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/capability.h>
26 #include <linux/freezer.h>
27 #include <linux/pid_namespace.h>
28 #include <linux/nsproxy.h>
30 #include <asm/param.h>
31 #include <asm/uaccess.h>
32 #include <asm/unistd.h>
33 #include <asm/siginfo.h>
34 #include "audit.h" /* audit_signal_info() */
37 * SLAB caches for signal bits.
40 static struct kmem_cache
*sigqueue_cachep
;
42 static int __sig_ignored(struct task_struct
*t
, int sig
)
46 /* Is it explicitly or implicitly ignored? */
48 handler
= t
->sighand
->action
[sig
- 1].sa
.sa_handler
;
49 return handler
== SIG_IGN
||
50 (handler
== SIG_DFL
&& sig_kernel_ignore(sig
));
53 static int sig_ignored(struct task_struct
*t
, int sig
)
56 * Tracers always want to know about signals..
58 if (t
->ptrace
& PT_PTRACED
)
62 * Blocked signals are never ignored, since the
63 * signal handler may change by the time it is
66 if (sigismember(&t
->blocked
, sig
) || sigismember(&t
->real_blocked
, sig
))
69 return __sig_ignored(t
, sig
);
73 * Re-calculate pending state from the set of locally pending
74 * signals, globally pending signals, and blocked signals.
76 static inline int has_pending_signals(sigset_t
*signal
, sigset_t
*blocked
)
81 switch (_NSIG_WORDS
) {
83 for (i
= _NSIG_WORDS
, ready
= 0; --i
>= 0 ;)
84 ready
|= signal
->sig
[i
] &~ blocked
->sig
[i
];
87 case 4: ready
= signal
->sig
[3] &~ blocked
->sig
[3];
88 ready
|= signal
->sig
[2] &~ blocked
->sig
[2];
89 ready
|= signal
->sig
[1] &~ blocked
->sig
[1];
90 ready
|= signal
->sig
[0] &~ blocked
->sig
[0];
93 case 2: ready
= signal
->sig
[1] &~ blocked
->sig
[1];
94 ready
|= signal
->sig
[0] &~ blocked
->sig
[0];
97 case 1: ready
= signal
->sig
[0] &~ blocked
->sig
[0];
102 #define PENDING(p,b) has_pending_signals(&(p)->signal, (b))
104 static int recalc_sigpending_tsk(struct task_struct
*t
)
106 if (t
->signal
->group_stop_count
> 0 ||
107 PENDING(&t
->pending
, &t
->blocked
) ||
108 PENDING(&t
->signal
->shared_pending
, &t
->blocked
)) {
109 set_tsk_thread_flag(t
, TIF_SIGPENDING
);
113 * We must never clear the flag in another thread, or in current
114 * when it's possible the current syscall is returning -ERESTART*.
115 * So we don't clear it here, and only callers who know they should do.
121 * After recalculating TIF_SIGPENDING, we need to make sure the task wakes up.
122 * This is superfluous when called on current, the wakeup is a harmless no-op.
124 void recalc_sigpending_and_wake(struct task_struct
*t
)
126 if (recalc_sigpending_tsk(t
))
127 signal_wake_up(t
, 0);
130 void recalc_sigpending(void)
132 if (!recalc_sigpending_tsk(current
) && !freezing(current
))
133 clear_thread_flag(TIF_SIGPENDING
);
137 /* Given the mask, find the first available signal that should be serviced. */
139 int next_signal(struct sigpending
*pending
, sigset_t
*mask
)
141 unsigned long i
, *s
, *m
, x
;
144 s
= pending
->signal
.sig
;
146 switch (_NSIG_WORDS
) {
148 for (i
= 0; i
< _NSIG_WORDS
; ++i
, ++s
, ++m
)
149 if ((x
= *s
&~ *m
) != 0) {
150 sig
= ffz(~x
) + i
*_NSIG_BPW
+ 1;
155 case 2: if ((x
= s
[0] &~ m
[0]) != 0)
157 else if ((x
= s
[1] &~ m
[1]) != 0)
164 case 1: if ((x
= *s
&~ *m
) != 0)
172 static struct sigqueue
*__sigqueue_alloc(struct task_struct
*t
, gfp_t flags
,
175 struct sigqueue
*q
= NULL
;
176 struct user_struct
*user
;
179 * In order to avoid problems with "switch_user()", we want to make
180 * sure that the compiler doesn't re-load "t->user"
184 atomic_inc(&user
->sigpending
);
185 if (override_rlimit
||
186 atomic_read(&user
->sigpending
) <=
187 t
->signal
->rlim
[RLIMIT_SIGPENDING
].rlim_cur
)
188 q
= kmem_cache_alloc(sigqueue_cachep
, flags
);
189 if (unlikely(q
== NULL
)) {
190 atomic_dec(&user
->sigpending
);
192 INIT_LIST_HEAD(&q
->list
);
194 q
->user
= get_uid(user
);
199 static void __sigqueue_free(struct sigqueue
*q
)
201 if (q
->flags
& SIGQUEUE_PREALLOC
)
203 atomic_dec(&q
->user
->sigpending
);
205 kmem_cache_free(sigqueue_cachep
, q
);
208 void flush_sigqueue(struct sigpending
*queue
)
212 sigemptyset(&queue
->signal
);
213 while (!list_empty(&queue
->list
)) {
214 q
= list_entry(queue
->list
.next
, struct sigqueue
, list
);
215 list_del_init(&q
->list
);
221 * Flush all pending signals for a task.
223 void flush_signals(struct task_struct
*t
)
227 spin_lock_irqsave(&t
->sighand
->siglock
, flags
);
228 clear_tsk_thread_flag(t
, TIF_SIGPENDING
);
229 flush_sigqueue(&t
->pending
);
230 flush_sigqueue(&t
->signal
->shared_pending
);
231 spin_unlock_irqrestore(&t
->sighand
->siglock
, flags
);
234 void ignore_signals(struct task_struct
*t
)
238 for (i
= 0; i
< _NSIG
; ++i
)
239 t
->sighand
->action
[i
].sa
.sa_handler
= SIG_IGN
;
245 * Flush all handlers for a task.
249 flush_signal_handlers(struct task_struct
*t
, int force_default
)
252 struct k_sigaction
*ka
= &t
->sighand
->action
[0];
253 for (i
= _NSIG
; i
!= 0 ; i
--) {
254 if (force_default
|| ka
->sa
.sa_handler
!= SIG_IGN
)
255 ka
->sa
.sa_handler
= SIG_DFL
;
257 sigemptyset(&ka
->sa
.sa_mask
);
262 int unhandled_signal(struct task_struct
*tsk
, int sig
)
264 if (is_global_init(tsk
))
266 if (tsk
->ptrace
& PT_PTRACED
)
268 return (tsk
->sighand
->action
[sig
-1].sa
.sa_handler
== SIG_IGN
) ||
269 (tsk
->sighand
->action
[sig
-1].sa
.sa_handler
== SIG_DFL
);
273 /* Notify the system that a driver wants to block all signals for this
274 * process, and wants to be notified if any signals at all were to be
275 * sent/acted upon. If the notifier routine returns non-zero, then the
276 * signal will be acted upon after all. If the notifier routine returns 0,
277 * then then signal will be blocked. Only one block per process is
278 * allowed. priv is a pointer to private data that the notifier routine
279 * can use to determine if the signal should be blocked or not. */
282 block_all_signals(int (*notifier
)(void *priv
), void *priv
, sigset_t
*mask
)
286 spin_lock_irqsave(¤t
->sighand
->siglock
, flags
);
287 current
->notifier_mask
= mask
;
288 current
->notifier_data
= priv
;
289 current
->notifier
= notifier
;
290 spin_unlock_irqrestore(¤t
->sighand
->siglock
, flags
);
293 /* Notify the system that blocking has ended. */
296 unblock_all_signals(void)
300 spin_lock_irqsave(¤t
->sighand
->siglock
, flags
);
301 current
->notifier
= NULL
;
302 current
->notifier_data
= NULL
;
304 spin_unlock_irqrestore(¤t
->sighand
->siglock
, flags
);
307 static int collect_signal(int sig
, struct sigpending
*list
, siginfo_t
*info
)
309 struct sigqueue
*q
, *first
= NULL
;
310 int still_pending
= 0;
312 if (unlikely(!sigismember(&list
->signal
, sig
)))
316 * Collect the siginfo appropriate to this signal. Check if
317 * there is another siginfo for the same signal.
319 list_for_each_entry(q
, &list
->list
, list
) {
320 if (q
->info
.si_signo
== sig
) {
329 list_del_init(&first
->list
);
330 copy_siginfo(info
, &first
->info
);
331 __sigqueue_free(first
);
333 sigdelset(&list
->signal
, sig
);
336 /* Ok, it wasn't in the queue. This must be
337 a fast-pathed signal or we must have been
338 out of queue space. So zero out the info.
340 sigdelset(&list
->signal
, sig
);
341 info
->si_signo
= sig
;
350 static int __dequeue_signal(struct sigpending
*pending
, sigset_t
*mask
,
353 int sig
= next_signal(pending
, mask
);
356 if (current
->notifier
) {
357 if (sigismember(current
->notifier_mask
, sig
)) {
358 if (!(current
->notifier
)(current
->notifier_data
)) {
359 clear_thread_flag(TIF_SIGPENDING
);
365 if (!collect_signal(sig
, pending
, info
))
373 * Dequeue a signal and return the element to the caller, which is
374 * expected to free it.
