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>
46 #define TIMEOUT_USEC (5 * USEC_PER_SEC)
47 #define FINALIZE_ATTEMPTS 50
49 static bool ignore_proc(pid_t pid) {
57 /* We are PID 1, let's not commit suicide */
61 r = get_process_uid(pid, &uid);
63 return true; /* not really, but better safe than sorry */
65 /* Non-root processes otherwise are always subject to be killed */
69 snprintf(buf, sizeof(buf), "/proc/%lu/cmdline", (unsigned long) pid);
74 return true; /* not really, but has the desired effect */
76 count = fread(&c, 1, 1, f);
79 /* Kernel threads have an empty cmdline */
83 /* Processes with argv[0][0] = '@' we ignore from the killing
86 * http://www.freedesktop.org/wiki/Software/systemd/RootStorageDaemons */
87 if (count == 1 && c == '@')
93 static int killall(int sign) {
96 unsigned int n_processes = 0;
98 dir = opendir("/proc");
102 while ((d = readdir(dir))) {
105 if (parse_pid(d->d_name, &pid) < 0)
108 if (ignore_proc(pid))
111 if (kill(pid, sign) == 0)
114 log_warning("Could not kill %d: %m", pid);
122 static void wait_for_children(int n_processes, sigset_t *mask) {
127 until = now(CLOCK_MONOTONIC) + TIMEOUT_USEC;
134 pid_t pid = waitpid(-1, NULL, WNOHANG);
139 if (pid < 0 && errno == ECHILD)
143 if (--n_processes == 0)
147 n = now(CLOCK_MONOTONIC);
151 timespec_store(&ts, until - n);
153 if ((k = sigtimedwait(mask, NULL, &ts)) != SIGCHLD) {
155 if (k < 0 && errno != EAGAIN) {
156 log_error("sigtimedwait() failed: %m");
161 log_warning("sigtimedwait() returned unexpected signal.");
166 static void send_signal(int sign) {
167 sigset_t mask, oldmask;
170 assert_se(sigemptyset(&mask) == 0);
171 assert_se(sigaddset(&mask, SIGCHLD) == 0);
172 assert_se(sigprocmask(SIG_BLOCK, &mask, &oldmask) == 0);
174 if (kill(-1, SIGSTOP) < 0 && errno != ESRCH)
175 log_warning("kill(-1, SIGSTOP) failed: %m");
177 n_processes = killall(sign);
179 if (kill(-1, SIGCONT) < 0 && errno != ESRCH)
180 log_warning("kill(-1, SIGCONT) failed: %m");
182 if (n_processes <= 0)
185 wait_for_children(n_processes, &mask);
188 sigprocmask(SIG_SETMASK, &oldmask, NULL);
191 static void ultimate_send_signal(int sign) {
192 sigset_t mask, oldmask;
195 assert_se(sigemptyset(&mask) == 0);
196 assert_se(sigaddset(&mask, SIGCHLD) == 0);
197 assert_se(sigprocmask(SIG_BLOCK, &mask, &oldmask) == 0);
199 if (kill(-1, SIGSTOP) < 0 && errno != ESRCH)
200 log_warning("kill(-1, SIGSTOP) failed: %m");
203 if (r < 0 && errno != ESRCH)
204 log_warning("kill(-1, %s) failed: %m", signal_to_string(sign));
206 if (kill(-1, SIGCONT) < 0 && errno != ESRCH)
207 log_warning("kill(-1, SIGCONT) failed: %m");
212 wait_for_children(0, &mask);
215 sigprocmask(SIG_SETMASK, &oldmask, NULL);
218 static int prepare_new_root(void) {
219 static const char dirs[] =
220 "/run/initramfs/oldroot\0"
221 "/run/initramfs/proc\0"
222 "/run/initramfs/sys\0"
223 "/run/initramfs/dev\0"
224 "/run/initramfs/run\0";
228 if (mount("/run/initramfs", "/run/initramfs", NULL, MS_BIND, NULL) < 0) {
229 log_error("Failed to mount bind /run/initramfs on /run/initramfs: %m");
233 if (mount(NULL, "/run/initramfs", NULL, MS_PRIVATE, NULL) < 0) {
234 log_error("Failed to make /run/initramfs private mount: %m");
238 NULSTR_FOREACH(dir, dirs)
239 if (mkdir_p(dir, 0755) < 0 && errno != EEXIST) {
240 log_error("Failed to mkdir %s: %m", dir);
244 if (mount("/sys", "/run/initramfs/sys", NULL, MS_BIND, NULL) < 0) {
245 log_error("Failed to mount bind /sys on /run/initramfs/sys: %m");
249 if (mount("/proc", "/run/initramfs/proc", NULL, MS_BIND, NULL) < 0) {
250 log_error("Failed to mount bind /proc on /run/initramfs/proc: %m");
254 if (mount("/dev", "/run/initramfs/dev", NULL, MS_BIND, NULL) < 0) {
255 log_error("Failed to mount bind /dev on /run/initramfs/dev: %m");
259 if (mount("/run", "/run/initramfs/run", NULL, MS_BIND, NULL) < 0) {
260 log_error("Failed to mount bind /run on /run/initramfs/run: %m");
267 static int pivot_to_new_root(void) {
270 chdir("/run/initramfs");
273 In case some evil process made "/" MS_SHARED
274 It works for pivot_root, but the ref count for the root device
275 is not decreasing :-/
277 if (mount(NULL, "/", NULL, MS_PRIVATE, NULL) < 0) {
278 log_error("Failed to make \"/\" private mount %m");
