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Commit | Line | Data |
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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * linux/kernel/signal.c | |
4 | * | |
5 | * Copyright (C) 1991, 1992 Linus Torvalds | |
6 | * | |
7 | * 1997-11-02 Modified for POSIX.1b signals by Richard Henderson | |
8 | * | |
9 | * 2003-06-02 Jim Houston - Concurrent Computer Corp. | |
10 | * Changes to use preallocated sigqueue structures | |
11 | * to allow signals to be sent reliably. | |
12 | */ | |
13 | ||
1da177e4 | 14 | #include <linux/slab.h> |
9984de1a | 15 | #include <linux/export.h> |
1da177e4 | 16 | #include <linux/init.h> |
589ee628 | 17 | #include <linux/sched/mm.h> |
8703e8a4 | 18 | #include <linux/sched/user.h> |
b17b0153 | 19 | #include <linux/sched/debug.h> |
29930025 | 20 | #include <linux/sched/task.h> |
68db0cf1 | 21 | #include <linux/sched/task_stack.h> |
32ef5517 | 22 | #include <linux/sched/cputime.h> |
3eb39f47 | 23 | #include <linux/file.h> |
1da177e4 | 24 | #include <linux/fs.h> |
b0b88e02 | 25 | #include <linux/mm.h> |
3eb39f47 | 26 | #include <linux/proc_fs.h> |
1da177e4 LT |
27 | #include <linux/tty.h> |
28 | #include <linux/binfmts.h> | |
179899fd | 29 | #include <linux/coredump.h> |
1da177e4 LT |
30 | #include <linux/security.h> |
31 | #include <linux/syscalls.h> | |
32 | #include <linux/ptrace.h> | |
7ed20e1a | 33 | #include <linux/signal.h> |
fba2afaa | 34 | #include <linux/signalfd.h> |
f84d49b2 | 35 | #include <linux/ratelimit.h> |
355f841a | 36 | #include <linux/task_work.h> |
c59ede7b | 37 | #include <linux/capability.h> |
7dfb7103 | 38 | #include <linux/freezer.h> |
84d73786 SB |
39 | #include <linux/pid_namespace.h> |
40 | #include <linux/nsproxy.h> | |
6b550f94 | 41 | #include <linux/user_namespace.h> |
0326f5a9 | 42 | #include <linux/uprobes.h> |
90268439 | 43 | #include <linux/compat.h> |
2b5faa4c | 44 | #include <linux/cn_proc.h> |
52f5684c | 45 | #include <linux/compiler.h> |
31ea70e0 | 46 | #include <linux/posix-timers.h> |
76f969e8 | 47 | #include <linux/cgroup.h> |
b48345aa | 48 | #include <linux/audit.h> |
01e6aac7 | 49 | #include <linux/sysctl.h> |
81b9d8ac | 50 | #include <uapi/linux/pidfd.h> |
52f5684c | 51 | |
d1eb650f MH |
52 | #define CREATE_TRACE_POINTS |
53 | #include <trace/events/signal.h> | |
84d73786 | 54 | |
1da177e4 | 55 | #include <asm/param.h> |
7c0f6ba6 | 56 | #include <linux/uaccess.h> |
1da177e4 LT |
57 | #include <asm/unistd.h> |
58 | #include <asm/siginfo.h> | |
d550bbd4 | 59 | #include <asm/cacheflush.h> |
307d522f | 60 | #include <asm/syscall.h> /* for syscall_get_* */ |
1da177e4 LT |
61 | |
62 | /* | |
63 | * SLAB caches for signal bits. | |
64 | */ | |
65 | ||
e18b890b | 66 | static struct kmem_cache *sigqueue_cachep; |
1da177e4 | 67 | |
f84d49b2 NO |
68 | int print_fatal_signals __read_mostly; |
69 | ||
35de254d | 70 | static void __user *sig_handler(struct task_struct *t, int sig) |
93585eea | 71 | { |
35de254d RM |
72 | return t->sighand->action[sig - 1].sa.sa_handler; |
73 | } | |
93585eea | 74 | |
e4a8b4ef | 75 | static inline bool sig_handler_ignored(void __user *handler, int sig) |
35de254d | 76 | { |
93585eea | 77 | /* Is it explicitly or implicitly ignored? */ |
93585eea | 78 | return handler == SIG_IGN || |
e4a8b4ef | 79 | (handler == SIG_DFL && sig_kernel_ignore(sig)); |
93585eea | 80 | } |
1da177e4 | 81 | |
41aaa481 | 82 | static bool sig_task_ignored(struct task_struct *t, int sig, bool force) |
1da177e4 | 83 | { |
35de254d | 84 | void __user *handler; |
1da177e4 | 85 | |
f008faff ON |
86 | handler = sig_handler(t, sig); |
87 | ||
86989c41 EB |
88 | /* SIGKILL and SIGSTOP may not be sent to the global init */ |
89 | if (unlikely(is_global_init(t) && sig_kernel_only(sig))) | |
90 | return true; | |
91 | ||
f008faff | 92 | if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) && |
ac253850 | 93 | handler == SIG_DFL && !(force && sig_kernel_only(sig))) |
41aaa481 | 94 | return true; |
f008faff | 95 | |
33da8e7c | 96 | /* Only allow kernel generated signals to this kthread */ |
e8b33b8c | 97 | if (unlikely((t->flags & PF_KTHREAD) && |
33da8e7c EB |
98 | (handler == SIG_KTHREAD_KERNEL) && !force)) |
99 | return true; | |
100 | ||
f008faff ON |
101 | return sig_handler_ignored(handler, sig); |
102 | } | |
103 | ||
6a0cdcd7 | 104 | static bool sig_ignored(struct task_struct *t, int sig, bool force) |
f008faff | 105 | { |
1da177e4 LT |
106 | /* |
107 | * Blocked signals are never ignored, since the | |
108 | * signal handler may change by the time it is | |
109 | * unblocked. | |
110 | */ | |
325d22df | 111 | if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig)) |
6a0cdcd7 | 112 | return false; |
1da177e4 | 113 | |
35de254d | 114 | /* |
628c1bcb ON |
115 | * Tracers may want to know about even ignored signal unless it |
116 | * is SIGKILL which can't be reported anyway but can be ignored | |
117 | * by SIGNAL_UNKILLABLE task. | |
35de254d | 118 | */ |
628c1bcb | 119 | if (t->ptrace && sig != SIGKILL) |
6a0cdcd7 | 120 | return false; |
628c1bcb ON |
121 | |
122 | return sig_task_ignored(t, sig, force); | |
1da177e4 LT |
123 | } |
124 | ||
125 | /* | |
126 | * Re-calculate pending state from the set of locally pending | |
127 | * signals, globally pending signals, and blocked signals. | |
128 | */ | |
938696a8 | 129 | static inline bool has_pending_signals(sigset_t *signal, sigset_t *blocked) |
1da177e4 LT |
130 | { |
131 | unsigned long ready; | |
132 | long i; | |
133 | ||
134 | switch (_NSIG_WORDS) { | |
135 | default: | |
136 | for (i = _NSIG_WORDS, ready = 0; --i >= 0 ;) | |
137 | ready |= signal->sig[i] &~ blocked->sig[i]; | |
138 | break; | |
139 | ||
140 | case 4: ready = signal->sig[3] &~ blocked->sig[3]; | |
141 | ready |= signal->sig[2] &~ blocked->sig[2]; | |
142 | ready |= signal->sig[1] &~ blocked->sig[1]; | |
143 | ready |= signal->sig[0] &~ blocked->sig[0]; | |
144 | break; | |
145 | ||
146 | case 2: ready = signal->sig[1] &~ blocked->sig[1]; | |
147 | ready |= signal->sig[0] &~ blocked->sig[0]; | |
148 | break; | |
149 | ||
150 | case 1: ready = signal->sig[0] &~ blocked->sig[0]; | |
151 | } | |
152 | return ready != 0; | |
153 | } | |
154 | ||
155 | #define PENDING(p,b) has_pending_signals(&(p)->signal, (b)) | |
156 | ||
09ae854e | 157 | static bool recalc_sigpending_tsk(struct task_struct *t) |
1da177e4 | 158 | { |
76f969e8 | 159 | if ((t->jobctl & (JOBCTL_PENDING_MASK | JOBCTL_TRAP_FREEZE)) || |
1da177e4 | 160 | PENDING(&t->pending, &t->blocked) || |
76f969e8 RG |
161 | PENDING(&t->signal->shared_pending, &t->blocked) || |
162 | cgroup_task_frozen(t)) { | |
1da177e4 | 163 | set_tsk_thread_flag(t, TIF_SIGPENDING); |
09ae854e | 164 | return true; |
7bb44ade | 165 | } |
09ae854e | 166 | |
b74d0deb RM |
167 | /* |
168 | * We must never clear the flag in another thread, or in current | |
169 | * when it's possible the current syscall is returning -ERESTART*. | |
170 | * So we don't clear it here, and only callers who know they should do. | |
171 | */ | |
09ae854e | 172 | return false; |
7bb44ade RM |
173 | } |
174 | ||
1da177e4 LT |
175 | void recalc_sigpending(void) |
176 | { | |
8df1947c | 177 | if (!recalc_sigpending_tsk(current) && !freezing(current)) |
b74d0deb RM |
178 | clear_thread_flag(TIF_SIGPENDING); |
179 | ||
1da177e4 | 180 | } |
fb50f5a4 | 181 | EXPORT_SYMBOL(recalc_sigpending); |
1da177e4 | 182 | |
088fe47c EB |
183 | void calculate_sigpending(void) |
184 | { | |
185 | /* Have any signals or users of TIF_SIGPENDING been delayed | |
186 | * until after fork? | |
187 | */ | |
188 | spin_lock_irq(¤t->sighand->siglock); | |
189 | set_tsk_thread_flag(current, TIF_SIGPENDING); | |
190 | recalc_sigpending(); | |
191 | spin_unlock_irq(¤t->sighand->siglock); | |
192 | } | |
193 | ||
1da177e4 LT |
194 | /* Given the mask, find the first available signal that should be serviced. */ |
195 | ||
a27341cd LT |
196 | #define SYNCHRONOUS_MASK \ |
197 | (sigmask(SIGSEGV) | sigmask(SIGBUS) | sigmask(SIGILL) | \ | |
a0727e8c | 198 | sigmask(SIGTRAP) | sigmask(SIGFPE) | sigmask(SIGSYS)) |
a27341cd | 199 | |
fba2afaa | 200 | int next_signal(struct sigpending *pending, sigset_t *mask) |
1da177e4 LT |
201 | { |
202 | unsigned long i, *s, *m, x; | |
203 | int sig = 0; | |
f84d49b2 | 204 | |
1da177e4 LT |
205 | s = pending->signal.sig; |
206 | m = mask->sig; | |
a27341cd LT |
207 | |
208 | /* | |
209 | * Handle the first word specially: it contains the | |
210 | * synchronous signals that need to be dequeued first. | |
211 | */ | |
212 | x = *s &~ *m; | |
213 | if (x) { | |
214 | if (x & SYNCHRONOUS_MASK) | |
215 | x &= SYNCHRONOUS_MASK; | |
216 | sig = ffz(~x) + 1; | |
217 | return sig; | |
218 | } | |
219 | ||
1da177e4 LT |
220 | switch (_NSIG_WORDS) { |
221 | default: | |
a27341cd LT |
222 | for (i = 1; i < _NSIG_WORDS; ++i) { |
223 | x = *++s &~ *++m; | |
224 | if (!x) | |
225 | continue; | |
226 | sig = ffz(~x) + i*_NSIG_BPW + 1; | |
227 | break; | |
228 | } | |
1da177e4 LT |
229 | break; |
230 | ||
a27341cd LT |
231 | case 2: |
232 | x = s[1] &~ m[1]; | |
233 | if (!x) | |
1da177e4 | 234 | break; |
a27341cd | 235 | sig = ffz(~x) + _NSIG_BPW + 1; |
1da177e4 LT |
236 | break; |
237 | ||
a27341cd LT |
238 | case 1: |
239 | /* Nothing to do */ | |
1da177e4 LT |
240 | break; |
241 | } | |
f84d49b2 | 242 | |
1da177e4 LT |
243 | return sig; |
244 | } | |
245 | ||
f84d49b2 NO |
246 | static inline void print_dropped_signal(int sig) |
247 | { | |
248 | static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 10); | |
249 | ||
250 | if (!print_fatal_signals) | |
251 | return; | |
252 | ||
253 | if (!__ratelimit(&ratelimit_state)) | |
254 | return; | |
255 | ||
747800ef | 256 | pr_info("%s/%d: reached RLIMIT_SIGPENDING, dropped signal %d\n", |
f84d49b2 NO |
257 | current->comm, current->pid, sig); |
258 | } | |
259 | ||
d79fdd6d | 260 | /** |
7dd3db54 | 261 | * task_set_jobctl_pending - set jobctl pending bits |
d79fdd6d | 262 | * @task: target task |
7dd3db54 | 263 | * @mask: pending bits to set |
d79fdd6d | 264 | * |
7dd3db54 TH |
265 | * Clear @mask from @task->jobctl. @mask must be subset of |
266 | * %JOBCTL_PENDING_MASK | %JOBCTL_STOP_CONSUME | %JOBCTL_STOP_SIGMASK | | |
267 | * %JOBCTL_TRAPPING. If stop signo is being set, the existing signo is | |
268 | * cleared. If @task is already being killed or exiting, this function | |
269 | * becomes noop. | |
270 | * | |
271 | * CONTEXT: | |
272 | * Must be called with @task->sighand->siglock held. | |
273 | * | |
274 | * RETURNS: | |
275 | * %true if @mask is set, %false if made noop because @task was dying. | |
276 | */ | |
b76808e6 | 277 | bool task_set_jobctl_pending(struct task_struct *task, unsigned long mask) |
7dd3db54 TH |
278 | { |
279 | BUG_ON(mask & ~(JOBCTL_PENDING_MASK | JOBCTL_STOP_CONSUME | | |
280 | JOBCTL_STOP_SIGMASK | JOBCTL_TRAPPING)); | |
281 | BUG_ON((mask & JOBCTL_TRAPPING) && !(mask & JOBCTL_PENDING_MASK)); | |
282 | ||
1e4cf0d3 | 283 | if (unlikely(fatal_signal_pending(task) || (task->flags & PF_EXITING))) |
7dd3db54 TH |
284 | return false; |
285 | ||
286 | if (mask & JOBCTL_STOP_SIGMASK) | |
287 | task->jobctl &= ~JOBCTL_STOP_SIGMASK; | |
288 | ||
289 | task->jobctl |= mask; | |
290 | return true; | |
291 | } | |
292 | ||
d79fdd6d | 293 | /** |
a8f072c1 | 294 | * task_clear_jobctl_trapping - clear jobctl trapping bit |
d79fdd6d TH |
295 | * @task: target task |
296 | * | |
a8f072c1 TH |
297 | * If JOBCTL_TRAPPING is set, a ptracer is waiting for us to enter TRACED. |
298 | * Clear it and wake up the ptracer. Note that we don't need any further | |
299 | * locking. @task->siglock guarantees that @task->parent points to the | |
300 | * ptracer. | |
d79fdd6d TH |
301 | * |
302 | * CONTEXT: | |
303 | * Must be called with @task->sighand->siglock held. | |
304 | */ | |
73ddff2b | 305 | void task_clear_jobctl_trapping(struct task_struct *task) |
d79fdd6d | 306 | { |
a8f072c1 TH |
307 | if (unlikely(task->jobctl & JOBCTL_TRAPPING)) { |
308 | task->jobctl &= ~JOBCTL_TRAPPING; | |
650226bd | 309 | smp_mb(); /* advised by wake_up_bit() */ |
62c124ff | 310 | wake_up_bit(&task->jobctl, JOBCTL_TRAPPING_BIT); |
d79fdd6d TH |
311 | } |
312 | } | |
313 | ||
e5c1902e | 314 | /** |
3759a0d9 | 315 | * task_clear_jobctl_pending - clear jobctl pending bits |
e5c1902e | 316 | * @task: target task |
3759a0d9 | 317 | * @mask: pending bits to clear |
e5c1902e | 318 | * |
3759a0d9 TH |
319 | * Clear @mask from @task->jobctl. @mask must be subset of |
320 | * %JOBCTL_PENDING_MASK. If %JOBCTL_STOP_PENDING is being cleared, other | |
321 | * STOP bits are cleared together. | |
e5c1902e | 322 | * |
6dfca329 TH |
323 | * If clearing of @mask leaves no stop or trap pending, this function calls |
324 | * task_clear_jobctl_trapping(). | |
e5c1902e TH |
325 | * |
326 | * CONTEXT: | |
327 | * Must be called with @task->sighand->siglock held. | |
328 | */ | |
b76808e6 | 329 | void task_clear_jobctl_pending(struct task_struct *task, unsigned long mask) |
e5c1902e | 330 | { |
3759a0d9 TH |
331 | BUG_ON(mask & ~JOBCTL_PENDING_MASK); |
332 | ||
333 | if (mask & JOBCTL_STOP_PENDING) | |
334 | mask |= JOBCTL_STOP_CONSUME | JOBCTL_STOP_DEQUEUED; | |
335 | ||
336 | task->jobctl &= ~mask; | |
6dfca329 TH |
337 | |
338 | if (!(task->jobctl & JOBCTL_PENDING_MASK)) | |
339 | task_clear_jobctl_trapping(task); | |
e5c1902e TH |
340 | } |
341 | ||
342 | /** | |
343 | * task_participate_group_stop - participate in a group stop | |
344 | * @task: task participating in a group stop | |
345 | * | |
a8f072c1 | 346 | * @task has %JOBCTL_STOP_PENDING set and is participating in a group stop. |
39efa3ef | 347 | * Group stop states are cleared and the group stop count is consumed if |
a8f072c1 | 348 | * %JOBCTL_STOP_CONSUME was set. If the consumption completes the group |
68d8681e | 349 | * stop, the appropriate `SIGNAL_*` flags are set. |
e5c1902e TH |
350 | * |
351 | * CONTEXT: | |
352 | * Must be called with @task->sighand->siglock held. | |
244056f9 TH |
353 | * |
354 | * RETURNS: | |
355 | * %true if group stop completion should be notified to the parent, %false | |
356 | * otherwise. | |
e5c1902e TH |
357 | */ |
358 | static bool task_participate_group_stop(struct task_struct *task) | |
359 | { | |
360 | struct signal_struct *sig = task->signal; | |
a8f072c1 | 361 | bool consume = task->jobctl & JOBCTL_STOP_CONSUME; |
e5c1902e | 362 | |
a8f072c1 | 363 | WARN_ON_ONCE(!(task->jobctl & JOBCTL_STOP_PENDING)); |
39efa3ef | 364 | |
3759a0d9 | 365 | task_clear_jobctl_pending(task, JOBCTL_STOP_PENDING); |
e5c1902e TH |
366 | |
367 | if (!consume) | |
368 | return false; | |
369 | ||
370 | if (!WARN_ON_ONCE(sig->group_stop_count == 0)) | |
371 | sig->group_stop_count--; | |
372 | ||
244056f9 TH |
373 | /* |
374 | * Tell the caller to notify completion iff we are entering into a | |
375 | * fresh group stop. Read comment in do_signal_stop() for details. | |
376 | */ | |
377 | if (!sig->group_stop_count && !(sig->flags & SIGNAL_STOP_STOPPED)) { | |
2d39b3cd | 378 | signal_set_stop_flags(sig, SIGNAL_STOP_STOPPED); |
e5c1902e TH |
379 | return true; |
380 | } | |
381 | return false; | |
382 | } | |
383 | ||
924de3b8 EB |
384 | void task_join_group_stop(struct task_struct *task) |
385 | { | |
7b3c36fc ON |
386 | unsigned long mask = current->jobctl & JOBCTL_STOP_SIGMASK; |
387 | struct signal_struct *sig = current->signal; | |
388 | ||
389 | if (sig->group_stop_count) { | |
390 | sig->group_stop_count++; | |
391 | mask |= JOBCTL_STOP_CONSUME; | |
392 | } else if (!(sig->flags & SIGNAL_STOP_STOPPED)) | |
393 | return; | |
394 | ||
924de3b8 | 395 | /* Have the new thread join an on-going signal group stop */ |
7b3c36fc | 396 | task_set_jobctl_pending(task, mask | JOBCTL_STOP_PENDING); |
924de3b8 EB |
397 | } |
398 | ||
c69e8d9c DH |
399 | /* |
400 | * allocate a new signal queue record | |
401 | * - this may be called without locks if and only if t == current, otherwise an | |
5aba085e | 402 | * appropriate lock must be held to stop the target task from exiting |
c69e8d9c | 403 | */ |
f84d49b2 | 404 | static struct sigqueue * |
69995ebb TG |
405 | __sigqueue_alloc(int sig, struct task_struct *t, gfp_t gfp_flags, |
406 | int override_rlimit, const unsigned int sigqueue_flags) | |
1da177e4 LT |
407 | { |
408 | struct sigqueue *q = NULL; | |
a287116a | 409 | struct ucounts *ucounts; |
d6469690 | 410 | long sigpending; |
1da177e4 | 411 | |
10b1fbdb | 412 | /* |
7cf7db8d TG |
413 | * Protect access to @t credentials. This can go away when all |
414 | * callers hold rcu read lock. | |
fda31c50 LT |
415 | * |
416 | * NOTE! A pending signal will hold on to the user refcount, | |
417 | * and we get/put the refcount only when the sigpending count | |
418 | * changes from/to zero. | |
10b1fbdb | 419 | */ |
7cf7db8d | 420 | rcu_read_lock(); |
d6469690 | 421 | ucounts = task_ucounts(t); |
15bc01ef | 422 | sigpending = inc_rlimit_get_ucounts(ucounts, UCOUNT_RLIMIT_SIGPENDING); |
7cf7db8d | 423 | rcu_read_unlock(); |
15bc01ef EB |
424 | if (!sigpending) |
425 | return NULL; | |
f84d49b2 | 426 | |
f3791f4d | 427 | if (override_rlimit || likely(sigpending <= task_rlimit(t, RLIMIT_SIGPENDING))) { |
b4b27b9e | 428 | q = kmem_cache_alloc(sigqueue_cachep, gfp_flags); |
f84d49b2 NO |
429 | } else { |
430 | print_dropped_signal(sig); | |
431 | } | |
432 | ||
1da177e4 | 433 | if (unlikely(q == NULL)) { |
15bc01ef | 434 | dec_rlimit_put_ucounts(ucounts, UCOUNT_RLIMIT_SIGPENDING); |
1da177e4 LT |
435 | } else { |
436 | INIT_LIST_HEAD(&q->list); | |
69995ebb | 437 | q->flags = sigqueue_flags; |
d6469690 | 438 | q->ucounts = ucounts; |
1da177e4 | 439 | } |
d84f4f99 | 440 | return q; |
1da177e4 LT |
441 | } |
442 | ||
514a01b8 | 443 | static void __sigqueue_free(struct sigqueue *q) |
1da177e4 LT |
444 | { |
445 | if (q->flags & SIGQUEUE_PREALLOC) | |
446 | return; | |
15bc01ef EB |
447 | if (q->ucounts) { |
448 | dec_rlimit_put_ucounts(q->ucounts, UCOUNT_RLIMIT_SIGPENDING); | |
d6469690 AG |
449 | q->ucounts = NULL; |
450 | } | |
b4b27b9e | 451 | kmem_cache_free(sigqueue_cachep, q); |
1da177e4 LT |
452 | } |
453 | ||
6a14c5c9 | 454 | void flush_sigqueue(struct sigpending *queue) |
1da177e4 LT |
455 | { |
456 | struct sigqueue *q; | |
457 | ||
458 | sigemptyset(&queue->signal); | |
459 | while (!list_empty(&queue->list)) { | |
460 | q = list_entry(queue->list.next, struct sigqueue , list); | |
461 | list_del_init(&q->list); | |
462 | __sigqueue_free(q); | |
463 | } | |
464 | } | |
465 | ||
466 | /* | |
9e7c8f8c | 467 | * Flush all pending signals for this kthread. |
1da177e4 | 468 | */ |
c81addc9 | 469 | void flush_signals(struct task_struct *t) |
1da177e4 LT |
470 | { |
471 | unsigned long flags; | |
472 | ||
473 | spin_lock_irqsave(&t->sighand->siglock, flags); | |
9e7c8f8c ON |
474 | clear_tsk_thread_flag(t, TIF_SIGPENDING); |
475 | flush_sigqueue(&t->pending); | |
476 | flush_sigqueue(&t->signal->shared_pending); | |
1da177e4 LT |
477 | spin_unlock_irqrestore(&t->sighand->siglock, flags); |
478 | } | |
fb50f5a4 | 479 | EXPORT_SYMBOL(flush_signals); |
1da177e4 | 480 | |
baa73d9e | 481 | #ifdef CONFIG_POSIX_TIMERS |
cbaffba1 ON |
482 | static void __flush_itimer_signals(struct sigpending *pending) |
483 | { | |
484 | sigset_t signal, retain; | |
485 | struct sigqueue *q, *n; | |
486 | ||
487 | signal = pending->signal; | |
488 | sigemptyset(&retain); | |
489 | ||
490 | list_for_each_entry_safe(q, n, &pending->list, list) { | |
491 | int sig = q->info.si_signo; | |
492 | ||
493 | if (likely(q->info.si_code != SI_TIMER)) { | |
494 | sigaddset(&retain, sig); | |
495 | } else { | |
496 | sigdelset(&signal, sig); | |
497 | list_del_init(&q->list); | |
498 | __sigqueue_free(q); | |
499 | } | |
500 | } | |
501 | ||
502 | sigorsets(&pending->signal, &signal, &retain); | |
503 | } | |
504 | ||
505 | void flush_itimer_signals(void) | |
506 | { | |
507 | struct task_struct *tsk = current; | |
508 | unsigned long flags; | |
509 | ||
510 | spin_lock_irqsave(&tsk->sighand->siglock, flags); | |
511 | __flush_itimer_signals(&tsk->pending); | |
512 | __flush_itimer_signals(&tsk->signal->shared_pending); | |
513 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags); | |
514 | } | |
baa73d9e | 515 | #endif |
cbaffba1 | 516 | |
10ab825b ON |
517 | void ignore_signals(struct task_struct *t) |
518 | { | |
519 | int i; | |
520 | ||
521 | for (i = 0; i < _NSIG; ++i) | |
522 | t->sighand->action[i].sa.sa_handler = SIG_IGN; | |
523 | ||
524 | flush_signals(t); | |
525 | } | |
526 | ||
1da177e4 LT |
527 | /* |
528 | * Flush all handlers for a task. | |
529 | */ | |
530 | ||
531 | void | |
532 | flush_signal_handlers(struct task_struct *t, int force_default) | |
533 | { | |
534 | int i; | |
535 | struct k_sigaction *ka = &t->sighand->action[0]; | |
536 | for (i = _NSIG ; i != 0 ; i--) { | |
537 | if (force_default || ka->sa.sa_handler != SIG_IGN) | |
538 | ka->sa.sa_handler = SIG_DFL; | |
539 | ka->sa.sa_flags = 0; | |
522cff14 | 540 | #ifdef __ARCH_HAS_SA_RESTORER |
2ca39528 KC |
541 | ka->sa.sa_restorer = NULL; |
542 | #endif | |
1da177e4 LT |
543 | sigemptyset(&ka->sa.sa_mask); |
544 | ka++; | |
545 | } | |
546 | } | |
547 | ||
67a48a24 | 548 | bool unhandled_signal(struct task_struct *tsk, int sig) |
abd4f750 | 549 | { |
445a91d2 | 550 | void __user *handler = tsk->sighand->action[sig-1].sa.sa_handler; |
b460cbc5 | 551 | if (is_global_init(tsk)) |
67a48a24 CB |
552 | return true; |
553 | ||
445a91d2 | 554 | if (handler != SIG_IGN && handler != SIG_DFL) |
67a48a24 CB |
555 | return false; |
556 | ||
5f0bc0b0 LT |
557 | /* If dying, we handle all new signals by ignoring them */ |
558 | if (fatal_signal_pending(tsk)) | |
559 | return false; | |
560 | ||
a288eecc TH |
561 | /* if ptraced, let the tracer determine */ |
562 | return !tsk->ptrace; | |
abd4f750 MAS |
563 | } |
564 | ||
ae7795bc | 565 | static void collect_signal(int sig, struct sigpending *list, kernel_siginfo_t *info, |
57db7e4a | 566 | bool *resched_timer) |
1da177e4 LT |
567 | { |
568 | struct sigqueue *q, *first = NULL; | |
1da177e4 | 569 | |
1da177e4 LT |
570 | /* |
571 | * Collect the siginfo appropriate to this signal. Check if | |
572 | * there is another siginfo for the same signal. | |
573 | */ | |
574 | list_for_each_entry(q, &list->list, list) { | |
575 | if (q->info.si_signo == sig) { | |
d4434207 ON |
576 | if (first) |
577 | goto still_pending; | |
1da177e4 LT |
578 | first = q; |
579 | } | |
580 | } | |
d4434207 ON |
581 | |
582 | sigdelset(&list->signal, sig); | |
583 | ||
1da177e4 | 584 | if (first) { |
d4434207 | 585 | still_pending: |
1da177e4 LT |
586 | list_del_init(&first->list); |
587 | copy_siginfo(info, &first->info); | |
57db7e4a EB |
588 | |
589 | *resched_timer = | |
590 | (first->flags & SIGQUEUE_PREALLOC) && | |
591 | (info->si_code == SI_TIMER) && | |
592 | (info->si_sys_private); | |
593 | ||
1da177e4 | 594 | __sigqueue_free(first); |
1da177e4 | 595 | } else { |
5aba085e RD |
596 | /* |
597 | * Ok, it wasn't in the queue. This must be | |
598 | * a fast-pathed signal or we must have been | |
599 | * out of queue space. So zero out the info. | |
1da177e4 | 600 | */ |
faf1f22b | 601 | clear_siginfo(info); |
1da177e4 LT |
602 | info->si_signo = sig; |
603 | info->si_errno = 0; | |
7486e5d9 | 604 | info->si_code = SI_USER; |
1da177e4 LT |
605 | info->si_pid = 0; |
606 | info->si_uid = 0; | |
607 | } | |
1da177e4 LT |
608 | } |
609 | ||
610 | static int __dequeue_signal(struct sigpending *pending, sigset_t *mask, | |
ae7795bc | 611 | kernel_siginfo_t *info, bool *resched_timer) |
1da177e4 | 612 | { |
27d91e07 | 613 | int sig = next_signal(pending, mask); |
1da177e4 | 614 | |
2e01fabe | 615 | if (sig) |
57db7e4a | 616 | collect_signal(sig, pending, info, resched_timer); |
1da177e4 LT |
617 | return sig; |
618 | } | |
619 | ||
620 | /* | |
5aba085e | 621 | * Dequeue a signal and return the element to the caller, which is |
1da177e4 LT |
622 | * expected to free it. |
623 | * | |
624 | * All callers have to hold the siglock. | |
625 | */ | |
5768d890 EB |
626 | int dequeue_signal(struct task_struct *tsk, sigset_t *mask, |
627 | kernel_siginfo_t *info, enum pid_type *type) | |
1da177e4 | 628 | { |
57db7e4a | 629 | bool resched_timer = false; |
c5363d03 | 630 | int signr; |
caec4e8d BH |
631 | |
632 | /* We only dequeue private signals from ourselves, we don't let | |
633 | * signalfd steal them | |
634 | */ | |
5768d890 | 635 | *type = PIDTYPE_PID; |
