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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/kernel/signal.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | * | |
6 | * 1997-11-02 Modified for POSIX.1b signals by Richard Henderson | |
7 | * | |
8 | * 2003-06-02 Jim Houston - Concurrent Computer Corp. | |
9 | * Changes to use preallocated sigqueue structures | |
10 | * to allow signals to be sent reliably. | |
11 | */ | |
12 | ||
1da177e4 LT |
13 | #include <linux/slab.h> |
14 | #include <linux/module.h> | |
1da177e4 LT |
15 | #include <linux/init.h> |
16 | #include <linux/sched.h> | |
17 | #include <linux/fs.h> | |
18 | #include <linux/tty.h> | |
19 | #include <linux/binfmts.h> | |
20 | #include <linux/security.h> | |
21 | #include <linux/syscalls.h> | |
22 | #include <linux/ptrace.h> | |
7ed20e1a | 23 | #include <linux/signal.h> |
fba2afaa | 24 | #include <linux/signalfd.h> |
35de254d | 25 | #include <linux/tracehook.h> |
c59ede7b | 26 | #include <linux/capability.h> |
7dfb7103 | 27 | #include <linux/freezer.h> |
84d73786 SB |
28 | #include <linux/pid_namespace.h> |
29 | #include <linux/nsproxy.h> | |
0a16b607 | 30 | #include <trace/sched.h> |
84d73786 | 31 | |
1da177e4 LT |
32 | #include <asm/param.h> |
33 | #include <asm/uaccess.h> | |
34 | #include <asm/unistd.h> | |
35 | #include <asm/siginfo.h> | |
e1396065 | 36 | #include "audit.h" /* audit_signal_info() */ |
1da177e4 LT |
37 | |
38 | /* | |
39 | * SLAB caches for signal bits. | |
40 | */ | |
41 | ||
e18b890b | 42 | static struct kmem_cache *sigqueue_cachep; |
1da177e4 | 43 | |
7e066fb8 MD |
44 | DEFINE_TRACE(sched_signal_send); |
45 | ||
35de254d | 46 | static void __user *sig_handler(struct task_struct *t, int sig) |
93585eea | 47 | { |
35de254d RM |
48 | return t->sighand->action[sig - 1].sa.sa_handler; |
49 | } | |
93585eea | 50 | |
35de254d RM |
51 | static int sig_handler_ignored(void __user *handler, int sig) |
52 | { | |
93585eea | 53 | /* Is it explicitly or implicitly ignored? */ |
93585eea PE |
54 | return handler == SIG_IGN || |
55 | (handler == SIG_DFL && sig_kernel_ignore(sig)); | |
56 | } | |
1da177e4 | 57 | |
f008faff | 58 | static int sig_task_ignored(struct task_struct *t, int sig) |
1da177e4 | 59 | { |
35de254d | 60 | void __user *handler; |
1da177e4 | 61 | |
f008faff ON |
62 | handler = sig_handler(t, sig); |
63 | ||
64 | if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) && | |
65 | handler == SIG_DFL) | |
66 | return 1; | |
67 | ||
68 | return sig_handler_ignored(handler, sig); | |
69 | } | |
70 | ||
71 | static int sig_ignored(struct task_struct *t, int sig) | |
72 | { | |
1da177e4 LT |
73 | /* |
74 | * Blocked signals are never ignored, since the | |
75 | * signal handler may change by the time it is | |
76 | * unblocked. | |
77 | */ | |
325d22df | 78 | if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig)) |
1da177e4 LT |
79 | return 0; |
80 | ||
f008faff | 81 | if (!sig_task_ignored(t, sig)) |
35de254d RM |
82 | return 0; |
83 | ||
84 | /* | |
85 | * Tracers may want to know about even ignored signals. | |
86 | */ | |
43918f2b | 87 | return !tracehook_consider_ignored_signal(t, sig); |
1da177e4 LT |
88 | } |
89 | ||
90 | /* | |
91 | * Re-calculate pending state from the set of locally pending | |
92 | * signals, globally pending signals, and blocked signals. | |
93 | */ | |
94 | static inline int has_pending_signals(sigset_t *signal, sigset_t *blocked) | |
95 | { | |
96 | unsigned long ready; | |
97 | long i; | |
98 | ||
99 | switch (_NSIG_WORDS) { | |
100 | default: | |
101 | for (i = _NSIG_WORDS, ready = 0; --i >= 0 ;) | |
102 | ready |= signal->sig[i] &~ blocked->sig[i]; | |
103 | break; | |
104 | ||
105 | case 4: ready = signal->sig[3] &~ blocked->sig[3]; | |
106 | ready |= signal->sig[2] &~ blocked->sig[2]; | |
107 | ready |= signal->sig[1] &~ blocked->sig[1]; | |
108 | ready |= signal->sig[0] &~ blocked->sig[0]; | |
109 | break; | |
110 | ||
111 | case 2: ready = signal->sig[1] &~ blocked->sig[1]; | |
112 | ready |= signal->sig[0] &~ blocked->sig[0]; | |
113 | break; | |
114 | ||
115 | case 1: ready = signal->sig[0] &~ blocked->sig[0]; | |
116 | } | |
117 | return ready != 0; | |
118 | } | |
119 | ||
120 | #define PENDING(p,b) has_pending_signals(&(p)->signal, (b)) | |
121 | ||
7bb44ade | 122 | static int recalc_sigpending_tsk(struct task_struct *t) |
1da177e4 LT |
123 | { |
124 | if (t->signal->group_stop_count > 0 || | |
125 | PENDING(&t->pending, &t->blocked) || | |
7bb44ade | 126 | PENDING(&t->signal->shared_pending, &t->blocked)) { |
1da177e4 | 127 | set_tsk_thread_flag(t, TIF_SIGPENDING); |
7bb44ade RM |
128 | return 1; |
129 | } | |
b74d0deb RM |
130 | /* |
131 | * We must never clear the flag in another thread, or in current | |
132 | * when it's possible the current syscall is returning -ERESTART*. | |
133 | * So we don't clear it here, and only callers who know they should do. | |
134 | */ | |
7bb44ade RM |
135 | return 0; |
136 | } | |
137 | ||
138 | /* | |
139 | * After recalculating TIF_SIGPENDING, we need to make sure the task wakes up. | |
140 | * This is superfluous when called on current, the wakeup is a harmless no-op. | |
141 | */ | |
142 | void recalc_sigpending_and_wake(struct task_struct *t) | |
143 | { | |
144 | if (recalc_sigpending_tsk(t)) | |
145 | signal_wake_up(t, 0); | |
1da177e4 LT |
146 | } |
147 | ||
148 | void recalc_sigpending(void) | |
149 | { | |
b787f7ba RM |
150 | if (unlikely(tracehook_force_sigpending())) |
151 | set_thread_flag(TIF_SIGPENDING); | |
152 | else if (!recalc_sigpending_tsk(current) && !freezing(current)) | |
b74d0deb RM |
153 | clear_thread_flag(TIF_SIGPENDING); |
154 | ||
1da177e4 LT |
155 | } |
156 | ||
157 | /* Given the mask, find the first available signal that should be serviced. */ | |
158 | ||
fba2afaa | 159 | int next_signal(struct sigpending *pending, sigset_t *mask) |
1da177e4 LT |
160 | { |
161 | unsigned long i, *s, *m, x; | |
162 | int sig = 0; | |
163 | ||
164 | s = pending->signal.sig; | |
165 | m = mask->sig; | |
166 | switch (_NSIG_WORDS) { | |
167 | default: | |
168 | for (i = 0; i < _NSIG_WORDS; ++i, ++s, ++m) | |
169 | if ((x = *s &~ *m) != 0) { | |
170 | sig = ffz(~x) + i*_NSIG_BPW + 1; | |
171 | break; | |
172 | } | |
173 | break; | |
174 | ||
175 | case 2: if ((x = s[0] &~ m[0]) != 0) | |
176 | sig = 1; | |
177 | else if ((x = s[1] &~ m[1]) != 0) | |
178 | sig = _NSIG_BPW + 1; | |
179 | else | |
180 | break; | |
181 | sig += ffz(~x); | |
182 | break; | |
183 | ||
184 | case 1: if ((x = *s &~ *m) != 0) | |
185 | sig = ffz(~x) + 1; | |
186 | break; | |
187 | } | |
188 | ||
189 | return sig; | |
190 | } | |
191 | ||
c69e8d9c DH |
192 | /* |
193 | * allocate a new signal queue record | |
194 | * - this may be called without locks if and only if t == current, otherwise an | |
d84f4f99 | 195 | * appopriate lock must be held to stop the target task from exiting |
c69e8d9c | 196 | */ |
dd0fc66f | 197 | static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags, |
1da177e4 LT |
198 | int override_rlimit) |
199 | { | |
200 | struct sigqueue *q = NULL; | |
10b1fbdb | 201 | struct user_struct *user; |
1da177e4 | 202 | |
10b1fbdb | 203 | /* |
c69e8d9c DH |
204 | * We won't get problems with the target's UID changing under us |
205 | * because changing it requires RCU be used, and if t != current, the | |
206 | * caller must be holding the RCU readlock (by way of a spinlock) and | |
207 | * we use RCU protection here | |
10b1fbdb | 208 | */ |
d84f4f99 | 209 | user = get_uid(__task_cred(t)->user); |
10b1fbdb | 210 | atomic_inc(&user->sigpending); |
1da177e4 | 211 | if (override_rlimit || |
10b1fbdb | 212 | atomic_read(&user->sigpending) <= |
1da177e4 LT |
213 | t->signal->rlim[RLIMIT_SIGPENDING].rlim_cur) |
214 | q = kmem_cache_alloc(sigqueue_cachep, flags); | |
215 | if (unlikely(q == NULL)) { | |
10b1fbdb | 216 | atomic_dec(&user->sigpending); |
d84f4f99 | 217 | free_uid(user); |
1da177e4 LT |
218 | } else { |
219 | INIT_LIST_HEAD(&q->list); | |
220 | q->flags = 0; | |
d84f4f99 | 221 | q->user = user; |
1da177e4 | 222 | } |
d84f4f99 DH |
223 | |
224 | return q; | |
1da177e4 LT |
225 | } |
226 | ||
514a01b8 | 227 | static void __sigqueue_free(struct sigqueue *q) |
1da177e4 LT |
228 | { |
229 | if (q->flags & SIGQUEUE_PREALLOC) | |
230 | return; | |
231 | atomic_dec(&q->user->sigpending); | |
232 | free_uid(q->user); | |
233 | kmem_cache_free(sigqueue_cachep, q); | |
234 | } | |
235 | ||
6a14c5c9 | 236 | void flush_sigqueue(struct sigpending *queue) |
1da177e4 LT |
237 | { |
238 | struct sigqueue *q; | |
239 | ||
240 | sigemptyset(&queue->signal); | |
241 | while (!list_empty(&queue->list)) { | |
242 | q = list_entry(queue->list.next, struct sigqueue , list); | |
243 | list_del_init(&q->list); | |
244 | __sigqueue_free(q); | |
245 | } | |
246 | } | |
247 | ||
248 | /* | |
249 | * Flush all pending signals for a task. | |
250 | */ | |
c81addc9 | 251 | void flush_signals(struct task_struct *t) |
1da177e4 LT |
252 | { |
253 | unsigned long flags; | |
254 | ||
255 | spin_lock_irqsave(&t->sighand->siglock, flags); | |
f5264481 | 256 | clear_tsk_thread_flag(t, TIF_SIGPENDING); |
1da177e4 LT |
257 | flush_sigqueue(&t->pending); |
258 | flush_sigqueue(&t->signal->shared_pending); | |
259 | spin_unlock_irqrestore(&t->sighand->siglock, flags); | |
260 | } | |
261 | ||
cbaffba1 ON |
262 | static void __flush_itimer_signals(struct sigpending *pending) |
263 | { | |
264 | sigset_t signal, retain; | |
265 | struct sigqueue *q, *n; | |
266 | ||
267 | signal = pending->signal; | |
268 | sigemptyset(&retain); | |
269 | ||
270 | list_for_each_entry_safe(q, n, &pending->list, list) { | |
271 | int sig = q->info.si_signo; | |
272 | ||
273 | if (likely(q->info.si_code != SI_TIMER)) { | |
274 | sigaddset(&retain, sig); | |
275 | } else { | |
276 | sigdelset(&signal, sig); | |
277 | list_del_init(&q->list); | |
278 | __sigqueue_free(q); | |
279 | } | |
280 | } | |
281 | ||
282 | sigorsets(&pending->signal, &signal, &retain); | |
283 | } | |
284 | ||
285 | void flush_itimer_signals(void) | |
286 | { | |
287 | struct task_struct *tsk = current; | |
288 | unsigned long flags; | |
289 | ||
290 | spin_lock_irqsave(&tsk->sighand->siglock, flags); | |
291 | __flush_itimer_signals(&tsk->pending); | |
292 | __flush_itimer_signals(&tsk->signal->shared_pending); | |
293 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags); | |
294 | } | |
295 | ||
10ab825b ON |
296 | void ignore_signals(struct task_struct *t) |
297 | { | |
298 | int i; | |
299 | ||
300 | for (i = 0; i < _NSIG; ++i) | |
301 | t->sighand->action[i].sa.sa_handler = SIG_IGN; | |
302 | ||
303 | flush_signals(t); | |
304 | } | |
305 | ||
1da177e4 LT |
306 | /* |
307 | * Flush all handlers for a task. | |
308 | */ | |
309 | ||
310 | void | |
311 | flush_signal_handlers(struct task_struct *t, int force_default) | |
312 | { | |
313 | int i; | |
314 | struct k_sigaction *ka = &t->sighand->action[0]; | |
315 | for (i = _NSIG ; i != 0 ; i--) { | |
316 | if (force_default || ka->sa.sa_handler != SIG_IGN) | |
317 | ka->sa.sa_handler = SIG_DFL; | |
318 | ka->sa.sa_flags = 0; | |
319 | sigemptyset(&ka->sa.sa_mask); | |
320 | ka++; | |
321 | } | |
322 | } | |
323 | ||
abd4f750 MAS |
324 | int unhandled_signal(struct task_struct *tsk, int sig) |
325 | { | |
445a91d2 | 326 | void __user *handler = tsk->sighand->action[sig-1].sa.sa_handler; |
b460cbc5 | 327 | if (is_global_init(tsk)) |
abd4f750 | 328 | return 1; |
445a91d2 | 329 | if (handler != SIG_IGN && handler != SIG_DFL) |
abd4f750 | 330 | return 0; |
43918f2b | 331 | return !tracehook_consider_fatal_signal(tsk, sig); |
abd4f750 MAS |
332 | } |
333 | ||
1da177e4 LT |
334 | |
335 | /* Notify the system that a driver wants to block all signals for this | |
336 | * process, and wants to be notified if any signals at all were to be | |
337 | * sent/acted upon. If the notifier routine returns non-zero, then the | |
338 | * signal will be acted upon after all. If the notifier routine returns 0, | |
339 | * then then signal will be blocked. Only one block per process is | |
340 | * allowed. priv is a pointer to private data that the notifier routine | |
341 | * can use to determine if the signal should be blocked or not. */ | |
