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bd3fa1d2 LP |
1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2010 ProFUSION embedded systems | |
7 | ||
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. | |
12 | ||
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. | |
17 | ||
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/>. | |
20 | ***/ | |
21 | ||
bd3fa1d2 | 22 | #include <errno.h> |
07630cea LP |
23 | #include <signal.h> |
24 | #include <sys/wait.h> | |
aaf7eb81 | 25 | #include <unistd.h> |
bd3fa1d2 | 26 | |
3ffd4af2 | 27 | #include "fd-util.h" |
6482f626 | 28 | #include "formats-util.h" |
3ffd4af2 | 29 | #include "killall.h" |
0b452006 | 30 | #include "process-util.h" |
07630cea LP |
31 | #include "set.h" |
32 | #include "string-util.h" | |
288a74cc | 33 | #include "terminal-util.h" |
07630cea | 34 | #include "util.h" |
bd3fa1d2 | 35 | |
aaf7eb81 | 36 | #define TIMEOUT_USEC (10 * USEC_PER_SEC) |
bd3fa1d2 LP |
37 | |
38 | static bool ignore_proc(pid_t pid) { | |
31885cd5 | 39 | _cleanup_fclose_ FILE *f = NULL; |
b68fa010 SP |
40 | char c; |
41 | const char *p; | |
bd3fa1d2 LP |
42 | size_t count; |
43 | uid_t uid; | |
44 | int r; | |
45 | ||
46 | /* We are PID 1, let's not commit suicide */ | |
47 | if (pid == 1) | |
48 | return true; | |
49 | ||
50 | r = get_process_uid(pid, &uid); | |
51 | if (r < 0) | |
52 | return true; /* not really, but better safe than sorry */ | |
53 | ||
54 | /* Non-root processes otherwise are always subject to be killed */ | |
55 | if (uid != 0) | |
56 | return false; | |
57 | ||
5841bd80 ZJS |
58 | p = procfs_file_alloca(pid, "cmdline"); |
59 | f = fopen(p, "re"); | |
bd3fa1d2 LP |
60 | if (!f) |
61 | return true; /* not really, but has the desired effect */ | |
62 | ||
63 | count = fread(&c, 1, 1, f); | |
bd3fa1d2 LP |
64 | |
65 | /* Kernel threads have an empty cmdline */ | |
66 | if (count <= 0) | |
67 | return true; | |
68 | ||
69 | /* Processes with argv[0][0] = '@' we ignore from the killing | |
70 | * spree. | |
71 | * | |
72 | * http://www.freedesktop.org/wiki/Software/systemd/RootStorageDaemons */ | |
73 | if (count == 1 && c == '@') | |
74 | return true; | |
75 | ||
76 | return false; | |
77 | } | |
78 | ||
aaf7eb81 | 79 | static void wait_for_children(Set *pids, sigset_t *mask) { |
bd3fa1d2 LP |
80 | usec_t until; |
81 | ||
82 | assert(mask); | |
83 | ||
aaf7eb81 LP |
84 | if (set_isempty(pids)) |
85 | return; | |
86 | ||
bd3fa1d2 LP |
87 | until = now(CLOCK_MONOTONIC) + TIMEOUT_USEC; |
88 | for (;;) { | |
89 | struct timespec ts; | |
90 | int k; | |
91 | usec_t n; | |
aaf7eb81 LP |
92 | void *p; |
93 | Iterator i; | |
bd3fa1d2 | 94 | |
aaf7eb81 LP |
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...). */ | |
bd3fa1d2 | 99 | for (;;) { |
aaf7eb81 | 100 | pid_t pid; |
bd3fa1d2 | 101 | |
aaf7eb81 | 102 | pid = waitpid(-1, NULL, WNOHANG); |
bd3fa1d2 LP |
103 | if (pid == 0) |
104 | break; | |
aaf7eb81 LP |
105 | if (pid < 0) { |
106 | if (errno == ECHILD) | |
107 | break; | |
bd3fa1d2 | 108 | |
56f64d95 | 109 | log_error_errno(errno, "waitpid() failed: %m"); |
bd3fa1d2 | 110 | return; |
aaf7eb81 LP |
111 | } |
112 | ||
fea72cc0 | 113 | (void) set_remove(pids, PID_TO_PTR(pid)); |
aaf7eb81 | 114 | } |
bd3fa1d2 | 115 | |
aaf7eb81 LP |
116 | /* Now explicitly check who might be remaining, who |
117 | * might not be our child. */ | |
118 | SET_FOREACH(p, pids, i) { | |
119 | ||
120 | /* We misuse getpgid as a check whether a | |
121 | * process still exists. */ | |
fea72cc0 | 122 | if (getpgid(PTR_TO_PID(p)) >= 0) |
aaf7eb81 LP |
123 | continue; |
124 | ||
125 | if (errno != ESRCH) | |
126 | continue; | |
127 | ||
128 | set_remove(pids, p); | |
