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) 1998, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Copyright 2016 Joyent, Inc.
  25  */
  26 
  27 #include <sys/types.h>
  28 #include <sys/param.h>
  29 #include <sys/systm.h>
  30 #include <sys/vm.h>
  31 #include <sys/proc.h>
  32 #include <sys/file.h>
  33 #include <sys/conf.h>
  34 #include <sys/kmem.h>
  35 #include <sys/mem.h>
  36 #include <sys/mman.h>
  37 #include <sys/vnode.h>
  38 #include <sys/errno.h>
  39 #include <sys/memlist.h>
  40 #include <sys/dumphdr.h>
  41 #include <sys/dumpadm.h>
  42 #include <sys/ksyms.h>
  43 #include <sys/compress.h>
  44 #include <sys/stream.h>
  45 #include <sys/strsun.h>
  46 #include <sys/cmn_err.h>
  47 #include <sys/bitmap.h>
  48 #include <sys/modctl.h>
  49 #include <sys/utsname.h>
  50 #include <sys/systeminfo.h>
  51 #include <sys/vmem.h>
  52 #include <sys/log.h>
  53 #include <sys/var.h>
  54 #include <sys/debug.h>
  55 #include <sys/sunddi.h>
  56 #include <fs/fs_subr.h>
  57 #include <sys/fs/snode.h>
  58 #include <sys/ontrap.h>
  59 #include <sys/panic.h>
  60 #include <sys/dkio.h>
  61 #include <sys/vtoc.h>
  62 #include <sys/errorq.h>
  63 #include <sys/fm/util.h>
  64 #include <sys/fs/zfs.h>
  65 
  66 #include <vm/hat.h>
  67 #include <vm/as.h>
  68 #include <vm/page.h>
  69 #include <vm/pvn.h>
  70 #include <vm/seg.h>
  71 #include <vm/seg_kmem.h>
  72 #include <sys/clock_impl.h>
  73 #include <sys/hold_page.h>
  74 
  75 #include <bzip2/bzlib.h>
  76 
  77 /*
  78  * Crash dump time is dominated by disk write time.  To reduce this,
  79  * the stronger compression method bzip2 is applied to reduce the dump
  80  * size and hence reduce I/O time.  However, bzip2 is much more
  81  * computationally expensive than the existing lzjb algorithm, so to
  82  * avoid increasing compression time, CPUs that are otherwise idle
  83  * during panic are employed to parallelize the compression task.
  84  * Many helper CPUs are needed to prevent bzip2 from being a
  85  * bottleneck, and on systems with too few CPUs, the lzjb algorithm is
  86  * parallelized instead. Lastly, I/O and compression are performed by
  87  * different CPUs, and are hence overlapped in time, unlike the older
  88  * serial code.
  89  *
  90  * Another important consideration is the speed of the dump
  91  * device. Faster disks need less CPUs in order to benefit from
  92  * parallel lzjb versus parallel bzip2. Therefore, the CPU count
  93  * threshold for switching from parallel lzjb to paralled bzip2 is
  94  * elevated for faster disks. The dump device speed is adduced from
  95  * the setting for dumpbuf.iosize, see dump_update_clevel.
  96  */
  97 
  98 /*
  99  * exported vars
 100  */
 101 kmutex_t        dump_lock;              /* lock for dump configuration */
 102 dumphdr_t       *dumphdr;               /* dump header */
 103 int             dump_conflags = DUMP_KERNEL; /* dump configuration flags */
 104 vnode_t         *dumpvp;                /* dump device vnode pointer */
 105 u_offset_t      dumpvp_size;            /* size of dump device, in bytes */
 106 char            *dumppath;              /* pathname of dump device */
 107 int             dump_timeout = 120;     /* timeout for dumping pages */
 108 int             dump_timeleft;          /* portion of dump_timeout remaining */
 109 int             dump_ioerr;             /* dump i/o error */
 110 int             dump_check_used;        /* enable check for used pages */
 111 char        *dump_stack_scratch; /* scratch area for saving stack summary */
 112 
 113 /*
 114  * Tunables for dump compression and parallelism. These can be set via
 115  * /etc/system.
 116  *
 117  * dump_ncpu_low        number of helpers for parallel lzjb
 118  *      This is also the minimum configuration.
 119  *
 120  * dump_bzip2_level     bzip2 compression level: 1-9
 121  *      Higher numbers give greater compression, but take more memory
 122  *      and time. Memory used per helper is ~(dump_bzip2_level * 1MB).
 123  *
 124  * dump_plat_mincpu     the cross-over limit for using bzip2 (per platform):
 125  *      if dump_plat_mincpu == 0, then always do single threaded dump
 126  *      if ncpu >= dump_plat_mincpu then try to use bzip2
 127  *
 128  * dump_metrics_on      if set, metrics are collected in the kernel, passed
 129  *      to savecore via the dump file, and recorded by savecore in
 130  *      METRICS.txt.
 131  */
 132 uint_t dump_ncpu_low = 4;       /* minimum config for parallel lzjb */
 133 uint_t dump_bzip2_level = 1;    /* bzip2 level (1-9) */
 134 
 135 /* Use dump_plat_mincpu_default unless this variable is set by /etc/system */
 136 #define MINCPU_NOT_SET  ((uint_t)-1)
 137 uint_t dump_plat_mincpu = MINCPU_NOT_SET;
 138 
 139 /* tunables for pre-reserved heap */
 140 uint_t dump_kmem_permap = 1024;
 141 uint_t dump_kmem_pages = 8;
 142 
 143 /* Define multiple buffers per helper to avoid stalling */
 144 #define NCBUF_PER_HELPER        2
 145 #define NCMAP_PER_HELPER        4
 146 
 147 /* minimum number of helpers configured */
 148 #define MINHELPERS      (dump_ncpu_low)
 149 #define MINCBUFS        (MINHELPERS * NCBUF_PER_HELPER)
 150 
 151 /*
 152  * Define constant parameters.
 153  *
 154  * CBUF_SIZE            size of an output buffer
 155  *
 156  * CBUF_MAPSIZE         size of virtual range for mapping pages
 157  *
 158  * CBUF_MAPNP           size of virtual range in pages
 159  *
 160  */
 161 #define DUMP_1KB        ((size_t)1 << 10)
 162 #define DUMP_1MB        ((size_t)1 << 20)
 163 #define CBUF_SIZE       ((size_t)1 << 17)
 164 #define CBUF_MAPSHIFT   (22)
 165 #define CBUF_MAPSIZE    ((size_t)1 << CBUF_MAPSHIFT)
 166 #define CBUF_MAPNP      ((size_t)1 << (CBUF_MAPSHIFT - PAGESHIFT))
 167 
 168 /*
 169  * Compression metrics are accumulated nano-second subtotals. The
 170  * results are normalized by the number of pages dumped. A report is
 171  * generated when dumpsys() completes and is saved in the dump image
 172  * after the trailing dump header.
 173  *
 174  * Metrics are always collected. Set the variable dump_metrics_on to
 175  * cause metrics to be saved in the crash file, where savecore will
 176  * save it in the file METRICS.txt.
 177  */
 178 #define PERPAGES \
 179         PERPAGE(bitmap) PERPAGE(map) PERPAGE(unmap) \
 180         PERPAGE(copy) PERPAGE(compress) \
 181         PERPAGE(write) \
 182         PERPAGE(inwait) PERPAGE(outwait)
 183 
 184 typedef struct perpage {
 185 #define PERPAGE(x) hrtime_t x;
 186         PERPAGES
 187 #undef PERPAGE
 188 } perpage_t;
 189 
 190 /*
 191  * This macro controls the code generation for collecting dump
 192  * performance information. By default, the code is generated, but
 193  * automatic saving of the information is disabled. If dump_metrics_on
 194  * is set to 1, the timing information is passed to savecore via the
 195  * crash file, where it is appended to the file dump-dir/METRICS.txt.
 196  */
 197 #define COLLECT_METRICS
 198 
 199 #ifdef COLLECT_METRICS
 200 uint_t dump_metrics_on = 0;     /* set to 1 to enable recording metrics */
 201 
 202 #define HRSTART(v, m)           v##ts.m = gethrtime()
 203 #define HRSTOP(v, m)            v.m += gethrtime() - v##ts.m
 204 #define HRBEGIN(v, m, s)        v##ts.m = gethrtime(); v.size += s
 205 #define HREND(v, m)             v.m += gethrtime() - v##ts.m
 206 #define HRNORM(v, m, n)         v.m /= (n)
 207 
 208 #else
 209 #define HRSTART(v, m)
 210 #define HRSTOP(v, m)
 211 #define HRBEGIN(v, m, s)
 212 #define HREND(v, m)
 213 #define HRNORM(v, m, n)
 214 #endif  /* COLLECT_METRICS */
 215 
 216 /*
 217  * Buffers for copying and compressing memory pages.
 218  *
 219  * cbuf_t buffer controllers: used for both input and output.
 220  *
 221  * The buffer state indicates how it is being used:
 222  *
 223  * CBUF_FREEMAP: CBUF_MAPSIZE virtual address range is available for
 224  * mapping input pages.
 225  *
 226  * CBUF_INREADY: input pages are mapped and ready for compression by a
 227  * helper.
 228  *
 229  * CBUF_USEDMAP: mapping has been consumed by a helper. Needs unmap.
 230  *
 231  * CBUF_FREEBUF: CBUF_SIZE output buffer, which is available.
 232  *
 233  * CBUF_WRITE: CBUF_SIZE block of compressed pages from a helper,
 234  * ready to write out.
 235  *
 236  * CBUF_ERRMSG: CBUF_SIZE block of error messages from a helper
 237  * (reports UE errors.)
 238  */
 239 
 240 typedef enum cbufstate {
 241         CBUF_FREEMAP,
 242         CBUF_INREADY,
 243         CBUF_USEDMAP,
 244         CBUF_FREEBUF,
 245         CBUF_WRITE,
 246         CBUF_ERRMSG
 247 } cbufstate_t;
 248 
 249 typedef struct cbuf cbuf_t;
 250 
 251 struct cbuf {
 252         cbuf_t *next;                   /* next in list */
 253         cbufstate_t state;              /* processing state */
 254         size_t used;                    /* amount used */
 255         size_t size;                    /* mem size */
 256         char *buf;                      /* kmem or vmem */
 257         pgcnt_t pagenum;                /* index to pfn map */
 258         pgcnt_t bitnum;                 /* first set bitnum */
 259         pfn_t pfn;                      /* first pfn in mapped range */
 260         int off;                        /* byte offset to first pfn */
 261 };
 262 
 263 static char dump_osimage_uuid[36 + 1];
 264 
 265 #define isdigit(ch)     ((ch) >= '0' && (ch) <= '9')
 266 #define isxdigit(ch)    (isdigit(ch) || ((ch) >= 'a' && (ch) <= 'f') || \
 267                         ((ch) >= 'A' && (ch) <= 'F'))
 268 
 269 /*
 270  * cqueue_t queues: a uni-directional channel for communication
 271  * from the master to helper tasks or vice-versa using put and
 272  * get primitives. Both mappings and data buffers are passed via
 273  * queues. Producers close a queue when done. The number of
 274  * active producers is reference counted so the consumer can
 275  * detect end of data. Concurrent access is mediated by atomic
 276  * operations for panic dump, or mutex/cv for live dump.
 277  *
 278  * There a four queues, used as follows:
 279  *
 280  * Queue                Dataflow                NewState
 281  * --------------------------------------------------
 282  * mainq                master -> master     FREEMAP
 283  * master has initialized or unmapped an input buffer
 284  * --------------------------------------------------
 285  * helperq              master -> helper     INREADY
 286  * master has mapped input for use by helper
 287  * --------------------------------------------------
 288  * mainq                master <- helper     USEDMAP
 289  * helper is done with input
 290  * --------------------------------------------------
 291  * freebufq             master -> helper     FREEBUF
 292  * master has initialized or written an output buffer
 293  * --------------------------------------------------
 294  * mainq                master <- helper     WRITE
 295  * block of compressed pages from a helper
 296  * --------------------------------------------------
 297  * mainq                master <- helper     ERRMSG
 298  * error messages from a helper (memory error case)
 299  * --------------------------------------------------
 300  * writerq              master <- master     WRITE
 301  * non-blocking queue of blocks to write
 302  * --------------------------------------------------
 303  */
 304 typedef struct cqueue {
 305         cbuf_t *volatile first;         /* first in list */
 306         cbuf_t *last;                   /* last in list */
 307         hrtime_t ts;                    /* timestamp */
 308         hrtime_t empty;                 /* total time empty */
 309         kmutex_t mutex;                 /* live state lock */
 310         kcondvar_t cv;                  /* live wait var */
 311         lock_t spinlock;                /* panic mode spin lock */
 312         volatile uint_t open;           /* producer ref count */
 313 } cqueue_t;
 314 
 315 /*
 316  * Convenience macros for using the cqueue functions
 317  * Note that the caller must have defined "dumpsync_t *ds"
 318  */
 319 #define CQ_IS_EMPTY(q)                                  \
 320         (ds->q.first == NULL)
 321 
 322 #define CQ_OPEN(q)                                      \
 323         atomic_inc_uint(&ds->q.open)
 324 
 325 #define CQ_CLOSE(q)                                     \
 326         dumpsys_close_cq(&ds->q, ds->live)
 327 
 328 #define CQ_PUT(q, cp, st)                               \
 329         dumpsys_put_cq(&ds->q, cp, st, ds->live)
 330 
 331 #define CQ_GET(q)                                       \
 332         dumpsys_get_cq(&ds->q, ds->live)
 333 
 334 /*
 335  * Dynamic state when dumpsys() is running.
 336  */
 337 typedef struct dumpsync {
 338         pgcnt_t npages;                 /* subtotal of pages dumped */
 339         pgcnt_t pages_mapped;           /* subtotal of pages mapped */
 340         pgcnt_t pages_used;             /* subtotal of pages used per map */
 341         size_t nwrite;                  /* subtotal of bytes written */
 342         uint_t live;                    /* running live dump */
 343         uint_t neednl;                  /* will need to print a newline */
 344         uint_t percent;                 /* dump progress */
 345         uint_t percent_done;            /* dump progress reported */
 346         int sec_done;                   /* dump progress last report time */
 347         cqueue_t freebufq;              /* free kmem bufs for writing */
 348         cqueue_t mainq;                 /* input for main task */
 349         cqueue_t helperq;               /* input for helpers */
 350         cqueue_t writerq;               /* input for writer */
 351         hrtime_t start;                 /* start time */
 352         hrtime_t elapsed;               /* elapsed time when completed */
 353         hrtime_t iotime;                /* time spent writing nwrite bytes */
 354         hrtime_t iowait;                /* time spent waiting for output */
 355         hrtime_t iowaitts;              /* iowait timestamp */
 356         perpage_t perpage;              /* metrics */
 357         perpage_t perpagets;
 358         int dumpcpu;                    /* master cpu */
 359 } dumpsync_t;
 360 
 361 static dumpsync_t dumpsync;             /* synchronization vars */
 362 
 363 /*
 364  * helper_t helpers: contains the context for a stream. CPUs run in
 365  * parallel at dump time; each CPU creates a single stream of
 366  * compression data.  Stream data is divided into CBUF_SIZE blocks.
 367  * The blocks are written in order within a stream. But, blocks from
 368  * multiple streams can be interleaved. Each stream is identified by a
 369  * unique tag.
