens || (dtrace_anon.dta_state != NULL &&
7411             dtrace_anon.dta_state->dts_necbs > 0))) {
7412                 if (!self) {
7413                         mutex_exit(&dtrace_lock);
7414                         mutex_exit(&mod_lock);
7415                         mutex_exit(&dtrace_provider_lock);
7416                 }
7417                 return (EBUSY);
7418         }
7419 
7420         /*
7421          * Attempt to destroy the probes associated with this provider.
7422          */
7423         for (i = 0; i < dtrace_nprobes; i++) {
7424                 if ((probe = dtrace_probes[i]) == NULL)
7425                         continue;
7426 
7427                 if (probe->dtpr_provider != old)
7428                         continue;
7429 
7430                 if (probe->dtpr_ecb == NULL)
7431                         continue;
7432 
7433                 /*
7434                  * If we are trying to unregister a defunct provider, and the
7435                  * provider was made defunct within the interval dictated by
7436                  * dtrace_unregister_defunct_reap, we'll (asynchronously)
7437                  * attempt to reap our enablings.  To denote that the provider
7438                  * should reattempt to unregister itself at some point in the
7439                  * future, we will return a differentiable error code (EAGAIN
7440                  * instead of EBUSY) in this case.
7441                  */
7442                 if (dtrace_gethrtime() - old->dtpv_defunct >
7443                     dtrace_unregister_defunct_reap)
7444                         noreap = 1;
7445 
7446                 if (!self) {
7447                         mutex_exit(&dtrace_lock);
7448                         mutex_exit(&mod_lock);
7449                         mutex_exit(&dtrace_provider_lock);
7450                 }
7451 
7452                 if (noreap)
7453                         return (EBUSY);
7454 
7455                 (void) taskq_dispatch(dtrace_taskq,
7456                     (task_func_t *)dtrace_enabling_reap, NULL, TQ_SLEEP);
7457 
7458                 return (EAGAIN);
7459         }
7460 
7461         /*
7462          * All of the probes for this provider are disabled; we can safely
7463          * remove all of them from their hash chains and from the probe array.
7464          */
7465         for (i = 0; i < dtrace_nprobes; i++) {
7466                 if ((probe = dtrace_probes[i]) == NULL)
7467                         continue;
7468 
7469                 if (probe->dtpr_provider != old)
7470                         continue;
7471 
7472                 dtrace_probes[i] = NULL;
7473 
7474                 dtrace_hash_remove(dtrace_bymod, probe);
7475                 dtrace_hash_remove(dtrace_byfunc, probe);
7476                 dtrace_hash_remove(dtrace_byname, probe);
7477 
7478                 if (first == NULL) {
7479                         first = probe;
7480                         probe->dtpr_nextmod = NULL;
7481                 } else {
7482                         probe->dtpr_nextmod = first;
7483                         first = probe;
7484                 }
7485         }
7486 
7487         /*
7488          * The provider's probes have been removed from the hash chains and
7489          * from the probe array.  Now issue a dtrace_sync() to be sure that
7490          * everyone has cleared out from any probe array processing.
7491          */
7492         dtrace_sync();
7493 
7494         for (probe = first; probe != NULL; probe = first) {
7495                 first = probe->dtpr_nextmod;
7496 
7497                 old->dtpv_pops.dtps_destroy(old->dtpv_arg, probe->dtpr_id,
7498                     probe->dtpr_arg);
7499                 kmem_free(probe->dtpr_mod, strlen(probe->dtpr_mod) + 1);
7500                 kmem_free(probe->dtpr_func, strlen(probe->dtpr_func) + 1);
7501                 kmem_free(probe->dtpr_name, strlen(probe->dtpr_name) + 1);
7502                 vmem_free(dtrace_arena, (void *)(uintptr_t)(probe->dtpr_id), 1);
7503                 kmem_free(probe, sizeof (dtrace_probe_t));
7504         }
7505 
7506         if ((prev = dtrace_provider) == old) {
7507                 ASSERT(self || dtrace_devi == NULL);
7508                 ASSERT(old->dtpv_next == NULL || dtrace_devi == NULL);
7509                 dtrace_provider = old->dtpv_next;
7510         } else {
7511                 while (prev != NULL && prev->dtpv_next != old)
7512                         prev = prev->dtpv_next;
7513 
7514                 if (prev == NULL) {
7515                         panic("attempt to unregister non-existent "
7516                             "dtrace provider %p\n", (void *)id);
7517                 }
7518 
7519                 prev->dtpv_next = old->dtpv_next;
7520         }
7521 
7522         if (!self) {
7523                 mutex_exit(&dtrace_lock);
7524                 mutex_exit(&mod_lock);
7525                 mutex_exit(&dtrace_provider_lock);
7526         }
7527 
7528         kmem_free(old->dtpv_name, strlen(old->dtpv_name) + 1);
7529         kmem_free(old, sizeof (dtrace_provider_t));
7530 
7531         return (0);
7532 }
7533 
7534 /*
7535  * Invalidate the specified provider.  All subsequent probe lookups for the
7536  * specified provider will fail, but its probes will not be removed.
7537  */
7538 void
7539 dtrace_invalidate(dtrace_provider_id_t id)
7540 {
7541         dtrace_provider_t *pvp = (dtrace_provider_t *)id;
7542 
7543         ASSERT(pvp->dtpv_pops.dtps_enable !=
7544             (int (*)(void *, dtrace_id_t, void *))dtrace_enable_nullop);
7545 
7546         mutex_enter(&dtrace_provider_lock);
7547         mutex_enter(&dtrace_lock);
7548 
7549         pvp->dtpv_defunct = dtrace_gethrtime();
7550 
7551         mutex_exit(&dtrace_lock);
7552         mutex_exit(&dtrace_provider_lock);
7553 }
7554 
7555 /*
7556  * Indicate whether or not DTrace has attached.
7557  */
7558 int
7559 dtrace_attached(void)
7560 {
7561         /*
7562          * dtrace_provider will be non-NULL iff the DTrace driver has
7563          * attached.  (It's non-NULL because DTrace is always itself a
7564          * provider.)
7565          */
7566         return (dtrace_provider != NULL);
7567 }
7568 
7569 /*
7570  * Remove all the unenabled probes for the given provider.  This function is
7571  * not unlike dtrace_unregister(), except that it doesn't remove the provider
7572  * -- just as many of its associated probes as it can.
7573  */
7574 int
7575 dtrace_condense(dtrace_provider_id_t id)
7576 {
7577         dtrace_provider_t *prov = (dtrace_provider_t *)id;
7578         int i;
7579         dtrace_probe_t *probe;
7580 
7581         /*
7582          * Make sure this isn't the dtrace provider itself.
7583          */
7584         ASSERT(prov->dtpv_pops.dtps_enable !=
7585             (int (*)(void *, dtrace_id_t, void *))dtrace_enable_nullop);
7586 
7587         mutex_enter(&dtrace_provider_lock);
7588         mutex_enter(&dtrace_lock);
7589 
7590         /*
7591          * Attempt to destroy the probes associated with this provider.
7592          */
7593         for (i = 0; i < dtrace_nprobes; i++) {
7594                 if ((probe = dtrace_probes[i]) == NULL)
7595                         continue;
7596 
7597                 if (probe->dtpr_provider != prov)
7598                         continue;
7599 
7600                 if (probe->dtpr_ecb != NULL)
7601                         continue;
7602 
7603                 dtrace_probes[i] = NULL;
7604 
7605                 dtrace_hash_remove(dtrace_bymod, probe);
7606                 dtrace_hash_remove(dtrace_byfunc, probe);
7607                 dtrace_hash_remove(dtrace_byname, probe);
7608 
7609                 prov->dtpv_pops.dtps_destroy(prov->dtpv_arg, i + 1,
7610                     probe->dtpr_arg);
7611                 kmem_free(probe->dtpr_mod, strlen(probe->dtpr_mod) + 1);
7612                 kmem_free(probe->dtpr_func, strlen(probe->dtpr_func) + 1);
7613                 kmem_free(probe->dtpr_name, strlen(probe->dtpr_name) + 1);
7614                 kmem_free(probe, sizeof (dtrace_probe_t));
7615                 vmem_free(dtrace_arena, (void *)((uintptr_t)i + 1), 1);
7616         }
7617 
7618         mutex_exit(&dtrace_lock);
7619         mutex_exit(&dtrace_provider_lock);
7620 
7621         return (0);
7622 }
7623 
7624 /*
7625  * DTrace Probe Management Functions
7626  *
7627  * The functions in this section perform the DTrace probe management,
7628  * including functions to create probes, look-up probes, and call into the
7629  * providers to request that probes be provided.  Some of these functions are
7630  * in the Provider-to-Framework API; these functions can be identified by the
7631  * fact that they are not declared "static".
7632  */
7633 
7634 /*
7635  * Create a probe with the specified module name, function name, and name.
7636  */
7637 dtrace_id_t
7638 dtrace_probe_create(dtrace_provider_id_t prov, const char *mod,
7639     const char *func, const char *name, int aframes, void *arg)
7640 {
7641         dtrace_probe_t *probe, **probes;
7642         dtrace_provider_t *provider = (dtrace_provider_t *)prov;
7643         dtrace_id_t id;
7644 
7645         if (provider == dtrace_provider) {
7646                 ASSERT(MUTEX_HELD(&dtrace_lock));
7647         } else {
7648                 mutex_enter(&dtrace_lock);
7649         }
7650 
7651         id = (dtrace_id_t)(uintptr_t)vmem_alloc(dtrace_arena, 1,
7652             VM_BESTFIT | VM_SLEEP);
7653         probe = kmem_zalloc(sizeof (dtrace_probe_t), KM_SLEEP);
7654 
7655         probe->dtpr_id = id;
7656         probe->dtpr_gen = dtrace_probegen++;
7657         probe->dtpr_mod = dtrace_strdup(mod);
7658         probe->dtpr_func = dtrace_strdup(func);
7659         probe->dtpr_name = dtrace_strdup(name);
7660         probe->dtpr_arg = arg;
7661         probe->dtpr_aframes = aframes;
7662         probe->dtpr_provider = provider;
7663 
7664         dtrace_hash_add(dtrace_bymod, probe);
7665         dtrace_hash_add(dtrace_byfunc, probe);
7666         dtrace_hash_add(dtrace_byname, probe);
7667 
7668         if (id - 1 >= dtrace_nprobes) {
7669                 size_t osize = dtrace_nprobes * sizeof (dtrace_probe_t *);
7670                 size_t nsize = osize << 1;
7671 
7672                 if (nsize == 0) {
7673                         ASSERT(osize == 0);
7674                         ASSERT(dtrace_probes == NULL);
7675                         nsize = sizeof (dtrace_probe_t *);
7676                 }
7677 
7678                 probes = kmem_zalloc(nsize, KM_SLEEP);
7679 
7680                 if (dtrace_probes == NULL) {
7681                         ASSERT(osize == 0);
7682                         dtrace_probes = probes;
7683                         dtrace_nprobes = 1;
7684                 } else {
7685                         dtrace_probe_t **oprobes = dtrace_probes;
7686 
7687                         bcopy(oprobes, probes, osize);
7688                         dtrace_membar_producer();
7689                         dtrace_probes = probes;
7690 
7691                         dtrace_sync();
7692 
7693                         /*
7694                          * All CPUs are now seeing the new probes array; we can
7695                          * safely free the old array.
7696                          */
7697                         kmem_free(oprobes, osize);
7698                         dtrace_nprobes <<= 1;
7699                 }
7700 
7701                 ASSERT(id - 1 < dtrace_nprobes);
7702         }
7703 
7704         ASSERT(dtrace_probes[id - 1] == NULL);
7705         dtrace_probes[id - 1] = probe;
7706 
7707         if (provider != dtrace_provider)
7708                 mutex_exit(&dtrace_lock);
7709 
7710         return (id);
7711 }
7712 
7713 static dtrace_probe_t *
7714 dtrace_probe_lookup_id(dtrace_id_t id)
7715 {
7716         ASSERT(MUTEX_HELD(&dtrace_lock));
7717 
7718         if (id == 0 || id > dtrace_nprobes)
7719                 return (NULL);
7720 
7721         return (dtrace_probes[id - 1]);
7722 }
7723 
7724 static int
7725 dtrace_probe_lookup_match(dtrace_probe_t *probe, void *arg)
7726 {
7727         *((dtrace_id_t *)arg) = probe->dtpr_id;
7728 
7729         return (DTRACE_MATCH_DONE);
7730 }
7731 
7732 /*
7733  * Look up a probe based on provider and one or more of module name, function
7734  * name and probe name.
7735  */
7736 dtrace_id_t
7737 dtrace_probe_lookup(dtrace_provider_id_t prid, const char *mod,
7738     const char *func, const char *name)
7739 {
7740         dtrace_probekey_t pkey;
7741         dtrace_id_t id;
7742         int match;
7743 
7744         pkey.dtpk_prov = ((dtrace_provider_t *)prid)->dtpv_name;
7745         pkey.dtpk_pmatch = &dtrace_match_string;
7746         pkey.dtpk_mod = mod;
7747         pkey.dtpk_mmatch = mod ? &dtrace_match_string : &dtrace_match_nul;
7748         pkey.dtpk_func = func;
7749         pkey.dtpk_fmatch = func ? &dtrace_match_string : &dtrace_match_nul;
7750         pkey.dtpk_name = name;
7751         pkey.dtpk_nmatch = name ? &dtrace_match_string : &dtrace_match_nul;
7752         pkey.dtpk_id = DTRACE_IDNONE;
7753 
7754         mutex_enter(&dtrace_lock);
7755         match = dtrace_match(&pkey, DTRACE_PRIV_ALL, 0, 0,
7756             dtrace_probe_lookup_match, &id);
7757         mutex_exit(&dtrace_lock);
7758 
7759         ASSERT(match == 1 || match == 0);
7760         return (match ? id : 0);
7761 }
7762 
7763 /*
7764  * Returns the probe argument associated with the specified probe.
7765  */
7766 void *
7767 dtrace_probe_arg(dtrace_provider_id_t id, dtrace_id_t pid)
7768 {
7769         dtrace_probe_t *probe;
7770         void *rval = NULL;
7771 
7772         mutex_enter(&dtrace_lock);
7773 
7774         if ((probe = dtrace_probe_lookup_id(pid)) != NULL &&
7775             probe->dtpr_provider == (dtrace_provider_t *)id)
7776                 rval = probe->dtpr_arg;
7777 
7778         mutex_exit(&dtrace_lock);
7779 
7780         return (rval);
7781 }
7782 
7783 /*
7784  * Copy a probe into a probe description.
7785  */
7786 static void
7787 dtrace_probe_description(const dtrace_probe_t *prp, dtrace_probedesc_t *pdp)
7788 {
7789         bzero(pdp, sizeof (dtrace_probedesc_t));
7790         pdp->dtpd_id = prp->dtpr_id;
7791 
7792         (void) strncpy(pdp->dtpd_provider,
7793             prp->dtpr_provider->dtpv_name, DTRACE_PROVNAMELEN - 1);
7794 
7795         (void) strncpy(pdp->dtpd_mod, prp->dtpr_mod, DTRACE_MODNAMELEN - 1);
7796         (void) strncpy(pdp->dtpd_func, prp->dtpr_func, DTRACE_FUNCNAMELEN - 1);
7797         (void) strncpy(pdp->dtpd_name, prp->dtpr_name, DTRACE_NAMELEN - 1);
7798 }
7799 
7800 /*
7801  * Called to indicate that a probe -- or probes -- should be provided by a
7802  * specfied provider.  If the specified description is NULL, the provider will
7803  * be told to provide all of its probes.  (This is done whenever a new
7804  * consumer comes along, or whenever a retained enabling is to be matched.) If
7805  * the specified description is non-NULL, the provider is given the
7806  * opportunity to dynamically provide the specified probe, allowing providers
7807  * to support the creation of probes on-the-fly.  (So-called _autocreated_
7808  * probes.)  If the provider is NULL, the operations will be applied to all
7809  * providers; if the provider is non-NULL the operations will only be applied
7810  * to the specified provider.  The dtrace_provider_lock must be held, and the
7811  * dtrace_lock must _not_ be held -- the provider's dtps_provide() operation
7812  * will need to grab the dtrace_lock when it reenters the framework through
7813  * dtrace_probe_lookup(), dtrace_probe_create(), etc.
7814  */
7815 static void
7816 dtrace_probe_provide(dtrace_probedesc_t *desc, dtrace_provider_t *prv)
7817 {
7818         struct modctl *ctl;
7819         int all = 0;
7820 
7821         ASSERT(MUTEX_HELD(&dtrace_provider_lock));
7822 
7823         if (prv == NULL) {
7824                 all = 1;
7825                 prv = dtrace_provider;
7826         }
7827 
7828         do {
7829                 /*
7830                  * First, call the blanket provide operation.
7831                  */
7832                 prv->dtpv_pops.dtps_provide(prv->dtpv_arg, desc);
7833 
7834                 /*
7835                  * Now call the per-module provide operation.  We will grab
7836                  * mod_lock to prevent the list from being modified.  Note
7837                  * that this also prevents the mod_busy bits from changing.
7838                  * (mod_busy can only be changed with mod_lock held.)
7839                  */
7840                 mutex_enter(&mod_lock);
7841 
7842                 ctl = &modules;
7843                 do {
7844                         if (ctl->mod_busy || ctl->mod_mp == NULL)
7845                                 continue;
7846 
7847                         prv->dtpv_pops.dtps_provide_module(prv->dtpv_arg, ctl);
7848 
7849                 } while ((ctl = ctl->mod_next) != &modules);
7850 
7851                 mutex_exit(&mod_lock);
7852         } while (all && (prv = prv->dtpv_next) != NULL);
7853 }
7854 
7855 /*
7856  * Iterate over each probe, and call the Framework-to-Provider API function
7857  * denoted by offs.
7858  */
7859 static void
7860 dtrace_probe_foreach(uintptr_t offs)
7861 {
7862         dtrace_provider_t *prov;
7863         void (*func)(void *, dtrace_id_t, void *);
7864         dtrace_probe_t *probe;
7865         dtrace_icookie_t cookie;
7866         int i;
7867 
7868         /*
7869          * We disable interrupts to walk through the probe array.  This is
7870          * safe -- the dtrace_sync() in dtrace_unregister() assures that we
7871          * won't see stale data.
7872          */
7873         cookie = dtrace_interrupt_disable();
7874 
7875         for (i = 0; i < dtrace_nprobes; i++) {
7876                 if ((probe = dtrace_probes[i]) == NULL)
7877                         continue;
7878 
7879                 if (probe->dtpr_ecb == NULL) {
7880                         /*
7881                          * This probe isn't enabled -- don't call the function.
7882                          */
7883                         continue;
7884                 }
7885 
7886                 prov = probe->dtpr_provider;
7887                 func = *((void(**)(void *, dtrace_id_t, void *))
7888                     ((uintptr_t)&prov->dtpv_pops + offs));
7889 
7890                 func(prov->dtpv_arg, i + 1, probe->dtpr_arg);
7891         }
7892 
7893         dtrace_interrupt_enable(cookie);
7894 }
7895 
7896 static int
7897 dtrace_probe_enable(const dtrace_probedesc_t *desc, dtrace_enabling_t *enab)
7898 {
7899         dtrace_probekey_t pkey;
7900         uint32_t priv;
7901         uid_t uid;
7902         zoneid_t zoneid;
7903 
7904         ASSERT(MUTEX_HELD(&dtrace_lock));
7905         dtrace_ecb_create_cache = NULL;
7906 
7907         if (desc == NULL) {
7908                 /*
7909                  * If we're passed a NULL description, we're being asked to
7910                  * create an ECB with a NULL probe.
7911                  */
7912                 (void) dtrace_ecb_create_enable(NULL, enab);
7913                 return (0);
7914         }
7915 
7916         dtrace_probekey(desc, &pkey);
7917         dtrace_cred2priv(enab->dten_vstate->dtvs_state->dts_cred.dcr_cred,
7918             &priv, &uid, &zoneid);
7919 
7920         return (dtrace_match(&pkey, priv, uid, zoneid, dtrace_ecb_create_enable,
7921             enab));
7922 }
7923 
7924 /*
7925  * DTrace Helper Provider Functions
7926  */
7927 static void
7928 dtrace_dofattr2attr(dtrace_attribute_t *attr, const dof_attr_t dofattr)
7929 {
7930         attr->dtat_name = DOF_ATTR_NAME(dofattr);
7931         attr->dtat_data = DOF_ATTR_DATA(dofattr);
7932         attr->dtat_class = DOF_ATTR_CLASS(dofattr);
7933 }
7934 
7935 static void
7936 dtrace_dofprov2hprov(dtrace_helper_provdesc_t *hprov,
7937     const dof_provider_t *dofprov, char *strtab)
7938 {
7939         hprov->dthpv_provname = strtab + dofprov->dofpv_name;
7940         dtrace_dofattr2attr(&hprov->dthpv_pattr.dtpa_provider,
7941             dofprov->dofpv_provattr);
7942         dtrace_dofattr2attr(&hprov->dthpv_pattr.dtpa_mod,
7943             dofprov->dofpv_modattr);
7944         dtrace_dofattr2attr(&hprov->dthpv_pattr.dtpa_func,
7945             dofprov->dofpv_funcattr);
7946         dtrace_dofattr2attr(&hprov->dthpv_pattr.dtpa_name,
7947             dofprov->dofpv_nameattr);
7948         dtrace_dofattr2attr(&hprov->dthpv_pattr.dtpa_args,
7949             dofprov->dofpv_argsattr);
7950 }
7951 
7952 static void
7953 dtrace_helper_provide_one(dof_helper_t *dhp, dof_sec_t *sec, pid_t pid)
7954 {
7955         uintptr_t daddr = (uintptr_t)dhp->dofhp_dof;
7956         dof_hdr_t *dof = (dof_hdr_t *)daddr;
7957         dof_sec_t *str_sec, *prb_sec, *arg_sec, *off_sec, *enoff_sec;
7958         dof_provider_t *provider;
7959         dof_probe_t *probe;
7960         uint32_t *off, *enoff;
7961         uint8_t *arg;
7962         char *strtab;
7963         uint_t i, nprobes;
7964         dtrace_helper_provdesc_t dhpv;
7965         dtrace_helper_probedesc_t dhpb;
7966         dtrace_meta_t *meta = dtrace_meta_pid;
7967         dtrace_mops_t *mops = &meta->dtm_mops;
7968         void *parg;
7969 
7970         provider = (dof_provider_t *)(uintptr_t)(daddr + sec->dofs_offset);
7971         str_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
7972             provider->dofpv_strtab * dof->dofh_secsize);
7973         prb_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
7974             provider->dofpv_probes * dof->dofh_secsize);
7975         arg_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
7976             provider->dofpv_prargs * dof->dofh_secsize);
7977         off_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
7978             provider->dofpv_proffs * dof->dofh_secsize);
7979 
7980         strtab = (char *)(uintptr_t)(daddr + str_sec->dofs_offset);
7981         off = (uint32_t *)(uintptr_t)(daddr + off_sec->dofs_offset);
7982         arg = (uint8_t *)(uintptr_t)(daddr + arg_sec->dofs_offset);
7983         enoff = NULL;
7984 
7985         /*
7986          * See dtrace_helper_provider_validate().
7987          */
7988         if (dof->dofh_ident[DOF_ID_VERSION] != DOF_VERSION_1 &&
7989             provider->dofpv_prenoffs != DOF_SECT_NONE) {
7990                 enoff_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
7991                     provider->dofpv_prenoffs * dof->dofh_secsize);
7992                 enoff = (uint32_t *)(uintptr_t)(daddr + enoff_sec->dofs_offset);
7993         }
7994 
7995         nprobes = prb_sec->dofs_size / prb_sec->dofs_entsize;
7996 
7997         /*
7998          * Create the provider.
7999          */
8000         dtrace_dofprov2hprov(&dhpv, provider, strtab);
8001 
8002         if ((parg = mops->dtms_provide_pid(meta->dtm_arg, &dhpv, pid)) == NULL)
8003                 return;
8004 
8005         meta->dtm_count++;
8006 
8007         /*
8008          * Create the probes.
8009          */
8010         for (i = 0; i < nprobes; i++) {
8011                 probe = (dof_probe_t *)(uintptr_t)(daddr +
8012                     prb_sec->dofs_offset + i * prb_sec->dofs_entsize);
8013 
8014                 dhpb.dthpb_mod = dhp->dofhp_mod;
8015                 dhpb.dthpb_func = strtab + probe->dofpr_func;
8016                 dhpb.dthpb_name = strtab + probe->dofpr_name;
8017                 dhpb.dthpb_base = probe->dofpr_addr;
8018                 dhpb.dthpb_offs = off + probe->dofpr_offidx;
8019                 dhpb.dthpb_noffs = probe->dofpr_noffs;
8020                 if (enoff != NULL) {
8021                         dhpb.dthpb_enoffs = enoff + probe->dofpr_enoffidx;
8022                         dhpb.dthpb_nenoffs = probe->dofpr_nenoffs;
8023                 } else {
8024                         dhpb.dthpb_enoffs = NULL;
8025                         dhpb.dthpb_nenoffs = 0;
8026                 }
8027                 dhpb.dthpb_args = arg + probe->dofpr_argidx;
8028                 dhpb.dthpb_nargc = probe->dofpr_nargc;
8029                 dhpb.dthpb_xargc = probe->dofpr_xargc;
8030                 dhpb.dthpb_ntypes = strtab + probe->dofpr_nargv;
8031                 dhpb.dthpb_xtypes = strtab + probe->dofpr_xargv;
8032 
8033                 mops->dtms_create_probe(meta->dtm_arg, parg, &dhpb);
8034         }
8035 }
8036 
8037 static void
8038 dtrace_helper_provide(dof_helper_t *dhp, pid_t pid)
8039 {
8040         uintptr_t daddr = (uintptr_t)dhp->dofhp_dof;
8041         dof_hdr_t *dof = (dof_hdr_t *)daddr;
8042         int i;
8043 
8044         ASSERT(MUTEX_HELD(&dtrace_meta_lock));
8045 
8046         for (i = 0; i < dof->dofh_secnum; i++) {
8047                 dof_sec_t *sec = (dof_sec_t *)(uintptr_t)(daddr +
8048                     dof->dofh_secoff + i * dof->dofh_secsize);
8049 
8050                 if (sec->dofs_type != DOF_SECT_PROVIDER)
8051                         continue;
8052 
8053                 dtrace_helper_provide_one(dhp, sec, pid);
8054         }
8055 
8056         /*
8057          * We may have just created probes, so we must now rematch against
8058          * any retained enablings.  Note that this call will acquire both
8059          * cpu_lock and dtrace_lock; the fact that we are holding
8060          * dtrace_meta_lock now is what defines the ordering with respect to
8061          * these three locks.
8062          */
8063         dtrace_enabling_matchall();
8064 }
8065 
8066 static void
8067 dtrace_helper_provider_remove_one(dof_helper_t *dhp, dof_sec_t *sec, pid_t pid)
8068 {
8069         uintptr_t daddr = (uintptr_t)dhp->dofhp_dof;
8070         dof_hdr_t *dof = (dof_hdr_t *)daddr;
8071         dof_sec_t *str_sec;
8072         dof_provider_t *provider;
8073         char *strtab;
8074         dtrace_helper_provdesc_t dhpv;
8075         dtrace_meta_t *meta = dtrace_meta_pid;
8076         dtrace_mops_t *mops = &meta->dtm_mops;
8077 
8078         provider = (dof_provider_t *)(uintptr_t)(daddr + sec->dofs_offset);
8079         str_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
8080             provider->dofpv_strtab * dof->dofh_secsize);
8081 
8082         strtab = (char *)(uintptr_t)(daddr + str_sec->dofs_offset);
8083 
8084         /*
8085          * Create the provider.
8086          */
8087         dtrace_dofprov2hprov(&dhpv, provider, strtab);
8088 
8089         mops->dtms_remove_pid(meta->dtm_arg, &dhpv, pid);
8090 
8091         meta->dtm_count--;
8092 }
8093 
8094 static void
8095 dtrace_helper_provider_remove(dof_helper_t *dhp, pid_t pid)
8096 {
8097         uintptr_t daddr = (uintptr_t)dhp->dofhp_dof;
8098         dof_hdr_t *dof = (dof_hdr_t *)daddr;
8099         int i;
8100 
8101         ASSERT(MUTEX_HELD(&dtrace_meta_lock));
8102 
8103         for (i = 0; i < dof->dofh_secnum; i++) {
8104                 dof_sec_t *sec = (dof_sec_t *)(uintptr_t)(daddr +
8105                     dof->dofh_secoff + i * dof->dofh_secsize);
8106 
8107                 if (sec->dofs_type != DOF_SECT_PROVIDER)
8108                         continue;
8109 
8110                 dtrace_helper_provider_remove_one(dhp, sec, pid);
8111         }
8112 }
8113 
8114 /*
8115  * DTrace Meta Provider-to-Framework API Functions
8116  *
8117  * These functions implement the Meta Provider-to-Framework API, as described
8118  * in <sys/dtrace.h>.
8119  */
8120 int
8121 dtrace_meta_register(const char *name, const dtrace_mops_t *mops, void *arg,
8122     dtrace_meta_provider_id_t *idp)
8123 {
8124         dtrace_meta_t *meta;
8125         dtrace_helpers_t *help, *next;
8126         int i;
8127 
8128         *idp = DTRACE_METAPROVNONE;
8129 
8130         /*
8131          * We strictly don't need the name, but we hold onto it for
8132          * debuggability. All hail error queues!
8133          */
8134         if (name == NULL) {
8135                 cmn_err(CE_WARN, "failed to register meta-provider: "
8136                     "invalid name");
8137                 return (EINVAL);
8138         }
8139 
8140         if (mops == NULL ||
8141             mops->dtms_create_probe == NULL ||
8142             mops->dtms_provide_pid == NULL ||
8143             mops->dtms_remove_pid == NULL) {
8144                 cmn_err(CE_WARN, "failed to register meta-register %s: "
8145                     "invalid ops", name);
8146                 return (EINVAL);
8147         }
8148 
8149         meta = kmem_zalloc(sizeof (dtrace_meta_t), KM_SLEEP);
8150         meta->dtm_mops = *mops;
8151         meta->dtm_name = kmem_alloc(strlen(name) + 1, KM_SLEEP);
8152         (void) strcpy(meta->dtm_name, name);
8153         meta->dtm_arg = arg;
8154 
8155         mutex_enter(&dtrace_meta_lock);
8156         mutex_enter(&dtrace_lock);
8157 
8158         if (dtrace_meta_pid != NULL) {
8159                 mutex_exit(&dtrace_lock);
8160                 mutex_exit(&dtrace_meta_lock);
8161                 cmn_err(CE_WARN, "failed to register meta-register %s: "
8162                     "user-land meta-provider exists", name);
8163                 kmem_free(meta->dtm_name, strlen(meta->dtm_name) + 1);
8164                 kmem_free(meta, sizeof (dtrace_meta_t));
8165                 return (EINVAL);
8166         }
8167 
8168         dtrace_meta_pid = meta;
8169         *idp = (dtrace_meta_provider_id_t)meta;
8170 
8171         /*
8172          * If there are providers and probes ready to go, pass them
8173          * off to the new meta provider now.
8174          */
8175 
8176         help = dtrace_deferred_pid;
8177         dtrace_deferred_pid = NULL;
8178 
8179         mutex_exit(&dtrace_lock);
8180 
8181         while (help != NULL) {
8182                 for (i = 0; i < help->dthps_nprovs; i++) {
8183                         dtrace_helper_provide(&help->dthps_provs[i]->dthp_prov,
8184                             help->dthps_pid);
8185                 }
8186 
8187                 next = help->dthps_next;
8188                 help->dthps_next = NULL;
8189                 help->dthps_prev = NULL;
8190                 help->dthps_deferred = 0;
8191                 help = next;
8192         }
8193 
8194         mutex_exit(&dtrace_meta_lock);
8195 
8196         return (0);
8197 }
8198 
8199 int
8200 dtrace_meta_unregister(dtrace_meta_provider_id_t id)
8201 {
8202         dtrace_meta_t **pp, *old = (dtrace_meta_t *)id;
8203 
8204         mutex_enter(&dtrace_meta_lock);
8205         mutex_enter(&dtrace_lock);
8206 
8207         if (old == dtrace_meta_pid) {
8208                 pp = &dtrace_meta_pid;
8209         } else {
8210                 panic("attempt to unregister non-existent "
8211                     "dtrace meta-provider %p\n", (void *)old);
8212         }
8213 
8214         if (old->dtm_count != 0) {
8215                 mutex_exit(&dtrace_lock);
8216                 mutex_exit(&dtrace_meta_lock);
8217                 return (EBUSY);
8218         }
8219 
8220         *pp = NULL;
8221 
8222         mutex_exit(&dtrace_lock);
8223         mutex_exit(&dtrace_meta_lock);
8224 
8225         kmem_free(old->dtm_name, strlen(old->dtm_name) + 1);
8226         kmem_free(old, sizeof (dtrace_meta_t));
8227 
8228         return (0);
8229 }
8230 
8231 
8232 /*
8233  * DTrace DIF Object Functions
8234  */
8235 static int
8236 dtrace_difo_err(uint_t pc, const char *format, ...)
8237 {
8238         if (dtrace_err_verbose) {
8239                 va_list alist;
8240 
8241                 (void) uprintf("dtrace DIF object error: [%u]: ", pc);
8242                 va_start(alist, format);
8243                 (void) vuprintf(format, alist);
8244                 va_end(alist);
8245         }
8246 
8247 #ifdef DTRACE_ERRDEBUG
8248         dtrace_errdebug(format);
8249 #endif
8250         return (1);
8251 }
8252 
8253 /*
8254  * Validate a DTrace DIF object by checking the IR instructions.  The following
8255  * rules are currently enforced by dtrace_difo_validate():
8256  *
8257  * 1. Each instruction must have a valid opcode
8258  * 2. Each register, string, variable, or subroutine reference must be valid
8259  * 3. No instruction can modify register %r0 (must be zero)
8260  * 4. All instruction reserved bits must be set to zero
8261  * 5. The last instruction must be a "ret" instruction
8262  * 6. All branch targets must reference a valid instruction _after_ the branch
8263  */
8264 static int
8265 dtrace_difo_validate(dtrace_difo_t *dp, dtrace_vstate_t *vstate, uint_t nregs,
8266     cred_t *cr)
8267 {
8268         int err = 0, i;
8269         int (*efunc)(uint_t pc, const char *, ...) = dtrace_difo_err;
8270         int kcheckload;
8271         uint_t pc;
8272 
8273         kcheckload = cr == NULL ||
8274             (vstate->dtvs_state->dts_cred.dcr_visible & DTRACE_CRV_KERNEL) == 0;
8275 
8276         dp->dtdo_destructive = 0;
8277 
8278         for (pc = 0; pc < dp->dtdo_len && err == 0; pc++) {
8279                 dif_instr_t instr = dp->dtdo_buf[pc];
8280 
8281                 uint_t r1 = DIF_INSTR_R1(instr);
8282                 uint_t r2 = DIF_INSTR_R2(instr);
8283                 uint_t rd = DIF_INSTR_RD(instr);
8284                 uint_t rs = DIF_INSTR_RS(instr);
8285                 uint_t label = DIF_INSTR_LABEL(instr);
8286                 uint_t v = DIF_INSTR_VAR(instr);
8287                 uint_t subr = DIF_INSTR_SUBR(instr);
8288                 uint_t type = DIF_INSTR_TYPE(instr);
8289                 uint_t op = DIF_INSTR_OP(instr);
8290 
8291                 switch (op) {
8292                 case DIF_OP_OR:
8293                 case DIF_OP_XOR:
8294                 case DIF_OP_AND:
8295                 case DIF_OP_SLL:
8296                 case DIF_OP_SRL:
8297                 case DIF_OP_SRA:
8298                 case DIF_OP_SUB:
8299                 case DIF_OP_ADD:
8300                 case DIF_OP_MUL:
8301                 case DIF_OP_SDIV:
8302                 case DIF_OP_UDIV:
8303                 case DIF_OP_SREM:
8304                 case DIF_OP_UREM:
8305                 case DIF_OP_COPYS:
8306                         if (r1 >= nregs)
8307                                 err += efunc(pc, "invalid register %u\n", r1);
8308                         if (r2 >= nregs)
8309                                 err += efunc(pc, "invalid register %u\n", r2);
8310                         if (rd >= nregs)
8311                                 err += efunc(pc, "invalid register %u\n", rd);
8312                         if (rd == 0)
8313                                 err += efunc(pc, "cannot write to %r0\n");
8314                         break;
8315                 case DIF_OP_NOT:
8316                 case DIF_OP_MOV:
8317                 case DIF_OP_ALLOCS:
8318                         if (r1 >= nregs)
8319                                 err += efunc(pc, "invalid register %u\n", r1);
8320                         if (r2 != 0)
8321                                 err += efunc(pc, "non-zero reserved bits\n");
8322                         if (rd >= nregs)
8323                                 err += efunc(pc, "invalid register %u\n", rd);
8324                         if (rd == 0)
8325                                 err += efunc(pc, "cannot write to %r0\n");
8326                         break;
8327                 case DIF_OP_LDSB:
8328                 case DIF_OP_LDSH:
8329                 case DIF_OP_LDSW:
8330                 case DIF_OP_LDUB:
8331                 case DIF_OP_LDUH:
8332                 case DIF_OP_LDUW:
8333                 case DIF_OP_LDX:
8334                         if (r1 >= nregs)
8335                                 err += efunc(pc, "invalid register %u\n", r1);
8336                         if (r2 != 0)
8337                                 err += efunc(pc, "non-zero reserved bits\n");
8338                         if (rd >= nregs)
8339                                 err += efunc(pc, "invalid register %u\n", rd);
8340                         if (rd == 0)
8341                                 err += efunc(pc, "cannot write to %r0\n");
8342                         if (kcheckload)
8343                                 dp->dtdo_buf[pc] = DIF_INSTR_LOAD(op +
8344                                     DIF_OP_RLDSB - DIF_OP_LDSB, r1, rd);
8345                         break;
8346                 case DIF_OP_RLDSB:
8347                 case DIF_OP_RLDSH:
8348                 case DIF_OP_RLDSW:
8349                 case DIF_OP_RLDUB:
8350                 case DIF_OP_RLDUH:
8351                 case DIF_OP_RLDUW:
8352                 case DIF_OP_RLDX:
8353                         if (r1 >= nregs)
8354                                 err += efunc(pc, "invalid register %u\n", r1);
8355                         if (r2 != 0)
8356                                 err += efunc(pc, "non-zero reserved bits\n");
8357                         if (rd >= nregs)
8358                                 err += efunc(pc, "invalid register %u\n", rd);
8359                         if (rd == 0)
8360                                 err += efunc(pc, "cannot write to %r0\n");
8361                         break;
8362                 case DIF_OP_ULDSB:
8363                 case DIF_OP_ULDSH:
8364                 case DIF_OP_ULDSW:
8365                 case DIF_OP_ULDUB:
8366                 case DIF_OP_ULDUH:
8367                 case DIF_OP_ULDUW:
8368                 case DIF_OP_ULDX:
8369                         if (r1 >= nregs)
8370                                 err += efunc(pc, "invalid register %u\n", r1);
8371                         if (r2 != 0)
8372                                 err += efunc(pc, "non-zero reserved bits\n");
8373                         if (rd >= nregs)
8374                                 err += efunc(pc, "invalid register %u\n", rd);
8375                         if (rd == 0)
8376                                 err += efunc(pc, "cannot write to %r0\n");
8377                         break;
8378                 case DIF_OP_STB:
8379                 case DIF_OP_STH:
8380                 case DIF_OP_STW:
8381                 case DIF_OP_STX:
8382                         if (r1 >= nregs)
8383                                 err += efunc(pc, "invalid register %u\n", r1);
8384                         if (r2 != 0)
8385                                 err += efunc(pc, "non-zero reserved bits\n");
8386                         if (rd >= nregs)
8387                                 err += efunc(pc, "invalid register %u\n", rd);
8388                         if (rd == 0)
8389                                 err += efunc(pc, "cannot write to 0 address\n");
8390                         break;
8391                 case DIF_OP_CMP:
8392                 case DIF_OP_SCMP:
8393                         if (r1 >= nregs)
8394                                 err += efunc(pc, "invalid register %u\n", r1);
8395                         if (r2 >= nregs)
8396                                 err += efunc(pc, "invalid register %u\n", r2);
8397                         if (rd != 0)
8398                                 err += efunc(pc, "non-zero reserved bits\n");
8399                         break;
8400                 case DIF_OP_TST:
8401                         if (r1 >= nregs)
8402                                 err += efunc(pc, "invalid register %u\n", r1);
8403                         if (r2 != 0 || rd != 0)
8404                                 err += efunc(pc, "non-zero reserved bits\n");
8405                         break;
8406                 case DIF_OP_BA:
8407                 case DIF_OP_BE:
8408                 case DIF_OP_BNE:
8409                 case DIF_OP_BG:
8410                 case DIF_OP_BGU:
8411                 case DIF_OP_BGE:
8412                 case DIF_OP_BGEU:
8413                 case DIF_OP_BL:
8414                 case DIF_OP_BLU:
8415                 case DIF_OP_BLE:
8416                 case DIF_OP_BLEU:
8417                         if (label >= dp->dtdo_len) {
8418                                 err += efunc(pc, "invalid branch target %u\n",
8419                                     label);
8420                         }
8421                         if (label <= pc) {
8422                                 err += efunc(pc, "backward branch to %u\n",
8423                                     label);
8424                         }
8425                         break;
8426                 case DIF_OP_RET:
8427                         if (r1 != 0 || r2 != 0)
8428                                 err += efunc(pc, "non-zero reserved bits\n");
8429                         if (rd >= nregs)
8430                                 err += efunc(pc, "invalid register %u\n", rd);
8431                         break;
8432                 case DIF_OP_NOP:
8433                 case DIF_OP_POPTS:
8434                 case DIF_OP_FLUSHTS:
8435                         if (r1 != 0 || r2 != 0 || rd != 0)
8436                                 err += efunc(pc, "non-zero reserved bits\n");
8437                         break;
8438                 case DIF_OP_SETX:
8439                         if (DIF_INSTR_INTEGER(instr) >= dp->dtdo_intlen) {
8440                                 err += efunc(pc, "invalid integer ref %u\n",
8441                                     DIF_INSTR_INTEGER(instr));
8442                         }
8443                         if (rd >= nregs)
8444                                 err += efunc(pc, "invalid register %u\n", rd);
8445                         if (rd == 0)
8446                                 err += efunc(pc, "cannot write to %r0\n");
8447                         break;
8448                 case DIF_OP_SETS:
8449                         if (DIF_INSTR_STRING(instr) >= dp->dtdo_strlen) {
8450                                 err += efunc(pc, "invalid string ref %u\n",
8451                                     DIF_INSTR_STRING(instr));
8452                         }
8453                         if (rd >= nregs)
8454                                 err += efunc(pc, "invalid register %u\n", rd);
8455                         if (rd == 0)
8456                                 err += efunc(pc, "cannot write to %r0\n");
8457                         break;
8458                 case DIF_OP_LDGA:
8459                 case DIF_OP_LDTA:
8460                         if (r1 > DIF_VAR_ARRAY_MAX)
8461                                 err += efunc(pc, "invalid array %u\n", r1);
8462                         if (r2 >= nregs)
8463                                 err += efunc(pc, "invalid register %u\n", r2);
8464                         if (rd >= nregs)
8465                                 err += efunc(pc, "invalid register %u\n", rd);
8466                         if (rd == 0)
8467                                 err += efunc(pc, "cannot write to %r0\n");
8468                         break;
8469                 case DIF_OP_LDGS:
8470                 case DIF_OP_LDTS:
8471                 case DIF_OP_LDLS:
8472                 case DIF_OP_LDGAA:
8473                 case DIF_OP_LDTAA:
8474                         if (v < DIF_VAR_OTHER_MIN || v > DIF_VAR_OTHER_MAX)
8475                                 err += efunc(pc, "invalid variable %u\n", v);
8476                         if (rd >= nregs)
8477                                 err += efunc(pc, "invalid register %u\n", rd);
8478                         if (rd == 0)
8479                                 err += efunc(pc, "cannot write to %r0\n");
8480                         break;
8481                 case DIF_OP_STGS:
8482                 case DIF_OP_STTS:
8483                 case DIF_OP_STLS:
8484                 case DIF_OP_STGAA:
8485                 case DIF_OP_STTAA:
8486                         if (v < DIF_VAR_OTHER_UBASE || v > DIF_VAR_OTHER_MAX)
8487                                 err += efunc(pc, "invalid variable %u\n", v);
8488                         if (rs >= nregs)
8489                                 err += efunc(pc, "invalid register %u\n", rd);
8490                         break;
8491                 case DIF_OP_CALL:
8492                         if (subr > DIF_SUBR_MAX)
8493                                 err += efunc(pc, "invalid subr %u\n", subr);
8494                         if (rd >= nregs)
8495                                 err += efunc(pc, "invalid register %u\n", rd);
8496                         if (rd == 0)
8497                                 err += efunc(pc, "cannot write to %r0\n");
8498 
8499                         if (subr == DIF_SUBR_COPYOUT ||
8500                             subr == DIF_SUBR_COPYOUTSTR) {
8501                                 dp->dtdo_destructive = 1;
8502                         }
8503 
8504                         if (subr == DIF_SUBR_GETF) {
8505                                 /*
8506                                  * If we have a getf() we need to record that
8507                                  * in our state.  Note that our state can be
8508                                  * NULL if this is a helper -- but in that
8509                                  * case, the call to getf() is itself illegal,
8510                                  * and will be caught (slightly later) when
8511                                  * the helper is validated.
