+++ /dev/null
-/* SPDX-License-Identifier: LGPL-2.1-or-later */
-/***
- Copyright © 2010 ProFUSION embedded systems
-***/
-
-#include <errno.h>
-#include <signal.h>
-#include <sys/wait.h>
-#include <unistd.h>
-
-#include "alloc-util.h"
-#include "def.h"
-#include "dirent-util.h"
-#include "fd-util.h"
-#include "format-util.h"
-#include "killall.h"
-#include "parse-util.h"
-#include "process-util.h"
-#include "set.h"
-#include "string-util.h"
-#include "terminal-util.h"
-#include "util.h"
-
-static bool ignore_proc(pid_t pid, bool warn_rootfs) {
- _cleanup_fclose_ FILE *f = NULL;
- const char *p;
- char c = 0;
- uid_t uid;
- int r;
-
- /* We are PID 1, let's not commit suicide */
- if (pid <= 1)
- return true;
-
- /* Ignore kernel threads */
- r = is_kernel_thread(pid);
- if (r != 0)
- return true; /* also ignore processes where we can't determine this */
-
- 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;
-
- p = procfs_file_alloca(pid, "cmdline");
- f = fopen(p, "re");
- if (!f)
- return true; /* not really, but has the desired effect */
-
- /* Try to read the first character of the command line. If the cmdline is empty (which might be the case for
- * kernel threads but potentially also other stuff), this line won't do anything, but we don't care much, as
- * actual kernel threads are already filtered out above. */
- (void) fread(&c, 1, 1, f);
-
- /* Processes with argv[0][0] = '@' we ignore from the killing spree.
- *
- * https://systemd.io/ROOT_STORAGE_DAEMONS */
- if (c != '@')
- return false;
-
- if (warn_rootfs &&
- pid_from_same_root_fs(pid) == 0) {
-
- _cleanup_free_ char *comm = NULL;
-
- (void) get_process_comm(pid, &comm);
-
- log_notice("Process " PID_FMT " (%s) has been marked to be excluded from killing. It is "
- "running from the root file system, and thus likely to block re-mounting of the "
- "root file system to read-only. Please consider moving it into an initrd file "
- "system instead.", pid, strna(comm));
- }
-
- return true;
-}
-
-static void log_children_no_yet_killed(Set *pids) {
- _cleanup_free_ char *lst_child = NULL;
- void *p;
-
- SET_FOREACH(p, pids) {
- _cleanup_free_ char *s = NULL;
-
- if (get_process_comm(PTR_TO_PID(p), &s) < 0)
- (void) asprintf(&s, PID_FMT, PTR_TO_PID(p));
-
- if (!strextend(&lst_child, ", ", s)) {
- log_oom();
- return;
- }
- }
-
- if (isempty(lst_child))
- return;
-
- log_warning("Waiting for process: %s", lst_child + 2);
-}
-
-static int wait_for_children(Set *pids, sigset_t *mask, usec_t timeout) {
- usec_t until, date_log_child, n;
-
- assert(mask);
-
- /* Return the number of children remaining in the pids set: That correspond to the number
- * of processes still "alive" after the timeout */
-
- if (set_isempty(pids))
- return 0;
-
- n = now(CLOCK_MONOTONIC);
- until = usec_add(n, timeout);
- date_log_child = usec_add(n, 10u * USEC_PER_SEC);
- if (date_log_child > until)
- date_log_child = usec_add(n, timeout / 2u);
-
- for (;;) {
- struct timespec ts;
- int k;
- void *p;
-
- /* First, let the kernel inform us about killed
- * children. Most processes will probably be our
- * children, but some are not (might be our
- * grandchildren instead...). */
- for (;;) {
- pid_t pid;
-
- pid = waitpid(-1, NULL, WNOHANG);
- if (pid == 0)
- break;
- if (pid < 0) {
- if (errno == ECHILD)
- break;
-
- return log_error_errno(errno, "waitpid() failed: %m");
- }
-
- (void) set_remove(pids, PID_TO_PTR(pid));
- }
-
- /* Now explicitly check who might be remaining, who
- * might not be our child. */
- SET_FOREACH(p, pids) {
-
- /* kill(pid, 0) sends no signal, but it tells
- * us whether the process still exists. */
- if (kill(PTR_TO_PID(p), 0) == 0)
- continue;
-
- if (errno != ESRCH)
- continue;
-
- set_remove(pids, p);
- }
-
- if (set_isempty(pids))
- return 0;
-
- n = now(CLOCK_MONOTONIC);
- if (date_log_child > 0 && n >= date_log_child) {
- log_children_no_yet_killed(pids);
- /* Log the children not yet killed only once */
- date_log_child = 0;
- }
-
- if (n >= until)
- return set_size(pids);
-
- if (date_log_child > 0)
- timespec_store(&ts, MIN(until - n, date_log_child - n));
- else
- timespec_store(&ts, until - n);
-
- k = sigtimedwait(mask, NULL, &ts);
- if (k != SIGCHLD) {
-
- if (k < 0 && errno != EAGAIN)
- return log_error_errno(errno, "sigtimedwait() failed: %m");
-
- if (k >= 0)
- log_warning("sigtimedwait() returned unexpected signal.");
- }
- }
-}
-
-static int killall(int sig, Set *pids, bool send_sighup) {
- _cleanup_closedir_ DIR *dir = NULL;
- struct dirent *d;
- int n_killed = 0;
-
- /* Send the specified signal to all remaining processes, if not excluded by ignore_proc().
