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bd3fa1d2 LP |
1 | /*** |
2 | This file is part of systemd. | |
3 | ||
4 | Copyright 2010 ProFUSION embedded systems | |
5 | ||
6 | systemd is free software; you can redistribute it and/or modify it | |
7 | under the terms of the GNU Lesser General Public License as published by | |
8 | the Free Software Foundation; either version 2.1 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | systemd is distributed in the hope that it will be useful, but | |
12 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Lesser General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Lesser General Public License | |
17 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
18 | ***/ | |
19 | ||
bd3fa1d2 | 20 | #include <errno.h> |
07630cea LP |
21 | #include <signal.h> |
22 | #include <sys/wait.h> | |
aaf7eb81 | 23 | #include <unistd.h> |
bd3fa1d2 | 24 | |
b5efdb8a | 25 | #include "alloc-util.h" |
d4506129 | 26 | #include "def.h" |
3ffd4af2 | 27 | #include "fd-util.h" |
f97b34a6 | 28 | #include "format-util.h" |
3ffd4af2 | 29 | #include "killall.h" |
6bedfcbb | 30 | #include "parse-util.h" |
0b452006 | 31 | #include "process-util.h" |
07630cea LP |
32 | #include "set.h" |
33 | #include "string-util.h" | |
288a74cc | 34 | #include "terminal-util.h" |
07630cea | 35 | #include "util.h" |
bd3fa1d2 | 36 | |
1359fffa | 37 | static bool ignore_proc(pid_t pid, bool warn_rootfs) { |
31885cd5 | 38 | _cleanup_fclose_ FILE *f = NULL; |
b68fa010 SP |
39 | char c; |
40 | const char *p; | |
bd3fa1d2 LP |
41 | size_t count; |
42 | uid_t uid; | |
43 | int r; | |
44 | ||
45 | /* We are PID 1, let's not commit suicide */ | |
46 | if (pid == 1) | |
47 | return true; | |
48 | ||
49 | r = get_process_uid(pid, &uid); | |
50 | if (r < 0) | |
51 | return true; /* not really, but better safe than sorry */ | |
52 | ||
53 | /* Non-root processes otherwise are always subject to be killed */ | |
54 | if (uid != 0) | |
55 | return false; | |
56 | ||
5841bd80 ZJS |
57 | p = procfs_file_alloca(pid, "cmdline"); |
58 | f = fopen(p, "re"); | |
bd3fa1d2 LP |
59 | if (!f) |
60 | return true; /* not really, but has the desired effect */ | |
61 | ||
62 | count = fread(&c, 1, 1, f); | |
bd3fa1d2 LP |
63 | |
64 | /* Kernel threads have an empty cmdline */ | |
65 | if (count <= 0) | |
66 | return true; | |
67 | ||
68 | /* Processes with argv[0][0] = '@' we ignore from the killing | |
69 | * spree. | |
70 | * | |
71 | * http://www.freedesktop.org/wiki/Software/systemd/RootStorageDaemons */ | |
1359fffa MS |
72 | if (c == '@' && warn_rootfs) { |
73 | _cleanup_free_ char *comm = NULL; | |
74 | ||
75 | r = pid_from_same_root_fs(pid); | |
76 | if (r < 0) | |
77 | return true; | |
78 | ||
79 | get_process_comm(pid, &comm); | |
80 | ||
81 | if (r) | |
61233823 | 82 | log_notice("Process " PID_FMT " (%s) has been marked to be excluded from killing. It is " |
