cmd/savecore/savecore.c

	savecore.c revision 6d89ca534e2138511ecb76c02bcec1bcb83f685b
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 1983, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2012, Joyent, Inc. All rights reserved.
 */
/*
 * Copyright 2012 Nexenta Systems, Inc. All rights reserved.
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <deflt.h>
#include <time.h>
#include <syslog.h>
#include <stropts.h>
#include <pthread.h>
#include <limits.h>
#include <atomic.h>
#include <libnvpair.h>
#include <libintl.h>
#include <sys/mem.h>
#include <sys/statvfs.h>
#include <sys/dumphdr.h>
#include <sys/dumpadm.h>
#include <sys/compress.h>
#include <sys/panic.h>
#include <sys/sysmacros.h>
#include <sys/stat.h>
#include <sys/resource.h>
#include <bzip2/bzlib.h>
#include <sys/fm/util.h>
#include <fm/libfmevent.h>
#include <sys/int_fmtio.h>


/* fread/fwrite buffer size */
#define FBUFSIZE        (1ULL << 20)

/* minimum size for output buffering */
#define MINCOREBLKSIZE      (1ULL << 17)

/* create this file if metrics collection is enabled in the kernel */
#define METRICSFILE "METRICS.csv"

static char progname[9] = "savecore";
static char *savedir;       /* savecore directory */
static char *dumpfile;      /* source of raw crash dump */
static long bounds = -1;        /* numeric suffix */
static long pagesize;       /* dump pagesize */
static int  dumpfd = -1;        /* dumpfile descriptor */
static dumphdr_t corehdr, dumphdr;  /* initial and terminal dumphdrs */
static boolean_t dump_incomplete;   /* dumphdr indicates incomplete */
static boolean_t fm_panic;      /* dump is the result of fm_panic */
static offset_t endoff;         /* offset of end-of-dump header */
static int  verbose;        /* chatty mode */
static int  disregard_valid_flag;   /* disregard valid flag */
static int  livedump;       /* dump the current running system */
static int  interactive;        /* user invoked; no syslog */
static int  csave;          /* save dump compressed */
static int  filemode;       /* processing file, not dump device */
static int  percent_done;       /* progress indicator */
static hrtime_t startts;        /* timestamp at start */
static volatile uint64_t saved;     /* count of pages written */
static volatile uint64_t zpages;    /* count of zero pages not written */
static dumpdatahdr_t datahdr;       /* compression info */
static long coreblksize;        /* preferred write size (st_blksize) */
static int  cflag;          /* run as savecore -c */
static int  mflag;          /* run as savecore -m */

/*
 * Payload information for the events we raise.  These are used
 * in raise_event to determine what payload to include.
 */
#define SC_PAYLOAD_SAVEDIR  0x0001  /* Include savedir in event */
#define SC_PAYLOAD_INSTANCE 0x0002  /* Include bounds instance number */
#define SC_PAYLOAD_IMAGEUUID    0x0004  /* Include dump OS instance uuid */
#define SC_PAYLOAD_CRASHTIME    0x0008  /* Include epoch crashtime */
#define SC_PAYLOAD_PANICSTR 0x0010  /* Include panic string */
#define SC_PAYLOAD_PANICSTACK   0x0020  /* Include panic string */
#define SC_PAYLOAD_FAILREASON   0x0040  /* Include failure reason */
#define SC_PAYLOAD_DUMPCOMPLETE 0x0080  /* Include completeness indicator */
#define SC_PAYLOAD_ISCOMPRESSED 0x0100  /* Dump is in vmdump.N form */
#define SC_PAYLOAD_DUMPADM_EN   0x0200  /* Is dumpadm enabled or not? */
#define SC_PAYLOAD_FM_PANIC 0x0400  /* Panic initiated by FMA */
#define SC_PAYLOAD_JUSTCHECKING 0x0800  /* Run with -c flag? */

enum sc_event_type {
    SC_EVENT_DUMP_PENDING,
    SC_EVENT_SAVECORE_FAILURE,
    SC_EVENT_DUMP_AVAILABLE
};

/*
 * Common payload
 */
#define _SC_PAYLOAD_CMN \
    SC_PAYLOAD_IMAGEUUID | \
    SC_PAYLOAD_CRASHTIME | \
    SC_PAYLOAD_PANICSTR | \
    SC_PAYLOAD_PANICSTACK | \
    SC_PAYLOAD_DUMPCOMPLETE | \
    SC_PAYLOAD_FM_PANIC | \
    SC_PAYLOAD_SAVEDIR

static const struct {
    const char *sce_subclass;
    uint32_t sce_payload;
} sc_event[] = {
    /*
     * SC_EVENT_DUMP_PENDING
     */
    {
        "dump_pending_on_device",
        _SC_PAYLOAD_CMN | SC_PAYLOAD_DUMPADM_EN |
            SC_PAYLOAD_JUSTCHECKING
    },

    /*
     * SC_EVENT_SAVECORE_FAILURE
     */
    {
        "savecore_failure",
        _SC_PAYLOAD_CMN | SC_PAYLOAD_INSTANCE | SC_PAYLOAD_FAILREASON
    },

    /*
     * SC_EVENT_DUMP_AVAILABLE
     */
    {
        "dump_available",
        _SC_PAYLOAD_CMN | SC_PAYLOAD_INSTANCE | SC_PAYLOAD_ISCOMPRESSED
    },
};

static void raise_event(enum sc_event_type, char *);

static void
usage(void)
{
    (void) fprintf(stderr,
        "usage: %s [-Lvd] [-f dumpfile] [dirname]\n", progname);
    exit(1);
}

#define SC_SL_NONE  0x0001  /* no syslog */
#define SC_SL_ERR   0x0002  /* syslog if !interactive, LOG_ERR */
#define SC_SL_WARN  0x0004  /* syslog if !interactive, LOG_WARNING */
#define SC_IF_VERBOSE   0x0008  /* message only if -v */
#define SC_IF_ISATTY    0x0010  /* message only if interactive */
#define SC_EXIT_OK  0x0020  /* exit(0) */
#define SC_EXIT_ERR 0x0040  /* exit(1) */
#define SC_EXIT_PEND    0x0080  /* exit(2) */
#define SC_EXIT_FM  0x0100  /* exit(3) */

#define _SC_ALLEXIT (SC_EXIT_OK | SC_EXIT_ERR | SC_EXIT_PEND | SC_EXIT_FM)

static void
logprint(uint32_t flags, char *message, ...)
{
    va_list args;
    char buf[1024];
    int do_always = ((flags & (SC_IF_VERBOSE | SC_IF_ISATTY)) == 0);
    int do_ifverb = (flags & SC_IF_VERBOSE) && verbose;
    int do_ifisatty = (flags & SC_IF_ISATTY) && interactive;
    int code;
    static int logprint_raised = 0;

    if (do_always || do_ifverb || do_ifisatty) {
        va_start(args, message);
        /*LINTED: E_SEC_PRINTF_VAR_FMT*/
        (void) vsnprintf(buf, sizeof (buf), message, args);
        (void) fprintf(stderr, "%s: %s\n", progname, buf);
        if (!interactive) {
            switch (flags & (SC_SL_NONE | SC_SL_ERR | SC_SL_WARN)) {
            case SC_SL_ERR:
                /*LINTED: E_SEC_PRINTF_VAR_FMT*/
                syslog(LOG_ERR, buf);
                break;

            case SC_SL_WARN:
                /*LINTED: E_SEC_PRINTF_VAR_FMT*/
                syslog(LOG_WARNING, buf);
                break;

            default:
                break;
            }
        }
        va_end(args);
    }

    switch (flags & _SC_ALLEXIT) {
    case 0:
        return;

    case SC_EXIT_OK:
        code = 0;
        break;

    case SC_EXIT_PEND:
        /*
         * Raise an ireport saying why we are exiting.  Do not
         * raise if run as savecore -m.  If something in the
         * raise_event codepath calls logprint avoid recursion.
         */
        if (!mflag && logprint_raised++ == 0)
            raise_event(SC_EVENT_SAVECORE_FAILURE, buf);
        code = 2;
        break;

    case SC_EXIT_FM:
        code = 3;
        break;

    case SC_EXIT_ERR:
    default:
        if (!mflag && logprint_raised++ == 0)
            raise_event(SC_EVENT_SAVECORE_FAILURE, buf);
        code = 1;
        break;
    }

