2 * linux/kernel/signal.c
4 * Copyright (C) 1991, 1992 Linus Torvalds
6 * 1997-11-02 Modified for POSIX.1b signals by Richard Henderson
8 * 2003-06-02 Jim Houston - Concurrent Computer Corp.
9 * Changes to use preallocated sigqueue structures
10 * to allow signals to be sent reliably.
13 #include <linux/slab.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/sched.h>
18 #include <linux/tty.h>
19 #include <linux/binfmts.h>
20 #include <linux/security.h>
21 #include <linux/syscalls.h>
22 #include <linux/ptrace.h>
23 #include <linux/signal.h>
24 #include <linux/signalfd.h>
25 #include <linux/tracehook.h>
26 #include <linux/capability.h>
27 #include <linux/freezer.h>
28 #include <linux/pid_namespace.h>
29 #include <linux/nsproxy.h>
31 #include <asm/param.h>
32 #include <asm/uaccess.h>
33 #include <asm/unistd.h>
34 #include <asm/siginfo.h>
35 #include "audit.h" /* audit_signal_info() */
38 * SLAB caches for signal bits.
41 static struct kmem_cache
*sigqueue_cachep
;
43 static void __user
*sig_handler(struct task_struct
*t
, int sig
)
45 return t
->sighand
->action
[sig
- 1].sa
.sa_handler
;
48 static int sig_handler_ignored(void __user
*handler
, int sig
)
50 /* Is it explicitly or implicitly ignored? */
51 return handler
== SIG_IGN
||
52 (handler
== SIG_DFL
&& sig_kernel_ignore(sig
));
55 static int sig_ignored(struct task_struct
*t
, int sig
)
60 * Blocked signals are never ignored, since the
61 * signal handler may change by the time it is
64 if (sigismember(&t
->blocked
, sig
) || sigismember(&t
->real_blocked
, sig
))
67 handler
= sig_handler(t
, sig
);
68 if (!sig_handler_ignored(handler
, sig
))
72 * Tracers may want to know about even ignored signals.
74 return !tracehook_consider_ignored_signal(t
, sig
, handler
);
78 * Re-calculate pending state from the set of locally pending
79 * signals, globally pending signals, and blocked signals.
81 static inline int has_pending_signals(sigset_t
*signal
, sigset_t
*blocked
)
86 switch (_NSIG_WORDS
) {
88 for (i
= _NSIG_WORDS
, ready
= 0; --i
>= 0 ;)
89 ready
|= signal
->sig
[i
] &~ blocked
->sig
[i
];
92 case 4: ready
= signal
->sig
[3] &~ blocked
->sig
[3];
93 ready
|= signal
->sig
[2] &~ blocked
->sig
[2];
94 ready
|= signal
->sig
[1] &~ blocked
->sig
[1];
95 ready
|= signal
->sig
[0] &~ blocked
->sig
[0];
98 case 2: ready
= signal
->sig
[1] &~ blocked
->sig
[1];
99 ready
|= signal
->sig
[0] &~ blocked
->sig
[0];
102 case 1: ready
= signal
->sig
[0] &~ blocked
->sig
[0];
107 #define PENDING(p,b) has_pending_signals(&(p)->signal, (b))
109 static int recalc_sigpending_tsk(struct task_struct
*t
)
111 if (t
->signal
->group_stop_count
> 0 ||
112 PENDING(&t
->pending
, &t
->blocked
) ||
113 PENDING(&t
->signal
->shared_pending
, &t
->blocked
)) {
114 set_tsk_thread_flag(t
, TIF_SIGPENDING
);
118 * We must never clear the flag in another thread, or in current
119 * when it's possible the current syscall is returning -ERESTART*.
120 * So we don't clear it here, and only callers who know they should do.
126 * After recalculating TIF_SIGPENDING, we need to make sure the task wakes up.
127 * This is superfluous when called on current, the wakeup is a harmless no-op.
129 void recalc_sigpending_and_wake(struct task_struct
*t
)
131 if (recalc_sigpending_tsk(t
))
132 signal_wake_up(t
, 0);
135 void recalc_sigpending(void)
137 if (unlikely(tracehook_force_sigpending()))
138 set_thread_flag(TIF_SIGPENDING
);
139 else if (!recalc_sigpending_tsk(current
) && !freezing(current
))
140 clear_thread_flag(TIF_SIGPENDING
);
144 /* Given the mask, find the first available signal that should be serviced. */
146 int next_signal(struct sigpending
*pending
, sigset_t
*mask
)
148 unsigned long i
, *s
, *m
, x
;
151 s
= pending
->signal
.sig
;
153 switch (_NSIG_WORDS
) {
155 for (i
= 0; i
< _NSIG_WORDS
; ++i
, ++s
, ++m
)
156 if ((x
= *s
&~ *m
) != 0) {
157 sig
= ffz(~x
) + i
*_NSIG_BPW
+ 1;
162 case 2: if ((x
= s
[0] &~ m
[0]) != 0)
164 else if ((x
= s
[1] &~ m
[1]) != 0)
171 case 1: if ((x
= *s
&~ *m
) != 0)
179 static struct sigqueue
*__sigqueue_alloc(struct task_struct
*t
, gfp_t flags
,
182 struct sigqueue
*q
= NULL
;
183 struct user_struct
*user
;
186 * In order to avoid problems with "switch_user()", we want to make
187 * sure that the compiler doesn't re-load "t->user"
191 atomic_inc(&user
->sigpending
);
192 if (override_rlimit
||
193 atomic_read(&user
->sigpending
) <=
194 t
->signal
->rlim
[RLIMIT_SIGPENDING
].rlim_cur
)
195 q
= kmem_cache_alloc(sigqueue_cachep
, flags
);
196 if (unlikely(q
== NULL
)) {
197 atomic_dec(&user
->sigpending
);
199 INIT_LIST_HEAD(&q
->list
);
201 q
->user
= get_uid(user
);
206 static void __sigqueue_free(struct sigqueue
*q
)
208 if (q
->flags
& SIGQUEUE_PREALLOC
)
210 atomic_dec(&q
->user
->sigpending
);
212 kmem_cache_free(sigqueue_cachep
, q
);
215 void flush_sigqueue(struct sigpending
*queue
)
219 sigemptyset(&queue
->signal
);
220 while (!list_empty(&queue
->list
)) {
221 q
= list_entry(queue
->list
.next
, struct sigqueue
, list
);
222 list_del_init(&q
->list
);
228 * Flush all pending signals for a task.
230 void flush_signals(struct task_struct
*t
)
234 spin_lock_irqsave(&t
->sighand
->siglock
, flags
);
235 clear_tsk_thread_flag(t
, TIF_SIGPENDING
);
236 flush_sigqueue(&t
->pending
);
237 flush_sigqueue(&t
->signal
->shared_pending
);
238 spin_unlock_irqrestore(&t
->sighand
->siglock
, flags
);
241 static void __flush_itimer_signals(struct sigpending
*pending
)
243 sigset_t signal
, retain
;
244 struct sigqueue
*q
, *n
;
246 signal
= pending
->signal
;
247 sigemptyset(&retain
);
249 list_for_each_entry_safe(q
, n
, &pending
->list
, list
) {
250 int sig
= q
->info
.si_signo
;
252 if (likely(q
->info
.si_code
!= SI_TIMER
)) {
253 sigaddset(&retain
, sig
);
255 sigdelset(&signal
, sig
);
256 list_del_init(&q
->list
);
261 sigorsets(&pending
->signal
, &signal
, &retain
);
264 void flush_itimer_signals(void)
266 struct task_struct
*tsk
= current
;
269 spin_lock_irqsave(&tsk
->sighand
->siglock
, flags
);
270 __flush_itimer_signals(&tsk
->pending
);
271 __flush_itimer_signals(&tsk
->signal
->shared_pending
);
272 spin_unlock_irqrestore(&tsk
->sighand
->siglock
, flags
);
275 void ignore_signals(struct task_struct
*t
)
279 for (i
= 0; i
< _NSIG
; ++i
)
280 t
->sighand
->action
[i
].sa
.sa_handler
= SIG_IGN
;
286 * Flush all handlers for a task.
290 flush_signal_handlers(struct task_struct
*t
, int force_default
)
293 struct k_sigaction
*ka
= &t
->sighand
->action
[0];
294 for (i
= _NSIG
; i
!= 0 ; i
--) {
295 if (force_default
|| ka
->sa
.sa_handler
!= SIG_IGN
)
296 ka
->sa
.sa_handler
= SIG_DFL
;
298 sigemptyset(&ka
->sa
.sa_mask
);
303 int unhandled_signal(struct task_struct
*tsk
, int sig
)
305 void __user
*handler
= tsk
->sighand
->action
[sig
-1].sa
.sa_handler
;
306 if (is_global_init(tsk
))
308 if (handler
!= SIG_IGN
&& handler
!= SIG_DFL
)
310 return !tracehook_consider_fatal_signal(tsk
, sig
, handler
);
314 /* Notify the system that a driver wants to block all signals for this
315 * process, and wants to be notified if any signals at all were to be
316 * sent/acted upon. If the notifier routine returns non-zero, then the
317 * signal will be acted upon after all. If the notifier routine returns 0,
318 * then then signal will be blocked. Only one block per process is
319 * allowed. priv is a pointer to private data that the notifier routine
320 * can use to determine if the signal should be blocked or not. */
323 block_all_signals(int (*notifier
)(void *priv
), void *priv
, sigset_t
*mask
)
327 spin_lock_irqsave(¤t
->sighand
->siglock
, flags
);
328 current
->notifier_mask
= mask
;
329 current
->notifier_data
= priv
;
330 current
->notifier
= notifier
;
331 spin_unlock_irqrestore(¤t
->sighand
->siglock
, flags
);
334 /* Notify the system that blocking has ended. */
337 unblock_all_signals(void)
341 spin_lock_irqsave(¤t
->sighand
->siglock
, flags
);
342 current
->notifier
= NULL
;
343 current
->notifier_data
= NULL
;
345 spin_unlock_irqrestore(¤t
->sighand
->siglock
, flags
);
348 static void collect_signal(int sig
, struct sigpending
*list
, siginfo_t
*info
)
350 struct sigqueue
*q
, *first
= NULL
;
353 * Collect the siginfo appropriate to this signal. Check if
354 * there is another siginfo for the same signal.
