]>
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> | |
0a16b607 | 30 | #include <trace/sched.h> |
84d73786 | 31 | |
1da177e4 LT |
32 | #include <asm/param.h> |
33 | #include <asm/uaccess.h> | |
34 | #include <asm/unistd.h> | |
35 | #include <asm/siginfo.h> | |
e1396065 | 36 | #include "audit.h" /* audit_signal_info() */ |
1da177e4 LT |
37 | |
38 | /* | |
39 | * SLAB caches for signal bits. | |
40 | */ | |
41 | ||
e18b890b | 42 | static struct kmem_cache *sigqueue_cachep; |
1da177e4 | 43 | |
7e066fb8 MD |
44 | DEFINE_TRACE(sched_signal_send); |
45 | ||
35de254d | 46 | static void __user *sig_handler(struct task_struct *t, int sig) |
93585eea | 47 | { |
35de254d RM |
48 | return t->sighand->action[sig - 1].sa.sa_handler; |
49 | } | |
93585eea | 50 | |
35de254d RM |
51 | static int sig_handler_ignored(void __user *handler, int sig) |
52 | { | |
93585eea | 53 | /* Is it explicitly or implicitly ignored? */ |
93585eea PE |
54 | return handler == SIG_IGN || |
55 | (handler == SIG_DFL && sig_kernel_ignore(sig)); | |
56 | } | |
1da177e4 LT |
57 | |
58 | static int sig_ignored(struct task_struct *t, int sig) | |
59 | { | |
35de254d | 60 | void __user *handler; |
1da177e4 LT |
61 | |
62 | /* | |
63 | * Blocked signals are never ignored, since the | |
64 | * signal handler may change by the time it is | |
65 | * unblocked. | |
66 | */ | |
325d22df | 67 | if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig)) |
1da177e4 LT |
68 | return 0; |
69 | ||
35de254d RM |
70 | handler = sig_handler(t, sig); |
71 | if (!sig_handler_ignored(handler, sig)) | |
72 | return 0; | |
73 | ||
74 | /* | |
75 | * Tracers may want to know about even ignored signals. | |
76 | */ | |
77 | return !tracehook_consider_ignored_signal(t, sig, handler); | |
1da177e4 LT |
78 | } |
79 | ||
80 | /* | |
81 | * Re-calculate pending state from the set of locally pending | |
82 | * signals, globally pending signals, and blocked signals. | |
83 | */ | |
84 | static inline int has_pending_signals(sigset_t *signal, sigset_t *blocked) | |
85 | { | |
86 | unsigned long ready; | |
87 | long i; | |
88 | ||
89 | switch (_NSIG_WORDS) { | |
90 | default: | |
91 | for (i = _NSIG_WORDS, ready = 0; --i >= 0 ;) | |
92 | ready |= signal->sig[i] &~ blocked->sig[i]; | |
93 | break; | |
94 | ||
95 | case 4: ready = signal->sig[3] &~ blocked->sig[3]; | |
96 | ready |= signal->sig[2] &~ blocked->sig[2]; | |
97 | ready |= signal->sig[1] &~ blocked->sig[1]; | |
98 | ready |= signal->sig[0] &~ blocked->sig[0]; | |
99 | break; | |
100 | ||
101 | case 2: ready = signal->sig[1] &~ blocked->sig[1]; | |
102 | ready |= signal->sig[0] &~ blocked->sig[0]; | |
103 | break; | |
104 | ||
105 | case 1: ready = signal->sig[0] &~ blocked->sig[0]; | |
106 | } | |
107 | return ready != 0; | |
108 | } | |
109 | ||
110 | #define PENDING(p,b) has_pending_signals(&(p)->signal, (b)) | |
111 | ||
7bb44ade | 112 | static int recalc_sigpending_tsk(struct task_struct *t) |
1da177e4 LT |
113 | { |
114 | if (t->signal->group_stop_count > 0 || | |
115 | PENDING(&t->pending, &t->blocked) || | |
7bb44ade | 116 | PENDING(&t->signal->shared_pending, &t->blocked)) { |
1da177e4 | 117 | set_tsk_thread_flag(t, TIF_SIGPENDING); |
7bb44ade RM |
118 | return 1; |
119 | } | |
b74d0deb RM |
120 | /* |
121 | * We must never clear the flag in another thread, or in current | |
122 | * when it's possible the current syscall is returning -ERESTART*. | |
123 | * So we don't clear it here, and only callers who know they should do. | |
124 | */ | |
7bb44ade RM |
125 | return 0; |
126 | } | |
127 | ||
128 | /* | |
129 | * After recalculating TIF_SIGPENDING, we need to make sure the task wakes up. | |
130 | * This is superfluous when called on current, the wakeup is a harmless no-op. | |
131 | */ | |
132 | void recalc_sigpending_and_wake(struct task_struct *t) | |
133 | { | |
134 | if (recalc_sigpending_tsk(t)) | |
135 | signal_wake_up(t, 0); | |
1da177e4 LT |
136 | } |
137 | ||
138 | void recalc_sigpending(void) | |
139 | { | |
b787f7ba RM |
140 | if (unlikely(tracehook_force_sigpending())) |
141 | set_thread_flag(TIF_SIGPENDING); | |
142 | else if (!recalc_sigpending_tsk(current) && !freezing(current)) | |
b74d0deb RM |
143 | clear_thread_flag(TIF_SIGPENDING); |
144 | ||
1da177e4 LT |
145 | } |
146 | ||
147 | /* Given the mask, find the first available signal that should be serviced. */ | |
148 | ||
fba2afaa | 149 | int next_signal(struct sigpending *pending, sigset_t *mask) |
1da177e4 LT |
150 | { |
151 | unsigned long i, *s, *m, x; | |
152 | int sig = 0; | |
153 | ||
154 | s = pending->signal.sig; | |
155 | m = mask->sig; | |
156 | switch (_NSIG_WORDS) { | |
157 | default: | |
158 | for (i = 0; i < _NSIG_WORDS; ++i, ++s, ++m) | |
159 | if ((x = *s &~ *m) != 0) { | |
160 | sig = ffz(~x) + i*_NSIG_BPW + 1; | |
161 | break; | |
162 | } | |
163 | break; | |
164 | ||
165 | case 2: if ((x = s[0] &~ m[0]) != 0) | |
166 | sig = 1; | |
167 | else if ((x = s[1] &~ m[1]) != 0) | |
168 | sig = _NSIG_BPW + 1; | |
169 | else | |
170 | break; | |
171 | sig += ffz(~x); | |
172 | break; | |
173 | ||
174 | case 1: if ((x = *s &~ *m) != 0) | |
175 | sig = ffz(~x) + 1; | |
176 | break; | |
177 | } | |
178 | ||
179 | return sig; | |
180 | } | |
181 | ||
c69e8d9c DH |
182 | /* |
183 | * allocate a new signal queue record | |
184 | * - this may be called without locks if and only if t == current, otherwise an | |
d84f4f99 | 185 | * appopriate lock must be held to stop the target task from exiting |
c69e8d9c | 186 | */ |
dd0fc66f | 187 | static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags, |
1da177e4 LT |
188 | int override_rlimit) |
189 | { | |
190 | struct sigqueue *q = NULL; | |
10b1fbdb | 191 | struct user_struct *user; |
1da177e4 | 192 | |
10b1fbdb | 193 | /* |
c69e8d9c DH |
194 | * We won't get problems with the target's UID changing under us |
195 | * because changing it requires RCU be used, and if t != current, the | |
196 | * caller must be holding the RCU readlock (by way of a spinlock) and | |
197 | * we use RCU protection here | |
10b1fbdb | 198 | */ |
d84f4f99 | 199 | user = get_uid(__task_cred(t)->user); |
10b1fbdb | 200 | atomic_inc(&user->sigpending); |
1da177e4 | 201 | if (override_rlimit || |
10b1fbdb | 202 | atomic_read(&user->sigpending) <= |
1da177e4 LT |
203 | t->signal->rlim[RLIMIT_SIGPENDING].rlim_cur) |
204 | q = kmem_cache_alloc(sigqueue_cachep, flags); | |
205 | if (unlikely(q == NULL)) { | |
10b1fbdb | 206 | atomic_dec(&user->sigpending); |
d84f4f99 | 207 | free_uid(user); |
1da177e4 LT |
208 | } else { |
209 | INIT_LIST_HEAD(&q->list); | |
210 | q->flags = 0; | |
d84f4f99 | 211 | q->user = user; |
1da177e4 | 212 | } |
d84f4f99 DH |
213 | |
214 | return q; | |
1da177e4 LT |
215 | } |
216 | ||
514a01b8 | 217 | static void __sigqueue_free(struct sigqueue *q) |
1da177e4 LT |
218 | { |
219 | if (q->flags & SIGQUEUE_PREALLOC) | |
220 | return; | |
221 | atomic_dec(&q->user->sigpending); | |
222 | free_uid(q->user); | |
223 | kmem_cache_free(sigqueue_cachep, q); | |
224 | } | |
225 | ||
6a14c5c9 | 226 | void flush_sigqueue(struct sigpending *queue) |
1da177e4 LT |
227 | { |
228 | struct sigqueue *q; | |
229 | ||
230 | sigemptyset(&queue->signal); | |
231 | while (!list_empty(&queue->list)) { | |
232 | q = list_entry(queue->list.next, struct sigqueue , list); | |
233 | list_del_init(&q->list); | |
234 | __sigqueue_free(q); | |
235 | } | |
236 | } | |
237 | ||
238 | /* | |
239 | * Flush all pending signals for a task. | |
240 | */ | |
3bcac026 DH |
241 | void __flush_signals(struct task_struct *t) |
242 | { | |
243 | clear_tsk_thread_flag(t, TIF_SIGPENDING); | |
244 | flush_sigqueue(&t->pending); | |
245 | flush_sigqueue(&t->signal->shared_pending); | |
246 | } | |
247 | ||
c81addc9 | 248 | void flush_signals(struct task_struct *t) |
1da177e4 LT |
249 | { |
250 | unsigned long flags; | |
251 | ||
252 | spin_lock_irqsave(&t->sighand->siglock, flags); | |
3bcac026 | 253 | __flush_signals(t); |
1da177e4 LT |
254 | spin_unlock_irqrestore(&t->sighand->siglock, flags); |
255 | } | |
256 | ||
cbaffba1 ON |
257 | static void __flush_itimer_signals(struct sigpending *pending) |
258 | { | |
259 | sigset_t signal, retain; | |
260 | struct sigqueue *q, *n; | |
261 | ||
262 | signal = pending->signal; | |
263 | sigemptyset(&retain); | |
264 | ||
265 | list_for_each_entry_safe(q, n, &pending->list, list) { | |
266 | int sig = q->info.si_signo; | |
267 | ||
268 | if (likely(q->info.si_code != SI_TIMER)) { | |
269 | sigaddset(&retain, sig); | |
270 | } else { | |
271 | sigdelset(&signal, sig); | |
272 | list_del_init(&q->list); | |
273 | __sigqueue_free(q); | |
274 | } | |
275 | } | |
276 | ||
277 | sigorsets(&pending->signal, &signal, &retain); | |
278 | } | |
279 | ||
280 | void flush_itimer_signals(void) | |
281 | { | |
282 | struct task_struct *tsk = current; | |
283 | unsigned long flags; | |
284 | ||
285 | spin_lock_irqsave(&tsk->sighand->siglock, flags); | |
286 | __flush_itimer_signals(&tsk->pending); | |
287 | __flush_itimer_signals(&tsk->signal->shared_pending); | |
288 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags); | |
289 | } | |
290 | ||
10ab825b ON |
291 | void ignore_signals(struct task_struct *t) |
292 | { | |
293 | int i; | |
294 | ||
295 | for (i = 0; i < _NSIG; ++i) | |
296 | t->sighand->action[i].sa.sa_handler = SIG_IGN; | |
297 | ||
298 | flush_signals(t); | |
299 | } | |
300 | ||
1da177e4 LT |
301 | /* |
302 | * Flush all handlers for a task. | |
303 | */ | |
304 | ||
305 | void | |
306 | flush_signal_handlers(struct task_struct *t, int force_default) | |
307 | { | |
308 | int i; | |
309 | struct k_sigaction *ka = &t->sighand->action[0]; | |
310 | for (i = _NSIG ; i != 0 ; i--) { | |
311 | if (force_default || ka->sa.sa_handler != SIG_IGN) | |
312 | ka->sa.sa_handler = SIG_DFL; | |
313 | ka->sa.sa_flags = 0; | |
314 | sigemptyset(&ka->sa.sa_mask); | |
315 | ka++; | |
316 | } | |
317 | } | |
318 | ||
abd4f750 MAS |
319 | int unhandled_signal(struct task_struct *tsk, int sig) |
320 | { | |
445a91d2 | 321 | void __user *handler = tsk->sighand->action[sig-1].sa.sa_handler; |
b460cbc5 | 322 | if (is_global_init(tsk)) |
abd4f750 | 323 | return 1; |
445a91d2 | 324 | if (handler != SIG_IGN && handler != SIG_DFL) |
abd4f750 | 325 | return 0; |
445a91d2 | 326 | return !tracehook_consider_fatal_signal(tsk, sig, handler); |
abd4f750 MAS |
327 | } |
328 | ||
1da177e4 LT |
329 | |
330 | /* Notify the system that a driver wants to block all signals for this | |
331 | * process, and wants to be notified if any signals at all were to be | |
332 | * sent/acted upon. If the notifier routine returns non-zero, then the | |
333 | * signal will be acted upon after all. If the notifier routine returns 0, | |
334 | * then then signal will be blocked. Only one block per process is | |
335 | * allowed. priv is a pointer to private data that the notifier routine | |
336 | * can use to determine if the signal should be blocked or not. */ | |
337 | ||
338 | void | |
339 | block_all_signals(int (*notifier)(void *priv), void *priv, sigset_t *mask) | |
340 | { | |
341 | unsigned long flags; | |
342 | ||
343 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
344 | current->notifier_mask = mask; | |
345 | current->notifier_data = priv; | |
346 | current->notifier = notifier; | |
347 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
348 | } | |
349 | ||
350 | /* Notify the system that blocking has ended. */ | |
351 | ||
352 | void | |
353 | unblock_all_signals(void) | |
354 | { | |
355 | unsigned long flags; | |
356 | ||
357 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
358 | current->notifier = NULL; | |
359 | current->notifier_data = NULL; | |
360 | recalc_sigpending(); | |
361 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
362 | } | |
363 | ||
100360f0 | 364 | static void collect_signal(int sig, struct sigpending *list, siginfo_t *info) |
1da177e4 LT |
365 | { |
366 | struct sigqueue *q, *first = NULL; | |
1da177e4 | 367 | |
1da177e4 LT |
368 | /* |
