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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/kernel/signal.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | * | |
6 | * 1997-11-02 Modified for POSIX.1b signals by Richard Henderson | |
7 | * | |
8 | * 2003-06-02 Jim Houston - Concurrent Computer Corp. | |
9 | * Changes to use preallocated sigqueue structures | |
10 | * to allow signals to be sent reliably. | |
11 | */ | |
12 | ||
1da177e4 | 13 | #include <linux/slab.h> |
9984de1a | 14 | #include <linux/export.h> |
1da177e4 | 15 | #include <linux/init.h> |
589ee628 | 16 | #include <linux/sched/mm.h> |
8703e8a4 | 17 | #include <linux/sched/user.h> |
b17b0153 | 18 | #include <linux/sched/debug.h> |
29930025 | 19 | #include <linux/sched/task.h> |
68db0cf1 | 20 | #include <linux/sched/task_stack.h> |
32ef5517 | 21 | #include <linux/sched/cputime.h> |
1da177e4 LT |
22 | #include <linux/fs.h> |
23 | #include <linux/tty.h> | |
24 | #include <linux/binfmts.h> | |
179899fd | 25 | #include <linux/coredump.h> |
1da177e4 LT |
26 | #include <linux/security.h> |
27 | #include <linux/syscalls.h> | |
28 | #include <linux/ptrace.h> | |
7ed20e1a | 29 | #include <linux/signal.h> |
fba2afaa | 30 | #include <linux/signalfd.h> |
f84d49b2 | 31 | #include <linux/ratelimit.h> |
35de254d | 32 | #include <linux/tracehook.h> |
c59ede7b | 33 | #include <linux/capability.h> |
7dfb7103 | 34 | #include <linux/freezer.h> |
84d73786 SB |
35 | #include <linux/pid_namespace.h> |
36 | #include <linux/nsproxy.h> | |
6b550f94 | 37 | #include <linux/user_namespace.h> |
0326f5a9 | 38 | #include <linux/uprobes.h> |
90268439 | 39 | #include <linux/compat.h> |
2b5faa4c | 40 | #include <linux/cn_proc.h> |
52f5684c | 41 | #include <linux/compiler.h> |
31ea70e0 | 42 | #include <linux/posix-timers.h> |
43347d56 | 43 | #include <linux/livepatch.h> |
52f5684c | 44 | |
d1eb650f MH |
45 | #define CREATE_TRACE_POINTS |
46 | #include <trace/events/signal.h> | |
84d73786 | 47 | |
1da177e4 | 48 | #include <asm/param.h> |
7c0f6ba6 | 49 | #include <linux/uaccess.h> |
1da177e4 LT |
50 | #include <asm/unistd.h> |
51 | #include <asm/siginfo.h> | |
d550bbd4 | 52 | #include <asm/cacheflush.h> |
e1396065 | 53 | #include "audit.h" /* audit_signal_info() */ |
1da177e4 LT |
54 | |
55 | /* | |
56 | * SLAB caches for signal bits. | |
57 | */ | |
58 | ||
e18b890b | 59 | static struct kmem_cache *sigqueue_cachep; |
1da177e4 | 60 | |
f84d49b2 NO |
61 | int print_fatal_signals __read_mostly; |
62 | ||
35de254d | 63 | static void __user *sig_handler(struct task_struct *t, int sig) |
93585eea | 64 | { |
35de254d RM |
65 | return t->sighand->action[sig - 1].sa.sa_handler; |
66 | } | |
93585eea | 67 | |
e4a8b4ef | 68 | static inline bool sig_handler_ignored(void __user *handler, int sig) |
35de254d | 69 | { |
93585eea | 70 | /* Is it explicitly or implicitly ignored? */ |
93585eea | 71 | return handler == SIG_IGN || |
e4a8b4ef | 72 | (handler == SIG_DFL && sig_kernel_ignore(sig)); |
93585eea | 73 | } |
1da177e4 | 74 | |
41aaa481 | 75 | static bool sig_task_ignored(struct task_struct *t, int sig, bool force) |
1da177e4 | 76 | { |
35de254d | 77 | void __user *handler; |
1da177e4 | 78 | |
f008faff ON |
79 | handler = sig_handler(t, sig); |
80 | ||
81 | if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) && | |
ac253850 | 82 | handler == SIG_DFL && !(force && sig_kernel_only(sig))) |
41aaa481 | 83 | return true; |
f008faff ON |
84 | |
85 | return sig_handler_ignored(handler, sig); | |
86 | } | |
87 | ||
6a0cdcd7 | 88 | static bool sig_ignored(struct task_struct *t, int sig, bool force) |
f008faff | 89 | { |
1da177e4 LT |
90 | /* |
91 | * Blocked signals are never ignored, since the | |
92 | * signal handler may change by the time it is | |
93 | * unblocked. | |
94 | */ | |
325d22df | 95 | if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig)) |
6a0cdcd7 | 96 | return false; |
1da177e4 | 97 | |
35de254d | 98 | /* |
628c1bcb ON |
99 | * Tracers may want to know about even ignored signal unless it |
100 | * is SIGKILL which can't be reported anyway but can be ignored | |
101 | * by SIGNAL_UNKILLABLE task. | |
35de254d | 102 | */ |
628c1bcb | 103 | if (t->ptrace && sig != SIGKILL) |
6a0cdcd7 | 104 | return false; |
628c1bcb ON |
105 | |
106 | return sig_task_ignored(t, sig, force); | |
1da177e4 LT |
107 | } |
108 | ||
109 | /* | |
110 | * Re-calculate pending state from the set of locally pending | |
111 | * signals, globally pending signals, and blocked signals. | |
112 | */ | |
113 | static inline int has_pending_signals(sigset_t *signal, sigset_t *blocked) | |
114 | { | |
115 | unsigned long ready; | |
116 | long i; | |
117 | ||
118 | switch (_NSIG_WORDS) { | |
119 | default: | |
120 | for (i = _NSIG_WORDS, ready = 0; --i >= 0 ;) | |
121 | ready |= signal->sig[i] &~ blocked->sig[i]; | |
122 | break; | |
123 | ||
124 | case 4: ready = signal->sig[3] &~ blocked->sig[3]; | |
125 | ready |= signal->sig[2] &~ blocked->sig[2]; | |
126 | ready |= signal->sig[1] &~ blocked->sig[1]; | |
127 | ready |= signal->sig[0] &~ blocked->sig[0]; | |
128 | break; | |
129 | ||
130 | case 2: ready = signal->sig[1] &~ blocked->sig[1]; | |
131 | ready |= signal->sig[0] &~ blocked->sig[0]; | |
132 | break; | |
133 | ||
134 | case 1: ready = signal->sig[0] &~ blocked->sig[0]; | |
135 | } | |
136 | return ready != 0; | |
137 | } | |
138 | ||
139 | #define PENDING(p,b) has_pending_signals(&(p)->signal, (b)) | |
140 | ||
7bb44ade | 141 | static int recalc_sigpending_tsk(struct task_struct *t) |
1da177e4 | 142 | { |
3759a0d9 | 143 | if ((t->jobctl & JOBCTL_PENDING_MASK) || |
1da177e4 | 144 | PENDING(&t->pending, &t->blocked) || |
7bb44ade | 145 | PENDING(&t->signal->shared_pending, &t->blocked)) { |
1da177e4 | 146 | set_tsk_thread_flag(t, TIF_SIGPENDING); |
7bb44ade RM |
147 | return 1; |
148 | } | |
b74d0deb RM |
149 | /* |
150 | * We must never clear the flag in another thread, or in current | |
151 | * when it's possible the current syscall is returning -ERESTART*. | |
152 | * So we don't clear it here, and only callers who know they should do. | |
153 | */ | |
7bb44ade RM |
154 | return 0; |
155 | } | |
156 | ||
157 | /* | |
158 | * After recalculating TIF_SIGPENDING, we need to make sure the task wakes up. | |
159 | * This is superfluous when called on current, the wakeup is a harmless no-op. | |
160 | */ | |
161 | void recalc_sigpending_and_wake(struct task_struct *t) | |
162 | { | |
163 | if (recalc_sigpending_tsk(t)) | |
164 | signal_wake_up(t, 0); | |
1da177e4 LT |
165 | } |
166 | ||
167 | void recalc_sigpending(void) | |
168 | { | |
43347d56 MB |
169 | if (!recalc_sigpending_tsk(current) && !freezing(current) && |
170 | !klp_patch_pending(current)) | |
b74d0deb RM |
171 | clear_thread_flag(TIF_SIGPENDING); |
172 | ||
1da177e4 LT |
173 | } |
174 | ||
175 | /* Given the mask, find the first available signal that should be serviced. */ | |
176 | ||
a27341cd LT |
177 | #define SYNCHRONOUS_MASK \ |
178 | (sigmask(SIGSEGV) | sigmask(SIGBUS) | sigmask(SIGILL) | \ | |
a0727e8c | 179 | sigmask(SIGTRAP) | sigmask(SIGFPE) | sigmask(SIGSYS)) |
a27341cd | 180 | |
fba2afaa | 181 | int next_signal(struct sigpending *pending, sigset_t *mask) |
1da177e4 LT |
182 | { |
183 | unsigned long i, *s, *m, x; | |
184 | int sig = 0; | |
f84d49b2 | 185 | |
1da177e4 LT |
186 | s = pending->signal.sig; |
187 | m = mask->sig; | |
a27341cd LT |
188 | |
189 | /* | |
190 | * Handle the first word specially: it contains the | |
191 | * synchronous signals that need to be dequeued first. | |
192 | */ | |
193 | x = *s &~ *m; | |
194 | if (x) { | |
195 | if (x & SYNCHRONOUS_MASK) | |
196 | x &= SYNCHRONOUS_MASK; | |
197 | sig = ffz(~x) + 1; | |
198 | return sig; | |
199 | } | |
200 | ||
1da177e4 LT |
201 | switch (_NSIG_WORDS) { |
202 | default: | |
a27341cd LT |
203 | for (i = 1; i < _NSIG_WORDS; ++i) { |
204 | x = *++s &~ *++m; | |
205 | if (!x) | |
206 | continue; | |
207 | sig = ffz(~x) + i*_NSIG_BPW + 1; | |
208 | break; | |
209 | } | |
1da177e4 LT |
210 | break; |
211 | ||
a27341cd LT |
212 | case 2: |
213 | x = s[1] &~ m[1]; | |
214 | if (!x) | |
1da177e4 | 215 | break; |
a27341cd | 216 | sig = ffz(~x) + _NSIG_BPW + 1; |
1da177e4 LT |
217 | break; |
218 | ||
a27341cd LT |
219 | case 1: |
220 | /* Nothing to do */ | |
1da177e4 LT |
221 | break; |
222 | } | |
f84d49b2 | 223 | |
1da177e4 LT |
224 | return sig; |
225 | } | |
226 | ||
f84d49b2 NO |
227 | static inline void print_dropped_signal(int sig) |
228 | { | |
229 | static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 10); | |
230 | ||
231 | if (!print_fatal_signals) | |
232 | return; | |
233 | ||
234 | if (!__ratelimit(&ratelimit_state)) | |
235 | return; | |
236 | ||
747800ef | 237 | pr_info("%s/%d: reached RLIMIT_SIGPENDING, dropped signal %d\n", |
f84d49b2 NO |
238 | current->comm, current->pid, sig); |
239 | } | |
240 | ||
d79fdd6d | 241 | /** |
7dd3db54 | 242 | * task_set_jobctl_pending - set jobctl pending bits |
d79fdd6d | 243 | * @task: target task |
7dd3db54 | 244 | * @mask: pending bits to set |
d79fdd6d | 245 | * |
7dd3db54 TH |
246 | * Clear @mask from @task->jobctl. @mask must be subset of |
247 | * %JOBCTL_PENDING_MASK | %JOBCTL_STOP_CONSUME | %JOBCTL_STOP_SIGMASK | | |
248 | * %JOBCTL_TRAPPING. If stop signo is being set, the existing signo is | |
249 | * cleared. If @task is already being killed or exiting, this function | |
250 | * becomes noop. | |
251 | * | |
252 | * CONTEXT: | |
253 | * Must be called with @task->sighand->siglock held. | |
254 | * | |
255 | * RETURNS: | |
256 | * %true if @mask is set, %false if made noop because @task was dying. | |
257 | */ | |
b76808e6 | 258 | bool task_set_jobctl_pending(struct task_struct *task, unsigned long mask) |
7dd3db54 TH |
259 | { |
260 | BUG_ON(mask & ~(JOBCTL_PENDING_MASK | JOBCTL_STOP_CONSUME | | |
261 | JOBCTL_STOP_SIGMASK | JOBCTL_TRAPPING)); | |
262 | BUG_ON((mask & JOBCTL_TRAPPING) && !(mask & JOBCTL_PENDING_MASK)); | |
263 | ||
264 | if (unlikely(fatal_signal_pending(task) || (task->flags & PF_EXITING))) | |
265 | return false; | |
266 | ||
267 | if (mask & JOBCTL_STOP_SIGMASK) | |
268 | task->jobctl &= ~JOBCTL_STOP_SIGMASK; | |
269 | ||
270 | task->jobctl |= mask; | |
271 | return true; | |
272 | } | |
273 | ||
d79fdd6d | 274 | /** |
a8f072c1 | 275 | * task_clear_jobctl_trapping - clear jobctl trapping bit |
d79fdd6d TH |
276 | * @task: target task |
277 | * | |
a8f072c1 TH |
278 | * If JOBCTL_TRAPPING is set, a ptracer is waiting for us to enter TRACED. |
279 | * Clear it and wake up the ptracer. Note that we don't need any further | |
280 | * locking. @task->siglock guarantees that @task->parent points to the | |
281 | * ptracer. | |
d79fdd6d TH |
282 | * |
283 | * CONTEXT: | |
284 | * Must be called with @task->sighand->siglock held. | |
285 | */ | |
73ddff2b | 286 | void task_clear_jobctl_trapping(struct task_struct *task) |
d79fdd6d | 287 | { |
a8f072c1 TH |
288 | if (unlikely(task->jobctl & JOBCTL_TRAPPING)) { |
289 | task->jobctl &= ~JOBCTL_TRAPPING; | |
650226bd | 290 | smp_mb(); /* advised by wake_up_bit() */ |
62c124ff | 291 | wake_up_bit(&task->jobctl, JOBCTL_TRAPPING_BIT); |
d79fdd6d TH |
292 | } |
293 | } | |
294 | ||
e5c1902e | 295 | /** |
3759a0d9 | 296 | * task_clear_jobctl_pending - clear jobctl pending bits |
e5c1902e | 297 | * @task: target task |
3759a0d9 | 298 | * @mask: pending bits to clear |
e5c1902e | 299 | * |
3759a0d9 TH |
300 | * Clear @mask from @task->jobctl. @mask must be subset of |
301 | * %JOBCTL_PENDING_MASK. If %JOBCTL_STOP_PENDING is being cleared, other | |
302 | * STOP bits are cleared together. | |
e5c1902e | 303 | * |
6dfca329 TH |
304 | * If clearing of @mask leaves no stop or trap pending, this function calls |
305 | * task_clear_jobctl_trapping(). | |
e5c1902e TH |
306 | * |
307 | * CONTEXT: | |
308 | * Must be called with @task->sighand->siglock held. | |
309 | */ | |
b76808e6 | 310 | void task_clear_jobctl_pending(struct task_struct *task, unsigned long mask) |
e5c1902e | 311 | { |
3759a0d9 TH |
312 | BUG_ON(mask & ~JOBCTL_PENDING_MASK); |
313 | ||
314 | if (mask & JOBCTL_STOP_PENDING) | |
315 | mask |= JOBCTL_STOP_CONSUME | JOBCTL_STOP_DEQUEUED; | |
316 | ||
317 | task->jobctl &= ~mask; | |
6dfca329 TH |
318 | |
319 | if (!(task->jobctl & JOBCTL_PENDING_MASK)) | |
320 | task_clear_jobctl_trapping(task); | |
e5c1902e TH |
321 | } |
322 | ||
323 | /** | |
324 | * task_participate_group_stop - participate in a group stop | |
325 | * @task: task participating in a group stop | |
326 | * | |
a8f072c1 | 327 | * @task has %JOBCTL_STOP_PENDING set and is participating in a group stop. |
39efa3ef | 328 | * Group stop states are cleared and the group stop count is consumed if |
a8f072c1 | 329 | * %JOBCTL_STOP_CONSUME was set. If the consumption completes the group |
39efa3ef | 330 | * stop, the appropriate %SIGNAL_* flags are set. |
e5c1902e TH |
331 | * |
332 | * CONTEXT: | |
333 | * Must be called with @task->sighand->siglock held. | |
244056f9 TH |
334 | * |
335 | * RETURNS: | |
336 | * %true if group stop completion should be notified to the parent, %false | |
337 | * otherwise. | |
e5c1902e TH |
338 | */ |
339 | static bool task_participate_group_stop(struct task_struct *task) | |
340 | { | |
341 | struct signal_struct *sig = task->signal; | |
a8f072c1 | 342 | bool consume = task->jobctl & JOBCTL_STOP_CONSUME; |
e5c1902e | 343 | |
a8f072c1 | 344 | WARN_ON_ONCE(!(task->jobctl & JOBCTL_STOP_PENDING)); |
39efa3ef | 345 | |
3759a0d9 | 346 | task_clear_jobctl_pending(task, JOBCTL_STOP_PENDING); |
e5c1902e TH |
347 | |
348 | if (!consume) | |
349 | return false; | |
350 | ||
351 | if (!WARN_ON_ONCE(sig->group_stop_count == 0)) | |
352 | sig->group_stop_count--; | |
353 | ||
244056f9 TH |
354 | /* |
355 | * Tell the caller to notify completion iff we are entering into a | |
356 | * fresh group stop. Read comment in do_signal_stop() for details. | |
357 | */ | |
358 | if (!sig->group_stop_count && !(sig->flags & SIGNAL_STOP_STOPPED)) { | |
2d39b3cd | 359 | signal_set_stop_flags(sig, SIGNAL_STOP_STOPPED); |
e5c1902e TH |
360 | return true; |
361 | } | |
362 | return false; | |
363 | } | |
364 | ||
c69e8d9c DH |
365 | /* |
366 | * allocate a new signal queue record | |
367 | * - this may be called without locks if and only if t == current, otherwise an | |
5aba085e | 368 | * appropriate lock must be held to stop the target task from exiting |
c69e8d9c | 369 | */ |
f84d49b2 NO |
370 | static struct sigqueue * |
371 | __sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags, int override_rlimit) | |
1da177e4 LT |
372 | { |
373 | struct sigqueue *q = NULL; | |
10b1fbdb | 374 | struct user_struct *user; |
1da177e4 | 375 | |
10b1fbdb | 376 | /* |
7cf7db8d TG |
377 | * Protect access to @t credentials. This can go away when all |
378 | * callers hold rcu read lock. | |
10b1fbdb | 379 | */ |
7cf7db8d | 380 | rcu_read_lock(); |
d84f4f99 | 381 | user = get_uid(__task_cred(t)->user); |
10b1fbdb | 382 | atomic_inc(&user->sigpending); |
7cf7db8d | 383 | rcu_read_unlock(); |
f84d49b2 | 384 | |
1da177e4 | 385 | if (override_rlimit || |
10b1fbdb | 386 | atomic_read(&user->sigpending) <= |
78d7d407 | 387 | task_rlimit(t, RLIMIT_SIGPENDING)) { |
1da177e4 | 388 | q = kmem_cache_alloc(sigqueue_cachep, flags); |
f84d49b2 NO |
389 | } else { |
390 | print_dropped_signal(sig); | |
391 | } | |
392 | ||
1da177e4 | 393 | if (unlikely(q == NULL)) { |
10b1fbdb | 394 | atomic_dec(&user->sigpending); |
d84f4f99 | 395 | free_uid(user); |
1da177e4 LT |
396 | } else { |
397 | INIT_LIST_HEAD(&q->list); | |
398 | q->flags = 0; | |
d84f4f99 | 399 | q->user = user; |
1da177e4 | 400 | } |
d84f4f99 DH |
401 | |
402 | return q; | |
1da177e4 LT |
403 | } |
404 | ||
514a01b8 | 405 | static void __sigqueue_free(struct sigqueue *q) |
1da177e4 LT |
406 | { |
407 | if (q->flags & SIGQUEUE_PREALLOC) | |
408 | return; | |
409 | atomic_dec(&q->user->sigpending); | |
410 | free_uid(q->user); | |
411 | kmem_cache_free(sigqueue_cachep, q); | |
412 | } | |
413 | ||
6a14c5c9 | 414 | void flush_sigqueue(struct sigpending *queue) |
1da177e4 LT |
415 | { |
416 | struct sigqueue *q; | |
417 | ||
418 | sigemptyset(&queue->signal); | |
419 | while (!list_empty(&queue->list)) { | |
420 | q = list_entry(queue->list.next, struct sigqueue , list); | |
421 | list_del_init(&q->list); | |
422 | __sigqueue_free(q); | |
423 | } | |
424 | } | |
425 | ||
426 | /* | |
9e7c8f8c | 427 | * Flush all pending signals for this kthread. |
1da177e4 | 428 | */ |
c81addc9 | 429 | void flush_signals(struct task_struct *t) |
1da177e4 LT |
430 | { |
431 | unsigned long flags; | |
432 | ||
433 | spin_lock_irqsave(&t->sighand->siglock, flags); | |
9e7c8f8c ON |
434 | clear_tsk_thread_flag(t, TIF_SIGPENDING); |
435 | flush_sigqueue(&t->pending); | |
436 | flush_sigqueue(&t->signal->shared_pending); | |
1da177e4 LT |
437 | spin_unlock_irqrestore(&t->sighand->siglock, flags); |
438 | } | |
439 | ||
baa73d9e | 440 | #ifdef CONFIG_POSIX_TIMERS |
cbaffba1 ON |
441 | static void __flush_itimer_signals(struct sigpending *pending) |
442 | { | |
443 | sigset_t signal, retain; | |
444 | struct sigqueue *q, *n; | |
445 | ||
446 | signal = pending->signal; | |
447 | sigemptyset(&retain); | |
448 | ||
449 | list_for_each_entry_safe(q, n, &pending->list, list) { | |
450 | int sig = q->info.si_signo; | |
451 | ||
452 | if (likely(q->info.si_code != SI_TIMER)) { | |
453 | sigaddset(&retain, sig); | |
454 | } else { | |
455 | sigdelset(&signal, sig); | |
456 | list_del_init(&q->list); | |
457 | __sigqueue_free(q); | |
458 | } | |
459 | } | |
460 | ||
461 | sigorsets(&pending->signal, &signal, &retain); | |
462 | } | |
463 | ||
464 | void flush_itimer_signals(void) | |
465 | { | |
466 | struct task_struct *tsk = current; | |
467 | unsigned long flags; | |
468 | ||
469 | spin_lock_irqsave(&tsk->sighand->siglock, flags); | |
470 | __flush_itimer_signals(&tsk->pending); | |
471 | __flush_itimer_signals(&tsk->signal->shared_pending); | |
472 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags); | |
473 | } | |
baa73d9e | 474 | #endif |
cbaffba1 | 475 | |
10ab825b ON |
476 | void ignore_signals(struct task_struct *t) |
477 | { | |
478 | int i; | |
479 | ||
480 | for (i = 0; i < _NSIG; ++i) | |
481 | t->sighand->action[i].sa.sa_handler = SIG_IGN; | |
482 | ||
483 | flush_signals(t); | |
484 | } | |
485 | ||
1da177e4 LT |
486 | /* |
487 | * Flush all handlers for a task. | |
488 | */ | |
489 | ||
490 | void | |
491 | flush_signal_handlers(struct task_struct *t, int force_default) | |
492 | { | |
493 | int i; | |
494 | struct k_sigaction *ka = &t->sighand->action[0]; | |
495 | for (i = _NSIG ; i != 0 ; i--) { | |
496 | if (force_default || ka->sa.sa_handler != SIG_IGN) | |
497 | ka->sa.sa_handler = SIG_DFL; | |
498 | ka->sa.sa_flags = 0; | |
522cff14 | 499 | #ifdef __ARCH_HAS_SA_RESTORER |
2ca39528 KC |
500 | ka->sa.sa_restorer = NULL; |
501 | #endif | |
1da177e4 LT |
502 | sigemptyset(&ka->sa.sa_mask); |
503 | ka++; | |
504 | } | |
505 | } | |
506 | ||
abd4f750 MAS |
507 | int unhandled_signal(struct task_struct *tsk, int sig) |
508 | { | |
445a91d2 | 509 | void __user *handler = tsk->sighand->action[sig-1].sa.sa_handler; |
b460cbc5 | 510 | if (is_global_init(tsk)) |
abd4f750 | 511 | return 1; |
445a91d2 | 512 | if (handler != SIG_IGN && handler != SIG_DFL) |
abd4f750 | 513 | return 0; |
a288eecc TH |
