cmd/dtrace/dtrace.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 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
/*
 * Copyright (c) 2012 by Delphix. All rights reserved.
 * Copyright (c) 2013, Joyent, Inc. All rights reserved.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>

#include <dtrace.h>
#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <strings.h>
#include <unistd.h>
#include <limits.h>
#include <fcntl.h>
#include <errno.h>
#include <signal.h>
#include <alloca.h>
#include <libgen.h>
#include <libproc.h>

typedef struct dtrace_cmd {
    void (*dc_func)(struct dtrace_cmd *);   /* function to compile arg */
    dtrace_probespec_t dc_spec;     /* probe specifier context */
    char *dc_arg;               /* argument from main argv */
    const char *dc_name;            /* name for error messages */
    const char *dc_desc;            /* desc for error messages */
    dtrace_prog_t *dc_prog;         /* program compiled from arg */
    char dc_ofile[PATH_MAX];        /* derived output file name */
} dtrace_cmd_t;

#define DMODE_VERS  0   /* display version information and exit (-V) */
#define DMODE_EXEC  1   /* compile program for enabling (-a/e/E) */
#define DMODE_ANON  2   /* compile program for anonymous tracing (-A) */
#define DMODE_LINK  3   /* compile program for linking with ELF (-G) */
#define DMODE_LIST  4   /* compile program and list probes (-l) */
#define DMODE_HEADER    5   /* compile program for headergen (-h) */

#define E_SUCCESS   0
#define E_ERROR     1
#define E_USAGE     2

static const char DTRACE_OPTSTR[] =
    "3:6:aAb:Bc:CD:ef:FGhHi:I:lL:m:n:o:p:P:qs:SU:vVwx:X:Z";

static char **g_argv;
static int g_argc;
static char **g_objv;
static int g_objc;
static dtrace_cmd_t *g_cmdv;
static int g_cmdc;
static struct ps_prochandle **g_psv;
static int g_psc;
static int g_pslive;
static char *g_pname;
static int g_quiet;
static int g_flowindent;
static int g_intr;
static int g_impatient;
static int g_newline;
static int g_total;
static int g_cflags;
static int g_oflags;
static int g_verbose;
static int g_exec = 1;
static int g_mode = DMODE_EXEC;
static int g_status = E_SUCCESS;
static int g_grabanon = 0;
static const char *g_ofile = NULL;
static FILE *g_ofp = stdout;
static dtrace_hdl_t *g_dtp;
static char *g_etcfile = "/etc/system";
static const char *g_etcbegin = "* vvvv Added by DTrace";
static const char *g_etcend = "* ^^^^ Added by DTrace";

static const char *g_etc[] =  {
"*",
"* The following forceload directives were added by dtrace(1M) to allow for",
"* tracing during boot.  If these directives are removed, the system will",
"* continue to function, but tracing will not occur during boot as desired.",
"* To remove these directives (and this block comment) automatically, run",
"* \"dtrace -A\" without additional arguments.  See the \"Anonymous Tracing\"",
"* chapter of the Solaris Dynamic Tracing Guide for details.",
"*",
NULL };

static int
usage(FILE *fp)
{
    static const char predact[] = "[[ predicate ] action ]";

    (void) fprintf(fp, "Usage: %s [-32|-64] [-aACeFGhHlqSvVwZ] "
        "[-b bufsz] [-c cmd] [-D name[=def]]\n\t[-I path] [-L path] "
        "[-o output] [-p pid] [-s script] [-U name]\n\t"
        "[-x opt[=val]] [-X a|c|s|t]\n\n"
        "\t[-P provider %s]\n"
        "\t[-m [ provider: ] module %s]\n"
        "\t[-f [[ provider: ] module: ] func %s]\n"
        "\t[-n [[[ provider: ] module: ] func: ] name %s]\n"
        "\t[-i probe-id %s] [ args ... ]\n\n", g_pname,
        predact, predact, predact, predact, predact);

    (void) fprintf(fp, "\tpredicate -> '/' D-expression '/'\n");
    (void) fprintf(fp, "\t   action -> '{' D-statements '}'\n");

    (void) fprintf(fp, "\n"
        "\t-32 generate 32-bit D programs and ELF files\n"
        "\t-64 generate 64-bit D programs and ELF files\n\n"
        "\t-a  claim anonymous tracing state\n"
        "\t-A  generate driver.conf(4) directives for anonymous tracing\n"
        "\t-b  set trace buffer size\n"
        "\t-c  run specified command and exit upon its completion\n"
        "\t-C  run cpp(1) preprocessor on script files\n"
        "\t-D  define symbol when invoking preprocessor\n"
        "\t-e  exit after compiling request but prior to enabling probes\n"
        "\t-f  enable or list probes matching the specified function name\n"
        "\t-F  coalesce trace output by function\n"
        "\t-G  generate an ELF file containing embedded dtrace program\n"
        "\t-h  generate a header file with definitions for static probes\n"
        "\t-H  print included files when invoking preprocessor\n"
        "\t-i  enable or list probes matching the specified probe id\n"
        "\t-I  add include directory to preprocessor search path\n"
        "\t-l  list probes matching specified criteria\n"
        "\t-L  add library directory to library search path\n"
        "\t-m  enable or list probes matching the specified module name\n"
        "\t-n  enable or list probes matching the specified probe name\n"
        "\t-o  set output file\n"
        "\t-p  grab specified process-ID and cache its symbol tables\n"
        "\t-P  enable or list probes matching the specified provider name\n"
        "\t-q  set quiet mode (only output explicitly traced data)\n"
        "\t-s  enable or list probes according to the specified D script\n"
        "\t-S  print D compiler intermediate code\n"
        "\t-U  undefine symbol when invoking preprocessor\n"
        "\t-v  set verbose mode (report stability attributes, arguments)\n"
        "\t-V  report DTrace API version\n"
        "\t-w  permit destructive actions\n"
        "\t-x  enable or modify compiler and tracing options\n"
        "\t-X  specify ISO C conformance settings for preprocessor\n"
        "\t-Z  permit probe descriptions that match zero probes\n");

    return (E_USAGE);
}

static void
verror(const char *fmt, va_list ap)
{
    int error = errno;

    (void) fprintf(stderr, "%s: ", g_pname);
    (void) vfprintf(stderr, fmt, ap);

    if (fmt[strlen(fmt) - 1] != '\n')
        (void) fprintf(stderr, ": %s\n", strerror(error));
}

/*PRINTFLIKE1*/
static void
fatal(const char *fmt, ...)
{
    va_list ap;

    va_start(ap, fmt);
    verror(fmt, ap);
    va_end(ap);

    exit(E_ERROR);
}

/*PRINTFLIKE1*/
static void
dfatal(const char *fmt, ...)
{
    va_list ap;

    va_start(ap, fmt);

    (void) fprintf(stderr, "%s: ", g_pname);
    if (fmt != NULL)
        (void) vfprintf(stderr, fmt, ap);

    va_end(ap);

    if (fmt != NULL && fmt[strlen(fmt) - 1] != '\n') {
        (void) fprintf(stderr, ": %s\n",
            dtrace_errmsg(g_dtp, dtrace_errno(g_dtp)));
    } else if (fmt == NULL) {
        (void) fprintf(stderr, "%s\n",
            dtrace_errmsg(g_dtp, dtrace_errno(g_dtp)));
    }