57db7e4a | 636 | signr = __dequeue_signal(&tsk->pending, mask, info, &resched_timer); |
8bfd9a7a | 637 | if (!signr) { |
5768d890 | 638 | *type = PIDTYPE_TGID; |
1da177e4 | 639 | signr = __dequeue_signal(&tsk->signal->shared_pending, |
57db7e4a | 640 | mask, info, &resched_timer); |
baa73d9e | 641 | #ifdef CONFIG_POSIX_TIMERS |
8bfd9a7a TG |
642 | /* |
643 | * itimer signal ? | |
644 | * | |
645 | * itimers are process shared and we restart periodic | |
646 | * itimers in the signal delivery path to prevent DoS | |
647 | * attacks in the high resolution timer case. This is | |
5aba085e | 648 | * compliant with the old way of self-restarting |
8bfd9a7a TG |
649 | * itimers, as the SIGALRM is a legacy signal and only |
650 | * queued once. Changing the restart behaviour to | |
651 | * restart the timer in the signal dequeue path is | |
652 | * reducing the timer noise on heavy loaded !highres | |
653 | * systems too. | |
654 | */ | |
655 | if (unlikely(signr == SIGALRM)) { | |
656 | struct hrtimer *tmr = &tsk->signal->real_timer; | |
657 | ||
658 | if (!hrtimer_is_queued(tmr) && | |
2456e855 | 659 | tsk->signal->it_real_incr != 0) { |
8bfd9a7a TG |
660 | hrtimer_forward(tmr, tmr->base->get_time(), |
661 | tsk->signal->it_real_incr); | |
662 | hrtimer_restart(tmr); | |
663 | } | |
664 | } | |
baa73d9e | 665 | #endif |
8bfd9a7a | 666 | } |
c5363d03 | 667 | |
b8fceee1 | 668 | recalc_sigpending(); |
c5363d03 PE |
669 | if (!signr) |
670 | return 0; | |
671 | ||
672 | if (unlikely(sig_kernel_stop(signr))) { | |
8bfd9a7a TG |
673 | /* |
674 | * Set a marker that we have dequeued a stop signal. Our | |
675 | * caller might release the siglock and then the pending | |
676 | * stop signal it is about to process is no longer in the | |
677 | * pending bitmasks, but must still be cleared by a SIGCONT | |
678 | * (and overruled by a SIGKILL). So those cases clear this | |
679 | * shared flag after we've set it. Note that this flag may | |
680 | * remain set after the signal we return is ignored or | |
681 | * handled. That doesn't matter because its only purpose | |
682 | * is to alert stop-signal processing code when another | |
683 | * processor has come along and cleared the flag. | |
684 | */ | |
a8f072c1 | 685 | current->jobctl |= JOBCTL_STOP_DEQUEUED; |
8bfd9a7a | 686 | } |
baa73d9e | 687 | #ifdef CONFIG_POSIX_TIMERS |
57db7e4a | 688 | if (resched_timer) { |
1da177e4 LT |
689 | /* |
690 | * Release the siglock to ensure proper locking order | |
691 | * of timer locks outside of siglocks. Note, we leave | |
692 | * irqs disabled here, since the posix-timers code is | |
693 | * about to disable them again anyway. | |
694 | */ | |
695 | spin_unlock(&tsk->sighand->siglock); | |
96fe3b07 | 696 | posixtimer_rearm(info); |
1da177e4 | 697 | spin_lock(&tsk->sighand->siglock); |
9943d3ac EB |
698 | |
699 | /* Don't expose the si_sys_private value to userspace */ | |
700 | info->si_sys_private = 0; | |
1da177e4 | 701 | } |
baa73d9e | 702 | #endif |
1da177e4 LT |
703 | return signr; |
704 | } | |
fb50f5a4 | 705 | EXPORT_SYMBOL_GPL(dequeue_signal); |
1da177e4 | 706 | |
7146db33 EB |
707 | static int dequeue_synchronous_signal(kernel_siginfo_t *info) |
708 | { | |
709 | struct task_struct *tsk = current; | |
710 | struct sigpending *pending = &tsk->pending; | |
711 | struct sigqueue *q, *sync = NULL; | |
712 | ||
713 | /* | |
714 | * Might a synchronous signal be in the queue? | |
715 | */ | |
716 | if (!((pending->signal.sig[0] & ~tsk->blocked.sig[0]) & SYNCHRONOUS_MASK)) | |
717 | return 0; | |
718 | ||
719 | /* | |
720 | * Return the first synchronous signal in the queue. | |
721 | */ | |
722 | list_for_each_entry(q, &pending->list, list) { | |
7665a47f | 723 | /* Synchronous signals have a positive si_code */ |
7146db33 EB |
724 | if ((q->info.si_code > SI_USER) && |
725 | (sigmask(q->info.si_signo) & SYNCHRONOUS_MASK)) { | |
726 | sync = q; | |
727 | goto next; | |
728 | } | |
729 | } | |
730 | return 0; | |
731 | next: | |
732 | /* | |
733 | * Check if there is another siginfo for the same signal. | |
734 | */ | |
735 | list_for_each_entry_continue(q, &pending->list, list) { | |
736 | if (q->info.si_signo == sync->info.si_signo) | |
737 | goto still_pending; | |
738 | } | |
739 | ||
740 | sigdelset(&pending->signal, sync->info.si_signo); | |
741 | recalc_sigpending(); | |
742 | still_pending: | |
743 | list_del_init(&sync->list); | |
744 | copy_siginfo(info, &sync->info); | |
745 | __sigqueue_free(sync); | |
746 | return info->si_signo; | |
747 | } | |
748 | ||
1da177e4 LT |
749 | /* |
750 | * Tell a process that it has a new active signal.. | |
751 | * | |
752 | * NOTE! we rely on the previous spin_lock to | |
753 | * lock interrupts for us! We can only be called with | |
754 | * "siglock" held, and the local interrupt must | |
755 | * have been disabled when that got acquired! | |
756 | * | |
757 | * No need to set need_resched since signal event passing | |
758 | * goes through ->blocked | |
759 | */ | |
910ffdb1 | 760 | void signal_wake_up_state(struct task_struct *t, unsigned int state) |
1da177e4 | 761 | { |
31cae1ea PZ |
762 | lockdep_assert_held(&t->sighand->siglock); |
763 | ||
1da177e4 | 764 | set_tsk_thread_flag(t, TIF_SIGPENDING); |
31cae1ea | 765 | |
1da177e4 | 766 | /* |
910ffdb1 | 767 | * TASK_WAKEKILL also means wake it up in the stopped/traced/killable |
f021a3c2 | 768 | * case. We don't check t->state here because there is a race with it |
1da177e4 LT |
769 | * executing another processor and just now entering stopped state. |
770 | * By using wake_up_state, we ensure the process will wake up and | |
771 | * handle its death signal. | |
772 | */ | |
910ffdb1 | 773 | if (!wake_up_state(t, state | TASK_INTERRUPTIBLE)) |
1da177e4 LT |
774 | kick_process(t); |
775 | } | |
776 | ||
71fabd5e GA |
777 | /* |
778 | * Remove signals in mask from the pending set and queue. | |
779 | * Returns 1 if any signals were found. | |
780 | * | |
781 | * All callers must be holding the siglock. | |
71fabd5e | 782 | */ |
8f11351e | 783 | static void flush_sigqueue_mask(sigset_t *mask, struct sigpending *s) |
71fabd5e GA |
784 | { |
785 | struct sigqueue *q, *n; | |
786 | sigset_t m; | |
787 | ||
788 | sigandsets(&m, mask, &s->signal); | |
789 | if (sigisemptyset(&m)) | |
8f11351e | 790 | return; |
71fabd5e | 791 | |
702a5073 | 792 | sigandnsets(&s->signal, &s->signal, mask); |
71fabd5e GA |
793 | list_for_each_entry_safe(q, n, &s->list, list) { |
794 | if (sigismember(mask, q->info.si_signo)) { | |
795 | list_del_init(&q->list); | |
796 | __sigqueue_free(q); | |
797 | } | |
798 | } | |
71fabd5e | 799 | } |
1da177e4 | 800 | |
ae7795bc | 801 | static inline int is_si_special(const struct kernel_siginfo *info) |
614c517d | 802 | { |
4ff4c31a | 803 | return info <= SEND_SIG_PRIV; |
614c517d ON |
804 | } |
805 | ||
ae7795bc | 806 | static inline bool si_fromuser(const struct kernel_siginfo *info) |
614c517d ON |
807 | { |
808 | return info == SEND_SIG_NOINFO || | |
809 | (!is_si_special(info) && SI_FROMUSER(info)); | |
810 | } | |
811 | ||
39fd3393 SH |
812 | /* |
813 | * called with RCU read lock from check_kill_permission() | |
814 | */ | |
2a9b9094 | 815 | static bool kill_ok_by_cred(struct task_struct *t) |
39fd3393 SH |
816 | { |
817 | const struct cred *cred = current_cred(); | |
818 | const struct cred *tcred = __task_cred(t); | |
819 | ||
2a9b9094 CB |
820 | return uid_eq(cred->euid, tcred->suid) || |
821 | uid_eq(cred->euid, tcred->uid) || | |
822 | uid_eq(cred->uid, tcred->suid) || | |
823 | uid_eq(cred->uid, tcred->uid) || | |
824 | ns_capable(tcred->user_ns, CAP_KILL); | |
39fd3393 SH |
825 | } |
826 | ||
1da177e4 LT |
827 | /* |
828 | * Bad permissions for sending the signal | |
694f690d | 829 | * - the caller must hold the RCU read lock |
1da177e4 | 830 | */ |
ae7795bc | 831 | static int check_kill_permission(int sig, struct kernel_siginfo *info, |
1da177e4 LT |
832 | struct task_struct *t) |
833 | { | |
2e2ba22e | 834 | struct pid *sid; |
3b5e9e53 ON |
835 | int error; |
836 | ||
7ed20e1a | 837 | if (!valid_signal(sig)) |
3b5e9e53 ON |
838 | return -EINVAL; |
839 | ||
614c517d | 840 | if (!si_fromuser(info)) |
3b5e9e53 | 841 | return 0; |
e54dc243 | 842 | |
3b5e9e53 ON |
843 | error = audit_signal_info(sig, t); /* Let audit system see the signal */ |
844 | if (error) | |
1da177e4 | 845 | return error; |
3b5e9e53 | 846 | |
065add39 | 847 | if (!same_thread_group(current, t) && |
39fd3393 | 848 | !kill_ok_by_cred(t)) { |
2e2ba22e ON |
849 | switch (sig) { |
850 | case SIGCONT: | |
2e2ba22e | 851 | sid = task_session(t); |
2e2ba22e ON |
852 | /* |
853 | * We don't return the error if sid == NULL. The | |
854 | * task was unhashed, the caller must notice this. | |
855 | */ | |
856 | if (!sid || sid == task_session(current)) | |
857 | break; | |
df561f66 | 858 | fallthrough; |
2e2ba22e ON |
859 | default: |
860 | return -EPERM; | |
861 | } | |
862 | } | |
c2f0c7c3 | 863 | |
6b4f3d01 | 864 | return security_task_kill(t, info, sig, NULL); |
1da177e4 LT |
865 | } |
866 | ||
fb1d910c TH |
867 | /** |
868 | * ptrace_trap_notify - schedule trap to notify ptracer | |
869 | * @t: tracee wanting to notify tracer | |
870 | * | |
871 | * This function schedules sticky ptrace trap which is cleared on the next | |
872 | * TRAP_STOP to notify ptracer of an event. @t must have been seized by | |
873 | * ptracer. | |
874 | * | |
544b2c91 TH |
875 | * If @t is running, STOP trap will be taken. If trapped for STOP and |
876 | * ptracer is listening for events, tracee is woken up so that it can | |
877 | * re-trap for the new event. If trapped otherwise, STOP trap will be | |
878 | * eventually taken without returning to userland after the existing traps | |
879 | * are finished by PTRACE_CONT. | |
fb1d910c TH |
880 | * |
881 | * CONTEXT: | |
882 | * Must be called with @task->sighand->siglock held. | |
883 | */ | |
884 | static void ptrace_trap_notify(struct task_struct *t) | |
885 | { | |
886 | WARN_ON_ONCE(!(t->ptrace & PT_SEIZED)); | |
cb3c19c9 | 887 | lockdep_assert_held(&t->sighand->siglock); |
fb1d910c TH |
888 | |
889 | task_set_jobctl_pending(t, JOBCTL_TRAP_NOTIFY); | |
910ffdb1 | 890 | ptrace_signal_wake_up(t, t->jobctl & JOBCTL_LISTENING); |
fb1d910c TH |
891 | } |
892 | ||
1da177e4 | 893 | /* |
7e695a5e ON |
894 | * Handle magic process-wide effects of stop/continue signals. Unlike |
895 | * the signal actions, these happen immediately at signal-generation | |
1da177e4 LT |
896 | * time regardless of blocking, ignoring, or handling. This does the |
897 | * actual continuing for SIGCONT, but not the actual stopping for stop | |
7e695a5e ON |
898 | * signals. The process stop is done as a signal action for SIG_DFL. |
899 | * | |
900 | * Returns true if the signal should be actually delivered, otherwise | |
901 | * it should be dropped. | |
1da177e4 | 902 | */ |
403bad72 | 903 | static bool prepare_signal(int sig, struct task_struct *p, bool force) |
1da177e4 | 904 | { |
ad16a460 | 905 | struct signal_struct *signal = p->signal; |
1da177e4 | 906 | struct task_struct *t; |
9490592f | 907 | sigset_t flush; |
1da177e4 | 908 | |
2f824d4d | 909 | if (signal->flags & SIGNAL_GROUP_EXIT) { |
a0287db0 | 910 | if (signal->core_state) |
403bad72 | 911 | return sig == SIGKILL; |
1da177e4 | 912 | /* |
9a95f78e | 913 | * The process is in the middle of dying, drop the signal. |
1da177e4 | 914 | */ |
9a95f78e | 915 | return false; |
7e695a5e | 916 | } else if (sig_kernel_stop(sig)) { |
1da177e4 LT |
917 | /* |
918 | * This is a stop signal. Remove SIGCONT from all queues. | |
919 | */ | |
9490592f | 920 | siginitset(&flush, sigmask(SIGCONT)); |
c09c1441 | 921 | flush_sigqueue_mask(&flush, &signal->shared_pending); |
9490592f | 922 | for_each_thread(p, t) |
c09c1441 | 923 | flush_sigqueue_mask(&flush, &t->pending); |
1da177e4 | 924 | } else if (sig == SIGCONT) { |
fc321d2e | 925 | unsigned int why; |
1da177e4 | 926 | /* |
1deac632 | 927 | * Remove all stop signals from all queues, wake all threads. |
1da177e4 | 928 | */ |
9490592f | 929 | siginitset(&flush, SIG_KERNEL_STOP_MASK); |
c09c1441 | 930 | flush_sigqueue_mask(&flush, &signal->shared_pending); |
9490592f | 931 | for_each_thread(p, t) { |
c09c1441 | 932 | flush_sigqueue_mask(&flush, &t->pending); |
3759a0d9 | 933 | task_clear_jobctl_pending(t, JOBCTL_STOP_PENDING); |
31cae1ea PZ |
934 | if (likely(!(t->ptrace & PT_SEIZED))) { |
935 | t->jobctl &= ~JOBCTL_STOPPED; | |
fb1d910c | 936 | wake_up_state(t, __TASK_STOPPED); |
31cae1ea | 937 | } else |
fb1d910c | 938 | ptrace_trap_notify(t); |
9490592f | 939 | } |
1da177e4 | 940 | |
fc321d2e ON |
941 | /* |
942 | * Notify the parent with CLD_CONTINUED if we were stopped. | |
943 | * | |
944 | * If we were in the middle of a group stop, we pretend it | |
945 | * was already finished, and then continued. Since SIGCHLD | |
946 | * doesn't queue we report only CLD_STOPPED, as if the next | |
947 | * CLD_CONTINUED was dropped. | |
948 | */ | |
949 | why = 0; | |
ad16a460 | 950 | if (signal->flags & SIGNAL_STOP_STOPPED) |
fc321d2e | 951 | why |= SIGNAL_CLD_CONTINUED; |
ad16a460 | 952 | else if (signal->group_stop_count) |
fc321d2e ON |
953 | why |= SIGNAL_CLD_STOPPED; |
954 | ||
955 | if (why) { | |
021e1ae3 | 956 | /* |
ae6d2ed7 | 957 | * The first thread which returns from do_signal_stop() |
021e1ae3 | 958 | * will take ->siglock, notice SIGNAL_CLD_MASK, and |
2e58f57d | 959 | * notify its parent. See get_signal(). |
021e1ae3 | 960 | */ |
2d39b3cd | 961 | signal_set_stop_flags(signal, why | SIGNAL_STOP_CONTINUED); |
ad16a460 ON |
962 | signal->group_stop_count = 0; |
963 | signal->group_exit_code = 0; | |
1da177e4 | 964 | } |
1da177e4 | 965 | } |
7e695a5e | 966 | |
def8cf72 | 967 | return !sig_ignored(p, sig, force); |
1da177e4 LT |
968 | } |
969 | ||
71f11dc0 ON |
970 | /* |
971 | * Test if P wants to take SIG. After we've checked all threads with this, | |
972 | * it's equivalent to finding no threads not blocking SIG. Any threads not | |
973 | * blocking SIG were ruled out because they are not running and already | |
974 | * have pending signals. Such threads will dequeue from the shared queue | |
975 | * as soon as they're available, so putting the signal on the shared queue | |
976 | * will be equivalent to sending it to one such thread. | |
977 | */ | |
acd14e62 | 978 | static inline bool wants_signal(int sig, struct task_struct *p) |
71f11dc0 ON |
979 | { |
980 | if (sigismember(&p->blocked, sig)) | |
acd14e62 CB |
981 | return false; |
982 | ||
71f11dc0 | 983 | if (p->flags & PF_EXITING) |
acd14e62 CB |
984 | return false; |
985 | ||
71f11dc0 | 986 | if (sig == SIGKILL) |
acd14e62 CB |
987 | return true; |
988 | ||
71f11dc0 | 989 | if (task_is_stopped_or_traced(p)) |
acd14e62 CB |
990 | return false; |
991 | ||
5c251e9d | 992 | return task_curr(p) || !task_sigpending(p); |
71f11dc0 ON |
993 | } |
994 | ||
07296149 | 995 | static void complete_signal(int sig, struct task_struct *p, enum pid_type type) |
71f11dc0 ON |
996 | { |
997 | struct signal_struct *signal = p->signal; | |
998 | struct task_struct *t; | |
999 | ||
1000 | /* | |
1001 | * Now find a thread we can wake up to take the signal off the queue. | |
1002 | * | |
bcb7ee79 | 1003 | * Try the suggested task first (may or may not be the main thread). |
71f11dc0 ON |
1004 | */ |
1005 | if (wants_signal(sig, p)) | |
1006 | t = p; | |
07296149 | 1007 | else if ((type == PIDTYPE_PID) || thread_group_empty(p)) |
71f11dc0 ON |
1008 | /* |
1009 | * There is just one thread and it does not need to be woken. | |
1010 | * It will dequeue unblocked signals before it runs again. | |
1011 | */ | |
1012 | return; | |
1013 | else { | |
1014 | /* | |
1015 | * Otherwise try to find a suitable thread. | |
1016 | */ | |
1017 | t = signal->curr_target; | |
1018 | while (!wants_signal(sig, t)) { | |
1019 | t = next_thread(t); | |
1020 | if (t == signal->curr_target) | |
1021 | /* | |
1022 | * No thread needs to be woken. | |
1023 | * Any eligible threads will see | |
1024 | * the signal in the queue soon. | |
1025 | */ | |
1026 | return; | |
1027 | } | |
1028 | signal->curr_target = t; | |
1029 | } | |
1030 | ||
1031 | /* | |
1032 | * Found a killable thread. If the signal will be fatal, | |
1033 | * then start taking the whole group down immediately. | |
1034 | */ | |
fae5fa44 | 1035 | if (sig_fatal(p, sig) && |
7ba03471 | 1036 | (signal->core_state || !(signal->flags & SIGNAL_GROUP_EXIT)) && |
71f11dc0 | 1037 | !sigismember(&t->real_blocked, sig) && |
42691579 | 1038 | (sig == SIGKILL || !p->ptrace)) { |
71f11dc0 ON |
1039 | /* |
1040 | * This signal will be fatal to the whole group. | |
1041 | */ | |
1042 | if (!sig_kernel_coredump(sig)) { | |
1043 | /* | |
1044 | * Start a group exit and wake everybody up. | |
1045 | * This way we don't have other threads | |
1046 | * running and doing things after a slower | |
1047 | * thread has the fatal signal pending. | |
1048 | */ | |
1049 | signal->flags = SIGNAL_GROUP_EXIT; | |
1050 | signal->group_exit_code = sig; | |
1051 | signal->group_stop_count = 0; | |
e5ecf29c | 1052 | __for_each_thread(signal, t) { |
6dfca329 | 1053 | task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK); |
71f11dc0 ON |
1054 | sigaddset(&t->pending.signal, SIGKILL); |
1055 | signal_wake_up(t, 1); | |
e5ecf29c | 1056 | } |
71f11dc0 ON |
1057 | return; |
1058 | } | |
1059 | } | |
1060 | ||
1061 | /* | |
1062 | * The signal is already in the shared-pending queue. | |
1063 | * Tell the chosen thread to wake up and dequeue it. | |
1064 | */ | |
1065 | signal_wake_up(t, sig == SIGKILL); | |
1066 | return; | |
1067 | } | |
1068 | ||
a19e2c01 | 1069 | static inline bool legacy_queue(struct sigpending *signals, int sig) |
af7fff9c PE |
1070 | { |
1071 | return (sig < SIGRTMIN) && sigismember(&signals->signal, sig); | |
1072 | } | |
1073 | ||
157cc181 EB |
1074 | static int __send_signal_locked(int sig, struct kernel_siginfo *info, |
1075 | struct task_struct *t, enum pid_type type, bool force) | |
1da177e4 | 1076 | { |
2ca3515a | 1077 | struct sigpending *pending; |
6e65acba | 1078 | struct sigqueue *q; |
7a0aeb14 | 1079 | int override_rlimit; |
6c303d3a | 1080 | int ret = 0, result; |
0a16b607 | 1081 | |
cb3c19c9 | 1082 | lockdep_assert_held(&t->sighand->siglock); |
921cf9f6 | 1083 | |
6c303d3a | 1084 | result = TRACE_SIGNAL_IGNORED; |
8ad23dea | 1085 | if (!prepare_signal(sig, t, force)) |
6c303d3a | 1086 | goto ret; |
2ca3515a | 1087 | |
5a883cee | 1088 | pending = (type != PIDTYPE_PID) ? &t->signal->shared_pending : &t->pending; |
2acb024d PE |
1089 | /* |
1090 | * Short-circuit ignored signals and support queuing | |
1091 | * exactly one non-rt signal, so that we can get more | |
1092 | * detailed information about the cause of the signal. | |
1093 | */ | |
6c303d3a | 1094 | result = TRACE_SIGNAL_ALREADY_PENDING; |
7e695a5e | 1095 | if (legacy_queue(pending, sig)) |
6c303d3a ON |
1096 | goto ret; |
1097 | ||
1098 | result = TRACE_SIGNAL_DELIVERED; | |
1da177e4 | 1099 | /* |
a692933a | 1100 | * Skip useless siginfo allocation for SIGKILL and kernel threads. |
1da177e4 | 1101 | */ |
e8b33b8c | 1102 | if ((sig == SIGKILL) || (t->flags & PF_KTHREAD)) |
1da177e4 LT |
1103 | goto out_set; |
1104 | ||
5aba085e RD |
1105 | /* |
1106 | * Real-time signals must be queued if sent by sigqueue, or | |
1107 | * some other real-time mechanism. It is implementation | |
1108 | * defined whether kill() does so. We attempt to do so, on | |
1109 | * the principle of least surprise, but since kill is not | |
1110 | * allowed to fail with EAGAIN when low on memory we just | |
1111 | * make sure at least one signal gets delivered and don't | |
1112 | * pass on the info struct. | |
1113 | */ | |
7a0aeb14 VN |
1114 | if (sig < SIGRTMIN) |
1115 | override_rlimit = (is_si_special(info) || info->si_code >= 0); | |
1116 | else | |
1117 | override_rlimit = 0; | |
1118 | ||
69995ebb TG |
1119 | q = __sigqueue_alloc(sig, t, GFP_ATOMIC, override_rlimit, 0); |
1120 | ||
1da177e4 | 1121 | if (q) { |
2ca3515a | 1122 | list_add_tail(&q->list, &pending->list); |
1da177e4 | 1123 | switch ((unsigned long) info) { |
b67a1b9e | 1124 | case (unsigned long) SEND_SIG_NOINFO: |
faf1f22b | 1125 | clear_siginfo(&q->info); |
1da177e4 LT |
1126 | q->info.si_signo = sig; |
1127 | q->info.si_errno = 0; | |
1128 | q->info.si_code = SI_USER; | |
9cd4fd10 | 1129 | q->info.si_pid = task_tgid_nr_ns(current, |
09bca05c | 1130 | task_active_pid_ns(t)); |
7a0cf094 EB |
1131 | rcu_read_lock(); |
1132 | q->info.si_uid = | |
1133 | from_kuid_munged(task_cred_xxx(t, user_ns), | |
1134 | current_uid()); | |
1135 | rcu_read_unlock(); | |
1da177e4 | 1136 | break; |
b67a1b9e | 1137 | case (unsigned long) SEND_SIG_PRIV: |
faf1f22b | 1138 | clear_siginfo(&q->info); |
1da177e4 LT |
1139 | q->info.si_signo = sig; |
1140 | q->info.si_errno = 0; | |
1141 | q->info.si_code = SI_KERNEL; | |
1142 | q->info.si_pid = 0; | |
1143 | q->info.si_uid = 0; | |
1144 | break; | |
1145 | default: | |
1146 | copy_siginfo(&q->info, info); | |
1147 | break; | |
1148 | } | |
8917bef3 EB |
1149 | } else if (!is_si_special(info) && |
1150 | sig >= SIGRTMIN && info->si_code != SI_USER) { | |
1151 | /* | |
1152 | * Queue overflow, abort. We may abort if the | |
1153 | * signal was rt and sent by user using something | |
1154 | * other than kill(). | |
1155 | */ | |
1156 | result = TRACE_SIGNAL_OVERFLOW_FAIL; | |
1157 | ret = -EAGAIN; | |
1158 | goto ret; | |
1159 | } else { | |
1160 | /* | |
1161 | * This is a silent loss of information. We still | |
1162 | * send the signal, but the *info bits are lost. | |
1163 | */ | |
1164 | result = TRACE_SIGNAL_LOSE_INFO; | |
1da177e4 LT |
1165 | } |
1166 | ||
1167 | out_set: | |
53c30337 | 1168 | signalfd_notify(t, sig); |
2ca3515a | 1169 | sigaddset(&pending->signal, sig); |
c3ad2c3b EB |
1170 | |
1171 | /* Let multiprocess signals appear after on-going forks */ | |
1172 | if (type > PIDTYPE_TGID) { | |
1173 | struct multiprocess_signals *delayed; | |
1174 | hlist_for_each_entry(delayed, &t->signal->multiprocess, node) { | |
1175 | sigset_t *signal = &delayed->signal; | |
1176 | /* Can't queue both a stop and a continue signal */ | |
1177 | if (sig == SIGCONT) | |
1178 | sigdelsetmask(signal, SIG_KERNEL_STOP_MASK); | |
1179 | else if (sig_kernel_stop(sig)) | |
1180 | sigdelset(signal, SIGCONT); | |
1181 | sigaddset(signal, sig); | |
1182 | } | |
1183 | } | |
1184 | ||
07296149 | 1185 | complete_signal(sig, t, type); |
6c303d3a | 1186 | ret: |
5a883cee | 1187 | trace_signal_generate(sig, info, t, type != PIDTYPE_PID, result); |
6c303d3a | 1188 | return ret; |
1da177e4 LT |
1189 | } |
1190 | ||
7a0cf094 EB |
1191 | static inline bool has_si_pid_and_uid(struct kernel_siginfo *info) |
1192 | { | |
1193 | bool ret = false; | |
1194 | switch (siginfo_layout(info->si_signo, info->si_code)) { | |
1195 | case SIL_KILL: | |
1196 | case SIL_CHLD: | |
1197 | case SIL_RT: | |
1198 | ret = true; | |
1199 | break; | |
1200 | case SIL_TIMER: | |
1201 | case SIL_POLL: | |
1202 | case SIL_FAULT: | |
9abcabe3 | 1203 | case SIL_FAULT_TRAPNO: |
7a0cf094 EB |
1204 | case SIL_FAULT_MCEERR: |
1205 | case SIL_FAULT_BNDERR: | |
1206 | case SIL_FAULT_PKUERR: | |
f4ac7302 | 1207 | case SIL_FAULT_PERF_EVENT: |
7a0cf094 EB |
1208 | case SIL_SYS: |
1209 | ret = false; | |
1210 | break; | |
1211 | } | |
1212 | return ret; | |
1213 | } | |
1214 | ||
157cc181 EB |
1215 | int send_signal_locked(int sig, struct kernel_siginfo *info, |
1216 | struct task_struct *t, enum pid_type type) | |
7978b567 | 1217 | { |
8ad23dea EB |
1218 | /* Should SIGKILL or SIGSTOP be received by a pid namespace init? */ |
1219 | bool force = false; | |
921cf9f6 | 1220 | |
8ad23dea EB |
1221 | if (info == SEND_SIG_NOINFO) { |
1222 | /* Force if sent from an ancestor pid namespace */ | |
1223 | force = !task_pid_nr_ns(current, task_active_pid_ns(t)); | |
1224 | } else if (info == SEND_SIG_PRIV) { | |
1225 | /* Don't ignore kernel generated signals */ | |
1226 | force = true; | |
1227 | } else if (has_si_pid_and_uid(info)) { | |
1228 | /* SIGKILL and SIGSTOP is special or has ids */ | |
7a0cf094 EB |
1229 | struct user_namespace *t_user_ns; |
1230 | ||
1231 | rcu_read_lock(); | |
1232 | t_user_ns = task_cred_xxx(t, user_ns); | |
1233 | if (current_user_ns() != t_user_ns) { | |
1234 | kuid_t uid = make_kuid(current_user_ns(), info->si_uid); | |
1235 | info->si_uid = from_kuid_munged(t_user_ns, uid); | |