376 * All callers have to hold the siglock.
378 int dequeue_signal(struct task_struct
*tsk
, sigset_t
*mask
, siginfo_t
*info
)
382 /* We only dequeue private signals from ourselves, we don't let
383 * signalfd steal them
385 signr
= __dequeue_signal(&tsk
->pending
, mask
, info
);
387 signr
= __dequeue_signal(&tsk
->signal
->shared_pending
,
392 * itimers are process shared and we restart periodic
393 * itimers in the signal delivery path to prevent DoS
394 * attacks in the high resolution timer case. This is
395 * compliant with the old way of self restarting
396 * itimers, as the SIGALRM is a legacy signal and only
397 * queued once. Changing the restart behaviour to
398 * restart the timer in the signal dequeue path is
399 * reducing the timer noise on heavy loaded !highres
402 if (unlikely(signr
== SIGALRM
)) {
403 struct hrtimer
*tmr
= &tsk
->signal
->real_timer
;
405 if (!hrtimer_is_queued(tmr
) &&
406 tsk
->signal
->it_real_incr
.tv64
!= 0) {
407 hrtimer_forward(tmr
, tmr
->base
->get_time(),
408 tsk
->signal
->it_real_incr
);
409 hrtimer_restart(tmr
);
418 if (unlikely(sig_kernel_stop(signr
))) {
420 * Set a marker that we have dequeued a stop signal. Our
421 * caller might release the siglock and then the pending
422 * stop signal it is about to process is no longer in the
423 * pending bitmasks, but must still be cleared by a SIGCONT
424 * (and overruled by a SIGKILL). So those cases clear this
425 * shared flag after we've set it. Note that this flag may
426 * remain set after the signal we return is ignored or
427 * handled. That doesn't matter because its only purpose
428 * is to alert stop-signal processing code when another
429 * processor has come along and cleared the flag.
431 if (!(tsk
->signal
->flags
& SIGNAL_GROUP_EXIT
))
432 tsk
->signal
->flags
|= SIGNAL_STOP_DEQUEUED
;
434 if ((info
->si_code
& __SI_MASK
) == __SI_TIMER
&& info
->si_sys_private
) {
436 * Release the siglock to ensure proper locking order
437 * of timer locks outside of siglocks. Note, we leave
438 * irqs disabled here, since the posix-timers code is
439 * about to disable them again anyway.
441 spin_unlock(&tsk
->sighand
->siglock
);
442 do_schedule_next_timer(info
);
443 spin_lock(&tsk
->sighand
->siglock
);
449 * Tell a process that it has a new active signal..
451 * NOTE! we rely on the previous spin_lock to
452 * lock interrupts for us! We can only be called with
453 * "siglock" held, and the local interrupt must
454 * have been disabled when that got acquired!
456 * No need to set need_resched since signal event passing
457 * goes through ->blocked
459 void signal_wake_up(struct task_struct
*t
, int resume
)
463 set_tsk_thread_flag(t
, TIF_SIGPENDING
);
466 * For SIGKILL, we want to wake it up in the stopped/traced/killable
467 * case. We don't check t->state here because there is a race with it
468 * executing another processor and just now entering stopped state.
469 * By using wake_up_state, we ensure the process will wake up and
470 * handle its death signal.
472 mask
= TASK_INTERRUPTIBLE
;
474 mask
|= TASK_WAKEKILL
;
475 if (!wake_up_state(t
, mask
))
480 * Remove signals in mask from the pending set and queue.
481 * Returns 1 if any signals were found.
483 * All callers must be holding the siglock.
485 * This version takes a sigset mask and looks at all signals,
486 * not just those in the first mask word.
488 static int rm_from_queue_full(sigset_t
*mask
, struct sigpending
*s
)
490 struct sigqueue
*q
, *n
;
493 sigandsets(&m
, mask
, &s
->signal
);
494 if (sigisemptyset(&m
))
497 signandsets(&s
->signal
, &s
->signal
, mask
);
498 list_for_each_entry_safe(q
, n
, &s
->list
, list
) {
499 if (sigismember(mask
, q
->info
.si_signo
)) {
500 list_del_init(&q
->list
);
507 * Remove signals in mask from the pending set and queue.
508 * Returns 1 if any signals were found.
510 * All callers must be holding the siglock.
512 static int rm_from_queue(unsigned long mask
, struct sigpending
*s
)
514 struct sigqueue
*q
, *n
;
516 if (!sigtestsetmask(&s
->signal
, mask
))
519 sigdelsetmask(&s
->signal
, mask
);
520 list_for_each_entry_safe(q
, n
, &s
->list
, list
) {
521 if (q
->info
.si_signo
< SIGRTMIN
&&
522 (mask
& sigmask(q
->info
.si_signo
))) {
523 list_del_init(&q
->list
);
531 * Bad permissions for sending the signal
533 static int check_kill_permission(int sig
, struct siginfo
*info
,
534 struct task_struct
*t
)
538 if (!valid_signal(sig
))
541 if (info
!= SEND_SIG_NOINFO
&& (is_si_special(info
) || SI_FROMKERNEL(info
)))
544 error
= audit_signal_info(sig
, t
); /* Let audit system see the signal */
548 if (((sig
!= SIGCONT
) || (task_session_nr(current
) != task_session_nr(t
)))
549 && (current
->euid
^ t
->suid
) && (current
->euid
^ t
->uid
)
550 && (current
->uid
^ t
->suid
) && (current
->uid
^ t
->uid
)
551 && !capable(CAP_KILL
))
554 return security_task_kill(t
, info
, sig
, 0);
558 static void do_notify_parent_cldstop(struct task_struct
*tsk
, int why
);
561 * Handle magic process-wide effects of stop/continue signals.
562 * Unlike the signal actions, these happen immediately at signal-generation
563 * time regardless of blocking, ignoring, or handling. This does the
564 * actual continuing for SIGCONT, but not the actual stopping for stop
565 * signals. The process stop is done as a signal action for SIG_DFL.
567 static void handle_stop_signal(int sig
, struct task_struct
*p
)
569 struct task_struct
*t
;
571 if (p
->signal
->flags
& SIGNAL_GROUP_EXIT
)
573 * The process is in the middle of dying already.
577 if (sig_kernel_stop(sig
)) {
579 * This is a stop signal. Remove SIGCONT from all queues.
581 rm_from_queue(sigmask(SIGCONT
), &p
->signal
->shared_pending
);
584 rm_from_queue(sigmask(SIGCONT
), &t
->pending
);
587 } else if (sig
== SIGCONT
) {
589 * Remove all stop signals from all queues,
590 * and wake all threads.
592 if (unlikely(p
->signal
->group_stop_count
> 0)) {
594 * There was a group stop in progress. We'll
595 * pretend it finished before we got here. We are
596 * obliged to report it to the parent: if the
597 * SIGSTOP happened "after" this SIGCONT, then it
598 * would have cleared this pending SIGCONT. If it
599 * happened "before" this SIGCONT, then the parent
600 * got the SIGCHLD about the stop finishing before
601 * the continue happened. We do the notification
602 * now, and it's as if the stop had finished and
603 * the SIGCHLD was pending on entry to this kill.
605 p
->signal
->group_stop_count
= 0;
606 p
->signal
->flags
= SIGNAL_STOP_CONTINUED
;
607 spin_unlock(&p
->sighand
->siglock
);
608 do_notify_parent_cldstop(p
, CLD_STOPPED
);
609 spin_lock(&p
->sighand
->siglock
);
611 rm_from_queue(SIG_KERNEL_STOP_MASK
, &p
->signal
->shared_pending
);
615 rm_from_queue(SIG_KERNEL_STOP_MASK
, &t
->pending
);
618 * If there is a handler for SIGCONT, we must make
619 * sure that no thread returns to user mode before
620 * we post the signal, in case it was the only
621 * thread eligible to run the signal handler--then
622 * it must not do anything between resuming and
623 * running the handler. With the TIF_SIGPENDING
624 * flag set, the thread will pause and acquire the
625 * siglock that we hold now and until we've queued
626 * the pending signal.
628 * Wake up the stopped thread _after_ setting
631 state
= __TASK_STOPPED
;
632 if (sig_user_defined(t
, SIGCONT
) && !sigismember(&t
->blocked
, SIGCONT
)) {
633 set_tsk_thread_flag(t
, TIF_SIGPENDING
);
634 state
|= TASK_INTERRUPTIBLE
;
636 wake_up_state(t
, state
);
641 if (p
->signal
->flags
& SIGNAL_STOP_STOPPED
) {
643 * We were in fact stopped, and are now continued.
644 * Notify the parent with CLD_CONTINUED.
646 p
->signal
->flags
= SIGNAL_STOP_CONTINUED
;
647 p
->signal
->group_exit_code
= 0;
648 spin_unlock(&p
->sighand
->siglock
);
649 do_notify_parent_cldstop(p
, CLD_CONTINUED
);
650 spin_lock(&p
->sighand
->siglock
);
653 * We are not stopped, but there could be a stop
654 * signal in the middle of being processed after
655 * being removed from the queue. Clear that too.
657 p
->signal
->flags
= 0;
659 } else if (sig
== SIGKILL
) {
661 * Make sure that any pending stop signal already dequeued
662 * is undone by the wakeup for SIGKILL.