514 | /* if ptraced, let the tracer determine */ |
515 | return !tsk->ptrace; | |
abd4f750 MAS |
516 | } |
517 | ||
57db7e4a EB |
518 | static void collect_signal(int sig, struct sigpending *list, siginfo_t *info, |
519 | bool *resched_timer) | |
1da177e4 LT |
520 | { |
521 | struct sigqueue *q, *first = NULL; | |
1da177e4 | 522 | |
1da177e4 LT |
523 | /* |
524 | * Collect the siginfo appropriate to this signal. Check if | |
525 | * there is another siginfo for the same signal. | |
526 | */ | |
527 | list_for_each_entry(q, &list->list, list) { | |
528 | if (q->info.si_signo == sig) { | |
d4434207 ON |
529 | if (first) |
530 | goto still_pending; | |
1da177e4 LT |
531 | first = q; |
532 | } | |
533 | } | |
d4434207 ON |
534 | |
535 | sigdelset(&list->signal, sig); | |
536 | ||
1da177e4 | 537 | if (first) { |
d4434207 | 538 | still_pending: |
1da177e4 LT |
539 | list_del_init(&first->list); |
540 | copy_siginfo(info, &first->info); | |
57db7e4a EB |
541 | |
542 | *resched_timer = | |
543 | (first->flags & SIGQUEUE_PREALLOC) && | |
544 | (info->si_code == SI_TIMER) && | |
545 | (info->si_sys_private); | |
546 | ||
1da177e4 | 547 | __sigqueue_free(first); |
1da177e4 | 548 | } else { |
5aba085e RD |
549 | /* |
550 | * Ok, it wasn't in the queue. This must be | |
551 | * a fast-pathed signal or we must have been | |
552 | * out of queue space. So zero out the info. | |
1da177e4 | 553 | */ |
faf1f22b | 554 | clear_siginfo(info); |
1da177e4 LT |
555 | info->si_signo = sig; |
556 | info->si_errno = 0; | |
7486e5d9 | 557 | info->si_code = SI_USER; |
1da177e4 LT |
558 | info->si_pid = 0; |
559 | info->si_uid = 0; | |
560 | } | |
1da177e4 LT |
561 | } |
562 | ||
563 | static int __dequeue_signal(struct sigpending *pending, sigset_t *mask, | |
57db7e4a | 564 | siginfo_t *info, bool *resched_timer) |
1da177e4 | 565 | { |
27d91e07 | 566 | int sig = next_signal(pending, mask); |
1da177e4 | 567 | |
2e01fabe | 568 | if (sig) |
57db7e4a | 569 | collect_signal(sig, pending, info, resched_timer); |
1da177e4 LT |
570 | return sig; |
571 | } | |
572 | ||
573 | /* | |
5aba085e | 574 | * Dequeue a signal and return the element to the caller, which is |
1da177e4 LT |
575 | * expected to free it. |
576 | * | |
577 | * All callers have to hold the siglock. | |
578 | */ | |
579 | int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info) | |
580 | { | |
57db7e4a | 581 | bool resched_timer = false; |
c5363d03 | 582 | int signr; |
caec4e8d BH |
583 | |
584 | /* We only dequeue private signals from ourselves, we don't let | |
585 | * signalfd steal them | |
586 | */ | |
57db7e4a | 587 | signr = __dequeue_signal(&tsk->pending, mask, info, &resched_timer); |
8bfd9a7a | 588 | if (!signr) { |
1da177e4 | 589 | signr = __dequeue_signal(&tsk->signal->shared_pending, |
57db7e4a | 590 | mask, info, &resched_timer); |
baa73d9e | 591 | #ifdef CONFIG_POSIX_TIMERS |
8bfd9a7a TG |
592 | /* |
593 | * itimer signal ? | |
594 | * | |
595 | * itimers are process shared and we restart periodic | |
596 | * itimers in the signal delivery path to prevent DoS | |
597 | * attacks in the high resolution timer case. This is | |
5aba085e | 598 | * compliant with the old way of self-restarting |
8bfd9a7a TG |
599 | * itimers, as the SIGALRM is a legacy signal and only |
600 | * queued once. Changing the restart behaviour to | |
601 | * restart the timer in the signal dequeue path is | |
602 | * reducing the timer noise on heavy loaded !highres | |
603 | * systems too. | |
604 | */ | |
605 | if (unlikely(signr == SIGALRM)) { | |
606 | struct hrtimer *tmr = &tsk->signal->real_timer; | |
607 | ||
608 | if (!hrtimer_is_queued(tmr) && | |
2456e855 | 609 | tsk->signal->it_real_incr != 0) { |
8bfd9a7a TG |
610 | hrtimer_forward(tmr, tmr->base->get_time(), |
611 | tsk->signal->it_real_incr); | |
612 | hrtimer_restart(tmr); | |
613 | } | |
614 | } | |
baa73d9e | 615 | #endif |
8bfd9a7a | 616 | } |
c5363d03 | 617 | |
b8fceee1 | 618 | recalc_sigpending(); |
c5363d03 PE |
619 | if (!signr) |
620 | return 0; | |
621 | ||
622 | if (unlikely(sig_kernel_stop(signr))) { | |
8bfd9a7a TG |
623 | /* |
624 | * Set a marker that we have dequeued a stop signal. Our | |
625 | * caller might release the siglock and then the pending | |
626 | * stop signal it is about to process is no longer in the | |
627 | * pending bitmasks, but must still be cleared by a SIGCONT | |
628 | * (and overruled by a SIGKILL). So those cases clear this | |
629 | * shared flag after we've set it. Note that this flag may | |
630 | * remain set after the signal we return is ignored or | |
631 | * handled. That doesn't matter because its only purpose | |
632 | * is to alert stop-signal processing code when another | |
633 | * processor has come along and cleared the flag. | |
634 | */ | |
a8f072c1 | 635 | current->jobctl |= JOBCTL_STOP_DEQUEUED; |
8bfd9a7a | 636 | } |
baa73d9e | 637 | #ifdef CONFIG_POSIX_TIMERS |
57db7e4a | 638 | if (resched_timer) { |
1da177e4 LT |
639 | /* |
640 | * Release the siglock to ensure proper locking order | |
641 | * of timer locks outside of siglocks. Note, we leave | |
642 | * irqs disabled here, since the posix-timers code is | |
643 | * about to disable them again anyway. | |
644 | */ | |
645 | spin_unlock(&tsk->sighand->siglock); | |
96fe3b07 | 646 | posixtimer_rearm(info); |
1da177e4 | 647 | spin_lock(&tsk->sighand->siglock); |
9943d3ac EB |
648 | |
649 | /* Don't expose the si_sys_private value to userspace */ | |
650 | info->si_sys_private = 0; | |
1da177e4 | 651 | } |
baa73d9e | 652 | #endif |
1da177e4 LT |
653 | return signr; |
654 | } | |
655 | ||
656 | /* | |
657 | * Tell a process that it has a new active signal.. | |
658 | * | |
659 | * NOTE! we rely on the previous spin_lock to | |
660 | * lock interrupts for us! We can only be called with | |
661 | * "siglock" held, and the local interrupt must | |
662 | * have been disabled when that got acquired! | |
663 | * | |
664 | * No need to set need_resched since signal event passing | |
665 | * goes through ->blocked | |
666 | */ | |
910ffdb1 | 667 | void signal_wake_up_state(struct task_struct *t, unsigned int state) |
1da177e4 | 668 | { |
1da177e4 | 669 | set_tsk_thread_flag(t, TIF_SIGPENDING); |
1da177e4 | 670 | /* |
910ffdb1 | 671 | * TASK_WAKEKILL also means wake it up in the stopped/traced/killable |
f021a3c2 | 672 | * case. We don't check t->state here because there is a race with it |
1da177e4 LT |
673 | * executing another processor and just now entering stopped state. |
674 | * By using wake_up_state, we ensure the process will wake up and | |
675 | * handle its death signal. | |
676 | */ | |
910ffdb1 | 677 | if (!wake_up_state(t, state | TASK_INTERRUPTIBLE)) |
1da177e4 LT |
678 | kick_process(t); |
679 | } | |
680 | ||
71fabd5e GA |
681 | /* |
682 | * Remove signals in mask from the pending set and queue. | |
683 | * Returns 1 if any signals were found. | |
684 | * | |
685 | * All callers must be holding the siglock. | |
71fabd5e | 686 | */ |
c09c1441 | 687 | static int flush_sigqueue_mask(sigset_t *mask, struct sigpending *s) |
71fabd5e GA |
688 | { |
689 | struct sigqueue *q, *n; | |
690 | sigset_t m; | |
691 | ||
692 | sigandsets(&m, mask, &s->signal); | |
693 | if (sigisemptyset(&m)) | |
694 | return 0; | |
695 | ||
702a5073 | 696 | sigandnsets(&s->signal, &s->signal, mask); |
71fabd5e GA |
697 | list_for_each_entry_safe(q, n, &s->list, list) { |
698 | if (sigismember(mask, q->info.si_signo)) { | |
699 | list_del_init(&q->list); | |
700 | __sigqueue_free(q); | |
701 | } | |
702 | } | |
703 | return 1; | |
704 | } | |
1da177e4 | 705 | |
614c517d ON |
706 | static inline int is_si_special(const struct siginfo *info) |
707 | { | |
708 | return info <= SEND_SIG_FORCED; | |
709 | } | |
710 | ||
711 | static inline bool si_fromuser(const struct siginfo *info) | |
712 | { | |
713 | return info == SEND_SIG_NOINFO || | |
714 | (!is_si_special(info) && SI_FROMUSER(info)); | |
715 | } | |
716 | ||
39fd3393 SH |
717 | /* |
718 | * called with RCU read lock from check_kill_permission() | |
719 | */ | |
2a9b9094 | 720 | static bool kill_ok_by_cred(struct task_struct *t) |
39fd3393 SH |
721 | { |
722 | const struct cred *cred = current_cred(); | |
723 | const struct cred *tcred = __task_cred(t); | |
724 | ||
2a9b9094 CB |
725 | return uid_eq(cred->euid, tcred->suid) || |
726 | uid_eq(cred->euid, tcred->uid) || | |
727 | uid_eq(cred->uid, tcred->suid) || | |
728 | uid_eq(cred->uid, tcred->uid) || | |
729 | ns_capable(tcred->user_ns, CAP_KILL); | |
39fd3393 SH |
730 | } |
731 | ||
1da177e4 LT |
732 | /* |
733 | * Bad permissions for sending the signal | |
694f690d | 734 | * - the caller must hold the RCU read lock |
1da177e4 LT |
735 | */ |
736 | static int check_kill_permission(int sig, struct siginfo *info, | |
737 | struct task_struct *t) | |
738 | { | |
2e2ba22e | 739 | struct pid *sid; |
3b5e9e53 ON |
740 | int error; |
741 | ||
7ed20e1a | 742 | if (!valid_signal(sig)) |
3b5e9e53 ON |
743 | return -EINVAL; |
744 | ||
614c517d | 745 | if (!si_fromuser(info)) |
3b5e9e53 | 746 | return 0; |
e54dc243 | 747 | |
3b5e9e53 ON |
748 | error = audit_signal_info(sig, t); /* Let audit system see the signal */ |
749 | if (error) | |
1da177e4 | 750 | return error; |
3b5e9e53 | 751 | |
065add39 | 752 | if (!same_thread_group(current, t) && |
39fd3393 | 753 | !kill_ok_by_cred(t)) { |
2e2ba22e ON |
754 | switch (sig) { |
755 | case SIGCONT: | |
2e2ba22e | 756 | sid = task_session(t); |
2e2ba22e ON |
757 | /* |
758 | * We don't return the error if sid == NULL. The | |
759 | * task was unhashed, the caller must notice this. | |
760 | */ | |
761 | if (!sid || sid == task_session(current)) | |
762 | break; | |
763 | default: | |
764 | return -EPERM; | |
765 | } | |
766 | } | |
c2f0c7c3 | 767 | |
6b4f3d01 | 768 | return security_task_kill(t, info, sig, NULL); |
1da177e4 LT |
769 | } |
770 | ||
fb1d910c TH |
771 | /** |
772 | * ptrace_trap_notify - schedule trap to notify ptracer | |
773 | * @t: tracee wanting to notify tracer | |
774 | * | |
775 | * This function schedules sticky ptrace trap which is cleared on the next | |
776 | * TRAP_STOP to notify ptracer of an event. @t must have been seized by | |
777 | * ptracer. | |
778 | * | |
544b2c91 TH |
779 | * If @t is running, STOP trap will be taken. If trapped for STOP and |
780 | * ptracer is listening for events, tracee is woken up so that it can | |
781 | * re-trap for the new event. If trapped otherwise, STOP trap will be | |
782 | * eventually taken without returning to userland after the existing traps | |
783 | * are finished by PTRACE_CONT. | |
fb1d910c TH |
784 | * |
785 | * CONTEXT: | |
786 | * Must be called with @task->sighand->siglock held. | |
787 | */ | |
788 | static void ptrace_trap_notify(struct task_struct *t) | |
789 | { | |
790 | WARN_ON_ONCE(!(t->ptrace & PT_SEIZED)); | |
791 | assert_spin_locked(&t->sighand->siglock); | |
792 | ||
793 | task_set_jobctl_pending(t, JOBCTL_TRAP_NOTIFY); | |
910ffdb1 | 794 | ptrace_signal_wake_up(t, t->jobctl & JOBCTL_LISTENING); |
fb1d910c TH |
795 | } |
796 | ||
1da177e4 | 797 | /* |
7e695a5e ON |
798 | * Handle magic process-wide effects of stop/continue signals. Unlike |
799 | * the signal actions, these happen immediately at signal-generation | |
1da177e4 LT |
800 | * time regardless of blocking, ignoring, or handling. This does the |
801 | * actual continuing for SIGCONT, but not the actual stopping for stop | |
7e695a5e ON |
802 | * signals. The process stop is done as a signal action for SIG_DFL. |
803 | * | |
804 | * Returns true if the signal should be actually delivered, otherwise | |
805 | * it should be dropped. | |
1da177e4 | 806 | */ |
403bad72 | 807 | static bool prepare_signal(int sig, struct task_struct *p, bool force) |
1da177e4 | 808 | { |
ad16a460 | 809 | struct signal_struct *signal = p->signal; |
1da177e4 | 810 | struct task_struct *t; |
9490592f | 811 | sigset_t flush; |
1da177e4 | 812 | |
403bad72 | 813 | if (signal->flags & (SIGNAL_GROUP_EXIT | SIGNAL_GROUP_COREDUMP)) { |
5fa534c9 | 814 | if (!(signal->flags & SIGNAL_GROUP_EXIT)) |
403bad72 | 815 | return sig == SIGKILL; |
1da177e4 | 816 | /* |
7e695a5e | 817 | * The process is in the middle of dying, nothing to do. |
1da177e4 | 818 | */ |
7e695a5e | 819 | } else if (sig_kernel_stop(sig)) { |
1da177e4 LT |
820 | /* |
821 | * This is a stop signal. Remove SIGCONT from all queues. | |
822 | */ | |
9490592f | 823 | siginitset(&flush, sigmask(SIGCONT)); |
c09c1441 | 824 | flush_sigqueue_mask(&flush, &signal->shared_pending); |
9490592f | 825 | for_each_thread(p, t) |
c09c1441 | 826 | flush_sigqueue_mask(&flush, &t->pending); |
1da177e4 | 827 | } else if (sig == SIGCONT) { |
fc321d2e | 828 | unsigned int why; |
1da177e4 | 829 | /* |
1deac632 | 830 | * Remove all stop signals from all queues, wake all threads. |
1da177e4 | 831 | */ |
9490592f | 832 | siginitset(&flush, SIG_KERNEL_STOP_MASK); |
c09c1441 | 833 | flush_sigqueue_mask(&flush, &signal->shared_pending); |
9490592f | 834 | for_each_thread(p, t) { |
c09c1441 | 835 | flush_sigqueue_mask(&flush, &t->pending); |
3759a0d9 | 836 | task_clear_jobctl_pending(t, JOBCTL_STOP_PENDING); |
fb1d910c TH |
837 | if (likely(!(t->ptrace & PT_SEIZED))) |
838 | wake_up_state(t, __TASK_STOPPED); | |
839 | else | |
840 | ptrace_trap_notify(t); | |
9490592f | 841 | } |
1da177e4 | 842 | |
fc321d2e ON |
843 | /* |
844 | * Notify the parent with CLD_CONTINUED if we were stopped. | |
845 | * | |
846 | * If we were in the middle of a group stop, we pretend it | |
847 | * was already finished, and then continued. Since SIGCHLD | |
848 | * doesn't queue we report only CLD_STOPPED, as if the next | |
849 | * CLD_CONTINUED was dropped. | |
850 | */ | |
851 | why = 0; | |
ad16a460 | 852 | if (signal->flags & SIGNAL_STOP_STOPPED) |
fc321d2e | 853 | why |= SIGNAL_CLD_CONTINUED; |
ad16a460 | 854 | else if (signal->group_stop_count) |
fc321d2e ON |
855 | why |= SIGNAL_CLD_STOPPED; |
856 | ||
857 | if (why) { | |
021e1ae3 | 858 | /* |
ae6d2ed7 | 859 | * The first thread which returns from do_signal_stop() |
021e1ae3 ON |
860 | * will take ->siglock, notice SIGNAL_CLD_MASK, and |
861 | * notify its parent. See get_signal_to_deliver(). | |
862 | */ | |
2d39b3cd | 863 | signal_set_stop_flags(signal, why | SIGNAL_STOP_CONTINUED); |
ad16a460 ON |
864 | signal->group_stop_count = 0; |
865 | signal->group_exit_code = 0; | |
1da177e4 | 866 | } |
1da177e4 | 867 | } |
7e695a5e | 868 | |
def8cf72 | 869 | return !sig_ignored(p, sig, force); |
1da177e4 LT |
870 | } |
871 | ||
71f11dc0 ON |
872 | /* |
873 | * Test if P wants to take SIG. After we've checked all threads with this, | |
874 | * it's equivalent to finding no threads not blocking SIG. Any threads not | |
875 | * blocking SIG were ruled out because they are not running and already | |
876 | * have pending signals. Such threads will dequeue from the shared queue | |
877 | * as soon as they're available, so putting the signal on the shared queue | |
878 | * will be equivalent to sending it to one such thread. | |
879 | */ | |
880 | static inline int wants_signal(int sig, struct task_struct *p) | |
881 | { | |
882 | if (sigismember(&p->blocked, sig)) | |
883 | return 0; | |
884 | if (p->flags & PF_EXITING) | |
885 | return 0; | |
886 | if (sig == SIGKILL) | |
887 | return 1; | |
888 | if (task_is_stopped_or_traced(p)) | |
889 | return 0; | |
890 | return task_curr(p) || !signal_pending(p); | |
891 | } | |
892 | ||
5fcd835b | 893 | static void complete_signal(int sig, struct task_struct *p, int group) |
71f11dc0 ON |
894 | { |
895 | struct signal_struct *signal = p->signal; | |
896 | struct task_struct *t; | |
897 | ||
898 | /* | |
899 | * Now find a thread we can wake up to take the signal off the queue. | |
900 | * | |
901 | * If the main thread wants the signal, it gets first crack. | |
902 | * Probably the least surprising to the average bear. | |
903 | */ | |
904 | if (wants_signal(sig, p)) | |
905 | t = p; | |
5fcd835b | 906 | else if (!group || thread_group_empty(p)) |
71f11dc0 ON |
907 | /* |
908 | * There is just one thread and it does not need to be woken. | |
909 | * It will dequeue unblocked signals before it runs again. | |
910 | */ | |
911 | return; | |
912 | else { | |
913 | /* | |
914 | * Otherwise try to find a suitable thread. | |
915 | */ | |
916 | t = signal->curr_target; | |
917 | while (!wants_signal(sig, t)) { | |
918 | t = next_thread(t); | |
919 | if (t == signal->curr_target) | |
920 | /* | |
921 | * No thread needs to be woken. | |
922 | * Any eligible threads will see | |
923 | * the signal in the queue soon. | |
924 | */ | |
925 | return; | |
926 | } | |
927 | signal->curr_target = t; | |
928 | } | |
929 | ||
930 | /* | |
931 | * Found a killable thread. If the signal will be fatal, | |
932 | * then start taking the whole group down immediately. | |
933 | */ | |
fae5fa44 | 934 | if (sig_fatal(p, sig) && |
42691579 | 935 | !(signal->flags & SIGNAL_GROUP_EXIT) && |
71f11dc0 | 936 | !sigismember(&t->real_blocked, sig) && |
42691579 | 937 | (sig == SIGKILL || !p->ptrace)) { |
71f11dc0 ON |
938 | /* |
939 | * This signal will be fatal to the whole group. | |
940 | */ | |
941 | if (!sig_kernel_coredump(sig)) { | |
942 | /* | |
943 | * Start a group exit and wake everybody up. | |
944 | * This way we don't have other threads | |
945 | * running and doing things after a slower | |
946 | * thread has the fatal signal pending. | |
947 | */ | |
948 | signal->flags = SIGNAL_GROUP_EXIT; | |
949 | signal->group_exit_code = sig; | |
950 | signal->group_stop_count = 0; | |
951 | t = p; | |
952 | do { | |
6dfca329 | 953 | task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK); |
71f11dc0 ON |
954 | sigaddset(&t->pending.signal, SIGKILL); |
955 | signal_wake_up(t, 1); | |
956 | } while_each_thread(p, t); | |
957 | return; | |
958 | } | |
959 | } | |
960 | ||
961 | /* | |
962 | * The signal is already in the shared-pending queue. | |
963 | * Tell the chosen thread to wake up and dequeue it. | |
964 | */ | |
965 | signal_wake_up(t, sig == SIGKILL); | |
966 | return; | |
967 | } | |
968 | ||
af7fff9c PE |
969 | static inline int legacy_queue(struct sigpending *signals, int sig) |
970 | { | |
971 | return (sig < SIGRTMIN) && sigismember(&signals->signal, sig); | |
972 | } | |
973 | ||
6b550f94 SH |
974 | #ifdef CONFIG_USER_NS |
975 | static inline void userns_fixup_signal_uid(struct siginfo *info, struct task_struct *t) | |
976 | { | |
977 | if (current_user_ns() == task_cred_xxx(t, user_ns)) | |
978 | return; | |
979 | ||
980 | if (SI_FROMKERNEL(info)) | |
981 | return; | |
982 | ||
078de5f7 EB |
983 | rcu_read_lock(); |
984 | info->si_uid = from_kuid_munged(task_cred_xxx(t, user_ns), | |
985 | make_kuid(current_user_ns(), info->si_uid)); | |
986 | rcu_read_unlock(); | |
6b550f94 SH |
987 | } |
988 | #else | |
989 | static inline void userns_fixup_signal_uid(struct siginfo *info, struct task_struct *t) | |
990 | { | |
991 | return; | |
992 | } | |
993 | #endif | |
994 | ||
7978b567 SB |
995 | static int __send_signal(int sig, struct siginfo *info, struct task_struct *t, |
996 | int group, int from_ancestor_ns) | |
1da177e4 | 997 | { |
2ca3515a | 998 | struct sigpending *pending; |
6e65acba | 999 | struct sigqueue *q; |
7a0aeb14 | 1000 | int override_rlimit; |
6c303d3a | 1001 | int ret = 0, result; |
0a16b607 | 1002 | |
6e65acba | 1003 | assert_spin_locked(&t->sighand->siglock); |