282 if (pivot_root(".", "oldroot") < 0) {
283 log_error("pivot failed: %m");
284 /* only chroot if pivot root succeded */
289 log_info("Successfully changed into root pivot.");
291 fd = open("/dev/console", O_RDWR);
293 log_error("Failed to open /dev/console: %m");
297 /* Initialize the controlling terminal */
299 ioctl(STDIN_FILENO, TIOCSCTTY, NULL);
305 int main(int argc, char *argv[]) {
308 bool need_umount = true, need_swapoff = true, need_loop_detach = true, need_dm_detach = true;
309 bool killed_everbody = false, in_container;
311 log_parse_environment();
312 log_set_target(LOG_TARGET_CONSOLE); /* syslog will die if not gone yet */
318 log_error("Not executed by init (pid 1).");
324 log_error("Invalid number of arguments.");
329 in_container = detect_container(NULL) > 0;
331 if (streq(argv[1], "reboot"))
333 else if (streq(argv[1], "poweroff"))
335 else if (streq(argv[1], "halt"))
336 cmd = RB_HALT_SYSTEM;
337 else if (streq(argv[1], "kexec"))
338 cmd = LINUX_REBOOT_CMD_KEXEC;
340 log_error("Unknown action '%s'.", argv[1]);
345 /* lock us into memory */
346 if (mlockall(MCL_CURRENT|MCL_FUTURE) != 0)
347 log_warning("Cannot lock process memory: %m");
349 log_info("Sending SIGTERM to remaining processes...");
350 send_signal(SIGTERM);
352 log_info("Sending SIGKILL to remaining processes...");
353 send_signal(SIGKILL);
356 need_swapoff = false;
358 /* Unmount all mountpoints, swaps, and loopback devices */
359 for (retries = 0; retries < FINALIZE_ATTEMPTS; retries++) {
360 bool changed = false;
363 log_info("Unmounting file systems.");
364 r = umount_all(&changed);
368 log_info("Not all file systems unmounted, %d left.", r);
370 log_error("Failed to unmount file systems: %s", strerror(-r));
374 log_info("Disabling swaps.");
375 r = swapoff_all(&changed);
377 need_swapoff = false;
379 log_info("Not all swaps are turned off, %d left.", r);
381 log_error("Failed to turn off swaps: %s", strerror(-r));
384 if (need_loop_detach) {
385 log_info("Detaching loop devices.");
386 r = loopback_detach_all(&changed);
388 need_loop_detach = false;
390 log_info("Not all loop devices detached, %d left.", r);
392 log_error("Failed to detach loop devices: %s", strerror(-r));
395 if (need_dm_detach) {
396 log_info("Detaching DM devices.");
397 r = dm_detach_all(&changed);
399 need_dm_detach = false;
401 log_warning("Not all DM devices detached, %d left.", r);
403 log_error("Failed to detach DM devices: %s", strerror(-r));
406 if (!need_umount && !need_swapoff && !need_loop_detach && !need_dm_detach) {
408 log_info("All filesystems, swaps, loop devices, DM devices detached.");
413 /* If in this iteration we didn't manage to
414 * unmount/deactivate anything, we either kill more
415 * processes, or simply give up */
418 if (killed_everbody) {
419 /* Hmm, we already killed everybody,
420 * let's just give up */
421 log_error("Cannot finalize remaining file systems and devices, giving up.");
425 log_warning("Cannot finalize remaining file systems and devices, trying to kill remaining processes.");
426 ultimate_send_signal(SIGTERM);
427 ultimate_send_signal(SIGKILL);
428 killed_everbody = true;
431 log_debug("Couldn't finalize remaining file systems and devices after %u retries, trying again.", retries+1);
434 if (retries >= FINALIZE_ATTEMPTS)
435 log_error("Too many iterations, giving up.");
437 execute_directory(SYSTEM_SHUTDOWN_PATH, NULL, NULL);
439 /* If we are in a container, just exit, this will kill our
440 * container for good. */
442 log_error("Exiting container.");
446 if (access("/run/initramfs/shutdown", X_OK) == 0) {
448 if (prepare_new_root() >= 0 &&
449 pivot_to_new_root() >= 0) {
450 execv("/shutdown", argv);
451 log_error("Failed to execute shutdown binary: %m");
457 if (cmd == LINUX_REBOOT_CMD_KEXEC) {
458 /* We cheat and exec kexec to avoid doing all its work */
462 log_error("Could not fork: %m. Falling back to normal reboot.");
464 wait_for_terminate_and_warn("kexec", pid);
465 log_warning("kexec failed. Falling back to normal reboot.");
468 const char *args[3] = { "/sbin/kexec", "-e", NULL };
469 execv(args[0], (char * const *) args);
477 log_error("Failed to invoke reboot(): %m");
481 log_error("Critical error while doing system shutdown: %s", strerror(-r));