1236 | } | |
1237 | rcu_read_unlock(); | |
921cf9f6 | 1238 | |
8ad23dea EB |
1239 | /* A kernel generated signal? */ |
1240 | force = (info->si_code == SI_KERNEL); | |
1241 | ||
1242 | /* From an ancestor pid namespace? */ | |
1243 | if (!task_pid_nr_ns(current, task_active_pid_ns(t))) { | |
7a0cf094 | 1244 | info->si_pid = 0; |
8ad23dea EB |
1245 | force = true; |
1246 | } | |
7a0cf094 | 1247 | } |
157cc181 | 1248 | return __send_signal_locked(sig, info, t, type, force); |
7978b567 SB |
1249 | } |
1250 | ||
4aaefee5 | 1251 | static void print_fatal_signal(int signr) |
45807a1d | 1252 | { |
6a542d1d | 1253 | struct pt_regs *regs = task_pt_regs(current); |
b0b88e02 VW |
1254 | struct file *exe_file; |
1255 | ||
1256 | exe_file = get_task_exe_file(current); | |
1257 | if (exe_file) { | |
1258 | pr_info("%pD: %s: potentially unexpected fatal signal %d.\n", | |
1259 | exe_file, current->comm, signr); | |
1260 | fput(exe_file); | |
1261 | } else { | |
1262 | pr_info("%s: potentially unexpected fatal signal %d.\n", | |
1263 | current->comm, signr); | |
1264 | } | |
45807a1d | 1265 | |
ca5cd877 | 1266 | #if defined(__i386__) && !defined(__arch_um__) |
747800ef | 1267 | pr_info("code at %08lx: ", regs->ip); |
45807a1d IM |
1268 | { |
1269 | int i; | |
1270 | for (i = 0; i < 16; i++) { | |
1271 | unsigned char insn; | |
1272 | ||
b45c6e76 AK |
1273 | if (get_user(insn, (unsigned char *)(regs->ip + i))) |
1274 | break; | |
747800ef | 1275 | pr_cont("%02x ", insn); |
45807a1d IM |
1276 | } |
1277 | } | |
747800ef | 1278 | pr_cont("\n"); |
45807a1d | 1279 | #endif |
3a9f84d3 | 1280 | preempt_disable(); |
45807a1d | 1281 | show_regs(regs); |
3a9f84d3 | 1282 | preempt_enable(); |
45807a1d IM |
1283 | } |
1284 | ||
1285 | static int __init setup_print_fatal_signals(char *str) | |
1286 | { | |
1287 | get_option (&str, &print_fatal_signals); | |
1288 | ||
1289 | return 1; | |
1290 | } | |
1291 | ||
1292 | __setup("print-fatal-signals=", setup_print_fatal_signals); | |
1da177e4 | 1293 | |
ae7795bc | 1294 | int do_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p, |
40b3b025 | 1295 | enum pid_type type) |
4a30debf ON |
1296 | { |
1297 | unsigned long flags; | |
1298 | int ret = -ESRCH; | |
1299 | ||
1300 | if (lock_task_sighand(p, &flags)) { | |
157cc181 | 1301 | ret = send_signal_locked(sig, info, p, type); |
4a30debf ON |
1302 | unlock_task_sighand(p, &flags); |
1303 | } | |
1304 | ||
1305 | return ret; | |
1306 | } | |
1307 | ||
e349d945 EB |
1308 | enum sig_handler { |
1309 | HANDLER_CURRENT, /* If reachable use the current handler */ | |
1310 | HANDLER_SIG_DFL, /* Always use SIG_DFL handler semantics */ | |
1311 | HANDLER_EXIT, /* Only visible as the process exit code */ | |
1312 | }; | |
1313 | ||
1da177e4 LT |
1314 | /* |
1315 | * Force a signal that the process can't ignore: if necessary | |
1316 | * we unblock the signal and change any SIG_IGN to SIG_DFL. | |
ae74c3b6 LT |
1317 | * |
1318 | * Note: If we unblock the signal, we always reset it to SIG_DFL, | |
1319 | * since we do not want to have a signal handler that was blocked | |
1320 | * be invoked when user space had explicitly blocked it. | |
1321 | * | |
80fe728d ON |
1322 | * We don't want to have recursive SIGSEGV's etc, for example, |
1323 | * that is why we also clear SIGNAL_UNKILLABLE. | |
1da177e4 | 1324 | */ |
59c0e696 | 1325 | static int |
e349d945 EB |
1326 | force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t, |
1327 | enum sig_handler handler) | |
1da177e4 LT |
1328 | { |
1329 | unsigned long int flags; | |
ae74c3b6 LT |
1330 | int ret, blocked, ignored; |
1331 | struct k_sigaction *action; | |
59c0e696 | 1332 | int sig = info->si_signo; |
1da177e4 LT |
1333 | |
1334 | spin_lock_irqsave(&t->sighand->siglock, flags); | |
ae74c3b6 LT |
1335 | action = &t->sighand->action[sig-1]; |
1336 | ignored = action->sa.sa_handler == SIG_IGN; | |
1337 | blocked = sigismember(&t->blocked, sig); | |
e349d945 | 1338 | if (blocked || ignored || (handler != HANDLER_CURRENT)) { |
ae74c3b6 | 1339 | action->sa.sa_handler = SIG_DFL; |
e349d945 EB |
1340 | if (handler == HANDLER_EXIT) |
1341 | action->sa.sa_flags |= SA_IMMUTABLE; | |
b454ec29 | 1342 | if (blocked) |
ae74c3b6 | 1343 | sigdelset(&t->blocked, sig); |
1da177e4 | 1344 | } |
eb61b591 JI |
1345 | /* |
1346 | * Don't clear SIGNAL_UNKILLABLE for traced tasks, users won't expect | |
5c72263e | 1347 | * debugging to leave init killable. But HANDLER_EXIT is always fatal. |
eb61b591 | 1348 | */ |
5c72263e KC |
1349 | if (action->sa.sa_handler == SIG_DFL && |
1350 | (!t->ptrace || (handler == HANDLER_EXIT))) | |
80fe728d | 1351 | t->signal->flags &= ~SIGNAL_UNKILLABLE; |
157cc181 | 1352 | ret = send_signal_locked(sig, info, t, PIDTYPE_PID); |
b454ec29 ON |
1353 | /* This can happen if the signal was already pending and blocked */ |
1354 | if (!task_sigpending(t)) | |
1355 | signal_wake_up(t, 0); | |
1da177e4 LT |
1356 | spin_unlock_irqrestore(&t->sighand->siglock, flags); |
1357 | ||
1358 | return ret; | |
1359 | } | |
1360 | ||
a89e9b8a | 1361 | int force_sig_info(struct kernel_siginfo *info) |
59c0e696 | 1362 | { |
e349d945 | 1363 | return force_sig_info_to_task(info, current, HANDLER_CURRENT); |
59c0e696 EB |
1364 | } |
1365 | ||
1da177e4 LT |
1366 | /* |
1367 | * Nuke all other threads in the group. | |
1368 | */ | |
09faef11 | 1369 | int zap_other_threads(struct task_struct *p) |
1da177e4 | 1370 | { |
61a7a5e2 | 1371 | struct task_struct *t; |
09faef11 | 1372 | int count = 0; |
1da177e4 | 1373 | |
1da177e4 LT |
1374 | p->signal->group_stop_count = 0; |
1375 | ||
61a7a5e2 | 1376 | for_other_threads(p, t) { |
6dfca329 | 1377 | task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK); |
f9010dbd MC |
1378 | /* Don't require de_thread to wait for the vhost_worker */ |
1379 | if ((t->flags & (PF_IO_WORKER | PF_USER_WORKER)) != PF_USER_WORKER) | |
1380 | count++; | |
09faef11 ON |
1381 | |
1382 | /* Don't bother with already dead threads */ | |
1da177e4 LT |
1383 | if (t->exit_state) |
1384 | continue; | |
1da177e4 | 1385 | sigaddset(&t->pending.signal, SIGKILL); |
1da177e4 LT |
1386 | signal_wake_up(t, 1); |
1387 | } | |
09faef11 ON |
1388 | |
1389 | return count; | |
1da177e4 LT |
1390 | } |
1391 | ||
b8ed374e NK |
1392 | struct sighand_struct *__lock_task_sighand(struct task_struct *tsk, |
1393 | unsigned long *flags) | |
f63ee72e ON |
1394 | { |
1395 | struct sighand_struct *sighand; | |
1396 | ||
59dc6f3c | 1397 | rcu_read_lock(); |
f63ee72e ON |
1398 | for (;;) { |
1399 | sighand = rcu_dereference(tsk->sighand); | |
59dc6f3c | 1400 | if (unlikely(sighand == NULL)) |
f63ee72e | 1401 | break; |
59dc6f3c | 1402 | |
392809b2 ON |
1403 | /* |
1404 | * This sighand can be already freed and even reused, but | |
5f0d5a3a | 1405 | * we rely on SLAB_TYPESAFE_BY_RCU and sighand_ctor() which |
392809b2 ON |
1406 | * initializes ->siglock: this slab can't go away, it has |
1407 | * the same object type, ->siglock can't be reinitialized. | |
1408 | * | |
1409 | * We need to ensure that tsk->sighand is still the same | |
1410 | * after we take the lock, we can race with de_thread() or | |
1411 | * __exit_signal(). In the latter case the next iteration | |
1412 | * must see ->sighand == NULL. | |
1413 | */ | |
59dc6f3c | 1414 | spin_lock_irqsave(&sighand->siglock, *flags); |
913292c9 | 1415 | if (likely(sighand == rcu_access_pointer(tsk->sighand))) |
f63ee72e | 1416 | break; |
59dc6f3c | 1417 | spin_unlock_irqrestore(&sighand->siglock, *flags); |
f63ee72e | 1418 | } |
59dc6f3c | 1419 | rcu_read_unlock(); |
f63ee72e ON |
1420 | |
1421 | return sighand; | |
1422 | } | |
1423 | ||
a5dec9f8 FW |
1424 | #ifdef CONFIG_LOCKDEP |
1425 | void lockdep_assert_task_sighand_held(struct task_struct *task) | |
1426 | { | |
1427 | struct sighand_struct *sighand; | |
1428 | ||
1429 | rcu_read_lock(); | |
1430 | sighand = rcu_dereference(task->sighand); | |
1431 | if (sighand) | |
1432 | lockdep_assert_held(&sighand->siglock); | |
1433 | else | |
1434 | WARN_ON_ONCE(1); | |
1435 | rcu_read_unlock(); | |
1436 | } | |
1437 | #endif | |
1438 | ||
c69e8d9c | 1439 | /* |
81b9d8ac ON |
1440 | * send signal info to all the members of a thread group or to the |
1441 | * individual thread if type == PIDTYPE_PID. | |
c69e8d9c | 1442 | */ |
ae7795bc EB |
1443 | int group_send_sig_info(int sig, struct kernel_siginfo *info, |
1444 | struct task_struct *p, enum pid_type type) | |
1da177e4 | 1445 | { |
694f690d DH |
1446 | int ret; |
1447 | ||
1448 | rcu_read_lock(); | |
1449 | ret = check_kill_permission(sig, info, p); | |
1450 | rcu_read_unlock(); | |
f63ee72e | 1451 | |
4a30debf | 1452 | if (!ret && sig) |
40b3b025 | 1453 | ret = do_send_sig_info(sig, info, p, type); |
1da177e4 LT |
1454 | |
1455 | return ret; | |
1456 | } | |
1457 | ||
1458 | /* | |
146a505d | 1459 | * __kill_pgrp_info() sends a signal to a process group: this is what the tty |
1da177e4 | 1460 | * control characters do (^C, ^Z etc) |
c69e8d9c | 1461 | * - the caller must hold at least a readlock on tasklist_lock |
1da177e4 | 1462 | */ |
ae7795bc | 1463 | int __kill_pgrp_info(int sig, struct kernel_siginfo *info, struct pid *pgrp) |
1da177e4 LT |
1464 | { |
1465 | struct task_struct *p = NULL; | |
39835204 | 1466 | int ret = -ESRCH; |
1da177e4 | 1467 | |
c4b92fc1 | 1468 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
01024980 | 1469 | int err = group_send_sig_info(sig, info, p, PIDTYPE_PGID); |
39835204 ON |
1470 | /* |
1471 | * If group_send_sig_info() succeeds at least once ret | |
1472 | * becomes 0 and after that the code below has no effect. | |
1473 | * Otherwise we return the last err or -ESRCH if this | |
1474 | * process group is empty. | |
1475 | */ | |
1476 | if (ret) | |
1477 | ret = err; | |
c4b92fc1 | 1478 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
39835204 ON |
1479 | |
1480 | return ret; | |
1da177e4 LT |
1481 | } |
1482 | ||
81b9d8ac ON |
1483 | static int kill_pid_info_type(int sig, struct kernel_siginfo *info, |
1484 | struct pid *pid, enum pid_type type) | |
1da177e4 | 1485 | { |
d36174bc | 1486 | int error = -ESRCH; |
1da177e4 LT |
1487 | struct task_struct *p; |
1488 | ||
eca1a089 PM |
1489 | for (;;) { |
1490 | rcu_read_lock(); | |
1491 | p = pid_task(pid, PIDTYPE_PID); | |
1492 | if (p) | |
81b9d8ac | 1493 | error = group_send_sig_info(sig, info, p, type); |
eca1a089 PM |
1494 | rcu_read_unlock(); |
1495 | if (likely(!p || error != -ESRCH)) | |
1496 | return error; | |
eca1a089 PM |
1497 | /* |
1498 | * The task was unhashed in between, try again. If it | |
1499 | * is dead, pid_task() will return NULL, if we race with | |
1500 | * de_thread() it will find the new leader. | |
1501 | */ | |
1502 | } | |
1da177e4 LT |
1503 | } |
1504 | ||
81b9d8ac ON |
1505 | int kill_pid_info(int sig, struct kernel_siginfo *info, struct pid *pid) |
1506 | { | |
1507 | return kill_pid_info_type(sig, info, pid, PIDTYPE_TGID); | |
1508 | } | |
1509 | ||
ae7795bc | 1510 | static int kill_proc_info(int sig, struct kernel_siginfo *info, pid_t pid) |
c4b92fc1 EB |
1511 | { |
1512 | int error; | |
1513 | rcu_read_lock(); | |
b488893a | 1514 | error = kill_pid_info(sig, info, find_vpid(pid)); |
c4b92fc1 EB |
1515 | rcu_read_unlock(); |
1516 | return error; | |
1517 | } | |
1518 | ||
bb17fcca CB |
1519 | static inline bool kill_as_cred_perm(const struct cred *cred, |
1520 | struct task_struct *target) | |
d178bc3a SH |
1521 | { |
1522 | const struct cred *pcred = __task_cred(target); | |
bb17fcca CB |
1523 | |
1524 | return uid_eq(cred->euid, pcred->suid) || | |
1525 | uid_eq(cred->euid, pcred->uid) || | |
1526 | uid_eq(cred->uid, pcred->suid) || | |
1527 | uid_eq(cred->uid, pcred->uid); | |
d178bc3a SH |
1528 | } |
1529 | ||
70f1b0d3 EB |
1530 | /* |
1531 | * The usb asyncio usage of siginfo is wrong. The glibc support | |
1532 | * for asyncio which uses SI_ASYNCIO assumes the layout is SIL_RT. | |
1533 | * AKA after the generic fields: | |
1534 | * kernel_pid_t si_pid; | |
1535 | * kernel_uid32_t si_uid; | |
1536 | * sigval_t si_value; | |
1537 | * | |
1538 | * Unfortunately when usb generates SI_ASYNCIO it assumes the layout | |
1539 | * after the generic fields is: | |
1540 | * void __user *si_addr; | |
1541 | * | |
1542 | * This is a practical problem when there is a 64bit big endian kernel | |
1543 | * and a 32bit userspace. As the 32bit address will encoded in the low | |
1544 | * 32bits of the pointer. Those low 32bits will be stored at higher | |
1545 | * address than appear in a 32 bit pointer. So userspace will not | |
1546 | * see the address it was expecting for it's completions. | |
1547 | * | |
1548 | * There is nothing in the encoding that can allow | |
1549 | * copy_siginfo_to_user32 to detect this confusion of formats, so | |
1550 | * handle this by requiring the caller of kill_pid_usb_asyncio to | |
1551 | * notice when this situration takes place and to store the 32bit | |
1552 | * pointer in sival_int, instead of sival_addr of the sigval_t addr | |
1553 | * parameter. | |
1554 | */ | |
1555 | int kill_pid_usb_asyncio(int sig, int errno, sigval_t addr, | |
1556 | struct pid *pid, const struct cred *cred) | |
46113830 | 1557 | { |
70f1b0d3 | 1558 | struct kernel_siginfo info; |
46113830 | 1559 | struct task_struct *p; |
14d8c9f3 | 1560 | unsigned long flags; |
70f1b0d3 EB |
1561 | int ret = -EINVAL; |
1562 | ||
eaec2b0b ZL |
1563 | if (!valid_signal(sig)) |
1564 | return ret; | |
1565 | ||
70f1b0d3 EB |
1566 | clear_siginfo(&info); |
1567 | info.si_signo = sig; | |
1568 | info.si_errno = errno; | |
1569 | info.si_code = SI_ASYNCIO; | |
1570 | *((sigval_t *)&info.si_pid) = addr; | |
46113830 | 1571 | |
14d8c9f3 | 1572 | rcu_read_lock(); |
2425c08b | 1573 | p = pid_task(pid, PIDTYPE_PID); |
46113830 HW |
1574 | if (!p) { |
1575 | ret = -ESRCH; | |
1576 | goto out_unlock; | |
1577 | } | |
70f1b0d3 | 1578 | if (!kill_as_cred_perm(cred, p)) { |
46113830 HW |
1579 | ret = -EPERM; |
1580 | goto out_unlock; | |
1581 | } | |
70f1b0d3 | 1582 | ret = security_task_kill(p, &info, sig, cred); |
8f95dc58 DQ |
1583 | if (ret) |
1584 | goto out_unlock; | |
14d8c9f3 TG |
1585 | |
1586 | if (sig) { | |
1587 | if (lock_task_sighand(p, &flags)) { | |
157cc181 | 1588 | ret = __send_signal_locked(sig, &info, p, PIDTYPE_TGID, false); |
14d8c9f3 TG |
1589 | unlock_task_sighand(p, &flags); |
1590 | } else | |
1591 | ret = -ESRCH; | |
46113830 HW |
1592 | } |
1593 | out_unlock: | |
14d8c9f3 | 1594 | rcu_read_unlock(); |
46113830 HW |
1595 | return ret; |
1596 | } | |
70f1b0d3 | 1597 | EXPORT_SYMBOL_GPL(kill_pid_usb_asyncio); |
1da177e4 LT |
1598 | |
1599 | /* | |
1600 | * kill_something_info() interprets pid in interesting ways just like kill(2). | |
1601 | * | |
1602 | * POSIX specifies that kill(-1,sig) is unspecified, but what we have | |
1603 | * is probably wrong. Should make it like BSD or SYSV. | |
1604 | */ | |
1605 | ||
ae7795bc | 1606 | static int kill_something_info(int sig, struct kernel_siginfo *info, pid_t pid) |
1da177e4 | 1607 | { |
8d42db18 | 1608 | int ret; |
d5df763b | 1609 | |
3075afdf ZL |
1610 | if (pid > 0) |
1611 | return kill_proc_info(sig, info, pid); | |
d5df763b | 1612 | |
4ea77014 | 1613 | /* -INT_MIN is undefined. Exclude this case to avoid a UBSAN warning */ |
1614 | if (pid == INT_MIN) | |
1615 | return -ESRCH; | |
1616 | ||
d5df763b PE |
1617 | read_lock(&tasklist_lock); |
1618 | if (pid != -1) { | |
1619 | ret = __kill_pgrp_info(sig, info, | |
1620 | pid ? find_vpid(-pid) : task_pgrp(current)); | |
1621 | } else { | |
1da177e4 LT |
1622 | int retval = 0, count = 0; |
1623 | struct task_struct * p; | |
1624 | ||
1da177e4 | 1625 | for_each_process(p) { |
d25141a8 SB |
1626 | if (task_pid_vnr(p) > 1 && |
1627 | !same_thread_group(p, current)) { | |
01024980 EB |
1628 | int err = group_send_sig_info(sig, info, p, |
1629 | PIDTYPE_MAX); | |
1da177e4 LT |
1630 | ++count; |
1631 | if (err != -EPERM) | |
1632 | retval = err; | |
1633 | } | |
1634 | } | |
8d42db18 | 1635 | ret = count ? retval : -ESRCH; |
1da177e4 | 1636 | } |
d5df763b PE |
1637 | read_unlock(&tasklist_lock); |
1638 | ||
8d42db18 | 1639 | return ret; |
1da177e4 LT |
1640 | } |
1641 | ||
1642 | /* | |
1643 | * These are for backward compatibility with the rest of the kernel source. | |
1644 | */ | |
1645 | ||
ae7795bc | 1646 | int send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p) |
1da177e4 | 1647 | { |
1da177e4 LT |
1648 | /* |
1649 | * Make sure legacy kernel users don't send in bad values | |
1650 | * (normal paths check this in check_kill_permission). | |
1651 | */ | |
7ed20e1a | 1652 | if (!valid_signal(sig)) |
1da177e4 LT |
1653 | return -EINVAL; |
1654 | ||
40b3b025 | 1655 | return do_send_sig_info(sig, info, p, PIDTYPE_PID); |
1da177e4 | 1656 | } |
fb50f5a4 | 1657 | EXPORT_SYMBOL(send_sig_info); |
1da177e4 | 1658 | |
b67a1b9e ON |
1659 | #define __si_special(priv) \ |
1660 | ((priv) ? SEND_SIG_PRIV : SEND_SIG_NOINFO) | |
1661 | ||
1da177e4 LT |
1662 | int |
1663 | send_sig(int sig, struct task_struct *p, int priv) | |
1664 | { | |
b67a1b9e | 1665 | return send_sig_info(sig, __si_special(priv), p); |
1da177e4 | 1666 | } |
fb50f5a4 | 1667 | EXPORT_SYMBOL(send_sig); |
1da177e4 | 1668 | |
3cf5d076 | 1669 | void force_sig(int sig) |
1da177e4 | 1670 | { |
ffafd23b EB |
1671 | struct kernel_siginfo info; |
1672 | ||
1673 | clear_siginfo(&info); | |
1674 | info.si_signo = sig; | |
1675 | info.si_errno = 0; | |
1676 | info.si_code = SI_KERNEL; | |
1677 | info.si_pid = 0; | |
1678 | info.si_uid = 0; | |
a89e9b8a | 1679 | force_sig_info(&info); |
1da177e4 | 1680 | } |
fb50f5a4 | 1681 | EXPORT_SYMBOL(force_sig); |
1da177e4 | 1682 | |
26d5badb EB |
1683 | void force_fatal_sig(int sig) |
1684 | { | |
1685 | struct kernel_siginfo info; | |
1686 | ||
1687 | clear_siginfo(&info); | |
1688 | info.si_signo = sig; | |
1689 | info.si_errno = 0; | |
1690 | info.si_code = SI_KERNEL; | |
1691 | info.si_pid = 0; | |
1692 | info.si_uid = 0; | |
e349d945 | 1693 | force_sig_info_to_task(&info, current, HANDLER_SIG_DFL); |
26d5badb EB |
1694 | } |
1695 | ||
fcb116bc EB |
1696 | void force_exit_sig(int sig) |
1697 | { | |
1698 | struct kernel_siginfo info; | |
1699 | ||
1700 | clear_siginfo(&info); | |
1701 | info.si_signo = sig; | |
1702 | info.si_errno = 0; | |
1703 | info.si_code = SI_KERNEL; | |
1704 | info.si_pid = 0; | |
1705 | info.si_uid = 0; | |
1706 | force_sig_info_to_task(&info, current, HANDLER_EXIT); | |
1707 | } | |
1708 | ||
1da177e4 LT |
1709 | /* |
1710 | * When things go south during signal handling, we | |
1711 | * will force a SIGSEGV. And if the signal that caused | |
1712 | * the problem was already a SIGSEGV, we'll want to | |
1713 | * make sure we don't even try to deliver the signal.. | |
1714 | */ | |
cb44c9a0 | 1715 | void force_sigsegv(int sig) |
1da177e4 | 1716 | { |
26d5badb EB |
1717 | if (sig == SIGSEGV) |
1718 | force_fatal_sig(SIGSEGV); | |
1719 | else | |
1720 | force_sig(SIGSEGV); | |
1da177e4 LT |
1721 | } |
1722 | ||
f5e83688 AB |
1723 | int force_sig_fault_to_task(int sig, int code, void __user *addr, |
1724 | struct task_struct *t) | |
f8ec6601 | 1725 | { |
ae7795bc | 1726 | struct kernel_siginfo info; |
f8ec6601 EB |
1727 | |
1728 | clear_siginfo(&info); | |
1729 | info.si_signo = sig; | |
1730 | info.si_errno = 0; | |
1731 | info.si_code = code; | |
1732 | info.si_addr = addr; | |
e349d945 | 1733 | return force_sig_info_to_task(&info, t, HANDLER_CURRENT); |
f8ec6601 EB |
1734 | } |
1735 | ||
f5e83688 | 1736 | int force_sig_fault(int sig, int code, void __user *addr) |
91ca180d | 1737 | { |
f5e83688 | 1738 | return force_sig_fault_to_task(sig, code, addr, current); |
f8ec6601 EB |
1739 | } |
1740 | ||
f5e83688 | 1741 | int send_sig_fault(int sig, int code, void __user *addr, struct task_struct *t) |
f8ec6601 | 1742 | { |
ae7795bc | 1743 | struct kernel_siginfo info; |
f8ec6601 EB |
1744 | |
1745 | clear_siginfo(&info); | |
1746 | info.si_signo = sig; | |
1747 | info.si_errno = 0; | |
1748 | info.si_code = code; | |
1749 | info.si_addr = addr; | |
f8ec6601 EB |
1750 | return send_sig_info(info.si_signo, &info, t); |
1751 | } | |
1752 | ||
f8eac901 | 1753 | int force_sig_mceerr(int code, void __user *addr, short lsb) |
38246735 | 1754 | { |
ae7795bc | 1755 | struct kernel_siginfo info; |
38246735 EB |
1756 | |
1757 | WARN_ON((code != BUS_MCEERR_AO) && (code != BUS_MCEERR_AR)); | |
1758 | clear_siginfo(&info); | |
1759 | info.si_signo = SIGBUS; | |
1760 | info.si_errno = 0; | |
1761 | info.si_code = code; | |
1762 | info.si_addr = addr; | |
1763 | info.si_addr_lsb = lsb; | |
a89e9b8a | 1764 | return force_sig_info(&info); |
38246735 EB |
1765 | } |
1766 | ||
1767 | int send_sig_mceerr(int code, void __user *addr, short lsb, struct task_struct *t) | |
1768 | { | |
ae7795bc | 1769 | struct kernel_siginfo info; |
38246735 EB |
1770 | |
1771 | WARN_ON((code != BUS_MCEERR_AO) && (code != BUS_MCEERR_AR)); | |
1772 | clear_siginfo(&info); | |
1773 | info.si_signo = SIGBUS; | |
1774 | info.si_errno = 0; | |
1775 | info.si_code = code; | |
1776 | info.si_addr = addr; | |
1777 | info.si_addr_lsb = lsb; | |
1778 | return send_sig_info(info.si_signo, &info, t); | |
1779 | } | |
1780 | EXPORT_SYMBOL(send_sig_mceerr); | |
38246735 | 1781 | |
38246735 EB |
1782 | int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper) |
1783 | { | |
ae7795bc | 1784 | struct kernel_siginfo info; |
38246735 EB |
1785 | |
1786 | clear_siginfo(&info); | |
1787 | info.si_signo = SIGSEGV; | |
1788 | info.si_errno = 0; | |
1789 | info.si_code = SEGV_BNDERR; | |
1790 | info.si_addr = addr; | |
1791 | info.si_lower = lower; | |
1792 | info.si_upper = upper; | |
a89e9b8a | 1793 | return force_sig_info(&info); |
38246735 | 1794 | } |
38246735 EB |
1795 | |
1796 | #ifdef SEGV_PKUERR | |
1797 | int force_sig_pkuerr(void __user *addr, u32 pkey) | |
1798 | { | |
ae7795bc | 1799 | struct kernel_siginfo info; |
38246735 EB |
1800 | |
1801 | clear_siginfo(&info); | |
1802 | info.si_signo = SIGSEGV; | |
1803 | info.si_errno = 0; | |
1804 | info.si_code = SEGV_PKUERR; | |
1805 | info.si_addr = addr; | |
1806 | info.si_pkey = pkey; | |
a89e9b8a | 1807 | return force_sig_info(&info); |
38246735 EB |
1808 | } |
1809 | #endif | |
f8ec6601 | 1810 | |
78ed93d7 | 1811 | int send_sig_perf(void __user *addr, u32 type, u64 sig_data) |
af5eeab7 EB |
1812 | { |
1813 | struct kernel_siginfo info; | |
1814 | ||
1815 | clear_siginfo(&info); | |
0683b531 EB |
1816 | info.si_signo = SIGTRAP; |
1817 | info.si_errno = 0; | |
1818 | info.si_code = TRAP_PERF; | |
1819 | info.si_addr = addr; | |
1820 | info.si_perf_data = sig_data; | |
1821 | info.si_perf_type = type; | |
1822 | ||
78ed93d7 ME |
1823 | /* |
1824 | * Signals generated by perf events should not terminate the whole | |
1825 | * process if SIGTRAP is blocked, however, delivering the signal | |
1826 | * asynchronously is better than not delivering at all. But tell user | |
1827 | * space if the signal was asynchronous, so it can clearly be | |
1828 | * distinguished from normal synchronous ones. | |
1829 | */ | |
1830 | info.si_perf_flags = sigismember(¤t->blocked, info.si_signo) ? | |
1831 | TRAP_PERF_FLAG_ASYNC : | |
1832 | 0; | |
1833 | ||
1834 | return send_sig_info(info.si_signo, &info, current); | |
af5eeab7 EB |
1835 | } |
1836 | ||
307d522f EB |
1837 | /** |
1838 | * force_sig_seccomp - signals the task to allow in-process syscall emulation | |
1839 | * @syscall: syscall number to send to userland | |
1840 | * @reason: filter-supplied reason code to send to userland (via si_errno) | |
6410349e | 1841 | * @force_coredump: true to trigger a coredump |
307d522f EB |
1842 | * |
1843 | * Forces a SIGSYS with a code of SYS_SECCOMP and related sigsys info. | |
1844 | */ | |
1845 | int force_sig_seccomp(int syscall, int reason, bool force_coredump) | |
1846 | { | |
1847 | struct kernel_siginfo info; | |
1848 | ||
1849 | clear_siginfo(&info); | |
1850 | info.si_signo = SIGSYS; | |
1851 | info.si_code = SYS_SECCOMP; | |
1852 | info.si_call_addr = (void __user *)KSTK_EIP(current); | |
1853 | info.si_errno = reason; | |
1854 | info.si_arch = syscall_get_arch(current); | |
1855 | info.si_syscall = syscall; | |
e349d945 EB |
1856 | return force_sig_info_to_task(&info, current, |
1857 | force_coredump ? HANDLER_EXIT : HANDLER_CURRENT); | |
307d522f EB |
1858 | } |
1859 | ||
f71dd7dc EB |
1860 | /* For the crazy architectures that include trap information in |