921cf9f6 | 1004 | |
6c303d3a | 1005 | result = TRACE_SIGNAL_IGNORED; |
629d362b ON |
1006 | if (!prepare_signal(sig, t, |
1007 | from_ancestor_ns || (info == SEND_SIG_FORCED))) | |
6c303d3a | 1008 | goto ret; |
2ca3515a ON |
1009 | |
1010 | pending = group ? &t->signal->shared_pending : &t->pending; | |
2acb024d PE |
1011 | /* |
1012 | * Short-circuit ignored signals and support queuing | |
1013 | * exactly one non-rt signal, so that we can get more | |
1014 | * detailed information about the cause of the signal. | |
1015 | */ | |
6c303d3a | 1016 | result = TRACE_SIGNAL_ALREADY_PENDING; |
7e695a5e | 1017 | if (legacy_queue(pending, sig)) |
6c303d3a ON |
1018 | goto ret; |
1019 | ||
1020 | result = TRACE_SIGNAL_DELIVERED; | |
1da177e4 LT |
1021 | /* |
1022 | * fast-pathed signals for kernel-internal things like SIGSTOP | |
1023 | * or SIGKILL. | |
1024 | */ | |
b67a1b9e | 1025 | if (info == SEND_SIG_FORCED) |
1da177e4 LT |
1026 | goto out_set; |
1027 | ||
5aba085e RD |
1028 | /* |
1029 | * Real-time signals must be queued if sent by sigqueue, or | |
1030 | * some other real-time mechanism. It is implementation | |
1031 | * defined whether kill() does so. We attempt to do so, on | |
1032 | * the principle of least surprise, but since kill is not | |
1033 | * allowed to fail with EAGAIN when low on memory we just | |
1034 | * make sure at least one signal gets delivered and don't | |
1035 | * pass on the info struct. | |
1036 | */ | |
7a0aeb14 VN |
1037 | if (sig < SIGRTMIN) |
1038 | override_rlimit = (is_si_special(info) || info->si_code >= 0); | |
1039 | else | |
1040 | override_rlimit = 0; | |
1041 | ||
75f296d9 | 1042 | q = __sigqueue_alloc(sig, t, GFP_ATOMIC, override_rlimit); |
1da177e4 | 1043 | if (q) { |
2ca3515a | 1044 | list_add_tail(&q->list, &pending->list); |
1da177e4 | 1045 | switch ((unsigned long) info) { |
b67a1b9e | 1046 | case (unsigned long) SEND_SIG_NOINFO: |
faf1f22b | 1047 | clear_siginfo(&q->info); |
1da177e4 LT |
1048 | q->info.si_signo = sig; |
1049 | q->info.si_errno = 0; | |
1050 | q->info.si_code = SI_USER; | |
9cd4fd10 | 1051 | q->info.si_pid = task_tgid_nr_ns(current, |
09bca05c | 1052 | task_active_pid_ns(t)); |
078de5f7 | 1053 | q->info.si_uid = from_kuid_munged(current_user_ns(), current_uid()); |
1da177e4 | 1054 | break; |
b67a1b9e | 1055 | case (unsigned long) SEND_SIG_PRIV: |
faf1f22b | 1056 | clear_siginfo(&q->info); |
1da177e4 LT |
1057 | q->info.si_signo = sig; |
1058 | q->info.si_errno = 0; | |
1059 | q->info.si_code = SI_KERNEL; | |
1060 | q->info.si_pid = 0; | |
1061 | q->info.si_uid = 0; | |
1062 | break; | |
1063 | default: | |
1064 | copy_siginfo(&q->info, info); | |
6588c1e3 SB |
1065 | if (from_ancestor_ns) |
1066 | q->info.si_pid = 0; | |
1da177e4 LT |
1067 | break; |
1068 | } | |
6b550f94 SH |
1069 | |
1070 | userns_fixup_signal_uid(&q->info, t); | |
1071 | ||
621d3121 | 1072 | } else if (!is_si_special(info)) { |
ba005e1f MH |
1073 | if (sig >= SIGRTMIN && info->si_code != SI_USER) { |
1074 | /* | |
1075 | * Queue overflow, abort. We may abort if the | |
1076 | * signal was rt and sent by user using something | |
1077 | * other than kill(). | |
1078 | */ | |
6c303d3a ON |
1079 | result = TRACE_SIGNAL_OVERFLOW_FAIL; |
1080 | ret = -EAGAIN; | |
1081 | goto ret; | |
ba005e1f MH |
1082 | } else { |
1083 | /* | |
1084 | * This is a silent loss of information. We still | |
1085 | * send the signal, but the *info bits are lost. | |
1086 | */ | |
6c303d3a | 1087 | result = TRACE_SIGNAL_LOSE_INFO; |
ba005e1f | 1088 | } |
1da177e4 LT |
1089 | } |
1090 | ||
1091 | out_set: | |
53c30337 | 1092 | signalfd_notify(t, sig); |
2ca3515a | 1093 | sigaddset(&pending->signal, sig); |
4cd4b6d4 | 1094 | complete_signal(sig, t, group); |
6c303d3a ON |
1095 | ret: |
1096 | trace_signal_generate(sig, info, t, group, result); | |
1097 | return ret; | |
1da177e4 LT |
1098 | } |
1099 | ||
7978b567 SB |
1100 | static int send_signal(int sig, struct siginfo *info, struct task_struct *t, |
1101 | int group) | |
1102 | { | |
921cf9f6 SB |
1103 | int from_ancestor_ns = 0; |
1104 | ||
1105 | #ifdef CONFIG_PID_NS | |
dd34200a ON |
1106 | from_ancestor_ns = si_fromuser(info) && |
1107 | !task_pid_nr_ns(current, task_active_pid_ns(t)); | |
921cf9f6 SB |
1108 | #endif |
1109 | ||
1110 | return __send_signal(sig, info, t, group, from_ancestor_ns); | |
7978b567 SB |
1111 | } |
1112 | ||
4aaefee5 | 1113 | static void print_fatal_signal(int signr) |
45807a1d | 1114 | { |
4aaefee5 | 1115 | struct pt_regs *regs = signal_pt_regs(); |
747800ef | 1116 | pr_info("potentially unexpected fatal signal %d.\n", signr); |
45807a1d | 1117 | |
ca5cd877 | 1118 | #if defined(__i386__) && !defined(__arch_um__) |
747800ef | 1119 | pr_info("code at %08lx: ", regs->ip); |
45807a1d IM |
1120 | { |
1121 | int i; | |
1122 | for (i = 0; i < 16; i++) { | |
1123 | unsigned char insn; | |
1124 | ||
b45c6e76 AK |
1125 | if (get_user(insn, (unsigned char *)(regs->ip + i))) |
1126 | break; | |
747800ef | 1127 | pr_cont("%02x ", insn); |
45807a1d IM |
1128 | } |
1129 | } | |
747800ef | 1130 | pr_cont("\n"); |
45807a1d | 1131 | #endif |
3a9f84d3 | 1132 | preempt_disable(); |
45807a1d | 1133 | show_regs(regs); |
3a9f84d3 | 1134 | preempt_enable(); |
45807a1d IM |
1135 | } |
1136 | ||
1137 | static int __init setup_print_fatal_signals(char *str) | |
1138 | { | |
1139 | get_option (&str, &print_fatal_signals); | |
1140 | ||
1141 | return 1; | |
1142 | } | |
1143 | ||
1144 | __setup("print-fatal-signals=", setup_print_fatal_signals); | |
1da177e4 | 1145 | |
4cd4b6d4 PE |
1146 | int |
1147 | __group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) | |
1148 | { | |
1149 | return send_signal(sig, info, p, 1); | |
1150 | } | |
1151 | ||
1da177e4 LT |
1152 | static int |
1153 | specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t) | |
1154 | { | |
4cd4b6d4 | 1155 | return send_signal(sig, info, t, 0); |
1da177e4 LT |
1156 | } |
1157 | ||
4a30debf ON |
1158 | int do_send_sig_info(int sig, struct siginfo *info, struct task_struct *p, |
1159 | bool group) | |
1160 | { | |
1161 | unsigned long flags; | |
1162 | int ret = -ESRCH; | |
1163 | ||
1164 | if (lock_task_sighand(p, &flags)) { | |
1165 | ret = send_signal(sig, info, p, group); | |
1166 | unlock_task_sighand(p, &flags); | |
1167 | } | |
1168 | ||
1169 | return ret; | |
1170 | } | |
1171 | ||
1da177e4 LT |
1172 | /* |
1173 | * Force a signal that the process can't ignore: if necessary | |
1174 | * we unblock the signal and change any SIG_IGN to SIG_DFL. | |
ae74c3b6 LT |
1175 | * |
1176 | * Note: If we unblock the signal, we always reset it to SIG_DFL, | |
1177 | * since we do not want to have a signal handler that was blocked | |
1178 | * be invoked when user space had explicitly blocked it. | |
1179 | * | |
80fe728d ON |
1180 | * We don't want to have recursive SIGSEGV's etc, for example, |
1181 | * that is why we also clear SIGNAL_UNKILLABLE. | |
1da177e4 | 1182 | */ |
1da177e4 LT |
1183 | int |
1184 | force_sig_info(int sig, struct siginfo *info, struct task_struct *t) | |
1185 | { | |
1186 | unsigned long int flags; | |
ae74c3b6 LT |
1187 | int ret, blocked, ignored; |
1188 | struct k_sigaction *action; | |
1da177e4 LT |
1189 | |
1190 | spin_lock_irqsave(&t->sighand->siglock, flags); | |
ae74c3b6 LT |
1191 | action = &t->sighand->action[sig-1]; |
1192 | ignored = action->sa.sa_handler == SIG_IGN; | |
1193 | blocked = sigismember(&t->blocked, sig); | |
1194 | if (blocked || ignored) { | |
1195 | action->sa.sa_handler = SIG_DFL; | |
1196 | if (blocked) { | |
1197 | sigdelset(&t->blocked, sig); | |
7bb44ade | 1198 | recalc_sigpending_and_wake(t); |
ae74c3b6 | 1199 | } |
1da177e4 | 1200 | } |
eb61b591 JI |
1201 | /* |
1202 | * Don't clear SIGNAL_UNKILLABLE for traced tasks, users won't expect | |
1203 | * debugging to leave init killable. | |
1204 | */ | |
1205 | if (action->sa.sa_handler == SIG_DFL && !t->ptrace) | |
80fe728d | 1206 | t->signal->flags &= ~SIGNAL_UNKILLABLE; |
1da177e4 LT |
1207 | ret = specific_send_sig_info(sig, info, t); |
1208 | spin_unlock_irqrestore(&t->sighand->siglock, flags); | |
1209 | ||
1210 | return ret; | |
1211 | } | |
1212 | ||
1da177e4 LT |
1213 | /* |
1214 | * Nuke all other threads in the group. | |
1215 | */ | |
09faef11 | 1216 | int zap_other_threads(struct task_struct *p) |
1da177e4 | 1217 | { |
09faef11 ON |
1218 | struct task_struct *t = p; |
1219 | int count = 0; | |
1da177e4 | 1220 | |
1da177e4 LT |
1221 | p->signal->group_stop_count = 0; |
1222 | ||
09faef11 | 1223 | while_each_thread(p, t) { |
6dfca329 | 1224 | task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK); |
09faef11 ON |
1225 | count++; |
1226 | ||
1227 | /* Don't bother with already dead threads */ | |
1da177e4 LT |
1228 | if (t->exit_state) |
1229 | continue; | |
1da177e4 | 1230 | sigaddset(&t->pending.signal, SIGKILL); |
1da177e4 LT |
1231 | signal_wake_up(t, 1); |
1232 | } | |
09faef11 ON |
1233 | |
1234 | return count; | |
1da177e4 LT |
1235 | } |
1236 | ||
b8ed374e NK |
1237 | struct sighand_struct *__lock_task_sighand(struct task_struct *tsk, |
1238 | unsigned long *flags) | |
f63ee72e ON |
1239 | { |
1240 | struct sighand_struct *sighand; | |
1241 | ||
59dc6f3c | 1242 | rcu_read_lock(); |
f63ee72e ON |
1243 | for (;;) { |
1244 | sighand = rcu_dereference(tsk->sighand); | |
59dc6f3c | 1245 | if (unlikely(sighand == NULL)) |
f63ee72e | 1246 | break; |
59dc6f3c | 1247 | |
392809b2 ON |
1248 | /* |
1249 | * This sighand can be already freed and even reused, but | |
5f0d5a3a | 1250 | * we rely on SLAB_TYPESAFE_BY_RCU and sighand_ctor() which |
392809b2 ON |
1251 | * initializes ->siglock: this slab can't go away, it has |
1252 | * the same object type, ->siglock can't be reinitialized. | |
1253 | * | |
1254 | * We need to ensure that tsk->sighand is still the same | |
1255 | * after we take the lock, we can race with de_thread() or | |
1256 | * __exit_signal(). In the latter case the next iteration | |
1257 | * must see ->sighand == NULL. | |
1258 | */ | |
59dc6f3c AMG |
1259 | spin_lock_irqsave(&sighand->siglock, *flags); |
1260 | if (likely(sighand == tsk->sighand)) | |
f63ee72e | 1261 | break; |
59dc6f3c | 1262 | spin_unlock_irqrestore(&sighand->siglock, *flags); |
f63ee72e | 1263 | } |
59dc6f3c | 1264 | rcu_read_unlock(); |
f63ee72e ON |
1265 | |
1266 | return sighand; | |
1267 | } | |
1268 | ||
c69e8d9c DH |
1269 | /* |
1270 | * send signal info to all the members of a group | |
c69e8d9c | 1271 | */ |
1da177e4 LT |
1272 | int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) |
1273 | { | |
694f690d DH |
1274 | int ret; |
1275 | ||
1276 | rcu_read_lock(); | |
1277 | ret = check_kill_permission(sig, info, p); | |
1278 | rcu_read_unlock(); | |
f63ee72e | 1279 | |
4a30debf ON |
1280 | if (!ret && sig) |
1281 | ret = do_send_sig_info(sig, info, p, true); | |
1da177e4 LT |
1282 | |
1283 | return ret; | |
1284 | } | |
1285 | ||
1286 | /* | |
146a505d | 1287 | * __kill_pgrp_info() sends a signal to a process group: this is what the tty |
1da177e4 | 1288 | * control characters do (^C, ^Z etc) |
c69e8d9c | 1289 | * - the caller must hold at least a readlock on tasklist_lock |
1da177e4 | 1290 | */ |
c4b92fc1 | 1291 | int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp) |
1da177e4 LT |
1292 | { |
1293 | struct task_struct *p = NULL; | |
1294 | int retval, success; | |
1295 | ||
1da177e4 LT |
1296 | success = 0; |
1297 | retval = -ESRCH; | |
c4b92fc1 | 1298 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
1da177e4 LT |
1299 | int err = group_send_sig_info(sig, info, p); |
1300 | success |= !err; | |
1301 | retval = err; | |
c4b92fc1 | 1302 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
1da177e4 LT |
1303 | return success ? 0 : retval; |
1304 | } | |
1305 | ||
c4b92fc1 | 1306 | int kill_pid_info(int sig, struct siginfo *info, struct pid *pid) |
1da177e4 | 1307 | { |
d36174bc | 1308 | int error = -ESRCH; |
1da177e4 LT |
1309 | struct task_struct *p; |
1310 | ||
eca1a089 PM |
1311 | for (;;) { |
1312 | rcu_read_lock(); | |
1313 | p = pid_task(pid, PIDTYPE_PID); | |
1314 | if (p) | |
1315 | error = group_send_sig_info(sig, info, p); | |
1316 | rcu_read_unlock(); | |
1317 | if (likely(!p || error != -ESRCH)) | |
1318 | return error; | |
6ca25b55 | 1319 | |
eca1a089 PM |
1320 | /* |
1321 | * The task was unhashed in between, try again. If it | |
1322 | * is dead, pid_task() will return NULL, if we race with | |
1323 | * de_thread() it will find the new leader. | |
1324 | */ | |
1325 | } | |
1da177e4 LT |
1326 | } |
1327 | ||
6c478ae9 | 1328 | static int kill_proc_info(int sig, struct siginfo *info, pid_t pid) |
c4b92fc1 EB |
1329 | { |
1330 | int error; | |
1331 | rcu_read_lock(); | |
b488893a | 1332 | error = kill_pid_info(sig, info, find_vpid(pid)); |
c4b92fc1 EB |
1333 | rcu_read_unlock(); |
1334 | return error; | |
1335 | } | |
1336 | ||
bb17fcca CB |
1337 | static inline bool kill_as_cred_perm(const struct cred *cred, |
1338 | struct task_struct *target) | |
d178bc3a SH |
1339 | { |
1340 | const struct cred *pcred = __task_cred(target); | |
bb17fcca CB |
1341 | |
1342 | return uid_eq(cred->euid, pcred->suid) || | |
1343 | uid_eq(cred->euid, pcred->uid) || | |
1344 | uid_eq(cred->uid, pcred->suid) || | |
1345 | uid_eq(cred->uid, pcred->uid); | |
d178bc3a SH |
1346 | } |
1347 | ||
2425c08b | 1348 | /* like kill_pid_info(), but doesn't use uid/euid of "current" */ |
d178bc3a | 1349 | int kill_pid_info_as_cred(int sig, struct siginfo *info, struct pid *pid, |
6b4f3d01 | 1350 | const struct cred *cred) |
46113830 HW |
1351 | { |
1352 | int ret = -EINVAL; | |
1353 | struct task_struct *p; | |
14d8c9f3 | 1354 | unsigned long flags; |
46113830 HW |
1355 | |
1356 | if (!valid_signal(sig)) | |
1357 | return ret; | |
1358 | ||
14d8c9f3 | 1359 | rcu_read_lock(); |
2425c08b | 1360 | p = pid_task(pid, PIDTYPE_PID); |
46113830 HW |
1361 | if (!p) { |
1362 | ret = -ESRCH; | |
1363 | goto out_unlock; | |
1364 | } | |
d178bc3a | 1365 | if (si_fromuser(info) && !kill_as_cred_perm(cred, p)) { |
46113830 HW |
1366 | ret = -EPERM; |
1367 | goto out_unlock; | |
1368 | } | |
6b4f3d01 | 1369 | ret = security_task_kill(p, info, sig, cred); |
8f95dc58 DQ |
1370 | if (ret) |
1371 | goto out_unlock; | |
14d8c9f3 TG |
1372 | |
1373 | if (sig) { | |
1374 | if (lock_task_sighand(p, &flags)) { | |
1375 | ret = __send_signal(sig, info, p, 1, 0); | |
1376 | unlock_task_sighand(p, &flags); | |
1377 | } else | |
1378 | ret = -ESRCH; | |
46113830 HW |
1379 | } |
1380 | out_unlock: | |
14d8c9f3 | 1381 | rcu_read_unlock(); |
46113830 HW |
1382 | return ret; |
1383 | } | |
d178bc3a | 1384 | EXPORT_SYMBOL_GPL(kill_pid_info_as_cred); |
1da177e4 LT |
1385 | |
1386 | /* | |
1387 | * kill_something_info() interprets pid in interesting ways just like kill(2). | |
1388 | * | |
1389 | * POSIX specifies that kill(-1,sig) is unspecified, but what we have | |
1390 | * is probably wrong. Should make it like BSD or SYSV. | |
1391 | */ | |
1392 | ||
bc64efd2 | 1393 | static int kill_something_info(int sig, struct siginfo *info, pid_t pid) |
1da177e4 | 1394 | { |
8d42db18 | 1395 | int ret; |
d5df763b PE |
1396 | |
1397 | if (pid > 0) { | |
1398 | rcu_read_lock(); | |
1399 | ret = kill_pid_info(sig, info, find_vpid(pid)); | |
1400 | rcu_read_unlock(); | |
1401 | return ret; | |
1402 | } | |
1403 | ||
4ea77014 | 1404 | /* -INT_MIN is undefined. Exclude this case to avoid a UBSAN warning */ |
1405 | if (pid == INT_MIN) | |
1406 | return -ESRCH; | |
1407 | ||
d5df763b PE |
1408 | read_lock(&tasklist_lock); |
1409 | if (pid != -1) { | |
1410 | ret = __kill_pgrp_info(sig, info, | |
1411 | pid ? find_vpid(-pid) : task_pgrp(current)); | |
1412 | } else { | |
1da177e4 LT |
1413 | int retval = 0, count = 0; |
1414 | struct task_struct * p; | |
1415 | ||
1da177e4 | 1416 | for_each_process(p) { |
d25141a8 SB |
1417 | if (task_pid_vnr(p) > 1 && |
1418 | !same_thread_group(p, current)) { | |
1da177e4 LT |
1419 | int err = group_send_sig_info(sig, info, p); |
1420 | ++count; | |
1421 | if (err != -EPERM) | |
1422 | retval = err; | |
1423 | } | |
1424 | } | |
8d42db18 | 1425 | ret = count ? retval : -ESRCH; |
1da177e4 | 1426 | } |
d5df763b PE |
1427 | read_unlock(&tasklist_lock); |
1428 | ||
8d42db18 | 1429 | return ret; |
1da177e4 LT |
1430 | } |
1431 | ||
1432 | /* | |
1433 | * These are for backward compatibility with the rest of the kernel source. | |
1434 | */ | |
1435 | ||
5aba085e | 1436 | int send_sig_info(int sig, struct siginfo *info, struct task_struct *p) |
1da177e4 | 1437 | { |
1da177e4 LT |
1438 | /* |
1439 | * Make sure legacy kernel users don't send in bad values | |
1440 | * (normal paths check this in check_kill_permission). | |
1441 | */ | |
7ed20e1a | 1442 | if (!valid_signal(sig)) |
1da177e4 LT |
1443 | return -EINVAL; |
1444 | ||
4a30debf | 1445 | return do_send_sig_info(sig, info, p, false); |
1da177e4 LT |
1446 | } |
1447 | ||
b67a1b9e ON |
1448 | #define __si_special(priv) \ |
1449 | ((priv) ? SEND_SIG_PRIV : SEND_SIG_NOINFO) | |
1450 | ||
1da177e4 LT |
1451 | int |
1452 | send_sig(int sig, struct task_struct *p, int priv) | |
1453 | { | |
b67a1b9e | 1454 | return send_sig_info(sig, __si_special(priv), p); |
1da177e4 LT |
1455 | } |
1456 | ||
52cba1a2 | 1457 | void force_sig(int sig, struct task_struct *p) |
1da177e4 | 1458 | { |
b67a1b9e | 1459 | force_sig_info(sig, SEND_SIG_PRIV, p); |
1da177e4 LT |
1460 | } |
1461 | ||
1462 | /* | |
1463 | * When things go south during signal handling, we | |
1464 | * will force a SIGSEGV. And if the signal that caused | |
1465 | * the problem was already a SIGSEGV, we'll want to | |
1466 | * make sure we don't even try to deliver the signal.. | |
1467 | */ | |
52cba1a2 | 1468 | void force_sigsegv(int sig, struct task_struct *p) |
1da177e4 LT |
1469 | { |
1470 | if (sig == SIGSEGV) { | |
1471 | unsigned long flags; | |
1472 | spin_lock_irqsave(&p->sighand->siglock, flags); | |
1473 | p->sighand->action[sig - 1].sa.sa_handler = SIG_DFL; | |
1474 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | |
1475 | } | |
1476 | force_sig(SIGSEGV, p); | |
1da177e4 LT |
1477 | } |
1478 | ||
f8ec6601 EB |
1479 | int force_sig_fault(int sig, int code, void __user *addr |
1480 | ___ARCH_SI_TRAPNO(int trapno) | |
1481 | ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr) | |
1482 | , struct task_struct *t) | |
1483 | { | |
1484 | struct siginfo info; | |
1485 | ||
1486 | clear_siginfo(&info); | |
1487 | info.si_signo = sig; | |
1488 | info.si_errno = 0; | |
1489 | info.si_code = code; | |
1490 | info.si_addr = addr; | |
1491 | #ifdef __ARCH_SI_TRAPNO | |
1492 | info.si_trapno = trapno; | |
1493 | #endif | |
1494 | #ifdef __ia64__ | |
1495 | info.si_imm = imm; | |
1496 | info.si_flags = flags; | |
1497 | info.si_isr = isr; | |
1498 | #endif | |
1499 | return force_sig_info(info.si_signo, &info, t); | |
1500 | } | |
1501 | ||
1502 | int send_sig_fault(int sig, int code, void __user *addr | |
1503 | ___ARCH_SI_TRAPNO(int trapno) | |
1504 | ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr) | |
1505 | , struct task_struct *t) | |
1506 | { | |
1507 | struct siginfo info; | |
1508 | ||
1509 | clear_siginfo(&info); | |
1510 | info.si_signo = sig; | |
1511 | info.si_errno = 0; | |
1512 | info.si_code = code; | |
1513 | info.si_addr = addr; | |
1514 | #ifdef __ARCH_SI_TRAPNO | |
1515 | info.si_trapno = trapno; | |
1516 | #endif | |
1517 | #ifdef __ia64__ | |