342 | ||
343 | void | |
344 | block_all_signals(int (*notifier)(void *priv), void *priv, sigset_t *mask) | |
345 | { | |
346 | unsigned long flags; | |
347 | ||
348 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
349 | current->notifier_mask = mask; | |
350 | current->notifier_data = priv; | |
351 | current->notifier = notifier; | |
352 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
353 | } | |
354 | ||
355 | /* Notify the system that blocking has ended. */ | |
356 | ||
357 | void | |
358 | unblock_all_signals(void) | |
359 | { | |
360 | unsigned long flags; | |
361 | ||
362 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
363 | current->notifier = NULL; | |
364 | current->notifier_data = NULL; | |
365 | recalc_sigpending(); | |
366 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
367 | } | |
368 | ||
100360f0 | 369 | static void collect_signal(int sig, struct sigpending *list, siginfo_t *info) |
1da177e4 LT |
370 | { |
371 | struct sigqueue *q, *first = NULL; | |
1da177e4 | 372 | |
1da177e4 LT |
373 | /* |
374 | * Collect the siginfo appropriate to this signal. Check if | |
375 | * there is another siginfo for the same signal. | |
376 | */ | |
377 | list_for_each_entry(q, &list->list, list) { | |
378 | if (q->info.si_signo == sig) { | |
d4434207 ON |
379 | if (first) |
380 | goto still_pending; | |
1da177e4 LT |
381 | first = q; |
382 | } | |
383 | } | |
d4434207 ON |
384 | |
385 | sigdelset(&list->signal, sig); | |
386 | ||
1da177e4 | 387 | if (first) { |
d4434207 | 388 | still_pending: |
1da177e4 LT |
389 | list_del_init(&first->list); |
390 | copy_siginfo(info, &first->info); | |
391 | __sigqueue_free(first); | |
1da177e4 | 392 | } else { |
1da177e4 LT |
393 | /* Ok, it wasn't in the queue. This must be |
394 | a fast-pathed signal or we must have been | |
395 | out of queue space. So zero out the info. | |
396 | */ | |
1da177e4 LT |
397 | info->si_signo = sig; |
398 | info->si_errno = 0; | |
399 | info->si_code = 0; | |
400 | info->si_pid = 0; | |
401 | info->si_uid = 0; | |
402 | } | |
1da177e4 LT |
403 | } |
404 | ||
405 | static int __dequeue_signal(struct sigpending *pending, sigset_t *mask, | |
406 | siginfo_t *info) | |
407 | { | |
27d91e07 | 408 | int sig = next_signal(pending, mask); |
1da177e4 | 409 | |
1da177e4 LT |
410 | if (sig) { |
411 | if (current->notifier) { | |
412 | if (sigismember(current->notifier_mask, sig)) { | |
413 | if (!(current->notifier)(current->notifier_data)) { | |
414 | clear_thread_flag(TIF_SIGPENDING); | |
415 | return 0; | |
416 | } | |
417 | } | |
418 | } | |
419 | ||
100360f0 | 420 | collect_signal(sig, pending, info); |
1da177e4 | 421 | } |
1da177e4 LT |
422 | |
423 | return sig; | |
424 | } | |
425 | ||
426 | /* | |
427 | * Dequeue a signal and return the element to the caller, which is | |
428 | * expected to free it. | |
429 | * | |
430 | * All callers have to hold the siglock. | |
431 | */ | |
432 | int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info) | |
433 | { | |
c5363d03 | 434 | int signr; |
caec4e8d BH |
435 | |
436 | /* We only dequeue private signals from ourselves, we don't let | |
437 | * signalfd steal them | |
438 | */ | |
b8fceee1 | 439 | signr = __dequeue_signal(&tsk->pending, mask, info); |
8bfd9a7a | 440 | if (!signr) { |
1da177e4 LT |
441 | signr = __dequeue_signal(&tsk->signal->shared_pending, |
442 | mask, info); | |
8bfd9a7a TG |
443 | /* |
444 | * itimer signal ? | |
445 | * | |
446 | * itimers are process shared and we restart periodic | |
447 | * itimers in the signal delivery path to prevent DoS | |
448 | * attacks in the high resolution timer case. This is | |
449 | * compliant with the old way of self restarting | |
450 | * itimers, as the SIGALRM is a legacy signal and only | |
451 | * queued once. Changing the restart behaviour to | |
452 | * restart the timer in the signal dequeue path is | |
453 | * reducing the timer noise on heavy loaded !highres | |
454 | * systems too. | |
455 | */ | |
456 | if (unlikely(signr == SIGALRM)) { | |
457 | struct hrtimer *tmr = &tsk->signal->real_timer; | |
458 | ||
459 | if (!hrtimer_is_queued(tmr) && | |
460 | tsk->signal->it_real_incr.tv64 != 0) { | |
461 | hrtimer_forward(tmr, tmr->base->get_time(), | |
462 | tsk->signal->it_real_incr); | |
463 | hrtimer_restart(tmr); | |
464 | } | |
465 | } | |
466 | } | |
c5363d03 | 467 | |
b8fceee1 | 468 | recalc_sigpending(); |
c5363d03 PE |
469 | if (!signr) |
470 | return 0; | |
471 | ||
472 | if (unlikely(sig_kernel_stop(signr))) { | |
8bfd9a7a TG |
473 | /* |
474 | * Set a marker that we have dequeued a stop signal. Our | |
475 | * caller might release the siglock and then the pending | |
476 | * stop signal it is about to process is no longer in the | |
477 | * pending bitmasks, but must still be cleared by a SIGCONT | |
478 | * (and overruled by a SIGKILL). So those cases clear this | |
479 | * shared flag after we've set it. Note that this flag may | |
480 | * remain set after the signal we return is ignored or | |
481 | * handled. That doesn't matter because its only purpose | |
482 | * is to alert stop-signal processing code when another | |
483 | * processor has come along and cleared the flag. | |
484 | */ | |
92413d77 | 485 | tsk->signal->flags |= SIGNAL_STOP_DEQUEUED; |
8bfd9a7a | 486 | } |
c5363d03 | 487 | if ((info->si_code & __SI_MASK) == __SI_TIMER && info->si_sys_private) { |
1da177e4 LT |
488 | /* |
489 | * Release the siglock to ensure proper locking order | |
490 | * of timer locks outside of siglocks. Note, we leave | |
491 | * irqs disabled here, since the posix-timers code is | |
492 | * about to disable them again anyway. | |
493 | */ | |
494 | spin_unlock(&tsk->sighand->siglock); | |
495 | do_schedule_next_timer(info); | |
496 | spin_lock(&tsk->sighand->siglock); | |
497 | } | |
498 | return signr; | |
499 | } | |
500 | ||
501 | /* | |
502 | * Tell a process that it has a new active signal.. | |
503 | * | |
504 | * NOTE! we rely on the previous spin_lock to | |
505 | * lock interrupts for us! We can only be called with | |
506 | * "siglock" held, and the local interrupt must | |
507 | * have been disabled when that got acquired! | |
508 | * | |
509 | * No need to set need_resched since signal event passing | |
510 | * goes through ->blocked | |
511 | */ | |
512 | void signal_wake_up(struct task_struct *t, int resume) | |
513 | { | |
514 | unsigned int mask; | |
515 | ||
516 | set_tsk_thread_flag(t, TIF_SIGPENDING); | |
517 | ||
518 | /* | |
f021a3c2 MW |
519 | * For SIGKILL, we want to wake it up in the stopped/traced/killable |
520 | * case. We don't check t->state here because there is a race with it | |
1da177e4 LT |
521 | * executing another processor and just now entering stopped state. |
522 | * By using wake_up_state, we ensure the process will wake up and | |
523 | * handle its death signal. | |
524 | */ | |
525 | mask = TASK_INTERRUPTIBLE; | |
526 | if (resume) | |
f021a3c2 | 527 | mask |= TASK_WAKEKILL; |
1da177e4 LT |
528 | if (!wake_up_state(t, mask)) |
529 | kick_process(t); | |
530 | } | |
531 | ||
71fabd5e GA |
532 | /* |
533 | * Remove signals in mask from the pending set and queue. | |
534 | * Returns 1 if any signals were found. | |
535 | * | |
536 | * All callers must be holding the siglock. | |
537 | * | |
538 | * This version takes a sigset mask and looks at all signals, | |
539 | * not just those in the first mask word. | |
540 | */ | |
541 | static int rm_from_queue_full(sigset_t *mask, struct sigpending *s) | |
542 | { | |
543 | struct sigqueue *q, *n; | |
544 | sigset_t m; | |
545 | ||
546 | sigandsets(&m, mask, &s->signal); | |
547 | if (sigisemptyset(&m)) | |
548 | return 0; | |
549 | ||
550 | signandsets(&s->signal, &s->signal, mask); | |
551 | list_for_each_entry_safe(q, n, &s->list, list) { | |
552 | if (sigismember(mask, q->info.si_signo)) { | |
553 | list_del_init(&q->list); | |
554 | __sigqueue_free(q); | |
555 | } | |
556 | } | |
557 | return 1; | |
558 | } | |
1da177e4 LT |
559 | /* |
560 | * Remove signals in mask from the pending set and queue. | |
561 | * Returns 1 if any signals were found. | |
562 | * | |
563 | * All callers must be holding the siglock. | |
564 | */ | |
565 | static int rm_from_queue(unsigned long mask, struct sigpending *s) | |
566 | { | |
567 | struct sigqueue *q, *n; | |
568 | ||
569 | if (!sigtestsetmask(&s->signal, mask)) | |
570 | return 0; | |
571 | ||
572 | sigdelsetmask(&s->signal, mask); | |
573 | list_for_each_entry_safe(q, n, &s->list, list) { | |
574 | if (q->info.si_signo < SIGRTMIN && | |
575 | (mask & sigmask(q->info.si_signo))) { | |
576 | list_del_init(&q->list); | |
577 | __sigqueue_free(q); | |
578 | } | |
579 | } | |
580 | return 1; | |
581 | } | |
582 | ||
583 | /* | |
584 | * Bad permissions for sending the signal | |
c69e8d9c | 585 | * - the caller must hold at least the RCU read lock |
1da177e4 LT |
586 | */ |
587 | static int check_kill_permission(int sig, struct siginfo *info, | |
588 | struct task_struct *t) | |
589 | { | |
c69e8d9c | 590 | const struct cred *cred = current_cred(), *tcred; |
2e2ba22e | 591 | struct pid *sid; |
3b5e9e53 ON |
592 | int error; |
593 | ||
7ed20e1a | 594 | if (!valid_signal(sig)) |
3b5e9e53 ON |
595 | return -EINVAL; |
596 | ||
597 | if (info != SEND_SIG_NOINFO && (is_si_special(info) || SI_FROMKERNEL(info))) | |
598 | return 0; | |
e54dc243 | 599 | |
3b5e9e53 ON |
600 | error = audit_signal_info(sig, t); /* Let audit system see the signal */ |
601 | if (error) | |
1da177e4 | 602 | return error; |
3b5e9e53 | 603 | |
c69e8d9c DH |
604 | tcred = __task_cred(t); |
605 | if ((cred->euid ^ tcred->suid) && | |
606 | (cred->euid ^ tcred->uid) && | |
607 | (cred->uid ^ tcred->suid) && | |
608 | (cred->uid ^ tcred->uid) && | |
2e2ba22e ON |
609 | !capable(CAP_KILL)) { |
610 | switch (sig) { | |
611 | case SIGCONT: | |
2e2ba22e | 612 | sid = task_session(t); |
2e2ba22e ON |
613 | /* |
614 | * We don't return the error if sid == NULL. The | |
615 | * task was unhashed, the caller must notice this. | |
616 | */ | |
617 | if (!sid || sid == task_session(current)) | |
618 | break; | |
619 | default: | |
620 | return -EPERM; | |
621 | } | |
622 | } | |
c2f0c7c3 | 623 | |
e54dc243 | 624 | return security_task_kill(t, info, sig, 0); |
1da177e4 LT |
625 | } |
626 | ||
1da177e4 | 627 | /* |
7e695a5e ON |
628 | * Handle magic process-wide effects of stop/continue signals. Unlike |
629 | * the signal actions, these happen immediately at signal-generation | |
1da177e4 LT |
630 | * time regardless of blocking, ignoring, or handling. This does the |
631 | * actual continuing for SIGCONT, but not the actual stopping for stop | |
7e695a5e ON |
632 | * signals. The process stop is done as a signal action for SIG_DFL. |
633 | * | |
634 | * Returns true if the signal should be actually delivered, otherwise | |
635 | * it should be dropped. | |
1da177e4 | 636 | */ |
7e695a5e | 637 | static int prepare_signal(int sig, struct task_struct *p) |
1da177e4 | 638 | { |
ad16a460 | 639 | struct signal_struct *signal = p->signal; |
1da177e4 LT |
640 | struct task_struct *t; |
641 | ||
7e695a5e | 642 | if (unlikely(signal->flags & SIGNAL_GROUP_EXIT)) { |
1da177e4 | 643 | /* |
7e695a5e | 644 | * The process is in the middle of dying, nothing to do. |
1da177e4 | 645 | */ |
7e695a5e | 646 | } else if (sig_kernel_stop(sig)) { |
1da177e4 LT |
647 | /* |
648 | * This is a stop signal. Remove SIGCONT from all queues. | |
649 | */ | |
ad16a460 | 650 | rm_from_queue(sigmask(SIGCONT), &signal->shared_pending); |
1da177e4 LT |
651 | t = p; |
652 | do { | |
653 | rm_from_queue(sigmask(SIGCONT), &t->pending); | |
ad16a460 | 654 | } while_each_thread(p, t); |
1da177e4 | 655 | } else if (sig == SIGCONT) { |
fc321d2e | 656 | unsigned int why; |
1da177e4 LT |
657 | /* |
658 | * Remove all stop signals from all queues, | |
659 | * and wake all threads. | |
660 | */ | |
ad16a460 | 661 | rm_from_queue(SIG_KERNEL_STOP_MASK, &signal->shared_pending); |
1da177e4 LT |
662 | t = p; |
663 | do { | |
664 | unsigned int state; | |
665 | rm_from_queue(SIG_KERNEL_STOP_MASK, &t->pending); | |
1da177e4 LT |
666 | /* |
667 | * If there is a handler for SIGCONT, we must make | |