369 | * Collect the siginfo appropriate to this signal. Check if | |
370 | * there is another siginfo for the same signal. | |
371 | */ | |
372 | list_for_each_entry(q, &list->list, list) { | |
373 | if (q->info.si_signo == sig) { | |
d4434207 ON |
374 | if (first) |
375 | goto still_pending; | |
1da177e4 LT |
376 | first = q; |
377 | } | |
378 | } | |
d4434207 ON |
379 | |
380 | sigdelset(&list->signal, sig); | |
381 | ||
1da177e4 | 382 | if (first) { |
d4434207 | 383 | still_pending: |
1da177e4 LT |
384 | list_del_init(&first->list); |
385 | copy_siginfo(info, &first->info); | |
386 | __sigqueue_free(first); | |
1da177e4 | 387 | } else { |
1da177e4 LT |
388 | /* Ok, it wasn't in the queue. This must be |
389 | a fast-pathed signal or we must have been | |
390 | out of queue space. So zero out the info. | |
391 | */ | |
1da177e4 LT |
392 | info->si_signo = sig; |
393 | info->si_errno = 0; | |
394 | info->si_code = 0; | |
395 | info->si_pid = 0; | |
396 | info->si_uid = 0; | |
397 | } | |
1da177e4 LT |
398 | } |
399 | ||
400 | static int __dequeue_signal(struct sigpending *pending, sigset_t *mask, | |
401 | siginfo_t *info) | |
402 | { | |
27d91e07 | 403 | int sig = next_signal(pending, mask); |
1da177e4 | 404 | |
1da177e4 LT |
405 | if (sig) { |
406 | if (current->notifier) { | |
407 | if (sigismember(current->notifier_mask, sig)) { | |
408 | if (!(current->notifier)(current->notifier_data)) { | |
409 | clear_thread_flag(TIF_SIGPENDING); | |
410 | return 0; | |
411 | } | |
412 | } | |
413 | } | |
414 | ||
100360f0 | 415 | collect_signal(sig, pending, info); |
1da177e4 | 416 | } |
1da177e4 LT |
417 | |
418 | return sig; | |
419 | } | |
420 | ||
421 | /* | |
422 | * Dequeue a signal and return the element to the caller, which is | |
423 | * expected to free it. | |
424 | * | |
425 | * All callers have to hold the siglock. | |
426 | */ | |
427 | int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info) | |
428 | { | |
c5363d03 | 429 | int signr; |
caec4e8d BH |
430 | |
431 | /* We only dequeue private signals from ourselves, we don't let | |
432 | * signalfd steal them | |
433 | */ | |
b8fceee1 | 434 | signr = __dequeue_signal(&tsk->pending, mask, info); |
8bfd9a7a | 435 | if (!signr) { |
1da177e4 LT |
436 | signr = __dequeue_signal(&tsk->signal->shared_pending, |
437 | mask, info); | |
8bfd9a7a TG |
438 | /* |
439 | * itimer signal ? | |
440 | * | |
441 | * itimers are process shared and we restart periodic | |
442 | * itimers in the signal delivery path to prevent DoS | |
443 | * attacks in the high resolution timer case. This is | |
444 | * compliant with the old way of self restarting | |
445 | * itimers, as the SIGALRM is a legacy signal and only | |
446 | * queued once. Changing the restart behaviour to | |
447 | * restart the timer in the signal dequeue path is | |
448 | * reducing the timer noise on heavy loaded !highres | |
449 | * systems too. | |
450 | */ | |
451 | if (unlikely(signr == SIGALRM)) { | |
452 | struct hrtimer *tmr = &tsk->signal->real_timer; | |
453 | ||
454 | if (!hrtimer_is_queued(tmr) && | |
455 | tsk->signal->it_real_incr.tv64 != 0) { | |
456 | hrtimer_forward(tmr, tmr->base->get_time(), | |
457 | tsk->signal->it_real_incr); | |
458 | hrtimer_restart(tmr); | |
459 | } | |
460 | } | |
461 | } | |
c5363d03 | 462 | |
b8fceee1 | 463 | recalc_sigpending(); |
c5363d03 PE |
464 | if (!signr) |
465 | return 0; | |
466 | ||
467 | if (unlikely(sig_kernel_stop(signr))) { | |
8bfd9a7a TG |
468 | /* |
469 | * Set a marker that we have dequeued a stop signal. Our | |
470 | * caller might release the siglock and then the pending | |
471 | * stop signal it is about to process is no longer in the | |
472 | * pending bitmasks, but must still be cleared by a SIGCONT | |
473 | * (and overruled by a SIGKILL). So those cases clear this | |
474 | * shared flag after we've set it. Note that this flag may | |
475 | * remain set after the signal we return is ignored or | |
476 | * handled. That doesn't matter because its only purpose | |
477 | * is to alert stop-signal processing code when another | |
478 | * processor has come along and cleared the flag. | |
479 | */ | |
92413d77 | 480 | tsk->signal->flags |= SIGNAL_STOP_DEQUEUED; |
8bfd9a7a | 481 | } |
c5363d03 | 482 | if ((info->si_code & __SI_MASK) == __SI_TIMER && info->si_sys_private) { |
1da177e4 LT |
483 | /* |
484 | * Release the siglock to ensure proper locking order | |
485 | * of timer locks outside of siglocks. Note, we leave | |
486 | * irqs disabled here, since the posix-timers code is | |
487 | * about to disable them again anyway. | |
488 | */ | |
489 | spin_unlock(&tsk->sighand->siglock); | |
490 | do_schedule_next_timer(info); | |
491 | spin_lock(&tsk->sighand->siglock); | |
492 | } | |
493 | return signr; | |
494 | } | |
495 | ||
496 | /* | |
497 | * Tell a process that it has a new active signal.. | |
498 | * | |
499 | * NOTE! we rely on the previous spin_lock to | |
500 | * lock interrupts for us! We can only be called with | |
501 | * "siglock" held, and the local interrupt must | |
502 | * have been disabled when that got acquired! | |
503 | * | |
504 | * No need to set need_resched since signal event passing | |
505 | * goes through ->blocked | |
506 | */ | |
507 | void signal_wake_up(struct task_struct *t, int resume) | |
508 | { | |
509 | unsigned int mask; | |
510 | ||
511 | set_tsk_thread_flag(t, TIF_SIGPENDING); | |
512 | ||
513 | /* | |
f021a3c2 MW |
514 | * For SIGKILL, we want to wake it up in the stopped/traced/killable |
515 | * case. We don't check t->state here because there is a race with it | |
1da177e4 LT |
516 | * executing another processor and just now entering stopped state. |
517 | * By using wake_up_state, we ensure the process will wake up and | |
518 | * handle its death signal. | |
519 | */ | |
520 | mask = TASK_INTERRUPTIBLE; | |
521 | if (resume) | |
f021a3c2 | 522 | mask |= TASK_WAKEKILL; |
1da177e4 LT |
523 | if (!wake_up_state(t, mask)) |
524 | kick_process(t); | |
525 | } | |
526 | ||
71fabd5e GA |
527 | /* |
528 | * Remove signals in mask from the pending set and queue. | |
529 | * Returns 1 if any signals were found. | |
530 | * | |
531 | * All callers must be holding the siglock. | |
532 | * | |
533 | * This version takes a sigset mask and looks at all signals, | |
534 | * not just those in the first mask word. | |
535 | */ | |
536 | static int rm_from_queue_full(sigset_t *mask, struct sigpending *s) | |
537 | { | |
538 | struct sigqueue *q, *n; | |
539 | sigset_t m; | |
540 | ||
541 | sigandsets(&m, mask, &s->signal); | |
542 | if (sigisemptyset(&m)) | |
543 | return 0; | |
544 | ||
545 | signandsets(&s->signal, &s->signal, mask); | |
546 | list_for_each_entry_safe(q, n, &s->list, list) { | |
547 | if (sigismember(mask, q->info.si_signo)) { | |
548 | list_del_init(&q->list); | |
549 | __sigqueue_free(q); | |
550 | } | |
551 | } | |
552 | return 1; | |
553 | } | |
1da177e4 LT |
554 | /* |
555 | * Remove signals in mask from the pending set and queue. | |
556 | * Returns 1 if any signals were found. | |
557 | * | |
558 | * All callers must be holding the siglock. | |
559 | */ | |
560 | static int rm_from_queue(unsigned long mask, struct sigpending *s) | |
561 | { | |
562 | struct sigqueue *q, *n; | |
563 | ||
564 | if (!sigtestsetmask(&s->signal, mask)) | |
565 | return 0; | |
566 | ||
567 | sigdelsetmask(&s->signal, mask); | |
568 | list_for_each_entry_safe(q, n, &s->list, list) { | |
569 | if (q->info.si_signo < SIGRTMIN && | |
570 | (mask & sigmask(q->info.si_signo))) { | |
571 | list_del_init(&q->list); | |
572 | __sigqueue_free(q); | |
573 | } | |
574 | } | |
575 | return 1; | |
576 | } | |
577 | ||
578 | /* | |
579 | * Bad permissions for sending the signal | |
c69e8d9c | 580 | * - the caller must hold at least the RCU read lock |
1da177e4 LT |
581 | */ |
582 | static int check_kill_permission(int sig, struct siginfo *info, | |
583 | struct task_struct *t) | |
584 | { | |
c69e8d9c | 585 | const struct cred *cred = current_cred(), *tcred; |
2e2ba22e | 586 | struct pid *sid; |
3b5e9e53 ON |
587 | int error; |
588 | ||
7ed20e1a | 589 | if (!valid_signal(sig)) |
3b5e9e53 ON |
590 | return -EINVAL; |
591 | ||
592 | if (info != SEND_SIG_NOINFO && (is_si_special(info) || SI_FROMKERNEL(info))) | |
593 | return 0; | |
e54dc243 | 594 | |
3b5e9e53 ON |
595 | error = audit_signal_info(sig, t); /* Let audit system see the signal */ |
596 | if (error) | |
1da177e4 | 597 | return error; |
3b5e9e53 | 598 | |
c69e8d9c DH |
599 | tcred = __task_cred(t); |
600 | if ((cred->euid ^ tcred->suid) && | |
601 | (cred->euid ^ tcred->uid) && | |
602 | (cred->uid ^ tcred->suid) && | |
603 | (cred->uid ^ tcred->uid) && | |
2e2ba22e ON |
604 | !capable(CAP_KILL)) { |
605 | switch (sig) { | |
606 | case SIGCONT: | |
2e2ba22e | 607 | sid = task_session(t); |
2e2ba22e ON |
608 | /* |
609 | * We don't return the error if sid == NULL. The | |
610 | * task was unhashed, the caller must notice this. | |
611 | */ | |
612 | if (!sid || sid == task_session(current)) | |
613 | break; | |
614 | default: | |
615 | return -EPERM; | |
616 | } | |
617 | } | |
c2f0c7c3 | 618 | |
e54dc243 | 619 | return security_task_kill(t, info, sig, 0); |
1da177e4 LT |
620 | } |
621 | ||
1da177e4 | 622 | /* |
7e695a5e ON |
623 | * Handle magic process-wide effects of stop/continue signals. Unlike |
624 | * the signal actions, these happen immediately at signal-generation | |
1da177e4 LT |
625 | * time regardless of blocking, ignoring, or handling. This does the |
626 | * actual continuing for SIGCONT, but not the actual stopping for stop | |
7e695a5e ON |
627 | * signals. The process stop is done as a signal action for SIG_DFL. |
628 | * | |
629 | * Returns true if the signal should be actually delivered, otherwise | |
630 | * it should be dropped. | |
1da177e4 | 631 | */ |
7e695a5e | 632 | static int prepare_signal(int sig, struct task_struct *p) |
1da177e4 | 633 | { |
ad16a460 | 634 | struct signal_struct *signal = p->signal; |
1da177e4 LT |
635 | struct task_struct *t; |
636 | ||
7e695a5e | 637 | if (unlikely(signal->flags & SIGNAL_GROUP_EXIT)) { |
1da177e4 | 638 | /* |
7e695a5e | 639 | * The process is in the middle of dying, nothing to do. |
1da177e4 | 640 | */ |
7e695a5e | 641 | } else if (sig_kernel_stop(sig)) { |
1da177e4 LT |
642 | /* |
643 | * This is a stop signal. Remove SIGCONT from all queues. | |
644 | */ | |
ad16a460 | 645 | rm_from_queue(sigmask(SIGCONT), &signal->shared_pending); |
1da177e4 LT |
646 | t = p; |
647 | do { | |
648 | rm_from_queue(sigmask(SIGCONT), &t->pending); | |
ad16a460 | 649 | } while_each_thread(p, t); |
1da177e4 | 650 | } else if (sig == SIGCONT) { |
fc321d2e | 651 | unsigned int why; |
1da177e4 LT |
652 | /* |
653 | * Remove all stop signals from all queues, | |
654 | * and wake all threads. | |
655 | */ | |
ad16a460 | 656 | rm_from_queue(SIG_KERNEL_STOP_MASK, &signal->shared_pending); |
1da177e4 LT |
657 | t = p; |
658 | do { | |
659 | unsigned int state; | |
660 | rm_from_queue(SIG_KERNEL_STOP_MASK, &t->pending); | |
1da177e4 LT |
661 | /* |
662 | * If there is a handler for SIGCONT, we must make | |
663 | * sure that no thread returns to user mode before | |
664 | * we post the signal, in case it was the only | |
665 | * thread eligible to run the signal handler--then | |
666 | * it must not do anything between resuming and | |
667 | * running the handler. With the TIF_SIGPENDING | |
668 | * flag set, the thread will pause and acquire the | |
669 | * siglock that we hold now and until we've queued | |
fc321d2e | 670 | * the pending signal. |
1da177e4 LT |
671 | * |
672 | * Wake up the stopped thread _after_ setting | |
673 | * TIF_SIGPENDING | |
674 | */ | |
f021a3c2 | 675 | state = __TASK_STOPPED; |
1da177e4 LT |
676 | if (sig_user_defined(t, SIGCONT) && !sigismember(&t->blocked, SIGCONT)) { |
677 | set_tsk_thread_flag(t, TIF_SIGPENDING); | |
678 | state |= TASK_INTERRUPTIBLE; | |
679 | } | |
680 | wake_up_state(t, state); | |
ad16a460 | 681 | } while_each_thread(p, t); |
1da177e4 | 682 | |
fc321d2e ON |
683 | /* |