    exit(code);
}

/*
 * System call / libc wrappers that exit on error.
 */
static int
Open(const char *name, int oflags, mode_t mode)
{
    int fd;

    if ((fd = open64(name, oflags, mode)) == -1)
        logprint(SC_SL_ERR | SC_EXIT_ERR, "open(\"%s\"): %s",
            name, strerror(errno));
    return (fd);
}

static void
Fread(void *buf, size_t size, FILE *f)
{
    if (fread(buf, size, 1, f) != 1)
        logprint(SC_SL_ERR | SC_EXIT_ERR, "fread: ferror %d feof %d",
            ferror(f), feof(f));
}

static void
Fwrite(void *buf, size_t size, FILE *f)
{
    if (fwrite(buf, size, 1, f) != 1)
        logprint(SC_SL_ERR | SC_EXIT_ERR, "fwrite: %s",
            strerror(errno));
}

static void
Fseek(offset_t off, FILE *f)
{
    if (fseeko64(f, off, SEEK_SET) != 0)
        logprint(SC_SL_ERR | SC_EXIT_ERR, "fseeko64: %s",
            strerror(errno));
}

typedef struct stat64 Stat_t;

static void
Fstat(int fd, Stat_t *sb, const char *fname)
{
    if (fstat64(fd, sb) != 0)
        logprint(SC_SL_ERR | SC_EXIT_ERR, "fstat(\"%s\"): %s", fname,
            strerror(errno));
}

static void
Stat(const char *fname, Stat_t *sb)
{
    if (stat64(fname, sb) != 0)
        logprint(SC_SL_ERR | SC_EXIT_ERR, "stat(\"%s\"): %s", fname,
            strerror(errno));
}

static void
Pread(int fd, void *buf, size_t size, offset_t off)
{
    ssize_t sz = pread64(fd, buf, size, off);

    if (sz < 0)
        logprint(SC_SL_ERR | SC_EXIT_ERR,
            "pread: %s", strerror(errno));
    else if (sz != size)
        logprint(SC_SL_ERR | SC_EXIT_ERR,
            "pread: size %ld != %ld", sz, size);
}

static void
Pwrite(int fd, void *buf, size_t size, off64_t off)
{
    if (pwrite64(fd, buf, size, off) != size)
        logprint(SC_SL_ERR | SC_EXIT_ERR, "pwrite: %s",
            strerror(errno));
}

static void *
Zalloc(size_t size)
{
    void *buf;

    if ((buf = calloc(size, 1)) == NULL)
        logprint(SC_SL_ERR | SC_EXIT_ERR, "calloc: %s",
            strerror(errno));
    return (buf);
}

static long
read_number_from_file(const char *filename, long default_value)
{
    long file_value = -1;
    FILE *fp;

    if ((fp = fopen(filename, "r")) != NULL) {
        (void) fscanf(fp, "%ld", &file_value);
        (void) fclose(fp);
    }
    return (file_value < 0 ? default_value : file_value);
}

static void
read_dumphdr(void)
{
    if (filemode)
        dumpfd = Open(dumpfile, O_RDONLY, 0644);
    else
        dumpfd = Open(dumpfile, O_RDWR | O_DSYNC, 0644);
    endoff = llseek(dumpfd, -DUMP_OFFSET, SEEK_END) & -DUMP_OFFSET;
    Pread(dumpfd, &dumphdr, sizeof (dumphdr), endoff);
    Pread(dumpfd, &datahdr, sizeof (datahdr), endoff + sizeof (dumphdr));

    pagesize = dumphdr.dump_pagesize;

    if (dumphdr.dump_magic != DUMP_MAGIC)
        logprint(SC_SL_NONE | SC_EXIT_PEND, "bad magic number %x",
            dumphdr.dump_magic);

    if ((dumphdr.dump_flags & DF_VALID) == 0 && !disregard_valid_flag)
        logprint(SC_SL_NONE | SC_IF_VERBOSE | SC_EXIT_OK,
            "dump already processed");

    if (dumphdr.dump_version != DUMP_VERSION)
        logprint(SC_SL_NONE | SC_IF_VERBOSE | SC_EXIT_PEND,
            "dump version (%d) != %s version (%d)",
            dumphdr.dump_version, progname, DUMP_VERSION);

    if (dumphdr.dump_wordsize != DUMP_WORDSIZE)
        logprint(SC_SL_NONE | SC_EXIT_PEND,
            "dump is from %u-bit kernel - cannot save on %u-bit kernel",
            dumphdr.dump_wordsize, DUMP_WORDSIZE);

    if (datahdr.dump_datahdr_magic == DUMP_DATAHDR_MAGIC) {
        if (datahdr.dump_datahdr_version != DUMP_DATAHDR_VERSION)
            logprint(SC_SL_NONE | SC_IF_VERBOSE | SC_EXIT_PEND,
                "dump data version (%d) != %s data version (%d)",
                datahdr.dump_datahdr_version, progname,
                DUMP_DATAHDR_VERSION);
    } else {
        (void) memset(&datahdr, 0, sizeof (datahdr));
        datahdr.dump_maxcsize = pagesize;
    }

    /*
     * Read the initial header, clear the valid bits, and compare headers.
     * The main header may have been overwritten by swapping if we're
     * using a swap partition as the dump device, in which case we bail.
     */
    Pread(dumpfd, &corehdr, sizeof (dumphdr_t), dumphdr.dump_start);

    corehdr.dump_flags &= ~DF_VALID;
    dumphdr.dump_flags &= ~DF_VALID;

    if (memcmp(&corehdr, &dumphdr, sizeof (dumphdr_t)) != 0) {
        /*
         * Clear valid bit so we don't complain on every invocation.
         */
        if (!filemode)
            Pwrite(dumpfd, &dumphdr, sizeof (dumphdr), endoff);
        logprint(SC_SL_ERR | SC_EXIT_ERR,
            "initial dump header corrupt");
    }
}

static void
check_space(int csave)
{
    struct statvfs fsb;
    int64_t spacefree, dumpsize, minfree, datasize;

    if (statvfs(".", &fsb) < 0)
        logprint(SC_SL_ERR | SC_EXIT_ERR, "statvfs: %s",
            strerror(errno));

    dumpsize = dumphdr.dump_data - dumphdr.dump_start;
    datasize = dumphdr.dump_npages * pagesize;
    if (!csave)
        dumpsize += datasize;
    else
        dumpsize += datahdr.dump_data_csize;

    spacefree = (int64_t)fsb.f_bavail * fsb.f_frsize;
    minfree = 1024LL * read_number_from_file("minfree", 1024);
    if (spacefree < minfree + dumpsize) {
        logprint(SC_SL_ERR | SC_EXIT_ERR,
            "not enough space in %s (%lld MB avail, %lld MB needed)",
            savedir, spacefree >> 20, (minfree + dumpsize) >> 20);
    }
}

static void
build_dump_map(int corefd, const pfn_t *pfn_table)
{
    long i;
    static long misses = 0;
    size_t dump_mapsize = (corehdr.dump_hashmask + 1) * sizeof (dump_map_t);
    mem_vtop_t vtop;
    dump_map_t *dmp = Zalloc(dump_mapsize);
    char *inbuf = Zalloc(FBUFSIZE);
    FILE *in = fdopen(dup(dumpfd), "rb");

    (void) setvbuf(in, inbuf, _IOFBF, FBUFSIZE);
    Fseek(dumphdr.dump_map, in);

    corehdr.dump_data = corehdr.dump_map + roundup(dump_mapsize, pagesize);

    for (i = 0; i < corehdr.dump_nvtop; i++) {
        long first = 0;
        long last = corehdr.dump_npages - 1;
        long middle = 0;
        pfn_t pfn = 0;
        uintptr_t h;

