fmd/common/fmd_mdb.c

/*
 * 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) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
 */

#include <sys/mdb_modapi.h>
#include <limits.h>

#include <fmd_trace.h>
#include <fmd_module.h>
#include <fmd_thread.h>
#include <fmd_ustat.h>
#include <fmd_event.h>
#include <fmd_case.h>
#include <fmd_buf.h>
#include <fmd_asru.h>
#include <fmd_ckpt.h>
#include <fmd_timerq.h>
#include <fmd_xprt.h>

#include <fmd.h>

typedef struct trwalk_state {
    struct trwalk_state *trw_next;
    fmd_tracebuf_t trw_data;
    pthread_t trw_tid;
    uintptr_t trw_base;
    const fmd_tracerec_t *trw_stop;
    fmd_tracerec_t *trw_xrec;
} trwalk_state_t;

typedef struct hashwalk_data {
    uintptr_t *hw_hash;
    uint_t hw_hashlen;
    uint_t hw_hashidx;
    const char *hw_name;
    void *hw_data;
    size_t hw_size;
    size_t hw_next;
} hashwalk_data_t;

static int fmd_stat(uintptr_t, uint_t, int, const mdb_arg_t *);
static int fmd_ustat(uintptr_t, uint_t, int, const mdb_arg_t *);

static int
trwalk_init(mdb_walk_state_t *wsp)
{
    uintptr_t addr;
    fmd_thread_t thr;
    fmd_t F;

    if (wsp->walk_addr != NULL) {
        mdb_warn("fmd_trace only supports global walks\n");
        return (WALK_ERR);
    }

    if (mdb_readvar(&F, "fmd") != sizeof (F)) {
        mdb_warn("failed to read fmd meta-data");
        return (WALK_ERR);
    }

    for (addr = (uintptr_t)F.d_thr_list.l_next; addr != NULL;
        addr = (uintptr_t)thr.thr_list.l_next) {

        size_t len, ptr_off, end_off;
        fmd_tracerec_t *buf;
        trwalk_state_t *t;

        if (mdb_vread(&thr, sizeof (thr), addr) != sizeof (thr)) {
            mdb_warn("failed to read thread at %p "
                "(some trace data will be unavailable)", addr);
            break;
        }

        t = mdb_zalloc(sizeof (trwalk_state_t), UM_SLEEP);
        t->trw_next = wsp->walk_data;
        wsp->walk_data = t;

        (void) mdb_vread(&t->trw_data,
            sizeof (t->trw_data), (uintptr_t)thr.thr_trdata);

        if (t->trw_data.tb_recs == 0)
            continue; /* no trace buffer allocated for thread */

        len = t->trw_data.tb_recs * t->trw_data.tb_size;
        buf = mdb_alloc(len, UM_SLEEP);

        t->trw_tid = thr.thr_tid;
        t->trw_base = (uintptr_t)t->trw_data.tb_buf;

        if (mdb_vread(buf, len, t->trw_base) == -1) {
            mdb_warn("failed to read buffer for t%u", t->trw_tid);
            bzero(buf, len);
        }

        end_off = (uintptr_t)t->trw_data.tb_end - t->trw_base;
        ptr_off = (uintptr_t)t->trw_data.tb_ptr - t->trw_base;

        t->trw_data.tb_buf = buf;
        t->trw_data.tb_end = (void *)((uintptr_t)buf + end_off);
        t->trw_data.tb_ptr = (void *)((uintptr_t)buf + ptr_off);

        if (t->trw_data.tb_ptr < t->trw_data.tb_buf ||
            t->trw_data.tb_ptr > t->trw_data.tb_end) {
            mdb_warn("trace record ptr for t%u is corrupt "
                "(some data may be unavailable)\n", t->trw_tid);
            t->trw_data.tb_ptr = t->trw_data.tb_buf;
        }

        t->trw_stop = t->trw_data.tb_ptr;
        t->trw_xrec = mdb_alloc(
            t->trw_data.tb_size + sizeof (uintptr_t), UM_SLEEP);
    }

    return (WALK_NEXT);
}

static fmd_tracerec_t *
trwalk_nextrec(trwalk_state_t *t)
{
    if (t->trw_stop == NULL)
        return (t->trw_data.tb_ptr);

    if (t->trw_data.tb_ptr == t->trw_data.tb_buf)
        t->trw_data.tb_ptr = t->trw_data.tb_end;
    else
        t->trw_data.tb_ptr = (fmd_tracerec_t *)
            ((uintptr_t)t->trw_data.tb_ptr - t->trw_data.tb_size);

    if (t->trw_data.tb_ptr == t->trw_stop)
        t->trw_stop = NULL; /* mark buffer as empty */

    return (t->trw_data.tb_ptr);
}

static int
trwalk_step(mdb_walk_state_t *wsp)
{
    trwalk_state_t *t, *oldest_t;
    hrtime_t oldest_time = 0;
    fmd_tracerec_t *trp;
    int status;

    for (t = wsp->walk_data; t != NULL; t = t->trw_next) {
        for (trp = t->trw_data.tb_ptr; t->trw_stop != NULL &&
            trp->tr_time == 0; trp = trwalk_nextrec(t))
            continue;

        if (t->trw_stop == NULL)
            continue; /* buffer has been emptied */

        if (trp->tr_time > oldest_time) {
            oldest_time = trp->tr_time;
            oldest_t = t;
        }
    }

    if (oldest_time == 0)
        return (WALK_DONE);

    t = oldest_t;
    trp = t->trw_data.tb_ptr;

    bcopy(trp, t->trw_xrec, t->trw_data.tb_size);
    t->trw_xrec->tr_depth = MIN(trp->tr_depth, t->trw_data.tb_frames);
    t->trw_xrec->tr_stack[t->trw_xrec->tr_depth] = t->trw_tid;

    status = wsp->walk_callback((uintptr_t)trp - (uintptr_t)
        t->trw_data.tb_buf + t->trw_base, t->trw_xrec, wsp->walk_cbdata);

    (void) trwalk_nextrec(t);
    return (status);
}

static void
trwalk_fini(mdb_walk_state_t *wsp)
{
    trwalk_state_t *t, *u;

    for (t = wsp->walk_data; t != NULL; t = u) {
        u = t->trw_next;
        mdb_free(t->trw_data.tb_buf,
            t->trw_data.tb_recs * t->trw_data.tb_size);
        mdb_free(t->trw_xrec, t->trw_data.tb_size + sizeof (uintptr_t));
        mdb_free(t, sizeof (trwalk_state_t));
    }
}

/*ARGSUSED*/
static int
trprint_msg(uintptr_t addr, const fmd_tracerec_t *trp, uintptr_t tid)
{
    if (tid == 0)
        mdb_printf("%3lu ", trp->tr_stack[trp->tr_depth]);
    else if (trp->tr_stack[trp->tr_depth] != tid)
        return (WALK_NEXT);

    mdb_printf("%016llx %04x %-5u %s\n",
        trp->tr_time, 1 << trp->tr_tag, trp->tr_errno, trp->tr_msg);

    return (WALK_NEXT);
}

/*ARGSUSED*/
static int
trprint_cpp(uintptr_t addr, const fmd_tracerec_t *trp, uintptr_t tid)
{
    char file[64];

    if (tid == 0)
        mdb_printf("%3lu ", trp->tr_stack[trp->tr_depth]);
    else if (trp->tr_stack[trp->tr_depth] != tid)
        return (WALK_NEXT);

    if (mdb_readstr(file, sizeof (file), (uintptr_t)trp->tr_file) <= 0)
        (void) strcpy(file, "???");

    mdb_printf("%016llx %04x %s: %u\n",
        trp->tr_time, 1 << trp->tr_tag, file, trp->tr_line);