1861 | * the errno field, instead of an actual errno value. | |
1862 | */ | |
1863 | int force_sig_ptrace_errno_trap(int errno, void __user *addr) | |
1864 | { | |
ae7795bc | 1865 | struct kernel_siginfo info; |
f71dd7dc EB |
1866 | |
1867 | clear_siginfo(&info); | |
1868 | info.si_signo = SIGTRAP; | |
1869 | info.si_errno = errno; | |
1870 | info.si_code = TRAP_HWBKPT; | |
1871 | info.si_addr = addr; | |
a89e9b8a | 1872 | return force_sig_info(&info); |
f71dd7dc EB |
1873 | } |
1874 | ||
2c9f7eaf EB |
1875 | /* For the rare architectures that include trap information using |
1876 | * si_trapno. | |
1877 | */ | |
1878 | int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno) | |
1879 | { | |
1880 | struct kernel_siginfo info; | |
1881 | ||
1882 | clear_siginfo(&info); | |
1883 | info.si_signo = sig; | |
1884 | info.si_errno = 0; | |
1885 | info.si_code = code; | |
1886 | info.si_addr = addr; | |
1887 | info.si_trapno = trapno; | |
1888 | return force_sig_info(&info); | |
1889 | } | |
1890 | ||
7de5f68d EB |
1891 | /* For the rare architectures that include trap information using |
1892 | * si_trapno. | |
1893 | */ | |
1894 | int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno, | |
1895 | struct task_struct *t) | |
1896 | { | |
1897 | struct kernel_siginfo info; | |
1898 | ||
1899 | clear_siginfo(&info); | |
1900 | info.si_signo = sig; | |
1901 | info.si_errno = 0; | |
1902 | info.si_code = code; | |
1903 | info.si_addr = addr; | |
1904 | info.si_trapno = trapno; | |
1905 | return send_sig_info(info.si_signo, &info, t); | |
1906 | } | |
1907 | ||
e1fb1dc0 | 1908 | static int kill_pgrp_info(int sig, struct kernel_siginfo *info, struct pid *pgrp) |
c4b92fc1 | 1909 | { |
146a505d | 1910 | int ret; |
146a505d | 1911 | read_lock(&tasklist_lock); |
e1fb1dc0 | 1912 | ret = __kill_pgrp_info(sig, info, pgrp); |
146a505d | 1913 | read_unlock(&tasklist_lock); |
146a505d | 1914 | return ret; |
c4b92fc1 | 1915 | } |
e1fb1dc0 CB |
1916 | |
1917 | int kill_pgrp(struct pid *pid, int sig, int priv) | |
1918 | { | |
1919 | return kill_pgrp_info(sig, __si_special(priv), pid); | |
1920 | } | |
c4b92fc1 EB |
1921 | EXPORT_SYMBOL(kill_pgrp); |
1922 | ||
1923 | int kill_pid(struct pid *pid, int sig, int priv) | |
1924 | { | |
1925 | return kill_pid_info(sig, __si_special(priv), pid); | |
1926 | } | |
1927 | EXPORT_SYMBOL(kill_pid); | |
1928 | ||
1da177e4 LT |
1929 | /* |
1930 | * These functions support sending signals using preallocated sigqueue | |
1931 | * structures. This is needed "because realtime applications cannot | |
1932 | * afford to lose notifications of asynchronous events, like timer | |
5aba085e | 1933 | * expirations or I/O completions". In the case of POSIX Timers |
1da177e4 LT |
1934 | * we allocate the sigqueue structure from the timer_create. If this |
1935 | * allocation fails we are able to report the failure to the application | |
1936 | * with an EAGAIN error. | |
1937 | */ | |
1da177e4 LT |
1938 | struct sigqueue *sigqueue_alloc(void) |
1939 | { | |
69995ebb | 1940 | return __sigqueue_alloc(-1, current, GFP_KERNEL, 0, SIGQUEUE_PREALLOC); |
1da177e4 LT |
1941 | } |
1942 | ||
1943 | void sigqueue_free(struct sigqueue *q) | |
1944 | { | |
1945 | unsigned long flags; | |
60187d27 ON |
1946 | spinlock_t *lock = ¤t->sighand->siglock; |
1947 | ||
1da177e4 LT |
1948 | BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); |
1949 | /* | |
c8e85b4f ON |
1950 | * We must hold ->siglock while testing q->list |
1951 | * to serialize with collect_signal() or with | |
da7978b0 | 1952 | * __exit_signal()->flush_sigqueue(). |
1da177e4 | 1953 | */ |
60187d27 | 1954 | spin_lock_irqsave(lock, flags); |
c8e85b4f ON |
1955 | q->flags &= ~SIGQUEUE_PREALLOC; |
1956 | /* | |
1957 | * If it is queued it will be freed when dequeued, | |
1958 | * like the "regular" sigqueue. | |
1959 | */ | |
60187d27 | 1960 | if (!list_empty(&q->list)) |
c8e85b4f | 1961 | q = NULL; |
60187d27 ON |
1962 | spin_unlock_irqrestore(lock, flags); |
1963 | ||
c8e85b4f ON |
1964 | if (q) |
1965 | __sigqueue_free(q); | |
1da177e4 LT |
1966 | } |
1967 | ||
24122c7f | 1968 | int send_sigqueue(struct sigqueue *q, struct pid *pid, enum pid_type type) |
9e3bd6c3 | 1969 | { |
e62e6650 | 1970 | int sig = q->info.si_signo; |
2ca3515a | 1971 | struct sigpending *pending; |
24122c7f | 1972 | struct task_struct *t; |
e62e6650 | 1973 | unsigned long flags; |
163566f6 | 1974 | int ret, result; |
2ca3515a | 1975 | |
4cd4b6d4 | 1976 | BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); |
e62e6650 ON |
1977 | |
1978 | ret = -1; | |
24122c7f | 1979 | rcu_read_lock(); |
bcb7ee79 DV |
1980 | |
1981 | /* | |
1982 | * This function is used by POSIX timers to deliver a timer signal. | |
1983 | * Where type is PIDTYPE_PID (such as for timers with SIGEV_THREAD_ID | |
1984 | * set), the signal must be delivered to the specific thread (queues | |
1985 | * into t->pending). | |
1986 | * | |
1987 | * Where type is not PIDTYPE_PID, signals must be delivered to the | |
1988 | * process. In this case, prefer to deliver to current if it is in | |
1989 | * the same thread group as the target process, which avoids | |
1990 | * unnecessarily waking up a potentially idle task. | |
1991 | */ | |
24122c7f | 1992 | t = pid_task(pid, type); |
bcb7ee79 DV |
1993 | if (!t) |
1994 | goto ret; | |
1995 | if (type != PIDTYPE_PID && same_thread_group(t, current)) | |
1996 | t = current; | |
1997 | if (!likely(lock_task_sighand(t, &flags))) | |
e62e6650 ON |
1998 | goto ret; |
1999 | ||
7e695a5e | 2000 | ret = 1; /* the signal is ignored */ |
163566f6 | 2001 | result = TRACE_SIGNAL_IGNORED; |
def8cf72 | 2002 | if (!prepare_signal(sig, t, false)) |
e62e6650 ON |
2003 | goto out; |
2004 | ||
2005 | ret = 0; | |
9e3bd6c3 PE |
2006 | if (unlikely(!list_empty(&q->list))) { |
2007 | /* | |
2008 | * If an SI_TIMER entry is already queue just increment | |
2009 | * the overrun count. | |
2010 | */ | |
9e3bd6c3 PE |
2011 | BUG_ON(q->info.si_code != SI_TIMER); |
2012 | q->info.si_overrun++; | |
163566f6 | 2013 | result = TRACE_SIGNAL_ALREADY_PENDING; |
e62e6650 | 2014 | goto out; |
9e3bd6c3 | 2015 | } |
ba661292 | 2016 | q->info.si_overrun = 0; |
9e3bd6c3 | 2017 | |
9e3bd6c3 | 2018 | signalfd_notify(t, sig); |
24122c7f | 2019 | pending = (type != PIDTYPE_PID) ? &t->signal->shared_pending : &t->pending; |
9e3bd6c3 PE |
2020 | list_add_tail(&q->list, &pending->list); |
2021 | sigaddset(&pending->signal, sig); | |
07296149 | 2022 | complete_signal(sig, t, type); |
163566f6 | 2023 | result = TRACE_SIGNAL_DELIVERED; |
e62e6650 | 2024 | out: |
24122c7f | 2025 | trace_signal_generate(sig, &q->info, t, type != PIDTYPE_PID, result); |
e62e6650 ON |
2026 | unlock_task_sighand(t, &flags); |
2027 | ret: | |
24122c7f | 2028 | rcu_read_unlock(); |
e62e6650 | 2029 | return ret; |
9e3bd6c3 PE |
2030 | } |
2031 | ||
64bef697 | 2032 | void do_notify_pidfd(struct task_struct *task) |
b53b0b9d | 2033 | { |
9ed52108 | 2034 | struct pid *pid = task_pid(task); |
b53b0b9d | 2035 | |
1caf7d50 | 2036 | WARN_ON(task->exit_state == 0); |
9ed52108 ON |
2037 | |
2038 | __wake_up(&pid->wait_pidfd, TASK_NORMAL, 0, | |
2039 | poll_to_key(EPOLLIN | EPOLLRDNORM)); | |
b53b0b9d JFG |
2040 | } |
2041 | ||
1da177e4 LT |
2042 | /* |
2043 | * Let a parent know about the death of a child. | |
2044 | * For a stopped/continued status change, use do_notify_parent_cldstop instead. | |
2b2a1ff6 | 2045 | * |
53c8f9f1 ON |
2046 | * Returns true if our parent ignored us and so we've switched to |
2047 | * self-reaping. | |
1da177e4 | 2048 | */ |
53c8f9f1 | 2049 | bool do_notify_parent(struct task_struct *tsk, int sig) |
1da177e4 | 2050 | { |
ae7795bc | 2051 | struct kernel_siginfo info; |
1da177e4 LT |
2052 | unsigned long flags; |
2053 | struct sighand_struct *psig; | |
53c8f9f1 | 2054 | bool autoreap = false; |
bde8285e | 2055 | u64 utime, stime; |
1da177e4 | 2056 | |
a382f8fe | 2057 | WARN_ON_ONCE(sig == -1); |
1da177e4 | 2058 | |
a382f8fe LT |
2059 | /* do_notify_parent_cldstop should have been called instead. */ |
2060 | WARN_ON_ONCE(task_is_stopped_or_traced(tsk)); | |
1da177e4 | 2061 | |
a382f8fe | 2062 | WARN_ON_ONCE(!tsk->ptrace && |
1da177e4 | 2063 | (tsk->group_leader != tsk || !thread_group_empty(tsk))); |
21e25205 | 2064 | /* |
64bef697 ON |
2065 | * tsk is a group leader and has no threads, wake up the |
2066 | * non-PIDFD_THREAD waiters. | |
21e25205 ON |
2067 | */ |
2068 | if (thread_group_empty(tsk)) | |
2069 | do_notify_pidfd(tsk); | |
b53b0b9d | 2070 | |
b6e238dc ON |
2071 | if (sig != SIGCHLD) { |
2072 | /* | |
2073 | * This is only possible if parent == real_parent. | |
2074 | * Check if it has changed security domain. | |
2075 | */ | |
d1e7fd64 | 2076 | if (tsk->parent_exec_id != READ_ONCE(tsk->parent->self_exec_id)) |
b6e238dc ON |
2077 | sig = SIGCHLD; |
2078 | } | |
2079 | ||
faf1f22b | 2080 | clear_siginfo(&info); |
1da177e4 LT |
2081 | info.si_signo = sig; |
2082 | info.si_errno = 0; | |
b488893a | 2083 | /* |
32084504 EB |
2084 | * We are under tasklist_lock here so our parent is tied to |
2085 | * us and cannot change. | |
b488893a | 2086 | * |
32084504 EB |
2087 | * task_active_pid_ns will always return the same pid namespace |
2088 | * until a task passes through release_task. | |
b488893a PE |
2089 | * |
2090 | * write_lock() currently calls preempt_disable() which is the | |
2091 | * same as rcu_read_lock(), but according to Oleg, this is not | |
2092 | * correct to rely on this | |
2093 | */ | |
2094 | rcu_read_lock(); | |
32084504 | 2095 | info.si_pid = task_pid_nr_ns(tsk, task_active_pid_ns(tsk->parent)); |
54ba47ed EB |
2096 | info.si_uid = from_kuid_munged(task_cred_xxx(tsk->parent, user_ns), |
2097 | task_uid(tsk)); | |
b488893a PE |
2098 | rcu_read_unlock(); |
2099 | ||
bde8285e FW |
2100 | task_cputime(tsk, &utime, &stime); |
2101 | info.si_utime = nsec_to_clock_t(utime + tsk->signal->utime); | |
2102 | info.si_stime = nsec_to_clock_t(stime + tsk->signal->stime); | |
1da177e4 LT |
2103 | |
2104 | info.si_status = tsk->exit_code & 0x7f; | |
2105 | if (tsk->exit_code & 0x80) | |
2106 | info.si_code = CLD_DUMPED; | |
2107 | else if (tsk->exit_code & 0x7f) | |
2108 | info.si_code = CLD_KILLED; | |
2109 | else { | |
2110 | info.si_code = CLD_EXITED; | |
2111 | info.si_status = tsk->exit_code >> 8; | |
2112 | } | |
2113 | ||
2114 | psig = tsk->parent->sighand; | |
2115 | spin_lock_irqsave(&psig->siglock, flags); | |
d21142ec | 2116 | if (!tsk->ptrace && sig == SIGCHLD && |
1da177e4 LT |
2117 | (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN || |
2118 | (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT))) { | |
2119 | /* | |
2120 | * We are exiting and our parent doesn't care. POSIX.1 | |
2121 | * defines special semantics for setting SIGCHLD to SIG_IGN | |
2122 | * or setting the SA_NOCLDWAIT flag: we should be reaped | |
2123 | * automatically and not left for our parent's wait4 call. | |
2124 | * Rather than having the parent do it as a magic kind of | |
2125 | * signal handler, we just set this to tell do_exit that we | |
2126 | * can be cleaned up without becoming a zombie. Note that | |
2127 | * we still call __wake_up_parent in this case, because a | |
2128 | * blocked sys_wait4 might now return -ECHILD. | |
2129 | * | |
2130 | * Whether we send SIGCHLD or not for SA_NOCLDWAIT | |
2131 | * is implementation-defined: we do (if you don't want | |
2132 | * it, just use SIG_IGN instead). | |
2133 | */ | |
53c8f9f1 | 2134 | autoreap = true; |
1da177e4 | 2135 | if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) |
53c8f9f1 | 2136 | sig = 0; |
1da177e4 | 2137 | } |
61e713bd EB |
2138 | /* |
2139 | * Send with __send_signal as si_pid and si_uid are in the | |
2140 | * parent's namespaces. | |
2141 | */ | |
53c8f9f1 | 2142 | if (valid_signal(sig) && sig) |
157cc181 | 2143 | __send_signal_locked(sig, &info, tsk->parent, PIDTYPE_TGID, false); |
1da177e4 LT |
2144 | __wake_up_parent(tsk, tsk->parent); |
2145 | spin_unlock_irqrestore(&psig->siglock, flags); | |
2b2a1ff6 | 2146 | |
53c8f9f1 | 2147 | return autoreap; |
1da177e4 LT |
2148 | } |
2149 | ||
75b95953 TH |
2150 | /** |
2151 | * do_notify_parent_cldstop - notify parent of stopped/continued state change | |
2152 | * @tsk: task reporting the state change | |
2153 | * @for_ptracer: the notification is for ptracer | |
2154 | * @why: CLD_{CONTINUED|STOPPED|TRAPPED} to report | |
2155 | * | |
2156 | * Notify @tsk's parent that the stopped/continued state has changed. If | |
2157 | * @for_ptracer is %false, @tsk's group leader notifies to its real parent. | |
2158 | * If %true, @tsk reports to @tsk->parent which should be the ptracer. | |
2159 | * | |
2160 | * CONTEXT: | |
2161 | * Must be called with tasklist_lock at least read locked. | |
2162 | */ | |
2163 | static void do_notify_parent_cldstop(struct task_struct *tsk, | |
2164 | bool for_ptracer, int why) | |
1da177e4 | 2165 | { |
ae7795bc | 2166 | struct kernel_siginfo info; |
1da177e4 | 2167 | unsigned long flags; |
bc505a47 | 2168 | struct task_struct *parent; |
1da177e4 | 2169 | struct sighand_struct *sighand; |
bde8285e | 2170 | u64 utime, stime; |
1da177e4 | 2171 | |
75b95953 | 2172 | if (for_ptracer) { |
bc505a47 | 2173 | parent = tsk->parent; |
75b95953 | 2174 | } else { |
bc505a47 ON |
2175 | tsk = tsk->group_leader; |
2176 | parent = tsk->real_parent; | |
2177 | } | |
2178 | ||
faf1f22b | 2179 | clear_siginfo(&info); |
1da177e4 LT |
2180 | info.si_signo = SIGCHLD; |
2181 | info.si_errno = 0; | |
b488893a | 2182 | /* |
5aba085e | 2183 | * see comment in do_notify_parent() about the following 4 lines |
b488893a PE |
2184 | */ |
2185 | rcu_read_lock(); | |
17cf22c3 | 2186 | info.si_pid = task_pid_nr_ns(tsk, task_active_pid_ns(parent)); |
54ba47ed | 2187 | info.si_uid = from_kuid_munged(task_cred_xxx(parent, user_ns), task_uid(tsk)); |
b488893a PE |
2188 | rcu_read_unlock(); |
2189 | ||
bde8285e FW |
2190 | task_cputime(tsk, &utime, &stime); |
2191 | info.si_utime = nsec_to_clock_t(utime); | |
2192 | info.si_stime = nsec_to_clock_t(stime); | |
1da177e4 LT |
2193 | |
2194 | info.si_code = why; | |
2195 | switch (why) { | |
2196 | case CLD_CONTINUED: | |
2197 | info.si_status = SIGCONT; | |
2198 | break; | |
2199 | case CLD_STOPPED: | |
2200 | info.si_status = tsk->signal->group_exit_code & 0x7f; | |
2201 | break; | |
2202 | case CLD_TRAPPED: | |
2203 | info.si_status = tsk->exit_code & 0x7f; | |
2204 | break; | |
2205 | default: | |
2206 | BUG(); | |
2207 | } | |
2208 | ||
2209 | sighand = parent->sighand; | |
2210 | spin_lock_irqsave(&sighand->siglock, flags); | |
2211 | if (sighand->action[SIGCHLD-1].sa.sa_handler != SIG_IGN && | |
2212 | !(sighand->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDSTOP)) | |
e71ba124 | 2213 | send_signal_locked(SIGCHLD, &info, parent, PIDTYPE_TGID); |
1da177e4 LT |
2214 | /* |
2215 | * Even if SIGCHLD is not generated, we must wake up wait4 calls. | |
2216 | */ | |
2217 | __wake_up_parent(tsk, parent); | |
2218 | spin_unlock_irqrestore(&sighand->siglock, flags); | |
2219 | } | |
2220 | ||
2221 | /* | |
2222 | * This must be called with current->sighand->siglock held. | |
2223 | * | |
2224 | * This should be the path for all ptrace stops. | |
2225 | * We always set current->last_siginfo while stopped here. | |
2226 | * That makes it a way to test a stopped process for | |
2227 | * being ptrace-stopped vs being job-control-stopped. | |
2228 | * | |
6487d1da EB |
2229 | * Returns the signal the ptracer requested the code resume |
2230 | * with. If the code did not stop because the tracer is gone, | |
2231 | * the stop signal remains unchanged unless clear_code. | |
1da177e4 | 2232 | */ |
57b6de08 EB |
2233 | static int ptrace_stop(int exit_code, int why, unsigned long message, |
2234 | kernel_siginfo_t *info) | |
b8401150 NK |
2235 | __releases(¤t->sighand->siglock) |
2236 | __acquires(¤t->sighand->siglock) | |
1da177e4 | 2237 | { |
ceb6bd67 TH |
2238 | bool gstop_done = false; |
2239 | ||
4f627af8 | 2240 | if (arch_ptrace_stop_needed()) { |
1a669c2f RM |
2241 | /* |
2242 | * The arch code has something special to do before a | |
2243 | * ptrace stop. This is allowed to block, e.g. for faults | |
2244 | * on user stack pages. We can't keep the siglock while | |
2245 | * calling arch_ptrace_stop, so we must release it now. | |
2246 | * To preserve proper semantics, we must do this before | |
2247 | * any signal bookkeeping like checking group_stop_count. | |
1a669c2f RM |
2248 | */ |
2249 | spin_unlock_irq(¤t->sighand->siglock); | |
4f627af8 | 2250 | arch_ptrace_stop(); |
1a669c2f | 2251 | spin_lock_irq(¤t->sighand->siglock); |
1a669c2f RM |
2252 | } |
2253 | ||
7d613f9f | 2254 | /* |
2500ad1c EB |
2255 | * After this point ptrace_signal_wake_up or signal_wake_up |
2256 | * will clear TASK_TRACED if ptrace_unlink happens or a fatal | |
2257 | * signal comes in. Handle previous ptrace_unlinks and fatal | |
2258 | * signals here to prevent ptrace_stop sleeping in schedule. | |
7d613f9f | 2259 | */ |
2500ad1c | 2260 | if (!current->ptrace || __fatal_signal_pending(current)) |
57b6de08 EB |
2261 | return exit_code; |
2262 | ||
b5bf9a90 | 2263 | set_special_state(TASK_TRACED); |
31cae1ea | 2264 | current->jobctl |= JOBCTL_TRACED; |
b5bf9a90 | 2265 | |
1da177e4 | 2266 | /* |
81be24b8 TH |
2267 | * We're committing to trapping. TRACED should be visible before |
2268 | * TRAPPING is cleared; otherwise, the tracer might fail do_wait(). | |
2269 | * Also, transition to TRACED and updates to ->jobctl should be | |
2270 | * atomic with respect to siglock and should be done after the arch | |
2271 | * hook as siglock is released and regrabbed across it. | |
b5bf9a90 PZ |
2272 | * |
2273 | * TRACER TRACEE | |
2274 | * | |
2275 | * ptrace_attach() | |
2276 | * [L] wait_on_bit(JOBCTL_TRAPPING) [S] set_special_state(TRACED) | |
2277 | * do_wait() | |
2278 | * set_current_state() smp_wmb(); | |
2279 | * ptrace_do_wait() | |
2280 | * wait_task_stopped() | |
2281 | * task_stopped_code() | |
2282 | * [L] task_is_traced() [S] task_clear_jobctl_trapping(); | |
1da177e4 | 2283 | */ |
b5bf9a90 | 2284 | smp_wmb(); |
1da177e4 | 2285 | |
336d4b81 | 2286 | current->ptrace_message = message; |
1da177e4 LT |
2287 | current->last_siginfo = info; |
2288 | current->exit_code = exit_code; | |
2289 | ||
d79fdd6d | 2290 | /* |
0ae8ce1c TH |
2291 | * If @why is CLD_STOPPED, we're trapping to participate in a group |
2292 | * stop. Do the bookkeeping. Note that if SIGCONT was delievered | |
73ddff2b TH |
2293 | * across siglock relocks since INTERRUPT was scheduled, PENDING |
2294 | * could be clear now. We act as if SIGCONT is received after | |
2295 | * TASK_TRACED is entered - ignore it. | |
d79fdd6d | 2296 | */ |
a8f072c1 | 2297 | if (why == CLD_STOPPED && (current->jobctl & JOBCTL_STOP_PENDING)) |
ceb6bd67 | 2298 | gstop_done = task_participate_group_stop(current); |
d79fdd6d | 2299 | |
fb1d910c | 2300 | /* any trap clears pending STOP trap, STOP trap clears NOTIFY */ |
73ddff2b | 2301 | task_clear_jobctl_pending(current, JOBCTL_TRAP_STOP); |
fb1d910c TH |
2302 | if (info && info->si_code >> 8 == PTRACE_EVENT_STOP) |
2303 | task_clear_jobctl_pending(current, JOBCTL_TRAP_NOTIFY); | |
73ddff2b | 2304 | |
81be24b8 | 2305 | /* entering a trap, clear TRAPPING */ |
a8f072c1 | 2306 | task_clear_jobctl_trapping(current); |
d79fdd6d | 2307 | |
1da177e4 LT |
2308 | spin_unlock_irq(¤t->sighand->siglock); |
2309 | read_lock(&tasklist_lock); | |
57b6de08 EB |
2310 | /* |
2311 | * Notify parents of the stop. | |
2312 | * | |
2313 | * While ptraced, there are two parents - the ptracer and | |
2314 | * the real_parent of the group_leader. The ptracer should | |
2315 | * know about every stop while the real parent is only | |
2316 | * interested in the completion of group stop. The states | |
2317 | * for the two don't interact with each other. Notify | |
2318 | * separately unless they're gonna be duplicates. | |
2319 | */ | |
2320 | if (current->ptrace) | |
ceb6bd67 | 2321 | do_notify_parent_cldstop(current, true, why); |
57b6de08 EB |
2322 | if (gstop_done && (!current->ptrace || ptrace_reparented(current))) |
2323 | do_notify_parent_cldstop(current, false, why); | |
ceb6bd67 | 2324 | |
57b6de08 | 2325 | /* |
a20d6f63 SAS |
2326 | * The previous do_notify_parent_cldstop() invocation woke ptracer. |
2327 | * One a PREEMPTION kernel this can result in preemption requirement | |
2328 | * which will be fulfilled after read_unlock() and the ptracer will be | |
2329 | * put on the CPU. | |
2330 | * The ptracer is in wait_task_inactive(, __TASK_TRACED) waiting for | |
2331 | * this task wait in schedule(). If this task gets preempted then it | |
2332 | * remains enqueued on the runqueue. The ptracer will observe this and | |
2333 | * then sleep for a delay of one HZ tick. In the meantime this task | |
2334 | * gets scheduled, enters schedule() and will wait for the ptracer. | |
57b6de08 | 2335 | * |
a20d6f63 SAS |
2336 | * This preemption point is not bad from a correctness point of |
2337 | * view but extends the runtime by one HZ tick time due to the | |
2338 | * ptracer's sleep. The preempt-disable section ensures that there | |
2339 | * will be no preemption between unlock and schedule() and so | |
2340 | * improving the performance since the ptracer will observe that | |
2341 | * the tracee is scheduled out once it gets on the CPU. | |
1aabbc53 SAS |
2342 | * |
2343 | * On PREEMPT_RT locking tasklist_lock does not disable preemption. | |
2344 | * Therefore the task can be preempted after do_notify_parent_cldstop() | |
2345 | * before unlocking tasklist_lock so there is no benefit in doing this. | |
2346 | * | |
2347 | * In fact disabling preemption is harmful on PREEMPT_RT because | |
2348 | * the spinlock_t in cgroup_enter_frozen() must not be acquired | |
2349 | * with preemption disabled due to the 'sleeping' spinlock | |
2350 | * substitution of RT. | |
57b6de08 | 2351 | */ |
1aabbc53 SAS |
2352 | if (!IS_ENABLED(CONFIG_PREEMPT_RT)) |
2353 | preempt_disable(); | |
57b6de08 EB |
2354 | read_unlock(&tasklist_lock); |
2355 | cgroup_enter_frozen(); | |
1aabbc53 SAS |
2356 | if (!IS_ENABLED(CONFIG_PREEMPT_RT)) |
2357 | preempt_enable_no_resched(); | |
f5d39b02 | 2358 | schedule(); |
57b6de08 | 2359 | cgroup_leave_frozen(true); |
1da177e4 LT |
2360 | |
2361 | /* | |
2362 | * We are back. Now reacquire the siglock before touching | |
2363 | * last_siginfo, so that we are sure to have synchronized with | |
2364 | * any signal-sending on another CPU that wants to examine it. | |
2365 | */ | |
2366 | spin_lock_irq(¤t->sighand->siglock); | |
57b6de08 | 2367 | exit_code = current->exit_code; |
1da177e4 | 2368 | current->last_siginfo = NULL; |
336d4b81 | 2369 | current->ptrace_message = 0; |
6487d1da | 2370 | current->exit_code = 0; |
1da177e4 | 2371 | |
544b2c91 | 2372 | /* LISTENING can be set only during STOP traps, clear it */ |
2500ad1c | 2373 | current->jobctl &= ~(JOBCTL_LISTENING | JOBCTL_PTRACE_FROZEN); |
544b2c91 | 2374 | |
1da177e4 LT |
2375 | /* |
2376 | * Queued signals ignored us while we were stopped for tracing. | |
2377 | * So check for any that we should take before resuming user mode. | |
b74d0deb | 2378 | * This sets TIF_SIGPENDING, but never clears it. |
1da177e4 | 2379 | */ |
b74d0deb | 2380 | recalc_sigpending_tsk(current); |
6487d1da | 2381 | return exit_code; |
1da177e4 LT |
2382 | } |
2383 | ||
6487d1da | 2384 | static int ptrace_do_notify(int signr, int exit_code, int why, unsigned long message) |
1da177e4 | 2385 | { |
ae7795bc | 2386 | kernel_siginfo_t info; |
1da177e4 | 2387 | |
faf1f22b | 2388 | clear_siginfo(&info); |
3544d72a | 2389 | info.si_signo = signr; |
1da177e4 | 2390 | info.si_code = exit_code; |
b488893a | 2391 | info.si_pid = task_pid_vnr(current); |
078de5f7 | 2392 | info.si_uid = from_kuid_munged(current_user_ns(), current_uid()); |
1da177e4 LT |
2393 | |
2394 | /* Let the debugger run. */ | |
57b6de08 | 2395 | return ptrace_stop(exit_code, why, message, &info); |
3544d72a TH |
2396 | } |
2397 | ||
6487d1da | 2398 | int ptrace_notify(int exit_code, unsigned long message) |
3544d72a | 2399 | { |
6487d1da EB |
2400 | int signr; |
2401 | ||
3544d72a | 2402 | BUG_ON((exit_code & (0x7f | ~0xffff)) != SIGTRAP); |
7f62d40d | 2403 | if (unlikely(task_work_pending(current))) |
f784e8a7 | 2404 | task_work_run(); |
3544d72a | 2405 | |
1da177e4 | 2406 | spin_lock_irq(¤t->sighand->siglock); |