        Fread(&vtop, sizeof (mem_vtop_t), in);
        while (last >= first) {
            middle = (first + last) / 2;
            pfn = pfn_table[middle];
            if (pfn == vtop.m_pfn)
                break;
            if (pfn < vtop.m_pfn)
                first = middle + 1;
            else
                last = middle - 1;
        }
        if (pfn != vtop.m_pfn) {
            if (++misses <= 10)
                (void) fprintf(stderr,
                    "pfn %ld not found for as=%p, va=%p\n",
                    vtop.m_pfn, (void *)vtop.m_as, vtop.m_va);
            continue;
        }

        dmp[i].dm_as = vtop.m_as;
        dmp[i].dm_va = (uintptr_t)vtop.m_va;
        dmp[i].dm_data = corehdr.dump_data +
            ((uint64_t)middle << corehdr.dump_pageshift);

        h = DUMP_HASH(&corehdr, dmp[i].dm_as, dmp[i].dm_va);
        dmp[i].dm_next = dmp[h].dm_first;
        dmp[h].dm_first = corehdr.dump_map + i * sizeof (dump_map_t);
    }

    Pwrite(corefd, dmp, dump_mapsize, corehdr.dump_map);
    free(dmp);
    (void) fclose(in);
    free(inbuf);
}

/*
 * Copy whole sections of the dump device to the file.
 */
static void
Copy(offset_t dumpoff, len_t nb, offset_t *offp, int fd, char *buf,
    size_t sz)
{
    size_t nr;
    offset_t off = *offp;

    while (nb > 0) {
        nr = sz < nb ? sz : (size_t)nb;
        Pread(dumpfd, buf, nr, dumpoff);
        Pwrite(fd, buf, nr, off);
        off += nr;
        dumpoff += nr;
        nb -= nr;
    }
    *offp = off;
}

/*
 * Copy pages when the dump data header is missing.
 * This supports older kernels with latest savecore.
 */
static void
CopyPages(offset_t *offp, int fd, char *buf, size_t sz)
{
    uint32_t csize;
    FILE *in = fdopen(dup(dumpfd), "rb");
    FILE *out = fdopen(dup(fd), "wb");
    char *cbuf = Zalloc(pagesize);
    char *outbuf = Zalloc(FBUFSIZE);
    pgcnt_t np = dumphdr.dump_npages;

    (void) setvbuf(out, outbuf, _IOFBF, FBUFSIZE);
    (void) setvbuf(in, buf, _IOFBF, sz);
    Fseek(dumphdr.dump_data, in);

    Fseek(*offp, out);
    while (np > 0) {
        Fread(&csize, sizeof (uint32_t), in);
        Fwrite(&csize, sizeof (uint32_t), out);
        *offp += sizeof (uint32_t);
        if (csize > pagesize || csize == 0) {
            logprint(SC_SL_ERR,
                "CopyPages: page %lu csize %d (0x%x) pagesize %d",
                dumphdr.dump_npages - np, csize, csize,
                pagesize);
            break;
        }
        Fread(cbuf, csize, in);
        Fwrite(cbuf, csize, out);
        *offp += csize;
        np--;
    }
    (void) fclose(in);
    (void) fclose(out);
    free(outbuf);
    free(buf);
}

/*
 * Concatenate dump contents into a new file.
 * Update corehdr with new offsets.
 */
static void
copy_crashfile(const char *corefile)
{
    int corefd = Open(corefile, O_WRONLY | O_CREAT | O_TRUNC, 0644);
    size_t bufsz = FBUFSIZE;
    char *inbuf = Zalloc(bufsz);
    offset_t coreoff;
    size_t nb;

    logprint(SC_SL_ERR | SC_IF_VERBOSE,
        "Copying %s to %s/%s\n", dumpfile, savedir, corefile);

    /*
     * This dump file is still compressed
     */
    corehdr.dump_flags |= DF_COMPRESSED | DF_VALID;

    /*
     * Leave room for corehdr, it is updated and written last
     */
    corehdr.dump_start = 0;
    coreoff = sizeof (corehdr);

    /*
     * Read in the compressed symbol table, copy it to corefile.
     */
    coreoff = roundup(coreoff, pagesize);
    corehdr.dump_ksyms = coreoff;
    Copy(dumphdr.dump_ksyms, dumphdr.dump_ksyms_csize, &coreoff, corefd,
        inbuf, bufsz);

    /*
     * Save the pfn table.
     */
    coreoff = roundup(coreoff, pagesize);
    corehdr.dump_pfn = coreoff;
    Copy(dumphdr.dump_pfn, dumphdr.dump_npages * sizeof (pfn_t), &coreoff,
        corefd, inbuf, bufsz);

    /*
     * Save the dump map.
     */
    coreoff = roundup(coreoff, pagesize);
    corehdr.dump_map = coreoff;
    Copy(dumphdr.dump_map, dumphdr.dump_nvtop * sizeof (mem_vtop_t),
        &coreoff, corefd, inbuf, bufsz);

    /*
     * Save the data pages.
     */
    coreoff = roundup(coreoff, pagesize);
    corehdr.dump_data = coreoff;
    if (datahdr.dump_data_csize != 0)
        Copy(dumphdr.dump_data, datahdr.dump_data_csize, &coreoff,
            corefd, inbuf, bufsz);
    else
        CopyPages(&coreoff, corefd, inbuf, bufsz);

    /*
     * Now write the modified dump header to front and end of the copy.
     * Make it look like a valid dump device.
     *
     * From dumphdr.h: Two headers are written out: one at the
     * beginning of the dump, and the other at the very end of the
     * dump device. The terminal header is at a known location
     * (end of device) so we can always find it.
     *
     * Pad with zeros to each DUMP_OFFSET boundary.
     */
    (void) memset(inbuf, 0, DUMP_OFFSET);

    nb = DUMP_OFFSET - (coreoff & (DUMP_OFFSET - 1));
    if (nb > 0) {
        Pwrite(corefd, inbuf, nb, coreoff);
        coreoff += nb;
    }

    Pwrite(corefd, &corehdr, sizeof (corehdr), coreoff);
    coreoff += sizeof (corehdr);

    Pwrite(corefd, &datahdr, sizeof (datahdr), coreoff);
    coreoff += sizeof (datahdr);

    nb = DUMP_OFFSET - (coreoff & (DUMP_OFFSET - 1));
    if (nb > 0) {
        Pwrite(corefd, inbuf, nb, coreoff);
    }

    free(inbuf);
    Pwrite(corefd, &corehdr, sizeof (corehdr), corehdr.dump_start);

    /*
     * Write out the modified dump header to the dump device.
     * The dump device has been processed, so DF_VALID is clear.
     */
    if (!filemode)
        Pwrite(dumpfd, &dumphdr, sizeof (dumphdr), endoff);

    (void) close(corefd);
}

/*
 * compressed streams
 */
typedef struct blockhdr blockhdr_t;
typedef struct block block_t;

struct blockhdr {
    block_t *head;
    block_t *tail;
};

struct block {
    block_t *next;
    char *block;
    int size;
};

typedef enum streamstate {
    STREAMSTART,
    STREAMPAGES
} streamstate_t;

typedef struct stream {
    streamstate_t state;
    int init;
    int tag;
    int bound;
    int nout;
    char *blkbuf;
    blockhdr_t blocks;
    pgcnt_t pagenum;
    pgcnt_t curpage;
    pgcnt_t npages;
    pgcnt_t done;
    bz_stream strm;
    dumpcsize_t sc;
    dumpstreamhdr_t sh;
} stream_t;

static stream_t *streams;
static stream_t *endstreams;

const int cs = sizeof (dumpcsize_t);

typedef struct tinfo {
    pthread_t tid;
    int corefd;
} tinfo_t;

static int threads_stop;
static int threads_active;
static tinfo_t *tinfo;
static tinfo_t *endtinfo;

static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t cvfree = PTHREAD_COND_INITIALIZER;
static pthread_cond_t cvwork = PTHREAD_COND_INITIALIZER;
static pthread_cond_t cvbarrier = PTHREAD_COND_INITIALIZER;

static blockhdr_t freeblocks;

static void
enqt(blockhdr_t *h, block_t *b)
{
    b->next = NULL;
    if (h->tail == NULL)
        h->head = b;
    else
        h->tail->next = b;
    h->tail = b;
}

static block_t *
deqh(blockhdr_t *h)
{
    block_t *b = h->head;

    if (b != NULL) {
        h->head = b->next;
        if (h->head == NULL)
            h->tail = NULL;
    }
    return (b);
}

static void *runstreams(void *arg);

static void
initstreams(int corefd, int nstreams, int maxcsize)
{
    int nthreads;
    int nblocks;
    int i;
    block_t *b;
    tinfo_t *t;

    nthreads = sysconf(_SC_NPROCESSORS_ONLN);
    if (nstreams < nthreads)
        nthreads = nstreams;
    if (nthreads < 1)
        nthreads = 1;
    nblocks = nthreads * 2;

    tinfo = Zalloc(nthreads * sizeof (tinfo_t));
    endtinfo = &tinfo[nthreads];

