source: mainline/uspace/lib/posix/signal.c@ d3ce33fa

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since d3ce33fa was d3ce33fa, checked in by Jiří Zárevúcky <zarevucky.jiri@…>, 14 years ago

signal.h: Add some functions and implementations
  • Property mode set to 100644
File size: 8.3 KB
Line 
1/*
2 * Copyright (c) 2011 Jiri Zarevucky
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup libposix
30 * @{
31 */
32/** @file
33 */
34
35#define LIBPOSIX_INTERNAL
36
37#include "signal.h"
38#include "internal/common.h"
39#include "limits.h"
40#include "stdlib.h"
41#include "string.h"
42#include "errno.h"
43
44#include "libc/fibril_synch.h"
45#include "libc/task.h"
46
47/* Used to serialize signal handling. */
48static FIBRIL_MUTEX_INITIALIZE(_signal_mutex);
49
50static posix_sigset_t _signal_mask = 0;
51
52#define DEFAULT_HANDLER { .sa_handler = SIG_DFL, \
53 .sa_mask = 0, .sa_flags = 0, .sa_sigaction = NULL }
54
55static struct posix_sigaction _signal_actions[_TOP_SIGNAL + 1] = {
56 DEFAULT_HANDLER, DEFAULT_HANDLER, DEFAULT_HANDLER, DEFAULT_HANDLER,
57 DEFAULT_HANDLER, DEFAULT_HANDLER, DEFAULT_HANDLER, DEFAULT_HANDLER,
58 DEFAULT_HANDLER, DEFAULT_HANDLER, DEFAULT_HANDLER, DEFAULT_HANDLER,
59 DEFAULT_HANDLER, DEFAULT_HANDLER, DEFAULT_HANDLER, DEFAULT_HANDLER,
60 DEFAULT_HANDLER, DEFAULT_HANDLER, DEFAULT_HANDLER, DEFAULT_HANDLER,
61 DEFAULT_HANDLER, DEFAULT_HANDLER, DEFAULT_HANDLER, DEFAULT_HANDLER,
62 DEFAULT_HANDLER, DEFAULT_HANDLER, DEFAULT_HANDLER, DEFAULT_HANDLER
63};
64
65void __posix_default_signal_handler(int signo)
66{
67 switch (signo) {
68 case SIGABRT:
69 abort();
70 case SIGQUIT:
71 fprintf(stderr, "Quit signal raised. Exiting.");
72 exit(EXIT_FAILURE);
73 case SIGINT:
74 fprintf(stderr, "Interrupt signal caught. Exiting.");
75 exit(EXIT_FAILURE);
76 case SIGTERM:
77 fprintf(stderr, "Termination signal caught. Exiting.");
78 exit(EXIT_FAILURE);
79 case SIGSTOP:
80 fprintf(stderr, "Stop signal caught, but unsupported. Ignoring.");
81 break;
82 case SIGKILL:
83 /* This will only occur when raise or similar is called. */
84 /* Commit suicide. */
85 task_kill(task_get_id());
86
87 /* Should not be reached. */
88 abort();
89 case SIGFPE:
90 case SIGBUS:
91 case SIGILL:
92 case SIGSEGV:
93 posix_psignal(signo, "Hardware exception raised by user code");
94 abort();
95 case SIGSYS:
96 case SIGXCPU:
97 case SIGXFSZ:
98 case SIGTRAP:
99 case SIGHUP:
100 case SIGPIPE:
101 case SIGPOLL:
102 case SIGURG:
103 case SIGTSTP:
104 case SIGTTIN:
105 case SIGTTOU:
106 posix_psignal(signo, "Unsupported signal caught");
107 abort();
108 case SIGCHLD:
109 case SIGUSR1:
110 case SIGUSR2:
111 case SIGALRM:
112 case SIGVTALRM:
113 case SIGPROF:
114 case SIGCONT:
115 /* ignored */
116 break;
117 }
118}
119
120void __posix_hold_signal_handler(int signo)
121{
122 /* Nothing */
123}
124
125void __posix_ignore_signal_handler(int signo)
126{
127 /* Nothing */
128}
129
130
131int posix_sigemptyset(posix_sigset_t *set)
132{
133 assert(set != NULL);
134
135 *set = 0;
136 return 0;
137}
138
139int posix_sigfillset(posix_sigset_t *set)
140{
141 assert(set != NULL);
142
143 *set = UINT32_MAX;
144 return 0;
145}
146
147int posix_sigaddset(posix_sigset_t *set, int signo)
148{
149 assert(set != NULL);
150
151 *set |= (1 << signo);
152 return 0;
153}
154
155int posix_sigdelset(posix_sigset_t *set, int signo)
156{
157 assert(set != NULL);
158
159 *set &= ~(1 << signo);
160 return 0;
161}
162
163int posix_sigismember(const posix_sigset_t *set, int signo)
164{
165 assert(set != NULL);
166
167 return (*set & (1 << signo)) != 0;
168}
169
170static void _sigaction_unsafe(int sig, const struct posix_sigaction *restrict act,
171 struct posix_sigaction *restrict oact)
172{
173 if (oact != NULL) {
174 memcpy(oact, &_signal_actions[sig],
175 sizeof(struct posix_sigaction));
176 }
177
178 if (act != NULL) {
179 memcpy(&_signal_actions[sig], act,
180 sizeof(struct posix_sigaction));
181 }
182}
183
184int posix_sigaction(int sig, const struct posix_sigaction *restrict act,
185 struct posix_sigaction *restrict oact)
186{
187 if (sig > _TOP_SIGNAL || (act != NULL &&