356 list_for_each_entry(q
, &list
->list
, list
) {
357 if (q
->info
.si_signo
== sig
) {
364 sigdelset(&list
->signal
, sig
);
368 list_del_init(&first
->list
);
369 copy_siginfo(info
, &first
->info
);
370 __sigqueue_free(first
);
372 /* Ok, it wasn't in the queue. This must be
373 a fast-pathed signal or we must have been
374 out of queue space. So zero out the info.
376 info
->si_signo
= sig
;
384 static int __dequeue_signal(struct sigpending
*pending
, sigset_t
*mask
,
387 int sig
= next_signal(pending
, mask
);
390 if (current
->notifier
) {
391 if (sigismember(current
->notifier_mask
, sig
)) {
392 if (!(current
->notifier
)(current
->notifier_data
)) {
393 clear_thread_flag(TIF_SIGPENDING
);
399 collect_signal(sig
, pending
, info
);
406 * Dequeue a signal and return the element to the caller, which is
407 * expected to free it.
409 * All callers have to hold the siglock.
411 int dequeue_signal(struct task_struct
*tsk
, sigset_t
*mask
, siginfo_t
*info
)
415 /* We only dequeue private signals from ourselves, we don't let
416 * signalfd steal them
418 signr
= __dequeue_signal(&tsk
->pending
, mask
, info
);
420 signr
= __dequeue_signal(&tsk
->signal
->shared_pending
,
425 * itimers are process shared and we restart periodic
426 * itimers in the signal delivery path to prevent DoS
427 * attacks in the high resolution timer case. This is
428 * compliant with the old way of self restarting
429 * itimers, as the SIGALRM is a legacy signal and only
430 * queued once. Changing the restart behaviour to
431 * restart the timer in the signal dequeue path is
432 * reducing the timer noise on heavy loaded !highres
435 if (unlikely(signr
== SIGALRM
)) {
436 struct hrtimer
*tmr
= &tsk
->signal
->real_timer
;
438 if (!hrtimer_is_queued(tmr
) &&
439 tsk
->signal
->it_real_incr
.tv64
!= 0) {
440 hrtimer_forward(tmr
, tmr
->base
->get_time(),
441 tsk
->signal
->it_real_incr
);
442 hrtimer_restart(tmr
);
451 if (unlikely(sig_kernel_stop(signr
))) {
453 * Set a marker that we have dequeued a stop signal. Our
454 * caller might release the siglock and then the pending
455 * stop signal it is about to process is no longer in the
456 * pending bitmasks, but must still be cleared by a SIGCONT
457 * (and overruled by a SIGKILL). So those cases clear this
458 * shared flag after we've set it. Note that this flag may
459 * remain set after the signal we return is ignored or
460 * handled. That doesn't matter because its only purpose
461 * is to alert stop-signal processing code when another
462 * processor has come along and cleared the flag.
464 tsk
->signal
->flags
|= SIGNAL_STOP_DEQUEUED
;
466 if ((info
->si_code
& __SI_MASK
) == __SI_TIMER
&& info
->si_sys_private
) {
468 * Release the siglock to ensure proper locking order
469 * of timer locks outside of siglocks. Note, we leave
470 * irqs disabled here, since the posix-timers code is
471 * about to disable them again anyway.
473 spin_unlock(&tsk
->sighand
->siglock
);
474 do_schedule_next_timer(info
);
475 spin_lock(&tsk
->sighand
->siglock
);
481 * Tell a process that it has a new active signal..
483 * NOTE! we rely on the previous spin_lock to
484 * lock interrupts for us! We can only be called with
485 * "siglock" held, and the local interrupt must
486 * have been disabled when that got acquired!
488 * No need to set need_resched since signal event passing
489 * goes through ->blocked
491 void signal_wake_up(struct task_struct
*t
, int resume
)
495 set_tsk_thread_flag(t
, TIF_SIGPENDING
);
498 * For SIGKILL, we want to wake it up in the stopped/traced/killable
499 * case. We don't check t->state here because there is a race with it
500 * executing another processor and just now entering stopped state.
501 * By using wake_up_state, we ensure the process will wake up and
502 * handle its death signal.
504 mask
= TASK_INTERRUPTIBLE
;
506 mask
|= TASK_WAKEKILL
;
507 if (!wake_up_state(t
, mask
))
512 * Remove signals in mask from the pending set and queue.
513 * Returns 1 if any signals were found.
515 * All callers must be holding the siglock.
517 * This version takes a sigset mask and looks at all signals,
518 * not just those in the first mask word.
520 static int rm_from_queue_full(sigset_t
*mask
, struct sigpending
*s
)
522 struct sigqueue
*q
, *n
;
525 sigandsets(&m
, mask
, &s
->signal
);
526 if (sigisemptyset(&m
))
529 signandsets(&s
->signal
, &s
->signal
, mask
);
530 list_for_each_entry_safe(q
, n
, &s
->list
, list
) {
531 if (sigismember(mask
, q
->info
.si_signo
)) {
532 list_del_init(&q
->list
);
539 * Remove signals in mask from the pending set and queue.
540 * Returns 1 if any signals were found.
542 * All callers must be holding the siglock.
544 static int rm_from_queue(unsigned long mask
, struct sigpending
*s
)
546 struct sigqueue
*q
, *n
;
548 if (!sigtestsetmask(&s
->signal
, mask
))
551 sigdelsetmask(&s
->signal
, mask
);
552 list_for_each_entry_safe(q
, n
, &s
->list
, list
) {
553 if (q
->info
.si_signo
< SIGRTMIN
&&
554 (mask
& sigmask(q
->info
.si_signo
))) {
555 list_del_init(&q
->list
);
563 * Bad permissions for sending the signal
565 static int check_kill_permission(int sig
, struct siginfo
*info
,
566 struct task_struct
*t
)
571 if (!valid_signal(sig
))
574 if (info
!= SEND_SIG_NOINFO
&& (is_si_special(info
) || SI_FROMKERNEL(info
)))
577 error
= audit_signal_info(sig
, t
); /* Let audit system see the signal */
581 if ((current
->euid
^ t
->suid
) && (current
->euid
^ t
->uid
) &&
582 (current
->uid
^ t
->suid
) && (current
->uid
^ t
->uid
) &&
583 !capable(CAP_KILL
)) {
586 sid
= task_session(t
);
588 * We don't return the error if sid == NULL. The
589 * task was unhashed, the caller must notice this.
591 if (!sid
|| sid
== task_session(current
))
598 return security_task_kill(t
, info
, sig
, 0);
602 * Handle magic process-wide effects of stop/continue signals. Unlike
603 * the signal actions, these happen immediately at signal-generation
604 * time regardless of blocking, ignoring, or handling. This does the
605 * actual continuing for SIGCONT, but not the actual stopping for stop
606 * signals. The process stop is done as a signal action for SIG_DFL.
608 * Returns true if the signal should be actually delivered, otherwise
609 * it should be dropped.
611 static int prepare_signal(int sig
, struct task_struct
*p
)
613 struct signal_struct
*signal
= p
->signal
;
614 struct task_struct
*t
;
616 if (unlikely(signal
->flags
& SIGNAL_GROUP_EXIT
)) {
618 * The process is in the middle of dying, nothing to do.
620 } else if (sig_kernel_stop(sig
)) {
622 * This is a stop signal. Remove SIGCONT from all queues.
624 rm_from_queue(sigmask(SIGCONT
), &signal
->shared_pending
);
627 rm_from_queue(sigmask(SIGCONT
), &t
->pending
);
628 } while_each_thread(p
, t
);
629 } else if (sig
== SIGCONT
) {
632 * Remove all stop signals from all queues,
633 * and wake all threads.
635 rm_from_queue(SIG_KERNEL_STOP_MASK
, &signal
->shared_pending
);
639 rm_from_queue(SIG_KERNEL_STOP_MASK
, &t
->pending
);
641 * If there is a handler for SIGCONT, we must make
642 * sure that no thread returns to user mode before
643 * we post the signal, in case it was the only
644 * thread eligible to run the signal handler--then
645 * it must not do anything between resuming and
646 * running the handler. With the TIF_SIGPENDING
647 * flag set, the thread will pause and acquire the
648 * siglock that we hold now and until we've queued
649 * the pending signal.
651 * Wake up the stopped thread _after_ setting
654 state
= __TASK_STOPPED
;
655 if (sig_user_defined(t
, SIGCONT
) && !sigismember(&t
->blocked
, SIGCONT
)) {
656 set_tsk_thread_flag(t
, TIF_SIGPENDING
);
657 state
|= TASK_INTERRUPTIBLE
;
659 wake_up_state(t
, state
);
660 } while_each_thread(p
, t
);
663 * Notify the parent with CLD_CONTINUED if we were stopped.
665 * If we were in the middle of a group stop, we pretend it
666 * was already finished, and then continued. Since SIGCHLD
667 * doesn't queue we report only CLD_STOPPED, as if the next
668 * CLD_CONTINUED was dropped.