668 | * sure that no thread returns to user mode before | |
669 | * we post the signal, in case it was the only | |
670 | * thread eligible to run the signal handler--then | |
671 | * it must not do anything between resuming and | |
672 | * running the handler. With the TIF_SIGPENDING | |
673 | * flag set, the thread will pause and acquire the | |
674 | * siglock that we hold now and until we've queued | |
fc321d2e | 675 | * the pending signal. |
1da177e4 LT |
676 | * |
677 | * Wake up the stopped thread _after_ setting | |
678 | * TIF_SIGPENDING | |
679 | */ | |
f021a3c2 | 680 | state = __TASK_STOPPED; |
1da177e4 LT |
681 | if (sig_user_defined(t, SIGCONT) && !sigismember(&t->blocked, SIGCONT)) { |
682 | set_tsk_thread_flag(t, TIF_SIGPENDING); | |
683 | state |= TASK_INTERRUPTIBLE; | |
684 | } | |
685 | wake_up_state(t, state); | |
ad16a460 | 686 | } while_each_thread(p, t); |
1da177e4 | 687 | |
fc321d2e ON |
688 | /* |
689 | * Notify the parent with CLD_CONTINUED if we were stopped. | |
690 | * | |
691 | * If we were in the middle of a group stop, we pretend it | |
692 | * was already finished, and then continued. Since SIGCHLD | |
693 | * doesn't queue we report only CLD_STOPPED, as if the next | |
694 | * CLD_CONTINUED was dropped. | |
695 | */ | |
696 | why = 0; | |
ad16a460 | 697 | if (signal->flags & SIGNAL_STOP_STOPPED) |
fc321d2e | 698 | why |= SIGNAL_CLD_CONTINUED; |
ad16a460 | 699 | else if (signal->group_stop_count) |
fc321d2e ON |
700 | why |= SIGNAL_CLD_STOPPED; |
701 | ||
702 | if (why) { | |
021e1ae3 ON |
703 | /* |
704 | * The first thread which returns from finish_stop() | |
705 | * will take ->siglock, notice SIGNAL_CLD_MASK, and | |
706 | * notify its parent. See get_signal_to_deliver(). | |
707 | */ | |
ad16a460 ON |
708 | signal->flags = why | SIGNAL_STOP_CONTINUED; |
709 | signal->group_stop_count = 0; | |
710 | signal->group_exit_code = 0; | |
1da177e4 LT |
711 | } else { |
712 | /* | |
713 | * We are not stopped, but there could be a stop | |
714 | * signal in the middle of being processed after | |
715 | * being removed from the queue. Clear that too. | |
716 | */ | |
ad16a460 | 717 | signal->flags &= ~SIGNAL_STOP_DEQUEUED; |
1da177e4 | 718 | } |
1da177e4 | 719 | } |
7e695a5e ON |
720 | |
721 | return !sig_ignored(p, sig); | |
1da177e4 LT |
722 | } |
723 | ||
71f11dc0 ON |
724 | /* |
725 | * Test if P wants to take SIG. After we've checked all threads with this, | |
726 | * it's equivalent to finding no threads not blocking SIG. Any threads not | |
727 | * blocking SIG were ruled out because they are not running and already | |
728 | * have pending signals. Such threads will dequeue from the shared queue | |
729 | * as soon as they're available, so putting the signal on the shared queue | |
730 | * will be equivalent to sending it to one such thread. | |
731 | */ | |
732 | static inline int wants_signal(int sig, struct task_struct *p) | |
733 | { | |
734 | if (sigismember(&p->blocked, sig)) | |
735 | return 0; | |
736 | if (p->flags & PF_EXITING) | |
737 | return 0; | |
738 | if (sig == SIGKILL) | |
739 | return 1; | |
740 | if (task_is_stopped_or_traced(p)) | |
741 | return 0; | |
742 | return task_curr(p) || !signal_pending(p); | |
743 | } | |
744 | ||
5fcd835b | 745 | static void complete_signal(int sig, struct task_struct *p, int group) |
71f11dc0 ON |
746 | { |
747 | struct signal_struct *signal = p->signal; | |
748 | struct task_struct *t; | |
749 | ||
750 | /* | |
751 | * Now find a thread we can wake up to take the signal off the queue. | |
752 | * | |
753 | * If the main thread wants the signal, it gets first crack. | |
754 | * Probably the least surprising to the average bear. | |
755 | */ | |
756 | if (wants_signal(sig, p)) | |
757 | t = p; | |
5fcd835b | 758 | else if (!group || thread_group_empty(p)) |
71f11dc0 ON |
759 | /* |
760 | * There is just one thread and it does not need to be woken. | |
761 | * It will dequeue unblocked signals before it runs again. | |
762 | */ | |
763 | return; | |
764 | else { | |
765 | /* | |
766 | * Otherwise try to find a suitable thread. | |
767 | */ | |
768 | t = signal->curr_target; | |
769 | while (!wants_signal(sig, t)) { | |
770 | t = next_thread(t); | |
771 | if (t == signal->curr_target) | |
772 | /* | |
773 | * No thread needs to be woken. | |
774 | * Any eligible threads will see | |
775 | * the signal in the queue soon. | |
776 | */ | |
777 | return; | |
778 | } | |
779 | signal->curr_target = t; | |
780 | } | |
781 | ||
782 | /* | |
783 | * Found a killable thread. If the signal will be fatal, | |
784 | * then start taking the whole group down immediately. | |
785 | */ | |
fae5fa44 ON |
786 | if (sig_fatal(p, sig) && |
787 | !(signal->flags & (SIGNAL_UNKILLABLE | SIGNAL_GROUP_EXIT)) && | |
71f11dc0 | 788 | !sigismember(&t->real_blocked, sig) && |
445a91d2 | 789 | (sig == SIGKILL || |
43918f2b | 790 | !tracehook_consider_fatal_signal(t, sig))) { |
71f11dc0 ON |
791 | /* |
792 | * This signal will be fatal to the whole group. | |
793 | */ | |
794 | if (!sig_kernel_coredump(sig)) { | |
795 | /* | |
796 | * Start a group exit and wake everybody up. | |
797 | * This way we don't have other threads | |
798 | * running and doing things after a slower | |
799 | * thread has the fatal signal pending. | |
800 | */ | |
801 | signal->flags = SIGNAL_GROUP_EXIT; | |
802 | signal->group_exit_code = sig; | |
803 | signal->group_stop_count = 0; | |
804 | t = p; | |
805 | do { | |
806 | sigaddset(&t->pending.signal, SIGKILL); | |
807 | signal_wake_up(t, 1); | |
808 | } while_each_thread(p, t); | |
809 | return; | |
810 | } | |
811 | } | |
812 | ||
813 | /* | |
814 | * The signal is already in the shared-pending queue. | |
815 | * Tell the chosen thread to wake up and dequeue it. | |
816 | */ | |
817 | signal_wake_up(t, sig == SIGKILL); | |
818 | return; | |
819 | } | |
820 | ||
af7fff9c PE |
821 | static inline int legacy_queue(struct sigpending *signals, int sig) |
822 | { | |
823 | return (sig < SIGRTMIN) && sigismember(&signals->signal, sig); | |
824 | } | |
825 | ||
1da177e4 | 826 | static int send_signal(int sig, struct siginfo *info, struct task_struct *t, |
2ca3515a | 827 | int group) |
1da177e4 | 828 | { |
2ca3515a | 829 | struct sigpending *pending; |
6e65acba | 830 | struct sigqueue *q; |
1da177e4 | 831 | |
0a16b607 MD |
832 | trace_sched_signal_send(sig, t); |
833 | ||
6e65acba | 834 | assert_spin_locked(&t->sighand->siglock); |
7e695a5e ON |
835 | if (!prepare_signal(sig, t)) |
836 | return 0; | |
2ca3515a ON |
837 | |
838 | pending = group ? &t->signal->shared_pending : &t->pending; | |
2acb024d PE |
839 | /* |
840 | * Short-circuit ignored signals and support queuing | |
841 | * exactly one non-rt signal, so that we can get more | |
842 | * detailed information about the cause of the signal. | |
843 | */ | |
7e695a5e | 844 | if (legacy_queue(pending, sig)) |
2acb024d | 845 | return 0; |
1da177e4 LT |
846 | /* |
847 | * fast-pathed signals for kernel-internal things like SIGSTOP | |
848 | * or SIGKILL. | |
849 | */ | |
b67a1b9e | 850 | if (info == SEND_SIG_FORCED) |
1da177e4 LT |
851 | goto out_set; |
852 | ||
853 | /* Real-time signals must be queued if sent by sigqueue, or | |
854 | some other real-time mechanism. It is implementation | |
855 | defined whether kill() does so. We attempt to do so, on | |
856 | the principle of least surprise, but since kill is not | |
857 | allowed to fail with EAGAIN when low on memory we just | |
858 | make sure at least one signal gets delivered and don't | |
859 | pass on the info struct. */ | |
860 | ||
861 | q = __sigqueue_alloc(t, GFP_ATOMIC, (sig < SIGRTMIN && | |
621d3121 | 862 | (is_si_special(info) || |
1da177e4 LT |
863 | info->si_code >= 0))); |
864 | if (q) { | |
2ca3515a | 865 | list_add_tail(&q->list, &pending->list); |
1da177e4 | 866 | switch ((unsigned long) info) { |
b67a1b9e | 867 | case (unsigned long) SEND_SIG_NOINFO: |
1da177e4 LT |
868 | q->info.si_signo = sig; |
869 | q->info.si_errno = 0; | |
870 | q->info.si_code = SI_USER; | |
9cd4fd10 | 871 | q->info.si_pid = task_tgid_nr_ns(current, |
09bca05c | 872 | task_active_pid_ns(t)); |
76aac0e9 | 873 | q->info.si_uid = current_uid(); |
1da177e4 | 874 | break; |
b67a1b9e | 875 | case (unsigned long) SEND_SIG_PRIV: |
1da177e4 LT |
876 | q->info.si_signo = sig; |
877 | q->info.si_errno = 0; | |
878 | q->info.si_code = SI_KERNEL; | |
879 | q->info.si_pid = 0; | |
880 | q->info.si_uid = 0; | |
881 | break; | |
882 | default: | |
883 | copy_siginfo(&q->info, info); | |
884 | break; | |
885 | } | |
621d3121 ON |
886 | } else if (!is_si_special(info)) { |
887 | if (sig >= SIGRTMIN && info->si_code != SI_USER) | |
1da177e4 LT |
888 | /* |
889 | * Queue overflow, abort. We may abort if the signal was rt | |
890 | * and sent by user using something other than kill(). | |
891 | */ | |
892 | return -EAGAIN; | |
1da177e4 LT |
893 | } |
894 | ||
895 | out_set: | |
53c30337 | 896 | signalfd_notify(t, sig); |
2ca3515a | 897 | sigaddset(&pending->signal, sig); |
4cd4b6d4 PE |
898 | complete_signal(sig, t, group); |
899 | return 0; | |
1da177e4 LT |
900 | } |
901 | ||
45807a1d IM |
902 | int print_fatal_signals; |
903 | ||
904 | static void print_fatal_signal(struct pt_regs *regs, int signr) | |
905 | { | |
906 | printk("%s/%d: potentially unexpected fatal signal %d.\n", | |
ba25f9dc | 907 | current->comm, task_pid_nr(current), signr); |
45807a1d | 908 | |
ca5cd877 | 909 | #if defined(__i386__) && !defined(__arch_um__) |
65ea5b03 | 910 | printk("code at %08lx: ", regs->ip); |
45807a1d IM |
911 | { |
912 | int i; | |
913 | for (i = 0; i < 16; i++) { | |
914 | unsigned char insn; | |
915 | ||
65ea5b03 | 916 | __get_user(insn, (unsigned char *)(regs->ip + i)); |
45807a1d IM |
917 | printk("%02x ", insn); |
918 | } | |
919 | } | |
920 | #endif | |
921 | printk("\n"); | |
3a9f84d3 | 922 | preempt_disable(); |
45807a1d | 923 | show_regs(regs); |
3a9f84d3 | 924 | preempt_enable(); |
45807a1d IM |
925 | } |
926 | ||
927 | static int __init setup_print_fatal_signals(char *str) | |
928 | { | |
929 | get_option (&str, &print_fatal_signals); | |
930 | ||
931 | return 1; | |
932 | } | |
933 | ||
934 | __setup("print-fatal-signals=", setup_print_fatal_signals); | |
1da177e4 | 935 | |
4cd4b6d4 PE |
936 | int |
937 | __group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) | |
938 | { | |
939 | return send_signal(sig, info, p, 1); | |
940 | } | |
941 | ||
1da177e4 LT |
942 | static int |
943 | specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t) | |
944 | { | |
4cd4b6d4 | 945 | return send_signal(sig, info, t, 0); |
1da177e4 LT |
946 | } |
947 | ||
948 | /* | |
949 | * Force a signal that the process can't ignore: if necessary | |
950 | * we unblock the signal and change any SIG_IGN to SIG_DFL. | |
ae74c3b6 LT |
951 | * |
952 | * Note: If we unblock the signal, we always reset it to SIG_DFL, | |
953 | * since we do not want to have a signal handler that was blocked | |
954 | * be invoked when user space had explicitly blocked it. | |
955 | * | |
80fe728d ON |
956 | * We don't want to have recursive SIGSEGV's etc, for example, |
957 | * that is why we also clear SIGNAL_UNKILLABLE. | |
1da177e4 | 958 | */ |
1da177e4 LT |
959 | int |
960 | force_sig_info(int sig, struct siginfo *info, struct task_struct *t) | |
961 | { | |
962 | unsigned long int flags; | |
ae74c3b6 LT |
963 | int ret, blocked, ignored; |
964 | struct k_sigaction *action; | |
1da177e4 LT |
965 | |
966 | spin_lock_irqsave(&t->sighand->siglock, flags); | |
ae74c3b6 LT |
967 | action = &t->sighand->action[sig-1]; |
968 | ignored = action->sa.sa_handler == SIG_IGN; | |
969 | blocked = sigismember(&t->blocked, sig); | |
970 | if (blocked || ignored) { | |
971 | action->sa.sa_handler = SIG_DFL; | |
972 | if (blocked) { | |
973 | sigdelset(&t->blocked, sig); | |
7bb44ade | 974 | recalc_sigpending_and_wake(t); |
ae74c3b6 | 975 | } |
1da177e4 | 976 | } |
80fe728d ON |
977 | if (action->sa.sa_handler == SIG_DFL) |
978 | t->signal->flags &= ~SIGNAL_UNKILLABLE; | |
1da177e4 LT |
979 | ret = specific_send_sig_info(sig, info, t); |
980 | spin_unlock_irqrestore(&t->sighand->siglock, flags); | |
981 | ||
982 | return ret; | |
