1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
|
/*
+----------------------------------------------------------------------+
| Zend Signal Handling |
+----------------------------------------------------------------------+
| Copyright (c) 2008 The PHP Group |
+----------------------------------------------------------------------+
| This source file is subject to version 3.01 of the PHP license, |
| that is bundled with this package in the file LICENSE, and is |
| available through the world-wide-web at the following url: |
| http://www.php.net/license/3_01.txt |
| If you did not receive a copy of the PHP license and are unable to |
| obtain it through the world-wide-web, please send a note to |
| license@php.net so we can mail you a copy immediately. |
+----------------------------------------------------------------------+
| Authors: Lucas Nealan <lucas@php.net> |
| Arnaud Le Blanc <lbarnaud@php.net> |
+----------------------------------------------------------------------+
This software was contributed to PHP by Facebook Inc. in 2008.
Future revisions and derivatives of this source code must acknowledge
Facebook Inc. as the original contributor of this module by leaving
this note intact in the source code.
All other licensing and usage conditions are those of the PHP Group.
*/
/* $Id$ */
#define _GNU_SOURCE
#include <string.h>
#include "zend.h"
#include "zend_globals.h"
#ifdef HAVE_SIGNAL_H
#include <signal.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef ZEND_SIGNALS
#include "zend_signal.h"
#ifdef ZTS
ZEND_API int zend_signal_globals_id;
#else
ZEND_API zend_signal_globals_t zend_signal_globals;
#endif /* not ZTS */
#define SIGNAL_BEGIN_CRITICAL() \
sigset_t oldmask; \
zend_sigprocmask(SIG_BLOCK, &global_sigmask, &oldmask);
#define SIGNAL_END_CRITICAL() \
zend_sigprocmask(SIG_SETMASK, &oldmask, NULL);
#ifdef ZTS
# define zend_sigprocmask(signo, set, oldset) tsrm_sigmask((signo), (set), (oldset))
#else
# define zend_sigprocmask(signo, set, oldset) sigprocmask((signo), (set), (oldset))
#endif
static void zend_signal_handler(int signo, siginfo_t *siginfo, void *context);
static int zend_signal_register(int signo, void (*handler)(int, siginfo_t*, void*));
#ifdef __CYGWIN__
#define TIMEOUT_SIG SIGALRM
#else
#define TIMEOUT_SIG SIGPROF
#endif
static int zend_sigs[] = { TIMEOUT_SIG, SIGHUP, SIGINT, SIGQUIT, SIGTERM, SIGUSR1, SIGUSR2 };
#define SA_FLAGS_MASK ~(SA_NODEFER | SA_RESETHAND)
/* True globals, written only at process startup */
static zend_signal_entry_t global_orig_handlers[NSIG];
static sigset_t global_sigmask;
/* {{{ zend_signal_handler_defer
* Blocks signals if in critical section */
void zend_signal_handler_defer(int signo, siginfo_t *siginfo, void *context)
{
int errno_save = errno;
zend_signal_queue_t *queue, *qtmp;
#ifdef ZTS
ZEND_TSRMLS_CACHE_UPDATE();
#endif
if (EXPECTED(SIGG(active))) {
if (UNEXPECTED(SIGG(depth) == 0)) { /* try to handle signal */
if (UNEXPECTED(SIGG(blocked))) {
SIGG(blocked) = 0;
}
if (EXPECTED(SIGG(running) == 0)) {
SIGG(running) = 1;
zend_signal_handler(signo, siginfo, context);
queue = SIGG(phead);
SIGG(phead) = NULL;
while (queue) {
zend_signal_handler(queue->zend_signal.signo, queue->zend_signal.siginfo, queue->zend_signal.context);
qtmp = queue->next;
queue->next = SIGG(pavail);
queue->zend_signal.signo = 0;
SIGG(pavail) = queue;
queue = qtmp;
}
SIGG(running) = 0;
}
} else { /* delay signal handling */
SIGG(blocked) = 1; /* signal is blocked */
if ((queue = SIGG(pavail))) { /* if none available it's simply forgotton */
SIGG(pavail) = queue->next;
queue->zend_signal.signo = signo;
queue->zend_signal.siginfo = siginfo;
queue->zend_signal.context = context;
queue->next = NULL;
if (SIGG(phead) && SIGG(ptail)) {
SIGG(ptail)->next = queue;