684 | * Notify the parent with CLD_CONTINUED if we were stopped. | |
685 | * | |
686 | * If we were in the middle of a group stop, we pretend it | |
687 | * was already finished, and then continued. Since SIGCHLD | |
688 | * doesn't queue we report only CLD_STOPPED, as if the next | |
689 | * CLD_CONTINUED was dropped. | |
690 | */ | |
691 | why = 0; | |
ad16a460 | 692 | if (signal->flags & SIGNAL_STOP_STOPPED) |
fc321d2e | 693 | why |= SIGNAL_CLD_CONTINUED; |
ad16a460 | 694 | else if (signal->group_stop_count) |
fc321d2e ON |
695 | why |= SIGNAL_CLD_STOPPED; |
696 | ||
697 | if (why) { | |
021e1ae3 ON |
698 | /* |
699 | * The first thread which returns from finish_stop() | |
700 | * will take ->siglock, notice SIGNAL_CLD_MASK, and | |
701 | * notify its parent. See get_signal_to_deliver(). | |
702 | */ | |
ad16a460 ON |
703 | signal->flags = why | SIGNAL_STOP_CONTINUED; |
704 | signal->group_stop_count = 0; | |
705 | signal->group_exit_code = 0; | |
1da177e4 LT |
706 | } else { |
707 | /* | |
708 | * We are not stopped, but there could be a stop | |
709 | * signal in the middle of being processed after | |
710 | * being removed from the queue. Clear that too. | |
711 | */ | |
ad16a460 | 712 | signal->flags &= ~SIGNAL_STOP_DEQUEUED; |
1da177e4 | 713 | } |
1da177e4 | 714 | } |
7e695a5e ON |
715 | |
716 | return !sig_ignored(p, sig); | |
1da177e4 LT |
717 | } |
718 | ||
71f11dc0 ON |
719 | /* |
720 | * Test if P wants to take SIG. After we've checked all threads with this, | |
721 | * it's equivalent to finding no threads not blocking SIG. Any threads not | |
722 | * blocking SIG were ruled out because they are not running and already | |
723 | * have pending signals. Such threads will dequeue from the shared queue | |
724 | * as soon as they're available, so putting the signal on the shared queue | |
725 | * will be equivalent to sending it to one such thread. | |
726 | */ | |
727 | static inline int wants_signal(int sig, struct task_struct *p) | |
728 | { | |
729 | if (sigismember(&p->blocked, sig)) | |
730 | return 0; | |
731 | if (p->flags & PF_EXITING) | |
732 | return 0; | |
733 | if (sig == SIGKILL) | |
734 | return 1; | |
735 | if (task_is_stopped_or_traced(p)) | |
736 | return 0; | |
737 | return task_curr(p) || !signal_pending(p); | |
738 | } | |
739 | ||
5fcd835b | 740 | static void complete_signal(int sig, struct task_struct *p, int group) |
71f11dc0 ON |
741 | { |
742 | struct signal_struct *signal = p->signal; | |
743 | struct task_struct *t; | |
744 | ||
745 | /* | |
746 | * Now find a thread we can wake up to take the signal off the queue. | |
747 | * | |
748 | * If the main thread wants the signal, it gets first crack. | |
749 | * Probably the least surprising to the average bear. | |
750 | */ | |
751 | if (wants_signal(sig, p)) | |
752 | t = p; | |
5fcd835b | 753 | else if (!group || thread_group_empty(p)) |
71f11dc0 ON |
754 | /* |
755 | * There is just one thread and it does not need to be woken. | |
756 | * It will dequeue unblocked signals before it runs again. | |
757 | */ | |
758 | return; | |
759 | else { | |
760 | /* | |
761 | * Otherwise try to find a suitable thread. | |
762 | */ | |
763 | t = signal->curr_target; | |
764 | while (!wants_signal(sig, t)) { | |
765 | t = next_thread(t); | |
766 | if (t == signal->curr_target) | |
767 | /* | |
768 | * No thread needs to be woken. | |
769 | * Any eligible threads will see | |
770 | * the signal in the queue soon. | |
771 | */ | |
772 | return; | |
773 | } | |
774 | signal->curr_target = t; | |
775 | } | |
776 | ||
777 | /* | |
778 | * Found a killable thread. If the signal will be fatal, | |
779 | * then start taking the whole group down immediately. | |
780 | */ | |
fae5fa44 ON |
781 | if (sig_fatal(p, sig) && |
782 | !(signal->flags & (SIGNAL_UNKILLABLE | SIGNAL_GROUP_EXIT)) && | |
71f11dc0 | 783 | !sigismember(&t->real_blocked, sig) && |
445a91d2 RM |
784 | (sig == SIGKILL || |
785 | !tracehook_consider_fatal_signal(t, sig, SIG_DFL))) { | |
71f11dc0 ON |
786 | /* |
787 | * This signal will be fatal to the whole group. | |
788 | */ | |
789 | if (!sig_kernel_coredump(sig)) { | |
790 | /* | |
791 | * Start a group exit and wake everybody up. | |
792 | * This way we don't have other threads | |
793 | * running and doing things after a slower | |
794 | * thread has the fatal signal pending. | |
795 | */ | |
796 | signal->flags = SIGNAL_GROUP_EXIT; | |
797 | signal->group_exit_code = sig; | |
798 | signal->group_stop_count = 0; | |
799 | t = p; | |
800 | do { | |
801 | sigaddset(&t->pending.signal, SIGKILL); | |
802 | signal_wake_up(t, 1); | |
803 | } while_each_thread(p, t); | |
804 | return; | |
805 | } | |
806 | } | |
807 | ||
808 | /* | |
809 | * The signal is already in the shared-pending queue. | |
810 | * Tell the chosen thread to wake up and dequeue it. | |
811 | */ | |
812 | signal_wake_up(t, sig == SIGKILL); | |
813 | return; | |
814 | } | |
815 | ||
af7fff9c PE |
816 | static inline int legacy_queue(struct sigpending *signals, int sig) |
817 | { | |
818 | return (sig < SIGRTMIN) && sigismember(&signals->signal, sig); | |
819 | } | |
820 | ||
1da177e4 | 821 | static int send_signal(int sig, struct siginfo *info, struct task_struct *t, |
2ca3515a | 822 | int group) |
1da177e4 | 823 | { |
2ca3515a | 824 | struct sigpending *pending; |
6e65acba | 825 | struct sigqueue *q; |
1da177e4 | 826 | |
0a16b607 MD |
827 | trace_sched_signal_send(sig, t); |
828 | ||
6e65acba | 829 | assert_spin_locked(&t->sighand->siglock); |
7e695a5e ON |
830 | if (!prepare_signal(sig, t)) |
831 | return 0; | |
2ca3515a ON |
832 | |
833 | pending = group ? &t->signal->shared_pending : &t->pending; | |
2acb024d PE |
834 | /* |
835 | * Short-circuit ignored signals and support queuing | |
836 | * exactly one non-rt signal, so that we can get more | |
837 | * detailed information about the cause of the signal. | |
838 | */ | |
7e695a5e | 839 | if (legacy_queue(pending, sig)) |
2acb024d | 840 | return 0; |
1da177e4 LT |
841 | /* |
842 | * fast-pathed signals for kernel-internal things like SIGSTOP | |
843 | * or SIGKILL. | |
844 | */ | |
b67a1b9e | 845 | if (info == SEND_SIG_FORCED) |
1da177e4 LT |
846 | goto out_set; |
847 | ||
848 | /* Real-time signals must be queued if sent by sigqueue, or | |
849 | some other real-time mechanism. It is implementation | |
850 | defined whether kill() does so. We attempt to do so, on | |
851 | the principle of least surprise, but since kill is not | |
852 | allowed to fail with EAGAIN when low on memory we just | |
853 | make sure at least one signal gets delivered and don't | |
854 | pass on the info struct. */ | |
855 | ||
856 | q = __sigqueue_alloc(t, GFP_ATOMIC, (sig < SIGRTMIN && | |
621d3121 | 857 | (is_si_special(info) || |
1da177e4 LT |
858 | info->si_code >= 0))); |
859 | if (q) { | |
2ca3515a | 860 | list_add_tail(&q->list, &pending->list); |
1da177e4 | 861 | switch ((unsigned long) info) { |
b67a1b9e | 862 | case (unsigned long) SEND_SIG_NOINFO: |
1da177e4 LT |
863 | q->info.si_signo = sig; |
864 | q->info.si_errno = 0; | |
865 | q->info.si_code = SI_USER; | |
9cd4fd10 | 866 | q->info.si_pid = task_tgid_nr_ns(current, |
09bca05c | 867 | task_active_pid_ns(t)); |
76aac0e9 | 868 | q->info.si_uid = current_uid(); |
1da177e4 | 869 | break; |
b67a1b9e | 870 | case (unsigned long) SEND_SIG_PRIV: |
1da177e4 LT |
871 | q->info.si_signo = sig; |
872 | q->info.si_errno = 0; | |
873 | q->info.si_code = SI_KERNEL; | |
874 | q->info.si_pid = 0; | |
875 | q->info.si_uid = 0; | |
876 | break; | |
877 | default: | |
878 | copy_siginfo(&q->info, info); | |
879 | break; | |
880 | } | |
621d3121 ON |
881 | } else if (!is_si_special(info)) { |
882 | if (sig >= SIGRTMIN && info->si_code != SI_USER) | |
1da177e4 LT |
883 | /* |
884 | * Queue overflow, abort. We may abort if the signal was rt | |
885 | * and sent by user using something other than kill(). | |
886 | */ | |
887 | return -EAGAIN; | |
1da177e4 LT |
888 | } |
889 | ||
890 | out_set: | |
53c30337 | 891 | signalfd_notify(t, sig); |
2ca3515a | 892 | sigaddset(&pending->signal, sig); |
4cd4b6d4 PE |
893 | complete_signal(sig, t, group); |
894 | return 0; | |
1da177e4 LT |
895 | } |
896 | ||
45807a1d IM |
897 | int print_fatal_signals; |
898 | ||
899 | static void print_fatal_signal(struct pt_regs *regs, int signr) | |
900 | { | |
901 | printk("%s/%d: potentially unexpected fatal signal %d.\n", | |
ba25f9dc | 902 | current->comm, task_pid_nr(current), signr); |
45807a1d | 903 | |
ca5cd877 | 904 | #if defined(__i386__) && !defined(__arch_um__) |
65ea5b03 | 905 | printk("code at %08lx: ", regs->ip); |
45807a1d IM |
906 | { |
907 | int i; | |
908 | for (i = 0; i < 16; i++) { | |
909 | unsigned char insn; | |
910 | ||
65ea5b03 | 911 | __get_user(insn, (unsigned char *)(regs->ip + i)); |
45807a1d IM |
912 | printk("%02x ", insn); |
913 | } | |
914 | } | |
915 | #endif | |
916 | printk("\n"); | |
3a9f84d3 | 917 | preempt_disable(); |
45807a1d | 918 | show_regs(regs); |
3a9f84d3 | 919 | preempt_enable(); |
45807a1d IM |
920 | } |
921 | ||
922 | static int __init setup_print_fatal_signals(char *str) | |
923 | { | |
924 | get_option (&str, &print_fatal_signals); | |
925 | ||
926 | return 1; | |
927 | } | |
928 | ||
929 | __setup("print-fatal-signals=", setup_print_fatal_signals); | |
1da177e4 | 930 | |
4cd4b6d4 PE |
931 | int |
932 | __group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) | |
933 | { | |
934 | return send_signal(sig, info, p, 1); | |
935 | } | |
936 | ||
1da177e4 LT |
937 | static int |
938 | specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t) | |
939 | { | |
4cd4b6d4 | 940 | return send_signal(sig, info, t, 0); |
1da177e4 LT |
941 | } |
942 | ||
943 | /* | |
944 | * Force a signal that the process can't ignore: if necessary | |
945 | * we unblock the signal and change any SIG_IGN to SIG_DFL. | |
ae74c3b6 LT |
946 | * |
947 | * Note: If we unblock the signal, we always reset it to SIG_DFL, | |
948 | * since we do not want to have a signal handler that was blocked | |
949 | * be invoked when user space had explicitly blocked it. | |
950 | * | |
80fe728d ON |
951 | * We don't want to have recursive SIGSEGV's etc, for example, |
952 | * that is why we also clear SIGNAL_UNKILLABLE. | |
1da177e4 | 953 | */ |
1da177e4 LT |
954 | int |
955 | force_sig_info(int sig, struct siginfo *info, struct task_struct *t) | |
956 | { | |
957 | unsigned long int flags; | |
ae74c3b6 LT |
958 | int ret, blocked, ignored; |
959 | struct k_sigaction *action; | |
1da177e4 LT |
960 | |
961 | spin_lock_irqsave(&t->sighand->siglock, flags); | |
ae74c3b6 LT |
962 | action = &t->sighand->action[sig-1]; |
963 | ignored = action->sa.sa_handler == SIG_IGN; | |
964 | blocked = sigismember(&t->blocked, sig); | |
965 | if (blocked || ignored) { | |
966 | action->sa.sa_handler = SIG_DFL; | |
967 | if (blocked) { | |
968 | sigdelset(&t->blocked, sig); | |
7bb44ade | 969 | recalc_sigpending_and_wake(t); |
ae74c3b6 | 970 | } |
1da177e4 | 971 | } |
80fe728d ON |
972 | if (action->sa.sa_handler == SIG_DFL) |
973 | t->signal->flags &= ~SIGNAL_UNKILLABLE; | |
1da177e4 LT |
974 | ret = specific_send_sig_info(sig, info, t); |
975 | spin_unlock_irqrestore(&t->sighand->siglock, flags); | |
976 | ||
977 | return ret; | |
978 | } | |
979 | ||
980 | void | |
981 | force_sig_specific(int sig, struct task_struct *t) | |
982 | { | |
b0423a0d | 983 | force_sig_info(sig, SEND_SIG_FORCED, t); |
1da177e4 LT |
984 | } |
985 | ||
1da177e4 LT |
986 | /* |
987 | * Nuke all other threads in the group. | |
988 | */ | |
989 | void zap_other_threads(struct task_struct *p) | |
990 | { | |
991 | struct task_struct *t; | |
992 | ||
1da177e4 LT |
993 | p->signal->group_stop_count = 0; |
994 | ||
1da177e4 LT |
995 | for (t = next_thread(p); t != p; t = next_thread(t)) { |
996 | /* | |
997 | * Don't bother with already dead threads | |
998 | */ | |
999 | if (t->exit_state) | |
1000 | continue; | |
1001 | ||
30e0fca6 | 1002 | /* SIGKILL will be handled before any pending SIGSTOP */ |