    /*
     * Close the DTrace handle to ensure that any controlled processes are
     * correctly restored and continued.
     */
    dtrace_close(g_dtp);

    exit(E_ERROR);
}

/*PRINTFLIKE1*/
static void
error(const char *fmt, ...)
{
    va_list ap;

    va_start(ap, fmt);
    verror(fmt, ap);
    va_end(ap);
}

/*PRINTFLIKE1*/
static void
notice(const char *fmt, ...)
{
    va_list ap;

    if (g_quiet)
        return; /* -q or quiet pragma suppresses notice()s */

    va_start(ap, fmt);
    verror(fmt, ap);
    va_end(ap);
}

/*PRINTFLIKE1*/
static void
oprintf(const char *fmt, ...)
{
    va_list ap;
    int n;

    if (g_ofp == NULL)
        return;

    va_start(ap, fmt);
    n = vfprintf(g_ofp, fmt, ap);
    va_end(ap);

    if (n < 0) {
        if (errno != EINTR) {
            fatal("failed to write to %s",
                g_ofile ? g_ofile : "<stdout>");
        }
        clearerr(g_ofp);
    }
}

static char **
make_argv(char *s)
{
    const char *ws = "\f\n\r\t\v ";
    char **argv = malloc(sizeof (char *) * (strlen(s) / 2 + 1));
    int argc = 0;
    char *p = s;

    if (argv == NULL)
        return (NULL);

    for (p = strtok(s, ws); p != NULL; p = strtok(NULL, ws))
        argv[argc++] = p;

    if (argc == 0)
        argv[argc++] = s;

    argv[argc] = NULL;
    return (argv);
}

static void
dof_prune(const char *fname)
{
    struct stat sbuf;
    size_t sz, i, j, mark, len;
    char *buf;
    int msg = 0, fd;

    if ((fd = open(fname, O_RDONLY)) == -1) {
        /*
         * This is okay only if the file doesn't exist at all.
         */
        if (errno != ENOENT)
            fatal("failed to open %s", fname);
        return;
    }

    if (fstat(fd, &sbuf) == -1)
        fatal("failed to fstat %s", fname);

    if ((buf = malloc((sz = sbuf.st_size) + 1)) == NULL)
        fatal("failed to allocate memory for %s", fname);

    if (read(fd, buf, sz) != sz)
        fatal("failed to read %s", fname);

    buf[sz] = '\0';
    (void) close(fd);

    if ((fd = open(fname, O_WRONLY | O_TRUNC)) == -1)
        fatal("failed to open %s for writing", fname);

    len = strlen("dof-data-");

    for (mark = 0, i = 0; i < sz; i++) {
        if (strncmp(&buf[i], "dof-data-", len) != 0)
            continue;

        /*
         * This is only a match if it's in the 0th column.
         */
        if (i != 0 && buf[i - 1] != '\n')
            continue;

        if (msg++ == 0) {
            error("cleaned up old anonymous "
                "enabling in %s\n", fname);
        }

        /*
         * We have a match.  First write out our data up until now.
         */
        if (i != mark) {
            if (write(fd, &buf[mark], i - mark) != i - mark)
                fatal("failed to write to %s", fname);
        }

        /*
         * Now scan forward until we scan past a newline.
         */
        for (j = i; j < sz && buf[j] != '\n'; j++)
            continue;

        /*
         * Reset our mark.
         */
        if ((mark = j + 1) >= sz)
            break;

        i = j;
    }

    if (mark < sz) {
        if (write(fd, &buf[mark], sz - mark) != sz - mark)
            fatal("failed to write to %s", fname);
    }

    (void) close(fd);
    free(buf);
}

static void
etcsystem_prune(void)
{
    struct stat sbuf;
    size_t sz;
    char *buf, *start, *end;
    int fd;
    char *fname = g_etcfile, *tmpname;

    if ((fd = open(fname, O_RDONLY)) == -1)
        fatal("failed to open %s", fname);

    if (fstat(fd, &sbuf) == -1)
        fatal("failed to fstat %s", fname);

    if ((buf = malloc((sz = sbuf.st_size) + 1)) == NULL)
        fatal("failed to allocate memory for %s", fname);

    if (read(fd, buf, sz) != sz)
        fatal("failed to read %s", fname);

    buf[sz] = '\0';
    (void) close(fd);

    if ((start = strstr(buf, g_etcbegin)) == NULL)
        goto out;

    if (strlen(buf) != sz) {
        fatal("embedded nul byte in %s; manual repair of %s "
            "required\n", fname, fname);
    }

    if (strstr(start + 1, g_etcbegin) != NULL) {
        fatal("multiple start sentinels in %s; manual repair of %s "
            "required\n", fname, fname);
    }

    if ((end = strstr(buf, g_etcend)) == NULL) {
        fatal("missing end sentinel in %s; manual repair of %s "
            "required\n", fname, fname);
    }

    if (start > end) {
        fatal("end sentinel preceeds start sentinel in %s; manual "
            "repair of %s required\n", fname, fname);
    }

    end += strlen(g_etcend) + 1;
    bcopy(end, start, strlen(end) + 1);

    tmpname = alloca(sz = strlen(fname) + 80);
    (void) snprintf(tmpname, sz, "%s.dtrace.%d", fname, getpid());

    if ((fd = open(tmpname,
        O_WRONLY | O_CREAT | O_EXCL, sbuf.st_mode)) == -1)
        fatal("failed to create %s", tmpname);

    if (write(fd, buf, strlen(buf)) < strlen(buf)) {
        (void) unlink(tmpname);
        fatal("failed to write to %s", tmpname);
    }

    (void) close(fd);

    if (chown(tmpname, sbuf.st_uid, sbuf.st_gid) != 0) {
        (void) unlink(tmpname);
        fatal("failed to chown(2) %s to uid %d, gid %d", tmpname,
            (int)sbuf.st_uid, (int)sbuf.st_gid);
    }

    if (rename(tmpname, fname) == -1)
        fatal("rename of %s to %s failed", tmpname, fname);

    error("cleaned up forceload directives in %s\n", fname);
out:
    free(buf);
}

static void
etcsystem_add(void)
{
    const char *mods[20];
    int nmods, line;

    if ((g_ofp = fopen(g_ofile = g_etcfile, "a")) == NULL)
        fatal("failed to open output file '%s'", g_ofile);

    oprintf("%s\n", g_etcbegin);

    for (line = 0; g_etc[line] != NULL; line++)
        oprintf("%s\n", g_etc[line]);

    nmods = dtrace_provider_modules(g_dtp, mods,
        sizeof (mods) / sizeof (char *) - 1);

    if (nmods >= sizeof (mods) / sizeof (char *))
        fatal("unexpectedly large number of modules!");

    mods[nmods++] = "dtrace";

    for (line = 0; line < nmods; line++)
        oprintf("forceload: drv/%s\n", mods[line]);

    oprintf("%s\n", g_etcend);

    if (fclose(g_ofp) == EOF)
        fatal("failed to close output file '%s'", g_ofile);

    error("added forceload directives to %s\n", g_ofile);
}

static void
print_probe_info(const dtrace_probeinfo_t *p)
{
    char buf[BUFSIZ];
    char *user;
    int i;

    oprintf("\n\tProbe Description Attributes\n");

    oprintf("\t\tIdentifier Names: %s\n",
        dtrace_stability_name(p->dtp_attr.dtat_name));
    oprintf("\t\tData Semantics:   %s\n",
        dtrace_stability_name(p->dtp_attr.dtat_data));
    oprintf("\t\tDependency Class: %s\n",
        dtrace_class_name(p->dtp_attr.dtat_class));

    oprintf("\n\tArgument Attributes\n");

