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>
30 #include <trace/sched.h>
32 #include <asm/param.h>
33 #include <asm/uaccess.h>
34 #include <asm/unistd.h>
35 #include <asm/siginfo.h>
36 #include "audit.h" /* audit_signal_info() */
39 * SLAB caches for signal bits.
42 static struct kmem_cache
*sigqueue_cachep
;
44 DEFINE_TRACE(sched_signal_send
);
46 static void __user
*sig_handler(struct task_struct
*t
, int sig
)
48 return t
->sighand
->action
[sig
- 1].sa
.sa_handler
;
51 static int sig_handler_ignored(void __user
*handler
, int sig
)
53 /* Is it explicitly or implicitly ignored? */
54 return handler
== SIG_IGN
||
55 (handler
== SIG_DFL
&& sig_kernel_ignore(sig
));
58 static int sig_task_ignored(struct task_struct
*t
, int sig
)
62 handler
= sig_handler(t
, sig
);
64 if (unlikely(t
->signal
->flags
& SIGNAL_UNKILLABLE
) &&
68 return sig_handler_ignored(handler
, sig
);
71 static int sig_ignored(struct task_struct
*t
, int sig
)
74 * Blocked signals are never ignored, since the
75 * signal handler may change by the time it is
78 if (sigismember(&t
->blocked
, sig
) || sigismember(&t
->real_blocked
, sig
))
81 if (!sig_task_ignored(t
, sig
))
85 * Tracers may want to know about even ignored signals.
87 return !tracehook_consider_ignored_signal(t
, sig
);
91 * Re-calculate pending state from the set of locally pending
92 * signals, globally pending signals, and blocked signals.
94 static inline int has_pending_signals(sigset_t
*signal
, sigset_t
*blocked
)
99 switch (_NSIG_WORDS
) {
101 for (i
= _NSIG_WORDS
, ready
= 0; --i
>= 0 ;)
102 ready
|= signal
->sig
[i
] &~ blocked
->sig
[i
];
105 case 4: ready
= signal
->sig
[3] &~ blocked
->sig
[3];
106 ready
|= signal
->sig
[2] &~ blocked
->sig
[2];
107 ready
|= signal
->sig
[1] &~ blocked
->sig
[1];
108 ready
|= signal
->sig
[0] &~ blocked
->sig
[0];
111 case 2: ready
= signal
->sig
[1] &~ blocked
->sig
[1];
112 ready
|= signal
->sig
[0] &~ blocked
->sig
[0];
115 case 1: ready
= signal
->sig
[0] &~ blocked
->sig
[0];
120 #define PENDING(p,b) has_pending_signals(&(p)->signal, (b))
122 static int recalc_sigpending_tsk(struct task_struct
*t
)
124 if (t
->signal
->group_stop_count
> 0 ||
125 PENDING(&t
->pending
, &t
->blocked
) ||
126 PENDING(&t
->signal
->shared_pending
, &t
->blocked
)) {
127 set_tsk_thread_flag(t
, TIF_SIGPENDING
);
131 * We must never clear the flag in another thread, or in current
132 * when it's possible the current syscall is returning -ERESTART*.
133 * So we don't clear it here, and only callers who know they should do.
139 * After recalculating TIF_SIGPENDING, we need to make sure the task wakes up.
140 * This is superfluous when called on current, the wakeup is a harmless no-op.
142 void recalc_sigpending_and_wake(struct task_struct
*t
)
144 if (recalc_sigpending_tsk(t
))
145 signal_wake_up(t
, 0);
148 void recalc_sigpending(void)
150 if (unlikely(tracehook_force_sigpending()))
151 set_thread_flag(TIF_SIGPENDING
);
152 else if (!recalc_sigpending_tsk(current
) && !freezing(current
))
153 clear_thread_flag(TIF_SIGPENDING
);
157 /* Given the mask, find the first available signal that should be serviced. */
159 int next_signal(struct sigpending
*pending
, sigset_t
*mask
)
161 unsigned long i
, *s
, *m
, x
;
164 s
= pending
->signal
.sig
;
166 switch (_NSIG_WORDS
) {
168 for (i
= 0; i
< _NSIG_WORDS
; ++i
, ++s
, ++m
)
169 if ((x
= *s
&~ *m
) != 0) {
170 sig
= ffz(~x
) + i
*_NSIG_BPW
+ 1;
175 case 2: if ((x
= s
[0] &~ m
[0]) != 0)
177 else if ((x
= s
[1] &~ m
[1]) != 0)
184 case 1: if ((x
= *s
&~ *m
) != 0)
193 * allocate a new signal queue record
194 * - this may be called without locks if and only if t == current, otherwise an
195 * appopriate lock must be held to stop the target task from exiting
197 static struct sigqueue
*__sigqueue_alloc(struct task_struct
*t
, gfp_t flags
,
200 struct sigqueue
*q
= NULL
;
201 struct user_struct
*user
;
204 * We won't get problems with the target's UID changing under us
205 * because changing it requires RCU be used, and if t != current, the
206 * caller must be holding the RCU readlock (by way of a spinlock) and
207 * we use RCU protection here
209 user
= get_uid(__task_cred(t
)->user
);
210 atomic_inc(&user
->sigpending
);
211 if (override_rlimit
||
212 atomic_read(&user
->sigpending
) <=
213 t
->signal
->rlim
[RLIMIT_SIGPENDING
].rlim_cur
)
214 q
= kmem_cache_alloc(sigqueue_cachep
, flags
);
215 if (unlikely(q
== NULL
)) {
216 atomic_dec(&user
->sigpending
);
219 INIT_LIST_HEAD(&q
->list
);
227 static void __sigqueue_free(struct sigqueue
*q
)
229 if (q
->flags
& SIGQUEUE_PREALLOC
)
231 atomic_dec(&q
->user
->sigpending
);
233 kmem_cache_free(sigqueue_cachep
, q
);
236 void flush_sigqueue(struct sigpending
*queue
)
240 sigemptyset(&queue
->signal
);
241 while (!list_empty(&queue
->list
)) {
242 q
= list_entry(queue
->list
.next
, struct sigqueue
, list
);
243 list_del_init(&q
->list
);
249 * Flush all pending signals for a task.
251 void flush_signals(struct task_struct
*t
)
255 spin_lock_irqsave(&t
->sighand
->siglock
, flags
);
256 clear_tsk_thread_flag(t
, TIF_SIGPENDING
);
257 flush_sigqueue(&t
->pending
);
258 flush_sigqueue(&t
->signal
->shared_pending
);
259 spin_unlock_irqrestore(&t
->sighand
->siglock
, flags
);
262 static void __flush_itimer_signals(struct sigpending
*pending
)
264 sigset_t signal
, retain
;
265 struct sigqueue
*q
, *n
;
267 signal
= pending
->signal
;
268 sigemptyset(&retain
);
270 list_for_each_entry_safe(q
, n
, &pending
->list
, list
) {
271 int sig
= q
->info
.si_signo
;
273 if (likely(q
->info
.si_code
!= SI_TIMER
)) {
274 sigaddset(&retain
, sig
);
276 sigdelset(&signal
, sig
);
277 list_del_init(&q
->list
);
282 sigorsets(&pending
->signal
, &signal
, &retain
);
285 void flush_itimer_signals(void)
287 struct task_struct
*tsk
= current
;
290 spin_lock_irqsave(&tsk
->sighand
->siglock
, flags
);
291 __flush_itimer_signals(&tsk
->pending
);
292 __flush_itimer_signals(&tsk
->signal
->shared_pending
);
293 spin_unlock_irqrestore(&tsk
->sighand
->siglock
, flags
);
296 void ignore_signals(struct task_struct
*t
)
300 for (i
= 0; i
< _NSIG
; ++i
)
301 t
->sighand
->action
[i
].sa
.sa_handler
= SIG_IGN
;
307 * Flush all handlers for a task.
311 flush_signal_handlers(struct task_struct
*t
, int force_default
)
314 struct k_sigaction
*ka
= &t
->sighand
->action
[0];
315 for (i
= _NSIG
; i
!= 0 ; i
--) {
316 if (force_default
|| ka
->sa
.sa_handler
!= SIG_IGN
)
317 ka
->sa
.sa_handler
= SIG_DFL
;
319 sigemptyset(&ka
->sa
.sa_mask
);
324 int unhandled_signal(struct task_struct
*tsk
, int sig
)
326 void __user
*handler
= tsk
->sighand
->action
[sig
-1].sa
.sa_handler
;
327 if (is_global_init(tsk
))
329 if (handler
!= SIG_IGN
&& handler
!= SIG_DFL
)
331 return !tracehook_consider_fatal_signal(tsk
, sig
);
335 /* Notify the system that a driver wants to block all signals for this
336 * process, and wants to be notified if any signals at all were to be
337 * sent/acted upon. If the notifier routine returns non-zero, then the
338 * signal will be acted upon after all. If the notifier routine returns 0,
339 * then then signal will be blocked. Only one block per process is
340 * allowed. priv is a pointer to private data that the notifier routine
341 * can use to determine if the signal should be blocked or not. */
344 block_all_signals(int (*notifier
)(void *priv
), void *priv
, sigset_t
*mask
)
348 spin_lock_irqsave(¤t
->sighand
->siglock
, flags
);
349 current
->notifier_mask
= mask
;
350 current
->notifier_data
= priv
;
351 current
->notifier
= notifier
;
352 spin_unlock_irqrestore(¤t
->sighand
->siglock
, flags
);
355 /* Notify the system that blocking has ended. */
358 unblock_all_signals(void)
362 spin_lock_irqsave(¤t
->sighand
->siglock
, flags
);
363 current
->notifier
= NULL
;
364 current
->notifier_data
= NULL
;
366 spin_unlock_irqrestore(¤t
->sighand
->siglock
, flags
);
369 static void collect_signal(int sig
, struct sigpending
*list
, siginfo_t
*info
)
371 struct sigqueue
*q
, *first
= NULL
;
374 * Collect the siginfo appropriate to this signal. Check if
375 * there is another siginfo for the same signal.