6487d1da | 2407 | signr = ptrace_do_notify(SIGTRAP, exit_code, CLD_TRAPPED, message); |
1da177e4 | 2408 | spin_unlock_irq(¤t->sighand->siglock); |
6487d1da | 2409 | return signr; |
1da177e4 LT |
2410 | } |
2411 | ||
73ddff2b TH |
2412 | /** |
2413 | * do_signal_stop - handle group stop for SIGSTOP and other stop signals | |
2414 | * @signr: signr causing group stop if initiating | |
2415 | * | |
2416 | * If %JOBCTL_STOP_PENDING is not set yet, initiate group stop with @signr | |
2417 | * and participate in it. If already set, participate in the existing | |
2418 | * group stop. If participated in a group stop (and thus slept), %true is | |
2419 | * returned with siglock released. | |
2420 | * | |
2421 | * If ptraced, this function doesn't handle stop itself. Instead, | |
2422 | * %JOBCTL_TRAP_STOP is scheduled and %false is returned with siglock | |
2423 | * untouched. The caller must ensure that INTERRUPT trap handling takes | |
2424 | * places afterwards. | |
2425 | * | |
2426 | * CONTEXT: | |
2427 | * Must be called with @current->sighand->siglock held, which is released | |
2428 | * on %true return. | |
2429 | * | |
2430 | * RETURNS: | |
2431 | * %false if group stop is already cancelled or ptrace trap is scheduled. | |
2432 | * %true if participated in group stop. | |
1da177e4 | 2433 | */ |
73ddff2b TH |
2434 | static bool do_signal_stop(int signr) |
2435 | __releases(¤t->sighand->siglock) | |
1da177e4 LT |
2436 | { |
2437 | struct signal_struct *sig = current->signal; | |
1da177e4 | 2438 | |
a8f072c1 | 2439 | if (!(current->jobctl & JOBCTL_STOP_PENDING)) { |
b76808e6 | 2440 | unsigned long gstop = JOBCTL_STOP_PENDING | JOBCTL_STOP_CONSUME; |
f558b7e4 ON |
2441 | struct task_struct *t; |
2442 | ||
a8f072c1 TH |
2443 | /* signr will be recorded in task->jobctl for retries */ |
2444 | WARN_ON_ONCE(signr & ~JOBCTL_STOP_SIGMASK); | |
d79fdd6d | 2445 | |
a8f072c1 | 2446 | if (!likely(current->jobctl & JOBCTL_STOP_DEQUEUED) || |
49697335 EB |
2447 | unlikely(sig->flags & SIGNAL_GROUP_EXIT) || |
2448 | unlikely(sig->group_exec_task)) | |
73ddff2b | 2449 | return false; |
1da177e4 | 2450 | /* |
408a37de TH |
2451 | * There is no group stop already in progress. We must |
2452 | * initiate one now. | |
2453 | * | |
2454 | * While ptraced, a task may be resumed while group stop is | |
2455 | * still in effect and then receive a stop signal and | |
2456 | * initiate another group stop. This deviates from the | |
2457 | * usual behavior as two consecutive stop signals can't | |
780006ea ON |
2458 | * cause two group stops when !ptraced. That is why we |
2459 | * also check !task_is_stopped(t) below. | |
408a37de TH |
2460 | * |
2461 | * The condition can be distinguished by testing whether | |
2462 | * SIGNAL_STOP_STOPPED is already set. Don't generate | |
2463 | * group_exit_code in such case. | |
2464 | * | |
2465 | * This is not necessary for SIGNAL_STOP_CONTINUED because | |
2466 | * an intervening stop signal is required to cause two | |
2467 | * continued events regardless of ptrace. | |
1da177e4 | 2468 | */ |
408a37de TH |
2469 | if (!(sig->flags & SIGNAL_STOP_STOPPED)) |
2470 | sig->group_exit_code = signr; | |
1da177e4 | 2471 | |
7dd3db54 | 2472 | sig->group_stop_count = 0; |
7dd3db54 TH |
2473 | if (task_set_jobctl_pending(current, signr | gstop)) |
2474 | sig->group_stop_count++; | |
1da177e4 | 2475 | |
61a7a5e2 | 2476 | for_other_threads(current, t) { |
1da177e4 | 2477 | /* |
a122b341 ON |
2478 | * Setting state to TASK_STOPPED for a group |
2479 | * stop is always done with the siglock held, | |
2480 | * so this check has no races. | |
1da177e4 | 2481 | */ |
7dd3db54 TH |
2482 | if (!task_is_stopped(t) && |
2483 | task_set_jobctl_pending(t, signr | gstop)) { | |
ae6d2ed7 | 2484 | sig->group_stop_count++; |
fb1d910c TH |
2485 | if (likely(!(t->ptrace & PT_SEIZED))) |
2486 | signal_wake_up(t, 0); | |
2487 | else | |
2488 | ptrace_trap_notify(t); | |
a122b341 | 2489 | } |
d79fdd6d | 2490 | } |
1da177e4 | 2491 | } |
73ddff2b | 2492 | |
d21142ec | 2493 | if (likely(!current->ptrace)) { |
5224fa36 | 2494 | int notify = 0; |
1da177e4 | 2495 | |
5224fa36 TH |
2496 | /* |
2497 | * If there are no other threads in the group, or if there | |
2498 | * is a group stop in progress and we are the last to stop, | |
2499 | * report to the parent. | |
2500 | */ | |
2501 | if (task_participate_group_stop(current)) | |
2502 | notify = CLD_STOPPED; | |
2503 | ||
31cae1ea | 2504 | current->jobctl |= JOBCTL_STOPPED; |
b5bf9a90 | 2505 | set_special_state(TASK_STOPPED); |
5224fa36 TH |
2506 | spin_unlock_irq(¤t->sighand->siglock); |
2507 | ||
62bcf9d9 TH |
2508 | /* |
2509 | * Notify the parent of the group stop completion. Because | |
2510 | * we're not holding either the siglock or tasklist_lock | |
2511 | * here, ptracer may attach inbetween; however, this is for | |
2512 | * group stop and should always be delivered to the real | |
2513 | * parent of the group leader. The new ptracer will get | |
2514 | * its notification when this task transitions into | |
2515 | * TASK_TRACED. | |
2516 | */ | |
5224fa36 TH |
2517 | if (notify) { |
2518 | read_lock(&tasklist_lock); | |
62bcf9d9 | 2519 | do_notify_parent_cldstop(current, false, notify); |
5224fa36 TH |
2520 | read_unlock(&tasklist_lock); |
2521 | } | |
2522 | ||
2523 | /* Now we don't run again until woken by SIGCONT or SIGKILL */ | |
76f969e8 | 2524 | cgroup_enter_frozen(); |
f5d39b02 | 2525 | schedule(); |
73ddff2b | 2526 | return true; |
d79fdd6d | 2527 | } else { |
73ddff2b TH |
2528 | /* |
2529 | * While ptraced, group stop is handled by STOP trap. | |
2530 | * Schedule it and let the caller deal with it. | |
2531 | */ | |
2532 | task_set_jobctl_pending(current, JOBCTL_TRAP_STOP); | |
2533 | return false; | |
ae6d2ed7 | 2534 | } |
73ddff2b | 2535 | } |
1da177e4 | 2536 | |
73ddff2b TH |
2537 | /** |
2538 | * do_jobctl_trap - take care of ptrace jobctl traps | |
2539 | * | |
3544d72a TH |
2540 | * When PT_SEIZED, it's used for both group stop and explicit |
2541 | * SEIZE/INTERRUPT traps. Both generate PTRACE_EVENT_STOP trap with | |
2542 | * accompanying siginfo. If stopped, lower eight bits of exit_code contain | |
2543 | * the stop signal; otherwise, %SIGTRAP. | |
2544 | * | |
2545 | * When !PT_SEIZED, it's used only for group stop trap with stop signal | |
2546 | * number as exit_code and no siginfo. | |
73ddff2b TH |
2547 | * |
2548 | * CONTEXT: | |
2549 | * Must be called with @current->sighand->siglock held, which may be | |
2550 | * released and re-acquired before returning with intervening sleep. | |
2551 | */ | |
2552 | static void do_jobctl_trap(void) | |
2553 | { | |
3544d72a | 2554 | struct signal_struct *signal = current->signal; |
73ddff2b | 2555 | int signr = current->jobctl & JOBCTL_STOP_SIGMASK; |
ae6d2ed7 | 2556 | |
3544d72a TH |
2557 | if (current->ptrace & PT_SEIZED) { |
2558 | if (!signal->group_stop_count && | |
2559 | !(signal->flags & SIGNAL_STOP_STOPPED)) | |
2560 | signr = SIGTRAP; | |
2561 | WARN_ON_ONCE(!signr); | |
2562 | ptrace_do_notify(signr, signr | (PTRACE_EVENT_STOP << 8), | |
336d4b81 | 2563 | CLD_STOPPED, 0); |
3544d72a TH |
2564 | } else { |
2565 | WARN_ON_ONCE(!signr); | |
57b6de08 | 2566 | ptrace_stop(signr, CLD_STOPPED, 0, NULL); |
ae6d2ed7 | 2567 | } |
1da177e4 LT |
2568 | } |
2569 | ||
76f969e8 RG |
2570 | /** |
2571 | * do_freezer_trap - handle the freezer jobctl trap | |
2572 | * | |
2573 | * Puts the task into frozen state, if only the task is not about to quit. | |
2574 | * In this case it drops JOBCTL_TRAP_FREEZE. | |
2575 | * | |
2576 | * CONTEXT: | |
2577 | * Must be called with @current->sighand->siglock held, | |
2578 | * which is always released before returning. | |
2579 | */ | |
2580 | static void do_freezer_trap(void) | |
2581 | __releases(¤t->sighand->siglock) | |
2582 | { | |
2583 | /* | |
2584 | * If there are other trap bits pending except JOBCTL_TRAP_FREEZE, | |
2585 | * let's make another loop to give it a chance to be handled. | |
2586 | * In any case, we'll return back. | |
2587 | */ | |
2588 | if ((current->jobctl & (JOBCTL_PENDING_MASK | JOBCTL_TRAP_FREEZE)) != | |
2589 | JOBCTL_TRAP_FREEZE) { | |
2590 | spin_unlock_irq(¤t->sighand->siglock); | |
2591 | return; | |
2592 | } | |
2593 | ||
2594 | /* | |
2595 | * Now we're sure that there is no pending fatal signal and no | |
2596 | * pending traps. Clear TIF_SIGPENDING to not get out of schedule() | |
2597 | * immediately (if there is a non-fatal signal pending), and | |
2598 | * put the task into sleep. | |
2599 | */ | |
f5d39b02 | 2600 | __set_current_state(TASK_INTERRUPTIBLE|TASK_FREEZABLE); |
76f969e8 RG |
2601 | clear_thread_flag(TIF_SIGPENDING); |
2602 | spin_unlock_irq(¤t->sighand->siglock); | |
2603 | cgroup_enter_frozen(); | |
f5d39b02 | 2604 | schedule(); |
76f969e8 RG |
2605 | } |
2606 | ||
5768d890 | 2607 | static int ptrace_signal(int signr, kernel_siginfo_t *info, enum pid_type type) |
18c98b65 | 2608 | { |
8a352418 ON |
2609 | /* |
2610 | * We do not check sig_kernel_stop(signr) but set this marker | |
2611 | * unconditionally because we do not know whether debugger will | |
2612 | * change signr. This flag has no meaning unless we are going | |
2613 | * to stop after return from ptrace_stop(). In this case it will | |
2614 | * be checked in do_signal_stop(), we should only stop if it was | |
2615 | * not cleared by SIGCONT while we were sleeping. See also the | |
2616 | * comment in dequeue_signal(). | |
2617 | */ | |
2618 | current->jobctl |= JOBCTL_STOP_DEQUEUED; | |
57b6de08 | 2619 | signr = ptrace_stop(signr, CLD_TRAPPED, 0, info); |
18c98b65 RM |
2620 | |
2621 | /* We're back. Did the debugger cancel the sig? */ | |
18c98b65 RM |
2622 | if (signr == 0) |
2623 | return signr; | |
2624 | ||
5aba085e RD |
2625 | /* |
2626 | * Update the siginfo structure if the signal has | |
2627 | * changed. If the debugger wanted something | |
2628 | * specific in the siginfo structure then it should | |
2629 | * have updated *info via PTRACE_SETSIGINFO. | |
2630 | */ | |
18c98b65 | 2631 | if (signr != info->si_signo) { |
faf1f22b | 2632 | clear_siginfo(info); |
18c98b65 RM |
2633 | info->si_signo = signr; |
2634 | info->si_errno = 0; | |
2635 | info->si_code = SI_USER; | |
6b550f94 | 2636 | rcu_read_lock(); |
18c98b65 | 2637 | info->si_pid = task_pid_vnr(current->parent); |
54ba47ed EB |
2638 | info->si_uid = from_kuid_munged(current_user_ns(), |
2639 | task_uid(current->parent)); | |
6b550f94 | 2640 | rcu_read_unlock(); |
18c98b65 RM |
2641 | } |
2642 | ||
2643 | /* If the (new) signal is now blocked, requeue it. */ | |
b171f667 EB |
2644 | if (sigismember(¤t->blocked, signr) || |
2645 | fatal_signal_pending(current)) { | |
157cc181 | 2646 | send_signal_locked(signr, info, current, type); |
18c98b65 RM |
2647 | signr = 0; |
2648 | } | |
2649 | ||
2650 | return signr; | |
2651 | } | |
2652 | ||
6ac05e83 PC |
2653 | static void hide_si_addr_tag_bits(struct ksignal *ksig) |
2654 | { | |
2655 | switch (siginfo_layout(ksig->sig, ksig->info.si_code)) { | |
2656 | case SIL_FAULT: | |
9abcabe3 | 2657 | case SIL_FAULT_TRAPNO: |
6ac05e83 PC |
2658 | case SIL_FAULT_MCEERR: |
2659 | case SIL_FAULT_BNDERR: | |
2660 | case SIL_FAULT_PKUERR: | |
f4ac7302 | 2661 | case SIL_FAULT_PERF_EVENT: |
6ac05e83 PC |
2662 | ksig->info.si_addr = arch_untagged_si_addr( |
2663 | ksig->info.si_addr, ksig->sig, ksig->info.si_code); | |
2664 | break; | |
2665 | case SIL_KILL: | |
2666 | case SIL_TIMER: | |
2667 | case SIL_POLL: | |
2668 | case SIL_CHLD: | |
2669 | case SIL_RT: | |
2670 | case SIL_SYS: | |
2671 | break; | |
2672 | } | |
2673 | } | |
2674 | ||
20ab7218 | 2675 | bool get_signal(struct ksignal *ksig) |
1da177e4 | 2676 | { |
f6b76d4f ON |
2677 | struct sighand_struct *sighand = current->sighand; |
2678 | struct signal_struct *signal = current->signal; | |
2679 | int signr; | |
1da177e4 | 2680 | |
8ba62d37 | 2681 | clear_notify_signal(); |
7f62d40d | 2682 | if (unlikely(task_work_pending(current))) |
35d0b389 JA |
2683 | task_work_run(); |
2684 | ||
8ba62d37 EB |
2685 | if (!task_sigpending(current)) |
2686 | return false; | |
12db8b69 | 2687 | |
0326f5a9 | 2688 | if (unlikely(uprobe_deny_signal())) |
20ab7218 | 2689 | return false; |
0326f5a9 | 2690 | |
13b1c3d4 | 2691 | /* |
5d8f72b5 ON |
2692 | * Do this once, we can't return to user-mode if freezing() == T. |
2693 | * do_signal_stop() and ptrace_stop() do freezable_schedule() and | |
2694 | * thus do not need another check after return. | |
13b1c3d4 | 2695 | */ |
fc558a74 RW |
2696 | try_to_freeze(); |
2697 | ||
5d8f72b5 | 2698 | relock: |
f6b76d4f | 2699 | spin_lock_irq(&sighand->siglock); |
e91b4816 | 2700 | |
021e1ae3 ON |
2701 | /* |
2702 | * Every stopped thread goes here after wakeup. Check to see if | |
2703 | * we should notify the parent, prepare_signal(SIGCONT) encodes | |
2704 | * the CLD_ si_code into SIGNAL_CLD_MASK bits. | |
2705 | */ | |
f6b76d4f | 2706 | if (unlikely(signal->flags & SIGNAL_CLD_MASK)) { |
c672af35 TH |
2707 | int why; |
2708 | ||
2709 | if (signal->flags & SIGNAL_CLD_CONTINUED) | |
2710 | why = CLD_CONTINUED; | |
2711 | else | |
2712 | why = CLD_STOPPED; | |
2713 | ||
f6b76d4f | 2714 | signal->flags &= ~SIGNAL_CLD_MASK; |
e4420551 | 2715 | |
ae6d2ed7 | 2716 | spin_unlock_irq(&sighand->siglock); |
fa00b80b | 2717 | |
ceb6bd67 TH |
2718 | /* |
2719 | * Notify the parent that we're continuing. This event is | |
2720 | * always per-process and doesn't make whole lot of sense | |
2721 | * for ptracers, who shouldn't consume the state via | |
2722 | * wait(2) either, but, for backward compatibility, notify | |
2723 | * the ptracer of the group leader too unless it's gonna be | |
2724 | * a duplicate. | |
2725 | */ | |
edf2ed15 | 2726 | read_lock(&tasklist_lock); |
ceb6bd67 TH |
2727 | do_notify_parent_cldstop(current, false, why); |
2728 | ||
bb3696da ON |
2729 | if (ptrace_reparented(current->group_leader)) |
2730 | do_notify_parent_cldstop(current->group_leader, | |
2731 | true, why); | |
edf2ed15 | 2732 | read_unlock(&tasklist_lock); |
ceb6bd67 | 2733 | |
e4420551 ON |
2734 | goto relock; |
2735 | } | |
2736 | ||
1da177e4 LT |
2737 | for (;;) { |
2738 | struct k_sigaction *ka; | |
5768d890 | 2739 | enum pid_type type; |
1be53963 | 2740 | |
e7f7c99b | 2741 | /* Has this task already been marked for death? */ |
49697335 EB |
2742 | if ((signal->flags & SIGNAL_GROUP_EXIT) || |
2743 | signal->group_exec_task) { | |
a436184e | 2744 | signr = SIGKILL; |
e7f7c99b EB |
2745 | sigdelset(¤t->pending.signal, SIGKILL); |
2746 | trace_signal_deliver(SIGKILL, SEND_SIG_NOINFO, | |
a436184e | 2747 | &sighand->action[SIGKILL-1]); |
e7f7c99b | 2748 | recalc_sigpending(); |
a436184e ON |
2749 | /* |
2750 | * implies do_group_exit() or return to PF_USER_WORKER, | |
2751 | * no need to initialize ksig->info/etc. | |
2752 | */ | |
e7f7c99b EB |
2753 | goto fatal; |
2754 | } | |
1be53963 | 2755 | |
dd1d6772 TH |
2756 | if (unlikely(current->jobctl & JOBCTL_STOP_PENDING) && |
2757 | do_signal_stop(0)) | |
7bcf6a2c | 2758 | goto relock; |
1be53963 | 2759 | |
76f969e8 RG |
2760 | if (unlikely(current->jobctl & |
2761 | (JOBCTL_TRAP_MASK | JOBCTL_TRAP_FREEZE))) { | |
2762 | if (current->jobctl & JOBCTL_TRAP_MASK) { | |
2763 | do_jobctl_trap(); | |
2764 | spin_unlock_irq(&sighand->siglock); | |
2765 | } else if (current->jobctl & JOBCTL_TRAP_FREEZE) | |
2766 | do_freezer_trap(); | |
2767 | ||
2768 | goto relock; | |
2769 | } | |
2770 | ||
2771 | /* | |
2772 | * If the task is leaving the frozen state, let's update | |
2773 | * cgroup counters and reset the frozen bit. | |
2774 | */ | |
2775 | if (unlikely(cgroup_task_frozen(current))) { | |
73ddff2b | 2776 | spin_unlock_irq(&sighand->siglock); |
cb2c4cd8 | 2777 | cgroup_leave_frozen(false); |
73ddff2b TH |
2778 | goto relock; |
2779 | } | |
1da177e4 | 2780 | |
7146db33 EB |
2781 | /* |
2782 | * Signals generated by the execution of an instruction | |
2783 | * need to be delivered before any other pending signals | |
2784 | * so that the instruction pointer in the signal stack | |
2785 | * frame points to the faulting instruction. | |
2786 | */ | |
5768d890 | 2787 | type = PIDTYPE_PID; |
7146db33 EB |
2788 | signr = dequeue_synchronous_signal(&ksig->info); |
2789 | if (!signr) | |
5768d890 EB |
2790 | signr = dequeue_signal(current, ¤t->blocked, |
2791 | &ksig->info, &type); | |
7bcf6a2c | 2792 | |
dd1d6772 TH |
2793 | if (!signr) |
2794 | break; /* will return 0 */ | |
7bcf6a2c | 2795 | |
00b06da2 EB |
2796 | if (unlikely(current->ptrace) && (signr != SIGKILL) && |
2797 | !(sighand->action[signr -1].sa.sa_flags & SA_IMMUTABLE)) { | |
5768d890 | 2798 | signr = ptrace_signal(signr, &ksig->info, type); |
dd1d6772 TH |
2799 | if (!signr) |
2800 | continue; | |
1da177e4 LT |
2801 | } |
2802 | ||
dd1d6772 TH |
2803 | ka = &sighand->action[signr-1]; |
2804 | ||
f9d4257e | 2805 | /* Trace actually delivered signals. */ |
828b1f65 | 2806 | trace_signal_deliver(signr, &ksig->info, ka); |
f9d4257e | 2807 | |
1da177e4 LT |
2808 | if (ka->sa.sa_handler == SIG_IGN) /* Do nothing. */ |
2809 | continue; | |
2810 | if (ka->sa.sa_handler != SIG_DFL) { | |
2811 | /* Run the handler. */ | |
828b1f65 | 2812 | ksig->ka = *ka; |
1da177e4 LT |
2813 | |
2814 | if (ka->sa.sa_flags & SA_ONESHOT) | |
2815 | ka->sa.sa_handler = SIG_DFL; | |
2816 | ||
2817 | break; /* will return non-zero "signr" value */ | |
2818 | } | |
2819 | ||
2820 | /* | |
2821 | * Now we are doing the default action for this signal. | |
2822 | */ | |
2823 | if (sig_kernel_ignore(signr)) /* Default is nothing. */ | |
2824 | continue; | |
2825 | ||
84d73786 | 2826 | /* |
0fbc26a6 | 2827 | * Global init gets no signals it doesn't want. |
b3bfa0cb SB |
2828 | * Container-init gets no signals it doesn't want from same |
2829 | * container. | |
2830 | * | |
2831 | * Note that if global/container-init sees a sig_kernel_only() | |
2832 | * signal here, the signal must have been generated internally | |
2833 | * or must have come from an ancestor namespace. In either | |
2834 | * case, the signal cannot be dropped. | |
84d73786 | 2835 | */ |
fae5fa44 | 2836 | if (unlikely(signal->flags & SIGNAL_UNKILLABLE) && |
b3bfa0cb | 2837 | !sig_kernel_only(signr)) |
1da177e4 LT |
2838 | continue; |
2839 | ||
2840 | if (sig_kernel_stop(signr)) { | |
2841 | /* | |
2842 | * The default action is to stop all threads in | |
2843 | * the thread group. The job control signals | |
2844 | * do nothing in an orphaned pgrp, but SIGSTOP | |
2845 | * always works. Note that siglock needs to be | |
2846 | * dropped during the call to is_orphaned_pgrp() | |
2847 | * because of lock ordering with tasklist_lock. | |
2848 | * This allows an intervening SIGCONT to be posted. | |
2849 | * We need to check for that and bail out if necessary. | |
2850 | */ | |
2851 | if (signr != SIGSTOP) { | |
f6b76d4f | 2852 | spin_unlock_irq(&sighand->siglock); |
1da177e4 LT |
2853 | |
2854 | /* signals can be posted during this window */ | |
2855 | ||
3e7cd6c4 | 2856 | if (is_current_pgrp_orphaned()) |
1da177e4 LT |
2857 | goto relock; |
2858 | ||
f6b76d4f | 2859 | spin_lock_irq(&sighand->siglock); |
1da177e4 LT |
2860 | } |
2861 | ||
49fd5f5a | 2862 | if (likely(do_signal_stop(signr))) { |
1da177e4 LT |
2863 | /* It released the siglock. */ |
2864 | goto relock; | |
2865 | } | |
2866 | ||
2867 | /* | |
2868 | * We didn't actually stop, due to a race | |
2869 | * with SIGCONT or something like that. | |
2870 | */ | |
2871 | continue; | |
2872 | } | |
2873 | ||
35634ffa | 2874 | fatal: |
f6b76d4f | 2875 | spin_unlock_irq(&sighand->siglock); |
f2b31bb5 RG |
2876 | if (unlikely(cgroup_task_frozen(current))) |
2877 | cgroup_leave_frozen(true); | |
1da177e4 LT |
2878 | |
2879 | /* | |
2880 | * Anything else is fatal, maybe with a core dump. | |
2881 | */ | |
2882 | current->flags |= PF_SIGNALED; | |
2dce81bf | 2883 | |
1da177e4 | 2884 | if (sig_kernel_coredump(signr)) { |
2dce81bf | 2885 | if (print_fatal_signals) |
49fd5f5a | 2886 | print_fatal_signal(signr); |
2b5faa4c | 2887 | proc_coredump_connector(current); |
1da177e4 LT |
2888 | /* |
2889 | * If it was able to dump core, this kills all | |
2890 | * other threads in the group and synchronizes with | |
2891 | * their demise. If we lost the race with another | |
2892 | * thread getting here, it set group_exit_code | |
2893 | * first and our do_group_exit call below will use | |
2894 | * that value and ignore the one we pass it. | |
2895 | */ | |
828b1f65 | 2896 | do_coredump(&ksig->info); |
1da177e4 LT |
2897 | } |
2898 | ||
10442994 | 2899 | /* |
f9010dbd | 2900 | * PF_USER_WORKER threads will catch and exit on fatal signals |
dd69edd6 ON |
2901 | * themselves. They have cleanup that must be performed, so we |
2902 | * cannot call do_exit() on their behalf. Note that ksig won't | |
2903 | * be properly initialized, PF_USER_WORKER's shouldn't use it. | |
10442994 | 2904 | */ |
f9010dbd | 2905 | if (current->flags & PF_USER_WORKER) |
10442994 JA |
2906 | goto out; |
2907 | ||
1da177e4 LT |
2908 | /* |
2909 | * Death signals, no core dump. | |
2910 | */ | |
49fd5f5a | 2911 | do_group_exit(signr); |
1da177e4 LT |
2912 | /* NOTREACHED */ |
2913 | } | |
f6b76d4f | 2914 | spin_unlock_irq(&sighand->siglock); |
dd69edd6 | 2915 | |
828b1f65 | 2916 | ksig->sig = signr; |
6ac05e83 | 2917 | |
dd69edd6 | 2918 | if (signr && !(ksig->ka.sa.sa_flags & SA_EXPOSE_TAGBITS)) |
6ac05e83 | 2919 | hide_si_addr_tag_bits(ksig); |
dd69edd6 | 2920 | out: |
49fd5f5a | 2921 | return signr > 0; |
1da177e4 LT |
2922 | } |
2923 | ||
5e6292c0 | 2924 | /** |
6410349e | 2925 | * signal_delivered - called after signal delivery to update blocked signals |
10b1c7ac | 2926 | * @ksig: kernel signal struct |
efee984c | 2927 | * @stepping: nonzero if debugger single-step or block-step in use |
5e6292c0 | 2928 | * |
e227867f | 2929 | * This function should be called when a signal has successfully been |
10b1c7ac | 2930 | * delivered. It updates the blocked signals accordingly (@ksig->ka.sa.sa_mask |
6410349e | 2931 | * is always blocked), and the signal itself is blocked unless %SA_NODEFER |
10b1c7ac | 2932 | * is set in @ksig->ka.sa.sa_flags. Tracing is notified. |
5e6292c0 | 2933 | */ |
10b1c7ac | 2934 | static void signal_delivered(struct ksignal *ksig, int stepping) |
5e6292c0 MF |
2935 | { |
2936 | sigset_t blocked; | |
2937 | ||
a610d6e6 AV |
2938 | /* A signal was successfully delivered, and the |
2939 | saved sigmask was stored on the signal frame, | |
2940 | and will be restored by sigreturn. So we can | |
2941 | simply clear the restore sigmask flag. */ | |
2942 | clear_restore_sigmask(); | |
2943 | ||
10b1c7ac RW |
2944 | sigorsets(&blocked, ¤t->blocked, &ksig->ka.sa.sa_mask); |
2945 | if (!(ksig->ka.sa.sa_flags & SA_NODEFER)) | |
2946 | sigaddset(&blocked, ksig->sig); | |
5e6292c0 | 2947 | set_current_blocked(&blocked); |
97c885d5 AV |
2948 | if (current->sas_ss_flags & SS_AUTODISARM) |
2949 | sas_ss_reset(current); | |
c145137d | 2950 | if (stepping) |
336d4b81 | 2951 | ptrace_notify(SIGTRAP, 0); |
5e6292c0 MF |
2952 | } |
2953 | ||
2ce5da17 AV |
2954 | void signal_setup_done(int failed, struct ksignal *ksig, int stepping) |
2955 | { | |
2956 | if (failed) | |
cb44c9a0 | 2957 | force_sigsegv(ksig->sig); |
2ce5da17 | 2958 | else |
10b1c7ac | 2959 | signal_delivered(ksig, stepping); |
2ce5da17 AV |
2960 | } |
2961 | ||
0edceb7b ON |
2962 | /* |
2963 | * It could be that complete_signal() picked us to notify about the | |
fec9993d ON |
2964 | * group-wide signal. Other threads should be notified now to take |
2965 | * the shared signals in @which since we will not. | |
0edceb7b | 2966 | */ |
f646e227 | 2967 | static void retarget_shared_pending(struct task_struct *tsk, sigset_t *which) |
0edceb7b | 2968 | { |
f646e227 | 2969 | sigset_t retarget; |
0edceb7b ON |
2970 | struct task_struct *t; |
2971 | ||
f646e227 ON |
2972 | sigandsets(&retarget, &tsk->signal->shared_pending.signal, which); |
2973 | if (sigisemptyset(&retarget)) | |
2974 | return; | |
2975 | ||
61a7a5e2 | 2976 | for_other_threads(tsk, t) { |
fec9993d ON |
2977 | if (t->flags & PF_EXITING) |
2978 | continue; | |
2979 | ||
2980 | if (!has_pending_signals(&retarget, &t->blocked)) | |
2981 | continue; | |
2982 | /* Remove the signals this thread can handle. */ | |
2983 | sigandsets(&retarget, &retarget, &t->blocked); | |
2984 | ||
5c251e9d | 2985 | if (!task_sigpending(t)) |
fec9993d ON |