    oprintf("\t\tIdentifier Names: %s\n",
        dtrace_stability_name(p->dtp_arga.dtat_name));
    oprintf("\t\tData Semantics:   %s\n",
        dtrace_stability_name(p->dtp_arga.dtat_data));
    oprintf("\t\tDependency Class: %s\n",
        dtrace_class_name(p->dtp_arga.dtat_class));

    oprintf("\n\tArgument Types\n");

    for (i = 0; i < p->dtp_argc; i++) {
        if (p->dtp_argv[i].dtt_flags & DTT_FL_USER)
            user = "userland ";
        else
            user = "";
        if (ctf_type_name(p->dtp_argv[i].dtt_ctfp,
            p->dtp_argv[i].dtt_type, buf, sizeof (buf)) == NULL)
            (void) strlcpy(buf, "(unknown)", sizeof (buf));
        oprintf("\t\targs[%d]: %s%s\n", i, user, buf);
    }

    if (p->dtp_argc == 0)
        oprintf("\t\tNone\n");

    oprintf("\n");
}

/*ARGSUSED*/
static int
info_stmt(dtrace_hdl_t *dtp, dtrace_prog_t *pgp,
    dtrace_stmtdesc_t *stp, dtrace_ecbdesc_t **last)
{
    dtrace_ecbdesc_t *edp = stp->dtsd_ecbdesc;
    dtrace_probedesc_t *pdp = &edp->dted_probe;
    dtrace_probeinfo_t p;

    if (edp == *last)
        return (0);

    oprintf("\n%s:%s:%s:%s\n",
        pdp->dtpd_provider, pdp->dtpd_mod, pdp->dtpd_func, pdp->dtpd_name);

    if (dtrace_probe_info(dtp, pdp, &p) == 0)
        print_probe_info(&p);

    *last = edp;
    return (0);
}

/*
 * Execute the specified program by enabling the corresponding instrumentation.
 * If -e has been specified, we get the program info but do not enable it.  If
 * -v has been specified, we print a stability report for the program.
 */
static void
exec_prog(const dtrace_cmd_t *dcp)
{
    dtrace_ecbdesc_t *last = NULL;
    dtrace_proginfo_t dpi;

    if (!g_exec) {
        dtrace_program_info(g_dtp, dcp->dc_prog, &dpi);
    } else if (dtrace_program_exec(g_dtp, dcp->dc_prog, &dpi) == -1) {
        dfatal("failed to enable '%s'", dcp->dc_name);
    } else {
        notice("%s '%s' matched %u probe%s\n",
            dcp->dc_desc, dcp->dc_name,
            dpi.dpi_matches, dpi.dpi_matches == 1 ? "" : "s");
    }

    if (g_verbose) {
        oprintf("\nStability attributes for %s %s:\n",
            dcp->dc_desc, dcp->dc_name);

        oprintf("\n\tMinimum Probe Description Attributes\n");
        oprintf("\t\tIdentifier Names: %s\n",
            dtrace_stability_name(dpi.dpi_descattr.dtat_name));
        oprintf("\t\tData Semantics:   %s\n",
            dtrace_stability_name(dpi.dpi_descattr.dtat_data));
        oprintf("\t\tDependency Class: %s\n",
            dtrace_class_name(dpi.dpi_descattr.dtat_class));

        oprintf("\n\tMinimum Statement Attributes\n");

        oprintf("\t\tIdentifier Names: %s\n",
            dtrace_stability_name(dpi.dpi_stmtattr.dtat_name));
        oprintf("\t\tData Semantics:   %s\n",
            dtrace_stability_name(dpi.dpi_stmtattr.dtat_data));
        oprintf("\t\tDependency Class: %s\n",
            dtrace_class_name(dpi.dpi_stmtattr.dtat_class));

        if (!g_exec) {
            (void) dtrace_stmt_iter(g_dtp, dcp->dc_prog,
                (dtrace_stmt_f *)info_stmt, &last);
        } else
            oprintf("\n");
    }

    g_total += dpi.dpi_matches;
}

/*
 * Print out the specified DOF buffer as a set of ASCII bytes appropriate for
 * storing in a driver.conf(4) file associated with the dtrace driver.
 */
static void
anon_prog(const dtrace_cmd_t *dcp, dof_hdr_t *dof, int n)
{
    const uchar_t *p, *q;

    if (dof == NULL)
        dfatal("failed to create DOF image for '%s'", dcp->dc_name);

    p = (uchar_t *)dof;
    q = p + dof->dofh_loadsz;

    oprintf("dof-data-%d=0x%x", n, *p++);

    while (p < q)
        oprintf(",0x%x", *p++);

    oprintf(";\n");
    dtrace_dof_destroy(g_dtp, dof);
}

/*
 * Link the specified D program in DOF form into an ELF file for use in either
 * helpers, userland provider definitions, or both.  If -o was specified, that
 * path is used as the output file name.  If -o wasn't specified and the input
 * program is from a script whose name is %.d, use basename(%.o) as the output
 * file name.  Otherwise we use "d.out" as the default output file name.
 */
static void
link_prog(dtrace_cmd_t *dcp)
{
    char *p;

    if (g_cmdc == 1 && g_ofile != NULL) {
        (void) strlcpy(dcp->dc_ofile, g_ofile, sizeof (dcp->dc_ofile));
    } else if ((p = strrchr(dcp->dc_arg, '.')) != NULL &&
        strcmp(p, ".d") == 0) {
        p[0] = '\0'; /* strip .d suffix */
        (void) snprintf(dcp->dc_ofile, sizeof (dcp->dc_ofile),
            "%s.o", basename(dcp->dc_arg));
    } else {
        (void) snprintf(dcp->dc_ofile, sizeof (dcp->dc_ofile),
            g_cmdc > 1 ?  "%s.%d" : "%s", "d.out", (int)(dcp - g_cmdv));
    }

    if (dtrace_program_link(g_dtp, dcp->dc_prog, DTRACE_D_PROBES,
        dcp->dc_ofile, g_objc, g_objv) != 0)
        dfatal("failed to link %s %s", dcp->dc_desc, dcp->dc_name);
}

/*ARGSUSED*/
static int
list_probe(dtrace_hdl_t *dtp, const dtrace_probedesc_t *pdp, void *arg)
{
    dtrace_probeinfo_t p;

    oprintf("%5d %10s %17s %33s %s\n", pdp->dtpd_id,
        pdp->dtpd_provider, pdp->dtpd_mod, pdp->dtpd_func, pdp->dtpd_name);

    if (g_verbose && dtrace_probe_info(dtp, pdp, &p) == 0)
        print_probe_info(&p);

    return (0);
}

/*ARGSUSED*/
static int
list_stmt(dtrace_hdl_t *dtp, dtrace_prog_t *pgp,
    dtrace_stmtdesc_t *stp, dtrace_ecbdesc_t **last)
{
    dtrace_ecbdesc_t *edp = stp->dtsd_ecbdesc;

    if (edp == *last)
        return (0);

    if (dtrace_probe_iter(g_dtp, &edp->dted_probe, list_probe, NULL) != 0) {
        error("failed to match %s:%s:%s:%s: %s\n",
            edp->dted_probe.dtpd_provider, edp->dted_probe.dtpd_mod,
            edp->dted_probe.dtpd_func, edp->dted_probe.dtpd_name,
            dtrace_errmsg(dtp, dtrace_errno(dtp)));
    }