377 list_for_each_entry(q
, &list
->list
, list
) {
378 if (q
->info
.si_signo
== sig
) {
385 sigdelset(&list
->signal
, sig
);
389 list_del_init(&first
->list
);
390 copy_siginfo(info
, &first
->info
);
391 __sigqueue_free(first
);
393 /* Ok, it wasn't in the queue. This must be
394 a fast-pathed signal or we must have been
395 out of queue space. So zero out the info.
397 info
->si_signo
= sig
;
405 static int __dequeue_signal(struct sigpending
*pending
, sigset_t
*mask
,
408 int sig
= next_signal(pending
, mask
);
411 if (current
->notifier
) {
412 if (sigismember(current
->notifier_mask
, sig
)) {
413 if (!(current
->notifier
)(current
->notifier_data
)) {
414 clear_thread_flag(TIF_SIGPENDING
);
420 collect_signal(sig
, pending
, info
);
427 * Dequeue a signal and return the element to the caller, which is
428 * expected to free it.
430 * All callers have to hold the siglock.
432 int dequeue_signal(struct task_struct
*tsk
, sigset_t
*mask
, siginfo_t
*info
)
436 /* We only dequeue private signals from ourselves, we don't let
437 * signalfd steal them
439 signr
= __dequeue_signal(&tsk
->pending
, mask
, info
);
441 signr
= __dequeue_signal(&tsk
->signal
->shared_pending
,
446 * itimers are process shared and we restart periodic
447 * itimers in the signal delivery path to prevent DoS
448 * attacks in the high resolution timer case. This is
449 * compliant with the old way of self restarting
450 * itimers, as the SIGALRM is a legacy signal and only
451 * queued once. Changing the restart behaviour to
452 * restart the timer in the signal dequeue path is
453 * reducing the timer noise on heavy loaded !highres
456 if (unlikely(signr
== SIGALRM
)) {
457 struct hrtimer
*tmr
= &tsk
->signal
->real_timer
;
459 if (!hrtimer_is_queued(tmr
) &&
460 tsk
->signal
->it_real_incr
.tv64
!= 0) {
461 hrtimer_forward(tmr
, tmr
->base
->get_time(),
462 tsk
->signal
->it_real_incr
);
463 hrtimer_restart(tmr
);
472 if (unlikely(sig_kernel_stop(signr
))) {
474 * Set a marker that we have dequeued a stop signal. Our
475 * caller might release the siglock and then the pending
476 * stop signal it is about to process is no longer in the
477 * pending bitmasks, but must still be cleared by a SIGCONT
478 * (and overruled by a SIGKILL). So those cases clear this
479 * shared flag after we've set it. Note that this flag may
480 * remain set after the signal we return is ignored or
481 * handled. That doesn't matter because its only purpose
482 * is to alert stop-signal processing code when another
483 * processor has come along and cleared the flag.
485 tsk
->signal
->flags
|= SIGNAL_STOP_DEQUEUED
;
487 if ((info
->si_code
& __SI_MASK
) == __SI_TIMER
&& info
->si_sys_private
) {
489 * Release the siglock to ensure proper locking order
490 * of timer locks outside of siglocks. Note, we leave
491 * irqs disabled here, since the posix-timers code is
492 * about to disable them again anyway.
494 spin_unlock(&tsk
->sighand
->siglock
);
495 do_schedule_next_timer(info
);
496 spin_lock(&tsk
->sighand
->siglock
);
502 * Tell a process that it has a new active signal..
504 * NOTE! we rely on the previous spin_lock to
505 * lock interrupts for us! We can only be called with
506 * "siglock" held, and the local interrupt must
507 * have been disabled when that got acquired!
509 * No need to set need_resched since signal event passing
510 * goes through ->blocked
512 void signal_wake_up(struct task_struct
*t
, int resume
)
516 set_tsk_thread_flag(t
, TIF_SIGPENDING
);
519 * For SIGKILL, we want to wake it up in the stopped/traced/killable
520 * case. We don't check t->state here because there is a race with it
521 * executing another processor and just now entering stopped state.
522 * By using wake_up_state, we ensure the process will wake up and
523 * handle its death signal.
525 mask
= TASK_INTERRUPTIBLE
;
527 mask
|= TASK_WAKEKILL
;
528 if (!wake_up_state(t
, mask
))
533 * Remove signals in mask from the pending set and queue.
534 * Returns 1 if any signals were found.
536 * All callers must be holding the siglock.
538 * This version takes a sigset mask and looks at all signals,
539 * not just those in the first mask word.
541 static int rm_from_queue_full(sigset_t
*mask
, struct sigpending
*s
)
543 struct sigqueue
*q
, *n
;
546 sigandsets(&m
, mask
, &s
->signal
);
547 if (sigisemptyset(&m
))
550 signandsets(&s
->signal
, &s
->signal
, mask
);
551 list_for_each_entry_safe(q
, n
, &s
->list
, list
) {
552 if (sigismember(mask
, q
->info
.si_signo
)) {
553 list_del_init(&q
->list
);
560 * Remove signals in mask from the pending set and queue.
561 * Returns 1 if any signals were found.
563 * All callers must be holding the siglock.
565 static int rm_from_queue(unsigned long mask
, struct sigpending
*s
)
567 struct sigqueue
*q
, *n
;
569 if (!sigtestsetmask(&s
->signal
, mask
))
572 sigdelsetmask(&s
->signal
, mask
);
573 list_for_each_entry_safe(q
, n
, &s
->list
, list
) {
574 if (q
->info
.si_signo
< SIGRTMIN
&&
575 (mask
& sigmask(q
->info
.si_signo
))) {
576 list_del_init(&q
->list
);
584 * Bad permissions for sending the signal
585 * - the caller must hold at least the RCU read lock
587 static int check_kill_permission(int sig
, struct siginfo
*info
,
588 struct task_struct
*t
)
590 const struct cred
*cred
= current_cred(), *tcred
;
594 if (!valid_signal(sig
))
597 if (info
!= SEND_SIG_NOINFO
&& (is_si_special(info
) || SI_FROMKERNEL(info
)))
600 error
= audit_signal_info(sig
, t
); /* Let audit system see the signal */
604 tcred
= __task_cred(t
);
605 if ((cred
->euid
^ tcred
->suid
) &&
606 (cred
->euid
^ tcred
->uid
) &&
607 (cred
->uid
^ tcred
->suid
) &&
608 (cred
->uid
^ tcred
->uid
) &&
609 !capable(CAP_KILL
)) {
612 sid
= task_session(t
);
614 * We don't return the error if sid == NULL. The
615 * task was unhashed, the caller must notice this.
617 if (!sid
|| sid
== task_session(current
))
624 return security_task_kill(t
, info
, sig
, 0);
628 * Handle magic process-wide effects of stop/continue signals. Unlike
629 * the signal actions, these happen immediately at signal-generation
630 * time regardless of blocking, ignoring, or handling. This does the
631 * actual continuing for SIGCONT, but not the actual stopping for stop
632 * signals. The process stop is done as a signal action for SIG_DFL.
634 * Returns true if the signal should be actually delivered, otherwise
635 * it should be dropped.
637 static int prepare_signal(int sig
, struct task_struct
*p
)
639 struct signal_struct
*signal
= p
->signal
;
640 struct task_struct
*t
;
642 if (unlikely(signal
->flags
& SIGNAL_GROUP_EXIT
)) {
644 * The process is in the middle of dying, nothing to do.
646 } else if (sig_kernel_stop(sig
)) {
648 * This is a stop signal. Remove SIGCONT from all queues.
650 rm_from_queue(sigmask(SIGCONT
), &signal
->shared_pending
);
653 rm_from_queue(sigmask(SIGCONT
), &t
->pending
);
654 } while_each_thread(p
, t
);
655 } else if (sig
== SIGCONT
) {
658 * Remove all stop signals from all queues,
659 * and wake all threads.
661 rm_from_queue(SIG_KERNEL_STOP_MASK
, &signal
->shared_pending
);
665 rm_from_queue(SIG_KERNEL_STOP_MASK
, &t
->pending
);
667 * If there is a handler for SIGCONT, we must make
668 * sure that no thread returns to user mode before
669 * we post the signal, in case it was the only
670 * thread eligible to run the signal handler--then
671 * it must not do anything between resuming and
672 * running the handler. With the TIF_SIGPENDING
673 * flag set, the thread will pause and acquire the
674 * siglock that we hold now and until we've queued
675 * the pending signal.
677 * Wake up the stopped thread _after_ setting
680 state
= __TASK_STOPPED
;
681 if (sig_user_defined(t
, SIGCONT
) && !sigismember(&t
->blocked
, SIGCONT
)) {
682 set_tsk_thread_flag(t
, TIF_SIGPENDING
);
683 state
|= TASK_INTERRUPTIBLE
;
685 wake_up_state(t
, state
);
686 } while_each_thread(p
, t
);
689 * Notify the parent with CLD_CONTINUED if we were stopped.
691 * If we were in the middle of a group stop, we pretend it
692 * was already finished, and then continued. Since SIGCHLD
693 * doesn't queue we report only CLD_STOPPED, as if the next
694 * CLD_CONTINUED was dropped.