664 p
->signal
->flags
= 0;
668 static inline int legacy_queue(struct sigpending
*signals
, int sig
)
670 return (sig
< SIGRTMIN
) && sigismember(&signals
->signal
, sig
);
673 static int send_signal(int sig
, struct siginfo
*info
, struct task_struct
*t
,
674 struct sigpending
*signals
)
676 struct sigqueue
* q
= NULL
;
679 * Short-circuit ignored signals and support queuing
680 * exactly one non-rt signal, so that we can get more
681 * detailed information about the cause of the signal.
683 if (sig_ignored(t
, sig
) || legacy_queue(signals
, sig
))
687 * Deliver the signal to listening signalfds. This must be called
688 * with the sighand lock held.
690 signalfd_notify(t
, sig
);
693 * fast-pathed signals for kernel-internal things like SIGSTOP
696 if (info
== SEND_SIG_FORCED
)
699 /* Real-time signals must be queued if sent by sigqueue, or
700 some other real-time mechanism. It is implementation
701 defined whether kill() does so. We attempt to do so, on
702 the principle of least surprise, but since kill is not
703 allowed to fail with EAGAIN when low on memory we just
704 make sure at least one signal gets delivered and don't
705 pass on the info struct. */
707 q
= __sigqueue_alloc(t
, GFP_ATOMIC
, (sig
< SIGRTMIN
&&
708 (is_si_special(info
) ||
709 info
->si_code
>= 0)));
711 list_add_tail(&q
->list
, &signals
->list
);
712 switch ((unsigned long) info
) {
713 case (unsigned long) SEND_SIG_NOINFO
:
714 q
->info
.si_signo
= sig
;
715 q
->info
.si_errno
= 0;
716 q
->info
.si_code
= SI_USER
;
717 q
->info
.si_pid
= task_pid_vnr(current
);
718 q
->info
.si_uid
= current
->uid
;
720 case (unsigned long) SEND_SIG_PRIV
:
721 q
->info
.si_signo
= sig
;
722 q
->info
.si_errno
= 0;
723 q
->info
.si_code
= SI_KERNEL
;
728 copy_siginfo(&q
->info
, info
);
731 } else if (!is_si_special(info
)) {
732 if (sig
>= SIGRTMIN
&& info
->si_code
!= SI_USER
)
734 * Queue overflow, abort. We may abort if the signal was rt
735 * and sent by user using something other than kill().
741 sigaddset(&signals
->signal
, sig
);
745 int print_fatal_signals
;
747 static void print_fatal_signal(struct pt_regs
*regs
, int signr
)
749 printk("%s/%d: potentially unexpected fatal signal %d.\n",
750 current
->comm
, task_pid_nr(current
), signr
);
752 #if defined(__i386__) && !defined(__arch_um__)
753 printk("code at %08lx: ", regs
->ip
);
756 for (i
= 0; i
< 16; i
++) {
759 __get_user(insn
, (unsigned char *)(regs
->ip
+ i
));
760 printk("%02x ", insn
);
768 static int __init
setup_print_fatal_signals(char *str
)
770 get_option (&str
, &print_fatal_signals
);
775 __setup("print-fatal-signals=", setup_print_fatal_signals
);
778 specific_send_sig_info(int sig
, struct siginfo
*info
, struct task_struct
*t
)
782 BUG_ON(!irqs_disabled());
783 assert_spin_locked(&t
->sighand
->siglock
);
785 ret
= send_signal(sig
, info
, t
, &t
->pending
);
789 if (!sigismember(&t
->blocked
, sig
))
790 signal_wake_up(t
, sig
== SIGKILL
);
795 * Force a signal that the process can't ignore: if necessary
796 * we unblock the signal and change any SIG_IGN to SIG_DFL.
798 * Note: If we unblock the signal, we always reset it to SIG_DFL,
799 * since we do not want to have a signal handler that was blocked
800 * be invoked when user space had explicitly blocked it.
802 * We don't want to have recursive SIGSEGV's etc, for example.
805 force_sig_info(int sig
, struct siginfo
*info
, struct task_struct
*t
)
807 unsigned long int flags
;
808 int ret
, blocked
, ignored
;
809 struct k_sigaction
*action
;
811 spin_lock_irqsave(&t
->sighand
->siglock
, flags
);
812 action
= &t
->sighand
->action
[sig
-1];
813 ignored
= action
->sa
.sa_handler
== SIG_IGN
;
814 blocked
= sigismember(&t
->blocked
, sig
);
815 if (blocked
|| ignored
) {
816 action
->sa
.sa_handler
= SIG_DFL
;
818 sigdelset(&t
->blocked
, sig
);
819 recalc_sigpending_and_wake(t
);
822 ret
= specific_send_sig_info(sig
, info
, t
);
823 spin_unlock_irqrestore(&t
->sighand
->siglock
, flags
);
829 force_sig_specific(int sig
, struct task_struct
*t
)
831 force_sig_info(sig
, SEND_SIG_FORCED
, t
);
835 * Test if P wants to take SIG. After we've checked all threads with this,
836 * it's equivalent to finding no threads not blocking SIG. Any threads not
837 * blocking SIG were ruled out because they are not running and already
838 * have pending signals. Such threads will dequeue from the shared queue
839 * as soon as they're available, so putting the signal on the shared queue
840 * will be equivalent to sending it to one such thread.
842 static inline int wants_signal(int sig
, struct task_struct
*p
)
844 if (sigismember(&p
->blocked
, sig
))
846 if (p
->flags
& PF_EXITING
)
850 if (task_is_stopped_or_traced(p
))
852 return task_curr(p
) || !signal_pending(p
);
856 __group_complete_signal(int sig
, struct task_struct
*p
)
858 struct task_struct
*t
;
861 * Now find a thread we can wake up to take the signal off the queue.
863 * If the main thread wants the signal, it gets first crack.
864 * Probably the least surprising to the average bear.
866 if (wants_signal(sig
, p
))
868 else if (thread_group_empty(p
))
870 * There is just one thread and it does not need to be woken.
871 * It will dequeue unblocked signals before it runs again.
876 * Otherwise try to find a suitable thread.
878 t
= p
->signal
->curr_target
;
880 /* restart balancing at this thread */
881 t
= p
->signal
->curr_target
= p
;
883 while (!wants_signal(sig
, t
)) {
885 if (t
== p
->signal
->curr_target
)
887 * No thread needs to be woken.
888 * Any eligible threads will see
889 * the signal in the queue soon.
893 p
->signal
->curr_target
= t
;
897 * Found a killable thread. If the signal will be fatal,
898 * then start taking the whole group down immediately.
900 if (sig_fatal(p
, sig
) && !(p
->signal
->flags
& SIGNAL_GROUP_EXIT
) &&
901 !sigismember(&t
->real_blocked
, sig
) &&
902 (sig
== SIGKILL
|| !(t
->ptrace
& PT_PTRACED
))) {
904 * This signal will be fatal to the whole group.
906 if (!sig_kernel_coredump(sig
)) {
908 * Start a group exit and wake everybody up.
909 * This way we don't have other threads
910 * running and doing things after a slower
911 * thread has the fatal signal pending.
913 p
->signal
->flags
= SIGNAL_GROUP_EXIT
;
914 p
->signal
->group_exit_code
= sig
;
915 p
->signal
->group_stop_count
= 0;
918 sigaddset(&t
->pending
.signal
, SIGKILL
);
919 signal_wake_up(t
, 1);
920 } while_each_thread(p
, t
);
926 * The signal is already in the shared-pending queue.
927 * Tell the chosen thread to wake up and dequeue it.
929 signal_wake_up(t
, sig
== SIGKILL
);
934 __group_send_sig_info(int sig
, struct siginfo
*info
, struct task_struct
*p
)
938 assert_spin_locked(&p
->sighand
->siglock
);
939 handle_stop_signal(sig
, p
);
942 * Put this signal on the shared-pending queue, or fail with EAGAIN.
943 * We always use the shared queue for process-wide signals,
944 * to avoid several races.
946 ret
= send_signal(sig
, info
, p
, &p
->signal
->shared_pending
);
950 __group_complete_signal(sig
, p
);
955 * Nuke all other threads in the group.
957 void zap_other_threads(struct task_struct
*p
)
959 struct task_struct
*t
;
961 p
->signal
->group_stop_count
= 0;
963 for (t
= next_thread(p
); t
!= p
; t
= next_thread(t
)) {
965 * Don't bother with already dead threads
970 /* SIGKILL will be handled before any pending SIGSTOP */
971 sigaddset(&t
->pending
.signal
, SIGKILL
);
972 signal_wake_up(t
, 1);
976 int __fatal_signal_pending(struct task_struct
*tsk
)
978 return sigismember(&tsk
->pending
.signal
, SIGKILL
);
980 EXPORT_SYMBOL(__fatal_signal_pending
);
982 struct sighand_struct
*lock_task_sighand(struct task_struct
*tsk
, unsigned long *flags
)
984 struct sighand_struct
*sighand
;
988 sighand
= rcu_dereference(tsk
->sighand
);
989 if (unlikely(sighand
== NULL
))
992 spin_lock_irqsave(&sighand
->siglock
, *flags
);
993 if (likely(sighand
== tsk
->sighand
))
995 spin_unlock_irqrestore(&sighand
->siglock
, *flags
);
1002 int group_send_sig_info(int sig
, struct siginfo
*info
, struct task_struct
*p
)
1004 unsigned long flags
;
1007 ret
= check_kill_permission(sig
, info
, p
);
1011 if (lock_task_sighand(p
, &flags
)) {
1012 ret
= __group_send_sig_info(sig
, info
, p
);
1013 unlock_task_sighand(p
, &flags
);
1021 * __kill_pgrp_info() sends a signal to a process group: this is what the tty
1022 * control characters do (^C, ^Z etc)
1025 int __kill_pgrp_info(int sig
, struct siginfo
*info
, struct pid
*pgrp
)
1027 struct task_struct
*p
= NULL
;
1028 int retval
, success
;
1032 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
1033 int err
= group_send_sig_info(sig
, info
, p
);
1036 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
1037 return success
? 0 : retval
;
1040 int kill_pid_info(int sig
, struct siginfo
*info
, struct pid
*pid
)
1043 struct task_struct
*p
;
1046 if (unlikely(sig_needs_tasklist(sig
)))
1047 read_lock(&tasklist_lock
);
1050 p
= pid_task(pid
, PIDTYPE_PID
);
1052 error
= group_send_sig_info(sig
, info
, p
);
1053 if (unlikely(error
== -ESRCH
))
1055 * The task was unhashed in between, try again.