    return (WALK_NEXT);
}

static void
trprint_stack(const fmd_tracerec_t *trp)
{
    uint8_t i;

    for (i = 0; i < trp->tr_depth; i++)
        mdb_printf("\t%a\n", trp->tr_stack[i]);

    if (trp->tr_depth != 0)
        mdb_printf("\n");
}

static int
trprint_msg_stack(uintptr_t addr, const fmd_tracerec_t *trp, uintptr_t tid)
{
    int status = trprint_msg(addr, trp, tid);
    trprint_stack(trp);
    return (status);
}

static int
trprint_cpp_stack(uintptr_t addr, const fmd_tracerec_t *trp, uintptr_t tid)
{
    int status = trprint_cpp(addr, trp, tid);
    trprint_stack(trp);
    return (status);
}

static int
fmd_trace(uintptr_t tid, uint_t flags, int argc, const mdb_arg_t *argv)
{
    int (*func)(uintptr_t, const fmd_tracerec_t *, uintptr_t);
    uint_t opt_c = FALSE, opt_s = FALSE;

    if (mdb_getopts(argc, argv,
        'c', MDB_OPT_SETBITS, TRUE, &opt_c,
        's', MDB_OPT_SETBITS, TRUE, &opt_s, NULL) != argc)
        return (DCMD_USAGE);

    if (!(flags & DCMD_ADDRSPEC)) {
        mdb_printf("TID ");
        tid = 0;
    }

    if (opt_c) {
        mdb_printf("%-16s %-4s FILE:LINE\n", "TIME", "TAG");
        func = opt_s ? trprint_cpp_stack : trprint_cpp;
    } else {
        mdb_printf("%-16s %-4s %-5s MSG\n", "TIME", "TAG", "ERRNO");
        func = opt_s ? trprint_msg_stack : trprint_msg;
    }

    if (mdb_walk("fmd_trace", (mdb_walk_cb_t)func, (void *)tid) == -1) {
        mdb_warn("failed to walk fmd_trace");
        return (DCMD_ERR);
    }

    return (DCMD_OK);
}

static int
hash_walk_init(mdb_walk_state_t *wsp, uintptr_t addr, uint_t hashlen,
    const char *name, size_t size, size_t next)
{
    hashwalk_data_t *hwp;
    size_t len = sizeof (uintptr_t) * hashlen;

    if (len == 0) {
        mdb_warn("failed to walk hash: invalid hash length\n");
        return (WALK_ERR);
    }

    hwp = mdb_alloc(sizeof (hashwalk_data_t), UM_SLEEP);
    hwp->hw_hash = mdb_zalloc(len, UM_SLEEP);
    (void) mdb_vread(hwp->hw_hash, len, addr);
    hwp->hw_hashlen = hashlen;
    hwp->hw_hashidx = 0;
    hwp->hw_name = name;
    hwp->hw_data = mdb_zalloc(size, UM_SLEEP);
    hwp->hw_size = size;
    hwp->hw_next = next;

    wsp->walk_addr = hwp->hw_hash[0];
    wsp->walk_data = hwp;

    return (WALK_NEXT);
}

static int
hash_walk_step(mdb_walk_state_t *wsp)
{
    hashwalk_data_t *hwp = wsp->walk_data;
    int rv;

    while (wsp->walk_addr == NULL) {
        if (++hwp->hw_hashidx < hwp->hw_hashlen)
            wsp->walk_addr = hwp->hw_hash[hwp->hw_hashidx];
        else
            return (WALK_DONE);
    }

    if (mdb_vread(hwp->hw_data, hwp->hw_size, wsp->walk_addr) == -1) {
        mdb_warn("failed to read %s at %p",
            hwp->hw_name, wsp->walk_addr);
        return (WALK_ERR);
    }

    rv = wsp->walk_callback(wsp->walk_addr, hwp->hw_data, wsp->walk_cbdata);
    wsp->walk_addr = *(uintptr_t *)((uintptr_t)hwp->hw_data + hwp->hw_next);
    return (rv);
}

static void
hash_walk_fini(mdb_walk_state_t *wsp)
{
    hashwalk_data_t *hwp = wsp->walk_data;

    mdb_free(hwp->hw_hash, sizeof (uintptr_t) * hwp->hw_hashlen);
    mdb_free(hwp->hw_data, hwp->hw_size);
    mdb_free(hwp, sizeof (hashwalk_data_t));
}

static int
ustat_walk_init(mdb_walk_state_t *wsp)
{
    fmd_ustat_t us;

    if (mdb_vread(&us, sizeof (us), wsp->walk_addr) != sizeof (us)) {
        mdb_warn("failed to read fmd_ustat_t at %p", wsp->walk_addr);
        return (WALK_ERR);
    }

    return (hash_walk_init(wsp,
        (uintptr_t)us.us_hash, us.us_hashlen, NULL, 0, 0));
}

static int
ustat_walk_step(mdb_walk_state_t *wsp)
{
    hashwalk_data_t *hwp = wsp->walk_data;
    fmd_ustat_elem_t ue;
    fmd_stat_t s;

    while (wsp->walk_addr == NULL) {
        if (++hwp->hw_hashidx < hwp->hw_hashlen)
            wsp->walk_addr = hwp->hw_hash[hwp->hw_hashidx];
        else
            return (WALK_DONE);
    }

    if (mdb_vread(&ue, sizeof (ue), wsp->walk_addr) != sizeof (ue) ||
        mdb_vread(&s, sizeof (s), (uintptr_t)ue.use_stat) != sizeof (s)) {
        mdb_warn("failed to read stat element at %p", wsp->walk_addr);
        return (WALK_ERR);
    }

    wsp->walk_addr = (uintptr_t)ue.use_next;

    return (wsp->walk_callback(
        (uintptr_t)ue.use_stat, &s, wsp->walk_cbdata));
}

struct fmd_cmd_data {
    int argc;
    const mdb_arg_t *argv;
};

/* ARGSUSED */
static int
module_ustat(uintptr_t addr, const void *data, void *wsp)
{
    fmd_module_t *modp = (fmd_module_t *)data;
    char name[PATH_MAX];
    const struct fmd_cmd_data *udp = wsp;

    if (mdb_readstr(name, sizeof (name), (uintptr_t)modp->mod_name) <= 0)
        (void) mdb_snprintf(name, sizeof (name), "<%p>",
            modp->mod_name);
    mdb_printf("%s\n", name);
    (void) fmd_ustat((uintptr_t)modp->mod_ustat,
        DCMD_ADDRSPEC | DCMD_LOOPFIRST, udp->argc, udp->argv);
    return (WALK_NEXT);
}

static int
fmd_ustat(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    if (!(flags & DCMD_ADDRSPEC)) {
        struct fmd_cmd_data ud;

        ud.argc = argc;
        ud.argv = argv;
        if (mdb_walk("fmd_module", module_ustat, &ud) == -1) {
            mdb_warn("failed to walk 'fmd_module'");
            return (DCMD_ERR);
        }
        return (DCMD_OK);
    }

    if (mdb_pwalk_dcmd("fmd_ustat", "fmd_stat", argc, argv, addr) != 0) {
        mdb_warn("failed to walk fmd_ustat at %p", addr);
        return (DCMD_ERR);
    }

    return (DCMD_OK);
}

/* ARGSUSED */
static int
module_stat(uintptr_t addr, const void *data, void *wsp)
{
    fmd_module_t *modp = (fmd_module_t *)data;
    char name[PATH_MAX];
    const struct fmd_cmd_data *udp = wsp;
    fmd_modstat_t *mod_stats;

    if (mdb_readstr(name, sizeof (name), (uintptr_t)modp->mod_name) <= 0) {
        (void) mdb_snprintf(name, sizeof (name), "<%p>",
            modp->mod_name);
    }
    mdb_printf("%s\n", name);
    mod_stats = modp->mod_stats;
    (void) fmd_stat((uintptr_t)&mod_stats->ms_loadtime,
        DCMD_ADDRSPEC | DCMD_LOOPFIRST, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_snaptime,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_accepted,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_debugdrop,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_memtotal,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_memlimit,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_buftotal,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_buflimit,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_thrtotal,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_thrlimit,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_doorthrtotal,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_doorthrlimit,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_caseopen,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_casesolved,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_caseclosed,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_ckpt_save,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_ckpt_restore,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_ckpt_zeroed,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_ckpt_cnt,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_ckpt_time,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_xprtopen,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_xprtlimit,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    (void) fmd_stat((uintptr_t)&mod_stats->ms_xprtqlimit,
        DCMD_ADDRSPEC | DCMD_LOOP, udp->argc, udp->argv);
    return (WALK_NEXT);
}