8512                                  */
8513                                 if (vstate->dtvs_state != NULL)
8514                                         vstate->dtvs_state->dts_getf++;
8515                         }
8516 
8517                         break;
8518                 case DIF_OP_PUSHTR:
8519                         if (type != DIF_TYPE_STRING && type != DIF_TYPE_CTF)
8520                                 err += efunc(pc, "invalid ref type %u\n", type);
8521                         if (r2 >= nregs)
8522                                 err += efunc(pc, "invalid register %u\n", r2);
8523                         if (rs >= nregs)
8524                                 err += efunc(pc, "invalid register %u\n", rs);
8525                         break;
8526                 case DIF_OP_PUSHTV:
8527                         if (type != DIF_TYPE_CTF)
8528                                 err += efunc(pc, "invalid val type %u\n", type);
8529                         if (r2 >= nregs)
8530                                 err += efunc(pc, "invalid register %u\n", r2);
8531                         if (rs >= nregs)
8532                                 err += efunc(pc, "invalid register %u\n", rs);
8533                         break;
8534                 default:
8535                         err += efunc(pc, "invalid opcode %u\n",
8536                             DIF_INSTR_OP(instr));
8537                 }
8538         }
8539 
8540         if (dp->dtdo_len != 0 &&
8541             DIF_INSTR_OP(dp->dtdo_buf[dp->dtdo_len - 1]) != DIF_OP_RET) {
8542                 err += efunc(dp->dtdo_len - 1,
8543                     "expected 'ret' as last DIF instruction\n");
8544         }
8545 
8546         if (!(dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF)) {
8547                 /*
8548                  * If we're not returning by reference, the size must be either
8549                  * 0 or the size of one of the base types.
8550                  */
8551                 switch (dp->dtdo_rtype.dtdt_size) {
8552                 case 0:
8553                 case sizeof (uint8_t):
8554                 case sizeof (uint16_t):
8555                 case sizeof (uint32_t):
8556                 case sizeof (uint64_t):
8557                         break;
8558 
8559                 default:
8560                         err += efunc(dp->dtdo_len - 1, "bad return size\n");
8561                 }
8562         }
8563 
8564         for (i = 0; i < dp->dtdo_varlen && err == 0; i++) {
8565                 dtrace_difv_t *v = &dp->dtdo_vartab[i], *existing = NULL;
8566                 dtrace_diftype_t *vt, *et;
8567                 uint_t id, ndx;
8568 
8569                 if (v->dtdv_scope != DIFV_SCOPE_GLOBAL &&
8570                     v->dtdv_scope != DIFV_SCOPE_THREAD &&
8571                     v->dtdv_scope != DIFV_SCOPE_LOCAL) {
8572                         err += efunc(i, "unrecognized variable scope %d\n",
8573                             v->dtdv_scope);
8574                         break;
8575                 }
8576 
8577                 if (v->dtdv_kind != DIFV_KIND_ARRAY &&
8578                     v->dtdv_kind != DIFV_KIND_SCALAR) {
8579                         err += efunc(i, "unrecognized variable type %d\n",
8580                             v->dtdv_kind);
8581                         break;
8582                 }
8583 
8584                 if ((id = v->dtdv_id) > DIF_VARIABLE_MAX) {
8585                         err += efunc(i, "%d exceeds variable id limit\n", id);
8586                         break;
8587                 }
8588 
8589                 if (id < DIF_VAR_OTHER_UBASE)
8590                         continue;
8591 
8592                 /*
8593                  * For user-defined variables, we need to check that this
8594                  * definition is identical to any previous definition that we
8595                  * encountered.
8596                  */
8597                 ndx = id - DIF_VAR_OTHER_UBASE;
8598 
8599                 switch (v->dtdv_scope) {
8600                 case DIFV_SCOPE_GLOBAL:
8601                         if (ndx < vstate->dtvs_nglobals) {
8602                                 dtrace_statvar_t *svar;
8603 
8604                                 if ((svar = vstate->dtvs_globals[ndx]) != NULL)
8605                                         existing = &svar->dtsv_var;
8606                         }
8607 
8608                         break;
8609 
8610                 case DIFV_SCOPE_THREAD:
8611                         if (ndx < vstate->dtvs_ntlocals)
8612                                 existing = &vstate->dtvs_tlocals[ndx];
8613                         break;
8614 
8615                 case DIFV_SCOPE_LOCAL:
8616                         if (ndx < vstate->dtvs_nlocals) {
8617                                 dtrace_statvar_t *svar;
8618 
8619                                 if ((svar = vstate->dtvs_locals[ndx]) != NULL)
8620                                         existing = &svar->dtsv_var;
8621                         }
8622 
8623                         break;
8624                 }
8625 
8626                 vt = &v->dtdv_type;
8627 
8628                 if (vt->dtdt_flags & DIF_TF_BYREF) {
8629                         if (vt->dtdt_size == 0) {
8630                                 err += efunc(i, "zero-sized variable\n");
8631                                 break;
8632                         }
8633 
8634                         if (v->dtdv_scope == DIFV_SCOPE_GLOBAL &&
8635                             vt->dtdt_size > dtrace_global_maxsize) {
8636                                 err += efunc(i, "oversized by-ref global\n");
8637                                 break;
8638                         }
8639                 }
8640 
8641                 if (existing == NULL || existing->dtdv_id == 0)
8642                         continue;
8643 
8644                 ASSERT(existing->dtdv_id == v->dtdv_id);
8645                 ASSERT(existing->dtdv_scope == v->dtdv_scope);
8646 
8647                 if (existing->dtdv_kind != v->dtdv_kind)
8648                         err += efunc(i, "%d changed variable kind\n", id);
8649 
8650                 et = &existing->dtdv_type;
8651 
8652                 if (vt->dtdt_flags != et->dtdt_flags) {
8653                         err += efunc(i, "%d changed variable type flags\n", id);
8654                         break;
8655                 }
8656 
8657                 if (vt->dtdt_size != 0 && vt->dtdt_size != et->dtdt_size) {
8658                         err += efunc(i, "%d changed variable type size\n", id);
8659                         break;
8660                 }
8661         }
8662 
8663         return (err);
8664 }
8665 
8666 /*
8667  * Validate a DTrace DIF object that it is to be used as a helper.  Helpers
8668  * are much more constrained than normal DIFOs.  Specifically, they may
8669  * not:
8670  *
8671  * 1. Make calls to subroutines other than copyin(), copyinstr() or
8672  *    miscellaneous string routines
8673  * 2. Access DTrace variables other than the args[] array, and the
8674  *    curthread, pid, ppid, tid, execname, zonename, uid and gid variables.
8675  * 3. Have thread-local variables.
8676  * 4. Have dynamic variables.
8677  */
8678 static int
8679 dtrace_difo_validate_helper(dtrace_difo_t *dp)
8680 {
8681         int (*efunc)(uint_t pc, const char *, ...) = dtrace_difo_err;
8682         int err = 0;
8683         uint_t pc;
8684 
8685         for (pc = 0; pc < dp->dtdo_len; pc++) {
8686                 dif_instr_t instr = dp->dtdo_buf[pc];
8687 
8688                 uint_t v = DIF_INSTR_VAR(instr);
8689                 uint_t subr = DIF_INSTR_SUBR(instr);
8690                 uint_t op = DIF_INSTR_OP(instr);
8691 
8692                 switch (op) {
8693                 case DIF_OP_OR:
8694                 case DIF_OP_XOR:
8695                 case DIF_OP_AND:
8696                 case DIF_OP_SLL:
8697                 case DIF_OP_SRL:
8698                 case DIF_OP_SRA:
8699                 case DIF_OP_SUB:
8700                 case DIF_OP_ADD:
8701                 case DIF_OP_MUL:
8702                 case DIF_OP_SDIV:
8703                 case DIF_OP_UDIV:
8704                 case DIF_OP_SREM:
8705                 case DIF_OP_UREM:
8706                 case DIF_OP_COPYS:
8707                 case DIF_OP_NOT:
8708                 case DIF_OP_MOV:
8709                 case DIF_OP_RLDSB:
8710                 case DIF_OP_RLDSH:
8711                 case DIF_OP_RLDSW:
8712                 case DIF_OP_RLDUB:
8713                 case DIF_OP_RLDUH:
8714                 case DIF_OP_RLDUW:
8715                 case DIF_OP_RLDX:
8716                 case DIF_OP_ULDSB:
8717                 case DIF_OP_ULDSH:
8718                 case DIF_OP_ULDSW:
8719                 case DIF_OP_ULDUB:
8720                 case DIF_OP_ULDUH:
8721                 case DIF_OP_ULDUW:
8722                 case DIF_OP_ULDX:
8723                 case DIF_OP_STB:
8724                 case DIF_OP_STH:
8725                 case DIF_OP_STW:
8726                 case DIF_OP_STX:
8727                 case DIF_OP_ALLOCS:
8728                 case DIF_OP_CMP:
8729                 case DIF_OP_SCMP:
8730                 case DIF_OP_TST:
8731                 case DIF_OP_BA:
8732                 case DIF_OP_BE:
8733                 case DIF_OP_BNE:
8734                 case DIF_OP_BG:
8735                 case DIF_OP_BGU:
8736                 case DIF_OP_BGE:
8737                 case DIF_OP_BGEU:
8738                 case DIF_OP_BL:
8739                 case DIF_OP_BLU:
8740                 case DIF_OP_BLE:
8741                 case DIF_OP_BLEU:
8742                 case DIF_OP_RET:
8743                 case DIF_OP_NOP:
8744                 case DIF_OP_POPTS:
8745                 case DIF_OP_FLUSHTS:
8746                 case DIF_OP_SETX:
8747                 case DIF_OP_SETS:
8748                 case DIF_OP_LDGA:
8749                 case DIF_OP_LDLS:
8750                 case DIF_OP_STGS:
8751                 case DIF_OP_STLS:
8752                 case DIF_OP_PUSHTR:
8753                 case DIF_OP_PUSHTV:
8754                         break;
8755 
8756                 case DIF_OP_LDGS:
8757                         if (v >= DIF_VAR_OTHER_UBASE)
8758                                 break;
8759 
8760                         if (v >= DIF_VAR_ARG0 && v <= DIF_VAR_ARG9)
8761                                 break;
8762 
8763                         if (v == DIF_VAR_CURTHREAD || v == DIF_VAR_PID ||
8764                             v == DIF_VAR_PPID || v == DIF_VAR_TID ||
8765                             v == DIF_VAR_EXECNAME || v == DIF_VAR_ZONENAME ||
8766                             v == DIF_VAR_UID || v == DIF_VAR_GID)
8767                                 break;
8768 
8769                         err += efunc(pc, "illegal variable %u\n", v);
8770                         break;
8771 
8772                 case DIF_OP_LDTA:
8773                 case DIF_OP_LDTS:
8774                 case DIF_OP_LDGAA:
8775                 case DIF_OP_LDTAA:
8776                         err += efunc(pc, "illegal dynamic variable load\n");
8777                         break;
8778 
8779                 case DIF_OP_STTS:
8780                 case DIF_OP_STGAA:
8781                 case DIF_OP_STTAA:
8782                         err += efunc(pc, "illegal dynamic variable store\n");
8783                         break;
8784 
8785                 case DIF_OP_CALL:
8786                         if (subr == DIF_SUBR_ALLOCA ||
8787                             subr == DIF_SUBR_BCOPY ||
8788                             subr == DIF_SUBR_COPYIN ||
8789                             subr == DIF_SUBR_COPYINTO ||
8790                             subr == DIF_SUBR_COPYINSTR ||
8791                             subr == DIF_SUBR_INDEX ||
8792                             subr == DIF_SUBR_INET_NTOA ||
8793                             subr == DIF_SUBR_INET_NTOA6 ||
8794                             subr == DIF_SUBR_INET_NTOP ||
8795                             subr == DIF_SUBR_LLTOSTR ||
8796                             subr == DIF_SUBR_RINDEX ||
8797                             subr == DIF_SUBR_STRCHR ||
8798                             subr == DIF_SUBR_STRJOIN ||
8799                             subr == DIF_SUBR_STRRCHR ||
8800                             subr == DIF_SUBR_STRSTR ||
8801                             subr == DIF_SUBR_HTONS ||
8802                             subr == DIF_SUBR_HTONL ||
8803                             subr == DIF_SUBR_HTONLL ||
8804                             subr == DIF_SUBR_NTOHS ||
8805                             subr == DIF_SUBR_NTOHL ||
8806                             subr == DIF_SUBR_NTOHLL)
8807                                 break;
8808 
8809                         err += efunc(pc, "invalid subr %u\n", subr);
8810                         break;
8811 
8812                 default:
8813                         err += efunc(pc, "invalid opcode %u\n",
8814                             DIF_INSTR_OP(instr));
8815                 }
8816         }
8817 
8818         return (err);
8819 }
8820 
8821 /*
8822  * Returns 1 if the expression in the DIF object can be cached on a per-thread
8823  * basis; 0 if not.
8824  */
8825 static int
8826 dtrace_difo_cacheable(dtrace_difo_t *dp)
8827 {
8828         int i;
8829 
8830         if (dp == NULL)
8831                 return (0);
8832 
8833         for (i = 0; i < dp->dtdo_varlen; i++) {
8834                 dtrace_difv_t *v = &dp->dtdo_vartab[i];
8835 
8836                 if (v->dtdv_scope != DIFV_SCOPE_GLOBAL)
8837                         continue;
8838 
8839                 switch (v->dtdv_id) {
8840                 case DIF_VAR_CURTHREAD:
8841                 case DIF_VAR_PID:
8842                 case DIF_VAR_TID:
8843                 case DIF_VAR_EXECNAME:
8844                 case DIF_VAR_ZONENAME:
8845                         break;
8846 
8847                 default:
8848                         return (0);
8849                 }
8850         }
8851 
8852         /*
8853          * This DIF object may be cacheable.  Now we need to look for any
8854          * array loading instructions, any memory loading instructions, or
8855          * any stores to thread-local variables.
8856          */
8857         for (i = 0; i < dp->dtdo_len; i++) {
8858                 uint_t op = DIF_INSTR_OP(dp->dtdo_buf[i]);
8859 
8860                 if ((op >= DIF_OP_LDSB && op <= DIF_OP_LDX) ||
8861                     (op >= DIF_OP_ULDSB && op <= DIF_OP_ULDX) ||
8862                     (op >= DIF_OP_RLDSB && op <= DIF_OP_RLDX) ||
8863                     op == DIF_OP_LDGA || op == DIF_OP_STTS)
8864                         return (0);
8865         }
8866 
8867         return (1);
8868 }
8869 
8870 static void
8871 dtrace_difo_hold(dtrace_difo_t *dp)
8872 {
8873         int i;
8874 
8875         ASSERT(MUTEX_HELD(&dtrace_lock));
8876 
8877         dp->dtdo_refcnt++;
8878         ASSERT(dp->dtdo_refcnt != 0);
8879 
8880         /*
8881          * We need to check this DIF object for references to the variable
8882          * DIF_VAR_VTIMESTAMP.
8883          */
8884         for (i = 0; i < dp->dtdo_varlen; i++) {
8885                 dtrace_difv_t *v = &dp->dtdo_vartab[i];
8886 
8887                 if (v->dtdv_id != DIF_VAR_VTIMESTAMP)
8888                         continue;
8889 
8890                 if (dtrace_vtime_references++ == 0)
8891                         dtrace_vtime_enable();
8892         }
8893 }
8894 
8895 /*
8896  * This routine calculates the dynamic variable chunksize for a given DIF
8897  * object.  The calculation is not fool-proof, and can probably be tricked by
8898  * malicious DIF -- but it works for all compiler-generated DIF.  Because this
8899  * calculation is likely imperfect, dtrace_dynvar() is able to gracefully fail
8900  * if a dynamic variable size exceeds the chunksize.
8901  */
8902 static void
8903 dtrace_difo_chunksize(dtrace_difo_t *dp, dtrace_vstate_t *vstate)
8904 {
8905         uint64_t sval;
8906         dtrace_key_t tupregs[DIF_DTR_NREGS + 2]; /* +2 for thread and id */
8907         const dif_instr_t *text = dp->dtdo_buf;
8908         uint_t pc, srd = 0;
8909         uint_t ttop = 0;
8910         size_t size, ksize;
8911         uint_t id, i;
8912 
8913         for (pc = 0; pc < dp->dtdo_len; pc++) {
8914                 dif_instr_t instr = text[pc];
8915                 uint_t op = DIF_INSTR_OP(instr);
8916                 uint_t rd = DIF_INSTR_RD(instr);
8917                 uint_t r1 = DIF_INSTR_R1(instr);
8918                 uint_t nkeys = 0;
8919                 uchar_t scope;
8920 
8921                 dtrace_key_t *key = tupregs;
8922 
8923                 switch (op) {
8924                 case DIF_OP_SETX:
8925                         sval = dp->dtdo_inttab[DIF_INSTR_INTEGER(instr)];
8926                         srd = rd;
8927                         continue;
8928 
8929                 case DIF_OP_STTS:
8930                         key = &tupregs[DIF_DTR_NREGS];
8931                         key[0].dttk_size = 0;
8932                         key[1].dttk_size = 0;
8933                         nkeys = 2;
8934                         scope = DIFV_SCOPE_THREAD;
8935                         break;
8936 
8937                 case DIF_OP_STGAA:
8938                 case DIF_OP_STTAA:
8939                         nkeys = ttop;
8940 
8941                         if (DIF_INSTR_OP(instr) == DIF_OP_STTAA)
8942                                 key[nkeys++].dttk_size = 0;
8943 
8944                         key[nkeys++].dttk_size = 0;
8945 
8946                         if (op == DIF_OP_STTAA) {
8947                                 scope = DIFV_SCOPE_THREAD;
8948                         } else {
8949                                 scope = DIFV_SCOPE_GLOBAL;
8950                         }
8951 
8952                         break;
8953 
8954                 case DIF_OP_PUSHTR:
8955                         if (ttop == DIF_DTR_NREGS)
8956                                 return;
8957 
8958                         if ((srd == 0 || sval == 0) && r1 == DIF_TYPE_STRING) {
8959                                 /*
8960                                  * If the register for the size of the "pushtr"
8961                                  * is %r0 (or the value is 0) and the type is
8962                                  * a string, we'll use the system-wide default
8963                                  * string size.
8964                                  */
8965                                 tupregs[ttop++].dttk_size =
8966                                     dtrace_strsize_default;
8967                         } else {
8968                                 if (srd == 0)
8969                                         return;
8970 
8971                                 tupregs[ttop++].dttk_size = sval;
8972                         }
8973 
8974                         break;
8975 
8976                 case DIF_OP_PUSHTV:
8977                         if (ttop == DIF_DTR_NREGS)
8978                                 return;
8979 
8980                         tupregs[ttop++].dttk_size = 0;
8981                         break;
8982 
8983                 case DIF_OP_FLUSHTS:
8984                         ttop = 0;
8985                         break;
8986 
8987                 case DIF_OP_POPTS:
8988                         if (ttop != 0)
8989                                 ttop--;
8990                         break;
8991                 }
8992 
8993                 sval = 0;
8994                 srd = 0;
8995 
8996                 if (nkeys == 0)
8997                         continue;
8998 
8999                 /*
9000                  * We have a dynamic variable allocation; calculate its size.
9001                  */
9002                 for (ksize = 0, i = 0; i < nkeys; i++)
9003                         ksize += P2ROUNDUP(key[i].dttk_size, sizeof (uint64_t));
9004 
9005                 size = sizeof (dtrace_dynvar_t);
9006                 size += sizeof (dtrace_key_t) * (nkeys - 1);
9007                 size += ksize;
9008 
9009                 /*
9010                  * Now we need to determine the size of the stored data.
9011                  */
9012                 id = DIF_INSTR_VAR(instr);
9013 
9014                 for (i = 0; i < dp->dtdo_varlen; i++) {
9015                         dtrace_difv_t *v = &dp->dtdo_vartab[i];
9016 
9017                         if (v->dtdv_id == id && v->dtdv_scope == scope) {
9018                                 size += v->dtdv_type.dtdt_size;
9019                                 break;
9020                         }
9021                 }
9022 
9023                 if (i == dp->dtdo_varlen)
9024                         return;
9025 
9026                 /*
9027                  * We have the size.  If this is larger than the chunk size
9028                  * for our dynamic variable state, reset the chunk size.
9029                  */
9030                 size = P2ROUNDUP(size, sizeof (uint64_t));
9031 
9032                 if (size > vstate->dtvs_dynvars.dtds_chunksize)
9033                         vstate->dtvs_dynvars.dtds_chunksize = size;
9034         }
9035 }
9036 
9037 static void
9038 dtrace_difo_init(dtrace_difo_t *dp, dtrace_vstate_t *vstate)
9039 {
9040         int i, oldsvars, osz, nsz, otlocals, ntlocals;
9041         uint_t id;
9042 
9043         ASSERT(MUTEX_HELD(&dtrace_lock));
9044         ASSERT(dp->dtdo_buf != NULL && dp->dtdo_len != 0);
9045 
9046         for (i = 0; i < dp->dtdo_varlen; i++) {
9047                 dtrace_difv_t *v = &dp->dtdo_vartab[i];
9048                 dtrace_statvar_t *svar, ***svarp;
9049                 size_t dsize = 0;
9050                 uint8_t scope = v->dtdv_scope;
9051                 int *np;
9052 
9053                 if ((id = v->dtdv_id) < DIF_VAR_OTHER_UBASE)
9054                         continue;
9055 
9056                 id -= DIF_VAR_OTHER_UBASE;
9057 
9058                 switch (scope) {
9059                 case DIFV_SCOPE_THREAD:
9060                         while (id >= (otlocals = vstate->dtvs_ntlocals)) {
9061                                 dtrace_difv_t *tlocals;
9062 
9063                                 if ((ntlocals = (otlocals << 1)) == 0)
9064                                         ntlocals = 1;
9065 
9066                                 osz = otlocals * sizeof (dtrace_difv_t);
9067                                 nsz = ntlocals * sizeof (dtrace_difv_t);
9068 
9069                                 tlocals = kmem_zalloc(nsz, KM_SLEEP);
9070 
9071                                 if (osz != 0) {
9072                                         bcopy(vstate->dtvs_tlocals,
9073                                             tlocals, osz);
9074                                         kmem_free(vstate->dtvs_tlocals, osz);
9075                                 }
9076 
9077                                 vstate->dtvs_tlocals = tlocals;
9078                                 vstate->dtvs_ntlocals = ntlocals;
9079                         }
9080 
9081                         vstate->dtvs_tlocals[id] = *v;
9082                         continue;
9083 
9084                 case DIFV_SCOPE_LOCAL:
9085                         np = &vstate->dtvs_nlocals;
9086                         svarp = &vstate->dtvs_locals;
9087 
9088                         if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF)
9089                                 dsize = NCPU * (v->dtdv_type.dtdt_size +
9090                                     sizeof (uint64_t));
9091                         else
9092                                 dsize = NCPU * sizeof (uint64_t);
9093 
9094                         break;
9095 
9096                 case DIFV_SCOPE_GLOBAL:
9097                         np = &vstate->dtvs_nglobals;
9098                         svarp = &vstate->dtvs_globals;
9099 
9100                         if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF)
9101                                 dsize = v->dtdv_type.dtdt_size +
9102                                     sizeof (uint64_t);
9103 
9104                         break;
9105 
9106                 default:
9107                         ASSERT(0);
9108                 }
9109 
9110                 while (id >= (oldsvars = *np)) {
9111                         dtrace_statvar_t **statics;
9112                         int newsvars, oldsize, newsize;
9113 
9114                         if ((newsvars = (oldsvars << 1)) == 0)
9115                                 newsvars = 1;
9116 
9117                         oldsize = oldsvars * sizeof (dtrace_statvar_t *);
9118                         newsize = newsvars * sizeof (dtrace_statvar_t *);
9119 
9120                         statics = kmem_zalloc(newsize, KM_SLEEP);
9121 
9122                         if (oldsize != 0) {
9123                                 bcopy(*svarp, statics, oldsize);
9124                                 kmem_free(*svarp, oldsize);
9125                         }
9126 
9127                         *svarp = statics;
9128                         *np = newsvars;
9129                 }
9130 
9131                 if ((svar = (*svarp)[id]) == NULL) {
9132                         svar = kmem_zalloc(sizeof (dtrace_statvar_t), KM_SLEEP);
9133                         svar->dtsv_var = *v;
9134 
9135                         if ((svar->dtsv_size = dsize) != 0) {
9136                                 svar->dtsv_data = (uint64_t)(uintptr_t)
9137                                     kmem_zalloc(dsize, KM_SLEEP);
9138                         }
9139 
9140                         (*svarp)[id] = svar;
9141                 }
9142 
9143                 svar->dtsv_refcnt++;
9144         }
9145 
9146         dtrace_difo_chunksize(dp, vstate);
9147         dtrace_difo_hold(dp);
9148 }
9149 
9150 static dtrace_difo_t *
9151 dtrace_difo_duplicate(dtrace_difo_t *dp, dtrace_vstate_t *vstate)
9152 {
9153         dtrace_difo_t *new;
9154         size_t sz;
9155 
9156         ASSERT(dp->dtdo_buf != NULL);
9157         ASSERT(dp->dtdo_refcnt != 0);
9158 
9159         new = kmem_zalloc(sizeof (dtrace_difo_t), KM_SLEEP);
9160 
9161         ASSERT(dp->dtdo_buf != NULL);
9162         sz = dp->dtdo_len * sizeof (dif_instr_t);
9163         new->dtdo_buf = kmem_alloc(sz, KM_SLEEP);
9164         bcopy(dp->dtdo_buf, new->dtdo_buf, sz);
9165         new->dtdo_len = dp->dtdo_len;
9166 
9167         if (dp->dtdo_strtab != NULL) {
9168                 ASSERT(dp->dtdo_strlen != 0);
9169                 new->dtdo_strtab = kmem_alloc(dp->dtdo_strlen, KM_SLEEP);
9170                 bcopy(dp->dtdo_strtab, new->dtdo_strtab, dp->dtdo_strlen);
9171                 new->dtdo_strlen = dp->dtdo_strlen;
9172         }
9173 
9174         if (dp->dtdo_inttab != NULL) {
9175                 ASSERT(dp->dtdo_intlen != 0);
9176                 sz = dp->dtdo_intlen * sizeof (uint64_t);
9177                 new->dtdo_inttab = kmem_alloc(sz, KM_SLEEP);
9178                 bcopy(dp->dtdo_inttab, new->dtdo_inttab, sz);
9179                 new->dtdo_intlen = dp->dtdo_intlen;
9180         }
9181 
9182         if (dp->dtdo_vartab != NULL) {
9183                 ASSERT(dp->dtdo_varlen != 0);
9184                 sz = dp->dtdo_varlen * sizeof (dtrace_difv_t);
9185                 new->dtdo_vartab = kmem_alloc(sz, KM_SLEEP);
9186                 bcopy(dp->dtdo_vartab, new->dtdo_vartab, sz);
9187                 new->dtdo_varlen = dp->dtdo_varlen;
9188         }
9189 
9190         dtrace_difo_init(new, vstate);
9191         return (new);
9192 }
9193 
9194 static void
9195 dtrace_difo_destroy(dtrace_difo_t *dp, dtrace_vstate_t *vstate)
9196 {
9197         int i;
9198 
9199         ASSERT(dp->dtdo_refcnt == 0);
9200 
9201         for (i = 0; i < dp->dtdo_varlen; i++) {
9202                 dtrace_difv_t *v = &dp->dtdo_vartab[i];
9203                 dtrace_statvar_t *svar, **svarp;
9204                 uint_t id;
9205                 uint8_t scope = v->dtdv_scope;
9206                 int *np;
9207 
9208                 switch (scope) {
9209                 case DIFV_SCOPE_THREAD:
9210                         continue;
9211 
9212                 case DIFV_SCOPE_LOCAL:
9213                         np = &vstate->dtvs_nlocals;
9214                         svarp = vstate->dtvs_locals;
9215                         break;
9216 
9217                 case DIFV_SCOPE_GLOBAL:
9218                         np = &vstate->dtvs_nglobals;
9219                         svarp = vstate->dtvs_globals;
9220                         break;
9221 
9222                 default:
9223                         ASSERT(0);
9224                 }
9225 
9226                 if ((id = v->dtdv_id) < DIF_VAR_OTHER_UBASE)
9227                         continue;
9228 
9229                 id -= DIF_VAR_OTHER_UBASE;
9230                 ASSERT(id < *np);
9231 
9232                 svar = svarp[id];
9233                 ASSERT(svar != NULL);
9234                 ASSERT(svar->dtsv_refcnt > 0);
9235 
9236                 if (--svar->dtsv_refcnt > 0)
9237                         continue;
9238 
9239                 if (svar->dtsv_size != 0) {
9240                         ASSERT(svar->dtsv_data != NULL);
9241                         kmem_free((void *)(uintptr_t)svar->dtsv_data,
9242                             svar->dtsv_size);
9243                 }
9244 
9245                 kmem_free(svar, sizeof (dtrace_statvar_t));
9246                 svarp[id] = NULL;
9247         }
9248 
9249         kmem_free(dp->dtdo_buf, dp->dtdo_len * sizeof (dif_instr_t));
9250         kmem_free(dp->dtdo_inttab, dp->dtdo_intlen * sizeof (uint64_t));
9251         kmem_free(dp->dtdo_strtab, dp->dtdo_strlen);
9252         kmem_free(dp->dtdo_vartab, dp->dtdo_varlen * sizeof (dtrace_difv_t));
9253 
9254         kmem_free(dp, sizeof (dtrace_difo_t));
9255 }
9256 
9257 static void
9258 dtrace_difo_release(dtrace_difo_t *dp, dtrace_vstate_t *vstate)
9259 {
9260         int i;
9261 
9262         ASSERT(MUTEX_HELD(&dtrace_lock));
9263         ASSERT(dp->dtdo_refcnt != 0);
9264 
9265         for (i = 0; i < dp->dtdo_varlen; i++) {
9266                 dtrace_difv_t *v = &dp->dtdo_vartab[i];
9267 
9268                 if (v->dtdv_id != DIF_VAR_VTIMESTAMP)
9269                         continue;
9270 
9271                 ASSERT(dtrace_vtime_references > 0);
9272                 if (--dtrace_vtime_references == 0)
9273                         dtrace_vtime_disable();
9274         }
9275 
9276         if (--dp->dtdo_refcnt == 0)
9277                 dtrace_difo_destroy(dp, vstate);
9278 }
9279 
9280 /*
9281  * DTrace Format Functions
9282  */
9283 static uint16_t
9284 dtrace_format_add(dtrace_state_t *state, char *str)
9285 {
9286         char *fmt, **new;
9287         uint16_t ndx, len = strlen(str) + 1;
9288 
9289         fmt = kmem_zalloc(len, KM_SLEEP);
9290         bcopy(str, fmt, len);
9291 
9292         for (ndx = 0; ndx < state->dts_nformats; ndx++) {
9293                 if (state->dts_formats[ndx] == NULL) {
9294                         state->dts_formats[ndx] = fmt;
9295                         return (ndx + 1);
9296                 }
9297         }
9298 
9299         if (state->dts_nformats == USHRT_MAX) {
9300                 /*
9301                  * This is only likely if a denial-of-service attack is being
9302                  * attempted.  As such, it's okay to fail silently here.
9303                  */
9304                 kmem_free(fmt, len);
9305                 return (0);
9306         }
9307 
9308         /*
9309          * For simplicity, we always resize the formats array to be exactly the
9310          * number of formats.
9311          */
9312         ndx = state->dts_nformats++;
9313         new = kmem_alloc((ndx + 1) * sizeof (char *), KM_SLEEP);
9314 
9315         if (state->dts_formats != NULL) {
9316                 ASSERT(ndx != 0);
9317                 bcopy(state->dts_formats, new, ndx * sizeof (char *));
9318                 kmem_free(state->dts_formats, ndx * sizeof (char *));
9319         }
9320 
9321         state->dts_formats = new;
9322         state->dts_formats[ndx] = fmt;
9323 
9324         return (ndx + 1);
9325 }
9326 
9327 static void
9328 dtrace_format_remove(dtrace_state_t *state, uint16_t format)
9329 {
9330         char *fmt;
9331 
9332         ASSERT(state->dts_formats != NULL);
9333         ASSERT(format <= state->dts_nformats);
9334         ASSERT(state->dts_formats[format - 1] != NULL);
9335 
9336         fmt = state->dts_formats[format - 1];
9337         kmem_free(fmt, strlen(fmt) + 1);
9338         state->dts_formats[format - 1] = NULL;
9339 }
9340 
9341 static void
9342 dtrace_format_destroy(dtrace_state_t *state)
9343 {
9344         int i;
9345 
9346         if (state->dts_nformats == 0) {
9347                 ASSERT(state->dts_formats == NULL);
9348                 return;
9349         }
9350 
9351         ASSERT(state->dts_formats != NULL);
9352 
9353         for (i = 0; i < state->dts_nformats; i++) {
9354                 char *fmt = state->dts_formats[i];
9355 
9356                 if (fmt == NULL)
9357                         continue;
9358 
9359                 kmem_free(fmt, strlen(fmt) + 1);
9360         }
9361 
9362         kmem_free(state->dts_formats, state->dts_nformats * sizeof (char *));
9363         state->dts_nformats = 0;
9364         state->dts_formats = NULL;
9365 }
9366 
9367 /*
9368  * DTrace Predicate Functions
9369  */
9370 static dtrace_predicate_t *
9371 dtrace_predicate_create(dtrace_difo_t *dp)
9372 {
9373         dtrace_predicate_t *pred;
9374 
9375         ASSERT(MUTEX_HELD(&dtrace_lock));
9376         ASSERT(dp->dtdo_refcnt != 0);
9377 
9378         pred = kmem_zalloc(sizeof (dtrace_predicate_t), KM_SLEEP);
9379         pred->dtp_difo = dp;
9380         pred->dtp_refcnt = 1;
9381 
9382         if (!dtrace_difo_cacheable(dp))
9383                 return (pred);
9384 
9385         if (dtrace_predcache_id == DTRACE_CACHEIDNONE) {
9386                 /*
9387                  * This is only theoretically possible -- we have had 2^32
9388                  * cacheable predicates on this machine.  We cannot allow any
9389                  * more predicates to become cacheable:  as unlikely as it is,
9390                  * there may be a thread caching a (now stale) predicate cache
9391                  * ID. (N.B.: the temptation is being successfully resisted to
9392                  * have this cmn_err() "Holy shit -- we executed this code!")
9393                  */
9394                 return (pred);
9395         }
9396 
9397         pred->dtp_cacheid = dtrace_predcache_id++;
9398 
9399         return (pred);
9400 }
9401 
9402 static void
9403 dtrace_predicate_hold(dtrace_predicate_t *pred)
9404 {
9405         ASSERT(MUTEX_HELD(&dtrace_lock));
9406         ASSERT(pred->dtp_difo != NULL && pred->dtp_difo->dtdo_refcnt != 0);
9407         ASSERT(pred->dtp_refcnt > 0);
9408 
9409         pred->dtp_refcnt++;
9410 }
9411 
9412 static void
9413 dtrace_predicate_release(dtrace_predicate_t *pred, dtrace_vstate_t *vstate)
9414 {
9415         dtrace_difo_t *dp = pred->dtp_difo;
9416 
9417         ASSERT(MUTEX_HELD(&dtrace_lock));
9418         ASSERT(dp != NULL && dp->dtdo_refcnt != 0);
9419         ASSERT(pred->dtp_refcnt > 0);
9420 
9421         if (--pred->dtp_refcnt == 0) {
9422                 dtrace_difo_release(pred->dtp_difo, vstate);
9423                 kmem_free(pred, sizeof (dtrace_predicate_t));
9424         }
9425 }
9426 
9427 /*
9428  * DTrace Action Description Functions
9429  */
9430 static dtrace_actdesc_t *
9431 dtrace_actdesc_create(dtrace_actkind_t kind, uint32_t ntuple,
9432     uint64_t uarg, uint64_t arg)
9433 {
9434         dtrace_actdesc_t *act;
9435 
9436         ASSERT(!DTRACEACT_ISPRINTFLIKE(kind) || (arg != NULL &&
9437             arg >= KERNELBASE) || (arg == NULL && kind == DTRACEACT_PRINTA));
9438 
9439         act = kmem_zalloc(sizeof (dtrace_actdesc_t), KM_SLEEP);
9440         act->dtad_kind = kind;
9441         act->dtad_ntuple = ntuple;
9442         act->dtad_uarg = uarg;
9443         act->dtad_arg = arg;
9444         act->dtad_refcnt = 1;
9445 
9446         return (act);
9447 }
9448 
9449 static void
9450 dtrace_actdesc_hold(dtrace_actdesc_t *act)
9451 {
9452         ASSERT(act->dtad_refcnt >= 1);
9453         act->dtad_refcnt++;
9454 }
9455 
9456 static void
9457 dtrace_actdesc_release(dtrace_actdesc_t *act, dtrace_vstate_t *vstate)
9458 {
9459         dtrace_actkind_t kind = act->dtad_kind;
9460         dtrace_difo_t *dp;
9461 
9462         ASSERT(act->dtad_refcnt >= 1);
9463 
9464         if (--act->dtad_refcnt != 0)
9465                 return;
9466 
9467         if ((dp = act->dtad_difo) != NULL)
9468                 dtrace_difo_release(dp, vstate);
9469 
9470         if (DTRACEACT_ISPRINTFLIKE(kind)) {
9471                 char *str = (char *)(uintptr_t)act->dtad_arg;
9472 
9473                 ASSERT((str != NULL && (uintptr_t)str >= KERNELBASE) ||
9474                     (str == NULL && act->dtad_kind == DTRACEACT_PRINTA));
9475 
9476                 if (str != NULL)
9477                         kmem_free(str, strlen(str) + 1);
9478         }
9479 
9480         kmem_free(act, sizeof (dtrace_actdesc_t));
9481 }
9482 
9483 /*
9484  * DTrace ECB Functions
9485  */
9486 static dtrace_ecb_t *
9487 dtrace_ecb_add(dtrace_state_t *state, dtrace_probe_t *probe)
9488 {
9489         dtrace_ecb_t *ecb;
9490         dtrace_epid_t epid;
9491 
9492         ASSERT(MUTEX_HELD(&dtrace_lock));
9493 
9494         ecb = kmem_zalloc(sizeof (dtrace_ecb_t), KM_SLEEP);
9495         ecb->dte_predicate = NULL;
9496         ecb->dte_probe = probe;
9497 
9498         /*
9499          * The default size is the size of the default action: recording
9500          * the epid.
9501          */
9502         ecb->dte_size = ecb->dte_needed = sizeof (dtrace_epid_t);
9503         ecb->dte_alignment = sizeof (dtrace_epid_t);
9504 
9505         epid = state->dts_epid++;
9506 
9507         if (epid - 1 >= state->dts_necbs) {
9508                 dtrace_ecb_t **oecbs = state->dts_ecbs, **ecbs;
9509                 int necbs = state->dts_necbs << 1;
9510 
9511                 ASSERT(epid == state->dts_necbs + 1);
9512 
9513                 if (necbs == 0) {
9514                         ASSERT(oecbs == NULL);
9515                         necbs = 1;
9516                 }
9517 
9518                 ecbs = kmem_zalloc(necbs * sizeof (*ecbs), KM_SLEEP);
9519 
9520                 if (oecbs != NULL)
9521                         bcopy(oecbs, ecbs, state->dts_necbs * sizeof (*ecbs));
9522 
9523                 dtrace_membar_producer();
9524                 state->dts_ecbs = ecbs;
9525 
9526                 if (oecbs != NULL) {
9527                         /*
9528                          * If this state is active, we must dtrace_sync()
9529                          * before we can free the old dts_ecbs array:  we're
9530                          * coming in hot, and there may be active ring
9531                          * buffer processing (which indexes into the dts_ecbs
9532                          * array) on another CPU.
9533                          */
9534                         if (state->dts_activity != DTRACE_ACTIVITY_INACTIVE)
9535                                 dtrace_sync();
9536 
9537                         kmem_free(oecbs, state->dts_necbs * sizeof (*ecbs));
9538                 }
9539 
9540                 dtrace_membar_producer();
9541                 state->dts_necbs = necbs;
9542         }
9543 
9544         ecb->dte_state = state;
9545 
9546         ASSERT(state->dts_ecbs[epid - 1] == NULL);
9547         dtrace_membar_producer();
9548         state->dts_ecbs[(ecb->dte_epid = epid) - 1] = ecb;
9549 
9550         return (ecb);
9551 }
9552 
9553 static int
9554 dtrace_ecb_enable(dtrace_ecb_t *ecb)
9555 {
9556         dtrace_probe_t *probe = ecb->dte_probe;
9557 
9558         ASSERT(MUTEX_HELD(&cpu_lock));
9559         ASSERT(MUTEX_HELD(&dtrace_lock));
9560         ASSERT(ecb->dte_next == NULL);
9561 
9562         if (probe == NULL) {
9563                 /*
9564                  * This is the NULL probe -- there's nothing to do.
9565                  */
9566                 return (0);
9567         }
9568 
9569         if (probe->dtpr_ecb == NULL) {
9570                 dtrace_provider_t *prov = probe->dtpr_provider;
9571 
9572                 /*
9573                  * We're the first ECB on this probe.
9574                  */
9575                 probe->dtpr_ecb = probe->dtpr_ecb_last = ecb;
9576 
9577                 if (ecb->dte_predicate != NULL)
9578                         probe->dtpr_predcache = ecb->dte_predicate->dtp_cacheid;
9579 
9580                 return (prov->dtpv_pops.dtps_enable(prov->dtpv_arg,
9581                     probe->dtpr_id, probe->dtpr_arg));
9582         } else {
9583                 /*
9584                  * This probe is already active.  Swing the last pointer to
9585                  * point to the new ECB, and issue a dtrace_sync() to assure
9586                  * that all CPUs have seen the change.
9587                  */
9588                 ASSERT(probe->dtpr_ecb_last != NULL);
9589                 probe->dtpr_ecb_last->dte_next = ecb;
9590                 probe->dtpr_ecb_last = ecb;
9591                 probe->dtpr_predcache = 0;
9592 
9593                 dtrace_sync();
9594                 return (0);
9595         }
9596 }
9597 
9598 static void
9599 dtrace_ecb_resize(dtrace_ecb_t *ecb)
9600 {
9601         uint32_t maxalign = sizeof (dtrace_epid_t);
9602         uint32_t align = sizeof (uint8_t), offs, diff;
9603         dtrace_action_t *act;
9604         int wastuple = 0;
9605         uint32_t aggbase = UINT32_MAX;
9606         dtrace_state_t *state = ecb->dte_state;
9607 
9608         /*
9609          * If we record anything, we always record the epid.  (And we always
9610          * record it first.)