1056 * If it is dead, pid_task() will return NULL,
1057 * if we race with de_thread() it will find the
1063 if (unlikely(sig_needs_tasklist(sig
)))
1064 read_unlock(&tasklist_lock
);
1070 kill_proc_info(int sig
, struct siginfo
*info
, pid_t pid
)
1074 error
= kill_pid_info(sig
, info
, find_vpid(pid
));
1079 /* like kill_pid_info(), but doesn't use uid/euid of "current" */
1080 int kill_pid_info_as_uid(int sig
, struct siginfo
*info
, struct pid
*pid
,
1081 uid_t uid
, uid_t euid
, u32 secid
)
1084 struct task_struct
*p
;
1086 if (!valid_signal(sig
))
1089 read_lock(&tasklist_lock
);
1090 p
= pid_task(pid
, PIDTYPE_PID
);
1095 if ((info
== SEND_SIG_NOINFO
|| (!is_si_special(info
) && SI_FROMUSER(info
)))
1096 && (euid
!= p
->suid
) && (euid
!= p
->uid
)
1097 && (uid
!= p
->suid
) && (uid
!= p
->uid
)) {
1101 ret
= security_task_kill(p
, info
, sig
, secid
);
1104 if (sig
&& p
->sighand
) {
1105 unsigned long flags
;
1106 spin_lock_irqsave(&p
->sighand
->siglock
, flags
);
1107 ret
= __group_send_sig_info(sig
, info
, p
);
1108 spin_unlock_irqrestore(&p
->sighand
->siglock
, flags
);
1111 read_unlock(&tasklist_lock
);
1114 EXPORT_SYMBOL_GPL(kill_pid_info_as_uid
);
1117 * kill_something_info() interprets pid in interesting ways just like kill(2).
1119 * POSIX specifies that kill(-1,sig) is unspecified, but what we have
1120 * is probably wrong. Should make it like BSD or SYSV.
1123 static int kill_something_info(int sig
, struct siginfo
*info
, int pid
)
1129 ret
= kill_pid_info(sig
, info
, find_vpid(pid
));
1134 read_lock(&tasklist_lock
);
1136 ret
= __kill_pgrp_info(sig
, info
,
1137 pid
? find_vpid(-pid
) : task_pgrp(current
));
1139 int retval
= 0, count
= 0;
1140 struct task_struct
* p
;
1142 for_each_process(p
) {
1143 if (p
->pid
> 1 && !same_thread_group(p
, current
)) {
1144 int err
= group_send_sig_info(sig
, info
, p
);
1150 ret
= count
? retval
: -ESRCH
;
1152 read_unlock(&tasklist_lock
);
1158 * These are for backward compatibility with the rest of the kernel source.
1162 * These two are the most common entry points. They send a signal
1163 * just to the specific thread.
1166 send_sig_info(int sig
, struct siginfo
*info
, struct task_struct
*p
)
1169 unsigned long flags
;
1172 * Make sure legacy kernel users don't send in bad values
1173 * (normal paths check this in check_kill_permission).
1175 if (!valid_signal(sig
))
1179 * We need the tasklist lock even for the specific
1180 * thread case (when we don't need to follow the group
1181 * lists) in order to avoid races with "p->sighand"
1182 * going away or changing from under us.
1184 read_lock(&tasklist_lock
);
1185 spin_lock_irqsave(&p
->sighand
->siglock
, flags
);
1186 ret
= specific_send_sig_info(sig
, info
, p
);
1187 spin_unlock_irqrestore(&p
->sighand
->siglock
, flags
);
1188 read_unlock(&tasklist_lock
);
1192 #define __si_special(priv) \
1193 ((priv) ? SEND_SIG_PRIV : SEND_SIG_NOINFO)
1196 send_sig(int sig
, struct task_struct
*p
, int priv
)
1198 return send_sig_info(sig
, __si_special(priv
), p
);
1202 force_sig(int sig
, struct task_struct
*p
)
1204 force_sig_info(sig
, SEND_SIG_PRIV
, p
);
1208 * When things go south during signal handling, we
1209 * will force a SIGSEGV. And if the signal that caused
1210 * the problem was already a SIGSEGV, we'll want to
1211 * make sure we don't even try to deliver the signal..
1214 force_sigsegv(int sig
, struct task_struct
*p
)
1216 if (sig
== SIGSEGV
) {
1217 unsigned long flags
;
1218 spin_lock_irqsave(&p
->sighand
->siglock
, flags
);
1219 p
->sighand
->action
[sig
- 1].sa
.sa_handler
= SIG_DFL
;
1220 spin_unlock_irqrestore(&p
->sighand
->siglock
, flags
);
1222 force_sig(SIGSEGV
, p
);
1226 int kill_pgrp(struct pid
*pid
, int sig
, int priv
)
1230 read_lock(&tasklist_lock
);
1231 ret
= __kill_pgrp_info(sig
, __si_special(priv
), pid
);
1232 read_unlock(&tasklist_lock
);
1236 EXPORT_SYMBOL(kill_pgrp
);
1238 int kill_pid(struct pid
*pid
, int sig
, int priv
)
1240 return kill_pid_info(sig
, __si_special(priv
), pid
);
1242 EXPORT_SYMBOL(kill_pid
);
1245 kill_proc(pid_t pid
, int sig
, int priv
)
1250 ret
= kill_pid_info(sig
, __si_special(priv
), find_pid(pid
));
1256 * These functions support sending signals using preallocated sigqueue
1257 * structures. This is needed "because realtime applications cannot
1258 * afford to lose notifications of asynchronous events, like timer
1259 * expirations or I/O completions". In the case of Posix Timers
1260 * we allocate the sigqueue structure from the timer_create. If this
1261 * allocation fails we are able to report the failure to the application
1262 * with an EAGAIN error.
1265 struct sigqueue
*sigqueue_alloc(void)
1269 if ((q
= __sigqueue_alloc(current
, GFP_KERNEL
, 0)))
1270 q
->flags
|= SIGQUEUE_PREALLOC
;
1274 void sigqueue_free(struct sigqueue
*q
)
1276 unsigned long flags
;
1277 spinlock_t
*lock
= ¤t
->sighand
->siglock
;
1279 BUG_ON(!(q
->flags
& SIGQUEUE_PREALLOC
));
1281 * If the signal is still pending remove it from the
1282 * pending queue. We must hold ->siglock while testing
1283 * q->list to serialize with collect_signal().
1285 spin_lock_irqsave(lock
, flags
);
1286 if (!list_empty(&q
->list
))
1287 list_del_init(&q
->list
);
1288 spin_unlock_irqrestore(lock
, flags
);
1290 q
->flags
&= ~SIGQUEUE_PREALLOC
;
1294 static int do_send_sigqueue(int sig
, struct sigqueue
*q
, struct task_struct
*t
,
1295 struct sigpending
*pending
)
1297 if (unlikely(!list_empty(&q
->list
))) {
1299 * If an SI_TIMER entry is already queue just increment
1300 * the overrun count.
1303 BUG_ON(q
->info
.si_code
!= SI_TIMER
);
1304 q
->info
.si_overrun
++;
1308 if (sig_ignored(t
, sig
))
1311 signalfd_notify(t
, sig
);
1312 list_add_tail(&q
->list
, &pending
->list
);
1313 sigaddset(&pending
->signal
, sig
);
1317 int send_sigqueue(int sig
, struct sigqueue
*q
, struct task_struct
*p
)
1319 unsigned long flags
;
1322 BUG_ON(!(q
->flags
& SIGQUEUE_PREALLOC
));
1325 * The rcu based delayed sighand destroy makes it possible to
1326 * run this without tasklist lock held. The task struct itself
1327 * cannot go away as create_timer did get_task_struct().
1329 * We return -1, when the task is marked exiting, so
1330 * posix_timer_event can redirect it to the group leader
1334 if (!likely(lock_task_sighand(p
, &flags
)))
1337 ret
= do_send_sigqueue(sig
, q
, p
, &p
->pending
);
1339 if (!sigismember(&p
->blocked
, sig
))
1340 signal_wake_up(p
, sig
== SIGKILL
);
1342 unlock_task_sighand(p
, &flags
);
1350 send_group_sigqueue(int sig
, struct sigqueue
*q
, struct task_struct
*p
)
1352 unsigned long flags
;
1355 BUG_ON(!(q
->flags
& SIGQUEUE_PREALLOC
));
1357 read_lock(&tasklist_lock
);
1358 /* Since it_lock is held, p->sighand cannot be NULL. */
1359 spin_lock_irqsave(&p
->sighand
->siglock
, flags
);
1360 handle_stop_signal(sig
, p
);
1362 ret
= do_send_sigqueue(sig
, q
, p
, &p
->signal
->shared_pending
);
1364 __group_complete_signal(sig
, p
);
1366 spin_unlock_irqrestore(&p
->sighand
->siglock
, flags
);
1367 read_unlock(&tasklist_lock
);
1372 * Wake up any threads in the parent blocked in wait* syscalls.