671 if (signal
->flags
& SIGNAL_STOP_STOPPED
)
672 why
|= SIGNAL_CLD_CONTINUED
;
673 else if (signal
->group_stop_count
)
674 why
|= SIGNAL_CLD_STOPPED
;
678 * The first thread which returns from finish_stop()
679 * will take ->siglock, notice SIGNAL_CLD_MASK, and
680 * notify its parent. See get_signal_to_deliver().
682 signal
->flags
= why
| SIGNAL_STOP_CONTINUED
;
683 signal
->group_stop_count
= 0;
684 signal
->group_exit_code
= 0;
687 * We are not stopped, but there could be a stop
688 * signal in the middle of being processed after
689 * being removed from the queue. Clear that too.
691 signal
->flags
&= ~SIGNAL_STOP_DEQUEUED
;
695 return !sig_ignored(p
, sig
);
699 * Test if P wants to take SIG. After we've checked all threads with this,
700 * it's equivalent to finding no threads not blocking SIG. Any threads not
701 * blocking SIG were ruled out because they are not running and already
702 * have pending signals. Such threads will dequeue from the shared queue
703 * as soon as they're available, so putting the signal on the shared queue
704 * will be equivalent to sending it to one such thread.
706 static inline int wants_signal(int sig
, struct task_struct
*p
)
708 if (sigismember(&p
->blocked
, sig
))
710 if (p
->flags
& PF_EXITING
)
714 if (task_is_stopped_or_traced(p
))
716 return task_curr(p
) || !signal_pending(p
);
719 static void complete_signal(int sig
, struct task_struct
*p
, int group
)
721 struct signal_struct
*signal
= p
->signal
;
722 struct task_struct
*t
;
725 * Now find a thread we can wake up to take the signal off the queue.
727 * If the main thread wants the signal, it gets first crack.
728 * Probably the least surprising to the average bear.
730 if (wants_signal(sig
, p
))
732 else if (!group
|| thread_group_empty(p
))
734 * There is just one thread and it does not need to be woken.
735 * It will dequeue unblocked signals before it runs again.
740 * Otherwise try to find a suitable thread.
742 t
= signal
->curr_target
;
743 while (!wants_signal(sig
, t
)) {
745 if (t
== signal
->curr_target
)
747 * No thread needs to be woken.
748 * Any eligible threads will see
749 * the signal in the queue soon.
753 signal
->curr_target
= t
;
757 * Found a killable thread. If the signal will be fatal,
758 * then start taking the whole group down immediately.
760 if (sig_fatal(p
, sig
) &&
761 !(signal
->flags
& (SIGNAL_UNKILLABLE
| SIGNAL_GROUP_EXIT
)) &&
762 !sigismember(&t
->real_blocked
, sig
) &&
764 !tracehook_consider_fatal_signal(t
, sig
, SIG_DFL
))) {
766 * This signal will be fatal to the whole group.
768 if (!sig_kernel_coredump(sig
)) {
770 * Start a group exit and wake everybody up.
771 * This way we don't have other threads
772 * running and doing things after a slower
773 * thread has the fatal signal pending.
775 signal
->flags
= SIGNAL_GROUP_EXIT
;
776 signal
->group_exit_code
= sig
;
777 signal
->group_stop_count
= 0;
780 sigaddset(&t
->pending
.signal
, SIGKILL
);
781 signal_wake_up(t
, 1);
782 } while_each_thread(p
, t
);
788 * The signal is already in the shared-pending queue.
789 * Tell the chosen thread to wake up and dequeue it.
791 signal_wake_up(t
, sig
== SIGKILL
);
795 static inline int legacy_queue(struct sigpending
*signals
, int sig
)
797 return (sig
< SIGRTMIN
) && sigismember(&signals
->signal
, sig
);
800 static int send_signal(int sig
, struct siginfo
*info
, struct task_struct
*t
,
803 struct sigpending
*pending
;
806 assert_spin_locked(&t
->sighand
->siglock
);
807 if (!prepare_signal(sig
, t
))
810 pending
= group
? &t
->signal
->shared_pending
: &t
->pending
;
812 * Short-circuit ignored signals and support queuing
813 * exactly one non-rt signal, so that we can get more
814 * detailed information about the cause of the signal.
816 if (legacy_queue(pending
, sig
))
819 * fast-pathed signals for kernel-internal things like SIGSTOP
822 if (info
== SEND_SIG_FORCED
)
825 /* Real-time signals must be queued if sent by sigqueue, or
826 some other real-time mechanism. It is implementation
827 defined whether kill() does so. We attempt to do so, on
828 the principle of least surprise, but since kill is not
829 allowed to fail with EAGAIN when low on memory we just
830 make sure at least one signal gets delivered and don't
831 pass on the info struct. */
833 q
= __sigqueue_alloc(t
, GFP_ATOMIC
, (sig
< SIGRTMIN
&&
834 (is_si_special(info
) ||
835 info
->si_code
>= 0)));
837 list_add_tail(&q
->list
, &pending
->list
);
838 switch ((unsigned long) info
) {
839 case (unsigned long) SEND_SIG_NOINFO
:
840 q
->info
.si_signo
= sig
;
841 q
->info
.si_errno
= 0;
842 q
->info
.si_code
= SI_USER
;
843 q
->info
.si_pid
= task_pid_vnr(current
);
844 q
->info
.si_uid
= current
->uid
;
846 case (unsigned long) SEND_SIG_PRIV
:
847 q
->info
.si_signo
= sig
;
848 q
->info
.si_errno
= 0;
849 q
->info
.si_code
= SI_KERNEL
;
854 copy_siginfo(&q
->info
, info
);
857 } else if (!is_si_special(info
)) {
858 if (sig
>= SIGRTMIN
&& info
->si_code
!= SI_USER
)
860 * Queue overflow, abort. We may abort if the signal was rt
861 * and sent by user using something other than kill().
867 signalfd_notify(t
, sig
);
868 sigaddset(&pending
->signal
, sig
);
869 complete_signal(sig
, t
, group
);
873 int print_fatal_signals
;
875 static void print_fatal_signal(struct pt_regs
*regs
, int signr
)
877 printk("%s/%d: potentially unexpected fatal signal %d.\n",
878 current
->comm
, task_pid_nr(current
), signr
);
880 #if defined(__i386__) && !defined(__arch_um__)
881 printk("code at %08lx: ", regs
->ip
);
884 for (i
= 0; i
< 16; i
++) {
887 __get_user(insn
, (unsigned char *)(regs
->ip
+ i
));
888 printk("%02x ", insn
);
896 static int __init
setup_print_fatal_signals(char *str
)
898 get_option (&str
, &print_fatal_signals
);
903 __setup("print-fatal-signals=", setup_print_fatal_signals
);
906 __group_send_sig_info(int sig
, struct siginfo
*info
, struct task_struct
*p
)
908 return send_signal(sig
, info
, p
, 1);
912 specific_send_sig_info(int sig
, struct siginfo
*info
, struct task_struct
*t
)
914 return send_signal(sig
, info
, t
, 0);
918 * Force a signal that the process can't ignore: if necessary
919 * we unblock the signal and change any SIG_IGN to SIG_DFL.
921 * Note: If we unblock the signal, we always reset it to SIG_DFL,
922 * since we do not want to have a signal handler that was blocked
923 * be invoked when user space had explicitly blocked it.
925 * We don't want to have recursive SIGSEGV's etc, for example,
926 * that is why we also clear SIGNAL_UNKILLABLE.
929 force_sig_info(int sig
, struct siginfo
*info
, struct task_struct
*t
)
931 unsigned long int flags
;
932 int ret
, blocked
, ignored
;
933 struct k_sigaction
*action
;
935 spin_lock_irqsave(&t
->sighand
->siglock
, flags
);
936 action
= &t
->sighand
->action
[sig
-1];
937 ignored
= action
->sa
.sa_handler
== SIG_IGN
;
938 blocked
= sigismember(&t
->blocked
, sig
);
939 if (blocked
|| ignored
) {
940 action
->sa
.sa_handler
= SIG_DFL
;
942 sigdelset(&t
->blocked
, sig
);
943 recalc_sigpending_and_wake(t
);
946 if (action
->sa
.sa_handler
== SIG_DFL
)
947 t
->signal
->flags
&= ~SIGNAL_UNKILLABLE
;
948 ret
= specific_send_sig_info(sig
, info
, t
);
949 spin_unlock_irqrestore(&t
->sighand
->siglock
, flags
);
955 force_sig_specific(int sig
, struct task_struct
*t
)
957 force_sig_info(sig
, SEND_SIG_FORCED
, t
);
961 * Nuke all other threads in the group.
