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/>.
30 #define TIMEOUT_USEC (5 * USEC_PER_SEC)
32 static bool ignore_proc(pid_t pid) {
40 /* We are PID 1, let's not commit suicide */
44 r = get_process_uid(pid, &uid);
46 return true; /* not really, but better safe than sorry */
48 /* Non-root processes otherwise are always subject to be killed */
52 snprintf(buf, sizeof(buf), "/proc/%lu/cmdline", (unsigned long) pid);
57 return true; /* not really, but has the desired effect */
59 count = fread(&c, 1, 1, f);
62 /* Kernel threads have an empty cmdline */
66 /* Processes with argv[0][0] = '@' we ignore from the killing
69 * http://www.freedesktop.org/wiki/Software/systemd/RootStorageDaemons */
70 if (count == 1 && c == '@')
76 static void wait_for_children(int n_processes, sigset_t *mask) {
81 until = now(CLOCK_MONOTONIC) + TIMEOUT_USEC;
88 pid_t pid = waitpid(-1, NULL, WNOHANG);
93 if (pid < 0 && errno == ECHILD)
97 if (--n_processes == 0)
101 n = now(CLOCK_MONOTONIC);
105 timespec_store(&ts, until - n);
107 if ((k = sigtimedwait(mask, NULL, &ts)) != SIGCHLD) {
109 if (k < 0 && errno != EAGAIN) {
110 log_error("sigtimedwait() failed: %m");
115 log_warning("sigtimedwait() returned unexpected signal.");
120 static int killall(int sig) {
123 unsigned int n_processes = 0;
125 dir = opendir("/proc");
129 while ((d = readdir(dir))) {
132 if (d->d_type != DT_DIR &&
133 d->d_type != DT_UNKNOWN)
136 if (parse_pid(d->d_name, &pid) < 0)
139 if (ignore_proc(pid))
142 if (sig == SIGKILL) {
143 _cleanup_free_ char *s;
145 get_process_comm(pid, &s);
146 log_notice("Sending SIGKILL to PID %lu (%s)", (unsigned long) pid, strna(s));
149 if (kill(pid, sig) >= 0)
151 else if (errno != ENOENT)
152 log_warning("Could not kill %d: %m", pid);
160 void broadcast_signal(int sig, bool wait_for_exit) {
161 sigset_t mask, oldmask;
164 assert_se(sigemptyset(&mask) == 0);
165 assert_se(sigaddset(&mask, SIGCHLD) == 0);
166 assert_se(sigprocmask(SIG_BLOCK, &mask, &oldmask) == 0);
168 if (kill(-1, SIGSTOP) < 0 && errno != ESRCH)
169 log_warning("kill(-1, SIGSTOP) failed: %m");
171 n_processes = killall(sig);
173 if (kill(-1, SIGCONT) < 0 && errno != ESRCH)
174 log_warning("kill(-1, SIGCONT) failed: %m");
176 if (n_processes <= 0)
180 wait_for_children(n_processes, &mask);
183 sigprocmask(SIG_SETMASK, &oldmask, NULL);