- * Returns the number of processes to which the specified signal was sent */
-
- dir = opendir("/proc");
- if (!dir)
- return log_warning_errno(errno, "opendir(/proc) failed: %m");
-
- FOREACH_DIRENT_ALL(d, dir, break) {
- pid_t pid;
- int r;
-
- if (!IN_SET(d->d_type, DT_DIR, DT_UNKNOWN))
- continue;
-
- if (parse_pid(d->d_name, &pid) < 0)
- continue;
-
- if (ignore_proc(pid, sig == SIGKILL && !in_initrd()))
- continue;
-
- if (sig == SIGKILL) {
- _cleanup_free_ char *s = NULL;
-
- (void) get_process_comm(pid, &s);
- log_notice("Sending SIGKILL to PID "PID_FMT" (%s).", pid, strna(s));
- }
-
- if (kill(pid, sig) >= 0) {
- n_killed++;
- if (pids) {
- r = set_put(pids, PID_TO_PTR(pid));
- if (r < 0)
- log_oom();
- }
- } else if (errno != ENOENT)
- log_warning_errno(errno, "Could not kill %d: %m", pid);
-
- if (send_sighup) {
- /* Optionally, also send a SIGHUP signal, but
- only if the process has a controlling
- tty. This is useful to allow handling of
- shells which ignore SIGTERM but react to
- SIGHUP. We do not send this to processes that
- have no controlling TTY since we don't want to
- trigger reloads of daemon processes. Also we
- make sure to only send this after SIGTERM so
- that SIGTERM is always first in the queue. */
-
- if (get_ctty_devnr(pid, NULL) >= 0)
- /* it's OK if the process is gone, just ignore the result */
- (void) kill(pid, SIGHUP);
- }
- }
-
- return n_killed;
-}
-
-int broadcast_signal(int sig, bool wait_for_exit, bool send_sighup, usec_t timeout) {
- int n_children_left;
- sigset_t mask, oldmask;
- _cleanup_set_free_ Set *pids = NULL;
-
- /* Send the specified signal to all remaining processes, if not excluded by ignore_proc().
- * Return:
- * - The number of processes still "alive" after the timeout (that should have been killed)
- * if the function needs to wait for the end of the processes (wait_for_exit).
- * - Otherwise, the number of processes to which the specified signal was sent */
-
- if (wait_for_exit)
- pids = set_new(NULL);
-
- 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_errno(errno, "kill(-1, SIGSTOP) failed: %m");
-
- n_children_left = killall(sig, pids, send_sighup);
-
- if (kill(-1, SIGCONT) < 0 && errno != ESRCH)
- log_warning_errno(errno, "kill(-1, SIGCONT) failed: %m");
-
- if (wait_for_exit && n_children_left > 0)
- n_children_left = wait_for_children(pids, &mask, timeout);
-
- assert_se(sigprocmask(SIG_SETMASK, &oldmask, NULL) == 0);
-
- return n_children_left;
-}
projects / thirdparty / systemd.git / blobdiff