9611          */
9612         offs = sizeof (dtrace_epid_t);
9613         ecb->dte_size = ecb->dte_needed = sizeof (dtrace_epid_t);
9614 
9615         for (act = ecb->dte_action; act != NULL; act = act->dta_next) {
9616                 dtrace_recdesc_t *rec = &act->dta_rec;
9617 
9618                 if ((align = rec->dtrd_alignment) > maxalign)
9619                         maxalign = align;
9620 
9621                 if (!wastuple && act->dta_intuple) {
9622                         /*
9623                          * This is the first record in a tuple.  Align the
9624                          * offset to be at offset 4 in an 8-byte aligned
9625                          * block.
9626                          */
9627                         diff = offs + sizeof (dtrace_aggid_t);
9628 
9629                         if (diff = (diff & (sizeof (uint64_t) - 1)))
9630                                 offs += sizeof (uint64_t) - diff;
9631 
9632                         aggbase = offs - sizeof (dtrace_aggid_t);
9633                         ASSERT(!(aggbase & (sizeof (uint64_t) - 1)));
9634                 }
9635 
9636                 /*LINTED*/
9637                 if (rec->dtrd_size != 0 && (diff = (offs & (align - 1)))) {
9638                         /*
9639                          * The current offset is not properly aligned; align it.
9640                          */
9641                         offs += align - diff;
9642                 }
9643 
9644                 rec->dtrd_offset = offs;
9645 
9646                 if (offs + rec->dtrd_size > ecb->dte_needed) {
9647                         ecb->dte_needed = offs + rec->dtrd_size;
9648 
9649                         if (ecb->dte_needed > state->dts_needed)
9650                                 state->dts_needed = ecb->dte_needed;
9651                 }
9652 
9653                 if (DTRACEACT_ISAGG(act->dta_kind)) {
9654                         dtrace_aggregation_t *agg = (dtrace_aggregation_t *)act;
9655                         dtrace_action_t *first = agg->dtag_first, *prev;
9656 
9657                         ASSERT(rec->dtrd_size != 0 && first != NULL);
9658                         ASSERT(wastuple);
9659                         ASSERT(aggbase != UINT32_MAX);
9660 
9661                         agg->dtag_base = aggbase;
9662 
9663                         while ((prev = first->dta_prev) != NULL &&
9664                             DTRACEACT_ISAGG(prev->dta_kind)) {
9665                                 agg = (dtrace_aggregation_t *)prev;
9666                                 first = agg->dtag_first;
9667                         }
9668 
9669                         if (prev != NULL) {
9670                                 offs = prev->dta_rec.dtrd_offset +
9671                                     prev->dta_rec.dtrd_size;
9672                         } else {
9673                                 offs = sizeof (dtrace_epid_t);
9674                         }
9675                         wastuple = 0;
9676                 } else {
9677                         if (!act->dta_intuple)
9678                                 ecb->dte_size = offs + rec->dtrd_size;
9679 
9680                         offs += rec->dtrd_size;
9681                 }
9682 
9683                 wastuple = act->dta_intuple;
9684         }
9685 
9686         if ((act = ecb->dte_action) != NULL &&
9687             !(act->dta_kind == DTRACEACT_SPECULATE && act->dta_next == NULL) &&
9688             ecb->dte_size == sizeof (dtrace_epid_t)) {
9689                 /*
9690                  * If the size is still sizeof (dtrace_epid_t), then all
9691                  * actions store no data; set the size to 0.
9692                  */
9693                 ecb->dte_alignment = maxalign;
9694                 ecb->dte_size = 0;
9695 
9696                 /*
9697                  * If the needed space is still sizeof (dtrace_epid_t), then
9698                  * all actions need no additional space; set the needed
9699                  * size to 0.
9700                  */
9701                 if (ecb->dte_needed == sizeof (dtrace_epid_t))
9702                         ecb->dte_needed = 0;
9703 
9704                 return;
9705         }
9706 
9707         /*
9708          * Set our alignment, and make sure that the dte_size and dte_needed
9709          * are aligned to the size of an EPID.
9710          */
9711         ecb->dte_alignment = maxalign;
9712         ecb->dte_size = (ecb->dte_size + (sizeof (dtrace_epid_t) - 1)) &
9713             ~(sizeof (dtrace_epid_t) - 1);
9714         ecb->dte_needed = (ecb->dte_needed + (sizeof (dtrace_epid_t) - 1)) &
9715             ~(sizeof (dtrace_epid_t) - 1);
9716         ASSERT(ecb->dte_size <= ecb->dte_needed);
9717 }
9718 
9719 static dtrace_action_t *
9720 dtrace_ecb_aggregation_create(dtrace_ecb_t *ecb, dtrace_actdesc_t *desc)
9721 {
9722         dtrace_aggregation_t *agg;
9723         size_t size = sizeof (uint64_t);
9724         int ntuple = desc->dtad_ntuple;
9725         dtrace_action_t *act;
9726         dtrace_recdesc_t *frec;
9727         dtrace_aggid_t aggid;
9728         dtrace_state_t *state = ecb->dte_state;
9729 
9730         agg = kmem_zalloc(sizeof (dtrace_aggregation_t), KM_SLEEP);
9731         agg->dtag_ecb = ecb;
9732 
9733         ASSERT(DTRACEACT_ISAGG(desc->dtad_kind));
9734 
9735         switch (desc->dtad_kind) {
9736         case DTRACEAGG_MIN:
9737                 agg->dtag_initial = INT64_MAX;
9738                 agg->dtag_aggregate = dtrace_aggregate_min;
9739                 break;
9740 
9741         case DTRACEAGG_MAX:
9742                 agg->dtag_initial = INT64_MIN;
9743                 agg->dtag_aggregate = dtrace_aggregate_max;
9744                 break;
9745 
9746         case DTRACEAGG_COUNT:
9747                 agg->dtag_aggregate = dtrace_aggregate_count;
9748                 break;
9749 
9750         case DTRACEAGG_QUANTIZE:
9751                 agg->dtag_aggregate = dtrace_aggregate_quantize;
9752                 size = (((sizeof (uint64_t) * NBBY) - 1) * 2 + 1) *
9753                     sizeof (uint64_t);
9754                 break;
9755 
9756         case DTRACEAGG_LQUANTIZE: {
9757                 uint16_t step = DTRACE_LQUANTIZE_STEP(desc->dtad_arg);
9758                 uint16_t levels = DTRACE_LQUANTIZE_LEVELS(desc->dtad_arg);
9759 
9760                 agg->dtag_initial = desc->dtad_arg;
9761                 agg->dtag_aggregate = dtrace_aggregate_lquantize;
9762 
9763                 if (step == 0 || levels == 0)
9764                         goto err;
9765 
9766                 size = levels * sizeof (uint64_t) + 3 * sizeof (uint64_t);
9767                 break;
9768         }
9769 
9770         case DTRACEAGG_LLQUANTIZE: {
9771                 uint16_t factor = DTRACE_LLQUANTIZE_FACTOR(desc->dtad_arg);
9772                 uint16_t low = DTRACE_LLQUANTIZE_LOW(desc->dtad_arg);
9773                 uint16_t high = DTRACE_LLQUANTIZE_HIGH(desc->dtad_arg);
9774                 uint16_t nsteps = DTRACE_LLQUANTIZE_NSTEP(desc->dtad_arg);
9775                 int64_t v;
9776 
9777                 agg->dtag_initial = desc->dtad_arg;
9778                 agg->dtag_aggregate = dtrace_aggregate_llquantize;
9779 
9780                 if (factor < 2 || low >= high || nsteps < factor)
9781                         goto err;
9782 
9783                 /*
9784                  * Now check that the number of steps evenly divides a power
9785                  * of the factor.  (This assures both integer bucket size and
9786                  * linearity within each magnitude.)
9787                  */
9788                 for (v = factor; v < nsteps; v *= factor)
9789                         continue;
9790 
9791                 if ((v % nsteps) || (nsteps % factor))
9792                         goto err;
9793 
9794                 size = (dtrace_aggregate_llquantize_bucket(factor,
9795                     low, high, nsteps, INT64_MAX) + 2) * sizeof (uint64_t);
9796                 break;
9797         }
9798 
9799         case DTRACEAGG_AVG:
9800                 agg->dtag_aggregate = dtrace_aggregate_avg;
9801                 size = sizeof (uint64_t) * 2;
9802                 break;
9803 
9804         case DTRACEAGG_STDDEV:
9805                 agg->dtag_aggregate = dtrace_aggregate_stddev;
9806                 size = sizeof (uint64_t) * 4;
9807                 break;
9808 
9809         case DTRACEAGG_SUM:
9810                 agg->dtag_aggregate = dtrace_aggregate_sum;
9811                 break;
9812 
9813         default:
9814                 goto err;
9815         }
9816 
9817         agg->dtag_action.dta_rec.dtrd_size = size;
9818 
9819         if (ntuple == 0)
9820                 goto err;
9821 
9822         /*
9823          * We must make sure that we have enough actions for the n-tuple.
9824          */
9825         for (act = ecb->dte_action_last; act != NULL; act = act->dta_prev) {
9826                 if (DTRACEACT_ISAGG(act->dta_kind))
9827                         break;
9828 
9829                 if (--ntuple == 0) {
9830                         /*
9831                          * This is the action with which our n-tuple begins.
9832                          */
9833                         agg->dtag_first = act;
9834                         goto success;
9835                 }
9836         }
9837 
9838         /*
9839          * This n-tuple is short by ntuple elements.  Return failure.
9840          */
9841         ASSERT(ntuple != 0);
9842 err:
9843         kmem_free(agg, sizeof (dtrace_aggregation_t));
9844         return (NULL);
9845 
9846 success:
9847         /*
9848          * If the last action in the tuple has a size of zero, it's actually
9849          * an expression argument for the aggregating action.
9850          */
9851         ASSERT(ecb->dte_action_last != NULL);
9852         act = ecb->dte_action_last;
9853 
9854         if (act->dta_kind == DTRACEACT_DIFEXPR) {
9855                 ASSERT(act->dta_difo != NULL);
9856 
9857                 if (act->dta_difo->dtdo_rtype.dtdt_size == 0)
9858                         agg->dtag_hasarg = 1;
9859         }
9860 
9861         /*
9862          * We need to allocate an id for this aggregation.
9863          */
9864         aggid = (dtrace_aggid_t)(uintptr_t)vmem_alloc(state->dts_aggid_arena, 1,
9865             VM_BESTFIT | VM_SLEEP);
9866 
9867         if (aggid - 1 >= state->dts_naggregations) {
9868                 dtrace_aggregation_t **oaggs = state->dts_aggregations;
9869                 dtrace_aggregation_t **aggs;
9870                 int naggs = state->dts_naggregations << 1;
9871                 int onaggs = state->dts_naggregations;
9872 
9873                 ASSERT(aggid == state->dts_naggregations + 1);
9874 
9875                 if (naggs == 0) {
9876                         ASSERT(oaggs == NULL);
9877                         naggs = 1;
9878                 }
9879 
9880                 aggs = kmem_zalloc(naggs * sizeof (*aggs), KM_SLEEP);
9881 
9882                 if (oaggs != NULL) {
9883                         bcopy(oaggs, aggs, onaggs * sizeof (*aggs));
9884                         kmem_free(oaggs, onaggs * sizeof (*aggs));
9885                 }
9886 
9887                 state->dts_aggregations = aggs;
9888                 state->dts_naggregations = naggs;
9889         }
9890 
9891         ASSERT(state->dts_aggregations[aggid - 1] == NULL);
9892         state->dts_aggregations[(agg->dtag_id = aggid) - 1] = agg;
9893 
9894         frec = &agg->dtag_first->dta_rec;
9895         if (frec->dtrd_alignment < sizeof (dtrace_aggid_t))
9896                 frec->dtrd_alignment = sizeof (dtrace_aggid_t);
9897 
9898         for (act = agg->dtag_first; act != NULL; act = act->dta_next) {
9899                 ASSERT(!act->dta_intuple);
9900                 act->dta_intuple = 1;
9901         }
9902 
9903         return (&agg->dtag_action);
9904 }
9905 
9906 static void
9907 dtrace_ecb_aggregation_destroy(dtrace_ecb_t *ecb, dtrace_action_t *act)
9908 {
9909         dtrace_aggregation_t *agg = (dtrace_aggregation_t *)act;
9910         dtrace_state_t *state = ecb->dte_state;
9911         dtrace_aggid_t aggid = agg->dtag_id;
9912 
9913         ASSERT(DTRACEACT_ISAGG(act->dta_kind));
9914         vmem_free(state->dts_aggid_arena, (void *)(uintptr_t)aggid, 1);
9915 
9916         ASSERT(state->dts_aggregations[aggid - 1] == agg);
9917         state->dts_aggregations[aggid - 1] = NULL;
9918 
9919         kmem_free(agg, sizeof (dtrace_aggregation_t));
9920 }
9921 
9922 static int
9923 dtrace_ecb_action_add(dtrace_ecb_t *ecb, dtrace_actdesc_t *desc)
9924 {
9925         dtrace_action_t *action, *last;
9926         dtrace_difo_t *dp = desc->dtad_difo;
9927         uint32_t size = 0, align = sizeof (uint8_t), mask;
9928         uint16_t format = 0;
9929         dtrace_recdesc_t *rec;
9930         dtrace_state_t *state = ecb->dte_state;
9931         dtrace_optval_t *opt = state->dts_options, nframes, strsize;
9932         uint64_t arg = desc->dtad_arg;
9933 
9934         ASSERT(MUTEX_HELD(&dtrace_lock));
9935         ASSERT(ecb->dte_action == NULL || ecb->dte_action->dta_refcnt == 1);
9936 
9937         if (DTRACEACT_ISAGG(desc->dtad_kind)) {
9938                 /*
9939                  * If this is an aggregating action, there must be neither
9940                  * a speculate nor a commit on the action chain.
9941                  */
9942                 dtrace_action_t *act;
9943 
9944                 for (act = ecb->dte_action; act != NULL; act = act->dta_next) {
9945                         if (act->dta_kind == DTRACEACT_COMMIT)
9946                                 return (EINVAL);
9947 
9948                         if (act->dta_kind == DTRACEACT_SPECULATE)
9949                                 return (EINVAL);
9950                 }
9951 
9952                 action = dtrace_ecb_aggregation_create(ecb, desc);
9953 
9954                 if (action == NULL)
9955                         return (EINVAL);
9956         } else {
9957                 if (DTRACEACT_ISDESTRUCTIVE(desc->dtad_kind) ||
9958                     (desc->dtad_kind == DTRACEACT_DIFEXPR &&
9959                     dp != NULL && dp->dtdo_destructive)) {
9960                         state->dts_destructive = 1;
9961                 }
9962 
9963                 switch (desc->dtad_kind) {
9964                 case DTRACEACT_PRINTF:
9965                 case DTRACEACT_PRINTA:
9966                 case DTRACEACT_SYSTEM:
9967                 case DTRACEACT_FREOPEN:
9968                 case DTRACEACT_DIFEXPR:
9969                         /*
9970                          * We know that our arg is a string -- turn it into a
9971                          * format.
9972                          */
9973                         if (arg == NULL) {
9974                                 ASSERT(desc->dtad_kind == DTRACEACT_PRINTA ||
9975                                     desc->dtad_kind == DTRACEACT_DIFEXPR);
9976                                 format = 0;
9977                         } else {
9978                                 ASSERT(arg != NULL);
9979                                 ASSERT(arg > KERNELBASE);
9980                                 format = dtrace_format_add(state,
9981                                     (char *)(uintptr_t)arg);
9982                         }
9983 
9984                         /*FALLTHROUGH*/
9985                 case DTRACEACT_LIBACT:
9986                 case DTRACEACT_TRACEMEM:
9987                 case DTRACEACT_TRACEMEM_DYNSIZE:
9988                         if (dp == NULL)
9989                                 return (EINVAL);
9990 
9991                         if ((size = dp->dtdo_rtype.dtdt_size) != 0)
9992                                 break;
9993 
9994                         if (dp->dtdo_rtype.dtdt_kind == DIF_TYPE_STRING) {
9995                                 if (!(dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF))
9996                                         return (EINVAL);
9997 
9998                                 size = opt[DTRACEOPT_STRSIZE];
9999                         }
10000 
10001                         break;
10002 
10003                 case DTRACEACT_STACK:
10004                         if ((nframes = arg) == 0) {
10005                                 nframes = opt[DTRACEOPT_STACKFRAMES];
10006                                 ASSERT(nframes > 0);
10007                                 arg = nframes;
10008                         }
10009 
10010                         size = nframes * sizeof (pc_t);
10011                         break;
10012 
10013                 case DTRACEACT_JSTACK:
10014                         if ((strsize = DTRACE_USTACK_STRSIZE(arg)) == 0)
10015                                 strsize = opt[DTRACEOPT_JSTACKSTRSIZE];
10016 
10017                         if ((nframes = DTRACE_USTACK_NFRAMES(arg)) == 0)
10018                                 nframes = opt[DTRACEOPT_JSTACKFRAMES];
10019 
10020                         arg = DTRACE_USTACK_ARG(nframes, strsize);
10021 
10022                         /*FALLTHROUGH*/
10023                 case DTRACEACT_USTACK:
10024                         if (desc->dtad_kind != DTRACEACT_JSTACK &&
10025                             (nframes = DTRACE_USTACK_NFRAMES(arg)) == 0) {
10026                                 strsize = DTRACE_USTACK_STRSIZE(arg);
10027                                 nframes = opt[DTRACEOPT_USTACKFRAMES];
10028                                 ASSERT(nframes > 0);
10029                                 arg = DTRACE_USTACK_ARG(nframes, strsize);
10030                         }
10031 
10032                         /*
10033                          * Save a slot for the pid.
10034                          */
10035                         size = (nframes + 1) * sizeof (uint64_t);
10036                         size += DTRACE_USTACK_STRSIZE(arg);
10037                         size = P2ROUNDUP(size, (uint32_t)(sizeof (uintptr_t)));
10038 
10039                         break;
10040 
10041                 case DTRACEACT_SYM:
10042                 case DTRACEACT_MOD:
10043                         if (dp == NULL || ((size = dp->dtdo_rtype.dtdt_size) !=
10044                             sizeof (uint64_t)) ||
10045                             (dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF))
10046                                 return (EINVAL);
10047                         break;
10048 
10049                 case DTRACEACT_USYM:
10050                 case DTRACEACT_UMOD:
10051                 case DTRACEACT_UADDR:
10052                         if (dp == NULL ||
10053                             (dp->dtdo_rtype.dtdt_size != sizeof (uint64_t)) ||
10054                             (dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF))
10055                                 return (EINVAL);
10056 
10057                         /*
10058                          * We have a slot for the pid, plus a slot for the
10059                          * argument.  To keep things simple (aligned with
10060                          * bitness-neutral sizing), we store each as a 64-bit
10061                          * quantity.
10062                          */
10063                         size = 2 * sizeof (uint64_t);
10064                         break;
10065 
10066                 case DTRACEACT_STOP:
10067                 case DTRACEACT_BREAKPOINT:
10068                 case DTRACEACT_PANIC:
10069                         break;
10070 
10071                 case DTRACEACT_CHILL:
10072                 case DTRACEACT_DISCARD:
10073                 case DTRACEACT_RAISE:
10074                         if (dp == NULL)
10075                                 return (EINVAL);
10076                         break;
10077 
10078                 case DTRACEACT_EXIT:
10079                         if (dp == NULL ||
10080                             (size = dp->dtdo_rtype.dtdt_size) != sizeof (int) ||
10081                             (dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF))
10082                                 return (EINVAL);
10083                         break;
10084 
10085                 case DTRACEACT_SPECULATE:
10086                         if (ecb->dte_size > sizeof (dtrace_epid_t))
10087                                 return (EINVAL);
10088 
10089                         if (dp == NULL)
10090                                 return (EINVAL);
10091 
10092                         state->dts_speculates = 1;
10093                         break;
10094 
10095                 case DTRACEACT_COMMIT: {
10096                         dtrace_action_t *act = ecb->dte_action;
10097 
10098                         for (; act != NULL; act = act->dta_next) {
10099                                 if (act->dta_kind == DTRACEACT_COMMIT)
10100                                         return (EINVAL);
10101                         }
10102 
10103                         if (dp == NULL)
10104                                 return (EINVAL);
10105                         break;
10106                 }
10107 
10108                 default:
10109                         return (EINVAL);
10110                 }
10111 
10112                 if (size != 0 || desc->dtad_kind == DTRACEACT_SPECULATE) {
10113                         /*
10114                          * If this is a data-storing action or a speculate,
10115                          * we must be sure that there isn't a commit on the
10116                          * action chain.
10117                          */
10118                         dtrace_action_t *act = ecb->dte_action;
10119 
10120                         for (; act != NULL; act = act->dta_next) {
10121                                 if (act->dta_kind == DTRACEACT_COMMIT)
10122                                         return (EINVAL);
10123                         }
10124                 }
10125 
10126                 action = kmem_zalloc(sizeof (dtrace_action_t), KM_SLEEP);
10127                 action->dta_rec.dtrd_size = size;
10128         }
10129 
10130         action->dta_refcnt = 1;
10131         rec = &action->dta_rec;
10132         size = rec->dtrd_size;
10133 
10134         for (mask = sizeof (uint64_t) - 1; size != 0 && mask > 0; mask >>= 1) {
10135                 if (!(size & mask)) {
10136                         align = mask + 1;
10137                         break;
10138                 }
10139         }
10140 
10141         action->dta_kind = desc->dtad_kind;
10142 
10143         if ((action->dta_difo = dp) != NULL)
10144                 dtrace_difo_hold(dp);
10145 
10146         rec->dtrd_action = action->dta_kind;
10147         rec->dtrd_arg = arg;
10148         rec->dtrd_uarg = desc->dtad_uarg;
10149         rec->dtrd_alignment = (uint16_t)align;
10150         rec->dtrd_format = format;
10151 
10152         if ((last = ecb->dte_action_last) != NULL) {
10153                 ASSERT(ecb->dte_action != NULL);
10154                 action->dta_prev = last;
10155                 last->dta_next = action;
10156         } else {
10157                 ASSERT(ecb->dte_action == NULL);
10158                 ecb->dte_action = action;
10159         }
10160 
10161         ecb->dte_action_last = action;
10162 
10163         return (0);
10164 }
10165 
10166 static void
10167 dtrace_ecb_action_remove(dtrace_ecb_t *ecb)
10168 {
10169         dtrace_action_t *act = ecb->dte_action, *next;
10170         dtrace_vstate_t *vstate = &ecb->dte_state->dts_vstate;
10171         dtrace_difo_t *dp;
10172         uint16_t format;
10173 
10174         if (act != NULL && act->dta_refcnt > 1) {
10175                 ASSERT(act->dta_next == NULL || act->dta_next->dta_refcnt == 1);
10176                 act->dta_refcnt--;
10177         } else {
10178                 for (; act != NULL; act = next) {
10179                         next = act->dta_next;
10180                         ASSERT(next != NULL || act == ecb->dte_action_last);
10181                         ASSERT(act->dta_refcnt == 1);
10182 
10183                         if ((format = act->dta_rec.dtrd_format) != 0)
10184                                 dtrace_format_remove(ecb->dte_state, format);
10185 
10186                         if ((dp = act->dta_difo) != NULL)
10187                                 dtrace_difo_release(dp, vstate);
10188 
10189                         if (DTRACEACT_ISAGG(act->dta_kind)) {
10190                                 dtrace_ecb_aggregation_destroy(ecb, act);
10191                         } else {
10192                                 kmem_free(act, sizeof (dtrace_action_t));
10193                         }
10194                 }
10195         }
10196 
10197         ecb->dte_action = NULL;
10198         ecb->dte_action_last = NULL;
10199         ecb->dte_size = sizeof (dtrace_epid_t);
10200 }
10201 
10202 static void
10203 dtrace_ecb_disable(dtrace_ecb_t *ecb)
10204 {
10205         /*
10206          * We disable the ECB by removing it from its probe.
10207          */
10208         dtrace_ecb_t *pecb, *prev = NULL;
10209         dtrace_probe_t *probe = ecb->dte_probe;
10210 
10211         ASSERT(MUTEX_HELD(&dtrace_lock));
10212 
10213         if (probe == NULL) {
10214                 /*
10215                  * This is the NULL probe; there is nothing to disable.
10216                  */
10217                 return;
10218         }
10219 
10220         for (pecb = probe->dtpr_ecb; pecb != NULL; pecb = pecb->dte_next) {
10221                 if (pecb == ecb)
10222                         break;
10223                 prev = pecb;
10224         }
10225 
10226         ASSERT(pecb != NULL);
10227 
10228         if (prev == NULL) {
10229                 probe->dtpr_ecb = ecb->dte_next;
10230         } else {
10231                 prev->dte_next = ecb->dte_next;
10232         }
10233 
10234         if (ecb == probe->dtpr_ecb_last) {
10235                 ASSERT(ecb->dte_next == NULL);
10236                 probe->dtpr_ecb_last = prev;
10237         }
10238 
10239         /*
10240          * The ECB has been disconnected from the probe; now sync to assure
10241          * that all CPUs have seen the change before returning.
10242          */
10243         dtrace_sync();
10244 
10245         if (probe->dtpr_ecb == NULL) {
10246                 /*
10247                  * That was the last ECB on the probe; clear the predicate
10248                  * cache ID for the probe, disable it and sync one more time
10249                  * to assure that we'll never hit it again.
10250                  */
10251                 dtrace_provider_t *prov = probe->dtpr_provider;
10252 
10253                 ASSERT(ecb->dte_next == NULL);
10254                 ASSERT(probe->dtpr_ecb_last == NULL);
10255                 probe->dtpr_predcache = DTRACE_CACHEIDNONE;
10256                 prov->dtpv_pops.dtps_disable(prov->dtpv_arg,
10257                     probe->dtpr_id, probe->dtpr_arg);
10258                 dtrace_sync();
10259         } else {
10260                 /*
10261                  * There is at least one ECB remaining on the probe.  If there
10262                  * is _exactly_ one, set the probe's predicate cache ID to be
10263                  * the predicate cache ID of the remaining ECB.
10264                  */
10265                 ASSERT(probe->dtpr_ecb_last != NULL);
10266                 ASSERT(probe->dtpr_predcache == DTRACE_CACHEIDNONE);
10267 
10268                 if (probe->dtpr_ecb == probe->dtpr_ecb_last) {
10269                         dtrace_predicate_t *p = probe->dtpr_ecb->dte_predicate;
10270 
10271                         ASSERT(probe->dtpr_ecb->dte_next == NULL);
10272 
10273                         if (p != NULL)
10274                                 probe->dtpr_predcache = p->dtp_cacheid;
10275                 }
10276 
10277                 ecb->dte_next = NULL;
10278         }
10279 }
10280 
10281 static void
10282 dtrace_ecb_destroy(dtrace_ecb_t *ecb)
10283 {
10284         dtrace_state_t *state = ecb->dte_state;
10285         dtrace_vstate_t *vstate = &state->dts_vstate;
10286         dtrace_predicate_t *pred;
10287         dtrace_epid_t epid = ecb->dte_epid;
10288 
10289         ASSERT(MUTEX_HELD(&dtrace_lock));
10290         ASSERT(ecb->dte_next == NULL);
10291         ASSERT(ecb->dte_probe == NULL || ecb->dte_probe->dtpr_ecb != ecb);
10292 
10293         if ((pred = ecb->dte_predicate) != NULL)
10294                 dtrace_predicate_release(pred, vstate);
10295 
10296         dtrace_ecb_action_remove(ecb);
10297 
10298         ASSERT(state->dts_ecbs[epid - 1] == ecb);
10299         state->dts_ecbs[epid - 1] = NULL;
10300 
10301         kmem_free(ecb, sizeof (dtrace_ecb_t));
10302 }
10303 
10304 static dtrace_ecb_t *
10305 dtrace_ecb_create(dtrace_state_t *state, dtrace_probe_t *probe,
10306     dtrace_enabling_t *enab)
10307 {
10308         dtrace_ecb_t *ecb;
10309         dtrace_predicate_t *pred;
10310         dtrace_actdesc_t *act;
10311         dtrace_provider_t *prov;
10312         dtrace_ecbdesc_t *desc = enab->dten_current;
10313 
10314         ASSERT(MUTEX_HELD(&dtrace_lock));
10315         ASSERT(state != NULL);
10316 
10317         ecb = dtrace_ecb_add(state, probe);
10318         ecb->dte_uarg = desc->dted_uarg;
10319 
10320         if ((pred = desc->dted_pred.dtpdd_predicate) != NULL) {
10321                 dtrace_predicate_hold(pred);
10322                 ecb->dte_predicate = pred;
10323         }
10324 
10325         if (probe != NULL) {
10326                 /*
10327                  * If the provider shows more leg than the consumer is old
10328                  * enough to see, we need to enable the appropriate implicit
10329                  * predicate bits to prevent the ecb from activating at
10330                  * revealing times.
10331                  *
10332                  * Providers specifying DTRACE_PRIV_USER at register time
10333                  * are stating that they need the /proc-style privilege
10334                  * model to be enforced, and this is what DTRACE_COND_OWNER
10335                  * and DTRACE_COND_ZONEOWNER will then do at probe time.
10336                  */
10337                 prov = probe->dtpr_provider;
10338                 if (!(state->dts_cred.dcr_visible & DTRACE_CRV_ALLPROC) &&
10339                     (prov->dtpv_priv.dtpp_flags & DTRACE_PRIV_USER))
10340                         ecb->dte_cond |= DTRACE_COND_OWNER;
10341 
10342                 if (!(state->dts_cred.dcr_visible & DTRACE_CRV_ALLZONE) &&
10343                     (prov->dtpv_priv.dtpp_flags & DTRACE_PRIV_USER))
10344                         ecb->dte_cond |= DTRACE_COND_ZONEOWNER;
10345 
10346                 /*
10347                  * If the provider shows us kernel innards and the user
10348                  * is lacking sufficient privilege, enable the
10349                  * DTRACE_COND_USERMODE implicit predicate.
10350                  */
10351                 if (!(state->dts_cred.dcr_visible & DTRACE_CRV_KERNEL) &&
10352                     (prov->dtpv_priv.dtpp_flags & DTRACE_PRIV_KERNEL))
10353                         ecb->dte_cond |= DTRACE_COND_USERMODE;
10354         }
10355 
10356         if (dtrace_ecb_create_cache != NULL) {
10357                 /*
10358                  * If we have a cached ecb, we'll use its action list instead
10359                  * of creating our own (saving both time and space).
10360                  */
10361                 dtrace_ecb_t *cached = dtrace_ecb_create_cache;
10362                 dtrace_action_t *act = cached->dte_action;
10363 
10364                 if (act != NULL) {
10365                         ASSERT(act->dta_refcnt > 0);
10366                         act->dta_refcnt++;
10367                         ecb->dte_action = act;
10368                         ecb->dte_action_last = cached->dte_action_last;
10369                         ecb->dte_needed = cached->dte_needed;
10370                         ecb->dte_size = cached->dte_size;
10371                         ecb->dte_alignment = cached->dte_alignment;
10372                 }
10373 
10374                 return (ecb);
10375         }
10376 
10377         for (act = desc->dted_action; act != NULL; act = act->dtad_next) {
10378                 if ((enab->dten_error = dtrace_ecb_action_add(ecb, act)) != 0) {
10379                         dtrace_ecb_destroy(ecb);
10380                         return (NULL);
10381                 }
10382         }
10383 
10384         dtrace_ecb_resize(ecb);
10385 
10386         return (dtrace_ecb_create_cache = ecb);
10387 }
10388 
10389 static int
10390 dtrace_ecb_create_enable(dtrace_probe_t *probe, void *arg)
10391 {
10392         dtrace_ecb_t *ecb;
10393         dtrace_enabling_t *enab = arg;
10394         dtrace_state_t *state = enab->dten_vstate->dtvs_state;
10395 
10396         ASSERT(state != NULL);
10397 
10398         if (probe != NULL && probe->dtpr_gen < enab->dten_probegen) {
10399                 /*
10400                  * This probe was created in a generation for which this
10401                  * enabling has previously created ECBs; we don't want to
10402                  * enable it again, so just kick out.
10403                  */
10404                 return (DTRACE_MATCH_NEXT);
10405         }
10406 
10407         if ((ecb = dtrace_ecb_create(state, probe, enab)) == NULL)
10408                 return (DTRACE_MATCH_DONE);
10409 
10410         if (dtrace_ecb_enable(ecb) < 0)
10411                 return (DTRACE_MATCH_FAIL);
10412 
10413         return (DTRACE_MATCH_NEXT);
10414 }
10415 
10416 static dtrace_ecb_t *
10417 dtrace_epid2ecb(dtrace_state_t *state, dtrace_epid_t id)
10418 {
10419         dtrace_ecb_t *ecb;
10420 
10421         ASSERT(MUTEX_HELD(&dtrace_lock));
10422 
10423         if (id == 0 || id > state->dts_necbs)
10424                 return (NULL);
10425 
10426         ASSERT(state->dts_necbs > 0 && state->dts_ecbs != NULL);
10427         ASSERT((ecb = state->dts_ecbs[id - 1]) == NULL || ecb->dte_epid == id);
10428 
10429         return (state->dts_ecbs[id - 1]);
10430 }
10431 
10432 static dtrace_aggregation_t *
10433 dtrace_aggid2agg(dtrace_state_t *state, dtrace_aggid_t id)
10434 {
10435         dtrace_aggregation_t *agg;
10436 
10437         ASSERT(MUTEX_HELD(&dtrace_lock));
10438 
10439         if (id == 0 || id > state->dts_naggregations)
10440                 return (NULL);
10441 
10442         ASSERT(state->dts_naggregations > 0 && state->dts_aggregations != NULL);
10443         ASSERT((agg = state->dts_aggregations[id - 1]) == NULL ||
10444             agg->dtag_id == id);
10445 
10446         return (state->dts_aggregations[id - 1]);
10447 }
10448 
10449 /*
10450  * DTrace Buffer Functions
10451  *
10452  * The following functions manipulate DTrace buffers.  Most of these functions
10453  * are called in the context of establishing or processing consumer state;
10454  * exceptions are explicitly noted.
10455  */
10456 
10457 /*
10458  * Note:  called from cross call context.  This function switches the two
10459  * buffers on a given CPU.  The atomicity of this operation is assured by
10460  * disabling interrupts while the actual switch takes place; the disabling of
10461  * interrupts serializes the execution with any execution of dtrace_probe() on
10462  * the same CPU.
10463  */
10464 static void
10465 dtrace_buffer_switch(dtrace_buffer_t *buf)
10466 {
10467         caddr_t tomax = buf->dtb_tomax;
10468         caddr_t xamot = buf->dtb_xamot;
10469         dtrace_icookie_t cookie;
10470         hrtime_t now = dtrace_gethrtime();
10471 
10472         ASSERT(!(buf->dtb_flags & DTRACEBUF_NOSWITCH));
10473         ASSERT(!(buf->dtb_flags & DTRACEBUF_RING));
10474 
10475         cookie = dtrace_interrupt_disable();
10476         buf->dtb_tomax = xamot;
10477         buf->dtb_xamot = tomax;
10478         buf->dtb_xamot_drops = buf->dtb_drops;
10479         buf->dtb_xamot_offset = buf->dtb_offset;
10480         buf->dtb_xamot_errors = buf->dtb_errors;
10481         buf->dtb_xamot_flags = buf->dtb_flags;
10482         buf->dtb_offset = 0;
10483         buf->dtb_drops = 0;
10484         buf->dtb_errors = 0;
10485         buf->dtb_flags &= ~(DTRACEBUF_ERROR | DTRACEBUF_DROPPED);
10486         buf->dtb_interval = now - buf->dtb_switched;
10487         buf->dtb_switched = now;
10488         dtrace_interrupt_enable(cookie);
10489 }
10490 
10491 /*
10492  * Note:  called from cross call context.  This function activates a buffer
10493  * on a CPU.  As with dtrace_buffer_switch(), the atomicity of the operation
10494  * is guaranteed by the disabling of interrupts.
10495  */
10496 static void
10497 dtrace_buffer_activate(dtrace_state_t *state)
10498 {
10499         dtrace_buffer_t *buf;
10500         dtrace_icookie_t cookie = dtrace_interrupt_disable();
10501 
10502         buf = &state->dts_buffer[CPU->cpu_id];
10503 
10504         if (buf->dtb_tomax != NULL) {
10505                 /*
10506                  * We might like to assert that the buffer is marked inactive,
10507                  * but this isn't necessarily true:  the buffer for the CPU
10508                  * that processes the BEGIN probe has its buffer activated
10509                  * manually.  In this case, we take the (harmless) action
10510                  * re-clearing the bit INACTIVE bit.
10511                  */
10512                 buf->dtb_flags &= ~DTRACEBUF_INACTIVE;
10513         }
10514 
10515         dtrace_interrupt_enable(cookie);
10516 }
10517 
10518 static int
10519 dtrace_buffer_alloc(dtrace_buffer_t *bufs, size_t size, int flags,
10520     processorid_t cpu, int *factor)
10521 {
10522         cpu_t *cp;
10523         dtrace_buffer_t *buf;
10524         int allocated = 0, desired = 0;
10525 
10526         ASSERT(MUTEX_HELD(&cpu_lock));
10527         ASSERT(MUTEX_HELD(&dtrace_lock));
10528 
10529         *factor = 1;
10530 
10531         if (size > dtrace_nonroot_maxsize &&
10532             !PRIV_POLICY_CHOICE(CRED(), PRIV_ALL, B_FALSE))
10533                 return (EFBIG);
10534 
10535         cp = cpu_list;
10536 
10537         do {
10538                 if (cpu != DTRACE_CPUALL && cpu != cp->cpu_id)
10539                         continue;
10540 
10541                 buf = &bufs[cp->cpu_id];
10542 
10543                 /*
10544                  * If there is already a buffer allocated for this CPU, it
10545                  * is only possible that this is a DR event.  In this case,
10546                  * the buffer size must match our specified size.
10547                  */
10548                 if (buf->dtb_tomax != NULL) {
10549                         ASSERT(buf->dtb_size == size);
10550                         continue;
10551                 }
10552 
10553                 ASSERT(buf->dtb_xamot == NULL);
10554 
10555                 if ((buf->dtb_tomax = kmem_zalloc(size,
10556                     KM_NOSLEEP | KM_NORMALPRI)) == NULL)
10557                         goto err;
10558 
10559                 buf->dtb_size = size;
10560                 buf->dtb_flags = flags;
10561                 buf->dtb_offset = 0;
10562                 buf->dtb_drops = 0;
10563 
10564                 if (flags & DTRACEBUF_NOSWITCH)
10565                         continue;
10566 
10567                 if ((buf->dtb_xamot = kmem_zalloc(size,
10568                     KM_NOSLEEP | KM_NORMALPRI)) == NULL)
10569                         goto err;
10570         } while ((cp = cp->cpu_next) != cpu_list);
10571 
10572         return (0);
10573 
10574 err:
10575         cp = cpu_list;
10576 
10577         do {
10578                 if (cpu != DTRACE_CPUALL && cpu != cp->cpu_id)
10579                         continue;
10580 
10581                 buf = &bufs[cp->cpu_id];
10582                 desired += 2;
10583 
10584                 if (buf->dtb_xamot != NULL) {
10585                         ASSERT(buf->dtb_tomax != NULL);
10586                         ASSERT(buf->dtb_size == size);
10587                         kmem_free(buf->dtb_xamot, size);
10588                         allocated++;
10589                 }
10590 
10591                 if (buf->dtb_tomax != NULL) {
10592                         ASSERT(buf->dtb_size == size);
10593                         kmem_free(buf->dtb_tomax, size);
10594                         allocated++;
10595                 }
10596 
10597                 buf->dtb_tomax = NULL;
10598                 buf->dtb_xamot = NULL;
10599                 buf->dtb_size = 0;
10600         } while ((cp = cp->cpu_next) != cpu_list);
10601 
10602         *factor = desired / (allocated > 0 ? allocated : 1);
10603 
10604         return (ENOMEM);
10605 }
10606 
10607 /*
10608  * Note:  called from probe context.  This function just increments the drop
10609  * count on a buffer.  It has been made a function to allow for the
10610  * possibility of understanding the source of mysterious drop counts.  (A
10611  * problem for which one may be particularly disappointed that DTrace cannot
10612  * be used to understand DTrace.)
10613  */
10614 static void
10615 dtrace_buffer_drop(dtrace_buffer_t *buf)
10616 {
10617         buf->dtb_drops++;
10618 }
10619 
10620 /*
10621  * Note:  called from probe context.  This function is called to reserve space
10622  * in a buffer.  If mstate is non-NULL, sets the scratch base and size in the
10623  * mstate.  Returns the new offset in the buffer, or a negative value if an
10624  * error has occurred.
10625  */
10626 static intptr_t
10627 dtrace_buffer_reserve(dtrace_buffer_t *buf, size_t needed, size_t align,
10628     dtrace_state_t *state, dtrace_mstate_t *mstate)
10629 {
10630         intptr_t offs = buf->dtb_offset, soffs;
10631         intptr_t woffs;
10632         caddr_t tomax;
10633         size_t total;
10634 
10635         if (buf->dtb_flags & DTRACEBUF_INACTIVE)
10636                 return (-1);
10637 
10638         if ((tomax = buf->dtb_tomax) == NULL) {
10639                 dtrace_buffer_drop(buf);
10640                 return (-1);
10641         }
10642 
10643         if (!(buf->dtb_flags & (DTRACEBUF_RING | DTRACEBUF_FILL))) {
10644                 while (offs & (align - 1)) {
10645                         /*
10646                          * Assert that our alignment is off by a number which
10647                          * is itself sizeof (uint32_t) aligned.
10648                          */
10649                         ASSERT(!((align - (offs & (align - 1))) &
10650                             (sizeof (uint32_t) - 1)));
10651                         DTRACE_STORE(uint32_t, tomax, offs, DTRACE_EPIDNONE);
10652                         offs += sizeof (uint32_t);
10653                 }
10654 
10655                 if ((soffs = offs + needed) > buf->dtb_size) {
10656                         dtrace_buffer_drop(buf);
10657                         return (-1);
10658                 }
10659 
10660                 if (mstate == NULL)
10661                         return (offs);
10662 
10663                 mstate->dtms_scratch_base = (uintptr_t)tomax + soffs;
10664                 mstate->dtms_scratch_size = buf->dtb_size - soffs;
10665                 mstate->dtms_scratch_ptr = mstate->dtms_scratch_base;
10666 
10667                 return (offs);
10668         }
10669 
10670         if (buf->dtb_flags & DTRACEBUF_FILL) {
10671                 if (state->dts_activity != DTRACE_ACTIVITY_COOLDOWN &&
10672                     (buf->dtb_flags & DTRACEBUF_FULL))
10673                         return (-1);
10674                 goto out;
10675         }
10676 
10677         total = needed + (offs & (align - 1));
10678 
10679         /*
10680          * For a ring buffer, life is quite a bit more complicated.  Before
10681          * we can store any padding, we need to adjust our wrapping offset.
10682          * (If we've never before wrapped or we're not about to, no adjustment
10683          * is required.)
10684          */
10685         if ((buf->dtb_flags & DTRACEBUF_WRAPPED) ||
10686             offs + total > buf->dtb_size) {
10687                 woffs = buf->dtb_xamot_offset;
10688 
10689                 if (offs + total > buf->dtb_size) {
10690                         /*
10691                          * We can't fit in the end of the buffer.  First, a
10692                          * sanity check that we can fit in the buffer at all.
10693                          */
10694                         if (total > buf->dtb_size) {
10695                                 dtrace_buffer_drop(buf);
10696                                 return (-1);
10697                         }
10698 
10699                         /*
10700                          * We're going to be storing at the top of the buffer,
10701                          * so now we need to deal with the wrapped offset.  We
10702                          * only reset our wrapped offset to 0 if it is
10703                          * currently greater than the current offset.  If it
10704                          * is less than the current offset, it is because a
10705                          * previous allocation induced a wrap -- but the
10706                          * allocation didn't subsequently take the space due
10707                          * to an error or false predicate evaluation.  In this
10708                          * case, we'll just leave the wrapped offset alone: if
10709                          * the wrapped offset hasn't been advanced far enough
10710                          * for this allocation, it will be adjusted in the
10711                          * lower loop.