1518 | info.si_imm = imm; | |
1519 | info.si_flags = flags; | |
1520 | info.si_isr = isr; | |
1521 | #endif | |
1522 | return send_sig_info(info.si_signo, &info, t); | |
1523 | } | |
1524 | ||
38246735 EB |
1525 | int force_sig_mceerr(int code, void __user *addr, short lsb, struct task_struct *t) |
1526 | { | |
1527 | struct siginfo info; | |
1528 | ||
1529 | WARN_ON((code != BUS_MCEERR_AO) && (code != BUS_MCEERR_AR)); | |
1530 | clear_siginfo(&info); | |
1531 | info.si_signo = SIGBUS; | |
1532 | info.si_errno = 0; | |
1533 | info.si_code = code; | |
1534 | info.si_addr = addr; | |
1535 | info.si_addr_lsb = lsb; | |
1536 | return force_sig_info(info.si_signo, &info, t); | |
1537 | } | |
1538 | ||
1539 | int send_sig_mceerr(int code, void __user *addr, short lsb, struct task_struct *t) | |
1540 | { | |
1541 | struct siginfo info; | |
1542 | ||
1543 | WARN_ON((code != BUS_MCEERR_AO) && (code != BUS_MCEERR_AR)); | |
1544 | clear_siginfo(&info); | |
1545 | info.si_signo = SIGBUS; | |
1546 | info.si_errno = 0; | |
1547 | info.si_code = code; | |
1548 | info.si_addr = addr; | |
1549 | info.si_addr_lsb = lsb; | |
1550 | return send_sig_info(info.si_signo, &info, t); | |
1551 | } | |
1552 | EXPORT_SYMBOL(send_sig_mceerr); | |
38246735 | 1553 | |
38246735 EB |
1554 | int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper) |
1555 | { | |
1556 | struct siginfo info; | |
1557 | ||
1558 | clear_siginfo(&info); | |
1559 | info.si_signo = SIGSEGV; | |
1560 | info.si_errno = 0; | |
1561 | info.si_code = SEGV_BNDERR; | |
1562 | info.si_addr = addr; | |
1563 | info.si_lower = lower; | |
1564 | info.si_upper = upper; | |
1565 | return force_sig_info(info.si_signo, &info, current); | |
1566 | } | |
38246735 EB |
1567 | |
1568 | #ifdef SEGV_PKUERR | |
1569 | int force_sig_pkuerr(void __user *addr, u32 pkey) | |
1570 | { | |
1571 | struct siginfo info; | |
1572 | ||
1573 | clear_siginfo(&info); | |
1574 | info.si_signo = SIGSEGV; | |
1575 | info.si_errno = 0; | |
1576 | info.si_code = SEGV_PKUERR; | |
1577 | info.si_addr = addr; | |
1578 | info.si_pkey = pkey; | |
1579 | return force_sig_info(info.si_signo, &info, current); | |
1580 | } | |
1581 | #endif | |
f8ec6601 | 1582 | |
f71dd7dc EB |
1583 | /* For the crazy architectures that include trap information in |
1584 | * the errno field, instead of an actual errno value. | |
1585 | */ | |
1586 | int force_sig_ptrace_errno_trap(int errno, void __user *addr) | |
1587 | { | |
1588 | struct siginfo info; | |
1589 | ||
1590 | clear_siginfo(&info); | |
1591 | info.si_signo = SIGTRAP; | |
1592 | info.si_errno = errno; | |
1593 | info.si_code = TRAP_HWBKPT; | |
1594 | info.si_addr = addr; | |
1595 | return force_sig_info(info.si_signo, &info, current); | |
1596 | } | |
1597 | ||
c4b92fc1 EB |
1598 | int kill_pgrp(struct pid *pid, int sig, int priv) |
1599 | { | |
146a505d PE |
1600 | int ret; |
1601 | ||
1602 | read_lock(&tasklist_lock); | |
1603 | ret = __kill_pgrp_info(sig, __si_special(priv), pid); | |
1604 | read_unlock(&tasklist_lock); | |
1605 | ||
1606 | return ret; | |
c4b92fc1 EB |
1607 | } |
1608 | EXPORT_SYMBOL(kill_pgrp); | |
1609 | ||
1610 | int kill_pid(struct pid *pid, int sig, int priv) | |
1611 | { | |
1612 | return kill_pid_info(sig, __si_special(priv), pid); | |
1613 | } | |
1614 | EXPORT_SYMBOL(kill_pid); | |
1615 | ||
1da177e4 LT |
1616 | /* |
1617 | * These functions support sending signals using preallocated sigqueue | |
1618 | * structures. This is needed "because realtime applications cannot | |
1619 | * afford to lose notifications of asynchronous events, like timer | |
5aba085e | 1620 | * expirations or I/O completions". In the case of POSIX Timers |
1da177e4 LT |
1621 | * we allocate the sigqueue structure from the timer_create. If this |
1622 | * allocation fails we are able to report the failure to the application | |
1623 | * with an EAGAIN error. | |
1624 | */ | |
1da177e4 LT |
1625 | struct sigqueue *sigqueue_alloc(void) |
1626 | { | |
f84d49b2 | 1627 | struct sigqueue *q = __sigqueue_alloc(-1, current, GFP_KERNEL, 0); |
1da177e4 | 1628 | |
f84d49b2 | 1629 | if (q) |
1da177e4 | 1630 | q->flags |= SIGQUEUE_PREALLOC; |
f84d49b2 NO |
1631 | |
1632 | return q; | |
1da177e4 LT |
1633 | } |
1634 | ||
1635 | void sigqueue_free(struct sigqueue *q) | |
1636 | { | |
1637 | unsigned long flags; | |
60187d27 ON |
1638 | spinlock_t *lock = ¤t->sighand->siglock; |
1639 | ||
1da177e4 LT |
1640 | BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); |
1641 | /* | |
c8e85b4f ON |
1642 | * We must hold ->siglock while testing q->list |
1643 | * to serialize with collect_signal() or with | |
da7978b0 | 1644 | * __exit_signal()->flush_sigqueue(). |
1da177e4 | 1645 | */ |
60187d27 | 1646 | spin_lock_irqsave(lock, flags); |
c8e85b4f ON |
1647 | q->flags &= ~SIGQUEUE_PREALLOC; |
1648 | /* | |
1649 | * If it is queued it will be freed when dequeued, | |
1650 | * like the "regular" sigqueue. | |
1651 | */ | |
60187d27 | 1652 | if (!list_empty(&q->list)) |
c8e85b4f | 1653 | q = NULL; |
60187d27 ON |
1654 | spin_unlock_irqrestore(lock, flags); |
1655 | ||
c8e85b4f ON |
1656 | if (q) |
1657 | __sigqueue_free(q); | |
1da177e4 LT |
1658 | } |
1659 | ||
ac5c2153 | 1660 | int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group) |
9e3bd6c3 | 1661 | { |
e62e6650 | 1662 | int sig = q->info.si_signo; |
2ca3515a | 1663 | struct sigpending *pending; |
e62e6650 | 1664 | unsigned long flags; |
163566f6 | 1665 | int ret, result; |
2ca3515a | 1666 | |
4cd4b6d4 | 1667 | BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); |
e62e6650 ON |
1668 | |
1669 | ret = -1; | |
1670 | if (!likely(lock_task_sighand(t, &flags))) | |
1671 | goto ret; | |
1672 | ||
7e695a5e | 1673 | ret = 1; /* the signal is ignored */ |
163566f6 | 1674 | result = TRACE_SIGNAL_IGNORED; |
def8cf72 | 1675 | if (!prepare_signal(sig, t, false)) |
e62e6650 ON |
1676 | goto out; |
1677 | ||
1678 | ret = 0; | |
9e3bd6c3 PE |
1679 | if (unlikely(!list_empty(&q->list))) { |
1680 | /* | |
1681 | * If an SI_TIMER entry is already queue just increment | |
1682 | * the overrun count. | |
1683 | */ | |
9e3bd6c3 PE |
1684 | BUG_ON(q->info.si_code != SI_TIMER); |
1685 | q->info.si_overrun++; | |
163566f6 | 1686 | result = TRACE_SIGNAL_ALREADY_PENDING; |
e62e6650 | 1687 | goto out; |
9e3bd6c3 | 1688 | } |
ba661292 | 1689 | q->info.si_overrun = 0; |
9e3bd6c3 | 1690 | |
9e3bd6c3 | 1691 | signalfd_notify(t, sig); |
2ca3515a | 1692 | pending = group ? &t->signal->shared_pending : &t->pending; |
9e3bd6c3 PE |
1693 | list_add_tail(&q->list, &pending->list); |
1694 | sigaddset(&pending->signal, sig); | |
4cd4b6d4 | 1695 | complete_signal(sig, t, group); |
163566f6 | 1696 | result = TRACE_SIGNAL_DELIVERED; |
e62e6650 | 1697 | out: |
163566f6 | 1698 | trace_signal_generate(sig, &q->info, t, group, result); |
e62e6650 ON |
1699 | unlock_task_sighand(t, &flags); |
1700 | ret: | |
1701 | return ret; | |
9e3bd6c3 PE |
1702 | } |
1703 | ||
1da177e4 LT |
1704 | /* |
1705 | * Let a parent know about the death of a child. | |
1706 | * For a stopped/continued status change, use do_notify_parent_cldstop instead. | |
2b2a1ff6 | 1707 | * |
53c8f9f1 ON |
1708 | * Returns true if our parent ignored us and so we've switched to |
1709 | * self-reaping. | |
1da177e4 | 1710 | */ |
53c8f9f1 | 1711 | bool do_notify_parent(struct task_struct *tsk, int sig) |
1da177e4 LT |
1712 | { |
1713 | struct siginfo info; | |
1714 | unsigned long flags; | |
1715 | struct sighand_struct *psig; | |
53c8f9f1 | 1716 | bool autoreap = false; |
bde8285e | 1717 | u64 utime, stime; |
1da177e4 LT |
1718 | |
1719 | BUG_ON(sig == -1); | |
1720 | ||
1721 | /* do_notify_parent_cldstop should have been called instead. */ | |
e1abb39c | 1722 | BUG_ON(task_is_stopped_or_traced(tsk)); |
1da177e4 | 1723 | |
d21142ec | 1724 | BUG_ON(!tsk->ptrace && |
1da177e4 LT |
1725 | (tsk->group_leader != tsk || !thread_group_empty(tsk))); |
1726 | ||
b6e238dc ON |
1727 | if (sig != SIGCHLD) { |
1728 | /* | |
1729 | * This is only possible if parent == real_parent. | |
1730 | * Check if it has changed security domain. | |
1731 | */ | |
1732 | if (tsk->parent_exec_id != tsk->parent->self_exec_id) | |
1733 | sig = SIGCHLD; | |
1734 | } | |
1735 | ||
faf1f22b | 1736 | clear_siginfo(&info); |
1da177e4 LT |
1737 | info.si_signo = sig; |
1738 | info.si_errno = 0; | |
b488893a | 1739 | /* |
32084504 EB |
1740 | * We are under tasklist_lock here so our parent is tied to |
1741 | * us and cannot change. | |
b488893a | 1742 | * |
32084504 EB |
1743 | * task_active_pid_ns will always return the same pid namespace |
1744 | * until a task passes through release_task. | |
b488893a PE |
1745 | * |
1746 | * write_lock() currently calls preempt_disable() which is the | |
1747 | * same as rcu_read_lock(), but according to Oleg, this is not | |
1748 | * correct to rely on this | |
1749 | */ | |
1750 | rcu_read_lock(); | |
32084504 | 1751 | info.si_pid = task_pid_nr_ns(tsk, task_active_pid_ns(tsk->parent)); |
54ba47ed EB |
1752 | info.si_uid = from_kuid_munged(task_cred_xxx(tsk->parent, user_ns), |
1753 | task_uid(tsk)); | |
b488893a PE |
1754 | rcu_read_unlock(); |
1755 | ||
bde8285e FW |
1756 | task_cputime(tsk, &utime, &stime); |
1757 | info.si_utime = nsec_to_clock_t(utime + tsk->signal->utime); | |
1758 | info.si_stime = nsec_to_clock_t(stime + tsk->signal->stime); | |
1da177e4 LT |
1759 | |
1760 | info.si_status = tsk->exit_code & 0x7f; | |
1761 | if (tsk->exit_code & 0x80) | |
1762 | info.si_code = CLD_DUMPED; | |
1763 | else if (tsk->exit_code & 0x7f) | |
1764 | info.si_code = CLD_KILLED; | |
1765 | else { | |
1766 | info.si_code = CLD_EXITED; | |
1767 | info.si_status = tsk->exit_code >> 8; | |
1768 | } | |
1769 | ||
1770 | psig = tsk->parent->sighand; | |
1771 | spin_lock_irqsave(&psig->siglock, flags); | |
d21142ec | 1772 | if (!tsk->ptrace && sig == SIGCHLD && |
1da177e4 LT |
1773 | (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN || |
1774 | (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT))) { | |
1775 | /* | |
1776 | * We are exiting and our parent doesn't care. POSIX.1 | |
1777 | * defines special semantics for setting SIGCHLD to SIG_IGN | |
1778 | * or setting the SA_NOCLDWAIT flag: we should be reaped | |
1779 | * automatically and not left for our parent's wait4 call. | |
1780 | * Rather than having the parent do it as a magic kind of | |
1781 | * signal handler, we just set this to tell do_exit that we | |
1782 | * can be cleaned up without becoming a zombie. Note that | |
1783 | * we still call __wake_up_parent in this case, because a | |
1784 | * blocked sys_wait4 might now return -ECHILD. | |
1785 | * | |
1786 | * Whether we send SIGCHLD or not for SA_NOCLDWAIT | |
1787 | * is implementation-defined: we do (if you don't want | |
1788 | * it, just use SIG_IGN instead). | |
1789 | */ | |
53c8f9f1 | 1790 | autoreap = true; |
1da177e4 | 1791 | if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) |
53c8f9f1 | 1792 | sig = 0; |
1da177e4 | 1793 | } |
53c8f9f1 | 1794 | if (valid_signal(sig) && sig) |
1da177e4 LT |
1795 | __group_send_sig_info(sig, &info, tsk->parent); |
1796 | __wake_up_parent(tsk, tsk->parent); | |
1797 | spin_unlock_irqrestore(&psig->siglock, flags); | |
2b2a1ff6 | 1798 | |
53c8f9f1 | 1799 | return autoreap; |
1da177e4 LT |
1800 | } |
1801 | ||
75b95953 TH |
1802 | /** |
1803 | * do_notify_parent_cldstop - notify parent of stopped/continued state change | |
1804 | * @tsk: task reporting the state change | |
1805 | * @for_ptracer: the notification is for ptracer | |
1806 | * @why: CLD_{CONTINUED|STOPPED|TRAPPED} to report | |
1807 | * | |
1808 | * Notify @tsk's parent that the stopped/continued state has changed. If | |
1809 | * @for_ptracer is %false, @tsk's group leader notifies to its real parent. | |
1810 | * If %true, @tsk reports to @tsk->parent which should be the ptracer. | |
1811 | * | |
1812 | * CONTEXT: | |
1813 | * Must be called with tasklist_lock at least read locked. | |
1814 | */ | |
1815 | static void do_notify_parent_cldstop(struct task_struct *tsk, | |
1816 | bool for_ptracer, int why) | |
1da177e4 LT |
1817 | { |
1818 | struct siginfo info; | |
1819 | unsigned long flags; | |
bc505a47 | 1820 | struct task_struct *parent; |
1da177e4 | 1821 | struct sighand_struct *sighand; |
bde8285e | 1822 | u64 utime, stime; |
1da177e4 | 1823 | |
75b95953 | 1824 | if (for_ptracer) { |
bc505a47 | 1825 | parent = tsk->parent; |
75b95953 | 1826 | } else { |
bc505a47 ON |
1827 | tsk = tsk->group_leader; |
1828 | parent = tsk->real_parent; | |
1829 | } | |
1830 | ||
faf1f22b | 1831 | clear_siginfo(&info); |
1da177e4 LT |
1832 | info.si_signo = SIGCHLD; |
1833 | info.si_errno = 0; | |
b488893a | 1834 | /* |
5aba085e | 1835 | * see comment in do_notify_parent() about the following 4 lines |
b488893a PE |
1836 | */ |
1837 | rcu_read_lock(); | |
17cf22c3 | 1838 | info.si_pid = task_pid_nr_ns(tsk, task_active_pid_ns(parent)); |
54ba47ed | 1839 | info.si_uid = from_kuid_munged(task_cred_xxx(parent, user_ns), task_uid(tsk)); |
b488893a PE |
1840 | rcu_read_unlock(); |
1841 | ||
bde8285e FW |
1842 | task_cputime(tsk, &utime, &stime); |
1843 | info.si_utime = nsec_to_clock_t(utime); | |
1844 | info.si_stime = nsec_to_clock_t(stime); | |
1da177e4 LT |
1845 | |
1846 | info.si_code = why; | |
1847 | switch (why) { | |
1848 | case CLD_CONTINUED: | |
1849 | info.si_status = SIGCONT; | |
1850 | break; | |
1851 | case CLD_STOPPED: | |
1852 | info.si_status = tsk->signal->group_exit_code & 0x7f; | |
1853 | break; | |
1854 | case CLD_TRAPPED: | |
1855 | info.si_status = tsk->exit_code & 0x7f; | |
1856 | break; | |
1857 | default: | |
1858 | BUG(); | |
1859 | } | |
1860 | ||
1861 | sighand = parent->sighand; | |
1862 | spin_lock_irqsave(&sighand->siglock, flags); | |
1863 | if (sighand->action[SIGCHLD-1].sa.sa_handler != SIG_IGN && | |
1864 | !(sighand->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDSTOP)) | |
1865 | __group_send_sig_info(SIGCHLD, &info, parent); | |
1866 | /* | |
1867 | * Even if SIGCHLD is not generated, we must wake up wait4 calls. | |
1868 | */ | |
1869 | __wake_up_parent(tsk, parent); | |
1870 | spin_unlock_irqrestore(&sighand->siglock, flags); | |
1871 | } | |
1872 | ||
6527de95 | 1873 | static inline bool may_ptrace_stop(void) |
d5f70c00 | 1874 | { |
d21142ec | 1875 | if (!likely(current->ptrace)) |
6527de95 | 1876 | return false; |
d5f70c00 ON |
1877 | /* |
1878 | * Are we in the middle of do_coredump? | |
1879 | * If so and our tracer is also part of the coredump stopping | |
1880 | * is a deadlock situation, and pointless because our tracer | |
1881 | * is dead so don't allow us to stop. | |
1882 | * If SIGKILL was already sent before the caller unlocked | |
999d9fc1 | 1883 | * ->siglock we must see ->core_state != NULL. Otherwise it |
d5f70c00 | 1884 | * is safe to enter schedule(). |
9899d11f ON |
1885 | * |
1886 | * This is almost outdated, a task with the pending SIGKILL can't | |
1887 | * block in TASK_TRACED. But PTRACE_EVENT_EXIT can be reported | |
1888 | * after SIGKILL was already dequeued. | |
d5f70c00 | 1889 | */ |
999d9fc1 | 1890 | if (unlikely(current->mm->core_state) && |
d5f70c00 | 1891 | unlikely(current->mm == current->parent->mm)) |
6527de95 | 1892 | return false; |
d5f70c00 | 1893 | |
6527de95 | 1894 | return true; |
d5f70c00 ON |
1895 | } |
1896 | ||
1a669c2f | 1897 | /* |
5aba085e | 1898 | * Return non-zero if there is a SIGKILL that should be waking us up. |
1a669c2f RM |
1899 | * Called with the siglock held. |
1900 | */ | |
1901 | static int sigkill_pending(struct task_struct *tsk) | |
1902 | { | |
3d749b9e ON |
1903 | return sigismember(&tsk->pending.signal, SIGKILL) || |
1904 | sigismember(&tsk->signal->shared_pending.signal, SIGKILL); | |
1a669c2f RM |
1905 | } |
1906 | ||
1da177e4 LT |
1907 | /* |
1908 | * This must be called with current->sighand->siglock held. | |
1909 | * | |
1910 | * This should be the path for all ptrace stops. | |
1911 | * We always set current->last_siginfo while stopped here. | |
1912 | * That makes it a way to test a stopped process for | |
1913 | * being ptrace-stopped vs being job-control-stopped. | |
1914 | * | |
20686a30 ON |
1915 | * If we actually decide not to stop at all because the tracer |
1916 | * is gone, we keep current->exit_code unless clear_code. | |
1da177e4 | 1917 | */ |
fe1bc6a0 | 1918 | static void ptrace_stop(int exit_code, int why, int clear_code, siginfo_t *info) |
b8401150 NK |
1919 | __releases(¤t->sighand->siglock) |
1920 | __acquires(¤t->sighand->siglock) | |
1da177e4 | 1921 | { |
ceb6bd67 TH |
1922 | bool gstop_done = false; |
1923 | ||
1a669c2f RM |
1924 | if (arch_ptrace_stop_needed(exit_code, info)) { |
1925 | /* | |
1926 | * The arch code has something special to do before a | |
1927 | * ptrace stop. This is allowed to block, e.g. for faults | |
1928 | * on user stack pages. We can't keep the siglock while | |
1929 | * calling arch_ptrace_stop, so we must release it now. | |
1930 | * To preserve proper semantics, we must do this before | |
1931 | * any signal bookkeeping like checking group_stop_count. | |
1932 | * Meanwhile, a SIGKILL could come in before we retake the | |
1933 | * siglock. That must prevent us from sleeping in TASK_TRACED. | |
1934 | * So after regaining the lock, we must check for SIGKILL. | |
1935 | */ | |
1936 | spin_unlock_irq(¤t->sighand->siglock); | |
1937 | arch_ptrace_stop(exit_code, info); | |
1938 | spin_lock_irq(¤t->sighand->siglock); | |
3d749b9e ON |
1939 | if (sigkill_pending(current)) |
1940 | return; | |
1a669c2f RM |
1941 | } |
1942 | ||
b5bf9a90 PZ |
1943 | set_special_state(TASK_TRACED); |
1944 | ||
1da177e4 | 1945 | /* |
81be24b8 TH |
1946 | * We're committing to trapping. TRACED should be visible before |
1947 | * TRAPPING is cleared; otherwise, the tracer might fail do_wait(). | |
1948 | * Also, transition to TRACED and updates to ->jobctl should be | |
1949 | * atomic with respect to siglock and should be done after the arch | |
1950 | * hook as siglock is released and regrabbed across it. | |
b5bf9a90 PZ |
1951 | * |
1952 | * TRACER TRACEE | |
1953 | * | |
1954 | * ptrace_attach() | |
1955 | * [L] wait_on_bit(JOBCTL_TRAPPING) [S] set_special_state(TRACED) | |
1956 | * do_wait() | |
1957 | * set_current_state() smp_wmb(); | |
1958 | * ptrace_do_wait() | |
1959 | * wait_task_stopped() | |
1960 | * task_stopped_code() | |
1961 | * [L] task_is_traced() [S] task_clear_jobctl_trapping(); | |
1da177e4 | 1962 | */ |
b5bf9a90 | 1963 | smp_wmb(); |
1da177e4 LT |
1964 | |
1965 | current->last_siginfo = info; | |
1966 | current->exit_code = exit_code; | |
1967 | ||
d79fdd6d | 1968 | /* |
0ae8ce1c TH |
1969 | * If @why is CLD_STOPPED, we're trapping to participate in a group |
1970 | * stop. Do the bookkeeping. Note that if SIGCONT was delievered | |
73ddff2b TH |
1971 | * across siglock relocks since INTERRUPT was scheduled, PENDING |
1972 | * could be clear now. We act as if SIGCONT is received after | |
1973 | * TASK_TRACED is entered - ignore it. | |
d79fdd6d | 1974 | */ |
a8f072c1 | 1975 | if (why == CLD_STOPPED && (current->jobctl & JOBCTL_STOP_PENDING)) |
ceb6bd67 | 1976 | gstop_done = task_participate_group_stop(current); |
d79fdd6d | 1977 | |
fb1d910c | 1978 | /* any trap clears pending STOP trap, STOP trap clears NOTIFY */ |
73ddff2b | 1979 | task_clear_jobctl_pending(current, JOBCTL_TRAP_STOP); |