963 void zap_other_threads(struct task_struct
*p
)
965 struct task_struct
*t
;
967 p
->signal
->group_stop_count
= 0;
969 for (t
= next_thread(p
); t
!= p
; t
= next_thread(t
)) {
971 * Don't bother with already dead threads
976 /* SIGKILL will be handled before any pending SIGSTOP */
977 sigaddset(&t
->pending
.signal
, SIGKILL
);
978 signal_wake_up(t
, 1);
982 int __fatal_signal_pending(struct task_struct
*tsk
)
984 return sigismember(&tsk
->pending
.signal
, SIGKILL
);
986 EXPORT_SYMBOL(__fatal_signal_pending
);
988 struct sighand_struct
*lock_task_sighand(struct task_struct
*tsk
, unsigned long *flags
)
990 struct sighand_struct
*sighand
;
994 sighand
= rcu_dereference(tsk
->sighand
);
995 if (unlikely(sighand
== NULL
))
998 spin_lock_irqsave(&sighand
->siglock
, *flags
);
999 if (likely(sighand
== tsk
->sighand
))
1001 spin_unlock_irqrestore(&sighand
->siglock
, *flags
);
1008 int group_send_sig_info(int sig
, struct siginfo
*info
, struct task_struct
*p
)
1010 unsigned long flags
;
1013 ret
= check_kill_permission(sig
, info
, p
);
1017 if (lock_task_sighand(p
, &flags
)) {
1018 ret
= __group_send_sig_info(sig
, info
, p
);
1019 unlock_task_sighand(p
, &flags
);
1027 * __kill_pgrp_info() sends a signal to a process group: this is what the tty
1028 * control characters do (^C, ^Z etc)
1031 int __kill_pgrp_info(int sig
, struct siginfo
*info
, struct pid
*pgrp
)
1033 struct task_struct
*p
= NULL
;
1034 int retval
, success
;
1038 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
1039 int err
= group_send_sig_info(sig
, info
, p
);
1042 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
1043 return success
? 0 : retval
;
1046 int kill_pid_info(int sig
, struct siginfo
*info
, struct pid
*pid
)
1049 struct task_struct
*p
;
1053 p
= pid_task(pid
, PIDTYPE_PID
);
1055 error
= group_send_sig_info(sig
, info
, p
);
1056 if (unlikely(error
== -ESRCH
))
1058 * The task was unhashed in between, try again.
1059 * If it is dead, pid_task() will return NULL,
1060 * if we race with de_thread() it will find the
1071 kill_proc_info(int sig
, struct siginfo
*info
, pid_t pid
)
1075 error
= kill_pid_info(sig
, info
, find_vpid(pid
));
1080 /* like kill_pid_info(), but doesn't use uid/euid of "current" */
1081 int kill_pid_info_as_uid(int sig
, struct siginfo
*info
, struct pid
*pid
,
1082 uid_t uid
, uid_t euid
, u32 secid
)
1085 struct task_struct
*p
;
1087 if (!valid_signal(sig
))
1090 read_lock(&tasklist_lock
);
1091 p
= pid_task(pid
, PIDTYPE_PID
);
1096 if ((info
== SEND_SIG_NOINFO
|| (!is_si_special(info
) && SI_FROMUSER(info
)))
1097 && (euid
!= p
->suid
) && (euid
!= p
->uid
)
1098 && (uid
!= p
->suid
) && (uid
!= p
->uid
)) {
1102 ret
= security_task_kill(p
, info
, sig
, secid
);
1105 if (sig
&& p
->sighand
) {
1106 unsigned long flags
;
1107 spin_lock_irqsave(&p
->sighand
->siglock
, flags
);
1108 ret
= __group_send_sig_info(sig
, info
, p
);
1109 spin_unlock_irqrestore(&p
->sighand
->siglock
, flags
);
1112 read_unlock(&tasklist_lock
);
1115 EXPORT_SYMBOL_GPL(kill_pid_info_as_uid
);
1118 * kill_something_info() interprets pid in interesting ways just like kill(2).
1120 * POSIX specifies that kill(-1,sig) is unspecified, but what we have
1121 * is probably wrong. Should make it like BSD or SYSV.
1124 static int kill_something_info(int sig
, struct siginfo
*info
, pid_t pid
)
1130 ret
= kill_pid_info(sig
, info
, find_vpid(pid
));
1135 read_lock(&tasklist_lock
);
1137 ret
= __kill_pgrp_info(sig
, info
,
1138 pid
? find_vpid(-pid
) : task_pgrp(current
));
1140 int retval
= 0, count
= 0;
1141 struct task_struct
* p
;
1143 for_each_process(p
) {
1144 if (task_pid_vnr(p
) > 1 &&
1145 !same_thread_group(p
, current
)) {
1146 int err
= group_send_sig_info(sig
, info
, p
);
1152 ret
= count
? retval
: -ESRCH
;
1154 read_unlock(&tasklist_lock
);
1160 * These are for backward compatibility with the rest of the kernel source.
1164 * The caller must ensure the task can't exit.
1167 send_sig_info(int sig
, struct siginfo
*info
, struct task_struct
*p
)
1170 unsigned long flags
;
1173 * Make sure legacy kernel users don't send in bad values
1174 * (normal paths check this in check_kill_permission).
1176 if (!valid_signal(sig
))
1179 spin_lock_irqsave(&p
->sighand
->siglock
, flags
);
1180 ret
= specific_send_sig_info(sig
, info
, p
);
1181 spin_unlock_irqrestore(&p
->sighand
->siglock
, flags
);
1185 #define __si_special(priv) \
1186 ((priv) ? SEND_SIG_PRIV : SEND_SIG_NOINFO)
1189 send_sig(int sig
, struct task_struct
*p
, int priv
)
1191 return send_sig_info(sig
, __si_special(priv
), p
);
1195 force_sig(int sig
, struct task_struct
*p
)
1197 force_sig_info(sig
, SEND_SIG_PRIV
, p
);
1201 * When things go south during signal handling, we
1202 * will force a SIGSEGV. And if the signal that caused
1203 * the problem was already a SIGSEGV, we'll want to
1204 * make sure we don't even try to deliver the signal..
1207 force_sigsegv(int sig
, struct task_struct
*p
)
1209 if (sig
== SIGSEGV
) {
1210 unsigned long flags
;
1211 spin_lock_irqsave(&p
->sighand
->siglock
, flags
);
1212 p
->sighand
->action
[sig
- 1].sa
.sa_handler
= SIG_DFL
;
1213 spin_unlock_irqrestore(&p
->sighand
->siglock
, flags
);
1215 force_sig(SIGSEGV
, p
);
1219 int kill_pgrp(struct pid
*pid
, int sig
, int priv
)
1223 read_lock(&tasklist_lock
);
1224 ret
= __kill_pgrp_info(sig
, __si_special(priv
), pid
);
1225 read_unlock(&tasklist_lock
);
1229 EXPORT_SYMBOL(kill_pgrp
);
1231 int kill_pid(struct pid
*pid
, int sig
, int priv
)
1233 return kill_pid_info(sig
, __si_special(priv
), pid
);
1235 EXPORT_SYMBOL(kill_pid
);
1238 * These functions support sending signals using preallocated sigqueue
1239 * structures. This is needed "because realtime applications cannot
1240 * afford to lose notifications of asynchronous events, like timer
1241 * expirations or I/O completions". In the case of Posix Timers
1242 * we allocate the sigqueue structure from the timer_create. If this
1243 * allocation fails we are able to report the failure to the application
1244 * with an EAGAIN error.
1247 struct sigqueue
*sigqueue_alloc(void)
1251 if ((q
= __sigqueue_alloc(current
, GFP_KERNEL
, 0)))
1252 q
->flags
|= SIGQUEUE_PREALLOC
;
1256 void sigqueue_free(struct sigqueue
*q
)
1258 unsigned long flags
;
1259 spinlock_t
*lock
= ¤t
->sighand
->siglock
;
1261 BUG_ON(!(q
->flags
& SIGQUEUE_PREALLOC
));
1263 * We must hold ->siglock while testing q->list
1264 * to serialize with collect_signal() or with
1265 * __exit_signal()->flush_sigqueue().
1267 spin_lock_irqsave(lock
, flags
);
1268 q
->flags
&= ~SIGQUEUE_PREALLOC
;
1270 * If it is queued it will be freed when dequeued,
1271 * like the "regular" sigqueue.
1273 if (!list_empty(&q
->list
))
1275 spin_unlock_irqrestore(lock
, flags
);
1281 int send_sigqueue(struct sigqueue
*q
, struct task_struct
*t
, int group
)
1283 int sig
= q
->info
.si_signo
;
1284 struct sigpending
*pending
;
1285 unsigned long flags
;
1288 BUG_ON(!(q
->flags
& SIGQUEUE_PREALLOC
));
1291 if (!likely(lock_task_sighand(t
, &flags
)))
1294 ret
= 1; /* the signal is ignored */
1295 if (!prepare_signal(sig
, t
))
1299 if (unlikely(!list_empty(&q
->list
))) {
1301 * If an SI_TIMER entry is already queue just increment
1302 * the overrun count.
1304 BUG_ON(q
->info
.si_code
!= SI_TIMER
);
1305 q
->info
.si_overrun
++;
1308 q
->info
.si_overrun
= 0;
1310 signalfd_notify(t
, sig
);
1311 pending
= group
? &t
->signal
->shared_pending
: &t
->pending
;
1312 list_add_tail(&q
->list
, &pending
->list
);
1313 sigaddset(&pending
->signal
, sig
);
1314 complete_signal(sig
, t
, group
);
1316 unlock_task_sighand(t
, &flags
);
1322 * Wake up any threads in the parent blocked in wait* syscalls.
1324 static inline void __wake_up_parent(struct task_struct
*p
,
1325 struct task_struct
*parent
)
1327 wake_up_interruptible_sync(&parent
->signal
->wait_chldexit
);
1331 * Let a parent know about the death of a child.
1332 * For a stopped/continued status change, use do_notify_parent_cldstop instead.
1334 * Returns -1 if our parent ignored us and so we've switched to
1335 * self-reaping, or else @sig.
1337 int do_notify_parent(struct task_struct
*tsk
, int sig
)
1339 struct siginfo info
;
1340 unsigned long flags
;
1341 struct sighand_struct
*psig
;
1346 /* do_notify_parent_cldstop should have been called instead. */
1347 BUG_ON(task_is_stopped_or_traced(tsk
));
1349 BUG_ON(!tsk
->ptrace
&&
1350 (tsk
->group_leader
!= tsk
|| !thread_group_empty(tsk
)));
1352 info
.si_signo
= sig
;
1355 * we are under tasklist_lock here so our parent is tied to
1356 * us and cannot exit and release its namespace.