10712                          */
10713                         if (buf->dtb_flags & DTRACEBUF_WRAPPED) {
10714                                 if (woffs >= offs)
10715                                         woffs = 0;
10716                         } else {
10717                                 woffs = 0;
10718                         }
10719 
10720                         /*
10721                          * Now we know that we're going to be storing to the
10722                          * top of the buffer and that there is room for us
10723                          * there.  We need to clear the buffer from the current
10724                          * offset to the end (there may be old gunk there).
10725                          */
10726                         while (offs < buf->dtb_size)
10727                                 tomax[offs++] = 0;
10728 
10729                         /*
10730                          * We need to set our offset to zero.  And because we
10731                          * are wrapping, we need to set the bit indicating as
10732                          * much.  We can also adjust our needed space back
10733                          * down to the space required by the ECB -- we know
10734                          * that the top of the buffer is aligned.
10735                          */
10736                         offs = 0;
10737                         total = needed;
10738                         buf->dtb_flags |= DTRACEBUF_WRAPPED;
10739                 } else {
10740                         /*
10741                          * There is room for us in the buffer, so we simply
10742                          * need to check the wrapped offset.
10743                          */
10744                         if (woffs < offs) {
10745                                 /*
10746                                  * The wrapped offset is less than the offset.
10747                                  * This can happen if we allocated buffer space
10748                                  * that induced a wrap, but then we didn't
10749                                  * subsequently take the space due to an error
10750                                  * or false predicate evaluation.  This is
10751                                  * okay; we know that _this_ allocation isn't
10752                                  * going to induce a wrap.  We still can't
10753                                  * reset the wrapped offset to be zero,
10754                                  * however: the space may have been trashed in
10755                                  * the previous failed probe attempt.  But at
10756                                  * least the wrapped offset doesn't need to
10757                                  * be adjusted at all...
10758                                  */
10759                                 goto out;
10760                         }
10761                 }
10762 
10763                 while (offs + total > woffs) {
10764                         dtrace_epid_t epid = *(uint32_t *)(tomax + woffs);
10765                         size_t size;
10766 
10767                         if (epid == DTRACE_EPIDNONE) {
10768                                 size = sizeof (uint32_t);
10769                         } else {
10770                                 ASSERT(epid <= state->dts_necbs);
10771                                 ASSERT(state->dts_ecbs[epid - 1] != NULL);
10772 
10773                                 size = state->dts_ecbs[epid - 1]->dte_size;
10774                         }
10775 
10776                         ASSERT(woffs + size <= buf->dtb_size);
10777                         ASSERT(size != 0);
10778 
10779                         if (woffs + size == buf->dtb_size) {
10780                                 /*
10781                                  * We've reached the end of the buffer; we want
10782                                  * to set the wrapped offset to 0 and break
10783                                  * out.  However, if the offs is 0, then we're
10784                                  * in a strange edge-condition:  the amount of
10785                                  * space that we want to reserve plus the size
10786                                  * of the record that we're overwriting is
10787                                  * greater than the size of the buffer.  This
10788                                  * is problematic because if we reserve the
10789                                  * space but subsequently don't consume it (due
10790                                  * to a failed predicate or error) the wrapped
10791                                  * offset will be 0 -- yet the EPID at offset 0
10792                                  * will not be committed.  This situation is
10793                                  * relatively easy to deal with:  if we're in
10794                                  * this case, the buffer is indistinguishable
10795                                  * from one that hasn't wrapped; we need only
10796                                  * finish the job by clearing the wrapped bit,
10797                                  * explicitly setting the offset to be 0, and
10798                                  * zero'ing out the old data in the buffer.
10799                                  */
10800                                 if (offs == 0) {
10801                                         buf->dtb_flags &= ~DTRACEBUF_WRAPPED;
10802                                         buf->dtb_offset = 0;
10803                                         woffs = total;
10804 
10805                                         while (woffs < buf->dtb_size)
10806                                                 tomax[woffs++] = 0;
10807                                 }
10808 
10809                                 woffs = 0;
10810                                 break;
10811                         }
10812 
10813                         woffs += size;
10814                 }
10815 
10816                 /*
10817                  * We have a wrapped offset.  It may be that the wrapped offset
10818                  * has become zero -- that's okay.
10819                  */
10820                 buf->dtb_xamot_offset = woffs;
10821         }
10822 
10823 out:
10824         /*
10825          * Now we can plow the buffer with any necessary padding.
10826          */
10827         while (offs & (align - 1)) {
10828                 /*
10829                  * Assert that our alignment is off by a number which
10830                  * is itself sizeof (uint32_t) aligned.
10831                  */
10832                 ASSERT(!((align - (offs & (align - 1))) &
10833                     (sizeof (uint32_t) - 1)));
10834                 DTRACE_STORE(uint32_t, tomax, offs, DTRACE_EPIDNONE);
10835                 offs += sizeof (uint32_t);
10836         }
10837 
10838         if (buf->dtb_flags & DTRACEBUF_FILL) {
10839                 if (offs + needed > buf->dtb_size - state->dts_reserve) {
10840                         buf->dtb_flags |= DTRACEBUF_FULL;
10841                         return (-1);
10842                 }
10843         }
10844 
10845         if (mstate == NULL)
10846                 return (offs);
10847 
10848         /*
10849          * For ring buffers and fill buffers, the scratch space is always
10850          * the inactive buffer.
10851          */
10852         mstate->dtms_scratch_base = (uintptr_t)buf->dtb_xamot;
10853         mstate->dtms_scratch_size = buf->dtb_size;
10854         mstate->dtms_scratch_ptr = mstate->dtms_scratch_base;
10855 
10856         return (offs);
10857 }
10858 
10859 static void
10860 dtrace_buffer_polish(dtrace_buffer_t *buf)
10861 {
10862         ASSERT(buf->dtb_flags & DTRACEBUF_RING);
10863         ASSERT(MUTEX_HELD(&dtrace_lock));
10864 
10865         if (!(buf->dtb_flags & DTRACEBUF_WRAPPED))
10866                 return;
10867 
10868         /*
10869          * We need to polish the ring buffer.  There are three cases:
10870          *
10871          * - The first (and presumably most common) is that there is no gap
10872          *   between the buffer offset and the wrapped offset.  In this case,
10873          *   there is nothing in the buffer that isn't valid data; we can
10874          *   mark the buffer as polished and return.
10875          *
10876          * - The second (less common than the first but still more common
10877          *   than the third) is that there is a gap between the buffer offset
10878          *   and the wrapped offset, and the wrapped offset is larger than the
10879          *   buffer offset.  This can happen because of an alignment issue, or
10880          *   can happen because of a call to dtrace_buffer_reserve() that
10881          *   didn't subsequently consume the buffer space.  In this case,
10882          *   we need to zero the data from the buffer offset to the wrapped
10883          *   offset.
10884          *
10885          * - The third (and least common) is that there is a gap between the
10886          *   buffer offset and the wrapped offset, but the wrapped offset is
10887          *   _less_ than the buffer offset.  This can only happen because a
10888          *   call to dtrace_buffer_reserve() induced a wrap, but the space
10889          *   was not subsequently consumed.  In this case, we need to zero the
10890          *   space from the offset to the end of the buffer _and_ from the
10891          *   top of the buffer to the wrapped offset.
10892          */
10893         if (buf->dtb_offset < buf->dtb_xamot_offset) {
10894                 bzero(buf->dtb_tomax + buf->dtb_offset,
10895                     buf->dtb_xamot_offset - buf->dtb_offset);
10896         }
10897 
10898         if (buf->dtb_offset > buf->dtb_xamot_offset) {
10899                 bzero(buf->dtb_tomax + buf->dtb_offset,
10900                     buf->dtb_size - buf->dtb_offset);
10901                 bzero(buf->dtb_tomax, buf->dtb_xamot_offset);
10902         }
10903 }
10904 
10905 /*
10906  * This routine determines if data generated at the specified time has likely
10907  * been entirely consumed at user-level.  This routine is called to determine
10908  * if an ECB on a defunct probe (but for an active enabling) can be safely
10909  * disabled and destroyed.
10910  */
10911 static int
10912 dtrace_buffer_consumed(dtrace_buffer_t *bufs, hrtime_t when)
10913 {
10914         int i;
10915 
10916         for (i = 0; i < NCPU; i++) {
10917                 dtrace_buffer_t *buf = &bufs[i];
10918 
10919                 if (buf->dtb_size == 0)
10920                         continue;
10921 
10922                 if (buf->dtb_flags & DTRACEBUF_RING)
10923                         return (0);
10924 
10925                 if (!buf->dtb_switched && buf->dtb_offset != 0)
10926                         return (0);
10927 
10928                 if (buf->dtb_switched - buf->dtb_interval < when)
10929                         return (0);
10930         }
10931 
10932         return (1);
10933 }
10934 
10935 static void
10936 dtrace_buffer_free(dtrace_buffer_t *bufs)
10937 {
10938         int i;
10939 
10940         for (i = 0; i < NCPU; i++) {
10941                 dtrace_buffer_t *buf = &bufs[i];
10942 
10943                 if (buf->dtb_tomax == NULL) {
10944                         ASSERT(buf->dtb_xamot == NULL);
10945                         ASSERT(buf->dtb_size == 0);
10946                         continue;
10947                 }
10948 
10949                 if (buf->dtb_xamot != NULL) {
10950                         ASSERT(!(buf->dtb_flags & DTRACEBUF_NOSWITCH));
10951                         kmem_free(buf->dtb_xamot, buf->dtb_size);
10952                 }
10953 
10954                 kmem_free(buf->dtb_tomax, buf->dtb_size);
10955                 buf->dtb_size = 0;
10956                 buf->dtb_tomax = NULL;
10957                 buf->dtb_xamot = NULL;
10958         }
10959 }
10960 
10961 /*
10962  * DTrace Enabling Functions
10963  */
10964 static dtrace_enabling_t *
10965 dtrace_enabling_create(dtrace_vstate_t *vstate)
10966 {
10967         dtrace_enabling_t *enab;
10968 
10969         enab = kmem_zalloc(sizeof (dtrace_enabling_t), KM_SLEEP);
10970         enab->dten_vstate = vstate;
10971 
10972         return (enab);
10973 }
10974 
10975 static void
10976 dtrace_enabling_add(dtrace_enabling_t *enab, dtrace_ecbdesc_t *ecb)
10977 {
10978         dtrace_ecbdesc_t **ndesc;
10979         size_t osize, nsize;
10980 
10981         /*
10982          * We can't add to enablings after we've enabled them, or after we've
10983          * retained them.
10984          */
10985         ASSERT(enab->dten_probegen == 0);
10986         ASSERT(enab->dten_next == NULL && enab->dten_prev == NULL);
10987 
10988         if (enab->dten_ndesc < enab->dten_maxdesc) {
10989                 enab->dten_desc[enab->dten_ndesc++] = ecb;
10990                 return;
10991         }
10992 
10993         osize = enab->dten_maxdesc * sizeof (dtrace_enabling_t *);
10994 
10995         if (enab->dten_maxdesc == 0) {
10996                 enab->dten_maxdesc = 1;
10997         } else {
10998                 enab->dten_maxdesc <<= 1;
10999         }
11000 
11001         ASSERT(enab->dten_ndesc < enab->dten_maxdesc);
11002 
11003         nsize = enab->dten_maxdesc * sizeof (dtrace_enabling_t *);
11004         ndesc = kmem_zalloc(nsize, KM_SLEEP);
11005         bcopy(enab->dten_desc, ndesc, osize);
11006         kmem_free(enab->dten_desc, osize);
11007 
11008         enab->dten_desc = ndesc;
11009         enab->dten_desc[enab->dten_ndesc++] = ecb;
11010 }
11011 
11012 static void
11013 dtrace_enabling_addlike(dtrace_enabling_t *enab, dtrace_ecbdesc_t *ecb,
11014     dtrace_probedesc_t *pd)
11015 {
11016         dtrace_ecbdesc_t *new;
11017         dtrace_predicate_t *pred;
11018         dtrace_actdesc_t *act;
11019 
11020         /*
11021          * We're going to create a new ECB description that matches the
11022          * specified ECB in every way, but has the specified probe description.
11023          */
11024         new = kmem_zalloc(sizeof (dtrace_ecbdesc_t), KM_SLEEP);
11025 
11026         if ((pred = ecb->dted_pred.dtpdd_predicate) != NULL)
11027                 dtrace_predicate_hold(pred);
11028 
11029         for (act = ecb->dted_action; act != NULL; act = act->dtad_next)
11030                 dtrace_actdesc_hold(act);
11031 
11032         new->dted_action = ecb->dted_action;
11033         new->dted_pred = ecb->dted_pred;
11034         new->dted_probe = *pd;
11035         new->dted_uarg = ecb->dted_uarg;
11036 
11037         dtrace_enabling_add(enab, new);
11038 }
11039 
11040 static void
11041 dtrace_enabling_dump(dtrace_enabling_t *enab)
11042 {
11043         int i;
11044 
11045         for (i = 0; i < enab->dten_ndesc; i++) {
11046                 dtrace_probedesc_t *desc = &enab->dten_desc[i]->dted_probe;
11047 
11048                 cmn_err(CE_NOTE, "enabling probe %d (%s:%s:%s:%s)", i,
11049                     desc->dtpd_provider, desc->dtpd_mod,
11050                     desc->dtpd_func, desc->dtpd_name);
11051         }
11052 }
11053 
11054 static void
11055 dtrace_enabling_destroy(dtrace_enabling_t *enab)
11056 {
11057         int i;
11058         dtrace_ecbdesc_t *ep;
11059         dtrace_vstate_t *vstate = enab->dten_vstate;
11060 
11061         ASSERT(MUTEX_HELD(&dtrace_lock));
11062 
11063         for (i = 0; i < enab->dten_ndesc; i++) {
11064                 dtrace_actdesc_t *act, *next;
11065                 dtrace_predicate_t *pred;
11066 
11067                 ep = enab->dten_desc[i];
11068 
11069                 if ((pred = ep->dted_pred.dtpdd_predicate) != NULL)
11070                         dtrace_predicate_release(pred, vstate);
11071 
11072                 for (act = ep->dted_action; act != NULL; act = next) {
11073                         next = act->dtad_next;
11074                         dtrace_actdesc_release(act, vstate);
11075                 }
11076 
11077                 kmem_free(ep, sizeof (dtrace_ecbdesc_t));
11078         }
11079 
11080         kmem_free(enab->dten_desc,
11081             enab->dten_maxdesc * sizeof (dtrace_enabling_t *));
11082 
11083         /*
11084          * If this was a retained enabling, decrement the dts_nretained count
11085          * and take it off of the dtrace_retained list.
11086          */
11087         if (enab->dten_prev != NULL || enab->dten_next != NULL ||
11088             dtrace_retained == enab) {
11089                 ASSERT(enab->dten_vstate->dtvs_state != NULL);
11090                 ASSERT(enab->dten_vstate->dtvs_state->dts_nretained > 0);
11091                 enab->dten_vstate->dtvs_state->dts_nretained--;
11092                 dtrace_retained_gen++;
11093         }
11094 
11095         if (enab->dten_prev == NULL) {
11096                 if (dtrace_retained == enab) {
11097                         dtrace_retained = enab->dten_next;
11098 
11099                         if (dtrace_retained != NULL)
11100                                 dtrace_retained->dten_prev = NULL;
11101                 }
11102         } else {
11103                 ASSERT(enab != dtrace_retained);
11104                 ASSERT(dtrace_retained != NULL);
11105                 enab->dten_prev->dten_next = enab->dten_next;
11106         }
11107 
11108         if (enab->dten_next != NULL) {
11109                 ASSERT(dtrace_retained != NULL);
11110                 enab->dten_next->dten_prev = enab->dten_prev;
11111         }
11112 
11113         kmem_free(enab, sizeof (dtrace_enabling_t));
11114 }
11115 
11116 static int
11117 dtrace_enabling_retain(dtrace_enabling_t *enab)
11118 {
11119         dtrace_state_t *state;
11120 
11121         ASSERT(MUTEX_HELD(&dtrace_lock));
11122         ASSERT(enab->dten_next == NULL && enab->dten_prev == NULL);
11123         ASSERT(enab->dten_vstate != NULL);
11124 
11125         state = enab->dten_vstate->dtvs_state;
11126         ASSERT(state != NULL);
11127 
11128         /*
11129          * We only allow each state to retain dtrace_retain_max enablings.
11130          */
11131         if (state->dts_nretained >= dtrace_retain_max)
11132                 return (ENOSPC);
11133 
11134         state->dts_nretained++;
11135         dtrace_retained_gen++;
11136 
11137         if (dtrace_retained == NULL) {
11138                 dtrace_retained = enab;
11139                 return (0);
11140         }
11141 
11142         enab->dten_next = dtrace_retained;
11143         dtrace_retained->dten_prev = enab;
11144         dtrace_retained = enab;
11145 
11146         return (0);
11147 }
11148 
11149 static int
11150 dtrace_enabling_replicate(dtrace_state_t *state, dtrace_probedesc_t *match,
11151     dtrace_probedesc_t *create)
11152 {
11153         dtrace_enabling_t *new, *enab;
11154         int found = 0, err = ENOENT;
11155 
11156         ASSERT(MUTEX_HELD(&dtrace_lock));
11157         ASSERT(strlen(match->dtpd_provider) < DTRACE_PROVNAMELEN);
11158         ASSERT(strlen(match->dtpd_mod) < DTRACE_MODNAMELEN);
11159         ASSERT(strlen(match->dtpd_func) < DTRACE_FUNCNAMELEN);
11160         ASSERT(strlen(match->dtpd_name) < DTRACE_NAMELEN);
11161 
11162         new = dtrace_enabling_create(&state->dts_vstate);
11163 
11164         /*
11165          * Iterate over all retained enablings, looking for enablings that
11166          * match the specified state.
11167          */
11168         for (enab = dtrace_retained; enab != NULL; enab = enab->dten_next) {
11169                 int i;
11170 
11171                 /*
11172                  * dtvs_state can only be NULL for helper enablings -- and
11173                  * helper enablings can't be retained.
11174                  */
11175                 ASSERT(enab->dten_vstate->dtvs_state != NULL);
11176 
11177                 if (enab->dten_vstate->dtvs_state != state)
11178                         continue;
11179 
11180                 /*
11181                  * Now iterate over each probe description; we're looking for
11182                  * an exact match to the specified probe description.
11183                  */
11184                 for (i = 0; i < enab->dten_ndesc; i++) {
11185                         dtrace_ecbdesc_t *ep = enab->dten_desc[i];
11186                         dtrace_probedesc_t *pd = &ep->dted_probe;
11187 
11188                         if (strcmp(pd->dtpd_provider, match->dtpd_provider))
11189                                 continue;
11190 
11191                         if (strcmp(pd->dtpd_mod, match->dtpd_mod))
11192                                 continue;
11193 
11194                         if (strcmp(pd->dtpd_func, match->dtpd_func))
11195                                 continue;
11196 
11197                         if (strcmp(pd->dtpd_name, match->dtpd_name))
11198                                 continue;
11199 
11200                         /*
11201                          * We have a winning probe!  Add it to our growing
11202                          * enabling.
11203                          */
11204                         found = 1;
11205                         dtrace_enabling_addlike(new, ep, create);
11206                 }
11207         }
11208 
11209         if (!found || (err = dtrace_enabling_retain(new)) != 0) {
11210                 dtrace_enabling_destroy(new);
11211                 return (err);
11212         }
11213 
11214         return (0);
11215 }
11216 
11217 static void
11218 dtrace_enabling_retract(dtrace_state_t *state)
11219 {
11220         dtrace_enabling_t *enab, *next;
11221 
11222         ASSERT(MUTEX_HELD(&dtrace_lock));
11223 
11224         /*
11225          * Iterate over all retained enablings, destroy the enablings retained
11226          * for the specified state.
11227          */
11228         for (enab = dtrace_retained; enab != NULL; enab = next) {
11229                 next = enab->dten_next;
11230 
11231                 /*
11232                  * dtvs_state can only be NULL for helper enablings -- and
11233                  * helper enablings can't be retained.
11234                  */
11235                 ASSERT(enab->dten_vstate->dtvs_state != NULL);
11236 
11237                 if (enab->dten_vstate->dtvs_state == state) {
11238                         ASSERT(state->dts_nretained > 0);
11239                         dtrace_enabling_destroy(enab);
11240                 }
11241         }
11242 
11243         ASSERT(state->dts_nretained == 0);
11244 }
11245 
11246 static int
11247 dtrace_enabling_match(dtrace_enabling_t *enab, int *nmatched)
11248 {
11249         int i = 0;
11250         int total_matched = 0, matched = 0;
11251 
11252         ASSERT(MUTEX_HELD(&cpu_lock));
11253         ASSERT(MUTEX_HELD(&dtrace_lock));
11254 
11255         for (i = 0; i < enab->dten_ndesc; i++) {
11256                 dtrace_ecbdesc_t *ep = enab->dten_desc[i];
11257 
11258                 enab->dten_current = ep;
11259                 enab->dten_error = 0;
11260 
11261                 /*
11262                  * If a provider failed to enable a probe then get out and
11263                  * let the consumer know we failed.
11264                  */
11265                 if ((matched = dtrace_probe_enable(&ep->dted_probe, enab)) < 0)
11266                         return (EBUSY);
11267 
11268                 total_matched += matched;
11269 
11270                 if (enab->dten_error != 0) {
11271                         /*
11272                          * If we get an error half-way through enabling the
11273                          * probes, we kick out -- perhaps with some number of
11274                          * them enabled.  Leaving enabled probes enabled may
11275                          * be slightly confusing for user-level, but we expect
11276                          * that no one will attempt to actually drive on in
11277                          * the face of such errors.  If this is an anonymous
11278                          * enabling (indicated with a NULL nmatched pointer),
11279                          * we cmn_err() a message.  We aren't expecting to
11280                          * get such an error -- such as it can exist at all,
11281                          * it would be a result of corrupted DOF in the driver
11282                          * properties.
11283                          */
11284                         if (nmatched == NULL) {
11285                                 cmn_err(CE_WARN, "dtrace_enabling_match() "
11286                                     "error on %p: %d", (void *)ep,
11287                                     enab->dten_error);
11288                         }
11289 
11290                         return (enab->dten_error);
11291                 }
11292         }
11293 
11294         enab->dten_probegen = dtrace_probegen;
11295         if (nmatched != NULL)
11296                 *nmatched = total_matched;
11297 
11298         return (0);
11299 }
11300 
11301 static void
11302 dtrace_enabling_matchall(void)
11303 {
11304         dtrace_enabling_t *enab;
11305 
11306         mutex_enter(&cpu_lock);
11307         mutex_enter(&dtrace_lock);
11308 
11309         /*
11310          * Iterate over all retained enablings to see if any probes match
11311          * against them.  We only perform this operation on enablings for which
11312          * we have sufficient permissions by virtue of being in the global zone
11313          * or in the same zone as the DTrace client.  Because we can be called
11314          * after dtrace_detach() has been called, we cannot assert that there
11315          * are retained enablings.  We can safely load from dtrace_retained,
11316          * however:  the taskq_destroy() at the end of dtrace_detach() will
11317          * block pending our completion.
11318          */
11319         for (enab = dtrace_retained; enab != NULL; enab = enab->dten_next) {
11320                 dtrace_cred_t *dcr = &enab->dten_vstate->dtvs_state->dts_cred;
11321                 cred_t *cr = dcr->dcr_cred;
11322                 zoneid_t zone = cr != NULL ? crgetzoneid(cr) : 0;
11323 
11324                 if ((dcr->dcr_visible & DTRACE_CRV_ALLZONE) || (cr != NULL &&
11325                     (zone == GLOBAL_ZONEID || getzoneid() == zone)))
11326                         (void) dtrace_enabling_match(enab, NULL);
11327         }
11328 
11329         mutex_exit(&dtrace_lock);
11330         mutex_exit(&cpu_lock);
11331 }
11332 
11333 /*
11334  * If an enabling is to be enabled without having matched probes (that is, if
11335  * dtrace_state_go() is to be called on the underlying dtrace_state_t), the
11336  * enabling must be _primed_ by creating an ECB for every ECB description.
11337  * This must be done to assure that we know the number of speculations, the
11338  * number of aggregations, the minimum buffer size needed, etc. before we
11339  * transition out of DTRACE_ACTIVITY_INACTIVE.  To do this without actually
11340  * enabling any probes, we create ECBs for every ECB decription, but with a
11341  * NULL probe -- which is exactly what this function does.
11342  */
11343 static void
11344 dtrace_enabling_prime(dtrace_state_t *state)
11345 {
11346         dtrace_enabling_t *enab;
11347         int i;
11348 
11349         for (enab = dtrace_retained; enab != NULL; enab = enab->dten_next) {
11350                 ASSERT(enab->dten_vstate->dtvs_state != NULL);
11351 
11352                 if (enab->dten_vstate->dtvs_state != state)
11353                         continue;
11354 
11355                 /*
11356                  * We don't want to prime an enabling more than once, lest
11357                  * we allow a malicious user to induce resource exhaustion.
11358                  * (The ECBs that result from priming an enabling aren't
11359                  * leaked -- but they also aren't deallocated until the
11360                  * consumer state is destroyed.)
11361                  */
11362                 if (enab->dten_primed)
11363                         continue;
11364 
11365                 for (i = 0; i < enab->dten_ndesc; i++) {
11366                         enab->dten_current = enab->dten_desc[i];
11367                         (void) dtrace_probe_enable(NULL, enab);
11368                 }
11369 
11370                 enab->dten_primed = 1;
11371         }
11372 }
11373 
11374 /*
11375  * Called to indicate that probes should be provided due to retained
11376  * enablings.  This is implemented in terms of dtrace_probe_provide(), but it
11377  * must take an initial lap through the enabling calling the dtps_provide()
11378  * entry point explicitly to allow for autocreated probes.
11379  */
11380 static void
11381 dtrace_enabling_provide(dtrace_provider_t *prv)
11382 {
11383         int i, all = 0;
11384         dtrace_probedesc_t desc;
11385         dtrace_genid_t gen;
11386 
11387         ASSERT(MUTEX_HELD(&dtrace_lock));
11388         ASSERT(MUTEX_HELD(&dtrace_provider_lock));
11389 
11390         if (prv == NULL) {
11391                 all = 1;
11392                 prv = dtrace_provider;
11393         }
11394 
11395         do {
11396                 dtrace_enabling_t *enab;
11397                 void *parg = prv->dtpv_arg;
11398 
11399 retry:
11400                 gen = dtrace_retained_gen;
11401                 for (enab = dtrace_retained; enab != NULL;
11402                     enab = enab->dten_next) {
11403                         for (i = 0; i < enab->dten_ndesc; i++) {
11404                                 desc = enab->dten_desc[i]->dted_probe;
11405                                 mutex_exit(&dtrace_lock);
11406                                 prv->dtpv_pops.dtps_provide(parg, &desc);
11407                                 mutex_enter(&dtrace_lock);
11408                                 /*
11409                                  * Process the retained enablings again if
11410                                  * they have changed while we weren't holding
11411                                  * dtrace_lock.
11412                                  */
11413                                 if (gen != dtrace_retained_gen)
11414                                         goto retry;
11415                         }
11416                 }
11417         } while (all && (prv = prv->dtpv_next) != NULL);
11418 
11419         mutex_exit(&dtrace_lock);
11420         dtrace_probe_provide(NULL, all ? NULL : prv);
11421         mutex_enter(&dtrace_lock);
11422 }
11423 
11424 /*
11425  * Called to reap ECBs that are attached to probes from defunct providers.
11426  */
11427 static void
11428 dtrace_enabling_reap(void)
11429 {
11430         dtrace_provider_t *prov;
11431         dtrace_probe_t *probe;
11432         dtrace_ecb_t *ecb;
11433         hrtime_t when;
11434         int i;
11435 
11436         mutex_enter(&cpu_lock);
11437         mutex_enter(&dtrace_lock);
11438 
11439         for (i = 0; i < dtrace_nprobes; i++) {
11440                 if ((probe = dtrace_probes[i]) == NULL)
11441                         continue;
11442 
11443                 if (probe->dtpr_ecb == NULL)
11444                         continue;
11445 
11446                 prov = probe->dtpr_provider;
11447 
11448                 if ((when = prov->dtpv_defunct) == 0)
11449                         continue;
11450 
11451                 /*
11452                  * We have ECBs on a defunct provider:  we want to reap these
11453                  * ECBs to allow the provider to unregister.  The destruction
11454                  * of these ECBs must be done carefully:  if we destroy the ECB
11455                  * and the consumer later wishes to consume an EPID that
11456                  * corresponds to the destroyed ECB (and if the EPID metadata
11457                  * has not been previously consumed), the consumer will abort
11458                  * processing on the unknown EPID.  To reduce (but not, sadly,
11459                  * eliminate) the possibility of this, we will only destroy an
11460                  * ECB for a defunct provider if, for the state that
11461                  * corresponds to the ECB:
11462                  *
11463                  *  (a) There is no speculative tracing (which can effectively
11464                  *      cache an EPID for an arbitrary amount of time).
11465                  *
11466                  *  (b) The principal buffers have been switched twice since the
11467                  *      provider became defunct.
11468                  *
11469                  *  (c) The aggregation buffers are of zero size or have been
11470                  *      switched twice since the provider became defunct.
11471                  *
11472                  * We use dts_speculates to determine (a) and call a function
11473                  * (dtrace_buffer_consumed()) to determine (b) and (c).  Note
11474                  * that as soon as we've been unable to destroy one of the ECBs
11475                  * associated with the probe, we quit trying -- reaping is only
11476                  * fruitful in as much as we can destroy all ECBs associated
11477                  * with the defunct provider's probes.
11478                  */
11479                 while ((ecb = probe->dtpr_ecb) != NULL) {
11480                         dtrace_state_t *state = ecb->dte_state;
11481                         dtrace_buffer_t *buf = state->dts_buffer;
11482                         dtrace_buffer_t *aggbuf = state->dts_aggbuffer;
11483 
11484                         if (state->dts_speculates)
11485                                 break;
11486 
11487                         if (!dtrace_buffer_consumed(buf, when))
11488                                 break;
11489 
11490                         if (!dtrace_buffer_consumed(aggbuf, when))
11491                                 break;
11492 
11493                         dtrace_ecb_disable(ecb);
11494                         ASSERT(probe->dtpr_ecb != ecb);
11495                         dtrace_ecb_destroy(ecb);
11496                 }
11497         }
11498 
11499         mutex_exit(&dtrace_lock);
11500         mutex_exit(&cpu_lock);
11501 }
11502 
11503 /*
11504  * DTrace DOF Functions
11505  */
11506 /*ARGSUSED*/
11507 static void
11508 dtrace_dof_error(dof_hdr_t *dof, const char *str)
11509 {
11510         if (dtrace_err_verbose)
11511                 cmn_err(CE_WARN, "failed to process DOF: %s", str);
11512 
11513 #ifdef DTRACE_ERRDEBUG
11514         dtrace_errdebug(str);
11515 #endif
11516 }
11517 
11518 /*
11519  * Create DOF out of a currently enabled state.  Right now, we only create
11520  * DOF containing the run-time options -- but this could be expanded to create
11521  * complete DOF representing the enabled state.
11522  */
11523 static dof_hdr_t *
11524 dtrace_dof_create(dtrace_state_t *state)
11525 {
11526         dof_hdr_t *dof;
11527         dof_sec_t *sec;
11528         dof_optdesc_t *opt;
11529         int i, len = sizeof (dof_hdr_t) +
11530             roundup(sizeof (dof_sec_t), sizeof (uint64_t)) +
11531             sizeof (dof_optdesc_t) * DTRACEOPT_MAX;
11532 
11533         ASSERT(MUTEX_HELD(&dtrace_lock));
11534 
11535         dof = kmem_zalloc(len, KM_SLEEP);
11536         dof->dofh_ident[DOF_ID_MAG0] = DOF_MAG_MAG0;
11537         dof->dofh_ident[DOF_ID_MAG1] = DOF_MAG_MAG1;
11538         dof->dofh_ident[DOF_ID_MAG2] = DOF_MAG_MAG2;
11539         dof->dofh_ident[DOF_ID_MAG3] = DOF_MAG_MAG3;
11540 
11541         dof->dofh_ident[DOF_ID_MODEL] = DOF_MODEL_NATIVE;
11542         dof->dofh_ident[DOF_ID_ENCODING] = DOF_ENCODE_NATIVE;
11543         dof->dofh_ident[DOF_ID_VERSION] = DOF_VERSION;
11544         dof->dofh_ident[DOF_ID_DIFVERS] = DIF_VERSION;
11545         dof->dofh_ident[DOF_ID_DIFIREG] = DIF_DIR_NREGS;
11546         dof->dofh_ident[DOF_ID_DIFTREG] = DIF_DTR_NREGS;
11547 
11548         dof->dofh_flags = 0;
11549         dof->dofh_hdrsize = sizeof (dof_hdr_t);
11550         dof->dofh_secsize = sizeof (dof_sec_t);
11551         dof->dofh_secnum = 1;        /* only DOF_SECT_OPTDESC */
11552         dof->dofh_secoff = sizeof (dof_hdr_t);
11553         dof->dofh_loadsz = len;
11554         dof->dofh_filesz = len;
11555         dof->dofh_pad = 0;
11556 
11557         /*
11558          * Fill in the option section header...
11559          */
11560         sec = (dof_sec_t *)((uintptr_t)dof + sizeof (dof_hdr_t));
11561         sec->dofs_type = DOF_SECT_OPTDESC;
11562         sec->dofs_align = sizeof (uint64_t);
11563         sec->dofs_flags = DOF_SECF_LOAD;
11564         sec->dofs_entsize = sizeof (dof_optdesc_t);
11565 
11566         opt = (dof_optdesc_t *)((uintptr_t)sec +
11567             roundup(sizeof (dof_sec_t), sizeof (uint64_t)));
11568 
11569         sec->dofs_offset = (uintptr_t)opt - (uintptr_t)dof;
11570         sec->dofs_size = sizeof (dof_optdesc_t) * DTRACEOPT_MAX;
11571 
11572         for (i = 0; i < DTRACEOPT_MAX; i++) {
11573                 opt[i].dofo_option = i;
11574                 opt[i].dofo_strtab = DOF_SECIDX_NONE;
11575                 opt[i].dofo_value = state->dts_options[i];
11576         }
11577 
11578         return (dof);
11579 }
11580 
11581 static dof_hdr_t *
11582 dtrace_dof_copyin(uintptr_t uarg, int *errp)
11583 {
11584         dof_hdr_t hdr, *dof;
11585 
11586         ASSERT(!MUTEX_HELD(&dtrace_lock));
11587 
11588         /*
11589          * First, we're going to copyin() the sizeof (dof_hdr_t).
11590          */
11591         if (copyin((void *)uarg, &hdr, sizeof (hdr)) != 0) {
11592                 dtrace_dof_error(NULL, "failed to copyin DOF header");
11593                 *errp = EFAULT;
11594                 return (NULL);
11595         }
11596 
11597         /*
11598          * Now we'll allocate the entire DOF and copy it in -- provided
11599          * that the length isn't outrageous.
11600          */
11601         if (hdr.dofh_loadsz >= dtrace_dof_maxsize) {
11602                 dtrace_dof_error(&hdr, "load size exceeds maximum");
11603                 *errp = E2BIG;
11604                 return (NULL);
11605         }
11606 
11607         if (hdr.dofh_loadsz < sizeof (hdr)) {
11608                 dtrace_dof_error(&hdr, "invalid load size");
11609                 *errp = EINVAL;
11610                 return (NULL);
11611         }
11612 
11613         dof = kmem_alloc(hdr.dofh_loadsz, KM_SLEEP);
11614 
11615         if (copyin((void *)uarg, dof, hdr.dofh_loadsz) != 0 ||
11616             dof->dofh_loadsz != hdr.dofh_loadsz) {
11617                 kmem_free(dof, hdr.dofh_loadsz);
11618                 *errp = EFAULT;
11619                 return (NULL);
11620         }
11621 
11622         return (dof);
11623 }
11624 
11625 static dof_hdr_t *
11626 dtrace_dof_property(const char *name)
11627 {
11628         uchar_t *buf;
11629         uint64_t loadsz;
11630         unsigned int len, i;
11631         dof_hdr_t *dof;
11632 
11633         /*
11634          * Unfortunately, array of values in .conf files are always (and
11635          * only) interpreted to be integer arrays.  We must read our DOF
11636          * as an integer array, and then squeeze it into a byte array.
11637          */
11638         if (ddi_prop_lookup_int_array(DDI_DEV_T_ANY, dtrace_devi, 0,
11639             (char *)name, (int **)&buf, &len) != DDI_PROP_SUCCESS)
11640                 return (NULL);
11641 
11642         for (i = 0; i < len; i++)
11643                 buf[i] = (uchar_t)(((int *)buf)[i]);
11644 
11645         if (len < sizeof (dof_hdr_t)) {
11646                 ddi_prop_free(buf);
11647                 dtrace_dof_error(NULL, "truncated header");
11648                 return (NULL);
11649         }
11650 
11651         if (len < (loadsz = ((dof_hdr_t *)buf)->dofh_loadsz)) {
11652                 ddi_prop_free(buf);
11653                 dtrace_dof_error(NULL, "truncated DOF");
11654                 return (NULL);
11655         }
11656 
11657         if (loadsz >= dtrace_dof_maxsize) {
11658                 ddi_prop_free(buf);
11659                 dtrace_dof_error(NULL, "oversized DOF");
11660                 return (NULL);
11661         }
11662 
11663         dof = kmem_alloc(loadsz, KM_SLEEP);
11664         bcopy(buf, dof, loadsz);
11665         ddi_prop_free(buf);
11666 
11667         return (dof);
11668 }
11669 
11670 static void
11671 dtrace_dof_destroy(dof_hdr_t *dof)
11672 {
11673         kmem_free(dof, dof->dofh_loadsz);
11674 }
11675 
11676 /*
11677  * Return the dof_sec_t pointer corresponding to a given section index.  If the
11678  * index is not valid, dtrace_dof_error() is called and NULL is returned.  If
11679  * a type other than DOF_SECT_NONE is specified, the header is checked against
11680  * this type and NULL is returned if the types do not match.
11681  */
11682 static dof_sec_t *
11683 dtrace_dof_sect(dof_hdr_t *dof, uint32_t type, dof_secidx_t i)
11684 {
11685         dof_sec_t *sec = (dof_sec_t *)(uintptr_t)
11686             ((uintptr_t)dof + dof->dofh_secoff + i * dof->dofh_secsize);
11687 
11688         if (i >= dof->dofh_secnum) {
11689                 dtrace_dof_error(dof, "referenced section index is invalid");
11690                 return (NULL);
11691         }
11692 
11693         if (!(sec->dofs_flags & DOF_SECF_LOAD)) {
11694                 dtrace_dof_error(dof, "referenced section is not loadable");
11695                 return (NULL);
11696         }
11697 
11698         if (type != DOF_SECT_NONE && type != sec->dofs_type) {
11699                 dtrace_dof_error(dof, "referenced section is the wrong type");
11700                 return (NULL);
11701         }
11702 
11703         return (sec);
11704 }
11705 
11706 static dtrace_probedesc_t *
11707 dtrace_dof_probedesc(dof_hdr_t *dof, dof_sec_t *sec, dtrace_probedesc_t *desc)
11708 {
11709         dof_probedesc_t *probe;
11710         dof_sec_t *strtab;
11711         uintptr_t daddr = (uintptr_t)dof;
11712         uintptr_t str;
11713         size_t size;
11714 
11715         if (sec->dofs_type != DOF_SECT_PROBEDESC) {
11716                 dtrace_dof_error(dof, "invalid probe section");
11717                 return (NULL);
11718         }
11719 
11720         if (sec->dofs_align != sizeof (dof_secidx_t)) {
11721                 dtrace_dof_error(dof, "bad alignment in probe description");
11722                 return (NULL);
11723         }
11724 
11725         if (sec->dofs_offset + sizeof (dof_probedesc_t) > dof->dofh_loadsz) {
11726                 dtrace_dof_error(dof, "truncated probe description");
11727                 return (NULL);
11728         }
11729 
11730         probe = (dof_probedesc_t *)(uintptr_t)(daddr + sec->dofs_offset);
11731         strtab = dtrace_dof_sect(dof, DOF_SECT_STRTAB, probe->dofp_strtab);
11732 
11733         if (strtab == NULL)
11734                 return (NULL);
11735 
11736         str = daddr + strtab->dofs_offset;
11737         size = strtab->dofs_size;
11738 
11739         if (probe->dofp_provider >= strtab->dofs_size) {
11740                 dtrace_dof_error(dof, "corrupt probe provider");
11741                 return (NULL);
11742         }
11743 
11744         (void) strncpy(desc->dtpd_provider,
11745             (char *)(str + probe->dofp_provider),
11746             MIN(DTRACE_PROVNAMELEN - 1, size - probe->dofp_provider));
11747 
11748         if (probe->dofp_mod >= strtab->dofs_size) {
11749                 dtrace_dof_error(dof, "corrupt probe module");
11750                 return (NULL);
11751         }
11752 
11753         (void) strncpy(desc->dtpd_mod, (char *)(str + probe->dofp_mod),
11754             MIN(DTRACE_MODNAMELEN - 1, size - probe->dofp_mod));
11755 
11756         if (probe->dofp_func >= strtab->dofs_size) {
11757                 dtrace_dof_error(dof, "corrupt probe function");
11758                 return (NULL);
11759         }
11760 
11761         (void) strncpy(desc->dtpd_func, (char *)(str + probe->dofp_func),
11762             MIN(DTRACE_FUNCNAMELEN - 1, size - probe->dofp_func));
11763 
11764         if (probe->dofp_name >= strtab->dofs_size) {
11765                 dtrace_dof_error(dof, "corrupt probe name");
11766                 return (NULL);
11767         }
11768 
11769         (void) strncpy(desc->dtpd_name, (char *)(str + probe->dofp_name),
11770             MIN(DTRACE_NAMELEN - 1, size - probe->dofp_name));
11771 
11772         return (desc);
11773 }
11774 
11775 static dtrace_difo_t *
11776 dtrace_dof_difo(dof_hdr_t *dof, dof_sec_t *sec, dtrace_vstate_t *vstate,
11777     cred_t *cr)
11778 {
11779         dtrace_difo_t *dp;
11780         size_t ttl = 0;
11781         dof_difohdr_t *dofd;
11782         uintptr_t daddr = (uintptr_t)dof;
11783         size_t max = dtrace_difo_maxsize;
11784         int i, l, n;
11785 
11786         static const struct {
11787                 int section;
11788                 int bufoffs;
11789                 int lenoffs;
11790                 int entsize;
11791                 int align;
11792                 const char *msg;
11793         } difo[] = {
11794                 { DOF_SECT_DIF, offsetof(dtrace_difo_t, dtdo_buf),
11795                 offsetof(dtrace_difo_t, dtdo_len), sizeof (dif_instr_t),
11796                 sizeof (dif_instr_t), "multiple DIF sections" },
11797 
11798                 { DOF_SECT_INTTAB, offsetof(dtrace_difo_t, dtdo_inttab),
11799                 offsetof(dtrace_difo_t, dtdo_intlen), sizeof (uint64_t),
11800                 sizeof (uint64_t), "multiple integer tables" },
11801 
11802                 { DOF_SECT_STRTAB, offsetof(dtrace_difo_t, dtdo_strtab),
11803                 offsetof(dtrace_difo_t, dtdo_strlen), 0,
11804                 sizeof (char), "multiple string tables" },
11805 
11806                 { DOF_SECT_VARTAB, offsetof(dtrace_difo_t, dtdo_vartab),
11807                 offsetof(dtrace_difo_t, dtdo_varlen), sizeof (dtrace_difv_t),
11808                 sizeof (uint_t), "multiple variable tables" },
11809 
11810                 { DOF_SECT_NONE, 0, 0, 0, NULL }
11811         };
11812 
11813         if (sec->dofs_type != DOF_SECT_DIFOHDR) {
11814                 dtrace_dof_error(dof, "invalid DIFO header section");
11815                 return (NULL);
11816         }
11817 
11818         if (sec->dofs_align != sizeof (dof_secidx_t)) {
11819                 dtrace_dof_error(dof, "bad alignment in DIFO header");
11820                 return (NULL);
11821         }
11822 
11823         if (sec->dofs_size < sizeof (dof_difohdr_t) ||
11824             sec->dofs_size % sizeof (dof_secidx_t)) {
11825                 dtrace_dof_error(dof, "bad size in DIFO header");
11826                 return (NULL);
11827         }
11828 
11829         dofd = (dof_difohdr_t *)(uintptr_t)(daddr + sec->dofs_offset);
11830         n = (sec->dofs_size - sizeof (*dofd)) / sizeof (dof_secidx_t) + 1;
11831 
11832         dp = kmem_zalloc(sizeof (dtrace_difo_t), KM_SLEEP);
11833         dp->dtdo_rtype = dofd->dofd_rtype;
11834 
11835         for (l = 0; l < n; l++) {
11836                 dof_sec_t *subsec;
11837                 void **bufp;
11838                 uint32_t *lenp;
11839 
11840                 if ((subsec = dtrace_dof_sect(dof, DOF_SECT_NONE,
11841                     dofd->dofd_links[l])) == NULL)
11842                         goto err; /* invalid section link */
11843 
11844                 if (ttl + subsec->dofs_size > max) {
11845                         dtrace_dof_error(dof, "exceeds maximum size");
11846                         goto err;
11847                 }
11848 
11849                 ttl += subsec->dofs_size;
11850 
11851                 for (i = 0; difo[i].section != DOF_SECT_NONE; i++) {
11852                         if (subsec->dofs_type != difo[i].section)
11853                                 continue;
11854 
11855                         if (!(subsec->dofs_flags & DOF_SECF_LOAD)) {
11856                                 dtrace_dof_error(dof, "section not loaded");
11857                                 goto err;
11858                         }
11859 
11860                         if (subsec->dofs_align != difo[i].align) {
11861                                 dtrace_dof_error(dof, "bad alignment");
11862                                 goto err;
11863                         }
11864 
11865                         bufp = (void **)((uintptr_t)dp + difo[i].bufoffs);
11866                         lenp = (uint32_t *)((uintptr_t)dp + difo[i].lenoffs);
11867 
11868                         if (*bufp != NULL) {
11869                                 dtrace_dof_error(dof, difo[i].msg);
11870                                 goto err;
11871                         }
11872 
11873                         if (difo[i].entsize != subsec->dofs_entsize) {
11874                                 dtrace_dof_error(dof, "entry size mismatch");
11875                                 goto err;
11876                         }
11877 
11878                         if (subsec->dofs_entsize != 0 &&
11879                             (subsec->dofs_size % subsec->dofs_entsize) != 0) {
11880                                 dtrace_dof_error(dof, "corrupt entry size");
11881                                 goto err;
11882                         }
11883 
11884                         *lenp = subsec->dofs_size;
11885                         *bufp = kmem_alloc(subsec->dofs_size, KM_SLEEP);
11886                         bcopy((char *)(uintptr_t)(daddr + subsec->dofs_offset),
11887                             *bufp, subsec->dofs_size);
11888 
11889                         if (subsec->dofs_entsize != 0)
11890                                 *lenp /= subsec->dofs_entsize;
11891 
11892                         break;
11893                 }
11894 
11895                 /*
11896                  * If we encounter a loadable DIFO sub-section that is not
11897                  * known to us, assume this is a broken program and fail.