fb1d910c TH |
1980 | if (info && info->si_code >> 8 == PTRACE_EVENT_STOP) |
1981 | task_clear_jobctl_pending(current, JOBCTL_TRAP_NOTIFY); | |
73ddff2b | 1982 | |
81be24b8 | 1983 | /* entering a trap, clear TRAPPING */ |
a8f072c1 | 1984 | task_clear_jobctl_trapping(current); |
d79fdd6d | 1985 | |
1da177e4 LT |
1986 | spin_unlock_irq(¤t->sighand->siglock); |
1987 | read_lock(&tasklist_lock); | |
3d749b9e | 1988 | if (may_ptrace_stop()) { |
ceb6bd67 TH |
1989 | /* |
1990 | * Notify parents of the stop. | |
1991 | * | |
1992 | * While ptraced, there are two parents - the ptracer and | |
1993 | * the real_parent of the group_leader. The ptracer should | |
1994 | * know about every stop while the real parent is only | |
1995 | * interested in the completion of group stop. The states | |
1996 | * for the two don't interact with each other. Notify | |
1997 | * separately unless they're gonna be duplicates. | |
1998 | */ | |
1999 | do_notify_parent_cldstop(current, true, why); | |
bb3696da | 2000 | if (gstop_done && ptrace_reparented(current)) |
ceb6bd67 TH |
2001 | do_notify_parent_cldstop(current, false, why); |
2002 | ||
53da1d94 MS |
2003 | /* |
2004 | * Don't want to allow preemption here, because | |
2005 | * sys_ptrace() needs this task to be inactive. | |
2006 | * | |
2007 | * XXX: implement read_unlock_no_resched(). | |
2008 | */ | |
2009 | preempt_disable(); | |
1da177e4 | 2010 | read_unlock(&tasklist_lock); |
53da1d94 | 2011 | preempt_enable_no_resched(); |
5d8f72b5 | 2012 | freezable_schedule(); |
1da177e4 LT |
2013 | } else { |
2014 | /* | |
2015 | * By the time we got the lock, our tracer went away. | |
6405f7f4 | 2016 | * Don't drop the lock yet, another tracer may come. |
ceb6bd67 TH |
2017 | * |
2018 | * If @gstop_done, the ptracer went away between group stop | |
2019 | * completion and here. During detach, it would have set | |
a8f072c1 TH |
2020 | * JOBCTL_STOP_PENDING on us and we'll re-enter |
2021 | * TASK_STOPPED in do_signal_stop() on return, so notifying | |
2022 | * the real parent of the group stop completion is enough. | |
1da177e4 | 2023 | */ |
ceb6bd67 TH |
2024 | if (gstop_done) |
2025 | do_notify_parent_cldstop(current, false, why); | |
2026 | ||
9899d11f | 2027 | /* tasklist protects us from ptrace_freeze_traced() */ |
6405f7f4 | 2028 | __set_current_state(TASK_RUNNING); |
20686a30 ON |
2029 | if (clear_code) |
2030 | current->exit_code = 0; | |
6405f7f4 | 2031 | read_unlock(&tasklist_lock); |
1da177e4 LT |
2032 | } |
2033 | ||
2034 | /* | |
2035 | * We are back. Now reacquire the siglock before touching | |
2036 | * last_siginfo, so that we are sure to have synchronized with | |
2037 | * any signal-sending on another CPU that wants to examine it. | |
2038 | */ | |
2039 | spin_lock_irq(¤t->sighand->siglock); | |
2040 | current->last_siginfo = NULL; | |
2041 | ||
544b2c91 TH |
2042 | /* LISTENING can be set only during STOP traps, clear it */ |
2043 | current->jobctl &= ~JOBCTL_LISTENING; | |
2044 | ||
1da177e4 LT |
2045 | /* |
2046 | * Queued signals ignored us while we were stopped for tracing. | |
2047 | * So check for any that we should take before resuming user mode. | |
b74d0deb | 2048 | * This sets TIF_SIGPENDING, but never clears it. |
1da177e4 | 2049 | */ |
b74d0deb | 2050 | recalc_sigpending_tsk(current); |
1da177e4 LT |
2051 | } |
2052 | ||
3544d72a | 2053 | static void ptrace_do_notify(int signr, int exit_code, int why) |
1da177e4 LT |
2054 | { |
2055 | siginfo_t info; | |
2056 | ||
faf1f22b | 2057 | clear_siginfo(&info); |
3544d72a | 2058 | info.si_signo = signr; |
1da177e4 | 2059 | info.si_code = exit_code; |
b488893a | 2060 | info.si_pid = task_pid_vnr(current); |
078de5f7 | 2061 | info.si_uid = from_kuid_munged(current_user_ns(), current_uid()); |
1da177e4 LT |
2062 | |
2063 | /* Let the debugger run. */ | |
3544d72a TH |
2064 | ptrace_stop(exit_code, why, 1, &info); |
2065 | } | |
2066 | ||
2067 | void ptrace_notify(int exit_code) | |
2068 | { | |
2069 | BUG_ON((exit_code & (0x7f | ~0xffff)) != SIGTRAP); | |
f784e8a7 ON |
2070 | if (unlikely(current->task_works)) |
2071 | task_work_run(); | |
3544d72a | 2072 | |
1da177e4 | 2073 | spin_lock_irq(¤t->sighand->siglock); |
3544d72a | 2074 | ptrace_do_notify(SIGTRAP, exit_code, CLD_TRAPPED); |
1da177e4 LT |
2075 | spin_unlock_irq(¤t->sighand->siglock); |
2076 | } | |
2077 | ||
73ddff2b TH |
2078 | /** |
2079 | * do_signal_stop - handle group stop for SIGSTOP and other stop signals | |
2080 | * @signr: signr causing group stop if initiating | |
2081 | * | |
2082 | * If %JOBCTL_STOP_PENDING is not set yet, initiate group stop with @signr | |
2083 | * and participate in it. If already set, participate in the existing | |
2084 | * group stop. If participated in a group stop (and thus slept), %true is | |
2085 | * returned with siglock released. | |
2086 | * | |
2087 | * If ptraced, this function doesn't handle stop itself. Instead, | |
2088 | * %JOBCTL_TRAP_STOP is scheduled and %false is returned with siglock | |
2089 | * untouched. The caller must ensure that INTERRUPT trap handling takes | |
2090 | * places afterwards. | |
2091 | * | |
2092 | * CONTEXT: | |
2093 | * Must be called with @current->sighand->siglock held, which is released | |
2094 | * on %true return. | |
2095 | * | |
2096 | * RETURNS: | |
2097 | * %false if group stop is already cancelled or ptrace trap is scheduled. | |
2098 | * %true if participated in group stop. | |
1da177e4 | 2099 | */ |
73ddff2b TH |
2100 | static bool do_signal_stop(int signr) |
2101 | __releases(¤t->sighand->siglock) | |
1da177e4 LT |
2102 | { |
2103 | struct signal_struct *sig = current->signal; | |
1da177e4 | 2104 | |
a8f072c1 | 2105 | if (!(current->jobctl & JOBCTL_STOP_PENDING)) { |
b76808e6 | 2106 | unsigned long gstop = JOBCTL_STOP_PENDING | JOBCTL_STOP_CONSUME; |
f558b7e4 ON |
2107 | struct task_struct *t; |
2108 | ||
a8f072c1 TH |
2109 | /* signr will be recorded in task->jobctl for retries */ |
2110 | WARN_ON_ONCE(signr & ~JOBCTL_STOP_SIGMASK); | |
d79fdd6d | 2111 | |
a8f072c1 | 2112 | if (!likely(current->jobctl & JOBCTL_STOP_DEQUEUED) || |
573cf9ad | 2113 | unlikely(signal_group_exit(sig))) |
73ddff2b | 2114 | return false; |
1da177e4 | 2115 | /* |
408a37de TH |
2116 | * There is no group stop already in progress. We must |
2117 | * initiate one now. | |
2118 | * | |
2119 | * While ptraced, a task may be resumed while group stop is | |
2120 | * still in effect and then receive a stop signal and | |
2121 | * initiate another group stop. This deviates from the | |
2122 | * usual behavior as two consecutive stop signals can't | |
780006ea ON |
2123 | * cause two group stops when !ptraced. That is why we |
2124 | * also check !task_is_stopped(t) below. | |
408a37de TH |
2125 | * |
2126 | * The condition can be distinguished by testing whether | |
2127 | * SIGNAL_STOP_STOPPED is already set. Don't generate | |
2128 | * group_exit_code in such case. | |
2129 | * | |
2130 | * This is not necessary for SIGNAL_STOP_CONTINUED because | |
2131 | * an intervening stop signal is required to cause two | |
2132 | * continued events regardless of ptrace. | |
1da177e4 | 2133 | */ |
408a37de TH |
2134 | if (!(sig->flags & SIGNAL_STOP_STOPPED)) |
2135 | sig->group_exit_code = signr; | |
1da177e4 | 2136 | |
7dd3db54 TH |
2137 | sig->group_stop_count = 0; |
2138 | ||
2139 | if (task_set_jobctl_pending(current, signr | gstop)) | |
2140 | sig->group_stop_count++; | |
1da177e4 | 2141 | |
8d38f203 ON |
2142 | t = current; |
2143 | while_each_thread(current, t) { | |
1da177e4 | 2144 | /* |
a122b341 ON |
2145 | * Setting state to TASK_STOPPED for a group |
2146 | * stop is always done with the siglock held, | |
2147 | * so this check has no races. | |
1da177e4 | 2148 | */ |
7dd3db54 TH |
2149 | if (!task_is_stopped(t) && |
2150 | task_set_jobctl_pending(t, signr | gstop)) { | |
ae6d2ed7 | 2151 | sig->group_stop_count++; |
fb1d910c TH |
2152 | if (likely(!(t->ptrace & PT_SEIZED))) |
2153 | signal_wake_up(t, 0); | |
2154 | else | |
2155 | ptrace_trap_notify(t); | |
a122b341 | 2156 | } |
d79fdd6d | 2157 | } |
1da177e4 | 2158 | } |
73ddff2b | 2159 | |
d21142ec | 2160 | if (likely(!current->ptrace)) { |
5224fa36 | 2161 | int notify = 0; |
1da177e4 | 2162 | |
5224fa36 TH |
2163 | /* |
2164 | * If there are no other threads in the group, or if there | |
2165 | * is a group stop in progress and we are the last to stop, | |
2166 | * report to the parent. | |
2167 | */ | |
2168 | if (task_participate_group_stop(current)) | |
2169 | notify = CLD_STOPPED; | |
2170 | ||
b5bf9a90 | 2171 | set_special_state(TASK_STOPPED); |
5224fa36 TH |
2172 | spin_unlock_irq(¤t->sighand->siglock); |
2173 | ||
62bcf9d9 TH |
2174 | /* |
2175 | * Notify the parent of the group stop completion. Because | |
2176 | * we're not holding either the siglock or tasklist_lock | |
2177 | * here, ptracer may attach inbetween; however, this is for | |
2178 | * group stop and should always be delivered to the real | |
2179 | * parent of the group leader. The new ptracer will get | |
2180 | * its notification when this task transitions into | |
2181 | * TASK_TRACED. | |
2182 | */ | |
5224fa36 TH |
2183 | if (notify) { |
2184 | read_lock(&tasklist_lock); | |
62bcf9d9 | 2185 | do_notify_parent_cldstop(current, false, notify); |
5224fa36 TH |
2186 | read_unlock(&tasklist_lock); |
2187 | } | |
2188 | ||
2189 | /* Now we don't run again until woken by SIGCONT or SIGKILL */ | |
5d8f72b5 | 2190 | freezable_schedule(); |
73ddff2b | 2191 | return true; |
d79fdd6d | 2192 | } else { |
73ddff2b TH |
2193 | /* |
2194 | * While ptraced, group stop is handled by STOP trap. | |
2195 | * Schedule it and let the caller deal with it. | |
2196 | */ | |
2197 | task_set_jobctl_pending(current, JOBCTL_TRAP_STOP); | |
2198 | return false; | |
ae6d2ed7 | 2199 | } |
73ddff2b | 2200 | } |
1da177e4 | 2201 | |
73ddff2b TH |
2202 | /** |
2203 | * do_jobctl_trap - take care of ptrace jobctl traps | |
2204 | * | |
3544d72a TH |
2205 | * When PT_SEIZED, it's used for both group stop and explicit |
2206 | * SEIZE/INTERRUPT traps. Both generate PTRACE_EVENT_STOP trap with | |
2207 | * accompanying siginfo. If stopped, lower eight bits of exit_code contain | |
2208 | * the stop signal; otherwise, %SIGTRAP. | |
2209 | * | |
2210 | * When !PT_SEIZED, it's used only for group stop trap with stop signal | |
2211 | * number as exit_code and no siginfo. | |
73ddff2b TH |
2212 | * |
2213 | * CONTEXT: | |
2214 | * Must be called with @current->sighand->siglock held, which may be | |
2215 | * released and re-acquired before returning with intervening sleep. | |
2216 | */ | |
2217 | static void do_jobctl_trap(void) | |
2218 | { | |
3544d72a | 2219 | struct signal_struct *signal = current->signal; |
73ddff2b | 2220 | int signr = current->jobctl & JOBCTL_STOP_SIGMASK; |
ae6d2ed7 | 2221 | |
3544d72a TH |
2222 | if (current->ptrace & PT_SEIZED) { |
2223 | if (!signal->group_stop_count && | |
2224 | !(signal->flags & SIGNAL_STOP_STOPPED)) | |
2225 | signr = SIGTRAP; | |
2226 | WARN_ON_ONCE(!signr); | |
2227 | ptrace_do_notify(signr, signr | (PTRACE_EVENT_STOP << 8), | |
2228 | CLD_STOPPED); | |
2229 | } else { | |
2230 | WARN_ON_ONCE(!signr); | |
2231 | ptrace_stop(signr, CLD_STOPPED, 0, NULL); | |
2232 | current->exit_code = 0; | |
ae6d2ed7 | 2233 | } |
1da177e4 LT |
2234 | } |
2235 | ||
94eb22d5 | 2236 | static int ptrace_signal(int signr, siginfo_t *info) |
18c98b65 | 2237 | { |
8a352418 ON |
2238 | /* |
2239 | * We do not check sig_kernel_stop(signr) but set this marker | |
2240 | * unconditionally because we do not know whether debugger will | |
2241 | * change signr. This flag has no meaning unless we are going | |
2242 | * to stop after return from ptrace_stop(). In this case it will | |
2243 | * be checked in do_signal_stop(), we should only stop if it was | |
2244 | * not cleared by SIGCONT while we were sleeping. See also the | |
2245 | * comment in dequeue_signal(). | |
2246 | */ | |
2247 | current->jobctl |= JOBCTL_STOP_DEQUEUED; | |
fe1bc6a0 | 2248 | ptrace_stop(signr, CLD_TRAPPED, 0, info); |
18c98b65 RM |
2249 | |
2250 | /* We're back. Did the debugger cancel the sig? */ | |
2251 | signr = current->exit_code; | |
2252 | if (signr == 0) | |
2253 | return signr; | |
2254 | ||
2255 | current->exit_code = 0; | |
2256 | ||
5aba085e RD |
2257 | /* |
2258 | * Update the siginfo structure if the signal has | |
2259 | * changed. If the debugger wanted something | |
2260 | * specific in the siginfo structure then it should | |
2261 | * have updated *info via PTRACE_SETSIGINFO. | |
2262 | */ | |
18c98b65 | 2263 | if (signr != info->si_signo) { |
faf1f22b | 2264 | clear_siginfo(info); |
18c98b65 RM |
2265 | info->si_signo = signr; |
2266 | info->si_errno = 0; | |
2267 | info->si_code = SI_USER; | |
6b550f94 | 2268 | rcu_read_lock(); |
18c98b65 | 2269 | info->si_pid = task_pid_vnr(current->parent); |
54ba47ed EB |
2270 | info->si_uid = from_kuid_munged(current_user_ns(), |
2271 | task_uid(current->parent)); | |
6b550f94 | 2272 | rcu_read_unlock(); |
18c98b65 RM |
2273 | } |
2274 | ||
2275 | /* If the (new) signal is now blocked, requeue it. */ | |
2276 | if (sigismember(¤t->blocked, signr)) { | |
2277 | specific_send_sig_info(signr, info, current); | |
2278 | signr = 0; | |
2279 | } | |
2280 | ||
2281 | return signr; | |
2282 | } | |
2283 | ||
828b1f65 | 2284 | int get_signal(struct ksignal *ksig) |
1da177e4 | 2285 | { |
f6b76d4f ON |
2286 | struct sighand_struct *sighand = current->sighand; |
2287 | struct signal_struct *signal = current->signal; | |
2288 | int signr; | |
1da177e4 | 2289 | |
f784e8a7 ON |
2290 | if (unlikely(current->task_works)) |
2291 | task_work_run(); | |
72667028 | 2292 | |
0326f5a9 SD |
2293 | if (unlikely(uprobe_deny_signal())) |
2294 | return 0; | |
2295 | ||
13b1c3d4 | 2296 | /* |
5d8f72b5 ON |
2297 | * Do this once, we can't return to user-mode if freezing() == T. |
2298 | * do_signal_stop() and ptrace_stop() do freezable_schedule() and | |
2299 | * thus do not need another check after return. | |
13b1c3d4 | 2300 | */ |
fc558a74 RW |
2301 | try_to_freeze(); |
2302 | ||
5d8f72b5 | 2303 | relock: |
f6b76d4f | 2304 | spin_lock_irq(&sighand->siglock); |
021e1ae3 ON |
2305 | /* |
2306 | * Every stopped thread goes here after wakeup. Check to see if | |
2307 | * we should notify the parent, prepare_signal(SIGCONT) encodes | |
2308 | * the CLD_ si_code into SIGNAL_CLD_MASK bits. | |
2309 | */ | |
f6b76d4f | 2310 | if (unlikely(signal->flags & SIGNAL_CLD_MASK)) { |
c672af35 TH |
2311 | int why; |
2312 | ||
2313 | if (signal->flags & SIGNAL_CLD_CONTINUED) | |
2314 | why = CLD_CONTINUED; | |
2315 | else | |
2316 | why = CLD_STOPPED; | |
2317 | ||
f6b76d4f | 2318 | signal->flags &= ~SIGNAL_CLD_MASK; |
e4420551 | 2319 | |
ae6d2ed7 | 2320 | spin_unlock_irq(&sighand->siglock); |
fa00b80b | 2321 | |
ceb6bd67 TH |
2322 | /* |
2323 | * Notify the parent that we're continuing. This event is | |
2324 | * always per-process and doesn't make whole lot of sense | |
2325 | * for ptracers, who shouldn't consume the state via | |
2326 | * wait(2) either, but, for backward compatibility, notify | |
2327 | * the ptracer of the group leader too unless it's gonna be | |
2328 | * a duplicate. | |
2329 | */ | |
edf2ed15 | 2330 | read_lock(&tasklist_lock); |
ceb6bd67 TH |
2331 | do_notify_parent_cldstop(current, false, why); |
2332 | ||
bb3696da ON |
2333 | if (ptrace_reparented(current->group_leader)) |
2334 | do_notify_parent_cldstop(current->group_leader, | |
2335 | true, why); | |
edf2ed15 | 2336 | read_unlock(&tasklist_lock); |
ceb6bd67 | 2337 | |
e4420551 ON |
2338 | goto relock; |
2339 | } | |
2340 | ||
1da177e4 LT |
2341 | for (;;) { |
2342 | struct k_sigaction *ka; | |
1be53963 | 2343 | |
dd1d6772 TH |
2344 | if (unlikely(current->jobctl & JOBCTL_STOP_PENDING) && |
2345 | do_signal_stop(0)) | |
7bcf6a2c | 2346 | goto relock; |
1be53963 | 2347 | |
73ddff2b TH |
2348 | if (unlikely(current->jobctl & JOBCTL_TRAP_MASK)) { |
2349 | do_jobctl_trap(); | |
2350 | spin_unlock_irq(&sighand->siglock); | |
2351 | goto relock; | |
2352 | } | |
1da177e4 | 2353 | |
828b1f65 | 2354 | signr = dequeue_signal(current, ¤t->blocked, &ksig->info); |
7bcf6a2c | 2355 | |
dd1d6772 TH |
2356 | if (!signr) |
2357 | break; /* will return 0 */ | |
7bcf6a2c | 2358 | |
8a352418 | 2359 | if (unlikely(current->ptrace) && signr != SIGKILL) { |
828b1f65 | 2360 | signr = ptrace_signal(signr, &ksig->info); |
dd1d6772 TH |
2361 | if (!signr) |
2362 | continue; | |
1da177e4 LT |
2363 | } |
2364 | ||
dd1d6772 TH |
2365 | ka = &sighand->action[signr-1]; |
2366 | ||
f9d4257e | 2367 | /* Trace actually delivered signals. */ |
828b1f65 | 2368 | trace_signal_deliver(signr, &ksig->info, ka); |
f9d4257e | 2369 | |
1da177e4 LT |
2370 | if (ka->sa.sa_handler == SIG_IGN) /* Do nothing. */ |
2371 | continue; | |
2372 | if (ka->sa.sa_handler != SIG_DFL) { | |
2373 | /* Run the handler. */ | |
828b1f65 | 2374 | ksig->ka = *ka; |
1da177e4 LT |
2375 | |
2376 | if (ka->sa.sa_flags & SA_ONESHOT) | |
2377 | ka->sa.sa_handler = SIG_DFL; | |
2378 | ||
2379 | break; /* will return non-zero "signr" value */ | |
2380 | } | |
2381 | ||
2382 | /* | |
2383 | * Now we are doing the default action for this signal. | |
2384 | */ | |
2385 | if (sig_kernel_ignore(signr)) /* Default is nothing. */ | |
2386 | continue; | |
2387 | ||
84d73786 | 2388 | /* |
0fbc26a6 | 2389 | * Global init gets no signals it doesn't want. |
b3bfa0cb SB |
2390 | * Container-init gets no signals it doesn't want from same |
2391 | * container. | |
2392 | * | |
2393 | * Note that if global/container-init sees a sig_kernel_only() | |
2394 | * signal here, the signal must have been generated internally | |
2395 | * or must have come from an ancestor namespace. In either | |
2396 | * case, the signal cannot be dropped. | |
84d73786 | 2397 | */ |
fae5fa44 | 2398 | if (unlikely(signal->flags & SIGNAL_UNKILLABLE) && |
b3bfa0cb | 2399 | !sig_kernel_only(signr)) |
1da177e4 LT |
2400 | continue; |
2401 | ||
2402 | if (sig_kernel_stop(signr)) { | |
2403 | /* | |
2404 | * The default action is to stop all threads in | |
2405 | * the thread group. The job control signals | |
2406 | * do nothing in an orphaned pgrp, but SIGSTOP | |
2407 | * always works. Note that siglock needs to be | |
2408 | * dropped during the call to is_orphaned_pgrp() | |
2409 | * because of lock ordering with tasklist_lock. | |
2410 | * This allows an intervening SIGCONT to be posted. | |
2411 | * We need to check for that and bail out if necessary. | |
2412 | */ | |
2413 | if (signr != SIGSTOP) { | |
f6b76d4f | 2414 | spin_unlock_irq(&sighand->siglock); |
1da177e4 LT |
2415 | |
2416 | /* signals can be posted during this window */ | |
2417 | ||
3e7cd6c4 | 2418 | if (is_current_pgrp_orphaned()) |
1da177e4 LT |
2419 | goto relock; |
2420 | ||
f6b76d4f | 2421 | spin_lock_irq(&sighand->siglock); |
1da177e4 LT |
2422 | } |
2423 | ||
828b1f65 | 2424 | if (likely(do_signal_stop(ksig->info.si_signo))) { |
1da177e4 LT |
2425 | /* It released the siglock. */ |
2426 | goto relock; | |
2427 | } | |
2428 | ||
2429 | /* | |
2430 | * We didn't actually stop, due to a race | |
2431 | * with SIGCONT or something like that. | |
2432 | */ | |
2433 | continue; | |
2434 | } | |
2435 | ||
f6b76d4f | 2436 | spin_unlock_irq(&sighand->siglock); |
1da177e4 LT |
2437 | |
2438 | /* | |
