Commit | Line | Data |
---|---|---|
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> | |
ad8d75ff | 30 | #include <trace/events/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 | |
35de254d | 44 | static void __user *sig_handler(struct task_struct *t, int sig) |
93585eea | 45 | { |
35de254d RM |
46 | return t->sighand->action[sig - 1].sa.sa_handler; |
47 | } | |
93585eea | 48 | |
35de254d RM |
49 | static int sig_handler_ignored(void __user *handler, int sig) |
50 | { | |
93585eea | 51 | /* Is it explicitly or implicitly ignored? */ |
93585eea PE |
52 | return handler == SIG_IGN || |
53 | (handler == SIG_DFL && sig_kernel_ignore(sig)); | |
54 | } | |
1da177e4 | 55 | |
921cf9f6 SB |
56 | static int sig_task_ignored(struct task_struct *t, int sig, |
57 | int from_ancestor_ns) | |
1da177e4 | 58 | { |
35de254d | 59 | void __user *handler; |
1da177e4 | 60 | |
f008faff ON |
61 | handler = sig_handler(t, sig); |
62 | ||
63 | if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) && | |
921cf9f6 | 64 | handler == SIG_DFL && !from_ancestor_ns) |
f008faff ON |
65 | return 1; |
66 | ||
67 | return sig_handler_ignored(handler, sig); | |
68 | } | |
69 | ||
921cf9f6 | 70 | static int sig_ignored(struct task_struct *t, int sig, int from_ancestor_ns) |
f008faff | 71 | { |
1da177e4 LT |
72 | /* |
73 | * Blocked signals are never ignored, since the | |
74 | * signal handler may change by the time it is | |
75 | * unblocked. | |
76 | */ | |
325d22df | 77 | if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig)) |
1da177e4 LT |
78 | return 0; |
79 | ||
921cf9f6 | 80 | if (!sig_task_ignored(t, sig, from_ancestor_ns)) |
35de254d RM |
81 | return 0; |
82 | ||
83 | /* | |
84 | * Tracers may want to know about even ignored signals. | |
85 | */ | |
43918f2b | 86 | return !tracehook_consider_ignored_signal(t, sig); |
1da177e4 LT |
87 | } |
88 | ||
89 | /* | |
90 | * Re-calculate pending state from the set of locally pending | |
91 | * signals, globally pending signals, and blocked signals. | |
92 | */ | |
93 | static inline int has_pending_signals(sigset_t *signal, sigset_t *blocked) | |
94 | { | |
95 | unsigned long ready; | |
96 | long i; | |
97 | ||
98 | switch (_NSIG_WORDS) { | |
99 | default: | |
100 | for (i = _NSIG_WORDS, ready = 0; --i >= 0 ;) | |
101 | ready |= signal->sig[i] &~ blocked->sig[i]; | |
102 | break; | |
103 | ||
104 | case 4: ready = signal->sig[3] &~ blocked->sig[3]; | |
105 | ready |= signal->sig[2] &~ blocked->sig[2]; | |
106 | ready |= signal->sig[1] &~ blocked->sig[1]; | |
107 | ready |= signal->sig[0] &~ blocked->sig[0]; | |
108 | break; | |
109 | ||
110 | case 2: ready = signal->sig[1] &~ blocked->sig[1]; | |
111 | ready |= signal->sig[0] &~ blocked->sig[0]; | |
112 | break; | |
113 | ||
114 | case 1: ready = signal->sig[0] &~ blocked->sig[0]; | |
115 | } | |
116 | return ready != 0; | |
117 | } | |
118 | ||
119 | #define PENDING(p,b) has_pending_signals(&(p)->signal, (b)) | |
120 | ||
7bb44ade | 121 | static int recalc_sigpending_tsk(struct task_struct *t) |
1da177e4 LT |
122 | { |
123 | if (t->signal->group_stop_count > 0 || | |
124 | PENDING(&t->pending, &t->blocked) || | |
7bb44ade | 125 | PENDING(&t->signal->shared_pending, &t->blocked)) { |
1da177e4 | 126 | set_tsk_thread_flag(t, TIF_SIGPENDING); |
7bb44ade RM |
127 | return 1; |
128 | } | |
b74d0deb RM |
129 | /* |
130 | * We must never clear the flag in another thread, or in current | |
131 | * when it's possible the current syscall is returning -ERESTART*. | |
132 | * So we don't clear it here, and only callers who know they should do. | |
133 | */ | |
7bb44ade RM |
134 | return 0; |
135 | } | |
136 | ||
137 | /* | |
138 | * After recalculating TIF_SIGPENDING, we need to make sure the task wakes up. | |
139 | * This is superfluous when called on current, the wakeup is a harmless no-op. | |
140 | */ | |
141 | void recalc_sigpending_and_wake(struct task_struct *t) | |
142 | { | |
143 | if (recalc_sigpending_tsk(t)) | |
144 | signal_wake_up(t, 0); | |
1da177e4 LT |
145 | } |
146 | ||
147 | void recalc_sigpending(void) | |
148 | { | |
b787f7ba RM |
149 | if (unlikely(tracehook_force_sigpending())) |
150 | set_thread_flag(TIF_SIGPENDING); | |
151 | else if (!recalc_sigpending_tsk(current) && !freezing(current)) | |
b74d0deb RM |
152 | clear_thread_flag(TIF_SIGPENDING); |
153 | ||
1da177e4 LT |
154 | } |
155 | ||
156 | /* Given the mask, find the first available signal that should be serviced. */ | |
157 | ||
fba2afaa | 158 | int next_signal(struct sigpending *pending, sigset_t *mask) |
1da177e4 LT |
159 | { |
160 | unsigned long i, *s, *m, x; | |
161 | int sig = 0; | |
162 | ||
163 | s = pending->signal.sig; | |
164 | m = mask->sig; | |
165 | switch (_NSIG_WORDS) { | |
166 | default: | |
167 | for (i = 0; i < _NSIG_WORDS; ++i, ++s, ++m) | |
168 | if ((x = *s &~ *m) != 0) { | |
169 | sig = ffz(~x) + i*_NSIG_BPW + 1; | |
170 | break; | |
171 | } | |
172 | break; | |
173 | ||
174 | case 2: if ((x = s[0] &~ m[0]) != 0) | |
175 | sig = 1; | |
176 | else if ((x = s[1] &~ m[1]) != 0) | |
177 | sig = _NSIG_BPW + 1; | |
178 | else | |
179 | break; | |
180 | sig += ffz(~x); | |
181 | break; | |
182 | ||
183 | case 1: if ((x = *s &~ *m) != 0) | |
184 | sig = ffz(~x) + 1; | |
185 | break; | |
186 | } | |
187 | ||
188 | return sig; | |
189 | } | |
190 | ||
c69e8d9c DH |
191 | /* |
192 | * allocate a new signal queue record | |
193 | * - this may be called without locks if and only if t == current, otherwise an | |
d84f4f99 | 194 | * appopriate lock must be held to stop the target task from exiting |
c69e8d9c | 195 | */ |
dd0fc66f | 196 | static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags, |
1da177e4 LT |
197 | int override_rlimit) |
198 | { | |
199 | struct sigqueue *q = NULL; | |
10b1fbdb | 200 | struct user_struct *user; |
1da177e4 | 201 | |
10b1fbdb | 202 | /* |
c69e8d9c DH |
203 | * We won't get problems with the target's UID changing under us |
204 | * because changing it requires RCU be used, and if t != current, the | |
205 | * caller must be holding the RCU readlock (by way of a spinlock) and | |
206 | * we use RCU protection here | |
10b1fbdb | 207 | */ |
d84f4f99 | 208 | user = get_uid(__task_cred(t)->user); |
10b1fbdb | 209 | atomic_inc(&user->sigpending); |
1da177e4 | 210 | if (override_rlimit || |
10b1fbdb | 211 | atomic_read(&user->sigpending) <= |
1da177e4 LT |
212 | t->signal->rlim[RLIMIT_SIGPENDING].rlim_cur) |
213 | q = kmem_cache_alloc(sigqueue_cachep, flags); | |
214 | if (unlikely(q == NULL)) { | |
10b1fbdb | 215 | atomic_dec(&user->sigpending); |
d84f4f99 | 216 | free_uid(user); |
1da177e4 LT |
217 | } else { |
218 | INIT_LIST_HEAD(&q->list); | |
219 | q->flags = 0; | |
d84f4f99 | 220 | q->user = user; |
1da177e4 | 221 | } |
d84f4f99 DH |
222 | |
223 | return q; | |
1da177e4 LT |
224 | } |
225 | ||
514a01b8 | 226 | static void __sigqueue_free(struct sigqueue *q) |
1da177e4 LT |
227 | { |
228 | if (q->flags & SIGQUEUE_PREALLOC) | |
229 | return; | |
230 | atomic_dec(&q->user->sigpending); | |
231 | free_uid(q->user); | |
232 | kmem_cache_free(sigqueue_cachep, q); | |
233 | } | |
234 | ||
6a14c5c9 | 235 | void flush_sigqueue(struct sigpending *queue) |
1da177e4 LT |
236 | { |
237 | struct sigqueue *q; | |
238 | ||
239 | sigemptyset(&queue->signal); | |
240 | while (!list_empty(&queue->list)) { | |
241 | q = list_entry(queue->list.next, struct sigqueue , list); | |
242 | list_del_init(&q->list); | |
243 | __sigqueue_free(q); | |
244 | } | |
245 | } | |
246 | ||
247 | /* | |
248 | * Flush all pending signals for a task. | |
249 | */ | |
3bcac026 DH |
250 | void __flush_signals(struct task_struct *t) |
251 | { | |
252 | clear_tsk_thread_flag(t, TIF_SIGPENDING); | |
253 | flush_sigqueue(&t->pending); | |
254 | flush_sigqueue(&t->signal->shared_pending); | |
255 | } | |
256 | ||
c81addc9 | 257 | void flush_signals(struct task_struct *t) |
1da177e4 LT |
258 | { |
259 | unsigned long flags; | |
260 | ||
261 | spin_lock_irqsave(&t->sighand->siglock, flags); | |
3bcac026 | 262 | __flush_signals(t); |
1da177e4 LT |
263 | spin_unlock_irqrestore(&t->sighand->siglock, flags); |
264 | } | |
265 | ||
cbaffba1 ON |
266 | static void __flush_itimer_signals(struct sigpending *pending) |
267 | { | |
268 | sigset_t signal, retain; | |
269 | struct sigqueue *q, *n; | |
270 | ||
271 | signal = pending->signal; | |
272 | sigemptyset(&retain); | |
273 | ||
274 | list_for_each_entry_safe(q, n, &pending->list, list) { | |
275 | int sig = q->info.si_signo; | |
276 | ||
277 | if (likely(q->info.si_code != SI_TIMER)) { | |
278 | sigaddset(&retain, sig); | |
279 | } else { | |
280 | sigdelset(&signal, sig); | |
281 | list_del_init(&q->list); | |
282 | __sigqueue_free(q); | |
283 | } | |
284 | } | |
285 | ||
286 | sigorsets(&pending->signal, &signal, &retain); | |
287 | } | |
288 | ||
289 | void flush_itimer_signals(void) | |
290 | { | |
291 | struct task_struct *tsk = current; | |
292 | unsigned long flags; | |
293 | ||
294 | spin_lock_irqsave(&tsk->sighand->siglock, flags); | |
295 | __flush_itimer_signals(&tsk->pending); | |
296 | __flush_itimer_signals(&tsk->signal->shared_pending); | |
297 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags); | |
298 | } | |
299 | ||
10ab825b ON |
300 | void ignore_signals(struct task_struct *t) |
301 | { | |
302 | int i; | |
303 | ||
304 | for (i = 0; i < _NSIG; ++i) | |
305 | t->sighand->action[i].sa.sa_handler = SIG_IGN; | |
306 | ||
307 | flush_signals(t); | |
308 | } | |
309 | ||
1da177e4 LT |
310 | /* |
311 | * Flush all handlers for a task. | |
312 | */ | |
313 | ||
314 | void | |
315 | flush_signal_handlers(struct task_struct *t, int force_default) | |
316 | { | |
317 | int i; | |
318 | struct k_sigaction *ka = &t->sighand->action[0]; | |
319 | for (i = _NSIG ; i != 0 ; i--) { | |
320 | if (force_default || ka->sa.sa_handler != SIG_IGN) | |
321 | ka->sa.sa_handler = SIG_DFL; | |
322 | ka->sa.sa_flags = 0; | |
323 | sigemptyset(&ka->sa.sa_mask); | |
324 | ka++; | |
325 | } | |
326 | } | |
327 | ||
abd4f750 MAS |
328 | int unhandled_signal(struct task_struct *tsk, int sig) |
329 | { | |
445a91d2 | 330 | void __user *handler = tsk->sighand->action[sig-1].sa.sa_handler; |
b460cbc5 | 331 | if (is_global_init(tsk)) |
abd4f750 | 332 | return 1; |
445a91d2 | 333 | if (handler != SIG_IGN && handler != SIG_DFL) |
abd4f750 | 334 | return 0; |
43918f2b | 335 | return !tracehook_consider_fatal_signal(tsk, sig); |
abd4f750 MAS |
336 | } |
337 | ||
1da177e4 LT |
338 | |
339 | /* Notify the system that a driver wants to block all signals for this | |
340 | * process, and wants to be notified if any signals at all were to be | |
341 | * sent/acted upon. If the notifier routine returns non-zero, then the | |
342 | * signal will be acted upon after all. If the notifier routine returns 0, | |
343 | * then then signal will be blocked. Only one block per process is | |
344 | * allowed. priv is a pointer to private data that the notifier routine | |
345 | * can use to determine if the signal should be blocked or not. */ | |
346 | ||
347 | void | |
348 | block_all_signals(int (*notifier)(void *priv), void *priv, sigset_t *mask) | |
349 | { | |
350 | unsigned long flags; | |
351 | ||
352 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
353 | current->notifier_mask = mask; | |
354 | current->notifier_data = priv; | |
355 | current->notifier = notifier; | |
356 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
357 | } | |
358 | ||
359 | /* Notify the system that blocking has ended. */ | |
360 | ||
361 | void | |
362 | unblock_all_signals(void) | |
363 | { | |
364 | unsigned long flags; | |
365 | ||
366 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
367 | current->notifier = NULL; | |
368 | current->notifier_data = NULL; | |
369 | recalc_sigpending(); | |
370 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
371 | } | |
372 | ||
100360f0 | 373 | static void collect_signal(int sig, struct sigpending *list, siginfo_t *info) |
1da177e4 LT |
374 | { |
375 | struct sigqueue *q, *first = NULL; | |
1da177e4 | 376 | |
1da177e4 LT |
377 | /* |
378 | * Collect the siginfo appropriate to this signal. Check if | |
379 | * there is another siginfo for the same signal. | |
380 | */ | |
381 | list_for_each_entry(q, &list->list, list) { | |
382 | if (q->info.si_signo == sig) { | |
