1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2010 ProFUSION embedded systems
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
23 #include <sys/types.h>
24 #include <sys/reboot.h>
25 #include <linux/reboot.h>
27 #include <sys/types.h>
29 #include <sys/mount.h>
30 #include <sys/syscall.h>
47 #define TIMEOUT_USEC (5 * USEC_PER_SEC)
48 #define FINALIZE_ATTEMPTS 50
50 static bool ignore_proc(pid_t pid) {
58 /* We are PID 1, let's not commit suicide */
62 r = get_process_uid(pid, &uid);
64 return true; /* not really, but better safe than sorry */
66 /* Non-root processes otherwise are always subject to be killed */
70 snprintf(buf, sizeof(buf), "/proc/%lu/cmdline", (unsigned long) pid);
75 return true; /* not really, but has the desired effect */
77 count = fread(&c, 1, 1, f);
80 /* Kernel threads have an empty cmdline */
84 /* Processes with argv[0][0] = '@' we ignore from the killing
87 * http://www.freedesktop.org/wiki/Software/systemd/RootStorageDaemons */
88 if (count == 1 && c == '@')
94 static int killall(int sign) {
97 unsigned int n_processes = 0;
99 dir = opendir("/proc");
103 while ((d = readdir(dir))) {
106 if (parse_pid(d->d_name, &pid) < 0)
109 if (ignore_proc(pid))
112 if (kill(pid, sign) == 0)
115 log_warning("Could not kill %d: %m", pid);
123 static void wait_for_children(int n_processes, sigset_t *mask) {
128 until = now(CLOCK_MONOTONIC) + TIMEOUT_USEC;
135 pid_t pid = waitpid(-1, NULL, WNOHANG);
140 if (pid < 0 && errno == ECHILD)
144 if (--n_processes == 0)
148 n = now(CLOCK_MONOTONIC);
152 timespec_store(&ts, until - n);
154 if ((k = sigtimedwait(mask, NULL, &ts)) != SIGCHLD) {
156 if (k < 0 && errno != EAGAIN) {
157 log_error("sigtimedwait() failed: %m");
162 log_warning("sigtimedwait() returned unexpected signal.");
167 static void send_signal(int sign) {
168 sigset_t mask, oldmask;
171 assert_se(sigemptyset(&mask) == 0);
172 assert_se(sigaddset(&mask, SIGCHLD) == 0);
173 assert_se(sigprocmask(SIG_BLOCK, &mask, &oldmask) == 0);
175 if (kill(-1, SIGSTOP) < 0 && errno != ESRCH)
176 log_warning("kill(-1, SIGSTOP) failed: %m");
178 n_processes = killall(sign);
180 if (kill(-1, SIGCONT) < 0 && errno != ESRCH)
181 log_warning("kill(-1, SIGCONT) failed: %m");
183 if (n_processes <= 0)
186 wait_for_children(n_processes, &mask);
189 sigprocmask(SIG_SETMASK, &oldmask, NULL);
192 static void ultimate_send_signal(int sign) {
193 sigset_t mask, oldmask;
196 assert_se(sigemptyset(&mask) == 0);
197 assert_se(sigaddset(&mask, SIGCHLD) == 0);
198 assert_se(sigprocmask(SIG_BLOCK, &mask, &oldmask) == 0);
200 if (kill(-1, SIGSTOP) < 0 && errno != ESRCH)
201 log_warning("kill(-1, SIGSTOP) failed: %m");
204 if (r < 0 && errno != ESRCH)
205 log_warning("kill(-1, %s) failed: %m", signal_to_string(sign));
207 if (kill(-1, SIGCONT) < 0 && errno != ESRCH)
208 log_warning("kill(-1, SIGCONT) failed: %m");
213 wait_for_children(0, &mask);
216 sigprocmask(SIG_SETMASK, &oldmask, NULL);
219 static int prepare_new_root(void) {
220 static const char dirs[] =
221 "/run/initramfs/oldroot\0"
222 "/run/initramfs/proc\0"
223 "/run/initramfs/sys\0"
224 "/run/initramfs/dev\0"
225 "/run/initramfs/run\0";
229 if (mount("/run/initramfs", "/run/initramfs", NULL, MS_BIND, NULL) < 0) {
230 log_error("Failed to mount bind /run/initramfs on /run/initramfs: %m");
234 if (mount(NULL, "/run/initramfs", NULL, MS_PRIVATE, NULL) < 0) {
235 log_error("Failed to make /run/initramfs private mount: %m");
239 NULSTR_FOREACH(dir, dirs)
240 if (mkdir_p(dir, 0755) < 0 && errno != EEXIST) {
241 log_error("Failed to mkdir %s: %m", dir);
245 if (mount("/sys", "/run/initramfs/sys", NULL, MS_BIND, NULL) < 0) {
246 log_error("Failed to mount bind /sys on /run/initramfs/sys: %m");
250 if (mount("/proc", "/run/initramfs/proc", NULL, MS_BIND, NULL) < 0) {
251 log_error("Failed to mount bind /proc on /run/initramfs/proc: %m");
255 if (mount("/dev", "/run/initramfs/dev", NULL, MS_BIND, NULL) < 0) {
256 log_error("Failed to mount bind /dev on /run/initramfs/dev: %m");
260 if (mount("/run", "/run/initramfs/run", NULL, MS_BIND, NULL) < 0) {
261 log_error("Failed to mount bind /run on /run/initramfs/run: %m");
268 static int pivot_to_new_root(void) {
271 chdir("/run/initramfs");
274 In case some evil process made "/" MS_SHARED
275 It works for pivot_root, but the ref count for the root device
276 is not decreasing :-/
278 if (mount(NULL, "/", NULL, MS_PRIVATE, NULL) < 0) {
