-static bool ignore_proc(pid_t pid) {
- char buf[PATH_MAX];
- FILE *f;
- char c;
- size_t count;
- uid_t uid;
- int r;
-
- /* We are PID 1, let's not commit suicide */
- if (pid == 1)
- return true;
-
- r = get_process_uid(pid, &uid);
- if (r < 0)
- return true; /* not really, but better safe than sorry */
-
- /* Non-root processes otherwise are always subject to be killed */
- if (uid != 0)
- return false;
-
- snprintf(buf, sizeof(buf), "/proc/%lu/cmdline", (unsigned long) pid);
- char_array_0(buf);
-
- f = fopen(buf, "re");
- if (!f)
- return true; /* not really, but has the desired effect */
-
- count = fread(&c, 1, 1, f);
- fclose(f);
-
- /* Kernel threads have an empty cmdline */
- if (count <= 0)
- return true;
-
- /* Processes with argv[0][0] = '@' we ignore from the killing
- * spree.
- *
- * http://www.freedesktop.org/wiki/Software/systemd/RootStorageDaemons */
- if (count == 1 && c == '@')
- return true;
-
- return false;
-}
-
-static int killall(int sign) {
- DIR *dir;
- struct dirent *d;
- unsigned int n_processes = 0;
-
- dir = opendir("/proc");
- if (!dir)
- return -errno;
-
- while ((d = readdir(dir))) {
- pid_t pid;
-
- if (parse_pid(d->d_name, &pid) < 0)
- continue;
-
- if (ignore_proc(pid))
- continue;
-
- if (kill(pid, sign) == 0)
- n_processes++;
- else
- log_warning("Could not kill %d: %m", pid);
- }
-
- closedir(dir);
-
- return n_processes;
-}
-
-static void wait_for_children(int n_processes, sigset_t *mask) {
- usec_t until;
-
- assert(mask);
-
- until = now(CLOCK_MONOTONIC) + TIMEOUT_USEC;
- for (;;) {
- struct timespec ts;
- int k;
- usec_t n;
-
- for (;;) {
- pid_t pid = waitpid(-1, NULL, WNOHANG);
-
- if (pid == 0)
- break;
-
- if (pid < 0 && errno == ECHILD)
- return;
-
- if (n_processes > 0)
- if (--n_processes == 0)
- return;
- }
-
- n = now(CLOCK_MONOTONIC);
- if (n >= until)
- return;
-
- timespec_store(&ts, until - n);
-
- if ((k = sigtimedwait(mask, NULL, &ts)) != SIGCHLD) {
-
- if (k < 0 && errno != EAGAIN) {
- log_error("sigtimedwait() failed: %m");
- return;
- }
-
- if (k >= 0)
- log_warning("sigtimedwait() returned unexpected signal.");
- }
- }
-}
-
-static void send_signal(int sign) {
- sigset_t mask, oldmask;
- int n_processes;
-
- assert_se(sigemptyset(&mask) == 0);
- assert_se(sigaddset(&mask, SIGCHLD) == 0);
- assert_se(sigprocmask(SIG_BLOCK, &mask, &oldmask) == 0);
-
- if (kill(-1, SIGSTOP) < 0 && errno != ESRCH)
- log_warning("kill(-1, SIGSTOP) failed: %m");
-
- n_processes = killall(sign);
-
- if (kill(-1, SIGCONT) < 0 && errno != ESRCH)
- log_warning("kill(-1, SIGCONT) failed: %m");
-
- if (n_processes <= 0)
- goto finish;
-
- wait_for_children(n_processes, &mask);
-
-finish:
- sigprocmask(SIG_SETMASK, &oldmask, NULL);
-}
-
-static void ultimate_send_signal(int sign) {
- sigset_t mask, oldmask;
- int r;
-
- assert_se(sigemptyset(&mask) == 0);
- assert_se(sigaddset(&mask, SIGCHLD) == 0);
- assert_se(sigprocmask(SIG_BLOCK, &mask, &oldmask) == 0);
-
- if (kill(-1, SIGSTOP) < 0 && errno != ESRCH)
- log_warning("kill(-1, SIGSTOP) failed: %m");
-
- r = kill(-1, sign);
- if (r < 0 && errno != ESRCH)
- log_warning("kill(-1, %s) failed: %m", signal_to_string(sign));
-
- if (kill(-1, SIGCONT) < 0 && errno != ESRCH)
- log_warning("kill(-1, SIGCONT) failed: %m");
-
- if (r < 0)
- goto finish;
-
- wait_for_children(0, &mask);
-
-finish:
- sigprocmask(SIG_SETMASK, &oldmask, NULL);
-}
-