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/smp_lock.h>
16 #include <linux/init.h>
17 #include <linux/sched.h>
19 #include <linux/tty.h>
20 #include <linux/binfmts.h>
21 #include <linux/security.h>
22 #include <linux/syscalls.h>
23 #include <linux/ptrace.h>
24 #include <linux/signal.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
;
43 * In POSIX a signal is sent either to a specific thread (Linux task)
44 * or to the process as a whole (Linux thread group). How the signal
45 * is sent determines whether it's to one thread or the whole group,
46 * which determines which signal mask(s) are involved in blocking it
47 * from being delivered until later. When the signal is delivered,
48 * either it's caught or ignored by a user handler or it has a default
49 * effect that applies to the whole thread group (POSIX process).
51 * The possible effects an unblocked signal set to SIG_DFL can have are:
52 * ignore - Nothing Happens
53 * terminate - kill the process, i.e. all threads in the group,
54 * similar to exit_group. The group leader (only) reports
55 * WIFSIGNALED status to its parent.
56 * coredump - write a core dump file describing all threads using
57 * the same mm and then kill all those threads
58 * stop - stop all the threads in the group, i.e. TASK_STOPPED state
60 * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored.
61 * Other signals when not blocked and set to SIG_DFL behaves as follows.
62 * The job control signals also have other special effects.
64 * +--------------------+------------------+
65 * | POSIX signal | default action |
66 * +--------------------+------------------+
67 * | SIGHUP | terminate |
68 * | SIGINT | terminate |
69 * | SIGQUIT | coredump |
70 * | SIGILL | coredump |
71 * | SIGTRAP | coredump |
72 * | SIGABRT/SIGIOT | coredump |
73 * | SIGBUS | coredump |
74 * | SIGFPE | coredump |
75 * | SIGKILL | terminate(+) |
76 * | SIGUSR1 | terminate |
77 * | SIGSEGV | coredump |
78 * | SIGUSR2 | terminate |
79 * | SIGPIPE | terminate |
80 * | SIGALRM | terminate |
81 * | SIGTERM | terminate |
82 * | SIGCHLD | ignore |
83 * | SIGCONT | ignore(*) |
84 * | SIGSTOP | stop(*)(+) |
85 * | SIGTSTP | stop(*) |
86 * | SIGTTIN | stop(*) |
87 * | SIGTTOU | stop(*) |
89 * | SIGXCPU | coredump |
90 * | SIGXFSZ | coredump |
91 * | SIGVTALRM | terminate |
92 * | SIGPROF | terminate |
93 * | SIGPOLL/SIGIO | terminate |
94 * | SIGSYS/SIGUNUSED | coredump |
95 * | SIGSTKFLT | terminate |
96 * | SIGWINCH | ignore |
97 * | SIGPWR | terminate |
98 * | SIGRTMIN-SIGRTMAX | terminate |
99 * +--------------------+------------------+
100 * | non-POSIX signal | default action |
101 * +--------------------+------------------+
102 * | SIGEMT | coredump |
103 * +--------------------+------------------+
105 * (+) For SIGKILL and SIGSTOP the action is "always", not just "default".
106 * (*) Special job control effects:
107 * When SIGCONT is sent, it resumes the process (all threads in the group)
108 * from TASK_STOPPED state and also clears any pending/queued stop signals
109 * (any of those marked with "stop(*)"). This happens regardless of blocking,
110 * catching, or ignoring SIGCONT. When any stop signal is sent, it clears
111 * any pending/queued SIGCONT signals; this happens regardless of blocking,
112 * catching, or ignored the stop signal, though (except for SIGSTOP) the
113 * default action of stopping the process may happen later or never.