697 if (signal
->flags
& SIGNAL_STOP_STOPPED
)
698 why
|= SIGNAL_CLD_CONTINUED
;
699 else if (signal
->group_stop_count
)
700 why
|= SIGNAL_CLD_STOPPED
;
704 * The first thread which returns from finish_stop()
705 * will take ->siglock, notice SIGNAL_CLD_MASK, and
706 * notify its parent. See get_signal_to_deliver().
708 signal
->flags
= why
| SIGNAL_STOP_CONTINUED
;
709 signal
->group_stop_count
= 0;
710 signal
->group_exit_code
= 0;
713 * We are not stopped, but there could be a stop
714 * signal in the middle of being processed after
715 * being removed from the queue. Clear that too.
717 signal
->flags
&= ~SIGNAL_STOP_DEQUEUED
;
721 return !sig_ignored(p
, sig
);
725 * Test if P wants to take SIG. After we've checked all threads with this,
726 * it's equivalent to finding no threads not blocking SIG. Any threads not
727 * blocking SIG were ruled out because they are not running and already
728 * have pending signals. Such threads will dequeue from the shared queue
729 * as soon as they're available, so putting the signal on the shared queue
730 * will be equivalent to sending it to one such thread.
732 static inline int wants_signal(int sig
, struct task_struct
*p
)
734 if (sigismember(&p
->blocked
, sig
))
736 if (p
->flags
& PF_EXITING
)
740 if (task_is_stopped_or_traced(p
))
742 return task_curr(p
) || !signal_pending(p
);
745 static void complete_signal(int sig
, struct task_struct
*p
, int group
)
747 struct signal_struct
*signal
= p
->signal
;
748 struct task_struct
*t
;
751 * Now find a thread we can wake up to take the signal off the queue.
753 * If the main thread wants the signal, it gets first crack.
754 * Probably the least surprising to the average bear.
756 if (wants_signal(sig
, p
))
758 else if (!group
|| thread_group_empty(p
))
760 * There is just one thread and it does not need to be woken.
761 * It will dequeue unblocked signals before it runs again.
766 * Otherwise try to find a suitable thread.
768 t
= signal
->curr_target
;
769 while (!wants_signal(sig
, t
)) {
771 if (t
== signal
->curr_target
)
773 * No thread needs to be woken.
774 * Any eligible threads will see
775 * the signal in the queue soon.
779 signal
->curr_target
= t
;
783 * Found a killable thread. If the signal will be fatal,
784 * then start taking the whole group down immediately.
786 if (sig_fatal(p
, sig
) &&
787 !(signal
->flags
& (SIGNAL_UNKILLABLE
| SIGNAL_GROUP_EXIT
)) &&
788 !sigismember(&t
->real_blocked
, sig
) &&
790 !tracehook_consider_fatal_signal(t
, sig
))) {
792 * This signal will be fatal to the whole group.
794 if (!sig_kernel_coredump(sig
)) {
796 * Start a group exit and wake everybody up.
797 * This way we don't have other threads
798 * running and doing things after a slower
799 * thread has the fatal signal pending.
801 signal
->flags
= SIGNAL_GROUP_EXIT
;
802 signal
->group_exit_code
= sig
;
803 signal
->group_stop_count
= 0;
806 sigaddset(&t
->pending
.signal
, SIGKILL
);
807 signal_wake_up(t
, 1);
808 } while_each_thread(p
, t
);
814 * The signal is already in the shared-pending queue.
815 * Tell the chosen thread to wake up and dequeue it.
817 signal_wake_up(t
, sig
== SIGKILL
);
821 static inline int legacy_queue(struct sigpending
*signals
, int sig
)
823 return (sig
< SIGRTMIN
) && sigismember(&signals
->signal
, sig
);
826 static int send_signal(int sig
, struct siginfo
*info
, struct task_struct
*t
,
829 struct sigpending
*pending
;
832 trace_sched_signal_send(sig
, t
);
834 assert_spin_locked(&t
->sighand
->siglock
);
835 if (!prepare_signal(sig
, t
))
838 pending
= group
? &t
->signal
->shared_pending
: &t
->pending
;
840 * Short-circuit ignored signals and support queuing
841 * exactly one non-rt signal, so that we can get more
842 * detailed information about the cause of the signal.
844 if (legacy_queue(pending
, sig
))
847 * fast-pathed signals for kernel-internal things like SIGSTOP
850 if (info
== SEND_SIG_FORCED
)
853 /* Real-time signals must be queued if sent by sigqueue, or
854 some other real-time mechanism. It is implementation
855 defined whether kill() does so. We attempt to do so, on
856 the principle of least surprise, but since kill is not
857 allowed to fail with EAGAIN when low on memory we just
858 make sure at least one signal gets delivered and don't
859 pass on the info struct. */
861 q
= __sigqueue_alloc(t
, GFP_ATOMIC
, (sig
< SIGRTMIN
&&
862 (is_si_special(info
) ||
863 info
->si_code
>= 0)));
865 list_add_tail(&q
->list
, &pending
->list
);
866 switch ((unsigned long) info
) {
867 case (unsigned long) SEND_SIG_NOINFO
:
868 q
->info
.si_signo
= sig
;
869 q
->info
.si_errno
= 0;
870 q
->info
.si_code
= SI_USER
;
871 q
->info
.si_pid
= task_tgid_nr_ns(current
,
872 task_active_pid_ns(t
));
873 q
->info
.si_uid
= current_uid();
875 case (unsigned long) SEND_SIG_PRIV
:
876 q
->info
.si_signo
= sig
;
877 q
->info
.si_errno
= 0;
878 q
->info
.si_code
= SI_KERNEL
;
883 copy_siginfo(&q
->info
, info
);
886 } else if (!is_si_special(info
)) {
887 if (sig
>= SIGRTMIN
&& info
->si_code
!= SI_USER
)
889 * Queue overflow, abort. We may abort if the signal was rt
890 * and sent by user using something other than kill().
896 signalfd_notify(t
, sig
);
897 sigaddset(&pending
->signal
, sig
);
898 complete_signal(sig
, t
, group
);
902 int print_fatal_signals
;
904 static void print_fatal_signal(struct pt_regs
*regs
, int signr
)
906 printk("%s/%d: potentially unexpected fatal signal %d.\n",
907 current
->comm
, task_pid_nr(current
), signr
);
909 #if defined(__i386__) && !defined(__arch_um__)
910 printk("code at %08lx: ", regs
->ip
);
913 for (i
= 0; i
< 16; i
++) {
916 __get_user(insn
, (unsigned char *)(regs
->ip
+ i
));
917 printk("%02x ", insn
);
927 static int __init
setup_print_fatal_signals(char *str
)
929 get_option (&str
, &print_fatal_signals
);
934 __setup("print-fatal-signals=", setup_print_fatal_signals
);
937 __group_send_sig_info(int sig
, struct siginfo
*info
, struct task_struct
*p
)
939 return send_signal(sig
, info
, p
, 1);
943 specific_send_sig_info(int sig
, struct siginfo
*info
, struct task_struct
*t
)
945 return send_signal(sig
, info
, t
, 0);
949 * Force a signal that the process can't ignore: if necessary
950 * we unblock the signal and change any SIG_IGN to SIG_DFL.
952 * Note: If we unblock the signal, we always reset it to SIG_DFL,
953 * since we do not want to have a signal handler that was blocked
954 * be invoked when user space had explicitly blocked it.
956 * We don't want to have recursive SIGSEGV's etc, for example,
957 * that is why we also clear SIGNAL_UNKILLABLE.
960 force_sig_info(int sig
, struct siginfo
*info
, struct task_struct
*t
)
962 unsigned long int flags
;
963 int ret
, blocked
, ignored
;
964 struct k_sigaction
*action
;
966 spin_lock_irqsave(&t
->sighand
->siglock
, flags
);
967 action
= &t
->sighand
->action
[sig
-1];
968 ignored
= action
->sa
.sa_handler
== SIG_IGN
;
969 blocked
= sigismember(&t
->blocked
, sig
);
970 if (blocked
|| ignored
) {
971 action
->sa
.sa_handler
= SIG_DFL
;
973 sigdelset(&t
->blocked
, sig
);
974 recalc_sigpending_and_wake(t
);
977 if (action
->sa
.sa_handler
== SIG_DFL
)
978 t
->signal
->flags
&= ~SIGNAL_UNKILLABLE
;
979 ret
= specific_send_sig_info(sig
, info
, t
);
980 spin_unlock_irqrestore(&t
->sighand
->siglock
, flags
);
986 force_sig_specific(int sig
, struct task_struct
*t
)
988 force_sig_info(sig
, SEND_SIG_FORCED
, t
);
992 * Nuke all other threads in the group.