d4434207 ON |
383 | if (first) |
384 | goto still_pending; | |
1da177e4 LT |
385 | first = q; |
386 | } | |
387 | } | |
d4434207 ON |
388 | |
389 | sigdelset(&list->signal, sig); | |
390 | ||
1da177e4 | 391 | if (first) { |
d4434207 | 392 | still_pending: |
1da177e4 LT |
393 | list_del_init(&first->list); |
394 | copy_siginfo(info, &first->info); | |
395 | __sigqueue_free(first); | |
1da177e4 | 396 | } else { |
1da177e4 LT |
397 | /* Ok, it wasn't in the queue. This must be |
398 | a fast-pathed signal or we must have been | |
399 | out of queue space. So zero out the info. | |
400 | */ | |
1da177e4 LT |
401 | info->si_signo = sig; |
402 | info->si_errno = 0; | |
403 | info->si_code = 0; | |
404 | info->si_pid = 0; | |
405 | info->si_uid = 0; | |
406 | } | |
1da177e4 LT |
407 | } |
408 | ||
409 | static int __dequeue_signal(struct sigpending *pending, sigset_t *mask, | |
410 | siginfo_t *info) | |
411 | { | |
27d91e07 | 412 | int sig = next_signal(pending, mask); |
1da177e4 | 413 | |
1da177e4 LT |
414 | if (sig) { |
415 | if (current->notifier) { | |
416 | if (sigismember(current->notifier_mask, sig)) { | |
417 | if (!(current->notifier)(current->notifier_data)) { | |
418 | clear_thread_flag(TIF_SIGPENDING); | |
419 | return 0; | |
420 | } | |
421 | } | |
422 | } | |
423 | ||
100360f0 | 424 | collect_signal(sig, pending, info); |
1da177e4 | 425 | } |
1da177e4 LT |
426 | |
427 | return sig; | |
428 | } | |
429 | ||
430 | /* | |
431 | * Dequeue a signal and return the element to the caller, which is | |
432 | * expected to free it. | |
433 | * | |
434 | * All callers have to hold the siglock. | |
435 | */ | |
436 | int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info) | |
437 | { | |
c5363d03 | 438 | int signr; |
caec4e8d BH |
439 | |
440 | /* We only dequeue private signals from ourselves, we don't let | |
441 | * signalfd steal them | |
442 | */ | |
b8fceee1 | 443 | signr = __dequeue_signal(&tsk->pending, mask, info); |
8bfd9a7a | 444 | if (!signr) { |
1da177e4 LT |
445 | signr = __dequeue_signal(&tsk->signal->shared_pending, |
446 | mask, info); | |
8bfd9a7a TG |
447 | /* |
448 | * itimer signal ? | |
449 | * | |
450 | * itimers are process shared and we restart periodic | |
451 | * itimers in the signal delivery path to prevent DoS | |
452 | * attacks in the high resolution timer case. This is | |
453 | * compliant with the old way of self restarting | |
454 | * itimers, as the SIGALRM is a legacy signal and only | |
455 | * queued once. Changing the restart behaviour to | |
456 | * restart the timer in the signal dequeue path is | |
457 | * reducing the timer noise on heavy loaded !highres | |
458 | * systems too. | |
459 | */ | |
460 | if (unlikely(signr == SIGALRM)) { | |
461 | struct hrtimer *tmr = &tsk->signal->real_timer; | |
462 | ||
463 | if (!hrtimer_is_queued(tmr) && | |
464 | tsk->signal->it_real_incr.tv64 != 0) { | |
465 | hrtimer_forward(tmr, tmr->base->get_time(), | |
466 | tsk->signal->it_real_incr); | |
467 | hrtimer_restart(tmr); | |
468 | } | |
469 | } | |
470 | } | |
c5363d03 | 471 | |
b8fceee1 | 472 | recalc_sigpending(); |
c5363d03 PE |
473 | if (!signr) |
474 | return 0; | |
475 | ||
476 | if (unlikely(sig_kernel_stop(signr))) { | |
8bfd9a7a TG |
477 | /* |
478 | * Set a marker that we have dequeued a stop signal. Our | |
479 | * caller might release the siglock and then the pending | |
480 | * stop signal it is about to process is no longer in the | |
481 | * pending bitmasks, but must still be cleared by a SIGCONT | |
482 | * (and overruled by a SIGKILL). So those cases clear this | |
483 | * shared flag after we've set it. Note that this flag may | |
484 | * remain set after the signal we return is ignored or | |
485 | * handled. That doesn't matter because its only purpose | |
486 | * is to alert stop-signal processing code when another | |
487 | * processor has come along and cleared the flag. | |
488 | */ | |
92413d77 | 489 | tsk->signal->flags |= SIGNAL_STOP_DEQUEUED; |
8bfd9a7a | 490 | } |
c5363d03 | 491 | if ((info->si_code & __SI_MASK) == __SI_TIMER && info->si_sys_private) { |
1da177e4 LT |
492 | /* |
493 | * Release the siglock to ensure proper locking order | |
494 | * of timer locks outside of siglocks. Note, we leave | |
495 | * irqs disabled here, since the posix-timers code is | |
496 | * about to disable them again anyway. | |
497 | */ | |
498 | spin_unlock(&tsk->sighand->siglock); | |
499 | do_schedule_next_timer(info); | |
500 | spin_lock(&tsk->sighand->siglock); | |
501 | } | |
502 | return signr; | |
503 | } | |
504 | ||
505 | /* | |
506 | * Tell a process that it has a new active signal.. | |
507 | * | |
508 | * NOTE! we rely on the previous spin_lock to | |
509 | * lock interrupts for us! We can only be called with | |
510 | * "siglock" held, and the local interrupt must | |
511 | * have been disabled when that got acquired! | |
512 | * | |
513 | * No need to set need_resched since signal event passing | |
514 | * goes through ->blocked | |
515 | */ | |
516 | void signal_wake_up(struct task_struct *t, int resume) | |
517 | { | |
518 | unsigned int mask; | |
519 | ||
520 | set_tsk_thread_flag(t, TIF_SIGPENDING); | |
521 | ||
522 | /* | |
f021a3c2 MW |
523 | * For SIGKILL, we want to wake it up in the stopped/traced/killable |
524 | * case. We don't check t->state here because there is a race with it | |
1da177e4 LT |
525 | * executing another processor and just now entering stopped state. |
526 | * By using wake_up_state, we ensure the process will wake up and | |
527 | * handle its death signal. | |
528 | */ | |
529 | mask = TASK_INTERRUPTIBLE; | |
530 | if (resume) | |
f021a3c2 | 531 | mask |= TASK_WAKEKILL; |
1da177e4 LT |
532 | if (!wake_up_state(t, mask)) |
533 | kick_process(t); | |
534 | } | |
535 | ||
71fabd5e GA |
536 | /* |
537 | * Remove signals in mask from the pending set and queue. | |
538 | * Returns 1 if any signals were found. | |
539 | * | |
540 | * All callers must be holding the siglock. | |
541 | * | |
542 | * This version takes a sigset mask and looks at all signals, | |
543 | * not just those in the first mask word. | |
544 | */ | |
545 | static int rm_from_queue_full(sigset_t *mask, struct sigpending *s) | |
546 | { | |
547 | struct sigqueue *q, *n; | |
548 | sigset_t m; | |
549 | ||
550 | sigandsets(&m, mask, &s->signal); | |
551 | if (sigisemptyset(&m)) | |
552 | return 0; | |
553 | ||
554 | signandsets(&s->signal, &s->signal, mask); | |
555 | list_for_each_entry_safe(q, n, &s->list, list) { | |
556 | if (sigismember(mask, q->info.si_signo)) { | |
557 | list_del_init(&q->list); | |
558 | __sigqueue_free(q); | |
559 | } | |
560 | } | |
561 | return 1; | |
562 | } | |
1da177e4 LT |
563 | /* |
564 | * Remove signals in mask from the pending set and queue. | |
565 | * Returns 1 if any signals were found. | |
566 | * | |
567 | * All callers must be holding the siglock. | |
568 | */ | |
569 | static int rm_from_queue(unsigned long mask, struct sigpending *s) | |
570 | { | |
571 | struct sigqueue *q, *n; | |
572 | ||
573 | if (!sigtestsetmask(&s->signal, mask)) | |
574 | return 0; | |
575 | ||
576 | sigdelsetmask(&s->signal, mask); | |
577 | list_for_each_entry_safe(q, n, &s->list, list) { | |
578 | if (q->info.si_signo < SIGRTMIN && | |
579 | (mask & sigmask(q->info.si_signo))) { | |
580 | list_del_init(&q->list); | |
581 | __sigqueue_free(q); | |
582 | } | |
583 | } | |
584 | return 1; | |
585 | } | |
586 | ||
587 | /* | |
588 | * Bad permissions for sending the signal | |
c69e8d9c | 589 | * - the caller must hold at least the RCU read lock |
1da177e4 LT |
590 | */ |
591 | static int check_kill_permission(int sig, struct siginfo *info, | |
592 | struct task_struct *t) | |
593 | { | |
c69e8d9c | 594 | const struct cred *cred = current_cred(), *tcred; |
2e2ba22e | 595 | struct pid *sid; |
3b5e9e53 ON |
596 | int error; |
597 | ||
7ed20e1a | 598 | if (!valid_signal(sig)) |
3b5e9e53 ON |
599 | return -EINVAL; |
600 | ||
601 | if (info != SEND_SIG_NOINFO && (is_si_special(info) || SI_FROMKERNEL(info))) | |
602 | return 0; | |
e54dc243 | 603 | |
3b5e9e53 ON |
604 | error = audit_signal_info(sig, t); /* Let audit system see the signal */ |
605 | if (error) | |
1da177e4 | 606 | return error; |
3b5e9e53 | 607 | |
c69e8d9c DH |
608 | tcred = __task_cred(t); |
609 | if ((cred->euid ^ tcred->suid) && | |
610 | (cred->euid ^ tcred->uid) && | |
611 | (cred->uid ^ tcred->suid) && | |
612 | (cred->uid ^ tcred->uid) && | |
2e2ba22e ON |
613 | !capable(CAP_KILL)) { |
614 | switch (sig) { | |
615 | case SIGCONT: | |
2e2ba22e | 616 | sid = task_session(t); |
2e2ba22e ON |
617 | /* |
618 | * We don't return the error if sid == NULL. The | |
619 | * task was unhashed, the caller must notice this. | |
620 | */ | |
621 | if (!sid || sid == task_session(current)) | |
622 | break; | |
623 | default: | |
624 | return -EPERM; | |
625 | } | |
626 | } | |
c2f0c7c3 | 627 | |
e54dc243 | 628 | return security_task_kill(t, info, sig, 0); |
1da177e4 LT |
629 | } |
630 | ||
1da177e4 | 631 | /* |
7e695a5e ON |
632 | * Handle magic process-wide effects of stop/continue signals. Unlike |
633 | * the signal actions, these happen immediately at signal-generation | |
1da177e4 LT |
634 | * time regardless of blocking, ignoring, or handling. This does the |
635 | * actual continuing for SIGCONT, but not the actual stopping for stop | |
7e695a5e ON |
636 | * signals. The process stop is done as a signal action for SIG_DFL. |
637 | * | |
638 | * Returns true if the signal should be actually delivered, otherwise | |
639 | * it should be dropped. | |
1da177e4 | 640 | */ |
921cf9f6 | 641 | static int prepare_signal(int sig, struct task_struct *p, int from_ancestor_ns) |
1da177e4 | 642 | { |
ad16a460 | 643 | struct signal_struct *signal = p->signal; |
1da177e4 LT |
644 | struct task_struct *t; |
645 | ||
7e695a5e | 646 | if (unlikely(signal->flags & SIGNAL_GROUP_EXIT)) { |
1da177e4 | 647 | /* |
7e695a5e | 648 | * The process is in the middle of dying, nothing to do. |
1da177e4 | 649 | */ |
7e695a5e | 650 | } else if (sig_kernel_stop(sig)) { |
1da177e4 LT |
651 | /* |
652 | * This is a stop signal. Remove SIGCONT from all queues. | |
653 | */ | |
ad16a460 | 654 | rm_from_queue(sigmask(SIGCONT), &signal->shared_pending); |
1da177e4 LT |
655 | t = p; |
656 | do { | |
657 | rm_from_queue(sigmask(SIGCONT), &t->pending); | |
ad16a460 | 658 | } while_each_thread(p, t); |
1da177e4 | 659 | } else if (sig == SIGCONT) { |
fc321d2e | 660 | unsigned int why; |
1da177e4 LT |
661 | /* |
662 | * Remove all stop signals from all queues, | |
663 | * and wake all threads. | |
664 | */ | |
ad16a460 | 665 | rm_from_queue(SIG_KERNEL_STOP_MASK, &signal->shared_pending); |
1da177e4 LT |
666 | t = p; |
667 | do { | |
668 | unsigned int state; | |
669 | rm_from_queue(SIG_KERNEL_STOP_MASK, &t->pending); | |
1da177e4 LT |
670 | /* |
671 | * If there is a handler for SIGCONT, we must make | |
672 | * sure that no thread returns to user mode before | |
673 | * we post the signal, in case it was the only | |
674 | * thread eligible to run the signal handler--then | |
675 | * it must not do anything between resuming and | |
676 | * running the handler. With the TIF_SIGPENDING | |
677 | * flag set, the thread will pause and acquire the | |
678 | * siglock that we hold now and until we've queued | |
fc321d2e | 679 | * the pending signal. |
1da177e4 LT |
680 | * |
681 | * Wake up the stopped thread _after_ setting | |
682 | * TIF_SIGPENDING | |
683 | */ | |
f021a3c2 | 684 | state = __TASK_STOPPED; |
1da177e4 LT |
685 | if (sig_user_defined(t, SIGCONT) && !sigismember(&t->blocked, SIGCONT)) { |
686 | set_tsk_thread_flag(t, TIF_SIGPENDING); | |
687 | state |= TASK_INTERRUPTIBLE; | |
688 | } | |
689 | wake_up_state(t, state); | |
ad16a460 | 690 | } while_each_thread(p, t); |
1da177e4 | 691 | |
fc321d2e ON |
692 | /* |
693 | * Notify the parent with CLD_CONTINUED if we were stopped. | |
694 | * | |
695 | * If we were in the middle of a group stop, we pretend it | |
696 | * was already finished, and then continued. Since SIGCHLD | |
697 | * doesn't queue we report only CLD_STOPPED, as if the next | |
698 | * CLD_CONTINUED was dropped. | |
699 | */ | |
700 | why = 0; | |
ad16a460 | 701 | if (signal->flags & SIGNAL_STOP_STOPPED) |
fc321d2e | 702 | why |= SIGNAL_CLD_CONTINUED; |
