1 /*
2 * Server signal handling
3 *
4 * Copyright (C) 2003 Alexandre Julliard
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but 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
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
19 */
20
21 #include "config.h"
22
23 #include <signal.h>
24 #include <stdio.h>
25 #include <sys/time.h>
26 #ifdef HAVE_POLL_H
27 #include <poll.h>
28 #endif
29 #ifdef HAVE_SYS_POLL_H
30 #include <sys/poll.h>
31 #endif
32 #ifdef HAVE_SYS_RESOURCE_H
33 #include <sys/resource.h>
34 #endif
35 #include <unistd.h>
36
37 #include "file.h"
38 #include "object.h"
39 #include "process.h"
40 #include "thread.h"
41 #include "request.h"
42
43 #if defined(linux) && defined(__SIGRTMIN)
44 /* the signal used by linuxthreads as exit signal for clone() threads */
45 # define SIG_PTHREAD_CANCEL (__SIGRTMIN+1)
46 #endif
47
48 typedef void (*signal_callback)(void);
49
50 struct handler
51 {
52 struct object obj; /* object header */
53 struct fd *fd; /* file descriptor for the pipe side */
54 int pipe_write; /* unix fd for the pipe write side */
55 volatile int pending; /* is signal pending? */
56 signal_callback callback; /* callback function */
57 };
58
59 static void handler_dump( struct object *obj, int verbose );
60 static void handler_destroy( struct object *obj );
61
62 static const struct object_ops handler_ops =
63 {
64 sizeof(struct handler), /* size */
65 handler_dump, /* dump */
66 no_get_type, /* get_type */
67 no_add_queue, /* add_queue */
68 NULL, /* remove_queue */
69 NULL, /* signaled */
70 NULL, /* satisfied */
71 no_signal, /* signal */
72 no_get_fd, /* get_fd */
73 no_map_access, /* map_access */
74 default_get_sd, /* get_sd */
75 default_set_sd, /* set_sd */
76 no_lookup_name, /* lookup_name */
77 no_open_file, /* open_file */
78 no_close_handle, /* close_handle */
79 handler_destroy /* destroy */
80 };
81
82 static void handler_poll_event( struct fd *fd, int event );
83
84 static const struct fd_ops handler_fd_ops =
85 {
86 NULL, /* get_poll_events */
87 handler_poll_event, /* poll_event */
88 NULL, /* flush */
89 NULL, /* get_fd_type */
90 NULL, /* ioctl */
91 NULL, /* queue_async */
92 NULL, /* reselect_async */
93 NULL /* cancel_async */
94 };
95
96 static struct handler *handler_sighup;
97 static struct handler *handler_sigterm;
98 static struct handler *handler_sigint;
99 static struct handler *handler_sigchld;
100 static struct handler *handler_sigio;
101
102 static int watchdog;
103
104 /* create a signal handler */
105 static struct handler *create_handler( signal_callback callback )
106 {
107 struct handler *handler;
108 int fd[2];
109
110 if (pipe( fd ) == -1) return NULL;
111 if (!(handler = alloc_object( &handler_ops )))
112 {
113 close( fd[0] );
114 close( fd[1] );
115 return NULL;
116 }
117 handler->pipe_write = fd[1];
118 handler->pending = 0;
119 handler->callback = callback;
120
121 if (!(handler->fd = create_anonymous_fd( &handler_fd_ops, fd[0], &handler->obj, 0 )))
122 {
123 release_object( handler );
124 return NULL;
125 }
126 set_fd_events( handler->fd, POLLIN );
127 make_object_static( &handler->obj );
128 return handler;
129 }
130
131 /* handle a signal received for a given handler */
132 static void do_signal( struct handler *handler )
133 {
134 if (!handler->pending)
135 {
136 char dummy = 0;
137 handler->pending = 1;
138 write( handler->pipe_write, &dummy, 1 );
139 }
140 }
141
142 static void handler_dump( struct object *obj, int verbose )
143 {
144 struct handler *handler = (struct handler *)obj;
145 fprintf( stderr, "Signal handler fd=%p\n", handler->fd );
146 }
147
148 static void handler_destroy( struct object *obj )
149 {
150 struct handler *handler = (struct handler *)obj;
151 if (handler->fd) release_object( handler->fd );
152 close( handler->pipe_write );
153 }
154
155 static void handler_poll_event( struct fd *fd, int event )
156 {
157 struct handler *handler = get_fd_user( fd );
158
159 if (event & (POLLERR | POLLHUP))
160 {
161 /* this is not supposed to happen */
162 fprintf( stderr, "wineserver: Error on signal handler pipe\n" );