/*ARGSUSED*/
static int
fmd_stat(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    char buf[512];
    fmd_stat_t s;

    if (argc != 0)
        return (DCMD_USAGE);

    if (DCMD_HDRSPEC(flags))
        mdb_printf("%<u>%-11s %-4s %-32s %s%</u>\n",
            "ADDR", "TYPE", "NAME", "VALUE");

    if (!(flags & DCMD_ADDRSPEC)) {
        struct fmd_cmd_data ud;

        ud.argc = argc;
        ud.argv = argv;

        if (mdb_walk("fmd_module", module_stat, &ud) == -1) {
            mdb_warn("failed to walk 'fmd_module'");
            return (DCMD_ERR);
        }
        return (DCMD_OK);
    }

    if (mdb_vread(&s, sizeof (s), addr) != sizeof (s)) {
        mdb_warn("failed to read statistic at %p", addr);
        return (DCMD_ERR);
    }

    switch (s.fmds_type) {
    case FMD_TYPE_BOOL:
        mdb_printf("%-11p %-4s %-32s %s\n", addr, "bool",
            s.fmds_name, s.fmds_value.bool ? "true" : "false");
        break;
    case FMD_TYPE_INT32:
        mdb_printf("%-11p %-4s %-32s %d\n", addr, "i32",
            s.fmds_name, s.fmds_value.i32);
        break;
    case FMD_TYPE_UINT32:
        mdb_printf("%-11p %-4s %-32s %u\n", addr, "ui32",
            s.fmds_name, s.fmds_value.i32);
        break;
    case FMD_TYPE_INT64:
        mdb_printf("%-11p %-4s %-32s %lld\n", addr, "i64",
            s.fmds_name, s.fmds_value.i64);
        break;
    case FMD_TYPE_UINT64:
        mdb_printf("%-11p %-4s %-32s %llu\n", addr, "ui64",
            s.fmds_name, s.fmds_value.ui64);
        break;
    case FMD_TYPE_STRING:
        if (mdb_readstr(buf, sizeof (buf),
            (uintptr_t)s.fmds_value.str) < 0) {
            (void) mdb_snprintf(buf, sizeof (buf), "<%p>",
                s.fmds_value.str);
        }
        mdb_printf("%-11p %-4s %-32s %s\n", addr, "str",
            s.fmds_name, buf);
        break;
    case FMD_TYPE_TIME:
        mdb_printf("%-11p %-4s %-32s %llu\n", addr, "time",
            s.fmds_name, s.fmds_value.ui64);
        break;
    case FMD_TYPE_SIZE:
        mdb_printf("%-11p %-4s %-32s %llu\n", addr, "size",
            s.fmds_name, s.fmds_value.ui64);
        break;
    default:
        mdb_printf("%-11p %-4u %-32s ???\n", addr,
            s.fmds_type, s.fmds_name);
        break;
    }

    return (DCMD_OK);
}

/*ARGSUSED*/
static int
fmd_event(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    char type[16], name[16];
    fmd_event_impl_t ev;

    if (argc != 0)
        return (DCMD_USAGE);

    if (mdb_vread(&ev, sizeof (ev), addr) != sizeof (ev)) {
        mdb_warn("failed to read fmd_event at %p", addr);
        return (DCMD_ERR);
    }

    if (DCMD_HDRSPEC(flags)) {
        mdb_printf("%<u>%-11s %-4s %-5s %-3s %-?s%</u>\n",
            "ADDR", "TYPE", "STATE", "REF", "NVPAIR");
    }

    switch (ev.ev_type) {
    case FMD_EVT_PROTOCOL:
        (void) strcpy(type, "PROT");
        break;
    case FMD_EVT_GC:
        (void) strcpy(type, "GC");
        break;
    case FMD_EVT_CLOSE:
        (void) strcpy(type, "CLSE");
        break;
    case FMD_EVT_TIMEOUT:
        (void) strcpy(type, "TIME");
        break;
    case FMD_EVT_STATS:
        (void) strcpy(type, "STAT");
        break;
    case FMD_EVT_PUBLISH:
        (void) strcpy(type, "PUBL");
        break;
    case FMD_EVT_TOPO:
        (void) strcpy(type, "TOPO");
        break;
    default:
        (void) mdb_snprintf(type, sizeof (type), "%u", ev.ev_type);
    }

    switch (ev.ev_state) {
    case FMD_EVS_RECEIVED:
        (void) strcpy(name, "RECVD");
        break;
    case FMD_EVS_ACCEPTED:
        (void) strcpy(name, "ACCPT");
        break;
    case FMD_EVS_DISCARDED:
        (void) strcpy(name, "DSCRD");
        break;
    case FMD_EVS_DIAGNOSED:
        (void) strcpy(name, "DIAGN");
        break;
    default:
        (void) mdb_snprintf(name, sizeof (name), "%u", ev.ev_state);
    }

    mdb_printf("%-11p %-4s %-5s %-3u %p\n",
        addr, type, name, ev.ev_refs, ev.ev_nvl);

    return (DCMD_OK);
}

static int
thread_walk_init(mdb_walk_state_t *wsp)
{
    fmd_t F;

    if (mdb_readvar(&F, "fmd") != sizeof (F)) {
        mdb_warn("failed to read fmd meta-data");
        return (WALK_ERR);
    }

    wsp->walk_addr = (uintptr_t)F.d_thr_list.l_next;
    return (WALK_NEXT);
}

static int
thread_walk_step(mdb_walk_state_t *wsp)
{
    uintptr_t addr = wsp->walk_addr;
    fmd_thread_t t;

    if (addr == NULL)
        return (WALK_DONE);

    if (mdb_vread(&t, sizeof (t), addr) != sizeof (t)) {
        mdb_warn("failed to read fmd_thread at %p", addr);
        return (WALK_ERR);
    }

    wsp->walk_addr = (uintptr_t)t.thr_list.l_next;
    return (wsp->walk_callback(addr, &t, wsp->walk_cbdata));
}

static int
fmd_thread(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    fmd_thread_t thr;

    if (!(flags & DCMD_ADDRSPEC))
        return (mdb_walk_dcmd("fmd_thread", "fmd_thread", argc, argv));

    if (argc != 0)
        return (DCMD_USAGE);

    if (mdb_vread(&thr, sizeof (thr), addr) != sizeof (thr)) {
        mdb_warn("failed to read fmd_thread at %p", addr);
        return (DCMD_ERR);
    }

    if (DCMD_HDRSPEC(flags)) {
        mdb_printf("%<u>%-11s %-11s %-8s %-16s%</u>\n",
            "ADDR", "MOD", "TID", "FUNC");
    }