} else {
SIGG(phead) = queue;
}
SIGG(ptail) = queue;
}
#if ZEND_DEBUG
else { /* this may not be safe to do, but could work and be useful */
zend_output_debug_string(0, "zend_signal: not enough queue storage, lost signal (%d)", signo);
}
#endif
}
} else {
/* need to just run handler if we're inactive and getting a signal */
zend_signal_handler(signo, siginfo, context);
}
errno = errno_save;
} /* }}} */
/* {{{ zend_signal_handler_unblock
* Handle deferred signal from HANDLE_UNBLOCK_ALARMS */
ZEND_API void zend_signal_handler_unblock(void)
{
zend_signal_queue_t *queue;
zend_signal_t zend_signal;
if (EXPECTED(SIGG(active))) {
SIGNAL_BEGIN_CRITICAL(); /* procmask to protect handler_defer as if it were called by the kernel */
queue = SIGG(phead);
SIGG(phead) = queue->next;
zend_signal = queue->zend_signal;
queue->next = SIGG(pavail);
queue->zend_signal.signo = 0;
SIGG(pavail) = queue;
zend_signal_handler_defer(zend_signal.signo, zend_signal.siginfo, zend_signal.context);
SIGNAL_END_CRITICAL();
}
}
/* }}} */
/* {{{ zend_signal_handler
* Call the previously registered handler for a signal
*/
static void zend_signal_handler(int signo, siginfo_t *siginfo, void *context)
{
int errno_save = errno;
struct sigaction sa;
sigset_t sigset;
zend_signal_entry_t p_sig = SIGG(handlers)[signo-1];
if (p_sig.handler == SIG_DFL) { /* raise default handler */
if (sigaction(signo, NULL, &sa) == 0) {
sa.sa_handler = SIG_DFL;
sigemptyset(&sa.sa_mask);
sigemptyset(&sigset);
sigaddset(&sigset, signo);
if (sigaction(signo, &sa, NULL) == 0) {
/* throw away any blocked signals */
zend_sigprocmask(SIG_UNBLOCK, &sigset, NULL);
#ifdef ZTS
# define RAISE_ERROR "raise() failed\n"
if (raise(signo) != 0) {
/* On some systems raise() fails with errno 3: No such process */
kill(getpid(), signo);
}
#else
kill(getpid(), signo);
#endif
}
}
} else if (p_sig.handler != SIG_IGN) { /* ignore SIG_IGN */
if (p_sig.flags & SA_SIGINFO) {
if (p_sig.flags & SA_RESETHAND) {
SIGG(handlers)[signo-1].flags = 0;
SIGG(handlers)[signo-1].handler = SIG_DFL;
}
(*(void (*)(int, siginfo_t*, void*))p_sig.handler)(signo, siginfo, context);
} else {
(*(void (*)(int))p_sig.handler)(signo);
}
}
errno = errno_save;
} /* }}} */
/* {{{ zend_sigaction
* Register a signal handler that will be deferred in critical sections */
ZEND_API int zend_sigaction(int signo, const struct sigaction *act, struct sigaction *oldact)
{
struct sigaction sa;
sigset_t sigset;
if (oldact != NULL) {
oldact->sa_flags = SIGG(handlers)[signo-1].flags;
oldact->sa_handler = (void *) SIGG(handlers)[signo-1].handler;
oldact->sa_mask = global_sigmask;
}
if (act != NULL) {
SIGG(handlers)[signo-1].flags = act->sa_flags;
if (act->sa_flags & SA_SIGINFO) {
SIGG(handlers)[signo-1].handler = (void *) act->sa_sigaction;
} else {
SIGG(handlers)[signo-1].handler = (void *) act->sa_handler;
}
memset(&sa, 0, sizeof(sa));
sa.sa_flags = SA_SIGINFO | (act->sa_flags & SA_FLAGS_MASK);
sa.sa_sigaction = zend_signal_handler_defer;
sa.sa_mask = global_sigmask;
if (sigaction(signo, &sa, NULL) < 0) {
zend_error_noreturn(E_ERROR, "Error installing signal handler for %d", signo);
}
/* unsure this signal is not blocked */
sigemptyset(&sigset);
sigaddset(&sigset, signo);
zend_sigprocmask(SIG_UNBLOCK, &sigset, NULL);
}
return SUCCESS;
}
/* }}} */
/* {{{ zend_signal
* Register a signal handler that will be deferred in critical sections */
ZEND_API int zend_signal(int signo, void (*handler)(int))
{
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
sa.sa_flags = 0;
sa.sa_handler = handler;
sa.sa_mask = global_sigmask;
return zend_sigaction(signo, &sa, NULL);
}
/* }}} */
/* {{{ zend_signal_register
* Set a handler for a signal we want to defer.
* Previously set handler must have been saved before.