1374 static inline void __wake_up_parent(struct task_struct
*p
,
1375 struct task_struct
*parent
)
1377 wake_up_interruptible_sync(&parent
->signal
->wait_chldexit
);
1381 * Let a parent know about the death of a child.
1382 * For a stopped/continued status change, use do_notify_parent_cldstop instead.
1385 void do_notify_parent(struct task_struct
*tsk
, int sig
)
1387 struct siginfo info
;
1388 unsigned long flags
;
1389 struct sighand_struct
*psig
;
1393 /* do_notify_parent_cldstop should have been called instead. */
1394 BUG_ON(task_is_stopped_or_traced(tsk
));
1396 BUG_ON(!tsk
->ptrace
&&
1397 (tsk
->group_leader
!= tsk
|| !thread_group_empty(tsk
)));
1399 info
.si_signo
= sig
;
1402 * we are under tasklist_lock here so our parent is tied to
1403 * us and cannot exit and release its namespace.
1405 * the only it can is to switch its nsproxy with sys_unshare,
1406 * bu uncharing pid namespaces is not allowed, so we'll always
1407 * see relevant namespace
1409 * write_lock() currently calls preempt_disable() which is the
1410 * same as rcu_read_lock(), but according to Oleg, this is not
1411 * correct to rely on this
1414 info
.si_pid
= task_pid_nr_ns(tsk
, tsk
->parent
->nsproxy
->pid_ns
);
1417 info
.si_uid
= tsk
->uid
;
1419 /* FIXME: find out whether or not this is supposed to be c*time. */
1420 info
.si_utime
= cputime_to_jiffies(cputime_add(tsk
->utime
,
1421 tsk
->signal
->utime
));
1422 info
.si_stime
= cputime_to_jiffies(cputime_add(tsk
->stime
,
1423 tsk
->signal
->stime
));
1425 info
.si_status
= tsk
->exit_code
& 0x7f;
1426 if (tsk
->exit_code
& 0x80)
1427 info
.si_code
= CLD_DUMPED
;
1428 else if (tsk
->exit_code
& 0x7f)
1429 info
.si_code
= CLD_KILLED
;
1431 info
.si_code
= CLD_EXITED
;
1432 info
.si_status
= tsk
->exit_code
>> 8;
1435 psig
= tsk
->parent
->sighand
;
1436 spin_lock_irqsave(&psig
->siglock
, flags
);
1437 if (!tsk
->ptrace
&& sig
== SIGCHLD
&&
1438 (psig
->action
[SIGCHLD
-1].sa
.sa_handler
== SIG_IGN
||
1439 (psig
->action
[SIGCHLD
-1].sa
.sa_flags
& SA_NOCLDWAIT
))) {
1441 * We are exiting and our parent doesn't care. POSIX.1
1442 * defines special semantics for setting SIGCHLD to SIG_IGN
1443 * or setting the SA_NOCLDWAIT flag: we should be reaped
1444 * automatically and not left for our parent's wait4 call.
1445 * Rather than having the parent do it as a magic kind of
1446 * signal handler, we just set this to tell do_exit that we
1447 * can be cleaned up without becoming a zombie. Note that
1448 * we still call __wake_up_parent in this case, because a
1449 * blocked sys_wait4 might now return -ECHILD.
1451 * Whether we send SIGCHLD or not for SA_NOCLDWAIT
1452 * is implementation-defined: we do (if you don't want
1453 * it, just use SIG_IGN instead).
1455 tsk
->exit_signal
= -1;
1456 if (psig
->action
[SIGCHLD
-1].sa
.sa_handler
== SIG_IGN
)
1459 if (valid_signal(sig
) && sig
> 0)
1460 __group_send_sig_info(sig
, &info
, tsk
->parent
);
1461 __wake_up_parent(tsk
, tsk
->parent
);
1462 spin_unlock_irqrestore(&psig
->siglock
, flags
);
1465 static void do_notify_parent_cldstop(struct task_struct
*tsk
, int why
)
1467 struct siginfo info
;
1468 unsigned long flags
;
1469 struct task_struct
*parent
;
1470 struct sighand_struct
*sighand
;
1472 if (tsk
->ptrace
& PT_PTRACED
)
1473 parent
= tsk
->parent
;
1475 tsk
= tsk
->group_leader
;
1476 parent
= tsk
->real_parent
;
1479 info
.si_signo
= SIGCHLD
;
1482 * see comment in do_notify_parent() abot the following 3 lines
1485 info
.si_pid
= task_pid_nr_ns(tsk
, tsk
->parent
->nsproxy
->pid_ns
);
1488 info
.si_uid
= tsk
->uid
;
1490 /* FIXME: find out whether or not this is supposed to be c*time. */
1491 info
.si_utime
= cputime_to_jiffies(tsk
->utime
);
1492 info
.si_stime
= cputime_to_jiffies(tsk
->stime
);
1497 info
.si_status
= SIGCONT
;
1500 info
.si_status
= tsk
->signal
->group_exit_code
& 0x7f;
1503 info
.si_status
= tsk
->exit_code
& 0x7f;
1509 sighand
= parent
->sighand
;
1510 spin_lock_irqsave(&sighand
->siglock
, flags
);
1511 if (sighand
->action
[SIGCHLD
-1].sa
.sa_handler
!= SIG_IGN
&&
1512 !(sighand
->action
[SIGCHLD
-1].sa
.sa_flags
& SA_NOCLDSTOP
))
1513 __group_send_sig_info(SIGCHLD
, &info
, parent
);
1515 * Even if SIGCHLD is not generated, we must wake up wait4 calls.
1517 __wake_up_parent(tsk
, parent
);
1518 spin_unlock_irqrestore(&sighand
->siglock
, flags
);
1521 static inline int may_ptrace_stop(void)
1523 if (!likely(current
->ptrace
& PT_PTRACED
))
1526 * Are we in the middle of do_coredump?
1527 * If so and our tracer is also part of the coredump stopping
1528 * is a deadlock situation, and pointless because our tracer
1529 * is dead so don't allow us to stop.
1530 * If SIGKILL was already sent before the caller unlocked
1531 * ->siglock we must see ->core_waiters != 0. Otherwise it
1532 * is safe to enter schedule().
1534 if (unlikely(current
->mm
->core_waiters
) &&
1535 unlikely(current
->mm
== current
->parent
->mm
))
1542 * Return nonzero if there is a SIGKILL that should be waking us up.
1543 * Called with the siglock held.
1545 static int sigkill_pending(struct task_struct
*tsk
)
1547 return ((sigismember(&tsk
->pending
.signal
, SIGKILL
) ||
1548 sigismember(&tsk
->signal
->shared_pending
.signal
, SIGKILL
)) &&
1549 !unlikely(sigismember(&tsk
->blocked
, SIGKILL
)));
1553 * This must be called with current->sighand->siglock held.
1555 * This should be the path for all ptrace stops.
1556 * We always set current->last_siginfo while stopped here.
1557 * That makes it a way to test a stopped process for
1558 * being ptrace-stopped vs being job-control-stopped.
1560 * If we actually decide not to stop at all because the tracer
1561 * is gone, we keep current->exit_code unless clear_code.
1563 static void ptrace_stop(int exit_code
, int clear_code
, siginfo_t
*info
)
1567 if (arch_ptrace_stop_needed(exit_code
, info
)) {
1569 * The arch code has something special to do before a
1570 * ptrace stop. This is allowed to block, e.g. for faults
1571 * on user stack pages. We can't keep the siglock while
1572 * calling arch_ptrace_stop, so we must release it now.
1573 * To preserve proper semantics, we must do this before
1574 * any signal bookkeeping like checking group_stop_count.
1575 * Meanwhile, a SIGKILL could come in before we retake the
1576 * siglock. That must prevent us from sleeping in TASK_TRACED.
1577 * So after regaining the lock, we must check for SIGKILL.
1579 spin_unlock_irq(¤t
->sighand
->siglock
);
1580 arch_ptrace_stop(exit_code
, info
);
1581 spin_lock_irq(¤t
->sighand
->siglock
);
1582 killed
= sigkill_pending(current
);
1586 * If there is a group stop in progress,
1587 * we must participate in the bookkeeping.
1589 if (current
->signal
->group_stop_count
> 0)
1590 --current
->signal
->group_stop_count
;
1592 current
->last_siginfo
= info
;
1593 current
->exit_code
= exit_code
;
1595 /* Let the debugger run. */
1596 __set_current_state(TASK_TRACED
);
1597 spin_unlock_irq(¤t
->sighand
->siglock
);
1598 read_lock(&tasklist_lock
);
1599 if (!unlikely(killed
) && may_ptrace_stop()) {
1600 do_notify_parent_cldstop(current
, CLD_TRAPPED
);
1601 read_unlock(&tasklist_lock
);
1605 * By the time we got the lock, our tracer went away.
1606 * Don't drop the lock yet, another tracer may come.
1608 __set_current_state(TASK_RUNNING
);
1610 current
->exit_code
= 0;
1611 read_unlock(&tasklist_lock
);
1615 * While in TASK_TRACED, we were considered "frozen enough".