1359fffa MS |
83 | "running from the root file system, and thus likely to block re-mounting of the " |
84 | "root file system to read-only. Please consider moving it into an initrd file " | |
85 | "system instead.", pid, strna(comm)); | |
86 | return true; | |
87 | } else if (c == '@') | |
bd3fa1d2 LP |
88 | return true; |
89 | ||
90 | return false; | |
91 | } | |
92 | ||
aaf7eb81 | 93 | static void wait_for_children(Set *pids, sigset_t *mask) { |
bd3fa1d2 LP |
94 | usec_t until; |
95 | ||
96 | assert(mask); | |
97 | ||
aaf7eb81 LP |
98 | if (set_isempty(pids)) |
99 | return; | |
100 | ||
d4506129 | 101 | until = now(CLOCK_MONOTONIC) + DEFAULT_TIMEOUT_USEC; |
bd3fa1d2 LP |
102 | for (;;) { |
103 | struct timespec ts; | |
104 | int k; | |
105 | usec_t n; | |
aaf7eb81 LP |
106 | void *p; |
107 | Iterator i; | |
bd3fa1d2 | 108 | |
aaf7eb81 LP |
109 | /* First, let the kernel inform us about killed |
110 | * children. Most processes will probably be our | |
111 | * children, but some are not (might be our | |
112 | * grandchildren instead...). */ | |
bd3fa1d2 | 113 | for (;;) { |
aaf7eb81 | 114 | pid_t pid; |
bd3fa1d2 | 115 | |
aaf7eb81 | 116 | pid = waitpid(-1, NULL, WNOHANG); |
bd3fa1d2 LP |
117 | if (pid == 0) |
118 | break; | |
aaf7eb81 LP |
119 | if (pid < 0) { |
120 | if (errno == ECHILD) | |
121 | break; | |
bd3fa1d2 | 122 | |
56f64d95 | 123 | log_error_errno(errno, "waitpid() failed: %m"); |
bd3fa1d2 | 124 | return; |
aaf7eb81 LP |
125 | } |
126 | ||
fea72cc0 | 127 | (void) set_remove(pids, PID_TO_PTR(pid)); |
aaf7eb81 | 128 | } |
bd3fa1d2 | 129 | |
aaf7eb81 LP |
130 | /* Now explicitly check who might be remaining, who |
131 | * might not be our child. */ | |
132 | SET_FOREACH(p, pids, i) { | |
133 | ||
134 | /* We misuse getpgid as a check whether a | |
135 | * process still exists. */ | |
fea72cc0 | 136 | if (getpgid(PTR_TO_PID(p)) >= 0) |
aaf7eb81 LP |
137 | continue; |
138 | ||
139 | if (errno != ESRCH) | |
140 | continue; | |
141 | ||
142 | set_remove(pids, p); | |
bd3fa1d2 LP |
143 | } |
144 | ||
aaf7eb81 LP |
145 | if (set_isempty(pids)) |
146 | return; | |
147 | ||
bd3fa1d2 LP |
148 | n = now(CLOCK_MONOTONIC); |
149 | if (n >= until) | |
150 | return; | |
151 | ||
152 | timespec_store(&ts, until - n); | |
aaf7eb81 LP |
153 | k = sigtimedwait(mask, NULL, &ts); |
154 | if (k != SIGCHLD) { | |
bd3fa1d2 LP |
155 | |
156 | if (k < 0 && errno != EAGAIN) { | |
56f64d95 | 157 | log_error_errno(errno, "sigtimedwait() failed: %m"); |
bd3fa1d2 LP |
158 | return; |
159 | } | |
160 | ||
161 | if (k >= 0) | |
162 | log_warning("sigtimedwait() returned unexpected signal."); | |
163 | } | |
164 | } | |
165 | } | |
166 | ||
0bee65f0 | 167 | static int killall(int sig, Set *pids, bool send_sighup) { |
aaf7eb81 | 168 | _cleanup_closedir_ DIR *dir = NULL; |
bd3fa1d2 | 169 | struct dirent *d; |
bd3fa1d2 LP |