983 | } | |
984 | ||
985 | void | |
986 | force_sig_specific(int sig, struct task_struct *t) | |
987 | { | |
b0423a0d | 988 | force_sig_info(sig, SEND_SIG_FORCED, t); |
1da177e4 LT |
989 | } |
990 | ||
1da177e4 LT |
991 | /* |
992 | * Nuke all other threads in the group. | |
993 | */ | |
994 | void zap_other_threads(struct task_struct *p) | |
995 | { | |
996 | struct task_struct *t; | |
997 | ||
1da177e4 LT |
998 | p->signal->group_stop_count = 0; |
999 | ||
1da177e4 LT |
1000 | for (t = next_thread(p); t != p; t = next_thread(t)) { |
1001 | /* | |
1002 | * Don't bother with already dead threads | |
1003 | */ | |
1004 | if (t->exit_state) | |
1005 | continue; | |
1006 | ||
30e0fca6 | 1007 | /* SIGKILL will be handled before any pending SIGSTOP */ |
1da177e4 | 1008 | sigaddset(&t->pending.signal, SIGKILL); |
1da177e4 LT |
1009 | signal_wake_up(t, 1); |
1010 | } | |
1011 | } | |
1012 | ||
b5606c2d | 1013 | int __fatal_signal_pending(struct task_struct *tsk) |
f776d12d MW |
1014 | { |
1015 | return sigismember(&tsk->pending.signal, SIGKILL); | |
1016 | } | |
13f09b95 | 1017 | EXPORT_SYMBOL(__fatal_signal_pending); |
f776d12d | 1018 | |
f63ee72e ON |
1019 | struct sighand_struct *lock_task_sighand(struct task_struct *tsk, unsigned long *flags) |
1020 | { | |
1021 | struct sighand_struct *sighand; | |
1022 | ||
1406f2d3 | 1023 | rcu_read_lock(); |
f63ee72e ON |
1024 | for (;;) { |
1025 | sighand = rcu_dereference(tsk->sighand); | |
1026 | if (unlikely(sighand == NULL)) | |
1027 | break; | |
1028 | ||
1029 | spin_lock_irqsave(&sighand->siglock, *flags); | |
1030 | if (likely(sighand == tsk->sighand)) | |
1031 | break; | |
1032 | spin_unlock_irqrestore(&sighand->siglock, *flags); | |
1033 | } | |
1406f2d3 | 1034 | rcu_read_unlock(); |
f63ee72e ON |
1035 | |
1036 | return sighand; | |
1037 | } | |
1038 | ||
c69e8d9c DH |
1039 | /* |
1040 | * send signal info to all the members of a group | |
1041 | * - the caller must hold the RCU read lock at least | |
1042 | */ | |
1da177e4 LT |
1043 | int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) |
1044 | { | |
1045 | unsigned long flags; | |
1046 | int ret; | |
1047 | ||
1048 | ret = check_kill_permission(sig, info, p); | |
f63ee72e ON |
1049 | |
1050 | if (!ret && sig) { | |
1051 | ret = -ESRCH; | |
1052 | if (lock_task_sighand(p, &flags)) { | |
1053 | ret = __group_send_sig_info(sig, info, p); | |
1054 | unlock_task_sighand(p, &flags); | |
2d89c929 | 1055 | } |
1da177e4 LT |
1056 | } |
1057 | ||
1058 | return ret; | |
1059 | } | |
1060 | ||
1061 | /* | |
146a505d | 1062 | * __kill_pgrp_info() sends a signal to a process group: this is what the tty |
1da177e4 | 1063 | * control characters do (^C, ^Z etc) |
c69e8d9c | 1064 | * - the caller must hold at least a readlock on tasklist_lock |
1da177e4 | 1065 | */ |
c4b92fc1 | 1066 | int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp) |
1da177e4 LT |
1067 | { |
1068 | struct task_struct *p = NULL; | |
1069 | int retval, success; | |
1070 | ||
1da177e4 LT |
1071 | success = 0; |
1072 | retval = -ESRCH; | |
c4b92fc1 | 1073 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
1da177e4 LT |
1074 | int err = group_send_sig_info(sig, info, p); |
1075 | success |= !err; | |
1076 | retval = err; | |
c4b92fc1 | 1077 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
1da177e4 LT |
1078 | return success ? 0 : retval; |
1079 | } | |
1080 | ||
c4b92fc1 | 1081 | int kill_pid_info(int sig, struct siginfo *info, struct pid *pid) |
1da177e4 | 1082 | { |
d36174bc | 1083 | int error = -ESRCH; |
1da177e4 LT |
1084 | struct task_struct *p; |
1085 | ||
e56d0903 | 1086 | rcu_read_lock(); |
d36174bc | 1087 | retry: |
c4b92fc1 | 1088 | p = pid_task(pid, PIDTYPE_PID); |
d36174bc | 1089 | if (p) { |
1da177e4 | 1090 | error = group_send_sig_info(sig, info, p); |
d36174bc ON |
1091 | if (unlikely(error == -ESRCH)) |
1092 | /* | |
1093 | * The task was unhashed in between, try again. | |
1094 | * If it is dead, pid_task() will return NULL, | |
1095 | * if we race with de_thread() it will find the | |
1096 | * new leader. | |
1097 | */ | |
1098 | goto retry; | |
1099 | } | |
e56d0903 | 1100 | rcu_read_unlock(); |
6ca25b55 | 1101 | |
1da177e4 LT |
1102 | return error; |
1103 | } | |
1104 | ||
c3de4b38 MW |
1105 | int |
1106 | kill_proc_info(int sig, struct siginfo *info, pid_t pid) | |
c4b92fc1 EB |
1107 | { |
1108 | int error; | |
1109 | rcu_read_lock(); | |
b488893a | 1110 | error = kill_pid_info(sig, info, find_vpid(pid)); |
c4b92fc1 EB |
1111 | rcu_read_unlock(); |
1112 | return error; | |
1113 | } | |
1114 | ||
2425c08b EB |
1115 | /* like kill_pid_info(), but doesn't use uid/euid of "current" */ |
1116 | int kill_pid_info_as_uid(int sig, struct siginfo *info, struct pid *pid, | |
8f95dc58 | 1117 | uid_t uid, uid_t euid, u32 secid) |
46113830 HW |
1118 | { |
1119 | int ret = -EINVAL; | |
1120 | struct task_struct *p; | |
c69e8d9c | 1121 | const struct cred *pcred; |
46113830 HW |
1122 | |
1123 | if (!valid_signal(sig)) | |
1124 | return ret; | |
1125 | ||
1126 | read_lock(&tasklist_lock); | |
2425c08b | 1127 | p = pid_task(pid, PIDTYPE_PID); |
46113830 HW |
1128 | if (!p) { |
1129 | ret = -ESRCH; | |
1130 | goto out_unlock; | |
1131 | } | |
c69e8d9c DH |
1132 | pcred = __task_cred(p); |
1133 | if ((info == SEND_SIG_NOINFO || | |
1134 | (!is_si_special(info) && SI_FROMUSER(info))) && | |
1135 | euid != pcred->suid && euid != pcred->uid && | |
1136 | uid != pcred->suid && uid != pcred->uid) { | |
46113830 HW |
1137 | ret = -EPERM; |
1138 | goto out_unlock; | |
1139 | } | |
8f95dc58 DQ |
1140 | ret = security_task_kill(p, info, sig, secid); |
1141 | if (ret) | |
1142 | goto out_unlock; | |
46113830 HW |
1143 | if (sig && p->sighand) { |
1144 | unsigned long flags; | |
1145 | spin_lock_irqsave(&p->sighand->siglock, flags); | |
1146 | ret = __group_send_sig_info(sig, info, p); | |
1147 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | |
1148 | } | |
1149 | out_unlock: | |
1150 | read_unlock(&tasklist_lock); | |
1151 | return ret; | |
1152 | } | |
2425c08b | 1153 | EXPORT_SYMBOL_GPL(kill_pid_info_as_uid); |
1da177e4 LT |
1154 | |
1155 | /* | |
1156 | * kill_something_info() interprets pid in interesting ways just like kill(2). | |
1157 | * | |
1158 | * POSIX specifies that kill(-1,sig) is unspecified, but what we have | |
1159 | * is probably wrong. Should make it like BSD or SYSV. | |
1160 | */ | |
1161 | ||
bc64efd2 | 1162 | static int kill_something_info(int sig, struct siginfo *info, pid_t pid) |
1da177e4 | 1163 | { |
8d42db18 | 1164 | int ret; |
d5df763b PE |
1165 | |
1166 | if (pid > 0) { | |
1167 | rcu_read_lock(); | |
1168 | ret = kill_pid_info(sig, info, find_vpid(pid)); | |
1169 | rcu_read_unlock(); | |
1170 | return ret; | |
1171 | } | |
1172 | ||
1173 | read_lock(&tasklist_lock); | |
1174 | if (pid != -1) { | |
1175 | ret = __kill_pgrp_info(sig, info, | |
1176 | pid ? find_vpid(-pid) : task_pgrp(current)); | |
1177 | } else { | |
1da177e4 LT |
1178 | int retval = 0, count = 0; |
1179 | struct task_struct * p; | |
1180 | ||
1da177e4 | 1181 | for_each_process(p) { |
d25141a8 SB |
1182 | if (task_pid_vnr(p) > 1 && |
1183 | !same_thread_group(p, current)) { | |
1da177e4 LT |
1184 | int err = group_send_sig_info(sig, info, p); |
1185 | ++count; | |
1186 | if (err != -EPERM) | |
1187 | retval = err; | |
1188 | } | |
1189 | } | |
8d42db18 | 1190 | ret = count ? retval : -ESRCH; |
1da177e4 | 1191 | } |
d5df763b PE |
1192 | read_unlock(&tasklist_lock); |
1193 | ||
8d42db18 | 1194 | return ret; |
1da177e4 LT |
1195 | } |
1196 | ||
1197 | /* | |
1198 | * These are for backward compatibility with the rest of the kernel source. | |
1199 | */ | |
1200 | ||
1201 | /* | |
08d2c30c | 1202 | * The caller must ensure the task can't exit. |
1da177e4 LT |
1203 | */ |
1204 | int | |
1205 | send_sig_info(int sig, struct siginfo *info, struct task_struct *p) | |
1206 | { | |
1207 | int ret; | |
1208 | unsigned long flags; | |
1209 | ||
1210 | /* | |
1211 | * Make sure legacy kernel users don't send in bad values | |
1212 | * (normal paths check this in check_kill_permission). | |
1213 | */ | |
7ed20e1a | 1214 | if (!valid_signal(sig)) |
1da177e4 LT |
1215 | return -EINVAL; |
1216 | ||
1da177e4 LT |
1217 | spin_lock_irqsave(&p->sighand->siglock, flags); |
1218 | ret = specific_send_sig_info(sig, info, p); | |
1219 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | |
1da177e4 LT |
1220 | return ret; |
1221 | } | |
1222 | ||
b67a1b9e ON |
1223 | #define __si_special(priv) \ |
1224 | ((priv) ? SEND_SIG_PRIV : SEND_SIG_NOINFO) | |
1225 | ||
1da177e4 LT |
1226 | int |
1227 | send_sig(int sig, struct task_struct *p, int priv) | |
1228 | { | |
b67a1b9e | 1229 | return send_sig_info(sig, __si_special(priv), p); |
1da177e4 LT |
1230 | } |
1231 | ||
1da177e4 LT |
1232 | void |
1233 | force_sig(int sig, struct task_struct *p) | |
1234 | { | |
b67a1b9e | 1235 | force_sig_info(sig, SEND_SIG_PRIV, p); |
1da177e4 LT |
1236 | } |
1237 | ||
1238 | /* | |
1239 | * When things go south during signal handling, we | |
1240 | * will force a SIGSEGV. And if the signal that caused | |
1241 | * the problem was already a SIGSEGV, we'll want to | |
1242 | * make sure we don't even try to deliver the signal.. | |
1243 | */ | |
1244 | int | |
1245 | force_sigsegv(int sig, struct task_struct *p) | |
1246 | { | |
1247 | if (sig == SIGSEGV) { | |
1248 | unsigned long flags; | |
1249 | spin_lock_irqsave(&p->sighand->siglock, flags); | |
1250 | p->sighand->action[sig - 1].sa.sa_handler = SIG_DFL; | |
1251 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | |
1252 | } | |
1253 | force_sig(SIGSEGV, p); | |
1254 | return 0; | |
1255 | } | |
1256 | ||
c4b92fc1 EB |
1257 | int kill_pgrp(struct pid *pid, int sig, int priv) |
1258 | { | |
146a505d PE |
1259 | int ret; |
1260 | ||
1261 | read_lock(&tasklist_lock); | |
1262 | ret = __kill_pgrp_info(sig, __si_special(priv), pid); | |
1263 | read_unlock(&tasklist_lock); | |
1264 | ||
1265 | return ret; | |
c4b92fc1 EB |
1266 | } |
1267 | EXPORT_SYMBOL(kill_pgrp); | |
1268 | ||
1269 | int kill_pid(struct pid *pid, int sig, int priv) | |
1270 | { | |
1271 | return kill_pid_info(sig, __si_special(priv), pid); | |
1272 | } | |
1273 | EXPORT_SYMBOL(kill_pid); | |
1274 | ||
1da177e4 LT |
1275 | /* |
1276 | * These functions support sending signals using preallocated sigqueue | |
1277 | * structures. This is needed "because realtime applications cannot | |
1278 | * afford to lose notifications of asynchronous events, like timer | |
1279 | * expirations or I/O completions". In the case of Posix Timers | |
1280 | * we allocate the sigqueue structure from the timer_create. If this | |
1281 | * allocation fails we are able to report the failure to the application | |
1282 | * with an EAGAIN error. | |
1283 | */ | |
1284 | ||
1285 | struct sigqueue *sigqueue_alloc(void) | |
1286 | { | |
1287 | struct sigqueue *q; | |
1288 | ||
1289 | if ((q = __sigqueue_alloc(current, GFP_KERNEL, 0))) | |
1290 | q->flags |= SIGQUEUE_PREALLOC; | |
1291 | return(q); | |
1292 | } | |
1293 | ||
1294 | void sigqueue_free(struct sigqueue *q) | |
1295 | { | |
1296 | unsigned long flags; | |
60187d27 ON |
1297 | spinlock_t *lock = ¤t->sighand->siglock; |
1298 | ||
1da177e4 LT |
1299 | BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); |
1300 | /* | |
c8e85b4f ON |
1301 | * We must hold ->siglock while testing q->list |
1302 | * to serialize with collect_signal() or with | |
da7978b0 | 1303 | * __exit_signal()->flush_sigqueue(). |
1da177e4 | 1304 | */ |
60187d27 | 1305 | spin_lock_irqsave(lock, flags); |
c8e85b4f ON |
1306 | q->flags &= ~SIGQUEUE_PREALLOC; |
1307 | /* | |
1308 | * If it is queued it will be freed when dequeued, | |
1309 | * like the "regular" sigqueue. | |
1310 | */ | |
60187d27 | 1311 | if (!list_empty(&q->list)) |
c8e85b4f | 1312 | q = NULL; |
60187d27 ON |
1313 | spin_unlock_irqrestore(lock, flags); |
1314 | ||
c8e85b4f ON |
1315 | if (q) |
1316 | __sigqueue_free(q); | |
1da177e4 LT |
1317 | } |
1318 | ||
ac5c2153 | 1319 | int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group) |
9e3bd6c3 | 1320 | { |
e62e6650 | 1321 | int sig = q->info.si_signo; |