2986 | signal_wake_up(t, 0); |
2987 | ||
2988 | if (sigisemptyset(&retarget)) | |
2989 | break; | |
0edceb7b ON |
2990 | } |
2991 | } | |
2992 | ||
d12619b5 ON |
2993 | void exit_signals(struct task_struct *tsk) |
2994 | { | |
2995 | int group_stop = 0; | |
f646e227 | 2996 | sigset_t unblocked; |
d12619b5 | 2997 | |
77e4ef99 TH |
2998 | /* |
2999 | * @tsk is about to have PF_EXITING set - lock out users which | |
3000 | * expect stable threadgroup. | |
3001 | */ | |
780de9dd | 3002 | cgroup_threadgroup_change_begin(tsk); |
77e4ef99 | 3003 | |
49697335 | 3004 | if (thread_group_empty(tsk) || (tsk->signal->flags & SIGNAL_GROUP_EXIT)) { |
af7f588d | 3005 | sched_mm_cid_exit_signals(tsk); |
5dee1707 | 3006 | tsk->flags |= PF_EXITING; |
780de9dd | 3007 | cgroup_threadgroup_change_end(tsk); |
5dee1707 | 3008 | return; |
d12619b5 ON |
3009 | } |
3010 | ||
5dee1707 | 3011 | spin_lock_irq(&tsk->sighand->siglock); |
d12619b5 ON |
3012 | /* |
3013 | * From now this task is not visible for group-wide signals, | |
3014 | * see wants_signal(), do_signal_stop(). | |
3015 | */ | |
af7f588d | 3016 | sched_mm_cid_exit_signals(tsk); |
d12619b5 | 3017 | tsk->flags |= PF_EXITING; |
77e4ef99 | 3018 | |
780de9dd | 3019 | cgroup_threadgroup_change_end(tsk); |
77e4ef99 | 3020 | |
5c251e9d | 3021 | if (!task_sigpending(tsk)) |
5dee1707 ON |
3022 | goto out; |
3023 | ||
f646e227 ON |
3024 | unblocked = tsk->blocked; |
3025 | signotset(&unblocked); | |
3026 | retarget_shared_pending(tsk, &unblocked); | |
5dee1707 | 3027 | |
a8f072c1 | 3028 | if (unlikely(tsk->jobctl & JOBCTL_STOP_PENDING) && |
e5c1902e | 3029 | task_participate_group_stop(tsk)) |
edf2ed15 | 3030 | group_stop = CLD_STOPPED; |
5dee1707 | 3031 | out: |
d12619b5 ON |
3032 | spin_unlock_irq(&tsk->sighand->siglock); |
3033 | ||
62bcf9d9 TH |
3034 | /* |
3035 | * If group stop has completed, deliver the notification. This | |
3036 | * should always go to the real parent of the group leader. | |
3037 | */ | |
ae6d2ed7 | 3038 | if (unlikely(group_stop)) { |
d12619b5 | 3039 | read_lock(&tasklist_lock); |
62bcf9d9 | 3040 | do_notify_parent_cldstop(tsk, false, group_stop); |
d12619b5 ON |
3041 | read_unlock(&tasklist_lock); |
3042 | } | |
3043 | } | |
3044 | ||
1da177e4 LT |
3045 | /* |
3046 | * System call entry points. | |
3047 | */ | |
3048 | ||
41c57892 RD |
3049 | /** |
3050 | * sys_restart_syscall - restart a system call | |
3051 | */ | |
754fe8d2 | 3052 | SYSCALL_DEFINE0(restart_syscall) |
1da177e4 | 3053 | { |
f56141e3 | 3054 | struct restart_block *restart = ¤t->restart_block; |
1da177e4 LT |
3055 | return restart->fn(restart); |
3056 | } | |
3057 | ||
3058 | long do_no_restart_syscall(struct restart_block *param) | |
3059 | { | |
3060 | return -EINTR; | |
3061 | } | |
3062 | ||
b182801a ON |
3063 | static void __set_task_blocked(struct task_struct *tsk, const sigset_t *newset) |
3064 | { | |
5c251e9d | 3065 | if (task_sigpending(tsk) && !thread_group_empty(tsk)) { |
b182801a ON |
3066 | sigset_t newblocked; |
3067 | /* A set of now blocked but previously unblocked signals. */ | |
702a5073 | 3068 | sigandnsets(&newblocked, newset, ¤t->blocked); |
b182801a ON |
3069 | retarget_shared_pending(tsk, &newblocked); |
3070 | } | |
3071 | tsk->blocked = *newset; | |
3072 | recalc_sigpending(); | |
3073 | } | |
3074 | ||
e6fa16ab ON |
3075 | /** |
3076 | * set_current_blocked - change current->blocked mask | |
3077 | * @newset: new mask | |
3078 | * | |
3079 | * It is wrong to change ->blocked directly, this helper should be used | |
3080 | * to ensure the process can't miss a shared signal we are going to block. | |
1da177e4 | 3081 | */ |
77097ae5 AV |
3082 | void set_current_blocked(sigset_t *newset) |
3083 | { | |
77097ae5 | 3084 | sigdelsetmask(newset, sigmask(SIGKILL) | sigmask(SIGSTOP)); |
0c4a8423 | 3085 | __set_current_blocked(newset); |
77097ae5 AV |
3086 | } |
3087 | ||
3088 | void __set_current_blocked(const sigset_t *newset) | |
e6fa16ab ON |
3089 | { |
3090 | struct task_struct *tsk = current; | |
3091 | ||
c7be96af WL |
3092 | /* |
3093 | * In case the signal mask hasn't changed, there is nothing we need | |
3094 | * to do. The current->blocked shouldn't be modified by other task. | |
3095 | */ | |
3096 | if (sigequalsets(&tsk->blocked, newset)) | |
3097 | return; | |
3098 | ||
e6fa16ab | 3099 | spin_lock_irq(&tsk->sighand->siglock); |
b182801a | 3100 | __set_task_blocked(tsk, newset); |
e6fa16ab ON |
3101 | spin_unlock_irq(&tsk->sighand->siglock); |
3102 | } | |
1da177e4 LT |
3103 | |
3104 | /* | |
3105 | * This is also useful for kernel threads that want to temporarily | |
3106 | * (or permanently) block certain signals. | |
3107 | * | |
3108 | * NOTE! Unlike the user-mode sys_sigprocmask(), the kernel | |
3109 | * interface happily blocks "unblockable" signals like SIGKILL | |
3110 | * and friends. | |
3111 | */ | |
3112 | int sigprocmask(int how, sigset_t *set, sigset_t *oldset) | |
3113 | { | |
73ef4aeb ON |
3114 | struct task_struct *tsk = current; |
3115 | sigset_t newset; | |
1da177e4 | 3116 | |
73ef4aeb | 3117 | /* Lockless, only current can change ->blocked, never from irq */ |
a26fd335 | 3118 | if (oldset) |
73ef4aeb | 3119 | *oldset = tsk->blocked; |
a26fd335 | 3120 | |
1da177e4 LT |
3121 | switch (how) { |
3122 | case SIG_BLOCK: | |
73ef4aeb | 3123 | sigorsets(&newset, &tsk->blocked, set); |
1da177e4 LT |
3124 | break; |
3125 | case SIG_UNBLOCK: | |
702a5073 | 3126 | sigandnsets(&newset, &tsk->blocked, set); |
1da177e4 LT |
3127 | break; |
3128 | case SIG_SETMASK: | |
73ef4aeb | 3129 | newset = *set; |
1da177e4 LT |
3130 | break; |
3131 | default: | |
73ef4aeb | 3132 | return -EINVAL; |
1da177e4 | 3133 | } |
a26fd335 | 3134 | |
77097ae5 | 3135 | __set_current_blocked(&newset); |
73ef4aeb | 3136 | return 0; |
1da177e4 | 3137 | } |
fb50f5a4 | 3138 | EXPORT_SYMBOL(sigprocmask); |
1da177e4 | 3139 | |
ded653cc DD |
3140 | /* |
3141 | * The api helps set app-provided sigmasks. | |
3142 | * | |
3143 | * This is useful for syscalls such as ppoll, pselect, io_pgetevents and | |
3144 | * epoll_pwait where a new sigmask is passed from userland for the syscalls. | |
b772434b ON |
3145 | * |
3146 | * Note that it does set_restore_sigmask() in advance, so it must be always | |
3147 | * paired with restore_saved_sigmask_unless() before return from syscall. | |
ded653cc | 3148 | */ |
b772434b | 3149 | int set_user_sigmask(const sigset_t __user *umask, size_t sigsetsize) |
ded653cc | 3150 | { |
b772434b | 3151 | sigset_t kmask; |
ded653cc | 3152 | |
b772434b ON |
3153 | if (!umask) |
3154 | return 0; | |
ded653cc DD |
3155 | if (sigsetsize != sizeof(sigset_t)) |
3156 | return -EINVAL; | |
b772434b | 3157 | if (copy_from_user(&kmask, umask, sizeof(sigset_t))) |
ded653cc DD |
3158 | return -EFAULT; |
3159 | ||
b772434b ON |
3160 | set_restore_sigmask(); |
3161 | current->saved_sigmask = current->blocked; | |
3162 | set_current_blocked(&kmask); | |
ded653cc DD |
3163 | |
3164 | return 0; | |
3165 | } | |
ded653cc DD |
3166 | |
3167 | #ifdef CONFIG_COMPAT | |
b772434b | 3168 | int set_compat_user_sigmask(const compat_sigset_t __user *umask, |
ded653cc DD |
3169 | size_t sigsetsize) |
3170 | { | |
b772434b | 3171 | sigset_t kmask; |
ded653cc | 3172 | |
b772434b ON |
3173 | if (!umask) |
3174 | return 0; | |
ded653cc DD |
3175 | if (sigsetsize != sizeof(compat_sigset_t)) |
3176 | return -EINVAL; | |
b772434b | 3177 | if (get_compat_sigset(&kmask, umask)) |
ded653cc DD |
3178 | return -EFAULT; |
3179 | ||
b772434b ON |
3180 | set_restore_sigmask(); |
3181 | current->saved_sigmask = current->blocked; | |
3182 | set_current_blocked(&kmask); | |
ded653cc DD |
3183 | |
3184 | return 0; | |
3185 | } | |
ded653cc DD |
3186 | #endif |
3187 | ||
41c57892 RD |
3188 | /** |
3189 | * sys_rt_sigprocmask - change the list of currently blocked signals | |
3190 | * @how: whether to add, remove, or set signals | |
ada9c933 | 3191 | * @nset: stores pending signals |
41c57892 RD |
3192 | * @oset: previous value of signal mask if non-null |
3193 | * @sigsetsize: size of sigset_t type | |
3194 | */ | |
bb7efee2 | 3195 | SYSCALL_DEFINE4(rt_sigprocmask, int, how, sigset_t __user *, nset, |
17da2bd9 | 3196 | sigset_t __user *, oset, size_t, sigsetsize) |
1da177e4 | 3197 | { |
1da177e4 | 3198 | sigset_t old_set, new_set; |
bb7efee2 | 3199 | int error; |
1da177e4 LT |
3200 | |
3201 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
3202 | if (sigsetsize != sizeof(sigset_t)) | |
bb7efee2 | 3203 | return -EINVAL; |
1da177e4 | 3204 | |
bb7efee2 ON |
3205 | old_set = current->blocked; |
3206 | ||
3207 | if (nset) { | |
3208 | if (copy_from_user(&new_set, nset, sizeof(sigset_t))) | |
3209 | return -EFAULT; | |
1da177e4 LT |
3210 | sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); |
3211 | ||
bb7efee2 | 3212 | error = sigprocmask(how, &new_set, NULL); |
1da177e4 | 3213 | if (error) |
bb7efee2 ON |
3214 | return error; |
3215 | } | |
1da177e4 | 3216 | |
bb7efee2 ON |
3217 | if (oset) { |
3218 | if (copy_to_user(oset, &old_set, sizeof(sigset_t))) | |
3219 | return -EFAULT; | |
1da177e4 | 3220 | } |
bb7efee2 ON |
3221 | |
3222 | return 0; | |
1da177e4 LT |
3223 | } |
3224 | ||
322a56cb | 3225 | #ifdef CONFIG_COMPAT |
322a56cb AV |
3226 | COMPAT_SYSCALL_DEFINE4(rt_sigprocmask, int, how, compat_sigset_t __user *, nset, |
3227 | compat_sigset_t __user *, oset, compat_size_t, sigsetsize) | |
1da177e4 | 3228 | { |
322a56cb AV |
3229 | sigset_t old_set = current->blocked; |
3230 | ||
3231 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
3232 | if (sigsetsize != sizeof(sigset_t)) | |
3233 | return -EINVAL; | |
3234 | ||
3235 | if (nset) { | |
322a56cb AV |
3236 | sigset_t new_set; |
3237 | int error; | |
3968cf62 | 3238 | if (get_compat_sigset(&new_set, nset)) |
322a56cb | 3239 | return -EFAULT; |
322a56cb AV |
3240 | sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); |
3241 | ||
3242 | error = sigprocmask(how, &new_set, NULL); | |
3243 | if (error) | |
3244 | return error; | |
3245 | } | |
f454322e | 3246 | return oset ? put_compat_sigset(oset, &old_set, sizeof(*oset)) : 0; |
322a56cb AV |
3247 | } |
3248 | #endif | |
1da177e4 | 3249 | |
b1d294c8 | 3250 | static void do_sigpending(sigset_t *set) |
1da177e4 | 3251 | { |
1da177e4 | 3252 | spin_lock_irq(¤t->sighand->siglock); |
fe9c1db2 | 3253 | sigorsets(set, ¤t->pending.signal, |
1da177e4 LT |
3254 | ¤t->signal->shared_pending.signal); |
3255 | spin_unlock_irq(¤t->sighand->siglock); | |
3256 | ||
3257 | /* Outside the lock because only this thread touches it. */ | |
fe9c1db2 | 3258 | sigandsets(set, ¤t->blocked, set); |
5aba085e | 3259 | } |
1da177e4 | 3260 | |
41c57892 RD |
3261 | /** |
3262 | * sys_rt_sigpending - examine a pending signal that has been raised | |
3263 | * while blocked | |
20f22ab4 | 3264 | * @uset: stores pending signals |
41c57892 RD |
3265 | * @sigsetsize: size of sigset_t type or larger |
3266 | */ | |
fe9c1db2 | 3267 | SYSCALL_DEFINE2(rt_sigpending, sigset_t __user *, uset, size_t, sigsetsize) |
1da177e4 | 3268 | { |
fe9c1db2 | 3269 | sigset_t set; |
176826af DL |
3270 | |
3271 | if (sigsetsize > sizeof(*uset)) | |
3272 | return -EINVAL; | |
3273 | ||
b1d294c8 CB |
3274 | do_sigpending(&set); |
3275 | ||
3276 | if (copy_to_user(uset, &set, sigsetsize)) | |
3277 | return -EFAULT; | |
3278 | ||
3279 | return 0; | |
fe9c1db2 AV |
3280 | } |
3281 | ||
3282 | #ifdef CONFIG_COMPAT | |
fe9c1db2 AV |
3283 | COMPAT_SYSCALL_DEFINE2(rt_sigpending, compat_sigset_t __user *, uset, |
3284 | compat_size_t, sigsetsize) | |
1da177e4 | 3285 | { |
fe9c1db2 | 3286 | sigset_t set; |
176826af DL |
3287 | |
3288 | if (sigsetsize > sizeof(*uset)) | |
3289 | return -EINVAL; | |
3290 | ||
b1d294c8 CB |
3291 | do_sigpending(&set); |
3292 | ||
3293 | return put_compat_sigset(uset, &set, sigsetsize); | |
1da177e4 | 3294 | } |
fe9c1db2 | 3295 | #endif |
1da177e4 | 3296 | |
4ce5f9c9 EB |
3297 | static const struct { |
3298 | unsigned char limit, layout; | |
3299 | } sig_sicodes[] = { | |
3300 | [SIGILL] = { NSIGILL, SIL_FAULT }, | |
3301 | [SIGFPE] = { NSIGFPE, SIL_FAULT }, | |
3302 | [SIGSEGV] = { NSIGSEGV, SIL_FAULT }, | |
3303 | [SIGBUS] = { NSIGBUS, SIL_FAULT }, | |
3304 | [SIGTRAP] = { NSIGTRAP, SIL_FAULT }, | |
3305 | #if defined(SIGEMT) | |
3306 | [SIGEMT] = { NSIGEMT, SIL_FAULT }, | |
3307 | #endif | |
3308 | [SIGCHLD] = { NSIGCHLD, SIL_CHLD }, | |
3309 | [SIGPOLL] = { NSIGPOLL, SIL_POLL }, | |
3310 | [SIGSYS] = { NSIGSYS, SIL_SYS }, | |
3311 | }; | |
3312 | ||
b2a2ab52 | 3313 | static bool known_siginfo_layout(unsigned sig, int si_code) |
4ce5f9c9 EB |
3314 | { |
3315 | if (si_code == SI_KERNEL) | |
3316 | return true; | |
3317 | else if ((si_code > SI_USER)) { | |
3318 | if (sig_specific_sicodes(sig)) { | |
3319 | if (si_code <= sig_sicodes[sig].limit) | |
3320 | return true; | |
3321 | } | |
3322 | else if (si_code <= NSIGPOLL) | |
3323 | return true; | |
3324 | } | |
3325 | else if (si_code >= SI_DETHREAD) | |
3326 | return true; | |
3327 | else if (si_code == SI_ASYNCNL) | |
3328 | return true; | |
3329 | return false; | |
3330 | } | |
3331 | ||
a3670058 | 3332 | enum siginfo_layout siginfo_layout(unsigned sig, int si_code) |
cc731525 EB |
3333 | { |
3334 | enum siginfo_layout layout = SIL_KILL; | |
3335 | if ((si_code > SI_USER) && (si_code < SI_KERNEL)) { | |
4ce5f9c9 EB |
3336 | if ((sig < ARRAY_SIZE(sig_sicodes)) && |
3337 | (si_code <= sig_sicodes[sig].limit)) { | |
3338 | layout = sig_sicodes[sig].layout; | |
31931c93 EB |
3339 | /* Handle the exceptions */ |
3340 | if ((sig == SIGBUS) && | |
3341 | (si_code >= BUS_MCEERR_AR) && (si_code <= BUS_MCEERR_AO)) | |
3342 | layout = SIL_FAULT_MCEERR; | |
3343 | else if ((sig == SIGSEGV) && (si_code == SEGV_BNDERR)) | |
3344 | layout = SIL_FAULT_BNDERR; | |
3345 | #ifdef SEGV_PKUERR | |
3346 | else if ((sig == SIGSEGV) && (si_code == SEGV_PKUERR)) | |
3347 | layout = SIL_FAULT_PKUERR; | |
3348 | #endif | |
ed8e5080 | 3349 | else if ((sig == SIGTRAP) && (si_code == TRAP_PERF)) |
f4ac7302 | 3350 | layout = SIL_FAULT_PERF_EVENT; |
2c9f7eaf EB |
3351 | else if (IS_ENABLED(CONFIG_SPARC) && |
3352 | (sig == SIGILL) && (si_code == ILL_ILLTRP)) | |
3353 | layout = SIL_FAULT_TRAPNO; | |
7de5f68d EB |
3354 | else if (IS_ENABLED(CONFIG_ALPHA) && |
3355 | ((sig == SIGFPE) || | |
3356 | ((sig == SIGTRAP) && (si_code == TRAP_UNK)))) | |
9abcabe3 | 3357 | layout = SIL_FAULT_TRAPNO; |
31931c93 | 3358 | } |
cc731525 EB |
3359 | else if (si_code <= NSIGPOLL) |
3360 | layout = SIL_POLL; | |
3361 | } else { | |
3362 | if (si_code == SI_TIMER) | |
3363 | layout = SIL_TIMER; | |
3364 | else if (si_code == SI_SIGIO) | |
3365 | layout = SIL_POLL; | |
3366 | else if (si_code < 0) | |
3367 | layout = SIL_RT; | |
cc731525 EB |
3368 | } |
3369 | return layout; | |
3370 | } | |
3371 | ||
4ce5f9c9 EB |
3372 | static inline char __user *si_expansion(const siginfo_t __user *info) |
3373 | { | |
3374 | return ((char __user *)info) + sizeof(struct kernel_siginfo); | |
3375 | } | |
3376 | ||
ae7795bc | 3377 | int copy_siginfo_to_user(siginfo_t __user *to, const kernel_siginfo_t *from) |
1da177e4 | 3378 | { |
4ce5f9c9 | 3379 | char __user *expansion = si_expansion(to); |
ae7795bc | 3380 | if (copy_to_user(to, from , sizeof(struct kernel_siginfo))) |
1da177e4 | 3381 | return -EFAULT; |
4ce5f9c9 | 3382 | if (clear_user(expansion, SI_EXPANSION_SIZE)) |
1da177e4 | 3383 | return -EFAULT; |
c999b933 | 3384 | return 0; |
1da177e4 LT |
3385 | } |
3386 | ||
601d5abf EB |
3387 | static int post_copy_siginfo_from_user(kernel_siginfo_t *info, |
3388 | const siginfo_t __user *from) | |
4cd2e0e7 | 3389 | { |
601d5abf | 3390 | if (unlikely(!known_siginfo_layout(info->si_signo, info->si_code))) { |
4ce5f9c9 EB |
3391 | char __user *expansion = si_expansion(from); |
3392 | char buf[SI_EXPANSION_SIZE]; | |
3393 | int i; | |
3394 | /* | |
3395 | * An unknown si_code might need more than | |
3396 | * sizeof(struct kernel_siginfo) bytes. Verify all of the | |
3397 | * extra bytes are 0. This guarantees copy_siginfo_to_user | |
3398 | * will return this data to userspace exactly. | |
3399 | */ | |
3400 | if (copy_from_user(&buf, expansion, SI_EXPANSION_SIZE)) | |
3401 | return -EFAULT; | |
3402 | for (i = 0; i < SI_EXPANSION_SIZE; i++) { | |
3403 | if (buf[i] != 0) | |
3404 | return -E2BIG; | |
3405 | } | |
3406 | } | |
4cd2e0e7 EB |
3407 | return 0; |
3408 | } | |
3409 | ||
601d5abf EB |
3410 | static int __copy_siginfo_from_user(int signo, kernel_siginfo_t *to, |
3411 | const siginfo_t __user *from) | |
3412 | { | |
3413 | if (copy_from_user(to, from, sizeof(struct kernel_siginfo))) | |
3414 | return -EFAULT; | |
3415 | to->si_signo = signo; | |
3416 | return post_copy_siginfo_from_user(to, from); | |
3417 | } | |
3418 | ||
3419 | int copy_siginfo_from_user(kernel_siginfo_t *to, const siginfo_t __user *from) | |
3420 | { | |
3421 | if (copy_from_user(to, from, sizeof(struct kernel_siginfo))) | |
3422 | return -EFAULT; | |
3423 | return post_copy_siginfo_from_user(to, from); | |
3424 | } | |
3425 | ||
212a36a1 | 3426 | #ifdef CONFIG_COMPAT |
c3b3f524 CH |
3427 | /** |
3428 | * copy_siginfo_to_external32 - copy a kernel siginfo into a compat user siginfo | |
3429 | * @to: compat siginfo destination | |
3430 | * @from: kernel siginfo source | |
3431 | * | |
3432 | * Note: This function does not work properly for the SIGCHLD on x32, but | |
3433 | * fortunately it doesn't have to. The only valid callers for this function are | |
3434 | * copy_siginfo_to_user32, which is overriden for x32 and the coredump code. | |
3435 | * The latter does not care because SIGCHLD will never cause a coredump. | |
3436 | */ | |
3437 | void copy_siginfo_to_external32(struct compat_siginfo *to, | |
3438 | const struct kernel_siginfo *from) | |
ea64d5ac | 3439 | { |
c3b3f524 | 3440 | memset(to, 0, sizeof(*to)); |
ea64d5ac | 3441 | |
c3b3f524 CH |
3442 | to->si_signo = from->si_signo; |
3443 | to->si_errno = from->si_errno; | |
3444 | to->si_code = from->si_code; | |
ea64d5ac EB |
3445 | switch(siginfo_layout(from->si_signo, from->si_code)) { |
3446 | case SIL_KILL: | |
c3b3f524 CH |
3447 | to->si_pid = from->si_pid; |
3448 | to->si_uid = from->si_uid; | |
ea64d5ac EB |
3449 | break; |
3450 | case SIL_TIMER: | |
c3b3f524 CH |
3451 | to->si_tid = from->si_tid; |
3452 | to->si_overrun = from->si_overrun; | |
3453 | to->si_int = from->si_int; | |
ea64d5ac EB |
3454 | break; |
3455 | case SIL_POLL: | |
c3b3f524 CH |
3456 | to->si_band = from->si_band; |
3457 | to->si_fd = from->si_fd; | |
ea64d5ac EB |
3458 | break; |
3459 | case SIL_FAULT: | |
c3b3f524 | 3460 | to->si_addr = ptr_to_compat(from->si_addr); |
9abcabe3 EB |
3461 | break; |
3462 | case SIL_FAULT_TRAPNO: | |
3463 | to->si_addr = ptr_to_compat(from->si_addr); | |
c3b3f524 | 3464 | to->si_trapno = from->si_trapno; |
31931c93 EB |
3465 | break; |
3466 | case SIL_FAULT_MCEERR: | |
c3b3f524 | 3467 | to->si_addr = ptr_to_compat(from->si_addr); |
c3b3f524 | 3468 | to->si_addr_lsb = from->si_addr_lsb; |
31931c93 EB |
3469 | break; |
3470 | case SIL_FAULT_BNDERR: | |
c3b3f524 | 3471 | to->si_addr = ptr_to_compat(from->si_addr); |
c3b3f524 CH |
3472 | to->si_lower = ptr_to_compat(from->si_lower); |
3473 | to->si_upper = ptr_to_compat(from->si_upper); | |
31931c93 EB |
3474 | break; |
3475 | case SIL_FAULT_PKUERR: | |
c3b3f524 | 3476 | to->si_addr = ptr_to_compat(from->si_addr); |
c3b3f524 | 3477 | to->si_pkey = from->si_pkey; |
ea64d5ac | 3478 | break; |
f4ac7302 | 3479 | case SIL_FAULT_PERF_EVENT: |
fb6cc127 | 3480 | to->si_addr = ptr_to_compat(from->si_addr); |
0683b531 EB |
3481 | to->si_perf_data = from->si_perf_data; |
3482 | to->si_perf_type = from->si_perf_type; | |
78ed93d7 | 3483 | to->si_perf_flags = from->si_perf_flags; |
fb6cc127 | 3484 | break; |
ea64d5ac | 3485 | case SIL_CHLD: |
c3b3f524 CH |
3486 | to->si_pid = from->si_pid; |
3487 | to->si_uid = from->si_uid; | |
3488 | to->si_status = from->si_status; | |
3489 | to->si_utime = from->si_utime; | |
3490 | to->si_stime = from->si_stime; | |
ea64d5ac EB |
3491 | break; |
3492 | case SIL_RT: | |
c3b3f524 CH |
3493 | to->si_pid = from->si_pid; |
3494 | to->si_uid = from->si_uid; | |
3495 | to->si_int = from->si_int; | |
ea64d5ac EB |
3496 | break; |
3497 | case SIL_SYS: | |
c3b3f524 CH |
3498 | to->si_call_addr = ptr_to_compat(from->si_call_addr); |
3499 | to->si_syscall = from->si_syscall; | |
3500 | to->si_arch = from->si_arch; | |
ea64d5ac EB |
3501 | break; |
3502 | } | |
c3b3f524 | 3503 | } |
ea64d5ac | 3504 | |
c3b3f524 CH |
3505 | int __copy_siginfo_to_user32(struct compat_siginfo __user *to, |
3506 | const struct kernel_siginfo *from) | |
3507 | { | |
3508 | struct compat_siginfo new; | |
3509 | ||
3510 | copy_siginfo_to_external32(&new, from); | |
ea64d5ac EB |
3511 | if (copy_to_user(to, &new, sizeof(struct compat_siginfo))) |
3512 | return -EFAULT; | |
ea64d5ac EB |
3513 | return 0; |
3514 | } | |
3515 | ||
601d5abf EB |
3516 | static int post_copy_siginfo_from_user32(kernel_siginfo_t *to, |
3517 | const struct compat_siginfo *from) | |
212a36a1 | 3518 | { |
212a36a1 | 3519 | clear_siginfo(to); |
601d5abf EB |
3520 | to->si_signo = from->si_signo; |
3521 | to->si_errno = from->si_errno; | |
3522 | to->si_code = from->si_code; | |
3523 | switch(siginfo_layout(from->si_signo, from->si_code)) { | |
212a36a1 | 3524 | case SIL_KILL: |
601d5abf EB |
3525 | to->si_pid = from->si_pid; |
3526 | to->si_uid = from->si_uid; | |
212a36a1 EB |
3527 | break; |
3528 | case SIL_TIMER: | |
601d5abf EB |
3529 | to->si_tid = from->si_tid; |
3530 | to->si_overrun = from->si_overrun; | |
3531 | to->si_int = from->si_int; | |
212a36a1 EB |
3532 | break; |
3533 | case SIL_POLL: | |
601d5abf EB |
3534 | to->si_band = from->si_band; |
3535 | to->si_fd = from->si_fd; | |
212a36a1 EB |
3536 | break; |
3537 | case SIL_FAULT: | |
601d5abf | 3538 | to->si_addr = compat_ptr(from->si_addr); |
9abcabe3 EB |
3539 | break; |
3540 | case SIL_FAULT_TRAPNO: | |
3541 | to->si_addr = compat_ptr(from->si_addr); | |
601d5abf | 3542 | to->si_trapno = from->si_trapno; |
31931c93 EB |
3543 | break; |
3544 | case SIL_FAULT_MCEERR: | |
601d5abf | 3545 | to->si_addr = compat_ptr(from->si_addr); |
601d5abf | 3546 | to->si_addr_lsb = from->si_addr_lsb; |
31931c93 EB |
3547 | break; |
3548 | case SIL_FAULT_BNDERR: | |
601d5abf | 3549 | to->si_addr = compat_ptr(from->si_addr); |
601d5abf EB |
3550 | to->si_lower = compat_ptr(from->si_lower); |
3551 | to->si_upper = compat_ptr(from->si_upper); | |
31931c93 EB |
3552 | break; |
3553 | case SIL_FAULT_PKUERR: | |
601d5abf | 3554 | to->si_addr = compat_ptr(from->si_addr); |
601d5abf | 3555 | to->si_pkey = from->si_pkey; |
212a36a1 | 3556 | break; |
f4ac7302 | 3557 | case SIL_FAULT_PERF_EVENT: |
fb6cc127 | 3558 | to->si_addr = compat_ptr(from->si_addr); |
0683b531 EB |
3559 | to->si_perf_data = from->si_perf_data; |
3560 | to->si_perf_type = from->si_perf_type; | |
78ed93d7 | 3561 | to->si_perf_flags = from->si_perf_flags; |
fb6cc127 | 3562 | break; |
212a36a1 | 3563 | case SIL_CHLD: |
601d5abf EB |
3564 | to->si_pid = from->si_pid; |
3565 | to->si_uid = from->si_uid; | |
3566 | to->si_status = from->si_status; | |
212a36a1 EB |
3567 | #ifdef CONFIG_X86_X32_ABI |
3568 | if (in_x32_syscall()) { | |
601d5abf EB |
3569 | to->si_utime = from->_sifields._sigchld_x32._utime; |
3570 | to->si_stime = from->_sifields._sigchld_x32._stime; | |
212a36a1 EB |
3571 | } else |
3572 | #endif | |
3573 | { | |
601d5abf EB |
3574 | to->si_utime = from->si_utime; |
3575 | to->si_stime = from->si_stime; | |
212a36a1 EB |
3576 | } |
3577 | break; | |
3578 | case SIL_RT: | |
601d5abf EB |
3579 | to->si_pid = from->si_pid; |
3580 | to->si_uid = from->si_uid; | |
3581 | to->si_int = from->si_int; | |
212a36a1 EB |
3582 | break; |
3583 | case SIL_SYS: | |
601d5abf EB |
3584 | to->si_call_addr = compat_ptr(from->si_call_addr); |
3585 | to->si_syscall = from->si_syscall; | |
3586 | to->si_arch = from->si_arch; | |
212a36a1 EB |
3587 | break; |
3588 | } | |
3589 | return 0; | |
3590 | } | |
601d5abf EB |
3591 | |
3592 | static int __copy_siginfo_from_user32(int signo, struct kernel_siginfo *to, | |
3593 | const struct compat_siginfo __user *ufrom) | |
3594 | { | |
3595 | struct compat_siginfo from; | |
3596 | ||
3597 | if (copy_from_user(&from, ufrom, sizeof(struct compat_siginfo))) | |
3598 | return -EFAULT; | |
3599 | ||
3600 | from.si_signo = signo; | |
3601 | return post_copy_siginfo_from_user32(to, &from); | |