1da177e4 | 1003 | sigaddset(&t->pending.signal, SIGKILL); |
1da177e4 LT |
1004 | signal_wake_up(t, 1); |
1005 | } | |
1006 | } | |
1007 | ||
b5606c2d | 1008 | int __fatal_signal_pending(struct task_struct *tsk) |
f776d12d MW |
1009 | { |
1010 | return sigismember(&tsk->pending.signal, SIGKILL); | |
1011 | } | |
13f09b95 | 1012 | EXPORT_SYMBOL(__fatal_signal_pending); |
f776d12d | 1013 | |
f63ee72e ON |
1014 | struct sighand_struct *lock_task_sighand(struct task_struct *tsk, unsigned long *flags) |
1015 | { | |
1016 | struct sighand_struct *sighand; | |
1017 | ||
1406f2d3 | 1018 | rcu_read_lock(); |
f63ee72e ON |
1019 | for (;;) { |
1020 | sighand = rcu_dereference(tsk->sighand); | |
1021 | if (unlikely(sighand == NULL)) | |
1022 | break; | |
1023 | ||
1024 | spin_lock_irqsave(&sighand->siglock, *flags); | |
1025 | if (likely(sighand == tsk->sighand)) | |
1026 | break; | |
1027 | spin_unlock_irqrestore(&sighand->siglock, *flags); | |
1028 | } | |
1406f2d3 | 1029 | rcu_read_unlock(); |
f63ee72e ON |
1030 | |
1031 | return sighand; | |
1032 | } | |
1033 | ||
c69e8d9c DH |
1034 | /* |
1035 | * send signal info to all the members of a group | |
1036 | * - the caller must hold the RCU read lock at least | |
1037 | */ | |
1da177e4 LT |
1038 | int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) |
1039 | { | |
1040 | unsigned long flags; | |
1041 | int ret; | |
1042 | ||
1043 | ret = check_kill_permission(sig, info, p); | |
f63ee72e ON |
1044 | |
1045 | if (!ret && sig) { | |
1046 | ret = -ESRCH; | |
1047 | if (lock_task_sighand(p, &flags)) { | |
1048 | ret = __group_send_sig_info(sig, info, p); | |
1049 | unlock_task_sighand(p, &flags); | |
2d89c929 | 1050 | } |
1da177e4 LT |
1051 | } |
1052 | ||
1053 | return ret; | |
1054 | } | |
1055 | ||
1056 | /* | |
146a505d | 1057 | * __kill_pgrp_info() sends a signal to a process group: this is what the tty |
1da177e4 | 1058 | * control characters do (^C, ^Z etc) |
c69e8d9c | 1059 | * - the caller must hold at least a readlock on tasklist_lock |
1da177e4 | 1060 | */ |
c4b92fc1 | 1061 | int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp) |
1da177e4 LT |
1062 | { |
1063 | struct task_struct *p = NULL; | |
1064 | int retval, success; | |
1065 | ||
1da177e4 LT |
1066 | success = 0; |
1067 | retval = -ESRCH; | |
c4b92fc1 | 1068 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
1da177e4 LT |
1069 | int err = group_send_sig_info(sig, info, p); |
1070 | success |= !err; | |
1071 | retval = err; | |
c4b92fc1 | 1072 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
1da177e4 LT |
1073 | return success ? 0 : retval; |
1074 | } | |
1075 | ||
c4b92fc1 | 1076 | int kill_pid_info(int sig, struct siginfo *info, struct pid *pid) |
1da177e4 | 1077 | { |
d36174bc | 1078 | int error = -ESRCH; |
1da177e4 LT |
1079 | struct task_struct *p; |
1080 | ||
e56d0903 | 1081 | rcu_read_lock(); |
d36174bc | 1082 | retry: |
c4b92fc1 | 1083 | p = pid_task(pid, PIDTYPE_PID); |
d36174bc | 1084 | if (p) { |
1da177e4 | 1085 | error = group_send_sig_info(sig, info, p); |
d36174bc ON |
1086 | if (unlikely(error == -ESRCH)) |
1087 | /* | |
1088 | * The task was unhashed in between, try again. | |
1089 | * If it is dead, pid_task() will return NULL, | |
1090 | * if we race with de_thread() it will find the | |
1091 | * new leader. | |
1092 | */ | |
1093 | goto retry; | |
1094 | } | |
e56d0903 | 1095 | rcu_read_unlock(); |
6ca25b55 | 1096 | |
1da177e4 LT |
1097 | return error; |
1098 | } | |
1099 | ||
c3de4b38 MW |
1100 | int |
1101 | kill_proc_info(int sig, struct siginfo *info, pid_t pid) | |
c4b92fc1 EB |
1102 | { |
1103 | int error; | |
1104 | rcu_read_lock(); | |
b488893a | 1105 | error = kill_pid_info(sig, info, find_vpid(pid)); |
c4b92fc1 EB |
1106 | rcu_read_unlock(); |
1107 | return error; | |
1108 | } | |
1109 | ||
2425c08b EB |
1110 | /* like kill_pid_info(), but doesn't use uid/euid of "current" */ |
1111 | int kill_pid_info_as_uid(int sig, struct siginfo *info, struct pid *pid, | |
8f95dc58 | 1112 | uid_t uid, uid_t euid, u32 secid) |
46113830 HW |
1113 | { |
1114 | int ret = -EINVAL; | |
1115 | struct task_struct *p; | |
c69e8d9c | 1116 | const struct cred *pcred; |
46113830 HW |
1117 | |
1118 | if (!valid_signal(sig)) | |
1119 | return ret; | |
1120 | ||
1121 | read_lock(&tasklist_lock); | |
2425c08b | 1122 | p = pid_task(pid, PIDTYPE_PID); |
46113830 HW |
1123 | if (!p) { |
1124 | ret = -ESRCH; | |
1125 | goto out_unlock; | |
1126 | } | |
c69e8d9c DH |
1127 | pcred = __task_cred(p); |
1128 | if ((info == SEND_SIG_NOINFO || | |
1129 | (!is_si_special(info) && SI_FROMUSER(info))) && | |
1130 | euid != pcred->suid && euid != pcred->uid && | |
1131 | uid != pcred->suid && uid != pcred->uid) { | |
46113830 HW |
1132 | ret = -EPERM; |
1133 | goto out_unlock; | |
1134 | } | |
8f95dc58 DQ |
1135 | ret = security_task_kill(p, info, sig, secid); |
1136 | if (ret) | |
1137 | goto out_unlock; | |
46113830 HW |
1138 | if (sig && p->sighand) { |
1139 | unsigned long flags; | |
1140 | spin_lock_irqsave(&p->sighand->siglock, flags); | |
1141 | ret = __group_send_sig_info(sig, info, p); | |
1142 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | |
1143 | } | |
1144 | out_unlock: | |
1145 | read_unlock(&tasklist_lock); | |
1146 | return ret; | |
1147 | } | |
2425c08b | 1148 | EXPORT_SYMBOL_GPL(kill_pid_info_as_uid); |
1da177e4 LT |
1149 | |
1150 | /* | |
1151 | * kill_something_info() interprets pid in interesting ways just like kill(2). | |
1152 | * | |
1153 | * POSIX specifies that kill(-1,sig) is unspecified, but what we have | |
1154 | * is probably wrong. Should make it like BSD or SYSV. | |
1155 | */ | |
1156 | ||
bc64efd2 | 1157 | static int kill_something_info(int sig, struct siginfo *info, pid_t pid) |
1da177e4 | 1158 | { |
8d42db18 | 1159 | int ret; |
d5df763b PE |
1160 | |
1161 | if (pid > 0) { | |
1162 | rcu_read_lock(); | |
1163 | ret = kill_pid_info(sig, info, find_vpid(pid)); | |
1164 | rcu_read_unlock(); | |
1165 | return ret; | |
1166 | } | |
1167 | ||
1168 | read_lock(&tasklist_lock); | |
1169 | if (pid != -1) { | |
1170 | ret = __kill_pgrp_info(sig, info, | |
1171 | pid ? find_vpid(-pid) : task_pgrp(current)); | |
1172 | } else { | |
1da177e4 LT |
1173 | int retval = 0, count = 0; |
1174 | struct task_struct * p; | |
1175 | ||
1da177e4 | 1176 | for_each_process(p) { |
d25141a8 SB |
1177 | if (task_pid_vnr(p) > 1 && |
1178 | !same_thread_group(p, current)) { | |
1da177e4 LT |
1179 | int err = group_send_sig_info(sig, info, p); |
1180 | ++count; | |
1181 | if (err != -EPERM) | |
1182 | retval = err; | |
1183 | } | |
1184 | } | |
8d42db18 | 1185 | ret = count ? retval : -ESRCH; |
1da177e4 | 1186 | } |
d5df763b PE |
1187 | read_unlock(&tasklist_lock); |
1188 | ||
8d42db18 | 1189 | return ret; |
1da177e4 LT |
1190 | } |
1191 | ||
1192 | /* | |
1193 | * These are for backward compatibility with the rest of the kernel source. | |
1194 | */ | |
1195 | ||
1196 | /* | |
08d2c30c | 1197 | * The caller must ensure the task can't exit. |
1da177e4 LT |
1198 | */ |
1199 | int | |
1200 | send_sig_info(int sig, struct siginfo *info, struct task_struct *p) | |
1201 | { | |
1202 | int ret; | |
1203 | unsigned long flags; | |
1204 | ||
1205 | /* | |
1206 | * Make sure legacy kernel users don't send in bad values | |
1207 | * (normal paths check this in check_kill_permission). | |
1208 | */ | |
7ed20e1a | 1209 | if (!valid_signal(sig)) |
1da177e4 LT |
1210 | return -EINVAL; |
1211 | ||
1da177e4 LT |
1212 | spin_lock_irqsave(&p->sighand->siglock, flags); |
1213 | ret = specific_send_sig_info(sig, info, p); | |
1214 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | |
1da177e4 LT |
1215 | return ret; |
1216 | } | |
1217 | ||
b67a1b9e ON |
1218 | #define __si_special(priv) \ |
1219 | ((priv) ? SEND_SIG_PRIV : SEND_SIG_NOINFO) | |
1220 | ||
1da177e4 LT |
1221 | int |
1222 | send_sig(int sig, struct task_struct *p, int priv) | |
1223 | { | |
b67a1b9e | 1224 | return send_sig_info(sig, __si_special(priv), p); |
1da177e4 LT |
1225 | } |
1226 | ||
1da177e4 LT |
1227 | void |
1228 | force_sig(int sig, struct task_struct *p) | |
1229 | { | |
b67a1b9e | 1230 | force_sig_info(sig, SEND_SIG_PRIV, p); |
1da177e4 LT |
1231 | } |
1232 | ||
1233 | /* | |
1234 | * When things go south during signal handling, we | |
1235 | * will force a SIGSEGV. And if the signal that caused | |
1236 | * the problem was already a SIGSEGV, we'll want to | |
1237 | * make sure we don't even try to deliver the signal.. | |
1238 | */ | |
1239 | int | |
1240 | force_sigsegv(int sig, struct task_struct *p) | |
1241 | { | |
1242 | if (sig == SIGSEGV) { | |
1243 | unsigned long flags; | |
1244 | spin_lock_irqsave(&p->sighand->siglock, flags); | |
1245 | p->sighand->action[sig - 1].sa.sa_handler = SIG_DFL; | |
1246 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | |
1247 | } | |
1248 | force_sig(SIGSEGV, p); | |
1249 | return 0; | |
1250 | } | |
1251 | ||
c4b92fc1 EB |
1252 | int kill_pgrp(struct pid *pid, int sig, int priv) |
1253 | { | |
146a505d PE |
1254 | int ret; |
1255 | ||
1256 | read_lock(&tasklist_lock); | |
1257 | ret = __kill_pgrp_info(sig, __si_special(priv), pid); | |
1258 | read_unlock(&tasklist_lock); | |
1259 | ||
1260 | return ret; | |
c4b92fc1 EB |
1261 | } |
1262 | EXPORT_SYMBOL(kill_pgrp); | |
1263 | ||
1264 | int kill_pid(struct pid *pid, int sig, int priv) | |
1265 | { | |
1266 | return kill_pid_info(sig, __si_special(priv), pid); | |
1267 | } | |
1268 | EXPORT_SYMBOL(kill_pid); | |
1269 | ||
1da177e4 LT |
1270 | /* |
1271 | * These functions support sending signals using preallocated sigqueue | |
1272 | * structures. This is needed "because realtime applications cannot | |
1273 | * afford to lose notifications of asynchronous events, like timer | |
1274 | * expirations or I/O completions". In the case of Posix Timers | |
1275 | * we allocate the sigqueue structure from the timer_create. If this | |
1276 | * allocation fails we are able to report the failure to the application | |
1277 | * with an EAGAIN error. | |
1278 | */ | |
1279 | ||
1280 | struct sigqueue *sigqueue_alloc(void) | |
1281 | { | |
1282 | struct sigqueue *q; | |
1283 | ||
1284 | if ((q = __sigqueue_alloc(current, GFP_KERNEL, 0))) | |
1285 | q->flags |= SIGQUEUE_PREALLOC; | |
1286 | return(q); | |
1287 | } | |
1288 | ||
1289 | void sigqueue_free(struct sigqueue *q) | |
1290 | { | |
1291 | unsigned long flags; | |
60187d27 ON |
1292 | spinlock_t *lock = ¤t->sighand->siglock; |
1293 | ||
1da177e4 LT |
1294 | BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); |
1295 | /* | |
c8e85b4f ON |
1296 | * We must hold ->siglock while testing q->list |
1297 | * to serialize with collect_signal() or with | |
da7978b0 | 1298 | * __exit_signal()->flush_sigqueue(). |
1da177e4 | 1299 | */ |
60187d27 | 1300 | spin_lock_irqsave(lock, flags); |
c8e85b4f ON |
1301 | q->flags &= ~SIGQUEUE_PREALLOC; |
1302 | /* | |
1303 | * If it is queued it will be freed when dequeued, | |
1304 | * like the "regular" sigqueue. | |
1305 | */ | |
60187d27 | 1306 | if (!list_empty(&q->list)) |
c8e85b4f | 1307 | q = NULL; |
60187d27 ON |
1308 | spin_unlock_irqrestore(lock, flags); |
1309 | ||
c8e85b4f ON |
1310 | if (q) |
1311 | __sigqueue_free(q); | |
1da177e4 LT |
1312 | } |
1313 | ||
ac5c2153 | 1314 | int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group) |
9e3bd6c3 | 1315 | { |
e62e6650 | 1316 | int sig = q->info.si_signo; |
2ca3515a | 1317 | struct sigpending *pending; |
e62e6650 ON |
1318 | unsigned long flags; |
1319 | int ret; | |
2ca3515a | 1320 | |
4cd4b6d4 | 1321 | BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); |
e62e6650 ON |
1322 | |
1323 | ret = -1; | |
1324 | if (!likely(lock_task_sighand(t, &flags))) | |
1325 | goto ret; | |
1326 | ||
7e695a5e ON |
1327 | ret = 1; /* the signal is ignored */ |
1328 | if (!prepare_signal(sig, t)) | |
e62e6650 ON |
1329 | goto out; |
1330 | ||
1331 | ret = 0; | |
9e3bd6c3 PE |
1332 | if (unlikely(!list_empty(&q->list))) { |
1333 | /* | |
1334 | * If an SI_TIMER entry is already queue just increment | |