ad16a460 | 703 | else if (signal->group_stop_count) |
fc321d2e ON |
704 | why |= SIGNAL_CLD_STOPPED; |
705 | ||
706 | if (why) { | |
021e1ae3 | 707 | /* |
ae6d2ed7 | 708 | * The first thread which returns from do_signal_stop() |
021e1ae3 ON |
709 | * will take ->siglock, notice SIGNAL_CLD_MASK, and |
710 | * notify its parent. See get_signal_to_deliver(). | |
711 | */ | |
ad16a460 ON |
712 | signal->flags = why | SIGNAL_STOP_CONTINUED; |
713 | signal->group_stop_count = 0; | |
714 | signal->group_exit_code = 0; | |
1da177e4 LT |
715 | } else { |
716 | /* | |
717 | * We are not stopped, but there could be a stop | |
718 | * signal in the middle of being processed after | |
719 | * being removed from the queue. Clear that too. | |
720 | */ | |
ad16a460 | 721 | signal->flags &= ~SIGNAL_STOP_DEQUEUED; |
1da177e4 | 722 | } |
1da177e4 | 723 | } |
7e695a5e | 724 | |
921cf9f6 | 725 | return !sig_ignored(p, sig, from_ancestor_ns); |
1da177e4 LT |
726 | } |
727 | ||
71f11dc0 ON |
728 | /* |
729 | * Test if P wants to take SIG. After we've checked all threads with this, | |
730 | * it's equivalent to finding no threads not blocking SIG. Any threads not | |
731 | * blocking SIG were ruled out because they are not running and already | |
732 | * have pending signals. Such threads will dequeue from the shared queue | |
733 | * as soon as they're available, so putting the signal on the shared queue | |
734 | * will be equivalent to sending it to one such thread. | |
735 | */ | |
736 | static inline int wants_signal(int sig, struct task_struct *p) | |
737 | { | |
738 | if (sigismember(&p->blocked, sig)) | |
739 | return 0; | |
740 | if (p->flags & PF_EXITING) | |
741 | return 0; | |
742 | if (sig == SIGKILL) | |
743 | return 1; | |
744 | if (task_is_stopped_or_traced(p)) | |
745 | return 0; | |
746 | return task_curr(p) || !signal_pending(p); | |
747 | } | |
748 | ||
5fcd835b | 749 | static void complete_signal(int sig, struct task_struct *p, int group) |
71f11dc0 ON |
750 | { |
751 | struct signal_struct *signal = p->signal; | |
752 | struct task_struct *t; | |
753 | ||
754 | /* | |
755 | * Now find a thread we can wake up to take the signal off the queue. | |
756 | * | |
757 | * If the main thread wants the signal, it gets first crack. | |
758 | * Probably the least surprising to the average bear. | |
759 | */ | |
760 | if (wants_signal(sig, p)) | |
761 | t = p; | |
5fcd835b | 762 | else if (!group || thread_group_empty(p)) |
71f11dc0 ON |
763 | /* |
764 | * There is just one thread and it does not need to be woken. | |
765 | * It will dequeue unblocked signals before it runs again. | |
766 | */ | |
767 | return; | |
768 | else { | |
769 | /* | |
770 | * Otherwise try to find a suitable thread. | |
771 | */ | |
772 | t = signal->curr_target; | |
773 | while (!wants_signal(sig, t)) { | |
774 | t = next_thread(t); | |
775 | if (t == signal->curr_target) | |
776 | /* | |
777 | * No thread needs to be woken. | |
778 | * Any eligible threads will see | |
779 | * the signal in the queue soon. | |
780 | */ | |
781 | return; | |
782 | } | |
783 | signal->curr_target = t; | |
784 | } | |
785 | ||
786 | /* | |
787 | * Found a killable thread. If the signal will be fatal, | |
788 | * then start taking the whole group down immediately. | |
789 | */ | |
fae5fa44 ON |
790 | if (sig_fatal(p, sig) && |
791 | !(signal->flags & (SIGNAL_UNKILLABLE | SIGNAL_GROUP_EXIT)) && | |
71f11dc0 | 792 | !sigismember(&t->real_blocked, sig) && |
445a91d2 | 793 | (sig == SIGKILL || |
43918f2b | 794 | !tracehook_consider_fatal_signal(t, sig))) { |
71f11dc0 ON |
795 | /* |
796 | * This signal will be fatal to the whole group. | |
797 | */ | |
798 | if (!sig_kernel_coredump(sig)) { | |
799 | /* | |
800 | * Start a group exit and wake everybody up. | |
801 | * This way we don't have other threads | |
802 | * running and doing things after a slower | |
803 | * thread has the fatal signal pending. | |
804 | */ | |
805 | signal->flags = SIGNAL_GROUP_EXIT; | |
806 | signal->group_exit_code = sig; | |
807 | signal->group_stop_count = 0; | |
808 | t = p; | |
809 | do { | |
810 | sigaddset(&t->pending.signal, SIGKILL); | |
811 | signal_wake_up(t, 1); | |
812 | } while_each_thread(p, t); | |
813 | return; | |
814 | } | |
815 | } | |
816 | ||
817 | /* | |
818 | * The signal is already in the shared-pending queue. | |
819 | * Tell the chosen thread to wake up and dequeue it. | |
820 | */ | |
821 | signal_wake_up(t, sig == SIGKILL); | |
822 | return; | |
823 | } | |
824 | ||
af7fff9c PE |
825 | static inline int legacy_queue(struct sigpending *signals, int sig) |
826 | { | |
827 | return (sig < SIGRTMIN) && sigismember(&signals->signal, sig); | |
828 | } | |
829 | ||
7978b567 SB |
830 | static int __send_signal(int sig, struct siginfo *info, struct task_struct *t, |
831 | int group, int from_ancestor_ns) | |
1da177e4 | 832 | { |
2ca3515a | 833 | struct sigpending *pending; |
6e65acba | 834 | struct sigqueue *q; |
7a0aeb14 | 835 | int override_rlimit; |
1da177e4 | 836 | |
0a16b607 MD |
837 | trace_sched_signal_send(sig, t); |
838 | ||
6e65acba | 839 | assert_spin_locked(&t->sighand->siglock); |
921cf9f6 SB |
840 | |
841 | if (!prepare_signal(sig, t, from_ancestor_ns)) | |
7e695a5e | 842 | return 0; |
2ca3515a ON |
843 | |
844 | pending = group ? &t->signal->shared_pending : &t->pending; | |
2acb024d PE |
845 | /* |
846 | * Short-circuit ignored signals and support queuing | |
847 | * exactly one non-rt signal, so that we can get more | |
848 | * detailed information about the cause of the signal. | |
849 | */ | |
7e695a5e | 850 | if (legacy_queue(pending, sig)) |
2acb024d | 851 | return 0; |
1da177e4 LT |
852 | /* |
853 | * fast-pathed signals for kernel-internal things like SIGSTOP | |
854 | * or SIGKILL. | |
855 | */ | |
b67a1b9e | 856 | if (info == SEND_SIG_FORCED) |
1da177e4 LT |
857 | goto out_set; |
858 | ||
859 | /* Real-time signals must be queued if sent by sigqueue, or | |
860 | some other real-time mechanism. It is implementation | |
861 | defined whether kill() does so. We attempt to do so, on | |
862 | the principle of least surprise, but since kill is not | |
863 | allowed to fail with EAGAIN when low on memory we just | |
864 | make sure at least one signal gets delivered and don't | |
865 | pass on the info struct. */ | |
866 | ||
7a0aeb14 VN |
867 | if (sig < SIGRTMIN) |
868 | override_rlimit = (is_si_special(info) || info->si_code >= 0); | |
869 | else | |
870 | override_rlimit = 0; | |
871 | ||
872 | q = __sigqueue_alloc(t, GFP_ATOMIC | __GFP_NOTRACK_FALSE_POSITIVE, | |
873 | override_rlimit); | |
1da177e4 | 874 | if (q) { |
2ca3515a | 875 | list_add_tail(&q->list, &pending->list); |
1da177e4 | 876 | switch ((unsigned long) info) { |
b67a1b9e | 877 | case (unsigned long) SEND_SIG_NOINFO: |
1da177e4 LT |
878 | q->info.si_signo = sig; |
879 | q->info.si_errno = 0; | |
880 | q->info.si_code = SI_USER; | |
9cd4fd10 | 881 | q->info.si_pid = task_tgid_nr_ns(current, |
09bca05c | 882 | task_active_pid_ns(t)); |
76aac0e9 | 883 | q->info.si_uid = current_uid(); |
1da177e4 | 884 | break; |
b67a1b9e | 885 | case (unsigned long) SEND_SIG_PRIV: |
1da177e4 LT |
886 | q->info.si_signo = sig; |
887 | q->info.si_errno = 0; | |
888 | q->info.si_code = SI_KERNEL; | |
889 | q->info.si_pid = 0; | |
890 | q->info.si_uid = 0; | |
891 | break; | |
892 | default: | |
893 | copy_siginfo(&q->info, info); | |
6588c1e3 SB |
894 | if (from_ancestor_ns) |
895 | q->info.si_pid = 0; | |
1da177e4 LT |
896 | break; |
897 | } | |
621d3121 ON |
898 | } else if (!is_si_special(info)) { |
899 | if (sig >= SIGRTMIN && info->si_code != SI_USER) | |
1da177e4 LT |
900 | /* |
901 | * Queue overflow, abort. We may abort if the signal was rt | |
902 | * and sent by user using something other than kill(). | |
903 | */ | |
904 | return -EAGAIN; | |
1da177e4 LT |
905 | } |
906 | ||
907 | out_set: | |
53c30337 | 908 | signalfd_notify(t, sig); |
2ca3515a | 909 | sigaddset(&pending->signal, sig); |
4cd4b6d4 PE |
910 | complete_signal(sig, t, group); |
911 | return 0; | |
1da177e4 LT |
912 | } |
913 | ||
7978b567 SB |
914 | static int send_signal(int sig, struct siginfo *info, struct task_struct *t, |
915 | int group) | |
916 | { | |
921cf9f6 SB |
917 | int from_ancestor_ns = 0; |
918 | ||
919 | #ifdef CONFIG_PID_NS | |
920 | if (!is_si_special(info) && SI_FROMUSER(info) && | |
921 | task_pid_nr_ns(current, task_active_pid_ns(t)) <= 0) | |
922 | from_ancestor_ns = 1; | |
923 | #endif | |
924 | ||
925 | return __send_signal(sig, info, t, group, from_ancestor_ns); | |
7978b567 SB |
926 | } |
927 | ||
45807a1d IM |
928 | int print_fatal_signals; |
929 | ||
930 | static void print_fatal_signal(struct pt_regs *regs, int signr) | |
931 | { | |
932 | printk("%s/%d: potentially unexpected fatal signal %d.\n", | |
ba25f9dc | 933 | current->comm, task_pid_nr(current), signr); |
45807a1d | 934 | |
ca5cd877 | 935 | #if defined(__i386__) && !defined(__arch_um__) |
65ea5b03 | 936 | printk("code at %08lx: ", regs->ip); |
45807a1d IM |
937 | { |
938 | int i; | |
939 | for (i = 0; i < 16; i++) { | |
940 | unsigned char insn; | |
941 | ||
65ea5b03 | 942 | __get_user(insn, (unsigned char *)(regs->ip + i)); |
45807a1d IM |
943 | printk("%02x ", insn); |
944 | } | |
945 | } | |
946 | #endif | |
947 | printk("\n"); | |
3a9f84d3 | 948 | preempt_disable(); |
45807a1d | 949 | show_regs(regs); |
3a9f84d3 | 950 | preempt_enable(); |
45807a1d IM |
951 | } |
952 | ||
953 | static int __init setup_print_fatal_signals(char *str) | |
954 | { | |
955 | get_option (&str, &print_fatal_signals); | |
956 | ||
957 | return 1; | |
958 | } | |
959 | ||
960 | __setup("print-fatal-signals=", setup_print_fatal_signals); | |
1da177e4 | 961 | |
4cd4b6d4 PE |
962 | int |
963 | __group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) | |
964 | { | |
965 | return send_signal(sig, info, p, 1); | |
966 | } | |
967 | ||
1da177e4 LT |
968 | static int |
969 | specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t) | |
970 | { | |
4cd4b6d4 | 971 | return send_signal(sig, info, t, 0); |
1da177e4 LT |
972 | } |
973 | ||
4a30debf ON |
974 | int do_send_sig_info(int sig, struct siginfo *info, struct task_struct *p, |
975 | bool group) | |
976 | { | |
977 | unsigned long flags; | |
978 | int ret = -ESRCH; | |
979 | ||
980 | if (lock_task_sighand(p, &flags)) { | |
981 | ret = send_signal(sig, info, p, group); | |
982 | unlock_task_sighand(p, &flags); | |
983 | } | |
984 | ||
985 | return ret; | |
986 | } | |
987 | ||
1da177e4 LT |
988 | /* |
989 | * Force a signal that the process can't ignore: if necessary | |
990 | * we unblock the signal and change any SIG_IGN to SIG_DFL. | |
ae74c3b6 LT |
991 | * |
992 | * Note: If we unblock the signal, we always reset it to SIG_DFL, | |
993 | * since we do not want to have a signal handler that was blocked | |
994 | * be invoked when user space had explicitly blocked it. | |
995 | * | |
80fe728d ON |
996 | * We don't want to have recursive SIGSEGV's etc, for example, |
997 | * that is why we also clear SIGNAL_UNKILLABLE. | |
1da177e4 | 998 | */ |
1da177e4 LT |
999 | int |
1000 | force_sig_info(int sig, struct siginfo *info, struct task_struct *t) | |
1001 | { | |
1002 | unsigned long int flags; | |
ae74c3b6 LT |
1003 | int ret, blocked, ignored; |
1004 | struct k_sigaction *action; | |
1da177e4 LT |
1005 | |
1006 | spin_lock_irqsave(&t->sighand->siglock, flags); | |
ae74c3b6 LT |
1007 | action = &t->sighand->action[sig-1]; |
1008 | ignored = action->sa.sa_handler == SIG_IGN; | |
1009 | blocked = sigismember(&t->blocked, sig); | |
1010 | if (blocked || ignored) { | |
1011 | action->sa.sa_handler = SIG_DFL; | |
1012 | if (blocked) { | |
1013 | sigdelset(&t->blocked, sig); | |
7bb44ade | 1014 | recalc_sigpending_and_wake(t); |
ae74c3b6 | 1015 | } |
1da177e4 | 1016 | } |
80fe728d ON |
1017 | if (action->sa.sa_handler == SIG_DFL) |
1018 | t->signal->flags &= ~SIGNAL_UNKILLABLE; | |
1da177e4 LT |
1019 | ret = specific_send_sig_info(sig, info, t); |
1020 | spin_unlock_irqrestore(&t->sighand->siglock, flags); | |
1021 | ||
1022 | return ret; | |
1023 | } | |
1024 | ||
1025 | void | |
1026 | force_sig_specific(int sig, struct task_struct *t) | |
1027 | { | |
b0423a0d | 1028 | force_sig_info(sig, SEND_SIG_FORCED, t); |
1da177e4 LT |
1029 | } |
1030 | ||
1da177e4 LT |