117 #define M_SIGEMT M(SIGEMT)
122 #if SIGRTMIN > BITS_PER_LONG
123 #define M(sig) (1ULL << ((sig)-1))
125 #define M(sig) (1UL << ((sig)-1))
127 #define T(sig, mask) (M(sig) & (mask))
129 #define SIG_KERNEL_ONLY_MASK (\
130 M(SIGKILL) | M(SIGSTOP) )
132 #define SIG_KERNEL_STOP_MASK (\
133 M(SIGSTOP) | M(SIGTSTP) | M(SIGTTIN) | M(SIGTTOU) )
135 #define SIG_KERNEL_COREDUMP_MASK (\
136 M(SIGQUIT) | M(SIGILL) | M(SIGTRAP) | M(SIGABRT) | \
137 M(SIGFPE) | M(SIGSEGV) | M(SIGBUS) | M(SIGSYS) | \
138 M(SIGXCPU) | M(SIGXFSZ) | M_SIGEMT )
140 #define SIG_KERNEL_IGNORE_MASK (\
141 M(SIGCONT) | M(SIGCHLD) | M(SIGWINCH) | M(SIGURG) )
143 #define sig_kernel_only(sig) \
144 (((sig) < SIGRTMIN) && T(sig, SIG_KERNEL_ONLY_MASK))
145 #define sig_kernel_coredump(sig) \
146 (((sig) < SIGRTMIN) && T(sig, SIG_KERNEL_COREDUMP_MASK))
147 #define sig_kernel_ignore(sig) \
148 (((sig) < SIGRTMIN) && T(sig, SIG_KERNEL_IGNORE_MASK))
149 #define sig_kernel_stop(sig) \
150 (((sig) < SIGRTMIN) && T(sig, SIG_KERNEL_STOP_MASK))
152 #define sig_needs_tasklist(sig) ((sig) == SIGCONT)
154 #define sig_user_defined(t, signr) \
155 (((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_DFL) && \
156 ((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_IGN))
158 #define sig_fatal(t, signr) \
159 (!T(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \
160 (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL)
162 static int sig_ignored(struct task_struct
*t
, int sig
)
164 void __user
* handler
;
167 * Tracers always want to know about signals..
169 if (t
->ptrace
& PT_PTRACED
)
173 * Blocked signals are never ignored, since the
174 * signal handler may change by the time it is
177 if (sigismember(&t
->blocked
, sig
))
180 /* Is it explicitly or implicitly ignored? */
181 handler
= t
->sighand
->action
[sig
-1].sa
.sa_handler
;
182 return handler
== SIG_IGN
||
183 (handler
== SIG_DFL
&& sig_kernel_ignore(sig
));
187 * Re-calculate pending state from the set of locally pending
188 * signals, globally pending signals, and blocked signals.
190 static inline int has_pending_signals(sigset_t
*signal
, sigset_t
*blocked
)
195 switch (_NSIG_WORDS
) {
197 for (i
= _NSIG_WORDS
, ready
= 0; --i
>= 0 ;)
198 ready
|= signal
->sig
[i
] &~ blocked
->sig
[i
];
201 case 4: ready
= signal
->sig
[3] &~ blocked
->sig
[3];
202 ready
|= signal
->sig
[2] &~ blocked
->sig
[2];
203 ready
|= signal
->sig
[1] &~ blocked
->sig
[1];
204 ready
|= signal
->sig
[0] &~ blocked
->sig
[0];
207 case 2: ready
= signal
->sig
[1] &~ blocked
->sig
[1];
208 ready
|= signal
->sig
[0] &~ blocked
->sig
[0];
211 case 1: ready
= signal
->sig
[0] &~ blocked
->sig
[0];
216 #define PENDING(p,b) has_pending_signals(&(p)->signal, (b))
218 fastcall
void recalc_sigpending_tsk(struct task_struct
*t
)
220 if (t
->signal
->group_stop_count
> 0 ||
222 PENDING(&t
->pending
, &t
->blocked
) ||
223 PENDING(&t
->signal
->shared_pending
, &t
->blocked
))
224 set_tsk_thread_flag(t
, TIF_SIGPENDING
);
226 clear_tsk_thread_flag(t
, TIF_SIGPENDING
);
229 void recalc_sigpending(void)
231 recalc_sigpending_tsk(current
);
234 /* Given the mask, find the first available signal that should be serviced. */
237 next_signal(struct sigpending
*pending
, sigset_t
*mask
)
239 unsigned long i
, *s
, *m
, x
;
242 s
= pending
->signal
.sig
;
244 switch (_NSIG_WORDS
) {
246 for (i
