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/>.
32 #define TIMEOUT_USEC (10 * USEC_PER_SEC)
34 static bool ignore_proc(pid_t pid) {
35 _cleanup_fclose_ FILE *f = NULL;
42 /* We are PID 1, let's not commit suicide */
46 r = get_process_uid(pid, &uid);
48 return true; /* not really, but better safe than sorry */
50 /* Non-root processes otherwise are always subject to be killed */
54 p = procfs_file_alloca(pid, "cmdline");
57 return true; /* not really, but has the desired effect */
59 count = fread(&c, 1, 1, f);
61 /* Kernel threads have an empty cmdline */
65 /* Processes with argv[0][0] = '@' we ignore from the killing
68 * http://www.freedesktop.org/wiki/Software/systemd/RootStorageDaemons */
69 if (count == 1 && c == '@')
75 static void wait_for_children(Set *pids, sigset_t *mask) {
80 if (set_isempty(pids))
83 until = now(CLOCK_MONOTONIC) + TIMEOUT_USEC;
91 /* First, let the kernel inform us about killed
92 * children. Most processes will probably be our
93 * children, but some are not (might be our
94 * grandchildren instead...). */
98 pid = waitpid(-1, NULL, WNOHANG);
105 log_error("waitpid() failed: %m");
109 set_remove(pids, ULONG_TO_PTR(pid));
112 /* Now explicitly check who might be remaining, who
113 * might not be our child. */
114 SET_FOREACH(p, pids, i) {
116 /* We misuse getpgid as a check whether a
117 * process still exists. */
118 if (getpgid((pid_t) PTR_TO_ULONG(p)) >= 0)
127 if (set_isempty(pids))
130 n = now(CLOCK_MONOTONIC);
134 timespec_store(&ts, until - n);
135 k = sigtimedwait(mask, NULL, &ts);
138 if (k < 0 && errno != EAGAIN) {
139 log_error("sigtimedwait() failed: %m");
144 log_warning("sigtimedwait() returned unexpected signal.");
149 static int killall(int sig, Set *pids, bool send_sighup) {
150 _cleanup_closedir_ DIR *dir = NULL;
153 dir = opendir("/proc");
157 while ((d = readdir(dir))) {
160 if (d->d_type != DT_DIR &&
161 d->d_type != DT_UNKNOWN)
164 if (parse_pid(d->d_name, &pid) < 0)
167 if (ignore_proc(pid))
170 if (sig == SIGKILL) {
171 _cleanup_free_ char *s = NULL;
173 get_process_comm(pid, &s);
174 log_notice("Sending SIGKILL to PID "PID_FMT" (%s).", pid, strna(s));
177 if (kill(pid, sig) >= 0) {
179 set_put(pids, ULONG_TO_PTR(pid));
180 } else if (errno != ENOENT)
181 log_warning("Could not kill %d: %m", pid);
184 /* Optionally, also send a SIGHUP signal, but
185 only if the process has a controlling
186 tty. This is useful to allow handling of
187 shells which ignore SIGTERM but react to
188 SIGHUP. We do not send this to processes that
189 have no controlling TTY since we don't want to
190 trigger reloads of daemon processes. Also we
191 make sure to only send this after SIGTERM so
192 that SIGTERM is always first in the queue. */
195 if (get_ctty_devnr(pid, NULL) >= 0)
200 return set_size(pids);
203 void broadcast_signal(int sig, bool wait_for_exit, bool send_sighup) {
204 sigset_t mask, oldmask;
208 pids = set_new(trivial_hash_func, trivial_compare_func);
210 assert_se(sigemptyset(&mask) == 0);
211 assert_se(sigaddset(&mask, SIGCHLD) == 0);
212 assert_se(sigprocmask(SIG_BLOCK, &mask, &oldmask) == 0);
214 if (kill(-1, SIGSTOP) < 0 && errno != ESRCH)
215 log_warning("kill(-1, SIGSTOP) failed: %m");
217 killall(sig, pids, send_sighup);
219 if (kill(-1, SIGCONT) < 0 && errno != ESRCH)
220 log_warning("kill(-1, SIGCONT) failed: %m");
223 wait_for_children(pids, &mask);
225 assert_se(sigprocmask(SIG_SETMASK, &oldmask, NULL) == 0);