1031 | /* |
1032 | * Nuke all other threads in the group. | |
1033 | */ | |
1034 | void zap_other_threads(struct task_struct *p) | |
1035 | { | |
1036 | struct task_struct *t; | |
1037 | ||
1da177e4 LT |
1038 | p->signal->group_stop_count = 0; |
1039 | ||
1da177e4 LT |
1040 | for (t = next_thread(p); t != p; t = next_thread(t)) { |
1041 | /* | |
1042 | * Don't bother with already dead threads | |
1043 | */ | |
1044 | if (t->exit_state) | |
1045 | continue; | |
1046 | ||
30e0fca6 | 1047 | /* SIGKILL will be handled before any pending SIGSTOP */ |
1da177e4 | 1048 | sigaddset(&t->pending.signal, SIGKILL); |
1da177e4 LT |
1049 | signal_wake_up(t, 1); |
1050 | } | |
1051 | } | |
1052 | ||
f63ee72e ON |
1053 | struct sighand_struct *lock_task_sighand(struct task_struct *tsk, unsigned long *flags) |
1054 | { | |
1055 | struct sighand_struct *sighand; | |
1056 | ||
1406f2d3 | 1057 | rcu_read_lock(); |
f63ee72e ON |
1058 | for (;;) { |
1059 | sighand = rcu_dereference(tsk->sighand); | |
1060 | if (unlikely(sighand == NULL)) | |
1061 | break; | |
1062 | ||
1063 | spin_lock_irqsave(&sighand->siglock, *flags); | |
1064 | if (likely(sighand == tsk->sighand)) | |
1065 | break; | |
1066 | spin_unlock_irqrestore(&sighand->siglock, *flags); | |
1067 | } | |
1406f2d3 | 1068 | rcu_read_unlock(); |
f63ee72e ON |
1069 | |
1070 | return sighand; | |
1071 | } | |
1072 | ||
c69e8d9c DH |
1073 | /* |
1074 | * send signal info to all the members of a group | |
1075 | * - the caller must hold the RCU read lock at least | |
1076 | */ | |
1da177e4 LT |
1077 | int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) |
1078 | { | |
4a30debf | 1079 | int ret = check_kill_permission(sig, info, p); |
f63ee72e | 1080 | |
4a30debf ON |
1081 | if (!ret && sig) |
1082 | ret = do_send_sig_info(sig, info, p, true); | |
1da177e4 LT |
1083 | |
1084 | return ret; | |
1085 | } | |
1086 | ||
1087 | /* | |
146a505d | 1088 | * __kill_pgrp_info() sends a signal to a process group: this is what the tty |
1da177e4 | 1089 | * control characters do (^C, ^Z etc) |
c69e8d9c | 1090 | * - the caller must hold at least a readlock on tasklist_lock |
1da177e4 | 1091 | */ |
c4b92fc1 | 1092 | int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp) |
1da177e4 LT |
1093 | { |
1094 | struct task_struct *p = NULL; | |
1095 | int retval, success; | |
1096 | ||
1da177e4 LT |
1097 | success = 0; |
1098 | retval = -ESRCH; | |
c4b92fc1 | 1099 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
1da177e4 LT |
1100 | int err = group_send_sig_info(sig, info, p); |
1101 | success |= !err; | |
1102 | retval = err; | |
c4b92fc1 | 1103 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
1da177e4 LT |
1104 | return success ? 0 : retval; |
1105 | } | |
1106 | ||
c4b92fc1 | 1107 | int kill_pid_info(int sig, struct siginfo *info, struct pid *pid) |
1da177e4 | 1108 | { |
d36174bc | 1109 | int error = -ESRCH; |
1da177e4 LT |
1110 | struct task_struct *p; |
1111 | ||
e56d0903 | 1112 | rcu_read_lock(); |
d36174bc | 1113 | retry: |
c4b92fc1 | 1114 | p = pid_task(pid, PIDTYPE_PID); |
d36174bc | 1115 | if (p) { |
1da177e4 | 1116 | error = group_send_sig_info(sig, info, p); |
d36174bc ON |
1117 | if (unlikely(error == -ESRCH)) |
1118 | /* | |
1119 | * The task was unhashed in between, try again. | |
1120 | * If it is dead, pid_task() will return NULL, | |
1121 | * if we race with de_thread() it will find the | |
1122 | * new leader. | |
1123 | */ | |
1124 | goto retry; | |
1125 | } | |
e56d0903 | 1126 | rcu_read_unlock(); |
6ca25b55 | 1127 | |
1da177e4 LT |
1128 | return error; |
1129 | } | |
1130 | ||
c3de4b38 MW |
1131 | int |
1132 | kill_proc_info(int sig, struct siginfo *info, pid_t pid) | |
c4b92fc1 EB |
1133 | { |
1134 | int error; | |
1135 | rcu_read_lock(); | |
b488893a | 1136 | error = kill_pid_info(sig, info, find_vpid(pid)); |
c4b92fc1 EB |
1137 | rcu_read_unlock(); |
1138 | return error; | |
1139 | } | |
1140 | ||
2425c08b EB |
1141 | /* like kill_pid_info(), but doesn't use uid/euid of "current" */ |
1142 | int kill_pid_info_as_uid(int sig, struct siginfo *info, struct pid *pid, | |
8f95dc58 | 1143 | uid_t uid, uid_t euid, u32 secid) |
46113830 HW |
1144 | { |
1145 | int ret = -EINVAL; | |
1146 | struct task_struct *p; | |
c69e8d9c | 1147 | const struct cred *pcred; |
46113830 HW |
1148 | |
1149 | if (!valid_signal(sig)) | |
1150 | return ret; | |
1151 | ||
1152 | read_lock(&tasklist_lock); | |
2425c08b | 1153 | p = pid_task(pid, PIDTYPE_PID); |
46113830 HW |
1154 | if (!p) { |
1155 | ret = -ESRCH; | |
1156 | goto out_unlock; | |
1157 | } | |
c69e8d9c DH |
1158 | pcred = __task_cred(p); |
1159 | if ((info == SEND_SIG_NOINFO || | |
1160 | (!is_si_special(info) && SI_FROMUSER(info))) && | |
1161 | euid != pcred->suid && euid != pcred->uid && | |
1162 | uid != pcred->suid && uid != pcred->uid) { | |
46113830 HW |
1163 | ret = -EPERM; |
1164 | goto out_unlock; | |
1165 | } | |
8f95dc58 DQ |
1166 | ret = security_task_kill(p, info, sig, secid); |
1167 | if (ret) | |
1168 | goto out_unlock; | |
46113830 HW |
1169 | if (sig && p->sighand) { |
1170 | unsigned long flags; | |
1171 | spin_lock_irqsave(&p->sighand->siglock, flags); | |
7978b567 | 1172 | ret = __send_signal(sig, info, p, 1, 0); |
46113830 HW |
1173 | spin_unlock_irqrestore(&p->sighand->siglock, flags); |
1174 | } | |
1175 | out_unlock: | |
1176 | read_unlock(&tasklist_lock); | |
1177 | return ret; | |
1178 | } | |
2425c08b | 1179 | EXPORT_SYMBOL_GPL(kill_pid_info_as_uid); |
1da177e4 LT |
1180 | |
1181 | /* | |
1182 | * kill_something_info() interprets pid in interesting ways just like kill(2). | |
1183 | * | |
1184 | * POSIX specifies that kill(-1,sig) is unspecified, but what we have | |
1185 | * is probably wrong. Should make it like BSD or SYSV. | |
1186 | */ | |
1187 | ||
bc64efd2 | 1188 | static int kill_something_info(int sig, struct siginfo *info, pid_t pid) |
1da177e4 | 1189 | { |
8d42db18 | 1190 | int ret; |
d5df763b PE |
1191 | |
1192 | if (pid > 0) { | |
1193 | rcu_read_lock(); | |
1194 | ret = kill_pid_info(sig, info, find_vpid(pid)); | |
1195 | rcu_read_unlock(); | |
1196 | return ret; | |
1197 | } | |
1198 | ||
1199 | read_lock(&tasklist_lock); | |
1200 | if (pid != -1) { | |
1201 | ret = __kill_pgrp_info(sig, info, | |
1202 | pid ? find_vpid(-pid) : task_pgrp(current)); | |
1203 | } else { | |
1da177e4 LT |
1204 | int retval = 0, count = 0; |
1205 | struct task_struct * p; | |
1206 | ||
1da177e4 | 1207 | for_each_process(p) { |
d25141a8 SB |
1208 | if (task_pid_vnr(p) > 1 && |
1209 | !same_thread_group(p, current)) { | |
1da177e4 LT |
1210 | int err = group_send_sig_info(sig, info, p); |
1211 | ++count; | |
1212 | if (err != -EPERM) | |
1213 | retval = err; | |
1214 | } | |
1215 | } | |
8d42db18 | 1216 | ret = count ? retval : -ESRCH; |
1da177e4 | 1217 | } |
d5df763b PE |
1218 | read_unlock(&tasklist_lock); |
1219 | ||
8d42db18 | 1220 | return ret; |
1da177e4 LT |
1221 | } |
1222 | ||
1223 | /* | |
1224 | * These are for backward compatibility with the rest of the kernel source. | |
1225 | */ | |
1226 | ||
1da177e4 LT |
1227 | int |
1228 | send_sig_info(int sig, struct siginfo *info, struct task_struct *p) | |
1229 | { | |
1da177e4 LT |
1230 | /* |
1231 | * Make sure legacy kernel users don't send in bad values | |
1232 | * (normal paths check this in check_kill_permission). | |
1233 | */ | |
7ed20e1a | 1234 | if (!valid_signal(sig)) |
1da177e4 LT |
1235 | return -EINVAL; |
1236 | ||
4a30debf | 1237 | return do_send_sig_info(sig, info, p, false); |
1da177e4 LT |
1238 | } |
1239 | ||
b67a1b9e ON |
1240 | #define __si_special(priv) \ |
1241 | ((priv) ? SEND_SIG_PRIV : SEND_SIG_NOINFO) | |
1242 | ||
1da177e4 LT |
1243 | int |
1244 | send_sig(int sig, struct task_struct *p, int priv) | |
1245 | { | |
b67a1b9e | 1246 | return send_sig_info(sig, __si_special(priv), p); |
1da177e4 LT |
1247 | } |
1248 | ||
1da177e4 LT |
1249 | void |
1250 | force_sig(int sig, struct task_struct *p) | |
1251 | { | |
b67a1b9e | 1252 | force_sig_info(sig, SEND_SIG_PRIV, p); |
1da177e4 LT |
1253 | } |
1254 | ||
1255 | /* | |
1256 | * When things go south during signal handling, we | |
1257 | * will force a SIGSEGV. And if the signal that caused | |
1258 | * the problem was already a SIGSEGV, we'll want to | |
1259 | * make sure we don't even try to deliver the signal.. | |
1260 | */ | |
1261 | int | |
1262 | force_sigsegv(int sig, struct task_struct *p) | |
1263 | { | |
1264 | if (sig == SIGSEGV) { | |
1265 | unsigned long flags; | |
1266 | spin_lock_irqsave(&p->sighand->siglock, flags); | |
1267 | p->sighand->action[sig - 1].sa.sa_handler = SIG_DFL; | |
1268 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | |
1269 | } | |
1270 | force_sig(SIGSEGV, p); | |
1271 | return 0; | |
1272 | } | |
1273 | ||
c4b92fc1 EB |
1274 | int kill_pgrp(struct pid *pid, int sig, int priv) |
1275 | { | |
146a505d PE |
1276 | int ret; |
1277 | ||
1278 | read_lock(&tasklist_lock); | |
1279 | ret = __kill_pgrp_info(sig, __si_special(priv), pid); | |
1280 | read_unlock(&tasklist_lock); | |
1281 | ||
1282 | return ret; | |
c4b92fc1 EB |
1283 | } |
1284 | EXPORT_SYMBOL(kill_pgrp); | |
1285 | ||
1286 | int kill_pid(struct pid *pid, int sig, int priv) | |
1287 | { | |
1288 | return kill_pid_info(sig, __si_special(priv), pid); | |
1289 | } | |
1290 | EXPORT_SYMBOL(kill_pid); | |
1291 | ||
1da177e4 LT |
1292 | /* |
1293 | * These functions support sending signals using preallocated sigqueue | |
1294 | * structures. This is needed "because realtime applications cannot | |
1295 | * afford to lose notifications of asynchronous events, like timer | |
1296 | * expirations or I/O completions". In the case of Posix Timers | |
1297 | * we allocate the sigqueue structure from the timer_create. If this | |
1298 | * allocation fails we are able to report the failure to the application | |
1299 | * with an EAGAIN error. | |
1300 | */ | |
1301 | ||
1302 | struct sigqueue *sigqueue_alloc(void) | |
1303 | { | |
1304 | struct sigqueue *q; | |
1305 | ||
1306 | if ((q = __sigqueue_alloc(current, GFP_KERNEL, 0))) | |
1307 | q->flags |= SIGQUEUE_PREALLOC; | |
1308 | return(q); | |
1309 | } | |
1310 | ||
1311 | void sigqueue_free(struct sigqueue *q) | |
1312 | { | |
1313 | unsigned long flags; | |
60187d27 ON |
1314 | spinlock_t *lock = ¤t->sighand->siglock; |
1315 | ||
1da177e4 LT |
1316 | BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); |
1317 | /* | |
c8e85b4f ON |
1318 | * We must hold ->siglock while testing q->list |
1319 | * to serialize with collect_signal() or with | |
da7978b0 | 1320 | * __exit_signal()->flush_sigqueue(). |
1da177e4 | 1321 | */ |
60187d27 | 1322 | spin_lock_irqsave(lock, flags); |
c8e85b4f ON |
1323 | q->flags &= ~SIGQUEUE_PREALLOC; |
1324 | /* | |
1325 | * If it is queued it will be freed when dequeued, | |
1326 | * like the "regular" sigqueue. | |
1327 | */ | |
60187d27 | 1328 | if (!list_empty(&q->list)) |
c8e85b4f | 1329 | q = NULL; |
60187d27 ON |
1330 | spin_unlock_irqrestore(lock, flags); |
1331 | ||
c8e85b4f ON |
1332 | if (q) |
1333 | __sigqueue_free(q); | |
1da177e4 LT |
1334 | } |
1335 | ||
ac5c2153 | 1336 | int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group) |
9e3bd6c3 | 1337 | { |
e62e6650 | 1338 | int sig = q->info.si_signo; |
2ca3515a | 1339 | struct sigpending *pending; |
e62e6650 ON |
1340 | unsigned long flags; |
1341 | int ret; | |
2ca3515a | 1342 | |
4cd4b6d4 | 1343 | BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); |
e62e6650 ON |
1344 | |
1345 | ret = -1; | |
1346 | if (!likely(lock_task_sighand(t, &flags))) | |
1347 | goto ret; | |
1348 | ||
7e695a5e | 1349 | ret = 1; /* the signal is ignored */ |
921cf9f6 | 1350 | if (!prepare_signal(sig, t, 0)) |
e62e6650 ON |
1351 | goto out; |
1352 | ||
1353 | ret = 0; | |
9e3bd6c3 PE |
1354 | if (unlikely(!list_empty(&q->list))) { |
1355 | /* | |
1356 | * If an SI_TIMER entry is already queue just increment | |
1357 | * the overrun count. | |
1358 | */ | |
9e3bd6c3 PE |
1359 | BUG_ON(q->info.si_code != SI_TIMER); |
1360 | q->info.si_overrun++; | |
e62e6650 | 1361 | goto out; |
9e3bd6c3 | 1362 | } |
ba661292 | 1363 | q->info.si_overrun = 0; |
9e3bd6c3 | 1364 | |
9e3bd6c3 | 1365 | signalfd_notify(t, sig); |
2ca3515a | 1366 | pending = group ? &t->signal->shared_pending : &t->pending; |
9e3bd6c3 PE |
1367 | list_add_tail(&q->list, &pending->list); |