11898                  */
11899                 if (difo[i].section == DOF_SECT_NONE &&
11900                     (subsec->dofs_flags & DOF_SECF_LOAD)) {
11901                         dtrace_dof_error(dof, "unrecognized DIFO subsection");
11902                         goto err;
11903                 }
11904         }
11905 
11906         if (dp->dtdo_buf == NULL) {
11907                 /*
11908                  * We can't have a DIF object without DIF text.
11909                  */
11910                 dtrace_dof_error(dof, "missing DIF text");
11911                 goto err;
11912         }
11913 
11914         /*
11915          * Before we validate the DIF object, run through the variable table
11916          * looking for the strings -- if any of their size are under, we'll set
11917          * their size to be the system-wide default string size.  Note that
11918          * this should _not_ happen if the "strsize" option has been set --
11919          * in this case, the compiler should have set the size to reflect the
11920          * setting of the option.
11921          */
11922         for (i = 0; i < dp->dtdo_varlen; i++) {
11923                 dtrace_difv_t *v = &dp->dtdo_vartab[i];
11924                 dtrace_diftype_t *t = &v->dtdv_type;
11925 
11926                 if (v->dtdv_id < DIF_VAR_OTHER_UBASE)
11927                         continue;
11928 
11929                 if (t->dtdt_kind == DIF_TYPE_STRING && t->dtdt_size == 0)
11930                         t->dtdt_size = dtrace_strsize_default;
11931         }
11932 
11933         if (dtrace_difo_validate(dp, vstate, DIF_DIR_NREGS, cr) != 0)
11934                 goto err;
11935 
11936         dtrace_difo_init(dp, vstate);
11937         return (dp);
11938 
11939 err:
11940         kmem_free(dp->dtdo_buf, dp->dtdo_len * sizeof (dif_instr_t));
11941         kmem_free(dp->dtdo_inttab, dp->dtdo_intlen * sizeof (uint64_t));
11942         kmem_free(dp->dtdo_strtab, dp->dtdo_strlen);
11943         kmem_free(dp->dtdo_vartab, dp->dtdo_varlen * sizeof (dtrace_difv_t));
11944 
11945         kmem_free(dp, sizeof (dtrace_difo_t));
11946         return (NULL);
11947 }
11948 
11949 static dtrace_predicate_t *
11950 dtrace_dof_predicate(dof_hdr_t *dof, dof_sec_t *sec, dtrace_vstate_t *vstate,
11951     cred_t *cr)
11952 {
11953         dtrace_difo_t *dp;
11954 
11955         if ((dp = dtrace_dof_difo(dof, sec, vstate, cr)) == NULL)
11956                 return (NULL);
11957 
11958         return (dtrace_predicate_create(dp));
11959 }
11960 
11961 static dtrace_actdesc_t *
11962 dtrace_dof_actdesc(dof_hdr_t *dof, dof_sec_t *sec, dtrace_vstate_t *vstate,
11963     cred_t *cr)
11964 {
11965         dtrace_actdesc_t *act, *first = NULL, *last = NULL, *next;
11966         dof_actdesc_t *desc;
11967         dof_sec_t *difosec;
11968         size_t offs;
11969         uintptr_t daddr = (uintptr_t)dof;
11970         uint64_t arg;
11971         dtrace_actkind_t kind;
11972 
11973         if (sec->dofs_type != DOF_SECT_ACTDESC) {
11974                 dtrace_dof_error(dof, "invalid action section");
11975                 return (NULL);
11976         }
11977 
11978         if (sec->dofs_offset + sizeof (dof_actdesc_t) > dof->dofh_loadsz) {
11979                 dtrace_dof_error(dof, "truncated action description");
11980                 return (NULL);
11981         }
11982 
11983         if (sec->dofs_align != sizeof (uint64_t)) {
11984                 dtrace_dof_error(dof, "bad alignment in action description");
11985                 return (NULL);
11986         }
11987 
11988         if (sec->dofs_size < sec->dofs_entsize) {
11989                 dtrace_dof_error(dof, "section entry size exceeds total size");
11990                 return (NULL);
11991         }
11992 
11993         if (sec->dofs_entsize != sizeof (dof_actdesc_t)) {
11994                 dtrace_dof_error(dof, "bad entry size in action description");
11995                 return (NULL);
11996         }
11997 
11998         if (sec->dofs_size / sec->dofs_entsize > dtrace_actions_max) {
11999                 dtrace_dof_error(dof, "actions exceed dtrace_actions_max");
12000                 return (NULL);
12001         }
12002 
12003         for (offs = 0; offs < sec->dofs_size; offs += sec->dofs_entsize) {
12004                 desc = (dof_actdesc_t *)(daddr +
12005                     (uintptr_t)sec->dofs_offset + offs);
12006                 kind = (dtrace_actkind_t)desc->dofa_kind;
12007 
12008                 if ((DTRACEACT_ISPRINTFLIKE(kind) &&
12009                     (kind != DTRACEACT_PRINTA ||
12010                     desc->dofa_strtab != DOF_SECIDX_NONE)) ||
12011                     (kind == DTRACEACT_DIFEXPR &&
12012                     desc->dofa_strtab != DOF_SECIDX_NONE)) {
12013                         dof_sec_t *strtab;
12014                         char *str, *fmt;
12015                         uint64_t i;
12016 
12017                         /*
12018                          * The argument to these actions is an index into the
12019                          * DOF string table.  For printf()-like actions, this
12020                          * is the format string.  For print(), this is the
12021                          * CTF type of the expression result.
12022                          */
12023                         if ((strtab = dtrace_dof_sect(dof,
12024                             DOF_SECT_STRTAB, desc->dofa_strtab)) == NULL)
12025                                 goto err;
12026 
12027                         str = (char *)((uintptr_t)dof +
12028                             (uintptr_t)strtab->dofs_offset);
12029 
12030                         for (i = desc->dofa_arg; i < strtab->dofs_size; i++) {
12031                                 if (str[i] == '\0')
12032                                         break;
12033                         }
12034 
12035                         if (i >= strtab->dofs_size) {
12036                                 dtrace_dof_error(dof, "bogus format string");
12037                                 goto err;
12038                         }
12039 
12040                         if (i == desc->dofa_arg) {
12041                                 dtrace_dof_error(dof, "empty format string");
12042                                 goto err;
12043                         }
12044 
12045                         i -= desc->dofa_arg;
12046                         fmt = kmem_alloc(i + 1, KM_SLEEP);
12047                         bcopy(&str[desc->dofa_arg], fmt, i + 1);
12048                         arg = (uint64_t)(uintptr_t)fmt;
12049                 } else {
12050                         if (kind == DTRACEACT_PRINTA) {
12051                                 ASSERT(desc->dofa_strtab == DOF_SECIDX_NONE);
12052                                 arg = 0;
12053                         } else {
12054                                 arg = desc->dofa_arg;
12055                         }
12056                 }
12057 
12058                 act = dtrace_actdesc_create(kind, desc->dofa_ntuple,
12059                     desc->dofa_uarg, arg);
12060 
12061                 if (last != NULL) {
12062                         last->dtad_next = act;
12063                 } else {
12064                         first = act;
12065                 }
12066 
12067                 last = act;
12068 
12069                 if (desc->dofa_difo == DOF_SECIDX_NONE)
12070                         continue;
12071 
12072                 if ((difosec = dtrace_dof_sect(dof,
12073                     DOF_SECT_DIFOHDR, desc->dofa_difo)) == NULL)
12074                         goto err;
12075 
12076                 act->dtad_difo = dtrace_dof_difo(dof, difosec, vstate, cr);
12077 
12078                 if (act->dtad_difo == NULL)
12079                         goto err;
12080         }
12081 
12082         ASSERT(first != NULL);
12083         return (first);
12084 
12085 err:
12086         for (act = first; act != NULL; act = next) {
12087                 next = act->dtad_next;
12088                 dtrace_actdesc_release(act, vstate);
12089         }
12090 
12091         return (NULL);
12092 }
12093 
12094 static dtrace_ecbdesc_t *
12095 dtrace_dof_ecbdesc(dof_hdr_t *dof, dof_sec_t *sec, dtrace_vstate_t *vstate,
12096     cred_t *cr)
12097 {
12098         dtrace_ecbdesc_t *ep;
12099         dof_ecbdesc_t *ecb;
12100         dtrace_probedesc_t *desc;
12101         dtrace_predicate_t *pred = NULL;
12102 
12103         if (sec->dofs_size < sizeof (dof_ecbdesc_t)) {
12104                 dtrace_dof_error(dof, "truncated ECB description");
12105                 return (NULL);
12106         }
12107 
12108         if (sec->dofs_align != sizeof (uint64_t)) {
12109                 dtrace_dof_error(dof, "bad alignment in ECB description");
12110                 return (NULL);
12111         }
12112 
12113         ecb = (dof_ecbdesc_t *)((uintptr_t)dof + (uintptr_t)sec->dofs_offset);
12114         sec = dtrace_dof_sect(dof, DOF_SECT_PROBEDESC, ecb->dofe_probes);
12115 
12116         if (sec == NULL)
12117                 return (NULL);
12118 
12119         ep = kmem_zalloc(sizeof (dtrace_ecbdesc_t), KM_SLEEP);
12120         ep->dted_uarg = ecb->dofe_uarg;
12121         desc = &ep->dted_probe;
12122 
12123         if (dtrace_dof_probedesc(dof, sec, desc) == NULL)
12124                 goto err;
12125 
12126         if (ecb->dofe_pred != DOF_SECIDX_NONE) {
12127                 if ((sec = dtrace_dof_sect(dof,
12128                     DOF_SECT_DIFOHDR, ecb->dofe_pred)) == NULL)
12129                         goto err;
12130 
12131                 if ((pred = dtrace_dof_predicate(dof, sec, vstate, cr)) == NULL)
12132                         goto err;
12133 
12134                 ep->dted_pred.dtpdd_predicate = pred;
12135         }
12136 
12137         if (ecb->dofe_actions != DOF_SECIDX_NONE) {
12138                 if ((sec = dtrace_dof_sect(dof,
12139                     DOF_SECT_ACTDESC, ecb->dofe_actions)) == NULL)
12140                         goto err;
12141 
12142                 ep->dted_action = dtrace_dof_actdesc(dof, sec, vstate, cr);
12143 
12144                 if (ep->dted_action == NULL)
12145                         goto err;
12146         }
12147 
12148         return (ep);
12149 
12150 err:
12151         if (pred != NULL)
12152                 dtrace_predicate_release(pred, vstate);
12153         kmem_free(ep, sizeof (dtrace_ecbdesc_t));
12154         return (NULL);
12155 }
12156 
12157 /*
12158  * Apply the relocations from the specified 'sec' (a DOF_SECT_URELHDR) to the
12159  * specified DOF.  At present, this amounts to simply adding 'ubase' to the
12160  * site of any user SETX relocations to account for load object base address.
12161  * In the future, if we need other relocations, this function can be extended.
12162  */
12163 static int
12164 dtrace_dof_relocate(dof_hdr_t *dof, dof_sec_t *sec, uint64_t ubase)
12165 {
12166         uintptr_t daddr = (uintptr_t)dof;
12167         dof_relohdr_t *dofr =
12168             (dof_relohdr_t *)(uintptr_t)(daddr + sec->dofs_offset);
12169         dof_sec_t *ss, *rs, *ts;
12170         dof_relodesc_t *r;
12171         uint_t i, n;
12172 
12173         if (sec->dofs_size < sizeof (dof_relohdr_t) ||
12174             sec->dofs_align != sizeof (dof_secidx_t)) {
12175                 dtrace_dof_error(dof, "invalid relocation header");
12176                 return (-1);
12177         }
12178 
12179         ss = dtrace_dof_sect(dof, DOF_SECT_STRTAB, dofr->dofr_strtab);
12180         rs = dtrace_dof_sect(dof, DOF_SECT_RELTAB, dofr->dofr_relsec);
12181         ts = dtrace_dof_sect(dof, DOF_SECT_NONE, dofr->dofr_tgtsec);
12182 
12183         if (ss == NULL || rs == NULL || ts == NULL)
12184                 return (-1); /* dtrace_dof_error() has been called already */
12185 
12186         if (rs->dofs_entsize < sizeof (dof_relodesc_t) ||
12187             rs->dofs_align != sizeof (uint64_t)) {
12188                 dtrace_dof_error(dof, "invalid relocation section");
12189                 return (-1);
12190         }
12191 
12192         r = (dof_relodesc_t *)(uintptr_t)(daddr + rs->dofs_offset);
12193         n = rs->dofs_size / rs->dofs_entsize;
12194 
12195         for (i = 0; i < n; i++) {
12196                 uintptr_t taddr = daddr + ts->dofs_offset + r->dofr_offset;
12197 
12198                 switch (r->dofr_type) {
12199                 case DOF_RELO_NONE:
12200                         break;
12201                 case DOF_RELO_SETX:
12202                         if (r->dofr_offset >= ts->dofs_size || r->dofr_offset +
12203                             sizeof (uint64_t) > ts->dofs_size) {
12204                                 dtrace_dof_error(dof, "bad relocation offset");
12205                                 return (-1);
12206                         }
12207 
12208                         if (!IS_P2ALIGNED(taddr, sizeof (uint64_t))) {
12209                                 dtrace_dof_error(dof, "misaligned setx relo");
12210                                 return (-1);
12211                         }
12212 
12213                         *(uint64_t *)taddr += ubase;
12214                         break;
12215                 default:
12216                         dtrace_dof_error(dof, "invalid relocation type");
12217                         return (-1);
12218                 }
12219 
12220                 r = (dof_relodesc_t *)((uintptr_t)r + rs->dofs_entsize);
12221         }
12222 
12223         return (0);
12224 }
12225 
12226 /*
12227  * The dof_hdr_t passed to dtrace_dof_slurp() should be a partially validated
12228  * header:  it should be at the front of a memory region that is at least
12229  * sizeof (dof_hdr_t) in size -- and then at least dof_hdr.dofh_loadsz in
12230  * size.  It need not be validated in any other way.
12231  */
12232 static int
12233 dtrace_dof_slurp(dof_hdr_t *dof, dtrace_vstate_t *vstate, cred_t *cr,
12234     dtrace_enabling_t **enabp, uint64_t ubase, int noprobes)
12235 {
12236         uint64_t len = dof->dofh_loadsz, seclen;
12237         uintptr_t daddr = (uintptr_t)dof;
12238         dtrace_ecbdesc_t *ep;
12239         dtrace_enabling_t *enab;
12240         uint_t i;
12241 
12242         ASSERT(MUTEX_HELD(&dtrace_lock));
12243         ASSERT(dof->dofh_loadsz >= sizeof (dof_hdr_t));
12244 
12245         /*
12246          * Check the DOF header identification bytes.  In addition to checking
12247          * valid settings, we also verify that unused bits/bytes are zeroed so
12248          * we can use them later without fear of regressing existing binaries.
12249          */
12250         if (bcmp(&dof->dofh_ident[DOF_ID_MAG0],
12251             DOF_MAG_STRING, DOF_MAG_STRLEN) != 0) {
12252                 dtrace_dof_error(dof, "DOF magic string mismatch");
12253                 return (-1);
12254         }
12255 
12256         if (dof->dofh_ident[DOF_ID_MODEL] != DOF_MODEL_ILP32 &&
12257             dof->dofh_ident[DOF_ID_MODEL] != DOF_MODEL_LP64) {
12258                 dtrace_dof_error(dof, "DOF has invalid data model");
12259                 return (-1);
12260         }
12261 
12262         if (dof->dofh_ident[DOF_ID_ENCODING] != DOF_ENCODE_NATIVE) {
12263                 dtrace_dof_error(dof, "DOF encoding mismatch");
12264                 return (-1);
12265         }
12266 
12267         if (dof->dofh_ident[DOF_ID_VERSION] != DOF_VERSION_1 &&
12268             dof->dofh_ident[DOF_ID_VERSION] != DOF_VERSION_2) {
12269                 dtrace_dof_error(dof, "DOF version mismatch");
12270                 return (-1);
12271         }
12272 
12273         if (dof->dofh_ident[DOF_ID_DIFVERS] != DIF_VERSION_2) {
12274                 dtrace_dof_error(dof, "DOF uses unsupported instruction set");
12275                 return (-1);
12276         }
12277 
12278         if (dof->dofh_ident[DOF_ID_DIFIREG] > DIF_DIR_NREGS) {
12279                 dtrace_dof_error(dof, "DOF uses too many integer registers");
12280                 return (-1);
12281         }
12282 
12283         if (dof->dofh_ident[DOF_ID_DIFTREG] > DIF_DTR_NREGS) {
12284                 dtrace_dof_error(dof, "DOF uses too many tuple registers");
12285                 return (-1);
12286         }
12287 
12288         for (i = DOF_ID_PAD; i < DOF_ID_SIZE; i++) {
12289                 if (dof->dofh_ident[i] != 0) {
12290                         dtrace_dof_error(dof, "DOF has invalid ident byte set");
12291                         return (-1);
12292                 }
12293         }
12294 
12295         if (dof->dofh_flags & ~DOF_FL_VALID) {
12296                 dtrace_dof_error(dof, "DOF has invalid flag bits set");
12297                 return (-1);
12298         }
12299 
12300         if (dof->dofh_secsize == 0) {
12301                 dtrace_dof_error(dof, "zero section header size");
12302                 return (-1);
12303         }
12304 
12305         /*
12306          * Check that the section headers don't exceed the amount of DOF
12307          * data.  Note that we cast the section size and number of sections
12308          * to uint64_t's to prevent possible overflow in the multiplication.
12309          */
12310         seclen = (uint64_t)dof->dofh_secnum * (uint64_t)dof->dofh_secsize;
12311 
12312         if (dof->dofh_secoff > len || seclen > len ||
12313             dof->dofh_secoff + seclen > len) {
12314                 dtrace_dof_error(dof, "truncated section headers");
12315                 return (-1);
12316         }
12317 
12318         if (!IS_P2ALIGNED(dof->dofh_secoff, sizeof (uint64_t))) {
12319                 dtrace_dof_error(dof, "misaligned section headers");
12320                 return (-1);
12321         }
12322 
12323         if (!IS_P2ALIGNED(dof->dofh_secsize, sizeof (uint64_t))) {
12324                 dtrace_dof_error(dof, "misaligned section size");
12325                 return (-1);
12326         }
12327 
12328         /*
12329          * Take an initial pass through the section headers to be sure that
12330          * the headers don't have stray offsets.  If the 'noprobes' flag is
12331          * set, do not permit sections relating to providers, probes, or args.
12332          */
12333         for (i = 0; i < dof->dofh_secnum; i++) {
12334                 dof_sec_t *sec = (dof_sec_t *)(daddr +
12335                     (uintptr_t)dof->dofh_secoff + i * dof->dofh_secsize);
12336 
12337                 if (noprobes) {
12338                         switch (sec->dofs_type) {
12339                         case DOF_SECT_PROVIDER:
12340                         case DOF_SECT_PROBES:
12341                         case DOF_SECT_PRARGS:
12342                         case DOF_SECT_PROFFS:
12343                                 dtrace_dof_error(dof, "illegal sections "
12344                                     "for enabling");
12345                                 return (-1);
12346                         }
12347                 }
12348 
12349                 if (DOF_SEC_ISLOADABLE(sec->dofs_type) &&
12350                     !(sec->dofs_flags & DOF_SECF_LOAD)) {
12351                         dtrace_dof_error(dof, "loadable section with load "
12352                             "flag unset");
12353                         return (-1);
12354                 }
12355 
12356                 if (!(sec->dofs_flags & DOF_SECF_LOAD))
12357                         continue; /* just ignore non-loadable sections */
12358 
12359                 if (sec->dofs_align & (sec->dofs_align - 1)) {
12360                         dtrace_dof_error(dof, "bad section alignment");
12361                         return (-1);
12362                 }
12363 
12364                 if (sec->dofs_offset & (sec->dofs_align - 1)) {
12365                         dtrace_dof_error(dof, "misaligned section");
12366                         return (-1);
12367                 }
12368 
12369                 if (sec->dofs_offset > len || sec->dofs_size > len ||
12370                     sec->dofs_offset + sec->dofs_size > len) {
12371                         dtrace_dof_error(dof, "corrupt section header");
12372                         return (-1);
12373                 }
12374 
12375                 if (sec->dofs_type == DOF_SECT_STRTAB && *((char *)daddr +
12376                     sec->dofs_offset + sec->dofs_size - 1) != '\0') {
12377                         dtrace_dof_error(dof, "non-terminating string table");
12378                         return (-1);
12379                 }
12380         }
12381 
12382         /*
12383          * Take a second pass through the sections and locate and perform any
12384          * relocations that are present.  We do this after the first pass to
12385          * be sure that all sections have had their headers validated.
12386          */
12387         for (i = 0; i < dof->dofh_secnum; i++) {
12388                 dof_sec_t *sec = (dof_sec_t *)(daddr +
12389                     (uintptr_t)dof->dofh_secoff + i * dof->dofh_secsize);
12390 
12391                 if (!(sec->dofs_flags & DOF_SECF_LOAD))
12392                         continue; /* skip sections that are not loadable */
12393 
12394                 switch (sec->dofs_type) {
12395                 case DOF_SECT_URELHDR:
12396                         if (dtrace_dof_relocate(dof, sec, ubase) != 0)
12397                                 return (-1);
12398                         break;
12399                 }
12400         }
12401 
12402         if ((enab = *enabp) == NULL)
12403                 enab = *enabp = dtrace_enabling_create(vstate);
12404 
12405         for (i = 0; i < dof->dofh_secnum; i++) {
12406                 dof_sec_t *sec = (dof_sec_t *)(daddr +
12407                     (uintptr_t)dof->dofh_secoff + i * dof->dofh_secsize);
12408 
12409                 if (sec->dofs_type != DOF_SECT_ECBDESC)
12410                         continue;
12411 
12412                 if ((ep = dtrace_dof_ecbdesc(dof, sec, vstate, cr)) == NULL) {
12413                         dtrace_enabling_destroy(enab);
12414                         *enabp = NULL;
12415                         return (-1);
12416                 }
12417 
12418                 dtrace_enabling_add(enab, ep);
12419         }
12420 
12421         return (0);
12422 }
12423 
12424 /*
12425  * Process DOF for any options.  This routine assumes that the DOF has been
12426  * at least processed by dtrace_dof_slurp().
12427  */
12428 static int
12429 dtrace_dof_options(dof_hdr_t *dof, dtrace_state_t *state)
12430 {
12431         int i, rval;
12432         uint32_t entsize;
12433         size_t offs;
12434         dof_optdesc_t *desc;
12435 
12436         for (i = 0; i < dof->dofh_secnum; i++) {
12437                 dof_sec_t *sec = (dof_sec_t *)((uintptr_t)dof +
12438                     (uintptr_t)dof->dofh_secoff + i * dof->dofh_secsize);
12439 
12440                 if (sec->dofs_type != DOF_SECT_OPTDESC)
12441                         continue;
12442 
12443                 if (sec->dofs_align != sizeof (uint64_t)) {
12444                         dtrace_dof_error(dof, "bad alignment in "
12445                             "option description");
12446                         return (EINVAL);
12447                 }
12448 
12449                 if ((entsize = sec->dofs_entsize) == 0) {
12450                         dtrace_dof_error(dof, "zeroed option entry size");
12451                         return (EINVAL);
12452                 }
12453 
12454                 if (entsize < sizeof (dof_optdesc_t)) {
12455                         dtrace_dof_error(dof, "bad option entry size");
12456                         return (EINVAL);
12457                 }
12458 
12459                 for (offs = 0; offs < sec->dofs_size; offs += entsize) {
12460                         desc = (dof_optdesc_t *)((uintptr_t)dof +
12461                             (uintptr_t)sec->dofs_offset + offs);
12462 
12463                         if (desc->dofo_strtab != DOF_SECIDX_NONE) {
12464                                 dtrace_dof_error(dof, "non-zero option string");
12465                                 return (EINVAL);
12466                         }
12467 
12468                         if (desc->dofo_value == DTRACEOPT_UNSET) {
12469                                 dtrace_dof_error(dof, "unset option");
12470                                 return (EINVAL);
12471                         }
12472 
12473                         if ((rval = dtrace_state_option(state,
12474                             desc->dofo_option, desc->dofo_value)) != 0) {
12475                                 dtrace_dof_error(dof, "rejected option");
12476                                 return (rval);
12477                         }
12478                 }
12479         }
12480 
12481         return (0);
12482 }
12483 
12484 /*
12485  * DTrace Consumer State Functions
12486  */
12487 int
12488 dtrace_dstate_init(dtrace_dstate_t *dstate, size_t size)
12489 {
12490         size_t hashsize, maxper, min, chunksize = dstate->dtds_chunksize;
12491         void *base;
12492         uintptr_t limit;
12493         dtrace_dynvar_t *dvar, *next, *start;
12494         int i;
12495 
12496         ASSERT(MUTEX_HELD(&dtrace_lock));
12497         ASSERT(dstate->dtds_base == NULL && dstate->dtds_percpu == NULL);
12498 
12499         bzero(dstate, sizeof (dtrace_dstate_t));
12500 
12501         if ((dstate->dtds_chunksize = chunksize) == 0)
12502                 dstate->dtds_chunksize = DTRACE_DYNVAR_CHUNKSIZE;
12503 
12504         if (size < (min = dstate->dtds_chunksize + sizeof (dtrace_dynhash_t)))
12505                 size = min;
12506 
12507         if ((base = kmem_zalloc(size, KM_NOSLEEP | KM_NORMALPRI)) == NULL)
12508                 return (ENOMEM);
12509 
12510         dstate->dtds_size = size;
12511         dstate->dtds_base = base;
12512         dstate->dtds_percpu = kmem_cache_alloc(dtrace_state_cache, KM_SLEEP);
12513         bzero(dstate->dtds_percpu, NCPU * sizeof (dtrace_dstate_percpu_t));
12514 
12515         hashsize = size / (dstate->dtds_chunksize + sizeof (dtrace_dynhash_t));
12516 
12517         if (hashsize != 1 && (hashsize & 1))
12518                 hashsize--;
12519 
12520         dstate->dtds_hashsize = hashsize;
12521         dstate->dtds_hash = dstate->dtds_base;
12522 
12523         /*
12524          * Set all of our hash buckets to point to the single sink, and (if
12525          * it hasn't already been set), set the sink's hash value to be the
12526          * sink sentinel value.  The sink is needed for dynamic variable
12527          * lookups to know that they have iterated over an entire, valid hash
12528          * chain.
12529          */
12530         for (i = 0; i < hashsize; i++)
12531                 dstate->dtds_hash[i].dtdh_chain = &dtrace_dynhash_sink;
12532 
12533         if (dtrace_dynhash_sink.dtdv_hashval != DTRACE_DYNHASH_SINK)
12534                 dtrace_dynhash_sink.dtdv_hashval = DTRACE_DYNHASH_SINK;
12535 
12536         /*
12537          * Determine number of active CPUs.  Divide free list evenly among
12538          * active CPUs.
12539          */
12540         start = (dtrace_dynvar_t *)
12541             ((uintptr_t)base + hashsize * sizeof (dtrace_dynhash_t));
12542         limit = (uintptr_t)base + size;
12543 
12544         maxper = (limit - (uintptr_t)start) / NCPU;
12545         maxper = (maxper / dstate->dtds_chunksize) * dstate->dtds_chunksize;
12546 
12547         for (i = 0; i < NCPU; i++) {
12548                 dstate->dtds_percpu[i].dtdsc_free = dvar = start;
12549 
12550                 /*
12551                  * If we don't even have enough chunks to make it once through
12552                  * NCPUs, we're just going to allocate everything to the first
12553                  * CPU.  And if we're on the last CPU, we're going to allocate
12554                  * whatever is left over.  In either case, we set the limit to
12555                  * be the limit of the dynamic variable space.
12556                  */
12557                 if (maxper == 0 || i == NCPU - 1) {
12558                         limit = (uintptr_t)base + size;
12559                         start = NULL;
12560                 } else {
12561                         limit = (uintptr_t)start + maxper;
12562                         start = (dtrace_dynvar_t *)limit;
12563                 }
12564 
12565                 ASSERT(limit <= (uintptr_t)base + size);
12566 
12567                 for (;;) {
12568                         next = (dtrace_dynvar_t *)((uintptr_t)dvar +
12569                             dstate->dtds_chunksize);
12570 
12571                         if ((uintptr_t)next + dstate->dtds_chunksize >= limit)
12572                                 break;
12573 
12574                         dvar->dtdv_next = next;
12575                         dvar = next;
12576                 }
12577 
12578                 if (maxper == 0)
12579                         break;
12580         }
12581 
12582         return (0);
12583 }
12584 
12585 void
12586 dtrace_dstate_fini(dtrace_dstate_t *dstate)
12587 {
12588         ASSERT(MUTEX_HELD(&cpu_lock));
12589 
12590         if (dstate->dtds_base == NULL)
12591                 return;
12592 
12593         kmem_free(dstate->dtds_base, dstate->dtds_size);
12594         kmem_cache_free(dtrace_state_cache, dstate->dtds_percpu);
12595 }
12596 
12597 static void
12598 dtrace_vstate_fini(dtrace_vstate_t *vstate)
12599 {
12600         /*
12601          * Logical XOR, where are you?
12602          */
12603         ASSERT((vstate->dtvs_nglobals == 0) ^ (vstate->dtvs_globals != NULL));
12604 
12605         if (vstate->dtvs_nglobals > 0) {
12606                 kmem_free(vstate->dtvs_globals, vstate->dtvs_nglobals *
12607                     sizeof (dtrace_statvar_t *));
12608         }
12609 
12610         if (vstate->dtvs_ntlocals > 0) {
12611                 kmem_free(vstate->dtvs_tlocals, vstate->dtvs_ntlocals *
12612                     sizeof (dtrace_difv_t));
12613         }
12614 
12615         ASSERT((vstate->dtvs_nlocals == 0) ^ (vstate->dtvs_locals != NULL));
12616 
12617         if (vstate->dtvs_nlocals > 0) {
12618                 kmem_free(vstate->dtvs_locals, vstate->dtvs_nlocals *
12619                     sizeof (dtrace_statvar_t *));
12620         }
12621 }
12622 
12623 static void
12624 dtrace_state_clean(dtrace_state_t *state)
12625 {
12626         if (state->dts_activity == DTRACE_ACTIVITY_INACTIVE)
12627                 return;
12628 
12629         dtrace_dynvar_clean(&state->dts_vstate.dtvs_dynvars);
12630         dtrace_speculation_clean(state);
12631 }
12632 
12633 static void
12634 dtrace_state_deadman(dtrace_state_t *state)
12635 {
12636         hrtime_t now;
12637 
12638         dtrace_sync();
12639 
12640         now = dtrace_gethrtime();
12641 
12642         if (state != dtrace_anon.dta_state &&
12643             now - state->dts_laststatus >= dtrace_deadman_user)
12644                 return;
12645 
12646         /*
12647          * We must be sure that dts_alive never appears to be less than the
12648          * value upon entry to dtrace_state_deadman(), and because we lack a
12649          * dtrace_cas64(), we cannot store to it atomically.  We thus instead
12650          * store INT64_MAX to it, followed by a memory barrier, followed by
12651          * the new value.  This assures that dts_alive never appears to be
12652          * less than its true value, regardless of the order in which the
12653          * stores to the underlying storage are issued.
12654          */
12655         state->dts_alive = INT64_MAX;
12656         dtrace_membar_producer();
12657         state->dts_alive = now;
12658 }
12659 
12660 dtrace_state_t *
12661 dtrace_state_create(dev_t *devp, cred_t *cr)
12662 {
12663         minor_t minor;
12664         major_t major;
12665         char c[30];
12666         dtrace_state_t *state;
12667         dtrace_optval_t *opt;
12668         int bufsize = NCPU * sizeof (dtrace_buffer_t), i;
12669 
12670         ASSERT(MUTEX_HELD(&dtrace_lock));
12671         ASSERT(MUTEX_HELD(&cpu_lock));
12672 
12673         minor = (minor_t)(uintptr_t)vmem_alloc(dtrace_minor, 1,
12674             VM_BESTFIT | VM_SLEEP);
12675 
12676         if (ddi_soft_state_zalloc(dtrace_softstate, minor) != DDI_SUCCESS) {
12677                 vmem_free(dtrace_minor, (void *)(uintptr_t)minor, 1);
12678                 return (NULL);
12679         }
12680 
12681         state = ddi_get_soft_state(dtrace_softstate, minor);
12682         state->dts_epid = DTRACE_EPIDNONE + 1;
12683 
12684         (void) snprintf(c, sizeof (c), "dtrace_aggid_%d", minor);
12685         state->dts_aggid_arena = vmem_create(c, (void *)1, UINT32_MAX, 1,
12686             NULL, NULL, NULL, 0, VM_SLEEP | VMC_IDENTIFIER);
12687 
12688         if (devp != NULL) {
12689                 major = getemajor(*devp);
12690         } else {
12691                 major = ddi_driver_major(dtrace_devi);
12692         }
12693 
12694         state->dts_dev = makedevice(major, minor);
12695 
12696         if (devp != NULL)
12697                 *devp = state->dts_dev;
12698 
12699         /*
12700          * We allocate NCPU buffers.  On the one hand, this can be quite
12701          * a bit of memory per instance (nearly 36K on a Starcat).  On the
12702          * other hand, it saves an additional memory reference in the probe
12703          * path.
12704          */
12705         state->dts_buffer = kmem_zalloc(bufsize, KM_SLEEP);
12706         state->dts_aggbuffer = kmem_zalloc(bufsize, KM_SLEEP);
12707         state->dts_cleaner = CYCLIC_NONE;
12708         state->dts_deadman = CYCLIC_NONE;
12709         state->dts_vstate.dtvs_state = state;
12710 
12711         for (i = 0; i < DTRACEOPT_MAX; i++)
12712                 state->dts_options[i] = DTRACEOPT_UNSET;
12713 
12714         /*
12715          * Set the default options.
12716          */
12717         opt = state->dts_options;
12718         opt[DTRACEOPT_BUFPOLICY] = DTRACEOPT_BUFPOLICY_SWITCH;
12719         opt[DTRACEOPT_BUFRESIZE] = DTRACEOPT_BUFRESIZE_AUTO;
12720         opt[DTRACEOPT_NSPEC] = dtrace_nspec_default;
12721         opt[DTRACEOPT_SPECSIZE] = dtrace_specsize_default;
12722         opt[DTRACEOPT_CPU] = (dtrace_optval_t)DTRACE_CPUALL;
12723         opt[DTRACEOPT_STRSIZE] = dtrace_strsize_default;
12724         opt[DTRACEOPT_STACKFRAMES] = dtrace_stackframes_default;
12725         opt[DTRACEOPT_USTACKFRAMES] = dtrace_ustackframes_default;
12726         opt[DTRACEOPT_CLEANRATE] = dtrace_cleanrate_default;
12727         opt[DTRACEOPT_AGGRATE] = dtrace_aggrate_default;
12728         opt[DTRACEOPT_SWITCHRATE] = dtrace_switchrate_default;
12729         opt[DTRACEOPT_STATUSRATE] = dtrace_statusrate_default;
12730         opt[DTRACEOPT_JSTACKFRAMES] = dtrace_jstackframes_default;
12731         opt[DTRACEOPT_JSTACKSTRSIZE] = dtrace_jstackstrsize_default;
12732 
12733         state->dts_activity = DTRACE_ACTIVITY_INACTIVE;
12734 
12735         /*
12736          * Depending on the user credentials, we set flag bits which alter probe
12737          * visibility or the amount of destructiveness allowed.  In the case of
12738          * actual anonymous tracing, or the possession of all privileges, all of
12739          * the normal checks are bypassed.
12740          */
12741         if (cr == NULL || PRIV_POLICY_ONLY(cr, PRIV_ALL, B_FALSE)) {
12742                 state->dts_cred.dcr_visible = DTRACE_CRV_ALL;
12743                 state->dts_cred.dcr_action = DTRACE_CRA_ALL;
12744         } else {
12745                 /*
12746                  * Set up the credentials for this instantiation.  We take a
12747                  * hold on the credential to prevent it from disappearing on
12748                  * us; this in turn prevents the zone_t referenced by this
12749                  * credential from disappearing.  This means that we can
12750                  * examine the credential and the zone from probe context.
12751                  */
12752                 crhold(cr);
12753                 state->dts_cred.dcr_cred = cr;
12754 
12755                 /*
12756                  * CRA_PROC means "we have *some* privilege for dtrace" and
12757                  * unlocks the use of variables like pid, zonename, etc.
12758                  */
12759                 if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_USER, B_FALSE) ||
12760                     PRIV_POLICY_ONLY(cr, PRIV_DTRACE_PROC, B_FALSE)) {
12761                         state->dts_cred.dcr_action |= DTRACE_CRA_PROC;
12762                 }
12763 
12764                 /*
12765                  * dtrace_user allows use of syscall and profile providers.
12766                  * If the user also has proc_owner and/or proc_zone, we
12767                  * extend the scope to include additional visibility and
12768                  * destructive power.
12769                  */
12770                 if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_USER, B_FALSE)) {
12771                         if (PRIV_POLICY_ONLY(cr, PRIV_PROC_OWNER, B_FALSE)) {
12772                                 state->dts_cred.dcr_visible |=
12773                                     DTRACE_CRV_ALLPROC;
12774 
12775                                 state->dts_cred.dcr_action |=
12776                                     DTRACE_CRA_PROC_DESTRUCTIVE_ALLUSER;
12777                         }
12778 
12779                         if (PRIV_POLICY_ONLY(cr, PRIV_PROC_ZONE, B_FALSE)) {
12780                                 state->dts_cred.dcr_visible |=
12781                                     DTRACE_CRV_ALLZONE;
12782 
12783                                 state->dts_cred.dcr_action |=
12784                                     DTRACE_CRA_PROC_DESTRUCTIVE_ALLZONE;
12785                         }
12786 
12787                         /*
12788                          * If we have all privs in whatever zone this is,
12789                          * we can do destructive things to processes which
12790                          * have altered credentials.
12791                          */
12792                         if (priv_isequalset(priv_getset(cr, PRIV_EFFECTIVE),
12793                             cr->cr_zone->zone_privset)) {
12794                                 state->dts_cred.dcr_action |=
12795                                     DTRACE_CRA_PROC_DESTRUCTIVE_CREDCHG;
12796                         }
12797                 }
12798 
12799                 /*
12800                  * Holding the dtrace_kernel privilege also implies that
12801                  * the user has the dtrace_user privilege from a visibility
12802                  * perspective.  But without further privileges, some
12803                  * destructive actions are not available.
12804                  */
12805                 if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_KERNEL, B_FALSE)) {
12806                         /*
12807                          * Make all probes in all zones visible.  However,
12808                          * this doesn't mean that all actions become available
12809                          * to all zones.
12810                          */
12811                         state->dts_cred.dcr_visible |= DTRACE_CRV_KERNEL |
12812                             DTRACE_CRV_ALLPROC | DTRACE_CRV_ALLZONE;
12813 
12814                         state->dts_cred.dcr_action |= DTRACE_CRA_KERNEL |
12815                             DTRACE_CRA_PROC;
12816                         /*
12817                          * Holding proc_owner means that destructive actions
12818                          * for *this* zone are allowed.
12819                          */
12820                         if (PRIV_POLICY_ONLY(cr, PRIV_PROC_OWNER, B_FALSE))
12821                                 state->dts_cred.dcr_action |=
12822                                     DTRACE_CRA_PROC_DESTRUCTIVE_ALLUSER;
12823 
12824                         /*
12825                          * Holding proc_zone means that destructive actions
12826                          * for this user/group ID in all zones is allowed.
12827                          */
12828                         if (PRIV_POLICY_ONLY(cr, PRIV_PROC_ZONE, B_FALSE))
12829                                 state->dts_cred.dcr_action |=
12830                                     DTRACE_CRA_PROC_DESTRUCTIVE_ALLZONE;
12831 
12832                         /*
12833                          * If we have all privs in whatever zone this is,
12834                          * we can do destructive things to processes which
12835                          * have altered credentials.
12836                          */
12837                         if (priv_isequalset(priv_getset(cr, PRIV_EFFECTIVE),
12838                             cr->cr_zone->zone_privset)) {
12839                                 state->dts_cred.dcr_action |=
12840                                     DTRACE_CRA_PROC_DESTRUCTIVE_CREDCHG;
12841                         }
12842                 }
12843 
12844                 /*
12845                  * Holding the dtrace_proc privilege gives control over fasttrap
12846                  * and pid providers.  We need to grant wider destructive
12847                  * privileges in the event that the user has proc_owner and/or
12848                  * proc_zone.