1335 | * the overrun count. | |
1336 | */ | |
9e3bd6c3 PE |
1337 | BUG_ON(q->info.si_code != SI_TIMER); |
1338 | q->info.si_overrun++; | |
e62e6650 | 1339 | goto out; |
9e3bd6c3 | 1340 | } |
ba661292 | 1341 | q->info.si_overrun = 0; |
9e3bd6c3 | 1342 | |
9e3bd6c3 | 1343 | signalfd_notify(t, sig); |
2ca3515a | 1344 | pending = group ? &t->signal->shared_pending : &t->pending; |
9e3bd6c3 PE |
1345 | list_add_tail(&q->list, &pending->list); |
1346 | sigaddset(&pending->signal, sig); | |
4cd4b6d4 | 1347 | complete_signal(sig, t, group); |
e62e6650 ON |
1348 | out: |
1349 | unlock_task_sighand(t, &flags); | |
1350 | ret: | |
1351 | return ret; | |
9e3bd6c3 PE |
1352 | } |
1353 | ||
1da177e4 LT |
1354 | /* |
1355 | * Wake up any threads in the parent blocked in wait* syscalls. | |
1356 | */ | |
1357 | static inline void __wake_up_parent(struct task_struct *p, | |
1358 | struct task_struct *parent) | |
1359 | { | |
1360 | wake_up_interruptible_sync(&parent->signal->wait_chldexit); | |
1361 | } | |
1362 | ||
1363 | /* | |
1364 | * Let a parent know about the death of a child. | |
1365 | * For a stopped/continued status change, use do_notify_parent_cldstop instead. | |
2b2a1ff6 RM |
1366 | * |
1367 | * Returns -1 if our parent ignored us and so we've switched to | |
1368 | * self-reaping, or else @sig. | |
1da177e4 | 1369 | */ |
2b2a1ff6 | 1370 | int do_notify_parent(struct task_struct *tsk, int sig) |
1da177e4 LT |
1371 | { |
1372 | struct siginfo info; | |
1373 | unsigned long flags; | |
1374 | struct sighand_struct *psig; | |
1b04624f | 1375 | int ret = sig; |
1da177e4 LT |
1376 | |
1377 | BUG_ON(sig == -1); | |
1378 | ||
1379 | /* do_notify_parent_cldstop should have been called instead. */ | |
e1abb39c | 1380 | BUG_ON(task_is_stopped_or_traced(tsk)); |
1da177e4 LT |
1381 | |
1382 | BUG_ON(!tsk->ptrace && | |
1383 | (tsk->group_leader != tsk || !thread_group_empty(tsk))); | |
1384 | ||
1385 | info.si_signo = sig; | |
1386 | info.si_errno = 0; | |
b488893a PE |
1387 | /* |
1388 | * we are under tasklist_lock here so our parent is tied to | |
1389 | * us and cannot exit and release its namespace. | |
1390 | * | |
1391 | * the only it can is to switch its nsproxy with sys_unshare, | |
1392 | * bu uncharing pid namespaces is not allowed, so we'll always | |
1393 | * see relevant namespace | |
1394 | * | |
1395 | * write_lock() currently calls preempt_disable() which is the | |
1396 | * same as rcu_read_lock(), but according to Oleg, this is not | |
1397 | * correct to rely on this | |
1398 | */ | |
1399 | rcu_read_lock(); | |
1400 | info.si_pid = task_pid_nr_ns(tsk, tsk->parent->nsproxy->pid_ns); | |
c69e8d9c | 1401 | info.si_uid = __task_cred(tsk)->uid; |
b488893a PE |
1402 | rcu_read_unlock(); |
1403 | ||
32bd671d PZ |
1404 | info.si_utime = cputime_to_clock_t(cputime_add(tsk->utime, |
1405 | tsk->signal->utime)); | |
1406 | info.si_stime = cputime_to_clock_t(cputime_add(tsk->stime, | |
1407 | tsk->signal->stime)); | |
1da177e4 LT |
1408 | |
1409 | info.si_status = tsk->exit_code & 0x7f; | |
1410 | if (tsk->exit_code & 0x80) | |
1411 | info.si_code = CLD_DUMPED; | |
1412 | else if (tsk->exit_code & 0x7f) | |
1413 | info.si_code = CLD_KILLED; | |
1414 | else { | |
1415 | info.si_code = CLD_EXITED; | |
1416 | info.si_status = tsk->exit_code >> 8; | |
1417 | } | |
1418 | ||
1419 | psig = tsk->parent->sighand; | |
1420 | spin_lock_irqsave(&psig->siglock, flags); | |
7ed0175a | 1421 | if (!tsk->ptrace && sig == SIGCHLD && |
1da177e4 LT |
1422 | (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN || |
1423 | (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT))) { | |
1424 | /* | |
1425 | * We are exiting and our parent doesn't care. POSIX.1 | |
1426 | * defines special semantics for setting SIGCHLD to SIG_IGN | |
1427 | * or setting the SA_NOCLDWAIT flag: we should be reaped | |
1428 | * automatically and not left for our parent's wait4 call. | |
1429 | * Rather than having the parent do it as a magic kind of | |
1430 | * signal handler, we just set this to tell do_exit that we | |
1431 | * can be cleaned up without becoming a zombie. Note that | |
1432 | * we still call __wake_up_parent in this case, because a | |
1433 | * blocked sys_wait4 might now return -ECHILD. | |
1434 | * | |
1435 | * Whether we send SIGCHLD or not for SA_NOCLDWAIT | |
1436 | * is implementation-defined: we do (if you don't want | |
1437 | * it, just use SIG_IGN instead). | |
1438 | */ | |
1b04624f | 1439 | ret = tsk->exit_signal = -1; |
1da177e4 | 1440 | if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) |
2b2a1ff6 | 1441 | sig = -1; |
1da177e4 | 1442 | } |
7ed20e1a | 1443 | if (valid_signal(sig) && sig > 0) |
1da177e4 LT |
1444 | __group_send_sig_info(sig, &info, tsk->parent); |
1445 | __wake_up_parent(tsk, tsk->parent); | |
1446 | spin_unlock_irqrestore(&psig->siglock, flags); | |
2b2a1ff6 | 1447 | |
1b04624f | 1448 | return ret; |
1da177e4 LT |
1449 | } |
1450 | ||
a1d5e21e | 1451 | static void do_notify_parent_cldstop(struct task_struct *tsk, int why) |
1da177e4 LT |
1452 | { |
1453 | struct siginfo info; | |
1454 | unsigned long flags; | |
bc505a47 | 1455 | struct task_struct *parent; |
1da177e4 LT |
1456 | struct sighand_struct *sighand; |
1457 | ||
a1d5e21e | 1458 | if (tsk->ptrace & PT_PTRACED) |
bc505a47 ON |
1459 | parent = tsk->parent; |
1460 | else { | |
1461 | tsk = tsk->group_leader; | |
1462 | parent = tsk->real_parent; | |
1463 | } | |
1464 | ||
1da177e4 LT |
1465 | info.si_signo = SIGCHLD; |
1466 | info.si_errno = 0; | |
b488893a PE |
1467 | /* |
1468 | * see comment in do_notify_parent() abot the following 3 lines | |
1469 | */ | |
1470 | rcu_read_lock(); | |
1471 | info.si_pid = task_pid_nr_ns(tsk, tsk->parent->nsproxy->pid_ns); | |
c69e8d9c | 1472 | info.si_uid = __task_cred(tsk)->uid; |
b488893a PE |
1473 | rcu_read_unlock(); |
1474 | ||
d8878ba3 MK |
1475 | info.si_utime = cputime_to_clock_t(tsk->utime); |
1476 | info.si_stime = cputime_to_clock_t(tsk->stime); | |
1da177e4 LT |
1477 | |
1478 | info.si_code = why; | |
1479 | switch (why) { | |
1480 | case CLD_CONTINUED: | |
1481 | info.si_status = SIGCONT; | |
1482 | break; | |
1483 | case CLD_STOPPED: | |
1484 | info.si_status = tsk->signal->group_exit_code & 0x7f; | |
1485 | break; | |
1486 | case CLD_TRAPPED: | |
1487 | info.si_status = tsk->exit_code & 0x7f; | |
1488 | break; | |
1489 | default: | |
1490 | BUG(); | |
1491 | } | |
1492 | ||
1493 | sighand = parent->sighand; | |
1494 | spin_lock_irqsave(&sighand->siglock, flags); | |
1495 | if (sighand->action[SIGCHLD-1].sa.sa_handler != SIG_IGN && | |
1496 | !(sighand->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDSTOP)) | |
1497 | __group_send_sig_info(SIGCHLD, &info, parent); | |
1498 | /* | |
1499 | * Even if SIGCHLD is not generated, we must wake up wait4 calls. | |
1500 | */ | |
1501 | __wake_up_parent(tsk, parent); | |
1502 | spin_unlock_irqrestore(&sighand->siglock, flags); | |
1503 | } | |
1504 | ||
d5f70c00 ON |
1505 | static inline int may_ptrace_stop(void) |
1506 | { | |
1507 | if (!likely(current->ptrace & PT_PTRACED)) | |
1508 | return 0; | |
d5f70c00 ON |
1509 | /* |
1510 | * Are we in the middle of do_coredump? | |
1511 | * If so and our tracer is also part of the coredump stopping | |
1512 | * is a deadlock situation, and pointless because our tracer | |
1513 | * is dead so don't allow us to stop. | |
1514 | * If SIGKILL was already sent before the caller unlocked | |
999d9fc1 | 1515 | * ->siglock we must see ->core_state != NULL. Otherwise it |
d5f70c00 ON |
1516 | * is safe to enter schedule(). |
1517 | */ | |
999d9fc1 | 1518 | if (unlikely(current->mm->core_state) && |
d5f70c00 ON |
1519 | unlikely(current->mm == current->parent->mm)) |
1520 | return 0; | |
1521 | ||
1522 | return 1; | |
1523 | } | |
1524 | ||
1a669c2f RM |
1525 | /* |
1526 | * Return nonzero if there is a SIGKILL that should be waking us up. | |
1527 | * Called with the siglock held. | |
1528 | */ | |
1529 | static int sigkill_pending(struct task_struct *tsk) | |
1530 | { | |
3d749b9e ON |
1531 | return sigismember(&tsk->pending.signal, SIGKILL) || |
1532 | sigismember(&tsk->signal->shared_pending.signal, SIGKILL); | |
1a669c2f RM |
1533 | } |
1534 | ||
1da177e4 LT |
1535 | /* |
1536 | * This must be called with current->sighand->siglock held. | |
1537 | * | |
1538 | * This should be the path for all ptrace stops. | |
1539 | * We always set current->last_siginfo while stopped here. | |
1540 | * That makes it a way to test a stopped process for | |
1541 | * being ptrace-stopped vs being job-control-stopped. | |
1542 | * | |
20686a30 ON |
1543 | * If we actually decide not to stop at all because the tracer |
1544 | * is gone, we keep current->exit_code unless clear_code. | |
1da177e4 | 1545 | */ |
20686a30 | 1546 | static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info) |
1da177e4 | 1547 | { |
1a669c2f RM |
1548 | if (arch_ptrace_stop_needed(exit_code, info)) { |
1549 | /* | |
1550 | * The arch code has something special to do before a | |
1551 | * ptrace stop. This is allowed to block, e.g. for faults | |
1552 | * on user stack pages. We can't keep the siglock while | |
1553 | * calling arch_ptrace_stop, so we must release it now. | |
1554 | * To preserve proper semantics, we must do this before | |
1555 | * any signal bookkeeping like checking group_stop_count. | |
1556 | * Meanwhile, a SIGKILL could come in before we retake the | |
1557 | * siglock. That must prevent us from sleeping in TASK_TRACED. | |
1558 | * So after regaining the lock, we must check for SIGKILL. | |
1559 | */ | |
1560 | spin_unlock_irq(¤t->sighand->siglock); | |
1561 | arch_ptrace_stop(exit_code, info); | |
1562 | spin_lock_irq(¤t->sighand->siglock); | |
3d749b9e ON |
1563 | if (sigkill_pending(current)) |
1564 | return; | |
1a669c2f RM |
1565 | } |
1566 | ||
1da177e4 LT |
1567 | /* |
1568 | * If there is a group stop in progress, | |
1569 | * we must participate in the bookkeeping. | |
1570 | */ | |
1571 | if (current->signal->group_stop_count > 0) | |
1572 | --current->signal->group_stop_count; | |
1573 | ||
1574 | current->last_siginfo = info; | |
1575 | current->exit_code = exit_code; | |
1576 | ||
1577 | /* Let the debugger run. */ | |
d9ae90ac | 1578 | __set_current_state(TASK_TRACED); |
1da177e4 LT |
1579 | spin_unlock_irq(¤t->sighand->siglock); |
1580 | read_lock(&tasklist_lock); | |
3d749b9e | 1581 | if (may_ptrace_stop()) { |
a1d5e21e | 1582 | do_notify_parent_cldstop(current, CLD_TRAPPED); |
53da1d94 MS |
1583 | /* |
1584 | * Don't want to allow preemption here, because | |
1585 | * sys_ptrace() needs this task to be inactive. | |
1586 | * | |
1587 | * XXX: implement read_unlock_no_resched(). | |
1588 | */ | |
1589 | preempt_disable(); | |
1da177e4 | 1590 | read_unlock(&tasklist_lock); |
53da1d94 | 1591 | preempt_enable_no_resched(); |
1da177e4 LT |
1592 | schedule(); |
1593 | } else { | |
1594 | /* | |
1595 | * By the time we got the lock, our tracer went away. | |
6405f7f4 | 1596 | * Don't drop the lock yet, another tracer may come. |
1da177e4 | 1597 | */ |
6405f7f4 | 1598 | __set_current_state(TASK_RUNNING); |
20686a30 ON |
1599 | if (clear_code) |
1600 | current->exit_code = 0; | |
6405f7f4 | 1601 | read_unlock(&tasklist_lock); |
1da177e4 LT |
1602 | } |
1603 | ||
13b1c3d4 RM |
1604 | /* |
1605 | * While in TASK_TRACED, we were considered "frozen enough". | |
1606 | * Now that we woke up, it's crucial if we're supposed to be | |
1607 | * frozen that we freeze now before running anything substantial. | |
1608 | */ | |
1609 | try_to_freeze(); | |
1610 | ||
1da177e4 LT |
1611 | /* |
1612 | * We are back. Now reacquire the siglock before touching | |
1613 | * last_siginfo, so that we are sure to have synchronized with | |
1614 | * any signal-sending on another CPU that wants to examine it. | |
1615 | */ | |
1616 | spin_lock_irq(¤t->sighand->siglock); | |
1617 | current->last_siginfo = NULL; | |
1618 | ||
1619 | /* | |
1620 | * Queued signals ignored us while we were stopped for tracing. | |