    /* init streams */
    streams = Zalloc(nstreams * sizeof (stream_t));
    endstreams = &streams[nstreams];

    /* init stream block buffers */
    for (i = 0; i < nblocks; i++) {
        b = Zalloc(sizeof (block_t));
        b->block = Zalloc(maxcsize);
        enqt(&freeblocks, b);
    }

    /* init worker threads */
    (void) pthread_mutex_lock(&lock);
    threads_active = 1;
    threads_stop = 0;
    for (t = tinfo; t != endtinfo; t++) {
        t->corefd = dup(corefd);
        if (t->corefd < 0) {
            nthreads = t - tinfo;
            endtinfo = t;
            break;
        }
        if (pthread_create(&t->tid, NULL, runstreams, t) != 0)
            logprint(SC_SL_ERR | SC_EXIT_ERR, "pthread_create: %s",
                strerror(errno));
    }
    (void) pthread_mutex_unlock(&lock);
}

static void
sbarrier()
{
    stream_t *s;

    (void) pthread_mutex_lock(&lock);
    for (s = streams; s != endstreams; s++) {
        while (s->bound || s->blocks.head != NULL)
            (void) pthread_cond_wait(&cvbarrier, &lock);
    }
    (void) pthread_mutex_unlock(&lock);
}

static void
stopstreams()
{
    tinfo_t *t;

    if (threads_active) {
        sbarrier();
        (void) pthread_mutex_lock(&lock);
        threads_stop = 1;
        (void) pthread_cond_signal(&cvwork);
        (void) pthread_mutex_unlock(&lock);
        for (t = tinfo; t != endtinfo; t++)
            (void) pthread_join(t->tid, NULL);
        free(tinfo);
        tinfo = NULL;
        threads_active = 0;
    }
}

static block_t *
getfreeblock()
{
    block_t *b;

    (void) pthread_mutex_lock(&lock);
    while ((b = deqh(&freeblocks)) == NULL)
        (void) pthread_cond_wait(&cvfree, &lock);
    (void) pthread_mutex_unlock(&lock);
    return (b);
}

/* data page offset from page number */
#define BTOP(b)     ((b) >> dumphdr.dump_pageshift)
#define PTOB(p)     ((p) << dumphdr.dump_pageshift)
#define DATAOFF(p)  (corehdr.dump_data + PTOB(p))

/* check for coreblksize boundary */
static int
isblkbnd(pgcnt_t pgnum)
{
    return (P2PHASE(DATAOFF(pgnum), coreblksize) == 0);
}

static int
iszpage(char *buf)
{
    size_t sz;
    uint64_t *pl;

    /*LINTED:E_BAD_PTR_CAST_ALIGN*/
    pl = (uint64_t *)(buf);
    for (sz = 0; sz < pagesize; sz += sizeof (*pl))
        if (*pl++ != 0)
            return (0);
    return (1);
}

volatile uint_t *hist;

/* write pages to the core file */
static void
putpage(int corefd, char *buf, pgcnt_t pgnum, pgcnt_t np)
{
    atomic_inc_uint(&hist[np]);
    if (np > 0)
        Pwrite(corefd, buf, PTOB(np), DATAOFF(pgnum));
}

/*
 * Process one lzjb block.
 * No object (stream header or page) will be split over a block boundary.
 */
static void
lzjbblock(int corefd, stream_t *s, char *block, size_t blocksz)
{
    int in = 0;
    int csize;
    int doflush;
    char *out;
    size_t dsize;
    dumpcsize_t sc;
    dumpstreamhdr_t sh;

    if (!s->init) {
        s->init = 1;
        if (s->blkbuf == NULL)
            s->blkbuf = Zalloc(coreblksize);
        s->state = STREAMSTART;
    }
    while (in < blocksz) {
        switch (s->state) {
        case STREAMSTART:
            (void) memcpy(&sh, block + in, sizeof (sh));
            in += sizeof (sh);
            if (strcmp(DUMP_STREAM_MAGIC, sh.stream_magic) != 0)
                logprint(SC_SL_ERR | SC_EXIT_ERR,
                    "LZJB STREAMSTART: bad stream header");
            if (sh.stream_npages > datahdr.dump_maxrange)
                logprint(SC_SL_ERR | SC_EXIT_ERR,
                    "LZJB STREAMSTART: bad range: %d > %d",
                    sh.stream_npages, datahdr.dump_maxrange);
            s->pagenum = sh.stream_pagenum;
            s->npages = sh.stream_npages;
            s->curpage = s->pagenum;
            s->nout = 0;
            s->done = 0;
            s->state = STREAMPAGES;
            break;
        case STREAMPAGES:
            (void) memcpy(&sc, block + in, cs);
            in += cs;
            csize = DUMP_GET_CSIZE(sc);
            if (csize > pagesize)
                logprint(SC_SL_ERR | SC_EXIT_ERR,
                    "LZJB STREAMPAGES: bad csize=%d", csize);

            out =  s->blkbuf + PTOB(s->nout);
            dsize = decompress(block + in, out, csize, pagesize);

            if (dsize != pagesize)
                logprint(SC_SL_ERR | SC_EXIT_ERR,
                    "LZJB STREAMPAGES: dsize %d != pagesize %d",
                    dsize, pagesize);

            in += csize;
            atomic_inc_64(&saved);

            doflush = 0;
            if (s->nout == 0 && iszpage(out)) {
                doflush = 1;
                atomic_inc_64(&zpages);
            } else if (++s->nout >= BTOP(coreblksize) ||
                isblkbnd(s->curpage + s->nout)) {
                doflush = 1;
            }
            if (++s->done >= s->npages) {
                s->state = STREAMSTART;
                doflush = 1;
            }
            if (doflush) {
                putpage(corefd, s->blkbuf, s->curpage, s->nout);
                s->nout = 0;
                s->curpage = s->pagenum + s->done;
            }
            break;
        }
    }
}

/* bzlib library reports errors with this callback */
void
bz_internal_error(int errcode)
{
    logprint(SC_SL_ERR | SC_EXIT_ERR, "bz_internal_error: err %s\n",
        BZ2_bzErrorString(errcode));
}

/*
 * Return one object in the stream.
 *
 * An object (stream header or page) will likely span an input block
 * of compression data. Return non-zero when an entire object has been
 * retrieved from the stream.
 */
static int
bz2decompress(stream_t *s, void *buf, size_t size)
{
    int rc;

    if (s->strm.avail_out == 0) {
        s->strm.next_out = buf;
        s->strm.avail_out = size;
    }
    while (s->strm.avail_in > 0) {
        rc = BZ2_bzDecompress(&s->strm);
        if (rc == BZ_STREAM_END) {
            rc = BZ2_bzDecompressReset(&s->strm);
            if (rc != BZ_OK)
                logprint(SC_SL_ERR | SC_EXIT_ERR,
                    "BZ2_bzDecompressReset: %s",
                    BZ2_bzErrorString(rc));
            continue;
        }

        if (s->strm.avail_out == 0)
            break;
    }
    return (s->strm.avail_out == 0);
}