= 0; i
< _NSIG_WORDS
; ++i
, ++s
, ++m
)
247 if ((x
= *s
&~ *m
) != 0) {
248 sig
= ffz(~x
) + i
*_NSIG_BPW
+ 1;
253 case 2: if ((x
= s
[0] &~ m
[0]) != 0)
255 else if ((x
= s
[1] &~ m
[1]) != 0)
262 case 1: if ((x
= *s
&~ *m
) != 0)
270 static struct sigqueue
*__sigqueue_alloc(struct task_struct
*t
, gfp_t flags
,
273 struct sigqueue
*q
= NULL
;
274 struct user_struct
*user
;
277 * In order to avoid problems with "switch_user()", we want to make
278 * sure that the compiler doesn't re-load "t->user"
282 atomic_inc(&user
->sigpending
);
283 if (override_rlimit
||
284 atomic_read(&user
->sigpending
) <=
285 t
->signal
->rlim
[RLIMIT_SIGPENDING
].rlim_cur
)
286 q
= kmem_cache_alloc(sigqueue_cachep
, flags
);
287 if (unlikely(q
== NULL
)) {
288 atomic_dec(&user
->sigpending
);
290 INIT_LIST_HEAD(&q
->list
);
292 q
->user
= get_uid(user
);
297 static void __sigqueue_free(struct sigqueue
*q
)
299 if (q
->flags
& SIGQUEUE_PREALLOC
)
301 atomic_dec(&q
->user
->sigpending
);
303 kmem_cache_free(sigqueue_cachep
, q
);
306 void flush_sigqueue(struct sigpending
*queue
)
310 sigemptyset(&queue
->signal
);
311 while (!list_empty(&queue
->list
)) {
312 q
= list_entry(queue
->list
.next
, struct sigqueue
, list
);
313 list_del_init(&q
->list
);
319 * Flush all pending signals for a task.
321 void flush_signals(struct task_struct
*t
)
325 spin_lock_irqsave(&t
->sighand
->siglock
, flags
);
326 clear_tsk_thread_flag(t
,TIF_SIGPENDING
);
327 flush_sigqueue(&t
->pending
);
328 flush_sigqueue(&t
->signal
->shared_pending
);
329 spin_unlock_irqrestore(&t
->sighand
->siglock
, flags
);
333 * Flush all handlers for a task.
337 flush_signal_handlers(struct task_struct
*t
, int force_default
)
340 struct k_sigaction
*ka
= &t
->sighand
->action
[0];
341 for (i
= _NSIG
; i
!= 0 ; i
--) {
342 if (force_default
|| ka
->sa
.sa_handler
!= SIG_IGN
)
343 ka
->sa
.sa_handler
= SIG_DFL
;
345 sigemptyset(&ka
->sa
.sa_mask
);
351 /* Notify the system that a driver wants to block all signals for this
352 * process, and wants to be notified if any signals at all were to be
353 * sent/acted upon. If the notifier routine returns non-zero, then the
354 * signal will be acted upon after all. If the notifier routine returns 0,
355 * then then signal will be blocked. Only one block per process is
356 * allowed. priv is a pointer to private data that the notifier routine
357 * can use to determine if the signal should be blocked or not. */
360 block_all_signals(int (*notifier
)(void *priv
), void *priv
, sigset_t
*mask
)
364 spin_lock_irqsave(¤t
->sighand
->siglock
, flags
);
365 current
->notifier_mask
= mask
;
366 current
->notifier_data
= priv
;
367 current
->notifier
= notifier
;
368 spin_unlock_irqrestore(¤t
->sighand
->siglock
, flags
);
371 /* Notify the system that blocking has ended. */
374 unblock_all_signals(void)
378 spin_lock_irqsave(¤t
->sighand
->siglock
, flags
);
379 current
->notifier
= NULL
;
380 current
->notifier_data
= NULL
;
382 spin_unlock_irqrestore(¤t
->sighand
->siglock
, flags
);
385 static int collect_signal(int sig
, struct sigpending
*list
, siginfo_t
*info
)
387 struct sigqueue
*q
, *first
= NULL
;
388 int still_pending
= 0;
390 if (unlikely(!sigismember(&list
->signal
, sig
)))
394 * Collect the siginfo appropriate to this signal. Check if
395 * there is another siginfo for the same signal.
