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git.ipfire.org Git - thirdparty/systemd.git/blob - src/core/killall.c
1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 This file is part of systemd.
5 Copyright 2010 ProFUSION embedded systems
13 #include "alloc-util.h"
15 #include "dirent-util.h"
17 #include "format-util.h"
19 #include "parse-util.h"
20 #include "process-util.h"
22 #include "string-util.h"
23 #include "terminal-util.h"
26 static bool ignore_proc(pid_t pid
, bool warn_rootfs
) {
27 _cleanup_fclose_
FILE *f
= NULL
;
34 /* We are PID 1, let's not commit suicide */
38 r
= get_process_uid(pid
, &uid
);
40 return true; /* not really, but better safe than sorry */
42 /* Non-root processes otherwise are always subject to be killed */
46 p
= procfs_file_alloca(pid
, "cmdline");
49 return true; /* not really, but has the desired effect */
51 count
= fread(&c
, 1, 1, f
);
53 /* Kernel threads have an empty cmdline */
57 /* Processes with argv[0][0] = '@' we ignore from the killing spree.
59 * http://www.freedesktop.org/wiki/Software/systemd/RootStorageDaemons */
64 pid_from_same_root_fs(pid
) == 0) {
66 _cleanup_free_
char *comm
= NULL
;
68 get_process_comm(pid
, &comm
);
70 log_notice("Process " PID_FMT
" (%s) has been marked to be excluded from killing. It is "
71 "running from the root file system, and thus likely to block re-mounting of the "
72 "root file system to read-only. Please consider moving it into an initrd file "
73 "system instead.", pid
, strna(comm
));
79 static void wait_for_children(Set
*pids
, sigset_t
*mask
, usec_t timeout
) {
84 if (set_isempty(pids
))
87 until
= now(CLOCK_MONOTONIC
) + timeout
;
95 /* First, let the kernel inform us about killed
96 * children. Most processes will probably be our
97 * children, but some are not (might be our
98 * grandchildren instead...). */
102 pid
= waitpid(-1, NULL
, WNOHANG
);
109 log_error_errno(errno
, "waitpid() failed: %m");
113 (void) set_remove(pids
, PID_TO_PTR(pid
));
116 /* Now explicitly check who might be remaining, who
117 * might not be our child. */
118 SET_FOREACH(p
, pids
, i
) {
120 /* kill(pid, 0) sends no signal, but it tells
121 * us whether the process still exists. */
122 if (kill(PTR_TO_PID(p
), 0) == 0)
131 if (set_isempty(pids
))
134 n
= now(CLOCK_MONOTONIC
);
138 timespec_store(&ts
, until
- n
);
139 k
= sigtimedwait(mask
, NULL
, &ts
);
142 if (k
< 0 && errno
!= EAGAIN
) {
143 log_error_errno(errno
, "sigtimedwait() failed: %m");
148 log_warning("sigtimedwait() returned unexpected signal.");
153 static int killall(int sig
, Set
*pids
, bool send_sighup
) {
154 _cleanup_closedir_
DIR *dir
= NULL
;
157 dir
= opendir("/proc");
161 FOREACH_DIRENT_ALL(d
, dir
, break) {
165 if (!IN_SET(d
->d_type
, DT_DIR
, DT_UNKNOWN
))
168 if (parse_pid(d
->d_name
, &pid
) < 0)
171 if (ignore_proc(pid
, sig
== SIGKILL
&& !in_initrd()))
174 if (sig
== SIGKILL
) {
175 _cleanup_free_
char *s
= NULL
;
177 get_process_comm(pid
, &s
);
178 log_notice("Sending SIGKILL to PID "PID_FMT
" (%s).", pid
, strna(s
));
181 if (kill(pid
, sig
) >= 0) {
183 r
= set_put(pids
, PID_TO_PTR(pid
));
187 } else if (errno
!= ENOENT
)
188 log_warning_errno(errno
, "Could not kill %d: %m", pid
);
191 /* Optionally, also send a SIGHUP signal, but
192 only if the process has a controlling
193 tty. This is useful to allow handling of
194 shells which ignore SIGTERM but react to
195 SIGHUP. We do not send this to processes that
196 have no controlling TTY since we don't want to
197 trigger reloads of daemon processes. Also we
198 make sure to only send this after SIGTERM so
199 that SIGTERM is always first in the queue. */
202 if (get_ctty_devnr(pid
, NULL
) >= 0)
203 /* it's OK if the process is gone, just ignore the result */
204 (void) kill(pid
, SIGHUP
);
208 return set_size(pids
);
211 void broadcast_signal(int sig
, bool wait_for_exit
, bool send_sighup
, usec_t timeout
) {
212 sigset_t mask
, oldmask
;
213 _cleanup_set_free_ Set
*pids
= NULL
;
216 pids
= set_new(NULL
);
218 assert_se(sigemptyset(&mask
) == 0);
219 assert_se(sigaddset(&mask
, SIGCHLD
) == 0);
220 assert_se(sigprocmask(SIG_BLOCK
, &mask
, &oldmask
) == 0);
222 if (kill(-1, SIGSTOP
) < 0 && errno
!= ESRCH
)
223 log_warning_errno(errno
, "kill(-1, SIGSTOP) failed: %m");
225 killall(sig
, pids
, send_sighup
);
227 if (kill(-1, SIGCONT
) < 0 && errno
!= ESRCH
)
228 log_warning_errno(errno
, "kill(-1, SIGCONT) failed: %m");
231 wait_for_children(pids
, &mask
, timeout
);
233 assert_se(sigprocmask(SIG_SETMASK
, &oldmask
, NULL
) == 0);