 370  */
 371 typedef struct helper {
 372         int helper;                     /* bound helper id */
 373         int tag;                        /* compression stream tag */
 374         perpage_t perpage;              /* per page metrics */
 375         perpage_t perpagets;            /* per page metrics (timestamps) */
 376         taskqid_t taskqid;              /* live dump task ptr */
 377         int in, out;                    /* buffer offsets */
 378         cbuf_t *cpin, *cpout, *cperr;   /* cbuf objects in process */
 379         dumpsync_t *ds;                 /* pointer to sync vars */
 380         size_t used;                    /* counts input consumed */
 381         char *page;                     /* buffer for page copy */
 382         char *lzbuf;                    /* lzjb output */
 383         bz_stream bzstream;             /* bzip2 state */
 384 } helper_t;
 385 
 386 #define MAINHELPER      (-1)            /* helper is also the main task */
 387 #define FREEHELPER      (-2)            /* unbound helper */
 388 #define DONEHELPER      (-3)            /* helper finished */
 389 
 390 /*
 391  * configuration vars for dumpsys
 392  */
 393 typedef struct dumpcfg {
 394         int     threshold;      /* ncpu threshold for bzip2 */
 395         int     nhelper;        /* number of helpers */
 396         int     nhelper_used;   /* actual number of helpers used */
 397         int     ncmap;          /* number VA pages for compression */
 398         int     ncbuf;          /* number of bufs for compression */
 399         int     ncbuf_used;     /* number of bufs in use */
 400         uint_t  clevel;         /* dump compression level */
 401         helper_t *helper;       /* array of helpers */
 402         cbuf_t  *cmap;          /* array of input (map) buffers */
 403         cbuf_t  *cbuf;          /* array of output  buffers */
 404         ulong_t *helpermap;     /* set of dumpsys helper CPU ids */
 405         ulong_t *bitmap;        /* bitmap for marking pages to dump */
 406         ulong_t *rbitmap;       /* bitmap for used CBUF_MAPSIZE ranges */
 407         pgcnt_t bitmapsize;     /* size of bitmap */
 408         pgcnt_t rbitmapsize;    /* size of bitmap for ranges */
 409         pgcnt_t found4m;        /* number ranges allocated by dump */
 410         pgcnt_t foundsm;        /* number small pages allocated by dump */
 411         pid_t   *pids;          /* list of process IDs at dump time */
 412         size_t  maxsize;        /* memory size needed at dump time */
 413         size_t  maxvmsize;      /* size of reserved VM */
 414         char    *maxvm;         /* reserved VM for spare pages */
 415         lock_t  helper_lock;    /* protect helper state */
 416         char    helpers_wanted; /* flag to enable parallelism */
 417 } dumpcfg_t;
 418 
 419 static dumpcfg_t dumpcfg;       /* config vars */
 420 
 421 /*
 422  * The dump I/O buffer.
 423  *
 424  * There is one I/O buffer used by dumpvp_write and dumvp_flush. It is
 425  * sized according to the optimum device transfer speed.
 426  */
 427 typedef struct dumpbuf {
 428         vnode_t *cdev_vp;       /* VCHR open of the dump device */
 429         len_t   vp_limit;       /* maximum write offset */
 430         offset_t vp_off;        /* current dump device offset */
 431         char    *cur;           /* dump write pointer */
 432         char    *start;         /* dump buffer address */
 433         char    *end;           /* dump buffer end */
 434         size_t  size;           /* size of dumpbuf in bytes */
 435         size_t  iosize;         /* best transfer size for device */
 436 } dumpbuf_t;
 437 
 438 dumpbuf_t dumpbuf;              /* I/O buffer */
 439 
 440 /*
 441  * The dump I/O buffer must be at least one page, at most xfer_size
 442  * bytes, and should scale with physmem in between.  The transfer size
 443  * passed in will either represent a global default (maxphys) or the
 444  * best size for the device.  The size of the dumpbuf I/O buffer is
 445  * limited by dumpbuf_limit (8MB by default) because the dump
 446  * performance saturates beyond a certain size.  The default is to
 447  * select 1/4096 of the memory.
 448  */
 449 static int      dumpbuf_fraction = 12;  /* memory size scale factor */
 450 static size_t   dumpbuf_limit = 8 * DUMP_1MB;   /* max I/O buf size */
 451 
 452 static size_t
 453 dumpbuf_iosize(size_t xfer_size)
 454 {
 455         size_t iosize = ptob(physmem >> dumpbuf_fraction);
 456 
 457         if (iosize < PAGESIZE)
 458                 iosize = PAGESIZE;
 459         else if (iosize > xfer_size)
 460                 iosize = xfer_size;
 461         if (iosize > dumpbuf_limit)
 462                 iosize = dumpbuf_limit;
 463         return (iosize & PAGEMASK);
 464 }
 465 
 466 /*
 467  * resize the I/O buffer
 468  */
 469 static void
 470 dumpbuf_resize(void)
 471 {
 472         char *old_buf = dumpbuf.start;
 473         size_t old_size = dumpbuf.size;
 474         char *new_buf;
 475         size_t new_size;
 476 
 477         ASSERT(MUTEX_HELD(&dump_lock));
 478 
 479         new_size = dumpbuf_iosize(MAX(dumpbuf.iosize, maxphys));
 480         if (new_size <= old_size)
 481                 return; /* no need to reallocate buffer */
 482 
 483         new_buf = kmem_alloc(new_size, KM_SLEEP);
 484         dumpbuf.size = new_size;
 485         dumpbuf.start = new_buf;
 486         dumpbuf.end = new_buf + new_size;
 487         kmem_free(old_buf, old_size);
 488 }
 489 
 490 /*
 491  * dump_update_clevel is called when dumpadm configures the dump device.
 492  *      Calculate number of helpers and buffers.
 493  *      Allocate the minimum configuration for now.
 494  *
 495  * When the dump file is configured we reserve a minimum amount of
 496  * memory for use at crash time. But we reserve VA for all the memory
 497  * we really want in order to do the fastest dump possible. The VA is
 498  * backed by pages not being dumped, according to the bitmap. If
 499  * there is insufficient spare memory, however, we fall back to the
 500  * minimum.
 501  *
 502  * Live dump (savecore -L) always uses the minimum config.
 503  *
 504  * clevel 0 is single threaded lzjb
 505  * clevel 1 is parallel lzjb
 506  * clevel 2 is parallel bzip2
 507  *
 508  * The ncpu threshold is selected with dump_plat_mincpu.
 509  * On OPL, set_platform_defaults() overrides the sun4u setting.
 510  * The actual values are defined via DUMP_PLAT_*_MINCPU macros.
 511  *
 512  * Architecture         Threshold       Algorithm
 513  * sun4u                <  51                parallel lzjb
 514  * sun4u                >= 51                parallel bzip2(*)
 515  * sun4u OPL            <  8         parallel lzjb
 516  * sun4u OPL            >= 8         parallel bzip2(*)
 517  * sun4v                <  128               parallel lzjb
 518  * sun4v                >= 128               parallel bzip2(*)
 519  * x86                  < 11         parallel lzjb
 520  * x86                  >= 11                parallel bzip2(*)
 521  * 32-bit               N/A             single-threaded lzjb
 522  *
 523  * (*) bzip2 is only chosen if there is sufficient available
 524  * memory for buffers at dump time. See dumpsys_get_maxmem().
 525  *
 526  * Faster dump devices have larger I/O buffers. The threshold value is
 527  * increased according to the size of the dump I/O buffer, because
 528  * parallel lzjb performs better with faster disks. For buffers >= 1MB
 529  * the threshold is 3X; for buffers >= 256K threshold is 2X.
 530  *
 531  * For parallel dumps, the number of helpers is ncpu-1. The CPU
 532  * running panic runs the main task. For single-threaded dumps, the
 533  * panic CPU does lzjb compression (it is tagged as MAINHELPER.)
 534  *
 535  * Need multiple buffers per helper so that they do not block waiting
 536  * for the main task.
 537  *                              parallel        single-threaded
 538  * Number of output buffers:    nhelper*2               1
 539  * Number of mapping buffers:   nhelper*4               1
 540  *
 541  */
 542 static void
 543 dump_update_clevel()
 544 {
 545         int tag;
 546         size_t bz2size;
 547         helper_t *hp, *hpend;
 548         cbuf_t *cp, *cpend;
 549         dumpcfg_t *old = &dumpcfg;
 550         dumpcfg_t newcfg = *old;
 551         dumpcfg_t *new = &newcfg;
 552 
 553         ASSERT(MUTEX_HELD(&dump_lock));
 554 
 555         /*
 556          * Free the previously allocated bufs and VM.
 557          */
 558         if (old->helper != NULL) {
 559 
 560                 /* helpers */
 561                 hpend = &old->helper[old->nhelper];
 562                 for (hp = old->helper; hp != hpend; hp++) {
 563                         if (hp->lzbuf != NULL)
 564                                 kmem_free(hp->lzbuf, PAGESIZE);
 565                         if (hp->page != NULL)
 566                                 kmem_free(hp->page, PAGESIZE);
 567                 }
 568                 kmem_free(old->helper, old->nhelper * sizeof (helper_t));
 569 
 570                 /* VM space for mapping pages */
 571                 cpend = &old->cmap[old->ncmap];
 572                 for (cp = old->cmap; cp != cpend; cp++)
 573                         vmem_xfree(heap_arena, cp->buf, CBUF_MAPSIZE);
 574                 kmem_free(old->cmap, old->ncmap * sizeof (cbuf_t));
 575 
 576                 /* output bufs */
 577                 cpend = &old->cbuf[old->ncbuf];
 578                 for (cp = old->cbuf; cp != cpend; cp++)
 579                         if (cp->buf != NULL)
 580                                 kmem_free(cp->buf, cp->size);
 581                 kmem_free(old->cbuf, old->ncbuf * sizeof (cbuf_t));
 582 
 583                 /* reserved VM for dumpsys_get_maxmem */
 584                 if (old->maxvmsize > 0)
 585                         vmem_xfree(heap_arena, old->maxvm, old->maxvmsize);
 586         }
 587 
 588         /*
 589          * Allocate memory and VM.
 590          * One CPU runs dumpsys, the rest are helpers.
 591          */
 592         new->nhelper = ncpus - 1;
 593         if (new->nhelper < 1)
 594                 new->nhelper = 1;
 595 
 596         if (new->nhelper > DUMP_MAX_NHELPER)
 597                 new->nhelper = DUMP_MAX_NHELPER;
 598 
 599         /* use platform default, unless /etc/system overrides */
 600         if (dump_plat_mincpu == MINCPU_NOT_SET)
 601                 dump_plat_mincpu = dump_plat_mincpu_default;
 602 
 603         /* increase threshold for faster disks */
 604         new->threshold = dump_plat_mincpu;
 605         if (dumpbuf.iosize >= DUMP_1MB)
 606                 new->threshold *= 3;
 607         else if (dumpbuf.iosize >= (256 * DUMP_1KB))
 608                 new->threshold *= 2;
 609 
 610         /* figure compression level based upon the computed threshold. */
 611         if (dump_plat_mincpu == 0 || new->nhelper < 2) {
 612                 new->clevel = 0;
 613                 new->nhelper = 1;
 614         } else if ((new->nhelper + 1) >= new->threshold) {
 615                 new->clevel = DUMP_CLEVEL_BZIP2;
 616         } else {
 617                 new->clevel = DUMP_CLEVEL_LZJB;
 618         }
 619 
 620         if (new->clevel == 0) {
 621                 new->ncbuf = 1;
 622                 new->ncmap = 1;
 623         } else {
 624                 new->ncbuf = NCBUF_PER_HELPER * new->nhelper;
 625                 new->ncmap = NCMAP_PER_HELPER * new->nhelper;
 626         }
 627 
 628         /*
 629          * Allocate new data structures and buffers for MINHELPERS,
 630          * and also figure the max desired size.
 631          */
 632         bz2size = BZ2_bzCompressInitSize(dump_bzip2_level);
 633         new->maxsize = 0;
 634         new->maxvmsize = 0;
 635         new->maxvm = NULL;
 636         tag = 1;
 637         new->helper = kmem_zalloc(new->nhelper * sizeof (helper_t), KM_SLEEP);
 638         hpend = &new->helper[new->nhelper];
 639         for (hp = new->helper; hp != hpend; hp++) {
 640                 hp->tag = tag++;
 641                 if (hp < &new->helper[MINHELPERS]) {
 642                         hp->lzbuf = kmem_alloc(PAGESIZE, KM_SLEEP);
 643                         hp->page = kmem_alloc(PAGESIZE, KM_SLEEP);
 644                 } else if (new->clevel < DUMP_CLEVEL_BZIP2) {
 645                         new->maxsize += 2 * PAGESIZE;
 646                 } else {
 647                         new->maxsize += PAGESIZE;
 648                 }
 649                 if (new->clevel >= DUMP_CLEVEL_BZIP2)
 650                         new->maxsize += bz2size;
 651         }
 652 
 653         new->cbuf = kmem_zalloc(new->ncbuf * sizeof (cbuf_t), KM_SLEEP);
 654         cpend = &new->cbuf[new->ncbuf];
 655         for (cp = new->cbuf; cp != cpend; cp++) {
 656                 cp->state = CBUF_FREEBUF;
 657                 cp->size = CBUF_SIZE;
 658                 if (cp < &new->cbuf[MINCBUFS])
 659                         cp->buf = kmem_alloc(cp->size, KM_SLEEP);
 660                 else
 661                         new->maxsize += cp->size;
 662         }
 663 
 664         new->cmap = kmem_zalloc(new->ncmap * sizeof (cbuf_t), KM_SLEEP);
 665         cpend = &new->cmap[new->ncmap];
 666         for (cp = new->cmap; cp != cpend; cp++) {
 667                 cp->state = CBUF_FREEMAP;
 668                 cp->size = CBUF_MAPSIZE;
 669                 cp->buf = vmem_xalloc(heap_arena, CBUF_MAPSIZE, CBUF_MAPSIZE,
 670                     0, 0, NULL, NULL, VM_SLEEP);
 671         }
 672 
 673         /* reserve VA to be backed with spare pages at crash time */
 674         if (new->maxsize > 0) {
 675                 new->maxsize = P2ROUNDUP(new->maxsize, PAGESIZE);
 676                 new->maxvmsize = P2ROUNDUP(new->maxsize, CBUF_MAPSIZE);
 677                 new->maxvm = vmem_xalloc(heap_arena, new->maxvmsize,
 678                     CBUF_MAPSIZE, 0, 0, NULL, NULL, VM_SLEEP);
 679         }
 680 
 681         /*
 682          * Reserve memory for kmem allocation calls made during crash
 683          * dump.  The hat layer allocates memory for each mapping
 684          * created, and the I/O path allocates buffers and data structs.
 685          * Add a few pages for safety.
 686          */
 687         kmem_dump_init((new->ncmap * dump_kmem_permap) +
 688             (dump_kmem_pages * PAGESIZE));
 689 
 690         /* set new config pointers */
 691         *old = *new;
 692 }
 693 
 694 /*
 695  * Define a struct memlist walker to optimize bitnum to pfn
 696  * lookup. The walker maintains the state of the list traversal.
 697  */
 698 typedef struct dumpmlw {
 699         struct memlist  *mp;            /* current memlist */
 700         pgcnt_t         basenum;        /* bitnum base offset */
 701         pgcnt_t         mppages;        /* current memlist size */
 702         pgcnt_t         mpleft;         /* size to end of current memlist */
 703         pfn_t           mpaddr;         /* first pfn in memlist */
 704 } dumpmlw_t;
 705 
 706 /* initialize the walker */
 707 static inline void
 708 dump_init_memlist_walker(dumpmlw_t *pw)
 709 {
 710         pw->mp = phys_install;
 711         pw->basenum = 0;
 712         pw->mppages = pw->mp->ml_size >> PAGESHIFT;
 713         pw->mpleft = pw->mppages;
 714         pw->mpaddr = pw->mp->ml_address >> PAGESHIFT;
 715 }
 716 
 717 /*
 718  * Lookup pfn given bitnum. The memlist can be quite long on some
 719  * systems (e.g.: one per board). To optimize sequential lookups, the
 720  * caller initializes and presents a memlist walker.