397 list_for_each_entry(q
, &list
->list
, list
) {
398 if (q
->info
.si_signo
== sig
) {
407 list_del_init(&first
->list
);
408 copy_siginfo(info
, &first
->info
);
409 __sigqueue_free(first
);
411 sigdelset(&list
->signal
, sig
);
414 /* Ok, it wasn't in the queue. This must be
415 a fast-pathed signal or we must have been
416 out of queue space. So zero out the info.
418 sigdelset(&list
->signal
, sig
);
419 info
->si_signo
= sig
;
428 static int __dequeue_signal(struct sigpending
*pending
, sigset_t
*mask
,
431 int sig
= next_signal(pending
, mask
);
434 if (current
->notifier
) {
435 if (sigismember(current
->notifier_mask
, sig
)) {
436 if (!(current
->notifier
)(current
->notifier_data
)) {
437 clear_thread_flag(TIF_SIGPENDING
);
443 if (!collect_signal(sig
, pending
, info
))
451 * Dequeue a signal and return the element to the caller, which is
452 * expected to free it.
454 * All callers have to hold the siglock.
456 int dequeue_signal(struct task_struct
*tsk
, sigset_t
*mask
, siginfo_t
*info
)
458 int signr
= __dequeue_signal(&tsk
->pending
, mask
, info
);
460 signr
= __dequeue_signal(&tsk
->signal
->shared_pending
,
462 recalc_sigpending_tsk(tsk
);
463 if (signr
&& unlikely(sig_kernel_stop(signr
))) {
465 * Set a marker that we have dequeued a stop signal. Our
466 * caller might release the siglock and then the pending
467 * stop signal it is about to process is no longer in the
468 * pending bitmasks, but must still be cleared by a SIGCONT
469 * (and overruled by a SIGKILL). So those cases clear this
470 * shared flag after we've set it. Note that this flag may
471 * remain set after the signal we return is ignored or
472 * handled. That doesn't matter because its only purpose
473 * is to alert stop-signal processing code when another
474 * processor has come along and cleared the flag.
476 if (!(tsk
->signal
->flags
& SIGNAL_GROUP_EXIT
))
477 tsk
->signal
->flags
|= SIGNAL_STOP_DEQUEUED
;
480 ((info
->si_code
& __SI_MASK
) == __SI_TIMER
) &&
481 info
->si_sys_private
){
483 * Release the siglock to ensure proper locking order
484 * of timer locks outside of siglocks. Note, we leave
485 * irqs disabled here, since the posix-timers code is
486 * about to disable them again anyway.
488 spin_unlock(&tsk
->sighand
->siglock
);
489 do_schedule_next_timer(info
);
490 spin_lock(&tsk
->sighand
->siglock
);
496 * Tell a process that it has a new active signal..
498 * NOTE! we rely on the previous spin_lock to
499 * lock interrupts for us! We can only be called with
500 * "siglock" held, and the local interrupt must
501 * have been disabled when that got acquired!
503 * No need to set need_resched since signal event passing
504 * goes through ->blocked
506 void signal_wake_up(struct task_struct
*t
, int resume
)
510 set_tsk_thread_flag(t
, TIF_SIGPENDING
);
513 * For SIGKILL, we want to wake it up in the stopped/traced case.