1358 * the only it can is to switch its nsproxy with sys_unshare,
1359 * bu uncharing pid namespaces is not allowed, so we'll always
1360 * see relevant namespace
1362 * write_lock() currently calls preempt_disable() which is the
1363 * same as rcu_read_lock(), but according to Oleg, this is not
1364 * correct to rely on this
1367 info
.si_pid
= task_pid_nr_ns(tsk
, tsk
->parent
->nsproxy
->pid_ns
);
1370 info
.si_uid
= tsk
->uid
;
1372 info
.si_utime
= cputime_to_clock_t(cputime_add(tsk
->utime
,
1373 tsk
->signal
->utime
));
1374 info
.si_stime
= cputime_to_clock_t(cputime_add(tsk
->stime
,
1375 tsk
->signal
->stime
));
1377 info
.si_status
= tsk
->exit_code
& 0x7f;
1378 if (tsk
->exit_code
& 0x80)
1379 info
.si_code
= CLD_DUMPED
;
1380 else if (tsk
->exit_code
& 0x7f)
1381 info
.si_code
= CLD_KILLED
;
1383 info
.si_code
= CLD_EXITED
;
1384 info
.si_status
= tsk
->exit_code
>> 8;
1387 psig
= tsk
->parent
->sighand
;
1388 spin_lock_irqsave(&psig
->siglock
, flags
);
1389 if (!tsk
->ptrace
&& sig
== SIGCHLD
&&
1390 (psig
->action
[SIGCHLD
-1].sa
.sa_handler
== SIG_IGN
||
1391 (psig
->action
[SIGCHLD
-1].sa
.sa_flags
& SA_NOCLDWAIT
))) {
1393 * We are exiting and our parent doesn't care. POSIX.1
1394 * defines special semantics for setting SIGCHLD to SIG_IGN
1395 * or setting the SA_NOCLDWAIT flag: we should be reaped
1396 * automatically and not left for our parent's wait4 call.
1397 * Rather than having the parent do it as a magic kind of
1398 * signal handler, we just set this to tell do_exit that we
1399 * can be cleaned up without becoming a zombie. Note that
1400 * we still call __wake_up_parent in this case, because a
1401 * blocked sys_wait4 might now return -ECHILD.
1403 * Whether we send SIGCHLD or not for SA_NOCLDWAIT
1404 * is implementation-defined: we do (if you don't want
1405 * it, just use SIG_IGN instead).
1407 ret
= tsk
->exit_signal
= -1;
1408 if (psig
->action
[SIGCHLD
-1].sa
.sa_handler
== SIG_IGN
)
1411 if (valid_signal(sig
) && sig
> 0)
1412 __group_send_sig_info(sig
, &info
, tsk
->parent
);
1413 __wake_up_parent(tsk
, tsk
->parent
);
1414 spin_unlock_irqrestore(&psig
->siglock
, flags
);
1419 static void do_notify_parent_cldstop(struct task_struct
*tsk
, int why
)
1421 struct siginfo info
;
1422 unsigned long flags
;
1423 struct task_struct
*parent
;
1424 struct sighand_struct
*sighand
;
1426 if (tsk
->ptrace
& PT_PTRACED
)
1427 parent
= tsk
->parent
;
1429 tsk
= tsk
->group_leader
;
1430 parent
= tsk
->real_parent
;
1433 info
.si_signo
= SIGCHLD
;
1436 * see comment in do_notify_parent() abot the following 3 lines
1439 info
.si_pid
= task_pid_nr_ns(tsk
, tsk
->parent
->nsproxy
->pid_ns
);
1442 info
.si_uid
= tsk
->uid
;
1444 info
.si_utime
= cputime_to_clock_t(tsk
->utime
);
1445 info
.si_stime
= cputime_to_clock_t(tsk
->stime
);
1450 info
.si_status
= SIGCONT
;
1453 info
.si_status
= tsk
->signal
->group_exit_code
& 0x7f;
1456 info
.si_status
= tsk
->exit_code
& 0x7f;
1462 sighand
= parent
->sighand
;
1463 spin_lock_irqsave(&sighand
->siglock
, flags
);
1464 if (sighand
->action
[SIGCHLD
-1].sa
.sa_handler
!= SIG_IGN
&&
1465 !(sighand
->action
[SIGCHLD
-1].sa
.sa_flags
& SA_NOCLDSTOP
))
1466 __group_send_sig_info(SIGCHLD
, &info
, parent
);
1468 * Even if SIGCHLD is not generated, we must wake up wait4 calls.
1470 __wake_up_parent(tsk
, parent
);
1471 spin_unlock_irqrestore(&sighand
->siglock
, flags
);
1474 static inline int may_ptrace_stop(void)
1476 if (!likely(current
->ptrace
& PT_PTRACED
))
1479 * Are we in the middle of do_coredump?
1480 * If so and our tracer is also part of the coredump stopping
1481 * is a deadlock situation, and pointless because our tracer
1482 * is dead so don't allow us to stop.
1483 * If SIGKILL was already sent before the caller unlocked
1484 * ->siglock we must see ->core_state != NULL. Otherwise it
1485 * is safe to enter schedule().
1487 if (unlikely(current
->mm
->core_state
) &&
1488 unlikely(current
->mm
== current
->parent
->mm
))
1495 * Return nonzero if there is a SIGKILL that should be waking us up.
1496 * Called with the siglock held.
1498 static int sigkill_pending(struct task_struct
*tsk
)
1500 return sigismember(&tsk
->pending
.signal
, SIGKILL
) ||
1501 sigismember(&tsk
->signal
->shared_pending
.signal
, SIGKILL
);
1505 * This must be called with current->sighand->siglock held.
1507 * This should be the path for all ptrace stops.
1508 * We always set current->last_siginfo while stopped here.
1509 * That makes it a way to test a stopped process for
1510 * being ptrace-stopped vs being job-control-stopped.
1512 * If we actually decide not to stop at all because the tracer
1513 * is gone, we keep current->exit_code unless clear_code.
1515 static void ptrace_stop(int exit_code
, int clear_code
, siginfo_t
*info
)
1517 if (arch_ptrace_stop_needed(exit_code
, info
)) {
1519 * The arch code has something special to do before a
1520 * ptrace stop. This is allowed to block, e.g. for faults
1521 * on user stack pages. We can't keep the siglock while
1522 * calling arch_ptrace_stop, so we must release it now.
1523 * To preserve proper semantics, we must do this before
1524 * any signal bookkeeping like checking group_stop_count.
1525 * Meanwhile, a SIGKILL could come in before we retake the
1526 * siglock. That must prevent us from sleeping in TASK_TRACED.
1527 * So after regaining the lock, we must check for SIGKILL.
1529 spin_unlock_irq(¤t
->sighand
->siglock
);
1530 arch_ptrace_stop(exit_code
, info
);
1531 spin_lock_irq(¤t
->sighand
->siglock
);
1532 if (sigkill_pending(current
))
1537 * If there is a group stop in progress,
1538 * we must participate in the bookkeeping.
1540 if (current
->signal
->group_stop_count
> 0)
1541 --current
->signal
->group_stop_count
;
1543 current
->last_siginfo
= info
;
1544 current
->exit_code
= exit_code
;
1546 /* Let the debugger run. */
1547 __set_current_state(TASK_TRACED
);
1548 spin_unlock_irq(¤t
->sighand
->siglock
);
1549 read_lock(&tasklist_lock
);
1550 if (may_ptrace_stop()) {
1551 do_notify_parent_cldstop(current
, CLD_TRAPPED
);
1553 * Don't want to allow preemption here, because
1554 * sys_ptrace() needs this task to be inactive.
1556 * XXX: implement read_unlock_no_resched().
1559 read_unlock(&tasklist_lock
);
1560 preempt_enable_no_resched();
1564 * By the time we got the lock, our tracer went away.
1565 * Don't drop the lock yet, another tracer may come.
1567 __set_current_state(TASK_RUNNING
);
1569 current
->exit_code
= 0;
1570 read_unlock(&tasklist_lock
);
1574 * While in TASK_TRACED, we were considered "frozen enough".
1575 * Now that we woke up, it's crucial if we're supposed to be
1576 * frozen that we freeze now before running anything substantial.
1581 * We are back. Now reacquire the siglock before touching
1582 * last_siginfo, so that we are sure to have synchronized with
1583 * any signal-sending on another CPU that wants to examine it.
1585 spin_lock_irq(¤t
->sighand
->siglock
);
1586 current
->last_siginfo
= NULL
;
1589 * Queued signals ignored us while we were stopped for tracing.
1590 * So check for any that we should take before resuming user mode.
1591 * This sets TIF_SIGPENDING, but never clears it.
1593 recalc_sigpending_tsk(current
);
1596 void ptrace_notify(int exit_code
)
1600 BUG_ON((exit_code
& (0x7f | ~0xffff)) != SIGTRAP
);
1602 memset(&info
, 0, sizeof info
);
1603 info
.si_signo
= SIGTRAP
;
1604 info
.si_code
= exit_code
;
1605 info
.si_pid
= task_pid_vnr(current
);
1606 info
.si_uid
= current
->uid
;
1608 /* Let the debugger run. */
1609 spin_lock_irq(¤t
->sighand
->siglock
);
1610 ptrace_stop(exit_code
, 1, &info
);
1611 spin_unlock_irq(¤t
->sighand
->siglock
);
1615 finish_stop(int stop_count
)
1618 * If there are no other threads in the group, or if there is
1619 * a group stop in progress and we are the last to stop,
1620 * report to the parent. When ptraced, every thread reports itself.