170 | |
171 | dir = opendir("/proc"); | |
172 | if (!dir) | |
173 | return -errno; | |
174 | ||
175 | while ((d = readdir(dir))) { | |
176 | pid_t pid; | |
60053efb | 177 | int r; |
bd3fa1d2 LP |
178 | |
179 | if (d->d_type != DT_DIR && | |
180 | d->d_type != DT_UNKNOWN) | |
181 | continue; | |
182 | ||
183 | if (parse_pid(d->d_name, &pid) < 0) | |
184 | continue; | |
185 | ||
1359fffa | 186 | if (ignore_proc(pid, sig == SIGKILL && !in_initrd())) |
bd3fa1d2 LP |
187 | continue; |
188 | ||
df758e98 | 189 | if (sig == SIGKILL) { |
3e09eb5c | 190 | _cleanup_free_ char *s = NULL; |
df758e98 KS |
191 | |
192 | get_process_comm(pid, &s); | |
ccd06097 | 193 | log_notice("Sending SIGKILL to PID "PID_FMT" (%s).", pid, strna(s)); |
df758e98 KS |
194 | } |
195 | ||
aaf7eb81 | 196 | if (kill(pid, sig) >= 0) { |
60053efb | 197 | if (pids) { |
fea72cc0 | 198 | r = set_put(pids, PID_TO_PTR(pid)); |
60053efb TA |
199 | if (r < 0) |
200 | log_oom(); | |
201 | } | |
aaf7eb81 | 202 | } else if (errno != ENOENT) |
56f64d95 | 203 | log_warning_errno(errno, "Could not kill %d: %m", pid); |
0bee65f0 LP |
204 | |
205 | if (send_sighup) { | |
206 | /* Optionally, also send a SIGHUP signal, but | |
207 | only if the process has a controlling | |
208 | tty. This is useful to allow handling of | |
209 | shells which ignore SIGTERM but react to | |
210 | SIGHUP. We do not send this to processes that | |
211 | have no controlling TTY since we don't want to | |
212 | trigger reloads of daemon processes. Also we | |
213 | make sure to only send this after SIGTERM so | |
214 | that SIGTERM is always first in the queue. */ | |
215 | ||
216 | ||
217 | if (get_ctty_devnr(pid, NULL) >= 0) | |
218 | kill(pid, SIGHUP); | |
219 | } | |
bd3fa1d2 LP |
220 | } |
221 | ||
aaf7eb81 | 222 | return set_size(pids); |
bd3fa1d2 LP |
223 | } |
224 | ||
6301a98c | 225 | void broadcast_signal(int sig, bool wait_for_exit, bool send_sighup) { |
bd3fa1d2 | 226 | sigset_t mask, oldmask; |
e1d75803 | 227 | _cleanup_set_free_ Set *pids = NULL; |
aaf7eb81 LP |
228 | |
229 | if (wait_for_exit) | |
d5099efc | 230 | pids = set_new(NULL); |
bd3fa1d2 LP |
231 | |
232 | assert_se(sigemptyset(&mask) == 0); | |
233 | assert_se(sigaddset(&mask, SIGCHLD) == 0); | |
234 | assert_se(sigprocmask(SIG_BLOCK, &mask, &oldmask) == 0); | |
235 | ||
236 | if (kill(-1, SIGSTOP) < 0 && errno != ESRCH) | |
56f64d95 | 237 | log_warning_errno(errno, "kill(-1, SIGSTOP) failed: %m"); |
bd3fa1d2 | 238 | |
0bee65f0 | 239 | killall(sig, pids, send_sighup); |
bd3fa1d2 LP |
240 | |
241 | if (kill(-1, SIGCONT) < 0 && errno != ESRCH) | |
56f64d95 | 242 | log_warning_errno(errno, "kill(-1, SIGCONT) failed: %m"); |
bd3fa1d2 | 243 | |
3d141780 | 244 | if (wait_for_exit) |
aaf7eb81 LP |
245 | wait_for_children(pids, &mask); |
246 | ||
247 | assert_se(sigprocmask(SIG_SETMASK, &oldmask, NULL) == 0); | |
bd3fa1d2 | 248 | } |