994 void zap_other_threads(struct task_struct
*p
)
996 struct task_struct
*t
;
998 p
->signal
->group_stop_count
= 0;
1000 for (t
= next_thread(p
); t
!= p
; t
= next_thread(t
)) {
1002 * Don't bother with already dead threads
1007 /* SIGKILL will be handled before any pending SIGSTOP */
1008 sigaddset(&t
->pending
.signal
, SIGKILL
);
1009 signal_wake_up(t
, 1);
1013 int __fatal_signal_pending(struct task_struct
*tsk
)
1015 return sigismember(&tsk
->pending
.signal
, SIGKILL
);
1017 EXPORT_SYMBOL(__fatal_signal_pending
);
1019 struct sighand_struct
*lock_task_sighand(struct task_struct
*tsk
, unsigned long *flags
)
1021 struct sighand_struct
*sighand
;
1025 sighand
= rcu_dereference(tsk
->sighand
);
1026 if (unlikely(sighand
== NULL
))
1029 spin_lock_irqsave(&sighand
->siglock
, *flags
);
1030 if (likely(sighand
== tsk
->sighand
))
1032 spin_unlock_irqrestore(&sighand
->siglock
, *flags
);
1040 * send signal info to all the members of a group
1041 * - the caller must hold the RCU read lock at least
1043 int group_send_sig_info(int sig
, struct siginfo
*info
, struct task_struct
*p
)
1045 unsigned long flags
;
1048 ret
= check_kill_permission(sig
, info
, p
);
1052 if (lock_task_sighand(p
, &flags
)) {
1053 ret
= __group_send_sig_info(sig
, info
, p
);
1054 unlock_task_sighand(p
, &flags
);
1062 * __kill_pgrp_info() sends a signal to a process group: this is what the tty
1063 * control characters do (^C, ^Z etc)
1064 * - the caller must hold at least a readlock on tasklist_lock
1066 int __kill_pgrp_info(int sig
, struct siginfo
*info
, struct pid
*pgrp
)
1068 struct task_struct
*p
= NULL
;
1069 int retval
, success
;
1073 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
1074 int err
= group_send_sig_info(sig
, info
, p
);
1077 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
1078 return success
? 0 : retval
;
1081 int kill_pid_info(int sig
, struct siginfo
*info
, struct pid
*pid
)
1084 struct task_struct
*p
;
1088 p
= pid_task(pid
, PIDTYPE_PID
);
1090 error
= group_send_sig_info(sig
, info
, p
);
1091 if (unlikely(error
== -ESRCH
))
1093 * The task was unhashed in between, try again.
1094 * If it is dead, pid_task() will return NULL,
1095 * if we race with de_thread() it will find the
1106 kill_proc_info(int sig
, struct siginfo
*info
, pid_t pid
)
1110 error
= kill_pid_info(sig
, info
, find_vpid(pid
));
1115 /* like kill_pid_info(), but doesn't use uid/euid of "current" */
1116 int kill_pid_info_as_uid(int sig
, struct siginfo
*info
, struct pid
*pid
,
1117 uid_t uid
, uid_t euid
, u32 secid
)
1120 struct task_struct
*p
;
1121 const struct cred
*pcred
;
1123 if (!valid_signal(sig
))
1126 read_lock(&tasklist_lock
);
1127 p
= pid_task(pid
, PIDTYPE_PID
);
1132 pcred
= __task_cred(p
);
1133 if ((info
== SEND_SIG_NOINFO
||
1134 (!is_si_special(info
) && SI_FROMUSER(info
))) &&
1135 euid
!= pcred
->suid
&& euid
!= pcred
->uid
&&
1136 uid
!= pcred
->suid
&& uid
!= pcred
->uid
) {
1140 ret
= security_task_kill(p
, info
, sig
, secid
);
1143 if (sig
&& p
->sighand
) {
1144 unsigned long flags
;
1145 spin_lock_irqsave(&p
->sighand
->siglock
, flags
);
1146 ret
= __group_send_sig_info(sig
, info
, p
);
1147 spin_unlock_irqrestore(&p
->sighand
->siglock
, flags
);
1150 read_unlock(&tasklist_lock
);
1153 EXPORT_SYMBOL_GPL(kill_pid_info_as_uid
);
1156 * kill_something_info() interprets pid in interesting ways just like kill(2).
1158 * POSIX specifies that kill(-1,sig) is unspecified, but what we have
1159 * is probably wrong. Should make it like BSD or SYSV.
1162 static int kill_something_info(int sig
, struct siginfo
*info
, pid_t pid
)
1168 ret
= kill_pid_info(sig
, info
, find_vpid(pid
));
1173 read_lock(&tasklist_lock
);
1175 ret
= __kill_pgrp_info(sig
, info
,
1176 pid
? find_vpid(-pid
) : task_pgrp(current
));
1178 int retval
= 0, count
= 0;
1179 struct task_struct
* p
;
1181 for_each_process(p
) {
1182 if (task_pid_vnr(p
) > 1 &&
1183 !same_thread_group(p
, current
)) {
1184 int err
= group_send_sig_info(sig
, info
, p
);
1190 ret
= count
? retval
: -ESRCH
;
1192 read_unlock(&tasklist_lock
);
1198 * These are for backward compatibility with the rest of the kernel source.
1202 * The caller must ensure the task can't exit.
1205 send_sig_info(int sig
, struct siginfo
*info
, struct task_struct
*p
)
1208 unsigned long flags
;
1211 * Make sure legacy kernel users don't send in bad values
1212 * (normal paths check this in check_kill_permission).
1214 if (!valid_signal(sig
))
1217 spin_lock_irqsave(&p
->sighand
->siglock
, flags
);
1218 ret
= specific_send_sig_info(sig
, info
, p
);
1219 spin_unlock_irqrestore(&p
->sighand
->siglock
, flags
);
1223 #define __si_special(priv) \
1224 ((priv) ? SEND_SIG_PRIV : SEND_SIG_NOINFO)
1227 send_sig(int sig
, struct task_struct
*p
, int priv
)
1229 return send_sig_info(sig
, __si_special(priv
), p
);
1233 force_sig(int sig
, struct task_struct
*p
)
1235 force_sig_info(sig
, SEND_SIG_PRIV
, p
);
1239 * When things go south during signal handling, we
1240 * will force a SIGSEGV. And if the signal that caused
1241 * the problem was already a SIGSEGV, we'll want to
1242 * make sure we don't even try to deliver the signal..
1245 force_sigsegv(int sig
, struct task_struct
*p
)
1247 if (sig
== SIGSEGV
) {
1248 unsigned long flags
;
1249 spin_lock_irqsave(&p
->sighand
->siglock
, flags
);
1250 p
->sighand
->action
[sig
- 1].sa
.sa_handler
= SIG_DFL
;
1251 spin_unlock_irqrestore(&p
->sighand
->siglock
, flags
);
1253 force_sig(SIGSEGV
, p
);
1257 int kill_pgrp(struct pid
*pid
, int sig
, int priv
)
1261 read_lock(&tasklist_lock
);
1262 ret
= __kill_pgrp_info(sig
, __si_special(priv
), pid
);
1263 read_unlock(&tasklist_lock
);
1267 EXPORT_SYMBOL(kill_pgrp
);
1269 int kill_pid(struct pid
*pid
, int sig
, int priv
)
1271 return kill_pid_info(sig
, __si_special(priv
), pid
);
1273 EXPORT_SYMBOL(kill_pid
);
1276 * These functions support sending signals using preallocated sigqueue
1277 * structures. This is needed "because realtime applications cannot
1278 * afford to lose notifications of asynchronous events, like timer
1279 * expirations or I/O completions". In the case of Posix Timers
1280 * we allocate the sigqueue structure from the timer_create. If this
1281 * allocation fails we are able to report the failure to the application
1282 * with an EAGAIN error.
1285 struct sigqueue
*sigqueue_alloc(void)
1289 if ((q
= __sigqueue_alloc(current
, GFP_KERNEL
, 0)))
1290 q
->flags
|= SIGQUEUE_PREALLOC
;
1294 void sigqueue_free(struct sigqueue
*q
)
1296 unsigned long flags
;
1297 spinlock_t
*lock
= ¤t
->sighand
->siglock
;
1299 BUG_ON(!(q
->flags
& SIGQUEUE_PREALLOC
));
1301 * We must hold ->siglock while testing q->list
1302 * to serialize with collect_signal() or with
1303 * __exit_signal()->flush_sigqueue().
1305 spin_lock_irqsave(lock
, flags
);
1306 q
->flags
&= ~SIGQUEUE_PREALLOC
;
1308 * If it is queued it will be freed when dequeued,
1309 * like the "regular" sigqueue.
1311 if (!list_empty(&q
->list
))
1313 spin_unlock_irqrestore(lock
, flags
);
1319 int send_sigqueue(struct sigqueue
*q
, struct task_struct
*t
, int group
)
1321 int sig
= q
->info
.si_signo
;
1322 struct sigpending
*pending
;
1323 unsigned long flags
;
1326 BUG_ON(!(q
->flags
& SIGQUEUE_PREALLOC
));
1329 if (!likely(lock_task_sighand(t
, &flags
)))
1332 ret
= 1; /* the signal is ignored */
1333 if (!prepare_signal(sig
, t
))
1337 if (unlikely(!list_empty(&q
->list
))) {
1339 * If an SI_TIMER entry is already queue just increment
1340 * the overrun count.
1342 BUG_ON(q
->info
.si_code
!= SI_TIMER
);
1343 q
->info
.si_overrun
++;
1346 q
->info
.si_overrun
= 0;
1348 signalfd_notify(t
, sig
);
1349 pending
= group
? &t
->signal
->shared_pending
: &t
->pending
;
1350 list_add_tail(&q
->list
, &pending
->list
);
1351 sigaddset(&pending
->signal
, sig
);
1352 complete_signal(sig
, t
, group
);
1354 unlock_task_sighand(t
, &flags
);
1360 * Wake up any threads in the parent blocked in wait* syscalls.
1362 static inline void __wake_up_parent(struct task_struct
*p
,
1363 struct task_struct
*parent
)
1365 wake_up_interruptible_sync(&parent
->signal
->wait_chldexit
);
1369 * Let a parent know about the death of a child.
1370 * For a stopped/continued status change, use do_notify_parent_cldstop instead.
1372 * Returns -1 if our parent ignored us and so we've switched to
1373 * self-reaping, or else @sig.
1375 int do_notify_parent(struct task_struct
*tsk
, int sig
)
1377 struct siginfo info
;
1378 unsigned long flags
;
1379 struct sighand_struct
*psig
;
1384 /* do_notify_parent_cldstop should have been called instead. */
1385 BUG_ON(task_is_stopped_or_traced(tsk
));
1387 BUG_ON(!tsk
->ptrace
&&
1388 (tsk
->group_leader
!= tsk
|| !thread_group_empty(tsk
)));
1390 info
.si_signo
= sig
;
1393 * we are under tasklist_lock here so our parent is tied to
1394 * us and cannot exit and release its namespace.
