Return to reboot.c CVS log

Up to [local] / src / sbin / reboot

reboot: don't wait for processes to die if there are none

If processes are already dead, reduce wait times between SIGTERM and
SIGKILL and wait time after SIGKILL.  The reboot syscall will cause
another sync later on, therefore the long wait times are not necessary
for disk i/o, either.

"makes sense" deraadt@

/*	$OpenBSD: reboot.c,v 1.38 2017/08/22 00:30:16 sf Exp $	*/
/*	$NetBSD: reboot.c,v 1.8 1995/10/05 05:36:22 mycroft Exp $	*/

/*
 * Copyright (c) 1980, 1986, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/types.h>
#include <sys/reboot.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <machine/cpu.h>
#include <signal.h>
#include <pwd.h>
#include <errno.h>
#include <err.h>
#include <fcntl.h>
#include <termios.h>
#include <syslog.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <paths.h>
#include <util.h>

void	usage(void);
extern char *__progname;

int	dohalt;

#define _PATH_RC	"/etc/rc"

static void
sleep_while_procs(int seconds)
{
	while (seconds > 0) {
		if (kill(-1, 0) == -1 && errno == ESRCH)
			return;
		sleep(1);
		seconds--;
	}
}

int
main(int argc, char *argv[])
{
	unsigned int i;
	struct passwd *pw;
	int ch, howto, lflag, nflag, pflag, qflag;
	char *p, *user;
	sigset_t mask;

	p = __progname;

	/* Nuke login shell */
	if (*p == '-')
		p++;

	howto = dohalt = lflag = nflag = pflag = qflag = 0;
	if (!strcmp(p, "halt")) {
		dohalt = 1;
		howto = RB_HALT;
	}

	while ((ch = getopt(argc, argv, "dlnpq")) != -1)
		switch (ch) {
		case 'd':
			howto |= RB_DUMP;
			break;
		case 'l':	/* Undocumented; used by shutdown. */
			lflag = 1;
			break;
		case 'n':
			nflag = 1;
			howto |= RB_NOSYNC;
			break;
		case 'p':
			/* Only works if we're called as halt. */
			if (dohalt) {
				pflag = 1;
				howto |= RB_POWERDOWN;
			}
			break;
		case 'q':
			qflag = 1;
			break;
		default:
			usage();
		}
	argc -= optind;
	argv += optind;

	if (argc)
		usage();

	if (geteuid())
		errx(1, "%s", strerror(EPERM));

#ifdef CPU_LIDACTION
	if (howto & RB_POWERDOWN) {
		/* Disable suspending on laptop lid close */
		int mib[] = {CTL_MACHDEP, CPU_LIDACTION};
		int lidaction = 0;

		if (sysctl(mib, 2, NULL, NULL, &lidaction,
		    sizeof(lidaction)) == -1 && errno != EOPNOTSUPP)
			warn("sysctl");
	}
#endif /* CPU_LIDACTION */

	if (qflag) {
		reboot(howto);
		err(1, "reboot");
	}

	/* Log the reboot. */
	if (!lflag)  {
		if ((user = getlogin()) == NULL)
			user = (pw = getpwuid(getuid())) ?
			    pw->pw_name : "???";
		if (dohalt) {
			openlog("halt", 0, LOG_AUTH | LOG_CONS);
			if (pflag) {
				syslog(LOG_CRIT,
					"halted (with powerdown) by %s", user);
			} else {
				syslog(LOG_CRIT, "halted by %s", user);
			}
		} else {
			openlog("reboot", 0, LOG_AUTH | LOG_CONS);
			syslog(LOG_CRIT, "rebooted by %s", user);
		}
	}
	logwtmp("~", "shutdown", "");

	/*
	 * Do a sync early on, so disks start transfers while we're off
	 * killing processes.  Don't worry about writes done before the
	 * processes die, the reboot system call syncs the disks.
	 */
	if (!nflag)
		sync();

	/* Just stop init -- if we fail, we'll restart it. */
	if (kill(1, SIGTSTP) == -1)
		err(1, "SIGTSTP init");

	/* Ignore the SIGHUP we get when our parent shell dies. */
	(void)signal(SIGHUP, SIG_IGN);

	/*
	 * If we're running in a pipeline, we don't want to die
	 * after killing whatever we're writing to.
	 */
	(void)signal(SIGPIPE, SIG_IGN);

	if (access(_PATH_RC, R_OK) != -1) {
		pid_t pid;
		struct termios t;
		int fd, status;

		switch ((pid = fork())) {
		case -1:
			break;
		case 0:
			if (revoke(_PATH_CONSOLE) == -1)
				warn("revoke");
			if (setsid() == -1)
				warn("setsid");
			fd = open(_PATH_CONSOLE, O_RDWR);
			if (fd == -1)
				warn("open");
			dup2(fd, 0);
			dup2(fd, 1);
			dup2(fd, 2);
			if (fd > 2)
				close(fd);

			/* At a minimum... */
			tcgetattr(0, &t);
			t.c_oflag |= (ONLCR | OPOST);
			tcsetattr(0, TCSANOW, &t);

			execl(_PATH_BSHELL, "sh", _PATH_RC, "shutdown", (char *)NULL);
			_exit(1);
		default:
			/* rc exits 2 if powerdown=YES in rc.shutdown */
			waitpid(pid, &status, 0);
			if (dohalt && WIFEXITED(status) && WEXITSTATUS(status) == 2)
				howto |= RB_POWERDOWN;
		}
	}

	/*
	 * Point of no return, block all signals so we are sure to
	 * reach the call to reboot(2) unmolested.
	 */
	sigfillset(&mask);
	sigprocmask(SIG_BLOCK, &mask, NULL);

	/* Send a SIGTERM first, a chance to save the buffers. */
	if (kill(-1, SIGTERM) == -1) {
		/*
		 * If ESRCH, everything's OK: we're the only non-system
		 * process!  That can happen e.g. via 'exec reboot' in
		 * single-user mode.
		 */
		if (errno != ESRCH) {
			warn("SIGTERM processes");
			goto restart;
		}
	}

	/*
	 * After the processes receive the signal, start the rest of the
	 * buffers on their way.  Wait 5 seconds between the SIGTERM and
	 * the SIGKILL to give everybody a chance.
	 */
	sleep_while_procs(2);
	if (!nflag)
		sync();
	sleep_while_procs(3);

	for (i = 1;; ++i) {
		if (kill(-1, SIGKILL) == -1) {
			if (errno == ESRCH)
				break;
			goto restart;
		}
		if (i > 5) {
			warnx("WARNING: some process(es) wouldn't die");
			break;
		}
		sleep_while_procs(2 * i);
	}

	reboot(howto);
	/* FALLTHROUGH */

restart:
	errx(1, kill(1, SIGHUP) == -1 ? "(can't restart init): " : "");
	/* NOTREACHED */
}

void
usage(void)
{
	fprintf(stderr, "usage: %s [-dn%sq]\n", __progname,
	    dohalt ? "p" : "");
	exit(1);
}