514 * We don't check t->state here because there is a race with it
515 * executing another processor and just now entering stopped state.
516 * By using wake_up_state, we ensure the process will wake up and
517 * handle its death signal.
519 mask
= TASK_INTERRUPTIBLE
;
521 mask
|= TASK_STOPPED
| TASK_TRACED
;
522 if (!wake_up_state(t
, mask
))
527 * Remove signals in mask from the pending set and queue.
528 * Returns 1 if any signals were found.
530 * All callers must be holding the siglock.
532 * This version takes a sigset mask and looks at all signals,
533 * not just those in the first mask word.
535 static int rm_from_queue_full(sigset_t
*mask
, struct sigpending
*s
)
537 struct sigqueue
*q
, *n
;
540 sigandsets(&m
, mask
, &s
->signal
);
541 if (sigisemptyset(&m
))
544 signandsets(&s
->signal
, &s
->signal
, mask
);
545 list_for_each_entry_safe(q
, n
, &s
->list
, list
) {
546 if (sigismember(mask
, q
->info
.si_signo
)) {
547 list_del_init(&q
->list
);
554 * Remove signals in mask from the pending set and queue.
555 * Returns 1 if any signals were found.
557 * All callers must be holding the siglock.
559 static int rm_from_queue(unsigned long mask
, struct sigpending
*s
)
561 struct sigqueue
*q
, *n
;
563 if (!sigtestsetmask(&s
->signal
, mask
))
566 sigdelsetmask(&s
->signal
, mask
);
567 list_for_each_entry_safe(q
, n
, &s
->list
, list
) {
568 if (q
->info
.si_signo
< SIGRTMIN
&&
569 (mask
& sigmask(q
->info
.si_signo
))) {
570 list_del_init(&q
->list
);
578 * Bad permissions for sending the signal
580 static int check_kill_permission(int sig
, struct siginfo
*info
,
581 struct task_struct
*t
)
584 if (!valid_signal(sig
))
587 if ((info
== SEND_SIG_NOINFO
|| (!is_si_special(info
) && SI_FROMUSER(info
)))
588 && ((sig
!= SIGCONT
) ||
589 (process_session(current
) != process_session(t
)))
590 && (current
->euid
^ t
->suid
) && (current
->euid
^ t
->uid
)
591 && (current
->uid
^ t
->suid
) && (current
->uid
^ t
->uid
)
592 && !capable(CAP_KILL
))
595 error
= security_task_kill(t
, info
, sig
, 0);
597 audit_signal_info(sig
, t
); /* Let audit system see the signal */
602 static void do_notify_parent_cldstop(struct task_struct
*tsk
, int why
);
605 * Handle magic process-wide effects of stop/continue signals.
606 * Unlike the signal actions, these happen immediately at signal-generation
607 * time regardless of blocking, ignoring, or handling. This does the
608 * actual continuing for SIGCONT, but not the actual stopping for stop
609 * signals. The process stop is done as a signal action for SIG_DFL.
611 static void handle_stop_signal(int sig
, struct task_struct
*p
)
613 struct task_struct
*t
;
615 if (p
->signal
->flags
& SIGNAL_GROUP_EXIT
)
617 * The process is in the middle of dying already.
621 if (sig_kernel_stop(sig
)) {
623 * This is a stop signal. Remove SIGCONT from all queues.
625 rm_from_queue(sigmask(SIGCONT
), &p
->signal
->shared_pending
);
628 rm_from_queue(sigmask(SIGCONT
), &t
->pending
);
631 } else if (sig
== SIGCONT
) {
633 * Remove all stop signals from all queues,
634 * and wake all threads.