1396 * the only it can is to switch its nsproxy with sys_unshare,
1397 * bu uncharing pid namespaces is not allowed, so we'll always
1398 * see relevant namespace
1400 * write_lock() currently calls preempt_disable() which is the
1401 * same as rcu_read_lock(), but according to Oleg, this is not
1402 * correct to rely on this
1405 info
.si_pid
= task_pid_nr_ns(tsk
, tsk
->parent
->nsproxy
->pid_ns
);
1406 info
.si_uid
= __task_cred(tsk
)->uid
;
1409 info
.si_utime
= cputime_to_clock_t(cputime_add(tsk
->utime
,
1410 tsk
->signal
->utime
));
1411 info
.si_stime
= cputime_to_clock_t(cputime_add(tsk
->stime
,
1412 tsk
->signal
->stime
));
1414 info
.si_status
= tsk
->exit_code
& 0x7f;
1415 if (tsk
->exit_code
& 0x80)
1416 info
.si_code
= CLD_DUMPED
;
1417 else if (tsk
->exit_code
& 0x7f)
1418 info
.si_code
= CLD_KILLED
;
1420 info
.si_code
= CLD_EXITED
;
1421 info
.si_status
= tsk
->exit_code
>> 8;
1424 psig
= tsk
->parent
->sighand
;
1425 spin_lock_irqsave(&psig
->siglock
, flags
);
1426 if (!tsk
->ptrace
&& sig
== SIGCHLD
&&
1427 (psig
->action
[SIGCHLD
-1].sa
.sa_handler
== SIG_IGN
||
1428 (psig
->action
[SIGCHLD
-1].sa
.sa_flags
& SA_NOCLDWAIT
))) {
1430 * We are exiting and our parent doesn't care. POSIX.1
1431 * defines special semantics for setting SIGCHLD to SIG_IGN
1432 * or setting the SA_NOCLDWAIT flag: we should be reaped
1433 * automatically and not left for our parent's wait4 call.
1434 * Rather than having the parent do it as a magic kind of
1435 * signal handler, we just set this to tell do_exit that we
1436 * can be cleaned up without becoming a zombie. Note that
1437 * we still call __wake_up_parent in this case, because a
1438 * blocked sys_wait4 might now return -ECHILD.
1440 * Whether we send SIGCHLD or not for SA_NOCLDWAIT
1441 * is implementation-defined: we do (if you don't want
1442 * it, just use SIG_IGN instead).
1444 ret
= tsk
->exit_signal
= -1;
1445 if (psig
->action
[SIGCHLD
-1].sa
.sa_handler
== SIG_IGN
)
1448 if (valid_signal(sig
) && sig
> 0)
1449 __group_send_sig_info(sig
, &info
, tsk
->parent
);
1450 __wake_up_parent(tsk
, tsk
->parent
);
1451 spin_unlock_irqrestore(&psig
->siglock
, flags
);
1456 static void do_notify_parent_cldstop(struct task_struct
*tsk
, int why
)
1458 struct siginfo info
;
1459 unsigned long flags
;
1460 struct task_struct
*parent
;
1461 struct sighand_struct
*sighand
;
1463 if (tsk
->ptrace
& PT_PTRACED
)
1464 parent
= tsk
->parent
;
1466 tsk
= tsk
->group_leader
;
1467 parent
= tsk
->real_parent
;
1470 info
.si_signo
= SIGCHLD
;
1473 * see comment in do_notify_parent() abot the following 3 lines
1476 info
.si_pid
= task_pid_nr_ns(tsk
, tsk
->parent
->nsproxy
->pid_ns
);
1477 info
.si_uid
= __task_cred(tsk
)->uid
;
1480 info
.si_utime
= cputime_to_clock_t(tsk
->utime
);
1481 info
.si_stime
= cputime_to_clock_t(tsk
->stime
);
1486 info
.si_status
= SIGCONT
;
1489 info
.si_status
= tsk
->signal
->group_exit_code
& 0x7f;
1492 info
.si_status
= tsk
->exit_code
& 0x7f;
1498 sighand
= parent
->sighand
;
1499 spin_lock_irqsave(&sighand
->siglock
, flags
);
1500 if (sighand
->action
[SIGCHLD
-1].sa
.sa_handler
!= SIG_IGN
&&
1501 !(sighand
->action
[SIGCHLD
-1].sa
.sa_flags
& SA_NOCLDSTOP
))
1502 __group_send_sig_info(SIGCHLD
, &info
, parent
);
1504 * Even if SIGCHLD is not generated, we must wake up wait4 calls.
1506 __wake_up_parent(tsk
, parent
);
1507 spin_unlock_irqrestore(&sighand
->siglock
, flags
);
1510 static inline int may_ptrace_stop(void)
1512 if (!likely(current
->ptrace
& PT_PTRACED
))
1515 * Are we in the middle of do_coredump?
1516 * If so and our tracer is also part of the coredump stopping
1517 * is a deadlock situation, and pointless because our tracer
1518 * is dead so don't allow us to stop.
1519 * If SIGKILL was already sent before the caller unlocked
1520 * ->siglock we must see ->core_state != NULL. Otherwise it
1521 * is safe to enter schedule().
1523 if (unlikely(current
->mm
->core_state
) &&
1524 unlikely(current
->mm
== current
->parent
->mm
))
1531 * Return nonzero if there is a SIGKILL that should be waking us up.
1532 * Called with the siglock held.
1534 static int sigkill_pending(struct task_struct
*tsk
)
1536 return sigismember(&tsk
->pending
.signal
, SIGKILL
) ||
1537 sigismember(&tsk
->signal
->shared_pending
.signal
, SIGKILL
);
1541 * This must be called with current->sighand->siglock held.
1543 * This should be the path for all ptrace stops.
1544 * We always set current->last_siginfo while stopped here.
1545 * That makes it a way to test a stopped process for
1546 * being ptrace-stopped vs being job-control-stopped.
1548 * If we actually decide not to stop at all because the tracer
1549 * is gone, we keep current->exit_code unless clear_code.
1551 static void ptrace_stop(int exit_code
, int clear_code
, siginfo_t
*info
)
1553 if (arch_ptrace_stop_needed(exit_code
, info
)) {
1555 * The arch code has something special to do before a
1556 * ptrace stop. This is allowed to block, e.g. for faults
1557 * on user stack pages. We can't keep the siglock while
1558 * calling arch_ptrace_stop, so we must release it now.
1559 * To preserve proper semantics, we must do this before
1560 * any signal bookkeeping like checking group_stop_count.
1561 * Meanwhile, a SIGKILL could come in before we retake the
1562 * siglock. That must prevent us from sleeping in TASK_TRACED.
1563 * So after regaining the lock, we must check for SIGKILL.
1565 spin_unlock_irq(¤t
->sighand
->siglock
);
1566 arch_ptrace_stop(exit_code
, info
);
1567 spin_lock_irq(¤t
->sighand
->siglock
);
1568 if (sigkill_pending(current
))
1573 * If there is a group stop in progress,
1574 * we must participate in the bookkeeping.
1576 if (current
->signal
->group_stop_count
> 0)
1577 --current
->signal
->group_stop_count
;
1579 current
->last_siginfo
= info
;
1580 current
->exit_code
= exit_code
;
1582 /* Let the debugger run. */
1583 __set_current_state(TASK_TRACED
);
1584 spin_unlock_irq(¤t
->sighand
->siglock
);
1585 read_lock(&tasklist_lock
);
1586 if (may_ptrace_stop()) {
1587 do_notify_parent_cldstop(current
, CLD_TRAPPED
);
1589 * Don't want to allow preemption here, because
1590 * sys_ptrace() needs this task to be inactive.
1592 * XXX: implement read_unlock_no_resched().
1595 read_unlock(&tasklist_lock
);
1596 preempt_enable_no_resched();
1600 * By the time we got the lock, our tracer went away.
1601 * Don't drop the lock yet, another tracer may come.
1603 __set_current_state(TASK_RUNNING
);
1605 current
->exit_code
= 0;
1606 read_unlock(&tasklist_lock
);
1610 * While in TASK_TRACED, we were considered "frozen enough".
1611 * Now that we woke up, it's crucial if we're supposed to be
1612 * frozen that we freeze now before running anything substantial.
1617 * We are back. Now reacquire the siglock before touching
1618 * last_siginfo, so that we are sure to have synchronized with
1619 * any signal-sending on another CPU that wants to examine it.
1621 spin_lock_irq(¤t
->sighand
->siglock
);
1622 current
->last_siginfo
= NULL
;
1625 * Queued signals ignored us while we were stopped for tracing.
1626 * So check for any that we should take before resuming user mode.
1627 * This sets TIF_SIGPENDING, but never clears it.
1629 recalc_sigpending_tsk(current
);
1632 void ptrace_notify(int exit_code
)
1636 BUG_ON((exit_code
& (0x7f | ~0xffff)) != SIGTRAP
);
1638 memset(&info
, 0, sizeof info
);
1639 info
.si_signo
= SIGTRAP
;
1640 info
.si_code
= exit_code
;
1641 info
.si_pid
= task_pid_vnr(current
);
1642 info
.si_uid
= current_uid();
1644 /* Let the debugger run. */
1645 spin_lock_irq(¤t
->sighand
->siglock
);
1646 ptrace_stop(exit_code
, 1, &info
);
1647 spin_unlock_irq(¤t
->sighand
->siglock
);
1651 finish_stop(int stop_count
)
1654 * If there are no other threads in the group, or if there is
1655 * a group stop in progress and we are the last to stop,
1656 * report to the parent. When ptraced, every thread reports itself.
