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
85 if (count == 1 && c == '@')
91 static int killall(int sign) {
94 unsigned int n_processes = 0;
96 dir = opendir("/proc");
100 while ((d = readdir(dir))) {
103 if (parse_pid(d->d_name, &pid) < 0)
106 if (ignore_proc(pid))
109 if (kill(pid, sign) == 0)
112 log_warning("Could not kill %d: %m", pid);
120 static void wait_for_children(int n_processes, sigset_t *mask) {
125 until = now(CLOCK_MONOTONIC) + TIMEOUT_USEC;
132 pid_t pid = waitpid(-1, NULL, WNOHANG);
137 if (pid < 0 && errno == ECHILD)
141 if (--n_processes == 0)
145 n = now(CLOCK_MONOTONIC);
149 timespec_store(&ts, until - n);
151 if ((k = sigtimedwait(mask, NULL, &ts)) != SIGCHLD) {
153 if (k < 0 && errno != EAGAIN) {
154 log_error("sigtimedwait() failed: %m");
159 log_warning("sigtimedwait() returned unexpected signal.");
164 static void send_signal(int sign) {
165 sigset_t mask, oldmask;
168 assert_se(sigemptyset(&mask) == 0);
169 assert_se(sigaddset(&mask, SIGCHLD) == 0);
170 assert_se(sigprocmask(SIG_BLOCK, &mask, &oldmask) == 0);
172 if (kill(-1, SIGSTOP) < 0 && errno != ESRCH)
173 log_warning("kill(-1, SIGSTOP) failed: %m");
175 n_processes = killall(sign);
177 if (kill(-1, SIGCONT) < 0 && errno != ESRCH)
178 log_warning("kill(-1, SIGCONT) failed: %m");
180 if (n_processes <= 0)
183 wait_for_children(n_processes, &mask);
186 sigprocmask(SIG_SETMASK, &oldmask, NULL);
189 static void ultimate_send_signal(int sign) {
190 sigset_t mask, oldmask;
193 assert_se(sigemptyset(&mask) == 0);
194 assert_se(sigaddset(&mask, SIGCHLD) == 0);
195 assert_se(sigprocmask(SIG_BLOCK, &mask, &oldmask) == 0);
197 if (kill(-1, SIGSTOP) < 0 && errno != ESRCH)
198 log_warning("kill(-1, SIGSTOP) failed: %m");
201 if (r < 0 && errno != ESRCH)
202 log_warning("kill(-1, %s) failed: %m", signal_to_string(sign));
204 if (kill(-1, SIGCONT) < 0 && errno != ESRCH)
205 log_warning("kill(-1, SIGCONT) failed: %m");
210 wait_for_children(0, &mask);
213 sigprocmask(SIG_SETMASK, &oldmask, NULL);
216 static int prepare_new_root(void) {
217 static const char dirs[] =
218 "/run/initramfs/oldroot\0"
219 "/run/initramfs/proc\0"
220 "/run/initramfs/sys\0"
221 "/run/initramfs/dev\0"
222 "/run/initramfs/run\0";
226 if (mount("/run/initramfs", "/run/initramfs", NULL, MS_BIND, NULL) < 0) {
227 log_error("Failed to mount bind /run/initramfs on /run/initramfs: %m");
231 if (mount(NULL, "/run/initramfs", NULL, MS_PRIVATE, NULL) < 0) {
232 log_error("Failed to make /run/initramfs private mount: %m");
236 NULSTR_FOREACH(dir, dirs)
237 if (mkdir_p(dir, 0755) < 0 && errno != EEXIST) {
238 log_error("Failed to mkdir %s: %m", dir);
242 if (mount("/sys", "/run/initramfs/sys", NULL, MS_BIND, NULL) < 0) {
243 log_error("Failed to mount bind /sys on /run/initramfs/sys: %m");
247 if (mount("/proc", "/run/initramfs/proc", NULL, MS_BIND, NULL) < 0) {
248 log_error("Failed to mount bind /proc on /run/initramfs/proc: %m");
252 if (mount("/dev", "/run/initramfs/dev", NULL, MS_BIND, NULL) < 0) {
253 log_error("Failed to mount bind /dev on /run/initramfs/dev: %m");
257 if (mount("/run", "/run/initramfs/run", NULL, MS_BIND, NULL) < 0) {
258 log_error("Failed to mount bind /run on /run/initramfs/run: %m");
265 static int pivot_to_new_root(void) {
268 chdir("/run/initramfs");
271 In case some evil process made "/" MS_SHARED
272 It works for pivot_root, but the ref count for the root device
273 is not decreasing :-/
275 if (mount(NULL, "/", NULL, MS_PRIVATE, NULL) < 0) {
276 log_error("Failed to make \"/\" private mount %m");
280 if (pivot_root(".", "oldroot") < 0) {
281 log_error("pivot failed: %m");
282 /* only chroot if pivot root succeded */
287 log_info("Successfully changed into root pivot.");
289 fd = open("/dev/console", O_RDWR);
291 log_error("Failed to open /dev/console: %m");
295 /* Initialize the controlling terminal */
297 ioctl(STDIN_FILENO, TIOCSCTTY, NULL);