    *last = edp;
    return (0);
}

/*
 * List the probes corresponding to the specified program by iterating over
 * each statement and then matching probes to the statement probe descriptions.
 */
static void
list_prog(const dtrace_cmd_t *dcp)
{
    dtrace_ecbdesc_t *last = NULL;

    (void) dtrace_stmt_iter(g_dtp, dcp->dc_prog,
        (dtrace_stmt_f *)list_stmt, &last);
}

static void
compile_file(dtrace_cmd_t *dcp)
{
    char *arg0;
    FILE *fp;

    if ((fp = fopen(dcp->dc_arg, "r")) == NULL)
        fatal("failed to open %s", dcp->dc_arg);

    arg0 = g_argv[0];
    g_argv[0] = dcp->dc_arg;

    if ((dcp->dc_prog = dtrace_program_fcompile(g_dtp, fp,
        g_cflags, g_argc, g_argv)) == NULL)
        dfatal("failed to compile script %s", dcp->dc_arg);

    g_argv[0] = arg0;
    (void) fclose(fp);

    dcp->dc_desc = "script";
    dcp->dc_name = dcp->dc_arg;
}

static void
compile_str(dtrace_cmd_t *dcp)
{
    char *p;

    if ((dcp->dc_prog = dtrace_program_strcompile(g_dtp, dcp->dc_arg,
        dcp->dc_spec, g_cflags | DTRACE_C_PSPEC, g_argc, g_argv)) == NULL)
        dfatal("invalid probe specifier %s", dcp->dc_arg);

    if ((p = strpbrk(dcp->dc_arg, "{/;")) != NULL)
        *p = '\0'; /* crop name for reporting */

    dcp->dc_desc = "description";
    dcp->dc_name = dcp->dc_arg;
}

/*ARGSUSED*/
static void
prochandler(struct ps_prochandle *P, const char *msg, void *arg)
{
    const psinfo_t *prp = Ppsinfo(P);
    int pid = Pstatus(P)->pr_pid;
    char name[SIG2STR_MAX];

    if (msg != NULL) {
        notice("pid %d: %s\n", pid, msg);
        return;
    }

    switch (Pstate(P)) {
    case PS_UNDEAD:
        /*
         * Ideally we would like to always report pr_wstat here, but it
         * isn't possible given current /proc semantics.  If we grabbed
         * the process, Ppsinfo() will either fail or return a zeroed
         * psinfo_t depending on how far the parent is in reaping it.
         * When /proc provides a stable pr_wstat in the status file,
         * this code can be improved by examining this new pr_wstat.
         */
        if (prp != NULL && WIFSIGNALED(prp->pr_wstat)) {
            notice("pid %d terminated by %s\n", pid,
                proc_signame(WTERMSIG(prp->pr_wstat),
                name, sizeof (name)));
        } else if (prp != NULL && WEXITSTATUS(prp->pr_wstat) != 0) {
            notice("pid %d exited with status %d\n",
                pid, WEXITSTATUS(prp->pr_wstat));
        } else {
            notice("pid %d has exited\n", pid);
        }
        g_pslive--;
        break;

    case PS_LOST:
        notice("pid %d exec'd a set-id or unobservable program\n", pid);
        g_pslive--;
        break;
    }
}

/*ARGSUSED*/
static int
errhandler(const dtrace_errdata_t *data, void *arg)
{
    error(data->dteda_msg);
    return (DTRACE_HANDLE_OK);
}

/*ARGSUSED*/
static int
drophandler(const dtrace_dropdata_t *data, void *arg)
{
    error(data->dtdda_msg);
    return (DTRACE_HANDLE_OK);
}

/*ARGSUSED*/
static int
setopthandler(const dtrace_setoptdata_t *data, void *arg)
{
    if (strcmp(data->dtsda_option, "quiet") == 0)
        g_quiet = data->dtsda_newval != DTRACEOPT_UNSET;

    if (strcmp(data->dtsda_option, "flowindent") == 0)
        g_flowindent = data->dtsda_newval != DTRACEOPT_UNSET;

    return (DTRACE_HANDLE_OK);
}

#define BUFDUMPHDR(hdr) \
    (void) printf("%s: %s%s\n", g_pname, hdr, strlen(hdr) > 0 ? ":" : "");

#define BUFDUMPSTR(ptr, field) \
    (void) printf("%s: %20s => ", g_pname, #field); \
    if ((ptr)->field != NULL) {         \
        const char *c = (ptr)->field;       \
        (void) printf("\"");            \
        do {                    \
            if (*c == '\n') {       \
                (void) printf("\\n");   \
                continue;       \
            }               \
                            \
            (void) printf("%c", *c);    \
        } while (*c++ != '\0');         \
        (void) printf("\"\n");          \
    } else {                    \
        (void) printf("<NULL>\n");      \
    }

#define BUFDUMPASSTR(ptr, field, str) \
    (void) printf("%s: %20s => %s\n", g_pname, #field, str);

#define BUFDUMP(ptr, field) \
    (void) printf("%s: %20s => %lld\n", g_pname, #field, \
        (long long)(ptr)->field);

#define BUFDUMPPTR(ptr, field) \
    (void) printf("%s: %20s => %s\n", g_pname, #field, \
        (ptr)->field != NULL ? "<non-NULL>" : "<NULL>");

/*ARGSUSED*/
static int
bufhandler(const dtrace_bufdata_t *bufdata, void *arg)
{
    const dtrace_aggdata_t *agg = bufdata->dtbda_aggdata;
    const dtrace_recdesc_t *rec = bufdata->dtbda_recdesc;
    const dtrace_probedesc_t *pd;
    uint32_t flags = bufdata->dtbda_flags;
    char buf[512], *c = buf, *end = c + sizeof (buf);
    int i, printed;

    struct {
        const char *name;
        uint32_t value;
    } flagnames[] = {
        { "AGGVAL",     DTRACE_BUFDATA_AGGVAL },
        { "AGGKEY",     DTRACE_BUFDATA_AGGKEY },
        { "AGGFORMAT",  DTRACE_BUFDATA_AGGFORMAT },
        { "AGGLAST",    DTRACE_BUFDATA_AGGLAST },
        { "???",        UINT32_MAX },
        { NULL }
    };

    if (bufdata->dtbda_probe != NULL) {
        pd = bufdata->dtbda_probe->dtpda_pdesc;
    } else if (agg != NULL) {
        pd = agg->dtada_pdesc;
    } else {
        pd = NULL;
    }

    BUFDUMPHDR(">>> Called buffer handler");
    BUFDUMPHDR("");

    BUFDUMPHDR("  dtrace_bufdata");
    BUFDUMPSTR(bufdata, dtbda_buffered);
    BUFDUMPPTR(bufdata, dtbda_probe);
    BUFDUMPPTR(bufdata, dtbda_aggdata);
    BUFDUMPPTR(bufdata, dtbda_recdesc);

    (void) snprintf(c, end - c, "0x%x ", bufdata->dtbda_flags);
    c += strlen(c);

    for (i = 0, printed = 0; flagnames[i].name != NULL; i++) {
        if (!(flags & flagnames[i].value))
            continue;

        (void) snprintf(c, end - c,
            "%s%s", printed++ ? " | " : "(", flagnames[i].name);
        c += strlen(c);
        flags &= ~flagnames[i].value;
    }

    if (printed)
        (void) snprintf(c, end - c, ")");