1368 | sigaddset(&pending->signal, sig); | |
4cd4b6d4 | 1369 | complete_signal(sig, t, group); |
e62e6650 ON |
1370 | out: |
1371 | unlock_task_sighand(t, &flags); | |
1372 | ret: | |
1373 | return ret; | |
9e3bd6c3 PE |
1374 | } |
1375 | ||
1da177e4 LT |
1376 | /* |
1377 | * Let a parent know about the death of a child. | |
1378 | * For a stopped/continued status change, use do_notify_parent_cldstop instead. | |
2b2a1ff6 RM |
1379 | * |
1380 | * Returns -1 if our parent ignored us and so we've switched to | |
1381 | * self-reaping, or else @sig. | |
1da177e4 | 1382 | */ |
2b2a1ff6 | 1383 | int do_notify_parent(struct task_struct *tsk, int sig) |
1da177e4 LT |
1384 | { |
1385 | struct siginfo info; | |
1386 | unsigned long flags; | |
1387 | struct sighand_struct *psig; | |
1b04624f | 1388 | int ret = sig; |
1da177e4 LT |
1389 | |
1390 | BUG_ON(sig == -1); | |
1391 | ||
1392 | /* do_notify_parent_cldstop should have been called instead. */ | |
e1abb39c | 1393 | BUG_ON(task_is_stopped_or_traced(tsk)); |
1da177e4 | 1394 | |
5cb11446 | 1395 | BUG_ON(!task_ptrace(tsk) && |
1da177e4 LT |
1396 | (tsk->group_leader != tsk || !thread_group_empty(tsk))); |
1397 | ||
1398 | info.si_signo = sig; | |
1399 | info.si_errno = 0; | |
b488893a PE |
1400 | /* |
1401 | * we are under tasklist_lock here so our parent is tied to | |
1402 | * us and cannot exit and release its namespace. | |
1403 | * | |
1404 | * the only it can is to switch its nsproxy with sys_unshare, | |
1405 | * bu uncharing pid namespaces is not allowed, so we'll always | |
1406 | * see relevant namespace | |
1407 | * | |
1408 | * write_lock() currently calls preempt_disable() which is the | |
1409 | * same as rcu_read_lock(), but according to Oleg, this is not | |
1410 | * correct to rely on this | |
1411 | */ | |
1412 | rcu_read_lock(); | |
1413 | info.si_pid = task_pid_nr_ns(tsk, tsk->parent->nsproxy->pid_ns); | |
c69e8d9c | 1414 | info.si_uid = __task_cred(tsk)->uid; |
b488893a PE |
1415 | rcu_read_unlock(); |
1416 | ||
32bd671d PZ |
1417 | info.si_utime = cputime_to_clock_t(cputime_add(tsk->utime, |
1418 | tsk->signal->utime)); | |
1419 | info.si_stime = cputime_to_clock_t(cputime_add(tsk->stime, | |
1420 | tsk->signal->stime)); | |
1da177e4 LT |
1421 | |
1422 | info.si_status = tsk->exit_code & 0x7f; | |
1423 | if (tsk->exit_code & 0x80) | |
1424 | info.si_code = CLD_DUMPED; | |
1425 | else if (tsk->exit_code & 0x7f) | |
1426 | info.si_code = CLD_KILLED; | |
1427 | else { | |
1428 | info.si_code = CLD_EXITED; | |
1429 | info.si_status = tsk->exit_code >> 8; | |
1430 | } | |
1431 | ||
1432 | psig = tsk->parent->sighand; | |
1433 | spin_lock_irqsave(&psig->siglock, flags); | |
5cb11446 | 1434 | if (!task_ptrace(tsk) && sig == SIGCHLD && |
1da177e4 LT |
1435 | (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN || |
1436 | (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT))) { | |
1437 | /* | |
1438 | * We are exiting and our parent doesn't care. POSIX.1 | |
1439 | * defines special semantics for setting SIGCHLD to SIG_IGN | |
1440 | * or setting the SA_NOCLDWAIT flag: we should be reaped | |
1441 | * automatically and not left for our parent's wait4 call. | |
1442 | * Rather than having the parent do it as a magic kind of | |
1443 | * signal handler, we just set this to tell do_exit that we | |
1444 | * can be cleaned up without becoming a zombie. Note that | |
1445 | * we still call __wake_up_parent in this case, because a | |
1446 | * blocked sys_wait4 might now return -ECHILD. | |
1447 | * | |
1448 | * Whether we send SIGCHLD or not for SA_NOCLDWAIT | |
1449 | * is implementation-defined: we do (if you don't want | |
1450 | * it, just use SIG_IGN instead). | |
1451 | */ | |
1b04624f | 1452 | ret = tsk->exit_signal = -1; |
1da177e4 | 1453 | if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) |
2b2a1ff6 | 1454 | sig = -1; |
1da177e4 | 1455 | } |
7ed20e1a | 1456 | if (valid_signal(sig) && sig > 0) |
1da177e4 LT |
1457 | __group_send_sig_info(sig, &info, tsk->parent); |
1458 | __wake_up_parent(tsk, tsk->parent); | |
1459 | spin_unlock_irqrestore(&psig->siglock, flags); | |
2b2a1ff6 | 1460 | |
1b04624f | 1461 | return ret; |
1da177e4 LT |
1462 | } |
1463 | ||
a1d5e21e | 1464 | static void do_notify_parent_cldstop(struct task_struct *tsk, int why) |
1da177e4 LT |
1465 | { |
1466 | struct siginfo info; | |
1467 | unsigned long flags; | |
bc505a47 | 1468 | struct task_struct *parent; |
1da177e4 LT |
1469 | struct sighand_struct *sighand; |
1470 | ||
5cb11446 | 1471 | if (task_ptrace(tsk)) |
bc505a47 ON |
1472 | parent = tsk->parent; |
1473 | else { | |
1474 | tsk = tsk->group_leader; | |
1475 | parent = tsk->real_parent; | |
1476 | } | |
1477 | ||
1da177e4 LT |
1478 | info.si_signo = SIGCHLD; |
1479 | info.si_errno = 0; | |
b488893a PE |
1480 | /* |
1481 | * see comment in do_notify_parent() abot the following 3 lines | |
1482 | */ | |
1483 | rcu_read_lock(); | |
d9265663 | 1484 | info.si_pid = task_pid_nr_ns(tsk, parent->nsproxy->pid_ns); |
c69e8d9c | 1485 | info.si_uid = __task_cred(tsk)->uid; |
b488893a PE |
1486 | rcu_read_unlock(); |
1487 | ||
d8878ba3 MK |
1488 | info.si_utime = cputime_to_clock_t(tsk->utime); |
1489 | info.si_stime = cputime_to_clock_t(tsk->stime); | |
1da177e4 LT |
1490 | |
1491 | info.si_code = why; | |
1492 | switch (why) { | |
1493 | case CLD_CONTINUED: | |
1494 | info.si_status = SIGCONT; | |
1495 | break; | |
1496 | case CLD_STOPPED: | |
1497 | info.si_status = tsk->signal->group_exit_code & 0x7f; | |
1498 | break; | |
1499 | case CLD_TRAPPED: | |
1500 | info.si_status = tsk->exit_code & 0x7f; | |
1501 | break; | |
1502 | default: | |
1503 | BUG(); | |
1504 | } | |
1505 | ||
1506 | sighand = parent->sighand; | |
1507 | spin_lock_irqsave(&sighand->siglock, flags); | |
1508 | if (sighand->action[SIGCHLD-1].sa.sa_handler != SIG_IGN && | |
1509 | !(sighand->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDSTOP)) | |
1510 | __group_send_sig_info(SIGCHLD, &info, parent); | |
1511 | /* | |
1512 | * Even if SIGCHLD is not generated, we must wake up wait4 calls. | |
1513 | */ | |
1514 | __wake_up_parent(tsk, parent); | |
1515 | spin_unlock_irqrestore(&sighand->siglock, flags); | |
1516 | } | |
1517 | ||
d5f70c00 ON |
1518 | static inline int may_ptrace_stop(void) |
1519 | { | |
5cb11446 | 1520 | if (!likely(task_ptrace(current))) |
d5f70c00 | 1521 | return 0; |
d5f70c00 ON |
1522 | /* |
1523 | * Are we in the middle of do_coredump? | |
1524 | * If so and our tracer is also part of the coredump stopping | |
1525 | * is a deadlock situation, and pointless because our tracer | |
1526 | * is dead so don't allow us to stop. | |
1527 | * If SIGKILL was already sent before the caller unlocked | |
999d9fc1 | 1528 | * ->siglock we must see ->core_state != NULL. Otherwise it |
d5f70c00 ON |
1529 | * is safe to enter schedule(). |
1530 | */ | |
999d9fc1 | 1531 | if (unlikely(current->mm->core_state) && |
d5f70c00 ON |
1532 | unlikely(current->mm == current->parent->mm)) |
1533 | return 0; | |
1534 | ||
1535 | return 1; | |
1536 | } | |
1537 | ||
1a669c2f RM |
1538 | /* |
1539 | * Return nonzero if there is a SIGKILL that should be waking us up. | |
1540 | * Called with the siglock held. | |
1541 | */ | |
1542 | static int sigkill_pending(struct task_struct *tsk) | |
1543 | { | |
3d749b9e ON |
1544 | return sigismember(&tsk->pending.signal, SIGKILL) || |
1545 | sigismember(&tsk->signal->shared_pending.signal, SIGKILL); | |
1a669c2f RM |
1546 | } |
1547 | ||
1da177e4 LT |
1548 | /* |
1549 | * This must be called with current->sighand->siglock held. | |
1550 | * | |
1551 | * This should be the path for all ptrace stops. | |
1552 | * We always set current->last_siginfo while stopped here. | |
1553 | * That makes it a way to test a stopped process for | |
1554 | * being ptrace-stopped vs being job-control-stopped. | |
1555 | * | |
20686a30 ON |
1556 | * If we actually decide not to stop at all because the tracer |
1557 | * is gone, we keep current->exit_code unless clear_code. | |
1da177e4 | 1558 | */ |
20686a30 | 1559 | static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info) |
1da177e4 | 1560 | { |
1a669c2f RM |
1561 | if (arch_ptrace_stop_needed(exit_code, info)) { |
1562 | /* | |
1563 | * The arch code has something special to do before a | |
1564 | * ptrace stop. This is allowed to block, e.g. for faults | |
1565 | * on user stack pages. We can't keep the siglock while | |
1566 | * calling arch_ptrace_stop, so we must release it now. | |
1567 | * To preserve proper semantics, we must do this before | |
1568 | * any signal bookkeeping like checking group_stop_count. | |
1569 | * Meanwhile, a SIGKILL could come in before we retake the | |
1570 | * siglock. That must prevent us from sleeping in TASK_TRACED. | |
1571 | * So after regaining the lock, we must check for SIGKILL. | |
1572 | */ | |
1573 | spin_unlock_irq(¤t->sighand->siglock); | |
1574 | arch_ptrace_stop(exit_code, info); | |
1575 | spin_lock_irq(¤t->sighand->siglock); | |
3d749b9e ON |
1576 | if (sigkill_pending(current)) |
1577 | return; | |
1a669c2f RM |
1578 | } |
1579 | ||
1da177e4 LT |
1580 | /* |
1581 | * If there is a group stop in progress, | |
1582 | * we must participate in the bookkeeping. | |
1583 | */ | |
1584 | if (current->signal->group_stop_count > 0) | |
1585 | --current->signal->group_stop_count; | |
1586 | ||
1587 | current->last_siginfo = info; | |
1588 | current->exit_code = exit_code; | |
1589 | ||
1590 | /* Let the debugger run. */ | |
d9ae90ac | 1591 | __set_current_state(TASK_TRACED); |
1da177e4 LT |
1592 | spin_unlock_irq(¤t->sighand->siglock); |
1593 | read_lock(&tasklist_lock); | |
3d749b9e | 1594 | if (may_ptrace_stop()) { |
a1d5e21e | 1595 | do_notify_parent_cldstop(current, CLD_TRAPPED); |
53da1d94 MS |
1596 | /* |
1597 | * Don't want to allow preemption here, because | |
1598 | * sys_ptrace() needs this task to be inactive. | |
1599 | * | |
1600 | * XXX: implement read_unlock_no_resched(). | |
1601 | */ | |
1602 | preempt_disable(); | |
1da177e4 | 1603 | read_unlock(&tasklist_lock); |
53da1d94 | 1604 | preempt_enable_no_resched(); |
1da177e4 LT |
1605 | schedule(); |
1606 | } else { | |
1607 | /* | |
1608 | * By the time we got the lock, our tracer went away. | |
6405f7f4 | 1609 | * Don't drop the lock yet, another tracer may come. |
1da177e4 | 1610 | */ |
6405f7f4 | 1611 | __set_current_state(TASK_RUNNING); |
20686a30 ON |
1612 | if (clear_code) |
1613 | current->exit_code = 0; | |
6405f7f4 | 1614 | read_unlock(&tasklist_lock); |
1da177e4 LT |
1615 | } |
1616 | ||
13b1c3d4 RM |
1617 | /* |
1618 | * While in TASK_TRACED, we were considered "frozen enough". | |
1619 | * Now that we woke up, it's crucial if we're supposed to be | |
1620 | * frozen that we freeze now before running anything substantial. | |
1621 | */ | |
1622 | try_to_freeze(); | |
1623 | ||
1da177e4 LT |
1624 | /* |
1625 | * We are back. Now reacquire the siglock before touching | |
1626 | * last_siginfo, so that we are sure to have synchronized with | |
1627 | * any signal-sending on another CPU that wants to examine it. | |
1628 | */ | |
1629 | spin_lock_irq(¤t->sighand->siglock); | |
1630 | current->last_siginfo = NULL; | |
1631 | ||
1632 | /* | |
1633 | * Queued signals ignored us while we were stopped for tracing. | |
1634 | * So check for any that we should take before resuming user mode. | |
b74d0deb | 1635 | * This sets TIF_SIGPENDING, but never clears it. |
1da177e4 | 1636 | */ |
b74d0deb | 1637 | recalc_sigpending_tsk(current); |
1da177e4 LT |
1638 | } |
1639 | ||
1640 | void ptrace_notify(int exit_code) | |
1641 | { | |
1642 | siginfo_t info; | |
1643 | ||
1644 | BUG_ON((exit_code & (0x7f | ~0xffff)) != SIGTRAP); | |
1645 | ||
1646 | memset(&info, 0, sizeof info); | |
1647 | info.si_signo = SIGTRAP; | |
1648 | info.si_code = exit_code; | |
b488893a | 1649 | info.si_pid = task_pid_vnr(current); |
76aac0e9 | 1650 | info.si_uid = current_uid(); |
1da177e4 LT |
1651 | |
1652 | /* Let the debugger run. */ | |
1653 | spin_lock_irq(¤t->sighand->siglock); | |
20686a30 | 1654 | ptrace_stop(exit_code, 1, &info); |
1da177e4 LT |
1655 | spin_unlock_irq(¤t->sighand->siglock); |
1656 | } | |
1657 | ||
1da177e4 LT |
1658 | /* |
1659 | * This performs the stopping for SIGSTOP and other stop signals. | |