1658 if (tracehook_notify_jctl(stop_count
== 0, CLD_STOPPED
)) {
1659 read_lock(&tasklist_lock
);
1660 do_notify_parent_cldstop(current
, CLD_STOPPED
);
1661 read_unlock(&tasklist_lock
);
1666 } while (try_to_freeze());
1668 * Now we don't run again until continued.
1670 current
->exit_code
= 0;
1674 * This performs the stopping for SIGSTOP and other stop signals.
1675 * We have to stop all threads in the thread group.
1676 * Returns nonzero if we've actually stopped and released the siglock.
1677 * Returns zero if we didn't stop and still hold the siglock.
1679 static int do_signal_stop(int signr
)
1681 struct signal_struct
*sig
= current
->signal
;
1684 if (sig
->group_stop_count
> 0) {
1686 * There is a group stop in progress. We don't need to
1687 * start another one.
1689 stop_count
= --sig
->group_stop_count
;
1691 struct task_struct
*t
;
1693 if (!likely(sig
->flags
& SIGNAL_STOP_DEQUEUED
) ||
1694 unlikely(signal_group_exit(sig
)))
1697 * There is no group stop already in progress.
1698 * We must initiate one now.
1700 sig
->group_exit_code
= signr
;
1703 for (t
= next_thread(current
); t
!= current
; t
= next_thread(t
))
1705 * Setting state to TASK_STOPPED for a group
1706 * stop is always done with the siglock held,
1707 * so this check has no races.
1709 if (!(t
->flags
& PF_EXITING
) &&
1710 !task_is_stopped_or_traced(t
)) {
1712 signal_wake_up(t
, 0);
1714 sig
->group_stop_count
= stop_count
;
1717 if (stop_count
== 0)
1718 sig
->flags
= SIGNAL_STOP_STOPPED
;
1719 current
->exit_code
= sig
->group_exit_code
;
1720 __set_current_state(TASK_STOPPED
);
1722 spin_unlock_irq(¤t
->sighand
->siglock
);
1723 finish_stop(stop_count
);
1727 static int ptrace_signal(int signr
, siginfo_t
*info
,
1728 struct pt_regs
*regs
, void *cookie
)
1730 if (!(current
->ptrace
& PT_PTRACED
))
1733 ptrace_signal_deliver(regs
, cookie
);
1735 /* Let the debugger run. */
1736 ptrace_stop(signr
, 0, info
);
1738 /* We're back. Did the debugger cancel the sig? */
1739 signr
= current
->exit_code
;
1743 current
->exit_code
= 0;
1745 /* Update the siginfo structure if the signal has
1746 changed. If the debugger wanted something
1747 specific in the siginfo structure then it should
1748 have updated *info via PTRACE_SETSIGINFO. */
1749 if (signr
!= info
->si_signo
) {
1750 info
->si_signo
= signr
;
1752 info
->si_code
= SI_USER
;
1753 info
->si_pid
= task_pid_vnr(current
->parent
);
1754 info
->si_uid
= task_uid(current
->parent
);
1757 /* If the (new) signal is now blocked, requeue it. */
1758 if (sigismember(¤t
->blocked
, signr
)) {
1759 specific_send_sig_info(signr
, info
, current
);
1766 int get_signal_to_deliver(siginfo_t
*info
, struct k_sigaction
*return_ka
,
1767 struct pt_regs
*regs
, void *cookie
)
1769 struct sighand_struct
*sighand
= current
->sighand
;
1770 struct signal_struct
*signal
= current
->signal
;
1775 * We'll jump back here after any time we were stopped in TASK_STOPPED.
1776 * While in TASK_STOPPED, we were considered "frozen enough".
1777 * Now that we woke up, it's crucial if we're supposed to be
1778 * frozen that we freeze now before running anything substantial.
1782 spin_lock_irq(&sighand
->siglock
);
1784 * Every stopped thread goes here after wakeup. Check to see if
1785 * we should notify the parent, prepare_signal(SIGCONT) encodes
1786 * the CLD_ si_code into SIGNAL_CLD_MASK bits.
1788 if (unlikely(signal
->flags
& SIGNAL_CLD_MASK
)) {
1789 int why
= (signal
->flags
& SIGNAL_STOP_CONTINUED
)
1790 ? CLD_CONTINUED
: CLD_STOPPED
;
1791 signal
->flags
&= ~SIGNAL_CLD_MASK
;
1792 spin_unlock_irq(&sighand
->siglock
);
1794 if (unlikely(!tracehook_notify_jctl(1, why
)))
1797 read_lock(&tasklist_lock
);
1798 do_notify_parent_cldstop(current
->group_leader
, why
);
1799 read_unlock(&tasklist_lock
);
1804 struct k_sigaction
*ka
;
1806 if (unlikely(signal
->group_stop_count
> 0) &&
1811 * Tracing can induce an artifical signal and choose sigaction.
1812 * The return value in @signr determines the default action,
1813 * but @info->si_signo is the signal number we will report.
1815 signr
= tracehook_get_signal(current
, regs
, info
, return_ka
);
1816 if (unlikely(signr
< 0))
1818 if (unlikely(signr
!= 0))
1821 signr
= dequeue_signal(current
, ¤t
->blocked
,
1825 break; /* will return 0 */
1827 if (signr
!= SIGKILL
) {
1828 signr
= ptrace_signal(signr
, info
,
1834 ka
= &sighand
->action
[signr
-1];
1837 if (ka
->sa
.sa_handler
== SIG_IGN
) /* Do nothing. */
1839 if (ka
->sa
.sa_handler
!= SIG_DFL
) {
1840 /* Run the handler. */
1843 if (ka
->sa
.sa_flags
& SA_ONESHOT
)
1844 ka
->sa
.sa_handler
= SIG_DFL
;
1846 break; /* will return non-zero "signr" value */
1850 * Now we are doing the default action for this signal.
1852 if (sig_kernel_ignore(signr
)) /* Default is nothing. */
1856 * Global init gets no signals it doesn't want.
1858 if (unlikely(signal
->flags
& SIGNAL_UNKILLABLE
) &&
1859 !signal_group_exit(signal
))
1862 if (sig_kernel_stop(signr
)) {
1864 * The default action is to stop all threads in
1865 * the thread group. The job control signals
1866 * do nothing in an orphaned pgrp, but SIGSTOP
1867 * always works. Note that siglock needs to be
1868 * dropped during the call to is_orphaned_pgrp()
1869 * because of lock ordering with tasklist_lock.
1870 * This allows an intervening SIGCONT to be posted.
1871 * We need to check for that and bail out if necessary.
1873 if (signr
!= SIGSTOP
) {
1874 spin_unlock_irq(&sighand
->siglock
);
1876 /* signals can be posted during this window */
1878 if (is_current_pgrp_orphaned())
1881 spin_lock_irq(&sighand
->siglock
);
1884 if (likely(do_signal_stop(info
->si_signo
))) {
1885 /* It released the siglock. */
1890 * We didn't actually stop, due to a race
1891 * with SIGCONT or something like that.
1896 spin_unlock_irq(&sighand
->siglock
);
1899 * Anything else is fatal, maybe with a core dump.
1901 current
->flags
|= PF_SIGNALED
;
1903 if (sig_kernel_coredump(signr
)) {
1904 if (print_fatal_signals
)
1905 print_fatal_signal(regs
, info
->si_signo
);
1907 * If it was able to dump core, this kills all
1908 * other threads in the group and synchronizes with
1909 * their demise. If we lost the race with another
1910 * thread getting here, it set group_exit_code
1911 * first and our do_group_exit call below will use
1912 * that value and ignore the one we pass it.
1914 do_coredump(info
->si_signo
, info
->si_signo
, regs
);
1918 * Death signals, no core dump.
1920 do_group_exit(info
->si_signo
);
1923 spin_unlock_irq(&sighand
->siglock
);
1927 void exit_signals(struct task_struct
*tsk
)
1930 struct task_struct
*t
;
1932 if (thread_group_empty(tsk
) || signal_group_exit(tsk
->signal
)) {
1933 tsk
->flags
|= PF_EXITING
;
1937 spin_lock_irq(&tsk
->sighand
->siglock
);
1939 * From now this task is not visible for group-wide signals,
1940 * see wants_signal(), do_signal_stop().
1942 tsk
->flags
|= PF_EXITING
;
1943 if (!signal_pending(tsk
))
1946 /* It could be that __group_complete_signal() choose us to
1947 * notify about group-wide signal. Another thread should be
1948 * woken now to take the signal since we will not.
1950 for (t
= tsk
; (t
= next_thread(t
)) != tsk
; )
1951 if (!signal_pending(t
) && !(t
->flags
& PF_EXITING
))
1952 recalc_sigpending_and_wake(t
);
1954 if (unlikely(tsk
->signal
->group_stop_count
) &&
1955 !--tsk
->signal
->group_stop_count
) {
1956 tsk
->signal
->flags
= SIGNAL_STOP_STOPPED
;
1960 spin_unlock_irq(&tsk
->sighand
->siglock
);
1962 if (unlikely(group_stop
) && tracehook_notify_jctl(1, CLD_STOPPED
)) {
1963 read_lock(&tasklist_lock
);
1964 do_notify_parent_cldstop(tsk
, CLD_STOPPED
);
1965 read_unlock(&tasklist_lock
);
1969 EXPORT_SYMBOL(recalc_sigpending
);
1970 EXPORT_SYMBOL_GPL(dequeue_signal
);
1971 EXPORT_SYMBOL(flush_signals
);
1972 EXPORT_SYMBOL(force_sig
);
1973 EXPORT_SYMBOL(send_sig
);
1974 EXPORT_SYMBOL(send_sig_info
);
1975 EXPORT_SYMBOL(sigprocmask
);
1976 EXPORT_SYMBOL(block_all_signals
);
1977 EXPORT_SYMBOL(unblock_all_signals
);
1981 * System call entry points.