1621 | * So check for any that we should take before resuming user mode. | |
b74d0deb | 1622 | * This sets TIF_SIGPENDING, but never clears it. |
1da177e4 | 1623 | */ |
b74d0deb | 1624 | recalc_sigpending_tsk(current); |
1da177e4 LT |
1625 | } |
1626 | ||
1627 | void ptrace_notify(int exit_code) | |
1628 | { | |
1629 | siginfo_t info; | |
1630 | ||
1631 | BUG_ON((exit_code & (0x7f | ~0xffff)) != SIGTRAP); | |
1632 | ||
1633 | memset(&info, 0, sizeof info); | |
1634 | info.si_signo = SIGTRAP; | |
1635 | info.si_code = exit_code; | |
b488893a | 1636 | info.si_pid = task_pid_vnr(current); |
76aac0e9 | 1637 | info.si_uid = current_uid(); |
1da177e4 LT |
1638 | |
1639 | /* Let the debugger run. */ | |
1640 | spin_lock_irq(¤t->sighand->siglock); | |
20686a30 | 1641 | ptrace_stop(exit_code, 1, &info); |
1da177e4 LT |
1642 | spin_unlock_irq(¤t->sighand->siglock); |
1643 | } | |
1644 | ||
1da177e4 LT |
1645 | static void |
1646 | finish_stop(int stop_count) | |
1647 | { | |
1648 | /* | |
1649 | * If there are no other threads in the group, or if there is | |
1650 | * a group stop in progress and we are the last to stop, | |
1651 | * report to the parent. When ptraced, every thread reports itself. | |
1652 | */ | |
fa00b80b | 1653 | if (tracehook_notify_jctl(stop_count == 0, CLD_STOPPED)) { |
a1d5e21e ON |
1654 | read_lock(&tasklist_lock); |
1655 | do_notify_parent_cldstop(current, CLD_STOPPED); | |
1656 | read_unlock(&tasklist_lock); | |
1657 | } | |
bc505a47 | 1658 | |
3df494a3 RW |
1659 | do { |
1660 | schedule(); | |
1661 | } while (try_to_freeze()); | |
1da177e4 LT |
1662 | /* |
1663 | * Now we don't run again until continued. | |
1664 | */ | |
1665 | current->exit_code = 0; | |
1666 | } | |
1667 | ||
1668 | /* | |
1669 | * This performs the stopping for SIGSTOP and other stop signals. | |
1670 | * We have to stop all threads in the thread group. | |
1671 | * Returns nonzero if we've actually stopped and released the siglock. | |
1672 | * Returns zero if we didn't stop and still hold the siglock. | |
1673 | */ | |
a122b341 | 1674 | static int do_signal_stop(int signr) |
1da177e4 LT |
1675 | { |
1676 | struct signal_struct *sig = current->signal; | |
dac27f4a | 1677 | int stop_count; |
1da177e4 | 1678 | |
1da177e4 LT |
1679 | if (sig->group_stop_count > 0) { |
1680 | /* | |
1681 | * There is a group stop in progress. We don't need to | |
1682 | * start another one. | |
1683 | */ | |
1da177e4 | 1684 | stop_count = --sig->group_stop_count; |
dac27f4a | 1685 | } else { |
f558b7e4 ON |
1686 | struct task_struct *t; |
1687 | ||
2b201a9e | 1688 | if (!likely(sig->flags & SIGNAL_STOP_DEQUEUED) || |
573cf9ad | 1689 | unlikely(signal_group_exit(sig))) |
f558b7e4 | 1690 | return 0; |
1da177e4 LT |
1691 | /* |
1692 | * There is no group stop already in progress. | |
a122b341 | 1693 | * We must initiate one now. |
1da177e4 | 1694 | */ |
a122b341 | 1695 | sig->group_exit_code = signr; |
1da177e4 | 1696 | |
a122b341 ON |
1697 | stop_count = 0; |
1698 | for (t = next_thread(current); t != current; t = next_thread(t)) | |
1da177e4 | 1699 | /* |
a122b341 ON |
1700 | * Setting state to TASK_STOPPED for a group |
1701 | * stop is always done with the siglock held, | |
1702 | * so this check has no races. | |
1da177e4 | 1703 | */ |
d12619b5 | 1704 | if (!(t->flags & PF_EXITING) && |
e1abb39c | 1705 | !task_is_stopped_or_traced(t)) { |
a122b341 ON |
1706 | stop_count++; |
1707 | signal_wake_up(t, 0); | |
1708 | } | |
1709 | sig->group_stop_count = stop_count; | |
1da177e4 LT |
1710 | } |
1711 | ||
dac27f4a ON |
1712 | if (stop_count == 0) |
1713 | sig->flags = SIGNAL_STOP_STOPPED; | |
1714 | current->exit_code = sig->group_exit_code; | |
1715 | __set_current_state(TASK_STOPPED); | |
1716 | ||
1717 | spin_unlock_irq(¤t->sighand->siglock); | |
1da177e4 LT |
1718 | finish_stop(stop_count); |
1719 | return 1; | |
1720 | } | |
1721 | ||
18c98b65 RM |
1722 | static int ptrace_signal(int signr, siginfo_t *info, |
1723 | struct pt_regs *regs, void *cookie) | |
1724 | { | |
1725 | if (!(current->ptrace & PT_PTRACED)) | |
1726 | return signr; | |
1727 | ||
1728 | ptrace_signal_deliver(regs, cookie); | |
1729 | ||
1730 | /* Let the debugger run. */ | |
1731 | ptrace_stop(signr, 0, info); | |
1732 | ||
1733 | /* We're back. Did the debugger cancel the sig? */ | |
1734 | signr = current->exit_code; | |
1735 | if (signr == 0) | |
1736 | return signr; | |
1737 | ||
1738 | current->exit_code = 0; | |
1739 | ||
1740 | /* Update the siginfo structure if the signal has | |
1741 | changed. If the debugger wanted something | |
1742 | specific in the siginfo structure then it should | |
1743 | have updated *info via PTRACE_SETSIGINFO. */ | |
1744 | if (signr != info->si_signo) { | |
1745 | info->si_signo = signr; | |
1746 | info->si_errno = 0; | |
1747 | info->si_code = SI_USER; | |
1748 | info->si_pid = task_pid_vnr(current->parent); | |
c69e8d9c | 1749 | info->si_uid = task_uid(current->parent); |
18c98b65 RM |
1750 | } |
1751 | ||
1752 | /* If the (new) signal is now blocked, requeue it. */ | |
1753 | if (sigismember(¤t->blocked, signr)) { | |
1754 | specific_send_sig_info(signr, info, current); | |
1755 | signr = 0; | |
1756 | } | |
1757 | ||
1758 | return signr; | |
1759 | } | |
1760 | ||
1da177e4 LT |
1761 | int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka, |
1762 | struct pt_regs *regs, void *cookie) | |
1763 | { | |
f6b76d4f ON |
1764 | struct sighand_struct *sighand = current->sighand; |
1765 | struct signal_struct *signal = current->signal; | |
1766 | int signr; | |
1da177e4 | 1767 | |
13b1c3d4 RM |
1768 | relock: |
1769 | /* | |
1770 | * We'll jump back here after any time we were stopped in TASK_STOPPED. | |
1771 | * While in TASK_STOPPED, we were considered "frozen enough". | |
1772 | * Now that we woke up, it's crucial if we're supposed to be | |
1773 | * frozen that we freeze now before running anything substantial. | |
1774 | */ | |
fc558a74 RW |
1775 | try_to_freeze(); |
1776 | ||
f6b76d4f | 1777 | spin_lock_irq(&sighand->siglock); |
021e1ae3 ON |
1778 | /* |
1779 | * Every stopped thread goes here after wakeup. Check to see if | |
1780 | * we should notify the parent, prepare_signal(SIGCONT) encodes | |
1781 | * the CLD_ si_code into SIGNAL_CLD_MASK bits. | |
1782 | */ | |
f6b76d4f ON |
1783 | if (unlikely(signal->flags & SIGNAL_CLD_MASK)) { |
1784 | int why = (signal->flags & SIGNAL_STOP_CONTINUED) | |
e4420551 | 1785 | ? CLD_CONTINUED : CLD_STOPPED; |
f6b76d4f ON |
1786 | signal->flags &= ~SIGNAL_CLD_MASK; |
1787 | spin_unlock_irq(&sighand->siglock); | |
e4420551 | 1788 | |
fa00b80b RM |
1789 | if (unlikely(!tracehook_notify_jctl(1, why))) |
1790 | goto relock; | |
1791 | ||
e4420551 ON |
1792 | read_lock(&tasklist_lock); |
1793 | do_notify_parent_cldstop(current->group_leader, why); | |
1794 | read_unlock(&tasklist_lock); | |
1795 | goto relock; | |
1796 | } | |
1797 | ||
1da177e4 LT |
1798 | for (;;) { |
1799 | struct k_sigaction *ka; | |
1800 | ||
f6b76d4f | 1801 | if (unlikely(signal->group_stop_count > 0) && |
f558b7e4 | 1802 | do_signal_stop(0)) |
1da177e4 LT |
1803 | goto relock; |
1804 | ||
7bcf6a2c RM |
1805 | /* |
1806 | * Tracing can induce an artifical signal and choose sigaction. | |
1807 | * The return value in @signr determines the default action, | |
1808 | * but @info->si_signo is the signal number we will report. | |
1809 | */ | |
1810 | signr = tracehook_get_signal(current, regs, info, return_ka); | |
1811 | if (unlikely(signr < 0)) | |
1812 | goto relock; | |
1813 | if (unlikely(signr != 0)) | |
1814 | ka = return_ka; | |
1815 | else { | |
1816 | signr = dequeue_signal(current, ¤t->blocked, | |
1817 | info); | |
1da177e4 | 1818 | |
18c98b65 | 1819 | if (!signr) |
7bcf6a2c RM |
1820 | break; /* will return 0 */ |
1821 | ||
1822 | if (signr != SIGKILL) { | |
1823 | signr = ptrace_signal(signr, info, | |
1824 | regs, cookie); | |
1825 | if (!signr) | |
1826 | continue; | |
1827 | } | |
1828 | ||
1829 | ka = &sighand->action[signr-1]; | |
1da177e4 LT |
1830 | } |
1831 | ||
1da177e4 LT |
1832 | if (ka->sa.sa_handler == SIG_IGN) /* Do nothing. */ |
1833 | continue; | |
1834 | if (ka->sa.sa_handler != SIG_DFL) { | |
1835 | /* Run the handler. */ | |
1836 | *return_ka = *ka; | |
1837 | ||
1838 | if (ka->sa.sa_flags & SA_ONESHOT) | |
1839 | ka->sa.sa_handler = SIG_DFL; | |
1840 | ||
1841 | break; /* will return non-zero "signr" value */ | |
1842 | } | |
1843 | ||
1844 | /* | |
1845 | * Now we are doing the default action for this signal. | |
1846 | */ | |
1847 | if (sig_kernel_ignore(signr)) /* Default is nothing. */ | |
1848 | continue; | |
1849 | ||
84d73786 | 1850 | /* |
0fbc26a6 | 1851 | * Global init gets no signals it doesn't want. |
84d73786 | 1852 | */ |
fae5fa44 ON |
1853 | if (unlikely(signal->flags & SIGNAL_UNKILLABLE) && |
1854 | !signal_group_exit(signal)) | |
1da177e4 LT |
1855 | continue; |
1856 | ||
1857 | if (sig_kernel_stop(signr)) { | |
1858 | /* | |
1859 | * The default action is to stop all threads in | |
1860 | * the thread group. The job control signals | |
1861 | * do nothing in an orphaned pgrp, but SIGSTOP | |
1862 | * always works. Note that siglock needs to be | |
1863 | * dropped during the call to is_orphaned_pgrp() | |
1864 | * because of lock ordering with tasklist_lock. | |
1865 | * This allows an intervening SIGCONT to be posted. | |
1866 | * We need to check for that and bail out if necessary. | |
1867 | */ | |
1868 | if (signr != SIGSTOP) { | |
f6b76d4f | 1869 | spin_unlock_irq(&sighand->siglock); |
1da177e4 LT |
1870 | |
1871 | /* signals can be posted during this window */ | |
1872 | ||
3e7cd6c4 | 1873 | if (is_current_pgrp_orphaned()) |
1da177e4 LT |
1874 | goto relock; |
1875 | ||
f6b76d4f | 1876 | spin_lock_irq(&sighand->siglock); |
1da177e4 LT |
1877 | } |
1878 | ||
7bcf6a2c | 1879 | if (likely(do_signal_stop(info->si_signo))) { |
1da177e4 LT |
1880 | /* It released the siglock. */ |
1881 | goto relock; | |
1882 | } | |
1883 | ||
1884 | /* | |
1885 | * We didn't actually stop, due to a race | |
1886 | * with SIGCONT or something like that. | |
1887 | */ | |
1888 | continue; | |
1889 | } | |
1890 | ||
f6b76d4f | 1891 | spin_unlock_irq(&sighand->siglock); |
1da177e4 LT |
1892 | |
1893 | /* | |
1894 | * Anything else is fatal, maybe with a core dump. | |
1895 | */ | |
1896 | current->flags |= PF_SIGNALED; | |
2dce81bf | 1897 | |
1da177e4 | 1898 | if (sig_kernel_coredump(signr)) { |
2dce81bf | 1899 | if (print_fatal_signals) |
7bcf6a2c | 1900 | print_fatal_signal(regs, info->si_signo); |
1da177e4 LT |
1901 | /* |
1902 | * If it was able to dump core, this kills all | |
1903 | * other threads in the group and synchronizes with | |
1904 | * their demise. If we lost the race with another | |
1905 | * thread getting here, it set group_exit_code | |
1906 | * first and our do_group_exit call below will use | |
1907 | * that value and ignore the one we pass it. | |
1908 | */ | |
7bcf6a2c | 1909 | do_coredump(info->si_signo, info->si_signo, regs); |
1da177e4 LT |
1910 | } |
1911 | ||
1912 | /* | |
1913 | * Death signals, no core dump. | |
1914 | */ | |
7bcf6a2c | 1915 | do_group_exit(info->si_signo); |
1da177e4 LT |
1916 | /* NOTREACHED */ |
1917 | } | |
f6b76d4f | 1918 | spin_unlock_irq(&sighand->siglock); |
1da177e4 LT |
1919 | return signr; |
1920 | } | |
1921 | ||
d12619b5 ON |
1922 | void exit_signals(struct task_struct *tsk) |
1923 | { | |
1924 | int group_stop = 0; | |
5dee1707 | 1925 | struct task_struct *t; |
d12619b5 | 1926 | |
5dee1707 ON |
1927 | if (thread_group_empty(tsk) || signal_group_exit(tsk->signal)) { |
1928 | tsk->flags |= PF_EXITING; | |
1929 | return; | |
d12619b5 ON |
1930 | } |
1931 | ||
5dee1707 | 1932 | spin_lock_irq(&tsk->sighand->siglock); |
d12619b5 ON |
1933 | /* |
1934 | * From now this task is not visible for group-wide signals, | |
1935 | * see wants_signal(), do_signal_stop(). | |
1936 | */ | |
1937 | tsk->flags |= PF_EXITING; | |
5dee1707 ON |
1938 | if (!signal_pending(tsk)) |
1939 | goto out; | |
1940 | ||
1941 | /* It could be that __group_complete_signal() choose us to | |