1622 if (tracehook_notify_jctl(stop_count
== 0, CLD_STOPPED
)) {
1623 read_lock(&tasklist_lock
);
1624 do_notify_parent_cldstop(current
, CLD_STOPPED
);
1625 read_unlock(&tasklist_lock
);
1630 } while (try_to_freeze());
1632 * Now we don't run again until continued.
1634 current
->exit_code
= 0;
1638 * This performs the stopping for SIGSTOP and other stop signals.
1639 * We have to stop all threads in the thread group.
1640 * Returns nonzero if we've actually stopped and released the siglock.
1641 * Returns zero if we didn't stop and still hold the siglock.
1643 static int do_signal_stop(int signr
)
1645 struct signal_struct
*sig
= current
->signal
;
1648 if (sig
->group_stop_count
> 0) {
1650 * There is a group stop in progress. We don't need to
1651 * start another one.
1653 stop_count
= --sig
->group_stop_count
;
1655 struct task_struct
*t
;
1657 if (!likely(sig
->flags
& SIGNAL_STOP_DEQUEUED
) ||
1658 unlikely(signal_group_exit(sig
)))
1661 * There is no group stop already in progress.
1662 * We must initiate one now.
1664 sig
->group_exit_code
= signr
;
1667 for (t
= next_thread(current
); t
!= current
; t
= next_thread(t
))
1669 * Setting state to TASK_STOPPED for a group
1670 * stop is always done with the siglock held,
1671 * so this check has no races.
1673 if (!(t
->flags
& PF_EXITING
) &&
1674 !task_is_stopped_or_traced(t
)) {
1676 signal_wake_up(t
, 0);
1678 sig
->group_stop_count
= stop_count
;
1681 if (stop_count
== 0)
1682 sig
->flags
= SIGNAL_STOP_STOPPED
;
1683 current
->exit_code
= sig
->group_exit_code
;
1684 __set_current_state(TASK_STOPPED
);
1686 spin_unlock_irq(¤t
->sighand
->siglock
);
1687 finish_stop(stop_count
);
1691 static int ptrace_signal(int signr
, siginfo_t
*info
,
1692 struct pt_regs
*regs
, void *cookie
)
1694 if (!(current
->ptrace
& PT_PTRACED
))
1697 ptrace_signal_deliver(regs
, cookie
);
1699 /* Let the debugger run. */
1700 ptrace_stop(signr
, 0, info
);
1702 /* We're back. Did the debugger cancel the sig? */
1703 signr
= current
->exit_code
;
1707 current
->exit_code
= 0;
1709 /* Update the siginfo structure if the signal has
1710 changed. If the debugger wanted something
1711 specific in the siginfo structure then it should
1712 have updated *info via PTRACE_SETSIGINFO. */
1713 if (signr
!= info
->si_signo
) {
1714 info
->si_signo
= signr
;
1716 info
->si_code
= SI_USER
;
1717 info
->si_pid
= task_pid_vnr(current
->parent
);
1718 info
->si_uid
= current
->parent
->uid
;
1721 /* If the (new) signal is now blocked, requeue it. */
1722 if (sigismember(¤t
->blocked
, signr
)) {
1723 specific_send_sig_info(signr
, info
, current
);
1730 int get_signal_to_deliver(siginfo_t
*info
, struct k_sigaction
*return_ka
,
1731 struct pt_regs
*regs
, void *cookie
)
1733 struct sighand_struct
*sighand
= current
->sighand
;
1734 struct signal_struct
*signal
= current
->signal
;
1739 * We'll jump back here after any time we were stopped in TASK_STOPPED.
1740 * While in TASK_STOPPED, we were considered "frozen enough".
1741 * Now that we woke up, it's crucial if we're supposed to be
1742 * frozen that we freeze now before running anything substantial.
1746 spin_lock_irq(&sighand
->siglock
);
1748 * Every stopped thread goes here after wakeup. Check to see if
1749 * we should notify the parent, prepare_signal(SIGCONT) encodes
1750 * the CLD_ si_code into SIGNAL_CLD_MASK bits.
1752 if (unlikely(signal
->flags
& SIGNAL_CLD_MASK
)) {
1753 int why
= (signal
->flags
& SIGNAL_STOP_CONTINUED
)
1754 ? CLD_CONTINUED
: CLD_STOPPED
;
1755 signal
->flags
&= ~SIGNAL_CLD_MASK
;
1756 spin_unlock_irq(&sighand
->siglock
);
1758 if (unlikely(!tracehook_notify_jctl(1, why
)))
1761 read_lock(&tasklist_lock
);
1762 do_notify_parent_cldstop(current
->group_leader
, why
);
1763 read_unlock(&tasklist_lock
);
1768 struct k_sigaction
*ka
;
1770 if (unlikely(signal
->group_stop_count
> 0) &&
1775 * Tracing can induce an artifical signal and choose sigaction.
1776 * The return value in @signr determines the default action,
1777 * but @info->si_signo is the signal number we will report.
1779 signr
= tracehook_get_signal(current
, regs
, info
, return_ka
);
1780 if (unlikely(signr
< 0))
1782 if (unlikely(signr
!= 0))
1785 signr
= dequeue_signal(current
, ¤t
->blocked
,
1789 break; /* will return 0 */
1791 if (signr
!= SIGKILL
) {
1792 signr
= ptrace_signal(signr
, info
,
1798 ka
= &sighand
->action
[signr
-1];
1801 if (ka
->sa
.sa_handler
== SIG_IGN
) /* Do nothing. */
1803 if (ka
->sa
.sa_handler
!= SIG_DFL
) {
1804 /* Run the handler. */
1807 if (ka
->sa
.sa_flags
& SA_ONESHOT
)
1808 ka
->sa
.sa_handler
= SIG_DFL
;
1810 break; /* will return non-zero "signr" value */
1814 * Now we are doing the default action for this signal.
1816 if (sig_kernel_ignore(signr
)) /* Default is nothing. */
1820 * Global init gets no signals it doesn't want.
1822 if (unlikely(signal
->flags
& SIGNAL_UNKILLABLE
) &&
1823 !signal_group_exit(signal
))
1826 if (sig_kernel_stop(signr
)) {
1828 * The default action is to stop all threads in
1829 * the thread group. The job control signals
1830 * do nothing in an orphaned pgrp, but SIGSTOP
1831 * always works. Note that siglock needs to be
1832 * dropped during the call to is_orphaned_pgrp()
1833 * because of lock ordering with tasklist_lock.
1834 * This allows an intervening SIGCONT to be posted.
1835 * We need to check for that and bail out if necessary.
1837 if (signr
!= SIGSTOP
) {
1838 spin_unlock_irq(&sighand
->siglock
);
1840 /* signals can be posted during this window */
1842 if (is_current_pgrp_orphaned())
1845 spin_lock_irq(&sighand
->siglock
);
1848 if (likely(do_signal_stop(info
->si_signo
))) {
1849 /* It released the siglock. */
1854 * We didn't actually stop, due to a race
1855 * with SIGCONT or something like that.
1860 spin_unlock_irq(&sighand
->siglock
);
1863 * Anything else is fatal, maybe with a core dump.
1865 current
->flags
|= PF_SIGNALED
;
1867 if (sig_kernel_coredump(signr
)) {
1868 if (print_fatal_signals
)
1869 print_fatal_signal(regs
, info
->si_signo
);
1871 * If it was able to dump core, this kills all
1872 * other threads in the group and synchronizes with
1873 * their demise. If we lost the race with another
1874 * thread getting here, it set group_exit_code
1875 * first and our do_group_exit call below will use
1876 * that value and ignore the one we pass it.
1878 do_coredump(info
->si_signo
, info
->si_signo
, regs
);
1882 * Death signals, no core dump.
1884 do_group_exit(info
->si_signo
);
1887 spin_unlock_irq(&sighand
->siglock
);
1891 void exit_signals(struct task_struct
*tsk
)
1894 struct task_struct
*t
;
1896 if (thread_group_empty(tsk
) || signal_group_exit(tsk
->signal
)) {
1897 tsk
->flags
|= PF_EXITING
;
1901 spin_lock_irq(&tsk
->sighand
->siglock
);
1903 * From now this task is not visible for group-wide signals,
1904 * see wants_signal(), do_signal_stop().
1906 tsk
->flags
|= PF_EXITING
;
1907 if (!signal_pending(tsk
))
1910 /* It could be that __group_complete_signal() choose us to
1911 * notify about group-wide signal. Another thread should be
1912 * woken now to take the signal since we will not.
1914 for (t
= tsk
; (t
= next_thread(t
)) != tsk
; )
1915 if (!signal_pending(t
) && !(t
->flags
& PF_EXITING
))
1916 recalc_sigpending_and_wake(t
);
1918 if (unlikely(tsk
->signal
->group_stop_count
) &&
1919 !--tsk
->signal
->group_stop_count
) {
1920 tsk
->signal
->flags
= SIGNAL_STOP_STOPPED
;
1924 spin_unlock_irq(&tsk
->sighand
->siglock
);
1926 if (unlikely(group_stop
) && tracehook_notify_jctl(1, CLD_STOPPED
)) {
1927 read_lock(&tasklist_lock
);
1928 do_notify_parent_cldstop(tsk
, CLD_STOPPED
);
1929 read_unlock(&tasklist_lock
);
1933 EXPORT_SYMBOL(recalc_sigpending
);
1934 EXPORT_SYMBOL_GPL(dequeue_signal
);
1935 EXPORT_SYMBOL(flush_signals
);
1936 EXPORT_SYMBOL(force_sig
);
1937 EXPORT_SYMBOL(send_sig
);
1938 EXPORT_SYMBOL(send_sig_info
);
1939 EXPORT_SYMBOL(sigprocmask
);
1940 EXPORT_SYMBOL(block_all_signals
);
1941 EXPORT_SYMBOL(unblock_all_signals
);
1945 * System call entry points.