1984 SYSCALL_DEFINE0(restart_syscall
)
1986 struct restart_block
*restart
= ¤t_thread_info()->restart_block
;
1987 return restart
->fn(restart
);
1990 long do_no_restart_syscall(struct restart_block
*param
)
1996 * We don't need to get the kernel lock - this is all local to this
1997 * particular thread.. (and that's good, because this is _heavily_
1998 * used by various programs)
2002 * This is also useful for kernel threads that want to temporarily
2003 * (or permanently) block certain signals.
2005 * NOTE! Unlike the user-mode sys_sigprocmask(), the kernel
2006 * interface happily blocks "unblockable" signals like SIGKILL
2009 int sigprocmask(int how
, sigset_t
*set
, sigset_t
*oldset
)
2013 spin_lock_irq(¤t
->sighand
->siglock
);
2015 *oldset
= current
->blocked
;
2020 sigorsets(¤t
->blocked
, ¤t
->blocked
, set
);
2023 signandsets(¤t
->blocked
, ¤t
->blocked
, set
);
2026 current
->blocked
= *set
;
2031 recalc_sigpending();
2032 spin_unlock_irq(¤t
->sighand
->siglock
);
2037 SYSCALL_DEFINE4(rt_sigprocmask
, int, how
, sigset_t __user
*, set
,
2038 sigset_t __user
*, oset
, size_t, sigsetsize
)
2040 int error
= -EINVAL
;
2041 sigset_t old_set
, new_set
;
2043 /* XXX: Don't preclude handling different sized sigset_t's. */
2044 if (sigsetsize
!= sizeof(sigset_t
))
2049 if (copy_from_user(&new_set
, set
, sizeof(*set
)))
2051 sigdelsetmask(&new_set
, sigmask(SIGKILL
)|sigmask(SIGSTOP
));
2053 error
= sigprocmask(how
, &new_set
, &old_set
);
2059 spin_lock_irq(¤t
->sighand
->siglock
);
2060 old_set
= current
->blocked
;
2061 spin_unlock_irq(¤t
->sighand
->siglock
);
2065 if (copy_to_user(oset
, &old_set
, sizeof(*oset
)))
2073 long do_sigpending(void __user
*set
, unsigned long sigsetsize
)
2075 long error
= -EINVAL
;
2078 if (sigsetsize
> sizeof(sigset_t
))
2081 spin_lock_irq(¤t
->sighand
->siglock
);
2082 sigorsets(&pending
, ¤t
->pending
.signal
,
2083 ¤t
->signal
->shared_pending
.signal
);
2084 spin_unlock_irq(¤t
->sighand
->siglock
);
2086 /* Outside the lock because only this thread touches it. */
2087 sigandsets(&pending
, ¤t
->blocked
, &pending
);
2090 if (!copy_to_user(set
, &pending
, sigsetsize
))
2097 SYSCALL_DEFINE2(rt_sigpending
, sigset_t __user
*, set
, size_t, sigsetsize
)
2099 return do_sigpending(set
, sigsetsize
);
2102 #ifndef HAVE_ARCH_COPY_SIGINFO_TO_USER
2104 int copy_siginfo_to_user(siginfo_t __user
*to
, siginfo_t
*from
)
2108 if (!access_ok (VERIFY_WRITE
, to
, sizeof(siginfo_t
)))
2110 if (from
->si_code
< 0)
2111 return __copy_to_user(to
, from
, sizeof(siginfo_t
))
2114 * If you change siginfo_t structure, please be sure
2115 * this code is fixed accordingly.
2116 * Please remember to update the signalfd_copyinfo() function
2117 * inside fs/signalfd.c too, in case siginfo_t changes.
2118 * It should never copy any pad contained in the structure
2119 * to avoid security leaks, but must copy the generic
2120 * 3 ints plus the relevant union member.
2122 err
= __put_user(from
->si_signo
, &to
->si_signo
);
2123 err
|= __put_user(from
->si_errno
, &to
->si_errno
);
2124 err
|= __put_user((short)from
->si_code
, &to
->si_code
);
2125 switch (from
->si_code
& __SI_MASK
) {
2127 err
|= __put_user(from
->si_pid
, &to
->si_pid
);
2128 err
|= __put_user(from
->si_uid
, &to
->si_uid
);
2131 err
|= __put_user(from
->si_tid
, &to
->si_tid
);
2132 err
|= __put_user(from
->si_overrun
, &to
->si_overrun
);
2133 err
|= __put_user(from
->si_ptr
, &to
->si_ptr
);
2136 err
|= __put_user(from
->si_band
, &to
->si_band
);
2137 err
|= __put_user(from
->si_fd
, &to
->si_fd
);
2140 err
|= __put_user(from
->si_addr
, &to
->si_addr
);
2141 #ifdef __ARCH_SI_TRAPNO
2142 err
|= __put_user(from
->si_trapno
, &to
->si_trapno
);
2146 err
|= __put_user(from
->si_pid
, &to
->si_pid
);
2147 err
|= __put_user(from
->si_uid
, &to
->si_uid
);
2148 err
|= __put_user(from
->si_status
, &to
->si_status
);
2149 err
|= __put_user(from
->si_utime
, &to
->si_utime
);
2150 err
|= __put_user(from
->si_stime
, &to
->si_stime
);
2152 case __SI_RT
: /* This is not generated by the kernel as of now. */
2153 case __SI_MESGQ
: /* But this is */
2154 err
|= __put_user(from
->si_pid
, &to
->si_pid
);
2155 err
|= __put_user(from
->si_uid
, &to
->si_uid
);
2156 err
|= __put_user(from
->si_ptr
, &to
->si_ptr
);
2158 default: /* this is just in case for now ... */
2159 err
|= __put_user(from
->si_pid
, &to
->si_pid
);
2160 err
|= __put_user(from
->si_uid
, &to
->si_uid
);
2168 SYSCALL_DEFINE4(rt_sigtimedwait
, const sigset_t __user
*, uthese
,
2169 siginfo_t __user
*, uinfo
, const struct timespec __user
*, uts
,
2178 /* XXX: Don't preclude handling different sized sigset_t's. */
2179 if (sigsetsize
!= sizeof(sigset_t
))
2182 if (copy_from_user(&these
, uthese
, sizeof(these
)))
2186 * Invert the set of allowed signals to get those we
2189 sigdelsetmask(&these
, sigmask(SIGKILL
)|sigmask(SIGSTOP
));
2193 if (copy_from_user(&ts
, uts
, sizeof(ts
)))
2195 if (ts
.tv_nsec
>= 1000000000L || ts
.tv_nsec
< 0
2200 spin_lock_irq(¤t
->sighand
->siglock
);
2201 sig
= dequeue_signal(current
, &these
, &info
);
2203 timeout
= MAX_SCHEDULE_TIMEOUT
;
2205 timeout
= (timespec_to_jiffies(&ts
)
2206 + (ts
.tv_sec
|| ts
.tv_nsec
));
2209 /* None ready -- temporarily unblock those we're
2210 * interested while we are sleeping in so that we'll
2211 * be awakened when they arrive. */
2212 current
->real_blocked
= current
->blocked
;
2213 sigandsets(¤t
->blocked
, ¤t
->blocked
, &these
);
2214 recalc_sigpending();
2215 spin_unlock_irq(¤t
->sighand
->siglock
);
2217 timeout
= schedule_timeout_interruptible(timeout
);
2219 spin_lock_irq(¤t
->sighand
->siglock
);
2220 sig
= dequeue_signal(current
, &these
, &info
);
2221 current
->blocked
= current
->real_blocked
;
2222 siginitset(¤t
->real_blocked
, 0);
2223 recalc_sigpending();
2226 spin_unlock_irq(¤t
->sighand
->siglock
);
2231 if (copy_siginfo_to_user(uinfo
, &info
))
2243 SYSCALL_DEFINE2(kill
, pid_t
, pid
, int, sig
)
2245 struct siginfo info
;
2247 info
.si_signo
= sig
;
2249 info
.si_code
= SI_USER
;
2250 info
.si_pid
= task_tgid_vnr(current
);
2251 info
.si_uid
= current_uid();
2253 return kill_something_info(sig
, &info
, pid
);
2256 static int do_tkill(pid_t tgid
, pid_t pid
, int sig
)
2259 struct siginfo info
;
2260 struct task_struct
*p
;
2261 unsigned long flags
;
2264 info
.si_signo
= sig
;
2266 info
.si_code
= SI_TKILL
;
2267 info
.si_pid
= task_tgid_vnr(current
);
2268 info
.si_uid
= current_uid();
2271 p
= find_task_by_vpid(pid
);
2272 if (p
&& (tgid
<= 0 || task_tgid_vnr(p
) == tgid
)) {
2273 error
= check_kill_permission(sig
, &info
, p
);
2275 * The null signal is a permissions and process existence
2276 * probe. No signal is actually delivered.
2278 * If lock_task_sighand() fails we pretend the task dies
2279 * after receiving the signal. The window is tiny, and the
2280 * signal is private anyway.