636 if (unlikely(p
->signal
->group_stop_count
> 0)) {
638 * There was a group stop in progress. We'll
639 * pretend it finished before we got here. We are
640 * obliged to report it to the parent: if the
641 * SIGSTOP happened "after" this SIGCONT, then it
642 * would have cleared this pending SIGCONT. If it
643 * happened "before" this SIGCONT, then the parent
644 * got the SIGCHLD about the stop finishing before
645 * the continue happened. We do the notification
646 * now, and it's as if the stop had finished and
647 * the SIGCHLD was pending on entry to this kill.
649 p
->signal
->group_stop_count
= 0;
650 p
->signal
->flags
= SIGNAL_STOP_CONTINUED
;
651 spin_unlock(&p
->sighand
->siglock
);
652 do_notify_parent_cldstop(p
, CLD_STOPPED
);
653 spin_lock(&p
->sighand
->siglock
);
655 rm_from_queue(SIG_KERNEL_STOP_MASK
, &p
->signal
->shared_pending
);
659 rm_from_queue(SIG_KERNEL_STOP_MASK
, &t
->pending
);
662 * If there is a handler for SIGCONT, we must make
663 * sure that no thread returns to user mode before
664 * we post the signal, in case it was the only
665 * thread eligible to run the signal handler--then
666 * it must not do anything between resuming and
667 * running the handler. With the TIF_SIGPENDING
668 * flag set, the thread will pause and acquire the
669 * siglock that we hold now and until we've queued
670 * the pending signal.
672 * Wake up the stopped thread _after_ setting
675 state
= TASK_STOPPED
;
676 if (sig_user_defined(t
, SIGCONT
) && !sigismember(&t
->blocked
, SIGCONT
)) {
677 set_tsk_thread_flag(t
, TIF_SIGPENDING
);
678 state
|= TASK_INTERRUPTIBLE
;
680 wake_up_state(t
, state
);
685 if (p
->signal
->flags
& SIGNAL_STOP_STOPPED
) {
687 * We were in fact stopped, and are now continued.
688 * Notify the parent with CLD_CONTINUED.
690 p
->signal
->flags
= SIGNAL_STOP_CONTINUED
;
691 p
->signal
->group_exit_code
= 0;
692 spin_unlock(&p
->sighand
->siglock
);
693 do_notify_parent_cldstop(p
, CLD_CONTINUED
);
694 spin_lock(&p
->sighand
->siglock
);
697 * We are not stopped, but there could be a stop
698 * signal in the middle of being processed after
699 * being removed from the queue. Clear that too.
701 p
->signal
->flags
= 0;
703 } else if (sig
== SIGKILL
) {
705 * Make sure that any pending stop signal already dequeued
706 * is undone by the wakeup for SIGKILL.
708 p
->signal
->flags
= 0;
712 static int send_signal(int sig
, struct siginfo
*info
, struct task_struct
*t
,
713 struct sigpending
*signals
)
715 struct sigqueue
* q
= NULL
;
719 * fast-pathed signals for kernel-internal things like SIGSTOP
722 if (info
== SEND_SIG_FORCED
)
725 /* Real-time signals must be queued if sent by sigqueue, or
726 some other real-time mechanism. It is implementation
727 defined whether kill() does so. We attempt to do so, on
728 the principle of least surprise, but since kill is not
729 allowed to fail with EAGAIN when low on memory we just
730 make sure at least one signal gets delivered and don't
731 pass on the info struct. */
733 q
= __sigqueue_alloc(t
, GFP_ATOMIC
, (sig
< SIGRTMIN
&&
734 (is_si_special(info
) ||
735 info
->si_code
>= 0)));
737 list_add_tail(&q
->list
, &signals
->list
);
738 switch ((unsigned long) info
) {
739 case (unsigned long) SEND_SIG_NOINFO
:
740 q
->info
.si_signo
= sig
;
741 q
->info
.si_errno
= 0;
742 q
->info
.si_code
= SI_USER
;
743 q
->info
.si_pid
= current
->pid
;
744 q
->info
.si_uid
= current
->uid
;
746 case (unsigned long) SEND_SIG_PRIV
:
747 q
->info
.si_signo
= sig
;
748 q
->info
.si_errno
= 0;
749 q
->info
.si_code
= SI_KERNEL
;
754 copy_siginfo(&q
->info
, info
);
757 } else if (!is_si_special(info
)) {
758 if (sig
>= SIGRTMIN
&& info
->si_code
!= SI_USER
)
760 * Queue overflow, abort. We may abort if the signal was rt
761 * and sent by user using something other than kill().