    mdb_printf("%-11p %-11p %-8u %a\n",
        addr, thr.thr_mod, thr.thr_tid, thr.thr_func);

    return (DCMD_OK);
}

static int
mod_walk_init(mdb_walk_state_t *wsp)
{
    fmd_t F;

    if (mdb_readvar(&F, "fmd") != sizeof (F)) {
        mdb_warn("failed to read fmd meta-data");
        return (WALK_ERR);
    }

    wsp->walk_addr = (uintptr_t)F.d_mod_list.l_next;
    return (WALK_NEXT);
}

static int
mod_walk_step(mdb_walk_state_t *wsp)
{
    uintptr_t addr = wsp->walk_addr;
    fmd_module_t m;

    if (addr == NULL)
        return (WALK_DONE);

    if (mdb_vread(&m, sizeof (m), addr) != sizeof (m)) {
        mdb_warn("failed to read fmd_module at %p", addr);
        return (WALK_ERR);
    }

    wsp->walk_addr = (uintptr_t)m.mod_list.l_next;
    return (wsp->walk_callback(addr, &m, wsp->walk_cbdata));
}

static int
fmd_module(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    fmd_module_t mod;
    char name[PATH_MAX];

    if (!(flags & DCMD_ADDRSPEC))
        return (mdb_walk_dcmd("fmd_module", "fmd_module", argc, argv));

    if (argc != 0)
        return (DCMD_USAGE);

    if (mdb_vread(&mod, sizeof (mod), addr) != sizeof (mod)) {
        mdb_warn("failed to read fmd_module at %p", addr);
        return (DCMD_ERR);
    }

    if (DCMD_HDRSPEC(flags)) {
        mdb_printf("%<u>%-11s %-16s %-11s %-4s %-?s %-16s%</u>\n",
            "ADDR", "OPS", "DATA", "FLAG", "USTAT", "NAME");
    }

    if (mdb_readstr(name, sizeof (name), (uintptr_t)mod.mod_name) <= 0)
        (void) mdb_snprintf(name, sizeof (name), "<%p>", mod.mod_name);

    mdb_printf("%-11p %-16a %-11p 0x%02x %-?p %s\n", addr,
        mod.mod_ops, mod.mod_data, mod.mod_flags, mod.mod_ustat, name);

    return (DCMD_OK);
}

static int
case_walk_init(mdb_walk_state_t *wsp)
{
    fmd_module_t mod;
    fmd_case_hash_t ch;
    fmd_t F;

    if (wsp->walk_addr != NULL) {
        if (mdb_vread(&mod, sizeof (mod), wsp->walk_addr) == -1) {
            mdb_warn("failed to read module at %p", wsp->walk_addr);
            return (WALK_ERR);
        }

        wsp->walk_addr = (uintptr_t)mod.mod_cases.l_next;
        return (WALK_NEXT);
    }

    if (mdb_readvar(&F, "fmd") != sizeof (F) ||
        mdb_vread(&ch, sizeof (ch), (uintptr_t)F.d_cases) != sizeof (ch)) {
        mdb_warn("failed to read fmd meta-data");
        return (WALK_ERR);
    }

    return (hash_walk_init(wsp, (uintptr_t)ch.ch_hash, ch.ch_hashlen,
        "fmd_case", sizeof (fmd_case_impl_t),
        OFFSETOF(fmd_case_impl_t, ci_next)));
}

static int
case_walk_step(mdb_walk_state_t *wsp)
{
    uintptr_t addr = wsp->walk_addr;
    fmd_case_impl_t ci;

    if (wsp->walk_data != NULL)
        return (hash_walk_step(wsp));

    if (addr == NULL)
        return (WALK_DONE);

    if (mdb_vread(&ci, sizeof (ci), addr) != sizeof (ci)) {
        mdb_warn("failed to read fmd_case at %p", addr);
        return (WALK_ERR);
    }

    wsp->walk_addr = (uintptr_t)ci.ci_list.l_next;
    return (wsp->walk_callback(addr, &ci, wsp->walk_cbdata));
}

static void
case_walk_fini(mdb_walk_state_t *wsp)
{
    if (wsp->walk_data != NULL)
        hash_walk_fini(wsp);
}

static int
fmd_case(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    char uuid[48], name[16];
    fmd_case_impl_t ci;

    if (!(flags & DCMD_ADDRSPEC)) {
        if (mdb_walk_dcmd("fmd_case", "fmd_case", argc, argv) != 0) {
            mdb_warn("failed to walk fmd_case hash");
            return (DCMD_ERR);
        }
        return (DCMD_OK);
    }

    if (mdb_vread(&ci, sizeof (ci), addr) != sizeof (ci)) {
        mdb_warn("failed to read fmd_case at %p", addr);
        return (DCMD_ERR);
    }

    if (DCMD_HDRSPEC(flags)) {
        mdb_printf("%<u>%-11s %-5s %-3s %-?s %-36s%</u>\n",
            "ADDR", "STATE", "REF", "DATA", "UUID");
    }

    if (mdb_readstr(uuid, sizeof (uuid), (uintptr_t)ci.ci_uuid) <= 0)
        (void) mdb_snprintf(uuid, sizeof (uuid), "<%p>", ci.ci_uuid);

    switch (ci.ci_state) {
    case FMD_CASE_UNSOLVED:
        (void) strcpy(name, "UNSLV");
        break;
    case FMD_CASE_SOLVED:
        (void) strcpy(name, "SOLVE");
        break;
    case FMD_CASE_CLOSE_WAIT:
        (void) strcpy(name, "CWAIT");
        break;
    case FMD_CASE_CLOSED:
        (void) strcpy(name, "CLOSE");
        break;
    case FMD_CASE_REPAIRED:
        (void) strcpy(name, "RPAIR");
        break;
    case FMD_CASE_RESOLVED:
        (void) strcpy(name, "RSLVD");
        break;
    default:
        (void) mdb_snprintf(name, sizeof (name), "%u", ci.ci_state);
    }

    mdb_printf("%-11p %-5s %-3u %-?p %s\n",
        addr, name, ci.ci_refs, ci.ci_data, uuid);

    return (DCMD_OK);
}

static int
buf_walk_init(mdb_walk_state_t *wsp)
{
    fmd_buf_hash_t bh;

    if (mdb_vread(&bh, sizeof (bh), wsp->walk_addr) != sizeof (bh)) {
        mdb_warn("failed to read fmd_buf_hash_t at %p", wsp->walk_addr);
        return (WALK_ERR);
    }

    return (hash_walk_init(wsp, (uintptr_t)bh.bh_hash, bh.bh_hashlen,
        "fmd_buf", sizeof (fmd_buf_t), OFFSETOF(fmd_buf_t, buf_next)));
}

/*ARGSUSED*/
static int
fmd_buf(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    char name[PATH_MAX];
    fmd_buf_t b;

    if (argc != 0 || !(flags & DCMD_ADDRSPEC))
        return (DCMD_USAGE);

    if (mdb_vread(&b, sizeof (b), addr) != sizeof (b)) {
        mdb_warn("failed to read fmd_buf at %p", addr);
        return (DCMD_ERR);
    }

    if (DCMD_HDRSPEC(flags)) {
        mdb_printf("%<u>%-11s %-32s %-5s %-?s %s%</u>\n",
            "ADDR", "NAME", "FLAGS", "DATA", "SIZE");
    }

    if (mdb_readstr(name, sizeof (name), (uintptr_t)b.buf_name) <= 0)
        (void) mdb_snprintf(name, sizeof (name), "<%p>", b.buf_name);

    mdb_printf("%-11p %-32s %-#5x %-?p %lu\n",
        addr, name, b.buf_flags, b.buf_data, b.buf_size);

    return (DCMD_OK);
}

static int
serd_walk_init(mdb_walk_state_t *wsp)
{
    fmd_serd_hash_t sh;

    if (mdb_vread(&sh, sizeof (sh), wsp->walk_addr) != sizeof (sh)) {
        mdb_warn("failed to read fmd_serd_hash at %p", wsp->walk_addr);
        return (WALK_ERR);
    }

    return (hash_walk_init(wsp, (uintptr_t)sh.sh_hash, sh.sh_hashlen,
        "fmd_serd_eng", sizeof (fmd_serd_eng_t),
        OFFSETOF(fmd_serd_eng_t, sg_next)));
}