1660 | * We have to stop all threads in the thread group. | |
1661 | * Returns nonzero if we've actually stopped and released the siglock. | |
1662 | * Returns zero if we didn't stop and still hold the siglock. | |
1663 | */ | |
a122b341 | 1664 | static int do_signal_stop(int signr) |
1da177e4 LT |
1665 | { |
1666 | struct signal_struct *sig = current->signal; | |
ae6d2ed7 | 1667 | int notify; |
1da177e4 | 1668 | |
ae6d2ed7 | 1669 | if (!sig->group_stop_count) { |
f558b7e4 ON |
1670 | struct task_struct *t; |
1671 | ||
2b201a9e | 1672 | if (!likely(sig->flags & SIGNAL_STOP_DEQUEUED) || |
573cf9ad | 1673 | unlikely(signal_group_exit(sig))) |
f558b7e4 | 1674 | return 0; |
1da177e4 LT |
1675 | /* |
1676 | * There is no group stop already in progress. | |
a122b341 | 1677 | * We must initiate one now. |
1da177e4 | 1678 | */ |
a122b341 | 1679 | sig->group_exit_code = signr; |
1da177e4 | 1680 | |
ae6d2ed7 | 1681 | sig->group_stop_count = 1; |
a122b341 | 1682 | for (t = next_thread(current); t != current; t = next_thread(t)) |
1da177e4 | 1683 | /* |
a122b341 ON |
1684 | * Setting state to TASK_STOPPED for a group |
1685 | * stop is always done with the siglock held, | |
1686 | * so this check has no races. | |
1da177e4 | 1687 | */ |
d12619b5 | 1688 | if (!(t->flags & PF_EXITING) && |
e1abb39c | 1689 | !task_is_stopped_or_traced(t)) { |
ae6d2ed7 | 1690 | sig->group_stop_count++; |
a122b341 ON |
1691 | signal_wake_up(t, 0); |
1692 | } | |
1da177e4 | 1693 | } |
ae6d2ed7 RM |
1694 | /* |
1695 | * If there are no other threads in the group, or if there is | |
1696 | * a group stop in progress and we are the last to stop, report | |
1697 | * to the parent. When ptraced, every thread reports itself. | |
1698 | */ | |
1699 | notify = sig->group_stop_count == 1 ? CLD_STOPPED : 0; | |
1700 | notify = tracehook_notify_jctl(notify, CLD_STOPPED); | |
1701 | /* | |
1702 | * tracehook_notify_jctl() can drop and reacquire siglock, so | |
1703 | * we keep ->group_stop_count != 0 before the call. If SIGCONT | |
1704 | * or SIGKILL comes in between ->group_stop_count == 0. | |
1705 | */ | |
1706 | if (sig->group_stop_count) { | |
1707 | if (!--sig->group_stop_count) | |
1708 | sig->flags = SIGNAL_STOP_STOPPED; | |
1709 | current->exit_code = sig->group_exit_code; | |
1710 | __set_current_state(TASK_STOPPED); | |
1711 | } | |
1712 | spin_unlock_irq(¤t->sighand->siglock); | |
1da177e4 | 1713 | |
ae6d2ed7 RM |
1714 | if (notify) { |
1715 | read_lock(&tasklist_lock); | |
1716 | do_notify_parent_cldstop(current, notify); | |
1717 | read_unlock(&tasklist_lock); | |
1718 | } | |
1719 | ||
1720 | /* Now we don't run again until woken by SIGCONT or SIGKILL */ | |
1721 | do { | |
1722 | schedule(); | |
1723 | } while (try_to_freeze()); | |
1724 | ||
1725 | tracehook_finish_jctl(); | |
1726 | current->exit_code = 0; | |
dac27f4a | 1727 | |
1da177e4 LT |
1728 | return 1; |
1729 | } | |
1730 | ||
18c98b65 RM |
1731 | static int ptrace_signal(int signr, siginfo_t *info, |
1732 | struct pt_regs *regs, void *cookie) | |
1733 | { | |
5cb11446 | 1734 | if (!task_ptrace(current)) |
18c98b65 RM |
1735 | return signr; |
1736 | ||
1737 | ptrace_signal_deliver(regs, cookie); | |
1738 | ||
1739 | /* Let the debugger run. */ | |
1740 | ptrace_stop(signr, 0, info); | |
1741 | ||
1742 | /* We're back. Did the debugger cancel the sig? */ | |
1743 | signr = current->exit_code; | |
1744 | if (signr == 0) | |
1745 | return signr; | |
1746 | ||
1747 | current->exit_code = 0; | |
1748 | ||
1749 | /* Update the siginfo structure if the signal has | |
1750 | changed. If the debugger wanted something | |
1751 | specific in the siginfo structure then it should | |
1752 | have updated *info via PTRACE_SETSIGINFO. */ | |
1753 | if (signr != info->si_signo) { | |
1754 | info->si_signo = signr; | |
1755 | info->si_errno = 0; | |
1756 | info->si_code = SI_USER; | |
1757 | info->si_pid = task_pid_vnr(current->parent); | |
c69e8d9c | 1758 | info->si_uid = task_uid(current->parent); |
18c98b65 RM |
1759 | } |
1760 | ||
1761 | /* If the (new) signal is now blocked, requeue it. */ | |
1762 | if (sigismember(¤t->blocked, signr)) { | |
1763 | specific_send_sig_info(signr, info, current); | |
1764 | signr = 0; | |
1765 | } | |
1766 | ||
1767 | return signr; | |
1768 | } | |
1769 | ||
1da177e4 LT |
1770 | int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka, |
1771 | struct pt_regs *regs, void *cookie) | |
1772 | { | |
f6b76d4f ON |
1773 | struct sighand_struct *sighand = current->sighand; |
1774 | struct signal_struct *signal = current->signal; | |
1775 | int signr; | |
1da177e4 | 1776 | |
13b1c3d4 RM |
1777 | relock: |
1778 | /* | |
1779 | * We'll jump back here after any time we were stopped in TASK_STOPPED. | |
1780 | * While in TASK_STOPPED, we were considered "frozen enough". | |
1781 | * Now that we woke up, it's crucial if we're supposed to be | |
1782 | * frozen that we freeze now before running anything substantial. | |
1783 | */ | |
fc558a74 RW |
1784 | try_to_freeze(); |
1785 | ||
f6b76d4f | 1786 | spin_lock_irq(&sighand->siglock); |
021e1ae3 ON |
1787 | /* |
1788 | * Every stopped thread goes here after wakeup. Check to see if | |
1789 | * we should notify the parent, prepare_signal(SIGCONT) encodes | |
1790 | * the CLD_ si_code into SIGNAL_CLD_MASK bits. | |
1791 | */ | |
f6b76d4f ON |
1792 | if (unlikely(signal->flags & SIGNAL_CLD_MASK)) { |
1793 | int why = (signal->flags & SIGNAL_STOP_CONTINUED) | |
e4420551 | 1794 | ? CLD_CONTINUED : CLD_STOPPED; |
f6b76d4f | 1795 | signal->flags &= ~SIGNAL_CLD_MASK; |
e4420551 | 1796 | |
ae6d2ed7 RM |
1797 | why = tracehook_notify_jctl(why, CLD_CONTINUED); |
1798 | spin_unlock_irq(&sighand->siglock); | |
fa00b80b | 1799 | |
ae6d2ed7 RM |
1800 | if (why) { |
1801 | read_lock(&tasklist_lock); | |
1802 | do_notify_parent_cldstop(current->group_leader, why); | |
1803 | read_unlock(&tasklist_lock); | |
1804 | } | |
e4420551 ON |
1805 | goto relock; |
1806 | } | |
1807 | ||
1da177e4 LT |
1808 | for (;;) { |
1809 | struct k_sigaction *ka; | |
1810 | ||
f6b76d4f | 1811 | if (unlikely(signal->group_stop_count > 0) && |
f558b7e4 | 1812 | do_signal_stop(0)) |
1da177e4 LT |
1813 | goto relock; |
1814 | ||
7bcf6a2c RM |
1815 | /* |
1816 | * Tracing can induce an artifical signal and choose sigaction. | |
1817 | * The return value in @signr determines the default action, | |
1818 | * but @info->si_signo is the signal number we will report. | |
1819 | */ | |
1820 | signr = tracehook_get_signal(current, regs, info, return_ka); | |
1821 | if (unlikely(signr < 0)) | |
1822 | goto relock; | |
1823 | if (unlikely(signr != 0)) | |
1824 | ka = return_ka; | |
1825 | else { | |
1826 | signr = dequeue_signal(current, ¤t->blocked, | |
1827 | info); | |
1da177e4 | 1828 | |
18c98b65 | 1829 | if (!signr) |
7bcf6a2c RM |
1830 | break; /* will return 0 */ |
1831 | ||
1832 | if (signr != SIGKILL) { | |
1833 | signr = ptrace_signal(signr, info, | |
1834 | regs, cookie); | |
1835 | if (!signr) | |
1836 | continue; | |
1837 | } | |
1838 | ||
1839 | ka = &sighand->action[signr-1]; | |
1da177e4 LT |
1840 | } |
1841 | ||
1da177e4 LT |
1842 | if (ka->sa.sa_handler == SIG_IGN) /* Do nothing. */ |
1843 | continue; | |
1844 | if (ka->sa.sa_handler != SIG_DFL) { | |
1845 | /* Run the handler. */ | |
1846 | *return_ka = *ka; | |
1847 | ||
1848 | if (ka->sa.sa_flags & SA_ONESHOT) | |
1849 | ka->sa.sa_handler = SIG_DFL; | |
1850 | ||
1851 | break; /* will return non-zero "signr" value */ | |
1852 | } | |
1853 | ||
1854 | /* | |
1855 | * Now we are doing the default action for this signal. | |
1856 | */ | |
1857 | if (sig_kernel_ignore(signr)) /* Default is nothing. */ | |
1858 | continue; | |
1859 | ||
84d73786 | 1860 | /* |
0fbc26a6 | 1861 | * Global init gets no signals it doesn't want. |
b3bfa0cb SB |
1862 | * Container-init gets no signals it doesn't want from same |
1863 | * container. | |
1864 | * | |
1865 | * Note that if global/container-init sees a sig_kernel_only() | |
1866 | * signal here, the signal must have been generated internally | |
1867 | * or must have come from an ancestor namespace. In either | |
1868 | * case, the signal cannot be dropped. | |
84d73786 | 1869 | */ |
fae5fa44 | 1870 | if (unlikely(signal->flags & SIGNAL_UNKILLABLE) && |
b3bfa0cb | 1871 | !sig_kernel_only(signr)) |
1da177e4 LT |
1872 | continue; |
1873 | ||
1874 | if (sig_kernel_stop(signr)) { | |
1875 | /* | |
1876 | * The default action is to stop all threads in | |
1877 | * the thread group. The job control signals | |
1878 | * do nothing in an orphaned pgrp, but SIGSTOP | |
1879 | * always works. Note that siglock needs to be | |
1880 | * dropped during the call to is_orphaned_pgrp() | |
1881 | * because of lock ordering with tasklist_lock. | |
1882 | * This allows an intervening SIGCONT to be posted. | |
1883 | * We need to check for that and bail out if necessary. | |
1884 | */ | |
1885 | if (signr != SIGSTOP) { | |
f6b76d4f | 1886 | spin_unlock_irq(&sighand->siglock); |
1da177e4 LT |
1887 | |
1888 | /* signals can be posted during this window */ | |
1889 | ||
3e7cd6c4 | 1890 | if (is_current_pgrp_orphaned()) |
1da177e4 LT |
1891 | goto relock; |
1892 | ||
f6b76d4f | 1893 | spin_lock_irq(&sighand->siglock); |
1da177e4 LT |
1894 | } |
1895 | ||
7bcf6a2c | 1896 | if (likely(do_signal_stop(info->si_signo))) { |
1da177e4 LT |
1897 | /* It released the siglock. */ |
1898 | goto relock; | |
1899 | } | |
1900 | ||
1901 | /* | |
1902 | * We didn't actually stop, due to a race | |
1903 | * with SIGCONT or something like that. | |
1904 | */ | |
1905 | continue; | |
1906 | } | |
1907 | ||
f6b76d4f | 1908 | spin_unlock_irq(&sighand->siglock); |
1da177e4 LT |
1909 | |
1910 | /* | |
1911 | * Anything else is fatal, maybe with a core dump. | |
1912 | */ | |
1913 | current->flags |= PF_SIGNALED; | |
2dce81bf | 1914 | |
1da177e4 | 1915 | if (sig_kernel_coredump(signr)) { |
2dce81bf | 1916 | if (print_fatal_signals) |
7bcf6a2c | 1917 | print_fatal_signal(regs, info->si_signo); |
1da177e4 LT |
1918 | /* |
1919 | * If it was able to dump core, this kills all | |
1920 | * other threads in the group and synchronizes with | |
1921 | * their demise. If we lost the race with another | |
1922 | * thread getting here, it set group_exit_code | |
1923 | * first and our do_group_exit call below will use | |
1924 | * that value and ignore the one we pass it. | |
1925 | */ | |
7bcf6a2c | 1926 | do_coredump(info->si_signo, info->si_signo, regs); |
1da177e4 LT |
1927 | } |
1928 | ||
1929 | /* | |
1930 | * Death signals, no core dump. | |
1931 | */ | |
7bcf6a2c | 1932 | do_group_exit(info->si_signo); |
1da177e4 LT |
1933 | /* NOTREACHED */ |
1934 | } | |
f6b76d4f | 1935 | spin_unlock_irq(&sighand->siglock); |
1da177e4 LT |
1936 | return signr; |
1937 | } | |
1938 | ||
d12619b5 ON |
1939 | void exit_signals(struct task_struct *tsk) |
1940 | { | |
1941 | int group_stop = 0; | |
5dee1707 | 1942 | struct task_struct *t; |
d12619b5 | 1943 | |
5dee1707 ON |
1944 | if (thread_group_empty(tsk) || signal_group_exit(tsk->signal)) { |
1945 | tsk->flags |= PF_EXITING; | |
1946 | return; | |
d12619b5 ON |
1947 | } |
1948 | ||
5dee1707 | 1949 | spin_lock_irq(&tsk->sighand->siglock); |
d12619b5 ON |
1950 | /* |
1951 | * From now this task is not visible for group-wide signals, | |
1952 | * see wants_signal(), do_signal_stop(). | |
1953 | */ | |
1954 | tsk->flags |= PF_EXITING; | |
5dee1707 ON |
1955 | if (!signal_pending(tsk)) |
1956 | goto out; | |
1957 | ||
1958 | /* It could be that __group_complete_signal() choose us to | |
1959 | * notify about group-wide signal. Another thread should be | |
1960 | * woken now to take the signal since we will not. | |
1961 | */ | |
1962 | for (t = tsk; (t = next_thread(t)) != tsk; ) | |
1963 | if (!signal_pending(t) && !(t->flags & PF_EXITING)) | |
1964 | recalc_sigpending_and_wake(t); | |
1965 | ||
1966 | if (unlikely(tsk->signal->group_stop_count) && | |
1967 | !--tsk->signal->group_stop_count) { | |
1968 | tsk->signal->flags = SIGNAL_STOP_STOPPED; | |
ae6d2ed7 | 1969 | group_stop = tracehook_notify_jctl(CLD_STOPPED, CLD_STOPPED); |
5dee1707 ON |
1970 | } |
1971 | out: | |
d12619b5 ON |
1972 | spin_unlock_irq(&tsk->sighand->siglock); |
1973 | ||
ae6d2ed7 | 1974 | if (unlikely(group_stop)) { |
d12619b5 | 1975 | read_lock(&tasklist_lock); |