3602 | } | |
3603 | ||
3604 | int copy_siginfo_from_user32(struct kernel_siginfo *to, | |
3605 | const struct compat_siginfo __user *ufrom) | |
3606 | { | |
3607 | struct compat_siginfo from; | |
3608 | ||
3609 | if (copy_from_user(&from, ufrom, sizeof(struct compat_siginfo))) | |
3610 | return -EFAULT; | |
3611 | ||
3612 | return post_copy_siginfo_from_user32(to, &from); | |
3613 | } | |
212a36a1 EB |
3614 | #endif /* CONFIG_COMPAT */ |
3615 | ||
943df148 ON |
3616 | /** |
3617 | * do_sigtimedwait - wait for queued signals specified in @which | |
3618 | * @which: queued signals to wait for | |
3619 | * @info: if non-null, the signal's siginfo is returned here | |
3620 | * @ts: upper bound on process time suspension | |
3621 | */ | |
ae7795bc | 3622 | static int do_sigtimedwait(const sigset_t *which, kernel_siginfo_t *info, |
49c39f84 | 3623 | const struct timespec64 *ts) |
943df148 | 3624 | { |
2456e855 | 3625 | ktime_t *to = NULL, timeout = KTIME_MAX; |
943df148 | 3626 | struct task_struct *tsk = current; |
943df148 | 3627 | sigset_t mask = *which; |
5768d890 | 3628 | enum pid_type type; |
2b1ecc3d | 3629 | int sig, ret = 0; |
943df148 ON |
3630 | |
3631 | if (ts) { | |
49c39f84 | 3632 | if (!timespec64_valid(ts)) |
943df148 | 3633 | return -EINVAL; |
49c39f84 | 3634 | timeout = timespec64_to_ktime(*ts); |
2b1ecc3d | 3635 | to = &timeout; |
943df148 ON |
3636 | } |
3637 | ||
3638 | /* | |
3639 | * Invert the set of allowed signals to get those we want to block. | |
3640 | */ | |
3641 | sigdelsetmask(&mask, sigmask(SIGKILL) | sigmask(SIGSTOP)); | |
3642 | signotset(&mask); | |
3643 | ||
3644 | spin_lock_irq(&tsk->sighand->siglock); | |
5768d890 | 3645 | sig = dequeue_signal(tsk, &mask, info, &type); |
2456e855 | 3646 | if (!sig && timeout) { |
943df148 ON |
3647 | /* |
3648 | * None ready, temporarily unblock those we're interested | |
3649 | * while we are sleeping in so that we'll be awakened when | |
b182801a ON |
3650 | * they arrive. Unblocking is always fine, we can avoid |
3651 | * set_current_blocked(). | |
943df148 ON |
3652 | */ |
3653 | tsk->real_blocked = tsk->blocked; | |
3654 | sigandsets(&tsk->blocked, &tsk->blocked, &mask); | |
3655 | recalc_sigpending(); | |
3656 | spin_unlock_irq(&tsk->sighand->siglock); | |
3657 | ||
f5d39b02 PZ |
3658 | __set_current_state(TASK_INTERRUPTIBLE|TASK_FREEZABLE); |
3659 | ret = schedule_hrtimeout_range(to, tsk->timer_slack_ns, | |
3660 | HRTIMER_MODE_REL); | |
943df148 | 3661 | spin_lock_irq(&tsk->sighand->siglock); |
b182801a | 3662 | __set_task_blocked(tsk, &tsk->real_blocked); |
6114041a | 3663 | sigemptyset(&tsk->real_blocked); |
5768d890 | 3664 | sig = dequeue_signal(tsk, &mask, info, &type); |
943df148 ON |
3665 | } |
3666 | spin_unlock_irq(&tsk->sighand->siglock); | |
3667 | ||
3668 | if (sig) | |
3669 | return sig; | |
2b1ecc3d | 3670 | return ret ? -EINTR : -EAGAIN; |
943df148 ON |
3671 | } |
3672 | ||
41c57892 RD |
3673 | /** |
3674 | * sys_rt_sigtimedwait - synchronously wait for queued signals specified | |
3675 | * in @uthese | |
3676 | * @uthese: queued signals to wait for | |
3677 | * @uinfo: if non-null, the signal's siginfo is returned here | |
3678 | * @uts: upper bound on process time suspension | |
3679 | * @sigsetsize: size of sigset_t type | |
3680 | */ | |
17da2bd9 | 3681 | SYSCALL_DEFINE4(rt_sigtimedwait, const sigset_t __user *, uthese, |
49c39f84 AB |
3682 | siginfo_t __user *, uinfo, |
3683 | const struct __kernel_timespec __user *, uts, | |
17da2bd9 | 3684 | size_t, sigsetsize) |
1da177e4 | 3685 | { |
1da177e4 | 3686 | sigset_t these; |
49c39f84 | 3687 | struct timespec64 ts; |
ae7795bc | 3688 | kernel_siginfo_t info; |
943df148 | 3689 | int ret; |
1da177e4 LT |
3690 | |
3691 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
3692 | if (sigsetsize != sizeof(sigset_t)) | |
3693 | return -EINVAL; | |
3694 | ||
3695 | if (copy_from_user(&these, uthese, sizeof(these))) | |
3696 | return -EFAULT; | |
5aba085e | 3697 | |
1da177e4 | 3698 | if (uts) { |
49c39f84 | 3699 | if (get_timespec64(&ts, uts)) |
1da177e4 | 3700 | return -EFAULT; |
1da177e4 LT |
3701 | } |
3702 | ||
943df148 | 3703 | ret = do_sigtimedwait(&these, &info, uts ? &ts : NULL); |
1da177e4 | 3704 | |
943df148 ON |
3705 | if (ret > 0 && uinfo) { |
3706 | if (copy_siginfo_to_user(uinfo, &info)) | |
3707 | ret = -EFAULT; | |
1da177e4 LT |
3708 | } |
3709 | ||
3710 | return ret; | |
3711 | } | |
3712 | ||
df8522a3 AB |
3713 | #ifdef CONFIG_COMPAT_32BIT_TIME |
3714 | SYSCALL_DEFINE4(rt_sigtimedwait_time32, const sigset_t __user *, uthese, | |
3715 | siginfo_t __user *, uinfo, | |
3716 | const struct old_timespec32 __user *, uts, | |
3717 | size_t, sigsetsize) | |
3718 | { | |
3719 | sigset_t these; | |
3720 | struct timespec64 ts; | |
3721 | kernel_siginfo_t info; | |
3722 | int ret; | |
3723 | ||
3724 | if (sigsetsize != sizeof(sigset_t)) | |
3725 | return -EINVAL; | |
3726 | ||
3727 | if (copy_from_user(&these, uthese, sizeof(these))) | |
3728 | return -EFAULT; | |
3729 | ||
3730 | if (uts) { | |
3731 | if (get_old_timespec32(&ts, uts)) | |
3732 | return -EFAULT; | |
3733 | } | |
3734 | ||
3735 | ret = do_sigtimedwait(&these, &info, uts ? &ts : NULL); | |
3736 | ||
3737 | if (ret > 0 && uinfo) { | |
3738 | if (copy_siginfo_to_user(uinfo, &info)) | |
3739 | ret = -EFAULT; | |
3740 | } | |
3741 | ||
3742 | return ret; | |
3743 | } | |
3744 | #endif | |
3745 | ||
1b3c872c | 3746 | #ifdef CONFIG_COMPAT |
2367c4b5 AB |
3747 | COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait_time64, compat_sigset_t __user *, uthese, |
3748 | struct compat_siginfo __user *, uinfo, | |
3749 | struct __kernel_timespec __user *, uts, compat_size_t, sigsetsize) | |
3750 | { | |
3751 | sigset_t s; | |
3752 | struct timespec64 t; | |
3753 | kernel_siginfo_t info; | |
3754 | long ret; | |
3755 | ||
3756 | if (sigsetsize != sizeof(sigset_t)) | |
3757 | return -EINVAL; | |
3758 | ||
3759 | if (get_compat_sigset(&s, uthese)) | |
3760 | return -EFAULT; | |
3761 | ||
3762 | if (uts) { | |
3763 | if (get_timespec64(&t, uts)) | |
3764 | return -EFAULT; | |
3765 | } | |
3766 | ||
3767 | ret = do_sigtimedwait(&s, &info, uts ? &t : NULL); | |
3768 | ||
3769 | if (ret > 0 && uinfo) { | |
3770 | if (copy_siginfo_to_user32(uinfo, &info)) | |
3771 | ret = -EFAULT; | |
3772 | } | |
3773 | ||
3774 | return ret; | |
3775 | } | |
3776 | ||
3777 | #ifdef CONFIG_COMPAT_32BIT_TIME | |
8dabe724 | 3778 | COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait_time32, compat_sigset_t __user *, uthese, |
1b3c872c | 3779 | struct compat_siginfo __user *, uinfo, |
9afc5eee | 3780 | struct old_timespec32 __user *, uts, compat_size_t, sigsetsize) |
1b3c872c | 3781 | { |
1b3c872c | 3782 | sigset_t s; |
49c39f84 | 3783 | struct timespec64 t; |
ae7795bc | 3784 | kernel_siginfo_t info; |
1b3c872c AV |
3785 | long ret; |
3786 | ||
3787 | if (sigsetsize != sizeof(sigset_t)) | |
3788 | return -EINVAL; | |
3789 | ||
3968cf62 | 3790 | if (get_compat_sigset(&s, uthese)) |
1b3c872c | 3791 | return -EFAULT; |
1b3c872c AV |
3792 | |
3793 | if (uts) { | |
49c39f84 | 3794 | if (get_old_timespec32(&t, uts)) |
1b3c872c AV |
3795 | return -EFAULT; |
3796 | } | |
3797 | ||
3798 | ret = do_sigtimedwait(&s, &info, uts ? &t : NULL); | |
3799 | ||
3800 | if (ret > 0 && uinfo) { | |
3801 | if (copy_siginfo_to_user32(uinfo, &info)) | |
3802 | ret = -EFAULT; | |
3803 | } | |
3804 | ||
3805 | return ret; | |
3806 | } | |
3807 | #endif | |
2367c4b5 | 3808 | #endif |
1b3c872c | 3809 | |
c044a950 ON |
3810 | static void prepare_kill_siginfo(int sig, struct kernel_siginfo *info, |
3811 | enum pid_type type) | |
3eb39f47 CB |
3812 | { |
3813 | clear_siginfo(info); | |
3814 | info->si_signo = sig; | |
3815 | info->si_errno = 0; | |
c044a950 | 3816 | info->si_code = (type == PIDTYPE_PID) ? SI_TKILL : SI_USER; |
3eb39f47 CB |
3817 | info->si_pid = task_tgid_vnr(current); |
3818 | info->si_uid = from_kuid_munged(current_user_ns(), current_uid()); | |
3819 | } | |
3820 | ||
41c57892 RD |
3821 | /** |
3822 | * sys_kill - send a signal to a process | |
3823 | * @pid: the PID of the process | |
3824 | * @sig: signal to be sent | |
3825 | */ | |
17da2bd9 | 3826 | SYSCALL_DEFINE2(kill, pid_t, pid, int, sig) |
1da177e4 | 3827 | { |
ae7795bc | 3828 | struct kernel_siginfo info; |
1da177e4 | 3829 | |
c044a950 | 3830 | prepare_kill_siginfo(sig, &info, PIDTYPE_TGID); |
1da177e4 LT |
3831 | |
3832 | return kill_something_info(sig, &info, pid); | |
3833 | } | |
3834 | ||
3eb39f47 CB |
3835 | /* |
3836 | * Verify that the signaler and signalee either are in the same pid namespace | |
3837 | * or that the signaler's pid namespace is an ancestor of the signalee's pid | |
3838 | * namespace. | |
3839 | */ | |
3840 | static bool access_pidfd_pidns(struct pid *pid) | |
3841 | { | |
3842 | struct pid_namespace *active = task_active_pid_ns(current); | |
3843 | struct pid_namespace *p = ns_of_pid(pid); | |
3844 | ||
3845 | for (;;) { | |
3846 | if (!p) | |
3847 | return false; | |
3848 | if (p == active) | |
3849 | break; | |
3850 | p = p->parent; | |
3851 | } | |
3852 | ||
3853 | return true; | |
3854 | } | |
3855 | ||
adc5d875 JH |
3856 | static int copy_siginfo_from_user_any(kernel_siginfo_t *kinfo, |
3857 | siginfo_t __user *info) | |
3eb39f47 CB |
3858 | { |
3859 | #ifdef CONFIG_COMPAT | |
3860 | /* | |
3861 | * Avoid hooking up compat syscalls and instead handle necessary | |
3862 | * conversions here. Note, this is a stop-gap measure and should not be | |
3863 | * considered a generic solution. | |
3864 | */ | |
3865 | if (in_compat_syscall()) | |
3866 | return copy_siginfo_from_user32( | |
3867 | kinfo, (struct compat_siginfo __user *)info); | |
3868 | #endif | |
3869 | return copy_siginfo_from_user(kinfo, info); | |
3870 | } | |
3871 | ||
2151ad1b CB |
3872 | static struct pid *pidfd_to_pid(const struct file *file) |
3873 | { | |
3695eae5 CB |
3874 | struct pid *pid; |
3875 | ||
3876 | pid = pidfd_pid(file); | |
3877 | if (!IS_ERR(pid)) | |
3878 | return pid; | |
2151ad1b CB |
3879 | |
3880 | return tgid_pidfd_to_pid(file); | |
3881 | } | |
3882 | ||
e1fb1dc0 CB |
3883 | #define PIDFD_SEND_SIGNAL_FLAGS \ |
3884 | (PIDFD_SIGNAL_THREAD | PIDFD_SIGNAL_THREAD_GROUP | \ | |
3885 | PIDFD_SIGNAL_PROCESS_GROUP) | |
3886 | ||
3eb39f47 | 3887 | /** |
c732327f CB |
3888 | * sys_pidfd_send_signal - Signal a process through a pidfd |
3889 | * @pidfd: file descriptor of the process | |
3890 | * @sig: signal to send | |
3891 | * @info: signal info | |
3892 | * @flags: future flags | |
3eb39f47 | 3893 | * |
81b9d8ac ON |
3894 | * Send the signal to the thread group or to the individual thread depending |
3895 | * on PIDFD_THREAD. | |
3896 | * In the future extension to @flags may be used to override the default scope | |
3897 | * of @pidfd. | |
3eb39f47 CB |
3898 | * |
3899 | * Return: 0 on success, negative errno on failure | |
3900 | */ | |
3901 | SYSCALL_DEFINE4(pidfd_send_signal, int, pidfd, int, sig, | |
3902 | siginfo_t __user *, info, unsigned int, flags) | |
3903 | { | |
3904 | int ret; | |
3905 | struct fd f; | |
3906 | struct pid *pid; | |
3907 | kernel_siginfo_t kinfo; | |
81b9d8ac | 3908 | enum pid_type type; |
3eb39f47 CB |
3909 | |
3910 | /* Enforce flags be set to 0 until we add an extension. */ | |
e1fb1dc0 CB |
3911 | if (flags & ~PIDFD_SEND_SIGNAL_FLAGS) |
3912 | return -EINVAL; | |
3913 | ||
3914 | /* Ensure that only a single signal scope determining flag is set. */ | |
3915 | if (hweight32(flags & PIDFD_SEND_SIGNAL_FLAGS) > 1) | |
3eb39f47 CB |
3916 | return -EINVAL; |
3917 | ||
738a7832 | 3918 | f = fdget(pidfd); |
3eb39f47 CB |
3919 | if (!f.file) |
3920 | return -EBADF; | |
3921 | ||
3922 | /* Is this a pidfd? */ | |
2151ad1b | 3923 | pid = pidfd_to_pid(f.file); |
3eb39f47 CB |
3924 | if (IS_ERR(pid)) { |
3925 | ret = PTR_ERR(pid); | |
3926 | goto err; | |
3927 | } | |
3928 | ||
3929 | ret = -EINVAL; | |
3930 | if (!access_pidfd_pidns(pid)) | |
3931 | goto err; | |
3932 | ||
e1fb1dc0 CB |
3933 | switch (flags) { |
3934 | case 0: | |
3935 | /* Infer scope from the type of pidfd. */ | |
3936 | if (f.file->f_flags & PIDFD_THREAD) | |
3937 | type = PIDTYPE_PID; | |
3938 | else | |
3939 | type = PIDTYPE_TGID; | |
3940 | break; | |
3941 | case PIDFD_SIGNAL_THREAD: | |
81b9d8ac | 3942 | type = PIDTYPE_PID; |
e1fb1dc0 CB |
3943 | break; |
3944 | case PIDFD_SIGNAL_THREAD_GROUP: | |
81b9d8ac | 3945 | type = PIDTYPE_TGID; |
e1fb1dc0 CB |
3946 | break; |
3947 | case PIDFD_SIGNAL_PROCESS_GROUP: | |
3948 | type = PIDTYPE_PGID; | |
3949 | break; | |
3950 | } | |
81b9d8ac | 3951 | |
3eb39f47 CB |
3952 | if (info) { |
3953 | ret = copy_siginfo_from_user_any(&kinfo, info); | |
3954 | if (unlikely(ret)) | |
3955 | goto err; | |
3956 | ||
3957 | ret = -EINVAL; | |
3958 | if (unlikely(sig != kinfo.si_signo)) | |
3959 | goto err; | |
3960 | ||
556a888a JH |
3961 | /* Only allow sending arbitrary signals to yourself. */ |
3962 | ret = -EPERM; | |
e1fb1dc0 | 3963 | if ((task_pid(current) != pid || type > PIDTYPE_TGID) && |
556a888a JH |
3964 | (kinfo.si_code >= 0 || kinfo.si_code == SI_TKILL)) |
3965 | goto err; | |
3eb39f47 | 3966 | } else { |
81b9d8ac | 3967 | prepare_kill_siginfo(sig, &kinfo, type); |
3eb39f47 CB |
3968 | } |
3969 | ||
e1fb1dc0 CB |
3970 | if (type == PIDTYPE_PGID) |
3971 | ret = kill_pgrp_info(sig, &kinfo, pid); | |
3972 | else | |
3973 | ret = kill_pid_info_type(sig, &kinfo, pid, type); | |
3eb39f47 CB |
3974 | err: |
3975 | fdput(f); | |
3976 | return ret; | |
3977 | } | |
3eb39f47 | 3978 | |
30b4ae8a | 3979 | static int |
ae7795bc | 3980 | do_send_specific(pid_t tgid, pid_t pid, int sig, struct kernel_siginfo *info) |
1da177e4 | 3981 | { |
1da177e4 | 3982 | struct task_struct *p; |
30b4ae8a | 3983 | int error = -ESRCH; |
1da177e4 | 3984 | |
3547ff3a | 3985 | rcu_read_lock(); |
228ebcbe | 3986 | p = find_task_by_vpid(pid); |
b488893a | 3987 | if (p && (tgid <= 0 || task_tgid_vnr(p) == tgid)) { |
30b4ae8a | 3988 | error = check_kill_permission(sig, info, p); |
1da177e4 LT |
3989 | /* |
3990 | * The null signal is a permissions and process existence | |
3991 | * probe. No signal is actually delivered. | |
3992 | */ | |
4a30debf | 3993 | if (!error && sig) { |
40b3b025 | 3994 | error = do_send_sig_info(sig, info, p, PIDTYPE_PID); |
4a30debf ON |
3995 | /* |
3996 | * If lock_task_sighand() failed we pretend the task | |
3997 | * dies after receiving the signal. The window is tiny, | |
3998 | * and the signal is private anyway. | |
3999 | */ | |
4000 | if (unlikely(error == -ESRCH)) | |
4001 | error = 0; | |
1da177e4 LT |
4002 | } |
4003 | } | |
3547ff3a | 4004 | rcu_read_unlock(); |
6dd69f10 | 4005 | |
1da177e4 LT |
4006 | return error; |
4007 | } | |
4008 | ||
30b4ae8a TG |
4009 | static int do_tkill(pid_t tgid, pid_t pid, int sig) |
4010 | { | |
ae7795bc | 4011 | struct kernel_siginfo info; |
30b4ae8a | 4012 | |
c044a950 | 4013 | prepare_kill_siginfo(sig, &info, PIDTYPE_PID); |
30b4ae8a TG |
4014 | |
4015 | return do_send_specific(tgid, pid, sig, &info); | |
4016 | } | |
4017 | ||
6dd69f10 VL |
4018 | /** |
4019 | * sys_tgkill - send signal to one specific thread | |
4020 | * @tgid: the thread group ID of the thread | |
4021 | * @pid: the PID of the thread | |
4022 | * @sig: signal to be sent | |
4023 | * | |
72fd4a35 | 4024 | * This syscall also checks the @tgid and returns -ESRCH even if the PID |
6dd69f10 VL |
4025 | * exists but it's not belonging to the target process anymore. This |
4026 | * method solves the problem of threads exiting and PIDs getting reused. | |
4027 | */ | |
a5f8fa9e | 4028 | SYSCALL_DEFINE3(tgkill, pid_t, tgid, pid_t, pid, int, sig) |
6dd69f10 VL |
4029 | { |
4030 | /* This is only valid for single tasks */ | |
4031 | if (pid <= 0 || tgid <= 0) | |
4032 | return -EINVAL; | |
4033 | ||
4034 | return do_tkill(tgid, pid, sig); | |
4035 | } | |
4036 | ||
41c57892 RD |
4037 | /** |
4038 | * sys_tkill - send signal to one specific task | |
4039 | * @pid: the PID of the task | |
4040 | * @sig: signal to be sent | |
4041 | * | |
1da177e4 LT |
4042 | * Send a signal to only one task, even if it's a CLONE_THREAD task. |
4043 | */ | |
a5f8fa9e | 4044 | SYSCALL_DEFINE2(tkill, pid_t, pid, int, sig) |
1da177e4 | 4045 | { |
1da177e4 LT |
4046 | /* This is only valid for single tasks */ |
4047 | if (pid <= 0) | |
4048 | return -EINVAL; | |
4049 | ||
6dd69f10 | 4050 | return do_tkill(0, pid, sig); |
1da177e4 LT |
4051 | } |
4052 | ||
ae7795bc | 4053 | static int do_rt_sigqueueinfo(pid_t pid, int sig, kernel_siginfo_t *info) |
75907d4d AV |
4054 | { |
4055 | /* Not even root can pretend to send signals from the kernel. | |
4056 | * Nor can they impersonate a kill()/tgkill(), which adds source info. | |
4057 | */ | |
66dd34ad | 4058 | if ((info->si_code >= 0 || info->si_code == SI_TKILL) && |
69828dce | 4059 | (task_pid_vnr(current) != pid)) |
75907d4d | 4060 | return -EPERM; |
69828dce | 4061 | |
75907d4d AV |
4062 | /* POSIX.1b doesn't mention process groups. */ |
4063 | return kill_proc_info(sig, info, pid); | |
4064 | } | |
4065 | ||
41c57892 RD |
4066 | /** |
4067 | * sys_rt_sigqueueinfo - send signal information to a signal | |
4068 | * @pid: the PID of the thread | |
4069 | * @sig: signal to be sent | |
4070 | * @uinfo: signal info to be sent | |
4071 | */ | |
a5f8fa9e HC |
4072 | SYSCALL_DEFINE3(rt_sigqueueinfo, pid_t, pid, int, sig, |
4073 | siginfo_t __user *, uinfo) | |
1da177e4 | 4074 | { |
ae7795bc | 4075 | kernel_siginfo_t info; |
601d5abf | 4076 | int ret = __copy_siginfo_from_user(sig, &info, uinfo); |
4cd2e0e7 EB |
4077 | if (unlikely(ret)) |
4078 | return ret; | |
75907d4d AV |
4079 | return do_rt_sigqueueinfo(pid, sig, &info); |
4080 | } | |
1da177e4 | 4081 | |
75907d4d | 4082 | #ifdef CONFIG_COMPAT |
75907d4d AV |
4083 | COMPAT_SYSCALL_DEFINE3(rt_sigqueueinfo, |
4084 | compat_pid_t, pid, | |
4085 | int, sig, | |
4086 | struct compat_siginfo __user *, uinfo) | |
4087 | { | |
ae7795bc | 4088 | kernel_siginfo_t info; |
601d5abf | 4089 | int ret = __copy_siginfo_from_user32(sig, &info, uinfo); |
75907d4d AV |
4090 | if (unlikely(ret)) |
4091 | return ret; | |
4092 | return do_rt_sigqueueinfo(pid, sig, &info); | |
1da177e4 | 4093 | } |
75907d4d | 4094 | #endif |
1da177e4 | 4095 | |
ae7795bc | 4096 | static int do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, kernel_siginfo_t *info) |
62ab4505 TG |
4097 | { |
4098 | /* This is only valid for single tasks */ | |
4099 | if (pid <= 0 || tgid <= 0) | |
4100 | return -EINVAL; | |
4101 | ||
4102 | /* Not even root can pretend to send signals from the kernel. | |
da48524e JT |
4103 | * Nor can they impersonate a kill()/tgkill(), which adds source info. |
4104 | */ | |
69828dce VD |
4105 | if ((info->si_code >= 0 || info->si_code == SI_TKILL) && |
4106 | (task_pid_vnr(current) != pid)) | |
62ab4505 | 4107 | return -EPERM; |
69828dce | 4108 | |
62ab4505 TG |
4109 | return do_send_specific(tgid, pid, sig, info); |
4110 | } | |
4111 | ||
4112 | SYSCALL_DEFINE4(rt_tgsigqueueinfo, pid_t, tgid, pid_t, pid, int, sig, | |
4113 | siginfo_t __user *, uinfo) | |
4114 | { | |
ae7795bc | 4115 | kernel_siginfo_t info; |
601d5abf | 4116 | int ret = __copy_siginfo_from_user(sig, &info, uinfo); |
4cd2e0e7 EB |
4117 | if (unlikely(ret)) |
4118 | return ret; | |
62ab4505 TG |
4119 | return do_rt_tgsigqueueinfo(tgid, pid, sig, &info); |
4120 | } | |
4121 | ||
9aae8fc0 AV |
4122 | #ifdef CONFIG_COMPAT |
4123 | COMPAT_SYSCALL_DEFINE4(rt_tgsigqueueinfo, | |
4124 | compat_pid_t, tgid, | |
4125 | compat_pid_t, pid, | |
4126 | int, sig, | |
4127 | struct compat_siginfo __user *, uinfo) | |
4128 | { | |
ae7795bc | 4129 | kernel_siginfo_t info; |
601d5abf | 4130 | int ret = __copy_siginfo_from_user32(sig, &info, uinfo); |
4cd2e0e7 EB |
4131 | if (unlikely(ret)) |
4132 | return ret; | |
9aae8fc0 AV |
4133 | return do_rt_tgsigqueueinfo(tgid, pid, sig, &info); |
4134 | } | |
4135 | #endif | |
4136 | ||
0341729b | 4137 | /* |
b4e74264 | 4138 | * For kthreads only, must not be used if cloned with CLONE_SIGHAND |
0341729b | 4139 | */ |
b4e74264 | 4140 | void kernel_sigaction(int sig, __sighandler_t action) |
0341729b | 4141 | { |
ec5955b8 | 4142 | spin_lock_irq(¤t->sighand->siglock); |
b4e74264 ON |
4143 | current->sighand->action[sig - 1].sa.sa_handler = action; |
4144 | if (action == SIG_IGN) { | |
4145 | sigset_t mask; | |
0341729b | 4146 | |
b4e74264 ON |
4147 | sigemptyset(&mask); |
4148 | sigaddset(&mask, sig); | |
580d34e4 | 4149 | |
b4e74264 ON |
4150 | flush_sigqueue_mask(&mask, ¤t->signal->shared_pending); |
4151 | flush_sigqueue_mask(&mask, ¤t->pending); | |
4152 | recalc_sigpending(); | |
4153 | } | |
0341729b ON |
4154 | spin_unlock_irq(¤t->sighand->siglock); |
4155 | } | |
b4e74264 | 4156 | EXPORT_SYMBOL(kernel_sigaction); |
0341729b | 4157 | |
68463510 DS |
4158 | void __weak sigaction_compat_abi(struct k_sigaction *act, |
4159 | struct k_sigaction *oact) | |
4160 | { | |
4161 | } | |
4162 | ||
88531f72 | 4163 | int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) |
1da177e4 | 4164 | { |
afe2b038 | 4165 | struct task_struct *p = current, *t; |
1da177e4 | 4166 | struct k_sigaction *k; |
71fabd5e | 4167 | sigset_t mask; |
1da177e4 | 4168 | |
7ed20e1a | 4169 | if (!valid_signal(sig) || sig < 1 || (act && sig_kernel_only(sig))) |
1da177e4 LT |
4170 | return -EINVAL; |
4171 | ||
afe2b038 | 4172 | k = &p->sighand->action[sig-1]; |
1da177e4 | 4173 | |
afe2b038 | 4174 | spin_lock_irq(&p->sighand->siglock); |
00b06da2 EB |
4175 | if (k->sa.sa_flags & SA_IMMUTABLE) { |
4176 | spin_unlock_irq(&p->sighand->siglock); | |
4177 | return -EINVAL; | |
4178 | } | |
1da177e4 LT |
4179 | if (oact) |
4180 | *oact = *k; | |
4181 | ||
a54f0dfd PC |
4182 | /* |
4183 | * Make sure that we never accidentally claim to support SA_UNSUPPORTED, | |
4184 | * e.g. by having an architecture use the bit in their uapi. | |
4185 | */ | |
4186 | BUILD_BUG_ON(UAPI_SA_FLAGS & SA_UNSUPPORTED); | |
4187 | ||
23acdc76 PC |
4188 | /* |
4189 | * Clear unknown flag bits in order to allow userspace to detect missing | |
4190 | * support for flag bits and to allow the kernel to use non-uapi bits | |
4191 | * internally. | |
4192 | */ | |
4193 | if (act) | |
4194 | act->sa.sa_flags &= UAPI_SA_FLAGS; | |
4195 | if (oact) | |
4196 | oact->sa.sa_flags &= UAPI_SA_FLAGS; | |
4197 | ||
68463510 DS |
4198 | sigaction_compat_abi(act, oact); |
4199 | ||
1da177e4 | 4200 | if (act) { |
9ac95f2f ON |
4201 | sigdelsetmask(&act->sa.sa_mask, |
4202 | sigmask(SIGKILL) | sigmask(SIGSTOP)); | |
88531f72 | 4203 | *k = *act; |
1da177e4 LT |
4204 | /* |
4205 | * POSIX 3.3.1.3: | |
4206 | * "Setting a signal action to SIG_IGN for a signal that is | |
4207 | * pending shall cause the pending signal to be discarded, | |
4208 | * whether or not it is blocked." | |
4209 | * | |
4210 | * "Setting a signal action to SIG_DFL for a signal that is | |
4211 | * pending and whose default action is to ignore the signal | |
4212 | * (for example, SIGCHLD), shall cause the pending signal to | |
4213 | * be discarded, whether or not it is blocked" | |
4214 | */ | |
afe2b038 | 4215 | if (sig_handler_ignored(sig_handler(p, sig), sig)) { |
71fabd5e GA |
4216 | sigemptyset(&mask); |
4217 | sigaddset(&mask, sig); | |
afe2b038 ON |
4218 | flush_sigqueue_mask(&mask, &p->signal->shared_pending); |
4219 | for_each_thread(p, t) | |
c09c1441 | 4220 | flush_sigqueue_mask(&mask, &t->pending); |
1da177e4 | 4221 | } |
1da177e4 LT |
4222 | } |
4223 | ||
afe2b038 | 4224 | spin_unlock_irq(&p->sighand->siglock); |
1da177e4 LT |
4225 | return 0; |
4226 | } | |
4227 | ||
1bdda24c TG |
4228 | #ifdef CONFIG_DYNAMIC_SIGFRAME |
4229 | static inline void sigaltstack_lock(void) | |
4230 | __acquires(¤t->sighand->siglock) | |
4231 | { | |
4232 | spin_lock_irq(¤t->sighand->siglock); | |
4233 | } | |
4234 | ||
4235 | static inline void sigaltstack_unlock(void) | |
4236 | __releases(¤t->sighand->siglock) | |
4237 | { | |
4238 | spin_unlock_irq(¤t->sighand->siglock); | |
4239 | } | |
4240 | #else | |
4241 | static inline void sigaltstack_lock(void) { } | |
4242 | static inline void sigaltstack_unlock(void) { } | |
4243 | #endif | |
4244 | ||
c09c1441 | 4245 | static int |
22839869 WD |
4246 | do_sigaltstack (const stack_t *ss, stack_t *oss, unsigned long sp, |
4247 | size_t min_ss_size) | |
1da177e4 | 4248 | { |
bcfe8ad8 | 4249 | struct task_struct *t = current; |
1bdda24c | 4250 | int ret = 0; |
1da177e4 | 4251 | |