 721  */
 722 static pfn_t
 723 dump_bitnum_to_pfn(pgcnt_t bitnum, dumpmlw_t *pw)
 724 {
 725         bitnum -= pw->basenum;
 726         while (pw->mp != NULL) {
 727                 if (bitnum < pw->mppages) {
 728                         pw->mpleft = pw->mppages - bitnum;
 729                         return (pw->mpaddr + bitnum);
 730                 }
 731                 bitnum -= pw->mppages;
 732                 pw->basenum += pw->mppages;
 733                 pw->mp = pw->mp->ml_next;
 734                 if (pw->mp != NULL) {
 735                         pw->mppages = pw->mp->ml_size >> PAGESHIFT;
 736                         pw->mpleft = pw->mppages;
 737                         pw->mpaddr = pw->mp->ml_address >> PAGESHIFT;
 738                 }
 739         }
 740         return (PFN_INVALID);
 741 }
 742 
 743 static pgcnt_t
 744 dump_pfn_to_bitnum(pfn_t pfn)
 745 {
 746         struct memlist *mp;
 747         pgcnt_t bitnum = 0;
 748 
 749         for (mp = phys_install; mp != NULL; mp = mp->ml_next) {
 750                 if (pfn >= (mp->ml_address >> PAGESHIFT) &&
 751                     pfn < ((mp->ml_address + mp->ml_size) >> PAGESHIFT))
 752                         return (bitnum + pfn - (mp->ml_address >> PAGESHIFT));
 753                 bitnum += mp->ml_size >> PAGESHIFT;
 754         }
 755         return ((pgcnt_t)-1);
 756 }
 757 
 758 /*
 759  * Set/test bitmap for a CBUF_MAPSIZE range which includes pfn. The
 760  * mapping of pfn to range index is imperfect because pfn and bitnum
 761  * do not have the same phase. To make sure a CBUF_MAPSIZE range is
 762  * covered, call this for both ends:
 763  *      dump_set_used(base)
 764  *      dump_set_used(base+CBUF_MAPNP-1)
 765  *
 766  * This is used during a panic dump to mark pages allocated by
 767  * dumpsys_get_maxmem(). The macro IS_DUMP_PAGE(pp) is used by
 768  * page_get_mnode_freelist() to make sure pages used by dump are never
 769  * allocated.
 770  */
 771 #define CBUF_MAPP2R(pfn)        ((pfn) >> (CBUF_MAPSHIFT - PAGESHIFT))
 772 
 773 static void
 774 dump_set_used(pfn_t pfn)
 775 {
 776 
 777         pgcnt_t bitnum, rbitnum;
 778 
 779         bitnum = dump_pfn_to_bitnum(pfn);
 780         ASSERT(bitnum != (pgcnt_t)-1);
 781 
 782         rbitnum = CBUF_MAPP2R(bitnum);
 783         ASSERT(rbitnum < dumpcfg.rbitmapsize);
 784 
 785         BT_SET(dumpcfg.rbitmap, rbitnum);
 786 }
 787 
 788 int
 789 dump_test_used(pfn_t pfn)
 790 {
 791         pgcnt_t bitnum, rbitnum;
 792 
 793         bitnum = dump_pfn_to_bitnum(pfn);
 794         ASSERT(bitnum != (pgcnt_t)-1);
 795 
 796         rbitnum = CBUF_MAPP2R(bitnum);
 797         ASSERT(rbitnum < dumpcfg.rbitmapsize);
 798 
 799         return (BT_TEST(dumpcfg.rbitmap, rbitnum));
 800 }
 801 
 802 /*
 803  * dumpbzalloc and dumpbzfree are callbacks from the bzip2 library.
 804  * dumpsys_get_maxmem() uses them for BZ2_bzCompressInit().
 805  */
 806 static void *
 807 dumpbzalloc(void *opaque, int items, int size)
 808 {
 809         size_t *sz;
 810         char *ret;
 811 
 812         ASSERT(opaque != NULL);
 813         sz = opaque;
 814         ret = dumpcfg.maxvm + *sz;
 815         *sz += items * size;
 816         *sz = P2ROUNDUP(*sz, BZ2_BZALLOC_ALIGN);
 817         ASSERT(*sz <= dumpcfg.maxvmsize);
 818         return (ret);
 819 }
 820 
 821 /*ARGSUSED*/
 822 static void
 823 dumpbzfree(void *opaque, void *addr)
 824 {
 825 }
 826 
 827 /*
 828  * Perform additional checks on the page to see if we can really use
 829  * it. The kernel (kas) pages are always set in the bitmap. However,
 830  * boot memory pages (prom_ppages or P_BOOTPAGES) are not in the
 831  * bitmap. So we check for them.
 832  */
 833 static inline int
 834 dump_pfn_check(pfn_t pfn)
 835 {
 836         page_t *pp = page_numtopp_nolock(pfn);
 837         if (pp == NULL || pp->p_pagenum != pfn ||
 838 #if defined(__sparc)
 839             pp->p_vnode == &promvp ||
 840 #else
 841             PP_ISBOOTPAGES(pp) ||
 842 #endif
 843             pp->p_toxic != 0)
 844                 return (0);
 845         return (1);
 846 }
 847 
 848 /*
 849  * Check a range to see if all contained pages are available and
 850  * return non-zero if the range can be used.
 851  */
 852 static inline int
 853 dump_range_check(pgcnt_t start, pgcnt_t end, pfn_t pfn)
 854 {
 855         for (; start < end; start++, pfn++) {
 856                 if (BT_TEST(dumpcfg.bitmap, start))
 857                         return (0);
 858                 if (!dump_pfn_check(pfn))
 859                         return (0);
 860         }
 861         return (1);
 862 }
 863 
 864 /*
 865  * dumpsys_get_maxmem() is called during panic. Find unused ranges
 866  * and use them for buffers. If we find enough memory switch to
 867  * parallel bzip2, otherwise use parallel lzjb.
 868  *
 869  * It searches the dump bitmap in 2 passes. The first time it looks
 870  * for CBUF_MAPSIZE ranges. On the second pass it uses small pages.
 871  */
 872 static void
 873 dumpsys_get_maxmem()
 874 {
 875         dumpcfg_t *cfg = &dumpcfg;
 876         cbuf_t *endcp = &cfg->cbuf[cfg->ncbuf];
 877         helper_t *endhp = &cfg->helper[cfg->nhelper];
 878         pgcnt_t bitnum, end;
 879         size_t sz, endsz, bz2size;
 880         pfn_t pfn, off;
 881         cbuf_t *cp;
 882         helper_t *hp, *ohp;
 883         dumpmlw_t mlw;
 884         int k;
 885 
 886         /*
 887          * Setting dump_plat_mincpu to 0 at any time forces a serial
 888          * dump.
 889          */
 890         if (dump_plat_mincpu == 0) {
 891                 cfg->clevel = 0;
 892                 return;
 893         }
 894 
 895         /*
 896          * There may be no point in looking for spare memory. If
 897          * dumping all memory, then none is spare. If doing a serial
 898          * dump, then already have buffers.
 899          */
 900         if (cfg->maxsize == 0 || cfg->clevel < DUMP_CLEVEL_LZJB ||
 901             (dump_conflags & DUMP_ALL) != 0) {
 902                 if (cfg->clevel > DUMP_CLEVEL_LZJB)
 903                         cfg->clevel = DUMP_CLEVEL_LZJB;
 904                 return;
 905         }
 906 
 907         sz = 0;
 908         cfg->found4m = 0;
 909         cfg->foundsm = 0;
 910 
 911         /* bitmap of ranges used to estimate which pfns are being used */
 912         bzero(dumpcfg.rbitmap, BT_SIZEOFMAP(dumpcfg.rbitmapsize));
 913 
 914         /* find ranges that are not being dumped to use for buffers */
 915         dump_init_memlist_walker(&mlw);
 916         for (bitnum = 0; bitnum < dumpcfg.bitmapsize; bitnum = end) {
 917                 dump_timeleft = dump_timeout;
 918                 end = bitnum + CBUF_MAPNP;
 919                 pfn = dump_bitnum_to_pfn(bitnum, &mlw);
 920                 ASSERT(pfn != PFN_INVALID);
 921 
 922                 /* skip partial range at end of mem segment */
 923                 if (mlw.mpleft < CBUF_MAPNP) {
 924                         end = bitnum + mlw.mpleft;
 925                         continue;
 926                 }
 927 
 928                 /* skip non aligned pages */
 929                 off = P2PHASE(pfn, CBUF_MAPNP);
 930                 if (off != 0) {
 931                         end -= off;
 932                         continue;
 933                 }
 934 
 935                 if (!dump_range_check(bitnum, end, pfn))
 936                         continue;
 937 
 938                 ASSERT((sz + CBUF_MAPSIZE) <= cfg->maxvmsize);
 939                 hat_devload(kas.a_hat, cfg->maxvm + sz, CBUF_MAPSIZE, pfn,
 940                     PROT_READ | PROT_WRITE, HAT_LOAD_NOCONSIST);
 941                 sz += CBUF_MAPSIZE;
 942                 cfg->found4m++;
 943 
 944                 /* set the bitmap for both ends to be sure to cover the range */
 945                 dump_set_used(pfn);
 946                 dump_set_used(pfn + CBUF_MAPNP - 1);
 947 
 948                 if (sz >= cfg->maxsize)
 949                         goto foundmax;
 950         }
 951 
 952         /* Add small pages if we can't find enough large pages. */
 953         dump_init_memlist_walker(&mlw);
 954         for (bitnum = 0; bitnum < dumpcfg.bitmapsize; bitnum = end) {
 955                 dump_timeleft = dump_timeout;
 956                 end = bitnum + CBUF_MAPNP;
 957                 pfn = dump_bitnum_to_pfn(bitnum, &mlw);
 958                 ASSERT(pfn != PFN_INVALID);
 959 
 960                 /* Find any non-aligned pages at start and end of segment. */
 961                 off = P2PHASE(pfn, CBUF_MAPNP);
 962                 if (mlw.mpleft < CBUF_MAPNP) {
 963                         end = bitnum + mlw.mpleft;
 964                 } else if (off != 0) {
 965                         end -= off;
 966                 } else if (cfg->found4m && dump_test_used(pfn)) {
 967                         continue;
 968                 }
 969 
 970                 for (; bitnum < end; bitnum++, pfn++) {
 971                         dump_timeleft = dump_timeout;
 972                         if (BT_TEST(dumpcfg.bitmap, bitnum))
 973                                 continue;
 974                         if (!dump_pfn_check(pfn))
 975                                 continue;
 976                         ASSERT((sz + PAGESIZE) <= cfg->maxvmsize);
 977                         hat_devload(kas.a_hat, cfg->maxvm + sz, PAGESIZE, pfn,
 978                             PROT_READ | PROT_WRITE, HAT_LOAD_NOCONSIST);
 979                         sz += PAGESIZE;
 980                         cfg->foundsm++;
 981                         dump_set_used(pfn);
 982                         if (sz >= cfg->maxsize)
 983                                 goto foundmax;
 984                 }
 985         }
 986 
 987         /* Fall back to lzjb if we did not get enough memory for bzip2. */
 988         endsz = (cfg->maxsize * cfg->threshold) / cfg->nhelper;
 989         if (sz < endsz) {
 990                 cfg->clevel = DUMP_CLEVEL_LZJB;
 991         }
 992 
 993         /* Allocate memory for as many helpers as we can. */
 994 foundmax:
 995 
 996         /* Byte offsets into memory found and mapped above */
 997         endsz = sz;
 998         sz = 0;
 999 
1000         /* Set the size for bzip2 state. Only bzip2 needs it. */
1001         bz2size = BZ2_bzCompressInitSize(dump_bzip2_level);
1002 
1003         /* Skip the preallocate output buffers. */
1004         cp = &cfg->cbuf[MINCBUFS];
1005 
1006         /* Use this to move memory up from the preallocated helpers. */
1007         ohp = cfg->helper;
1008 
1009         /* Loop over all helpers and allocate memory. */
1010         for (hp = cfg->helper; hp < endhp; hp++) {
1011 
1012                 /* Skip preallocated helpers by checking hp->page. */
1013                 if (hp->page == NULL) {
1014                         if (cfg->clevel <= DUMP_CLEVEL_LZJB) {
1015                                 /* lzjb needs 2 1-page buffers */
1016                                 if ((sz + (2 * PAGESIZE)) > endsz)
1017                                         break;
1018                                 hp->page = cfg->maxvm + sz;
1019                                 sz += PAGESIZE;
1020                                 hp->lzbuf = cfg->maxvm + sz;
1021                                 sz += PAGESIZE;
1022 
1023                         } else if (ohp->lzbuf != NULL) {
1024                                 /* re-use the preallocted lzjb page for bzip2 */
1025                                 hp->page = ohp->lzbuf;
1026                                 ohp->lzbuf = NULL;
1027                                 ++ohp;
1028 
1029                         } else {
1030                                 /* bzip2 needs a 1-page buffer */
1031                                 if ((sz + PAGESIZE) > endsz)
1032                                         break;
1033                                 hp->page = cfg->maxvm + sz;
1034                                 sz += PAGESIZE;
1035                         }
1036                 }
1037 
1038                 /*
1039                  * Add output buffers per helper. The number of
1040                  * buffers per helper is determined by the ratio of
1041                  * ncbuf to nhelper.
1042                  */
1043                 for (k = 0; cp < endcp && (sz + CBUF_SIZE) <= endsz &&
1044                     k < NCBUF_PER_HELPER; k++) {
1045                         cp->state = CBUF_FREEBUF;
1046                         cp->size = CBUF_SIZE;
1047                         cp->buf = cfg->maxvm + sz;
1048                         sz += CBUF_SIZE;
1049                         ++cp;
1050                 }
1051 
1052                 /*
1053                  * bzip2 needs compression state. Use the dumpbzalloc
1054                  * and dumpbzfree callbacks to allocate the memory.
1055                  * bzip2 does allocation only at init time.
1056                  */
1057                 if (cfg->clevel >= DUMP_CLEVEL_BZIP2) {
1058                         if ((sz + bz2size) > endsz) {
1059                                 hp->page = NULL;
1060                                 break;
1061                         } else {
1062                                 hp->bzstream.opaque = &sz;
1063                                 hp->bzstream.bzalloc = dumpbzalloc;
1064                                 hp->bzstream.bzfree = dumpbzfree;
1065                                 (void) BZ2_bzCompressInit(&hp->bzstream,
1066                                     dump_bzip2_level, 0, 0);
1067                                 hp->bzstream.opaque = NULL;
1068                         }
1069                 }
1070         }
1071 
1072         /* Finish allocating output buffers */
1073         for (; cp < endcp && (sz + CBUF_SIZE) <= endsz; cp++) {
1074                 cp->state = CBUF_FREEBUF;
1075                 cp->size = CBUF_SIZE;
1076                 cp->buf = cfg->maxvm + sz;
1077                 sz += CBUF_SIZE;
1078         }
1079 
1080         /* Enable IS_DUMP_PAGE macro, which checks for pages we took. */
1081         if (cfg->found4m || cfg->foundsm)
1082                 dump_check_used = 1;
1083 
1084         ASSERT(sz <= endsz);
1085 }
1086 
1087 static void
1088 dumphdr_init(void)
1089 {
1090         pgcnt_t npages = 0;
1091 
1092         ASSERT(MUTEX_HELD(&dump_lock));
1093 
1094         if (dumphdr == NULL) {
1095                 dumphdr = kmem_zalloc(sizeof (dumphdr_t), KM_SLEEP);
1096                 dumphdr->dump_magic = DUMP_MAGIC;
1097                 dumphdr->dump_version = DUMP_VERSION;
1098                 dumphdr->dump_wordsize = DUMP_WORDSIZE;
1099                 dumphdr->dump_pageshift = PAGESHIFT;
1100                 dumphdr->dump_pagesize = PAGESIZE;
1101                 dumphdr->dump_utsname = utsname;
1102                 (void) strcpy(dumphdr->dump_platform, platform);
1103                 dumpbuf.size = dumpbuf_iosize(maxphys);
1104                 dumpbuf.start = kmem_alloc(dumpbuf.size, KM_SLEEP);
1105                 dumpbuf.end = dumpbuf.start + dumpbuf.size;
1106                 dumpcfg.pids = kmem_alloc(v.v_proc * sizeof (pid_t), KM_SLEEP);
1107                 dumpcfg.helpermap = kmem_zalloc(BT_SIZEOFMAP(NCPU), KM_SLEEP);
1108                 LOCK_INIT_HELD(&dumpcfg.helper_lock);
1109                 dump_stack_scratch = kmem_alloc(STACK_BUF_SIZE, KM_SLEEP);
1110                 (void) strncpy(dumphdr->dump_uuid, dump_get_uuid(),
1111                     sizeof (dumphdr->dump_uuid));
1112         }
1113 
1114         npages = num_phys_pages();
1115 
1116         if (dumpcfg.bitmapsize != npages) {
1117                 size_t rlen = CBUF_MAPP2R(P2ROUNDUP(npages, CBUF_MAPNP));
1118                 void *map = kmem_alloc(BT_SIZEOFMAP(npages), KM_SLEEP);
1119                 void *rmap = kmem_alloc(BT_SIZEOFMAP(rlen), KM_SLEEP);
1120 
1121                 if (dumpcfg.bitmap != NULL)
1122                         kmem_free(dumpcfg.bitmap, BT_SIZEOFMAP(dumpcfg.