/*
 * Process one bzip2 block.
 * The interface is documented here:
 * http://www.bzip.org/1.0.5/bzip2-manual-1.0.5.html
 */
static void
bz2block(int corefd, stream_t *s, char *block, size_t blocksz)
{
    int rc = 0;
    int doflush;
    char *out;

    if (!s->init) {
        s->init = 1;
        rc = BZ2_bzDecompressInit(&s->strm, 0, 0);
        if (rc != BZ_OK)
            logprint(SC_SL_ERR | SC_EXIT_ERR,
                "BZ2_bzDecompressInit: %s", BZ2_bzErrorString(rc));
        if (s->blkbuf == NULL)
            s->blkbuf = Zalloc(coreblksize);
        s->strm.avail_out = 0;
        s->state = STREAMSTART;
    }
    s->strm.next_in = block;
    s->strm.avail_in = blocksz;

    while (s->strm.avail_in > 0) {
        switch (s->state) {
        case STREAMSTART:
            if (!bz2decompress(s, &s->sh, sizeof (s->sh)))
                return;
            if (strcmp(DUMP_STREAM_MAGIC, s->sh.stream_magic) != 0)
                logprint(SC_SL_ERR | SC_EXIT_ERR,
                    "BZ2 STREAMSTART: bad stream header");
            if (s->sh.stream_npages > datahdr.dump_maxrange)
                logprint(SC_SL_ERR | SC_EXIT_ERR,
                    "BZ2 STREAMSTART: bad range: %d > %d",
                    s->sh.stream_npages, datahdr.dump_maxrange);
            s->pagenum = s->sh.stream_pagenum;
            s->npages = s->sh.stream_npages;
            s->curpage = s->pagenum;
            s->nout = 0;
            s->done = 0;
            s->state = STREAMPAGES;
            break;
        case STREAMPAGES:
            out = s->blkbuf + PTOB(s->nout);
            if (!bz2decompress(s, out, pagesize))
                return;

            atomic_inc_64(&saved);

            doflush = 0;
            if (s->nout == 0 && iszpage(out)) {
                doflush = 1;
                atomic_inc_64(&zpages);
            } else if (++s->nout >= BTOP(coreblksize) ||
                isblkbnd(s->curpage + s->nout)) {
                doflush = 1;
            }
            if (++s->done >= s->npages) {
                s->state = STREAMSTART;
                doflush = 1;
            }
            if (doflush) {
                putpage(corefd, s->blkbuf, s->curpage, s->nout);
                s->nout = 0;
                s->curpage = s->pagenum + s->done;
            }
            break;
        }
    }
}

/* report progress */
static void
report_progress()
{
    int sec, percent;

    if (!interactive)
        return;

    percent = saved * 100LL / corehdr.dump_npages;
    if (percent > percent_done) {
        sec = (gethrtime() - startts) / 1000 / 1000 / 1000;
        (void) printf("\r%2d:%02d %3d%% done", sec / 60, sec % 60,
            percent);
        (void) fflush(stdout);
        percent_done = percent;
    }
}

/* thread body */
static void *
runstreams(void *arg)
{
    tinfo_t *t = arg;
    stream_t *s;
    block_t *b;
    int bound;

    (void) pthread_mutex_lock(&lock);
    while (!threads_stop) {
        bound = 0;
        for (s = streams; s != endstreams; s++) {
            if (s->bound || s->blocks.head == NULL)
                continue;
            s->bound = 1;
            bound = 1;
            (void) pthread_cond_signal(&cvwork);
            while (s->blocks.head != NULL) {
                b = deqh(&s->blocks);
                (void) pthread_mutex_unlock(&lock);

                if (datahdr.dump_clevel < DUMP_CLEVEL_BZIP2)
                    lzjbblock(t->corefd, s, b->block,
                        b->size);
                else
                    bz2block(t->corefd, s, b->block,
                        b->size);

                (void) pthread_mutex_lock(&lock);
                enqt(&freeblocks, b);
                (void) pthread_cond_signal(&cvfree);

                report_progress();
            }
            s->bound = 0;
            (void) pthread_cond_signal(&cvbarrier);
        }
        if (!bound && !threads_stop)
            (void) pthread_cond_wait(&cvwork, &lock);
    }
    (void) close(t->corefd);
    (void) pthread_cond_signal(&cvwork);
    (void) pthread_mutex_unlock(&lock);
    return (arg);
}

/*
 * Process compressed pages.
 *
 * The old format, now called single-threaded lzjb, is a 32-bit size
 * word followed by 'size' bytes of lzjb compression data for one
 * page. The new format extends this by storing a 12-bit "tag" in the
 * upper bits of the size word. When the size word is pagesize or
 * less, it is assumed to be one lzjb page. When the size word is
 * greater than pagesize, it is assumed to be a "stream block",
 * belonging to up to 4095 streams. In practice, the number of streams
 * is set to one less than the number of CPUs running at crash
 * time. One CPU processes the crash dump, the remaining CPUs
 * separately process groups of data pages.
 *
 * savecore creates a thread per stream, but never more threads than
 * the number of CPUs running savecore. This is because savecore can
 * be processing a crash file from a remote machine, which may have
 * more CPUs.
 *
 * When the kernel uses parallel lzjb or parallel bzip2, we expect a
 * series of 128KB blocks of compression data. In this case, each
 * block has a "tag", in the range 1-4095. Each block is handed off to
 * to the threads running "runstreams". The dump format is either lzjb
 * or bzip2, never a mixture. These threads, in turn, process the
 * compression data for groups of pages. Groups of pages are delimited
 * by a "stream header", which indicates a starting pfn and number of
 * pages. When a stream block has been read, the condition variable
 * "cvwork" is signalled, which causes one of the avaiable threads to
 * wake up and process the stream.
 *
 * In the parallel case there will be streams blocks encoding all data
 * pages. The stream of blocks is terminated by a zero size
 * word. There can be a few lzjb pages tacked on the end, depending on
 * the architecture. The sbarrier function ensures that all stream
 * blocks have been processed so that the page number for the few
 * single pages at the end can be known.
 */
static void
decompress_pages(int corefd)
{
    char *cpage = NULL;
    char *dpage = NULL;
    char *out;
    pgcnt_t curpage = 0;
    block_t *b;
    FILE *dumpf;
    FILE *tracef = NULL;
    stream_t *s;
    size_t dsize;
    size_t insz = FBUFSIZE;
    char *inbuf = Zalloc(insz);
    uint32_t csize;
    dumpcsize_t dcsize;
    int nstreams = datahdr.dump_nstreams;
    int maxcsize = datahdr.dump_maxcsize;
    int nout = 0, tag, doflush;

    dumpf = fdopen(dup(dumpfd), "rb");
    if (dumpf == NULL)
        logprint(SC_SL_ERR | SC_EXIT_ERR, "fdopen: %s",
            strerror(errno));

    (void) setvbuf(dumpf, inbuf, _IOFBF, insz);
    Fseek(dumphdr.dump_data, dumpf);

    /*LINTED: E_CONSTANT_CONDITION*/
    while (1) {

        /*
         * The csize word delimits stream blocks.
         * See dumphdr.h for a description.
         */
        Fread(&dcsize, sizeof (dcsize), dumpf);

        tag = DUMP_GET_TAG(dcsize);
        csize = DUMP_GET_CSIZE(dcsize);

        if (tag != 0) {     /* a stream block */

            if (nstreams == 0)
                logprint(SC_SL_ERR | SC_EXIT_ERR,
                    "starting data header is missing");

            if (tag > nstreams)
                logprint(SC_SL_ERR | SC_EXIT_ERR,
                    "stream tag %d not in range 1..%d",
                    tag, nstreams);

            if (csize > maxcsize)
                logprint(SC_SL_ERR | SC_EXIT_ERR,
                    "block size 0x%x > max csize 0x%x",
                    csize, maxcsize);

            if (streams == NULL)
                initstreams(corefd, nstreams, maxcsize);
            s = &streams[tag - 1];
            s->tag = tag;

            b = getfreeblock();
            b->size = csize;
            Fread(b->block, csize, dumpf);

            (void) pthread_mutex_lock(&lock);
            enqt(&s->blocks, b);
            if (!s->bound)
                (void) pthread_cond_signal(&cvwork);
            (void) pthread_mutex_unlock(&lock);

        } else if (csize > 0) {     /* one lzjb page */

            if (csize > pagesize)
                logprint(SC_SL_ERR | SC_EXIT_ERR,
                    "csize 0x%x > pagesize 0x%x",
                    csize, pagesize);

            if (cpage == NULL)
                cpage = Zalloc(pagesize);
            if (dpage == NULL) {
                dpage = Zalloc(coreblksize);
                nout = 0;
            }

            Fread(cpage, csize, dumpf);

            out = dpage + PTOB(nout);
            dsize = decompress(cpage, out, csize, pagesize);

            if (dsize != pagesize)
                logprint(SC_SL_ERR | SC_EXIT_ERR,
                    "dsize 0x%x != pagesize 0x%x",
                    dsize, pagesize);