1942 | * notify about group-wide signal. Another thread should be | |
1943 | * woken now to take the signal since we will not. | |
1944 | */ | |
1945 | for (t = tsk; (t = next_thread(t)) != tsk; ) | |
1946 | if (!signal_pending(t) && !(t->flags & PF_EXITING)) | |
1947 | recalc_sigpending_and_wake(t); | |
1948 | ||
1949 | if (unlikely(tsk->signal->group_stop_count) && | |
1950 | !--tsk->signal->group_stop_count) { | |
1951 | tsk->signal->flags = SIGNAL_STOP_STOPPED; | |
1952 | group_stop = 1; | |
1953 | } | |
1954 | out: | |
d12619b5 ON |
1955 | spin_unlock_irq(&tsk->sighand->siglock); |
1956 | ||
fa00b80b | 1957 | if (unlikely(group_stop) && tracehook_notify_jctl(1, CLD_STOPPED)) { |
d12619b5 ON |
1958 | read_lock(&tasklist_lock); |
1959 | do_notify_parent_cldstop(tsk, CLD_STOPPED); | |
1960 | read_unlock(&tasklist_lock); | |
1961 | } | |
1962 | } | |
1963 | ||
1da177e4 LT |
1964 | EXPORT_SYMBOL(recalc_sigpending); |
1965 | EXPORT_SYMBOL_GPL(dequeue_signal); | |
1966 | EXPORT_SYMBOL(flush_signals); | |
1967 | EXPORT_SYMBOL(force_sig); | |
1da177e4 LT |
1968 | EXPORT_SYMBOL(send_sig); |
1969 | EXPORT_SYMBOL(send_sig_info); | |
1970 | EXPORT_SYMBOL(sigprocmask); | |
1971 | EXPORT_SYMBOL(block_all_signals); | |
1972 | EXPORT_SYMBOL(unblock_all_signals); | |
1973 | ||
1974 | ||
1975 | /* | |
1976 | * System call entry points. | |
1977 | */ | |
1978 | ||
754fe8d2 | 1979 | SYSCALL_DEFINE0(restart_syscall) |
1da177e4 LT |
1980 | { |
1981 | struct restart_block *restart = ¤t_thread_info()->restart_block; | |
1982 | return restart->fn(restart); | |
1983 | } | |
1984 | ||
1985 | long do_no_restart_syscall(struct restart_block *param) | |
1986 | { | |
1987 | return -EINTR; | |
1988 | } | |
1989 | ||
1990 | /* | |
1991 | * We don't need to get the kernel lock - this is all local to this | |
1992 | * particular thread.. (and that's good, because this is _heavily_ | |
1993 | * used by various programs) | |
1994 | */ | |
1995 | ||
1996 | /* | |
1997 | * This is also useful for kernel threads that want to temporarily | |
1998 | * (or permanently) block certain signals. | |
1999 | * | |
2000 | * NOTE! Unlike the user-mode sys_sigprocmask(), the kernel | |
2001 | * interface happily blocks "unblockable" signals like SIGKILL | |
2002 | * and friends. | |
2003 | */ | |
2004 | int sigprocmask(int how, sigset_t *set, sigset_t *oldset) | |
2005 | { | |
2006 | int error; | |
1da177e4 LT |
2007 | |
2008 | spin_lock_irq(¤t->sighand->siglock); | |
a26fd335 ON |
2009 | if (oldset) |
2010 | *oldset = current->blocked; | |
2011 | ||
1da177e4 LT |
2012 | error = 0; |
2013 | switch (how) { | |
2014 | case SIG_BLOCK: | |
2015 | sigorsets(¤t->blocked, ¤t->blocked, set); | |
2016 | break; | |
2017 | case SIG_UNBLOCK: | |
2018 | signandsets(¤t->blocked, ¤t->blocked, set); | |
2019 | break; | |
2020 | case SIG_SETMASK: | |
2021 | current->blocked = *set; | |
2022 | break; | |
2023 | default: | |
2024 | error = -EINVAL; | |
2025 | } | |
2026 | recalc_sigpending(); | |
2027 | spin_unlock_irq(¤t->sighand->siglock); | |
a26fd335 | 2028 | |
1da177e4 LT |
2029 | return error; |
2030 | } | |
2031 | ||
17da2bd9 HC |
2032 | SYSCALL_DEFINE4(rt_sigprocmask, int, how, sigset_t __user *, set, |
2033 | sigset_t __user *, oset, size_t, sigsetsize) | |
1da177e4 LT |
2034 | { |
2035 | int error = -EINVAL; | |
2036 | sigset_t old_set, new_set; | |
2037 | ||
2038 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
2039 | if (sigsetsize != sizeof(sigset_t)) | |
2040 | goto out; | |
2041 | ||
2042 | if (set) { | |
2043 | error = -EFAULT; | |
2044 | if (copy_from_user(&new_set, set, sizeof(*set))) | |
2045 | goto out; | |
2046 | sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); | |
2047 | ||
2048 | error = sigprocmask(how, &new_set, &old_set); | |
2049 | if (error) | |
2050 | goto out; | |
2051 | if (oset) | |
2052 | goto set_old; | |
2053 | } else if (oset) { | |
2054 | spin_lock_irq(¤t->sighand->siglock); | |
2055 | old_set = current->blocked; | |
2056 | spin_unlock_irq(¤t->sighand->siglock); | |
2057 | ||
2058 | set_old: | |
2059 | error = -EFAULT; | |
2060 | if (copy_to_user(oset, &old_set, sizeof(*oset))) | |
2061 | goto out; | |
2062 | } | |
2063 | error = 0; | |
2064 | out: | |
2065 | return error; | |
2066 | } | |
2067 | ||
2068 | long do_sigpending(void __user *set, unsigned long sigsetsize) | |
2069 | { | |
2070 | long error = -EINVAL; | |
2071 | sigset_t pending; | |
2072 | ||
2073 | if (sigsetsize > sizeof(sigset_t)) | |
2074 | goto out; | |
2075 | ||
2076 | spin_lock_irq(¤t->sighand->siglock); | |
2077 | sigorsets(&pending, ¤t->pending.signal, | |
2078 | ¤t->signal->shared_pending.signal); | |
2079 | spin_unlock_irq(¤t->sighand->siglock); | |
2080 | ||
2081 | /* Outside the lock because only this thread touches it. */ | |
2082 | sigandsets(&pending, ¤t->blocked, &pending); | |
2083 | ||
2084 | error = -EFAULT; | |
2085 | if (!copy_to_user(set, &pending, sigsetsize)) | |
2086 | error = 0; | |
2087 | ||
2088 | out: | |
2089 | return error; | |
2090 | } | |
2091 | ||
17da2bd9 | 2092 | SYSCALL_DEFINE2(rt_sigpending, sigset_t __user *, set, size_t, sigsetsize) |
1da177e4 LT |
2093 | { |
2094 | return do_sigpending(set, sigsetsize); | |
2095 | } | |
2096 | ||
2097 | #ifndef HAVE_ARCH_COPY_SIGINFO_TO_USER | |
2098 | ||
2099 | int copy_siginfo_to_user(siginfo_t __user *to, siginfo_t *from) | |
2100 | { | |
2101 | int err; | |
2102 | ||
2103 | if (!access_ok (VERIFY_WRITE, to, sizeof(siginfo_t))) | |
2104 | return -EFAULT; | |
2105 | if (from->si_code < 0) | |
2106 | return __copy_to_user(to, from, sizeof(siginfo_t)) | |
2107 | ? -EFAULT : 0; | |
2108 | /* | |
2109 | * If you change siginfo_t structure, please be sure | |
2110 | * this code is fixed accordingly. | |
fba2afaa DL |
2111 | * Please remember to update the signalfd_copyinfo() function |
2112 | * inside fs/signalfd.c too, in case siginfo_t changes. | |
1da177e4 LT |
2113 | * It should never copy any pad contained in the structure |
2114 | * to avoid security leaks, but must copy the generic | |
2115 | * 3 ints plus the relevant union member. | |
2116 | */ | |
2117 | err = __put_user(from->si_signo, &to->si_signo); | |
2118 | err |= __put_user(from->si_errno, &to->si_errno); | |
2119 | err |= __put_user((short)from->si_code, &to->si_code); | |
2120 | switch (from->si_code & __SI_MASK) { | |
2121 | case __SI_KILL: | |
2122 | err |= __put_user(from->si_pid, &to->si_pid); | |
2123 | err |= __put_user(from->si_uid, &to->si_uid); | |
2124 | break; | |
2125 | case __SI_TIMER: | |
2126 | err |= __put_user(from->si_tid, &to->si_tid); | |
2127 | err |= __put_user(from->si_overrun, &to->si_overrun); | |
2128 | err |= __put_user(from->si_ptr, &to->si_ptr); | |
2129 | break; | |
2130 | case __SI_POLL: | |
2131 | err |= __put_user(from->si_band, &to->si_band); | |
2132 | err |= __put_user(from->si_fd, &to->si_fd); | |
2133 | break; | |
2134 | case __SI_FAULT: | |
2135 | err |= __put_user(from->si_addr, &to->si_addr); | |
2136 | #ifdef __ARCH_SI_TRAPNO | |
2137 | err |= __put_user(from->si_trapno, &to->si_trapno); | |
2138 | #endif | |
2139 | break; | |
2140 | case __SI_CHLD: | |
2141 | err |= __put_user(from->si_pid, &to->si_pid); | |
2142 | err |= __put_user(from->si_uid, &to->si_uid); | |
2143 | err |= __put_user(from->si_status, &to->si_status); | |
2144 | err |= __put_user(from->si_utime, &to->si_utime); | |
2145 | err |= __put_user(from->si_stime, &to->si_stime); | |
2146 | break; | |
2147 | case __SI_RT: /* This is not generated by the kernel as of now. */ | |
2148 | case __SI_MESGQ: /* But this is */ | |
2149 | err |= __put_user(from->si_pid, &to->si_pid); | |
2150 | err |= __put_user(from->si_uid, &to->si_uid); | |
2151 | err |= __put_user(from->si_ptr, &to->si_ptr); | |
2152 | break; | |
2153 | default: /* this is just in case for now ... */ | |
2154 | err |= __put_user(from->si_pid, &to->si_pid); | |
2155 | err |= __put_user(from->si_uid, &to->si_uid); | |
2156 | break; | |
2157 | } | |
2158 | return err; | |
2159 | } | |
2160 | ||
2161 | #endif | |
2162 | ||
17da2bd9 HC |
2163 | SYSCALL_DEFINE4(rt_sigtimedwait, const sigset_t __user *, uthese, |
2164 | siginfo_t __user *, uinfo, const struct timespec __user *, uts, | |
2165 | size_t, sigsetsize) | |
1da177e4 LT |
2166 | { |
2167 | int ret, sig; | |
2168 | sigset_t these; | |
2169 | struct timespec ts; | |
2170 | siginfo_t info; | |
2171 | long timeout = 0; | |
2172 | ||
2173 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
2174 | if (sigsetsize != sizeof(sigset_t)) | |
2175 | return -EINVAL; | |
2176 | ||
2177 | if (copy_from_user(&these, uthese, sizeof(these))) | |
2178 | return -EFAULT; | |
2179 | ||
2180 | /* | |
2181 | * Invert the set of allowed signals to get those we | |
2182 | * want to block. | |
2183 | */ | |
2184 | sigdelsetmask(&these, sigmask(SIGKILL)|sigmask(SIGSTOP)); | |
2185 | signotset(&these); | |
2186 | ||
2187 | if (uts) { | |
2188 | if (copy_from_user(&ts, uts, sizeof(ts))) | |
2189 | return -EFAULT; | |
2190 | if (ts.tv_nsec >= 1000000000L || ts.tv_nsec < 0 | |
2191 | || ts.tv_sec < 0) | |
2192 | return -EINVAL; | |
2193 | } | |
2194 | ||
2195 | spin_lock_irq(¤t->sighand->siglock); | |
2196 | sig = dequeue_signal(current, &these, &info); | |
2197 | if (!sig) { | |
2198 | timeout = MAX_SCHEDULE_TIMEOUT; | |
2199 | if (uts) | |
2200 | timeout = (timespec_to_jiffies(&ts) | |
2201 | + (ts.tv_sec || ts.tv_nsec)); | |
2202 | ||
2203 | if (timeout) { | |
2204 | /* None ready -- temporarily unblock those we're | |
2205 | * interested while we are sleeping in so that we'll | |
2206 | * be awakened when they arrive. */ | |
2207 | current->real_blocked = current->blocked; | |
2208 | sigandsets(¤t->blocked, ¤t->blocked, &these); | |
2209 | recalc_sigpending(); | |
2210 | spin_unlock_irq(¤t->sighand->siglock); | |
2211 | ||
75bcc8c5 | 2212 | timeout = schedule_timeout_interruptible(timeout); |
1da177e4 | 2213 | |
1da177e4 LT |
2214 | spin_lock_irq(¤t->sighand->siglock); |
2215 | sig = dequeue_signal(current, &these, &info); | |
2216 | current->blocked = current->real_blocked; | |
2217 | siginitset(¤t->real_blocked, 0); | |
2218 | recalc_sigpending(); | |
2219 | } | |
2220 | } | |
2221 | spin_unlock_irq(¤t->sighand->siglock); | |
2222 | ||
2223 | if (sig) { | |
2224 | ret = sig; | |
2225 | if (uinfo) { | |
2226 | if (copy_siginfo_to_user(uinfo, &info)) | |
2227 | ret = -EFAULT; | |
2228 | } | |
2229 | } else { | |
2230 | ret = -EAGAIN; | |
2231 | if (timeout) | |
2232 | ret = -EINTR; | |
2233 | } | |
2234 | ||
2235 | return ret; | |
2236 | } | |
2237 | ||
17da2bd9 | 2238 | SYSCALL_DEFINE2(kill, pid_t, pid, int, sig) |
1da177e4 LT |
2239 | { |
2240 | struct siginfo info; | |
2241 | ||
2242 | info.si_signo = sig; | |
2243 | info.si_errno = 0; | |
2244 | info.si_code = SI_USER; | |
b488893a | 2245 | info.si_pid = task_tgid_vnr(current); |
76aac0e9 | 2246 | info.si_uid = current_uid(); |
1da177e4 LT |
2247 | |
2248 | return kill_something_info(sig, &info, pid); | |
2249 | } | |
2250 | ||
bc64efd2 | 2251 | static int do_tkill(pid_t tgid, pid_t pid, int sig) |
1da177e4 | 2252 | { |
1da177e4 | 2253 | int error; |
6dd69f10 | 2254 | struct siginfo info; |
1da177e4 | 2255 | struct task_struct *p; |
3547ff3a | 2256 | unsigned long flags; |
1da177e4 | 2257 | |
6dd69f10 | 2258 | error = -ESRCH; |
1da177e4 LT |
2259 | info.si_signo = sig; |
2260 | info.si_errno = 0; | |
2261 | info.si_code = SI_TKILL; | |
b488893a | 2262 | info.si_pid = task_tgid_vnr(current); |
76aac0e9 | 2263 | info.si_uid = current_uid(); |
1da177e4 | 2264 | |
3547ff3a | 2265 | rcu_read_lock(); |
228ebcbe | 2266 | p = find_task_by_vpid(pid); |
b488893a | 2267 | if (p && (tgid <= 0 || task_tgid_vnr(p) == tgid)) { |
1da177e4 LT |
2268 | error = check_kill_permission(sig, &info, p); |
2269 | /* | |
2270 | * The null signal is a permissions and process existence | |
2271 | * probe. No signal is actually delivered. | |
3547ff3a ON |
2272 | * |
2273 | * If lock_task_sighand() fails we pretend the task dies | |