2282 if (!error
&& sig
&& lock_task_sighand(p
, &flags
)) {
2283 error
= specific_send_sig_info(sig
, &info
, p
);
2284 unlock_task_sighand(p
, &flags
);
2293 * sys_tgkill - send signal to one specific thread
2294 * @tgid: the thread group ID of the thread
2295 * @pid: the PID of the thread
2296 * @sig: signal to be sent
2298 * This syscall also checks the @tgid and returns -ESRCH even if the PID
2299 * exists but it's not belonging to the target process anymore. This
2300 * method solves the problem of threads exiting and PIDs getting reused.
2302 SYSCALL_DEFINE3(tgkill
, pid_t
, tgid
, pid_t
, pid
, int, sig
)
2304 /* This is only valid for single tasks */
2305 if (pid
<= 0 || tgid
<= 0)
2308 return do_tkill(tgid
, pid
, sig
);
2312 * Send a signal to only one task, even if it's a CLONE_THREAD task.
2314 SYSCALL_DEFINE2(tkill
, pid_t
, pid
, int, sig
)
2316 /* This is only valid for single tasks */
2320 return do_tkill(0, pid
, sig
);
2323 SYSCALL_DEFINE3(rt_sigqueueinfo
, pid_t
, pid
, int, sig
,
2324 siginfo_t __user
*, uinfo
)
2328 if (copy_from_user(&info
, uinfo
, sizeof(siginfo_t
)))
2331 /* Not even root can pretend to send signals from the kernel.
2332 Nor can they impersonate a kill(), which adds source info. */
2333 if (info
.si_code
>= 0)
2335 info
.si_signo
= sig
;
2337 /* POSIX.1b doesn't mention process groups. */
2338 return kill_proc_info(sig
, &info
, pid
);
2341 int do_sigaction(int sig
, struct k_sigaction
*act
, struct k_sigaction
*oact
)
2343 struct task_struct
*t
= current
;
2344 struct k_sigaction
*k
;
2347 if (!valid_signal(sig
) || sig
< 1 || (act
&& sig_kernel_only(sig
)))
2350 k
= &t
->sighand
->action
[sig
-1];
2352 spin_lock_irq(¤t
->sighand
->siglock
);
2357 sigdelsetmask(&act
->sa
.sa_mask
,
2358 sigmask(SIGKILL
) | sigmask(SIGSTOP
));
2362 * "Setting a signal action to SIG_IGN for a signal that is
2363 * pending shall cause the pending signal to be discarded,
2364 * whether or not it is blocked."
2366 * "Setting a signal action to SIG_DFL for a signal that is
2367 * pending and whose default action is to ignore the signal
2368 * (for example, SIGCHLD), shall cause the pending signal to
2369 * be discarded, whether or not it is blocked"
2371 if (sig_handler_ignored(sig_handler(t
, sig
), sig
)) {
2373 sigaddset(&mask
, sig
);
2374 rm_from_queue_full(&mask
, &t
->signal
->shared_pending
);
2376 rm_from_queue_full(&mask
, &t
->pending
);
2378 } while (t
!= current
);
2382 spin_unlock_irq(¤t
->sighand
->siglock
);
2387 do_sigaltstack (const stack_t __user
*uss
, stack_t __user
*uoss
, unsigned long sp
)
2393 oss
.ss_sp
= (void __user
*) current
->sas_ss_sp
;
2394 oss
.ss_size
= current
->sas_ss_size
;
2395 oss
.ss_flags
= sas_ss_flags(sp
);
2404 if (!access_ok(VERIFY_READ
, uss
, sizeof(*uss
))
2405 || __get_user(ss_sp
, &uss
->ss_sp
)
2406 || __get_user(ss_flags
, &uss
->ss_flags
)
2407 || __get_user(ss_size
, &uss
->ss_size
))
2411 if (on_sig_stack(sp
))
2417 * Note - this code used to test ss_flags incorrectly
2418 * old code may have been written using ss_flags==0
2419 * to mean ss_flags==SS_ONSTACK (as this was the only
2420 * way that worked) - this fix preserves that older
2423 if (ss_flags
!= SS_DISABLE
&& ss_flags
!= SS_ONSTACK
&& ss_flags
!= 0)
2426 if (ss_flags
== SS_DISABLE
) {
2431 if (ss_size
< MINSIGSTKSZ
)
2435 current
->sas_ss_sp
= (unsigned long) ss_sp
;
2436 current
->sas_ss_size
= ss_size
;
2441 if (copy_to_user(uoss
, &oss
, sizeof(oss
)))
2450 #ifdef __ARCH_WANT_SYS_SIGPENDING
2452 SYSCALL_DEFINE1(sigpending
, old_sigset_t __user
*, set
)
2454 return do_sigpending(set
, sizeof(*set
));
2459 #ifdef __ARCH_WANT_SYS_SIGPROCMASK
2460 /* Some platforms have their own version with special arguments others
2461 support only sys_rt_sigprocmask. */
2463 SYSCALL_DEFINE3(sigprocmask
, int, how
, old_sigset_t __user
*, set
,
2464 old_sigset_t __user
*, oset
)
2467 old_sigset_t old_set
, new_set
;
2471 if (copy_from_user(&new_set
, set
, sizeof(*set
)))
2473 new_set
&= ~(sigmask(SIGKILL
) | sigmask(SIGSTOP
));
2475 spin_lock_irq(¤t
->sighand
->siglock
);
2476 old_set
= current
->blocked
.sig
[0];
2484 sigaddsetmask(¤t
->blocked
, new_set
);
2487 sigdelsetmask(¤t
->blocked
, new_set
);
2490 current
->blocked
.sig
[0] = new_set
;
2494 recalc_sigpending();
2495 spin_unlock_irq(¤t
->sighand
->siglock
);
2501 old_set
= current
->blocked
.sig
[0];
2504 if (copy_to_user(oset
, &old_set
, sizeof(*oset
)))
2511 #endif /* __ARCH_WANT_SYS_SIGPROCMASK */
2513 #ifdef __ARCH_WANT_SYS_RT_SIGACTION
2514 SYSCALL_DEFINE4(rt_sigaction
, int, sig
,
2515 const struct sigaction __user
*, act
,
2516 struct sigaction __user
*, oact
,
2519 struct k_sigaction new_sa
, old_sa
;
2522 /* XXX: Don't preclude handling different sized sigset_t's. */
2523 if (sigsetsize
!= sizeof(sigset_t
))
2527 if (copy_from_user(&new_sa
.sa
, act
, sizeof(new_sa
.sa
)))
2531 ret
= do_sigaction(sig
, act
? &new_sa
: NULL
, oact
? &old_sa
: NULL
);
2534 if (copy_to_user(oact
, &old_sa
.sa
, sizeof(old_sa
.sa
)))
2540 #endif /* __ARCH_WANT_SYS_RT_SIGACTION */
2542 #ifdef __ARCH_WANT_SYS_SGETMASK
2545 * For backwards compatibility. Functionality superseded by sigprocmask.
2547 SYSCALL_DEFINE0(sgetmask
)
2550 return current
->blocked
.sig
[0];
2553 SYSCALL_DEFINE1(ssetmask
, int, newmask
)
2557 spin_lock_irq(¤t
->sighand
->siglock
);
2558 old
= current
->blocked
.sig
[0];
2560 siginitset(¤t
->blocked
, newmask
& ~(sigmask(SIGKILL
)|
2562 recalc_sigpending();
2563 spin_unlock_irq(¤t
->sighand
->siglock
);
2567 #endif /* __ARCH_WANT_SGETMASK */
2569 #ifdef __ARCH_WANT_SYS_SIGNAL
2571 * For backwards compatibility. Functionality superseded by sigaction.
2573 SYSCALL_DEFINE2(signal
, int, sig
, __sighandler_t
, handler
)
2575 struct k_sigaction new_sa
, old_sa
;
2578 new_sa
.sa
.sa_handler
= handler
;
2579 new_sa
.sa
.sa_flags
= SA_ONESHOT
| SA_NOMASK
;
2580 sigemptyset(&new_sa
.sa
.sa_mask
);
2582 ret
= do_sigaction(sig
, &new_sa
, &old_sa
);
2584 return ret
? ret
: (unsigned long)old_sa
.sa
.sa_handler
;
2586 #endif /* __ARCH_WANT_SYS_SIGNAL */
2588 #ifdef __ARCH_WANT_SYS_PAUSE
2590 SYSCALL_DEFINE0(pause
)
2592 current
->state
= TASK_INTERRUPTIBLE
;
2594 return -ERESTARTNOHAND
;
2599 #ifdef __ARCH_WANT_SYS_RT_SIGSUSPEND
2600 SYSCALL_DEFINE2(rt_sigsuspend
, sigset_t __user
*, unewset
, size_t, sigsetsize
)
2604 /* XXX: Don't preclude handling different sized sigset_t's. */
2605 if (sigsetsize
!= sizeof(sigset_t
))
2608 if (copy_from_user(&newset
, unewset
, sizeof(newset
)))
2610 sigdelsetmask(&newset
, sigmask(SIGKILL
)|sigmask(SIGSTOP
));
2612 spin_lock_irq(¤t
->sighand
->siglock
);
2613 current
->saved_sigmask
= current
->blocked
;
2614 current
->blocked
= newset
;
2615 recalc_sigpending();
2616 spin_unlock_irq(¤t
->sighand
->siglock
);
2618 current
->state
= TASK_INTERRUPTIBLE
;
2620 set_restore_sigmask();
2621 return -ERESTARTNOHAND
;
2623 #endif /* __ARCH_WANT_SYS_RT_SIGSUSPEND */
2625 __attribute__((weak
)) const char *arch_vma_name(struct vm_area_struct
*vma
)
2630 void __init
signals_init(void)
2632 sigqueue_cachep
= KMEM_CACHE(sigqueue
, SLAB_PANIC
);