1616 * Now that we woke up, it's crucial if we're supposed to be
1617 * frozen that we freeze now before running anything substantial.
1622 * We are back. Now reacquire the siglock before touching
1623 * last_siginfo, so that we are sure to have synchronized with
1624 * any signal-sending on another CPU that wants to examine it.
1626 spin_lock_irq(¤t
->sighand
->siglock
);
1627 current
->last_siginfo
= NULL
;
1630 * Queued signals ignored us while we were stopped for tracing.
1631 * So check for any that we should take before resuming user mode.
1632 * This sets TIF_SIGPENDING, but never clears it.
1634 recalc_sigpending_tsk(current
);
1637 void ptrace_notify(int exit_code
)
1641 BUG_ON((exit_code
& (0x7f | ~0xffff)) != SIGTRAP
);
1643 memset(&info
, 0, sizeof info
);
1644 info
.si_signo
= SIGTRAP
;
1645 info
.si_code
= exit_code
;
1646 info
.si_pid
= task_pid_vnr(current
);
1647 info
.si_uid
= current
->uid
;
1649 /* Let the debugger run. */
1650 spin_lock_irq(¤t
->sighand
->siglock
);
1651 ptrace_stop(exit_code
, 1, &info
);
1652 spin_unlock_irq(¤t
->sighand
->siglock
);
1656 finish_stop(int stop_count
)
1659 * If there are no other threads in the group, or if there is
1660 * a group stop in progress and we are the last to stop,
1661 * report to the parent. When ptraced, every thread reports itself.
1663 if (stop_count
== 0 || (current
->ptrace
& PT_PTRACED
)) {
1664 read_lock(&tasklist_lock
);
1665 do_notify_parent_cldstop(current
, CLD_STOPPED
);
1666 read_unlock(&tasklist_lock
);
1671 } while (try_to_freeze());
1673 * Now we don't run again until continued.
1675 current
->exit_code
= 0;
1679 * This performs the stopping for SIGSTOP and other stop signals.
1680 * We have to stop all threads in the thread group.
1681 * Returns nonzero if we've actually stopped and released the siglock.
1682 * Returns zero if we didn't stop and still hold the siglock.
1684 static int do_signal_stop(int signr
)
1686 struct signal_struct
*sig
= current
->signal
;
1689 if (sig
->group_stop_count
> 0) {
1691 * There is a group stop in progress. We don't need to
1692 * start another one.
1694 stop_count
= --sig
->group_stop_count
;
1696 struct task_struct
*t
;
1698 if (!likely(sig
->flags
& SIGNAL_STOP_DEQUEUED
) ||
1699 unlikely(signal_group_exit(sig
)))
1702 * There is no group stop already in progress.
1703 * We must initiate one now.
1705 sig
->group_exit_code
= signr
;
1708 for (t
= next_thread(current
); t
!= current
; t
= next_thread(t
))
1710 * Setting state to TASK_STOPPED for a group
1711 * stop is always done with the siglock held,
1712 * so this check has no races.
1714 if (!(t
->flags
& PF_EXITING
) &&
1715 !task_is_stopped_or_traced(t
)) {
1717 signal_wake_up(t
, 0);
1719 sig
->group_stop_count
= stop_count
;
1722 if (stop_count
== 0)
1723 sig
->flags
= SIGNAL_STOP_STOPPED
;
1724 current
->exit_code
= sig
->group_exit_code
;
1725 __set_current_state(TASK_STOPPED
);
1727 spin_unlock_irq(¤t
->sighand
->siglock
);
1728 finish_stop(stop_count
);
1732 static int ptrace_signal(int signr
, siginfo_t
*info
,
1733 struct pt_regs
*regs
, void *cookie
)
1735 if (!(current
->ptrace
& PT_PTRACED
))
1738 ptrace_signal_deliver(regs
, cookie
);
1740 /* Let the debugger run. */
1741 ptrace_stop(signr
, 0, info
);
1743 /* We're back. Did the debugger cancel the sig? */
1744 signr
= current
->exit_code
;
1748 current
->exit_code
= 0;
1750 /* Update the siginfo structure if the signal has
1751 changed. If the debugger wanted something
1752 specific in the siginfo structure then it should
1753 have updated *info via PTRACE_SETSIGINFO. */
1754 if (signr
!= info
->si_signo
) {
1755 info
->si_signo
= signr
;
1757 info
->si_code
= SI_USER
;
1758 info
->si_pid
= task_pid_vnr(current
->parent
);
1759 info
->si_uid
= current
->parent
->uid
;
1762 /* If the (new) signal is now blocked, requeue it. */
1763 if (sigismember(¤t
->blocked
, signr
)) {
1764 specific_send_sig_info(signr
, info
, current
);
1771 int get_signal_to_deliver(siginfo_t
*info
, struct k_sigaction
*return_ka
,
1772 struct pt_regs
*regs
, void *cookie
)
1774 sigset_t
*mask
= ¤t
->blocked
;
1779 * We'll jump back here after any time we were stopped in TASK_STOPPED.
1780 * While in TASK_STOPPED, we were considered "frozen enough".
1781 * Now that we woke up, it's crucial if we're supposed to be
1782 * frozen that we freeze now before running anything substantial.
1786 spin_lock_irq(¤t
->sighand
->siglock
);
1788 struct k_sigaction
*ka
;
1790 if (unlikely(current
->signal
->group_stop_count
> 0) &&
1794 signr
= dequeue_signal(current
, mask
, info
);
1797 break; /* will return 0 */
1799 if (signr
!= SIGKILL
) {
1800 signr
= ptrace_signal(signr
, info
, regs
, cookie
);
1805 ka
= ¤t
->sighand
->action
[signr
-1];
1806 if (ka
->sa
.sa_handler
== SIG_IGN
) /* Do nothing. */
1808 if (ka
->sa
.sa_handler
!= SIG_DFL
) {
1809 /* Run the handler. */
1812 if (ka
->sa
.sa_flags
& SA_ONESHOT
)
1813 ka
->sa
.sa_handler
= SIG_DFL
;
1815 break; /* will return non-zero "signr" value */
1819 * Now we are doing the default action for this signal.
1821 if (sig_kernel_ignore(signr
)) /* Default is nothing. */
1825 * Global init gets no signals it doesn't want.
1827 if (is_global_init(current
))
1830 if (sig_kernel_stop(signr
)) {
1832 * The default action is to stop all threads in
1833 * the thread group. The job control signals
1834 * do nothing in an orphaned pgrp, but SIGSTOP
1835 * always works. Note that siglock needs to be
1836 * dropped during the call to is_orphaned_pgrp()
1837 * because of lock ordering with tasklist_lock.
1838 * This allows an intervening SIGCONT to be posted.
1839 * We need to check for that and bail out if necessary.
1841 if (signr
!= SIGSTOP
) {
1842 spin_unlock_irq(¤t
->sighand
->siglock
);
1844 /* signals can be posted during this window */
1846 if (is_current_pgrp_orphaned())
1849 spin_lock_irq(¤t
->sighand
->siglock
);
1852 if (likely(do_signal_stop(signr
))) {
1853 /* It released the siglock. */
1858 * We didn't actually stop, due to a race
1859 * with SIGCONT or something like that.
1864 spin_unlock_irq(¤t
->sighand
->siglock
);
1867 * Anything else is fatal, maybe with a core dump.
1869 current
->flags
|= PF_SIGNALED
;
1870 if ((signr
!= SIGKILL
) && print_fatal_signals
)
1871 print_fatal_signal(regs
, signr
);
1872 if (sig_kernel_coredump(signr
)) {
1874 * If it was able to dump core, this kills all
1875 * other threads in the group and synchronizes with
1876 * their demise. If we lost the race with another
1877 * thread getting here, it set group_exit_code
1878 * first and our do_group_exit call below will use
1879 * that value and ignore the one we pass it.
1881 do_coredump((long)signr
, signr
, regs
);
1885 * Death signals, no core dump.
1887 do_group_exit(signr
);
1890 spin_unlock_irq(¤t
->sighand
->siglock
);
1894 void exit_signals(struct task_struct
*tsk
)
1897 struct task_struct
*t
;
1899 if (thread_group_empty(tsk
) || signal_group_exit(tsk
->signal
)) {
1900 tsk
->flags
|= PF_EXITING
;
1904 spin_lock_irq(&tsk
->sighand
->siglock
);
1906 * From now this task is not visible for group-wide signals,
1907 * see wants_signal(), do_signal_stop().
1909 tsk
->flags
|= PF_EXITING
;
1910 if (!signal_pending(tsk
))
1913 /* It could be that __group_complete_signal() choose us to
1914 * notify about group-wide signal. Another thread should be
1915 * woken now to take the signal since we will not.
1917 for (t
= tsk
; (t
= next_thread(t
)) != tsk
; )
1918 if (!signal_pending(t
) && !(t
->flags
& PF_EXITING
))
1919 recalc_sigpending_and_wake(t
);
1921 if (unlikely(tsk
->signal
->group_stop_count
) &&
1922 !--tsk
->signal
->group_stop_count
) {
1923 tsk
->signal
->flags
= SIGNAL_STOP_STOPPED
;
1927 spin_unlock_irq(&tsk
->sighand
->siglock
);
1929 if (unlikely(group_stop
)) {
1930 read_lock(&tasklist_lock
);
1931 do_notify_parent_cldstop(tsk
, CLD_STOPPED
);
1932 read_unlock(&tasklist_lock
);
1936 EXPORT_SYMBOL(recalc_sigpending
);
1937 EXPORT_SYMBOL_GPL(dequeue_signal
);
1938 EXPORT_SYMBOL(flush_signals
);
1939 EXPORT_SYMBOL(force_sig
);
1940 EXPORT_SYMBOL(kill_proc
);
1941 EXPORT_SYMBOL(ptrace_notify
);
1942 EXPORT_SYMBOL(send_sig
);
1943 EXPORT_SYMBOL(send_sig_info
);
1944 EXPORT_SYMBOL(sigprocmask
);
1945 EXPORT_SYMBOL(block_all_signals
);
1946 EXPORT_SYMBOL(unblock_all_signals
);
1950 * System call entry points.