    BUFDUMPASSTR(bufdata, dtbda_flags, buf);
    BUFDUMPHDR("");

    if (pd != NULL) {
        BUFDUMPHDR("  dtrace_probedesc");
        BUFDUMPSTR(pd, dtpd_provider);
        BUFDUMPSTR(pd, dtpd_mod);
        BUFDUMPSTR(pd, dtpd_func);
        BUFDUMPSTR(pd, dtpd_name);
        BUFDUMPHDR("");
    }

    if (rec != NULL) {
        BUFDUMPHDR("  dtrace_recdesc");
        BUFDUMP(rec, dtrd_action);
        BUFDUMP(rec, dtrd_size);

        if (agg != NULL) {
            uint8_t *data;
            int lim = rec->dtrd_size;

            (void) sprintf(buf, "%d (data: ", rec->dtrd_offset);
            c = buf + strlen(buf);

            if (lim > sizeof (uint64_t))
                lim = sizeof (uint64_t);

            data = (uint8_t *)agg->dtada_data + rec->dtrd_offset;

            for (i = 0; i < lim; i++) {
                (void) snprintf(c, end - c, "%s%02x",
                    i == 0 ? "" : " ", *data++);
                c += strlen(c);
            }

            (void) snprintf(c, end - c,
                "%s)", lim < rec->dtrd_size ? " ..." : "");
            BUFDUMPASSTR(rec, dtrd_offset, buf);
        } else {
            BUFDUMP(rec, dtrd_offset);
        }

        BUFDUMPHDR("");
    }

    if (agg != NULL) {
        dtrace_aggdesc_t *desc = agg->dtada_desc;

        BUFDUMPHDR("  dtrace_aggdesc");
        BUFDUMPSTR(desc, dtagd_name);
        BUFDUMP(desc, dtagd_varid);
        BUFDUMP(desc, dtagd_id);
        BUFDUMP(desc, dtagd_nrecs);
        BUFDUMPHDR("");
    }

    return (DTRACE_HANDLE_OK);
}

/*ARGSUSED*/
static int
chewrec(const dtrace_probedata_t *data, const dtrace_recdesc_t *rec, void *arg)
{
    dtrace_actkind_t act;
    uintptr_t addr;

    if (rec == NULL) {
        /*
         * We have processed the final record; output the newline if
         * we're not in quiet mode.
         */
        if (!g_quiet)
            oprintf("\n");

        return (DTRACE_CONSUME_NEXT);
    }

    act = rec->dtrd_action;
    addr = (uintptr_t)data->dtpda_data;

    if (act == DTRACEACT_EXIT) {
        g_status = *((uint32_t *)addr);
        return (DTRACE_CONSUME_NEXT);
    }

    return (DTRACE_CONSUME_THIS);
}

/*ARGSUSED*/
static int
chew(const dtrace_probedata_t *data, void *arg)
{
    dtrace_probedesc_t *pd = data->dtpda_pdesc;
    processorid_t cpu = data->dtpda_cpu;
    static int heading;

    if (g_impatient) {
        g_newline = 0;
        return (DTRACE_CONSUME_ABORT);
    }

    if (heading == 0) {
        if (!g_flowindent) {
            if (!g_quiet) {
                oprintf("%3s %6s %32s\n",
                    "CPU", "ID", "FUNCTION:NAME");
            }
        } else {
            oprintf("%3s %-41s\n", "CPU", "FUNCTION");
        }
        heading = 1;
    }

    if (!g_flowindent) {
        if (!g_quiet) {
            char name[DTRACE_FUNCNAMELEN + DTRACE_NAMELEN + 2];

            (void) snprintf(name, sizeof (name), "%s:%s",
                pd->dtpd_func, pd->dtpd_name);

            oprintf("%3d %6d %32s ", cpu, pd->dtpd_id, name);
        }
    } else {
        int indent = data->dtpda_indent;
        char *name;
        size_t len;

        if (data->dtpda_flow == DTRACEFLOW_NONE) {
            len = indent + DTRACE_FUNCNAMELEN + DTRACE_NAMELEN + 5;
            name = alloca(len);
            (void) snprintf(name, len, "%*s%s%s:%s", indent, "",
                data->dtpda_prefix, pd->dtpd_func,
                pd->dtpd_name);
        } else {
            len = indent + DTRACE_FUNCNAMELEN + 5;
            name = alloca(len);
            (void) snprintf(name, len, "%*s%s%s", indent, "",
                data->dtpda_prefix, pd->dtpd_func);
        }

        oprintf("%3d %-41s ", cpu, name);
    }

    return (DTRACE_CONSUME_THIS);
}

static void
go(void)
{
    int i;

    struct {
        char *name;
        char *optname;
        dtrace_optval_t val;
    } bufs[] = {
        { "buffer size", "bufsize" },
        { "aggregation size", "aggsize" },
        { "speculation size", "specsize" },
        { "dynamic variable size", "dynvarsize" },
        { NULL }
    }, rates[] = {
        { "cleaning rate", "cleanrate" },
        { "status rate", "statusrate" },
        { NULL }
    };

    for (i = 0; bufs[i].name != NULL; i++) {
        if (dtrace_getopt(g_dtp, bufs[i].optname, &bufs[i].val) == -1)
            fatal("couldn't get option %s", bufs[i].optname);
    }

    for (i = 0; rates[i].name != NULL; i++) {
        if (dtrace_getopt(g_dtp, rates[i].optname, &rates[i].val) == -1)
            fatal("couldn't get option %s", rates[i].optname);
    }

    if (dtrace_go(g_dtp) == -1)
        dfatal("could not enable tracing");

    for (i = 0; bufs[i].name != NULL; i++) {
        dtrace_optval_t j = 0, mul = 10;
        dtrace_optval_t nsize;

        if (bufs[i].val == DTRACEOPT_UNSET)
            continue;

        (void) dtrace_getopt(g_dtp, bufs[i].optname, &nsize);

        if (nsize == DTRACEOPT_UNSET || nsize == 0)
            continue;

        if (nsize >= bufs[i].val - sizeof (uint64_t))
            continue;

        for (; (INT64_C(1) << mul) <= nsize; j++, mul += 10)
            continue;

        if (!(nsize & ((INT64_C(1) << (mul - 10)) - 1))) {
            error("%s lowered to %lld%c\n", bufs[i].name,
                (long long)nsize >> (mul - 10), " kmgtpe"[j]);
        } else {
            error("%s lowered to %lld bytes\n", bufs[i].name,
                (long long)nsize);
        }
    }

    for (i = 0; rates[i].name != NULL; i++) {
        dtrace_optval_t nval;
        char *dir;

        if (rates[i].val == DTRACEOPT_UNSET)
            continue;

        (void) dtrace_getopt(g_dtp, rates[i].optname, &nval);

        if (nval == DTRACEOPT_UNSET || nval == 0)
            continue;

        if (rates[i].val == nval)
            continue;

        dir = nval > rates[i].val ? "reduced" : "increased";

        if (nval <= NANOSEC && (NANOSEC % nval) == 0) {
            error("%s %s to %lld hz\n", rates[i].name, dir,
                (long long)NANOSEC / (long long)nval);
            continue;
        }

        if ((nval % NANOSEC) == 0) {
            error("%s %s to once every %lld seconds\n",
                rates[i].name, dir,
                (long long)nval / (long long)NANOSEC);
            continue;
        }

        error("%s %s to once every %lld nanoseconds\n",
            rates[i].name, dir, (long long)nval);
    }
}