1123                             bitmapsize));
1124                 if (dumpcfg.rbitmap != NULL)
1125                         kmem_free(dumpcfg.rbitmap, BT_SIZEOFMAP(dumpcfg.
1126                             rbitmapsize));
1127                 dumpcfg.bitmap = map;
1128                 dumpcfg.bitmapsize = npages;
1129                 dumpcfg.rbitmap = rmap;
1130                 dumpcfg.rbitmapsize = rlen;
1131         }
1132 }
1133 
1134 /*
1135  * Establish a new dump device.
1136  */
1137 int
1138 dumpinit(vnode_t *vp, char *name, int justchecking)
1139 {
1140         vnode_t *cvp;
1141         vattr_t vattr;
1142         vnode_t *cdev_vp;
1143         int error = 0;
1144 
1145         ASSERT(MUTEX_HELD(&dump_lock));
1146 
1147         dumphdr_init();
1148 
1149         cvp = common_specvp(vp);
1150         if (cvp == dumpvp)
1151                 return (0);
1152 
1153         /*
1154          * Determine whether this is a plausible dump device.  We want either:
1155          * (1) a real device that's not mounted and has a cb_dump routine, or
1156          * (2) a swapfile on some filesystem that has a vop_dump routine.
1157          */
1158         if ((error = VOP_OPEN(&cvp, FREAD | FWRITE, kcred, NULL)) != 0)
1159                 return (error);
1160 
1161         vattr.va_mask = AT_SIZE | AT_TYPE | AT_RDEV;
1162         if ((error = VOP_GETATTR(cvp, &vattr, 0, kcred, NULL)) == 0) {
1163                 if (vattr.va_type == VBLK || vattr.va_type == VCHR) {
1164                         if (devopsp[getmajor(vattr.va_rdev)]->
1165                             devo_cb_ops->cb_dump == nodev)
1166                                 error = ENOTSUP;
1167                         else if (vfs_devismounted(vattr.va_rdev))
1168                                 error = EBUSY;
1169                         if (strcmp(ddi_driver_name(VTOS(cvp)->s_dip),
1170                             ZFS_DRIVER) == 0 &&
1171                             IS_SWAPVP(common_specvp(cvp)))
1172                                         error = EBUSY;
1173                 } else {
1174                         if (vn_matchopval(cvp, VOPNAME_DUMP, fs_nosys) ||
1175                             !IS_SWAPVP(cvp))
1176                                 error = ENOTSUP;
1177                 }
1178         }
1179 
1180         if (error == 0 && vattr.va_size < 2 * DUMP_LOGSIZE + DUMP_ERPTSIZE)
1181                 error = ENOSPC;
1182 
1183         if (error || justchecking) {
1184                 (void) VOP_CLOSE(cvp, FREAD | FWRITE, 1, (offset_t)0,
1185                     kcred, NULL);
1186                 return (error);
1187         }
1188 
1189         VN_HOLD(cvp);
1190 
1191         if (dumpvp != NULL)
1192                 dumpfini();     /* unconfigure the old dump device */
1193 
1194         dumpvp = cvp;
1195         dumpvp_size = vattr.va_size & -DUMP_OFFSET;
1196         dumppath = kmem_alloc(strlen(name) + 1, KM_SLEEP);
1197         (void) strcpy(dumppath, name);
1198         dumpbuf.iosize = 0;
1199 
1200         /*
1201          * If the dump device is a block device, attempt to open up the
1202          * corresponding character device and determine its maximum transfer
1203          * size.  We use this information to potentially resize dumpbuf to a
1204          * larger and more optimal size for performing i/o to the dump device.
1205          */
1206         if (cvp->v_type == VBLK &&
1207             (cdev_vp = makespecvp(VTOS(cvp)->s_dev, VCHR)) != NULL) {
1208                 if (VOP_OPEN(&cdev_vp, FREAD | FWRITE, kcred, NULL) == 0) {
1209                         size_t blk_size;
1210                         struct dk_cinfo dki;
1211                         struct dk_minfo minf;
1212 
1213                         if (VOP_IOCTL(cdev_vp, DKIOCGMEDIAINFO,
1214                             (intptr_t)&minf, FKIOCTL, kcred, NULL, NULL)
1215                             == 0 && minf.dki_lbsize != 0)
1216                                 blk_size = minf.dki_lbsize;
1217                         else
1218                                 blk_size = DEV_BSIZE;
1219 
1220                         if (VOP_IOCTL(cdev_vp, DKIOCINFO, (intptr_t)&dki,
1221                             FKIOCTL, kcred, NULL, NULL) == 0) {
1222                                 dumpbuf.iosize = dki.dki_maxtransfer * blk_size;
1223                                 dumpbuf_resize();
1224                         }
1225                         /*
1226                          * If we are working with a zvol then dumpify it
1227                          * if it's not being used as swap.
1228                          */
1229                         if (strcmp(dki.dki_dname, ZVOL_DRIVER) == 0) {
1230                                 if (IS_SWAPVP(common_specvp(cvp)))
1231                                         error = EBUSY;
1232                                 else if ((error = VOP_IOCTL(cdev_vp,
1233                                     DKIOCDUMPINIT, NULL, FKIOCTL, kcred,
1234                                     NULL, NULL)) != 0)
1235                                         dumpfini();
1236                         }
1237 
1238                         (void) VOP_CLOSE(cdev_vp, FREAD | FWRITE, 1, 0,
1239                             kcred, NULL);
1240                 }
1241 
1242                 VN_RELE(cdev_vp);
1243         }
1244 
1245         cmn_err(CE_CONT, "?dump on %s size %llu MB\n", name, dumpvp_size >> 20);
1246 
1247         dump_update_clevel();
1248 
1249         return (error);
1250 }
1251 
1252 void
1253 dumpfini(void)
1254 {
1255         vattr_t vattr;
1256         boolean_t is_zfs = B_FALSE;
1257         vnode_t *cdev_vp;
1258         ASSERT(MUTEX_HELD(&dump_lock));
1259 
1260         kmem_free(dumppath, strlen(dumppath) + 1);
1261 
1262         /*
1263          * Determine if we are using zvols for our dump device
1264          */
1265         vattr.va_mask = AT_RDEV;
1266         if (VOP_GETATTR(dumpvp, &vattr, 0, kcred, NULL) == 0) {
1267                 is_zfs = (getmajor(vattr.va_rdev) ==
1268                     ddi_name_to_major(ZFS_DRIVER)) ? B_TRUE : B_FALSE;
1269         }
1270 
1271         /*
1272          * If we have a zvol dump device then we call into zfs so
1273          * that it may have a chance to cleanup.
1274          */
1275         if (is_zfs &&
1276             (cdev_vp = makespecvp(VTOS(dumpvp)->s_dev, VCHR)) != NULL) {
1277                 if (VOP_OPEN(&cdev_vp, FREAD | FWRITE, kcred, NULL) == 0) {
1278                         (void) VOP_IOCTL(cdev_vp, DKIOCDUMPFINI, NULL, FKIOCTL,
1279                             kcred, NULL, NULL);
1280                         (void) VOP_CLOSE(cdev_vp, FREAD | FWRITE, 1, 0,
1281                             kcred, NULL);
1282                 }
1283                 VN_RELE(cdev_vp);
1284         }
1285 
1286         (void) VOP_CLOSE(dumpvp, FREAD | FWRITE, 1, (offset_t)0, kcred, NULL);
1287 
1288         VN_RELE(dumpvp);
1289 
1290         dumpvp = NULL;
1291         dumpvp_size = 0;
1292         dumppath = NULL;
1293 }
1294 
1295 static offset_t
1296 dumpvp_flush(void)
1297 {
1298         size_t size = P2ROUNDUP(dumpbuf.cur - dumpbuf.start, PAGESIZE);
1299         hrtime_t iotime;
1300         int err;
1301 
1302         if (dumpbuf.vp_off + size > dumpbuf.vp_limit) {
1303                 dump_ioerr = ENOSPC;
1304                 dumpbuf.vp_off = dumpbuf.vp_limit;
1305         } else if (size != 0) {
1306                 iotime = gethrtime();
1307                 dumpsync.iowait += iotime - dumpsync.iowaitts;
1308                 if (panicstr)
1309                         err = VOP_DUMP(dumpvp, dumpbuf.start,
1310                             lbtodb(dumpbuf.vp_off), btod(size), NULL);
1311                 else
1312                         err = vn_rdwr(UIO_WRITE, dumpbuf.cdev_vp != NULL ?
1313                             dumpbuf.cdev_vp : dumpvp, dumpbuf.start, size,
1314                             dumpbuf.vp_off, UIO_SYSSPACE, 0, dumpbuf.vp_limit,
1315                             kcred, 0);
1316                 if (err && dump_ioerr == 0)
1317                         dump_ioerr = err;
1318                 dumpsync.iowaitts = gethrtime();
1319                 dumpsync.iotime += dumpsync.iowaitts - iotime;
1320                 dumpsync.nwrite += size;
1321                 dumpbuf.vp_off += size;
1322         }
1323         dumpbuf.cur = dumpbuf.start;
1324         dump_timeleft = dump_timeout;
1325         return (dumpbuf.vp_off);
1326 }
1327 
1328 /* maximize write speed by keeping seek offset aligned with size */
1329 void
1330 dumpvp_write(const void *va, size_t size)
1331 {
1332         size_t len, off, sz;
1333 
1334         while (size != 0) {
1335                 len = MIN(size, dumpbuf.end - dumpbuf.cur);
1336                 if (len == 0) {
1337                         off = P2PHASE(dumpbuf.vp_off, dumpbuf.size);
1338                         if (off == 0 || !ISP2(dumpbuf.size)) {
1339                                 (void) dumpvp_flush();
1340                         } else {
1341                                 sz = dumpbuf.size - off;
1342                                 dumpbuf.cur = dumpbuf.start + sz;
1343                                 (void) dumpvp_flush();
1344                                 ovbcopy(dumpbuf.start + sz, dumpbuf.start, off);
1345                                 dumpbuf.cur += off;
1346                         }
1347                 } else {
1348                         bcopy(va, dumpbuf.cur, len);
1349                         va = (char *)va + len;
1350                         dumpbuf.cur += len;
1351                         size -= len;
1352                 }
1353         }
1354 }
1355 
1356 /*ARGSUSED*/
1357 static void
1358 dumpvp_ksyms_write(const void *src, void *dst, size_t size)
1359 {
1360         dumpvp_write(src, size);
1361 }
1362 
1363 /*
1364  * Mark 'pfn' in the bitmap and dump its translation table entry.
1365  */
1366 void
1367 dump_addpage(struct as *as, void *va, pfn_t pfn)
1368 {
1369         mem_vtop_t mem_vtop;
1370         pgcnt_t bitnum;
1371 
1372         if ((bitnum = dump_pfn_to_bitnum(pfn)) != (pgcnt_t)-1) {
1373                 if (!BT_TEST(dumpcfg.bitmap, bitnum)) {
1374                         dumphdr->dump_npages++;
1375                         BT_SET(dumpcfg.bitmap, bitnum);
1376                 }
1377                 dumphdr->dump_nvtop++;
1378                 mem_vtop.m_as = as;
1379                 mem_vtop.m_va = va;
1380                 mem_vtop.m_pfn = pfn;
1381                 dumpvp_write(&mem_vtop, sizeof (mem_vtop_t));
1382         }
1383         dump_timeleft = dump_timeout;
1384 }
1385 
1386 /*
1387  * Mark 'pfn' in the bitmap
1388  */
1389 void
1390 dump_page(pfn_t pfn)
1391 {
1392         pgcnt_t bitnum;
1393 
1394         if ((bitnum = dump_pfn_to_bitnum(pfn)) != (pgcnt_t)-1) {
1395                 if (!BT_TEST(dumpcfg.bitmap, bitnum)) {
1396                         dumphdr->dump_npages++;
1397                         BT_SET(dumpcfg.bitmap, bitnum);
1398                 }
1399         }
1400         dump_timeleft = dump_timeout;
1401 }
1402 
1403 /*
1404  * Dump the <as, va, pfn> information for a given address space.
1405  * SEGOP_DUMP() will call dump_addpage() for each page in the segment.
1406  */
1407 static void
1408 dump_as(struct as *as)
1409 {
1410         struct seg *seg;
1411 
1412         AS_LOCK_ENTER(as, RW_READER);
1413         for (seg = AS_SEGFIRST(as); seg; seg = AS_SEGNEXT(as, seg)) {
1414                 if (seg->s_as != as)
1415                         break;
1416                 if (seg->s_ops == NULL)
1417                         continue;
1418                 SEGOP_DUMP(seg);
1419         }
1420         AS_LOCK_EXIT(as);
1421 
1422         if (seg != NULL)
1423                 cmn_err(CE_WARN, "invalid segment %p in address space %p",
1424                     (void *)seg, (void *)as);
1425 }
1426 
1427 static int
1428 dump_process(pid_t pid)
1429 {
1430         proc_t *p = sprlock(pid);
1431 
1432         if (p == NULL)
1433                 return (-1);
1434         if (p->p_as != &kas) {
1435                 mutex_exit(&p->p_lock);
1436                 dump_as(p->p_as);
1437                 mutex_enter(&p->p_lock);
1438         }
1439 
1440         sprunlock(p);
1441 
1442         return (0);
1443 }
1444 
1445 /*
1446  * The following functions (dump_summary(), dump_ereports(), and
1447  * dump_messages()), write data to an uncompressed area within the
1448  * crashdump. The layout of these is
1449  *
1450  * +------------------------------------------------------------+
1451  * |     compressed pages       | summary | ereports | messages |
1452  * +------------------------------------------------------------+
1453  *
1454  * With the advent of saving a compressed crash dump by default, we
1455  * need to save a little more data to describe the failure mode in
1456  * an uncompressed buffer available before savecore uncompresses
1457  * the dump. Initially this is a copy of the stack trace. Additional
1458  * summary information should be added here.