/* ARGSUSED */
static int
module_serd(uintptr_t addr, const void *data, void *wsp)
{
    fmd_module_t *modp = (fmd_module_t *)data;

    if (modp->mod_serds.sh_count != 0) {
        modp = (fmd_module_t *)addr;
        (void) mdb_pwalk_dcmd("fmd_serd", "fmd_serd", 0, 0,
            (uintptr_t)&modp->mod_serds);
    }
    return (WALK_NEXT);
}

/*ARGSUSED*/
static int
fmd_serd(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    char name[PATH_MAX];
    fmd_serd_eng_t sg;

    if (argc != 0)
        return (DCMD_USAGE);
    if (!(flags & DCMD_ADDRSPEC)) {
        if (mdb_walk("fmd_module", module_serd, 0) == -1) {
            mdb_warn("failed to walk 'fmd_module'");
            return (DCMD_ERR);
        }
        return (DCMD_OK);
    }

    if (mdb_vread(&sg, sizeof (sg), addr) != sizeof (sg)) {
        mdb_warn("failed to read fmd_serd_eng at %p", addr);
        return (DCMD_ERR);
    }

    if (DCMD_HDRSPEC(flags)) {
        mdb_printf("%<u>%-11s %-32s %-3s F >%-2s %-16s%</u>\n",
            "ADDR", "NAME", "CNT", "N", "T");
    }

    if (mdb_readstr(name, sizeof (name), (uintptr_t)sg.sg_name) <= 0)
        (void) mdb_snprintf(name, sizeof (name), "<%p>", sg.sg_name);

    mdb_printf("%-11p %-32s %-3u %c >%-2u %lluns\n",
        addr, name, sg.sg_count, (sg.sg_flags & FMD_SERD_FIRED) ? 'F' : ' ',
        sg.sg_n, (u_longlong_t)sg.sg_t);

    return (DCMD_OK);
}

static int
asru_walk_init(mdb_walk_state_t *wsp)
{
    fmd_asru_hash_t ah;
    fmd_t F;

    if (wsp->walk_addr == NULL && mdb_readvar(&F, "fmd") != sizeof (F)) {
        mdb_warn("failed to read fmd meta-data");
        return (WALK_ERR);
    }

    if (wsp->walk_addr == NULL)
        wsp->walk_addr = (uintptr_t)F.d_asrus;

    if (mdb_vread(&ah, sizeof (ah), wsp->walk_addr) != sizeof (ah)) {
        mdb_warn("failed to read asru_hash at %p", wsp->walk_addr);
        return (WALK_ERR);
    }

    return (hash_walk_init(wsp, (uintptr_t)ah.ah_hash, ah.ah_hashlen,
        "fmd_asru", sizeof (fmd_asru_t), OFFSETOF(fmd_asru_t, asru_next)));
}

static int
fmd_asru(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    char uuid[48], name[PATH_MAX];
    fmd_asru_t a;

    if (!(flags & DCMD_ADDRSPEC)) {
        if (mdb_walk_dcmd("fmd_asru", "fmd_asru", argc, argv) != 0) {
            mdb_warn("failed to walk fmd_asru hash");
            return (DCMD_ERR);
        }
        return (DCMD_OK);
    }

    if (mdb_vread(&a, sizeof (a), addr) != sizeof (a)) {
        mdb_warn("failed to read fmd_asru at %p", addr);
        return (DCMD_ERR);
    }

    if (DCMD_HDRSPEC(flags))
        mdb_printf("%<u>%-8s %-36s %s%</u>\n", "ADDR", "UUID", "NAME");

    if (mdb_readstr(uuid, sizeof (uuid), (uintptr_t)a.asru_uuid) <= 0)
        (void) mdb_snprintf(uuid, sizeof (uuid), "<%p>", a.asru_uuid);
    if (mdb_readstr(name, sizeof (name), (uintptr_t)a.asru_name) <= 0)
        (void) mdb_snprintf(name, sizeof (name), "<%p>", a.asru_name);

    mdb_printf("%-8p %-36s %s\n", addr, uuid, name);
    return (DCMD_OK);
}

static int
al_walk_init(mdb_walk_state_t *wsp)
{
    fmd_asru_hash_t ah;
    fmd_t F;

    if (wsp->walk_addr == NULL && mdb_readvar(&F, "fmd") != sizeof (F)) {
        mdb_warn("failed to read fmd meta-data");
        return (WALK_ERR);
    }

    if (wsp->walk_addr == NULL)
        wsp->walk_addr = (uintptr_t)F.d_asrus;

    if (mdb_vread(&ah, sizeof (ah), wsp->walk_addr) != sizeof (ah)) {
        mdb_warn("failed to read asru_hash at %p", wsp->walk_addr);
        return (WALK_ERR);
    }

    return (hash_walk_init(wsp, (uintptr_t)ah.ah_rsrc_hash, ah.ah_hashlen,
        "fmd_asru_link", sizeof (fmd_asru_link_t), OFFSETOF(fmd_asru_link_t,
        al_rsrc_next)));
}

static int
fmd_asru_link(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    char uuid[48], name[PATH_MAX];
    fmd_asru_link_t a;

    if (!(flags & DCMD_ADDRSPEC)) {
        if (mdb_walk_dcmd("fmd_asru_link", "fmd_asru_link", argc,
            argv) != 0) {
            mdb_warn("failed to walk fmd_asru_link hash");
            return (DCMD_ERR);
        }
        return (DCMD_OK);
    }

    if (mdb_vread(&a, sizeof (a), addr) != sizeof (a)) {
        mdb_warn("failed to read fmd_asru_link at %p", addr);
        return (DCMD_ERR);
    }

    if (DCMD_HDRSPEC(flags))
        mdb_printf("%<u>%-8s %-36s %s%</u>\n", "ADDR", "UUID", "NAME");

    if (mdb_readstr(uuid, sizeof (uuid), (uintptr_t)a.al_uuid) <= 0)
        (void) mdb_snprintf(uuid, sizeof (uuid), "<%p>", a.al_uuid);
    if (mdb_readstr(name, sizeof (name), (uintptr_t)a.al_rsrc_name) <= 0)
        (void) mdb_snprintf(name, sizeof (name), "<%p>",
            a.al_rsrc_name);

    mdb_printf("%-8p %-36s %s\n", addr, uuid, name);
    return (DCMD_OK);
}

/*ARGSUSED*/
static int
fcf_hdr(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    fcf_hdr_t h;

    if (argc != 0)
        return (DCMD_USAGE);

    if (!(flags & DCMD_ADDRSPEC))
        addr = 0; /* assume base of file in file target */

    if (mdb_vread(&h, sizeof (h), addr) != sizeof (h)) {
        mdb_warn("failed to read header at %p", addr);
        return (DCMD_ERR);
    }

    mdb_printf("fcfh_ident.id_magic = 0x%x, %c, %c, %c\n",
        h.fcfh_ident[FCF_ID_MAG0], h.fcfh_ident[FCF_ID_MAG1],
        h.fcfh_ident[FCF_ID_MAG2], h.fcfh_ident[FCF_ID_MAG3]);