2439 | * Anything else is fatal, maybe with a core dump. | |
2440 | */ | |
2441 | current->flags |= PF_SIGNALED; | |
2dce81bf | 2442 | |
1da177e4 | 2443 | if (sig_kernel_coredump(signr)) { |
2dce81bf | 2444 | if (print_fatal_signals) |
828b1f65 | 2445 | print_fatal_signal(ksig->info.si_signo); |
2b5faa4c | 2446 | proc_coredump_connector(current); |
1da177e4 LT |
2447 | /* |
2448 | * If it was able to dump core, this kills all | |
2449 | * other threads in the group and synchronizes with | |
2450 | * their demise. If we lost the race with another | |
2451 | * thread getting here, it set group_exit_code | |
2452 | * first and our do_group_exit call below will use | |
2453 | * that value and ignore the one we pass it. | |
2454 | */ | |
828b1f65 | 2455 | do_coredump(&ksig->info); |
1da177e4 LT |
2456 | } |
2457 | ||
2458 | /* | |
2459 | * Death signals, no core dump. | |
2460 | */ | |
828b1f65 | 2461 | do_group_exit(ksig->info.si_signo); |
1da177e4 LT |
2462 | /* NOTREACHED */ |
2463 | } | |
f6b76d4f | 2464 | spin_unlock_irq(&sighand->siglock); |
828b1f65 RW |
2465 | |
2466 | ksig->sig = signr; | |
2467 | return ksig->sig > 0; | |
1da177e4 LT |
2468 | } |
2469 | ||
5e6292c0 | 2470 | /** |
efee984c | 2471 | * signal_delivered - |
10b1c7ac | 2472 | * @ksig: kernel signal struct |
efee984c | 2473 | * @stepping: nonzero if debugger single-step or block-step in use |
5e6292c0 | 2474 | * |
e227867f | 2475 | * This function should be called when a signal has successfully been |
10b1c7ac | 2476 | * delivered. It updates the blocked signals accordingly (@ksig->ka.sa.sa_mask |
efee984c | 2477 | * is always blocked, and the signal itself is blocked unless %SA_NODEFER |
10b1c7ac | 2478 | * is set in @ksig->ka.sa.sa_flags. Tracing is notified. |
5e6292c0 | 2479 | */ |
10b1c7ac | 2480 | static void signal_delivered(struct ksignal *ksig, int stepping) |
5e6292c0 MF |
2481 | { |
2482 | sigset_t blocked; | |
2483 | ||
a610d6e6 AV |
2484 | /* A signal was successfully delivered, and the |
2485 | saved sigmask was stored on the signal frame, | |
2486 | and will be restored by sigreturn. So we can | |
2487 | simply clear the restore sigmask flag. */ | |
2488 | clear_restore_sigmask(); | |
2489 | ||
10b1c7ac RW |
2490 | sigorsets(&blocked, ¤t->blocked, &ksig->ka.sa.sa_mask); |
2491 | if (!(ksig->ka.sa.sa_flags & SA_NODEFER)) | |
2492 | sigaddset(&blocked, ksig->sig); | |
5e6292c0 | 2493 | set_current_blocked(&blocked); |
df5601f9 | 2494 | tracehook_signal_handler(stepping); |
5e6292c0 MF |
2495 | } |
2496 | ||
2ce5da17 AV |
2497 | void signal_setup_done(int failed, struct ksignal *ksig, int stepping) |
2498 | { | |
2499 | if (failed) | |
2500 | force_sigsegv(ksig->sig, current); | |
2501 | else | |
10b1c7ac | 2502 | signal_delivered(ksig, stepping); |
2ce5da17 AV |
2503 | } |
2504 | ||
0edceb7b ON |
2505 | /* |
2506 | * It could be that complete_signal() picked us to notify about the | |
fec9993d ON |
2507 | * group-wide signal. Other threads should be notified now to take |
2508 | * the shared signals in @which since we will not. | |
0edceb7b | 2509 | */ |
f646e227 | 2510 | static void retarget_shared_pending(struct task_struct *tsk, sigset_t *which) |
0edceb7b | 2511 | { |
f646e227 | 2512 | sigset_t retarget; |
0edceb7b ON |
2513 | struct task_struct *t; |
2514 | ||
f646e227 ON |
2515 | sigandsets(&retarget, &tsk->signal->shared_pending.signal, which); |
2516 | if (sigisemptyset(&retarget)) | |
2517 | return; | |
2518 | ||
0edceb7b ON |
2519 | t = tsk; |
2520 | while_each_thread(tsk, t) { | |
fec9993d ON |
2521 | if (t->flags & PF_EXITING) |
2522 | continue; | |
2523 | ||
2524 | if (!has_pending_signals(&retarget, &t->blocked)) | |
2525 | continue; | |
2526 | /* Remove the signals this thread can handle. */ | |
2527 | sigandsets(&retarget, &retarget, &t->blocked); | |
2528 | ||
2529 | if (!signal_pending(t)) | |
2530 | signal_wake_up(t, 0); | |
2531 | ||
2532 | if (sigisemptyset(&retarget)) | |
2533 | break; | |
0edceb7b ON |
2534 | } |
2535 | } | |
2536 | ||
d12619b5 ON |
2537 | void exit_signals(struct task_struct *tsk) |
2538 | { | |
2539 | int group_stop = 0; | |
f646e227 | 2540 | sigset_t unblocked; |
d12619b5 | 2541 | |
77e4ef99 TH |
2542 | /* |
2543 | * @tsk is about to have PF_EXITING set - lock out users which | |
2544 | * expect stable threadgroup. | |
2545 | */ | |
780de9dd | 2546 | cgroup_threadgroup_change_begin(tsk); |
77e4ef99 | 2547 | |
5dee1707 ON |
2548 | if (thread_group_empty(tsk) || signal_group_exit(tsk->signal)) { |
2549 | tsk->flags |= PF_EXITING; | |
780de9dd | 2550 | cgroup_threadgroup_change_end(tsk); |
5dee1707 | 2551 | return; |
d12619b5 ON |
2552 | } |
2553 | ||
5dee1707 | 2554 | spin_lock_irq(&tsk->sighand->siglock); |
d12619b5 ON |
2555 | /* |
2556 | * From now this task is not visible for group-wide signals, | |
2557 | * see wants_signal(), do_signal_stop(). | |
2558 | */ | |
2559 | tsk->flags |= PF_EXITING; | |
77e4ef99 | 2560 | |
780de9dd | 2561 | cgroup_threadgroup_change_end(tsk); |
77e4ef99 | 2562 | |
5dee1707 ON |
2563 | if (!signal_pending(tsk)) |
2564 | goto out; | |
2565 | ||
f646e227 ON |
2566 | unblocked = tsk->blocked; |
2567 | signotset(&unblocked); | |
2568 | retarget_shared_pending(tsk, &unblocked); | |
5dee1707 | 2569 | |
a8f072c1 | 2570 | if (unlikely(tsk->jobctl & JOBCTL_STOP_PENDING) && |
e5c1902e | 2571 | task_participate_group_stop(tsk)) |
edf2ed15 | 2572 | group_stop = CLD_STOPPED; |
5dee1707 | 2573 | out: |
d12619b5 ON |
2574 | spin_unlock_irq(&tsk->sighand->siglock); |
2575 | ||
62bcf9d9 TH |
2576 | /* |
2577 | * If group stop has completed, deliver the notification. This | |
2578 | * should always go to the real parent of the group leader. | |
2579 | */ | |
ae6d2ed7 | 2580 | if (unlikely(group_stop)) { |
d12619b5 | 2581 | read_lock(&tasklist_lock); |
62bcf9d9 | 2582 | do_notify_parent_cldstop(tsk, false, group_stop); |
d12619b5 ON |
2583 | read_unlock(&tasklist_lock); |
2584 | } | |
2585 | } | |
2586 | ||
1da177e4 LT |
2587 | EXPORT_SYMBOL(recalc_sigpending); |
2588 | EXPORT_SYMBOL_GPL(dequeue_signal); | |
2589 | EXPORT_SYMBOL(flush_signals); | |
2590 | EXPORT_SYMBOL(force_sig); | |
1da177e4 LT |
2591 | EXPORT_SYMBOL(send_sig); |
2592 | EXPORT_SYMBOL(send_sig_info); | |
2593 | EXPORT_SYMBOL(sigprocmask); | |
1da177e4 LT |
2594 | |
2595 | /* | |
2596 | * System call entry points. | |
2597 | */ | |
2598 | ||
41c57892 RD |
2599 | /** |
2600 | * sys_restart_syscall - restart a system call | |
2601 | */ | |
754fe8d2 | 2602 | SYSCALL_DEFINE0(restart_syscall) |
1da177e4 | 2603 | { |
f56141e3 | 2604 | struct restart_block *restart = ¤t->restart_block; |
1da177e4 LT |
2605 | return restart->fn(restart); |
2606 | } | |
2607 | ||
2608 | long do_no_restart_syscall(struct restart_block *param) | |
2609 | { | |
2610 | return -EINTR; | |
2611 | } | |
2612 | ||
b182801a ON |
2613 | static void __set_task_blocked(struct task_struct *tsk, const sigset_t *newset) |
2614 | { | |
2615 | if (signal_pending(tsk) && !thread_group_empty(tsk)) { | |
2616 | sigset_t newblocked; | |
2617 | /* A set of now blocked but previously unblocked signals. */ | |
702a5073 | 2618 | sigandnsets(&newblocked, newset, ¤t->blocked); |
b182801a ON |
2619 | retarget_shared_pending(tsk, &newblocked); |
2620 | } | |
2621 | tsk->blocked = *newset; | |
2622 | recalc_sigpending(); | |
2623 | } | |
2624 | ||
e6fa16ab ON |
2625 | /** |
2626 | * set_current_blocked - change current->blocked mask | |
2627 | * @newset: new mask | |
2628 | * | |
2629 | * It is wrong to change ->blocked directly, this helper should be used | |
2630 | * to ensure the process can't miss a shared signal we are going to block. | |
1da177e4 | 2631 | */ |
77097ae5 AV |
2632 | void set_current_blocked(sigset_t *newset) |
2633 | { | |
77097ae5 | 2634 | sigdelsetmask(newset, sigmask(SIGKILL) | sigmask(SIGSTOP)); |
0c4a8423 | 2635 | __set_current_blocked(newset); |
77097ae5 AV |
2636 | } |
2637 | ||
2638 | void __set_current_blocked(const sigset_t *newset) | |
e6fa16ab ON |
2639 | { |
2640 | struct task_struct *tsk = current; | |
2641 | ||
c7be96af WL |
2642 | /* |
2643 | * In case the signal mask hasn't changed, there is nothing we need | |
2644 | * to do. The current->blocked shouldn't be modified by other task. | |
2645 | */ | |
2646 | if (sigequalsets(&tsk->blocked, newset)) | |
2647 | return; | |
2648 | ||
e6fa16ab | 2649 | spin_lock_irq(&tsk->sighand->siglock); |
b182801a | 2650 | __set_task_blocked(tsk, newset); |
e6fa16ab ON |
2651 | spin_unlock_irq(&tsk->sighand->siglock); |
2652 | } | |
1da177e4 LT |
2653 | |
2654 | /* | |
2655 | * This is also useful for kernel threads that want to temporarily | |
2656 | * (or permanently) block certain signals. | |
2657 | * | |
2658 | * NOTE! Unlike the user-mode sys_sigprocmask(), the kernel | |
2659 | * interface happily blocks "unblockable" signals like SIGKILL | |
2660 | * and friends. | |
2661 | */ | |
2662 | int sigprocmask(int how, sigset_t *set, sigset_t *oldset) | |
2663 | { | |
73ef4aeb ON |
2664 | struct task_struct *tsk = current; |
2665 | sigset_t newset; | |
1da177e4 | 2666 | |
73ef4aeb | 2667 | /* Lockless, only current can change ->blocked, never from irq */ |
a26fd335 | 2668 | if (oldset) |
73ef4aeb | 2669 | *oldset = tsk->blocked; |
a26fd335 | 2670 | |
1da177e4 LT |
2671 | switch (how) { |
2672 | case SIG_BLOCK: | |
73ef4aeb | 2673 | sigorsets(&newset, &tsk->blocked, set); |
1da177e4 LT |
2674 | break; |
2675 | case SIG_UNBLOCK: | |
702a5073 | 2676 | sigandnsets(&newset, &tsk->blocked, set); |
1da177e4 LT |
2677 | break; |
2678 | case SIG_SETMASK: | |
73ef4aeb | 2679 | newset = *set; |
1da177e4 LT |
2680 | break; |
2681 | default: | |
73ef4aeb | 2682 | return -EINVAL; |
1da177e4 | 2683 | } |
a26fd335 | 2684 | |
77097ae5 | 2685 | __set_current_blocked(&newset); |
73ef4aeb | 2686 | return 0; |
1da177e4 LT |
2687 | } |
2688 | ||
41c57892 RD |
2689 | /** |
2690 | * sys_rt_sigprocmask - change the list of currently blocked signals | |
2691 | * @how: whether to add, remove, or set signals | |
ada9c933 | 2692 | * @nset: stores pending signals |
41c57892 RD |
2693 | * @oset: previous value of signal mask if non-null |
2694 | * @sigsetsize: size of sigset_t type | |
2695 | */ | |
bb7efee2 | 2696 | SYSCALL_DEFINE4(rt_sigprocmask, int, how, sigset_t __user *, nset, |
17da2bd9 | 2697 | sigset_t __user *, oset, size_t, sigsetsize) |
1da177e4 | 2698 | { |
1da177e4 | 2699 | sigset_t old_set, new_set; |
bb7efee2 | 2700 | int error; |
1da177e4 LT |
2701 | |
2702 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
2703 | if (sigsetsize != sizeof(sigset_t)) | |
bb7efee2 | 2704 | return -EINVAL; |
1da177e4 | 2705 | |
bb7efee2 ON |
2706 | old_set = current->blocked; |
2707 | ||
2708 | if (nset) { | |
2709 | if (copy_from_user(&new_set, nset, sizeof(sigset_t))) | |
2710 | return -EFAULT; | |
1da177e4 LT |
2711 | sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); |
2712 | ||
bb7efee2 | 2713 | error = sigprocmask(how, &new_set, NULL); |
1da177e4 | 2714 | if (error) |
bb7efee2 ON |
2715 | return error; |
2716 | } | |
1da177e4 | 2717 | |
bb7efee2 ON |
2718 | if (oset) { |
2719 | if (copy_to_user(oset, &old_set, sizeof(sigset_t))) | |
2720 | return -EFAULT; | |
1da177e4 | 2721 | } |
bb7efee2 ON |
2722 | |
2723 | return 0; | |
1da177e4 LT |
2724 | } |
2725 | ||
322a56cb | 2726 | #ifdef CONFIG_COMPAT |
322a56cb AV |
2727 | COMPAT_SYSCALL_DEFINE4(rt_sigprocmask, int, how, compat_sigset_t __user *, nset, |
2728 | compat_sigset_t __user *, oset, compat_size_t, sigsetsize) | |
1da177e4 | 2729 | { |
322a56cb AV |
2730 | sigset_t old_set = current->blocked; |
2731 | ||
2732 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
2733 | if (sigsetsize != sizeof(sigset_t)) | |
2734 | return -EINVAL; | |
2735 | ||
2736 | if (nset) { | |
322a56cb AV |
2737 | sigset_t new_set; |
2738 | int error; | |
3968cf62 | 2739 | if (get_compat_sigset(&new_set, nset)) |
322a56cb | 2740 | return -EFAULT; |
322a56cb AV |
2741 | sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); |
2742 | ||
2743 | error = sigprocmask(how, &new_set, NULL); | |
2744 | if (error) | |
2745 | return error; | |
2746 | } | |
f454322e | 2747 | return oset ? put_compat_sigset(oset, &old_set, sizeof(*oset)) : 0; |
322a56cb AV |
2748 | } |
2749 | #endif | |
1da177e4 | 2750 | |
b1d294c8 | 2751 | static void do_sigpending(sigset_t *set) |
1da177e4 | 2752 | { |
1da177e4 | 2753 | spin_lock_irq(¤t->sighand->siglock); |
fe9c1db2 | 2754 | sigorsets(set, ¤t->pending.signal, |
1da177e4 LT |
2755 | ¤t->signal->shared_pending.signal); |
2756 | spin_unlock_irq(¤t->sighand->siglock); | |
2757 | ||
2758 | /* Outside the lock because only this thread touches it. */ | |
fe9c1db2 | 2759 | sigandsets(set, ¤t->blocked, set); |
5aba085e | 2760 | } |
1da177e4 | 2761 | |
41c57892 RD |
2762 | /** |
2763 | * sys_rt_sigpending - examine a pending signal that has been raised | |
2764 | * while blocked | |
20f22ab4 | 2765 | * @uset: stores pending signals |
41c57892 RD |
2766 | * @sigsetsize: size of sigset_t type or larger |
2767 | */ | |
fe9c1db2 | 2768 | SYSCALL_DEFINE2(rt_sigpending, sigset_t __user *, uset, size_t, sigsetsize) |
1da177e4 | 2769 | { |
fe9c1db2 | 2770 | sigset_t set; |
176826af DL |
2771 | |
2772 | if (sigsetsize > sizeof(*uset)) | |
2773 | return -EINVAL; | |
2774 | ||
b1d294c8 CB |
2775 | do_sigpending(&set); |
2776 | ||
2777 | if (copy_to_user(uset, &set, sigsetsize)) | |
2778 | return -EFAULT; | |
2779 | ||
2780 | return 0; | |
fe9c1db2 AV |
2781 | } |
2782 | ||
2783 | #ifdef CONFIG_COMPAT | |
fe9c1db2 AV |
2784 | COMPAT_SYSCALL_DEFINE2(rt_sigpending, compat_sigset_t __user *, uset, |
2785 | compat_size_t, sigsetsize) | |
1da177e4 | 2786 | { |
fe9c1db2 | 2787 | sigset_t set; |
176826af DL |
2788 | |
2789 | if (sigsetsize > sizeof(*uset)) | |
2790 | return -EINVAL; | |
2791 | ||
b1d294c8 CB |
2792 | do_sigpending(&set); |
2793 | ||
2794 | return put_compat_sigset(uset, &set, sigsetsize); | |
1da177e4 | 2795 | } |
fe9c1db2 | 2796 | #endif |
1da177e4 | 2797 | |
cc731525 EB |
2798 | enum siginfo_layout siginfo_layout(int sig, int si_code) |
2799 | { | |
2800 | enum siginfo_layout layout = SIL_KILL; | |
2801 | if ((si_code > SI_USER) && (si_code < SI_KERNEL)) { | |
2802 | static const struct { | |
2803 | unsigned char limit, layout; | |
2804 | } filter[] = { | |
2805 | [SIGILL] = { NSIGILL, SIL_FAULT }, | |
2806 | [SIGFPE] = { NSIGFPE, SIL_FAULT }, | |
2807 | [SIGSEGV] = { NSIGSEGV, SIL_FAULT }, | |
2808 | [SIGBUS] = { NSIGBUS, SIL_FAULT }, | |
2809 | [SIGTRAP] = { NSIGTRAP, SIL_FAULT }, | |
c3aff086 | 2810 | #if defined(SIGEMT) && defined(NSIGEMT) |
cc731525 EB |
2811 | [SIGEMT] = { NSIGEMT, SIL_FAULT }, |
2812 | #endif | |
2813 | [SIGCHLD] = { NSIGCHLD, SIL_CHLD }, | |
2814 | [SIGPOLL] = { NSIGPOLL, SIL_POLL }, | |
cc731525 | 2815 | [SIGSYS] = { NSIGSYS, SIL_SYS }, |
cc731525 | 2816 | }; |
31931c93 | 2817 | if ((sig < ARRAY_SIZE(filter)) && (si_code <= filter[sig].limit)) { |
cc731525 | 2818 | layout = filter[sig].layout; |
31931c93 EB |
2819 | /* Handle the exceptions */ |
2820 | if ((sig == SIGBUS) && | |
2821 | (si_code >= BUS_MCEERR_AR) && (si_code <= BUS_MCEERR_AO)) | |
2822 | layout = SIL_FAULT_MCEERR; | |
2823 | else if ((sig == SIGSEGV) && (si_code == SEGV_BNDERR)) | |
2824 | layout = SIL_FAULT_BNDERR; | |
2825 | #ifdef SEGV_PKUERR | |
2826 | else if ((sig == SIGSEGV) && (si_code == SEGV_PKUERR)) | |
2827 | layout = SIL_FAULT_PKUERR; | |
2828 | #endif | |
2829 | } | |
cc731525 EB |
2830 | else if (si_code <= NSIGPOLL) |
2831 | layout = SIL_POLL; | |
2832 | } else { | |
2833 | if (si_code == SI_TIMER) | |
2834 | layout = SIL_TIMER; | |
2835 | else if (si_code == SI_SIGIO) | |
2836 | layout = SIL_POLL; | |
2837 | else if (si_code < 0) | |
2838 | layout = SIL_RT; | |
cc731525 EB |
2839 | } |
2840 | return layout; | |
2841 | } | |
2842 | ||
ce395960 | 2843 | int copy_siginfo_to_user(siginfo_t __user *to, const siginfo_t *from) |
1da177e4 | 2844 | { |
c999b933 | 2845 | if (copy_to_user(to, from , sizeof(struct siginfo))) |
1da177e4 | 2846 | return -EFAULT; |
c999b933 | 2847 | return 0; |
1da177e4 LT |
2848 | } |
2849 | ||
212a36a1 | 2850 | #ifdef CONFIG_COMPAT |
ea64d5ac EB |
2851 | int copy_siginfo_to_user32(struct compat_siginfo __user *to, |
2852 | const struct siginfo *from) | |
2853 | #if defined(CONFIG_X86_X32_ABI) || defined(CONFIG_IA32_EMULATION) | |
2854 | { | |
2855 | return __copy_siginfo_to_user32(to, from, in_x32_syscall()); | |
2856 | } | |
2857 | int __copy_siginfo_to_user32(struct compat_siginfo __user *to, | |
2858 | const struct siginfo *from, bool x32_ABI) | |
2859 | #endif | |
2860 | { | |
2861 | struct compat_siginfo new; | |
2862 | memset(&new, 0, sizeof(new)); | |
2863 | ||
2864 | new.si_signo = from->si_signo; | |
2865 | new.si_errno = from->si_errno; | |
2866 | new.si_code = from->si_code; | |
2867 | switch(siginfo_layout(from->si_signo, from->si_code)) { | |
2868 | case SIL_KILL: | |
2869 | new.si_pid = from->si_pid; | |
2870 | new.si_uid = from->si_uid; | |
2871 | break; | |
2872 | case SIL_TIMER: | |
2873 | new.si_tid = from->si_tid; | |
2874 | new.si_overrun = from->si_overrun; | |
2875 | new.si_int = from->si_int; | |
2876 | break; | |
2877 | case SIL_POLL: | |
2878 | new.si_band = from->si_band; | |
2879 | new.si_fd = from->si_fd; | |
2880 | break; | |
2881 | case SIL_FAULT: | |
2882 | new.si_addr = ptr_to_compat(from->si_addr); | |
2883 | #ifdef __ARCH_SI_TRAPNO | |
2884 | new.si_trapno = from->si_trapno; | |
2885 | #endif | |
31931c93 EB |
2886 | break; |
2887 | case SIL_FAULT_MCEERR: | |
2888 | new.si_addr = ptr_to_compat(from->si_addr); | |
2889 | #ifdef __ARCH_SI_TRAPNO | |
2890 | new.si_trapno = from->si_trapno; | |
ea64d5ac | 2891 | #endif |
31931c93 EB |
2892 | new.si_addr_lsb = from->si_addr_lsb; |
2893 | break; | |
2894 | case SIL_FAULT_BNDERR: | |
2895 | new.si_addr = ptr_to_compat(from->si_addr); | |
2896 | #ifdef __ARCH_SI_TRAPNO | |
2897 | new.si_trapno = from->si_trapno; | |
ea64d5ac | 2898 | #endif |
31931c93 EB |
2899 | new.si_lower = ptr_to_compat(from->si_lower); |
2900 | new.si_upper = ptr_to_compat(from->si_upper); | |
2901 | break; | |
2902 | case SIL_FAULT_PKUERR: | |
2903 | new.si_addr = ptr_to_compat(from->si_addr); | |
2904 | #ifdef __ARCH_SI_TRAPNO | |
2905 | new.si_trapno = from->si_trapno; | |
ea64d5ac | 2906 | #endif |
31931c93 | 2907 | new.si_pkey = from->si_pkey; |
ea64d5ac EB |
2908 | break; |
2909 | case SIL_CHLD: | |
2910 | new.si_pid = from->si_pid; | |
2911 | new.si_uid = from->si_uid; | |
2912 | new.si_status = from->si_status; | |
2913 | #ifdef CONFIG_X86_X32_ABI | |
2914 | if (x32_ABI) { | |
2915 | new._sifields._sigchld_x32._utime = from->si_utime; | |
2916 | new._sifields._sigchld_x32._stime = from->si_stime; | |
2917 | } else | |
2918 | #endif | |
2919 | { | |
2920 | new.si_utime = from->si_utime; | |
2921 | new.si_stime = from->si_stime; | |
2922 | } | |
2923 | break; | |
2924 | case SIL_RT: | |
2925 | new.si_pid = from->si_pid; | |
2926 | new.si_uid = from->si_uid; | |
2927 | new.si_int = from->si_int; | |
2928 | break; | |
2929 | case SIL_SYS: | |
2930 | new.si_call_addr = ptr_to_compat(from->si_call_addr); | |
2931 | new.si_syscall = from->si_syscall; | |
2932 | new.si_arch = from->si_arch; | |
2933 | break; | |
2934 | } | |
2935 | ||
2936 | if (copy_to_user(to, &new, sizeof(struct compat_siginfo))) | |
2937 | return -EFAULT; | |
2938 | ||
2939 | return 0; | |
2940 | } | |
2941 | ||