163 release_object( handler );
164 }
165 else if (event & POLLIN)
166 {
167 char dummy;
168
169 handler->pending = 0;
170 read( get_unix_fd( handler->fd ), &dummy, 1 );
171 handler->callback();
172 }
173 }
174
175 /* SIGHUP callback */
176 static void sighup_callback(void)
177 {
178 #ifdef DEBUG_OBJECTS
179 dump_objects();
180 #endif
181 }
182
183 /* SIGTERM callback */
184 static void sigterm_callback(void)
185 {
186 flush_registry();
187 exit(1);
188 }
189
190 /* SIGINT callback */
191 static void sigint_callback(void)
192 {
193 shutdown_master_socket();
194 }
195
196 /* SIGHUP handler */
197 static void do_sighup( int signum )
198 {
199 do_signal( handler_sighup );
200 }
201
202 /* SIGTERM handler */
203 static void do_sigterm( int signum )
204 {
205 do_signal( handler_sigterm );
206 }
207
208 /* SIGINT handler */
209 static void do_sigint( int signum )
210 {
211 do_signal( handler_sigint );
212 }
213
214 /* SIGALRM handler */
215 static void do_sigalrm( int signum )
216 {
217 watchdog = 1;
218 }
219
220 /* SIGCHLD handler */
221 static void do_sigchld( int signum )
222 {
223 do_signal( handler_sigchld );
224 }
225
226 /* SIGSEGV handler */
227 static void do_sigsegv( int signum )
228 {
229 fprintf( stderr, "wineserver crashed, please enable coredumps (ulimit -c unlimited) and restart.\n");
230 abort();
231 }
232
233 /* SIGIO handler */
234 #ifdef HAVE_SIGINFO_T_SI_FD
235 static void do_sigio( int signum, siginfo_t *si, void *x )
236 {
237 do_signal( handler_sigio );
238 do_change_notify( si->si_fd );
239 }
240 #endif
241
242 void start_watchdog(void)
243 {
244 alarm( 3 );
245 watchdog = 0;
246 }
247
248 void stop_watchdog(void)
249 {
250 alarm( 0 );
251 watchdog = 0;
252 }
253
254 int watchdog_triggered(void)
255 {
256 return watchdog != 0;
257 }
258
259 static int core_dump_disabled( void )
260 {
261 int r = 0;
262 #ifdef RLIMIT_CORE
263 struct rlimit lim;
264
265 r = !getrlimit(RLIMIT_CORE, &lim) && (lim.rlim_cur == 0);
266 #endif
267 return r;
268 }
269
270 void init_signals(void)
271 {
272 struct sigaction action;
273 sigset_t blocked_sigset;
274
275 if (!(handler_sighup = create_handler( sighup_callback ))) goto error;
276 if (!(handler_sigterm = create_handler( sigterm_callback ))) goto error;
277 if (!(handler_sigint = create_handler( sigint_callback ))) goto error;
278 if (!(handler_sigchld = create_handler( sigchld_callback ))) goto error;
279 if (!(handler_sigio = create_handler( sigio_callback ))) goto error;
280
281 sigemptyset( &blocked_sigset );
282 sigaddset( &blocked_sigset, SIGCHLD );
283 sigaddset( &blocked_sigset, SIGHUP );
284 sigaddset( &blocked_sigset, SIGINT );
285 sigaddset( &blocked_sigset, SIGALRM );
286 sigaddset( &blocked_sigset, SIGIO );
287 sigaddset( &blocked_sigset, SIGQUIT );
288 sigaddset( &blocked_sigset, SIGTERM );
289 #ifdef SIG_PTHREAD_CANCEL
290 sigaddset( &blocked_sigset, SIG_PTHREAD_CANCEL );
291 #endif
292
293 action.sa_mask = blocked_sigset;
294 action.sa_flags = 0;
295 action.sa_handler = do_sigchld;
296 sigaction( SIGCHLD, &action, NULL );
297 #ifdef SIG_PTHREAD_CANCEL
298 sigaction( SIG_PTHREAD_CANCEL, &action, NULL );
299 #endif
300 action.sa_handler = do_sighup;
301 sigaction( SIGHUP, &action, NULL );
302 action.sa_handler = do_sigint;
303 sigaction( SIGINT, &action, NULL );
304 action.sa_handler = do_sigalrm;
305 sigaction( SIGALRM, &action, NULL );
306 action.sa_handler = do_sigterm;
307 sigaction( SIGQUIT, &action, NULL );
308 sigaction( SIGTERM, &action, NULL );
309 if (core_dump_disabled())
310 {
311 action.sa_handler = do_sigsegv;
312 sigaction( SIGSEGV, &action, NULL );
313 }
314 action.sa_handler = SIG_IGN;
315 sigaction( SIGXFSZ, &action, NULL );
316 #ifdef HAVE_SIGINFO_T_SI_FD
317 action.sa_sigaction = do_sigio;
318 action.sa_flags = SA_SIGINFO;
319 sigaction( SIGIO, &action, NULL );
320 #endif
321 return;
322
323 error:
324 fprintf( stderr, "failed to initialize signal handlers\n" );
325 exit(1);
326 }
327
This page was automatically generated by the
LXR engine.
Visit the LXR main site for more
information.