    switch (h.fcfh_ident[FCF_ID_MODEL]) {
    case FCF_MODEL_ILP32:
        mdb_printf("fcfh_ident.id_model = ILP32\n");
        break;
    case FCF_MODEL_LP64:
        mdb_printf("fcfh_ident.id_model = LP64\n");
        break;
    default:
        mdb_printf("fcfh_ident.id_model = 0x%x\n",
            h.fcfh_ident[FCF_ID_MODEL]);
    }

    switch (h.fcfh_ident[FCF_ID_ENCODING]) {
    case FCF_ENCODE_LSB:
        mdb_printf("fcfh_ident.id_encoding = LSB\n");
        break;
    case FCF_ENCODE_MSB:
        mdb_printf("fcfh_ident.id_encoding = MSB\n");
        break;
    default:
        mdb_printf("fcfh_ident.id_encoding = 0x%x\n",
            h.fcfh_ident[FCF_ID_ENCODING]);
    }

    mdb_printf("fcfh_ident.id_version = %u\n",
        h.fcfh_ident[FCF_ID_VERSION]);

    mdb_printf("fcfh_flags = 0x%x\n", h.fcfh_flags);
    mdb_printf("fcfh_hdrsize = %u\n", h.fcfh_hdrsize);
    mdb_printf("fcfh_secsize = %u\n", h.fcfh_secsize);
    mdb_printf("fcfh_secnum = %u\n", h.fcfh_secnum);
    mdb_printf("fcfh_secoff = %llu\n", h.fcfh_secoff);
    mdb_printf("fcfh_filesz = %llu\n", h.fcfh_filesz);
    mdb_printf("fcfh_cgen = %llu\n", h.fcfh_cgen);

    return (DCMD_OK);
}

static int fcf_sec(uintptr_t, uint_t, int, const mdb_arg_t *);
/*ARGSUSED*/
static int
fcf_sec_one(uintptr_t addr, void *ignored, uint_t *secp)
{

    mdb_printf("%3d ", (*secp)++);
    (void) fcf_sec(addr, DCMD_ADDRSPEC | DCMD_LOOP, 0, NULL);
    return (WALK_NEXT);
}

/*ARGSUSED*/
static int
fcf_sec(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    static const char *const types[] = {
        "none",     /* FCF_SECT_NONE */
        "strtab",   /* FCF_SECT_STRTAB */
        "module",   /* FCF_SECT_MODULE */
        "case",     /* FCF_SECT_CASE */
        "bufs",     /* FCF_SECT_BUFS */
        "buffer",   /* FCF_SECT_BUFFER */
        "serd",     /* FCF_SECT_SERD */
        "events",   /* FCF_SECT_EVENTS */
        "nvlists",  /* FCF_SECT_NVLISTS */
    };

    uint_t sec = 0;
    fcf_sec_t s;

    if (!(flags & DCMD_ADDRSPEC))
        mdb_printf("%<u>%-3s ", "NDX");

    if (!(flags & DCMD_ADDRSPEC) || DCMD_HDRSPEC(flags)) {
        mdb_printf("%<u>%?s %-10s %-5s %-5s %-5s %-6s %-5s%</u>\n",
            "ADDR", "TYPE", "ALIGN", "FLAGS", "ENTSZ", "OFF", "SIZE");
    }

    if (!(flags & DCMD_ADDRSPEC)) {
        if (mdb_walk("fcf_sec", (mdb_walk_cb_t)fcf_sec_one, &sec) < 0) {
            mdb_warn("failed to walk fcf_sec");
            return (DCMD_ERR);
        }
        return (DCMD_OK);
    }

    if (argc != 0)
        return (DCMD_USAGE);

    if (mdb_vread(&s, sizeof (s), addr) != sizeof (s)) {
        mdb_warn("failed to read section header at %p", addr);
        return (DCMD_ERR);
    }

    mdb_printf("%?p ", addr);

    if (s.fcfs_type < sizeof (types) / sizeof (types[0]))
        mdb_printf("%-10s ", types[s.fcfs_type]);
    else
        mdb_printf("%-10u ", s.fcfs_type);

    mdb_printf("%-5u %-#5x %-#5x %-6llx %-#5llx\n", s.fcfs_align,
        s.fcfs_flags, s.fcfs_entsize, s.fcfs_offset, s.fcfs_size);

    return (DCMD_OK);
}

static int
fcf_sec_walk_init(mdb_walk_state_t *wsp)
{
    fcf_hdr_t h, *hp;
    size_t size;

    if (mdb_vread(&h, sizeof (h), wsp->walk_addr) != sizeof (h)) {
        mdb_warn("failed to read FCF header at %p", wsp->walk_addr);
        return (WALK_ERR);
    }

    size = sizeof (fcf_hdr_t) + sizeof (fcf_sec_t) * h.fcfh_secnum;
    hp = mdb_alloc(size, UM_SLEEP);

    if (mdb_vread(hp, size, wsp->walk_addr) != size) {
        mdb_warn("failed to read FCF sections at %p", wsp->walk_addr);
        mdb_free(hp, size);
        return (WALK_ERR);
    }

    wsp->walk_data = hp;
    wsp->walk_arg = 0;

    return (WALK_NEXT);
}

static int
fcf_sec_walk_step(mdb_walk_state_t *wsp)
{
    uint_t i = (uint_t)wsp->walk_arg;
    size_t off = sizeof (fcf_hdr_t) + sizeof (fcf_sec_t) * i;
    fcf_hdr_t *hp = wsp->walk_data;
    fcf_sec_t *sp = (fcf_sec_t *)((uintptr_t)hp + off);

    if (i >= hp->fcfh_secnum)
        return (WALK_DONE);

    wsp->walk_arg = (void *)(i + 1);
    return (wsp->walk_callback(wsp->walk_addr + off, sp, wsp->walk_cbdata));
}

static void
fcf_sec_walk_fini(mdb_walk_state_t *wsp)
{
    fcf_hdr_t *hp = wsp->walk_data;
    mdb_free(hp, sizeof (fcf_hdr_t) + sizeof (fcf_sec_t) * hp->fcfh_secnum);
}

/*ARGSUSED*/
static int
fcf_case(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    fcf_case_t fcfc;

    if (argc != 0)
        return (DCMD_USAGE);

    if (mdb_vread(&fcfc, sizeof (fcfc), addr) != sizeof (fcfc)) {
        mdb_warn("failed to read case at %p", addr);
        return (DCMD_ERR);
    }

    mdb_printf("fcfc_uuid = 0x%x\n", fcfc.fcfc_uuid);
    mdb_printf("fcfc_state = %u\n", fcfc.fcfc_state);
    mdb_printf("fcfc_bufs = %u\n", fcfc.fcfc_bufs);
    mdb_printf("fcfc_events = %u\n", fcfc.fcfc_events);
    mdb_printf("fcfc_suspects = %u\n", fcfc.fcfc_suspects);

    return (DCMD_OK);
}

/*ARGSUSED*/
static int
fcf_event(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    fcf_event_t fcfe;

    if (argc != 0)
        return (DCMD_USAGE);

    if (mdb_vread(&fcfe, sizeof (fcfe), addr) != sizeof (fcfe)) {
        mdb_warn("failed to read event at %p", addr);
        return (DCMD_ERR);
    }

    mdb_printf("fcfe_todsec = %llu (%Y)\n",
        fcfe.fcfe_todsec, (time_t)fcfe.fcfe_todsec);
    mdb_printf("fcfe_todnsec = %llu\n", fcfe.fcfe_todnsec);
    mdb_printf("fcfe_major = %u\n", fcfe.fcfe_major);
    mdb_printf("fcfe_minor = %u\n", fcfe.fcfe_minor);
    mdb_printf("fcfe_inode = %llu\n", fcfe.fcfe_inode);
    mdb_printf("fcfe_offset = %llu\n", fcfe.fcfe_offset);