188 (sig == SIGKILL || sig == SIGSTOP))) {
189 errno = EINVAL;
190 return -1;
191 }
192
193 if (sig > _TOP_CATCHABLE_SIGNAL) {
194 posix_psignal(sig,
195 "WARNING: registering handler for a partially"
196 " or fully unsupported signal. This handler may only be"
197 " invoked by the raise() function, which may not be what"
198 " the application developer intended.\nSignal name");
199 }
200
201 fibril_mutex_lock(&_signal_mutex);
202 _sigaction_unsafe(sig, act, oact);
203 fibril_mutex_unlock(&_signal_mutex);
204
205 return 0;
206}
207
208void (*posix_signal(int sig, void (*func)(int)))(int)
209{
210 struct posix_sigaction new = {
211 .sa_handler = func,
212 .sa_mask = 0,
213 .sa_flags = 0,
214 .sa_sigaction = NULL
215 };
216 struct posix_sigaction old;
217 if (posix_sigaction(sig, func == NULL ? NULL : &new, &old) == 0) {
218 return old.sa_handler;
219 } else {
220 return SIG_ERR;
221 }
222}
223
224static int _raise_sigaction(int signo, posix_siginfo_t *siginfo)
225{
226 assert(signo >= 0 && signo <= _TOP_SIGNAL);
227 assert(siginfo != NULL);
228
229 fibril_mutex_lock(&_signal_mutex);
230
231 struct posix_sigaction action = _signal_actions[signo];
232
233 if (posix_sigismember(&_signal_mask, signo) ||
234 action.sa_handler == SIG_HOLD) {
235 // TODO: queue signal
236 fibril_mutex_unlock(&_signal_mutex);
237 return -1;
238 }
239
240 /* Modifying signal mask is unnecessary,
241 * signal handling is serialized.
242 */
243
244 if ((action.sa_flags & SA_RESETHAND) && signo != SIGILL && signo != SIGTRAP) {
245 _signal_actions[signo] = (struct posix_sigaction) DEFAULT_HANDLER;
246 };
247
248 if (action.sa_flags & SA_SIGINFO) {
249 assert(action.sa_sigaction != NULL);
250 action.sa_sigaction(signo, siginfo, NULL);
251 } else {
252 assert(action.sa_handler != NULL);
253 action.sa_handler(signo);
254 }
255
256 fibril_mutex_unlock(&_signal_mutex);
257
258 return 0;
259}
260
261int posix_raise(int sig)
262{
263 if (sig >= 0 && sig <= _TOP_SIGNAL) {
264 posix_siginfo_t siginfo = {
265 .si_signo = sig,
266 .si_code = SI_USER
267 };
268 return _raise_sigaction(sig, &siginfo);
269 } else {
270 errno = EINVAL;
271 return -1;
272 }
273}
274
275int posix_kill(posix_pid_t pid, int signo)
276{
277 if (pid < 1) {
278 // TODO
279 errno = ENOTSUP;
280 return -1;
281 }
282
283 if (pid == task_get_id()) {
284 return posix_raise(signo);
285 }
286
287 if (pid > _TOP_SIGNAL) {
288 errno = EINVAL;
289 return -1;
290 }
291
292 switch (signo) {
293 case SIGKILL:
294 task_kill(pid);
295 break;
296 default:
297 /* Nothing else supported yet. */
298 errno = ENOTSUP;
299 return -1;
300 }
301
302 return 0;
303}
304
305int posix_killpg(posix_pid_t pid, int sig)
306{
307 assert(pid > 1);
308 return posix_kill(-pid, sig);
309}
310
311void posix_psiginfo(const posix_siginfo_t *pinfo, const char *message)
312{
313 assert(pinfo != NULL);
314 posix_psignal(pinfo->si_signo, message);
315 // TODO: print si_code
316}
317
318void posix_psignal(int signum, const char *message)
319{
320 char *sigmsg = posix_strsignal(signum);
321 if (message == NULL || *message == '\0') {
322 fprintf(stderr, "%s\n", sigmsg);
323 } else {
324 fprintf(stderr, "%s: %s\n", message, sigmsg);
325 }
326}
327
328int posix_thread_sigmask(int how, const posix_sigset_t *restrict set,
329 posix_sigset_t *restrict oset)
330{
331 fibril_mutex_lock(&_signal_mutex);
332
333 if (oset != NULL) {
334 *oset = _signal_mask;
335 }
336 if (set != NULL) {
337 switch (how) {
338 case SIG_BLOCK:
339 _signal_mask |= *set;
340 break;
341 case SIG_UNBLOCK:
342 _signal_mask &= ~*set;
343 break;
344 case SIG_SETMASK:
345 _signal_mask = *set;
346 break;
347 default:
348 fibril_mutex_unlock(&_signal_mutex);
349 return EINVAL;
350 }
351 }
352
353 // TODO: queued signal handling
354
355 fibril_mutex_unlock(&_signal_mutex);
356
357 return 0;
358}
359
360int posix_sigprocmask(int how, const posix_sigset_t *restrict set,
361 posix_sigset_t *restrict oset)
362{
363 int result = posix_thread_sigmask(how, set, oset);
364 if (result != 0) {
365 errno = result;
366 return -1;
367 }
368 return 0;
369}
370
371/** @}
372 */
373
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