1948 SYSCALL_DEFINE0(restart_syscall
)
1950 struct restart_block
*restart
= ¤t_thread_info()->restart_block
;
1951 return restart
->fn(restart
);
1954 long do_no_restart_syscall(struct restart_block
*param
)
1960 * We don't need to get the kernel lock - this is all local to this
1961 * particular thread.. (and that's good, because this is _heavily_
1962 * used by various programs)
1966 * This is also useful for kernel threads that want to temporarily
1967 * (or permanently) block certain signals.
1969 * NOTE! Unlike the user-mode sys_sigprocmask(), the kernel
1970 * interface happily blocks "unblockable" signals like SIGKILL
1973 int sigprocmask(int how
, sigset_t
*set
, sigset_t
*oldset
)
1977 spin_lock_irq(¤t
->sighand
->siglock
);
1979 *oldset
= current
->blocked
;
1984 sigorsets(¤t
->blocked
, ¤t
->blocked
, set
);
1987 signandsets(¤t
->blocked
, ¤t
->blocked
, set
);
1990 current
->blocked
= *set
;
1995 recalc_sigpending();
1996 spin_unlock_irq(¤t
->sighand
->siglock
);
2001 SYSCALL_DEFINE4(rt_sigprocmask
, int, how
, sigset_t __user
*, set
,
2002 sigset_t __user
*, oset
, size_t, sigsetsize
)
2004 int error
= -EINVAL
;
2005 sigset_t old_set
, new_set
;
2007 /* XXX: Don't preclude handling different sized sigset_t's. */
2008 if (sigsetsize
!= sizeof(sigset_t
))
2013 if (copy_from_user(&new_set
, set
, sizeof(*set
)))
2015 sigdelsetmask(&new_set
, sigmask(SIGKILL
)|sigmask(SIGSTOP
));
2017 error
= sigprocmask(how
, &new_set
, &old_set
);
2023 spin_lock_irq(¤t
->sighand
->siglock
);
2024 old_set
= current
->blocked
;
2025 spin_unlock_irq(¤t
->sighand
->siglock
);
2029 if (copy_to_user(oset
, &old_set
, sizeof(*oset
)))
2037 long do_sigpending(void __user
*set
, unsigned long sigsetsize
)
2039 long error
= -EINVAL
;
2042 if (sigsetsize
> sizeof(sigset_t
))
2045 spin_lock_irq(¤t
->sighand
->siglock
);
2046 sigorsets(&pending
, ¤t
->pending
.signal
,
2047 ¤t
->signal
->shared_pending
.signal
);
2048 spin_unlock_irq(¤t
->sighand
->siglock
);
2050 /* Outside the lock because only this thread touches it. */
2051 sigandsets(&pending
, ¤t
->blocked
, &pending
);
2054 if (!copy_to_user(set
, &pending
, sigsetsize
))
2061 SYSCALL_DEFINE2(rt_sigpending
, sigset_t __user
*, set
, size_t, sigsetsize
)
2063 return do_sigpending(set
, sigsetsize
);
2066 #ifndef HAVE_ARCH_COPY_SIGINFO_TO_USER
2068 int copy_siginfo_to_user(siginfo_t __user
*to
, siginfo_t
*from
)
2072 if (!access_ok (VERIFY_WRITE
, to
, sizeof(siginfo_t
)))
2074 if (from
->si_code
< 0)
2075 return __copy_to_user(to
, from
, sizeof(siginfo_t
))
2078 * If you change siginfo_t structure, please be sure
2079 * this code is fixed accordingly.
2080 * Please remember to update the signalfd_copyinfo() function
2081 * inside fs/signalfd.c too, in case siginfo_t changes.
2082 * It should never copy any pad contained in the structure
2083 * to avoid security leaks, but must copy the generic
2084 * 3 ints plus the relevant union member.
2086 err
= __put_user(from
->si_signo
, &to
->si_signo
);
2087 err
|= __put_user(from
->si_errno
, &to
->si_errno
);
2088 err
|= __put_user((short)from
->si_code
, &to
->si_code
);
2089 switch (from
->si_code
& __SI_MASK
) {
2091 err
|= __put_user(from
->si_pid
, &to
->si_pid
);
2092 err
|= __put_user(from
->si_uid
, &to
->si_uid
);
2095 err
|= __put_user(from
->si_tid
, &to
->si_tid
);
2096 err
|= __put_user(from
->si_overrun
, &to
->si_overrun
);
2097 err
|= __put_user(from
->si_ptr
, &to
->si_ptr
);
2100 err
|= __put_user(from
->si_band
, &to
->si_band
);
2101 err
|= __put_user(from
->si_fd
, &to
->si_fd
);
2104 err
|= __put_user(from
->si_addr
, &to
->si_addr
);
2105 #ifdef __ARCH_SI_TRAPNO
2106 err
|= __put_user(from
->si_trapno
, &to
->si_trapno
);
2110 err
|= __put_user(from
->si_pid
, &to
->si_pid
);
2111 err
|= __put_user(from
->si_uid
, &to
->si_uid
);
2112 err
|= __put_user(from
->si_status
, &to
->si_status
);
2113 err
|= __put_user(from
->si_utime
, &to
->si_utime
);
2114 err
|= __put_user(from
->si_stime
, &to
->si_stime
);
2116 case __SI_RT
: /* This is not generated by the kernel as of now. */
2117 case __SI_MESGQ
: /* But this is */
2118 err
|= __put_user(from
->si_pid
, &to
->si_pid
);
2119 err
|= __put_user(from
->si_uid
, &to
->si_uid
);
2120 err
|= __put_user(from
->si_ptr
, &to
->si_ptr
);
2122 default: /* this is just in case for now ... */
2123 err
|= __put_user(from
->si_pid
, &to
->si_pid
);
2124 err
|= __put_user(from
->si_uid
, &to
->si_uid
);
2132 SYSCALL_DEFINE4(rt_sigtimedwait
, const sigset_t __user
*, uthese
,
2133 siginfo_t __user
*, uinfo
, const struct timespec __user
*, uts
,
2142 /* XXX: Don't preclude handling different sized sigset_t's. */
2143 if (sigsetsize
!= sizeof(sigset_t
))
2146 if (copy_from_user(&these
, uthese
, sizeof(these
)))
2150 * Invert the set of allowed signals to get those we
2153 sigdelsetmask(&these
, sigmask(SIGKILL
)|sigmask(SIGSTOP
));
2157 if (copy_from_user(&ts
, uts
, sizeof(ts
)))
2159 if (ts
.tv_nsec
>= 1000000000L || ts
.tv_nsec
< 0
2164 spin_lock_irq(¤t
->sighand
->siglock
);
2165 sig
= dequeue_signal(current
, &these
, &info
);
2167 timeout
= MAX_SCHEDULE_TIMEOUT
;
2169 timeout
= (timespec_to_jiffies(&ts
)
2170 + (ts
.tv_sec
|| ts
.tv_nsec
));
2173 /* None ready -- temporarily unblock those we're
2174 * interested while we are sleeping in so that we'll
2175 * be awakened when they arrive. */
2176 current
->real_blocked
= current
->blocked
;
2177 sigandsets(¤t
->blocked
, ¤t
->blocked
, &these
);
2178 recalc_sigpending();
2179 spin_unlock_irq(¤t
->sighand
->siglock
);
2181 timeout
= schedule_timeout_interruptible(timeout
);
2183 spin_lock_irq(¤t
->sighand
->siglock
);
2184 sig
= dequeue_signal(current
, &these
, &info
);
2185 current
->blocked
= current
->real_blocked
;
2186 siginitset(¤t
->real_blocked
, 0);
2187 recalc_sigpending();
2190 spin_unlock_irq(¤t
->sighand
->siglock
);
2195 if (copy_siginfo_to_user(uinfo
, &info
))
2207 SYSCALL_DEFINE2(kill
, pid_t
, pid
, int, sig
)
2209 struct siginfo info
;
2211 info
.si_signo
= sig
;
2213 info
.si_code
= SI_USER
;
2214 info
.si_pid
= task_tgid_vnr(current
);
2215 info
.si_uid
= current
->uid
;
2217 return kill_something_info(sig
, &info
, pid
);
2220 static int do_tkill(pid_t tgid
, pid_t pid
, int sig
)
2223 struct siginfo info
;
2224 struct task_struct
*p
;
2225 unsigned long flags
;
2228 info
.si_signo
= sig
;
2230 info
.si_code
= SI_TKILL
;
2231 info
.si_pid
= task_tgid_vnr(current
);
2232 info
.si_uid
= current
->uid
;
2235 p
= find_task_by_vpid(pid
);
2236 if (p
&& (tgid
<= 0 || task_tgid_vnr(p
) == tgid
)) {
2237 error
= check_kill_permission(sig
, &info
, p
);
2239 * The null signal is a permissions and process existence
2240 * probe. No signal is actually delivered.
2242 * If lock_task_sighand() fails we pretend the task dies
2243 * after receiving the signal. The window is tiny, and the
2244 * signal is private anyway.