303 int main(int argc, char *argv[]) {
306 bool need_umount = true, need_swapoff = true, need_loop_detach = true, need_dm_detach = true;
307 bool killed_everbody = false, in_container;
309 log_parse_environment();
310 log_set_target(LOG_TARGET_CONSOLE); /* syslog will die if not gone yet */
316 log_error("Not executed by init (pid 1).");
322 log_error("Invalid number of arguments.");
327 in_container = detect_container(NULL) > 0;
329 if (streq(argv[1], "reboot"))
331 else if (streq(argv[1], "poweroff"))
333 else if (streq(argv[1], "halt"))
334 cmd = RB_HALT_SYSTEM;
335 else if (streq(argv[1], "kexec"))
336 cmd = LINUX_REBOOT_CMD_KEXEC;
338 log_error("Unknown action '%s'.", argv[1]);
343 /* lock us into memory */
344 if (mlockall(MCL_CURRENT|MCL_FUTURE) != 0)
345 log_warning("Cannot lock process memory: %m");
347 log_info("Sending SIGTERM to remaining processes...");
348 send_signal(SIGTERM);
350 log_info("Sending SIGKILL to remaining processes...");
351 send_signal(SIGKILL);
354 need_swapoff = false;
356 /* Unmount all mountpoints, swaps, and loopback devices */
357 for (retries = 0; retries < FINALIZE_ATTEMPTS; retries++) {
358 bool changed = false;
361 log_info("Unmounting file systems.");
362 r = umount_all(&changed);
366 log_info("Not all file systems unmounted, %d left.", r);
368 log_error("Failed to unmount file systems: %s", strerror(-r));
372 log_info("Disabling swaps.");
373 r = swapoff_all(&changed);
375 need_swapoff = false;
377 log_info("Not all swaps are turned off, %d left.", r);
379 log_error("Failed to turn off swaps: %s", strerror(-r));
382 if (need_loop_detach) {
383 log_info("Detaching loop devices.");
384 r = loopback_detach_all(&changed);
386 need_loop_detach = false;
388 log_info("Not all loop devices detached, %d left.", r);
390 log_error("Failed to detach loop devices: %s", strerror(-r));
393 if (need_dm_detach) {
394 log_info("Detaching DM devices.");
395 r = dm_detach_all(&changed);
397 need_dm_detach = false;
399 log_warning("Not all DM devices detached, %d left.", r);
401 log_error("Failed to detach DM devices: %s", strerror(-r));
404 if (!need_umount && !need_swapoff && !need_loop_detach && !need_dm_detach) {
406 log_info("All filesystems, swaps, loop devices, DM devices detached.");
411 /* If in this iteration we didn't manage to
412 * unmount/deactivate anything, we either kill more
413 * processes, or simply give up */
416 if (killed_everbody) {
417 /* Hmm, we already killed everybody,
418 * let's just give up */
419 log_error("Cannot finalize remaining file systems and devices, giving up.");
423 log_warning("Cannot finalize remaining file systems and devices, trying to kill remaining processes.");
424 ultimate_send_signal(SIGTERM);
425 ultimate_send_signal(SIGKILL);
426 killed_everbody = true;
429 log_debug("Couldn't finalize remaining file systems and devices after %u retries, trying again.", retries+1);
432 if (retries >= FINALIZE_ATTEMPTS)
433 log_error("Too many iterations, giving up.");
435 execute_directory(SYSTEM_SHUTDOWN_PATH, NULL, NULL);
437 /* If we are in a container, just exit, this will kill our
438 * container for good. */
440 log_error("Exiting container.");
444 if (access("/run/initramfs/shutdown", X_OK) == 0) {
446 if (prepare_new_root() >= 0 &&
447 pivot_to_new_root() >= 0) {
448 execv("/shutdown", argv);
449 log_error("Failed to execute shutdown binary: %m");
455 if (cmd == LINUX_REBOOT_CMD_KEXEC) {
456 /* We cheat and exec kexec to avoid doing all its work */
460 log_error("Could not fork: %m. Falling back to normal reboot.");
462 wait_for_terminate_and_warn("kexec", pid);
463 log_warning("kexec failed. Falling back to normal reboot.");
466 const char *args[3] = { "/sbin/kexec", "-e", NULL };
467 execv(args[0], (char * const *) args);
475 log_error("Failed to invoke reboot(): %m");
479 log_error("Critical error while doing system shutdown: %s", strerror(-r));