]>
Commit | Line | Data |
---|---|---|
663996b3 MS |
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 | ||
22 | #include <sys/wait.h> | |
23 | #include <signal.h> | |
24 | #include <errno.h> | |
25 | #include <unistd.h> | |
26 | ||
27 | #include "util.h" | |
28 | #include "def.h" | |
29 | #include "killall.h" | |
30 | #include "set.h" | |
31 | ||
32 | #define TIMEOUT_USEC (10 * USEC_PER_SEC) | |
33 | ||
34 | static bool ignore_proc(pid_t pid) { | |
35 | _cleanup_fclose_ FILE *f = NULL; | |
60f067b4 JS |
36 | char c; |
37 | const char *p; | |
663996b3 MS |
38 | size_t count; |
39 | uid_t uid; | |
40 | int r; | |
41 | ||
42 | /* We are PID 1, let's not commit suicide */ | |
43 | if (pid == 1) | |
44 | return true; | |
45 | ||
46 | r = get_process_uid(pid, &uid); | |
47 | if (r < 0) | |
48 | return true; /* not really, but better safe than sorry */ | |
49 | ||
50 | /* Non-root processes otherwise are always subject to be killed */ | |
51 | if (uid != 0) | |
52 | return false; | |
53 | ||
14228c0d MB |
54 | p = procfs_file_alloca(pid, "cmdline"); |
55 | f = fopen(p, "re"); | |
663996b3 MS |
56 | if (!f) |
57 | return true; /* not really, but has the desired effect */ | |
58 | ||
59 | count = fread(&c, 1, 1, f); | |
60 | ||
61 | /* Kernel threads have an empty cmdline */ | |
62 | if (count <= 0) | |
63 | return true; | |
64 | ||
65 | /* Processes with argv[0][0] = '@' we ignore from the killing | |
66 | * spree. | |
67 | * | |
68 | * http://www.freedesktop.org/wiki/Software/systemd/RootStorageDaemons */ | |
69 | if (count == 1 && c == '@') | |
70 | return true; | |
71 | ||
72 | return false; | |
73 | } | |
74 | ||
75 | static void wait_for_children(Set *pids, sigset_t *mask) { | |
76 | usec_t until; | |
77 | ||
78 | assert(mask); | |
79 | ||
80 | if (set_isempty(pids)) | |
81 | return; | |
82 | ||
83 | until = now(CLOCK_MONOTONIC) + TIMEOUT_USEC; | |
84 | for (;;) { | |
85 | struct timespec ts; | |
86 | int k; | |
87 | usec_t n; | |
88 | void *p; | |
89 | Iterator i; | |
90 | ||
91 | /* First, let the kernel inform us about killed | |
92 | * children. Most processes will probably be our | |
93 | * children, but some are not (might be our | |
94 | * grandchildren instead...). */ | |
95 | for (;;) { | |
96 | pid_t pid; | |
97 | ||
98 | pid = waitpid(-1, NULL, WNOHANG); | |
99 | if (pid == 0) | |
100 | break; | |
101 | if (pid < 0) { | |
102 | if (errno == ECHILD) | |
103 | break; | |
104 | ||
105 | log_error("waitpid() failed: %m"); | |
106 | return; | |
107 | } | |
108 | ||
109 | set_remove(pids, ULONG_TO_PTR(pid)); | |
110 | } | |
111 | ||
112 | /* Now explicitly check who might be remaining, who | |
113 | * might not be our child. */ | |
114 | SET_FOREACH(p, pids, i) { | |
115 | ||
116 | /* We misuse getpgid as a check whether a | |
117 | * process still exists. */ | |
118 | if (getpgid((pid_t) PTR_TO_ULONG(p)) >= 0) | |
119 | continue; | |
120 | ||
121 | if (errno != ESRCH) | |
122 | continue; | |
123 | ||
124 | set_remove(pids, p); | |
125 | } | |
126 | ||
127 | if (set_isempty(pids)) | |
128 | return; | |
129 | ||
130 | n = now(CLOCK_MONOTONIC); | |
131 | if (n >= until) | |