1953 asmlinkage
long sys_restart_syscall(void)
1955 struct restart_block
*restart
= ¤t_thread_info()->restart_block
;
1956 return restart
->fn(restart
);
1959 long do_no_restart_syscall(struct restart_block
*param
)
1965 * We don't need to get the kernel lock - this is all local to this
1966 * particular thread.. (and that's good, because this is _heavily_
1967 * used by various programs)
1971 * This is also useful for kernel threads that want to temporarily
1972 * (or permanently) block certain signals.
1974 * NOTE! Unlike the user-mode sys_sigprocmask(), the kernel
1975 * interface happily blocks "unblockable" signals like SIGKILL
1978 int sigprocmask(int how
, sigset_t
*set
, sigset_t
*oldset
)
1982 spin_lock_irq(¤t
->sighand
->siglock
);
1984 *oldset
= current
->blocked
;
1989 sigorsets(¤t
->blocked
, ¤t
->blocked
, set
);
1992 signandsets(¤t
->blocked
, ¤t
->blocked
, set
);
1995 current
->blocked
= *set
;
2000 recalc_sigpending();
2001 spin_unlock_irq(¤t
->sighand
->siglock
);
2007 sys_rt_sigprocmask(int how
, sigset_t __user
*set
, sigset_t __user
*oset
, size_t sigsetsize
)
2009 int error
= -EINVAL
;
2010 sigset_t old_set
, new_set
;
2012 /* XXX: Don't preclude handling different sized sigset_t's. */
2013 if (sigsetsize
!= sizeof(sigset_t
))
2018 if (copy_from_user(&new_set
, set
, sizeof(*set
)))
2020 sigdelsetmask(&new_set
, sigmask(SIGKILL
)|sigmask(SIGSTOP
));
2022 error
= sigprocmask(how
, &new_set
, &old_set
);
2028 spin_lock_irq(¤t
->sighand
->siglock
);
2029 old_set
= current
->blocked
;
2030 spin_unlock_irq(¤t
->sighand
->siglock
);
2034 if (copy_to_user(oset
, &old_set
, sizeof(*oset
)))
2042 long do_sigpending(void __user
*set
, unsigned long sigsetsize
)
2044 long error
= -EINVAL
;
2047 if (sigsetsize
> sizeof(sigset_t
))
2050 spin_lock_irq(¤t
->sighand
->siglock
);
2051 sigorsets(&pending
, ¤t
->pending
.signal
,
2052 ¤t
->signal
->shared_pending
.signal
);
2053 spin_unlock_irq(¤t
->sighand
->siglock
);
2055 /* Outside the lock because only this thread touches it. */
2056 sigandsets(&pending
, ¤t
->blocked
, &pending
);
2059 if (!copy_to_user(set
, &pending
, sigsetsize
))
2067 sys_rt_sigpending(sigset_t __user
*set
, size_t sigsetsize
)
2069 return do_sigpending(set
, sigsetsize
);
2072 #ifndef HAVE_ARCH_COPY_SIGINFO_TO_USER
2074 int copy_siginfo_to_user(siginfo_t __user
*to
, siginfo_t
*from
)
2078 if (!access_ok (VERIFY_WRITE
, to
, sizeof(siginfo_t
)))
2080 if (from
->si_code
< 0)
2081 return __copy_to_user(to
, from
, sizeof(siginfo_t
))
2084 * If you change siginfo_t structure, please be sure
2085 * this code is fixed accordingly.
2086 * Please remember to update the signalfd_copyinfo() function
2087 * inside fs/signalfd.c too, in case siginfo_t changes.
2088 * It should never copy any pad contained in the structure
2089 * to avoid security leaks, but must copy the generic
2090 * 3 ints plus the relevant union member.
2092 err
= __put_user(from
->si_signo
, &to
->si_signo
);
2093 err
|= __put_user(from
->si_errno
, &to
->si_errno
);
2094 err
|= __put_user((short)from
->si_code
, &to
->si_code
);
2095 switch (from
->si_code
& __SI_MASK
) {
2097 err
|= __put_user(from
->si_pid
, &to
->si_pid
);
2098 err
|= __put_user(from
->si_uid
, &to
->si_uid
);
2101 err
|= __put_user(from
->si_tid
, &to
->si_tid
);
2102 err
|= __put_user(from
->si_overrun
, &to
->si_overrun
);
2103 err
|= __put_user(from
->si_ptr
, &to
->si_ptr
);
2106 err
|= __put_user(from
->si_band
, &to
->si_band
);
2107 err
|= __put_user(from
->si_fd
, &to
->si_fd
);
2110 err
|= __put_user(from
->si_addr
, &to
->si_addr
);
2111 #ifdef __ARCH_SI_TRAPNO
2112 err
|= __put_user(from
->si_trapno
, &to
->si_trapno
);
2116 err
|= __put_user(from
->si_pid
, &to
->si_pid
);
2117 err
|= __put_user(from
->si_uid
, &to
->si_uid
);
2118 err
|= __put_user(from
->si_status
, &to
->si_status
);
2119 err
|= __put_user(from
->si_utime
, &to
->si_utime
);
2120 err
|= __put_user(from
->si_stime
, &to
->si_stime
);
2122 case __SI_RT
: /* This is not generated by the kernel as of now. */
2123 case __SI_MESGQ
: /* But this is */
2124 err
|= __put_user(from
->si_pid
, &to
->si_pid
);
2125 err
|= __put_user(from
->si_uid
, &to
->si_uid
);
2126 err
|= __put_user(from
->si_ptr
, &to
->si_ptr
);
2128 default: /* this is just in case for now ... */
2129 err
|= __put_user(from
->si_pid
, &to
->si_pid
);
2130 err
|= __put_user(from
->si_uid
, &to
->si_uid
);
2139 sys_rt_sigtimedwait(const sigset_t __user
*uthese
,
2140 siginfo_t __user
*uinfo
,
2141 const struct timespec __user
*uts
,
2150 /* XXX: Don't preclude handling different sized sigset_t's. */
2151 if (sigsetsize
!= sizeof(sigset_t
))
2154 if (copy_from_user(&these
, uthese
, sizeof(these
)))
2158 * Invert the set of allowed signals to get those we
2161 sigdelsetmask(&these
, sigmask(SIGKILL
)|sigmask(SIGSTOP
));
2165 if (copy_from_user(&ts
, uts
, sizeof(ts
)))
2167 if (ts
.tv_nsec
>= 1000000000L || ts
.tv_nsec
< 0
2172 spin_lock_irq(¤t
->sighand
->siglock
);
2173 sig
= dequeue_signal(current
, &these
, &info
);
2175 timeout
= MAX_SCHEDULE_TIMEOUT
;
2177 timeout
= (timespec_to_jiffies(&ts
)
2178 + (ts
.tv_sec
|| ts
.tv_nsec
));
2181 /* None ready -- temporarily unblock those we're
2182 * interested while we are sleeping in so that we'll
2183 * be awakened when they arrive. */
2184 current
->real_blocked
= current
->blocked
;
2185 sigandsets(¤t
->blocked
, ¤t
->blocked
, &these
);
2186 recalc_sigpending();
2187 spin_unlock_irq(¤t
->sighand
->siglock
);
2189 timeout
= schedule_timeout_interruptible(timeout
);
2191 spin_lock_irq(¤t
->sighand
->siglock
);
2192 sig
= dequeue_signal(current
, &these
, &info
);
2193 current
->blocked
= current
->real_blocked
;
2194 siginitset(¤t
->real_blocked
, 0);
2195 recalc_sigpending();
2198 spin_unlock_irq(¤t
->sighand
->siglock
);
2203 if (copy_siginfo_to_user(uinfo
, &info
))
2216 sys_kill(int pid
, int sig
)
2218 struct siginfo info
;
2220 info
.si_signo
= sig
;
2222 info
.si_code
= SI_USER
;
2223 info
.si_pid
= task_tgid_vnr(current
);
2224 info
.si_uid
= current
->uid
;
2226 return kill_something_info(sig
, &info
, pid
);
2229 static int do_tkill(int tgid
, int pid
, int sig
)
2232 struct siginfo info
;
2233 struct task_struct
*p
;
2236 info
.si_signo
= sig
;
2238 info
.si_code
= SI_TKILL
;
2239 info
.si_pid
= task_tgid_vnr(current
);
2240 info
.si_uid
= current
->uid
;
2242 read_lock(&tasklist_lock
);
2243 p
= find_task_by_vpid(pid
);
2244 if (p
&& (tgid
<= 0 || task_tgid_vnr(p
) == tgid
)) {
2245 error
= check_kill_permission(sig
, &info
, p
);
2247 * The null signal is a permissions and process existence
2248 * probe. No signal is actually delivered.