2246 if (!error
&& sig
&& lock_task_sighand(p
, &flags
)) {
2247 error
= specific_send_sig_info(sig
, &info
, p
);
2248 unlock_task_sighand(p
, &flags
);
2257 * sys_tgkill - send signal to one specific thread
2258 * @tgid: the thread group ID of the thread
2259 * @pid: the PID of the thread
2260 * @sig: signal to be sent
2262 * This syscall also checks the @tgid and returns -ESRCH even if the PID
2263 * exists but it's not belonging to the target process anymore. This
2264 * method solves the problem of threads exiting and PIDs getting reused.
2266 SYSCALL_DEFINE3(tgkill
, pid_t
, tgid
, pid_t
, pid
, int, sig
)
2268 /* This is only valid for single tasks */
2269 if (pid
<= 0 || tgid
<= 0)
2272 return do_tkill(tgid
, pid
, sig
);
2276 * Send a signal to only one task, even if it's a CLONE_THREAD task.
2278 SYSCALL_DEFINE2(tkill
, pid_t
, pid
, int, sig
)
2280 /* This is only valid for single tasks */
2284 return do_tkill(0, pid
, sig
);
2287 SYSCALL_DEFINE3(rt_sigqueueinfo
, pid_t
, pid
, int, sig
,
2288 siginfo_t __user
*, uinfo
)
2292 if (copy_from_user(&info
, uinfo
, sizeof(siginfo_t
)))
2295 /* Not even root can pretend to send signals from the kernel.
2296 Nor can they impersonate a kill(), which adds source info. */
2297 if (info
.si_code
>= 0)
2299 info
.si_signo
= sig
;
2301 /* POSIX.1b doesn't mention process groups. */
2302 return kill_proc_info(sig
, &info
, pid
);
2305 int do_sigaction(int sig
, struct k_sigaction
*act
, struct k_sigaction
*oact
)
2307 struct task_struct
*t
= current
;
2308 struct k_sigaction
*k
;
2311 if (!valid_signal(sig
) || sig
< 1 || (act
&& sig_kernel_only(sig
)))
2314 k
= &t
->sighand
->action
[sig
-1];
2316 spin_lock_irq(¤t
->sighand
->siglock
);
2321 sigdelsetmask(&act
->sa
.sa_mask
,
2322 sigmask(SIGKILL
) | sigmask(SIGSTOP
));
2326 * "Setting a signal action to SIG_IGN for a signal that is
2327 * pending shall cause the pending signal to be discarded,
2328 * whether or not it is blocked."
2330 * "Setting a signal action to SIG_DFL for a signal that is
2331 * pending and whose default action is to ignore the signal
2332 * (for example, SIGCHLD), shall cause the pending signal to
2333 * be discarded, whether or not it is blocked"
2335 if (sig_handler_ignored(sig_handler(t
, sig
), sig
)) {
2337 sigaddset(&mask
, sig
);
2338 rm_from_queue_full(&mask
, &t
->signal
->shared_pending
);
2340 rm_from_queue_full(&mask
, &t
->pending
);
2342 } while (t
!= current
);
2346 spin_unlock_irq(¤t
->sighand
->siglock
);
2351 do_sigaltstack (const stack_t __user
*uss
, stack_t __user
*uoss
, unsigned long sp
)
2357 oss
.ss_sp
= (void __user
*) current
->sas_ss_sp
;
2358 oss
.ss_size
= current
->sas_ss_size
;
2359 oss
.ss_flags
= sas_ss_flags(sp
);
2368 if (!access_ok(VERIFY_READ
, uss
, sizeof(*uss
))
2369 || __get_user(ss_sp
, &uss
->ss_sp
)
2370 || __get_user(ss_flags
, &uss
->ss_flags
)
2371 || __get_user(ss_size
, &uss
->ss_size
))
2375 if (on_sig_stack(sp
))
2381 * Note - this code used to test ss_flags incorrectly
2382 * old code may have been written using ss_flags==0
2383 * to mean ss_flags==SS_ONSTACK (as this was the only
2384 * way that worked) - this fix preserves that older
2387 if (ss_flags
!= SS_DISABLE
&& ss_flags
!= SS_ONSTACK
&& ss_flags
!= 0)
2390 if (ss_flags
== SS_DISABLE
) {
2395 if (ss_size
< MINSIGSTKSZ
)
2399 current
->sas_ss_sp
= (unsigned long) ss_sp
;
2400 current
->sas_ss_size
= ss_size
;
2405 if (copy_to_user(uoss
, &oss
, sizeof(oss
)))
2414 #ifdef __ARCH_WANT_SYS_SIGPENDING
2416 SYSCALL_DEFINE1(sigpending
, old_sigset_t __user
*, set
)
2418 return do_sigpending(set
, sizeof(*set
));
2423 #ifdef __ARCH_WANT_SYS_SIGPROCMASK
2424 /* Some platforms have their own version with special arguments others
2425 support only sys_rt_sigprocmask. */
2427 SYSCALL_DEFINE3(sigprocmask
, int, how
, old_sigset_t __user
*, set
,
2428 old_sigset_t __user
*, oset
)
2431 old_sigset_t old_set
, new_set
;
2435 if (copy_from_user(&new_set
, set
, sizeof(*set
)))
2437 new_set
&= ~(sigmask(SIGKILL
) | sigmask(SIGSTOP
));
2439 spin_lock_irq(¤t
->sighand
->siglock
);
2440 old_set
= current
->blocked
.sig
[0];
2448 sigaddsetmask(¤t
->blocked
, new_set
);
2451 sigdelsetmask(¤t
->blocked
, new_set
);
2454 current
->blocked
.sig
[0] = new_set
;
2458 recalc_sigpending();
2459 spin_unlock_irq(¤t
->sighand
->siglock
);
2465 old_set
= current
->blocked
.sig
[0];
2468 if (copy_to_user(oset
, &old_set
, sizeof(*oset
)))
2475 #endif /* __ARCH_WANT_SYS_SIGPROCMASK */
2477 #ifdef __ARCH_WANT_SYS_RT_SIGACTION
2478 SYSCALL_DEFINE4(rt_sigaction
, int, sig
,
2479 const struct sigaction __user
*, act
,
2480 struct sigaction __user
*, oact
,
2483 struct k_sigaction new_sa
, old_sa
;
2486 /* XXX: Don't preclude handling different sized sigset_t's. */
2487 if (sigsetsize
!= sizeof(sigset_t
))
2491 if (copy_from_user(&new_sa
.sa
, act
, sizeof(new_sa
.sa
)))
2495 ret
= do_sigaction(sig
, act
? &new_sa
: NULL
, oact
? &old_sa
: NULL
);
2498 if (copy_to_user(oact
, &old_sa
.sa
, sizeof(old_sa
.sa
)))
2504 #endif /* __ARCH_WANT_SYS_RT_SIGACTION */
2506 #ifdef __ARCH_WANT_SYS_SGETMASK
2509 * For backwards compatibility. Functionality superseded by sigprocmask.
2511 SYSCALL_DEFINE0(sgetmask
)
2514 return current
->blocked
.sig
[0];
2517 SYSCALL_DEFINE1(ssetmask
, int, newmask
)
2521 spin_lock_irq(¤t
->sighand
->siglock
);
2522 old
= current
->blocked
.sig
[0];
2524 siginitset(¤t
->blocked
, newmask
& ~(sigmask(SIGKILL
)|
2526 recalc_sigpending();
2527 spin_unlock_irq(¤t
->sighand
->siglock
);
2531 #endif /* __ARCH_WANT_SGETMASK */
2533 #ifdef __ARCH_WANT_SYS_SIGNAL
2535 * For backwards compatibility. Functionality superseded by sigaction.
2537 SYSCALL_DEFINE2(signal
, int, sig
, __sighandler_t
, handler
)
2539 struct k_sigaction new_sa
, old_sa
;
2542 new_sa
.sa
.sa_handler
= handler
;
2543 new_sa
.sa
.sa_flags
= SA_ONESHOT
| SA_NOMASK
;
2544 sigemptyset(&new_sa
.sa
.sa_mask
);
2546 ret
= do_sigaction(sig
, &new_sa
, &old_sa
);
2548 return ret
? ret
: (unsigned long)old_sa
.sa
.sa_handler
;
2550 #endif /* __ARCH_WANT_SYS_SIGNAL */
2552 #ifdef __ARCH_WANT_SYS_PAUSE
2554 SYSCALL_DEFINE0(pause
)
2556 current
->state
= TASK_INTERRUPTIBLE
;
2558 return -ERESTARTNOHAND
;
2563 #ifdef __ARCH_WANT_SYS_RT_SIGSUSPEND
2564 SYSCALL_DEFINE2(rt_sigsuspend
, sigset_t __user
*, unewset
, size_t, sigsetsize
)
2568 /* XXX: Don't preclude handling different sized sigset_t's. */
2569 if (sigsetsize
!= sizeof(sigset_t
))
2572 if (copy_from_user(&newset
, unewset
, sizeof(newset
)))
2574 sigdelsetmask(&newset
, sigmask(SIGKILL
)|sigmask(SIGSTOP
));
2576 spin_lock_irq(¤t
->sighand
->siglock
);
2577 current
->saved_sigmask
= current
->blocked
;
2578 current
->blocked
= newset
;
2579 recalc_sigpending();
2580 spin_unlock_irq(¤t
->sighand
->siglock
);
2582 current
->state
= TASK_INTERRUPTIBLE
;
2584 set_restore_sigmask();
2585 return -ERESTARTNOHAND
;
2587 #endif /* __ARCH_WANT_SYS_RT_SIGSUSPEND */
2589 __attribute__((weak
)) const char *arch_vma_name(struct vm_area_struct
*vma
)
2594 void __init
signals_init(void)
2596 sigqueue_cachep
= KMEM_CACHE(sigqueue
, SLAB_PANIC
);