12849                  */
12850                 if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_PROC, B_FALSE)) {
12851                         if (PRIV_POLICY_ONLY(cr, PRIV_PROC_OWNER, B_FALSE))
12852                                 state->dts_cred.dcr_action |=
12853                                     DTRACE_CRA_PROC_DESTRUCTIVE_ALLUSER;
12854 
12855                         if (PRIV_POLICY_ONLY(cr, PRIV_PROC_ZONE, B_FALSE))
12856                                 state->dts_cred.dcr_action |=
12857                                     DTRACE_CRA_PROC_DESTRUCTIVE_ALLZONE;
12858                 }
12859         }
12860 
12861         return (state);
12862 }
12863 
12864 static int
12865 dtrace_state_buffer(dtrace_state_t *state, dtrace_buffer_t *buf, int which)
12866 {
12867         dtrace_optval_t *opt = state->dts_options, size;
12868         processorid_t cpu;
12869         int flags = 0, rval, factor, divisor = 1;
12870 
12871         ASSERT(MUTEX_HELD(&dtrace_lock));
12872         ASSERT(MUTEX_HELD(&cpu_lock));
12873         ASSERT(which < DTRACEOPT_MAX);
12874         ASSERT(state->dts_activity == DTRACE_ACTIVITY_INACTIVE ||
12875             (state == dtrace_anon.dta_state &&
12876             state->dts_activity == DTRACE_ACTIVITY_ACTIVE));
12877 
12878         if (opt[which] == DTRACEOPT_UNSET || opt[which] == 0)
12879                 return (0);
12880 
12881         if (opt[DTRACEOPT_CPU] != DTRACEOPT_UNSET)
12882                 cpu = opt[DTRACEOPT_CPU];
12883 
12884         if (which == DTRACEOPT_SPECSIZE)
12885                 flags |= DTRACEBUF_NOSWITCH;
12886 
12887         if (which == DTRACEOPT_BUFSIZE) {
12888                 if (opt[DTRACEOPT_BUFPOLICY] == DTRACEOPT_BUFPOLICY_RING)
12889                         flags |= DTRACEBUF_RING;
12890 
12891                 if (opt[DTRACEOPT_BUFPOLICY] == DTRACEOPT_BUFPOLICY_FILL)
12892                         flags |= DTRACEBUF_FILL;
12893 
12894                 if (state != dtrace_anon.dta_state ||
12895                     state->dts_activity != DTRACE_ACTIVITY_ACTIVE)
12896                         flags |= DTRACEBUF_INACTIVE;
12897         }
12898 
12899         for (size = opt[which]; size >= sizeof (uint64_t); size /= divisor) {
12900                 /*
12901                  * The size must be 8-byte aligned.  If the size is not 8-byte
12902                  * aligned, drop it down by the difference.
12903                  */
12904                 if (size & (sizeof (uint64_t) - 1))
12905                         size -= size & (sizeof (uint64_t) - 1);
12906 
12907                 if (size < state->dts_reserve) {
12908                         /*
12909                          * Buffers always must be large enough to accommodate
12910                          * their prereserved space.  We return E2BIG instead
12911                          * of ENOMEM in this case to allow for user-level
12912                          * software to differentiate the cases.
12913                          */
12914                         return (E2BIG);
12915                 }
12916 
12917                 rval = dtrace_buffer_alloc(buf, size, flags, cpu, &factor);
12918 
12919                 if (rval != ENOMEM) {
12920                         opt[which] = size;
12921                         return (rval);
12922                 }
12923 
12924                 if (opt[DTRACEOPT_BUFRESIZE] == DTRACEOPT_BUFRESIZE_MANUAL)
12925                         return (rval);
12926 
12927                 for (divisor = 2; divisor < factor; divisor <<= 1)
12928                         continue;
12929         }
12930 
12931         return (ENOMEM);
12932 }
12933 
12934 static int
12935 dtrace_state_buffers(dtrace_state_t *state)
12936 {
12937         dtrace_speculation_t *spec = state->dts_speculations;
12938         int rval, i;
12939 
12940         if ((rval = dtrace_state_buffer(state, state->dts_buffer,
12941             DTRACEOPT_BUFSIZE)) != 0)
12942                 return (rval);
12943 
12944         if ((rval = dtrace_state_buffer(state, state->dts_aggbuffer,
12945             DTRACEOPT_AGGSIZE)) != 0)
12946                 return (rval);
12947 
12948         for (i = 0; i < state->dts_nspeculations; i++) {
12949                 if ((rval = dtrace_state_buffer(state,
12950                     spec[i].dtsp_buffer, DTRACEOPT_SPECSIZE)) != 0)
12951                         return (rval);
12952         }
12953 
12954         return (0);
12955 }
12956 
12957 static void
12958 dtrace_state_prereserve(dtrace_state_t *state)
12959 {
12960         dtrace_ecb_t *ecb;
12961         dtrace_probe_t *probe;
12962 
12963         state->dts_reserve = 0;
12964 
12965         if (state->dts_options[DTRACEOPT_BUFPOLICY] != DTRACEOPT_BUFPOLICY_FILL)
12966                 return;
12967 
12968         /*
12969          * If our buffer policy is a "fill" buffer policy, we need to set the
12970          * prereserved space to be the space required by the END probes.
12971          */
12972         probe = dtrace_probes[dtrace_probeid_end - 1];
12973         ASSERT(probe != NULL);
12974 
12975         for (ecb = probe->dtpr_ecb; ecb != NULL; ecb = ecb->dte_next) {
12976                 if (ecb->dte_state != state)
12977                         continue;
12978 
12979                 state->dts_reserve += ecb->dte_needed + ecb->dte_alignment;
12980         }
12981 }
12982 
12983 static int
12984 dtrace_state_go(dtrace_state_t *state, processorid_t *cpu)
12985 {
12986         dtrace_optval_t *opt = state->dts_options, sz, nspec;
12987         dtrace_speculation_t *spec;
12988         dtrace_buffer_t *buf;
12989         cyc_handler_t hdlr;
12990         cyc_time_t when;
12991         int rval = 0, i, bufsize = NCPU * sizeof (dtrace_buffer_t);
12992         dtrace_icookie_t cookie;
12993 
12994         mutex_enter(&cpu_lock);
12995         mutex_enter(&dtrace_lock);
12996 
12997         if (state->dts_activity != DTRACE_ACTIVITY_INACTIVE) {
12998                 rval = EBUSY;
12999                 goto out;
13000         }
13001 
13002         /*
13003          * Before we can perform any checks, we must prime all of the
13004          * retained enablings that correspond to this state.
13005          */
13006         dtrace_enabling_prime(state);
13007 
13008         if (state->dts_destructive && !state->dts_cred.dcr_destructive) {
13009                 rval = EACCES;
13010                 goto out;
13011         }
13012 
13013         dtrace_state_prereserve(state);
13014 
13015         /*
13016          * Now we want to do is try to allocate our speculations.
13017          * We do not automatically resize the number of speculations; if
13018          * this fails, we will fail the operation.
13019          */
13020         nspec = opt[DTRACEOPT_NSPEC];
13021         ASSERT(nspec != DTRACEOPT_UNSET);
13022 
13023         if (nspec > INT_MAX) {
13024                 rval = ENOMEM;
13025                 goto out;
13026         }
13027 
13028         spec = kmem_zalloc(nspec * sizeof (dtrace_speculation_t),
13029             KM_NOSLEEP | KM_NORMALPRI);
13030 
13031         if (spec == NULL) {
13032                 rval = ENOMEM;
13033                 goto out;
13034         }
13035 
13036         state->dts_speculations = spec;
13037         state->dts_nspeculations = (int)nspec;
13038 
13039         for (i = 0; i < nspec; i++) {
13040                 if ((buf = kmem_zalloc(bufsize,
13041                     KM_NOSLEEP | KM_NORMALPRI)) == NULL) {
13042                         rval = ENOMEM;
13043                         goto err;
13044                 }
13045 
13046                 spec[i].dtsp_buffer = buf;
13047         }
13048 
13049         if (opt[DTRACEOPT_GRABANON] != DTRACEOPT_UNSET) {
13050                 if (dtrace_anon.dta_state == NULL) {
13051                         rval = ENOENT;
13052                         goto out;
13053                 }
13054 
13055                 if (state->dts_necbs != 0) {
13056                         rval = EALREADY;
13057                         goto out;
13058                 }
13059 
13060                 state->dts_anon = dtrace_anon_grab();
13061                 ASSERT(state->dts_anon != NULL);
13062                 state = state->dts_anon;
13063 
13064                 /*
13065                  * We want "grabanon" to be set in the grabbed state, so we'll
13066                  * copy that option value from the grabbing state into the
13067                  * grabbed state.
13068                  */
13069                 state->dts_options[DTRACEOPT_GRABANON] =
13070                     opt[DTRACEOPT_GRABANON];
13071 
13072                 *cpu = dtrace_anon.dta_beganon;
13073 
13074                 /*
13075                  * If the anonymous state is active (as it almost certainly
13076                  * is if the anonymous enabling ultimately matched anything),
13077                  * we don't allow any further option processing -- but we
13078                  * don't return failure.
13079                  */
13080                 if (state->dts_activity != DTRACE_ACTIVITY_INACTIVE)
13081                         goto out;
13082         }
13083 
13084         if (opt[DTRACEOPT_AGGSIZE] != DTRACEOPT_UNSET &&
13085             opt[DTRACEOPT_AGGSIZE] != 0) {
13086                 if (state->dts_aggregations == NULL) {
13087                         /*
13088                          * We're not going to create an aggregation buffer
13089                          * because we don't have any ECBs that contain
13090                          * aggregations -- set this option to 0.
13091                          */
13092                         opt[DTRACEOPT_AGGSIZE] = 0;
13093                 } else {
13094                         /*
13095                          * If we have an aggregation buffer, we must also have
13096                          * a buffer to use as scratch.
13097                          */
13098                         if (opt[DTRACEOPT_BUFSIZE] == DTRACEOPT_UNSET ||
13099                             opt[DTRACEOPT_BUFSIZE] < state->dts_needed) {
13100                                 opt[DTRACEOPT_BUFSIZE] = state->dts_needed;
13101                         }
13102                 }
13103         }
13104 
13105         if (opt[DTRACEOPT_SPECSIZE] != DTRACEOPT_UNSET &&
13106             opt[DTRACEOPT_SPECSIZE] != 0) {
13107                 if (!state->dts_speculates) {
13108                         /*
13109                          * We're not going to create speculation buffers
13110                          * because we don't have any ECBs that actually
13111                          * speculate -- set the speculation size to 0.
13112                          */
13113                         opt[DTRACEOPT_SPECSIZE] = 0;
13114                 }
13115         }
13116 
13117         /*
13118          * The bare minimum size for any buffer that we're actually going to
13119          * do anything to is sizeof (uint64_t).
13120          */
13121         sz = sizeof (uint64_t);
13122 
13123         if ((state->dts_needed != 0 && opt[DTRACEOPT_BUFSIZE] < sz) ||
13124             (state->dts_speculates && opt[DTRACEOPT_SPECSIZE] < sz) ||
13125             (state->dts_aggregations != NULL && opt[DTRACEOPT_AGGSIZE] < sz)) {
13126                 /*
13127                  * A buffer size has been explicitly set to 0 (or to a size
13128                  * that will be adjusted to 0) and we need the space -- we
13129                  * need to return failure.  We return ENOSPC to differentiate
13130                  * it from failing to allocate a buffer due to failure to meet
13131                  * the reserve (for which we return E2BIG).
13132                  */
13133                 rval = ENOSPC;
13134                 goto out;
13135         }
13136 
13137         if ((rval = dtrace_state_buffers(state)) != 0)
13138                 goto err;
13139 
13140         if ((sz = opt[DTRACEOPT_DYNVARSIZE]) == DTRACEOPT_UNSET)
13141                 sz = dtrace_dstate_defsize;
13142 
13143         do {
13144                 rval = dtrace_dstate_init(&state->dts_vstate.dtvs_dynvars, sz);
13145 
13146                 if (rval == 0)
13147                         break;
13148 
13149                 if (opt[DTRACEOPT_BUFRESIZE] == DTRACEOPT_BUFRESIZE_MANUAL)
13150                         goto err;
13151         } while (sz >>= 1);
13152 
13153         opt[DTRACEOPT_DYNVARSIZE] = sz;
13154 
13155         if (rval != 0)
13156                 goto err;
13157 
13158         if (opt[DTRACEOPT_STATUSRATE] > dtrace_statusrate_max)
13159                 opt[DTRACEOPT_STATUSRATE] = dtrace_statusrate_max;
13160 
13161         if (opt[DTRACEOPT_CLEANRATE] == 0)
13162                 opt[DTRACEOPT_CLEANRATE] = dtrace_cleanrate_max;
13163 
13164         if (opt[DTRACEOPT_CLEANRATE] < dtrace_cleanrate_min)
13165                 opt[DTRACEOPT_CLEANRATE] = dtrace_cleanrate_min;
13166 
13167         if (opt[DTRACEOPT_CLEANRATE] > dtrace_cleanrate_max)
13168                 opt[DTRACEOPT_CLEANRATE] = dtrace_cleanrate_max;
13169 
13170         hdlr.cyh_func = (cyc_func_t)dtrace_state_clean;
13171         hdlr.cyh_arg = state;
13172         hdlr.cyh_level = CY_LOW_LEVEL;
13173 
13174         when.cyt_when = 0;
13175         when.cyt_interval = opt[DTRACEOPT_CLEANRATE];
13176 
13177         state->dts_cleaner = cyclic_add(&hdlr, &when);
13178 
13179         hdlr.cyh_func = (cyc_func_t)dtrace_state_deadman;
13180         hdlr.cyh_arg = state;
13181         hdlr.cyh_level = CY_LOW_LEVEL;
13182 
13183         when.cyt_when = 0;
13184         when.cyt_interval = dtrace_deadman_interval;
13185 
13186         state->dts_alive = state->dts_laststatus = dtrace_gethrtime();
13187         state->dts_deadman = cyclic_add(&hdlr, &when);
13188 
13189         state->dts_activity = DTRACE_ACTIVITY_WARMUP;
13190 
13191         if (state->dts_getf != 0 &&
13192             !(state->dts_cred.dcr_visible & DTRACE_CRV_KERNEL)) {
13193                 /*
13194                  * We don't have kernel privs but we have at least one call
13195                  * to getf(); we need to bump our zone's count, and (if
13196                  * this is the first enabling to have an unprivileged call
13197                  * to getf()) we need to hook into closef().
13198                  */
13199                 state->dts_cred.dcr_cred->cr_zone->zone_dtrace_getf++;
13200 
13201                 if (dtrace_getf++ == 0) {
13202                         ASSERT(dtrace_closef == NULL);
13203                         dtrace_closef = dtrace_getf_barrier;
13204                 }
13205         }
13206 
13207         /*
13208          * Now it's time to actually fire the BEGIN probe.  We need to disable
13209          * interrupts here both to record the CPU on which we fired the BEGIN
13210          * probe (the data from this CPU will be processed first at user
13211          * level) and to manually activate the buffer for this CPU.
13212          */
13213         cookie = dtrace_interrupt_disable();
13214         *cpu = CPU->cpu_id;
13215         ASSERT(state->dts_buffer[*cpu].dtb_flags & DTRACEBUF_INACTIVE);
13216         state->dts_buffer[*cpu].dtb_flags &= ~DTRACEBUF_INACTIVE;
13217 
13218         dtrace_probe(dtrace_probeid_begin,
13219             (uint64_t)(uintptr_t)state, 0, 0, 0, 0);
13220         dtrace_interrupt_enable(cookie);
13221         /*
13222          * We may have had an exit action from a BEGIN probe; only change our
13223          * state to ACTIVE if we're still in WARMUP.
13224          */
13225         ASSERT(state->dts_activity == DTRACE_ACTIVITY_WARMUP ||
13226             state->dts_activity == DTRACE_ACTIVITY_DRAINING);
13227 
13228         if (state->dts_activity == DTRACE_ACTIVITY_WARMUP)
13229                 state->dts_activity = DTRACE_ACTIVITY_ACTIVE;
13230 
13231         /*
13232          * Regardless of whether or not now we're in ACTIVE or DRAINING, we
13233          * want each CPU to transition its principal buffer out of the
13234          * INACTIVE state.  Doing this assures that no CPU will suddenly begin
13235          * processing an ECB halfway down a probe's ECB chain; all CPUs will
13236          * atomically transition from processing none of a state's ECBs to
13237          * processing all of them.
13238          */
13239         dtrace_xcall(DTRACE_CPUALL,
13240             (dtrace_xcall_t)dtrace_buffer_activate, state);
13241         goto out;
13242 
13243 err:
13244         dtrace_buffer_free(state->dts_buffer);
13245         dtrace_buffer_free(state->dts_aggbuffer);
13246 
13247         if ((nspec = state->dts_nspeculations) == 0) {
13248                 ASSERT(state->dts_speculations == NULL);
13249                 goto out;
13250         }
13251 
13252         spec = state->dts_speculations;
13253         ASSERT(spec != NULL);
13254 
13255         for (i = 0; i < state->dts_nspeculations; i++) {
13256                 if ((buf = spec[i].dtsp_buffer) == NULL)
13257                         break;
13258 
13259                 dtrace_buffer_free(buf);
13260                 kmem_free(buf, bufsize);
13261         }
13262 
13263         kmem_free(spec, nspec * sizeof (dtrace_speculation_t));
13264         state->dts_nspeculations = 0;
13265         state->dts_speculations = NULL;
13266 
13267 out:
13268         mutex_exit(&dtrace_lock);
13269         mutex_exit(&cpu_lock);
13270 
13271         return (rval);
13272 }
13273 
13274 static int
13275 dtrace_state_stop(dtrace_state_t *state, processorid_t *cpu)
13276 {
13277         dtrace_icookie_t cookie;
13278 
13279         ASSERT(MUTEX_HELD(&dtrace_lock));
13280 
13281         if (state->dts_activity != DTRACE_ACTIVITY_ACTIVE &&
13282             state->dts_activity != DTRACE_ACTIVITY_DRAINING)
13283                 return (EINVAL);
13284 
13285         /*
13286          * We'll set the activity to DTRACE_ACTIVITY_DRAINING, and issue a sync
13287          * to be sure that every CPU has seen it.  See below for the details
13288          * on why this is done.
13289          */
13290         state->dts_activity = DTRACE_ACTIVITY_DRAINING;
13291         dtrace_sync();
13292 
13293         /*
13294          * By this point, it is impossible for any CPU to be still processing
13295          * with DTRACE_ACTIVITY_ACTIVE.  We can thus set our activity to
13296          * DTRACE_ACTIVITY_COOLDOWN and know that we're not racing with any
13297          * other CPU in dtrace_buffer_reserve().  This allows dtrace_probe()
13298          * and callees to know that the activity is DTRACE_ACTIVITY_COOLDOWN
13299          * iff we're in the END probe.
13300          */
13301         state->dts_activity = DTRACE_ACTIVITY_COOLDOWN;
13302         dtrace_sync();
13303         ASSERT(state->dts_activity == DTRACE_ACTIVITY_COOLDOWN);
13304 
13305         /*
13306          * Finally, we can release the reserve and call the END probe.  We
13307          * disable interrupts across calling the END probe to allow us to
13308          * return the CPU on which we actually called the END probe.  This
13309          * allows user-land to be sure that this CPU's principal buffer is
13310          * processed last.
13311          */
13312         state->dts_reserve = 0;
13313 
13314         cookie = dtrace_interrupt_disable();
13315         *cpu = CPU->cpu_id;
13316         dtrace_probe(dtrace_probeid_end,
13317             (uint64_t)(uintptr_t)state, 0, 0, 0, 0);
13318         dtrace_interrupt_enable(cookie);
13319 
13320         state->dts_activity = DTRACE_ACTIVITY_STOPPED;
13321         dtrace_sync();
13322 
13323         if (state->dts_getf != 0 &&
13324             !(state->dts_cred.dcr_visible & DTRACE_CRV_KERNEL)) {
13325                 /*
13326                  * We don't have kernel privs but we have at least one call
13327                  * to getf(); we need to lower our zone's count, and (if
13328                  * this is the last enabling to have an unprivileged call
13329                  * to getf()) we need to clear the closef() hook.
13330                  */
13331                 ASSERT(state->dts_cred.dcr_cred->cr_zone->zone_dtrace_getf > 0);
13332                 ASSERT(dtrace_closef == dtrace_getf_barrier);
13333                 ASSERT(dtrace_getf > 0);
13334 
13335                 state->dts_cred.dcr_cred->cr_zone->zone_dtrace_getf--;
13336 
13337                 if (--dtrace_getf == 0)
13338                         dtrace_closef = NULL;
13339         }
13340 
13341         return (0);
13342 }
13343 
13344 static int
13345 dtrace_state_option(dtrace_state_t *state, dtrace_optid_t option,
13346     dtrace_optval_t val)
13347 {
13348         ASSERT(MUTEX_HELD(&dtrace_lock));
13349 
13350         if (state->dts_activity != DTRACE_ACTIVITY_INACTIVE)
13351                 return (EBUSY);
13352 
13353         if (option >= DTRACEOPT_MAX)
13354                 return (EINVAL);
13355 
13356         if (option != DTRACEOPT_CPU && val < 0)
13357                 return (EINVAL);
13358 
13359         switch (option) {
13360         case DTRACEOPT_DESTRUCTIVE:
13361                 if (dtrace_destructive_disallow)
13362                         return (EACCES);
13363 
13364                 state->dts_cred.dcr_destructive = 1;
13365                 break;
13366 
13367         case DTRACEOPT_BUFSIZE:
13368         case DTRACEOPT_DYNVARSIZE:
13369         case DTRACEOPT_AGGSIZE:
13370         case DTRACEOPT_SPECSIZE:
13371         case DTRACEOPT_STRSIZE:
13372                 if (val < 0)
13373                         return (EINVAL);
13374 
13375                 if (val >= LONG_MAX) {
13376                         /*
13377                          * If this is an otherwise negative value, set it to
13378                          * the highest multiple of 128m less than LONG_MAX.
13379                          * Technically, we're adjusting the size without
13380                          * regard to the buffer resizing policy, but in fact,
13381                          * this has no effect -- if we set the buffer size to
13382                          * ~LONG_MAX and the buffer policy is ultimately set to
13383                          * be "manual", the buffer allocation is guaranteed to
13384                          * fail, if only because the allocation requires two
13385                          * buffers.  (We set the the size to the highest
13386                          * multiple of 128m because it ensures that the size
13387                          * will remain a multiple of a megabyte when
13388                          * repeatedly halved -- all the way down to 15m.)
13389                          */
13390                         val = LONG_MAX - (1 << 27) + 1;
13391                 }
13392         }
13393 
13394         state->dts_options[option] = val;
13395 
13396         return (0);
13397 }
13398 
13399 static void
13400 dtrace_state_destroy(dtrace_state_t *state)
13401 {
13402         dtrace_ecb_t *ecb;
13403         dtrace_vstate_t *vstate = &state->dts_vstate;
13404         minor_t minor = getminor(state->dts_dev);
13405         int i, bufsize = NCPU * sizeof (dtrace_buffer_t);
13406         dtrace_speculation_t *spec = state->dts_speculations;
13407         int nspec = state->dts_nspeculations;
13408         uint32_t match;
13409 
13410         ASSERT(MUTEX_HELD(&dtrace_lock));
13411         ASSERT(MUTEX_HELD(&cpu_lock));
13412 
13413         /*
13414          * First, retract any retained enablings for this state.
13415          */
13416         dtrace_enabling_retract(state);
13417         ASSERT(state->dts_nretained == 0);
13418 
13419         if (state->dts_activity == DTRACE_ACTIVITY_ACTIVE ||
13420             state->dts_activity == DTRACE_ACTIVITY_DRAINING) {
13421                 /*
13422                  * We have managed to come into dtrace_state_destroy() on a
13423                  * hot enabling -- almost certainly because of a disorderly
13424                  * shutdown of a consumer.  (That is, a consumer that is
13425                  * exiting without having called dtrace_stop().) In this case,
13426                  * we're going to set our activity to be KILLED, and then
13427                  * issue a sync to be sure that everyone is out of probe
13428                  * context before we start blowing away ECBs.
13429                  */
13430                 state->dts_activity = DTRACE_ACTIVITY_KILLED;
13431                 dtrace_sync();
13432         }
13433 
13434         /*
13435          * Release the credential hold we took in dtrace_state_create().
13436          */
13437         if (state->dts_cred.dcr_cred != NULL)
13438                 crfree(state->dts_cred.dcr_cred);
13439 
13440         /*
13441          * Now we can safely disable and destroy any enabled probes.  Because
13442          * any DTRACE_PRIV_KERNEL probes may actually be slowing our progress
13443          * (especially if they're all enabled), we take two passes through the
13444          * ECBs:  in the first, we disable just DTRACE_PRIV_KERNEL probes, and
13445          * in the second we disable whatever is left over.
13446          */
13447         for (match = DTRACE_PRIV_KERNEL; ; match = 0) {
13448                 for (i = 0; i < state->dts_necbs; i++) {
13449                         if ((ecb = state->dts_ecbs[i]) == NULL)
13450                                 continue;
13451 
13452                         if (match && ecb->dte_probe != NULL) {
13453                                 dtrace_probe_t *probe = ecb->dte_probe;
13454                                 dtrace_provider_t *prov = probe->dtpr_provider;
13455 
13456                                 if (!(prov->dtpv_priv.dtpp_flags & match))
13457                                         continue;
13458                         }
13459 
13460                         dtrace_ecb_disable(ecb);
13461                         dtrace_ecb_destroy(ecb);
13462                 }
13463 
13464                 if (!match)
13465                         break;
13466         }
13467 
13468         /*
13469          * Before we free the buffers, perform one more sync to assure that
13470          * every CPU is out of probe context.
13471          */
13472         dtrace_sync();
13473 
13474         dtrace_buffer_free(state->dts_buffer);
13475         dtrace_buffer_free(state->dts_aggbuffer);
13476 
13477         for (i = 0; i < nspec; i++)
13478                 dtrace_buffer_free(spec[i].dtsp_buffer);
13479 
13480         if (state->dts_cleaner != CYCLIC_NONE)
13481                 cyclic_remove(state->dts_cleaner);
13482 
13483         if (state->dts_deadman != CYCLIC_NONE)
13484                 cyclic_remove(state->dts_deadman);
13485 
13486         dtrace_dstate_fini(&vstate->dtvs_dynvars);
13487         dtrace_vstate_fini(vstate);
13488         kmem_free(state->dts_ecbs, state->dts_necbs * sizeof (dtrace_ecb_t *));
13489 
13490         if (state->dts_aggregations != NULL) {
13491 #ifdef DEBUG
13492                 for (i = 0; i < state->dts_naggregations; i++)
13493                         ASSERT(state->dts_aggregations[i] == NULL);
13494 #endif
13495                 ASSERT(state->dts_naggregations > 0);
13496                 kmem_free(state->dts_aggregations,
13497                     state->dts_naggregations * sizeof (dtrace_aggregation_t *));
13498         }
13499 
13500         kmem_free(state->dts_buffer, bufsize);
13501         kmem_free(state->dts_aggbuffer, bufsize);
13502 
13503         for (i = 0; i < nspec; i++)
13504                 kmem_free(spec[i].dtsp_buffer, bufsize);
13505 
13506         kmem_free(spec, nspec * sizeof (dtrace_speculation_t));
13507 
13508         dtrace_format_destroy(state);
13509 
13510         vmem_destroy(state->dts_aggid_arena);
13511         ddi_soft_state_free(dtrace_softstate, minor);
13512         vmem_free(dtrace_minor, (void *)(uintptr_t)minor, 1);
13513 }
13514 
13515 /*
13516  * DTrace Anonymous Enabling Functions
13517  */
13518 static dtrace_state_t *
13519 dtrace_anon_grab(void)
13520 {
13521         dtrace_state_t *state;
13522 
13523         ASSERT(MUTEX_HELD(&dtrace_lock));
13524 
13525         if ((state = dtrace_anon.dta_state) == NULL) {
13526                 ASSERT(dtrace_anon.dta_enabling == NULL);
13527                 return (NULL);
13528         }
13529 
13530         ASSERT(dtrace_anon.dta_enabling != NULL);
13531         ASSERT(dtrace_retained != NULL);
13532 
13533         dtrace_enabling_destroy(dtrace_anon.dta_enabling);
13534         dtrace_anon.dta_enabling = NULL;
13535         dtrace_anon.dta_state = NULL;
13536 
13537         return (state);
13538 }
13539 
13540 static void
13541 dtrace_anon_property(void)
13542 {
13543         int i, rv;
13544         dtrace_state_t *state;
13545         dof_hdr_t *dof;
13546         char c[32];             /* enough for "dof-data-" + digits */
13547 
13548         ASSERT(MUTEX_HELD(&dtrace_lock));
13549         ASSERT(MUTEX_HELD(&cpu_lock));
13550 
13551         for (i = 0; ; i++) {
13552                 (void) snprintf(c, sizeof (c), "dof-data-%d", i);
13553 
13554                 dtrace_err_verbose = 1;
13555 
13556                 if ((dof = dtrace_dof_property(c)) == NULL) {
13557                         dtrace_err_verbose = 0;
13558                         break;
13559                 }
13560 
13561                 /*
13562                  * We want to create anonymous state, so we need to transition
13563                  * the kernel debugger to indicate that DTrace is active.  If
13564                  * this fails (e.g. because the debugger has modified text in
13565                  * some way), we won't continue with the processing.
13566                  */
13567                 if (kdi_dtrace_set(KDI_DTSET_DTRACE_ACTIVATE) != 0) {
13568                         cmn_err(CE_NOTE, "kernel debugger active; anonymous "
13569                             "enabling ignored.");
13570                         dtrace_dof_destroy(dof);
13571                         break;
13572                 }
13573 
13574                 /*
13575                  * If we haven't allocated an anonymous state, we'll do so now.
13576                  */
13577                 if ((state = dtrace_anon.dta_state) == NULL) {
13578                         state = dtrace_state_create(NULL, NULL);
13579                         dtrace_anon.dta_state = state;
13580 
13581                         if (state == NULL) {
13582                                 /*
13583                                  * This basically shouldn't happen:  the only
13584                                  * failure mode from dtrace_state_create() is a
13585                                  * failure of ddi_soft_state_zalloc() that
13586                                  * itself should never happen.  Still, the
13587                                  * interface allows for a failure mode, and
13588                                  * we want to fail as gracefully as possible:
13589                                  * we'll emit an error message and cease
13590                                  * processing anonymous state in this case.
13591                                  */
13592                                 cmn_err(CE_WARN, "failed to create "
13593                                     "anonymous state");
13594                                 dtrace_dof_destroy(dof);
13595                                 break;
13596                         }
13597                 }
13598 
13599                 rv = dtrace_dof_slurp(dof, &state->dts_vstate, CRED(),
13600                     &dtrace_anon.dta_enabling, 0, B_TRUE);
13601 
13602                 if (rv == 0)
13603                         rv = dtrace_dof_options(dof, state);
13604 
13605                 dtrace_err_verbose = 0;
13606                 dtrace_dof_destroy(dof);
13607 
13608                 if (rv != 0) {
13609                         /*
13610                          * This is malformed DOF; chuck any anonymous state
13611                          * that we created.
13612                          */
13613                         ASSERT(dtrace_anon.dta_enabling == NULL);
13614                         dtrace_state_destroy(state);
13615                         dtrace_anon.dta_state = NULL;
13616                         break;
13617                 }
13618 
13619                 ASSERT(dtrace_anon.dta_enabling != NULL);
13620         }
13621 
13622         if (dtrace_anon.dta_enabling != NULL) {
13623                 int rval;
13624 
13625                 /*
13626                  * dtrace_enabling_retain() can only fail because we are
13627                  * trying to retain more enablings than are allowed -- but
13628                  * we only have one anonymous enabling, and we are guaranteed
13629                  * to be allowed at least one retained enabling; we assert
13630                  * that dtrace_enabling_retain() returns success.
13631                  */
13632                 rval = dtrace_enabling_retain(dtrace_anon.dta_enabling);
13633                 ASSERT(rval == 0);
13634 
13635                 dtrace_enabling_dump(dtrace_anon.dta_enabling);
13636         }
13637 }
13638 
13639 /*
13640  * DTrace Helper Functions
13641  */
13642 static void
13643 dtrace_helper_trace(dtrace_helper_action_t *helper,
13644     dtrace_mstate_t *mstate, dtrace_vstate_t *vstate, int where)
13645 {
13646         uint32_t size, next, nnext, i;
13647         dtrace_helptrace_t *ent;
13648         uint16_t flags = cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
13649 
13650         if (!dtrace_helptrace_enabled)
13651                 return;
13652 
13653         ASSERT(vstate->dtvs_nlocals <= dtrace_helptrace_nlocals);
13654 
13655         /*
13656          * What would a tracing framework be without its own tracing
13657          * framework?  (Well, a hell of a lot simpler, for starters...)
13658          */
13659         size = sizeof (dtrace_helptrace_t) + dtrace_helptrace_nlocals *
13660             sizeof (uint64_t) - sizeof (uint64_t);
13661 
13662         /*
13663          * Iterate until we can allocate a slot in the trace buffer.
13664          */
13665         do {
13666                 next = dtrace_helptrace_next;
13667 
13668                 if (next + size < dtrace_helptrace_bufsize) {
13669                         nnext = next + size;
13670                 } else {
13671                         nnext = size;
13672                 }
13673         } while (dtrace_cas32(&dtrace_helptrace_next, next, nnext) != next);
13674 
13675         /*
13676          * We have our slot; fill it in.
13677          */
13678         if (nnext == size)
13679                 next = 0;
13680 
13681         ent = (dtrace_helptrace_t *)&dtrace_helptrace_buffer[next];
13682         ent->dtht_helper = helper;
13683         ent->dtht_where = where;
13684         ent->dtht_nlocals = vstate->dtvs_nlocals;
13685 
13686         ent->dtht_fltoffs = (mstate->dtms_present & DTRACE_MSTATE_FLTOFFS) ?
13687             mstate->dtms_fltoffs : -1;
13688         ent->dtht_fault = DTRACE_FLAGS2FLT(flags);
13689         ent->dtht_illval = cpu_core[CPU->cpu_id].cpuc_dtrace_illval;
13690 
13691         for (i = 0; i < vstate->dtvs_nlocals; i++) {
13692                 dtrace_statvar_t *svar;
13693 
13694                 if ((svar = vstate->dtvs_locals[i]) == NULL)
13695                         continue;
13696 
13697                 ASSERT(svar->dtsv_size >= NCPU * sizeof (uint64_t));
13698                 ent->dtht_locals[i] =
13699                     ((uint64_t *)(uintptr_t)svar->dtsv_data)[CPU->cpu_id];
13700         }
13701 }
13702 
13703 static uint64_t
13704 dtrace_helper(int which, dtrace_mstate_t *mstate,
13705     dtrace_state_t *state, uint64_t arg0, uint64_t arg1)
13706 {
13707         uint16_t *flags = &cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
13708         uint64_t sarg0 = mstate->dtms_arg[0];
13709         uint64_t sarg1 = mstate->dtms_arg[1];
13710         uint64_t rval;
13711         dtrace_helpers_t *helpers = curproc->p_dtrace_helpers;
13712         dtrace_helper_action_t *helper;
13713         dtrace_vstate_t *vstate;
13714         dtrace_difo_t *pred;
13715         int i, trace = dtrace_helptrace_enabled;
13716 
13717         ASSERT(which >= 0 && which < DTRACE_NHELPER_ACTIONS);
13718 
13719         if (helpers == NULL)
13720                 return (0);
13721 
13722         if ((helper = helpers->dthps_actions[which]) == NULL)
13723                 return (0);
13724 
13725         vstate = &helpers->dthps_vstate;
13726         mstate->dtms_arg[0] = arg0;
13727         mstate->dtms_arg[1] = arg1;
13728 
13729         /*
13730          * Now iterate over each helper.  If its predicate evaluates to 'true',
13731          * we'll call the corresponding actions.  Note that the below calls
13732          * to dtrace_dif_emulate() may set faults in machine state.  This is
13733          * okay:  our caller (the outer dtrace_dif_emulate()) will simply plow
13734          * the stored DIF offset with its own (which is the desired behavior).
13735          * Also, note the calls to dtrace_dif_emulate() may allocate scratch
13736          * from machine state; this is okay, too.
13737          */
13738         for (; helper != NULL; helper = helper->dtha_next) {
13739                 if ((pred = helper->dtha_predicate) != NULL) {
13740                         if (trace)
13741                                 dtrace_helper_trace(helper, mstate, vstate, 0);
13742 
13743                         if (!dtrace_dif_emulate(pred, mstate, vstate, state))
13744                                 goto next;
13745 
13746                         if (*flags & CPU_DTRACE_FAULT)
13747                                 goto err;
13748                 }
13749 
13750                 for (i = 0; i < helper->dtha_nactions; i++) {
13751                         if (trace)
13752                                 dtrace_helper_trace(helper,
13753                                     mstate, vstate, i + 1);
13754 
13755                         rval = dtrace_dif_emulate(helper->dtha_actions[i],
13756                             mstate, vstate, state);
13757 
13758                         if (*flags & CPU_DTRACE_FAULT)
13759                                 goto err;
13760                 }
13761 
13762 next:
13763                 if (trace)
13764                         dtrace_helper_trace(helper, mstate, vstate,
13765                             DTRACE_HELPTRACE_NEXT);
13766         }
13767 
13768         if (trace)
13769                 dtrace_helper_trace(helper, mstate, vstate,
13770                     DTRACE_HELPTRACE_DONE);
13771 
13772         /*
13773          * Restore the arg0 that we saved upon entry.
13774          */
13775         mstate->dtms_arg[0] = sarg0;
13776         mstate->dtms_arg[1] = sarg1;
13777 
13778         return (rval);
13779 
13780 err:
13781         if (trace)
13782                 dtrace_helper_trace(helper, mstate, vstate,
13783                     DTRACE_HELPTRACE_ERR);
13784 
13785         /*
13786          * Restore the arg0 that we saved upon entry.
13787          */
13788         mstate->dtms_arg[0] = sarg0;
13789         mstate->dtms_arg[1] = sarg1;
13790 
13791         return (NULL);
13792 }
13793 
13794 static void
13795 dtrace_helper_action_destroy(dtrace_helper_action_t *helper,
13796     dtrace_vstate_t *vstate)
13797 {
13798         int i;
13799 
13800         if (helper->dtha_predicate != NULL)
13801                 dtrace_difo_release(helper->dtha_predicate, vstate);
13802 
13803         for (i = 0; i < helper->dtha_nactions; i++) {
13804                 ASSERT(helper->dtha_actions[i] != NULL);
13805                 dtrace_difo_release(helper->dtha_actions[i], vstate);
13806         }
13807 
13808         kmem_free(helper->dtha_actions,
13809             helper->dtha_nactions * sizeof (dtrace_difo_t *));
13810         kmem_free(helper, sizeof (dtrace_helper_action_t));
13811 }
13812 
13813 static int
13814 dtrace_helper_destroygen(int gen)
13815 {
13816         proc_t *p = curproc;
13817         dtrace_helpers_t *help = p->p_dtrace_helpers;
13818         dtrace_vstate_t *vstate;
13819         int i;
13820 
13821         ASSERT(MUTEX_HELD(&dtrace_lock));
13822 
13823         if (help == NULL || gen > help->dthps_generation)
13824                 return (EINVAL);
13825 
13826         vstate = &help->dthps_vstate;
13827 
13828         for (i = 0; i < DTRACE_NHELPER_ACTIONS; i++) {
13829                 dtrace_helper_action_t *last = NULL, *h, *next;
13830 
13831                 for (h = help->dthps_actions[i]; h != NULL; h = next) {
13832                         next = h->dtha_next;
13833 
13834                         if (h->dtha_generation == gen) {
13835                                 if (last != NULL) {
13836                                         last->dtha_next = next;
13837                                 } else {
13838                                         help->dthps_actions[i] = next;
13839                                 }
13840 
13841                                 dtrace_helper_action_destroy(h, vstate);
13842                         } else {
13843                                 last = h;
13844                         }
13845                 }
13846         }
13847 
13848         /*
13849          * Interate until we've cleared out all helper providers with the
13850          * given generation number.
13851          */
13852         for (;;) {
13853                 dtrace_helper_provider_t *prov;
13854 
13855                 /*
13856                  * Look for a helper provider with the right generation. We
13857                  * have to start back at the beginning of the list each time
13858                  * because we drop dtrace_lock. It's unlikely that we'll make
13859                  * more than two passes.
13860                  */
13861                 for (i = 0; i < help->dthps_nprovs; i++) {
13862                         prov = help->dthps_provs[i];
13863 
13864                         if (prov->dthp_generation == gen)
13865                                 break;
13866                 }
13867 
13868                 /*
13869                  * If there were no matches, we're done.
13870                  */
13871                 if (i == help->dthps_nprovs)
13872                         break;
13873 
13874                 /*
13875                  * Move the last helper provider into this slot.
13876                  */
13877                 help->dthps_nprovs--;
13878                 help->dthps_provs[i] = help->dthps_provs[help->dthps_nprovs];
13879                 help->dthps_provs[help->dthps_nprovs] = NULL;
13880 
13881                 mutex_exit(&dtrace_lock);
13882 
13883                 /*
13884                  * If we have a meta provider, remove this helper provider.
13885                  */
13886                 mutex_enter(&dtrace_meta_lock);
13887                 if (dtrace_meta_pid != NULL) {
13888                         ASSERT(dtrace_deferred_pid == NULL);
13889                         dtrace_helper_provider_remove(&prov->dthp_prov,
13890                             p->p_pid);
13891                 }
13892                 mutex_exit(&dtrace_meta_lock);
13893 
13894                 dtrace_helper_provider_destroy(prov);
13895 
13896                 mutex_enter(&dtrace_lock);
13897         }
13898 
13899         return (0);
13900 }
13901 
13902 static int
13903 dtrace_helper_validate(dtrace_helper_action_t *helper)
13904 {
13905         int err = 0, i;
13906         dtrace_difo_t *dp;
13907 
13908         if ((dp = helper->dtha_predicate) != NULL)
13909                 err += dtrace_difo_validate_helper(dp);
13910 
13911         for (i = 0; i < helper->dtha_nactions; i++)
13912                 err += dtrace_difo_validate_helper(helper->dtha_actions[i]);
13913 
13914         return (err == 0);
13915 }
13916 
13917 static int
13918 dtrace_helper_action_add(int which, dtrace_ecbdesc_t *ep)
13919 {
13920         dtrace_helpers_t *help;
13921         dtrace_helper_action_t *helper, *last;
13922         dtrace_actdesc_t *act;
13923         dtrace_vstate_t *vstate;
13924         dtrace_predicate_t *pred;
13925         int count = 0, nactions = 0, i;
13926 
13927         if (which < 0 || which >= DTRACE_NHELPER_ACTIONS)
13928                 return (EINVAL);
13929 
13930         help = curproc->p_dtrace_helpers;
13931         last = help->dthps_actions[which];
13932         vstate = &help->dthps_vstate;
13933 
13934         for (count = 0; last != NULL; last = last->dtha_next) {
13935                 count++;
13936                 if (last->dtha_next == NULL)
13937                         break;
13938         }
13939 
13940         /*
13941          * If we already have dtrace_helper_actions_max helper actions for this
13942          * helper action type, we'll refuse to add a new one.