2ca3515a | 1322 | struct sigpending *pending; |
e62e6650 ON |
1323 | unsigned long flags; |
1324 | int ret; | |
2ca3515a | 1325 | |
4cd4b6d4 | 1326 | BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); |
e62e6650 ON |
1327 | |
1328 | ret = -1; | |
1329 | if (!likely(lock_task_sighand(t, &flags))) | |
1330 | goto ret; | |
1331 | ||
7e695a5e ON |
1332 | ret = 1; /* the signal is ignored */ |
1333 | if (!prepare_signal(sig, t)) | |
e62e6650 ON |
1334 | goto out; |
1335 | ||
1336 | ret = 0; | |
9e3bd6c3 PE |
1337 | if (unlikely(!list_empty(&q->list))) { |
1338 | /* | |
1339 | * If an SI_TIMER entry is already queue just increment | |
1340 | * the overrun count. | |
1341 | */ | |
9e3bd6c3 PE |
1342 | BUG_ON(q->info.si_code != SI_TIMER); |
1343 | q->info.si_overrun++; | |
e62e6650 | 1344 | goto out; |
9e3bd6c3 | 1345 | } |
ba661292 | 1346 | q->info.si_overrun = 0; |
9e3bd6c3 | 1347 | |
9e3bd6c3 | 1348 | signalfd_notify(t, sig); |
2ca3515a | 1349 | pending = group ? &t->signal->shared_pending : &t->pending; |
9e3bd6c3 PE |
1350 | list_add_tail(&q->list, &pending->list); |
1351 | sigaddset(&pending->signal, sig); | |
4cd4b6d4 | 1352 | complete_signal(sig, t, group); |
e62e6650 ON |
1353 | out: |
1354 | unlock_task_sighand(t, &flags); | |
1355 | ret: | |
1356 | return ret; | |
9e3bd6c3 PE |
1357 | } |
1358 | ||
1da177e4 LT |
1359 | /* |
1360 | * Wake up any threads in the parent blocked in wait* syscalls. | |
1361 | */ | |
1362 | static inline void __wake_up_parent(struct task_struct *p, | |
1363 | struct task_struct *parent) | |
1364 | { | |
1365 | wake_up_interruptible_sync(&parent->signal->wait_chldexit); | |
1366 | } | |
1367 | ||
1368 | /* | |
1369 | * Let a parent know about the death of a child. | |
1370 | * For a stopped/continued status change, use do_notify_parent_cldstop instead. | |
2b2a1ff6 RM |
1371 | * |
1372 | * Returns -1 if our parent ignored us and so we've switched to | |
1373 | * self-reaping, or else @sig. | |
1da177e4 | 1374 | */ |
2b2a1ff6 | 1375 | int do_notify_parent(struct task_struct *tsk, int sig) |
1da177e4 LT |
1376 | { |
1377 | struct siginfo info; | |
1378 | unsigned long flags; | |
1379 | struct sighand_struct *psig; | |
1b04624f | 1380 | int ret = sig; |
1da177e4 LT |
1381 | |
1382 | BUG_ON(sig == -1); | |
1383 | ||
1384 | /* do_notify_parent_cldstop should have been called instead. */ | |
e1abb39c | 1385 | BUG_ON(task_is_stopped_or_traced(tsk)); |
1da177e4 LT |
1386 | |
1387 | BUG_ON(!tsk->ptrace && | |
1388 | (tsk->group_leader != tsk || !thread_group_empty(tsk))); | |
1389 | ||
1390 | info.si_signo = sig; | |
1391 | info.si_errno = 0; | |
b488893a PE |
1392 | /* |
1393 | * we are under tasklist_lock here so our parent is tied to | |
1394 | * us and cannot exit and release its namespace. | |
1395 | * | |
1396 | * the only it can is to switch its nsproxy with sys_unshare, | |
1397 | * bu uncharing pid namespaces is not allowed, so we'll always | |
1398 | * see relevant namespace | |
1399 | * | |
1400 | * write_lock() currently calls preempt_disable() which is the | |
1401 | * same as rcu_read_lock(), but according to Oleg, this is not | |
1402 | * correct to rely on this | |
1403 | */ | |
1404 | rcu_read_lock(); | |
1405 | info.si_pid = task_pid_nr_ns(tsk, tsk->parent->nsproxy->pid_ns); | |
c69e8d9c | 1406 | info.si_uid = __task_cred(tsk)->uid; |
b488893a PE |
1407 | rcu_read_unlock(); |
1408 | ||
32bd671d PZ |
1409 | info.si_utime = cputime_to_clock_t(cputime_add(tsk->utime, |
1410 | tsk->signal->utime)); | |
1411 | info.si_stime = cputime_to_clock_t(cputime_add(tsk->stime, | |
1412 | tsk->signal->stime)); | |
1da177e4 LT |
1413 | |
1414 | info.si_status = tsk->exit_code & 0x7f; | |
1415 | if (tsk->exit_code & 0x80) | |
1416 | info.si_code = CLD_DUMPED; | |
1417 | else if (tsk->exit_code & 0x7f) | |
1418 | info.si_code = CLD_KILLED; | |
1419 | else { | |
1420 | info.si_code = CLD_EXITED; | |
1421 | info.si_status = tsk->exit_code >> 8; | |
1422 | } | |
1423 | ||
1424 | psig = tsk->parent->sighand; | |
1425 | spin_lock_irqsave(&psig->siglock, flags); | |
7ed0175a | 1426 | if (!tsk->ptrace && sig == SIGCHLD && |
1da177e4 LT |
1427 | (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN || |
1428 | (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT))) { | |
1429 | /* | |
1430 | * We are exiting and our parent doesn't care. POSIX.1 | |
1431 | * defines special semantics for setting SIGCHLD to SIG_IGN | |
1432 | * or setting the SA_NOCLDWAIT flag: we should be reaped | |
1433 | * automatically and not left for our parent's wait4 call. | |
1434 | * Rather than having the parent do it as a magic kind of | |
1435 | * signal handler, we just set this to tell do_exit that we | |
1436 | * can be cleaned up without becoming a zombie. Note that | |
1437 | * we still call __wake_up_parent in this case, because a | |
1438 | * blocked sys_wait4 might now return -ECHILD. | |
1439 | * | |
1440 | * Whether we send SIGCHLD or not for SA_NOCLDWAIT | |
1441 | * is implementation-defined: we do (if you don't want | |
1442 | * it, just use SIG_IGN instead). | |
1443 | */ | |
1b04624f | 1444 | ret = tsk->exit_signal = -1; |
1da177e4 | 1445 | if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) |
2b2a1ff6 | 1446 | sig = -1; |
1da177e4 | 1447 | } |
7ed20e1a | 1448 | if (valid_signal(sig) && sig > 0) |
1da177e4 LT |
1449 | __group_send_sig_info(sig, &info, tsk->parent); |
1450 | __wake_up_parent(tsk, tsk->parent); | |
1451 | spin_unlock_irqrestore(&psig->siglock, flags); | |
2b2a1ff6 | 1452 | |
1b04624f | 1453 | return ret; |
1da177e4 LT |
1454 | } |
1455 | ||
a1d5e21e | 1456 | static void do_notify_parent_cldstop(struct task_struct *tsk, int why) |
1da177e4 LT |
1457 | { |
1458 | struct siginfo info; | |
1459 | unsigned long flags; | |
bc505a47 | 1460 | struct task_struct *parent; |
1da177e4 LT |
1461 | struct sighand_struct *sighand; |
1462 | ||
a1d5e21e | 1463 | if (tsk->ptrace & PT_PTRACED) |
bc505a47 ON |
1464 | parent = tsk->parent; |
1465 | else { | |
1466 | tsk = tsk->group_leader; | |
1467 | parent = tsk->real_parent; | |
1468 | } | |
1469 | ||
1da177e4 LT |
1470 | info.si_signo = SIGCHLD; |
1471 | info.si_errno = 0; | |
b488893a PE |
1472 | /* |
1473 | * see comment in do_notify_parent() abot the following 3 lines | |
1474 | */ | |
1475 | rcu_read_lock(); | |
1476 | info.si_pid = task_pid_nr_ns(tsk, tsk->parent->nsproxy->pid_ns); | |
c69e8d9c | 1477 | info.si_uid = __task_cred(tsk)->uid; |
b488893a PE |
1478 | rcu_read_unlock(); |
1479 | ||
d8878ba3 MK |
1480 | info.si_utime = cputime_to_clock_t(tsk->utime); |
1481 | info.si_stime = cputime_to_clock_t(tsk->stime); | |
1da177e4 LT |
1482 | |
1483 | info.si_code = why; | |
1484 | switch (why) { | |
1485 | case CLD_CONTINUED: | |
1486 | info.si_status = SIGCONT; | |
1487 | break; | |
1488 | case CLD_STOPPED: | |
1489 | info.si_status = tsk->signal->group_exit_code & 0x7f; | |
1490 | break; | |
1491 | case CLD_TRAPPED: | |
1492 | info.si_status = tsk->exit_code & 0x7f; | |
1493 | break; | |
1494 | default: | |
1495 | BUG(); | |
1496 | } | |
1497 | ||
1498 | sighand = parent->sighand; | |
1499 | spin_lock_irqsave(&sighand->siglock, flags); | |
1500 | if (sighand->action[SIGCHLD-1].sa.sa_handler != SIG_IGN && | |
1501 | !(sighand->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDSTOP)) | |
1502 | __group_send_sig_info(SIGCHLD, &info, parent); | |
1503 | /* | |
1504 | * Even if SIGCHLD is not generated, we must wake up wait4 calls. | |
1505 | */ | |
1506 | __wake_up_parent(tsk, parent); | |
1507 | spin_unlock_irqrestore(&sighand->siglock, flags); | |
1508 | } | |
1509 | ||
d5f70c00 ON |
1510 | static inline int may_ptrace_stop(void) |
1511 | { | |
1512 | if (!likely(current->ptrace & PT_PTRACED)) | |
1513 | return 0; | |
d5f70c00 ON |
1514 | /* |
1515 | * Are we in the middle of do_coredump? | |
1516 | * If so and our tracer is also part of the coredump stopping | |
1517 | * is a deadlock situation, and pointless because our tracer | |
1518 | * is dead so don't allow us to stop. | |
1519 | * If SIGKILL was already sent before the caller unlocked | |
999d9fc1 | 1520 | * ->siglock we must see ->core_state != NULL. Otherwise it |
d5f70c00 ON |
1521 | * is safe to enter schedule(). |
1522 | */ | |
999d9fc1 | 1523 | if (unlikely(current->mm->core_state) && |
d5f70c00 ON |
1524 | unlikely(current->mm == current->parent->mm)) |
1525 | return 0; | |
1526 | ||
1527 | return 1; | |
1528 | } | |
1529 | ||
1a669c2f RM |
1530 | /* |
1531 | * Return nonzero if there is a SIGKILL that should be waking us up. | |
1532 | * Called with the siglock held. | |
1533 | */ | |
1534 | static int sigkill_pending(struct task_struct *tsk) | |
1535 | { | |
3d749b9e ON |
1536 | return sigismember(&tsk->pending.signal, SIGKILL) || |
1537 | sigismember(&tsk->signal->shared_pending.signal, SIGKILL); | |
1a669c2f RM |
1538 | } |
1539 | ||
1da177e4 LT |
1540 | /* |
1541 | * This must be called with current->sighand->siglock held. | |
1542 | * | |
1543 | * This should be the path for all ptrace stops. | |
1544 | * We always set current->last_siginfo while stopped here. | |
1545 | * That makes it a way to test a stopped process for | |
1546 | * being ptrace-stopped vs being job-control-stopped. | |
1547 | * | |
20686a30 ON |
1548 | * If we actually decide not to stop at all because the tracer |
1549 | * is gone, we keep current->exit_code unless clear_code. | |
1da177e4 | 1550 | */ |
20686a30 | 1551 | static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info) |
1da177e4 | 1552 | { |
1a669c2f RM |
1553 | if (arch_ptrace_stop_needed(exit_code, info)) { |
1554 | /* | |
1555 | * The arch code has something special to do before a | |
1556 | * ptrace stop. This is allowed to block, e.g. for faults | |
1557 | * on user stack pages. We can't keep the siglock while | |
1558 | * calling arch_ptrace_stop, so we must release it now. | |
1559 | * To preserve proper semantics, we must do this before | |
1560 | * any signal bookkeeping like checking group_stop_count. | |
1561 | * Meanwhile, a SIGKILL could come in before we retake the | |
1562 | * siglock. That must prevent us from sleeping in TASK_TRACED. | |
1563 | * So after regaining the lock, we must check for SIGKILL. | |
1564 | */ | |
1565 | spin_unlock_irq(¤t->sighand->siglock); | |
1566 | arch_ptrace_stop(exit_code, info); | |
1567 | spin_lock_irq(¤t->sighand->siglock); | |
3d749b9e ON |
1568 | if (sigkill_pending(current)) |
1569 | return; | |
1a669c2f RM |
1570 | } |
1571 | ||
1da177e4 LT |
1572 | /* |
1573 | * If there is a group stop in progress, | |
1574 | * we must participate in the bookkeeping. | |
1575 | */ | |
1576 | if (current->signal->group_stop_count > 0) | |
1577 | --current->signal->group_stop_count; | |
1578 | ||
1579 | current->last_siginfo = info; | |
1580 | current->exit_code = exit_code; | |
1581 | ||
1582 | /* Let the debugger run. */ | |
d9ae90ac | 1583 | __set_current_state(TASK_TRACED); |
1da177e4 LT |
1584 | spin_unlock_irq(¤t->sighand->siglock); |
1585 | read_lock(&tasklist_lock); | |
3d749b9e | 1586 | if (may_ptrace_stop()) { |
a1d5e21e | 1587 | do_notify_parent_cldstop(current, CLD_TRAPPED); |
53da1d94 MS |
1588 | /* |
1589 | * Don't want to allow preemption here, because | |
1590 | * sys_ptrace() needs this task to be inactive. | |
1591 | * | |
1592 | * XXX: implement read_unlock_no_resched(). | |
1593 | */ | |
1594 | preempt_disable(); | |
1da177e4 | 1595 | read_unlock(&tasklist_lock); |
53da1d94 | 1596 | preempt_enable_no_resched(); |
1da177e4 LT |
1597 | schedule(); |
1598 | } else { | |
1599 | /* | |
1600 | * By the time we got the lock, our tracer went away. | |
6405f7f4 | 1601 | * Don't drop the lock yet, another tracer may come. |
1da177e4 | 1602 | */ |
6405f7f4 | 1603 | __set_current_state(TASK_RUNNING); |
20686a30 ON |
1604 | if (clear_code) |
1605 | current->exit_code = 0; | |
6405f7f4 | 1606 | read_unlock(&tasklist_lock); |
1da177e4 LT |
1607 | } |
1608 | ||
13b1c3d4 RM |
1609 | /* |
1610 | * While in TASK_TRACED, we were considered "frozen enough". | |
1611 | * Now that we woke up, it's crucial if we're supposed to be | |
1612 | * frozen that we freeze now before running anything substantial. | |
1613 | */ | |
1614 | try_to_freeze(); | |