2250 if (!error
&& sig
&& p
->sighand
) {
2251 spin_lock_irq(&p
->sighand
->siglock
);
2252 handle_stop_signal(sig
, p
);
2253 error
= specific_send_sig_info(sig
, &info
, p
);
2254 spin_unlock_irq(&p
->sighand
->siglock
);
2257 read_unlock(&tasklist_lock
);
2263 * sys_tgkill - send signal to one specific thread
2264 * @tgid: the thread group ID of the thread
2265 * @pid: the PID of the thread
2266 * @sig: signal to be sent
2268 * This syscall also checks the @tgid and returns -ESRCH even if the PID
2269 * exists but it's not belonging to the target process anymore. This
2270 * method solves the problem of threads exiting and PIDs getting reused.
2272 asmlinkage
long sys_tgkill(int tgid
, int pid
, int sig
)
2274 /* This is only valid for single tasks */
2275 if (pid
<= 0 || tgid
<= 0)
2278 return do_tkill(tgid
, pid
, sig
);
2282 * Send a signal to only one task, even if it's a CLONE_THREAD task.
2285 sys_tkill(int pid
, int sig
)
2287 /* This is only valid for single tasks */
2291 return do_tkill(0, pid
, sig
);
2295 sys_rt_sigqueueinfo(int pid
, int sig
, siginfo_t __user
*uinfo
)
2299 if (copy_from_user(&info
, uinfo
, sizeof(siginfo_t
)))
2302 /* Not even root can pretend to send signals from the kernel.
2303 Nor can they impersonate a kill(), which adds source info. */
2304 if (info
.si_code
>= 0)
2306 info
.si_signo
= sig
;
2308 /* POSIX.1b doesn't mention process groups. */
2309 return kill_proc_info(sig
, &info
, pid
);
2312 int do_sigaction(int sig
, struct k_sigaction
*act
, struct k_sigaction
*oact
)
2314 struct task_struct
*t
= current
;
2315 struct k_sigaction
*k
;
2318 if (!valid_signal(sig
) || sig
< 1 || (act
&& sig_kernel_only(sig
)))
2321 k
= &t
->sighand
->action
[sig
-1];
2323 spin_lock_irq(¤t
->sighand
->siglock
);
2328 sigdelsetmask(&act
->sa
.sa_mask
,
2329 sigmask(SIGKILL
) | sigmask(SIGSTOP
));
2333 * "Setting a signal action to SIG_IGN for a signal that is
2334 * pending shall cause the pending signal to be discarded,
2335 * whether or not it is blocked."
2337 * "Setting a signal action to SIG_DFL for a signal that is
2338 * pending and whose default action is to ignore the signal
2339 * (for example, SIGCHLD), shall cause the pending signal to
2340 * be discarded, whether or not it is blocked"
2342 if (__sig_ignored(t
, sig
)) {
2344 sigaddset(&mask
, sig
);
2345 rm_from_queue_full(&mask
, &t
->signal
->shared_pending
);
2347 rm_from_queue_full(&mask
, &t
->pending
);
2349 } while (t
!= current
);
2353 spin_unlock_irq(¤t
->sighand
->siglock
);
2358 do_sigaltstack (const stack_t __user
*uss
, stack_t __user
*uoss
, unsigned long sp
)
2364 oss
.ss_sp
= (void __user
*) current
->sas_ss_sp
;
2365 oss
.ss_size
= current
->sas_ss_size
;
2366 oss
.ss_flags
= sas_ss_flags(sp
);
2375 if (!access_ok(VERIFY_READ
, uss
, sizeof(*uss
))
2376 || __get_user(ss_sp
, &uss
->ss_sp
)
2377 || __get_user(ss_flags
, &uss
->ss_flags
)
2378 || __get_user(ss_size
, &uss
->ss_size
))
2382 if (on_sig_stack(sp
))
2388 * Note - this code used to test ss_flags incorrectly
2389 * old code may have been written using ss_flags==0
2390 * to mean ss_flags==SS_ONSTACK (as this was the only
2391 * way that worked) - this fix preserves that older
2394 if (ss_flags
!= SS_DISABLE
&& ss_flags
!= SS_ONSTACK
&& ss_flags
!= 0)
2397 if (ss_flags
== SS_DISABLE
) {
2402 if (ss_size
< MINSIGSTKSZ
)
2406 current
->sas_ss_sp
= (unsigned long) ss_sp
;
2407 current
->sas_ss_size
= ss_size
;
2412 if (copy_to_user(uoss
, &oss
, sizeof(oss
)))
2421 #ifdef __ARCH_WANT_SYS_SIGPENDING
2424 sys_sigpending(old_sigset_t __user
*set
)
2426 return do_sigpending(set
, sizeof(*set
));
2431 #ifdef __ARCH_WANT_SYS_SIGPROCMASK
2432 /* Some platforms have their own version with special arguments others
2433 support only sys_rt_sigprocmask. */
2436 sys_sigprocmask(int how
, old_sigset_t __user
*set
, old_sigset_t __user
*oset
)
2439 old_sigset_t old_set
, new_set
;
2443 if (copy_from_user(&new_set
, set
, sizeof(*set
)))
2445 new_set
&= ~(sigmask(SIGKILL
) | sigmask(SIGSTOP
));
2447 spin_lock_irq(¤t
->sighand
->siglock
);
2448 old_set
= current
->blocked
.sig
[0];
2456 sigaddsetmask(¤t
->blocked
, new_set
);
2459 sigdelsetmask(¤t
->blocked
, new_set
);
2462 current
->blocked
.sig
[0] = new_set
;
2466 recalc_sigpending();
2467 spin_unlock_irq(¤t
->sighand
->siglock
);
2473 old_set
= current
->blocked
.sig
[0];
2476 if (copy_to_user(oset
, &old_set
, sizeof(*oset
)))
2483 #endif /* __ARCH_WANT_SYS_SIGPROCMASK */
2485 #ifdef __ARCH_WANT_SYS_RT_SIGACTION
2487 sys_rt_sigaction(int sig
,
2488 const struct sigaction __user
*act
,
2489 struct sigaction __user
*oact
,
2492 struct k_sigaction new_sa
, old_sa
;
2495 /* XXX: Don't preclude handling different sized sigset_t's. */
2496 if (sigsetsize
!= sizeof(sigset_t
))
2500 if (copy_from_user(&new_sa
.sa
, act
, sizeof(new_sa
.sa
)))
2504 ret
= do_sigaction(sig
, act
? &new_sa
: NULL
, oact
? &old_sa
: NULL
);
2507 if (copy_to_user(oact
, &old_sa
.sa
, sizeof(old_sa
.sa
)))
2513 #endif /* __ARCH_WANT_SYS_RT_SIGACTION */
2515 #ifdef __ARCH_WANT_SYS_SGETMASK
2518 * For backwards compatibility. Functionality superseded by sigprocmask.
2524 return current
->blocked
.sig
[0];
2528 sys_ssetmask(int newmask
)
2532 spin_lock_irq(¤t
->sighand
->siglock
);
2533 old
= current
->blocked
.sig
[0];
2535 siginitset(¤t
->blocked
, newmask
& ~(sigmask(SIGKILL
)|
2537 recalc_sigpending();
2538 spin_unlock_irq(¤t
->sighand
->siglock
);
2542 #endif /* __ARCH_WANT_SGETMASK */
2544 #ifdef __ARCH_WANT_SYS_SIGNAL
2546 * For backwards compatibility. Functionality superseded by sigaction.
2548 asmlinkage
unsigned long
2549 sys_signal(int sig
, __sighandler_t handler
)
2551 struct k_sigaction new_sa
, old_sa
;
2554 new_sa
.sa
.sa_handler
= handler
;
2555 new_sa
.sa
.sa_flags
= SA_ONESHOT
| SA_NOMASK
;
2556 sigemptyset(&new_sa
.sa
.sa_mask
);
2558 ret
= do_sigaction(sig
, &new_sa
, &old_sa
);
2560 return ret
? ret
: (unsigned long)old_sa
.sa
.sa_handler
;
2562 #endif /* __ARCH_WANT_SYS_SIGNAL */
2564 #ifdef __ARCH_WANT_SYS_PAUSE
2569 current
->state
= TASK_INTERRUPTIBLE
;
2571 return -ERESTARTNOHAND
;
2576 #ifdef __ARCH_WANT_SYS_RT_SIGSUSPEND
2577 asmlinkage
long sys_rt_sigsuspend(sigset_t __user
*unewset
, size_t sigsetsize
)
2581 /* XXX: Don't preclude handling different sized sigset_t's. */
2582 if (sigsetsize
!= sizeof(sigset_t
))
2585 if (copy_from_user(&newset
, unewset
, sizeof(newset
)))
2587 sigdelsetmask(&newset
, sigmask(SIGKILL
)|sigmask(SIGSTOP
));
2589 spin_lock_irq(¤t
->sighand
->siglock
);
2590 current
->saved_sigmask
= current
->blocked
;
2591 current
->blocked
= newset
;
2592 recalc_sigpending();
2593 spin_unlock_irq(¤t
->sighand
->siglock
);
2595 current
->state
= TASK_INTERRUPTIBLE
;
2597 set_thread_flag(TIF_RESTORE_SIGMASK
);
2598 return -ERESTARTNOHAND
;
2600 #endif /* __ARCH_WANT_SYS_RT_SIGSUSPEND */
2602 __attribute__((weak
)) const char *arch_vma_name(struct vm_area_struct
*vma
)
2607 void __init
signals_init(void)
2609 sigqueue_cachep
= KMEM_CACHE(sigqueue
, SLAB_PANIC
);