1459  */
1460 
1461 void
1462 dump_summary(void)
1463 {
1464         u_offset_t dumpvp_start;
1465         summary_dump_t sd;
1466 
1467         if (dumpvp == NULL || dumphdr == NULL)
1468                 return;
1469 
1470         dumpbuf.cur = dumpbuf.start;
1471 
1472         dumpbuf.vp_limit = dumpvp_size - (DUMP_OFFSET + DUMP_LOGSIZE +
1473             DUMP_ERPTSIZE);
1474         dumpvp_start = dumpbuf.vp_limit - DUMP_SUMMARYSIZE;
1475         dumpbuf.vp_off = dumpvp_start;
1476 
1477         sd.sd_magic = SUMMARY_MAGIC;
1478         sd.sd_ssum = checksum32(dump_stack_scratch, STACK_BUF_SIZE);
1479         dumpvp_write(&sd, sizeof (sd));
1480         dumpvp_write(dump_stack_scratch, STACK_BUF_SIZE);
1481 
1482         sd.sd_magic = 0; /* indicate end of summary */
1483         dumpvp_write(&sd, sizeof (sd));
1484         (void) dumpvp_flush();
1485 }
1486 
1487 void
1488 dump_ereports(void)
1489 {
1490         u_offset_t dumpvp_start;
1491         erpt_dump_t ed;
1492 
1493         if (dumpvp == NULL || dumphdr == NULL)
1494                 return;
1495 
1496         dumpbuf.cur = dumpbuf.start;
1497         dumpbuf.vp_limit = dumpvp_size - (DUMP_OFFSET + DUMP_LOGSIZE);
1498         dumpvp_start = dumpbuf.vp_limit - DUMP_ERPTSIZE;
1499         dumpbuf.vp_off = dumpvp_start;
1500 
1501         fm_ereport_dump();
1502         if (panicstr)
1503                 errorq_dump();
1504 
1505         bzero(&ed, sizeof (ed)); /* indicate end of ereports */
1506         dumpvp_write(&ed, sizeof (ed));
1507         (void) dumpvp_flush();
1508 
1509         if (!panicstr) {
1510                 (void) VOP_PUTPAGE(dumpvp, dumpvp_start,
1511                     (size_t)(dumpbuf.vp_off - dumpvp_start),
1512                     B_INVAL | B_FORCE, kcred, NULL);
1513         }
1514 }
1515 
1516 void
1517 dump_messages(void)
1518 {
1519         log_dump_t ld;
1520         mblk_t *mctl, *mdata;
1521         queue_t *q, *qlast;
1522         u_offset_t dumpvp_start;
1523 
1524         if (dumpvp == NULL || dumphdr == NULL || log_consq == NULL)
1525                 return;
1526 
1527         dumpbuf.cur = dumpbuf.start;
1528         dumpbuf.vp_limit = dumpvp_size - DUMP_OFFSET;
1529         dumpvp_start = dumpbuf.vp_limit - DUMP_LOGSIZE;
1530         dumpbuf.vp_off = dumpvp_start;
1531 
1532         qlast = NULL;
1533         do {
1534                 for (q = log_consq; q->q_next != qlast; q = q->q_next)
1535                         continue;
1536                 for (mctl = q->q_first; mctl != NULL; mctl = mctl->b_next) {
1537                         dump_timeleft = dump_timeout;
1538                         mdata = mctl->b_cont;
1539                         ld.ld_magic = LOG_MAGIC;
1540                         ld.ld_msgsize = MBLKL(mctl->b_cont);
1541                         ld.ld_csum = checksum32(mctl->b_rptr, MBLKL(mctl));
1542                         ld.ld_msum = checksum32(mdata->b_rptr, MBLKL(mdata));
1543                         dumpvp_write(&ld, sizeof (ld));
1544                         dumpvp_write(mctl->b_rptr, MBLKL(mctl));
1545                         dumpvp_write(mdata->b_rptr, MBLKL(mdata));
1546                 }
1547         } while ((qlast = q) != log_consq);
1548 
1549         ld.ld_magic = 0;                /* indicate end of messages */
1550         dumpvp_write(&ld, sizeof (ld));
1551         (void) dumpvp_flush();
1552         if (!panicstr) {
1553                 (void) VOP_PUTPAGE(dumpvp, dumpvp_start,
1554                     (size_t)(dumpbuf.vp_off - dumpvp_start),
1555                     B_INVAL | B_FORCE, kcred, NULL);
1556         }
1557 }
1558 
1559 /*
1560  * The following functions are called on multiple CPUs during dump.
1561  * They must not use most kernel services, because all cross-calls are
1562  * disabled during panic. Therefore, blocking locks and cache flushes
1563  * will not work.
1564  */
1565 
1566 /*
1567  * Copy pages, trapping ECC errors. Also, for robustness, trap data
1568  * access in case something goes wrong in the hat layer and the
1569  * mapping is broken.
1570  */
1571 static int
1572 dump_pagecopy(void *src, void *dst)
1573 {
1574         long *wsrc = (long *)src;
1575         long *wdst = (long *)dst;
1576         const ulong_t ncopies = PAGESIZE / sizeof (long);
1577         volatile int w = 0;
1578         volatile int ueoff = -1;
1579         on_trap_data_t otd;
1580 
1581         if (on_trap(&otd, OT_DATA_EC | OT_DATA_ACCESS)) {
1582                 if (ueoff == -1)
1583                         ueoff = w * sizeof (long);
1584                 /* report "bad ECC" or "bad address" */
1585 #ifdef _LP64
1586                 if (otd.ot_trap & OT_DATA_EC)
1587                         wdst[w++] = 0x00badecc00badecc;
1588                 else
1589                         wdst[w++] = 0x00badadd00badadd;
1590 #else
1591                 if (otd.ot_trap & OT_DATA_EC)
1592                         wdst[w++] = 0x00badecc;
1593                 else
1594                         wdst[w++] = 0x00badadd;
1595 #endif
1596         }
1597         while (w < ncopies) {
1598                 wdst[w] = wsrc[w];
1599                 w++;
1600         }
1601         no_trap();
1602         return (ueoff);
1603 }
1604 
1605 static void
1606 dumpsys_close_cq(cqueue_t *cq, int live)
1607 {
1608         if (live) {
1609                 mutex_enter(&cq->mutex);
1610                 atomic_dec_uint(&cq->open);
1611                 cv_signal(&cq->cv);
1612                 mutex_exit(&cq->mutex);
1613         } else {
1614                 atomic_dec_uint(&cq->open);
1615         }
1616 }
1617 
1618 static inline void
1619 dumpsys_spinlock(lock_t *lp)
1620 {
1621         uint_t backoff = 0;
1622         int loop_count = 0;
1623 
1624         while (LOCK_HELD(lp) || !lock_spin_try(lp)) {
1625                 if (++loop_count >= ncpus) {
1626                         backoff = mutex_lock_backoff(0);
1627                         loop_count = 0;
1628                 } else {
1629                         backoff = mutex_lock_backoff(backoff);
1630                 }
1631                 mutex_lock_delay(backoff);
1632         }
1633 }
1634 
1635 static inline void
1636 dumpsys_spinunlock(lock_t *lp)
1637 {
1638         lock_clear(lp);
1639 }
1640 
1641 static inline void
1642 dumpsys_lock(cqueue_t *cq, int live)
1643 {
1644         if (live)
1645                 mutex_enter(&cq->mutex);
1646         else
1647                 dumpsys_spinlock(&cq->spinlock);
1648 }
1649 
1650 static inline void
1651 dumpsys_unlock(cqueue_t *cq, int live, int signal)
1652 {
1653         if (live) {
1654                 if (signal)
1655                         cv_signal(&cq->cv);
1656                 mutex_exit(&cq->mutex);
1657         } else {
1658                 dumpsys_spinunlock(&cq->spinlock);
1659         }
1660 }
1661 
1662 static void
1663 dumpsys_wait_cq(cqueue_t *cq, int live)
1664 {
1665         if (live) {
1666                 cv_wait(&cq->cv, &cq->mutex);
1667         } else {
1668                 dumpsys_spinunlock(&cq->spinlock);
1669                 while (cq->open)
1670                         if (cq->first)
1671                                 break;
1672                 dumpsys_spinlock(&cq->spinlock);
1673         }
1674 }
1675 
1676 static void
1677 dumpsys_put_cq(cqueue_t *cq, cbuf_t *cp, int newstate, int live)
1678 {
1679         if (cp == NULL)
1680                 return;
1681 
1682         dumpsys_lock(cq, live);
1683 
1684         if (cq->ts != 0) {
1685                 cq->empty += gethrtime() - cq->ts;
1686                 cq->ts = 0;
1687         }
1688 
1689         cp->state = newstate;
1690         cp->next = NULL;
1691         if (cq->last == NULL)
1692                 cq->first = cp;
1693         else
1694                 cq->last->next = cp;
1695         cq->last = cp;
1696 
1697         dumpsys_unlock(cq, live, 1);
1698 }
1699 
1700 static cbuf_t *
1701 dumpsys_get_cq(cqueue_t *cq, int live)
1702 {
1703         cbuf_t *cp;
1704         hrtime_t now = gethrtime();
1705 
1706         dumpsys_lock(cq, live);
1707 
1708         /* CONSTCOND */
1709         while (1) {
1710                 cp = (cbuf_t *)cq->first;
1711                 if (cp == NULL) {
1712                         if (cq->open == 0)
1713                                 break;
1714                         dumpsys_wait_cq(cq, live);
1715                         continue;
1716                 }
1717                 cq->first = cp->next;
1718                 if (cq->first == NULL) {
1719                         cq->last = NULL;
1720                         cq->ts = now;
1721                 }
1722                 break;
1723         }
1724 
1725         dumpsys_unlock(cq, live, cq->first != NULL || cq->open == 0);
1726         return (cp);
1727 }
1728 
1729 /*
1730  * Send an error message to the console. If the main task is running
1731  * just write the message via uprintf. If a helper is running the
1732  * message has to be put on a queue for the main task. Setting fmt to
1733  * NULL means flush the error message buffer. If fmt is not NULL, just
1734  * add the text to the existing buffer.
1735  */
1736 static void
1737 dumpsys_errmsg(helper_t *hp, const char *fmt, ...)
1738 {
1739         dumpsync_t *ds = hp->ds;
1740         cbuf_t *cp = hp->cperr;
1741         va_list adx;
1742 
1743         if (hp->helper == MAINHELPER) {
1744                 if (fmt != NULL) {
1745                         if (ds->neednl) {
1746                                 uprintf("\n");
1747                                 ds->neednl = 0;
1748                         }
1749                         va_start(adx, fmt);
1750                         vuprintf(fmt, adx);
1751                         va_end(adx);
1752                 }
1753         } else if (fmt == NULL) {
1754                 if (cp != NULL) {
1755                         CQ_PUT(mainq, cp, CBUF_ERRMSG);
1756                         hp->cperr = NULL;
1757                 }
1758         } else {
1759                 if (hp->cperr == NULL) {
1760                         cp = CQ_GET(freebufq);
1761                         hp->cperr = cp;
1762                         cp->used = 0;
1763                 }
1764                 va_start(adx, fmt);
1765                 cp->used += vsnprintf(cp->buf + cp->used, cp->size - cp->used,
1766                     fmt, adx);
1767                 va_end(adx);
1768                 if ((cp->used + LOG_MSGSIZE) > cp->size) {
1769                         CQ_PUT(mainq, cp, CBUF_ERRMSG);
1770                         hp->cperr = NULL;
1771                 }
1772         }
1773 }
1774 
1775 /*
1776  * Write an output buffer to the dump file. If the main task is
1777  * running just write the data. If a helper is running the output is
1778  * placed on a queue for the main task.
1779  */
1780 static void
1781 dumpsys_swrite(helper_t *hp, cbuf_t *cp, size_t used)
1782 {
1783         dumpsync_t *ds = hp->ds;
1784 
1785         if (hp->helper == MAINHELPER) {
1786                 HRSTART(ds->perpage, write);
1787                 dumpvp_write(cp->buf, used);
1788                 HRSTOP(ds->perpage, write);
1789                 CQ_PUT(freebufq, cp, CBUF_FREEBUF);
1790         } else {
1791                 cp->used = used;
1792                 CQ_PUT(mainq, cp, CBUF_WRITE);
1793         }
1794 }
1795 
1796 /*
1797  * Copy one page within the mapped range. The offset starts at 0 and
1798  * is relative to the first pfn. cp->buf + cp->off is the address of
1799  * the first pfn. If dump_pagecopy returns a UE offset, create an
1800  * error message.  Returns the offset to the next pfn in the range
1801  * selected by the bitmap.
1802  */
1803 static int
1804 dumpsys_copy_page(helper_t *hp, int offset)
1805 {
1806         cbuf_t *cp = hp->cpin;
1807         int ueoff;
1808 
1809         ASSERT(cp->off + offset + PAGESIZE <= cp->size);
1810         ASSERT(BT_TEST(dumpcfg.bitmap, cp->bitnum));
1811 
1812         ueoff = dump_pagecopy(cp->buf + cp->off + offset, hp->page);
1813 
1814         /* ueoff is the offset in the page to a UE error */
1815         if (ueoff != -1) {
1816                 uint64_t pa = ptob(cp->pfn) + offset + ueoff;
1817 
1818                 dumpsys_errmsg(hp, "cpu %d: memory error at PA 0x%08x.%08x\n",
1819                     CPU->cpu_id, (uint32_t)(pa >> 32), (uint32_t)pa);
1820         }
1821 
1822         /*
1823          * Advance bitnum and offset to the next input page for the
1824          * next call to this function.
1825          */
1826         offset += PAGESIZE;
1827         cp->bitnum++;
1828         while (cp->off + offset < cp->size) {
1829                 if (BT_TEST(dumpcfg.bitmap, cp->bitnum))
1830                         break;
1831                 offset += PAGESIZE;
1832                 cp->bitnum++;
1833         }
1834 
1835         return (offset);
1836 }
1837 
1838 /*
1839  * Read the helper queue, and copy one mapped page. Return 0 when
1840  * done. Return 1 when a page has been copied into hp->page.
1841  */
1842 static int
1843 dumpsys_sread(helper_t *hp)
1844 {
1845         dumpsync_t *ds = hp->ds;
1846 
1847         /* CONSTCOND */
1848         while (1) {
1849 
1850                 /* Find the next input buffer. */
1851                 if (hp->cpin == NULL) {
1852                         HRSTART(hp->perpage, inwait);
1853 
1854                         /* CONSTCOND */
1855                         while (1) {
1856                                 hp->cpin = CQ_GET(helperq);
1857                                 dump_timeleft = dump_timeout;
1858 
1859                                 /*
1860                                  * NULL return means the helper queue
1861                                  * is closed and empty.
1862                                  */
1863                                 if (hp->cpin == NULL)
1864                                         break;
1865 
1866                                 /* Have input, check for dump I/O error. */
1867                                 if (!dump_ioerr)
1868                                         break;
1869 
1870                                 /*
1871                                  * If an I/O error occurs, stay in the
1872                                  * loop in order to empty the helper
1873                                  * queue. Return the buffers to the
1874                                  * main task to unmap and free it.
1875                                  */
1876                                 hp->cpin->used = 0;
1877                                 CQ_PUT(mainq, hp->cpin, CBUF_USEDMAP);
1878                         }
1879                         HRSTOP(hp->perpage, inwait);
1880 
1881                         /* Stop here when the helper queue is closed. */
1882                         if (hp->cpin == NULL)
1883                                 break;
1884 
1885                         /* Set the offset=0 to get the first pfn. */
1886                         hp->in = 0;
1887 
1888                         /* Set the total processed to 0 */
1889                         hp->used = 0;
1890                 }
1891 
1892                 /* Process the next page. */
1893                 if (hp->used < hp->cpin->used) {
1894 
1895                         /*
1896                          * Get the next page from the input buffer and
1897                          * return a copy.
1898                          */
1899                         ASSERT(hp->in != -1);
1900                         HRSTART(hp->perpage, copy);
1901                         hp->in = dumpsys_copy_page(hp, hp->in);
1902                         hp->used += PAGESIZE;
1903                         HRSTOP(hp->perpage, copy);
1904                         break;
1905 
1906                 } else {
1907 
1908                         /*
1909                          * Done with the input. Flush the VM and
1910                          * return the buffer to the main task.