/*ARGSUSED*/
static void
intr(int signo)
{
    if (!g_intr)
        g_newline = 1;

    if (g_intr++)
        g_impatient = 1;
}

int
main(int argc, char *argv[])
{
    dtrace_bufdesc_t buf;
    struct sigaction act, oact;
    dtrace_status_t status[2];
    dtrace_optval_t opt;
    dtrace_cmd_t *dcp;

    int done = 0, mode = 0;
    int err, i;
    char c, *p, **v;
    struct ps_prochandle *P;
    pid_t pid;

    g_pname = basename(argv[0]);

    if (argc == 1)
        return (usage(stderr));

    if ((g_argv = malloc(sizeof (char *) * argc)) == NULL ||
        (g_cmdv = malloc(sizeof (dtrace_cmd_t) * argc)) == NULL ||
        (g_psv = malloc(sizeof (struct ps_prochandle *) * argc)) == NULL)
        fatal("failed to allocate memory for arguments");

    g_argv[g_argc++] = argv[0]; /* propagate argv[0] to D as $0/$$0 */
    argv[0] = g_pname;      /* rewrite argv[0] for getopt errors */

    bzero(status, sizeof (status));
    bzero(&buf, sizeof (buf));

    /*
     * Make an initial pass through argv[] processing any arguments that
     * affect our behavior mode (g_mode) and flags used for dtrace_open().
     * We also accumulate arguments that are not affiliated with getopt
     * options into g_argv[], and abort if any invalid options are found.
     */
    for (optind = 1; optind < argc; optind++) {
        while ((c = getopt(argc, argv, DTRACE_OPTSTR)) != EOF) {
            switch (c) {
            case '3':
                if (strcmp(optarg, "2") != 0) {
                    (void) fprintf(stderr,
                        "%s: illegal option -- 3%s\n",
                        argv[0], optarg);
                    return (usage(stderr));
                }
                g_oflags &= ~DTRACE_O_LP64;
                g_oflags |= DTRACE_O_ILP32;
                break;

            case '6':
                if (strcmp(optarg, "4") != 0) {
                    (void) fprintf(stderr,
                        "%s: illegal option -- 6%s\n",
                        argv[0], optarg);
                    return (usage(stderr));
                }
                g_oflags &= ~DTRACE_O_ILP32;
                g_oflags |= DTRACE_O_LP64;
                break;

            case 'a':
                g_grabanon++; /* also checked in pass 2 below */
                break;

            case 'A':
                g_mode = DMODE_ANON;
                g_exec = 0;
                mode++;
                break;

            case 'e':
                g_exec = 0;
                done = 1;
                break;

            case 'h':
                g_mode = DMODE_HEADER;
                g_oflags |= DTRACE_O_NODEV;
                g_cflags |= DTRACE_C_ZDEFS; /* -h implies -Z */
                g_exec = 0;
                mode++;
                break;

            case 'G':
                g_mode = DMODE_LINK;
                g_oflags |= DTRACE_O_NODEV;
                g_cflags |= DTRACE_C_ZDEFS; /* -G implies -Z */
                g_exec = 0;
                mode++;
                break;

            case 'l':
                g_mode = DMODE_LIST;
                g_cflags |= DTRACE_C_ZDEFS; /* -l implies -Z */
                mode++;
                break;

            case 'V':
                g_mode = DMODE_VERS;
                mode++;
                break;

            default:
                if (strchr(DTRACE_OPTSTR, c) == NULL)
                    return (usage(stderr));
            }
        }

        if (optind < argc)
            g_argv[g_argc++] = argv[optind];
    }

    if (mode > 1) {
        (void) fprintf(stderr, "%s: only one of the [-AGhlV] options "
            "can be specified at a time\n", g_pname);
        return (E_USAGE);
    }

    if (g_mode == DMODE_VERS)
        return (printf("%s: %s\n", g_pname, _dtrace_version) <= 0);

    /*
     * If we're in linker mode and the data model hasn't been specified,
     * we try to guess the appropriate setting by examining the object
     * files. We ignore certain errors since we'll catch them later when
     * we actually process the object files.
     */
    if (g_mode == DMODE_LINK &&
        (g_oflags & (DTRACE_O_ILP32 | DTRACE_O_LP64)) == 0 &&
        elf_version(EV_CURRENT) != EV_NONE) {
        int fd;
        Elf *elf;
        GElf_Ehdr ehdr;

        for (i = 1; i < g_argc; i++) {
            if ((fd = open64(g_argv[i], O_RDONLY)) == -1)
                break;

            if ((elf = elf_begin(fd, ELF_C_READ, NULL)) == NULL) {
                (void) close(fd);
                break;
            }

            if (elf_kind(elf) != ELF_K_ELF ||
                gelf_getehdr(elf, &ehdr) == NULL) {
                (void) close(fd);
                (void) elf_end(elf);
                break;
            }

            (void) close(fd);
            (void) elf_end(elf);

            if (ehdr.e_ident[EI_CLASS] == ELFCLASS64) {
                if (g_oflags & DTRACE_O_ILP32) {
                    fatal("can't mix 32-bit and 64-bit "
                        "object files\n");
                }
                g_oflags |= DTRACE_O_LP64;
            } else if (ehdr.e_ident[EI_CLASS] == ELFCLASS32) {
                if (g_oflags & DTRACE_O_LP64) {
                    fatal("can't mix 32-bit and 64-bit "
                        "object files\n");
                }
                g_oflags |= DTRACE_O_ILP32;
            } else {
                break;
            }
        }
    }

    /*
     * Open libdtrace.  If we are not actually going to be enabling any
     * instrumentation attempt to reopen libdtrace using DTRACE_O_NODEV.
     */
    while ((g_dtp = dtrace_open(DTRACE_VERSION, g_oflags, &err)) == NULL) {
        if (!(g_oflags & DTRACE_O_NODEV) && !g_exec && !g_grabanon) {
            g_oflags |= DTRACE_O_NODEV;
            continue;
        }

        fatal("failed to initialize dtrace: %s\n",
            dtrace_errmsg(NULL, err));
    }

    (void) dtrace_setopt(g_dtp, "bufsize", "4m");
    (void) dtrace_setopt(g_dtp, "aggsize", "4m");
    (void) dtrace_setopt(g_dtp, "temporal", "yes");

    /*
     * If -G is specified, enable -xlink=dynamic and -xunodefs to permit
     * references to undefined symbols to remain as unresolved relocations.
     * If -A is specified, enable -xlink=primary to permit static linking
     * only to kernel symbols that are defined in a primary kernel module.
     */
    if (g_mode == DMODE_LINK) {
        (void) dtrace_setopt(g_dtp, "linkmode", "dynamic");
        (void) dtrace_setopt(g_dtp, "unodefs", NULL);

        /*
         * Use the remaining arguments as the list of object files
         * when in linker mode.
         */
        g_objc = g_argc - 1;
        g_objv = g_argv + 1;

        /*
         * We still use g_argv[0], the name of the executable.
         */
        g_argc = 1;
    } else if (g_mode == DMODE_ANON)
        (void) dtrace_setopt(g_dtp, "linkmode", "primary");