212a36a1 EB |
2942 | int copy_siginfo_from_user32(struct siginfo *to, |
2943 | const struct compat_siginfo __user *ufrom) | |
2944 | { | |
2945 | struct compat_siginfo from; | |
2946 | ||
2947 | if (copy_from_user(&from, ufrom, sizeof(struct compat_siginfo))) | |
2948 | return -EFAULT; | |
2949 | ||
2950 | clear_siginfo(to); | |
2951 | to->si_signo = from.si_signo; | |
2952 | to->si_errno = from.si_errno; | |
2953 | to->si_code = from.si_code; | |
2954 | switch(siginfo_layout(from.si_signo, from.si_code)) { | |
2955 | case SIL_KILL: | |
2956 | to->si_pid = from.si_pid; | |
2957 | to->si_uid = from.si_uid; | |
2958 | break; | |
2959 | case SIL_TIMER: | |
2960 | to->si_tid = from.si_tid; | |
2961 | to->si_overrun = from.si_overrun; | |
2962 | to->si_int = from.si_int; | |
2963 | break; | |
2964 | case SIL_POLL: | |
2965 | to->si_band = from.si_band; | |
2966 | to->si_fd = from.si_fd; | |
2967 | break; | |
2968 | case SIL_FAULT: | |
2969 | to->si_addr = compat_ptr(from.si_addr); | |
2970 | #ifdef __ARCH_SI_TRAPNO | |
2971 | to->si_trapno = from.si_trapno; | |
2972 | #endif | |
31931c93 EB |
2973 | break; |
2974 | case SIL_FAULT_MCEERR: | |
2975 | to->si_addr = compat_ptr(from.si_addr); | |
2976 | #ifdef __ARCH_SI_TRAPNO | |
2977 | to->si_trapno = from.si_trapno; | |
212a36a1 | 2978 | #endif |
31931c93 EB |
2979 | to->si_addr_lsb = from.si_addr_lsb; |
2980 | break; | |
2981 | case SIL_FAULT_BNDERR: | |
2982 | to->si_addr = compat_ptr(from.si_addr); | |
2983 | #ifdef __ARCH_SI_TRAPNO | |
2984 | to->si_trapno = from.si_trapno; | |
212a36a1 | 2985 | #endif |
31931c93 EB |
2986 | to->si_lower = compat_ptr(from.si_lower); |
2987 | to->si_upper = compat_ptr(from.si_upper); | |
2988 | break; | |
2989 | case SIL_FAULT_PKUERR: | |
2990 | to->si_addr = compat_ptr(from.si_addr); | |
2991 | #ifdef __ARCH_SI_TRAPNO | |
2992 | to->si_trapno = from.si_trapno; | |
212a36a1 | 2993 | #endif |
31931c93 | 2994 | to->si_pkey = from.si_pkey; |
212a36a1 EB |
2995 | break; |
2996 | case SIL_CHLD: | |
2997 | to->si_pid = from.si_pid; | |
2998 | to->si_uid = from.si_uid; | |
2999 | to->si_status = from.si_status; | |
3000 | #ifdef CONFIG_X86_X32_ABI | |
3001 | if (in_x32_syscall()) { | |
3002 | to->si_utime = from._sifields._sigchld_x32._utime; | |
3003 | to->si_stime = from._sifields._sigchld_x32._stime; | |
3004 | } else | |
3005 | #endif | |
3006 | { | |
3007 | to->si_utime = from.si_utime; | |
3008 | to->si_stime = from.si_stime; | |
3009 | } | |
3010 | break; | |
3011 | case SIL_RT: | |
3012 | to->si_pid = from.si_pid; | |
3013 | to->si_uid = from.si_uid; | |
3014 | to->si_int = from.si_int; | |
3015 | break; | |
3016 | case SIL_SYS: | |
3017 | to->si_call_addr = compat_ptr(from.si_call_addr); | |
3018 | to->si_syscall = from.si_syscall; | |
3019 | to->si_arch = from.si_arch; | |
3020 | break; | |
3021 | } | |
3022 | return 0; | |
3023 | } | |
3024 | #endif /* CONFIG_COMPAT */ | |
3025 | ||
943df148 ON |
3026 | /** |
3027 | * do_sigtimedwait - wait for queued signals specified in @which | |
3028 | * @which: queued signals to wait for | |
3029 | * @info: if non-null, the signal's siginfo is returned here | |
3030 | * @ts: upper bound on process time suspension | |
3031 | */ | |
1b3c872c | 3032 | static int do_sigtimedwait(const sigset_t *which, siginfo_t *info, |
2b1ecc3d | 3033 | const struct timespec *ts) |
943df148 | 3034 | { |
2456e855 | 3035 | ktime_t *to = NULL, timeout = KTIME_MAX; |
943df148 | 3036 | struct task_struct *tsk = current; |
943df148 | 3037 | sigset_t mask = *which; |
2b1ecc3d | 3038 | int sig, ret = 0; |
943df148 ON |
3039 | |
3040 | if (ts) { | |
3041 | if (!timespec_valid(ts)) | |
3042 | return -EINVAL; | |
2b1ecc3d TG |
3043 | timeout = timespec_to_ktime(*ts); |
3044 | to = &timeout; | |
943df148 ON |
3045 | } |
3046 | ||
3047 | /* | |
3048 | * Invert the set of allowed signals to get those we want to block. | |
3049 | */ | |
3050 | sigdelsetmask(&mask, sigmask(SIGKILL) | sigmask(SIGSTOP)); | |
3051 | signotset(&mask); | |
3052 | ||
3053 | spin_lock_irq(&tsk->sighand->siglock); | |
3054 | sig = dequeue_signal(tsk, &mask, info); | |
2456e855 | 3055 | if (!sig && timeout) { |
943df148 ON |
3056 | /* |
3057 | * None ready, temporarily unblock those we're interested | |
3058 | * while we are sleeping in so that we'll be awakened when | |
b182801a ON |
3059 | * they arrive. Unblocking is always fine, we can avoid |
3060 | * set_current_blocked(). | |
943df148 ON |
3061 | */ |
3062 | tsk->real_blocked = tsk->blocked; | |
3063 | sigandsets(&tsk->blocked, &tsk->blocked, &mask); | |
3064 | recalc_sigpending(); | |
3065 | spin_unlock_irq(&tsk->sighand->siglock); | |
3066 | ||
2b1ecc3d TG |
3067 | __set_current_state(TASK_INTERRUPTIBLE); |
3068 | ret = freezable_schedule_hrtimeout_range(to, tsk->timer_slack_ns, | |
3069 | HRTIMER_MODE_REL); | |
943df148 | 3070 | spin_lock_irq(&tsk->sighand->siglock); |
b182801a | 3071 | __set_task_blocked(tsk, &tsk->real_blocked); |
6114041a | 3072 | sigemptyset(&tsk->real_blocked); |
b182801a | 3073 | sig = dequeue_signal(tsk, &mask, info); |
943df148 ON |
3074 | } |
3075 | spin_unlock_irq(&tsk->sighand->siglock); | |
3076 | ||
3077 | if (sig) | |
3078 | return sig; | |
2b1ecc3d | 3079 | return ret ? -EINTR : -EAGAIN; |
943df148 ON |
3080 | } |
3081 | ||
41c57892 RD |
3082 | /** |
3083 | * sys_rt_sigtimedwait - synchronously wait for queued signals specified | |
3084 | * in @uthese | |
3085 | * @uthese: queued signals to wait for | |
3086 | * @uinfo: if non-null, the signal's siginfo is returned here | |
3087 | * @uts: upper bound on process time suspension | |
3088 | * @sigsetsize: size of sigset_t type | |
3089 | */ | |
17da2bd9 HC |
3090 | SYSCALL_DEFINE4(rt_sigtimedwait, const sigset_t __user *, uthese, |
3091 | siginfo_t __user *, uinfo, const struct timespec __user *, uts, | |
3092 | size_t, sigsetsize) | |
1da177e4 | 3093 | { |
1da177e4 LT |
3094 | sigset_t these; |
3095 | struct timespec ts; | |
3096 | siginfo_t info; | |
943df148 | 3097 | int ret; |
1da177e4 LT |
3098 | |
3099 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
3100 | if (sigsetsize != sizeof(sigset_t)) | |
3101 | return -EINVAL; | |
3102 | ||
3103 | if (copy_from_user(&these, uthese, sizeof(these))) | |
3104 | return -EFAULT; | |
5aba085e | 3105 | |
1da177e4 LT |
3106 | if (uts) { |
3107 | if (copy_from_user(&ts, uts, sizeof(ts))) | |
3108 | return -EFAULT; | |
1da177e4 LT |
3109 | } |
3110 | ||
943df148 | 3111 | ret = do_sigtimedwait(&these, &info, uts ? &ts : NULL); |
1da177e4 | 3112 | |
943df148 ON |
3113 | if (ret > 0 && uinfo) { |
3114 | if (copy_siginfo_to_user(uinfo, &info)) | |
3115 | ret = -EFAULT; | |
1da177e4 LT |
3116 | } |
3117 | ||
3118 | return ret; | |
3119 | } | |
3120 | ||
1b3c872c AV |
3121 | #ifdef CONFIG_COMPAT |
3122 | COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait, compat_sigset_t __user *, uthese, | |
3123 | struct compat_siginfo __user *, uinfo, | |
3124 | struct compat_timespec __user *, uts, compat_size_t, sigsetsize) | |
3125 | { | |
1b3c872c AV |
3126 | sigset_t s; |
3127 | struct timespec t; | |
3128 | siginfo_t info; | |
3129 | long ret; | |
3130 | ||
3131 | if (sigsetsize != sizeof(sigset_t)) | |
3132 | return -EINVAL; | |
3133 | ||
3968cf62 | 3134 | if (get_compat_sigset(&s, uthese)) |
1b3c872c | 3135 | return -EFAULT; |
1b3c872c AV |
3136 | |
3137 | if (uts) { | |
3138 | if (compat_get_timespec(&t, uts)) | |
3139 | return -EFAULT; | |
3140 | } | |
3141 | ||
3142 | ret = do_sigtimedwait(&s, &info, uts ? &t : NULL); | |
3143 | ||
3144 | if (ret > 0 && uinfo) { | |
3145 | if (copy_siginfo_to_user32(uinfo, &info)) | |
3146 | ret = -EFAULT; | |
3147 | } | |
3148 | ||
3149 | return ret; | |
3150 | } | |
3151 | #endif | |
3152 | ||
41c57892 RD |
3153 | /** |
3154 | * sys_kill - send a signal to a process | |
3155 | * @pid: the PID of the process | |
3156 | * @sig: signal to be sent | |
3157 | */ | |
17da2bd9 | 3158 | SYSCALL_DEFINE2(kill, pid_t, pid, int, sig) |
1da177e4 LT |
3159 | { |
3160 | struct siginfo info; | |
3161 | ||
faf1f22b | 3162 | clear_siginfo(&info); |
1da177e4 LT |
3163 | info.si_signo = sig; |
3164 | info.si_errno = 0; | |
3165 | info.si_code = SI_USER; | |
b488893a | 3166 | info.si_pid = task_tgid_vnr(current); |
078de5f7 | 3167 | info.si_uid = from_kuid_munged(current_user_ns(), current_uid()); |
1da177e4 LT |
3168 | |
3169 | return kill_something_info(sig, &info, pid); | |
3170 | } | |
3171 | ||
30b4ae8a TG |
3172 | static int |
3173 | do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info) | |
1da177e4 | 3174 | { |
1da177e4 | 3175 | struct task_struct *p; |
30b4ae8a | 3176 | int error = -ESRCH; |
1da177e4 | 3177 | |
3547ff3a | 3178 | rcu_read_lock(); |
228ebcbe | 3179 | p = find_task_by_vpid(pid); |
b488893a | 3180 | if (p && (tgid <= 0 || task_tgid_vnr(p) == tgid)) { |
30b4ae8a | 3181 | error = check_kill_permission(sig, info, p); |
1da177e4 LT |
3182 | /* |
3183 | * The null signal is a permissions and process existence | |
3184 | * probe. No signal is actually delivered. | |
3185 | */ | |
4a30debf ON |
3186 | if (!error && sig) { |
3187 | error = do_send_sig_info(sig, info, p, false); | |
3188 | /* | |
3189 | * If lock_task_sighand() failed we pretend the task | |
3190 | * dies after receiving the signal. The window is tiny, | |
3191 | * and the signal is private anyway. | |
3192 | */ | |
3193 | if (unlikely(error == -ESRCH)) | |
3194 | error = 0; | |
1da177e4 LT |
3195 | } |
3196 | } | |
3547ff3a | 3197 | rcu_read_unlock(); |
6dd69f10 | 3198 | |
1da177e4 LT |
3199 | return error; |
3200 | } | |
3201 | ||
30b4ae8a TG |
3202 | static int do_tkill(pid_t tgid, pid_t pid, int sig) |
3203 | { | |
5f74972c | 3204 | struct siginfo info; |
30b4ae8a | 3205 | |
5f74972c | 3206 | clear_siginfo(&info); |
30b4ae8a TG |
3207 | info.si_signo = sig; |
3208 | info.si_errno = 0; | |
3209 | info.si_code = SI_TKILL; | |
3210 | info.si_pid = task_tgid_vnr(current); | |
078de5f7 | 3211 | info.si_uid = from_kuid_munged(current_user_ns(), current_uid()); |
30b4ae8a TG |
3212 | |
3213 | return do_send_specific(tgid, pid, sig, &info); | |
3214 | } | |
3215 | ||
6dd69f10 VL |
3216 | /** |
3217 | * sys_tgkill - send signal to one specific thread | |
3218 | * @tgid: the thread group ID of the thread | |
3219 | * @pid: the PID of the thread | |
3220 | * @sig: signal to be sent | |
3221 | * | |
72fd4a35 | 3222 | * This syscall also checks the @tgid and returns -ESRCH even if the PID |
6dd69f10 VL |
3223 | * exists but it's not belonging to the target process anymore. This |
3224 | * method solves the problem of threads exiting and PIDs getting reused. | |
3225 | */ | |
a5f8fa9e | 3226 | SYSCALL_DEFINE3(tgkill, pid_t, tgid, pid_t, pid, int, sig) |
6dd69f10 VL |
3227 | { |
3228 | /* This is only valid for single tasks */ | |
3229 | if (pid <= 0 || tgid <= 0) | |
3230 | return -EINVAL; | |
3231 | ||
3232 | return do_tkill(tgid, pid, sig); | |
3233 | } | |
3234 | ||
41c57892 RD |
3235 | /** |
3236 | * sys_tkill - send signal to one specific task | |
3237 | * @pid: the PID of the task | |
3238 | * @sig: signal to be sent | |
3239 | * | |
1da177e4 LT |
3240 | * Send a signal to only one task, even if it's a CLONE_THREAD task. |
3241 | */ | |
a5f8fa9e | 3242 | SYSCALL_DEFINE2(tkill, pid_t, pid, int, sig) |
1da177e4 | 3243 | { |
1da177e4 LT |
3244 | /* This is only valid for single tasks */ |
3245 | if (pid <= 0) | |
3246 | return -EINVAL; | |
3247 | ||
6dd69f10 | 3248 | return do_tkill(0, pid, sig); |
1da177e4 LT |
3249 | } |
3250 | ||
75907d4d AV |
3251 | static int do_rt_sigqueueinfo(pid_t pid, int sig, siginfo_t *info) |
3252 | { | |
3253 | /* Not even root can pretend to send signals from the kernel. | |
3254 | * Nor can they impersonate a kill()/tgkill(), which adds source info. | |
3255 | */ | |
66dd34ad | 3256 | if ((info->si_code >= 0 || info->si_code == SI_TKILL) && |
69828dce | 3257 | (task_pid_vnr(current) != pid)) |
75907d4d | 3258 | return -EPERM; |
69828dce | 3259 | |
75907d4d AV |
3260 | info->si_signo = sig; |
3261 | ||
3262 | /* POSIX.1b doesn't mention process groups. */ | |
3263 | return kill_proc_info(sig, info, pid); | |
3264 | } | |
3265 | ||
41c57892 RD |
3266 | /** |
3267 | * sys_rt_sigqueueinfo - send signal information to a signal | |
3268 | * @pid: the PID of the thread | |
3269 | * @sig: signal to be sent | |
3270 | * @uinfo: signal info to be sent | |
3271 | */ | |
a5f8fa9e HC |
3272 | SYSCALL_DEFINE3(rt_sigqueueinfo, pid_t, pid, int, sig, |
3273 | siginfo_t __user *, uinfo) | |
1da177e4 LT |
3274 | { |
3275 | siginfo_t info; | |
1da177e4 LT |
3276 | if (copy_from_user(&info, uinfo, sizeof(siginfo_t))) |
3277 | return -EFAULT; | |
75907d4d AV |
3278 | return do_rt_sigqueueinfo(pid, sig, &info); |
3279 | } | |
1da177e4 | 3280 | |
75907d4d | 3281 | #ifdef CONFIG_COMPAT |
75907d4d AV |
3282 | COMPAT_SYSCALL_DEFINE3(rt_sigqueueinfo, |
3283 | compat_pid_t, pid, | |
3284 | int, sig, | |
3285 | struct compat_siginfo __user *, uinfo) | |
3286 | { | |
eb5346c3 | 3287 | siginfo_t info; |
75907d4d AV |
3288 | int ret = copy_siginfo_from_user32(&info, uinfo); |
3289 | if (unlikely(ret)) | |
3290 | return ret; | |
3291 | return do_rt_sigqueueinfo(pid, sig, &info); | |
1da177e4 | 3292 | } |
75907d4d | 3293 | #endif |
1da177e4 | 3294 | |
9aae8fc0 | 3295 | static int do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, siginfo_t *info) |
62ab4505 TG |
3296 | { |
3297 | /* This is only valid for single tasks */ | |
3298 | if (pid <= 0 || tgid <= 0) | |
3299 | return -EINVAL; | |
3300 | ||
3301 | /* Not even root can pretend to send signals from the kernel. | |
da48524e JT |
3302 | * Nor can they impersonate a kill()/tgkill(), which adds source info. |
3303 | */ | |
69828dce VD |
3304 | if ((info->si_code >= 0 || info->si_code == SI_TKILL) && |
3305 | (task_pid_vnr(current) != pid)) | |
62ab4505 | 3306 | return -EPERM; |
69828dce | 3307 | |
62ab4505 TG |
3308 | info->si_signo = sig; |
3309 | ||
3310 | return do_send_specific(tgid, pid, sig, info); | |
3311 | } | |
3312 | ||
3313 | SYSCALL_DEFINE4(rt_tgsigqueueinfo, pid_t, tgid, pid_t, pid, int, sig, | |
3314 | siginfo_t __user *, uinfo) | |
3315 | { | |
3316 | siginfo_t info; | |
3317 | ||
3318 | if (copy_from_user(&info, uinfo, sizeof(siginfo_t))) | |
3319 | return -EFAULT; | |
3320 | ||
3321 | return do_rt_tgsigqueueinfo(tgid, pid, sig, &info); | |
3322 | } | |
3323 | ||
9aae8fc0 AV |
3324 | #ifdef CONFIG_COMPAT |
3325 | COMPAT_SYSCALL_DEFINE4(rt_tgsigqueueinfo, | |
3326 | compat_pid_t, tgid, | |
3327 | compat_pid_t, pid, | |
3328 | int, sig, | |
3329 | struct compat_siginfo __user *, uinfo) | |
3330 | { | |
eb5346c3 | 3331 | siginfo_t info; |
9aae8fc0 AV |
3332 | |
3333 | if (copy_siginfo_from_user32(&info, uinfo)) | |
3334 | return -EFAULT; | |
3335 | return do_rt_tgsigqueueinfo(tgid, pid, sig, &info); | |
3336 | } | |
3337 | #endif | |
3338 | ||
0341729b | 3339 | /* |
b4e74264 | 3340 | * For kthreads only, must not be used if cloned with CLONE_SIGHAND |
0341729b | 3341 | */ |
b4e74264 | 3342 | void kernel_sigaction(int sig, __sighandler_t action) |
0341729b | 3343 | { |
ec5955b8 | 3344 | spin_lock_irq(¤t->sighand->siglock); |
b4e74264 ON |
3345 | current->sighand->action[sig - 1].sa.sa_handler = action; |
3346 | if (action == SIG_IGN) { | |
3347 | sigset_t mask; | |
0341729b | 3348 | |
b4e74264 ON |
3349 | sigemptyset(&mask); |
3350 | sigaddset(&mask, sig); | |
580d34e4 | 3351 | |
b4e74264 ON |
3352 | flush_sigqueue_mask(&mask, ¤t->signal->shared_pending); |
3353 | flush_sigqueue_mask(&mask, ¤t->pending); | |
3354 | recalc_sigpending(); | |
3355 | } | |
0341729b ON |
3356 | spin_unlock_irq(¤t->sighand->siglock); |
3357 | } | |
b4e74264 | 3358 | EXPORT_SYMBOL(kernel_sigaction); |
0341729b | 3359 | |
68463510 DS |
3360 | void __weak sigaction_compat_abi(struct k_sigaction *act, |
3361 | struct k_sigaction *oact) | |
3362 | { | |
3363 | } | |
3364 | ||
88531f72 | 3365 | int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) |
1da177e4 | 3366 | { |
afe2b038 | 3367 | struct task_struct *p = current, *t; |
1da177e4 | 3368 | struct k_sigaction *k; |
71fabd5e | 3369 | sigset_t mask; |
1da177e4 | 3370 | |
7ed20e1a | 3371 | if (!valid_signal(sig) || sig < 1 || (act && sig_kernel_only(sig))) |
1da177e4 LT |
3372 | return -EINVAL; |
3373 | ||
afe2b038 | 3374 | k = &p->sighand->action[sig-1]; |
1da177e4 | 3375 | |
afe2b038 | 3376 | spin_lock_irq(&p->sighand->siglock); |
1da177e4 LT |
3377 | if (oact) |
3378 | *oact = *k; | |
3379 | ||
68463510 DS |
3380 | sigaction_compat_abi(act, oact); |
3381 | ||
1da177e4 | 3382 | if (act) { |
9ac95f2f ON |
3383 | sigdelsetmask(&act->sa.sa_mask, |
3384 | sigmask(SIGKILL) | sigmask(SIGSTOP)); | |
88531f72 | 3385 | *k = *act; |
1da177e4 LT |
3386 | /* |
3387 | * POSIX 3.3.1.3: | |
3388 | * "Setting a signal action to SIG_IGN for a signal that is | |
3389 | * pending shall cause the pending signal to be discarded, | |
3390 | * whether or not it is blocked." | |
3391 | * | |
3392 | * "Setting a signal action to SIG_DFL for a signal that is | |
3393 | * pending and whose default action is to ignore the signal | |
3394 | * (for example, SIGCHLD), shall cause the pending signal to | |
3395 | * be discarded, whether or not it is blocked" | |
3396 | */ | |
afe2b038 | 3397 | if (sig_handler_ignored(sig_handler(p, sig), sig)) { |
71fabd5e GA |
3398 | sigemptyset(&mask); |
3399 | sigaddset(&mask, sig); | |
afe2b038 ON |
3400 | flush_sigqueue_mask(&mask, &p->signal->shared_pending); |
3401 | for_each_thread(p, t) | |
c09c1441 | 3402 | flush_sigqueue_mask(&mask, &t->pending); |
1da177e4 | 3403 | } |
1da177e4 LT |
3404 | } |
3405 | ||
afe2b038 | 3406 | spin_unlock_irq(&p->sighand->siglock); |
1da177e4 LT |
3407 | return 0; |
3408 | } | |
3409 | ||
c09c1441 | 3410 | static int |
bcfe8ad8 | 3411 | do_sigaltstack (const stack_t *ss, stack_t *oss, unsigned long sp) |
1da177e4 | 3412 | { |
bcfe8ad8 | 3413 | struct task_struct *t = current; |
1da177e4 | 3414 | |
bcfe8ad8 AV |
3415 | if (oss) { |
3416 | memset(oss, 0, sizeof(stack_t)); | |
3417 | oss->ss_sp = (void __user *) t->sas_ss_sp; | |
3418 | oss->ss_size = t->sas_ss_size; | |
3419 | oss->ss_flags = sas_ss_flags(sp) | | |
3420 | (current->sas_ss_flags & SS_FLAG_BITS); | |
3421 | } | |
1da177e4 | 3422 | |
bcfe8ad8 AV |
3423 | if (ss) { |
3424 | void __user *ss_sp = ss->ss_sp; | |
3425 | size_t ss_size = ss->ss_size; | |
3426 | unsigned ss_flags = ss->ss_flags; | |
407bc16a | 3427 | int ss_mode; |
1da177e4 | 3428 | |
bcfe8ad8 AV |
3429 | if (unlikely(on_sig_stack(sp))) |
3430 | return -EPERM; | |
1da177e4 | 3431 | |
407bc16a | 3432 | ss_mode = ss_flags & ~SS_FLAG_BITS; |
bcfe8ad8 AV |
3433 | if (unlikely(ss_mode != SS_DISABLE && ss_mode != SS_ONSTACK && |
3434 | ss_mode != 0)) | |
3435 | return -EINVAL; | |
1da177e4 | 3436 | |
407bc16a | 3437 | if (ss_mode == SS_DISABLE) { |
1da177e4 LT |
3438 | ss_size = 0; |
3439 | ss_sp = NULL; | |
3440 | } else { | |
bcfe8ad8 AV |
3441 | if (unlikely(ss_size < MINSIGSTKSZ)) |
3442 | return -ENOMEM; | |
1da177e4 LT |
3443 | } |
3444 | ||
bcfe8ad8 AV |
3445 | t->sas_ss_sp = (unsigned long) ss_sp; |
3446 | t->sas_ss_size = ss_size; | |
3447 | t->sas_ss_flags = ss_flags; | |
1da177e4 | 3448 | } |
bcfe8ad8 | 3449 | return 0; |
1da177e4 | 3450 | } |
bcfe8ad8 | 3451 | |
6bf9adfc AV |
3452 | SYSCALL_DEFINE2(sigaltstack,const stack_t __user *,uss, stack_t __user *,uoss) |
3453 | { | |
bcfe8ad8 AV |