1615 | ||
1da177e4 LT |
1616 | /* |
1617 | * We are back. Now reacquire the siglock before touching | |
1618 | * last_siginfo, so that we are sure to have synchronized with | |
1619 | * any signal-sending on another CPU that wants to examine it. | |
1620 | */ | |
1621 | spin_lock_irq(¤t->sighand->siglock); | |
1622 | current->last_siginfo = NULL; | |
1623 | ||
1624 | /* | |
1625 | * Queued signals ignored us while we were stopped for tracing. | |
1626 | * So check for any that we should take before resuming user mode. | |
b74d0deb | 1627 | * This sets TIF_SIGPENDING, but never clears it. |
1da177e4 | 1628 | */ |
b74d0deb | 1629 | recalc_sigpending_tsk(current); |
1da177e4 LT |
1630 | } |
1631 | ||
1632 | void ptrace_notify(int exit_code) | |
1633 | { | |
1634 | siginfo_t info; | |
1635 | ||
1636 | BUG_ON((exit_code & (0x7f | ~0xffff)) != SIGTRAP); | |
1637 | ||
1638 | memset(&info, 0, sizeof info); | |
1639 | info.si_signo = SIGTRAP; | |
1640 | info.si_code = exit_code; | |
b488893a | 1641 | info.si_pid = task_pid_vnr(current); |
76aac0e9 | 1642 | info.si_uid = current_uid(); |
1da177e4 LT |
1643 | |
1644 | /* Let the debugger run. */ | |
1645 | spin_lock_irq(¤t->sighand->siglock); | |
20686a30 | 1646 | ptrace_stop(exit_code, 1, &info); |
1da177e4 LT |
1647 | spin_unlock_irq(¤t->sighand->siglock); |
1648 | } | |
1649 | ||
1da177e4 LT |
1650 | static void |
1651 | finish_stop(int stop_count) | |
1652 | { | |
1653 | /* | |
1654 | * If there are no other threads in the group, or if there is | |
1655 | * a group stop in progress and we are the last to stop, | |
1656 | * report to the parent. When ptraced, every thread reports itself. | |
1657 | */ | |
fa00b80b | 1658 | if (tracehook_notify_jctl(stop_count == 0, CLD_STOPPED)) { |
a1d5e21e ON |
1659 | read_lock(&tasklist_lock); |
1660 | do_notify_parent_cldstop(current, CLD_STOPPED); | |
1661 | read_unlock(&tasklist_lock); | |
1662 | } | |
bc505a47 | 1663 | |
3df494a3 RW |
1664 | do { |
1665 | schedule(); | |
1666 | } while (try_to_freeze()); | |
1da177e4 LT |
1667 | /* |
1668 | * Now we don't run again until continued. | |
1669 | */ | |
1670 | current->exit_code = 0; | |
1671 | } | |
1672 | ||
1673 | /* | |
1674 | * This performs the stopping for SIGSTOP and other stop signals. | |
1675 | * We have to stop all threads in the thread group. | |
1676 | * Returns nonzero if we've actually stopped and released the siglock. | |
1677 | * Returns zero if we didn't stop and still hold the siglock. | |
1678 | */ | |
a122b341 | 1679 | static int do_signal_stop(int signr) |
1da177e4 LT |
1680 | { |
1681 | struct signal_struct *sig = current->signal; | |
dac27f4a | 1682 | int stop_count; |
1da177e4 | 1683 | |
1da177e4 LT |
1684 | if (sig->group_stop_count > 0) { |
1685 | /* | |
1686 | * There is a group stop in progress. We don't need to | |
1687 | * start another one. | |
1688 | */ | |
1da177e4 | 1689 | stop_count = --sig->group_stop_count; |
dac27f4a | 1690 | } else { |
f558b7e4 ON |
1691 | struct task_struct *t; |
1692 | ||
2b201a9e | 1693 | if (!likely(sig->flags & SIGNAL_STOP_DEQUEUED) || |
573cf9ad | 1694 | unlikely(signal_group_exit(sig))) |
f558b7e4 | 1695 | return 0; |
1da177e4 LT |
1696 | /* |
1697 | * There is no group stop already in progress. | |
a122b341 | 1698 | * We must initiate one now. |
1da177e4 | 1699 | */ |
a122b341 | 1700 | sig->group_exit_code = signr; |
1da177e4 | 1701 | |
a122b341 ON |
1702 | stop_count = 0; |
1703 | for (t = next_thread(current); t != current; t = next_thread(t)) | |
1da177e4 | 1704 | /* |
a122b341 ON |
1705 | * Setting state to TASK_STOPPED for a group |
1706 | * stop is always done with the siglock held, | |
1707 | * so this check has no races. | |
1da177e4 | 1708 | */ |
d12619b5 | 1709 | if (!(t->flags & PF_EXITING) && |
e1abb39c | 1710 | !task_is_stopped_or_traced(t)) { |
a122b341 ON |
1711 | stop_count++; |
1712 | signal_wake_up(t, 0); | |
1713 | } | |
1714 | sig->group_stop_count = stop_count; | |
1da177e4 LT |
1715 | } |
1716 | ||
dac27f4a ON |
1717 | if (stop_count == 0) |
1718 | sig->flags = SIGNAL_STOP_STOPPED; | |
1719 | current->exit_code = sig->group_exit_code; | |
1720 | __set_current_state(TASK_STOPPED); | |
1721 | ||
1722 | spin_unlock_irq(¤t->sighand->siglock); | |
1da177e4 LT |
1723 | finish_stop(stop_count); |
1724 | return 1; | |
1725 | } | |
1726 | ||
18c98b65 RM |
1727 | static int ptrace_signal(int signr, siginfo_t *info, |
1728 | struct pt_regs *regs, void *cookie) | |
1729 | { | |
1730 | if (!(current->ptrace & PT_PTRACED)) | |
1731 | return signr; | |
1732 | ||
1733 | ptrace_signal_deliver(regs, cookie); | |
1734 | ||
1735 | /* Let the debugger run. */ | |
1736 | ptrace_stop(signr, 0, info); | |
1737 | ||
1738 | /* We're back. Did the debugger cancel the sig? */ | |
1739 | signr = current->exit_code; | |
1740 | if (signr == 0) | |
1741 | return signr; | |
1742 | ||
1743 | current->exit_code = 0; | |
1744 | ||
1745 | /* Update the siginfo structure if the signal has | |
1746 | changed. If the debugger wanted something | |
1747 | specific in the siginfo structure then it should | |
1748 | have updated *info via PTRACE_SETSIGINFO. */ | |
1749 | if (signr != info->si_signo) { | |
1750 | info->si_signo = signr; | |
1751 | info->si_errno = 0; | |
1752 | info->si_code = SI_USER; | |
1753 | info->si_pid = task_pid_vnr(current->parent); | |
c69e8d9c | 1754 | info->si_uid = task_uid(current->parent); |
18c98b65 RM |
1755 | } |
1756 | ||
1757 | /* If the (new) signal is now blocked, requeue it. */ | |
1758 | if (sigismember(¤t->blocked, signr)) { | |
1759 | specific_send_sig_info(signr, info, current); | |
1760 | signr = 0; | |
1761 | } | |
1762 | ||
1763 | return signr; | |
1764 | } | |
1765 | ||
1da177e4 LT |
1766 | int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka, |
1767 | struct pt_regs *regs, void *cookie) | |
1768 | { | |
f6b76d4f ON |
1769 | struct sighand_struct *sighand = current->sighand; |
1770 | struct signal_struct *signal = current->signal; | |
1771 | int signr; | |
1da177e4 | 1772 | |
13b1c3d4 RM |
1773 | relock: |
1774 | /* | |
1775 | * We'll jump back here after any time we were stopped in TASK_STOPPED. | |
1776 | * While in TASK_STOPPED, we were considered "frozen enough". | |
1777 | * Now that we woke up, it's crucial if we're supposed to be | |
1778 | * frozen that we freeze now before running anything substantial. | |
1779 | */ | |
fc558a74 RW |
1780 | try_to_freeze(); |
1781 | ||
f6b76d4f | 1782 | spin_lock_irq(&sighand->siglock); |
021e1ae3 ON |
1783 | /* |
1784 | * Every stopped thread goes here after wakeup. Check to see if | |
1785 | * we should notify the parent, prepare_signal(SIGCONT) encodes | |
1786 | * the CLD_ si_code into SIGNAL_CLD_MASK bits. | |
1787 | */ | |
f6b76d4f ON |
1788 | if (unlikely(signal->flags & SIGNAL_CLD_MASK)) { |
1789 | int why = (signal->flags & SIGNAL_STOP_CONTINUED) | |
e4420551 | 1790 | ? CLD_CONTINUED : CLD_STOPPED; |
f6b76d4f ON |
1791 | signal->flags &= ~SIGNAL_CLD_MASK; |
1792 | spin_unlock_irq(&sighand->siglock); | |
e4420551 | 1793 | |
fa00b80b RM |
1794 | if (unlikely(!tracehook_notify_jctl(1, why))) |
1795 | goto relock; | |
1796 | ||
e4420551 ON |
1797 | read_lock(&tasklist_lock); |
1798 | do_notify_parent_cldstop(current->group_leader, why); | |
1799 | read_unlock(&tasklist_lock); | |
1800 | goto relock; | |
1801 | } | |
1802 | ||
1da177e4 LT |
1803 | for (;;) { |
1804 | struct k_sigaction *ka; | |
1805 | ||
f6b76d4f | 1806 | if (unlikely(signal->group_stop_count > 0) && |
f558b7e4 | 1807 | do_signal_stop(0)) |
1da177e4 LT |
1808 | goto relock; |
1809 | ||
7bcf6a2c RM |
1810 | /* |
1811 | * Tracing can induce an artifical signal and choose sigaction. | |
1812 | * The return value in @signr determines the default action, | |
1813 | * but @info->si_signo is the signal number we will report. | |
1814 | */ | |
1815 | signr = tracehook_get_signal(current, regs, info, return_ka); | |
1816 | if (unlikely(signr < 0)) | |
1817 | goto relock; | |
1818 | if (unlikely(signr != 0)) | |
1819 | ka = return_ka; | |
1820 | else { | |
1821 | signr = dequeue_signal(current, ¤t->blocked, | |
1822 | info); | |
1da177e4 | 1823 | |
18c98b65 | 1824 | if (!signr) |
7bcf6a2c RM |
1825 | break; /* will return 0 */ |
1826 | ||
1827 | if (signr != SIGKILL) { | |
1828 | signr = ptrace_signal(signr, info, | |
1829 | regs, cookie); | |
1830 | if (!signr) | |
1831 | continue; | |
1832 | } | |
1833 | ||
1834 | ka = &sighand->action[signr-1]; | |
1da177e4 LT |
1835 | } |
1836 | ||
1da177e4 LT |
1837 | if (ka->sa.sa_handler == SIG_IGN) /* Do nothing. */ |
1838 | continue; | |
1839 | if (ka->sa.sa_handler != SIG_DFL) { | |
1840 | /* Run the handler. */ | |
1841 | *return_ka = *ka; | |
1842 | ||
1843 | if (ka->sa.sa_flags & SA_ONESHOT) | |
1844 | ka->sa.sa_handler = SIG_DFL; | |
1845 | ||
1846 | break; /* will return non-zero "signr" value */ | |
1847 | } | |
1848 | ||
1849 | /* | |
1850 | * Now we are doing the default action for this signal. | |
1851 | */ | |
1852 | if (sig_kernel_ignore(signr)) /* Default is nothing. */ | |
1853 | continue; | |
1854 | ||
84d73786 | 1855 | /* |
0fbc26a6 | 1856 | * Global init gets no signals it doesn't want. |
84d73786 | 1857 | */ |
fae5fa44 ON |
1858 | if (unlikely(signal->flags & SIGNAL_UNKILLABLE) && |
1859 | !signal_group_exit(signal)) | |
1da177e4 LT |
1860 | continue; |
1861 | ||
1862 | if (sig_kernel_stop(signr)) { | |
1863 | /* | |
1864 | * The default action is to stop all threads in | |
1865 | * the thread group. The job control signals | |
1866 | * do nothing in an orphaned pgrp, but SIGSTOP | |
1867 | * always works. Note that siglock needs to be | |
1868 | * dropped during the call to is_orphaned_pgrp() | |
1869 | * because of lock ordering with tasklist_lock. | |
1870 | * This allows an intervening SIGCONT to be posted. | |
1871 | * We need to check for that and bail out if necessary. | |
1872 | */ | |
1873 | if (signr != SIGSTOP) { | |
f6b76d4f | 1874 | spin_unlock_irq(&sighand->siglock); |
1da177e4 LT |
1875 | |
1876 | /* signals can be posted during this window */ | |
1877 | ||
3e7cd6c4 | 1878 | if (is_current_pgrp_orphaned()) |
1da177e4 LT |
1879 | goto relock; |
1880 | ||
f6b76d4f | 1881 | spin_lock_irq(&sighand->siglock); |
1da177e4 LT |
1882 | } |
1883 | ||
7bcf6a2c | 1884 | if (likely(do_signal_stop(info->si_signo))) { |
1da177e4 LT |
1885 | /* It released the siglock. */ |
1886 | goto relock; | |
1887 | } | |
1888 | ||
1889 | /* | |
1890 | * We didn't actually stop, due to a race | |
1891 | * with SIGCONT or something like that. | |
1892 | */ | |
1893 | continue; | |
1894 | } | |
1895 | ||
f6b76d4f | 1896 | spin_unlock_irq(&sighand->siglock); |
1da177e4 LT |
1897 | |
1898 | /* | |
1899 | * Anything else is fatal, maybe with a core dump. | |
1900 | */ | |
1901 | current->flags |= PF_SIGNALED; | |
2dce81bf | 1902 | |
1da177e4 | 1903 | if (sig_kernel_coredump(signr)) { |
2dce81bf | 1904 | if (print_fatal_signals) |
7bcf6a2c | 1905 | print_fatal_signal(regs, info->si_signo); |
1da177e4 LT |
1906 | /* |
1907 | * If it was able to dump core, this kills all | |
1908 | * other threads in the group and synchronizes with | |
1909 | * their demise. If we lost the race with another | |
1910 | * thread getting here, it set group_exit_code | |
1911 | * first and our do_group_exit call below will use | |
1912 | * that value and ignore the one we pass it. | |
1913 | */ | |
7bcf6a2c | 1914 | do_coredump(info->si_signo, info->si_signo, regs); |
1da177e4 LT |
1915 | } |
1916 | ||
1917 | /* | |
1918 | * Death signals, no core dump. | |
1919 | */ | |
7bcf6a2c | 1920 | do_group_exit(info->si_signo); |
1da177e4 LT |
1921 | /* NOTREACHED */ |
1922 | } | |
f6b76d4f | 1923 | spin_unlock_irq(&sighand->siglock); |
1da177e4 LT |
1924 | return signr; |
1925 | } | |
1926 | ||
d12619b5 ON |
1927 | void exit_signals(struct task_struct *tsk) |
1928 | { | |
1929 | int group_stop = 0; | |
5dee1707 | 1930 | struct task_struct *t; |
d12619b5 | 1931 | |
5dee1707 ON |
1932 | if (thread_group_empty(tsk) || signal_group_exit(tsk->signal)) { |
1933 | tsk->flags |= PF_EXITING; | |
1934 | return; | |
d12619b5 ON |
1935 | } |
1936 | ||
5dee1707 | 1937 | spin_lock_irq(&tsk->sighand->siglock); |
d12619b5 ON |
