preap.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (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 2003 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 <ctype.h>
#include <string.h>
#include <signal.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <libproc.h>
#define NOREAP_TIME 60 /* wait 60 seconds before allow a reap */
static volatile int interrupt;
static int Fflag;
static char *command;
static void
intr(int sig)
{
interrupt = sig;
}
static int
open_usage(pid_t pid, int *perr)
{
char path[64];
struct stat64 st;
int fd;
(void) snprintf(path, sizeof (path), "/proc/%d/usage", (int)pid);
/*
* Attempt to open the usage file, and return the fd if we can
* confirm this is a regular file provided by /proc.
*/
if ((fd = open64(path, O_RDONLY)) >= 0) {
if (fstat64(fd, &st) != 0 || !S_ISREG(st.st_mode) ||
strcmp(st.st_fstype, "proc") != 0) {
(void) close(fd);
fd = -1;
}
} else if (errno == EACCES || errno == EPERM)
*perr = G_PERM;
return (fd);
}
static int
proc_usage(pid_t pid, prusage_t *pup, int *perr)
{
int fd;
*perr = G_NOPROC;
if ((fd = open_usage(pid, perr)) != -1) {
if (read(fd, pup, sizeof (prusage_t)) == sizeof (prusage_t)) {
*perr = 0;
(void) close(fd);
return (0);
}
/*
* If the read failed, the process may have gone away.
*/
(void) close(fd);
}
return (-1);
}
/*
* Force the parent process (ppid) to wait for its child process (pid).
*/
static int
reap(char *arg, pid_t *reap_pid, int *exit_status)
{
struct ps_prochandle *Pr;
siginfo_t siginfo;
psinfo_t psinfo;
prusage_t usage;
pid_t pid, ppid;
time_t elapsed;
int gret;
/*
* get the specified pid and the psinfo struct
*/
if ((pid = proc_arg_psinfo(arg, PR_ARG_PIDS, &psinfo, &gret)) == -1) {
(void) fprintf(stderr, "%s: cannot examine %s: %s\n",
command, arg, Pgrab_error(gret));
return (1);
}
if (psinfo.pr_nlwp != 0) {
(void) fprintf(stderr, "%s: process not defunct: %d\n",
command, (int)pid);
return (1);
}
*exit_status = psinfo.pr_wstat;
*reap_pid = psinfo.pr_pid;
ppid = psinfo.pr_ppid;
if (ppid == 1) {
(void) fprintf(stderr, "%s: Failed to reap %d: the only "
"non-defunct ancestor is 'init'\n", command,
(int)pid);
return (1);
}
if (proc_usage(pid, &usage, &gret) == 0) {
elapsed = usage.pr_tstamp.tv_sec - usage.pr_term.tv_sec;
} else {
(void) fprintf(stderr, "%s: cannot examine %d: %s\n",
command, (int)pid, Pgrab_error(gret));
return (1);
}
if ((Fflag == 0) && (elapsed < NOREAP_TIME)) {
(void) fprintf(stderr, "%s: unsafe to reap %d; it has been "
"defunct less than %d seconds\n", command, (int)pid,
NOREAP_TIME);
return (1);
}
if ((Pr = Pgrab(ppid, Fflag | PGRAB_NOSTOP, &gret)) == NULL) {
(void) fprintf(stderr, "%s: cannot examine %d: %s\n", command,
(int)ppid, Pgrab_error(gret));
return (1);
}
if ((Fflag == 0) && (Pstate(Pr) == PS_STOP)) {
Prelease(Pr, 0);
(void) fprintf(stderr, "%s: unsafe to reap %d; parent is "
"stopped and may reap status upon restart\n", command,
(int)pid);
return (1);
}
/*
* Pstop() will fail if the process to be stopped has become a zombie.
* This means that we can say with certainty that the child of this
* process has not changed parents (i.e. been reparented to init) once
* the Pstop() succeeds.
*/
if (Pstop(Pr, 1000) != 0) {
Prelease(Pr, 0);
(void) fprintf(stderr, "%s: failed to stop %d: %s", command,
(int)ppid, strerror(errno));
return (1);
}
if (pr_waitid(Pr, P_PID, pid, &siginfo, WEXITED|WNOHANG) != 0) {
Prelease(Pr, 0);
(void) fprintf(stderr, "%s: waitid() in process %d failed: %s",
command, (int)ppid, strerror(errno));
return (1);
}
Prelease(Pr, 0);
return (0);
}
static void
print_exit_status(pid_t pid, int wstat)
{
(void) printf("%d: ", (int)pid);
if (WIFSIGNALED(wstat)) {
char buf[SIG2STR_MAX];
int sig = WTERMSIG(wstat);
if (sig2str(sig, buf) == 0)
(void) printf("killed by signal %s", buf);
else
(void) printf("killed by signal %d", sig);
if (WCOREDUMP(wstat))
(void) printf(" (core dumped)");
} else {
(void) printf("exited with status %d", WEXITSTATUS(wstat));
}
(void) printf("\n");
}
int
main(int argc, char *argv[])
{
int retc = 0;
int opt;
int errflg = 0;
if ((command = strrchr(argv[0], '/')) != NULL)
command++;
else
command = argv[0];
while ((opt = getopt(argc, argv, "F")) != EOF) {
switch (opt) {
case 'F': /* force grabbing (no O_EXCL) */
Fflag = PGRAB_FORCE;
break;
default:
errflg = 1;
break;
}
}
argc -= optind;
argv += optind;
if (errflg || argc <= 0) {
(void) fprintf(stderr, "usage: %s pid ...\n", command);
(void) fprintf(stderr, " (Reap a defunct process by forcing "
"its parent to wait(2) for it)\n");
exit(2);
}
/* catch signals from terminal */
if (sigset(SIGHUP, SIG_IGN) == SIG_DFL)
(void) sigset(SIGHUP, intr);
if (sigset(SIGINT, SIG_IGN) == SIG_DFL)
(void) sigset(SIGINT, intr);
if (sigset(SIGPIPE, SIG_IGN) == SIG_DFL)
(void) sigset(SIGPIPE, intr);
if (sigset(SIGQUIT, SIG_IGN) == SIG_DFL)
(void) sigset(SIGQUIT, intr);
(void) sigset(SIGTERM, intr);
while (--argc >= 0 && !interrupt) {
pid_t pid;
int wstat, r;
retc += r = reap(*argv++, &pid, &wstat);
if (r == 0)
print_exit_status(pid, wstat);
}
if (interrupt && retc == 0)
retc++;
return (retc == 0 ? 0 : 1);
}