279 log_error("Failed to make \"/\" private mount %m");
283 if (pivot_root(".", "oldroot") < 0) {
284 log_error("pivot failed: %m");
285 /* only chroot if pivot root succeded */
290 log_info("Successfully changed into root pivot.");
292 fd = open("/dev/console", O_RDWR);
294 log_error("Failed to open /dev/console: %m");
298 /* Initialize the controlling terminal */
300 ioctl(STDIN_FILENO, TIOCSCTTY, NULL);
306 int main(int argc, char *argv[]) {
309 bool need_umount = true, need_swapoff = true, need_loop_detach = true, need_dm_detach = true;
310 bool killed_everbody = false, in_container, use_watchdog = false;
312 log_parse_environment();
313 log_set_target(LOG_TARGET_CONSOLE); /* syslog will die if not gone yet */
319 log_error("Not executed by init (pid 1).");
325 log_error("Invalid number of arguments.");
330 in_container = detect_container(NULL) > 0;
332 if (streq(argv[1], "reboot"))
334 else if (streq(argv[1], "poweroff"))
336 else if (streq(argv[1], "halt"))
337 cmd = RB_HALT_SYSTEM;
338 else if (streq(argv[1], "kexec"))
339 cmd = LINUX_REBOOT_CMD_KEXEC;
341 log_error("Unknown action '%s'.", argv[1]);
346 use_watchdog = !!getenv("WATCHDOG_USEC");
348 /* lock us into memory */
349 if (mlockall(MCL_CURRENT|MCL_FUTURE) != 0)
350 log_warning("Cannot lock process memory: %m");
352 log_info("Sending SIGTERM to remaining processes...");
353 send_signal(SIGTERM);
355 log_info("Sending SIGKILL to remaining processes...");
356 send_signal(SIGKILL);
359 need_swapoff = false;
361 /* Unmount all mountpoints, swaps, and loopback devices */
362 for (retries = 0; retries < FINALIZE_ATTEMPTS; retries++) {
363 bool changed = false;
369 log_info("Unmounting file systems.");
370 r = umount_all(&changed);
374 log_info("Not all file systems unmounted, %d left.", r);
376 log_error("Failed to unmount file systems: %s", strerror(-r));
380 log_info("Disabling swaps.");
381 r = swapoff_all(&changed);
383 need_swapoff = false;
385 log_info("Not all swaps are turned off, %d left.", r);
387 log_error("Failed to turn off swaps: %s", strerror(-r));
390 if (need_loop_detach) {
391 log_info("Detaching loop devices.");
392 r = loopback_detach_all(&changed);
394 need_loop_detach = false;
396 log_info("Not all loop devices detached, %d left.", r);
398 log_error("Failed to detach loop devices: %s", strerror(-r));
401 if (need_dm_detach) {
402 log_info("Detaching DM devices.");
403 r = dm_detach_all(&changed);
405 need_dm_detach = false;
407 log_warning("Not all DM devices detached, %d left.", r);
409 log_error("Failed to detach DM devices: %s", strerror(-r));
412 if (!need_umount && !need_swapoff && !need_loop_detach && !need_dm_detach) {
414 log_info("All filesystems, swaps, loop devices, DM devices detached.");
419 /* If in this iteration we didn't manage to
420 * unmount/deactivate anything, we either kill more
421 * processes, or simply give up */
424 if (killed_everbody) {
425 /* Hmm, we already killed everybody,
426 * let's just give up */
427 log_error("Cannot finalize remaining file systems and devices, giving up.");
431 log_warning("Cannot finalize remaining file systems and devices, trying to kill remaining processes.");
432 ultimate_send_signal(SIGTERM);
433 ultimate_send_signal(SIGKILL);
434 killed_everbody = true;
437 log_debug("Couldn't finalize remaining file systems and devices after %u retries, trying again.", retries+1);
440 if (retries >= FINALIZE_ATTEMPTS)
441 log_error("Too many iterations, giving up.");
443 execute_directory(SYSTEM_SHUTDOWN_PATH, NULL, NULL);
445 /* If we are in a container, just exit, this will kill our
446 * container for good. */
448 log_error("Exiting container.");
452 if (access("/run/initramfs/shutdown", X_OK) == 0) {
454 if (prepare_new_root() >= 0 &&
455 pivot_to_new_root() >= 0) {
456 execv("/shutdown", argv);
457 log_error("Failed to execute shutdown binary: %m");
463 if (cmd == LINUX_REBOOT_CMD_KEXEC) {
464 /* We cheat and exec kexec to avoid doing all its work */
468 log_error("Could not fork: %m. Falling back to normal reboot.");
470 wait_for_terminate_and_warn("kexec", pid);
471 log_warning("kexec failed. Falling back to normal reboot.");
474 const char *args[3] = { "/sbin/kexec", "-e", NULL };
475 execv(args[0], (char * const *) args);
483 log_error("Failed to invoke reboot(): %m");
487 log_error("Critical error while doing system shutdown: %s", strerror(-r));