            /*
             * wait for streams to flush so that 'saved' is correct
             */
            if (threads_active)
                sbarrier();

            doflush = 0;
            if (nout == 0)
                curpage = saved;

            atomic_inc_64(&saved);

            if (nout == 0 && iszpage(dpage)) {
                doflush = 1;
                atomic_inc_64(&zpages);
            } else if (++nout >= BTOP(coreblksize) ||
                isblkbnd(curpage + nout) ||
                saved >= dumphdr.dump_npages) {
                doflush = 1;
            }

            if (doflush) {
                putpage(corefd, dpage, curpage, nout);
                nout = 0;
            }

            report_progress();

            /*
             * Non-streams lzjb does not use blocks.  Stop
             * here if all the pages have been decompressed.
             */
            if (saved >= dumphdr.dump_npages)
                break;

        } else {
            break;          /* end of data */
        }
    }

    stopstreams();
    if (tracef != NULL)
        (void) fclose(tracef);
    (void) fclose(dumpf);
    if (inbuf)
        free(inbuf);
    if (cpage)
        free(cpage);
    if (dpage)
        free(dpage);
    if (streams)
        free(streams);
}

static void
build_corefile(const char *namelist, const char *corefile)
{
    size_t pfn_table_size = dumphdr.dump_npages * sizeof (pfn_t);
    size_t ksyms_size = dumphdr.dump_ksyms_size;
    size_t ksyms_csize = dumphdr.dump_ksyms_csize;
    pfn_t *pfn_table;
    char *ksyms_base = Zalloc(ksyms_size);
    char *ksyms_cbase = Zalloc(ksyms_csize);
    size_t ksyms_dsize;
    Stat_t st;
    int corefd = Open(corefile, O_WRONLY | O_CREAT | O_TRUNC, 0644);
    int namefd = Open(namelist, O_WRONLY | O_CREAT | O_TRUNC, 0644);

    (void) printf("Constructing namelist %s/%s\n", savedir, namelist);

    /*
     * Determine the optimum write size for the core file
     */
    Fstat(corefd, &st, corefile);

    if (verbose > 1)
        (void) printf("%s: %ld block size\n", corefile,
            (long)st.st_blksize);
    coreblksize = st.st_blksize;
    if (coreblksize < MINCOREBLKSIZE || !ISP2(coreblksize))
        coreblksize = MINCOREBLKSIZE;

    hist = Zalloc((sizeof (uint64_t) * BTOP(coreblksize)) + 1);

    /*
     * This dump file is now uncompressed
     */
    corehdr.dump_flags &= ~DF_COMPRESSED;

    /*
     * Read in the compressed symbol table, copy it to corefile,
     * decompress it, and write the result to namelist.
     */
    corehdr.dump_ksyms = pagesize;
    Pread(dumpfd, ksyms_cbase, ksyms_csize, dumphdr.dump_ksyms);
    Pwrite(corefd, ksyms_cbase, ksyms_csize, corehdr.dump_ksyms);

    ksyms_dsize = decompress(ksyms_cbase, ksyms_base, ksyms_csize,
        ksyms_size);
    if (ksyms_dsize != ksyms_size)
        logprint(SC_SL_WARN,
            "bad data in symbol table, %lu of %lu bytes saved",
            ksyms_dsize, ksyms_size);

    Pwrite(namefd, ksyms_base, ksyms_size, 0);
    (void) close(namefd);
    free(ksyms_cbase);
    free(ksyms_base);

    (void) printf("Constructing corefile %s/%s\n", savedir, corefile);

    /*
     * Read in and write out the pfn table.
     */
    pfn_table = Zalloc(pfn_table_size);
    corehdr.dump_pfn = corehdr.dump_ksyms + roundup(ksyms_size, pagesize);
    Pread(dumpfd, pfn_table, pfn_table_size, dumphdr.dump_pfn);
    Pwrite(corefd, pfn_table, pfn_table_size, corehdr.dump_pfn);

    /*
     * Convert the raw translation data into a hashed dump map.
     */
    corehdr.dump_map = corehdr.dump_pfn + roundup(pfn_table_size, pagesize);
    build_dump_map(corefd, pfn_table);
    free(pfn_table);

    /*
     * Decompress the pages
     */
    decompress_pages(corefd);
    (void) printf(": %ld of %ld pages saved\n", (pgcnt_t)saved,
        dumphdr.dump_npages);

    if (verbose)
        (void) printf("%ld (%ld%%) zero pages were not written\n",
            (pgcnt_t)zpages, (pgcnt_t)zpages * 100 /
            dumphdr.dump_npages);

    if (saved != dumphdr.dump_npages)
        logprint(SC_SL_WARN, "bad data after page %ld", saved);

    /*
     * Write out the modified dump headers.
     */
    Pwrite(corefd, &corehdr, sizeof (corehdr), 0);
    if (!filemode)
        Pwrite(dumpfd, &dumphdr, sizeof (dumphdr), endoff);

    (void) close(corefd);
}

/*
 * When the system panics, the kernel saves all undelivered messages (messages
 * that never made it out to syslogd(1M)) in the dump.  At a mimimum, the
 * panic message itself will always fall into this category.  Upon reboot,
 * the syslog startup script runs savecore -m to recover these messages.
 *
 * To do this, we read the unsent messages from the dump and send them to
 * /dev/conslog on priority band 1.  This has the effect of prepending them
 * to any already-accumulated messages in the console backlog, thus preserving
 * temporal ordering across the reboot.
 *
 * Note: since savecore -m is used *only* for this purpose, it does *not*
 * attempt to save the crash dump.  The dump will be saved later, after
 * syslogd(1M) starts, by the savecore startup script.
 */
static int
message_save(void)
{
    offset_t dumpoff = -(DUMP_OFFSET + DUMP_LOGSIZE);
    offset_t ldoff;
    log_dump_t ld;
    log_ctl_t lc;
    struct strbuf ctl, dat;
    int logfd;

    logfd = Open("/dev/conslog", O_WRONLY, 0644);
    dumpfd = Open(dumpfile, O_RDWR | O_DSYNC, 0644);
    dumpoff = llseek(dumpfd, dumpoff, SEEK_END) & -DUMP_OFFSET;

    ctl.buf = (void *)&lc;
    ctl.len = sizeof (log_ctl_t);

    dat.buf = Zalloc(DUMP_LOGSIZE);

    for (;;) {
        ldoff = dumpoff;

        Pread(dumpfd, &ld, sizeof (log_dump_t), dumpoff);
        dumpoff += sizeof (log_dump_t);
        dat.len = ld.ld_msgsize;

        if (ld.ld_magic == 0)
            break;

        if (ld.ld_magic != LOG_MAGIC)
            logprint(SC_SL_ERR | SC_IF_VERBOSE | SC_EXIT_ERR,
                "bad magic %x", ld.ld_magic);

        if (dat.len >= DUMP_LOGSIZE)
            logprint(SC_SL_ERR | SC_IF_VERBOSE | SC_EXIT_ERR,
                "bad size %d", ld.ld_msgsize);

        Pread(dumpfd, ctl.buf, ctl.len, dumpoff);
        dumpoff += ctl.len;

        if (ld.ld_csum != checksum32(ctl.buf, ctl.len))
            logprint(SC_SL_ERR | SC_IF_VERBOSE | SC_EXIT_OK,
                "bad log_ctl checksum");

        lc.flags |= SL_LOGONLY;

        Pread(dumpfd, dat.buf, dat.len, dumpoff);
        dumpoff += dat.len;

        if (ld.ld_msum != checksum32(dat.buf, dat.len))
            logprint(SC_SL_ERR | SC_IF_VERBOSE | SC_EXIT_OK,
                "bad message checksum");

        if (putpmsg(logfd, &ctl, &dat, 1, MSG_BAND) == -1)
            logprint(SC_SL_ERR | SC_EXIT_ERR, "putpmsg: %s",
                strerror(errno));

        ld.ld_magic = 0;    /* clear magic so we never save twice */
        Pwrite(dumpfd, &ld, sizeof (log_dump_t), ldoff);
    }
    return (0);
}

static long
getbounds(const char *f)
{
    long b = -1;
    const char *p = strrchr(f, '/');

    if (p == NULL || strncmp(p, "vmdump", 6) != 0)
        p = strstr(f, "vmdump");

    if (p != NULL && *p == '/')
        p++;