ae6d2ed7 | 1976 | do_notify_parent_cldstop(tsk, group_stop); |
d12619b5 ON |
1977 | read_unlock(&tasklist_lock); |
1978 | } | |
1979 | } | |
1980 | ||
1da177e4 LT |
1981 | EXPORT_SYMBOL(recalc_sigpending); |
1982 | EXPORT_SYMBOL_GPL(dequeue_signal); | |
1983 | EXPORT_SYMBOL(flush_signals); | |
1984 | EXPORT_SYMBOL(force_sig); | |
1da177e4 LT |
1985 | EXPORT_SYMBOL(send_sig); |
1986 | EXPORT_SYMBOL(send_sig_info); | |
1987 | EXPORT_SYMBOL(sigprocmask); | |
1988 | EXPORT_SYMBOL(block_all_signals); | |
1989 | EXPORT_SYMBOL(unblock_all_signals); | |
1990 | ||
1991 | ||
1992 | /* | |
1993 | * System call entry points. | |
1994 | */ | |
1995 | ||
754fe8d2 | 1996 | SYSCALL_DEFINE0(restart_syscall) |
1da177e4 LT |
1997 | { |
1998 | struct restart_block *restart = ¤t_thread_info()->restart_block; | |
1999 | return restart->fn(restart); | |
2000 | } | |
2001 | ||
2002 | long do_no_restart_syscall(struct restart_block *param) | |
2003 | { | |
2004 | return -EINTR; | |
2005 | } | |
2006 | ||
2007 | /* | |
2008 | * We don't need to get the kernel lock - this is all local to this | |
2009 | * particular thread.. (and that's good, because this is _heavily_ | |
2010 | * used by various programs) | |
2011 | */ | |
2012 | ||
2013 | /* | |
2014 | * This is also useful for kernel threads that want to temporarily | |
2015 | * (or permanently) block certain signals. | |
2016 | * | |
2017 | * NOTE! Unlike the user-mode sys_sigprocmask(), the kernel | |
2018 | * interface happily blocks "unblockable" signals like SIGKILL | |
2019 | * and friends. | |
2020 | */ | |
2021 | int sigprocmask(int how, sigset_t *set, sigset_t *oldset) | |
2022 | { | |
2023 | int error; | |
1da177e4 LT |
2024 | |
2025 | spin_lock_irq(¤t->sighand->siglock); | |
a26fd335 ON |
2026 | if (oldset) |
2027 | *oldset = current->blocked; | |
2028 | ||
1da177e4 LT |
2029 | error = 0; |
2030 | switch (how) { | |
2031 | case SIG_BLOCK: | |
2032 | sigorsets(¤t->blocked, ¤t->blocked, set); | |
2033 | break; | |
2034 | case SIG_UNBLOCK: | |
2035 | signandsets(¤t->blocked, ¤t->blocked, set); | |
2036 | break; | |
2037 | case SIG_SETMASK: | |
2038 | current->blocked = *set; | |
2039 | break; | |
2040 | default: | |
2041 | error = -EINVAL; | |
2042 | } | |
2043 | recalc_sigpending(); | |
2044 | spin_unlock_irq(¤t->sighand->siglock); | |
a26fd335 | 2045 | |
1da177e4 LT |
2046 | return error; |
2047 | } | |
2048 | ||
17da2bd9 HC |
2049 | SYSCALL_DEFINE4(rt_sigprocmask, int, how, sigset_t __user *, set, |
2050 | sigset_t __user *, oset, size_t, sigsetsize) | |
1da177e4 LT |
2051 | { |
2052 | int error = -EINVAL; | |
2053 | sigset_t old_set, new_set; | |
2054 | ||
2055 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
2056 | if (sigsetsize != sizeof(sigset_t)) | |
2057 | goto out; | |
2058 | ||
2059 | if (set) { | |
2060 | error = -EFAULT; | |
2061 | if (copy_from_user(&new_set, set, sizeof(*set))) | |
2062 | goto out; | |
2063 | sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); | |
2064 | ||
2065 | error = sigprocmask(how, &new_set, &old_set); | |
2066 | if (error) | |
2067 | goto out; | |
2068 | if (oset) | |
2069 | goto set_old; | |
2070 | } else if (oset) { | |
2071 | spin_lock_irq(¤t->sighand->siglock); | |
2072 | old_set = current->blocked; | |
2073 | spin_unlock_irq(¤t->sighand->siglock); | |
2074 | ||
2075 | set_old: | |
2076 | error = -EFAULT; | |
2077 | if (copy_to_user(oset, &old_set, sizeof(*oset))) | |
2078 | goto out; | |
2079 | } | |
2080 | error = 0; | |
2081 | out: | |
2082 | return error; | |
2083 | } | |
2084 | ||
2085 | long do_sigpending(void __user *set, unsigned long sigsetsize) | |
2086 | { | |
2087 | long error = -EINVAL; | |
2088 | sigset_t pending; | |
2089 | ||
2090 | if (sigsetsize > sizeof(sigset_t)) | |
2091 | goto out; | |
2092 | ||
2093 | spin_lock_irq(¤t->sighand->siglock); | |
2094 | sigorsets(&pending, ¤t->pending.signal, | |
2095 | ¤t->signal->shared_pending.signal); | |
2096 | spin_unlock_irq(¤t->sighand->siglock); | |
2097 | ||
2098 | /* Outside the lock because only this thread touches it. */ | |
2099 | sigandsets(&pending, ¤t->blocked, &pending); | |
2100 | ||
2101 | error = -EFAULT; | |
2102 | if (!copy_to_user(set, &pending, sigsetsize)) | |
2103 | error = 0; | |
2104 | ||
2105 | out: | |
2106 | return error; | |
2107 | } | |
2108 | ||
17da2bd9 | 2109 | SYSCALL_DEFINE2(rt_sigpending, sigset_t __user *, set, size_t, sigsetsize) |
1da177e4 LT |
2110 | { |
2111 | return do_sigpending(set, sigsetsize); | |
2112 | } | |
2113 | ||
2114 | #ifndef HAVE_ARCH_COPY_SIGINFO_TO_USER | |
2115 | ||
2116 | int copy_siginfo_to_user(siginfo_t __user *to, siginfo_t *from) | |
2117 | { | |
2118 | int err; | |
2119 | ||
2120 | if (!access_ok (VERIFY_WRITE, to, sizeof(siginfo_t))) | |
2121 | return -EFAULT; | |
2122 | if (from->si_code < 0) | |
2123 | return __copy_to_user(to, from, sizeof(siginfo_t)) | |
2124 | ? -EFAULT : 0; | |
2125 | /* | |
2126 | * If you change siginfo_t structure, please be sure | |
2127 | * this code is fixed accordingly. | |
fba2afaa DL |
2128 | * Please remember to update the signalfd_copyinfo() function |
2129 | * inside fs/signalfd.c too, in case siginfo_t changes. | |
1da177e4 LT |
2130 | * It should never copy any pad contained in the structure |
2131 | * to avoid security leaks, but must copy the generic | |
2132 | * 3 ints plus the relevant union member. | |
2133 | */ | |
2134 | err = __put_user(from->si_signo, &to->si_signo); | |
2135 | err |= __put_user(from->si_errno, &to->si_errno); | |
2136 | err |= __put_user((short)from->si_code, &to->si_code); | |
2137 | switch (from->si_code & __SI_MASK) { | |
2138 | case __SI_KILL: | |
2139 | err |= __put_user(from->si_pid, &to->si_pid); | |
2140 | err |= __put_user(from->si_uid, &to->si_uid); | |
2141 | break; | |
2142 | case __SI_TIMER: | |
2143 | err |= __put_user(from->si_tid, &to->si_tid); | |
2144 | err |= __put_user(from->si_overrun, &to->si_overrun); | |
2145 | err |= __put_user(from->si_ptr, &to->si_ptr); | |
2146 | break; | |
2147 | case __SI_POLL: | |
2148 | err |= __put_user(from->si_band, &to->si_band); | |
2149 | err |= __put_user(from->si_fd, &to->si_fd); | |
2150 | break; | |
2151 | case __SI_FAULT: | |
2152 | err |= __put_user(from->si_addr, &to->si_addr); | |
2153 | #ifdef __ARCH_SI_TRAPNO | |
2154 | err |= __put_user(from->si_trapno, &to->si_trapno); | |
2155 | #endif | |
2156 | break; | |
2157 | case __SI_CHLD: | |
2158 | err |= __put_user(from->si_pid, &to->si_pid); | |
2159 | err |= __put_user(from->si_uid, &to->si_uid); | |
2160 | err |= __put_user(from->si_status, &to->si_status); | |
2161 | err |= __put_user(from->si_utime, &to->si_utime); | |
2162 | err |= __put_user(from->si_stime, &to->si_stime); | |
2163 | break; | |
2164 | case __SI_RT: /* This is not generated by the kernel as of now. */ | |
2165 | case __SI_MESGQ: /* But this is */ | |
2166 | err |= __put_user(from->si_pid, &to->si_pid); | |
2167 | err |= __put_user(from->si_uid, &to->si_uid); | |
2168 | err |= __put_user(from->si_ptr, &to->si_ptr); | |
2169 | break; | |
2170 | default: /* this is just in case for now ... */ | |
2171 | err |= __put_user(from->si_pid, &to->si_pid); | |
2172 | err |= __put_user(from->si_uid, &to->si_uid); | |
2173 | break; | |
2174 | } | |
2175 | return err; | |
2176 | } | |
2177 | ||
2178 | #endif | |
2179 | ||
17da2bd9 HC |
2180 | SYSCALL_DEFINE4(rt_sigtimedwait, const sigset_t __user *, uthese, |
2181 | siginfo_t __user *, uinfo, const struct timespec __user *, uts, | |
2182 | size_t, sigsetsize) | |
1da177e4 LT |
2183 | { |
2184 | int ret, sig; | |
2185 | sigset_t these; | |
2186 | struct timespec ts; | |
2187 | siginfo_t info; | |
2188 | long timeout = 0; | |
2189 | ||
2190 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
2191 | if (sigsetsize != sizeof(sigset_t)) | |
2192 | return -EINVAL; | |
2193 | ||
2194 | if (copy_from_user(&these, uthese, sizeof(these))) | |
2195 | return -EFAULT; | |
2196 | ||
2197 | /* | |
2198 | * Invert the set of allowed signals to get those we | |
2199 | * want to block. | |
2200 | */ | |
2201 | sigdelsetmask(&these, sigmask(SIGKILL)|sigmask(SIGSTOP)); | |
2202 | signotset(&these); | |
2203 | ||
2204 | if (uts) { | |
2205 | if (copy_from_user(&ts, uts, sizeof(ts))) | |
2206 | return -EFAULT; | |
2207 | if (ts.tv_nsec >= 1000000000L || ts.tv_nsec < 0 | |
2208 | || ts.tv_sec < 0) | |
2209 | return -EINVAL; | |
2210 | } | |
2211 | ||
2212 | spin_lock_irq(¤t->sighand->siglock); | |
2213 | sig = dequeue_signal(current, &these, &info); | |
2214 | if (!sig) { | |
2215 | timeout = MAX_SCHEDULE_TIMEOUT; | |
2216 | if (uts) | |
2217 | timeout = (timespec_to_jiffies(&ts) | |
2218 | + (ts.tv_sec || ts.tv_nsec)); | |
2219 | ||
2220 | if (timeout) { | |
2221 | /* None ready -- temporarily unblock those we're | |
2222 | * interested while we are sleeping in so that we'll | |
2223 | * be awakened when they arrive. */ | |
2224 | current->real_blocked = current->blocked; | |
2225 | sigandsets(¤t->blocked, ¤t->blocked, &these); | |
2226 | recalc_sigpending(); | |
2227 | spin_unlock_irq(¤t->sighand->siglock); | |
2228 | ||
75bcc8c5 | 2229 | timeout = schedule_timeout_interruptible(timeout); |
1da177e4 | 2230 | |
1da177e4 LT |
2231 | spin_lock_irq(¤t->sighand->siglock); |
2232 | sig = dequeue_signal(current, &these, &info); | |
2233 | current->blocked = current->real_blocked; | |
2234 | siginitset(¤t->real_blocked, 0); | |
2235 | recalc_sigpending(); | |
2236 | } | |
2237 | } | |
2238 | spin_unlock_irq(¤t->sighand->siglock); | |
2239 | ||
2240 | if (sig) { | |
2241 | ret = sig; | |
2242 | if (uinfo) { | |
2243 | if (copy_siginfo_to_user(uinfo, &info)) | |
2244 | ret = -EFAULT; | |
2245 | } | |
2246 | } else { | |
2247 | ret = -EAGAIN; | |
2248 | if (timeout) | |
2249 | ret = -EINTR; | |
2250 | } | |
2251 | ||
2252 | return ret; | |
2253 | } | |
2254 | ||
17da2bd9 | 2255 | SYSCALL_DEFINE2(kill, pid_t, pid, int, sig) |
1da177e4 LT |
2256 | { |
2257 | struct siginfo info; | |
2258 | ||
2259 | info.si_signo = sig; | |
2260 | info.si_errno = 0; | |
2261 | info.si_code = SI_USER; | |
b488893a | 2262 | info.si_pid = task_tgid_vnr(current); |
76aac0e9 | 2263 | info.si_uid = current_uid(); |
1da177e4 LT |
2264 | |
2265 | return kill_something_info(sig, &info, pid); | |
2266 | } | |
2267 | ||
30b4ae8a TG |
2268 | static int |
2269 | do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info) | |
1da177e4 | 2270 | { |
1da177e4 | 2271 | struct task_struct *p; |
30b4ae8a | 2272 | int error = -ESRCH; |
1da177e4 | 2273 | |
3547ff3a | 2274 | rcu_read_lock(); |
228ebcbe | 2275 | p = find_task_by_vpid(pid); |
b488893a | 2276 | if (p && (tgid <= 0 || task_tgid_vnr(p) == tgid)) { |
30b4ae8a | 2277 | error = check_kill_permission(sig, info, p); |
1da177e4 LT |
2278 | /* |
2279 | * The null signal is a permissions and process existence | |
2280 | * probe. No signal is actually delivered. | |
2281 | */ | |
4a30debf ON |
2282 | if (!error && sig) { |
2283 | error = do_send_sig_info(sig, info, p, false); | |
2284 | /* | |
2285 | * If lock_task_sighand() failed we pretend the task | |
2286 | * dies after receiving the signal. The window is tiny, | |
2287 | * and the signal is private anyway. | |
2288 | */ | |
2289 | if (unlikely(error == -ESRCH)) | |
2290 | error = 0; | |
1da177e4 LT |
2291 | } |
2292 | } | |
3547ff3a | 2293 | rcu_read_unlock(); |
6dd69f10 | 2294 | |
1da177e4 LT |
2295 | return error; |
2296 | } | |
2297 | ||
30b4ae8a TG |
2298 | static int do_tkill(pid_t tgid, pid_t pid, int sig) |
2299 | { | |
2300 | struct siginfo info; | |
2301 | ||
2302 | info.si_signo = sig; | |
2303 | info.si_errno = 0; | |
2304 | info.si_code = SI_TKILL; | |
2305 | info.si_pid = task_tgid_vnr(current); | |
2306 | info.si_uid = current_uid(); | |
2307 | ||
2308 | return do_send_specific(tgid, pid, sig, &info); | |
2309 | } | |
2310 | ||
6dd69f10 VL |
2311 | /** |
2312 | * sys_tgkill - send signal to one specific thread | |
2313 | * @tgid: the thread group ID of the thread | |
2314 | * @pid: the PID of the thread | |
2315 | * @sig: signal to be sent | |
2316 | * | |
72fd4a35 | 2317 | * This syscall also checks the @tgid and returns -ESRCH even if the PID |
6dd69f10 VL |
2318 | * exists but it's not belonging to the target process anymore. This |
2319 | * method solves the problem of threads exiting and PIDs getting reused. | |