    /*
     * Now that we have libdtrace open, make a second pass through argv[]
     * to perform any dtrace_setopt() calls and change any compiler flags.
     * We also accumulate any program specifications into our g_cmdv[] at
     * this time; these will compiled as part of the fourth processing pass.
     */
    for (optind = 1; optind < argc; optind++) {
        while ((c = getopt(argc, argv, DTRACE_OPTSTR)) != EOF) {
            switch (c) {
            case 'a':
                if (dtrace_setopt(g_dtp, "grabanon", 0) != 0)
                    dfatal("failed to set -a");
                break;

            case 'b':
                if (dtrace_setopt(g_dtp,
                    "bufsize", optarg) != 0)
                    dfatal("failed to set -b %s", optarg);
                break;

            case 'B':
                g_ofp = NULL;
                break;

            case 'C':
                g_cflags |= DTRACE_C_CPP;
                break;

            case 'D':
                if (dtrace_setopt(g_dtp, "define", optarg) != 0)
                    dfatal("failed to set -D %s", optarg);
                break;

            case 'f':
                dcp = &g_cmdv[g_cmdc++];
                dcp->dc_func = compile_str;
                dcp->dc_spec = DTRACE_PROBESPEC_FUNC;
                dcp->dc_arg = optarg;
                break;

            case 'F':
                if (dtrace_setopt(g_dtp, "flowindent", 0) != 0)
                    dfatal("failed to set -F");
                break;

            case 'H':
                if (dtrace_setopt(g_dtp, "cpphdrs", 0) != 0)
                    dfatal("failed to set -H");
                break;

            case 'i':
                dcp = &g_cmdv[g_cmdc++];
                dcp->dc_func = compile_str;
                dcp->dc_spec = DTRACE_PROBESPEC_NAME;
                dcp->dc_arg = optarg;
                break;

            case 'I':
                if (dtrace_setopt(g_dtp, "incdir", optarg) != 0)
                    dfatal("failed to set -I %s", optarg);
                break;

            case 'L':
                if (dtrace_setopt(g_dtp, "libdir", optarg) != 0)
                    dfatal("failed to set -L %s", optarg);
                break;

            case 'm':
                dcp = &g_cmdv[g_cmdc++];
                dcp->dc_func = compile_str;
                dcp->dc_spec = DTRACE_PROBESPEC_MOD;
                dcp->dc_arg = optarg;
                break;

            case 'n':
                dcp = &g_cmdv[g_cmdc++];
                dcp->dc_func = compile_str;
                dcp->dc_spec = DTRACE_PROBESPEC_NAME;
                dcp->dc_arg = optarg;
                break;

            case 'P':
                dcp = &g_cmdv[g_cmdc++];
                dcp->dc_func = compile_str;
                dcp->dc_spec = DTRACE_PROBESPEC_PROVIDER;
                dcp->dc_arg = optarg;
                break;

            case 'q':
                if (dtrace_setopt(g_dtp, "quiet", 0) != 0)
                    dfatal("failed to set -q");
                break;

            case 'o':
                g_ofile = optarg;
                break;

            case 's':
                dcp = &g_cmdv[g_cmdc++];
                dcp->dc_func = compile_file;
                dcp->dc_spec = DTRACE_PROBESPEC_NONE;
                dcp->dc_arg = optarg;
                break;

            case 'S':
                g_cflags |= DTRACE_C_DIFV;
                break;

            case 'U':
                if (dtrace_setopt(g_dtp, "undef", optarg) != 0)
                    dfatal("failed to set -U %s", optarg);
                break;

            case 'v':
                g_verbose++;
                break;

            case 'w':
                if (dtrace_setopt(g_dtp, "destructive", 0) != 0)
                    dfatal("failed to set -w");
                break;

            case 'x':
                if ((p = strchr(optarg, '=')) != NULL)
                    *p++ = '\0';

                if (dtrace_setopt(g_dtp, optarg, p) != 0)
                    dfatal("failed to set -x %s", optarg);
                break;

            case 'X':
                if (dtrace_setopt(g_dtp, "stdc", optarg) != 0)
                    dfatal("failed to set -X %s", optarg);
                break;

            case 'Z':
                g_cflags |= DTRACE_C_ZDEFS;
                break;

            default:
                if (strchr(DTRACE_OPTSTR, c) == NULL)
                    return (usage(stderr));
            }
        }
    }

    if (g_ofp == NULL && g_mode != DMODE_EXEC) {
        (void) fprintf(stderr, "%s: -B not valid in combination"
            " with [-AGl] options\n", g_pname);
        return (E_USAGE);
    }

    if (g_ofp == NULL && g_ofile != NULL) {
        (void) fprintf(stderr, "%s: -B not valid in combination"
            " with -o option\n", g_pname);
        return (E_USAGE);
    }

    /*
     * In our third pass we handle any command-line options related to
     * grabbing or creating victim processes.  The behavior of these calls
     * may been affected by any library options set by the second pass.
     */
    for (optind = 1; optind < argc; optind++) {
        while ((c = getopt(argc, argv, DTRACE_OPTSTR)) != EOF) {
            switch (c) {
            case 'c':
                if ((v = make_argv(optarg)) == NULL)
                    fatal("failed to allocate memory");

                P = dtrace_proc_create(g_dtp, v[0], v);
                if (P == NULL)
                    dfatal(NULL); /* dtrace_errmsg() only */

                g_psv[g_psc++] = P;
                free(v);
                break;

            case 'p':
                errno = 0;
                pid = strtol(optarg, &p, 10);

                if (errno != 0 || p == optarg || p[0] != '\0')
                    fatal("invalid pid: %s\n", optarg);

                P = dtrace_proc_grab(g_dtp, pid, 0);
                if (P == NULL)
                    dfatal(NULL); /* dtrace_errmsg() only */

                g_psv[g_psc++] = P;
                break;
            }
        }
    }

    /*
     * In our fourth pass we finish g_cmdv[] by calling dc_func to convert
     * each string or file specification into a compiled program structure.
     */
    for (i = 0; i < g_cmdc; i++)
        g_cmdv[i].dc_func(&g_cmdv[i]);

    if (g_mode != DMODE_LIST) {
        if (dtrace_handle_err(g_dtp, &errhandler, NULL) == -1)
            dfatal("failed to establish error handler");

        if (dtrace_handle_drop(g_dtp, &drophandler, NULL) == -1)
            dfatal("failed to establish drop handler");

        if (dtrace_handle_proc(g_dtp, &prochandler, NULL) == -1)
            dfatal("failed to establish proc handler");

        if (dtrace_handle_setopt(g_dtp, &setopthandler, NULL) == -1)
            dfatal("failed to establish setopt handler");

        if (g_ofp == NULL &&
            dtrace_handle_buffered(g_dtp, &bufhandler, NULL) == -1)
            dfatal("failed to establish buffered handler");
    }

    (void) dtrace_getopt(g_dtp, "flowindent", &opt);
    g_flowindent = opt != DTRACEOPT_UNSET;

    (void) dtrace_getopt(g_dtp, "grabanon", &opt);
    g_grabanon = opt != DTRACEOPT_UNSET;

    (void) dtrace_getopt(g_dtp, "quiet", &opt);
    g_quiet = opt != DTRACEOPT_UNSET;

    /*
     * Now make a fifth and final pass over the options that have been
     * turned into programs and saved in g_cmdv[], performing any mode-
     * specific processing.  If g_mode is DMODE_EXEC, we will break out
     * of the switch() and continue on to the data processing loop.  For
     * other modes, we will exit dtrace once mode-specific work is done.
     */
    switch (g_mode) {
    case DMODE_EXEC:
        if (g_ofile != NULL && (g_ofp = fopen(g_ofile, "a")) == NULL)
            fatal("failed to open output file '%s'", g_ofile);

        for (i = 0; i < g_cmdc; i++)
            exec_prog(&g_cmdv[i]);

        if (done && !g_grabanon) {
            dtrace_close(g_dtp);
            return (g_status);
        }
        break;

    case DMODE_ANON:
        if (g_ofile == NULL)
            g_ofile = "/kernel/drv/dtrace.conf";

        dof_prune(g_ofile); /* strip out any old DOF directives */
        etcsystem_prune(); /* string out any forceload directives */

        if (g_cmdc == 0) {
            dtrace_close(g_dtp);
            return (g_status);
        }

        if ((g_ofp = fopen(g_ofile, "a")) == NULL)
            fatal("failed to open output file '%s'", g_ofile);

        for (i = 0; i < g_cmdc; i++) {
            anon_prog(&g_cmdv[i],
                dtrace_dof_create(g_dtp, g_cmdv[i].dc_prog, 0), i);
        }