1911                          */
1912                         if (panicstr && hp->helper != MAINHELPER)
1913                                 hat_flush_range(kas.a_hat,
1914                                     hp->cpin->buf, hp->cpin->size);
1915                         dumpsys_errmsg(hp, NULL);
1916                         CQ_PUT(mainq, hp->cpin, CBUF_USEDMAP);
1917                         hp->cpin = NULL;
1918                 }
1919         }
1920 
1921         return (hp->cpin != NULL);
1922 }
1923 
1924 /*
1925  * Compress size bytes starting at buf with bzip2
1926  * mode:
1927  *      BZ_RUN          add one more compressed page
1928  *      BZ_FINISH       no more input, flush the state
1929  */
1930 static void
1931 dumpsys_bzrun(helper_t *hp, void *buf, size_t size, int mode)
1932 {
1933         dumpsync_t *ds = hp->ds;
1934         const int CSIZE = sizeof (dumpcsize_t);
1935         bz_stream *ps = &hp->bzstream;
1936         int rc = 0;
1937         uint32_t csize;
1938         dumpcsize_t cs;
1939 
1940         /* Set input pointers to new input page */
1941         if (size > 0) {
1942                 ps->avail_in = size;
1943                 ps->next_in = buf;
1944         }
1945 
1946         /* CONSTCOND */
1947         while (1) {
1948 
1949                 /* Quit when all input has been consumed */
1950                 if (ps->avail_in == 0 && mode == BZ_RUN)
1951                         break;
1952 
1953                 /* Get a new output buffer */
1954                 if (hp->cpout == NULL) {
1955                         HRSTART(hp->perpage, outwait);
1956                         hp->cpout = CQ_GET(freebufq);
1957                         HRSTOP(hp->perpage, outwait);
1958                         ps->avail_out = hp->cpout->size - CSIZE;
1959                         ps->next_out = hp->cpout->buf + CSIZE;
1960                 }
1961 
1962                 /* Compress input, or finalize */
1963                 HRSTART(hp->perpage, compress);
1964                 rc = BZ2_bzCompress(ps, mode);
1965                 HRSTOP(hp->perpage, compress);
1966 
1967                 /* Check for error */
1968                 if (mode == BZ_RUN && rc != BZ_RUN_OK) {
1969                         dumpsys_errmsg(hp, "%d: BZ_RUN error %s at page %lx\n",
1970                             hp->helper, BZ2_bzErrorString(rc),
1971                             hp->cpin->pagenum);
1972                         break;
1973                 }
1974 
1975                 /* Write the buffer if it is full, or we are flushing */
1976                 if (ps->avail_out == 0 || mode == BZ_FINISH) {
1977                         csize = hp->cpout->size - CSIZE - ps->avail_out;
1978                         cs = DUMP_SET_TAG(csize, hp->tag);
1979                         if (csize > 0) {
1980                                 (void) memcpy(hp->cpout->buf, &cs, CSIZE);
1981                                 dumpsys_swrite(hp, hp->cpout, csize + CSIZE);
1982                                 hp->cpout = NULL;
1983                         }
1984                 }
1985 
1986                 /* Check for final complete */
1987                 if (mode == BZ_FINISH) {
1988                         if (rc == BZ_STREAM_END)
1989                                 break;
1990                         if (rc != BZ_FINISH_OK) {
1991                                 dumpsys_errmsg(hp, "%d: BZ_FINISH error %s\n",
1992                                     hp->helper, BZ2_bzErrorString(rc));
1993                                 break;
1994                         }
1995                 }
1996         }
1997 
1998         /* Cleanup state and buffers */
1999         if (mode == BZ_FINISH) {
2000 
2001                 /* Reset state so that it is re-usable. */
2002                 (void) BZ2_bzCompressReset(&hp->bzstream);
2003 
2004                 /* Give any unused outout buffer to the main task */
2005                 if (hp->cpout != NULL) {
2006                         hp->cpout->used = 0;
2007                         CQ_PUT(mainq, hp->cpout, CBUF_ERRMSG);
2008                         hp->cpout = NULL;
2009                 }
2010         }
2011 }
2012 
2013 static void
2014 dumpsys_bz2compress(helper_t *hp)
2015 {
2016         dumpsync_t *ds = hp->ds;
2017         dumpstreamhdr_t sh;
2018 
2019         (void) strcpy(sh.stream_magic, DUMP_STREAM_MAGIC);
2020         sh.stream_pagenum = (pgcnt_t)-1;
2021         sh.stream_npages = 0;
2022         hp->cpin = NULL;
2023         hp->cpout = NULL;
2024         hp->cperr = NULL;
2025         hp->in = 0;
2026         hp->out = 0;
2027         hp->bzstream.avail_in = 0;
2028 
2029         /* Bump reference to mainq while we are running */
2030         CQ_OPEN(mainq);
2031 
2032         /* Get one page at a time */
2033         while (dumpsys_sread(hp)) {
2034                 if (sh.stream_pagenum != hp->cpin->pagenum) {
2035                         sh.stream_pagenum = hp->cpin->pagenum;
2036                         sh.stream_npages = btop(hp->cpin->used);
2037                         dumpsys_bzrun(hp, &sh, sizeof (sh), BZ_RUN);
2038                 }
2039                 dumpsys_bzrun(hp, hp->page, PAGESIZE, 0);
2040         }
2041 
2042         /* Done with input, flush any partial buffer */
2043         if (sh.stream_pagenum != (pgcnt_t)-1) {
2044                 dumpsys_bzrun(hp, NULL, 0, BZ_FINISH);
2045                 dumpsys_errmsg(hp, NULL);
2046         }
2047 
2048         ASSERT(hp->cpin == NULL && hp->cpout == NULL && hp->cperr == NULL);
2049 
2050         /* Decrement main queue count, we are done */
2051         CQ_CLOSE(mainq);
2052 }
2053 
2054 /*
2055  * Compress with lzjb
2056  * write stream block if full or size==0
2057  * if csize==0 write stream header, else write <csize, data>
2058  * size==0 is a call to flush a buffer
2059  * hp->cpout is the buffer we are flushing or filling
2060  * hp->out is the next index to fill data
2061  * osize is either csize+data, or the size of a stream header
2062  */
2063 static void
2064 dumpsys_lzjbrun(helper_t *hp, size_t csize, void *buf, size_t size)
2065 {
2066         dumpsync_t *ds = hp->ds;
2067         const int CSIZE = sizeof (dumpcsize_t);
2068         dumpcsize_t cs;
2069         size_t osize = csize > 0 ? CSIZE + size : size;
2070 
2071         /* If flush, and there is no buffer, just return */
2072         if (size == 0 && hp->cpout == NULL)
2073                 return;
2074 
2075         /* If flush, or cpout is full, write it out */
2076         if (size == 0 ||
2077             hp->cpout != NULL && hp->out + osize > hp->cpout->size) {
2078 
2079                 /* Set tag+size word at the front of the stream block. */
2080                 cs = DUMP_SET_TAG(hp->out - CSIZE, hp->tag);
2081                 (void) memcpy(hp->cpout->buf, &cs, CSIZE);
2082 
2083                 /* Write block to dump file. */
2084                 dumpsys_swrite(hp, hp->cpout, hp->out);
2085 
2086                 /* Clear pointer to indicate we need a new buffer */
2087                 hp->cpout = NULL;
2088 
2089                 /* flushing, we are done */
2090                 if (size == 0)
2091                         return;
2092         }
2093 
2094         /* Get an output buffer if we dont have one. */
2095         if (hp->cpout == NULL) {
2096                 HRSTART(hp->perpage, outwait);
2097                 hp->cpout = CQ_GET(freebufq);
2098                 HRSTOP(hp->perpage, outwait);
2099                 hp->out = CSIZE;
2100         }
2101 
2102         /* Store csize word. This is the size of compressed data. */
2103         if (csize > 0) {
2104                 cs = DUMP_SET_TAG(csize, 0);
2105                 (void) memcpy(hp->cpout->buf + hp->out, &cs, CSIZE);
2106                 hp->out += CSIZE;
2107         }
2108 
2109         /* Store the data. */
2110         (void) memcpy(hp->cpout->buf + hp->out, buf, size);
2111         hp->out += size;
2112 }
2113 
2114 static void
2115 dumpsys_lzjbcompress(helper_t *hp)
2116 {
2117         dumpsync_t *ds = hp->ds;
2118         size_t csize;
2119         dumpstreamhdr_t sh;
2120 
2121         (void) strcpy(sh.stream_magic, DUMP_STREAM_MAGIC);
2122         sh.stream_pagenum = (pfn_t)-1;
2123         sh.stream_npages = 0;
2124         hp->cpin = NULL;
2125         hp->cpout = NULL;
2126         hp->cperr = NULL;
2127         hp->in = 0;
2128         hp->out = 0;
2129 
2130         /* Bump reference to mainq while we are running */
2131         CQ_OPEN(mainq);
2132 
2133         /* Get one page at a time */
2134         while (dumpsys_sread(hp)) {
2135 
2136                 /* Create a stream header for each new input map */
2137                 if (sh.stream_pagenum != hp->cpin->pagenum) {
2138                         sh.stream_pagenum = hp->cpin->pagenum;
2139                         sh.stream_npages = btop(hp->cpin->used);
2140                         dumpsys_lzjbrun(hp, 0, &sh, sizeof (sh));
2141                 }
2142 
2143                 /* Compress one page */
2144                 HRSTART(hp->perpage, compress);
2145                 csize = compress(hp->page, hp->lzbuf, PAGESIZE);
2146                 HRSTOP(hp->perpage, compress);
2147 
2148                 /* Add csize+data to output block */
2149                 ASSERT(csize > 0 && csize <= PAGESIZE);
2150                 dumpsys_lzjbrun(hp, csize, hp->lzbuf, csize);
2151         }
2152 
2153         /* Done with input, flush any partial buffer */
2154         if (sh.stream_pagenum != (pfn_t)-1) {
2155                 dumpsys_lzjbrun(hp, 0, NULL, 0);
2156                 dumpsys_errmsg(hp, NULL);
2157         }
2158 
2159         ASSERT(hp->cpin == NULL && hp->cpout == NULL && hp->cperr == NULL);
2160 
2161         /* Decrement main queue count, we are done */
2162         CQ_CLOSE(mainq);
2163 }
2164 
2165 /*
2166  * Dump helper called from panic_idle() to compress pages.  CPUs in
2167  * this path must not call most kernel services.
2168  *
2169  * During panic, all but one of the CPUs is idle. These CPUs are used
2170  * as helpers working in parallel to copy and compress memory
2171  * pages. During a panic, however, these processors cannot call any
2172  * kernel services. This is because mutexes become no-ops during
2173  * panic, and, cross-call interrupts are inhibited.  Therefore, during
2174  * panic dump the helper CPUs communicate with the panic CPU using
2175  * memory variables. All memory mapping and I/O is performed by the
2176  * panic CPU.
2177  *
2178  * At dump configuration time, helper_lock is set and helpers_wanted
2179  * is 0. dumpsys() decides whether to set helpers_wanted before
2180  * clearing helper_lock.
2181  *
2182  * At panic time, idle CPUs spin-wait on helper_lock, then alternately
2183  * take the lock and become a helper, or return.
2184  */
2185 void
2186 dumpsys_helper()
2187 {
2188         dumpsys_spinlock(&dumpcfg.helper_lock);
2189         if (dumpcfg.helpers_wanted) {
2190                 helper_t *hp, *hpend = &dumpcfg.helper[dumpcfg.nhelper];
2191 
2192                 for (hp = dumpcfg.helper; hp != hpend; hp++) {
2193                         if (hp->helper == FREEHELPER) {
2194                                 hp->helper = CPU->cpu_id;
2195                                 BT_SET(dumpcfg.helpermap, CPU->cpu_seqid);
2196 
2197                                 dumpsys_spinunlock(&dumpcfg.helper_lock);
2198 
2199                                 if (dumpcfg.clevel < DUMP_CLEVEL_BZIP2)
2200                                         dumpsys_lzjbcompress(hp);
2201                                 else
2202                                         dumpsys_bz2compress(hp);
2203 
2204                                 hp->helper = DONEHELPER;
2205                                 return;
2206                         }
2207                 }
2208 
2209                 /* No more helpers are needed. */
2210                 dumpcfg.helpers_wanted = 0;
2211 
2212         }
2213         dumpsys_spinunlock(&dumpcfg.helper_lock);
2214 }
2215 
2216 /*
2217  * No-wait helper callable in spin loops.
2218  *
2219  * Do not wait for helper_lock. Just check helpers_wanted. The caller
2220  * may decide to continue. This is the "c)ontinue, s)ync, r)eset? s"
2221  * case.
2222  */
2223 void
2224 dumpsys_helper_nw()
2225 {
2226         if (dumpcfg.helpers_wanted)
2227                 dumpsys_helper();
2228 }
2229 
2230 /*
2231  * Dump helper for live dumps.
2232  * These run as a system task.
2233  */
2234 static void
2235 dumpsys_live_helper(void *arg)
2236 {
2237         helper_t *hp = arg;
2238 
2239         BT_ATOMIC_SET(dumpcfg.helpermap, CPU->cpu_seqid);
2240         if (dumpcfg.clevel < DUMP_CLEVEL_BZIP2)
2241                 dumpsys_lzjbcompress(hp);
2242         else
2243                 dumpsys_bz2compress(hp);
2244 }
2245 
2246 /*
2247  * Compress one page with lzjb (single threaded case)
2248  */
2249 static void
2250 dumpsys_lzjb_page(helper_t *hp, cbuf_t *cp)
2251 {
2252         dumpsync_t *ds = hp->ds;
2253         uint32_t csize;
2254 
2255         hp->helper = MAINHELPER;
2256         hp->in = 0;
2257         hp->used = 0;
2258         hp->cpin = cp;
2259         while (hp->used < cp->used) {
2260                 HRSTART(hp->perpage, copy);
2261                 hp->in = dumpsys_copy_page(hp, hp->in);
2262                 hp->used += PAGESIZE;
2263                 HRSTOP(hp->perpage, copy);
2264 
2265                 HRSTART(hp->perpage, compress);
2266                 csize = compress(hp->page, hp->lzbuf, PAGESIZE);
2267                 HRSTOP(hp->perpage, compress);
2268 
2269                 HRSTART(hp->perpage, write);
2270                 dumpvp_write(&csize, sizeof (csize));
2271                 dumpvp_write(hp->lzbuf, csize);
2272                 HRSTOP(hp->perpage, write);
2273         }
2274         CQ_PUT(mainq, hp->cpin, CBUF_USEDMAP);
2275         hp->cpin = NULL;
2276 }
2277 
2278 /*
2279  * Main task to dump pages. This is called on the dump CPU.
2280  */
2281 static void
2282 dumpsys_main_task(void *arg)
2283 {
2284         dumpsync_t *ds = arg;
2285         pgcnt_t pagenum = 0, bitnum = 0, hibitnum;
2286         dumpmlw_t mlw;
2287         cbuf_t *cp;
2288         pgcnt_t baseoff, pfnoff;
2289         pfn_t base, pfn;
2290         int i, dumpserial;
2291 
2292         /*
2293          * Fall back to serial mode if there are no helpers.
2294          * dump_plat_mincpu can be set to 0 at any time.
2295          * dumpcfg.helpermap must contain at least one member.
2296          */
2297         dumpserial = 1;
2298 
2299         if (dump_plat_mincpu != 0 && dumpcfg.clevel != 0) {
2300                 for (i = 0; i < BT_BITOUL(NCPU); ++i) {
2301                         if (dumpcfg.helpermap[i] != 0) {
2302                                 dumpserial = 0;
2303                                 break;
2304                         }
2305                 }
2306         }
2307 
2308         if (dumpserial) {
2309                 dumpcfg.clevel = 0;
2310                 if (dumpcfg.helper[0].lzbuf == NULL)
2311                         dumpcfg.helper[0].lzbuf = dumpcfg.helper[1].page;
2312         }
2313 
2314         dump_init_memlist_walker(&mlw);
2315 
2316         for (;;) {
2317                 int sec = (gethrtime() - ds->start) / NANOSEC;
2318 
2319                 /*
2320                  * Render a simple progress display on the system console to
2321                  * make clear to the operator that the system has not hung.