3454 | stack_t new, old; |
3455 | int err; | |
3456 | if (uss && copy_from_user(&new, uss, sizeof(stack_t))) | |
3457 | return -EFAULT; | |
3458 | err = do_sigaltstack(uss ? &new : NULL, uoss ? &old : NULL, | |
3459 | current_user_stack_pointer()); | |
3460 | if (!err && uoss && copy_to_user(uoss, &old, sizeof(stack_t))) | |
3461 | err = -EFAULT; | |
3462 | return err; | |
6bf9adfc | 3463 | } |
1da177e4 | 3464 | |
5c49574f AV |
3465 | int restore_altstack(const stack_t __user *uss) |
3466 | { | |
bcfe8ad8 AV |
3467 | stack_t new; |
3468 | if (copy_from_user(&new, uss, sizeof(stack_t))) | |
3469 | return -EFAULT; | |
3470 | (void)do_sigaltstack(&new, NULL, current_user_stack_pointer()); | |
5c49574f | 3471 | /* squash all but EFAULT for now */ |
bcfe8ad8 | 3472 | return 0; |
5c49574f AV |
3473 | } |
3474 | ||
c40702c4 AV |
3475 | int __save_altstack(stack_t __user *uss, unsigned long sp) |
3476 | { | |
3477 | struct task_struct *t = current; | |
2a742138 SS |
3478 | int err = __put_user((void __user *)t->sas_ss_sp, &uss->ss_sp) | |
3479 | __put_user(t->sas_ss_flags, &uss->ss_flags) | | |
c40702c4 | 3480 | __put_user(t->sas_ss_size, &uss->ss_size); |
2a742138 SS |
3481 | if (err) |
3482 | return err; | |
3483 | if (t->sas_ss_flags & SS_AUTODISARM) | |
3484 | sas_ss_reset(t); | |
3485 | return 0; | |
c40702c4 AV |
3486 | } |
3487 | ||
90268439 | 3488 | #ifdef CONFIG_COMPAT |
6203deb0 DB |
3489 | static int do_compat_sigaltstack(const compat_stack_t __user *uss_ptr, |
3490 | compat_stack_t __user *uoss_ptr) | |
90268439 AV |
3491 | { |
3492 | stack_t uss, uoss; | |
3493 | int ret; | |
90268439 AV |
3494 | |
3495 | if (uss_ptr) { | |
3496 | compat_stack_t uss32; | |
90268439 AV |
3497 | if (copy_from_user(&uss32, uss_ptr, sizeof(compat_stack_t))) |
3498 | return -EFAULT; | |
3499 | uss.ss_sp = compat_ptr(uss32.ss_sp); | |
3500 | uss.ss_flags = uss32.ss_flags; | |
3501 | uss.ss_size = uss32.ss_size; | |
3502 | } | |
bcfe8ad8 | 3503 | ret = do_sigaltstack(uss_ptr ? &uss : NULL, &uoss, |
90268439 | 3504 | compat_user_stack_pointer()); |
90268439 | 3505 | if (ret >= 0 && uoss_ptr) { |
bcfe8ad8 AV |
3506 | compat_stack_t old; |
3507 | memset(&old, 0, sizeof(old)); | |
3508 | old.ss_sp = ptr_to_compat(uoss.ss_sp); | |
3509 | old.ss_flags = uoss.ss_flags; | |
3510 | old.ss_size = uoss.ss_size; | |
3511 | if (copy_to_user(uoss_ptr, &old, sizeof(compat_stack_t))) | |
90268439 AV |
3512 | ret = -EFAULT; |
3513 | } | |
3514 | return ret; | |
3515 | } | |
3516 | ||
6203deb0 DB |
3517 | COMPAT_SYSCALL_DEFINE2(sigaltstack, |
3518 | const compat_stack_t __user *, uss_ptr, | |
3519 | compat_stack_t __user *, uoss_ptr) | |
3520 | { | |
3521 | return do_compat_sigaltstack(uss_ptr, uoss_ptr); | |
3522 | } | |
3523 | ||
90268439 AV |
3524 | int compat_restore_altstack(const compat_stack_t __user *uss) |
3525 | { | |
6203deb0 | 3526 | int err = do_compat_sigaltstack(uss, NULL); |
90268439 AV |
3527 | /* squash all but -EFAULT for now */ |
3528 | return err == -EFAULT ? err : 0; | |
3529 | } | |
c40702c4 AV |
3530 | |
3531 | int __compat_save_altstack(compat_stack_t __user *uss, unsigned long sp) | |
3532 | { | |
441398d3 | 3533 | int err; |
c40702c4 | 3534 | struct task_struct *t = current; |
441398d3 SS |
3535 | err = __put_user(ptr_to_compat((void __user *)t->sas_ss_sp), |
3536 | &uss->ss_sp) | | |
3537 | __put_user(t->sas_ss_flags, &uss->ss_flags) | | |
c40702c4 | 3538 | __put_user(t->sas_ss_size, &uss->ss_size); |
441398d3 SS |
3539 | if (err) |
3540 | return err; | |
3541 | if (t->sas_ss_flags & SS_AUTODISARM) | |
3542 | sas_ss_reset(t); | |
3543 | return 0; | |
c40702c4 | 3544 | } |
90268439 | 3545 | #endif |
1da177e4 LT |
3546 | |
3547 | #ifdef __ARCH_WANT_SYS_SIGPENDING | |
3548 | ||
41c57892 RD |
3549 | /** |
3550 | * sys_sigpending - examine pending signals | |
d53238cd | 3551 | * @uset: where mask of pending signal is returned |
41c57892 | 3552 | */ |
d53238cd | 3553 | SYSCALL_DEFINE1(sigpending, old_sigset_t __user *, uset) |
1da177e4 | 3554 | { |
d53238cd | 3555 | sigset_t set; |
d53238cd DB |
3556 | |
3557 | if (sizeof(old_sigset_t) > sizeof(*uset)) | |
3558 | return -EINVAL; | |
3559 | ||
b1d294c8 CB |
3560 | do_sigpending(&set); |
3561 | ||
3562 | if (copy_to_user(uset, &set, sizeof(old_sigset_t))) | |
3563 | return -EFAULT; | |
3564 | ||
3565 | return 0; | |
1da177e4 LT |
3566 | } |
3567 | ||
8f13621a AV |
3568 | #ifdef CONFIG_COMPAT |
3569 | COMPAT_SYSCALL_DEFINE1(sigpending, compat_old_sigset_t __user *, set32) | |
3570 | { | |
3571 | sigset_t set; | |
b1d294c8 CB |
3572 | |
3573 | do_sigpending(&set); | |
3574 | ||
3575 | return put_user(set.sig[0], set32); | |
8f13621a AV |
3576 | } |
3577 | #endif | |
3578 | ||
1da177e4 LT |
3579 | #endif |
3580 | ||
3581 | #ifdef __ARCH_WANT_SYS_SIGPROCMASK | |
41c57892 RD |
3582 | /** |
3583 | * sys_sigprocmask - examine and change blocked signals | |
3584 | * @how: whether to add, remove, or set signals | |
b013c399 | 3585 | * @nset: signals to add or remove (if non-null) |
41c57892 RD |
3586 | * @oset: previous value of signal mask if non-null |
3587 | * | |
5aba085e RD |
3588 | * Some platforms have their own version with special arguments; |
3589 | * others support only sys_rt_sigprocmask. | |
3590 | */ | |
1da177e4 | 3591 | |
b013c399 | 3592 | SYSCALL_DEFINE3(sigprocmask, int, how, old_sigset_t __user *, nset, |
b290ebe2 | 3593 | old_sigset_t __user *, oset) |
1da177e4 | 3594 | { |
1da177e4 | 3595 | old_sigset_t old_set, new_set; |
2e4f7c77 | 3596 | sigset_t new_blocked; |
1da177e4 | 3597 | |
b013c399 | 3598 | old_set = current->blocked.sig[0]; |
1da177e4 | 3599 | |
b013c399 ON |
3600 | if (nset) { |
3601 | if (copy_from_user(&new_set, nset, sizeof(*nset))) | |
3602 | return -EFAULT; | |
1da177e4 | 3603 | |
2e4f7c77 | 3604 | new_blocked = current->blocked; |
1da177e4 | 3605 | |
1da177e4 | 3606 | switch (how) { |
1da177e4 | 3607 | case SIG_BLOCK: |
2e4f7c77 | 3608 | sigaddsetmask(&new_blocked, new_set); |
1da177e4 LT |
3609 | break; |
3610 | case SIG_UNBLOCK: | |
2e4f7c77 | 3611 | sigdelsetmask(&new_blocked, new_set); |
1da177e4 LT |
3612 | break; |
3613 | case SIG_SETMASK: | |
2e4f7c77 | 3614 | new_blocked.sig[0] = new_set; |
1da177e4 | 3615 | break; |
2e4f7c77 ON |
3616 | default: |
3617 | return -EINVAL; | |
1da177e4 LT |
3618 | } |
3619 | ||
0c4a8423 | 3620 | set_current_blocked(&new_blocked); |
b013c399 ON |
3621 | } |
3622 | ||
3623 | if (oset) { | |
1da177e4 | 3624 | if (copy_to_user(oset, &old_set, sizeof(*oset))) |
b013c399 | 3625 | return -EFAULT; |
1da177e4 | 3626 | } |
b013c399 ON |
3627 | |
3628 | return 0; | |
1da177e4 LT |
3629 | } |
3630 | #endif /* __ARCH_WANT_SYS_SIGPROCMASK */ | |
3631 | ||
eaca6eae | 3632 | #ifndef CONFIG_ODD_RT_SIGACTION |
41c57892 RD |
3633 | /** |
3634 | * sys_rt_sigaction - alter an action taken by a process | |
3635 | * @sig: signal to be sent | |
f9fa0bc1 RD |
3636 | * @act: new sigaction |
3637 | * @oact: used to save the previous sigaction | |
41c57892 RD |
3638 | * @sigsetsize: size of sigset_t type |
3639 | */ | |
d4e82042 HC |
3640 | SYSCALL_DEFINE4(rt_sigaction, int, sig, |
3641 | const struct sigaction __user *, act, | |
3642 | struct sigaction __user *, oact, | |
3643 | size_t, sigsetsize) | |
1da177e4 LT |
3644 | { |
3645 | struct k_sigaction new_sa, old_sa; | |
d8f993b3 | 3646 | int ret; |
1da177e4 LT |
3647 | |
3648 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
3649 | if (sigsetsize != sizeof(sigset_t)) | |
d8f993b3 | 3650 | return -EINVAL; |
1da177e4 | 3651 | |
d8f993b3 CB |
3652 | if (act && copy_from_user(&new_sa.sa, act, sizeof(new_sa.sa))) |
3653 | return -EFAULT; | |
1da177e4 LT |
3654 | |
3655 | ret = do_sigaction(sig, act ? &new_sa : NULL, oact ? &old_sa : NULL); | |
d8f993b3 CB |
3656 | if (ret) |
3657 | return ret; | |
1da177e4 | 3658 | |
d8f993b3 CB |
3659 | if (oact && copy_to_user(oact, &old_sa.sa, sizeof(old_sa.sa))) |
3660 | return -EFAULT; | |
3661 | ||
3662 | return 0; | |
1da177e4 | 3663 | } |
08d32fe5 | 3664 | #ifdef CONFIG_COMPAT |
08d32fe5 AV |
3665 | COMPAT_SYSCALL_DEFINE4(rt_sigaction, int, sig, |
3666 | const struct compat_sigaction __user *, act, | |
3667 | struct compat_sigaction __user *, oact, | |
3668 | compat_size_t, sigsetsize) | |
3669 | { | |
3670 | struct k_sigaction new_ka, old_ka; | |
08d32fe5 AV |
3671 | #ifdef __ARCH_HAS_SA_RESTORER |
3672 | compat_uptr_t restorer; | |
3673 | #endif | |
3674 | int ret; | |
3675 | ||
3676 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
3677 | if (sigsetsize != sizeof(compat_sigset_t)) | |
3678 | return -EINVAL; | |
3679 | ||
3680 | if (act) { | |
3681 | compat_uptr_t handler; | |
3682 | ret = get_user(handler, &act->sa_handler); | |
3683 | new_ka.sa.sa_handler = compat_ptr(handler); | |
3684 | #ifdef __ARCH_HAS_SA_RESTORER | |
3685 | ret |= get_user(restorer, &act->sa_restorer); | |
3686 | new_ka.sa.sa_restorer = compat_ptr(restorer); | |
3687 | #endif | |
3968cf62 | 3688 | ret |= get_compat_sigset(&new_ka.sa.sa_mask, &act->sa_mask); |
3ddc5b46 | 3689 | ret |= get_user(new_ka.sa.sa_flags, &act->sa_flags); |
08d32fe5 AV |
3690 | if (ret) |
3691 | return -EFAULT; | |
08d32fe5 AV |
3692 | } |
3693 | ||
3694 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
3695 | if (!ret && oact) { | |
08d32fe5 AV |
3696 | ret = put_user(ptr_to_compat(old_ka.sa.sa_handler), |
3697 | &oact->sa_handler); | |
f454322e DL |
3698 | ret |= put_compat_sigset(&oact->sa_mask, &old_ka.sa.sa_mask, |
3699 | sizeof(oact->sa_mask)); | |
3ddc5b46 | 3700 | ret |= put_user(old_ka.sa.sa_flags, &oact->sa_flags); |
08d32fe5 AV |
3701 | #ifdef __ARCH_HAS_SA_RESTORER |
3702 | ret |= put_user(ptr_to_compat(old_ka.sa.sa_restorer), | |
3703 | &oact->sa_restorer); | |
3704 | #endif | |
3705 | } | |
3706 | return ret; | |
3707 | } | |
3708 | #endif | |
eaca6eae | 3709 | #endif /* !CONFIG_ODD_RT_SIGACTION */ |
1da177e4 | 3710 | |
495dfbf7 AV |
3711 | #ifdef CONFIG_OLD_SIGACTION |
3712 | SYSCALL_DEFINE3(sigaction, int, sig, | |
3713 | const struct old_sigaction __user *, act, | |
3714 | struct old_sigaction __user *, oact) | |
3715 | { | |
3716 | struct k_sigaction new_ka, old_ka; | |
3717 | int ret; | |
3718 | ||
3719 | if (act) { | |
3720 | old_sigset_t mask; | |
3721 | if (!access_ok(VERIFY_READ, act, sizeof(*act)) || | |
3722 | __get_user(new_ka.sa.sa_handler, &act->sa_handler) || | |
3723 | __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) || | |
3724 | __get_user(new_ka.sa.sa_flags, &act->sa_flags) || | |
3725 | __get_user(mask, &act->sa_mask)) | |
3726 | return -EFAULT; | |
3727 | #ifdef __ARCH_HAS_KA_RESTORER | |
3728 | new_ka.ka_restorer = NULL; | |
3729 | #endif | |
3730 | siginitset(&new_ka.sa.sa_mask, mask); | |
3731 | } | |
3732 | ||
3733 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
3734 | ||
3735 | if (!ret && oact) { | |
3736 | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || | |
3737 | __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || | |
3738 | __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) || | |
3739 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags) || | |
3740 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask)) | |
3741 | return -EFAULT; | |
3742 | } | |
3743 | ||
3744 | return ret; | |
3745 | } | |
3746 | #endif | |
3747 | #ifdef CONFIG_COMPAT_OLD_SIGACTION | |
3748 | COMPAT_SYSCALL_DEFINE3(sigaction, int, sig, | |
3749 | const struct compat_old_sigaction __user *, act, | |
3750 | struct compat_old_sigaction __user *, oact) | |
3751 | { | |
3752 | struct k_sigaction new_ka, old_ka; | |
3753 | int ret; | |
3754 | compat_old_sigset_t mask; | |
3755 | compat_uptr_t handler, restorer; | |
3756 | ||
3757 | if (act) { | |
3758 | if (!access_ok(VERIFY_READ, act, sizeof(*act)) || | |
3759 | __get_user(handler, &act->sa_handler) || | |
3760 | __get_user(restorer, &act->sa_restorer) || | |
3761 | __get_user(new_ka.sa.sa_flags, &act->sa_flags) || | |
3762 | __get_user(mask, &act->sa_mask)) | |
3763 | return -EFAULT; | |
3764 | ||
3765 | #ifdef __ARCH_HAS_KA_RESTORER | |
3766 | new_ka.ka_restorer = NULL; | |
3767 | #endif | |
3768 | new_ka.sa.sa_handler = compat_ptr(handler); | |
3769 | new_ka.sa.sa_restorer = compat_ptr(restorer); | |
3770 | siginitset(&new_ka.sa.sa_mask, mask); | |
3771 | } | |
3772 | ||
3773 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
3774 | ||
3775 | if (!ret && oact) { | |
3776 | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || | |
3777 | __put_user(ptr_to_compat(old_ka.sa.sa_handler), | |
3778 | &oact->sa_handler) || | |
3779 | __put_user(ptr_to_compat(old_ka.sa.sa_restorer), | |
3780 | &oact->sa_restorer) || | |
3781 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags) || | |
3782 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask)) | |
3783 | return -EFAULT; | |
3784 | } | |
3785 | return ret; | |
3786 | } | |
3787 | #endif | |
1da177e4 | 3788 | |
f6187769 | 3789 | #ifdef CONFIG_SGETMASK_SYSCALL |
1da177e4 LT |
3790 | |
3791 | /* | |
3792 | * For backwards compatibility. Functionality superseded by sigprocmask. | |
3793 | */ | |
a5f8fa9e | 3794 | SYSCALL_DEFINE0(sgetmask) |
1da177e4 LT |
3795 | { |
3796 | /* SMP safe */ | |
3797 | return current->blocked.sig[0]; | |
3798 | } | |
3799 | ||
a5f8fa9e | 3800 | SYSCALL_DEFINE1(ssetmask, int, newmask) |
1da177e4 | 3801 | { |
c1095c6d ON |
3802 | int old = current->blocked.sig[0]; |
3803 | sigset_t newset; | |
1da177e4 | 3804 | |
5ba53ff6 | 3805 | siginitset(&newset, newmask); |
c1095c6d | 3806 | set_current_blocked(&newset); |
1da177e4 LT |
3807 | |
3808 | return old; | |
3809 | } | |
f6187769 | 3810 | #endif /* CONFIG_SGETMASK_SYSCALL */ |
1da177e4 LT |
3811 | |
3812 | #ifdef __ARCH_WANT_SYS_SIGNAL | |
3813 | /* | |
3814 | * For backwards compatibility. Functionality superseded by sigaction. | |
3815 | */ | |
a5f8fa9e | 3816 | SYSCALL_DEFINE2(signal, int, sig, __sighandler_t, handler) |
1da177e4 LT |
3817 | { |
3818 | struct k_sigaction new_sa, old_sa; | |
3819 | int ret; | |
3820 | ||
3821 | new_sa.sa.sa_handler = handler; | |
3822 | new_sa.sa.sa_flags = SA_ONESHOT | SA_NOMASK; | |
c70d3d70 | 3823 | sigemptyset(&new_sa.sa.sa_mask); |
1da177e4 LT |
3824 | |
3825 | ret = do_sigaction(sig, &new_sa, &old_sa); | |
3826 | ||
3827 | return ret ? ret : (unsigned long)old_sa.sa.sa_handler; | |
3828 | } | |
3829 | #endif /* __ARCH_WANT_SYS_SIGNAL */ | |
3830 | ||
3831 | #ifdef __ARCH_WANT_SYS_PAUSE | |
3832 | ||
a5f8fa9e | 3833 | SYSCALL_DEFINE0(pause) |
1da177e4 | 3834 | { |
d92fcf05 | 3835 | while (!signal_pending(current)) { |
1df01355 | 3836 | __set_current_state(TASK_INTERRUPTIBLE); |
d92fcf05 ON |
3837 | schedule(); |
3838 | } | |
1da177e4 LT |
3839 | return -ERESTARTNOHAND; |
3840 | } | |
3841 | ||
3842 | #endif | |
3843 | ||
9d8a7652 | 3844 | static int sigsuspend(sigset_t *set) |
68f3f16d | 3845 | { |
68f3f16d AV |
3846 | current->saved_sigmask = current->blocked; |
3847 | set_current_blocked(set); | |
3848 | ||
823dd322 SL |
3849 | while (!signal_pending(current)) { |
3850 | __set_current_state(TASK_INTERRUPTIBLE); | |
3851 | schedule(); | |
3852 | } | |
68f3f16d AV |
3853 | set_restore_sigmask(); |
3854 | return -ERESTARTNOHAND; | |
3855 | } | |
68f3f16d | 3856 | |
41c57892 RD |
3857 | /** |
3858 | * sys_rt_sigsuspend - replace the signal mask for a value with the | |
3859 | * @unewset value until a signal is received | |
3860 | * @unewset: new signal mask value | |
3861 | * @sigsetsize: size of sigset_t type | |
3862 | */ | |
d4e82042 | 3863 | SYSCALL_DEFINE2(rt_sigsuspend, sigset_t __user *, unewset, size_t, sigsetsize) |
150256d8 DW |
3864 | { |
3865 | sigset_t newset; | |
3866 | ||
3867 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
3868 | if (sigsetsize != sizeof(sigset_t)) | |
3869 | return -EINVAL; | |
3870 | ||
3871 | if (copy_from_user(&newset, unewset, sizeof(newset))) | |
3872 | return -EFAULT; | |
68f3f16d | 3873 | return sigsuspend(&newset); |
150256d8 | 3874 | } |
ad4b65a4 AV |
3875 | |
3876 | #ifdef CONFIG_COMPAT | |
3877 | COMPAT_SYSCALL_DEFINE2(rt_sigsuspend, compat_sigset_t __user *, unewset, compat_size_t, sigsetsize) | |
3878 | { | |
ad4b65a4 | 3879 | sigset_t newset; |
ad4b65a4 AV |
3880 | |
3881 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
3882 | if (sigsetsize != sizeof(sigset_t)) | |
3883 | return -EINVAL; | |
3884 | ||
3968cf62 | 3885 | if (get_compat_sigset(&newset, unewset)) |
ad4b65a4 | 3886 | return -EFAULT; |
ad4b65a4 | 3887 | return sigsuspend(&newset); |
ad4b65a4 AV |
3888 | } |
3889 | #endif | |
150256d8 | 3890 | |
0a0e8cdf AV |
3891 | #ifdef CONFIG_OLD_SIGSUSPEND |
3892 | SYSCALL_DEFINE1(sigsuspend, old_sigset_t, mask) | |
3893 | { | |
3894 | sigset_t blocked; | |
3895 | siginitset(&blocked, mask); | |
3896 | return sigsuspend(&blocked); | |
3897 | } | |
3898 | #endif | |
3899 | #ifdef CONFIG_OLD_SIGSUSPEND3 | |
3900 | SYSCALL_DEFINE3(sigsuspend, int, unused1, int, unused2, old_sigset_t, mask) | |
3901 | { | |
3902 | sigset_t blocked; | |
3903 | siginitset(&blocked, mask); | |
3904 | return sigsuspend(&blocked); | |
3905 | } | |
3906 | #endif | |
150256d8 | 3907 | |
52f5684c | 3908 | __weak const char *arch_vma_name(struct vm_area_struct *vma) |
f269fdd1 DH |
3909 | { |
3910 | return NULL; | |
3911 | } | |
3912 | ||
1da177e4 LT |
3913 | void __init signals_init(void) |
3914 | { | |
41b27154 HD |
3915 | /* If this check fails, the __ARCH_SI_PREAMBLE_SIZE value is wrong! */ |
3916 | BUILD_BUG_ON(__ARCH_SI_PREAMBLE_SIZE | |
3917 | != offsetof(struct siginfo, _sifields._pad)); | |
aba1be2f | 3918 | BUILD_BUG_ON(sizeof(struct siginfo) != SI_MAX_SIZE); |
41b27154 | 3919 | |
0a31bd5f | 3920 | sigqueue_cachep = KMEM_CACHE(sigqueue, SLAB_PANIC); |
1da177e4 | 3921 | } |
67fc4e0c JW |
3922 | |
3923 | #ifdef CONFIG_KGDB_KDB | |
3924 | #include <linux/kdb.h> | |
3925 | /* | |
0b44bf9a | 3926 | * kdb_send_sig - Allows kdb to send signals without exposing |
67fc4e0c JW |
3927 | * signal internals. This function checks if the required locks are |
3928 | * available before calling the main signal code, to avoid kdb | |
3929 | * deadlocks. | |
3930 | */ | |
0b44bf9a | 3931 | void kdb_send_sig(struct task_struct *t, int sig) |
67fc4e0c JW |
3932 | { |
3933 | static struct task_struct *kdb_prev_t; | |
0b44bf9a | 3934 | int new_t, ret; |
67fc4e0c JW |
3935 | if (!spin_trylock(&t->sighand->siglock)) { |
3936 | kdb_printf("Can't do kill command now.\n" | |
3937 | "The sigmask lock is held somewhere else in " | |
3938 | "kernel, try again later\n"); | |
3939 | return; | |
3940 | } | |
67fc4e0c JW |
3941 | new_t = kdb_prev_t != t; |
3942 | kdb_prev_t = t; | |
3943 | if (t->state != TASK_RUNNING && new_t) { | |
0b44bf9a | 3944 | spin_unlock(&t->sighand->siglock); |
67fc4e0c JW |
3945 | kdb_printf("Process is not RUNNING, sending a signal from " |
3946 | "kdb risks deadlock\n" | |
3947 | "on the run queue locks. " | |
3948 | "The signal has _not_ been sent.\n" | |
3949 | "Reissue the kill command if you want to risk " | |
3950 | "the deadlock.\n"); | |
3951 | return; | |
3952 | } | |
0b44bf9a EB |
3953 | ret = send_signal(sig, SEND_SIG_PRIV, t, false); |
3954 | spin_unlock(&t->sighand->siglock); | |
3955 | if (ret) | |
67fc4e0c JW |
3956 | kdb_printf("Fail to deliver Signal %d to process %d.\n", |
3957 | sig, t->pid); | |
3958 | else | |
3959 | kdb_printf("Signal %d is sent to process %d.\n", sig, t->pid); | |
3960 | } | |
3961 | #endif /* CONFIG_KGDB_KDB */ |