767 sigaddset(&signals
->signal
, sig
);
771 #define LEGACY_QUEUE(sigptr, sig) \
772 (((sig) < SIGRTMIN) && sigismember(&(sigptr)->signal, (sig)))
776 specific_send_sig_info(int sig
, struct siginfo
*info
, struct task_struct
*t
)
780 BUG_ON(!irqs_disabled());
781 assert_spin_locked(&t
->sighand
->siglock
);
783 /* Short-circuit ignored signals. */
784 if (sig_ignored(t
, sig
))
787 /* Support queueing exactly one non-rt signal, so that we
788 can get more detailed information about the cause of
790 if (LEGACY_QUEUE(&t
->pending
, sig
))
793 ret
= send_signal(sig
, info
, t
, &t
->pending
);
794 if (!ret
&& !sigismember(&t
->blocked
, sig
))
795 signal_wake_up(t
, sig
== SIGKILL
);
801 * Force a signal that the process can't ignore: if necessary
802 * we unblock the signal and change any SIG_IGN to SIG_DFL.
804 * Note: If we unblock the signal, we always reset it to SIG_DFL,
805 * since we do not want to have a signal handler that was blocked
806 * be invoked when user space had explicitly blocked it.
808 * We don't want to have recursive SIGSEGV's etc, for example.
811 force_sig_info(int sig
, struct siginfo
*info
, struct task_struct
*t
)
813 unsigned long int flags
;
814 int ret
, blocked
, ignored
;
815 struct k_sigaction
*action
;
817 spin_lock_irqsave(&t
->sighand
->siglock
, flags
);
818 action
= &t
->sighand
->action
[sig
-1];
819 ignored
= action
->sa
.sa_handler
== SIG_IGN
;
820 blocked
= sigismember(&t
->blocked
, sig
);
821 if (blocked
|| ignored
) {
822 action
->sa
.sa_handler
= SIG_DFL
;
824 sigdelset(&t
->blocked
, sig
);
825 recalc_sigpending_tsk(t
);
828 ret
= specific_send_sig_info(sig
, info
, t
);
829 spin_unlock_irqrestore(&t
->sighand
->siglock
, flags
);
835 force_sig_specific(int sig
, struct task_struct
*t
)
837 force_sig_info(sig
, SEND_SIG_FORCED
, t
);
841 * Test if P wants to take SIG. After we've checked all threads with this,
842 * it's equivalent to finding no threads not blocking SIG. Any threads not
843 * blocking SIG were ruled out because they are not running and already
844 * have pending signals. Such threads will dequeue from the shared queue
845 * as soon as they're available, so putting the signal on the shared queue
846 * will be equivalent to sending it to one such thread.
848 static inline int wants_signal(int sig
, struct task_struct
*p
)
850 if (sigismember(&p
->blocked
, sig
))
852 if (p
->flags
& PF_EXITING
)
856 if (p
->state
& (TASK_STOPPED
| TASK_TRACED
))
858 return task_curr(p
) || !signal_pending(p
);
862 __group_complete_signal(int sig
, struct task_struct
*p
)
864 struct task_struct
*t
;
867 * Now find a thread we can wake up to take the signal off the queue.
869 * If the main thread wants the signal, it gets first crack.
870 * Probably the least surprising to the average bear.
872 if (wants_signal(sig
, p
))
874 else if (thread_group_empty(p
))
876 * There is just one thread and it does not need to be woken.
877 * It will dequeue unblocked signals before it runs again.
882 * Otherwise try to find a suitable thread.