        /*
         * Dump out the DOF corresponding to the error handler and the
         * current options as the final DOF property in the .conf file.
         */
        anon_prog(NULL, dtrace_geterr_dof(g_dtp), i++);
        anon_prog(NULL, dtrace_getopt_dof(g_dtp), i++);

        if (fclose(g_ofp) == EOF)
            fatal("failed to close output file '%s'", g_ofile);

        /*
         * These messages would use notice() rather than error(), but
         * we don't want them suppressed when -A is run on a D program
         * that itself contains a #pragma D option quiet.
         */
        error("saved anonymous enabling in %s\n", g_ofile);
        etcsystem_add();
        error("run update_drv(1M) or reboot to enable changes\n");

        dtrace_close(g_dtp);
        return (g_status);

    case DMODE_LINK:
        if (g_cmdc == 0) {
            (void) fprintf(stderr, "%s: -G requires one or more "
                "scripts or enabling options\n", g_pname);
            dtrace_close(g_dtp);
            return (E_USAGE);
        }

        for (i = 0; i < g_cmdc; i++)
            link_prog(&g_cmdv[i]);

        if (g_cmdc > 1 && g_ofile != NULL) {
            char **objv = alloca(g_cmdc * sizeof (char *));

            for (i = 0; i < g_cmdc; i++)
                objv[i] = g_cmdv[i].dc_ofile;

            if (dtrace_program_link(g_dtp, NULL, DTRACE_D_PROBES,
                g_ofile, g_cmdc, objv) != 0)
                dfatal(NULL); /* dtrace_errmsg() only */
        }

        dtrace_close(g_dtp);
        return (g_status);

    case DMODE_LIST:
        if (g_ofile != NULL && (g_ofp = fopen(g_ofile, "a")) == NULL)
            fatal("failed to open output file '%s'", g_ofile);

        oprintf("%5s %10s %17s %33s %s\n",
            "ID", "PROVIDER", "MODULE", "FUNCTION", "NAME");

        for (i = 0; i < g_cmdc; i++)
            list_prog(&g_cmdv[i]);

        if (g_cmdc == 0)
            (void) dtrace_probe_iter(g_dtp, NULL, list_probe, NULL);

        dtrace_close(g_dtp);
        return (g_status);

    case DMODE_HEADER:
        if (g_cmdc == 0) {
            (void) fprintf(stderr, "%s: -h requires one or more "
                "scripts or enabling options\n", g_pname);
            dtrace_close(g_dtp);
            return (E_USAGE);
        }

        if (g_ofile == NULL) {
            char *p;

            if (g_cmdc > 1) {
                (void) fprintf(stderr, "%s: -h requires an "
                    "output file if multiple scripts are "
                    "specified\n", g_pname);
                dtrace_close(g_dtp);
                return (E_USAGE);
            }

            if ((p = strrchr(g_cmdv[0].dc_arg, '.')) == NULL ||
                strcmp(p, ".d") != 0) {
                (void) fprintf(stderr, "%s: -h requires an "
                    "output file if no scripts are "
                    "specified\n", g_pname);
                dtrace_close(g_dtp);
                return (E_USAGE);
            }

            p[0] = '\0'; /* strip .d suffix */
            g_ofile = p = g_cmdv[0].dc_ofile;
            (void) snprintf(p, sizeof (g_cmdv[0].dc_ofile),
                "%s.h", basename(g_cmdv[0].dc_arg));
        }

        if ((g_ofp = fopen(g_ofile, "w")) == NULL)
            fatal("failed to open header file '%s'", g_ofile);

        oprintf("/*\n * Generated by dtrace(1M).\n */\n\n");

        if (dtrace_program_header(g_dtp, g_ofp, g_ofile) != 0 ||
            fclose(g_ofp) == EOF)
            dfatal("failed to create header file %s", g_ofile);

        dtrace_close(g_dtp);
        return (g_status);
    }

    /*
     * If -a and -Z were not specified and no probes have been matched, no
     * probe criteria was specified on the command line and we abort.
     */
    if (g_total == 0 && !g_grabanon && !(g_cflags & DTRACE_C_ZDEFS))
        dfatal("no probes %s\n", g_cmdc ? "matched" : "specified");

    /*
     * Start tracing.  Once we dtrace_go(), reload any options that affect
     * our globals in case consuming anonymous state has changed them.
     */
    go();

    (void) dtrace_getopt(g_dtp, "flowindent", &opt);
    g_flowindent = opt != DTRACEOPT_UNSET;

    (void) dtrace_getopt(g_dtp, "grabanon", &opt);
    g_grabanon = opt != DTRACEOPT_UNSET;

    (void) dtrace_getopt(g_dtp, "quiet", &opt);
    g_quiet = opt != DTRACEOPT_UNSET;

    (void) dtrace_getopt(g_dtp, "destructive", &opt);
    if (opt != DTRACEOPT_UNSET)
        notice("allowing destructive actions\n");

    (void) sigemptyset(&act.sa_mask);
    act.sa_flags = 0;
    act.sa_handler = intr;

    if (sigaction(SIGINT, NULL, &oact) == 0 && oact.sa_handler != SIG_IGN)
        (void) sigaction(SIGINT, &act, NULL);

    if (sigaction(SIGTERM, NULL, &oact) == 0 && oact.sa_handler != SIG_IGN)
        (void) sigaction(SIGTERM, &act, NULL);

    /*
     * Now that tracing is active and we are ready to consume trace data,
     * continue any grabbed or created processes, setting them running
     * using the /proc control mechanism inside of libdtrace.
     */
    for (i = 0; i < g_psc; i++)
        dtrace_proc_continue(g_dtp, g_psv[i]);

    g_pslive = g_psc; /* count for prochandler() */

    do {
        if (!g_intr && !done)
            dtrace_sleep(g_dtp);

        if (g_newline) {
            /*
             * Output a newline just to make the output look
             * slightly cleaner.  Note that we do this even in
             * "quiet" mode...
             */
            oprintf("\n");
            g_newline = 0;
        }

        if (done || g_intr || (g_psc != 0 && g_pslive == 0)) {
            done = 1;
            if (dtrace_stop(g_dtp) == -1)
                dfatal("couldn't stop tracing");
        }

        switch (dtrace_work(g_dtp, g_ofp, chew, chewrec, NULL)) {
        case DTRACE_WORKSTATUS_DONE:
            done = 1;
            break;
        case DTRACE_WORKSTATUS_OKAY:
            break;
        default:
            if (!g_impatient && dtrace_errno(g_dtp) != EINTR)
                dfatal("processing aborted");
        }

        if (g_ofp != NULL && fflush(g_ofp) == EOF)
            clearerr(g_ofp);
    } while (!done);

    oprintf("\n");

    if (!g_impatient) {
        if (dtrace_aggregate_print(g_dtp, g_ofp, NULL) == -1 &&
            dtrace_errno(g_dtp) != EINTR)
            dfatal("failed to print aggregations");
    }

    dtrace_close(g_dtp);
    return (g_status);
}