    return (DCMD_OK);
}

/*ARGSUSED*/
static int
fcf_serd(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    fcf_serd_t fcfd;

    if (argc != 0)
        return (DCMD_USAGE);

    if (mdb_vread(&fcfd, sizeof (fcfd), addr) != sizeof (fcfd)) {
        mdb_warn("failed to read serd at %p", addr);
        return (DCMD_ERR);
    }

    mdb_printf("fcfd_name = 0x%x\n", fcfd.fcfd_name);
    mdb_printf("fcfd_events = %u\n", fcfd.fcfd_events);
    mdb_printf("fcfd_n = >%u\n", fcfd.fcfd_n);
    mdb_printf("fcfd_t = %lluns\n", fcfd.fcfd_t);

    return (DCMD_OK);
}

static int
tmq_walk_init(mdb_walk_state_t *wsp)
{
    fmd_timerq_t tmq;
    fmd_t F;

    if (wsp->walk_addr == NULL && mdb_readvar(&F, "fmd") != sizeof (F)) {
        mdb_warn("failed to read fmd meta-data");
        return (WALK_ERR);
    }

    if (wsp->walk_addr == NULL)
        wsp->walk_addr = (uintptr_t)F.d_timers;

    if (mdb_vread(&tmq, sizeof (tmq), wsp->walk_addr) != sizeof (tmq)) {
        mdb_warn("failed to read timerq at %p", wsp->walk_addr);
        return (WALK_ERR);
    }

    wsp->walk_addr = (uintptr_t)tmq.tmq_list.l_next;
    return (WALK_NEXT);
}

static int
tmq_walk_step(mdb_walk_state_t *wsp)
{
    uintptr_t addr = wsp->walk_addr;
    fmd_timer_t tmr;

    if (addr == NULL)
        return (WALK_DONE);

    if (mdb_vread(&tmr, sizeof (tmr), addr) != sizeof (tmr)) {
        mdb_warn("failed to read fmd_timer at %p", addr);
        return (WALK_ERR);
    }

    wsp->walk_addr = (uintptr_t)tmr.tmr_list.l_next;
    return (wsp->walk_callback(addr, &tmr, wsp->walk_cbdata));
}

static int
fmd_timer(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    char name[32], func[MDB_SYM_NAMLEN];
    fmd_timer_t t;

    if (!(flags & DCMD_ADDRSPEC)) {
        if (mdb_walk_dcmd("fmd_timerq", "fmd_timer", argc, argv) != 0) {
            mdb_warn("failed to walk fmd_timerq");
            return (DCMD_ERR);
        }
        return (DCMD_OK);
    }

    if (mdb_vread(&t, sizeof (t), addr) != sizeof (t)) {
        mdb_warn("failed to read fmd_timer at %p", addr);
        return (DCMD_ERR);
    }

    if (DCMD_HDRSPEC(flags)) {
        mdb_printf("%<u>%-8s %-20s %-4s %-18s %-8s %s%</u>\n",
            "ADDR", "MODULE", "ID", "HRTIME", "ARG", "FUNC");
    }

    if (mdb_readstr(name, sizeof (name), (uintptr_t)
        t.tmr_ids + OFFSETOF(fmd_idspace_t, ids_name)) <= 0)
        (void) mdb_snprintf(name, sizeof (name), "<%p>", t.tmr_ids);

    if (mdb_lookup_by_addr((uintptr_t)t.tmr_func, MDB_SYM_FUZZY,
        func, sizeof (func), NULL) != 0)
        (void) mdb_snprintf(func, sizeof (func), "<%p>", t.tmr_func);

    mdb_printf("%-8p %-20s %4d 0x%-16llx %-8p %s\n",
        addr, name, t.tmr_id, t.tmr_hrt, t.tmr_arg, func);
    return (DCMD_OK);
}

static int
xprt_walk_init(mdb_walk_state_t *wsp)
{
    fmd_module_t m;

    if (wsp->walk_addr == NULL) {
        mdb_warn("transport walker requires fmd_module_t address\n");
        return (WALK_ERR);
    }

    if (mdb_vread(&m, sizeof (m), wsp->walk_addr) != sizeof (m)) {
        mdb_warn("failed to read module at %p", wsp->walk_addr);
        return (WALK_ERR);
    }

    wsp->walk_addr = (uintptr_t)m.mod_transports.l_next;
    return (WALK_NEXT);
}

static int
xprt_walk_step(mdb_walk_state_t *wsp)
{
    uintptr_t addr = wsp->walk_addr;
    fmd_xprt_impl_t xi;

    if (addr == NULL)
        return (WALK_DONE);

    if (mdb_vread(&xi, sizeof (xi), addr) != sizeof (xi)) {
        mdb_warn("failed to read fmd_xprt at %p", addr);
        return (WALK_ERR);
    }

    wsp->walk_addr = (uintptr_t)xi.xi_list.l_next;
    return (wsp->walk_callback(addr, &xi, wsp->walk_cbdata));
}

static int
xpc_walk_init(mdb_walk_state_t *wsp)
{
    fmd_xprt_class_hash_t xch;

    if (mdb_vread(&xch, sizeof (xch), wsp->walk_addr) != sizeof (xch)) {
        mdb_warn("failed to read fmd_xprt_class_hash at %p",
            wsp->walk_addr);
        return (WALK_ERR);
    }

    return (hash_walk_init(wsp, (uintptr_t)xch.xch_hash, xch.xch_hashlen,
        "fmd_xprt_class", sizeof (fmd_xprt_class_t),
        OFFSETOF(fmd_xprt_class_t, xc_next)));
}

/*ARGSUSED*/
static int
fmd_xprt_class(uintptr_t addr, const void *data, void *arg)
{
    const fmd_xprt_class_t *xcp = data;
    char name[1024];

    if (mdb_readstr(name, sizeof (name), (uintptr_t)xcp->xc_class) <= 0)
        (void) mdb_snprintf(name, sizeof (name), "<%p>", xcp->xc_class);

    mdb_printf("%-8p %-4u %s\n", addr, xcp->xc_refs, name);
    return (WALK_NEXT);
}

static int
fmd_xprt(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    uint_t opt_s = FALSE, opt_l = FALSE, opt_r = FALSE, opt_u = FALSE;
    fmd_xprt_impl_t xi;

    if (mdb_getopts(argc, argv,
        'l', MDB_OPT_SETBITS, TRUE, &opt_l,
        'r', MDB_OPT_SETBITS, TRUE, &opt_r,
        's', MDB_OPT_SETBITS, TRUE, &opt_s,
        'u', MDB_OPT_SETBITS, TRUE, &opt_u, NULL) != argc)
        return (DCMD_USAGE);

    if (!(flags & DCMD_ADDRSPEC)) {
        if (mdb_walk_dcmd("fmd_xprt", "fmd_xprt", argc, argv) != 0) {
            mdb_warn("failed to walk fmd_xprt");
            return (DCMD_ERR);
        }
        return (DCMD_OK);
    }

    if (mdb_vread(&xi, sizeof (xi), addr) != sizeof (xi)) {
        mdb_warn("failed to read fmd_xprt at %p", addr);
        return (DCMD_ERR);
    }

    if (DCMD_HDRSPEC(flags)) {
        mdb_printf("%<u>%-8s %-4s %-4s %-5s %s%</u>\n",
            "ADDR", "ID", "VERS", "FLAGS", "STATE");
    }