    (void) sscanf(p ? p : f, "vmdump.%ld", &b);

    return (b);
}

static void
stack_retrieve(char *stack)
{
    summary_dump_t sd;
    offset_t dumpoff = -(DUMP_OFFSET + DUMP_LOGSIZE +
        DUMP_ERPTSIZE);
    dumpoff -= DUMP_SUMMARYSIZE;

    dumpfd = Open(dumpfile, O_RDWR | O_DSYNC, 0644);
    dumpoff = llseek(dumpfd, dumpoff, SEEK_END) & -DUMP_OFFSET;

    Pread(dumpfd, &sd, sizeof (summary_dump_t), dumpoff);
    dumpoff += sizeof (summary_dump_t);

    if (sd.sd_magic == 0) {
        *stack = '\0';
        return;
    }

    if (sd.sd_magic != SUMMARY_MAGIC) {
        *stack = '\0';
        logprint(SC_SL_NONE | SC_IF_VERBOSE,
            "bad summary magic %x", sd.sd_magic);
        return;
    }
    Pread(dumpfd, stack, STACK_BUF_SIZE, dumpoff);
    if (sd.sd_ssum != checksum32(stack, STACK_BUF_SIZE))
        logprint(SC_SL_NONE | SC_IF_VERBOSE, "bad stack checksum");
}

static void
raise_event(enum sc_event_type evidx, char *warn_string)
{
    uint32_t pl = sc_event[evidx].sce_payload;
    char panic_stack[STACK_BUF_SIZE];
    nvlist_t *attr = NULL;
    char uuidbuf[36 + 1];
    int err = 0;

    if (nvlist_alloc(&attr, NV_UNIQUE_NAME, 0) != 0)
        goto publish;   /* try to send payload-free event */

    if (pl & SC_PAYLOAD_SAVEDIR && savedir != NULL)
        err |= nvlist_add_string(attr, "dumpdir", savedir);

    if (pl & SC_PAYLOAD_INSTANCE && bounds != -1)
        err |= nvlist_add_int64(attr, "instance", bounds);

    if (pl & SC_PAYLOAD_ISCOMPRESSED) {
        err |= nvlist_add_boolean_value(attr, "compressed",
            csave ? B_TRUE : B_FALSE);
    }

    if (pl & SC_PAYLOAD_DUMPADM_EN) {
        char *disabled = defread("DUMPADM_ENABLE=no");

        err |= nvlist_add_boolean_value(attr, "savecore-enabled",
            disabled ? B_FALSE : B_TRUE);
    }

    if (pl & SC_PAYLOAD_IMAGEUUID) {
        (void) strncpy(uuidbuf, corehdr.dump_uuid, 36);
        uuidbuf[36] = '\0';
        err |= nvlist_add_string(attr, "os-instance-uuid", uuidbuf);
    }

    if (pl & SC_PAYLOAD_CRASHTIME) {
        err |= nvlist_add_int64(attr, "crashtime",
            (int64_t)corehdr.dump_crashtime);
    }

    if (pl & SC_PAYLOAD_PANICSTR && corehdr.dump_panicstring[0] != '\0') {
        err |= nvlist_add_string(attr, "panicstr",
            corehdr.dump_panicstring);
    }

    if (pl & SC_PAYLOAD_PANICSTACK) {
        stack_retrieve(panic_stack);

        if (panic_stack[0] != '\0') {
            /*
             * The summary page may not be present if the dump
             * was previously recorded compressed.
             */
            (void) nvlist_add_string(attr, "panicstack",
                panic_stack);
        }
    }

    /* add warning string if this is an ireport for dump failure */
    if (pl & SC_PAYLOAD_FAILREASON && warn_string != NULL)
        (void) nvlist_add_string(attr, "failure-reason", warn_string);

    if (pl & SC_PAYLOAD_DUMPCOMPLETE)
        err |= nvlist_add_boolean_value(attr, "dump-incomplete",
            dump_incomplete ? B_TRUE : B_FALSE);

    if (pl & SC_PAYLOAD_FM_PANIC) {
        err |= nvlist_add_boolean_value(attr, "fm-panic",
            fm_panic ? B_TRUE : B_FALSE);
    }

    if (pl & SC_PAYLOAD_JUSTCHECKING) {
        err |= nvlist_add_boolean_value(attr, "will-attempt-savecore",
            cflag ? B_FALSE : B_TRUE);
    }

    if (err)
        logprint(SC_SL_WARN, "Errors while constructing '%s' "
            "event payload; will try to publish anyway.");
publish:
    if (fmev_rspublish_nvl(FMEV_RULESET_ON_SUNOS,
        "panic", sc_event[evidx].sce_subclass, FMEV_HIPRI,
        attr) != FMEV_SUCCESS) {
        logprint(SC_SL_ERR, "failed to publish '%s' event: %s",
            sc_event[evidx].sce_subclass, fmev_strerror(fmev_errno));
        nvlist_free(attr);
    }

}


int
main(int argc, char *argv[])
{
    int i, c, bfd;
    Stat_t st;
    struct rlimit rl;
    long filebounds = -1;
    char namelist[30], corefile[30], boundstr[30];
    dumpfile = NULL;

    startts = gethrtime();

    (void) getrlimit(RLIMIT_NOFILE, &rl);
    rl.rlim_cur = rl.rlim_max;
    (void) setrlimit(RLIMIT_NOFILE, &rl);

    openlog(progname, LOG_ODELAY, LOG_AUTH);

    (void) defopen("/etc/dumpadm.conf");
    savedir = defread("DUMPADM_SAVDIR=");
    if (savedir != NULL)
        savedir = strdup(savedir);

    while ((c = getopt(argc, argv, "Lvcdmf:")) != EOF) {
        switch (c) {
        case 'L':
            livedump++;
            break;
        case 'v':
            verbose++;
            break;
        case 'c':
            cflag++;
            break;
        case 'd':
            disregard_valid_flag++;
            break;
        case 'm':
            mflag++;
            break;
        case 'f':
            dumpfile = optarg;
            filebounds = getbounds(dumpfile);
            break;
        case '?':
            usage();
        }
    }

    /*
     * If doing something other than extracting an existing dump (i.e.
     * dumpfile has been provided as an option), the user must be root.
     */
    if (geteuid() != 0 && dumpfile == NULL) {
        (void) fprintf(stderr, "%s: %s %s\n", progname,
            gettext("you must be root to use"), progname);
        exit(1);
    }

    interactive = isatty(STDOUT_FILENO);

    if (cflag && livedump)
        usage();

    if (dumpfile == NULL || livedump)
        dumpfd = Open("/dev/dump", O_RDONLY, 0444);

    if (dumpfile == NULL) {
        dumpfile = Zalloc(MAXPATHLEN);
        if (ioctl(dumpfd, DIOCGETDEV, dumpfile) == -1)
            logprint(SC_SL_NONE | SC_IF_ISATTY | SC_EXIT_ERR,
                "no dump device configured");
    }

    if (mflag)
        return (message_save());

    if (optind == argc - 1)
        savedir = argv[optind];

    if (savedir == NULL || optind < argc - 1)
        usage();

    if (livedump && ioctl(dumpfd, DIOCDUMP, NULL) == -1)
        logprint(SC_SL_NONE | SC_EXIT_ERR,
            "dedicated dump device required");

    (void) close(dumpfd);
    dumpfd = -1;

    Stat(dumpfile, &st);

    filemode = S_ISREG(st.st_mode);

    if (!filemode && defread("DUMPADM_CSAVE=off") == NULL)
        csave = 1;

    read_dumphdr();

    /*
     * We want this message to go to the log file, but not the console.
     * There's no good way to do that with the existing syslog facility.
     * We could extend it to handle this, but there doesn't seem to be
     * a general need for it, so we isolate the complexity here instead.
     */
    if (dumphdr.dump_panicstring[0] != '\0') {
        int logfd = Open("/dev/conslog", O_WRONLY, 0644);
        log_ctl_t lc;
        struct strbuf ctl, dat;
        char msg[DUMP_PANICSIZE + 100];
        char fmt[] = "reboot after panic: %s";
        uint32_t msgid;

        STRLOG_MAKE_MSGID(fmt, msgid);