bcfe8ad8 AV |
4252 | if (oss) { |
4253 | memset(oss, 0, sizeof(stack_t)); | |
4254 | oss->ss_sp = (void __user *) t->sas_ss_sp; | |
4255 | oss->ss_size = t->sas_ss_size; | |
4256 | oss->ss_flags = sas_ss_flags(sp) | | |
4257 | (current->sas_ss_flags & SS_FLAG_BITS); | |
4258 | } | |
1da177e4 | 4259 | |
bcfe8ad8 AV |
4260 | if (ss) { |
4261 | void __user *ss_sp = ss->ss_sp; | |
4262 | size_t ss_size = ss->ss_size; | |
4263 | unsigned ss_flags = ss->ss_flags; | |
407bc16a | 4264 | int ss_mode; |
1da177e4 | 4265 | |
bcfe8ad8 AV |
4266 | if (unlikely(on_sig_stack(sp))) |
4267 | return -EPERM; | |
1da177e4 | 4268 | |
407bc16a | 4269 | ss_mode = ss_flags & ~SS_FLAG_BITS; |
bcfe8ad8 AV |
4270 | if (unlikely(ss_mode != SS_DISABLE && ss_mode != SS_ONSTACK && |
4271 | ss_mode != 0)) | |
4272 | return -EINVAL; | |
1da177e4 | 4273 | |
6c3118c3 CB |
4274 | /* |
4275 | * Return before taking any locks if no actual | |
4276 | * sigaltstack changes were requested. | |
4277 | */ | |
4278 | if (t->sas_ss_sp == (unsigned long)ss_sp && | |
4279 | t->sas_ss_size == ss_size && | |
4280 | t->sas_ss_flags == ss_flags) | |
4281 | return 0; | |
4282 | ||
1bdda24c | 4283 | sigaltstack_lock(); |
407bc16a | 4284 | if (ss_mode == SS_DISABLE) { |
1da177e4 LT |
4285 | ss_size = 0; |
4286 | ss_sp = NULL; | |
4287 | } else { | |
22839869 | 4288 | if (unlikely(ss_size < min_ss_size)) |
1bdda24c TG |
4289 | ret = -ENOMEM; |
4290 | if (!sigaltstack_size_valid(ss_size)) | |
4291 | ret = -ENOMEM; | |
1da177e4 | 4292 | } |
1bdda24c TG |
4293 | if (!ret) { |
4294 | t->sas_ss_sp = (unsigned long) ss_sp; | |
4295 | t->sas_ss_size = ss_size; | |
4296 | t->sas_ss_flags = ss_flags; | |
4297 | } | |
4298 | sigaltstack_unlock(); | |
1da177e4 | 4299 | } |
1bdda24c | 4300 | return ret; |
1da177e4 | 4301 | } |
bcfe8ad8 | 4302 | |
6bf9adfc AV |
4303 | SYSCALL_DEFINE2(sigaltstack,const stack_t __user *,uss, stack_t __user *,uoss) |
4304 | { | |
bcfe8ad8 AV |
4305 | stack_t new, old; |
4306 | int err; | |
4307 | if (uss && copy_from_user(&new, uss, sizeof(stack_t))) | |
4308 | return -EFAULT; | |
4309 | err = do_sigaltstack(uss ? &new : NULL, uoss ? &old : NULL, | |
22839869 WD |
4310 | current_user_stack_pointer(), |
4311 | MINSIGSTKSZ); | |
bcfe8ad8 AV |
4312 | if (!err && uoss && copy_to_user(uoss, &old, sizeof(stack_t))) |
4313 | err = -EFAULT; | |
4314 | return err; | |
6bf9adfc | 4315 | } |
1da177e4 | 4316 | |
5c49574f AV |
4317 | int restore_altstack(const stack_t __user *uss) |
4318 | { | |
bcfe8ad8 AV |
4319 | stack_t new; |
4320 | if (copy_from_user(&new, uss, sizeof(stack_t))) | |
4321 | return -EFAULT; | |
22839869 WD |
4322 | (void)do_sigaltstack(&new, NULL, current_user_stack_pointer(), |
4323 | MINSIGSTKSZ); | |
5c49574f | 4324 | /* squash all but EFAULT for now */ |
bcfe8ad8 | 4325 | return 0; |
5c49574f AV |
4326 | } |
4327 | ||
c40702c4 AV |
4328 | int __save_altstack(stack_t __user *uss, unsigned long sp) |
4329 | { | |
4330 | struct task_struct *t = current; | |
2a742138 SS |
4331 | int err = __put_user((void __user *)t->sas_ss_sp, &uss->ss_sp) | |
4332 | __put_user(t->sas_ss_flags, &uss->ss_flags) | | |
c40702c4 | 4333 | __put_user(t->sas_ss_size, &uss->ss_size); |
97c885d5 | 4334 | return err; |
c40702c4 AV |
4335 | } |
4336 | ||
90268439 | 4337 | #ifdef CONFIG_COMPAT |
6203deb0 DB |
4338 | static int do_compat_sigaltstack(const compat_stack_t __user *uss_ptr, |
4339 | compat_stack_t __user *uoss_ptr) | |
90268439 AV |
4340 | { |
4341 | stack_t uss, uoss; | |
4342 | int ret; | |
90268439 AV |
4343 | |
4344 | if (uss_ptr) { | |
4345 | compat_stack_t uss32; | |
90268439 AV |
4346 | if (copy_from_user(&uss32, uss_ptr, sizeof(compat_stack_t))) |
4347 | return -EFAULT; | |
4348 | uss.ss_sp = compat_ptr(uss32.ss_sp); | |
4349 | uss.ss_flags = uss32.ss_flags; | |
4350 | uss.ss_size = uss32.ss_size; | |
4351 | } | |
bcfe8ad8 | 4352 | ret = do_sigaltstack(uss_ptr ? &uss : NULL, &uoss, |
22839869 WD |
4353 | compat_user_stack_pointer(), |
4354 | COMPAT_MINSIGSTKSZ); | |
90268439 | 4355 | if (ret >= 0 && uoss_ptr) { |
bcfe8ad8 AV |
4356 | compat_stack_t old; |
4357 | memset(&old, 0, sizeof(old)); | |
4358 | old.ss_sp = ptr_to_compat(uoss.ss_sp); | |
4359 | old.ss_flags = uoss.ss_flags; | |
4360 | old.ss_size = uoss.ss_size; | |
4361 | if (copy_to_user(uoss_ptr, &old, sizeof(compat_stack_t))) | |
90268439 AV |
4362 | ret = -EFAULT; |
4363 | } | |
4364 | return ret; | |
4365 | } | |
4366 | ||
6203deb0 DB |
4367 | COMPAT_SYSCALL_DEFINE2(sigaltstack, |
4368 | const compat_stack_t __user *, uss_ptr, | |
4369 | compat_stack_t __user *, uoss_ptr) | |
4370 | { | |
4371 | return do_compat_sigaltstack(uss_ptr, uoss_ptr); | |
4372 | } | |
4373 | ||
90268439 AV |
4374 | int compat_restore_altstack(const compat_stack_t __user *uss) |
4375 | { | |
6203deb0 | 4376 | int err = do_compat_sigaltstack(uss, NULL); |
90268439 AV |
4377 | /* squash all but -EFAULT for now */ |
4378 | return err == -EFAULT ? err : 0; | |
4379 | } | |
c40702c4 AV |
4380 | |
4381 | int __compat_save_altstack(compat_stack_t __user *uss, unsigned long sp) | |
4382 | { | |
441398d3 | 4383 | int err; |
c40702c4 | 4384 | struct task_struct *t = current; |
441398d3 SS |
4385 | err = __put_user(ptr_to_compat((void __user *)t->sas_ss_sp), |
4386 | &uss->ss_sp) | | |
4387 | __put_user(t->sas_ss_flags, &uss->ss_flags) | | |
c40702c4 | 4388 | __put_user(t->sas_ss_size, &uss->ss_size); |
97c885d5 | 4389 | return err; |
c40702c4 | 4390 | } |
90268439 | 4391 | #endif |
1da177e4 LT |
4392 | |
4393 | #ifdef __ARCH_WANT_SYS_SIGPENDING | |
4394 | ||
41c57892 RD |
4395 | /** |
4396 | * sys_sigpending - examine pending signals | |
d53238cd | 4397 | * @uset: where mask of pending signal is returned |
41c57892 | 4398 | */ |
d53238cd | 4399 | SYSCALL_DEFINE1(sigpending, old_sigset_t __user *, uset) |
1da177e4 | 4400 | { |
d53238cd | 4401 | sigset_t set; |
d53238cd DB |
4402 | |
4403 | if (sizeof(old_sigset_t) > sizeof(*uset)) | |
4404 | return -EINVAL; | |
4405 | ||
b1d294c8 CB |
4406 | do_sigpending(&set); |
4407 | ||
4408 | if (copy_to_user(uset, &set, sizeof(old_sigset_t))) | |
4409 | return -EFAULT; | |
4410 | ||
4411 | return 0; | |
1da177e4 LT |
4412 | } |
4413 | ||
8f13621a AV |
4414 | #ifdef CONFIG_COMPAT |
4415 | COMPAT_SYSCALL_DEFINE1(sigpending, compat_old_sigset_t __user *, set32) | |
4416 | { | |
4417 | sigset_t set; | |
b1d294c8 CB |
4418 | |
4419 | do_sigpending(&set); | |
4420 | ||
4421 | return put_user(set.sig[0], set32); | |
8f13621a AV |
4422 | } |
4423 | #endif | |
4424 | ||
1da177e4 LT |
4425 | #endif |
4426 | ||
4427 | #ifdef __ARCH_WANT_SYS_SIGPROCMASK | |
41c57892 RD |
4428 | /** |
4429 | * sys_sigprocmask - examine and change blocked signals | |
4430 | * @how: whether to add, remove, or set signals | |
b013c399 | 4431 | * @nset: signals to add or remove (if non-null) |
41c57892 RD |
4432 | * @oset: previous value of signal mask if non-null |
4433 | * | |
5aba085e RD |
4434 | * Some platforms have their own version with special arguments; |
4435 | * others support only sys_rt_sigprocmask. | |
4436 | */ | |
1da177e4 | 4437 | |
b013c399 | 4438 | SYSCALL_DEFINE3(sigprocmask, int, how, old_sigset_t __user *, nset, |
b290ebe2 | 4439 | old_sigset_t __user *, oset) |
1da177e4 | 4440 | { |
1da177e4 | 4441 | old_sigset_t old_set, new_set; |
2e4f7c77 | 4442 | sigset_t new_blocked; |
1da177e4 | 4443 | |
b013c399 | 4444 | old_set = current->blocked.sig[0]; |
1da177e4 | 4445 | |
b013c399 ON |
4446 | if (nset) { |
4447 | if (copy_from_user(&new_set, nset, sizeof(*nset))) | |
4448 | return -EFAULT; | |
1da177e4 | 4449 | |
2e4f7c77 | 4450 | new_blocked = current->blocked; |
1da177e4 | 4451 | |
1da177e4 | 4452 | switch (how) { |
1da177e4 | 4453 | case SIG_BLOCK: |
2e4f7c77 | 4454 | sigaddsetmask(&new_blocked, new_set); |
1da177e4 LT |
4455 | break; |
4456 | case SIG_UNBLOCK: | |
2e4f7c77 | 4457 | sigdelsetmask(&new_blocked, new_set); |
1da177e4 LT |
4458 | break; |
4459 | case SIG_SETMASK: | |
2e4f7c77 | 4460 | new_blocked.sig[0] = new_set; |
1da177e4 | 4461 | break; |
2e4f7c77 ON |
4462 | default: |
4463 | return -EINVAL; | |
1da177e4 LT |
4464 | } |
4465 | ||
0c4a8423 | 4466 | set_current_blocked(&new_blocked); |
b013c399 ON |
4467 | } |
4468 | ||
4469 | if (oset) { | |
1da177e4 | 4470 | if (copy_to_user(oset, &old_set, sizeof(*oset))) |
b013c399 | 4471 | return -EFAULT; |
1da177e4 | 4472 | } |
b013c399 ON |
4473 | |
4474 | return 0; | |
1da177e4 LT |
4475 | } |
4476 | #endif /* __ARCH_WANT_SYS_SIGPROCMASK */ | |
4477 | ||
eaca6eae | 4478 | #ifndef CONFIG_ODD_RT_SIGACTION |
41c57892 RD |
4479 | /** |
4480 | * sys_rt_sigaction - alter an action taken by a process | |
4481 | * @sig: signal to be sent | |
f9fa0bc1 RD |
4482 | * @act: new sigaction |
4483 | * @oact: used to save the previous sigaction | |
41c57892 RD |
4484 | * @sigsetsize: size of sigset_t type |
4485 | */ | |
d4e82042 HC |
4486 | SYSCALL_DEFINE4(rt_sigaction, int, sig, |
4487 | const struct sigaction __user *, act, | |
4488 | struct sigaction __user *, oact, | |
4489 | size_t, sigsetsize) | |
1da177e4 LT |
4490 | { |
4491 | struct k_sigaction new_sa, old_sa; | |
d8f993b3 | 4492 | int ret; |
1da177e4 LT |
4493 | |
4494 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
4495 | if (sigsetsize != sizeof(sigset_t)) | |
d8f993b3 | 4496 | return -EINVAL; |
1da177e4 | 4497 | |
d8f993b3 CB |
4498 | if (act && copy_from_user(&new_sa.sa, act, sizeof(new_sa.sa))) |
4499 | return -EFAULT; | |
1da177e4 LT |
4500 | |
4501 | ret = do_sigaction(sig, act ? &new_sa : NULL, oact ? &old_sa : NULL); | |
d8f993b3 CB |
4502 | if (ret) |
4503 | return ret; | |
1da177e4 | 4504 | |
d8f993b3 CB |
4505 | if (oact && copy_to_user(oact, &old_sa.sa, sizeof(old_sa.sa))) |
4506 | return -EFAULT; | |
4507 | ||
4508 | return 0; | |
1da177e4 | 4509 | } |
08d32fe5 | 4510 | #ifdef CONFIG_COMPAT |
08d32fe5 AV |
4511 | COMPAT_SYSCALL_DEFINE4(rt_sigaction, int, sig, |
4512 | const struct compat_sigaction __user *, act, | |
4513 | struct compat_sigaction __user *, oact, | |
4514 | compat_size_t, sigsetsize) | |
4515 | { | |
4516 | struct k_sigaction new_ka, old_ka; | |
08d32fe5 AV |
4517 | #ifdef __ARCH_HAS_SA_RESTORER |
4518 | compat_uptr_t restorer; | |
4519 | #endif | |
4520 | int ret; | |
4521 | ||
4522 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
4523 | if (sigsetsize != sizeof(compat_sigset_t)) | |
4524 | return -EINVAL; | |
4525 | ||
4526 | if (act) { | |
4527 | compat_uptr_t handler; | |
4528 | ret = get_user(handler, &act->sa_handler); | |
4529 | new_ka.sa.sa_handler = compat_ptr(handler); | |
4530 | #ifdef __ARCH_HAS_SA_RESTORER | |
4531 | ret |= get_user(restorer, &act->sa_restorer); | |
4532 | new_ka.sa.sa_restorer = compat_ptr(restorer); | |
4533 | #endif | |
3968cf62 | 4534 | ret |= get_compat_sigset(&new_ka.sa.sa_mask, &act->sa_mask); |
3ddc5b46 | 4535 | ret |= get_user(new_ka.sa.sa_flags, &act->sa_flags); |
08d32fe5 AV |
4536 | if (ret) |
4537 | return -EFAULT; | |
08d32fe5 AV |
4538 | } |
4539 | ||
4540 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
4541 | if (!ret && oact) { | |
08d32fe5 AV |
4542 | ret = put_user(ptr_to_compat(old_ka.sa.sa_handler), |
4543 | &oact->sa_handler); | |
f454322e DL |
4544 | ret |= put_compat_sigset(&oact->sa_mask, &old_ka.sa.sa_mask, |
4545 | sizeof(oact->sa_mask)); | |
3ddc5b46 | 4546 | ret |= put_user(old_ka.sa.sa_flags, &oact->sa_flags); |
08d32fe5 AV |
4547 | #ifdef __ARCH_HAS_SA_RESTORER |
4548 | ret |= put_user(ptr_to_compat(old_ka.sa.sa_restorer), | |
4549 | &oact->sa_restorer); | |
4550 | #endif | |
4551 | } | |
4552 | return ret; | |
4553 | } | |
4554 | #endif | |
eaca6eae | 4555 | #endif /* !CONFIG_ODD_RT_SIGACTION */ |
1da177e4 | 4556 | |
495dfbf7 AV |
4557 | #ifdef CONFIG_OLD_SIGACTION |
4558 | SYSCALL_DEFINE3(sigaction, int, sig, | |
4559 | const struct old_sigaction __user *, act, | |
4560 | struct old_sigaction __user *, oact) | |
4561 | { | |
4562 | struct k_sigaction new_ka, old_ka; | |
4563 | int ret; | |
4564 | ||
4565 | if (act) { | |
4566 | old_sigset_t mask; | |
96d4f267 | 4567 | if (!access_ok(act, sizeof(*act)) || |
495dfbf7 AV |
4568 | __get_user(new_ka.sa.sa_handler, &act->sa_handler) || |
4569 | __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) || | |
4570 | __get_user(new_ka.sa.sa_flags, &act->sa_flags) || | |
4571 | __get_user(mask, &act->sa_mask)) | |
4572 | return -EFAULT; | |
4573 | #ifdef __ARCH_HAS_KA_RESTORER | |
4574 | new_ka.ka_restorer = NULL; | |
4575 | #endif | |
4576 | siginitset(&new_ka.sa.sa_mask, mask); | |
4577 | } | |
4578 | ||
4579 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
4580 | ||
4581 | if (!ret && oact) { | |
96d4f267 | 4582 | if (!access_ok(oact, sizeof(*oact)) || |
495dfbf7 AV |
4583 | __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || |
4584 | __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) || | |
4585 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags) || | |
4586 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask)) | |
4587 | return -EFAULT; | |
4588 | } | |
4589 | ||
4590 | return ret; | |
4591 | } | |
4592 | #endif | |
4593 | #ifdef CONFIG_COMPAT_OLD_SIGACTION | |
4594 | COMPAT_SYSCALL_DEFINE3(sigaction, int, sig, | |
4595 | const struct compat_old_sigaction __user *, act, | |
4596 | struct compat_old_sigaction __user *, oact) | |
4597 | { | |
4598 | struct k_sigaction new_ka, old_ka; | |
4599 | int ret; | |
4600 | compat_old_sigset_t mask; | |
4601 | compat_uptr_t handler, restorer; | |
4602 | ||
4603 | if (act) { | |
96d4f267 | 4604 | if (!access_ok(act, sizeof(*act)) || |
495dfbf7 AV |
4605 | __get_user(handler, &act->sa_handler) || |
4606 | __get_user(restorer, &act->sa_restorer) || | |
4607 | __get_user(new_ka.sa.sa_flags, &act->sa_flags) || | |
4608 | __get_user(mask, &act->sa_mask)) | |
4609 | return -EFAULT; | |
4610 | ||
4611 | #ifdef __ARCH_HAS_KA_RESTORER | |
4612 | new_ka.ka_restorer = NULL; | |
4613 | #endif | |
4614 | new_ka.sa.sa_handler = compat_ptr(handler); | |
4615 | new_ka.sa.sa_restorer = compat_ptr(restorer); | |
4616 | siginitset(&new_ka.sa.sa_mask, mask); | |
4617 | } | |
4618 | ||
4619 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
4620 | ||
4621 | if (!ret && oact) { | |
96d4f267 | 4622 | if (!access_ok(oact, sizeof(*oact)) || |
495dfbf7 AV |
4623 | __put_user(ptr_to_compat(old_ka.sa.sa_handler), |
4624 | &oact->sa_handler) || | |
4625 | __put_user(ptr_to_compat(old_ka.sa.sa_restorer), | |
4626 | &oact->sa_restorer) || | |
4627 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags) || | |
4628 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask)) | |
4629 | return -EFAULT; | |
4630 | } | |
4631 | return ret; | |
4632 | } | |
4633 | #endif | |
1da177e4 | 4634 | |
f6187769 | 4635 | #ifdef CONFIG_SGETMASK_SYSCALL |
1da177e4 LT |
4636 | |
4637 | /* | |
4638 | * For backwards compatibility. Functionality superseded by sigprocmask. | |
4639 | */ | |
a5f8fa9e | 4640 | SYSCALL_DEFINE0(sgetmask) |
1da177e4 LT |
4641 | { |
4642 | /* SMP safe */ | |
4643 | return current->blocked.sig[0]; | |
4644 | } | |
4645 | ||
a5f8fa9e | 4646 | SYSCALL_DEFINE1(ssetmask, int, newmask) |
1da177e4 | 4647 | { |
c1095c6d ON |
4648 | int old = current->blocked.sig[0]; |
4649 | sigset_t newset; | |
1da177e4 | 4650 | |
5ba53ff6 | 4651 | siginitset(&newset, newmask); |
c1095c6d | 4652 | set_current_blocked(&newset); |
1da177e4 LT |
4653 | |
4654 | return old; | |
4655 | } | |
f6187769 | 4656 | #endif /* CONFIG_SGETMASK_SYSCALL */ |
1da177e4 LT |
4657 | |
4658 | #ifdef __ARCH_WANT_SYS_SIGNAL | |
4659 | /* | |
4660 | * For backwards compatibility. Functionality superseded by sigaction. | |
4661 | */ | |
a5f8fa9e | 4662 | SYSCALL_DEFINE2(signal, int, sig, __sighandler_t, handler) |
1da177e4 LT |
4663 | { |
4664 | struct k_sigaction new_sa, old_sa; | |
4665 | int ret; | |
4666 | ||
4667 | new_sa.sa.sa_handler = handler; | |
4668 | new_sa.sa.sa_flags = SA_ONESHOT | SA_NOMASK; | |
c70d3d70 | 4669 | sigemptyset(&new_sa.sa.sa_mask); |
1da177e4 LT |
4670 | |
4671 | ret = do_sigaction(sig, &new_sa, &old_sa); | |
4672 | ||
4673 | return ret ? ret : (unsigned long)old_sa.sa.sa_handler; | |
4674 | } | |
4675 | #endif /* __ARCH_WANT_SYS_SIGNAL */ | |
4676 | ||
4677 | #ifdef __ARCH_WANT_SYS_PAUSE | |
4678 | ||
a5f8fa9e | 4679 | SYSCALL_DEFINE0(pause) |
1da177e4 | 4680 | { |
d92fcf05 | 4681 | while (!signal_pending(current)) { |
1df01355 | 4682 | __set_current_state(TASK_INTERRUPTIBLE); |
d92fcf05 ON |
4683 | schedule(); |
4684 | } | |
1da177e4 LT |
4685 | return -ERESTARTNOHAND; |
4686 | } | |
4687 | ||
4688 | #endif | |
4689 | ||
9d8a7652 | 4690 | static int sigsuspend(sigset_t *set) |
68f3f16d | 4691 | { |
68f3f16d AV |
4692 | current->saved_sigmask = current->blocked; |
4693 | set_current_blocked(set); | |
4694 | ||
823dd322 SL |
4695 | while (!signal_pending(current)) { |
4696 | __set_current_state(TASK_INTERRUPTIBLE); | |
4697 | schedule(); | |
4698 | } | |
68f3f16d AV |
4699 | set_restore_sigmask(); |
4700 | return -ERESTARTNOHAND; | |
4701 | } | |
68f3f16d | 4702 | |
41c57892 RD |
4703 | /** |
4704 | * sys_rt_sigsuspend - replace the signal mask for a value with the | |
4705 | * @unewset value until a signal is received | |
4706 | * @unewset: new signal mask value | |
4707 | * @sigsetsize: size of sigset_t type | |
4708 | */ | |
d4e82042 | 4709 | SYSCALL_DEFINE2(rt_sigsuspend, sigset_t __user *, unewset, size_t, sigsetsize) |
150256d8 DW |
4710 | { |
4711 | sigset_t newset; | |
4712 | ||
4713 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
4714 | if (sigsetsize != sizeof(sigset_t)) | |
4715 | return -EINVAL; | |
4716 | ||
4717 | if (copy_from_user(&newset, unewset, sizeof(newset))) | |
4718 | return -EFAULT; | |
68f3f16d | 4719 | return sigsuspend(&newset); |
150256d8 | 4720 | } |
ad4b65a4 AV |
4721 | |
4722 | #ifdef CONFIG_COMPAT | |
4723 | COMPAT_SYSCALL_DEFINE2(rt_sigsuspend, compat_sigset_t __user *, unewset, compat_size_t, sigsetsize) | |
4724 | { | |
ad4b65a4 | 4725 | sigset_t newset; |
ad4b65a4 AV |
4726 | |
4727 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
4728 | if (sigsetsize != sizeof(sigset_t)) | |
4729 | return -EINVAL; | |
4730 | ||
3968cf62 | 4731 | if (get_compat_sigset(&newset, unewset)) |
ad4b65a4 | 4732 | return -EFAULT; |
ad4b65a4 | 4733 | return sigsuspend(&newset); |
ad4b65a4 AV |
4734 | } |
4735 | #endif | |
150256d8 | 4736 | |
0a0e8cdf AV |
4737 | #ifdef CONFIG_OLD_SIGSUSPEND |
4738 | SYSCALL_DEFINE1(sigsuspend, old_sigset_t, mask) | |
4739 | { | |
4740 | sigset_t blocked; | |
4741 | siginitset(&blocked, mask); | |
4742 | return sigsuspend(&blocked); | |
4743 | } | |
4744 | #endif | |
4745 | #ifdef CONFIG_OLD_SIGSUSPEND3 | |
4746 | SYSCALL_DEFINE3(sigsuspend, int, unused1, int, unused2, old_sigset_t, mask) | |
4747 | { | |
4748 | sigset_t blocked; | |
4749 | siginitset(&blocked, mask); | |
4750 | return sigsuspend(&blocked); | |
4751 | } | |
4752 | #endif | |
150256d8 | 4753 | |
52f5684c | 4754 | __weak const char *arch_vma_name(struct vm_area_struct *vma) |
f269fdd1 DH |
4755 | { |
4756 | return NULL; | |
4757 | } | |
4758 | ||
ae7795bc | 4759 | static inline void siginfo_buildtime_checks(void) |
1da177e4 | 4760 | { |
aba1be2f | 4761 | BUILD_BUG_ON(sizeof(struct siginfo) != SI_MAX_SIZE); |
41b27154 | 4762 | |
ae7795bc EB |
4763 | /* Verify the offsets in the two siginfos match */ |
4764 | #define CHECK_OFFSET(field) \ | |
4765 | BUILD_BUG_ON(offsetof(siginfo_t, field) != offsetof(kernel_siginfo_t, field)) | |
4766 | ||
4767 | /* kill */ | |
4768 | CHECK_OFFSET(si_pid); | |
4769 | CHECK_OFFSET(si_uid); | |
4770 | ||
4771 | /* timer */ | |
4772 | CHECK_OFFSET(si_tid); | |
4773 | CHECK_OFFSET(si_overrun); | |
4774 | CHECK_OFFSET(si_value); | |
4775 | ||
4776 | /* rt */ | |
4777 | CHECK_OFFSET(si_pid); | |
4778 | CHECK_OFFSET(si_uid); | |
4779 | CHECK_OFFSET(si_value); | |
4780 | ||
4781 | /* sigchld */ | |
4782 | CHECK_OFFSET(si_pid); | |
4783 | CHECK_OFFSET(si_uid); | |
4784 | CHECK_OFFSET(si_status); | |
4785 | CHECK_OFFSET(si_utime); | |
4786 | CHECK_OFFSET(si_stime); | |
4787 | ||
4788 | /* sigfault */ | |
4789 | CHECK_OFFSET(si_addr); | |
add0b32e | 4790 | CHECK_OFFSET(si_trapno); |
ae7795bc EB |
4791 | CHECK_OFFSET(si_addr_lsb); |
4792 | CHECK_OFFSET(si_lower); | |
4793 | CHECK_OFFSET(si_upper); | |
4794 | CHECK_OFFSET(si_pkey); | |
0683b531 EB |
4795 | CHECK_OFFSET(si_perf_data); |
4796 | CHECK_OFFSET(si_perf_type); | |
78ed93d7 | 4797 | CHECK_OFFSET(si_perf_flags); |
ae7795bc EB |
4798 | |
4799 | /* sigpoll */ | |
4800 | CHECK_OFFSET(si_band); | |
4801 | CHECK_OFFSET(si_fd); | |
4802 | ||
4803 | /* sigsys */ | |
4804 | CHECK_OFFSET(si_call_addr); | |
4805 | CHECK_OFFSET(si_syscall); | |
4806 | CHECK_OFFSET(si_arch); | |
4807 | #undef CHECK_OFFSET | |
70f1b0d3 EB |
4808 | |
4809 | /* usb asyncio */ | |
4810 | BUILD_BUG_ON(offsetof(struct siginfo, si_pid) != | |
4811 | offsetof(struct siginfo, si_addr)); | |
4812 | if (sizeof(int) == sizeof(void __user *)) { | |
4813 | BUILD_BUG_ON(sizeof_field(struct siginfo, si_pid) != | |
4814 | sizeof(void __user *)); | |
4815 | } else { | |
4816 | BUILD_BUG_ON((sizeof_field(struct siginfo, si_pid) + | |
4817 | sizeof_field(struct siginfo, si_uid)) != | |
4818 | sizeof(void __user *)); | |
4819 | BUILD_BUG_ON(offsetofend(struct siginfo, si_pid) != | |
4820 | offsetof(struct siginfo, si_uid)); | |
4821 | } | |
4822 | #ifdef CONFIG_COMPAT | |
4823 | BUILD_BUG_ON(offsetof(struct compat_siginfo, si_pid) != | |
4824 | offsetof(struct compat_siginfo, si_addr)); | |
4825 | BUILD_BUG_ON(sizeof_field(struct compat_siginfo, si_pid) != | |
4826 | sizeof(compat_uptr_t)); | |
4827 | BUILD_BUG_ON(sizeof_field(struct compat_siginfo, si_pid) != | |
4828 | sizeof_field(struct siginfo, si_pid)); | |
4829 | #endif | |
ae7795bc EB |
4830 | } |
4831 | ||
01e6aac7 LC |
4832 | #if defined(CONFIG_SYSCTL) |
4833 | static struct ctl_table signal_debug_table[] = { | |
4834 | #ifdef CONFIG_SYSCTL_EXCEPTION_TRACE | |
4835 | { | |
4836 | .procname = "exception-trace", | |
4837 | .data = &show_unhandled_signals, | |
4838 | .maxlen = sizeof(int), | |
4839 | .mode = 0644, | |
4840 | .proc_handler = proc_dointvec | |
4841 | }, | |
4842 | #endif | |
4843 | { } | |
4844 | }; | |
4845 | ||
4846 | static int __init init_signal_sysctls(void) | |
4847 | { | |
4848 | register_sysctl_init("debug", signal_debug_table); | |
4849 | return 0; | |
4850 | } | |
4851 | early_initcall(init_signal_sysctls); | |
4852 | #endif /* CONFIG_SYSCTL */ | |
4853 | ||
ae7795bc EB |
4854 | void __init signals_init(void) |
4855 | { | |
4856 | siginfo_buildtime_checks(); | |
4857 | ||
5f58c398 | 4858 | sigqueue_cachep = KMEM_CACHE(sigqueue, SLAB_PANIC | SLAB_ACCOUNT); |
1da177e4 | 4859 | } |
67fc4e0c JW |
4860 | |
4861 | #ifdef CONFIG_KGDB_KDB | |
4862 | #include <linux/kdb.h> | |
4863 | /* | |
0b44bf9a | 4864 | * kdb_send_sig - Allows kdb to send signals without exposing |
67fc4e0c JW |
4865 | * signal internals. This function checks if the required locks are |
4866 | * available before calling the main signal code, to avoid kdb | |
4867 | * deadlocks. | |
4868 | */ | |
0b44bf9a | 4869 | void kdb_send_sig(struct task_struct *t, int sig) |
67fc4e0c JW |
4870 | { |
4871 | static struct task_struct *kdb_prev_t; | |
0b44bf9a | 4872 | int new_t, ret; |
67fc4e0c JW |
4873 | if (!spin_trylock(&t->sighand->siglock)) { |
4874 | kdb_printf("Can't do kill command now.\n" | |
4875 | "The sigmask lock is held somewhere else in " | |
4876 | "kernel, try again later\n"); | |
4877 | return; | |
4878 | } | |
67fc4e0c JW |
4879 | new_t = kdb_prev_t != t; |
4880 | kdb_prev_t = t; | |
b03fbd4f | 4881 | if (!task_is_running(t) && new_t) { |
0b44bf9a | 4882 | spin_unlock(&t->sighand->siglock); |
67fc4e0c JW |
4883 | kdb_printf("Process is not RUNNING, sending a signal from " |
4884 | "kdb risks deadlock\n" | |
4885 | "on the run queue locks. " | |
4886 | "The signal has _not_ been sent.\n" | |
4887 | "Reissue the kill command if you want to risk " | |
4888 | "the deadlock.\n"); | |
4889 | return; | |
4890 | } | |
157cc181 | 4891 | ret = send_signal_locked(sig, SEND_SIG_PRIV, t, PIDTYPE_PID); |
0b44bf9a EB |
4892 | spin_unlock(&t->sighand->siglock); |
4893 | if (ret) | |
67fc4e0c JW |
4894 | kdb_printf("Fail to deliver Signal %d to process %d.\n", |
4895 | sig, t->pid); | |
4896 | else | |
4897 | kdb_printf("Signal %d is sent to process %d.\n", sig, t->pid); | |
4898 | } | |
4899 | #endif /* CONFIG_KGDB_KDB */ |