132 | return; | |
133 | ||
134 | timespec_store(&ts, until - n); | |
135 | k = sigtimedwait(mask, NULL, &ts); | |
136 | if (k != SIGCHLD) { | |
137 | ||
138 | if (k < 0 && errno != EAGAIN) { | |
139 | log_error("sigtimedwait() failed: %m"); | |
140 | return; | |
141 | } | |
142 | ||
143 | if (k >= 0) | |
144 | log_warning("sigtimedwait() returned unexpected signal."); | |
145 | } | |
146 | } | |
147 | } | |
148 | ||
60f067b4 | 149 | static int killall(int sig, Set *pids, bool send_sighup) { |
663996b3 MS |
150 | _cleanup_closedir_ DIR *dir = NULL; |
151 | struct dirent *d; | |
152 | ||
153 | dir = opendir("/proc"); | |
154 | if (!dir) | |
155 | return -errno; | |
156 | ||
157 | while ((d = readdir(dir))) { | |
158 | pid_t pid; | |
159 | ||
160 | if (d->d_type != DT_DIR && | |
161 | d->d_type != DT_UNKNOWN) | |
162 | continue; | |
163 | ||
164 | if (parse_pid(d->d_name, &pid) < 0) | |
165 | continue; | |
166 | ||
167 | if (ignore_proc(pid)) | |
168 | continue; | |
169 | ||
170 | if (sig == SIGKILL) { | |
e842803a | 171 | _cleanup_free_ char *s = NULL; |
663996b3 MS |
172 | |
173 | get_process_comm(pid, &s); | |
60f067b4 | 174 | log_notice("Sending SIGKILL to PID "PID_FMT" (%s).", pid, strna(s)); |
663996b3 MS |
175 | } |
176 | ||
177 | if (kill(pid, sig) >= 0) { | |
178 | if (pids) | |
60f067b4 | 179 | set_put(pids, ULONG_TO_PTR(pid)); |
663996b3 MS |
180 | } else if (errno != ENOENT) |
181 | log_warning("Could not kill %d: %m", pid); | |
60f067b4 JS |
182 | |
183 | if (send_sighup) { | |
184 | /* Optionally, also send a SIGHUP signal, but | |
185 | only if the process has a controlling | |
186 | tty. This is useful to allow handling of | |
187 | shells which ignore SIGTERM but react to | |
188 | SIGHUP. We do not send this to processes that | |
189 | have no controlling TTY since we don't want to | |
190 | trigger reloads of daemon processes. Also we | |
191 | make sure to only send this after SIGTERM so | |
192 | that SIGTERM is always first in the queue. */ | |
193 | ||
194 | ||
195 | if (get_ctty_devnr(pid, NULL) >= 0) | |
196 | kill(pid, SIGHUP); | |
197 | } | |
663996b3 MS |
198 | } |
199 | ||
200 | return set_size(pids); | |
201 | } | |
202 | ||
60f067b4 | 203 | void broadcast_signal(int sig, bool wait_for_exit, bool send_sighup) { |
663996b3 | 204 | sigset_t mask, oldmask; |
e842803a | 205 | _cleanup_set_free_ Set *pids = NULL; |
663996b3 MS |
206 | |
207 | if (wait_for_exit) | |
5eef597e | 208 | pids = set_new(NULL); |
663996b3 MS |
209 | |
210 | assert_se(sigemptyset(&mask) == 0); | |
211 | assert_se(sigaddset(&mask, SIGCHLD) == 0); | |
212 | assert_se(sigprocmask(SIG_BLOCK, &mask, &oldmask) == 0); | |
213 | ||
214 | if (kill(-1, SIGSTOP) < 0 && errno != ESRCH) | |
215 | log_warning("kill(-1, SIGSTOP) failed: %m"); | |
216 | ||
60f067b4 | 217 | killall(sig, pids, send_sighup); |
663996b3 MS |
218 | |
219 | if (kill(-1, SIGCONT) < 0 && errno != ESRCH) | |
220 | log_warning("kill(-1, SIGCONT) failed: %m"); | |
221 | ||
222 | if (wait_for_exit) | |
223 | wait_for_children(pids, &mask); | |
224 | ||
225 | assert_se(sigprocmask(SIG_SETMASK, &oldmask, NULL) == 0); | |
663996b3 | 226 | } |