13943          */
13944         if (count >= dtrace_helper_actions_max)
13945                 return (ENOSPC);
13946 
13947         helper = kmem_zalloc(sizeof (dtrace_helper_action_t), KM_SLEEP);
13948         helper->dtha_generation = help->dthps_generation;
13949 
13950         if ((pred = ep->dted_pred.dtpdd_predicate) != NULL) {
13951                 ASSERT(pred->dtp_difo != NULL);
13952                 dtrace_difo_hold(pred->dtp_difo);
13953                 helper->dtha_predicate = pred->dtp_difo;
13954         }
13955 
13956         for (act = ep->dted_action; act != NULL; act = act->dtad_next) {
13957                 if (act->dtad_kind != DTRACEACT_DIFEXPR)
13958                         goto err;
13959 
13960                 if (act->dtad_difo == NULL)
13961                         goto err;
13962 
13963                 nactions++;
13964         }
13965 
13966         helper->dtha_actions = kmem_zalloc(sizeof (dtrace_difo_t *) *
13967             (helper->dtha_nactions = nactions), KM_SLEEP);
13968 
13969         for (act = ep->dted_action, i = 0; act != NULL; act = act->dtad_next) {
13970                 dtrace_difo_hold(act->dtad_difo);
13971                 helper->dtha_actions[i++] = act->dtad_difo;
13972         }
13973 
13974         if (!dtrace_helper_validate(helper))
13975                 goto err;
13976 
13977         if (last == NULL) {
13978                 help->dthps_actions[which] = helper;
13979         } else {
13980                 last->dtha_next = helper;
13981         }
13982 
13983         if (vstate->dtvs_nlocals > dtrace_helptrace_nlocals) {
13984                 dtrace_helptrace_nlocals = vstate->dtvs_nlocals;
13985                 dtrace_helptrace_next = 0;
13986         }
13987 
13988         return (0);
13989 err:
13990         dtrace_helper_action_destroy(helper, vstate);
13991         return (EINVAL);
13992 }
13993 
13994 static void
13995 dtrace_helper_provider_register(proc_t *p, dtrace_helpers_t *help,
13996     dof_helper_t *dofhp)
13997 {
13998         ASSERT(MUTEX_NOT_HELD(&dtrace_lock));
13999 
14000         mutex_enter(&dtrace_meta_lock);
14001         mutex_enter(&dtrace_lock);
14002 
14003         if (!dtrace_attached() || dtrace_meta_pid == NULL) {
14004                 /*
14005                  * If the dtrace module is loaded but not attached, or if
14006                  * there aren't isn't a meta provider registered to deal with
14007                  * these provider descriptions, we need to postpone creating
14008                  * the actual providers until later.
14009                  */
14010 
14011                 if (help->dthps_next == NULL && help->dthps_prev == NULL &&
14012                     dtrace_deferred_pid != help) {
14013                         help->dthps_deferred = 1;
14014                         help->dthps_pid = p->p_pid;
14015                         help->dthps_next = dtrace_deferred_pid;
14016                         help->dthps_prev = NULL;
14017                         if (dtrace_deferred_pid != NULL)
14018                                 dtrace_deferred_pid->dthps_prev = help;
14019                         dtrace_deferred_pid = help;
14020                 }
14021 
14022                 mutex_exit(&dtrace_lock);
14023 
14024         } else if (dofhp != NULL) {
14025                 /*
14026                  * If the dtrace module is loaded and we have a particular
14027                  * helper provider description, pass that off to the
14028                  * meta provider.
14029                  */
14030 
14031                 mutex_exit(&dtrace_lock);
14032 
14033                 dtrace_helper_provide(dofhp, p->p_pid);
14034 
14035         } else {
14036                 /*
14037                  * Otherwise, just pass all the helper provider descriptions
14038                  * off to the meta provider.
14039                  */
14040 
14041                 int i;
14042                 mutex_exit(&dtrace_lock);
14043 
14044                 for (i = 0; i < help->dthps_nprovs; i++) {
14045                         dtrace_helper_provide(&help->dthps_provs[i]->dthp_prov,
14046                             p->p_pid);
14047                 }
14048         }
14049 
14050         mutex_exit(&dtrace_meta_lock);
14051 }
14052 
14053 static int
14054 dtrace_helper_provider_add(dof_helper_t *dofhp, int gen)
14055 {
14056         dtrace_helpers_t *help;
14057         dtrace_helper_provider_t *hprov, **tmp_provs;
14058         uint_t tmp_maxprovs, i;
14059 
14060         ASSERT(MUTEX_HELD(&dtrace_lock));
14061 
14062         help = curproc->p_dtrace_helpers;
14063         ASSERT(help != NULL);
14064 
14065         /*
14066          * If we already have dtrace_helper_providers_max helper providers,
14067          * we're refuse to add a new one.
14068          */
14069         if (help->dthps_nprovs >= dtrace_helper_providers_max)
14070                 return (ENOSPC);
14071 
14072         /*
14073          * Check to make sure this isn't a duplicate.
14074          */
14075         for (i = 0; i < help->dthps_nprovs; i++) {
14076                 if (dofhp->dofhp_addr ==
14077                     help->dthps_provs[i]->dthp_prov.dofhp_addr)
14078                         return (EALREADY);
14079         }
14080 
14081         hprov = kmem_zalloc(sizeof (dtrace_helper_provider_t), KM_SLEEP);
14082         hprov->dthp_prov = *dofhp;
14083         hprov->dthp_ref = 1;
14084         hprov->dthp_generation = gen;
14085 
14086         /*
14087          * Allocate a bigger table for helper providers if it's already full.
14088          */
14089         if (help->dthps_maxprovs == help->dthps_nprovs) {
14090                 tmp_maxprovs = help->dthps_maxprovs;
14091                 tmp_provs = help->dthps_provs;
14092 
14093                 if (help->dthps_maxprovs == 0)
14094                         help->dthps_maxprovs = 2;
14095                 else
14096                         help->dthps_maxprovs *= 2;
14097                 if (help->dthps_maxprovs > dtrace_helper_providers_max)
14098                         help->dthps_maxprovs = dtrace_helper_providers_max;
14099 
14100                 ASSERT(tmp_maxprovs < help->dthps_maxprovs);
14101 
14102                 help->dthps_provs = kmem_zalloc(help->dthps_maxprovs *
14103                     sizeof (dtrace_helper_provider_t *), KM_SLEEP);
14104 
14105                 if (tmp_provs != NULL) {
14106                         bcopy(tmp_provs, help->dthps_provs, tmp_maxprovs *
14107                             sizeof (dtrace_helper_provider_t *));
14108                         kmem_free(tmp_provs, tmp_maxprovs *
14109                             sizeof (dtrace_helper_provider_t *));
14110                 }
14111         }
14112 
14113         help->dthps_provs[help->dthps_nprovs] = hprov;
14114         help->dthps_nprovs++;
14115 
14116         return (0);
14117 }
14118 
14119 static void
14120 dtrace_helper_provider_destroy(dtrace_helper_provider_t *hprov)
14121 {
14122         mutex_enter(&dtrace_lock);
14123 
14124         if (--hprov->dthp_ref == 0) {
14125                 dof_hdr_t *dof;
14126                 mutex_exit(&dtrace_lock);
14127                 dof = (dof_hdr_t *)(uintptr_t)hprov->dthp_prov.dofhp_dof;
14128                 dtrace_dof_destroy(dof);
14129                 kmem_free(hprov, sizeof (dtrace_helper_provider_t));
14130         } else {
14131                 mutex_exit(&dtrace_lock);
14132         }
14133 }
14134 
14135 static int
14136 dtrace_helper_provider_validate(dof_hdr_t *dof, dof_sec_t *sec)
14137 {
14138         uintptr_t daddr = (uintptr_t)dof;
14139         dof_sec_t *str_sec, *prb_sec, *arg_sec, *off_sec, *enoff_sec;
14140         dof_provider_t *provider;
14141         dof_probe_t *probe;
14142         uint8_t *arg;
14143         char *strtab, *typestr;
14144         dof_stridx_t typeidx;
14145         size_t typesz;
14146         uint_t nprobes, j, k;
14147 
14148         ASSERT(sec->dofs_type == DOF_SECT_PROVIDER);
14149 
14150         if (sec->dofs_offset & (sizeof (uint_t) - 1)) {
14151                 dtrace_dof_error(dof, "misaligned section offset");
14152                 return (-1);
14153         }
14154 
14155         /*
14156          * The section needs to be large enough to contain the DOF provider
14157          * structure appropriate for the given version.
14158          */
14159         if (sec->dofs_size <
14160             ((dof->dofh_ident[DOF_ID_VERSION] == DOF_VERSION_1) ?
14161             offsetof(dof_provider_t, dofpv_prenoffs) :
14162             sizeof (dof_provider_t))) {
14163                 dtrace_dof_error(dof, "provider section too small");
14164                 return (-1);
14165         }
14166 
14167         provider = (dof_provider_t *)(uintptr_t)(daddr + sec->dofs_offset);
14168         str_sec = dtrace_dof_sect(dof, DOF_SECT_STRTAB, provider->dofpv_strtab);
14169         prb_sec = dtrace_dof_sect(dof, DOF_SECT_PROBES, provider->dofpv_probes);
14170         arg_sec = dtrace_dof_sect(dof, DOF_SECT_PRARGS, provider->dofpv_prargs);
14171         off_sec = dtrace_dof_sect(dof, DOF_SECT_PROFFS, provider->dofpv_proffs);
14172 
14173         if (str_sec == NULL || prb_sec == NULL ||
14174             arg_sec == NULL || off_sec == NULL)
14175                 return (-1);
14176 
14177         enoff_sec = NULL;
14178 
14179         if (dof->dofh_ident[DOF_ID_VERSION] != DOF_VERSION_1 &&
14180             provider->dofpv_prenoffs != DOF_SECT_NONE &&
14181             (enoff_sec = dtrace_dof_sect(dof, DOF_SECT_PRENOFFS,
14182             provider->dofpv_prenoffs)) == NULL)
14183                 return (-1);
14184 
14185         strtab = (char *)(uintptr_t)(daddr + str_sec->dofs_offset);
14186 
14187         if (provider->dofpv_name >= str_sec->dofs_size ||
14188             strlen(strtab + provider->dofpv_name) >= DTRACE_PROVNAMELEN) {
14189                 dtrace_dof_error(dof, "invalid provider name");
14190                 return (-1);
14191         }
14192 
14193         if (prb_sec->dofs_entsize == 0 ||
14194             prb_sec->dofs_entsize > prb_sec->dofs_size) {
14195                 dtrace_dof_error(dof, "invalid entry size");
14196                 return (-1);
14197         }
14198 
14199         if (prb_sec->dofs_entsize & (sizeof (uintptr_t) - 1)) {
14200                 dtrace_dof_error(dof, "misaligned entry size");
14201                 return (-1);
14202         }
14203 
14204         if (off_sec->dofs_entsize != sizeof (uint32_t)) {
14205                 dtrace_dof_error(dof, "invalid entry size");
14206                 return (-1);
14207         }
14208 
14209         if (off_sec->dofs_offset & (sizeof (uint32_t) - 1)) {
14210                 dtrace_dof_error(dof, "misaligned section offset");
14211                 return (-1);
14212         }
14213 
14214         if (arg_sec->dofs_entsize != sizeof (uint8_t)) {
14215                 dtrace_dof_error(dof, "invalid entry size");
14216                 return (-1);
14217         }
14218 
14219         arg = (uint8_t *)(uintptr_t)(daddr + arg_sec->dofs_offset);
14220 
14221         nprobes = prb_sec->dofs_size / prb_sec->dofs_entsize;
14222 
14223         /*
14224          * Take a pass through the probes to check for errors.
14225          */
14226         for (j = 0; j < nprobes; j++) {
14227                 probe = (dof_probe_t *)(uintptr_t)(daddr +
14228                     prb_sec->dofs_offset + j * prb_sec->dofs_entsize);
14229 
14230                 if (probe->dofpr_func >= str_sec->dofs_size) {
14231                         dtrace_dof_error(dof, "invalid function name");
14232                         return (-1);
14233                 }
14234 
14235                 if (strlen(strtab + probe->dofpr_func) >= DTRACE_FUNCNAMELEN) {
14236                         dtrace_dof_error(dof, "function name too long");
14237                         return (-1);
14238                 }
14239 
14240                 if (probe->dofpr_name >= str_sec->dofs_size ||
14241                     strlen(strtab + probe->dofpr_name) >= DTRACE_NAMELEN) {
14242                         dtrace_dof_error(dof, "invalid probe name");
14243                         return (-1);
14244                 }
14245 
14246                 /*
14247                  * The offset count must not wrap the index, and the offsets
14248                  * must also not overflow the section's data.
14249                  */
14250                 if (probe->dofpr_offidx + probe->dofpr_noffs <
14251                     probe->dofpr_offidx ||
14252                     (probe->dofpr_offidx + probe->dofpr_noffs) *
14253                     off_sec->dofs_entsize > off_sec->dofs_size) {
14254                         dtrace_dof_error(dof, "invalid probe offset");
14255                         return (-1);
14256                 }
14257 
14258                 if (dof->dofh_ident[DOF_ID_VERSION] != DOF_VERSION_1) {
14259                         /*
14260                          * If there's no is-enabled offset section, make sure
14261                          * there aren't any is-enabled offsets. Otherwise
14262                          * perform the same checks as for probe offsets
14263                          * (immediately above).
14264                          */
14265                         if (enoff_sec == NULL) {
14266                                 if (probe->dofpr_enoffidx != 0 ||
14267                                     probe->dofpr_nenoffs != 0) {
14268                                         dtrace_dof_error(dof, "is-enabled "
14269                                             "offsets with null section");
14270                                         return (-1);
14271                                 }
14272                         } else if (probe->dofpr_enoffidx +
14273                             probe->dofpr_nenoffs < probe->dofpr_enoffidx ||
14274                             (probe->dofpr_enoffidx + probe->dofpr_nenoffs) *
14275                             enoff_sec->dofs_entsize > enoff_sec->dofs_size) {
14276                                 dtrace_dof_error(dof, "invalid is-enabled "
14277                                     "offset");
14278                                 return (-1);
14279                         }
14280 
14281                         if (probe->dofpr_noffs + probe->dofpr_nenoffs == 0) {
14282                                 dtrace_dof_error(dof, "zero probe and "
14283                                     "is-enabled offsets");
14284                                 return (-1);
14285                         }
14286                 } else if (probe->dofpr_noffs == 0) {
14287                         dtrace_dof_error(dof, "zero probe offsets");
14288                         return (-1);
14289                 }
14290 
14291                 if (probe->dofpr_argidx + probe->dofpr_xargc <
14292                     probe->dofpr_argidx ||
14293                     (probe->dofpr_argidx + probe->dofpr_xargc) *
14294                     arg_sec->dofs_entsize > arg_sec->dofs_size) {
14295                         dtrace_dof_error(dof, "invalid args");
14296                         return (-1);
14297                 }
14298 
14299                 typeidx = probe->dofpr_nargv;
14300                 typestr = strtab + probe->dofpr_nargv;
14301                 for (k = 0; k < probe->dofpr_nargc; k++) {
14302                         if (typeidx >= str_sec->dofs_size) {
14303                                 dtrace_dof_error(dof, "bad "
14304                                     "native argument type");
14305                                 return (-1);
14306                         }
14307 
14308                         typesz = strlen(typestr) + 1;
14309                         if (typesz > DTRACE_ARGTYPELEN) {
14310                                 dtrace_dof_error(dof, "native "
14311                                     "argument type too long");
14312                                 return (-1);
14313                         }
14314                         typeidx += typesz;
14315                         typestr += typesz;
14316                 }
14317 
14318                 typeidx = probe->dofpr_xargv;
14319                 typestr = strtab + probe->dofpr_xargv;
14320                 for (k = 0; k < probe->dofpr_xargc; k++) {
14321                         if (arg[probe->dofpr_argidx + k] > probe->dofpr_nargc) {
14322                                 dtrace_dof_error(dof, "bad "
14323                                     "native argument index");
14324                                 return (-1);
14325                         }
14326 
14327                         if (typeidx >= str_sec->dofs_size) {
14328                                 dtrace_dof_error(dof, "bad "
14329                                     "translated argument type");
14330                                 return (-1);
14331                         }
14332 
14333                         typesz = strlen(typestr) + 1;
14334                         if (typesz > DTRACE_ARGTYPELEN) {
14335                                 dtrace_dof_error(dof, "translated argument "
14336                                     "type too long");
14337                                 return (-1);
14338                         }
14339 
14340                         typeidx += typesz;
14341                         typestr += typesz;
14342                 }
14343         }
14344 
14345         return (0);
14346 }
14347 
14348 static int
14349 dtrace_helper_slurp(dof_hdr_t *dof, dof_helper_t *dhp)
14350 {
14351         dtrace_helpers_t *help;
14352         dtrace_vstate_t *vstate;
14353         dtrace_enabling_t *enab = NULL;
14354         int i, gen, rv, nhelpers = 0, nprovs = 0, destroy = 1;
14355         uintptr_t daddr = (uintptr_t)dof;
14356 
14357         ASSERT(MUTEX_HELD(&dtrace_lock));
14358 
14359         if ((help = curproc->p_dtrace_helpers) == NULL)
14360                 help = dtrace_helpers_create(curproc);
14361 
14362         vstate = &help->dthps_vstate;
14363 
14364         if ((rv = dtrace_dof_slurp(dof, vstate, NULL, &enab,
14365             dhp != NULL ? dhp->dofhp_addr : 0, B_FALSE)) != 0) {
14366                 dtrace_dof_destroy(dof);
14367                 return (rv);
14368         }
14369 
14370         /*
14371          * Look for helper providers and validate their descriptions.
14372          */
14373         if (dhp != NULL) {
14374                 for (i = 0; i < dof->dofh_secnum; i++) {
14375                         dof_sec_t *sec = (dof_sec_t *)(uintptr_t)(daddr +
14376                             dof->dofh_secoff + i * dof->dofh_secsize);
14377 
14378                         if (sec->dofs_type != DOF_SECT_PROVIDER)
14379                                 continue;
14380 
14381                         if (dtrace_helper_provider_validate(dof, sec) != 0) {
14382                                 dtrace_enabling_destroy(enab);
14383                                 dtrace_dof_destroy(dof);
14384                                 return (-1);
14385                         }
14386 
14387                         nprovs++;
14388                 }
14389         }
14390 
14391         /*
14392          * Now we need to walk through the ECB descriptions in the enabling.
14393          */
14394         for (i = 0; i < enab->dten_ndesc; i++) {
14395                 dtrace_ecbdesc_t *ep = enab->dten_desc[i];
14396                 dtrace_probedesc_t *desc = &ep->dted_probe;
14397 
14398                 if (strcmp(desc->dtpd_provider, "dtrace") != 0)
14399                         continue;
14400 
14401                 if (strcmp(desc->dtpd_mod, "helper") != 0)
14402                         continue;
14403 
14404                 if (strcmp(desc->dtpd_func, "ustack") != 0)
14405                         continue;
14406 
14407                 if ((rv = dtrace_helper_action_add(DTRACE_HELPER_ACTION_USTACK,
14408                     ep)) != 0) {
14409                         /*
14410                          * Adding this helper action failed -- we are now going
14411                          * to rip out the entire generation and return failure.
14412                          */
14413                         (void) dtrace_helper_destroygen(help->dthps_generation);
14414                         dtrace_enabling_destroy(enab);
14415                         dtrace_dof_destroy(dof);
14416                         return (-1);
14417                 }
14418 
14419                 nhelpers++;
14420         }
14421 
14422         if (nhelpers < enab->dten_ndesc)
14423                 dtrace_dof_error(dof, "unmatched helpers");
14424 
14425         gen = help->dthps_generation++;
14426         dtrace_enabling_destroy(enab);
14427 
14428         if (dhp != NULL && nprovs > 0) {
14429                 dhp->dofhp_dof = (uint64_t)(uintptr_t)dof;
14430                 if (dtrace_helper_provider_add(dhp, gen) == 0) {
14431                         mutex_exit(&dtrace_lock);
14432                         dtrace_helper_provider_register(curproc, help, dhp);
14433                         mutex_enter(&dtrace_lock);
14434 
14435                         destroy = 0;
14436                 }
14437         }
14438 
14439         if (destroy)
14440                 dtrace_dof_destroy(dof);
14441 
14442         return (gen);
14443 }
14444 
14445 static dtrace_helpers_t *
14446 dtrace_helpers_create(proc_t *p)
14447 {
14448         dtrace_helpers_t *help;
14449 
14450         ASSERT(MUTEX_HELD(&dtrace_lock));
14451         ASSERT(p->p_dtrace_helpers == NULL);
14452 
14453         help = kmem_zalloc(sizeof (dtrace_helpers_t), KM_SLEEP);
14454         help->dthps_actions = kmem_zalloc(sizeof (dtrace_helper_action_t *) *
14455             DTRACE_NHELPER_ACTIONS, KM_SLEEP);
14456 
14457         p->p_dtrace_helpers = help;
14458         dtrace_helpers++;
14459 
14460         return (help);
14461 }
14462 
14463 static void
14464 dtrace_helpers_destroy(void)
14465 {
14466         dtrace_helpers_t *help;
14467         dtrace_vstate_t *vstate;
14468         proc_t *p = curproc;
14469         int i;
14470 
14471         mutex_enter(&dtrace_lock);
14472 
14473         ASSERT(p->p_dtrace_helpers != NULL);
14474         ASSERT(dtrace_helpers > 0);
14475 
14476         help = p->p_dtrace_helpers;
14477         vstate = &help->dthps_vstate;
14478 
14479         /*
14480          * We're now going to lose the help from this process.
14481          */
14482         p->p_dtrace_helpers = NULL;
14483         dtrace_sync();
14484 
14485         /*
14486          * Destory the helper actions.
14487          */
14488         for (i = 0; i < DTRACE_NHELPER_ACTIONS; i++) {
14489                 dtrace_helper_action_t *h, *next;
14490 
14491                 for (h = help->dthps_actions[i]; h != NULL; h = next) {
14492                         next = h->dtha_next;
14493                         dtrace_helper_action_destroy(h, vstate);
14494                         h = next;
14495                 }
14496         }
14497 
14498         mutex_exit(&dtrace_lock);
14499 
14500         /*
14501          * Destroy the helper providers.
14502          */
14503         if (help->dthps_maxprovs > 0) {
14504                 mutex_enter(&dtrace_meta_lock);
14505                 if (dtrace_meta_pid != NULL) {
14506                         ASSERT(dtrace_deferred_pid == NULL);
14507 
14508                         for (i = 0; i < help->dthps_nprovs; i++) {
14509                                 dtrace_helper_provider_remove(
14510                                     &help->dthps_provs[i]->dthp_prov, p->p_pid);
14511                         }
14512                 } else {
14513                         mutex_enter(&dtrace_lock);
14514                         ASSERT(help->dthps_deferred == 0 ||
14515                             help->dthps_next != NULL ||
14516                             help->dthps_prev != NULL ||
14517                             help == dtrace_deferred_pid);
14518 
14519                         /*
14520                          * Remove the helper from the deferred list.
14521                          */
14522                         if (help->dthps_next != NULL)
14523                                 help->dthps_next->dthps_prev = help->dthps_prev;
14524                         if (help->dthps_prev != NULL)
14525                                 help->dthps_prev->dthps_next = help->dthps_next;
14526                         if (dtrace_deferred_pid == help) {
14527                                 dtrace_deferred_pid = help->dthps_next;
14528                                 ASSERT(help->dthps_prev == NULL);
14529                         }
14530 
14531                         mutex_exit(&dtrace_lock);
14532                 }
14533 
14534                 mutex_exit(&dtrace_meta_lock);
14535 
14536                 for (i = 0; i < help->dthps_nprovs; i++) {
14537                         dtrace_helper_provider_destroy(help->dthps_provs[i]);
14538                 }
14539 
14540                 kmem_free(help->dthps_provs, help->dthps_maxprovs *
14541                     sizeof (dtrace_helper_provider_t *));
14542         }
14543 
14544         mutex_enter(&dtrace_lock);
14545 
14546         dtrace_vstate_fini(&help->dthps_vstate);
14547         kmem_free(help->dthps_actions,
14548             sizeof (dtrace_helper_action_t *) * DTRACE_NHELPER_ACTIONS);
14549         kmem_free(help, sizeof (dtrace_helpers_t));
14550 
14551         --dtrace_helpers;
14552         mutex_exit(&dtrace_lock);
14553 }
14554 
14555 static void
14556 dtrace_helpers_duplicate(proc_t *from, proc_t *to)
14557 {
14558         dtrace_helpers_t *help, *newhelp;
14559         dtrace_helper_action_t *helper, *new, *last;
14560         dtrace_difo_t *dp;
14561         dtrace_vstate_t *vstate;
14562         int i, j, sz, hasprovs = 0;
14563 
14564         mutex_enter(&dtrace_lock);
14565         ASSERT(from->p_dtrace_helpers != NULL);
14566         ASSERT(dtrace_helpers > 0);
14567 
14568         help = from->p_dtrace_helpers;
14569         newhelp = dtrace_helpers_create(to);
14570         ASSERT(to->p_dtrace_helpers != NULL);
14571 
14572         newhelp->dthps_generation = help->dthps_generation;
14573         vstate = &newhelp->dthps_vstate;
14574 
14575         /*
14576          * Duplicate the helper actions.
14577          */
14578         for (i = 0; i < DTRACE_NHELPER_ACTIONS; i++) {
14579                 if ((helper = help->dthps_actions[i]) == NULL)
14580                         continue;
14581 
14582                 for (last = NULL; helper != NULL; helper = helper->dtha_next) {
14583                         new = kmem_zalloc(sizeof (dtrace_helper_action_t),
14584                             KM_SLEEP);
14585                         new->dtha_generation = helper->dtha_generation;
14586 
14587                         if ((dp = helper->dtha_predicate) != NULL) {
14588                                 dp = dtrace_difo_duplicate(dp, vstate);
14589                                 new->dtha_predicate = dp;
14590                         }
14591 
14592                         new->dtha_nactions = helper->dtha_nactions;
14593                         sz = sizeof (dtrace_difo_t *) * new->dtha_nactions;
14594                         new->dtha_actions = kmem_alloc(sz, KM_SLEEP);
14595 
14596                         for (j = 0; j < new->dtha_nactions; j++) {
14597                                 dtrace_difo_t *dp = helper->dtha_actions[j];
14598 
14599                                 ASSERT(dp != NULL);
14600                                 dp = dtrace_difo_duplicate(dp, vstate);
14601                                 new->dtha_actions[j] = dp;
14602                         }
14603 
14604                         if (last != NULL) {
14605                                 last->dtha_next = new;
14606                         } else {
14607                                 newhelp->dthps_actions[i] = new;
14608                         }
14609 
14610                         last = new;
14611                 }
14612         }
14613 
14614         /*
14615          * Duplicate the helper providers and register them with the
14616          * DTrace framework.
14617          */
14618         if (help->dthps_nprovs > 0) {
14619                 newhelp->dthps_nprovs = help->dthps_nprovs;
14620                 newhelp->dthps_maxprovs = help->dthps_nprovs;
14621                 newhelp->dthps_provs = kmem_alloc(newhelp->dthps_nprovs *
14622                     sizeof (dtrace_helper_provider_t *), KM_SLEEP);
14623                 for (i = 0; i < newhelp->dthps_nprovs; i++) {
14624                         newhelp->dthps_provs[i] = help->dthps_provs[i];
14625                         newhelp->dthps_provs[i]->dthp_ref++;
14626                 }
14627 
14628                 hasprovs = 1;
14629         }
14630 
14631         mutex_exit(&dtrace_lock);
14632 
14633         if (hasprovs)
14634                 dtrace_helper_provider_register(to, newhelp, NULL);
14635 }
14636 
14637 /*
14638  * DTrace Hook Functions
14639  */
14640 static void
14641 dtrace_module_loaded(struct modctl *ctl)
14642 {
14643         dtrace_provider_t *prv;
14644 
14645         mutex_enter(&dtrace_provider_lock);
14646         mutex_enter(&mod_lock);
14647 
14648         ASSERT(ctl->mod_busy);
14649 
14650         /*
14651          * We're going to call each providers per-module provide operation
14652          * specifying only this module.
14653          */
14654         for (prv = dtrace_provider; prv != NULL; prv = prv->dtpv_next)
14655                 prv->dtpv_pops.dtps_provide_module(prv->dtpv_arg, ctl);
14656 
14657         mutex_exit(&mod_lock);
14658         mutex_exit(&dtrace_provider_lock);
14659 
14660         /*
14661          * If we have any retained enablings, we need to match against them.
14662          * Enabling probes requires that cpu_lock be held, and we cannot hold
14663          * cpu_lock here -- it is legal for cpu_lock to be held when loading a
14664          * module.  (In particular, this happens when loading scheduling
14665          * classes.)  So if we have any retained enablings, we need to dispatch
14666          * our task queue to do the match for us.
14667          */
14668         mutex_enter(&dtrace_lock);
14669 
14670         if (dtrace_retained == NULL) {
14671                 mutex_exit(&dtrace_lock);
14672                 return;
14673         }
14674 
14675         (void) taskq_dispatch(dtrace_taskq,
14676             (task_func_t *)dtrace_enabling_matchall, NULL, TQ_SLEEP);
14677 
14678         mutex_exit(&dtrace_lock);
14679 
14680         /*
14681          * And now, for a little heuristic sleaze:  in general, we want to
14682          * match modules as soon as they load.  However, we cannot guarantee
14683          * this, because it would lead us to the lock ordering violation
14684          * outlined above.  The common case, of course, is that cpu_lock is
14685          * _not_ held -- so we delay here for a clock tick, hoping that that's
14686          * long enough for the task queue to do its work.  If it's not, it's
14687          * not a serious problem -- it just means that the module that we
14688          * just loaded may not be immediately instrumentable.
14689          */
14690         delay(1);
14691 }
14692 
14693 static void
14694 dtrace_module_unloaded(struct modctl *ctl)
14695 {
14696         dtrace_probe_t template, *probe, *first, *next;
14697         dtrace_provider_t *prov;
14698 
14699         template.dtpr_mod = ctl->mod_modname;
14700 
14701         mutex_enter(&dtrace_provider_lock);
14702         mutex_enter(&mod_lock);
14703         mutex_enter(&dtrace_lock);
14704 
14705         if (dtrace_bymod == NULL) {
14706                 /*
14707                  * The DTrace module is loaded (obviously) but not attached;
14708                  * we don't have any work to do.
14709                  */
14710                 mutex_exit(&dtrace_provider_lock);
14711                 mutex_exit(&mod_lock);
14712                 mutex_exit(&dtrace_lock);
14713                 return;
14714         }
14715 
14716         for (probe = first = dtrace_hash_lookup(dtrace_bymod, &template);
14717             probe != NULL; probe = probe->dtpr_nextmod) {
14718                 if (probe->dtpr_ecb != NULL) {
14719                         mutex_exit(&dtrace_provider_lock);
14720                         mutex_exit(&mod_lock);
14721                         mutex_exit(&dtrace_lock);
14722 
14723                         /*
14724                          * This shouldn't _actually_ be possible -- we're
14725                          * unloading a module that has an enabled probe in it.
14726                          * (It's normally up to the provider to make sure that
14727                          * this can't happen.)  However, because dtps_enable()
14728                          * doesn't have a failure mode, there can be an
14729                          * enable/unload race.  Upshot:  we don't want to
14730                          * assert, but we're not going to disable the
14731                          * probe, either.
14732                          */
14733                         if (dtrace_err_verbose) {
14734                                 cmn_err(CE_WARN, "unloaded module '%s' had "
14735                                     "enabled probes", ctl->mod_modname);
14736                         }
14737 
14738                         return;
14739                 }
14740         }
14741 
14742         probe = first;
14743 
14744         for (first = NULL; probe != NULL; probe = next) {
14745                 ASSERT(dtrace_probes[probe->dtpr_id - 1] == probe);
14746 
14747                 dtrace_probes[probe->dtpr_id - 1] = NULL;
14748 
14749                 next = probe->dtpr_nextmod;
14750                 dtrace_hash_remove(dtrace_bymod, probe);
14751                 dtrace_hash_remove(dtrace_byfunc, probe);
14752                 dtrace_hash_remove(dtrace_byname, probe);
14753 
14754                 if (first == NULL) {
14755                         first = probe;
14756                         probe->dtpr_nextmod = NULL;
14757                 } else {
14758                         probe->dtpr_nextmod = first;
14759                         first = probe;
14760                 }
14761         }
14762 
14763         /*
14764          * We've removed all of the module's probes from the hash chains and
14765          * from the probe array.  Now issue a dtrace_sync() to be sure that
14766          * everyone has cleared out from any probe array processing.
14767          */
14768         dtrace_sync();
14769 
14770         for (probe = first; probe != NULL; probe = first) {
14771                 first = probe->dtpr_nextmod;
14772                 prov = probe->dtpr_provider;
14773                 prov->dtpv_pops.dtps_destroy(prov->dtpv_arg, probe->dtpr_id,
14774                     probe->dtpr_arg);
14775                 kmem_free(probe->dtpr_mod, strlen(probe->dtpr_mod) + 1);
14776                 kmem_free(probe->dtpr_func, strlen(probe->dtpr_func) + 1);
14777                 kmem_free(probe->dtpr_name, strlen(probe->dtpr_name) + 1);
14778                 vmem_free(dtrace_arena, (void *)(uintptr_t)probe->dtpr_id, 1);
14779                 kmem_free(probe, sizeof (dtrace_probe_t));
14780         }
14781 
14782         mutex_exit(&dtrace_lock);
14783         mutex_exit(&mod_lock);
14784         mutex_exit(&dtrace_provider_lock);
14785 }
14786 
14787 void
14788 dtrace_suspend(void)
14789 {
14790         dtrace_probe_foreach(offsetof(dtrace_pops_t, dtps_suspend));
14791 }
14792 
14793 void
14794 dtrace_resume(void)
14795 {
14796         dtrace_probe_foreach(offsetof(dtrace_pops_t, dtps_resume));
14797 }
14798 
14799 static int
14800 dtrace_cpu_setup(cpu_setup_t what, processorid_t cpu)
14801 {
14802         ASSERT(MUTEX_HELD(&cpu_lock));
14803         mutex_enter(&dtrace_lock);
14804 
14805         switch (what) {
14806         case CPU_CONFIG: {
14807                 dtrace_state_t *state;
14808                 dtrace_optval_t *opt, rs, c;
14809 
14810                 /*
14811                  * For now, we only allocate a new buffer for anonymous state.
14812                  */
14813                 if ((state = dtrace_anon.dta_state) == NULL)
14814                         break;
14815 
14816                 if (state->dts_activity != DTRACE_ACTIVITY_ACTIVE)
14817                         break;
14818 
14819                 opt = state->dts_options;
14820                 c = opt[DTRACEOPT_CPU];
14821 
14822                 if (c != DTRACE_CPUALL && c != DTRACEOPT_UNSET && c != cpu)
14823                         break;
14824 
14825                 /*
14826                  * Regardless of what the actual policy is, we're going to
14827                  * temporarily set our resize policy to be manual.  We're
14828                  * also going to temporarily set our CPU option to denote
14829                  * the newly configured CPU.
14830                  */
14831                 rs = opt[DTRACEOPT_BUFRESIZE];
14832                 opt[DTRACEOPT_BUFRESIZE] = DTRACEOPT_BUFRESIZE_MANUAL;
14833                 opt[DTRACEOPT_CPU] = (dtrace_optval_t)cpu;
14834 
14835                 (void) dtrace_state_buffers(state);
14836 
14837                 opt[DTRACEOPT_BUFRESIZE] = rs;
14838                 opt[DTRACEOPT_CPU] = c;
14839 
14840                 break;
14841         }
14842 
14843         case CPU_UNCONFIG:
14844                 /*
14845                  * We don't free the buffer in the CPU_UNCONFIG case.  (The
14846                  * buffer will be freed when the consumer exits.)
14847                  */
14848                 break;
14849 
14850         default:
14851                 break;
14852         }
14853 
14854         mutex_exit(&dtrace_lock);
14855         return (0);
14856 }
14857 
14858 static void
14859 dtrace_cpu_setup_initial(processorid_t cpu)
14860 {
14861         (void) dtrace_cpu_setup(CPU_CONFIG, cpu);
14862 }
14863 
14864 static void
14865 dtrace_toxrange_add(uintptr_t base, uintptr_t limit)
14866 {
14867         if (dtrace_toxranges >= dtrace_toxranges_max) {
14868                 int osize, nsize;
14869                 dtrace_toxrange_t *range;
14870 
14871                 osize = dtrace_toxranges_max * sizeof (dtrace_toxrange_t);
14872 
14873                 if (osize == 0) {
14874                         ASSERT(dtrace_toxrange == NULL);
14875                         ASSERT(dtrace_toxranges_max == 0);
14876                         dtrace_toxranges_max = 1;
14877                 } else {
14878                         dtrace_toxranges_max <<= 1;
14879                 }
14880 
14881                 nsize = dtrace_toxranges_max * sizeof (dtrace_toxrange_t);
14882                 range = kmem_zalloc(nsize, KM_SLEEP);
14883 
14884                 if (dtrace_toxrange != NULL) {
14885                         ASSERT(osize != 0);
14886                         bcopy(dtrace_toxrange, range, osize);
14887                         kmem_free(dtrace_toxrange, osize);
14888                 }
14889 
14890                 dtrace_toxrange = range;
14891         }
14892 
14893         ASSERT(dtrace_toxrange[dtrace_toxranges].dtt_base == NULL);
14894         ASSERT(dtrace_toxrange[dtrace_toxranges].dtt_limit == NULL);
14895 
14896         dtrace_toxrange[dtrace_toxranges].dtt_base = base;
14897         dtrace_toxrange[dtrace_toxranges].dtt_limit = limit;
14898         dtrace_toxranges++;
14899 }
14900 
14901 static void
14902 dtrace_getf_barrier()
14903 {
14904         /*
14905          * When we have unprivileged (that is, non-DTRACE_CRV_KERNEL) enablings
14906          * that contain calls to getf(), this routine will be called on every
14907          * closef() before either the underlying vnode is released or the
14908          * file_t itself is freed.  By the time we are here, it is essential
14909          * that the file_t can no longer be accessed from a call to getf()
14910          * in probe context -- that assures that a dtrace_sync() can be used
14911          * to clear out any enablings referring to the old structures.
14912          */
14913         if (curthread->t_procp->p_zone->zone_dtrace_getf != 0 ||
14914             kcred->cr_zone->zone_dtrace_getf != 0)
14915                 dtrace_sync();
14916 }
14917 
14918 /*
14919  * DTrace Driver Cookbook Functions
14920  */
14921 /*ARGSUSED*/
14922 static int
14923 dtrace_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
14924 {
14925         dtrace_provider_id_t id;
14926         dtrace_state_t *state = NULL;
14927         dtrace_enabling_t *enab;
14928 
14929         mutex_enter(&cpu_lock);
14930         mutex_enter(&dtrace_provider_lock);
14931         mutex_enter(&dtrace_lock);
14932 
14933         if (ddi_soft_state_init(&dtrace_softstate,
14934             sizeof (dtrace_state_t), 0) != 0) {
14935                 cmn_err(CE_NOTE, "/dev/dtrace failed to initialize soft state");
14936                 mutex_exit(&cpu_lock);
14937                 mutex_exit(&dtrace_provider_lock);
14938                 mutex_exit(&dtrace_lock);
14939                 return (DDI_FAILURE);
14940         }
14941 
14942         if (ddi_create_minor_node(devi, DTRACEMNR_DTRACE, S_IFCHR,
14943             DTRACEMNRN_DTRACE, DDI_PSEUDO, NULL) == DDI_FAILURE ||
14944             ddi_create_minor_node(devi, DTRACEMNR_HELPER, S_IFCHR,
14945             DTRACEMNRN_HELPER, DDI_PSEUDO, NULL) == DDI_FAILURE) {
14946                 cmn_err(CE_NOTE, "/dev/dtrace couldn't create minor nodes");
14947                 ddi_remove_minor_node(devi, NULL);
14948                 ddi_soft_state_fini(&dtrace_softstate);
14949                 mutex_exit(&cpu_lock);
14950                 mutex_exit(&dtrace_provider_lock);
14951                 mutex_exit(&dtrace_lock);
14952                 return (DDI_FAILURE);
14953         }
14954 
14955         ddi_report_dev(devi);
14956         dtrace_devi = devi;
14957 
14958         dtrace_modload = dtrace_module_loaded;
14959         dtrace_modunload = dtrace_module_unloaded;
14960         dtrace_cpu_init = dtrace_cpu_setup_initial;
14961         dtrace_helpers_cleanup = dtrace_helpers_destroy;
14962         dtrace_helpers_fork = dtrace_helpers_duplicate;
14963         dtrace_cpustart_init = dtrace_suspend;
14964         dtrace_cpustart_fini = dtrace_resume;
14965         dtrace_debugger_init = dtrace_suspend;
14966         dtrace_debugger_fini = dtrace_resume;
14967 
14968         register_cpu_setup_func((cpu_setup_func_t *)dtrace_cpu_setup, NULL);
14969 
14970         ASSERT(MUTEX_HELD(&cpu_lock));
14971 
14972         dtrace_arena = vmem_create("dtrace", (void *)1, UINT32_MAX, 1,
14973             NULL, NULL, NULL, 0, VM_SLEEP | VMC_IDENTIFIER);
14974         dtrace_minor = vmem_create("dtrace_minor", (void *)DTRACEMNRN_CLONE,
14975             UINT32_MAX - DTRACEMNRN_CLONE, 1, NULL, NULL, NULL, 0,
14976             VM_SLEEP | VMC_IDENTIFIER);
14977         dtrace_taskq = taskq_create("dtrace_taskq", 1, maxclsyspri,
14978             1, INT_MAX, 0);
14979 
14980         dtrace_state_cache = kmem_cache_create("dtrace_state_cache",
14981             sizeof (dtrace_dstate_percpu_t) * NCPU, DTRACE_STATE_ALIGN,
14982             NULL, NULL, NULL, NULL, NULL, 0);
14983 
14984         ASSERT(MUTEX_HELD(&cpu_lock));
14985         dtrace_bymod = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_mod),
14986             offsetof(dtrace_probe_t, dtpr_nextmod),
14987             offsetof(dtrace_probe_t, dtpr_prevmod));
14988 
14989         dtrace_byfunc = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_func),
14990             offsetof(dtrace_probe_t, dtpr_nextfunc),
14991             offsetof(dtrace_probe_t, dtpr_prevfunc));
14992 
14993         dtrace_byname = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_name),
14994             offsetof(dtrace_probe_t, dtpr_nextname),
14995             offsetof(dtrace_probe_t, dtpr_prevname));
14996 
14997         if (dtrace_retain_max < 1) {
14998                 cmn_err(CE_WARN, "illegal value (%lu) for dtrace_retain_max; "
14999                     "setting to 1", dtrace_retain_max);
15000                 dtrace_retain_max = 1;
15001         }
15002 
15003         /*
15004          * Now discover our toxic ranges.
15005          */
15006         dtrace_toxic_ranges(dtrace_toxrange_add);
15007 
15008         /*
15009          * Before we register ourselves as a provider to our own framework,
15010          * we would like to assert that dtrace_provider is NULL -- but that's
15011          * not true if we were loaded as a dependency of a DTrace provider.
15012          * Once we've registered, we can assert that dtrace_provider is our
15013          * pseudo provider.
15014          */
15015         (void) dtrace_register("dtrace", &dtrace_provider_attr,
15016             DTRACE_PRIV_NONE, 0, &dtrace_provider_ops, NULL, &id);
15017 
15018         ASSERT(dtrace_provider != NULL);
15019         ASSERT((dtrace_provider_id_t)dtrace_provider == id);
15020 
15021         dtrace_probeid_begin = dtrace_probe_create((dtrace_provider_id_t)
15022             dtrace_provider, NULL, NULL, "BEGIN", 0, NULL);
15023         dtrace_probeid_end = dtrace_probe_create((dtrace_provider_id_t)
15024             dtrace_provider, NULL, NULL, "END", 0, NULL);
15025         dtrace_probeid_error = dtrace_probe_create((dtrace_provider_id_t)
15026             dtrace_provider, NULL, NULL, "ERROR", 1, NULL);
15027 
15028         dtrace_anon_property();
15029         mutex_exit(&cpu_lock);
15030 
15031         /*
15032          * If DTrace helper tracing is enabled, we need to allocate the
15033          * trace buffer and initialize the values.
15034          */
15035         if (dtrace_helptrace_enabled) {
15036                 ASSERT(dtrace_helptrace_buffer == NULL);
15037                 dtrace_helptrace_buffer =
15038                     kmem_zalloc(dtrace_helptrace_bufsize, KM_SLEEP);
15039                 dtrace_helptrace_next = 0;
15040         }
15041 
15042         /*
15043          * If there are already providers, we must ask them to provide their
15044          * probes, and then match any anonymous enabling against them.  Note
15045          * that there should be no other retained enablings at this time:
15046          * the only retained enablings at this time should be the anonymous
15047          * enabling.