2322                  * Emit an update when dump progress has advanced by one
2323                  * percent, or when no update has been drawn in the last
2324                  * second.
2325                  */
2326                 if (ds->percent > ds->percent_done || sec > ds->sec_done) {
2327                         ds->sec_done = sec;
2328                         ds->percent_done = ds->percent;
2329                         uprintf("^\rdumping: %2d:%02d %3d%% done",
2330                             sec / 60, sec % 60, ds->percent);
2331                         ds->neednl = 1;
2332                 }
2333 
2334                 while (CQ_IS_EMPTY(mainq) && !CQ_IS_EMPTY(writerq)) {
2335 
2336                         /* the writerq never blocks */
2337                         cp = CQ_GET(writerq);
2338                         if (cp == NULL)
2339                                 break;
2340 
2341                         dump_timeleft = dump_timeout;
2342 
2343                         HRSTART(ds->perpage, write);
2344                         dumpvp_write(cp->buf, cp->used);
2345                         HRSTOP(ds->perpage, write);
2346 
2347                         CQ_PUT(freebufq, cp, CBUF_FREEBUF);
2348                 }
2349 
2350                 /*
2351                  * Wait here for some buffers to process. Returns NULL
2352                  * when all helpers have terminated and all buffers
2353                  * have been processed.
2354                  */
2355                 cp = CQ_GET(mainq);
2356 
2357                 if (cp == NULL) {
2358 
2359                         /* Drain the write queue. */
2360                         if (!CQ_IS_EMPTY(writerq))
2361                                 continue;
2362 
2363                         /* Main task exits here. */
2364                         break;
2365                 }
2366 
2367                 dump_timeleft = dump_timeout;
2368 
2369                 switch (cp->state) {
2370 
2371                 case CBUF_FREEMAP:
2372 
2373                         /*
2374                          * Note that we drop CBUF_FREEMAP buffers on
2375                          * the floor (they will not be on any cqueue)
2376                          * when we no longer need them.
2377                          */
2378                         if (bitnum >= dumpcfg.bitmapsize)
2379                                 break;
2380 
2381                         if (dump_ioerr) {
2382                                 bitnum = dumpcfg.bitmapsize;
2383                                 CQ_CLOSE(helperq);
2384                                 break;
2385                         }
2386 
2387                         HRSTART(ds->perpage, bitmap);
2388                         for (; bitnum < dumpcfg.bitmapsize; bitnum++)
2389                                 if (BT_TEST(dumpcfg.bitmap, bitnum))
2390                                         break;
2391                         HRSTOP(ds->perpage, bitmap);
2392                         dump_timeleft = dump_timeout;
2393 
2394                         if (bitnum >= dumpcfg.bitmapsize) {
2395                                 CQ_CLOSE(helperq);
2396                                 break;
2397                         }
2398 
2399                         /*
2400                          * Try to map CBUF_MAPSIZE ranges. Can't
2401                          * assume that memory segment size is a
2402                          * multiple of CBUF_MAPSIZE. Can't assume that
2403                          * the segment starts on a CBUF_MAPSIZE
2404                          * boundary.
2405                          */
2406                         pfn = dump_bitnum_to_pfn(bitnum, &mlw);
2407                         ASSERT(pfn != PFN_INVALID);
2408                         ASSERT(bitnum + mlw.mpleft <= dumpcfg.bitmapsize);
2409 
2410                         base = P2ALIGN(pfn, CBUF_MAPNP);
2411                         if (base < mlw.mpaddr) {
2412                                 base = mlw.mpaddr;
2413                                 baseoff = P2PHASE(base, CBUF_MAPNP);
2414                         } else {
2415                                 baseoff = 0;
2416                         }
2417 
2418                         pfnoff = pfn - base;
2419                         if (pfnoff + mlw.mpleft < CBUF_MAPNP) {
2420                                 hibitnum = bitnum + mlw.mpleft;
2421                                 cp->size = ptob(pfnoff + mlw.mpleft);
2422                         } else {
2423                                 hibitnum = bitnum - pfnoff + CBUF_MAPNP -
2424                                     baseoff;
2425                                 cp->size = CBUF_MAPSIZE - ptob(baseoff);
2426                         }
2427 
2428                         cp->pfn = pfn;
2429                         cp->bitnum = bitnum++;
2430                         cp->pagenum = pagenum++;
2431                         cp->off = ptob(pfnoff);
2432 
2433                         for (; bitnum < hibitnum; bitnum++)
2434                                 if (BT_TEST(dumpcfg.bitmap, bitnum))
2435                                         pagenum++;
2436 
2437                         dump_timeleft = dump_timeout;
2438                         cp->used = ptob(pagenum - cp->pagenum);
2439 
2440                         HRSTART(ds->perpage, map);
2441                         hat_devload(kas.a_hat, cp->buf, cp->size, base,
2442                             PROT_READ, HAT_LOAD_NOCONSIST);
2443                         HRSTOP(ds->perpage, map);
2444 
2445                         ds->pages_mapped += btop(cp->size);
2446                         ds->pages_used += pagenum - cp->pagenum;
2447 
2448                         CQ_OPEN(mainq);
2449 
2450                         /*
2451                          * If there are no helpers the main task does
2452                          * non-streams lzjb compress.
2453                          */
2454                         if (dumpserial) {
2455                                 dumpsys_lzjb_page(dumpcfg.helper, cp);
2456                                 break;
2457                         }
2458 
2459                         /* pass mapped pages to a helper */
2460                         CQ_PUT(helperq, cp, CBUF_INREADY);
2461 
2462                         /* the last page was done */
2463                         if (bitnum >= dumpcfg.bitmapsize)
2464                                 CQ_CLOSE(helperq);
2465 
2466                         break;
2467 
2468                 case CBUF_USEDMAP:
2469 
2470                         ds->npages += btop(cp->used);
2471 
2472                         HRSTART(ds->perpage, unmap);
2473                         hat_unload(kas.a_hat, cp->buf, cp->size, HAT_UNLOAD);
2474                         HRSTOP(ds->perpage, unmap);
2475 
2476                         if (bitnum < dumpcfg.bitmapsize)
2477                                 CQ_PUT(mainq, cp, CBUF_FREEMAP);
2478                         CQ_CLOSE(mainq);
2479 
2480                         ASSERT(ds->npages <= dumphdr->dump_npages);
2481                         ds->percent = ds->npages * 100LL / dumphdr->dump_npages;
2482                         break;
2483 
2484                 case CBUF_WRITE:
2485 
2486                         CQ_PUT(writerq, cp, CBUF_WRITE);
2487                         break;
2488 
2489                 case CBUF_ERRMSG:
2490 
2491                         if (cp->used > 0) {
2492                                 cp->buf[cp->size - 2] = '\n';
2493                                 cp->buf[cp->size - 1] = '\0';
2494                                 if (ds->neednl) {
2495                                         uprintf("\n%s", cp->buf);
2496                                         ds->neednl = 0;
2497                                 } else {
2498                                         uprintf("%s", cp->buf);
2499                                 }
2500                                 /* wait for console output */
2501                                 drv_usecwait(200000);
2502                                 dump_timeleft = dump_timeout;
2503                         }
2504                         CQ_PUT(freebufq, cp, CBUF_FREEBUF);
2505                         break;
2506 
2507                 default:
2508                         uprintf("dump: unexpected buffer state %d, "
2509                             "buffer will be lost\n", cp->state);
2510                         break;
2511 
2512                 } /* end switch */
2513         }
2514 }
2515 
2516 #ifdef  COLLECT_METRICS
2517 size_t
2518 dumpsys_metrics(dumpsync_t *ds, char *buf, size_t size)
2519 {
2520         dumpcfg_t *cfg = &dumpcfg;
2521         int myid = CPU->cpu_seqid;
2522         int i, compress_ratio;
2523         int sec, iorate;
2524         helper_t *hp, *hpend = &cfg->helper[cfg->nhelper];
2525         char *e = buf + size;
2526         char *p = buf;
2527 
2528         sec = ds->elapsed / (1000 * 1000 * 1000ULL);
2529         if (sec < 1)
2530                 sec = 1;
2531 
2532         if (ds->iotime < 1)
2533                 ds->iotime = 1;
2534         iorate = (ds->nwrite * 100000ULL) / ds->iotime;
2535 
2536         compress_ratio = 100LL * ds->npages / btopr(ds->nwrite + 1);
2537 
2538 #define P(...) (p += p < e ? snprintf(p, e - p, __VA_ARGS__) : 0)
2539 
2540         P("Master cpu_seqid,%d\n", CPU->cpu_seqid);
2541         P("Master cpu_id,%d\n", CPU->cpu_id);
2542         P("dump_flags,0x%x\n", dumphdr->dump_flags);
2543         P("dump_ioerr,%d\n", dump_ioerr);
2544 
2545         P("Helpers:\n");
2546         for (i = 0; i < ncpus; i++) {
2547                 if ((i & 15) == 0)
2548                         P(",,%03d,", i);
2549                 if (i == myid)
2550                         P("   M");
2551                 else if (BT_TEST(cfg->helpermap, i))
2552                         P("%4d", cpu_seq[i]->cpu_id);
2553                 else
2554                         P("   *");
2555                 if ((i & 15) == 15)
2556                         P("\n");
2557         }
2558 
2559         P("ncbuf_used,%d\n", cfg->ncbuf_used);
2560         P("ncmap,%d\n", cfg->ncmap);
2561 
2562         P("Found %ldM ranges,%ld\n", (CBUF_MAPSIZE / DUMP_1MB), cfg->found4m);
2563         P("Found small pages,%ld\n", cfg->foundsm);
2564 
2565         P("Compression level,%d\n", cfg->clevel);
2566         P("Compression type,%s %s\n", cfg->clevel == 0 ? "serial" : "parallel",
2567             cfg->clevel >= DUMP_CLEVEL_BZIP2 ? "bzip2" : "lzjb");
2568         P("Compression ratio,%d.%02d\n", compress_ratio / 100, compress_ratio %
2569             100);
2570         P("nhelper_used,%d\n", cfg->nhelper_used);
2571 
2572         P("Dump I/O rate MBS,%d.%02d\n", iorate / 100, iorate % 100);
2573         P("..total bytes,%lld\n", (u_longlong_t)ds->nwrite);
2574         P("..total nsec,%lld\n", (u_longlong_t)ds->iotime);
2575         P("dumpbuf.iosize,%ld\n", dumpbuf.iosize);
2576         P("dumpbuf.size,%ld\n", dumpbuf.size);
2577 
2578         P("Dump pages/sec,%llu\n", (u_longlong_t)ds->npages / sec);
2579         P("Dump pages,%llu\n", (u_longlong_t)ds->npages);
2580         P("Dump time,%d\n", sec);
2581 
2582         if (ds->pages_mapped > 0)
2583                 P("per-cent map utilization,%d\n", (int)((100 * ds->pages_used)
2584                     / ds->pages_mapped));
2585 
2586         P("\nPer-page metrics:\n");
2587         if (ds->npages > 0) {
2588                 for (hp = cfg->helper; hp != hpend; hp++) {
2589 #define PERPAGE(x)      ds->perpage.x += hp->perpage.x;
2590                         PERPAGES;
2591 #undef PERPAGE
2592                 }
2593 #define PERPAGE(x) \
2594                 P("%s nsec/page,%d\n", #x, (int)(ds->perpage.x / ds->npages));
2595                 PERPAGES;
2596 #undef PERPAGE
2597                 P("freebufq.empty,%d\n", (int)(ds->freebufq.empty /
2598                     ds->npages));
2599                 P("helperq.empty,%d\n", (int)(ds->helperq.empty /
2600                     ds->npages));
2601                 P("writerq.empty,%d\n", (int)(ds->writerq.empty /
2602                     ds->npages));
2603                 P("mainq.empty,%d\n", (int)(ds->mainq.empty / ds->npages));
2604 
2605                 P("I/O wait nsec/page,%llu\n", (u_longlong_t)(ds->iowait /
2606                     ds->npages));
2607         }
2608 #undef P
2609         if (p < e)
2610                 bzero(p, e - p);
2611         return (p - buf);
2612 }
2613 #endif  /* COLLECT_METRICS */
2614 
2615 /*
2616  * Dump the system.
2617  */
2618 void
2619 dumpsys(void)
2620 {
2621         dumpsync_t *ds = &dumpsync;
2622         taskq_t *livetaskq = NULL;
2623         pfn_t pfn;
2624         pgcnt_t bitnum;
2625         proc_t *p;
2626         helper_t *hp, *hpend = &dumpcfg.helper[dumpcfg.nhelper];
2627         cbuf_t *cp;
2628         pid_t npids, pidx;
2629         char *content;
2630         char *buf;
2631         size_t size;
2632         int save_dump_clevel;
2633         dumpmlw_t mlw;
2634         dumpcsize_t datatag;
2635         dumpdatahdr_t datahdr;
2636 
2637         if (dumpvp == NULL || dumphdr == NULL) {
2638                 uprintf("skipping system dump - no dump device configured\n");
2639                 if (panicstr) {
2640                         dumpcfg.helpers_wanted = 0;
2641                         dumpsys_spinunlock(&dumpcfg.helper_lock);
2642                 }
2643                 return;
2644         }
2645         dumpbuf.cur = dumpbuf.start;
2646 
2647         /* clear the sync variables */
2648         ASSERT(dumpcfg.nhelper > 0);
2649         bzero(ds, sizeof (*ds));
2650         ds->dumpcpu = CPU->cpu_id;
2651 
2652         /*
2653          * Calculate the starting block for dump.  If we're dumping on a
2654          * swap device, start 1/5 of the way in; otherwise, start at the
2655          * beginning.  And never use the first page -- it may be a disk label.
2656          */
2657         if (dumpvp->v_flag & VISSWAP)
2658                 dumphdr->dump_start = P2ROUNDUP(dumpvp_size / 5, DUMP_OFFSET);
2659         else
2660                 dumphdr->dump_start = DUMP_OFFSET;
2661 
2662         dumphdr->dump_flags = DF_VALID | DF_COMPLETE | DF_LIVE | DF_COMPRESSED;
2663         dumphdr->dump_crashtime = gethrestime_sec();
2664         dumphdr->dump_npages = 0;
2665         dumphdr->dump_nvtop = 0;
2666         bzero(dumpcfg.bitmap, BT_SIZEOFMAP(dumpcfg.bitmapsize));
2667         dump_timeleft = dump_timeout;
2668 
2669         if (panicstr) {
2670                 dumphdr->dump_flags &= ~DF_LIVE;
2671                 (void) VOP_DUMPCTL(dumpvp, DUMP_FREE, NULL, NULL);
2672                 (void) VOP_DUMPCTL(dumpvp, DUMP_ALLOC, NULL, NULL);
2673                 (void) vsnprintf(dumphdr->dump_panicstring, DUMP_PANICSIZE,
2674                     panicstr, panicargs);
2675 
2676         }
2677 
2678         if (dump_conflags & DUMP_ALL)
2679                 content = "all";
2680         else if (dump_conflags & DUMP_CURPROC)
2681                 content = "kernel + curproc";
2682         else
2683                 content = "kernel";
2684         uprintf("dumping to %s, offset %lld, content: %s\n", dumppath,
2685             dumphdr->dump_start, content);
2686 
2687         /* Make sure nodename is current */
2688         bcopy(utsname.nodename, dumphdr->dump_utsname.nodename, SYS_NMLN);
2689 
2690         /*
2691          * If this is a live dump, try to open a VCHR vnode for better
2692          * performance. We must take care to flush the buffer cache
2693          * first.