1938 | /* |
1939 | * From now this task is not visible for group-wide signals, | |
1940 | * see wants_signal(), do_signal_stop(). | |
1941 | */ | |
1942 | tsk->flags |= PF_EXITING; | |
5dee1707 ON |
1943 | if (!signal_pending(tsk)) |
1944 | goto out; | |
1945 | ||
1946 | /* It could be that __group_complete_signal() choose us to | |
1947 | * notify about group-wide signal. Another thread should be | |
1948 | * woken now to take the signal since we will not. | |
1949 | */ | |
1950 | for (t = tsk; (t = next_thread(t)) != tsk; ) | |
1951 | if (!signal_pending(t) && !(t->flags & PF_EXITING)) | |
1952 | recalc_sigpending_and_wake(t); | |
1953 | ||
1954 | if (unlikely(tsk->signal->group_stop_count) && | |
1955 | !--tsk->signal->group_stop_count) { | |
1956 | tsk->signal->flags = SIGNAL_STOP_STOPPED; | |
1957 | group_stop = 1; | |
1958 | } | |
1959 | out: | |
d12619b5 ON |
1960 | spin_unlock_irq(&tsk->sighand->siglock); |
1961 | ||
fa00b80b | 1962 | if (unlikely(group_stop) && tracehook_notify_jctl(1, CLD_STOPPED)) { |
d12619b5 ON |
1963 | read_lock(&tasklist_lock); |
1964 | do_notify_parent_cldstop(tsk, CLD_STOPPED); | |
1965 | read_unlock(&tasklist_lock); | |
1966 | } | |
1967 | } | |
1968 | ||
1da177e4 LT |
1969 | EXPORT_SYMBOL(recalc_sigpending); |
1970 | EXPORT_SYMBOL_GPL(dequeue_signal); | |
1971 | EXPORT_SYMBOL(flush_signals); | |
1972 | EXPORT_SYMBOL(force_sig); | |
1da177e4 LT |
1973 | EXPORT_SYMBOL(send_sig); |
1974 | EXPORT_SYMBOL(send_sig_info); | |
1975 | EXPORT_SYMBOL(sigprocmask); | |
1976 | EXPORT_SYMBOL(block_all_signals); | |
1977 | EXPORT_SYMBOL(unblock_all_signals); | |
1978 | ||
1979 | ||
1980 | /* | |
1981 | * System call entry points. | |
1982 | */ | |
1983 | ||
754fe8d2 | 1984 | SYSCALL_DEFINE0(restart_syscall) |
1da177e4 LT |
1985 | { |
1986 | struct restart_block *restart = ¤t_thread_info()->restart_block; | |
1987 | return restart->fn(restart); | |
1988 | } | |
1989 | ||
1990 | long do_no_restart_syscall(struct restart_block *param) | |
1991 | { | |
1992 | return -EINTR; | |
1993 | } | |
1994 | ||
1995 | /* | |
1996 | * We don't need to get the kernel lock - this is all local to this | |
1997 | * particular thread.. (and that's good, because this is _heavily_ | |
1998 | * used by various programs) | |
1999 | */ | |
2000 | ||
2001 | /* | |
2002 | * This is also useful for kernel threads that want to temporarily | |
2003 | * (or permanently) block certain signals. | |
2004 | * | |
2005 | * NOTE! Unlike the user-mode sys_sigprocmask(), the kernel | |
2006 | * interface happily blocks "unblockable" signals like SIGKILL | |
2007 | * and friends. | |
2008 | */ | |
2009 | int sigprocmask(int how, sigset_t *set, sigset_t *oldset) | |
2010 | { | |
2011 | int error; | |
1da177e4 LT |
2012 | |
2013 | spin_lock_irq(¤t->sighand->siglock); | |
a26fd335 ON |
2014 | if (oldset) |
2015 | *oldset = current->blocked; | |
2016 | ||
1da177e4 LT |
2017 | error = 0; |
2018 | switch (how) { | |
2019 | case SIG_BLOCK: | |
2020 | sigorsets(¤t->blocked, ¤t->blocked, set); | |
2021 | break; | |
2022 | case SIG_UNBLOCK: | |
2023 | signandsets(¤t->blocked, ¤t->blocked, set); | |
2024 | break; | |
2025 | case SIG_SETMASK: | |
2026 | current->blocked = *set; | |
2027 | break; | |
2028 | default: | |
2029 | error = -EINVAL; | |
2030 | } | |
2031 | recalc_sigpending(); | |
2032 | spin_unlock_irq(¤t->sighand->siglock); | |
a26fd335 | 2033 | |
1da177e4 LT |
2034 | return error; |
2035 | } | |
2036 | ||
17da2bd9 HC |
2037 | SYSCALL_DEFINE4(rt_sigprocmask, int, how, sigset_t __user *, set, |
2038 | sigset_t __user *, oset, size_t, sigsetsize) | |
1da177e4 LT |
2039 | { |
2040 | int error = -EINVAL; | |
2041 | sigset_t old_set, new_set; | |
2042 | ||
2043 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
2044 | if (sigsetsize != sizeof(sigset_t)) | |
2045 | goto out; | |
2046 | ||
2047 | if (set) { | |
2048 | error = -EFAULT; | |
2049 | if (copy_from_user(&new_set, set, sizeof(*set))) | |
2050 | goto out; | |
2051 | sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); | |
2052 | ||
2053 | error = sigprocmask(how, &new_set, &old_set); | |
2054 | if (error) | |
2055 | goto out; | |
2056 | if (oset) | |
2057 | goto set_old; | |
2058 | } else if (oset) { | |
2059 | spin_lock_irq(¤t->sighand->siglock); | |
2060 | old_set = current->blocked; | |
2061 | spin_unlock_irq(¤t->sighand->siglock); | |
2062 | ||
2063 | set_old: | |
2064 | error = -EFAULT; | |
2065 | if (copy_to_user(oset, &old_set, sizeof(*oset))) | |
2066 | goto out; | |
2067 | } | |
2068 | error = 0; | |
2069 | out: | |
2070 | return error; | |
2071 | } | |
2072 | ||
2073 | long do_sigpending(void __user *set, unsigned long sigsetsize) | |
2074 | { | |
2075 | long error = -EINVAL; | |
2076 | sigset_t pending; | |
2077 | ||
2078 | if (sigsetsize > sizeof(sigset_t)) | |
2079 | goto out; | |
2080 | ||
2081 | spin_lock_irq(¤t->sighand->siglock); | |
2082 | sigorsets(&pending, ¤t->pending.signal, | |
2083 | ¤t->signal->shared_pending.signal); | |
2084 | spin_unlock_irq(¤t->sighand->siglock); | |
2085 | ||
2086 | /* Outside the lock because only this thread touches it. */ | |
2087 | sigandsets(&pending, ¤t->blocked, &pending); | |
2088 | ||
2089 | error = -EFAULT; | |
2090 | if (!copy_to_user(set, &pending, sigsetsize)) | |
2091 | error = 0; | |
2092 | ||
2093 | out: | |
2094 | return error; | |
2095 | } | |
2096 | ||
17da2bd9 | 2097 | SYSCALL_DEFINE2(rt_sigpending, sigset_t __user *, set, size_t, sigsetsize) |
1da177e4 LT |
2098 | { |
2099 | return do_sigpending(set, sigsetsize); | |
2100 | } | |
2101 | ||
2102 | #ifndef HAVE_ARCH_COPY_SIGINFO_TO_USER | |
2103 | ||
2104 | int copy_siginfo_to_user(siginfo_t __user *to, siginfo_t *from) | |
2105 | { | |
2106 | int err; | |
2107 | ||
2108 | if (!access_ok (VERIFY_WRITE, to, sizeof(siginfo_t))) | |
2109 | return -EFAULT; | |
2110 | if (from->si_code < 0) | |
2111 | return __copy_to_user(to, from, sizeof(siginfo_t)) | |
2112 | ? -EFAULT : 0; | |
2113 | /* | |
2114 | * If you change siginfo_t structure, please be sure | |
2115 | * this code is fixed accordingly. | |
fba2afaa DL |
2116 | * Please remember to update the signalfd_copyinfo() function |
2117 | * inside fs/signalfd.c too, in case siginfo_t changes. | |
1da177e4 LT |
2118 | * It should never copy any pad contained in the structure |
2119 | * to avoid security leaks, but must copy the generic | |
2120 | * 3 ints plus the relevant union member. | |
2121 | */ | |
2122 | err = __put_user(from->si_signo, &to->si_signo); | |
2123 | err |= __put_user(from->si_errno, &to->si_errno); | |
2124 | err |= __put_user((short)from->si_code, &to->si_code); | |
2125 | switch (from->si_code & __SI_MASK) { | |
2126 | case __SI_KILL: | |
2127 | err |= __put_user(from->si_pid, &to->si_pid); | |
2128 | err |= __put_user(from->si_uid, &to->si_uid); | |
2129 | break; | |
2130 | case __SI_TIMER: | |
2131 | err |= __put_user(from->si_tid, &to->si_tid); | |
2132 | err |= __put_user(from->si_overrun, &to->si_overrun); | |
2133 | err |= __put_user(from->si_ptr, &to->si_ptr); | |
2134 | break; | |
2135 | case __SI_POLL: | |
2136 | err |= __put_user(from->si_band, &to->si_band); | |
2137 | err |= __put_user(from->si_fd, &to->si_fd); | |
2138 | break; | |
2139 | case __SI_FAULT: | |
2140 | err |= __put_user(from->si_addr, &to->si_addr); | |
2141 | #ifdef __ARCH_SI_TRAPNO | |
2142 | err |= __put_user(from->si_trapno, &to->si_trapno); | |
2143 | #endif | |
2144 | break; | |
2145 | case __SI_CHLD: | |
2146 | err |= __put_user(from->si_pid, &to->si_pid); | |
2147 | err |= __put_user(from->si_uid, &to->si_uid); | |
2148 | err |= __put_user(from->si_status, &to->si_status); | |
2149 | err |= __put_user(from->si_utime, &to->si_utime); | |
2150 | err |= __put_user(from->si_stime, &to->si_stime); | |
2151 | break; | |
2152 | case __SI_RT: /* This is not generated by the kernel as of now. */ | |
2153 | case __SI_MESGQ: /* But this is */ | |
2154 | err |= __put_user(from->si_pid, &to->si_pid); | |
2155 | err |= __put_user(from->si_uid, &to->si_uid); | |
2156 | err |= __put_user(from->si_ptr, &to->si_ptr); | |
2157 | break; | |
2158 | default: /* this is just in case for now ... */ | |
2159 | err |= __put_user(from->si_pid, &to->si_pid); | |
2160 | err |= __put_user(from->si_uid, &to->si_uid); | |
2161 | break; | |
2162 | } | |
2163 | return err; | |
2164 | } | |
2165 | ||
2166 | #endif | |
2167 | ||
17da2bd9 HC |
2168 | SYSCALL_DEFINE4(rt_sigtimedwait, const sigset_t __user *, uthese, |
2169 | siginfo_t __user *, uinfo, const struct timespec __user *, uts, | |
2170 | size_t, sigsetsize) | |
1da177e4 LT |
2171 | { |
2172 | int ret, sig; | |
2173 | sigset_t these; | |
2174 | struct timespec ts; | |
2175 | siginfo_t info; | |
2176 | long timeout = 0; | |
2177 | ||
2178 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
2179 | if (sigsetsize != sizeof(sigset_t)) | |
2180 | return -EINVAL; | |
2181 | ||
2182 | if (copy_from_user(&these, uthese, sizeof(these))) | |
2183 | return -EFAULT; | |
2184 | ||
2185 | /* | |
2186 | * Invert the set of allowed signals to get those we | |
2187 | * want to block. | |
2188 | */ | |
2189 | sigdelsetmask(&these, sigmask(SIGKILL)|sigmask(SIGSTOP)); | |
2190 | signotset(&these); | |
2191 | ||
2192 | if (uts) { | |
2193 | if (copy_from_user(&ts, uts, sizeof(ts))) | |
2194 | return -EFAULT; | |
2195 | if (ts.tv_nsec >= 1000000000L || ts.tv_nsec < 0 | |
2196 | || ts.tv_sec < 0) | |
2197 | return -EINVAL; | |
2198 | } | |
2199 | ||
2200 | spin_lock_irq(¤t->sighand->siglock); | |
2201 | sig = dequeue_signal(current, &these, &info); | |
2202 | if (!sig) { | |
2203 | timeout = MAX_SCHEDULE_TIMEOUT; | |
2204 | if (uts) | |
2205 | timeout = (timespec_to_jiffies(&ts) | |
2206 | + (ts.tv_sec || ts.tv_nsec)); | |
2207 | ||
2208 | if (timeout) { | |
2209 | /* None ready -- temporarily unblock those we're | |
2210 | * interested while we are sleeping in so that we'll | |
2211 | * be awakened when they arrive. */ | |
2212 | current->real_blocked = current->blocked; | |
2213 | sigandsets(¤t->blocked, ¤t->blocked, &these); | |
2214 | recalc_sigpending(); | |
2215 | spin_unlock_irq(¤t->sighand->siglock); | |
2216 | ||
75bcc8c5 | 2217 | timeout = schedule_timeout_interruptible(timeout); |
1da177e4 | 2218 | |
1da177e4 LT |
2219 | spin_lock_irq(¤t->sighand->siglock); |
2220 | sig = dequeue_signal(current, &these, &info); | |
2221 | current->blocked = current->real_blocked; | |
2222 | siginitset(¤t->real_blocked, 0); | |
2223 | recalc_sigpending(); | |
2224 | } | |
2225 | } | |
2226 | spin_unlock_irq(¤t->sighand->siglock); | |
2227 | ||
2228 | if (sig) { | |
2229 | ret = sig; | |
2230 | if (uinfo) { | |
2231 | if (copy_siginfo_to_user(uinfo, &info)) | |
2232 | ret = -EFAULT; | |
2233 | } | |
2234 | } else { | |
2235 | ret = -EAGAIN; | |
2236 | if (timeout) | |
2237 | ret = -EINTR; | |
2238 | } | |
2239 | ||
2240 | return ret; | |
2241 | } | |
2242 | ||
17da2bd9 | 2243 | SYSCALL_DEFINE2(kill, pid_t, pid, int, sig) |
1da177e4 LT |
2244 | { |
2245 | struct siginfo info; | |
2246 | ||
2247 | info.si_signo = sig; | |
2248 | info.si_errno = 0; | |
2249 | info.si_code = SI_USER; | |
b488893a | 2250 | info.si_pid = task_tgid_vnr(current); |
76aac0e9 | 2251 | info.si_uid = current_uid(); |
1da177e4 LT |
2252 | |
2253 | return kill_something_info(sig, &info, pid); | |
2254 | } | |
2255 | ||
bc64efd2 | 2256 | static int do_tkill(pid_t tgid, pid_t pid, int sig) |
1da177e4 | 2257 | { |
1da177e4 | 2258 | int error; |
6dd69f10 | 2259 | struct siginfo info; |
1da177e4 | 2260 | struct task_struct *p; |
3547ff3a | 2261 | unsigned long flags; |
1da177e4 | 2262 | |
6dd69f10 | 2263 | error = -ESRCH; |
1da177e4 LT |
2264 | info.si_signo = sig; |
2265 | info.si_errno = 0; | |
2266 | info.si_code = SI_TKILL; | |
b488893a | 2267 | info.si_pid = task_tgid_vnr(current); |
76aac0e9 | 2268 | info.si_uid = current_uid(); |
1da177e4 | 2269 | |
3547ff3a | 2270 | rcu_read_lock(); |
228ebcbe | 2271 | p = find_task_by_vpid(pid); |
b488893a | 2272 | if (p && (tgid <= 0 || task_tgid_vnr(p) == tgid)) { |
1da177e4 LT |
2273 | error = check_kill_permission(sig, &info, p); |
2274 | /* | |
2275 | * The null signal is a permissions and process existence | |
