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 Lesser General Public License as published by
10 the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
18 You should have received a copy of the GNU Lesser General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
31 #define TIMEOUT_USEC (10 * USEC_PER_SEC)
33 static bool ignore_proc(pid_t pid) {
34 _cleanup_fclose_ FILE *f = NULL;
41 /* We are PID 1, let's not commit suicide */
45 r = get_process_uid(pid, &uid);
47 return true; /* not really, but better safe than sorry */
49 /* Non-root processes otherwise are always subject to be killed */
53 p = procfs_file_alloca(pid, "cmdline");
56 return true; /* not really, but has the desired effect */
58 count = fread(&c, 1, 1, f);
60 /* Kernel threads have an empty cmdline */
64 /* Processes with argv[0][0] = '@' we ignore from the killing
67 * http://www.freedesktop.org/wiki/Software/systemd/RootStorageDaemons */
68 if (count == 1 && c == '@')
74 static void wait_for_children(Set *pids, sigset_t *mask) {
79 if (set_isempty(pids))
82 until = now(CLOCK_MONOTONIC) + TIMEOUT_USEC;
90 /* First, let the kernel inform us about killed
91 * children. Most processes will probably be our
92 * children, but some are not (might be our
93 * grandchildren instead...). */
97 pid = waitpid(-1, NULL, WNOHANG);
104 log_error_errno(errno, "waitpid() failed: %m");
108 set_remove(pids, ULONG_TO_PTR(pid));
111 /* Now explicitly check who might be remaining, who
112 * might not be our child. */
113 SET_FOREACH(p, pids, i) {
115 /* We misuse getpgid as a check whether a
116 * process still exists. */
117 if (getpgid((pid_t) PTR_TO_ULONG(p)) >= 0)
126 if (set_isempty(pids))
129 n = now(CLOCK_MONOTONIC);
133 timespec_store(&ts, until - n);
134 k = sigtimedwait(mask, NULL, &ts);
137 if (k < 0 && errno != EAGAIN) {
138 log_error_errno(errno, "sigtimedwait() failed: %m");
143 log_warning("sigtimedwait() returned unexpected signal.");
148 static int killall(int sig, Set *pids, bool send_sighup) {
149 _cleanup_closedir_ DIR *dir = NULL;
152 dir = opendir("/proc");
156 while ((d = readdir(dir))) {
159 if (d->d_type != DT_DIR &&
160 d->d_type != DT_UNKNOWN)
163 if (parse_pid(d->d_name, &pid) < 0)
166 if (ignore_proc(pid))
169 if (sig == SIGKILL) {
170 _cleanup_free_ char *s = NULL;
172 get_process_comm(pid, &s);
173 log_notice("Sending SIGKILL to PID "PID_FMT" (%s).", pid, strna(s));
176 if (kill(pid, sig) >= 0) {
178 set_put(pids, ULONG_TO_PTR(pid));
179 } else if (errno != ENOENT)
180 log_warning_errno(errno, "Could not kill %d: %m", pid);
183 /* Optionally, also send a SIGHUP signal, but
184 only if the process has a controlling
185 tty. This is useful to allow handling of
186 shells which ignore SIGTERM but react to
187 SIGHUP. We do not send this to processes that
188 have no controlling TTY since we don't want to
189 trigger reloads of daemon processes. Also we
190 make sure to only send this after SIGTERM so
191 that SIGTERM is always first in the queue. */
194 if (get_ctty_devnr(pid, NULL) >= 0)
199 return set_size(pids);
202 void broadcast_signal(int sig, bool wait_for_exit, bool send_sighup) {
203 sigset_t mask, oldmask;
204 _cleanup_set_free_ Set *pids = NULL;
207 pids = set_new(NULL);
209 assert_se(sigemptyset(&mask) == 0);
210 assert_se(sigaddset(&mask, SIGCHLD) == 0);
211 assert_se(sigprocmask(SIG_BLOCK, &mask, &oldmask) == 0);
213 if (kill(-1, SIGSTOP) < 0 && errno != ESRCH)
214 log_warning_errno(errno, "kill(-1, SIGSTOP) failed: %m");
216 killall(sig, pids, send_sighup);
218 if (kill(-1, SIGCONT) < 0 && errno != ESRCH)
219 log_warning_errno(errno, "kill(-1, SIGCONT) failed: %m");
222 wait_for_children(pids, &mask);
224 assert_se(sigprocmask(SIG_SETMASK, &oldmask, NULL) == 0);