15048          */
15049         if (dtrace_anon.dta_enabling != NULL) {
15050                 ASSERT(dtrace_retained == dtrace_anon.dta_enabling);
15051 
15052                 dtrace_enabling_provide(NULL);
15053                 state = dtrace_anon.dta_state;
15054 
15055                 /*
15056                  * We couldn't hold cpu_lock across the above call to
15057                  * dtrace_enabling_provide(), but we must hold it to actually
15058                  * enable the probes.  We have to drop all of our locks, pick
15059                  * up cpu_lock, and regain our locks before matching the
15060                  * retained anonymous enabling.
15061                  */
15062                 mutex_exit(&dtrace_lock);
15063                 mutex_exit(&dtrace_provider_lock);
15064 
15065                 mutex_enter(&cpu_lock);
15066                 mutex_enter(&dtrace_provider_lock);
15067                 mutex_enter(&dtrace_lock);
15068 
15069                 if ((enab = dtrace_anon.dta_enabling) != NULL)
15070                         (void) dtrace_enabling_match(enab, NULL);
15071 
15072                 mutex_exit(&cpu_lock);
15073         }
15074 
15075         mutex_exit(&dtrace_lock);
15076         mutex_exit(&dtrace_provider_lock);
15077 
15078         if (state != NULL) {
15079                 /*
15080                  * If we created any anonymous state, set it going now.
15081                  */
15082                 (void) dtrace_state_go(state, &dtrace_anon.dta_beganon);
15083         }
15084 
15085         return (DDI_SUCCESS);
15086 }
15087 
15088 /*ARGSUSED*/
15089 static int
15090 dtrace_open(dev_t *devp, int flag, int otyp, cred_t *cred_p)
15091 {
15092         dtrace_state_t *state;
15093         uint32_t priv;
15094         uid_t uid;
15095         zoneid_t zoneid;
15096 
15097         if (getminor(*devp) == DTRACEMNRN_HELPER)
15098                 return (0);
15099 
15100         /*
15101          * If this wasn't an open with the "helper" minor, then it must be
15102          * the "dtrace" minor.
15103          */
15104         if (getminor(*devp) != DTRACEMNRN_DTRACE)
15105                 return (ENXIO);
15106 
15107         /*
15108          * If no DTRACE_PRIV_* bits are set in the credential, then the
15109          * caller lacks sufficient permission to do anything with DTrace.
15110          */
15111         dtrace_cred2priv(cred_p, &priv, &uid, &zoneid);
15112         if (priv == DTRACE_PRIV_NONE)
15113                 return (EACCES);
15114 
15115         /*
15116          * Ask all providers to provide all their probes.
15117          */
15118         mutex_enter(&dtrace_provider_lock);
15119         dtrace_probe_provide(NULL, NULL);
15120         mutex_exit(&dtrace_provider_lock);
15121 
15122         mutex_enter(&cpu_lock);
15123         mutex_enter(&dtrace_lock);
15124         dtrace_opens++;
15125         dtrace_membar_producer();
15126 
15127         /*
15128          * If the kernel debugger is active (that is, if the kernel debugger
15129          * modified text in some way), we won't allow the open.
15130          */
15131         if (kdi_dtrace_set(KDI_DTSET_DTRACE_ACTIVATE) != 0) {
15132                 dtrace_opens--;
15133                 mutex_exit(&cpu_lock);
15134                 mutex_exit(&dtrace_lock);
15135                 return (EBUSY);
15136         }
15137 
15138         state = dtrace_state_create(devp, cred_p);
15139         mutex_exit(&cpu_lock);
15140 
15141         if (state == NULL) {
15142                 if (--dtrace_opens == 0 && dtrace_anon.dta_enabling == NULL)
15143                         (void) kdi_dtrace_set(KDI_DTSET_DTRACE_DEACTIVATE);
15144                 mutex_exit(&dtrace_lock);
15145                 return (EAGAIN);
15146         }
15147 
15148         mutex_exit(&dtrace_lock);
15149 
15150         return (0);
15151 }
15152 
15153 /*ARGSUSED*/
15154 static int
15155 dtrace_close(dev_t dev, int flag, int otyp, cred_t *cred_p)
15156 {
15157         minor_t minor = getminor(dev);
15158         dtrace_state_t *state;
15159 
15160         if (minor == DTRACEMNRN_HELPER)
15161                 return (0);
15162 
15163         state = ddi_get_soft_state(dtrace_softstate, minor);
15164 
15165         mutex_enter(&cpu_lock);
15166         mutex_enter(&dtrace_lock);
15167 
15168         if (state->dts_anon) {
15169                 /*
15170                  * There is anonymous state. Destroy that first.
15171                  */
15172                 ASSERT(dtrace_anon.dta_state == NULL);
15173                 dtrace_state_destroy(state->dts_anon);
15174         }
15175 
15176         dtrace_state_destroy(state);
15177         ASSERT(dtrace_opens > 0);
15178 
15179         /*
15180          * Only relinquish control of the kernel debugger interface when there
15181          * are no consumers and no anonymous enablings.
15182          */
15183         if (--dtrace_opens == 0 && dtrace_anon.dta_enabling == NULL)
15184                 (void) kdi_dtrace_set(KDI_DTSET_DTRACE_DEACTIVATE);
15185 
15186         mutex_exit(&dtrace_lock);
15187         mutex_exit(&cpu_lock);
15188 
15189         return (0);
15190 }
15191 
15192 /*ARGSUSED*/
15193 static int
15194 dtrace_ioctl_helper(int cmd, intptr_t arg, int *rv)
15195 {
15196         int rval;
15197         dof_helper_t help, *dhp = NULL;
15198 
15199         switch (cmd) {
15200         case DTRACEHIOC_ADDDOF:
15201                 if (copyin((void *)arg, &help, sizeof (help)) != 0) {
15202                         dtrace_dof_error(NULL, "failed to copyin DOF helper");
15203                         return (EFAULT);
15204                 }
15205 
15206                 dhp = &help;
15207                 arg = (intptr_t)help.dofhp_dof;
15208                 /*FALLTHROUGH*/
15209 
15210         case DTRACEHIOC_ADD: {
15211                 dof_hdr_t *dof = dtrace_dof_copyin(arg, &rval);
15212 
15213                 if (dof == NULL)
15214                         return (rval);
15215 
15216                 mutex_enter(&dtrace_lock);
15217 
15218                 /*
15219                  * dtrace_helper_slurp() takes responsibility for the dof --
15220                  * it may free it now or it may save it and free it later.
15221                  */
15222                 if ((rval = dtrace_helper_slurp(dof, dhp)) != -1) {
15223                         *rv = rval;
15224                         rval = 0;
15225                 } else {
15226                         rval = EINVAL;
15227                 }
15228 
15229                 mutex_exit(&dtrace_lock);
15230                 return (rval);
15231         }
15232 
15233         case DTRACEHIOC_REMOVE: {
15234                 mutex_enter(&dtrace_lock);
15235                 rval = dtrace_helper_destroygen(arg);
15236                 mutex_exit(&dtrace_lock);
15237 
15238                 return (rval);
15239         }
15240 
15241         default:
15242                 break;
15243         }
15244 
15245         return (ENOTTY);
15246 }
15247 
15248 /*ARGSUSED*/
15249 static int
15250 dtrace_ioctl(dev_t dev, int cmd, intptr_t arg, int md, cred_t *cr, int *rv)
15251 {
15252         minor_t minor = getminor(dev);
15253         dtrace_state_t *state;
15254         int rval;
15255 
15256         if (minor == DTRACEMNRN_HELPER)
15257                 return (dtrace_ioctl_helper(cmd, arg, rv));
15258 
15259         state = ddi_get_soft_state(dtrace_softstate, minor);
15260 
15261         if (state->dts_anon) {
15262                 ASSERT(dtrace_anon.dta_state == NULL);
15263                 state = state->dts_anon;
15264         }
15265 
15266         switch (cmd) {
15267         case DTRACEIOC_PROVIDER: {
15268                 dtrace_providerdesc_t pvd;
15269                 dtrace_provider_t *pvp;
15270 
15271                 if (copyin((void *)arg, &pvd, sizeof (pvd)) != 0)
15272                         return (EFAULT);
15273 
15274                 pvd.dtvd_name[DTRACE_PROVNAMELEN - 1] = '\0';
15275                 mutex_enter(&dtrace_provider_lock);
15276 
15277                 for (pvp = dtrace_provider; pvp != NULL; pvp = pvp->dtpv_next) {
15278                         if (strcmp(pvp->dtpv_name, pvd.dtvd_name) == 0)
15279                                 break;
15280                 }
15281 
15282                 mutex_exit(&dtrace_provider_lock);
15283 
15284                 if (pvp == NULL)
15285                         return (ESRCH);
15286 
15287                 bcopy(&pvp->dtpv_priv, &pvd.dtvd_priv, sizeof (dtrace_ppriv_t));
15288                 bcopy(&pvp->dtpv_attr, &pvd.dtvd_attr, sizeof (dtrace_pattr_t));
15289                 if (copyout(&pvd, (void *)arg, sizeof (pvd)) != 0)
15290                         return (EFAULT);
15291 
15292                 return (0);
15293         }
15294 
15295         case DTRACEIOC_EPROBE: {
15296                 dtrace_eprobedesc_t epdesc;
15297                 dtrace_ecb_t *ecb;
15298                 dtrace_action_t *act;
15299                 void *buf;
15300                 size_t size;
15301                 uintptr_t dest;
15302                 int nrecs;
15303 
15304                 if (copyin((void *)arg, &epdesc, sizeof (epdesc)) != 0)
15305                         return (EFAULT);
15306 
15307                 mutex_enter(&dtrace_lock);
15308 
15309                 if ((ecb = dtrace_epid2ecb(state, epdesc.dtepd_epid)) == NULL) {
15310                         mutex_exit(&dtrace_lock);
15311                         return (EINVAL);
15312                 }
15313 
15314                 if (ecb->dte_probe == NULL) {
15315                         mutex_exit(&dtrace_lock);
15316                         return (EINVAL);
15317                 }
15318 
15319                 epdesc.dtepd_probeid = ecb->dte_probe->dtpr_id;
15320                 epdesc.dtepd_uarg = ecb->dte_uarg;
15321                 epdesc.dtepd_size = ecb->dte_size;
15322 
15323                 nrecs = epdesc.dtepd_nrecs;
15324                 epdesc.dtepd_nrecs = 0;
15325                 for (act = ecb->dte_action; act != NULL; act = act->dta_next) {
15326                         if (DTRACEACT_ISAGG(act->dta_kind) || act->dta_intuple)
15327                                 continue;
15328 
15329                         epdesc.dtepd_nrecs++;
15330                 }
15331 
15332                 /*
15333                  * Now that we have the size, we need to allocate a temporary
15334                  * buffer in which to store the complete description.  We need
15335                  * the temporary buffer to be able to drop dtrace_lock()
15336                  * across the copyout(), below.
15337                  */
15338                 size = sizeof (dtrace_eprobedesc_t) +
15339                     (epdesc.dtepd_nrecs * sizeof (dtrace_recdesc_t));
15340 
15341                 buf = kmem_alloc(size, KM_SLEEP);
15342                 dest = (uintptr_t)buf;
15343 
15344                 bcopy(&epdesc, (void *)dest, sizeof (epdesc));
15345                 dest += offsetof(dtrace_eprobedesc_t, dtepd_rec[0]);
15346 
15347                 for (act = ecb->dte_action; act != NULL; act = act->dta_next) {
15348                         if (DTRACEACT_ISAGG(act->dta_kind) || act->dta_intuple)
15349                                 continue;
15350 
15351                         if (nrecs-- == 0)
15352                                 break;
15353 
15354                         bcopy(&act->dta_rec, (void *)dest,
15355                             sizeof (dtrace_recdesc_t));
15356                         dest += sizeof (dtrace_recdesc_t);
15357                 }
15358 
15359                 mutex_exit(&dtrace_lock);
15360 
15361                 if (copyout(buf, (void *)arg, dest - (uintptr_t)buf) != 0) {
15362                         kmem_free(buf, size);
15363                         return (EFAULT);
15364                 }
15365 
15366                 kmem_free(buf, size);
15367                 return (0);
15368         }
15369 
15370         case DTRACEIOC_AGGDESC: {
15371                 dtrace_aggdesc_t aggdesc;
15372                 dtrace_action_t *act;
15373                 dtrace_aggregation_t *agg;
15374                 int nrecs;
15375                 uint32_t offs;
15376                 dtrace_recdesc_t *lrec;
15377                 void *buf;
15378                 size_t size;
15379                 uintptr_t dest;
15380 
15381                 if (copyin((void *)arg, &aggdesc, sizeof (aggdesc)) != 0)
15382                         return (EFAULT);
15383 
15384                 mutex_enter(&dtrace_lock);
15385 
15386                 if ((agg = dtrace_aggid2agg(state, aggdesc.dtagd_id)) == NULL) {
15387                         mutex_exit(&dtrace_lock);
15388                         return (EINVAL);
15389                 }
15390 
15391                 aggdesc.dtagd_epid = agg->dtag_ecb->dte_epid;
15392 
15393                 nrecs = aggdesc.dtagd_nrecs;
15394                 aggdesc.dtagd_nrecs = 0;
15395 
15396                 offs = agg->dtag_base;
15397                 lrec = &agg->dtag_action.dta_rec;
15398                 aggdesc.dtagd_size = lrec->dtrd_offset + lrec->dtrd_size - offs;
15399 
15400                 for (act = agg->dtag_first; ; act = act->dta_next) {
15401                         ASSERT(act->dta_intuple ||
15402                             DTRACEACT_ISAGG(act->dta_kind));
15403 
15404                         /*
15405                          * If this action has a record size of zero, it
15406                          * denotes an argument to the aggregating action.
15407                          * Because the presence of this record doesn't (or
15408                          * shouldn't) affect the way the data is interpreted,
15409                          * we don't copy it out to save user-level the
15410                          * confusion of dealing with a zero-length record.
15411                          */
15412                         if (act->dta_rec.dtrd_size == 0) {
15413                                 ASSERT(agg->dtag_hasarg);
15414                                 continue;
15415                         }
15416 
15417                         aggdesc.dtagd_nrecs++;
15418 
15419                         if (act == &agg->dtag_action)
15420                                 break;
15421                 }
15422 
15423                 /*
15424                  * Now that we have the size, we need to allocate a temporary
15425                  * buffer in which to store the complete description.  We need
15426                  * the temporary buffer to be able to drop dtrace_lock()
15427                  * across the copyout(), below.
15428                  */
15429                 size = sizeof (dtrace_aggdesc_t) +
15430                     (aggdesc.dtagd_nrecs * sizeof (dtrace_recdesc_t));
15431 
15432                 buf = kmem_alloc(size, KM_SLEEP);
15433                 dest = (uintptr_t)buf;
15434 
15435                 bcopy(&aggdesc, (void *)dest, sizeof (aggdesc));
15436                 dest += offsetof(dtrace_aggdesc_t, dtagd_rec[0]);
15437 
15438                 for (act = agg->dtag_first; ; act = act->dta_next) {
15439                         dtrace_recdesc_t rec = act->dta_rec;
15440 
15441                         /*
15442                          * See the comment in the above loop for why we pass
15443                          * over zero-length records.
15444                          */
15445                         if (rec.dtrd_size == 0) {
15446                                 ASSERT(agg->dtag_hasarg);
15447                                 continue;
15448                         }
15449 
15450                         if (nrecs-- == 0)
15451                                 break;
15452 
15453                         rec.dtrd_offset -= offs;
15454                         bcopy(&rec, (void *)dest, sizeof (rec));
15455                         dest += sizeof (dtrace_recdesc_t);
15456 
15457                         if (act == &agg->dtag_action)
15458                                 break;
15459                 }
15460 
15461                 mutex_exit(&dtrace_lock);
15462 
15463                 if (copyout(buf, (void *)arg, dest - (uintptr_t)buf) != 0) {
15464                         kmem_free(buf, size);
15465                         return (EFAULT);
15466                 }
15467 
15468                 kmem_free(buf, size);
15469                 return (0);
15470         }
15471 
15472         case DTRACEIOC_ENABLE: {
15473                 dof_hdr_t *dof;
15474                 dtrace_enabling_t *enab = NULL;
15475                 dtrace_vstate_t *vstate;
15476                 int err = 0;
15477 
15478                 *rv = 0;
15479 
15480                 /*
15481                  * If a NULL argument has been passed, we take this as our
15482                  * cue to reevaluate our enablings.
15483                  */
15484                 if (arg == NULL) {
15485                         dtrace_enabling_matchall();
15486 
15487                         return (0);
15488                 }
15489 
15490                 if ((dof = dtrace_dof_copyin(arg, &rval)) == NULL)
15491                         return (rval);
15492 
15493                 mutex_enter(&cpu_lock);
15494                 mutex_enter(&dtrace_lock);
15495                 vstate = &state->dts_vstate;
15496 
15497                 if (state->dts_activity != DTRACE_ACTIVITY_INACTIVE) {
15498                         mutex_exit(&dtrace_lock);
15499                         mutex_exit(&cpu_lock);
15500                         dtrace_dof_destroy(dof);
15501                         return (EBUSY);
15502                 }
15503 
15504                 if (dtrace_dof_slurp(dof, vstate, cr, &enab, 0, B_TRUE) != 0) {
15505                         mutex_exit(&dtrace_lock);
15506                         mutex_exit(&cpu_lock);
15507                         dtrace_dof_destroy(dof);
15508                         return (EINVAL);
15509                 }
15510 
15511                 if ((rval = dtrace_dof_options(dof, state)) != 0) {
15512                         dtrace_enabling_destroy(enab);
15513                         mutex_exit(&dtrace_lock);
15514                         mutex_exit(&cpu_lock);
15515                         dtrace_dof_destroy(dof);
15516                         return (rval);
15517                 }
15518 
15519                 if ((err = dtrace_enabling_match(enab, rv)) == 0) {
15520                         err = dtrace_enabling_retain(enab);
15521                 } else {
15522                         dtrace_enabling_destroy(enab);
15523                 }
15524 
15525                 mutex_exit(&cpu_lock);
15526                 mutex_exit(&dtrace_lock);
15527                 dtrace_dof_destroy(dof);
15528 
15529                 return (err);
15530         }
15531 
15532         case DTRACEIOC_REPLICATE: {
15533                 dtrace_repldesc_t desc;
15534                 dtrace_probedesc_t *match = &desc.dtrpd_match;
15535                 dtrace_probedesc_t *create = &desc.dtrpd_create;
15536                 int err;
15537 
15538                 if (copyin((void *)arg, &desc, sizeof (desc)) != 0)
15539                         return (EFAULT);
15540 
15541                 match->dtpd_provider[DTRACE_PROVNAMELEN - 1] = '\0';
15542                 match->dtpd_mod[DTRACE_MODNAMELEN - 1] = '\0';
15543                 match->dtpd_func[DTRACE_FUNCNAMELEN - 1] = '\0';
15544                 match->dtpd_name[DTRACE_NAMELEN - 1] = '\0';
15545 
15546                 create->dtpd_provider[DTRACE_PROVNAMELEN - 1] = '\0';
15547                 create->dtpd_mod[DTRACE_MODNAMELEN - 1] = '\0';
15548                 create->dtpd_func[DTRACE_FUNCNAMELEN - 1] = '\0';
15549                 create->dtpd_name[DTRACE_NAMELEN - 1] = '\0';
15550 
15551                 mutex_enter(&dtrace_lock);
15552                 err = dtrace_enabling_replicate(state, match, create);
15553                 mutex_exit(&dtrace_lock);
15554 
15555                 return (err);
15556         }
15557 
15558         case DTRACEIOC_PROBEMATCH:
15559         case DTRACEIOC_PROBES: {
15560                 dtrace_probe_t *probe = NULL;
15561                 dtrace_probedesc_t desc;
15562                 dtrace_probekey_t pkey;
15563                 dtrace_id_t i;
15564                 int m = 0;
15565                 uint32_t priv;
15566                 uid_t uid;
15567                 zoneid_t zoneid;
15568 
15569                 if (copyin((void *)arg, &desc, sizeof (desc)) != 0)
15570                         return (EFAULT);
15571 
15572                 desc.dtpd_provider[DTRACE_PROVNAMELEN - 1] = '\0';
15573                 desc.dtpd_mod[DTRACE_MODNAMELEN - 1] = '\0';
15574                 desc.dtpd_func[DTRACE_FUNCNAMELEN - 1] = '\0';
15575                 desc.dtpd_name[DTRACE_NAMELEN - 1] = '\0';
15576 
15577                 /*
15578                  * Before we attempt to match this probe, we want to give
15579                  * all providers the opportunity to provide it.
15580                  */
15581                 if (desc.dtpd_id == DTRACE_IDNONE) {
15582                         mutex_enter(&dtrace_provider_lock);
15583                         dtrace_probe_provide(&desc, NULL);
15584                         mutex_exit(&dtrace_provider_lock);
15585                         desc.dtpd_id++;
15586                 }
15587 
15588                 if (cmd == DTRACEIOC_PROBEMATCH)  {
15589                         dtrace_probekey(&desc, &pkey);
15590                         pkey.dtpk_id = DTRACE_IDNONE;
15591                 }
15592 
15593                 dtrace_cred2priv(cr, &priv, &uid, &zoneid);
15594 
15595                 mutex_enter(&dtrace_lock);
15596 
15597                 if (cmd == DTRACEIOC_PROBEMATCH) {
15598                         for (i = desc.dtpd_id; i <= dtrace_nprobes; i++) {
15599                                 if ((probe = dtrace_probes[i - 1]) != NULL &&
15600                                     (m = dtrace_match_probe(probe, &pkey,
15601                                     priv, uid, zoneid)) != 0)
15602                                         break;
15603                         }
15604 
15605                         if (m < 0) {
15606                                 mutex_exit(&dtrace_lock);
15607                                 return (EINVAL);
15608                         }
15609 
15610                 } else {
15611                         for (i = desc.dtpd_id; i <= dtrace_nprobes; i++) {
15612                                 if ((probe = dtrace_probes[i - 1]) != NULL &&
15613                                     dtrace_match_priv(probe, priv, uid, zoneid))
15614                                         break;
15615                         }
15616                 }
15617 
15618                 if (probe == NULL) {
15619                         mutex_exit(&dtrace_lock);
15620                         return (ESRCH);
15621                 }
15622 
15623                 dtrace_probe_description(probe, &desc);
15624                 mutex_exit(&dtrace_lock);
15625 
15626                 if (copyout(&desc, (void *)arg, sizeof (desc)) != 0)
15627                         return (EFAULT);
15628 
15629                 return (0);
15630         }
15631 
15632         case DTRACEIOC_PROBEARG: {
15633                 dtrace_argdesc_t desc;
15634                 dtrace_probe_t *probe;
15635                 dtrace_provider_t *prov;
15636 
15637                 if (copyin((void *)arg, &desc, sizeof (desc)) != 0)
15638                         return (EFAULT);
15639 
15640                 if (desc.dtargd_id == DTRACE_IDNONE)
15641                         return (EINVAL);
15642 
15643                 if (desc.dtargd_ndx == DTRACE_ARGNONE)
15644                         return (EINVAL);
15645 
15646                 mutex_enter(&dtrace_provider_lock);
15647                 mutex_enter(&mod_lock);
15648                 mutex_enter(&dtrace_lock);
15649 
15650                 if (desc.dtargd_id > dtrace_nprobes) {
15651                         mutex_exit(&dtrace_lock);
15652                         mutex_exit(&mod_lock);
15653                         mutex_exit(&dtrace_provider_lock);
15654                         return (EINVAL);
15655                 }
15656 
15657                 if ((probe = dtrace_probes[desc.dtargd_id - 1]) == NULL) {
15658                         mutex_exit(&dtrace_lock);
15659                         mutex_exit(&mod_lock);
15660                         mutex_exit(&dtrace_provider_lock);
15661                         return (EINVAL);
15662                 }
15663 
15664                 mutex_exit(&dtrace_lock);
15665 
15666                 prov = probe->dtpr_provider;
15667 
15668                 if (prov->dtpv_pops.dtps_getargdesc == NULL) {
15669                         /*
15670                          * There isn't any typed information for this probe.
15671                          * Set the argument number to DTRACE_ARGNONE.
15672                          */
15673                         desc.dtargd_ndx = DTRACE_ARGNONE;
15674                 } else {
15675                         desc.dtargd_native[0] = '\0';
15676                         desc.dtargd_xlate[0] = '\0';
15677                         desc.dtargd_mapping = desc.dtargd_ndx;
15678 
15679                         prov->dtpv_pops.dtps_getargdesc(prov->dtpv_arg,
15680                             probe->dtpr_id, probe->dtpr_arg, &desc);
15681                 }
15682 
15683                 mutex_exit(&mod_lock);
15684                 mutex_exit(&dtrace_provider_lock);
15685 
15686                 if (copyout(&desc, (void *)arg, sizeof (desc)) != 0)
15687                         return (EFAULT);
15688 
15689                 return (0);
15690         }
15691 
15692         case DTRACEIOC_GO: {
15693                 processorid_t cpuid;
15694                 rval = dtrace_state_go(state, &cpuid);
15695 
15696                 if (rval != 0)
15697                         return (rval);
15698 
15699                 if (copyout(&cpuid, (void *)arg, sizeof (cpuid)) != 0)
15700                         return (EFAULT);
15701 
15702                 return (0);
15703         }
15704 
15705         case DTRACEIOC_STOP: {
15706                 processorid_t cpuid;
15707 
15708                 mutex_enter(&dtrace_lock);
15709                 rval = dtrace_state_stop(state, &cpuid);
15710                 mutex_exit(&dtrace_lock);
15711 
15712                 if (rval != 0)
15713                         return (rval);
15714 
15715                 if (copyout(&cpuid, (void *)arg, sizeof (cpuid)) != 0)
15716                         return (EFAULT);
15717 
15718                 return (0);
15719         }
15720 
15721         case DTRACEIOC_DOFGET: {
15722                 dof_hdr_t hdr, *dof;
15723                 uint64_t len;
15724 
15725                 if (copyin((void *)arg, &hdr, sizeof (hdr)) != 0)
15726                         return (EFAULT);
15727 
15728                 mutex_enter(&dtrace_lock);
15729                 dof = dtrace_dof_create(state);
15730                 mutex_exit(&dtrace_lock);
15731 
15732                 len = MIN(hdr.dofh_loadsz, dof->dofh_loadsz);
15733                 rval = copyout(dof, (void *)arg, len);
15734                 dtrace_dof_destroy(dof);
15735 
15736                 return (rval == 0 ? 0 : EFAULT);
15737         }
15738 
15739         case DTRACEIOC_AGGSNAP:
15740         case DTRACEIOC_BUFSNAP: {
15741                 dtrace_bufdesc_t desc;
15742                 caddr_t cached;
15743                 dtrace_buffer_t *buf;
15744 
15745                 if (copyin((void *)arg, &desc, sizeof (desc)) != 0)
15746                         return (EFAULT);
15747 
15748                 if (desc.dtbd_cpu < 0 || desc.dtbd_cpu >= NCPU)
15749                         return (EINVAL);
15750 
15751                 mutex_enter(&dtrace_lock);
15752 
15753                 if (cmd == DTRACEIOC_BUFSNAP) {
15754                         buf = &state->dts_buffer[desc.dtbd_cpu];
15755                 } else {
15756                         buf = &state->dts_aggbuffer[desc.dtbd_cpu];
15757                 }
15758 
15759                 if (buf->dtb_flags & (DTRACEBUF_RING | DTRACEBUF_FILL)) {
15760                         size_t sz = buf->dtb_offset;
15761 
15762                         if (state->dts_activity != DTRACE_ACTIVITY_STOPPED) {
15763                                 mutex_exit(&dtrace_lock);
15764                                 return (EBUSY);
15765                         }
15766 
15767                         /*
15768                          * If this buffer has already been consumed, we're
15769                          * going to indicate that there's nothing left here
15770                          * to consume.
15771                          */
15772                         if (buf->dtb_flags & DTRACEBUF_CONSUMED) {
15773                                 mutex_exit(&dtrace_lock);
15774 
15775                                 desc.dtbd_size = 0;
15776                                 desc.dtbd_drops = 0;
15777                                 desc.dtbd_errors = 0;
15778                                 desc.dtbd_oldest = 0;
15779                                 sz = sizeof (desc);
15780 
15781                                 if (copyout(&desc, (void *)arg, sz) != 0)
15782                                         return (EFAULT);
15783 
15784                                 return (0);
15785                         }
15786 
15787                         /*
15788                          * If this is a ring buffer that has wrapped, we want
15789                          * to copy the whole thing out.
15790                          */
15791                         if (buf->dtb_flags & DTRACEBUF_WRAPPED) {
15792                                 dtrace_buffer_polish(buf);
15793                                 sz = buf->dtb_size;
15794                         }
15795 
15796                         if (copyout(buf->dtb_tomax, desc.dtbd_data, sz) != 0) {
15797                                 mutex_exit(&dtrace_lock);
15798                                 return (EFAULT);
15799                         }
15800 
15801                         desc.dtbd_size = sz;
15802                         desc.dtbd_drops = buf->dtb_drops;
15803                         desc.dtbd_errors = buf->dtb_errors;
15804                         desc.dtbd_oldest = buf->dtb_xamot_offset;
15805 
15806                         mutex_exit(&dtrace_lock);
15807 
15808                         if (copyout(&desc, (void *)arg, sizeof (desc)) != 0)
15809                                 return (EFAULT);
15810 
15811                         buf->dtb_flags |= DTRACEBUF_CONSUMED;
15812 
15813                         return (0);
15814                 }
15815 
15816                 if (buf->dtb_tomax == NULL) {
15817                         ASSERT(buf->dtb_xamot == NULL);
15818                         mutex_exit(&dtrace_lock);
15819                         return (ENOENT);
15820                 }
15821 
15822                 cached = buf->dtb_tomax;
15823                 ASSERT(!(buf->dtb_flags & DTRACEBUF_NOSWITCH));
15824 
15825                 dtrace_xcall(desc.dtbd_cpu,
15826                     (dtrace_xcall_t)dtrace_buffer_switch, buf);
15827 
15828                 state->dts_errors += buf->dtb_xamot_errors;
15829 
15830                 /*
15831                  * If the buffers did not actually switch, then the cross call
15832                  * did not take place -- presumably because the given CPU is
15833                  * not in the ready set.  If this is the case, we'll return
15834                  * ENOENT.
15835                  */
15836                 if (buf->dtb_tomax == cached) {
15837                         ASSERT(buf->dtb_xamot != cached);
15838                         mutex_exit(&dtrace_lock);
15839                         return (ENOENT);
15840                 }
15841 
15842                 ASSERT(cached == buf->dtb_xamot);
15843 
15844                 /*
15845                  * We have our snapshot; now copy it out.
15846                  */
15847                 if (copyout(buf->dtb_xamot, desc.dtbd_data,
15848                     buf->dtb_xamot_offset) != 0) {
15849                         mutex_exit(&dtrace_lock);
15850                         return (EFAULT);
15851                 }
15852 
15853                 desc.dtbd_size = buf->dtb_xamot_offset;
15854                 desc.dtbd_drops = buf->dtb_xamot_drops;
15855                 desc.dtbd_errors = buf->dtb_xamot_errors;
15856                 desc.dtbd_oldest = 0;
15857 
15858                 mutex_exit(&dtrace_lock);
15859 
15860                 /*
15861                  * Finally, copy out the buffer description.
15862                  */
15863                 if (copyout(&desc, (void *)arg, sizeof (desc)) != 0)
15864                         return (EFAULT);
15865 
15866                 return (0);
15867         }
15868 
15869         case DTRACEIOC_CONF: {
15870                 dtrace_conf_t conf;
15871 
15872                 bzero(&conf, sizeof (conf));
15873                 conf.dtc_difversion = DIF_VERSION;
15874                 conf.dtc_difintregs = DIF_DIR_NREGS;
15875                 conf.dtc_diftupregs = DIF_DTR_NREGS;
15876                 conf.dtc_ctfmodel = CTF_MODEL_NATIVE;
15877 
15878                 if (copyout(&conf, (void *)arg, sizeof (conf)) != 0)
15879                         return (EFAULT);
15880 
15881                 return (0);
15882         }
15883 
15884         case DTRACEIOC_STATUS: {
15885                 dtrace_status_t stat;
15886                 dtrace_dstate_t *dstate;
15887                 int i, j;
15888                 uint64_t nerrs;
15889 
15890                 /*
15891                  * See the comment in dtrace_state_deadman() for the reason
15892                  * for setting dts_laststatus to INT64_MAX before setting
15893                  * it to the correct value.
15894                  */
15895                 state->dts_laststatus = INT64_MAX;
15896                 dtrace_membar_producer();
15897                 state->dts_laststatus = dtrace_gethrtime();
15898 
15899                 bzero(&stat, sizeof (stat));
15900 
15901                 mutex_enter(&dtrace_lock);
15902 
15903                 if (state->dts_activity == DTRACE_ACTIVITY_INACTIVE) {
15904                         mutex_exit(&dtrace_lock);
15905                         return (ENOENT);
15906                 }
15907 
15908                 if (state->dts_activity == DTRACE_ACTIVITY_DRAINING)
15909                         stat.dtst_exiting = 1;
15910 
15911                 nerrs = state->dts_errors;
15912                 dstate = &state->dts_vstate.dtvs_dynvars;
15913 
15914                 for (i = 0; i < NCPU; i++) {
15915                         dtrace_dstate_percpu_t *dcpu = &dstate->dtds_percpu[i];
15916 
15917                         stat.dtst_dyndrops += dcpu->dtdsc_drops;
15918                         stat.dtst_dyndrops_dirty += dcpu->dtdsc_dirty_drops;
15919                         stat.dtst_dyndrops_rinsing += dcpu->dtdsc_rinsing_drops;
15920 
15921                         if (state->dts_buffer[i].dtb_flags & DTRACEBUF_FULL)
15922                                 stat.dtst_filled++;
15923 
15924                         nerrs += state->dts_buffer[i].dtb_errors;
15925 
15926                         for (j = 0; j < state->dts_nspeculations; j++) {
15927                                 dtrace_speculation_t *spec;
15928                                 dtrace_buffer_t *buf;
15929 
15930                                 spec = &state->dts_speculations[j];
15931                                 buf = &spec->dtsp_buffer[i];
15932                                 stat.dtst_specdrops += buf->dtb_xamot_drops;
15933                         }
15934                 }
15935 
15936                 stat.dtst_specdrops_busy = state->dts_speculations_busy;
15937                 stat.dtst_specdrops_unavail = state->dts_speculations_unavail;
15938                 stat.dtst_stkstroverflows = state->dts_stkstroverflows;
15939                 stat.dtst_dblerrors = state->dts_dblerrors;
15940                 stat.dtst_killed =
15941                     (state->dts_activity == DTRACE_ACTIVITY_KILLED);
15942                 stat.dtst_errors = nerrs;
15943 
15944                 mutex_exit(&dtrace_lock);
15945 
15946                 if (copyout(&stat, (void *)arg, sizeof (stat)) != 0)
15947                         return (EFAULT);
15948 
15949                 return (0);
15950         }
15951 
15952         case DTRACEIOC_FORMAT: {
15953                 dtrace_fmtdesc_t fmt;
15954                 char *str;
15955                 int len;
15956 
15957                 if (copyin((void *)arg, &fmt, sizeof (fmt)) != 0)
15958                         return (EFAULT);
15959 
15960                 mutex_enter(&dtrace_lock);
15961 
15962                 if (fmt.dtfd_format == 0 ||
15963                     fmt.dtfd_format > state->dts_nformats) {
15964                         mutex_exit(&dtrace_lock);
15965                         return (EINVAL);
15966                 }
15967 
15968                 /*
15969                  * Format strings are allocated contiguously and they are
15970                  * never freed; if a format index is less than the number
15971                  * of formats, we can assert that the format map is non-NULL
15972                  * and that the format for the specified index is non-NULL.
15973                  */
15974                 ASSERT(state->dts_formats != NULL);
15975                 str = state->dts_formats[fmt.dtfd_format - 1];
15976                 ASSERT(str != NULL);
15977 
15978                 len = strlen(str) + 1;
15979 
15980                 if (len > fmt.dtfd_length) {
15981                         fmt.dtfd_length = len;
15982 
15983                         if (copyout(&fmt, (void *)arg, sizeof (fmt)) != 0) {
15984                                 mutex_exit(&dtrace_lock);
15985                                 return (EINVAL);
15986                         }
15987                 } else {
15988                         if (copyout(str, fmt.dtfd_string, len) != 0) {
15989                                 mutex_exit(&dtrace_lock);
15990                                 return (EINVAL);
15991                         }
15992                 }
15993 
15994                 mutex_exit(&dtrace_lock);
15995                 return (0);
15996         }
15997 
15998         default:
15999                 break;
16000         }
16001 
16002         return (ENOTTY);
16003 }
16004 
16005 /*ARGSUSED*/
16006 static int
16007 dtrace_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
16008 {
16009         dtrace_state_t *state;
16010 
16011         switch (cmd) {
16012         case DDI_DETACH:
16013                 break;
16014 
16015         case DDI_SUSPEND:
16016                 return (DDI_SUCCESS);
16017 
16018         default:
16019                 return (DDI_FAILURE);
16020         }
16021 
16022         mutex_enter(&cpu_lock);
16023         mutex_enter(&dtrace_provider_lock);
16024         mutex_enter(&dtrace_lock);
16025 
16026         ASSERT(dtrace_opens == 0);
16027 
16028         if (dtrace_helpers > 0) {
16029                 mutex_exit(&dtrace_provider_lock);
16030                 mutex_exit(&dtrace_lock);
16031                 mutex_exit(&cpu_lock);
16032                 return (DDI_FAILURE);
16033         }
16034 
16035         if (dtrace_unregister((dtrace_provider_id_t)dtrace_provider) != 0) {
16036                 mutex_exit(&dtrace_provider_lock);
16037                 mutex_exit(&dtrace_lock);
16038                 mutex_exit(&cpu_lock);
16039                 return (DDI_FAILURE);
16040         }
16041 
16042         dtrace_provider = NULL;
16043 
16044         if ((state = dtrace_anon_grab()) != NULL) {
16045                 /*
16046                  * If there were ECBs on this state, the provider should
16047                  * have not been allowed to detach; assert that there is
16048                  * none.
16049                  */
16050                 ASSERT(state->dts_necbs == 0);
16051                 dtrace_state_destroy(state);
16052 
16053                 /*
16054                  * If we're being detached with anonymous state, we need to
16055                  * indicate to the kernel debugger that DTrace is now inactive.
16056                  */
16057                 (void) kdi_dtrace_set(KDI_DTSET_DTRACE_DEACTIVATE);
16058         }
16059 
16060         bzero(&dtrace_anon, sizeof (dtrace_anon_t));
16061         unregister_cpu_setup_func((cpu_setup_func_t *)dtrace_cpu_setup, NULL);
16062         dtrace_cpu_init = NULL;
16063         dtrace_helpers_cleanup = NULL;
16064         dtrace_helpers_fork = NULL;
16065         dtrace_cpustart_init = NULL;
16066         dtrace_cpustart_fini = NULL;
16067         dtrace_debugger_init = NULL;
16068         dtrace_debugger_fini = NULL;
16069         dtrace_modload = NULL;
16070         dtrace_modunload = NULL;
16071 
16072         ASSERT(dtrace_getf == 0);
16073         ASSERT(dtrace_closef == NULL);
16074 
16075         mutex_exit(&cpu_lock);
16076 
16077         if (dtrace_helptrace_enabled) {
16078                 kmem_free(dtrace_helptrace_buffer, dtrace_helptrace_bufsize);
16079                 dtrace_helptrace_buffer = NULL;
16080         }
16081 
16082         kmem_free(dtrace_probes, dtrace_nprobes * sizeof (dtrace_probe_t *));
16083         dtrace_probes = NULL;
16084         dtrace_nprobes = 0;
16085 
16086         dtrace_hash_destroy(dtrace_bymod);
16087         dtrace_hash_destroy(dtrace_byfunc);
16088         dtrace_hash_destroy(dtrace_byname);
16089         dtrace_bymod = NULL;
16090         dtrace_byfunc = NULL;
16091         dtrace_byname = NULL;
16092 
16093         kmem_cache_destroy(dtrace_state_cache);
16094         vmem_destroy(dtrace_minor);
16095         vmem_destroy(dtrace_arena);
16096 
16097         if (dtrace_toxrange != NULL) {
16098                 kmem_free(dtrace_toxrange,
16099                     dtrace_toxranges_max * sizeof (dtrace_toxrange_t));
16100                 dtrace_toxrange = NULL;
16101                 dtrace_toxranges = 0;
16102                 dtrace_toxranges_max = 0;
16103         }
16104 
16105         ddi_remove_minor_node(dtrace_devi, NULL);
16106         dtrace_devi = NULL;
16107 
16108         ddi_soft_state_fini(&dtrace_softstate);
16109 
16110         ASSERT(dtrace_vtime_references == 0);
16111         ASSERT(dtrace_opens == 0);
16112         ASSERT(dtrace_retained == NULL);
16113 
16114         mutex_exit(&dtrace_lock);
16115         mutex_exit(&dtrace_provider_lock);
16116 
16117         /*
16118          * We don't destroy the task queue until after we have dropped our
16119          * locks (taskq_destroy() may block on running tasks).  To prevent
16120          * attempting to do work after we have effectively detached but before
16121          * the task queue has been destroyed, all tasks dispatched via the
16122          * task queue must check that DTrace is still attached before
16123          * performing any operation.
16124          */
16125         taskq_destroy(dtrace_taskq);
16126         dtrace_taskq = NULL;
16127 
16128         return (DDI_SUCCESS);
16129 }
16130 
16131 /*ARGSUSED*/
16132 static int
16133 dtrace_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result)
16134 {
16135         int error;
16136 
16137         switch (infocmd) {
16138         case DDI_INFO_DEVT2DEVINFO:
16139                 *result = (void *)dtrace_devi;
16140                 error = DDI_SUCCESS;
16141                 break;
16142         case DDI_INFO_DEVT2INSTANCE:
16143                 *result = (void *)0;
16144                 error = DDI_SUCCESS;
16145                 break;
16146         default:
16147                 error = DDI_FAILURE;
16148         }
16149         return (error);
16150 }
16151 
16152 static struct cb_ops dtrace_cb_ops = {
16153         dtrace_open,            /* open */
16154         dtrace_close,           /* close */
16155         nulldev,                /* strategy */
16156         nulldev,                /* print */
16157         nodev,                  /* dump */
16158         nodev,                  /* read */
16159         nodev,                  /* write */
16160         dtrace_ioctl,           /* ioctl */
16161         nodev,                  /* devmap */
16162         nodev,                  /* mmap */
16163         nodev,                  /* segmap */
16164         nochpoll,               /* poll */
16165         ddi_prop_op,            /* cb_prop_op */
16166         0,                      /* streamtab  */
16167         D_NEW | D_MP            /* Driver compatibility flag */
16168 };
16169 
16170 static struct dev_ops dtrace_ops = {
16171         DEVO_REV,               /* devo_rev */
16172         0,                      /* refcnt */
16173         dtrace_info,            /* get_dev_info */
16174         nulldev,                /* identify */
16175         nulldev,                /* probe */
16176         dtrace_attach,          /* attach */
16177         dtrace_detach,          /* detach */
16178         nodev,                  /* reset */
16179         &dtrace_cb_ops,             /* driver operations */
16180         NULL,                   /* bus operations */
16181         nodev,                  /* dev power */
16182         ddi_quiesce_not_needed,         /* quiesce */
16183 };
16184 
16185 static struct modldrv modldrv = {
16186         &mod_driverops,             /* module type (this is a pseudo driver) */
16187         "Dynamic Tracing",      /* name of module */
16188         &dtrace_ops,                /* driver ops */
16189 };
16190 
16191 static struct modlinkage modlinkage = {
16192         MODREV_1,
16193         (void *)&modldrv,
16194         NULL
16195 };
16196 
16197 int
16198 _init(void)
16199 {
16200         return (mod_install(&modlinkage));
16201 }
16202 
16203 int
16204 _info(struct modinfo *modinfop)
16205 {
16206         return (mod_info(&modlinkage, modinfop));
16207 }
16208 
16209 int
16210 _fini(void)
16211 {
16212         return (mod_remove(&modlinkage));
16213 }