    mdb_printf("%-8p %-4d %-4u %-5x %a\n",
        addr, xi.xi_id, xi.xi_version, xi.xi_flags, xi.xi_state);

    if (opt_l | opt_s) {
        (void) mdb_inc_indent(4);
        mdb_printf("Local subscriptions requested by peer:\n");
        mdb_printf("%<u>%-8s %-4s %s%</u>\n", "ADDR", "REFS", "CLASS");
        (void) mdb_pwalk("fmd_xprt_class", fmd_xprt_class, &xi,
            addr + OFFSETOF(fmd_xprt_impl_t, xi_lsub));
        (void) mdb_dec_indent(4);
    }

    if (opt_r | opt_s) {
        (void) mdb_inc_indent(4);
        mdb_printf("Remote subscriptions requested of peer:\n");
        mdb_printf("%<u>%-8s %-4s %s%</u>\n", "ADDR", "REFS", "CLASS");
        (void) mdb_pwalk("fmd_xprt_class", fmd_xprt_class, &xi,
            addr + OFFSETOF(fmd_xprt_impl_t, xi_rsub));
        (void) mdb_dec_indent(4);
    }

    if (opt_u | opt_s) {
        (void) mdb_inc_indent(4);
        mdb_printf("Pending unsubscription acknowledgements:\n");
        mdb_printf("%<u>%-8s %-4s %s%</u>\n", "ADDR", "REFS", "CLASS");
        (void) mdb_pwalk("fmd_xprt_class", fmd_xprt_class, &xi,
            addr + OFFSETOF(fmd_xprt_impl_t, xi_usub));
        (void) mdb_dec_indent(4);
    }

    return (DCMD_OK);
}

static int
tsnap_walk_init(mdb_walk_state_t *wsp)
{
    fmd_t F;

    if (mdb_readvar(&F, "fmd") != sizeof (F)) {
        mdb_warn("failed to read fmd meta-data");
        return (WALK_ERR);
    }

    wsp->walk_addr = (uintptr_t)F.d_topo_list.l_next;
    return (WALK_NEXT);
}

static int
tsnap_walk_step(mdb_walk_state_t *wsp)
{
    uintptr_t addr = wsp->walk_addr;
    fmd_topo_t ftp;

    if (addr == NULL)
        return (WALK_DONE);

    if (mdb_vread(&ftp, sizeof (ftp), addr) != sizeof (ftp)) {
        mdb_warn("failed to read fmd_topo_t at %p", addr);
        return (WALK_ERR);
    }

    wsp->walk_addr = (uintptr_t)ftp.ft_list.l_next;
    return (wsp->walk_callback(addr, &ftp, wsp->walk_cbdata));
}

static int
mq_walk_init(mdb_walk_state_t *wsp)
{
    fmd_module_t m;
    struct fmd_eventq eq;

    if (wsp->walk_addr == NULL) {
        mdb_warn("NULL fmd_module_t passed in");
        return (WALK_ERR);
    }

    if (mdb_vread(&m, sizeof (m), wsp->walk_addr) != sizeof (m)) {
        mdb_warn("failed to read fmd_module_t at %p", wsp->walk_addr);
        return (WALK_ERR);
    }
    if (mdb_vread(&eq, sizeof (eq), (uintptr_t)m.mod_queue)
        != sizeof (eq)) {
        mdb_warn("failed to read fmd_eventq at %p", wsp->walk_addr);
        return (WALK_ERR);
    }

    wsp->walk_addr = (uintptr_t)eq.eq_list.l_next;

    return (WALK_NEXT);
}

static int
mq_walk_step(mdb_walk_state_t *wsp)
{
    uintptr_t addr = wsp->walk_addr;
    fmd_eventqelem_t eqe;

    if (addr == NULL)
        return (WALK_DONE);

    if (mdb_vread(&eqe, sizeof (eqe), addr) != sizeof (eqe)) {
        mdb_warn("failed to read fmd_eventqelem_t at %p", addr);
        return (WALK_ERR);
    }

    wsp->walk_addr = (uintptr_t)eqe.eqe_list.l_next;
    return (wsp->walk_callback(addr, &eqe, wsp->walk_cbdata));
}

static const mdb_dcmd_t dcmds[] = {
    { "fcf_case", "?", "print a FCF case", fcf_case },
    { "fcf_event", "?", "print a FCF event", fcf_event },
    { "fcf_hdr", "?", "print a FCF header", fcf_hdr },
    { "fcf_sec", ":", "print a FCF section header", fcf_sec },
    { "fcf_serd", "?", "print a FCF serd engine", fcf_serd },
    { "fmd_trace", "?[-cs]", "display thread trace buffer(s)", fmd_trace },
    { "fmd_ustat", "[:]", "display statistics collection", fmd_ustat },
    { "fmd_stat", "[:]", "display statistic structure", fmd_stat },
    { "fmd_event", NULL, "display event structure", fmd_event },
    { "fmd_thread", "?", "display thread or list of threads", fmd_thread },
    { "fmd_module", "?", "display module or list of modules", fmd_module },
    { "fmd_case", ":", "display case file structure", fmd_case },
    { "fmd_buf", ":", "display buffer structure", fmd_buf },
    { "fmd_serd", "[:]", "display serd engine structure", fmd_serd },
    { "fmd_asru", "?", "display asru resource structure", fmd_asru },
    { "fmd_asru_link", "?", "display resource structure", fmd_asru_link },
    { "fmd_timer", "?", "display pending timer(s)", fmd_timer },
    { "fmd_xprt", "?[-lrsu]", "display event transport(s)", fmd_xprt },
    { NULL }
};

static const mdb_walker_t walkers[] = {
    { "fcf_sec", "walk FCF section header table given header address",
        fcf_sec_walk_init, fcf_sec_walk_step, fcf_sec_walk_fini },
    { "fmd_trace", "walk per-thread trace buffers",
        trwalk_init, trwalk_step, trwalk_fini },
    { "fmd_ustat", "walk per-collection statistics",
        ustat_walk_init, ustat_walk_step, hash_walk_fini },
    { "fmd_thread", "walk list of all fmd_thread_t's",
        thread_walk_init, thread_walk_step, NULL },
    { "fmd_module", "walk list of all fmd_module_t's",
        mod_walk_init, mod_walk_step, NULL },
    { "fmd_case", "walk per-module case objects",
        case_walk_init, case_walk_step, case_walk_fini },
    { "fmd_buf", "walk per-buf_hash buffers",
        buf_walk_init, hash_walk_step, hash_walk_fini },
    { "fmd_serd", "walk per-serd_hash engines",
        serd_walk_init, hash_walk_step, hash_walk_fini },
    { "fmd_asru", "walk asru resource hash",
        asru_walk_init, hash_walk_step, hash_walk_fini },
    { "fmd_asru_link", "walk resource hash",
        al_walk_init, hash_walk_step, hash_walk_fini },
    { "fmd_timerq", "walk timer queue",
        tmq_walk_init, tmq_walk_step, NULL },
    { "fmd_xprt", "walk per-module list of transports",
        xprt_walk_init, xprt_walk_step, NULL },
    { "fmd_xprt_class", "walk hash table of subscription classes",
        xpc_walk_init, hash_walk_step, hash_walk_fini },
    { "fmd_topo", "walk fmd's list of topo snapshots",
        tsnap_walk_init, tsnap_walk_step, NULL },
    { "fmd_mod_queue", "walk per-module event queue",
        mq_walk_init, mq_walk_step, NULL },
    { NULL, NULL, NULL, NULL, NULL }
};

static const mdb_modinfo_t modinfo = { MDB_API_VERSION, dcmds, walkers };

const mdb_modinfo_t *
_mdb_init(void)
{
    return (&modinfo);
}