bd3fa1d2 LP |
129 | } |
130 | ||
aaf7eb81 LP |
131 | if (set_isempty(pids)) |
132 | return; | |
133 | ||
bd3fa1d2 LP |
134 | n = now(CLOCK_MONOTONIC); |
135 | if (n >= until) | |
136 | return; | |
137 | ||
138 | timespec_store(&ts, until - n); | |
aaf7eb81 LP |
139 | k = sigtimedwait(mask, NULL, &ts); |
140 | if (k != SIGCHLD) { | |
bd3fa1d2 LP |
141 | |
142 | if (k < 0 && errno != EAGAIN) { | |
56f64d95 | 143 | log_error_errno(errno, "sigtimedwait() failed: %m"); |
bd3fa1d2 LP |
144 | return; |
145 | } | |
146 | ||
147 | if (k >= 0) | |
148 | log_warning("sigtimedwait() returned unexpected signal."); | |
149 | } | |
150 | } | |
151 | } | |
152 | ||
0bee65f0 | 153 | static int killall(int sig, Set *pids, bool send_sighup) { |
aaf7eb81 | 154 | _cleanup_closedir_ DIR *dir = NULL; |
bd3fa1d2 | 155 | struct dirent *d; |
bd3fa1d2 LP |
156 | |
157 | dir = opendir("/proc"); | |
158 | if (!dir) | |
159 | return -errno; | |
160 | ||
161 | while ((d = readdir(dir))) { | |
162 | pid_t pid; | |
60053efb | 163 | int r; |
bd3fa1d2 LP |
164 | |
165 | if (d->d_type != DT_DIR && | |
166 | d->d_type != DT_UNKNOWN) | |
167 | continue; | |
168 | ||
169 | if (parse_pid(d->d_name, &pid) < 0) | |
170 | continue; | |
171 | ||
172 | if (ignore_proc(pid)) | |
173 | continue; | |
174 | ||
df758e98 | 175 | if (sig == SIGKILL) { |
3e09eb5c | 176 | _cleanup_free_ char *s = NULL; |
df758e98 KS |
177 | |
178 | get_process_comm(pid, &s); | |
ccd06097 | 179 | log_notice("Sending SIGKILL to PID "PID_FMT" (%s).", pid, strna(s)); |
df758e98 KS |
180 | } |
181 | ||
aaf7eb81 | 182 | if (kill(pid, sig) >= 0) { |
60053efb | 183 | if (pids) { |
fea72cc0 | 184 | r = set_put(pids, PID_TO_PTR(pid)); |
60053efb TA |
185 | if (r < 0) |
186 | log_oom(); | |
187 | } | |
aaf7eb81 | 188 | } else if (errno != ENOENT) |
56f64d95 | 189 | log_warning_errno(errno, "Could not kill %d: %m", pid); |
0bee65f0 LP |
190 | |
191 | if (send_sighup) { | |
192 | /* Optionally, also send a SIGHUP signal, but | |
193 | only if the process has a controlling | |
194 | tty. This is useful to allow handling of | |
195 | shells which ignore SIGTERM but react to | |
196 | SIGHUP. We do not send this to processes that | |
197 | have no controlling TTY since we don't want to | |
198 | trigger reloads of daemon processes. Also we | |
199 | make sure to only send this after SIGTERM so | |
200 | that SIGTERM is always first in the queue. */ | |
201 | ||
202 | ||
203 | if (get_ctty_devnr(pid, NULL) >= 0) | |
204 | kill(pid, SIGHUP); | |
205 | } | |
bd3fa1d2 LP |
206 | } |
207 | ||
aaf7eb81 | 208 | return set_size(pids); |
bd3fa1d2 LP |
209 | } |
210 | ||
6301a98c | 211 | void broadcast_signal(int sig, bool wait_for_exit, bool send_sighup) { |
bd3fa1d2 | 212 | sigset_t mask, oldmask; |
e1d75803 | 213 | _cleanup_set_free_ Set *pids = NULL; |
aaf7eb81 LP |
214 | |
215 | if (wait_for_exit) | |
d5099efc | 216 | pids = set_new(NULL); |
bd3fa1d2 LP |
217 | |
218 | assert_se(sigemptyset(&mask) == 0); | |
219 | assert_se(sigaddset(&mask, SIGCHLD) == 0); | |
220 | assert_se(sigprocmask(SIG_BLOCK, &mask, &oldmask) == 0); | |
221 | ||
222 | if (kill(-1, SIGSTOP) < 0 && errno != ESRCH) | |
56f64d95 | 223 | log_warning_errno(errno, "kill(-1, SIGSTOP) failed: %m"); |
bd3fa1d2 | 224 | |
0bee65f0 | 225 | killall(sig, pids, send_sighup); |
bd3fa1d2 LP |
226 | |
227 | if (kill(-1, SIGCONT) < 0 && errno != ESRCH) | |
56f64d95 | 228 | log_warning_errno(errno, "kill(-1, SIGCONT) failed: %m"); |
bd3fa1d2 | 229 | |
3d141780 | 230 | if (wait_for_exit) |
aaf7eb81 LP |
231 | wait_for_children(pids, &mask); |
232 | ||
233 | assert_se(sigprocmask(SIG_SETMASK, &oldmask, NULL) == 0); | |
bd3fa1d2 | 234 | } |