2320 | */ | |
a5f8fa9e | 2321 | SYSCALL_DEFINE3(tgkill, pid_t, tgid, pid_t, pid, int, sig) |
6dd69f10 VL |
2322 | { |
2323 | /* This is only valid for single tasks */ | |
2324 | if (pid <= 0 || tgid <= 0) | |
2325 | return -EINVAL; | |
2326 | ||
2327 | return do_tkill(tgid, pid, sig); | |
2328 | } | |
2329 | ||
1da177e4 LT |
2330 | /* |
2331 | * Send a signal to only one task, even if it's a CLONE_THREAD task. | |
2332 | */ | |
a5f8fa9e | 2333 | SYSCALL_DEFINE2(tkill, pid_t, pid, int, sig) |
1da177e4 | 2334 | { |
1da177e4 LT |
2335 | /* This is only valid for single tasks */ |
2336 | if (pid <= 0) | |
2337 | return -EINVAL; | |
2338 | ||
6dd69f10 | 2339 | return do_tkill(0, pid, sig); |
1da177e4 LT |
2340 | } |
2341 | ||
a5f8fa9e HC |
2342 | SYSCALL_DEFINE3(rt_sigqueueinfo, pid_t, pid, int, sig, |
2343 | siginfo_t __user *, uinfo) | |
1da177e4 LT |
2344 | { |
2345 | siginfo_t info; | |
2346 | ||
2347 | if (copy_from_user(&info, uinfo, sizeof(siginfo_t))) | |
2348 | return -EFAULT; | |
2349 | ||
2350 | /* Not even root can pretend to send signals from the kernel. | |
2351 | Nor can they impersonate a kill(), which adds source info. */ | |
2352 | if (info.si_code >= 0) | |
2353 | return -EPERM; | |
2354 | info.si_signo = sig; | |
2355 | ||
2356 | /* POSIX.1b doesn't mention process groups. */ | |
2357 | return kill_proc_info(sig, &info, pid); | |
2358 | } | |
2359 | ||
62ab4505 TG |
2360 | long do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, siginfo_t *info) |
2361 | { | |
2362 | /* This is only valid for single tasks */ | |
2363 | if (pid <= 0 || tgid <= 0) | |
2364 | return -EINVAL; | |
2365 | ||
2366 | /* Not even root can pretend to send signals from the kernel. | |
2367 | Nor can they impersonate a kill(), which adds source info. */ | |
2368 | if (info->si_code >= 0) | |
2369 | return -EPERM; | |
2370 | info->si_signo = sig; | |
2371 | ||
2372 | return do_send_specific(tgid, pid, sig, info); | |
2373 | } | |
2374 | ||
2375 | SYSCALL_DEFINE4(rt_tgsigqueueinfo, pid_t, tgid, pid_t, pid, int, sig, | |
2376 | siginfo_t __user *, uinfo) | |
2377 | { | |
2378 | siginfo_t info; | |
2379 | ||
2380 | if (copy_from_user(&info, uinfo, sizeof(siginfo_t))) | |
2381 | return -EFAULT; | |
2382 | ||
2383 | return do_rt_tgsigqueueinfo(tgid, pid, sig, &info); | |
2384 | } | |
2385 | ||
88531f72 | 2386 | int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) |
1da177e4 | 2387 | { |
93585eea | 2388 | struct task_struct *t = current; |
1da177e4 | 2389 | struct k_sigaction *k; |
71fabd5e | 2390 | sigset_t mask; |
1da177e4 | 2391 | |
7ed20e1a | 2392 | if (!valid_signal(sig) || sig < 1 || (act && sig_kernel_only(sig))) |
1da177e4 LT |
2393 | return -EINVAL; |
2394 | ||
93585eea | 2395 | k = &t->sighand->action[sig-1]; |
1da177e4 LT |
2396 | |
2397 | spin_lock_irq(¤t->sighand->siglock); | |
1da177e4 LT |
2398 | if (oact) |
2399 | *oact = *k; | |
2400 | ||
2401 | if (act) { | |
9ac95f2f ON |
2402 | sigdelsetmask(&act->sa.sa_mask, |
2403 | sigmask(SIGKILL) | sigmask(SIGSTOP)); | |
88531f72 | 2404 | *k = *act; |
1da177e4 LT |
2405 | /* |
2406 | * POSIX 3.3.1.3: | |
2407 | * "Setting a signal action to SIG_IGN for a signal that is | |
2408 | * pending shall cause the pending signal to be discarded, | |
2409 | * whether or not it is blocked." | |
2410 | * | |
2411 | * "Setting a signal action to SIG_DFL for a signal that is | |
2412 | * pending and whose default action is to ignore the signal | |
2413 | * (for example, SIGCHLD), shall cause the pending signal to | |
2414 | * be discarded, whether or not it is blocked" | |
2415 | */ | |
35de254d | 2416 | if (sig_handler_ignored(sig_handler(t, sig), sig)) { |
71fabd5e GA |
2417 | sigemptyset(&mask); |
2418 | sigaddset(&mask, sig); | |
2419 | rm_from_queue_full(&mask, &t->signal->shared_pending); | |
1da177e4 | 2420 | do { |
71fabd5e | 2421 | rm_from_queue_full(&mask, &t->pending); |
1da177e4 LT |
2422 | t = next_thread(t); |
2423 | } while (t != current); | |
1da177e4 | 2424 | } |
1da177e4 LT |
2425 | } |
2426 | ||
2427 | spin_unlock_irq(¤t->sighand->siglock); | |
2428 | return 0; | |
2429 | } | |
2430 | ||
2431 | int | |
2432 | do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long sp) | |
2433 | { | |
2434 | stack_t oss; | |
2435 | int error; | |
2436 | ||
0083fc2c LT |
2437 | oss.ss_sp = (void __user *) current->sas_ss_sp; |
2438 | oss.ss_size = current->sas_ss_size; | |
2439 | oss.ss_flags = sas_ss_flags(sp); | |
1da177e4 LT |
2440 | |
2441 | if (uss) { | |
2442 | void __user *ss_sp; | |
2443 | size_t ss_size; | |
2444 | int ss_flags; | |
2445 | ||
2446 | error = -EFAULT; | |
0dd8486b LT |
2447 | if (!access_ok(VERIFY_READ, uss, sizeof(*uss))) |
2448 | goto out; | |
2449 | error = __get_user(ss_sp, &uss->ss_sp) | | |
2450 | __get_user(ss_flags, &uss->ss_flags) | | |
2451 | __get_user(ss_size, &uss->ss_size); | |
2452 | if (error) | |
1da177e4 LT |
2453 | goto out; |
2454 | ||
2455 | error = -EPERM; | |
2456 | if (on_sig_stack(sp)) | |
2457 | goto out; | |
2458 | ||
2459 | error = -EINVAL; | |
2460 | /* | |
2461 | * | |
2462 | * Note - this code used to test ss_flags incorrectly | |
2463 | * old code may have been written using ss_flags==0 | |
2464 | * to mean ss_flags==SS_ONSTACK (as this was the only | |
2465 | * way that worked) - this fix preserves that older | |
2466 | * mechanism | |
2467 | */ | |
2468 | if (ss_flags != SS_DISABLE && ss_flags != SS_ONSTACK && ss_flags != 0) | |
2469 | goto out; | |
2470 | ||
2471 | if (ss_flags == SS_DISABLE) { | |
2472 | ss_size = 0; | |
2473 | ss_sp = NULL; | |
2474 | } else { | |
2475 | error = -ENOMEM; | |
2476 | if (ss_size < MINSIGSTKSZ) | |
2477 | goto out; | |
2478 | } | |
2479 | ||
2480 | current->sas_ss_sp = (unsigned long) ss_sp; | |
2481 | current->sas_ss_size = ss_size; | |
2482 | } | |
2483 | ||
0083fc2c | 2484 | error = 0; |
1da177e4 LT |
2485 | if (uoss) { |
2486 | error = -EFAULT; | |
0083fc2c | 2487 | if (!access_ok(VERIFY_WRITE, uoss, sizeof(*uoss))) |
1da177e4 | 2488 | goto out; |
0083fc2c LT |
2489 | error = __put_user(oss.ss_sp, &uoss->ss_sp) | |
2490 | __put_user(oss.ss_size, &uoss->ss_size) | | |
2491 | __put_user(oss.ss_flags, &uoss->ss_flags); | |
1da177e4 LT |
2492 | } |
2493 | ||
1da177e4 LT |
2494 | out: |
2495 | return error; | |
2496 | } | |
2497 | ||
2498 | #ifdef __ARCH_WANT_SYS_SIGPENDING | |
2499 | ||
b290ebe2 | 2500 | SYSCALL_DEFINE1(sigpending, old_sigset_t __user *, set) |
1da177e4 LT |
2501 | { |
2502 | return do_sigpending(set, sizeof(*set)); | |
2503 | } | |
2504 | ||
2505 | #endif | |
2506 | ||
2507 | #ifdef __ARCH_WANT_SYS_SIGPROCMASK | |
2508 | /* Some platforms have their own version with special arguments others | |
2509 | support only sys_rt_sigprocmask. */ | |
2510 | ||
b290ebe2 HC |
2511 | SYSCALL_DEFINE3(sigprocmask, int, how, old_sigset_t __user *, set, |
2512 | old_sigset_t __user *, oset) | |
1da177e4 LT |
2513 | { |
2514 | int error; | |
2515 | old_sigset_t old_set, new_set; | |
2516 | ||
2517 | if (set) { | |
2518 | error = -EFAULT; | |
2519 | if (copy_from_user(&new_set, set, sizeof(*set))) | |
2520 | goto out; | |
2521 | new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP)); | |
2522 | ||
2523 | spin_lock_irq(¤t->sighand->siglock); | |
2524 | old_set = current->blocked.sig[0]; | |
2525 | ||
2526 | error = 0; | |
2527 | switch (how) { | |
2528 | default: | |
2529 | error = -EINVAL; | |
2530 | break; | |
2531 | case SIG_BLOCK: | |
2532 | sigaddsetmask(¤t->blocked, new_set); | |
2533 | break; | |
2534 | case SIG_UNBLOCK: | |
2535 | sigdelsetmask(¤t->blocked, new_set); | |
2536 | break; | |
2537 | case SIG_SETMASK: | |
2538 | current->blocked.sig[0] = new_set; | |
2539 | break; | |
2540 | } | |
2541 | ||
2542 | recalc_sigpending(); | |
2543 | spin_unlock_irq(¤t->sighand->siglock); | |
2544 | if (error) | |
2545 | goto out; | |
2546 | if (oset) | |
2547 | goto set_old; | |
2548 | } else if (oset) { | |
2549 | old_set = current->blocked.sig[0]; | |
2550 | set_old: | |
2551 | error = -EFAULT; | |
2552 | if (copy_to_user(oset, &old_set, sizeof(*oset))) | |
2553 | goto out; | |
2554 | } | |
2555 | error = 0; | |
2556 | out: | |
2557 | return error; | |
2558 | } | |
2559 | #endif /* __ARCH_WANT_SYS_SIGPROCMASK */ | |
2560 | ||
2561 | #ifdef __ARCH_WANT_SYS_RT_SIGACTION | |
d4e82042 HC |
2562 | SYSCALL_DEFINE4(rt_sigaction, int, sig, |
2563 | const struct sigaction __user *, act, | |
2564 | struct sigaction __user *, oact, | |
2565 | size_t, sigsetsize) | |
1da177e4 LT |
2566 | { |
2567 | struct k_sigaction new_sa, old_sa; | |
2568 | int ret = -EINVAL; | |
2569 | ||
2570 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
2571 | if (sigsetsize != sizeof(sigset_t)) | |
2572 | goto out; | |
2573 | ||
2574 | if (act) { | |
2575 | if (copy_from_user(&new_sa.sa, act, sizeof(new_sa.sa))) | |
2576 | return -EFAULT; | |
2577 | } | |
2578 | ||
2579 | ret = do_sigaction(sig, act ? &new_sa : NULL, oact ? &old_sa : NULL); | |
2580 | ||
2581 | if (!ret && oact) { | |
2582 | if (copy_to_user(oact, &old_sa.sa, sizeof(old_sa.sa))) | |
2583 | return -EFAULT; | |
2584 | } | |
2585 | out: | |
2586 | return ret; | |
2587 | } | |
2588 | #endif /* __ARCH_WANT_SYS_RT_SIGACTION */ | |
2589 | ||
2590 | #ifdef __ARCH_WANT_SYS_SGETMASK | |
2591 | ||
2592 | /* | |
2593 | * For backwards compatibility. Functionality superseded by sigprocmask. | |
2594 | */ | |
a5f8fa9e | 2595 | SYSCALL_DEFINE0(sgetmask) |
1da177e4 LT |
2596 | { |
2597 | /* SMP safe */ | |
2598 | return current->blocked.sig[0]; | |
2599 | } | |
2600 | ||
a5f8fa9e | 2601 | SYSCALL_DEFINE1(ssetmask, int, newmask) |
1da177e4 LT |
2602 | { |
2603 | int old; | |
2604 | ||
2605 | spin_lock_irq(¤t->sighand->siglock); | |
2606 | old = current->blocked.sig[0]; | |
2607 | ||
2608 | siginitset(¤t->blocked, newmask & ~(sigmask(SIGKILL)| | |
2609 | sigmask(SIGSTOP))); | |
2610 | recalc_sigpending(); | |
2611 | spin_unlock_irq(¤t->sighand->siglock); | |
2612 | ||
2613 | return old; | |
2614 | } | |
2615 | #endif /* __ARCH_WANT_SGETMASK */ | |
2616 | ||
2617 | #ifdef __ARCH_WANT_SYS_SIGNAL | |
2618 | /* | |
2619 | * For backwards compatibility. Functionality superseded by sigaction. | |
2620 | */ | |
a5f8fa9e | 2621 | SYSCALL_DEFINE2(signal, int, sig, __sighandler_t, handler) |
1da177e4 LT |
2622 | { |
2623 | struct k_sigaction new_sa, old_sa; | |
2624 | int ret; | |
2625 | ||
2626 | new_sa.sa.sa_handler = handler; | |
2627 | new_sa.sa.sa_flags = SA_ONESHOT | SA_NOMASK; | |
c70d3d70 | 2628 | sigemptyset(&new_sa.sa.sa_mask); |
1da177e4 LT |
2629 | |
2630 | ret = do_sigaction(sig, &new_sa, &old_sa); | |
2631 | ||
2632 | return ret ? ret : (unsigned long)old_sa.sa.sa_handler; | |
2633 | } | |
2634 | #endif /* __ARCH_WANT_SYS_SIGNAL */ | |
2635 | ||
2636 | #ifdef __ARCH_WANT_SYS_PAUSE | |
2637 | ||
a5f8fa9e | 2638 | SYSCALL_DEFINE0(pause) |
1da177e4 LT |
2639 | { |
2640 | current->state = TASK_INTERRUPTIBLE; | |
2641 | schedule(); | |
2642 | return -ERESTARTNOHAND; | |
2643 | } | |
2644 | ||
2645 | #endif | |
2646 | ||
150256d8 | 2647 | #ifdef __ARCH_WANT_SYS_RT_SIGSUSPEND |
d4e82042 | 2648 | SYSCALL_DEFINE2(rt_sigsuspend, sigset_t __user *, unewset, size_t, sigsetsize) |
150256d8 DW |
2649 | { |
2650 | sigset_t newset; | |
2651 | ||
2652 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
2653 | if (sigsetsize != sizeof(sigset_t)) | |
2654 | return -EINVAL; | |
2655 | ||
2656 | if (copy_from_user(&newset, unewset, sizeof(newset))) | |
2657 | return -EFAULT; | |
2658 | sigdelsetmask(&newset, sigmask(SIGKILL)|sigmask(SIGSTOP)); | |
2659 | ||
2660 | spin_lock_irq(¤t->sighand->siglock); | |
2661 | current->saved_sigmask = current->blocked; | |
2662 | current->blocked = newset; | |
2663 | recalc_sigpending(); | |
2664 | spin_unlock_irq(¤t->sighand->siglock); | |
2665 | ||
2666 | current->state = TASK_INTERRUPTIBLE; | |
2667 | schedule(); | |
4e4c22c7 | 2668 | set_restore_sigmask(); |
150256d8 DW |
2669 | return -ERESTARTNOHAND; |
2670 | } | |
2671 | #endif /* __ARCH_WANT_SYS_RT_SIGSUSPEND */ | |
2672 | ||
f269fdd1 DH |
2673 | __attribute__((weak)) const char *arch_vma_name(struct vm_area_struct *vma) |
2674 | { | |
2675 | return NULL; | |
2676 | } | |
2677 | ||
1da177e4 LT |
2678 | void __init signals_init(void) |
2679 | { | |
0a31bd5f | 2680 | sigqueue_cachep = KMEM_CACHE(sigqueue, SLAB_PANIC); |
1da177e4 | 2681 | } |