ptools/prun/prun.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.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <signal.h>
#include <libproc.h>

static  int start(char *);
static  int lwpstart(int *, const lwpstatus_t *, const lwpsinfo_t *);

static  char    *command;
static  const char *lwps;
static  struct  ps_prochandle *P;

int
main(int argc, char **argv)
{
    int rc = 0;

    if ((command = strrchr(argv[0], '/')) != NULL)
        command++;
    else
        command = argv[0];

    if (argc <= 1) {
        (void) fprintf(stderr, "usage:\t%s pid[/lwps] ...\n", command);
        (void) fprintf(stderr, "  (set stopped processes or lwps "
            "running)\n");
        return (2);
    }

    while (--argc > 0)
        rc += start(*++argv);

    return (rc);
}

static int
start(char *arg)
{
    int gcode;
    int rc = 0;

    if ((P = proc_arg_xgrab(arg, NULL, PR_ARG_PIDS, PGRAB_FORCE |
        PGRAB_RETAIN | PGRAB_NOSTOP, &gcode, &lwps)) == NULL) {
        (void) fprintf(stderr, "%s: cannot control %s: %s\n",
            command, arg, Pgrab_error(gcode));
        return (1);
    }

    /*
     * If the victim is stopped because of a job control signal, we
     * need to send it SIGCONT to get it moving again, otherwise
     * the agent will not be able to run, and so will not be able to
     * exit the process.
     */
    (void) kill(Pstatus(P)->pr_pid, SIGCONT);

    /*
     * if the agent already exists, Pcreate_agent will adopt the
     * extant agent so that we can destroy it
     */
    if (Pstatus(P)->pr_lwp.pr_flags & PR_AGENT) {
        if (Pcreate_agent(P) != 0) {
            (void) fprintf(stderr,
                "%s: cannot remove agent from %s: %s\n",
                command, arg, strerror(errno));

            Prelease(P, 0);
            return (1);
        }

        Pdestroy_agent(P);
    }

    if (lwps != NULL) {
        /*
         * The user provided an lwp specification. Let's consider the
         * lwp specification as a mask.  We iterate over all lwps in the
         * process and set running every lwp, which matches the mask.
         * If there is no lwp matching the mask or an error occured
         * during the iteration, set the return code to 1 as indication
         * of an error.  We need to unset run-on-last-close flag,
         * otherwise *all* lwps could be set running after detaching
         * from the process and not only lwps, which were selected.
         */
        int lwpcount = 0;

        (void) Punsetflags(P, PR_RLC);
        (void) Plwp_iter_all(P, (proc_lwp_all_f *)lwpstart, &lwpcount);

        if (lwpcount == 0) {
            (void) fprintf(stderr, "%s: cannot control %s:"
                " no matching LWPs found\n", command, arg);
            rc = 1;
        } else if (lwpcount == -1)
            rc = 1;
    } else {
        (void) Psetrun(P, 0, 0);    /* Set the process running. */
    }

    /*
     * Prelease could change the tracing flags or leave the victim hung
     * so we free the handle by hand.
     */
    Pfree(P);
    return (rc);
}

/* ARGSUSED */
static int
lwpstart(int *lwpcount, const lwpstatus_t *status, const lwpsinfo_t *info)
{
    struct ps_lwphandle *L;
    int gcode;

    if (proc_lwp_in_set(lwps, info->pr_lwpid)) {
        /*
         * There is a race between the callback from the iterator and
         * grabbing of the lwp.  If the lwp has already exited, Lgrab
         * will return the error code G_NOPROC.  It's not a real error,
         * only if there is no lwp matching the specification.
         */
        if ((L = Lgrab(P, info->pr_lwpid, &gcode)) != NULL) {
            (void) Lsetrun(L, 0, 0);
            Lfree(L);
            if (*lwpcount >= 0)
                (*lwpcount)++;
        } else if (gcode != G_NOPROC) {
            (void) fprintf(stderr, "%s: cannot control %d/%d: %s\n",
                command, (int)Pstatus(P)->pr_pid,
                (int)info->pr_lwpid, Lgrab_error(gcode));
            *lwpcount = -1;
        }
    }
    return (0);
}