        /* LINTED: E_SEC_SPRINTF_UNBOUNDED_COPY */
        (void) sprintf(msg, "%s: [ID %u FACILITY_AND_PRIORITY] ",
            progname, msgid);
        /* LINTED: E_SEC_PRINTF_VAR_FMT */
        (void) sprintf(msg + strlen(msg), fmt,
            dumphdr.dump_panicstring);

        lc.pri = LOG_AUTH | LOG_ERR;
        lc.flags = SL_CONSOLE | SL_LOGONLY;
        lc.level = 0;

        ctl.buf = (void *)&lc;
        ctl.len = sizeof (log_ctl_t);

        dat.buf = (void *)msg;
        dat.len = strlen(msg) + 1;

        (void) putmsg(logfd, &ctl, &dat, 0);
        (void) close(logfd);
    }

    if ((dumphdr.dump_flags & DF_COMPLETE) == 0) {
        logprint(SC_SL_WARN, "incomplete dump on dump device");
        dump_incomplete = B_TRUE;
    }

    if (dumphdr.dump_fm_panic)
        fm_panic = B_TRUE;

    /*
     * We have a valid dump on a dump device and know as much about
     * it as we're going to at this stage.  Raise an event for
     * logging and so that FMA can open a case for this panic.
     * Avoid this step for FMA-initiated panics - FMA will replay
     * ereports off the dump device independently of savecore and
     * will make a diagnosis, so we don't want to open two cases
     * for the same event.  Also avoid raising an event for a
     * livedump, or when we inflating a compressed dump.
     */
    if (!fm_panic && !livedump && !filemode)
        raise_event(SC_EVENT_DUMP_PENDING, NULL);

    logprint(SC_SL_WARN, "System dump time: %s",
        ctime(&dumphdr.dump_crashtime));

    /*
     * Option -c is designed for use from svc-dumpadm where we know
     * that dumpadm -n is in effect but run savecore -c just to
     * get the above dump_pending_on_device event raised.  If it is run
     * interactively then just print further panic details.
     */
    if (cflag) {
        char *disabled = defread("DUMPADM_ENABLE=no");
        int lvl = interactive ? SC_SL_WARN : SC_SL_ERR;
        int ec = fm_panic ? SC_EXIT_FM : SC_EXIT_PEND;

        logprint(lvl | ec,
            "Panic crashdump pending on dump device%s "
            "run savecore(1M) manually to extract. "
            "Image UUID %s%s.",
            disabled ? " but dumpadm -n in effect;" : ";",
            corehdr.dump_uuid,
            fm_panic ?  "(fault-management initiated)" : "");
        /*NOTREACHED*/
    }

    if (chdir(savedir) == -1)
        logprint(SC_SL_ERR | SC_EXIT_ERR, "chdir(\"%s\"): %s",
            savedir, strerror(errno));

    check_space(csave);

    if (filebounds < 0)
        bounds = read_number_from_file("bounds", 0);
    else
        bounds = filebounds;

    if (csave) {
        size_t metrics_size = datahdr.dump_metrics;

        (void) sprintf(corefile, "vmdump.%ld", bounds);

        datahdr.dump_metrics = 0;

        logprint(SC_SL_ERR,
            "Saving compressed system crash dump in %s/%s",
            savedir, corefile);

        copy_crashfile(corefile);

        /*
         * Raise a fault management event that indicates the system
         * has panicked. We know a reasonable amount about the
         * condition at this time, but the dump is still compressed.
         */
        if (!livedump && !fm_panic)
            raise_event(SC_EVENT_DUMP_AVAILABLE, NULL);

        if (metrics_size > 0) {
            int sec = (gethrtime() - startts) / 1000 / 1000 / 1000;
            FILE *mfile = fopen(METRICSFILE, "a");
            char *metrics = Zalloc(metrics_size + 1);

            Pread(dumpfd, metrics, metrics_size, endoff +
                sizeof (dumphdr) + sizeof (datahdr));

            if (sec < 1)
                sec = 1;

            if (mfile == NULL) {
                logprint(SC_SL_WARN,
                    "Can't create %s:\n%s",
                    METRICSFILE, metrics);
            } else {
                (void) fprintf(mfile, "[[[[,,,");
                for (i = 0; i < argc; i++)
                    (void) fprintf(mfile, "%s ", argv[i]);
                (void) fprintf(mfile, "\n");
                (void) fprintf(mfile, ",,,%s %s %s %s %s\n",
                    dumphdr.dump_utsname.sysname,
                    dumphdr.dump_utsname.nodename,
                    dumphdr.dump_utsname.release,
                    dumphdr.dump_utsname.version,
                    dumphdr.dump_utsname.machine);
                (void) fprintf(mfile, ",,,%s dump time %s\n",
                    dumphdr.dump_flags & DF_LIVE ? "Live" :
                    "Crash", ctime(&dumphdr.dump_crashtime));
                (void) fprintf(mfile, ",,,%s/%s\n", savedir,
                    corefile);
                (void) fprintf(mfile, "Metrics:\n%s\n",
                    metrics);
                (void) fprintf(mfile, "Copy pages,%ld\n",
                    dumphdr.  dump_npages);
                (void) fprintf(mfile, "Copy time,%d\n", sec);
                (void) fprintf(mfile, "Copy pages/sec,%ld\n",
                    dumphdr.dump_npages / sec);
                (void) fprintf(mfile, "]]]]\n");
                (void) fclose(mfile);
            }
            free(metrics);
        }

        logprint(SC_SL_ERR,
            "Decompress the crash dump with "
            "\n'savecore -vf %s/%s'",
            savedir, corefile);

    } else {
        (void) sprintf(namelist, "unix.%ld", bounds);
        (void) sprintf(corefile, "vmcore.%ld", bounds);

        if (interactive && filebounds >= 0 && access(corefile, F_OK)
            == 0)
            logprint(SC_SL_NONE | SC_EXIT_ERR,
                "%s already exists: remove with "
                "'rm -f %s/{unix,vmcore}.%ld'",
                corefile, savedir, bounds);

        logprint(SC_SL_ERR,
            "saving system crash dump in %s/{unix,vmcore}.%ld",
            savedir, bounds);

        build_corefile(namelist, corefile);

        if (!livedump && !filemode && !fm_panic)
            raise_event(SC_EVENT_DUMP_AVAILABLE, NULL);

        if (access(METRICSFILE, F_OK) == 0) {
            int sec = (gethrtime() - startts) / 1000 / 1000 / 1000;
            FILE *mfile = fopen(METRICSFILE, "a");

            if (sec < 1)
                sec = 1;

            (void) fprintf(mfile, "[[[[,,,");
            for (i = 0; i < argc; i++)
                (void) fprintf(mfile, "%s ", argv[i]);
            (void) fprintf(mfile, "\n");
            (void) fprintf(mfile, ",,,%s/%s\n", savedir, corefile);
            (void) fprintf(mfile, ",,,%s %s %s %s %s\n",
                dumphdr.dump_utsname.sysname,
                dumphdr.dump_utsname.nodename,
                dumphdr.dump_utsname.release,
                dumphdr.dump_utsname.version,
                dumphdr.dump_utsname.machine);
            (void) fprintf(mfile, "Uncompress pages,%"PRIu64"\n",
                saved);
            (void) fprintf(mfile, "Uncompress time,%d\n", sec);
            (void) fprintf(mfile, "Uncompress pages/sec,%"
                PRIu64"\n", saved / sec);
            (void) fprintf(mfile, "]]]]\n");
            (void) fclose(mfile);
        }
    }

    if (filebounds < 0) {
        (void) sprintf(boundstr, "%ld\n", bounds + 1);
        bfd = Open("bounds", O_WRONLY | O_CREAT | O_TRUNC, 0644);
        Pwrite(bfd, boundstr, strlen(boundstr), 0);
        (void) close(bfd);
    }

    if (verbose) {
        int sec = (gethrtime() - startts) / 1000 / 1000 / 1000;

        (void) printf("%d:%02d dump %s is done\n",
            sec / 60, sec % 60,
            csave ? "copy" : "decompress");
    }

    if (verbose > 1 && hist != NULL) {
        int i, nw;

        for (i = 1, nw = 0; i <= BTOP(coreblksize); ++i)
            nw += hist[i] * i;
        (void) printf("pages count     %%\n");
        for (i = 0; i <= BTOP(coreblksize); ++i) {
            if (hist[i] == 0)
                continue;
            (void) printf("%3d   %5u  %6.2f\n",
                i, hist[i], 100.0 * hist[i] * i / nw);
        }
    }

    (void) close(dumpfd);
    dumpfd = -1;

    return (0);
}