2694          */
2695         if (!panicstr) {
2696                 vnode_t *cdev_vp, *cmn_cdev_vp;
2697 
2698                 ASSERT(dumpbuf.cdev_vp == NULL);
2699                 cdev_vp = makespecvp(VTOS(dumpvp)->s_dev, VCHR);
2700                 if (cdev_vp != NULL) {
2701                         cmn_cdev_vp = common_specvp(cdev_vp);
2702                         if (VOP_OPEN(&cmn_cdev_vp, FREAD | FWRITE, kcred, NULL)
2703                             == 0) {
2704                                 if (vn_has_cached_data(dumpvp))
2705                                         (void) pvn_vplist_dirty(dumpvp, 0, NULL,
2706                                             B_INVAL | B_TRUNC, kcred);
2707                                 dumpbuf.cdev_vp = cmn_cdev_vp;
2708                         } else {
2709                                 VN_RELE(cdev_vp);
2710                         }
2711                 }
2712         }
2713 
2714         /*
2715          * Store a hires timestamp so we can look it up during debugging.
2716          */
2717         lbolt_debug_entry();
2718 
2719         /*
2720          * Leave room for the message and ereport save areas and terminal dump
2721          * header.
2722          */
2723         dumpbuf.vp_limit = dumpvp_size - DUMP_LOGSIZE - DUMP_OFFSET -
2724             DUMP_ERPTSIZE;
2725 
2726         /*
2727          * Write out the symbol table.  It's no longer compressed,
2728          * so its 'size' and 'csize' are equal.
2729          */
2730         dumpbuf.vp_off = dumphdr->dump_ksyms = dumphdr->dump_start + PAGESIZE;
2731         dumphdr->dump_ksyms_size = dumphdr->dump_ksyms_csize =
2732             ksyms_snapshot(dumpvp_ksyms_write, NULL, LONG_MAX);
2733 
2734         /*
2735          * Write out the translation map.
2736          */
2737         dumphdr->dump_map = dumpvp_flush();
2738         dump_as(&kas);
2739         dumphdr->dump_nvtop += dump_plat_addr();
2740 
2741         /*
2742          * call into hat, which may have unmapped pages that also need to
2743          * be in the dump
2744          */
2745         hat_dump();
2746 
2747         if (dump_conflags & DUMP_ALL) {
2748                 mutex_enter(&pidlock);
2749 
2750                 for (npids = 0, p = practive; p != NULL; p = p->p_next)
2751                         dumpcfg.pids[npids++] = p->p_pid;
2752 
2753                 mutex_exit(&pidlock);
2754 
2755                 for (pidx = 0; pidx < npids; pidx++)
2756                         (void) dump_process(dumpcfg.pids[pidx]);
2757 
2758                 dump_init_memlist_walker(&mlw);
2759                 for (bitnum = 0; bitnum < dumpcfg.bitmapsize; bitnum++) {
2760                         dump_timeleft = dump_timeout;
2761                         pfn = dump_bitnum_to_pfn(bitnum, &mlw);
2762                         /*
2763                          * Some hypervisors do not have all pages available to
2764                          * be accessed by the guest OS.  Check for page
2765                          * accessibility.
2766                          */
2767                         if (plat_hold_page(pfn, PLAT_HOLD_NO_LOCK, NULL) !=
2768                             PLAT_HOLD_OK)
2769                                 continue;
2770                         BT_SET(dumpcfg.bitmap, bitnum);
2771                 }
2772                 dumphdr->dump_npages = dumpcfg.bitmapsize;
2773                 dumphdr->dump_flags |= DF_ALL;
2774 
2775         } else if (dump_conflags & DUMP_CURPROC) {
2776                 /*
2777                  * Determine which pid is to be dumped.  If we're panicking, we
2778                  * dump the process associated with panic_thread (if any).  If
2779                  * this is a live dump, we dump the process associated with
2780                  * curthread.
2781                  */
2782                 npids = 0;
2783                 if (panicstr) {
2784                         if (panic_thread != NULL &&
2785                             panic_thread->t_procp != NULL &&
2786                             panic_thread->t_procp != &p0) {
2787                                 dumpcfg.pids[npids++] =
2788                                     panic_thread->t_procp->p_pid;
2789                         }
2790                 } else {
2791                         dumpcfg.pids[npids++] = curthread->t_procp->p_pid;
2792                 }
2793 
2794                 if (npids && dump_process(dumpcfg.pids[0]) == 0)
2795                         dumphdr->dump_flags |= DF_CURPROC;
2796                 else
2797                         dumphdr->dump_flags |= DF_KERNEL;
2798 
2799         } else {
2800                 dumphdr->dump_flags |= DF_KERNEL;
2801         }
2802 
2803         dumphdr->dump_hashmask = (1 << highbit(dumphdr->dump_nvtop - 1)) - 1;
2804 
2805         /*
2806          * Write out the pfn table.
2807          */
2808         dumphdr->dump_pfn = dumpvp_flush();
2809         dump_init_memlist_walker(&mlw);
2810         for (bitnum = 0; bitnum < dumpcfg.bitmapsize; bitnum++) {
2811                 dump_timeleft = dump_timeout;
2812                 if (!BT_TEST(dumpcfg.bitmap, bitnum))
2813                         continue;
2814                 pfn = dump_bitnum_to_pfn(bitnum, &mlw);
2815                 ASSERT(pfn != PFN_INVALID);
2816                 dumpvp_write(&pfn, sizeof (pfn_t));
2817         }
2818         dump_plat_pfn();
2819 
2820         /*
2821          * Write out all the pages.
2822          * Map pages, copy them handling UEs, compress, and write them out.
2823          * Cooperate with any helpers running on CPUs in panic_idle().
2824          */
2825         dumphdr->dump_data = dumpvp_flush();
2826 
2827         bzero(dumpcfg.helpermap, BT_SIZEOFMAP(NCPU));
2828         ds->live = dumpcfg.clevel > 0 &&
2829             (dumphdr->dump_flags & DF_LIVE) != 0;
2830 
2831         save_dump_clevel = dumpcfg.clevel;
2832         if (panicstr)
2833                 dumpsys_get_maxmem();
2834         else if (dumpcfg.clevel >= DUMP_CLEVEL_BZIP2)
2835                 dumpcfg.clevel = DUMP_CLEVEL_LZJB;
2836 
2837         dumpcfg.nhelper_used = 0;
2838         for (hp = dumpcfg.helper; hp != hpend; hp++) {
2839                 if (hp->page == NULL) {
2840                         hp->helper = DONEHELPER;
2841                         continue;
2842                 }
2843                 ++dumpcfg.nhelper_used;
2844                 hp->helper = FREEHELPER;
2845                 hp->taskqid = NULL;
2846                 hp->ds = ds;
2847                 bzero(&hp->perpage, sizeof (hp->perpage));
2848                 if (dumpcfg.clevel >= DUMP_CLEVEL_BZIP2)
2849                         (void) BZ2_bzCompressReset(&hp->bzstream);
2850         }
2851 
2852         CQ_OPEN(freebufq);
2853         CQ_OPEN(helperq);
2854 
2855         dumpcfg.ncbuf_used = 0;
2856         for (cp = dumpcfg.cbuf; cp != &dumpcfg.cbuf[dumpcfg.ncbuf]; cp++) {
2857                 if (cp->buf != NULL) {
2858                         CQ_PUT(freebufq, cp, CBUF_FREEBUF);
2859                         ++dumpcfg.ncbuf_used;
2860                 }
2861         }
2862 
2863         for (cp = dumpcfg.cmap; cp != &dumpcfg.cmap[dumpcfg.ncmap]; cp++)
2864                 CQ_PUT(mainq, cp, CBUF_FREEMAP);
2865 
2866         ds->start = gethrtime();
2867         ds->iowaitts = ds->start;
2868 
2869         /* start helpers */
2870         if (ds->live) {
2871                 int n = dumpcfg.nhelper_used;
2872                 int pri = MINCLSYSPRI - 25;
2873 
2874                 livetaskq = taskq_create("LiveDump", n, pri, n, n,
2875                     TASKQ_PREPOPULATE);
2876                 for (hp = dumpcfg.helper; hp != hpend; hp++) {
2877                         if (hp->page == NULL)
2878                                 continue;
2879                         hp->helper = hp - dumpcfg.helper;
2880                         hp->taskqid = taskq_dispatch(livetaskq,
2881                             dumpsys_live_helper, (void *)hp, TQ_NOSLEEP);
2882                 }
2883 
2884         } else {
2885                 if (panicstr)
2886                         kmem_dump_begin();
2887                 dumpcfg.helpers_wanted = dumpcfg.clevel > 0;
2888                 dumpsys_spinunlock(&dumpcfg.helper_lock);
2889         }
2890 
2891         /* run main task */
2892         dumpsys_main_task(ds);
2893 
2894         ds->elapsed = gethrtime() - ds->start;
2895         if (ds->elapsed < 1)
2896                 ds->elapsed = 1;
2897 
2898         if (livetaskq != NULL)
2899                 taskq_destroy(livetaskq);
2900 
2901         if (ds->neednl) {
2902                 uprintf("\n");
2903                 ds->neednl = 0;
2904         }
2905 
2906         /* record actual pages dumped */
2907         dumphdr->dump_npages = ds->npages;
2908 
2909         /* platform-specific data */
2910         dumphdr->dump_npages += dump_plat_data(dumpcfg.cbuf[0].buf);
2911 
2912         /* note any errors by clearing DF_COMPLETE */
2913         if (dump_ioerr || ds->npages < dumphdr->dump_npages)
2914                 dumphdr->dump_flags &= ~DF_COMPLETE;
2915 
2916         /* end of stream blocks */
2917         datatag = 0;
2918         dumpvp_write(&datatag, sizeof (datatag));
2919 
2920         bzero(&datahdr, sizeof (datahdr));
2921 
2922         /* buffer for metrics */
2923         buf = dumpcfg.cbuf[0].buf;
2924         size = MIN(dumpcfg.cbuf[0].size, DUMP_OFFSET - sizeof (dumphdr_t) -
2925             sizeof (dumpdatahdr_t));
2926 
2927         /* finish the kmem intercepts, collect kmem verbose info */
2928         if (panicstr) {
2929                 datahdr.dump_metrics = kmem_dump_finish(buf, size);
2930                 buf += datahdr.dump_metrics;
2931                 size -= datahdr.dump_metrics;
2932         }
2933 
2934         /* record in the header whether this is a fault-management panic */
2935         if (panicstr)
2936                 dumphdr->dump_fm_panic = is_fm_panic();
2937 
2938         /* compression info in data header */
2939         datahdr.dump_datahdr_magic = DUMP_DATAHDR_MAGIC;
2940         datahdr.dump_datahdr_version = DUMP_DATAHDR_VERSION;
2941         datahdr.dump_maxcsize = CBUF_SIZE;
2942         datahdr.dump_maxrange = CBUF_MAPSIZE / PAGESIZE;
2943         datahdr.dump_nstreams = dumpcfg.nhelper_used;
2944         datahdr.dump_clevel = dumpcfg.clevel;
2945 #ifdef COLLECT_METRICS
2946         if (dump_metrics_on)
2947                 datahdr.dump_metrics += dumpsys_metrics(ds, buf, size);
2948 #endif
2949         datahdr.dump_data_csize = dumpvp_flush() - dumphdr->dump_data;
2950 
2951         /*
2952          * Write out the initial and terminal dump headers.
2953          */
2954         dumpbuf.vp_off = dumphdr->dump_start;
2955         dumpvp_write(dumphdr, sizeof (dumphdr_t));
2956         (void) dumpvp_flush();
2957 
2958         dumpbuf.vp_limit = dumpvp_size;
2959         dumpbuf.vp_off = dumpbuf.vp_limit - DUMP_OFFSET;
2960         dumpvp_write(dumphdr, sizeof (dumphdr_t));
2961         dumpvp_write(&datahdr, sizeof (dumpdatahdr_t));
2962         dumpvp_write(dumpcfg.cbuf[0].buf, datahdr.dump_metrics);
2963 
2964         (void) dumpvp_flush();
2965 
2966         uprintf("\r%3d%% done: %llu pages dumped, ",
2967             ds->percent_done, (u_longlong_t)ds->npages);
2968 
2969         if (dump_ioerr == 0) {
2970                 uprintf("dump succeeded\n");
2971         } else {
2972                 uprintf("dump failed: error %d\n", dump_ioerr);
2973 #ifdef DEBUG
2974                 if (panicstr)
2975                         debug_enter("dump failed");
2976 #endif
2977         }
2978 
2979         /*
2980          * Write out all undelivered messages.  This has to be the *last*
2981          * thing we do because the dump process itself emits messages.
2982          */
2983         if (panicstr) {
2984                 dump_summary();
2985                 dump_ereports();
2986                 dump_messages();
2987         }
2988 
2989         delay(2 * hz);  /* let people see the 'done' message */
2990         dump_timeleft = 0;
2991         dump_ioerr = 0;
2992 
2993         /* restore settings after live dump completes */
2994         if (!panicstr) {
2995                 dumpcfg.clevel = save_dump_clevel;
2996 
2997                 /* release any VCHR open of the dump device */
2998                 if (dumpbuf.cdev_vp != NULL) {
2999                         (void) VOP_CLOSE(dumpbuf.cdev_vp, FREAD | FWRITE, 1, 0,
3000                             kcred, NULL);
3001                         VN_RELE(dumpbuf.cdev_vp);
3002                         dumpbuf.cdev_vp = NULL;
3003                 }
3004         }
3005 }
3006 
3007 /*
3008  * This function is called whenever the memory size, as represented
3009  * by the phys_install list, changes.
3010  */
3011 void
3012 dump_resize()
3013 {
3014         mutex_enter(&dump_lock);
3015         dumphdr_init();
3016         dumpbuf_resize();
3017         dump_update_clevel();
3018         mutex_exit(&dump_lock);
3019 }
3020 
3021 /*
3022  * This function allows for dynamic resizing of a dump area. It assumes that
3023  * the underlying device has update its appropriate size(9P).
3024  */
3025 int
3026 dumpvp_resize()
3027 {
3028         int error;
3029         vattr_t vattr;
3030 
3031         mutex_enter(&dump_lock);
3032         vattr.va_mask = AT_SIZE;
3033         if ((error = VOP_GETATTR(dumpvp, &vattr, 0, kcred, NULL)) != 0) {
3034                 mutex_exit(&dump_lock);
3035                 return (error);
3036         }
3037 
3038         if (error == 0 && vattr.va_size < 2 * DUMP_LOGSIZE + DUMP_ERPTSIZE) {
3039                 mutex_exit(&dump_lock);
3040                 return (ENOSPC);
3041         }
3042 
3043         dumpvp_size = vattr.va_size & -DUMP_OFFSET;
3044         mutex_exit(&dump_lock);
3045         return (0);
3046 }
3047 
3048 int
3049 dump_set_uuid(const char *uuidstr)
3050 {
3051         const char *ptr;
3052         int i;
3053 
3054         if (uuidstr == NULL || strnlen(uuidstr, 36 + 1) != 36)
3055                 return (EINVAL);
3056 
3057         /* uuid_parse is not common code so check manually */
3058         for (i = 0, ptr = uuidstr; i < 36; i++, ptr++) {
3059                 switch (i) {
3060                 case 8:
3061                 case 13:
3062                 case 18:
3063                 case 23:
3064                         if (*ptr != '-')
3065                                 return (EINVAL);
3066                         break;
3067 
3068                 default:
3069                         if (!isxdigit(*ptr))
3070                                 return (EINVAL);
3071                         break;
3072                 }
3073         }
3074 
3075         if (dump_osimage_uuid[0] != '\0')
3076                 return (EALREADY);
3077 
3078         (void) strncpy(dump_osimage_uuid, uuidstr, 36 + 1);
3079 
3080         cmn_err(CE_CONT, "?This Solaris instance has UUID %s\n",
3081             dump_osimage_uuid);
3082 
3083         return (0);
3084 }
3085 
3086 const char *
3087 dump_get_uuid(void)
3088 {
3089         return (dump_osimage_uuid[0] != '\0' ? dump_osimage_uuid : "");
3090 }