2276 | * probe. No signal is actually delivered. | |
3547ff3a ON |
2277 | * |
2278 | * If lock_task_sighand() fails we pretend the task dies | |
2279 | * after receiving the signal. The window is tiny, and the | |
2280 | * signal is private anyway. | |
1da177e4 | 2281 | */ |
3547ff3a | 2282 | if (!error && sig && lock_task_sighand(p, &flags)) { |
1da177e4 | 2283 | error = specific_send_sig_info(sig, &info, p); |
3547ff3a | 2284 | unlock_task_sighand(p, &flags); |
1da177e4 LT |
2285 | } |
2286 | } | |
3547ff3a | 2287 | rcu_read_unlock(); |
6dd69f10 | 2288 | |
1da177e4 LT |
2289 | return error; |
2290 | } | |
2291 | ||
6dd69f10 VL |
2292 | /** |
2293 | * sys_tgkill - send signal to one specific thread | |
2294 | * @tgid: the thread group ID of the thread | |
2295 | * @pid: the PID of the thread | |
2296 | * @sig: signal to be sent | |
2297 | * | |
72fd4a35 | 2298 | * This syscall also checks the @tgid and returns -ESRCH even if the PID |
6dd69f10 VL |
2299 | * exists but it's not belonging to the target process anymore. This |
2300 | * method solves the problem of threads exiting and PIDs getting reused. | |
2301 | */ | |
a5f8fa9e | 2302 | SYSCALL_DEFINE3(tgkill, pid_t, tgid, pid_t, pid, int, sig) |
6dd69f10 VL |
2303 | { |
2304 | /* This is only valid for single tasks */ | |
2305 | if (pid <= 0 || tgid <= 0) | |
2306 | return -EINVAL; | |
2307 | ||
2308 | return do_tkill(tgid, pid, sig); | |
2309 | } | |
2310 | ||
1da177e4 LT |
2311 | /* |
2312 | * Send a signal to only one task, even if it's a CLONE_THREAD task. | |
2313 | */ | |
a5f8fa9e | 2314 | SYSCALL_DEFINE2(tkill, pid_t, pid, int, sig) |
1da177e4 | 2315 | { |
1da177e4 LT |
2316 | /* This is only valid for single tasks */ |
2317 | if (pid <= 0) | |
2318 | return -EINVAL; | |
2319 | ||
6dd69f10 | 2320 | return do_tkill(0, pid, sig); |
1da177e4 LT |
2321 | } |
2322 | ||
a5f8fa9e HC |
2323 | SYSCALL_DEFINE3(rt_sigqueueinfo, pid_t, pid, int, sig, |
2324 | siginfo_t __user *, uinfo) | |
1da177e4 LT |
2325 | { |
2326 | siginfo_t info; | |
2327 | ||
2328 | if (copy_from_user(&info, uinfo, sizeof(siginfo_t))) | |
2329 | return -EFAULT; | |
2330 | ||
2331 | /* Not even root can pretend to send signals from the kernel. | |
2332 | Nor can they impersonate a kill(), which adds source info. */ | |
2333 | if (info.si_code >= 0) | |
2334 | return -EPERM; | |
2335 | info.si_signo = sig; | |
2336 | ||
2337 | /* POSIX.1b doesn't mention process groups. */ | |
2338 | return kill_proc_info(sig, &info, pid); | |
2339 | } | |
2340 | ||
88531f72 | 2341 | int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) |
1da177e4 | 2342 | { |
93585eea | 2343 | struct task_struct *t = current; |
1da177e4 | 2344 | struct k_sigaction *k; |
71fabd5e | 2345 | sigset_t mask; |
1da177e4 | 2346 | |
7ed20e1a | 2347 | if (!valid_signal(sig) || sig < 1 || (act && sig_kernel_only(sig))) |
1da177e4 LT |
2348 | return -EINVAL; |
2349 | ||
93585eea | 2350 | k = &t->sighand->action[sig-1]; |
1da177e4 LT |
2351 | |
2352 | spin_lock_irq(¤t->sighand->siglock); | |
1da177e4 LT |
2353 | if (oact) |
2354 | *oact = *k; | |
2355 | ||
2356 | if (act) { | |
9ac95f2f ON |
2357 | sigdelsetmask(&act->sa.sa_mask, |
2358 | sigmask(SIGKILL) | sigmask(SIGSTOP)); | |
88531f72 | 2359 | *k = *act; |
1da177e4 LT |
2360 | /* |
2361 | * POSIX 3.3.1.3: | |
2362 | * "Setting a signal action to SIG_IGN for a signal that is | |
2363 | * pending shall cause the pending signal to be discarded, | |
2364 | * whether or not it is blocked." | |
2365 | * | |
2366 | * "Setting a signal action to SIG_DFL for a signal that is | |
2367 | * pending and whose default action is to ignore the signal | |
2368 | * (for example, SIGCHLD), shall cause the pending signal to | |
2369 | * be discarded, whether or not it is blocked" | |
2370 | */ | |
35de254d | 2371 | if (sig_handler_ignored(sig_handler(t, sig), sig)) { |
71fabd5e GA |
2372 | sigemptyset(&mask); |
2373 | sigaddset(&mask, sig); | |
2374 | rm_from_queue_full(&mask, &t->signal->shared_pending); | |
1da177e4 | 2375 | do { |
71fabd5e | 2376 | rm_from_queue_full(&mask, &t->pending); |
1da177e4 LT |
2377 | t = next_thread(t); |
2378 | } while (t != current); | |
1da177e4 | 2379 | } |
1da177e4 LT |
2380 | } |
2381 | ||
2382 | spin_unlock_irq(¤t->sighand->siglock); | |
2383 | return 0; | |
2384 | } | |
2385 | ||
2386 | int | |
2387 | do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long sp) | |
2388 | { | |
2389 | stack_t oss; | |
2390 | int error; | |
2391 | ||
2392 | if (uoss) { | |
2393 | oss.ss_sp = (void __user *) current->sas_ss_sp; | |
2394 | oss.ss_size = current->sas_ss_size; | |
2395 | oss.ss_flags = sas_ss_flags(sp); | |
2396 | } | |
2397 | ||
2398 | if (uss) { | |
2399 | void __user *ss_sp; | |
2400 | size_t ss_size; | |
2401 | int ss_flags; | |
2402 | ||
2403 | error = -EFAULT; | |
2404 | if (!access_ok(VERIFY_READ, uss, sizeof(*uss)) | |
2405 | || __get_user(ss_sp, &uss->ss_sp) | |
2406 | || __get_user(ss_flags, &uss->ss_flags) | |
2407 | || __get_user(ss_size, &uss->ss_size)) | |
2408 | goto out; | |
2409 | ||
2410 | error = -EPERM; | |
2411 | if (on_sig_stack(sp)) | |
2412 | goto out; | |
2413 | ||
2414 | error = -EINVAL; | |
2415 | /* | |
2416 | * | |
2417 | * Note - this code used to test ss_flags incorrectly | |
2418 | * old code may have been written using ss_flags==0 | |
2419 | * to mean ss_flags==SS_ONSTACK (as this was the only | |
2420 | * way that worked) - this fix preserves that older | |
2421 | * mechanism | |
2422 | */ | |
2423 | if (ss_flags != SS_DISABLE && ss_flags != SS_ONSTACK && ss_flags != 0) | |
2424 | goto out; | |
2425 | ||
2426 | if (ss_flags == SS_DISABLE) { | |
2427 | ss_size = 0; | |
2428 | ss_sp = NULL; | |
2429 | } else { | |
2430 | error = -ENOMEM; | |
2431 | if (ss_size < MINSIGSTKSZ) | |
2432 | goto out; | |
2433 | } | |
2434 | ||
2435 | current->sas_ss_sp = (unsigned long) ss_sp; | |
2436 | current->sas_ss_size = ss_size; | |
2437 | } | |
2438 | ||
2439 | if (uoss) { | |
2440 | error = -EFAULT; | |
2441 | if (copy_to_user(uoss, &oss, sizeof(oss))) | |
2442 | goto out; | |
2443 | } | |
2444 | ||
2445 | error = 0; | |
2446 | out: | |
2447 | return error; | |
2448 | } | |
2449 | ||
2450 | #ifdef __ARCH_WANT_SYS_SIGPENDING | |
2451 | ||
b290ebe2 | 2452 | SYSCALL_DEFINE1(sigpending, old_sigset_t __user *, set) |
1da177e4 LT |
2453 | { |
2454 | return do_sigpending(set, sizeof(*set)); | |
2455 | } | |
2456 | ||
2457 | #endif | |
2458 | ||
2459 | #ifdef __ARCH_WANT_SYS_SIGPROCMASK | |
2460 | /* Some platforms have their own version with special arguments others | |
2461 | support only sys_rt_sigprocmask. */ | |
2462 | ||
b290ebe2 HC |
2463 | SYSCALL_DEFINE3(sigprocmask, int, how, old_sigset_t __user *, set, |
2464 | old_sigset_t __user *, oset) | |
1da177e4 LT |
2465 | { |
2466 | int error; | |
2467 | old_sigset_t old_set, new_set; | |
2468 | ||
2469 | if (set) { | |
2470 | error = -EFAULT; | |
2471 | if (copy_from_user(&new_set, set, sizeof(*set))) | |
2472 | goto out; | |
2473 | new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP)); | |
2474 | ||
2475 | spin_lock_irq(¤t->sighand->siglock); | |
2476 | old_set = current->blocked.sig[0]; | |
2477 | ||
2478 | error = 0; | |
2479 | switch (how) { | |
2480 | default: | |
2481 | error = -EINVAL; | |
2482 | break; | |
2483 | case SIG_BLOCK: | |
2484 | sigaddsetmask(¤t->blocked, new_set); | |
2485 | break; | |
2486 | case SIG_UNBLOCK: | |
2487 | sigdelsetmask(¤t->blocked, new_set); | |
2488 | break; | |
2489 | case SIG_SETMASK: | |
2490 | current->blocked.sig[0] = new_set; | |
2491 | break; | |
2492 | } | |
2493 | ||
2494 | recalc_sigpending(); | |
2495 | spin_unlock_irq(¤t->sighand->siglock); | |
2496 | if (error) | |
2497 | goto out; | |
2498 | if (oset) | |
2499 | goto set_old; | |
2500 | } else if (oset) { | |
2501 | old_set = current->blocked.sig[0]; | |
2502 | set_old: | |
2503 | error = -EFAULT; | |
2504 | if (copy_to_user(oset, &old_set, sizeof(*oset))) | |
2505 | goto out; | |
2506 | } | |
2507 | error = 0; | |
2508 | out: | |
2509 | return error; | |
2510 | } | |
2511 | #endif /* __ARCH_WANT_SYS_SIGPROCMASK */ | |
2512 | ||
2513 | #ifdef __ARCH_WANT_SYS_RT_SIGACTION | |
d4e82042 HC |
2514 | SYSCALL_DEFINE4(rt_sigaction, int, sig, |
2515 | const struct sigaction __user *, act, | |
2516 | struct sigaction __user *, oact, | |
2517 | size_t, sigsetsize) | |
1da177e4 LT |
2518 | { |
2519 | struct k_sigaction new_sa, old_sa; | |
2520 | int ret = -EINVAL; | |
2521 | ||
2522 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
2523 | if (sigsetsize != sizeof(sigset_t)) | |
2524 | goto out; | |
2525 | ||
2526 | if (act) { | |
2527 | if (copy_from_user(&new_sa.sa, act, sizeof(new_sa.sa))) | |
2528 | return -EFAULT; | |
2529 | } | |
2530 | ||
2531 | ret = do_sigaction(sig, act ? &new_sa : NULL, oact ? &old_sa : NULL); | |
2532 | ||
2533 | if (!ret && oact) { | |
2534 | if (copy_to_user(oact, &old_sa.sa, sizeof(old_sa.sa))) | |
2535 | return -EFAULT; | |
2536 | } | |
2537 | out: | |
2538 | return ret; | |
2539 | } | |
2540 | #endif /* __ARCH_WANT_SYS_RT_SIGACTION */ | |
2541 | ||
2542 | #ifdef __ARCH_WANT_SYS_SGETMASK | |
2543 | ||
2544 | /* | |
2545 | * For backwards compatibility. Functionality superseded by sigprocmask. | |
2546 | */ | |
a5f8fa9e | 2547 | SYSCALL_DEFINE0(sgetmask) |
1da177e4 LT |
2548 | { |
2549 | /* SMP safe */ | |
2550 | return current->blocked.sig[0]; | |
2551 | } | |
2552 | ||
a5f8fa9e | 2553 | SYSCALL_DEFINE1(ssetmask, int, newmask) |
1da177e4 LT |
2554 | { |
2555 | int old; | |
2556 | ||
2557 | spin_lock_irq(¤t->sighand->siglock); | |
2558 | old = current->blocked.sig[0]; | |
2559 | ||
2560 | siginitset(¤t->blocked, newmask & ~(sigmask(SIGKILL)| | |
2561 | sigmask(SIGSTOP))); | |
2562 | recalc_sigpending(); | |
2563 | spin_unlock_irq(¤t->sighand->siglock); | |
2564 | ||
2565 | return old; | |
2566 | } | |
2567 | #endif /* __ARCH_WANT_SGETMASK */ | |
2568 | ||
2569 | #ifdef __ARCH_WANT_SYS_SIGNAL | |
2570 | /* | |
2571 | * For backwards compatibility. Functionality superseded by sigaction. | |
2572 | */ | |
a5f8fa9e | 2573 | SYSCALL_DEFINE2(signal, int, sig, __sighandler_t, handler) |
1da177e4 LT |
2574 | { |
2575 | struct k_sigaction new_sa, old_sa; | |
2576 | int ret; | |
2577 | ||
2578 | new_sa.sa.sa_handler = handler; | |
2579 | new_sa.sa.sa_flags = SA_ONESHOT | SA_NOMASK; | |
c70d3d70 | 2580 | sigemptyset(&new_sa.sa.sa_mask); |
1da177e4 LT |
2581 | |
2582 | ret = do_sigaction(sig, &new_sa, &old_sa); | |
2583 | ||
2584 | return ret ? ret : (unsigned long)old_sa.sa.sa_handler; | |
2585 | } | |
2586 | #endif /* __ARCH_WANT_SYS_SIGNAL */ | |
2587 | ||
2588 | #ifdef __ARCH_WANT_SYS_PAUSE | |
2589 | ||
a5f8fa9e | 2590 | SYSCALL_DEFINE0(pause) |
1da177e4 LT |
2591 | { |
2592 | current->state = TASK_INTERRUPTIBLE; | |
2593 | schedule(); | |
2594 | return -ERESTARTNOHAND; | |
2595 | } | |
2596 | ||
2597 | #endif | |
2598 | ||
150256d8 | 2599 | #ifdef __ARCH_WANT_SYS_RT_SIGSUSPEND |
d4e82042 | 2600 | SYSCALL_DEFINE2(rt_sigsuspend, sigset_t __user *, unewset, size_t, sigsetsize) |
150256d8 DW |
2601 | { |
2602 | sigset_t newset; | |
2603 | ||
2604 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
2605 | if (sigsetsize != sizeof(sigset_t)) | |
2606 | return -EINVAL; | |
2607 | ||
2608 | if (copy_from_user(&newset, unewset, sizeof(newset))) | |
2609 | return -EFAULT; | |
2610 | sigdelsetmask(&newset, sigmask(SIGKILL)|sigmask(SIGSTOP)); | |
2611 | ||
2612 | spin_lock_irq(¤t->sighand->siglock); | |
2613 | current->saved_sigmask = current->blocked; | |
2614 | current->blocked = newset; | |
2615 | recalc_sigpending(); | |
2616 | spin_unlock_irq(¤t->sighand->siglock); | |
2617 | ||
2618 | current->state = TASK_INTERRUPTIBLE; | |
2619 | schedule(); | |
4e4c22c7 | 2620 | set_restore_sigmask(); |
150256d8 DW |
2621 | return -ERESTARTNOHAND; |
2622 | } | |
2623 | #endif /* __ARCH_WANT_SYS_RT_SIGSUSPEND */ | |
2624 | ||
f269fdd1 DH |
2625 | __attribute__((weak)) const char *arch_vma_name(struct vm_area_struct *vma) |
2626 | { | |
2627 | return NULL; | |
2628 | } | |
2629 | ||
1da177e4 LT |
2630 | void __init signals_init(void) |
2631 | { | |
0a31bd5f | 2632 | sigqueue_cachep = KMEM_CACHE(sigqueue, SLAB_PANIC); |
1da177e4 | 2633 | } |