2274 | * after receiving the signal. The window is tiny, and the | |
2275 | * signal is private anyway. | |
1da177e4 | 2276 | */ |
3547ff3a | 2277 | if (!error && sig && lock_task_sighand(p, &flags)) { |
1da177e4 | 2278 | error = specific_send_sig_info(sig, &info, p); |
3547ff3a | 2279 | unlock_task_sighand(p, &flags); |
1da177e4 LT |
2280 | } |
2281 | } | |
3547ff3a | 2282 | rcu_read_unlock(); |
6dd69f10 | 2283 | |
1da177e4 LT |
2284 | return error; |
2285 | } | |
2286 | ||
6dd69f10 VL |
2287 | /** |
2288 | * sys_tgkill - send signal to one specific thread | |
2289 | * @tgid: the thread group ID of the thread | |
2290 | * @pid: the PID of the thread | |
2291 | * @sig: signal to be sent | |
2292 | * | |
72fd4a35 | 2293 | * This syscall also checks the @tgid and returns -ESRCH even if the PID |
6dd69f10 VL |
2294 | * exists but it's not belonging to the target process anymore. This |
2295 | * method solves the problem of threads exiting and PIDs getting reused. | |
2296 | */ | |
a5f8fa9e | 2297 | SYSCALL_DEFINE3(tgkill, pid_t, tgid, pid_t, pid, int, sig) |
6dd69f10 VL |
2298 | { |
2299 | /* This is only valid for single tasks */ | |
2300 | if (pid <= 0 || tgid <= 0) | |
2301 | return -EINVAL; | |
2302 | ||
2303 | return do_tkill(tgid, pid, sig); | |
2304 | } | |
2305 | ||
1da177e4 LT |
2306 | /* |
2307 | * Send a signal to only one task, even if it's a CLONE_THREAD task. | |
2308 | */ | |
a5f8fa9e | 2309 | SYSCALL_DEFINE2(tkill, pid_t, pid, int, sig) |
1da177e4 | 2310 | { |
1da177e4 LT |
2311 | /* This is only valid for single tasks */ |
2312 | if (pid <= 0) | |
2313 | return -EINVAL; | |
2314 | ||
6dd69f10 | 2315 | return do_tkill(0, pid, sig); |
1da177e4 LT |
2316 | } |
2317 | ||
a5f8fa9e HC |
2318 | SYSCALL_DEFINE3(rt_sigqueueinfo, pid_t, pid, int, sig, |
2319 | siginfo_t __user *, uinfo) | |
1da177e4 LT |
2320 | { |
2321 | siginfo_t info; | |
2322 | ||
2323 | if (copy_from_user(&info, uinfo, sizeof(siginfo_t))) | |
2324 | return -EFAULT; | |
2325 | ||
2326 | /* Not even root can pretend to send signals from the kernel. | |
2327 | Nor can they impersonate a kill(), which adds source info. */ | |
2328 | if (info.si_code >= 0) | |
2329 | return -EPERM; | |
2330 | info.si_signo = sig; | |
2331 | ||
2332 | /* POSIX.1b doesn't mention process groups. */ | |
2333 | return kill_proc_info(sig, &info, pid); | |
2334 | } | |
2335 | ||
88531f72 | 2336 | int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) |
1da177e4 | 2337 | { |
93585eea | 2338 | struct task_struct *t = current; |
1da177e4 | 2339 | struct k_sigaction *k; |
71fabd5e | 2340 | sigset_t mask; |
1da177e4 | 2341 | |
7ed20e1a | 2342 | if (!valid_signal(sig) || sig < 1 || (act && sig_kernel_only(sig))) |
1da177e4 LT |
2343 | return -EINVAL; |
2344 | ||
93585eea | 2345 | k = &t->sighand->action[sig-1]; |
1da177e4 LT |
2346 | |
2347 | spin_lock_irq(¤t->sighand->siglock); | |
1da177e4 LT |
2348 | if (oact) |
2349 | *oact = *k; | |
2350 | ||
2351 | if (act) { | |
9ac95f2f ON |
2352 | sigdelsetmask(&act->sa.sa_mask, |
2353 | sigmask(SIGKILL) | sigmask(SIGSTOP)); | |
88531f72 | 2354 | *k = *act; |
1da177e4 LT |
2355 | /* |
2356 | * POSIX 3.3.1.3: | |
2357 | * "Setting a signal action to SIG_IGN for a signal that is | |
2358 | * pending shall cause the pending signal to be discarded, | |
2359 | * whether or not it is blocked." | |
2360 | * | |
2361 | * "Setting a signal action to SIG_DFL for a signal that is | |
2362 | * pending and whose default action is to ignore the signal | |
2363 | * (for example, SIGCHLD), shall cause the pending signal to | |
2364 | * be discarded, whether or not it is blocked" | |
2365 | */ | |
35de254d | 2366 | if (sig_handler_ignored(sig_handler(t, sig), sig)) { |
71fabd5e GA |
2367 | sigemptyset(&mask); |
2368 | sigaddset(&mask, sig); | |
2369 | rm_from_queue_full(&mask, &t->signal->shared_pending); | |
1da177e4 | 2370 | do { |
71fabd5e | 2371 | rm_from_queue_full(&mask, &t->pending); |
1da177e4 LT |
2372 | t = next_thread(t); |
2373 | } while (t != current); | |
1da177e4 | 2374 | } |
1da177e4 LT |
2375 | } |
2376 | ||
2377 | spin_unlock_irq(¤t->sighand->siglock); | |
2378 | return 0; | |
2379 | } | |
2380 | ||
2381 | int | |
2382 | do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long sp) | |
2383 | { | |
2384 | stack_t oss; | |
2385 | int error; | |
2386 | ||
2387 | if (uoss) { | |
2388 | oss.ss_sp = (void __user *) current->sas_ss_sp; | |
2389 | oss.ss_size = current->sas_ss_size; | |
2390 | oss.ss_flags = sas_ss_flags(sp); | |
2391 | } | |
2392 | ||
2393 | if (uss) { | |
2394 | void __user *ss_sp; | |
2395 | size_t ss_size; | |
2396 | int ss_flags; | |
2397 | ||
2398 | error = -EFAULT; | |
2399 | if (!access_ok(VERIFY_READ, uss, sizeof(*uss)) | |
2400 | || __get_user(ss_sp, &uss->ss_sp) | |
2401 | || __get_user(ss_flags, &uss->ss_flags) | |
2402 | || __get_user(ss_size, &uss->ss_size)) | |
2403 | goto out; | |
2404 | ||
2405 | error = -EPERM; | |
2406 | if (on_sig_stack(sp)) | |
2407 | goto out; | |
2408 | ||
2409 | error = -EINVAL; | |
2410 | /* | |
2411 | * | |
2412 | * Note - this code used to test ss_flags incorrectly | |
2413 | * old code may have been written using ss_flags==0 | |
2414 | * to mean ss_flags==SS_ONSTACK (as this was the only | |
2415 | * way that worked) - this fix preserves that older | |
2416 | * mechanism | |
2417 | */ | |
2418 | if (ss_flags != SS_DISABLE && ss_flags != SS_ONSTACK && ss_flags != 0) | |
2419 | goto out; | |
2420 | ||
2421 | if (ss_flags == SS_DISABLE) { | |
2422 | ss_size = 0; | |
2423 | ss_sp = NULL; | |
2424 | } else { | |
2425 | error = -ENOMEM; | |
2426 | if (ss_size < MINSIGSTKSZ) | |
2427 | goto out; | |
2428 | } | |
2429 | ||
2430 | current->sas_ss_sp = (unsigned long) ss_sp; | |
2431 | current->sas_ss_size = ss_size; | |
2432 | } | |
2433 | ||
2434 | if (uoss) { | |
2435 | error = -EFAULT; | |
2436 | if (copy_to_user(uoss, &oss, sizeof(oss))) | |
2437 | goto out; | |
2438 | } | |
2439 | ||
2440 | error = 0; | |
2441 | out: | |
2442 | return error; | |
2443 | } | |
2444 | ||
2445 | #ifdef __ARCH_WANT_SYS_SIGPENDING | |
2446 | ||
b290ebe2 | 2447 | SYSCALL_DEFINE1(sigpending, old_sigset_t __user *, set) |
1da177e4 LT |
2448 | { |
2449 | return do_sigpending(set, sizeof(*set)); | |
2450 | } | |
2451 | ||
2452 | #endif | |
2453 | ||
2454 | #ifdef __ARCH_WANT_SYS_SIGPROCMASK | |
2455 | /* Some platforms have their own version with special arguments others | |
2456 | support only sys_rt_sigprocmask. */ | |
2457 | ||
b290ebe2 HC |
2458 | SYSCALL_DEFINE3(sigprocmask, int, how, old_sigset_t __user *, set, |
2459 | old_sigset_t __user *, oset) | |
1da177e4 LT |
2460 | { |
2461 | int error; | |
2462 | old_sigset_t old_set, new_set; | |
2463 | ||
2464 | if (set) { | |
2465 | error = -EFAULT; | |
2466 | if (copy_from_user(&new_set, set, sizeof(*set))) | |
2467 | goto out; | |
2468 | new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP)); | |
2469 | ||
2470 | spin_lock_irq(¤t->sighand->siglock); | |
2471 | old_set = current->blocked.sig[0]; | |
2472 | ||
2473 | error = 0; | |
2474 | switch (how) { | |
2475 | default: | |
2476 | error = -EINVAL; | |
2477 | break; | |
2478 | case SIG_BLOCK: | |
2479 | sigaddsetmask(¤t->blocked, new_set); | |
2480 | break; | |
2481 | case SIG_UNBLOCK: | |
2482 | sigdelsetmask(¤t->blocked, new_set); | |
2483 | break; | |
2484 | case SIG_SETMASK: | |
2485 | current->blocked.sig[0] = new_set; | |
2486 | break; | |
2487 | } | |
2488 | ||
2489 | recalc_sigpending(); | |
2490 | spin_unlock_irq(¤t->sighand->siglock); | |
2491 | if (error) | |
2492 | goto out; | |
2493 | if (oset) | |
2494 | goto set_old; | |
2495 | } else if (oset) { | |
2496 | old_set = current->blocked.sig[0]; | |
2497 | set_old: | |
2498 | error = -EFAULT; | |
2499 | if (copy_to_user(oset, &old_set, sizeof(*oset))) | |
2500 | goto out; | |
2501 | } | |
2502 | error = 0; | |
2503 | out: | |
2504 | return error; | |
2505 | } | |
2506 | #endif /* __ARCH_WANT_SYS_SIGPROCMASK */ | |
2507 | ||
2508 | #ifdef __ARCH_WANT_SYS_RT_SIGACTION | |
d4e82042 HC |
2509 | SYSCALL_DEFINE4(rt_sigaction, int, sig, |
2510 | const struct sigaction __user *, act, | |
2511 | struct sigaction __user *, oact, | |
2512 | size_t, sigsetsize) | |
1da177e4 LT |
2513 | { |
2514 | struct k_sigaction new_sa, old_sa; | |
2515 | int ret = -EINVAL; | |
2516 | ||
2517 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
2518 | if (sigsetsize != sizeof(sigset_t)) | |
2519 | goto out; | |
2520 | ||
2521 | if (act) { | |
2522 | if (copy_from_user(&new_sa.sa, act, sizeof(new_sa.sa))) | |
2523 | return -EFAULT; | |
2524 | } | |
2525 | ||
2526 | ret = do_sigaction(sig, act ? &new_sa : NULL, oact ? &old_sa : NULL); | |
2527 | ||
2528 | if (!ret && oact) { | |
2529 | if (copy_to_user(oact, &old_sa.sa, sizeof(old_sa.sa))) | |
2530 | return -EFAULT; | |
2531 | } | |
2532 | out: | |
2533 | return ret; | |
2534 | } | |
2535 | #endif /* __ARCH_WANT_SYS_RT_SIGACTION */ | |
2536 | ||
2537 | #ifdef __ARCH_WANT_SYS_SGETMASK | |
2538 | ||
2539 | /* | |
2540 | * For backwards compatibility. Functionality superseded by sigprocmask. | |
2541 | */ | |
a5f8fa9e | 2542 | SYSCALL_DEFINE0(sgetmask) |
1da177e4 LT |
2543 | { |
2544 | /* SMP safe */ | |
2545 | return current->blocked.sig[0]; | |
2546 | } | |
2547 | ||
a5f8fa9e | 2548 | SYSCALL_DEFINE1(ssetmask, int, newmask) |
1da177e4 LT |
2549 | { |
2550 | int old; | |
2551 | ||
2552 | spin_lock_irq(¤t->sighand->siglock); | |
2553 | old = current->blocked.sig[0]; | |
2554 | ||
2555 | siginitset(¤t->blocked, newmask & ~(sigmask(SIGKILL)| | |
2556 | sigmask(SIGSTOP))); | |
2557 | recalc_sigpending(); | |
2558 | spin_unlock_irq(¤t->sighand->siglock); | |
2559 | ||
2560 | return old; | |
2561 | } | |
2562 | #endif /* __ARCH_WANT_SGETMASK */ | |
2563 | ||
2564 | #ifdef __ARCH_WANT_SYS_SIGNAL | |
2565 | /* | |
2566 | * For backwards compatibility. Functionality superseded by sigaction. | |
2567 | */ | |
a5f8fa9e | 2568 | SYSCALL_DEFINE2(signal, int, sig, __sighandler_t, handler) |
1da177e4 LT |
2569 | { |
2570 | struct k_sigaction new_sa, old_sa; | |
2571 | int ret; | |
2572 | ||
2573 | new_sa.sa.sa_handler = handler; | |
2574 | new_sa.sa.sa_flags = SA_ONESHOT | SA_NOMASK; | |
c70d3d70 | 2575 | sigemptyset(&new_sa.sa.sa_mask); |
1da177e4 LT |
2576 | |
2577 | ret = do_sigaction(sig, &new_sa, &old_sa); | |
2578 | ||
2579 | return ret ? ret : (unsigned long)old_sa.sa.sa_handler; | |
2580 | } | |
2581 | #endif /* __ARCH_WANT_SYS_SIGNAL */ | |
2582 | ||
2583 | #ifdef __ARCH_WANT_SYS_PAUSE | |
2584 | ||
a5f8fa9e | 2585 | SYSCALL_DEFINE0(pause) |
1da177e4 LT |
2586 | { |
2587 | current->state = TASK_INTERRUPTIBLE; | |
2588 | schedule(); | |
2589 | return -ERESTARTNOHAND; | |
2590 | } | |
2591 | ||
2592 | #endif | |
2593 | ||
150256d8 | 2594 | #ifdef __ARCH_WANT_SYS_RT_SIGSUSPEND |
d4e82042 | 2595 | SYSCALL_DEFINE2(rt_sigsuspend, sigset_t __user *, unewset, size_t, sigsetsize) |
150256d8 DW |
2596 | { |
2597 | sigset_t newset; | |
2598 | ||
2599 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
2600 | if (sigsetsize != sizeof(sigset_t)) | |
2601 | return -EINVAL; | |
2602 | ||
2603 | if (copy_from_user(&newset, unewset, sizeof(newset))) | |
2604 | return -EFAULT; | |
2605 | sigdelsetmask(&newset, sigmask(SIGKILL)|sigmask(SIGSTOP)); | |
2606 | ||
2607 | spin_lock_irq(¤t->sighand->siglock); | |
2608 | current->saved_sigmask = current->blocked; | |
2609 | current->blocked = newset; | |
2610 | recalc_sigpending(); | |
2611 | spin_unlock_irq(¤t->sighand->siglock); | |
2612 | ||
2613 | current->state = TASK_INTERRUPTIBLE; | |
2614 | schedule(); | |
4e4c22c7 | 2615 | set_restore_sigmask(); |
150256d8 DW |
2616 | return -ERESTARTNOHAND; |
2617 | } | |
2618 | #endif /* __ARCH_WANT_SYS_RT_SIGSUSPEND */ | |
2619 | ||
f269fdd1 DH |
2620 | __attribute__((weak)) const char *arch_vma_name(struct vm_area_struct *vma) |
2621 | { | |
2622 | return NULL; | |
2623 | } | |
2624 | ||
1da177e4 LT |
2625 | void __init signals_init(void) |
2626 | { | |
0a31bd5f | 2627 | sigqueue_cachep = KMEM_CACHE(sigqueue, SLAB_PANIC); |
1da177e4 | 2628 | } |