root/usr/src/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(8) 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(5) 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(5) 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;
        int c;
        char *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(8) 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(8).\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);
}