*/
static int zend_signal_register(int signo, void (*handler)(int, siginfo_t*, void*))
{
struct sigaction sa;
if (sigaction(signo, NULL, &sa) == 0) {
if ((sa.sa_flags & SA_SIGINFO) && sa.sa_sigaction == handler) {
return FAILURE;
}
SIGG(handlers)[signo-1].flags = sa.sa_flags;
if (sa.sa_flags & SA_SIGINFO) {
SIGG(handlers)[signo-1].handler = (void *)sa.sa_sigaction;
} else {
SIGG(handlers)[signo-1].handler = (void *)sa.sa_handler;
}
sa.sa_flags = SA_SIGINFO; /* we'll use a siginfo handler */
sa.sa_sigaction = handler;
sa.sa_mask = global_sigmask;
if (sigaction(signo, &sa, NULL) < 0) {
zend_error_noreturn(E_ERROR, "Error installing signal handler for %d", signo);
}
return SUCCESS;
}
return FAILURE;
} /* }}} */
/* {{{ zend_signal_activate
* Install our signal handlers, per request */
void zend_signal_activate(void)
{
size_t x;
memcpy(&SIGG(handlers), &global_orig_handlers, sizeof(global_orig_handlers));
for (x = 0; x < sizeof(zend_sigs) / sizeof(*zend_sigs); x++) {
zend_signal_register(zend_sigs[x], zend_signal_handler_defer);
}
SIGG(active) = 1;
SIGG(depth) = 0;
} /* }}} */
/* {{{ zend_signal_deactivate
* */
void zend_signal_deactivate(void)
{
if (SIGG(check)) {
size_t x;
struct sigaction sa;
if (SIGG(depth) != 0) {
zend_error(E_CORE_WARNING, "zend_signal: shutdown with non-zero blocking depth (%d)", SIGG(depth));
}
/* did anyone steal our installed handler */
for (x = 0; x < sizeof(zend_sigs) / sizeof(*zend_sigs); x++) {
sigaction(zend_sigs[x], NULL, &sa);
if (sa.sa_sigaction != zend_signal_handler_defer) {
zend_error(E_CORE_WARNING, "zend_signal: handler was replaced for signal (%d) after startup", zend_sigs[x]);
}
}
}
SIGNAL_BEGIN_CRITICAL();
SIGG(active) = 0;
SIGG(running) = 0;
SIGG(blocked) = 0;
SIGG(depth) = 0;
SIGNAL_END_CRITICAL();
}
/* }}} */
static void zend_signal_globals_ctor(zend_signal_globals_t *zend_signal_globals) /* {{{ */
{
size_t x;
memset(zend_signal_globals, 0, sizeof(*zend_signal_globals));
for (x = 0; x < sizeof(zend_signal_globals->pstorage) / sizeof(*zend_signal_globals->pstorage); ++x) {
zend_signal_queue_t *queue = &zend_signal_globals->pstorage[x];
queue->zend_signal.signo = 0;
queue->next = zend_signal_globals->pavail;
zend_signal_globals->pavail = queue;
}
}
/* }}} */
void zend_signal_init(void) /* {{{ */
{
int signo;
struct sigaction sa;
/* Save previously registered signal handlers into orig_handlers */
memset(&global_orig_handlers, 0, sizeof(global_orig_handlers));
for (signo = 1; signo < NSIG; ++signo) {
if (sigaction(signo, NULL, &sa) == 0) {
global_orig_handlers[signo-1].flags = sa.sa_flags;
if (sa.sa_flags & SA_SIGINFO) {
global_orig_handlers[signo-1].handler = (void *) sa.sa_sigaction;
} else {
global_orig_handlers[signo-1].handler = (void *) sa.sa_handler;
}
}
}
}
/* }}} */
/* {{{ zend_signal_startup
* alloc zend signal globals */
void zend_signal_startup(void)
{
#ifdef ZTS
ts_allocate_id(&zend_signal_globals_id, sizeof(zend_signal_globals_t), (ts_allocate_ctor) zend_signal_globals_ctor, NULL);
#else
zend_signal_globals_ctor(&zend_signal_globals);
#endif
/* Used to block signals during execution of signal handlers */
sigfillset(&global_sigmask);
sigdelset(&global_sigmask, SIGILL);
sigdelset(&global_sigmask, SIGABRT);
sigdelset(&global_sigmask, SIGFPE);
sigdelset(&global_sigmask, SIGKILL);
sigdelset(&global_sigmask, SIGSEGV);
sigdelset(&global_sigmask, SIGCONT);
sigdelset(&global_sigmask, SIGSTOP);
sigdelset(&global_sigmask, SIGTSTP);
sigdelset(&global_sigmask, SIGTTIN);
sigdelset(&global_sigmask, SIGTTOU);
#ifdef SIGBUS
sigdelset(&global_sigmask, SIGBUS);
#endif
#ifdef SIGSYS
sigdelset(&global_sigmask, SIGSYS);
#endif
#ifdef SIGTRAP
sigdelset(&global_sigmask, SIGTRAP);
#endif
zend_signal_init();
}
/* }}} */
#endif /* ZEND_SIGNALS */
/*
* Local variables:
* tab-width: 4
* c-basic-offset: 4
* indent-tabs-mode: t
* End:
* vim600: fdm=marker
* vim: noet sw=4 ts=4
*/
|