884 t
= p
->signal
->curr_target
;
886 /* restart balancing at this thread */
887 t
= p
->signal
->curr_target
= p
;
889 while (!wants_signal(sig
, t
)) {
891 if (t
== p
->signal
->curr_target
)
893 * No thread needs to be woken.
894 * Any eligible threads will see
895 * the signal in the queue soon.
899 p
->signal
->curr_target
= t
;
903 * Found a killable thread. If the signal will be fatal,
904 * then start taking the whole group down immediately.
906 if (sig_fatal(p
, sig
) && !(p
->signal
->flags
& SIGNAL_GROUP_EXIT
) &&
907 !sigismember(&t
->real_blocked
, sig
) &&
908 (sig
== SIGKILL
|| !(t
->ptrace
& PT_PTRACED
))) {
910 * This signal will be fatal to the whole group.
912 if (!sig_kernel_coredump(sig
)) {
914 * Start a group exit and wake everybody up.
915 * This way we don't have other threads
916 * running and doing things after a slower
917 * thread has the fatal signal pending.
919 p
->signal
->flags
= SIGNAL_GROUP_EXIT
;
920 p
->signal
->group_exit_code
= sig
;
921 p
->signal
->group_stop_count
= 0;
924 sigaddset(&t
->pending
.signal
, SIGKILL
);
925 signal_wake_up(t
, 1);
932 * There will be a core dump. We make all threads other
933 * than the chosen one go into a group stop so that nothing
934 * happens until it gets scheduled, takes the signal off
935 * the shared queue, and does the core dump. This is a
936 * little more complicated than strictly necessary, but it
937 * keeps the signal state that winds up in the core dump
938 * unchanged from the death state, e.g. which thread had
939 * the core-dump signal unblocked.
941 rm_from_queue(SIG_KERNEL_STOP_MASK
, &t
->pending
);
942 rm_from_queue(SIG_KERNEL_STOP_MASK
, &p
->signal
->shared_pending
);
943 p
->signal
->group_stop_count
= 0;
944 p
->signal
->group_exit_task
= t
;
947 p
->signal
->group_stop_count
++;
948 signal_wake_up(t
, 0);
951 wake_up_process(p
->signal
->group_exit_task
);
956 * The signal is already in the shared-pending queue.
957 * Tell the chosen thread to wake up and dequeue it.
959 signal_wake_up(t
, sig
== SIGKILL
);
964 __group_send_sig_info(int sig
, struct siginfo
*info
, struct task_struct
*p
)
968 assert_spin_locked(&p
->sighand
->siglock
);
969 handle_stop_signal(sig
, p
);
971 /* Short-circuit ignored signals. */
972 if (sig_ignored(p
, sig
))
975 if (LEGACY_QUEUE(&p
->signal
->shared_pending
, sig
))
976 /* This is a non-RT signal and we already have one queued. */
980 * Put this signal on the shared-pending queue, or fail with EAGAIN.
981 * We always use the shared queue for process-wide signals,
982 * to avoid several races.
984 ret
= send_signal(sig
, info
, p
, &p
->signal
->shared_pending
);
988 __group_complete_signal(sig
, p
);
993 * Nuke all other threads in the group.
995 void zap_other_threads(struct task_struct
*p
)
997 struct task_struct
*t
;
999 p
->signal
->flags
= SIGNAL_GROUP_EXIT
;
1000 p
->signal
->group_stop_count
= 0;
1002 if (thread_group_empty(p
))
1005 for (t
= next_thread(p
); t
!= p
; t
= next_thread(t
)) {
1007 * Don't bother with already dead threads
1013 * We don't want to notify the parent, since we are
1014 * killed as part of a thread group due to another
1015 * thread doing an execve() or similar. So set the
1016 * exit signal to -1 to allow immediate reaping of
1017 * the process. But don't detach the thread group
1020 if (t
!= p
->group_leader
)
1021 t
->exit_signal
= -1;
1023 /* SIGKILL will be handled before any pending SIGSTOP */
1024 sigaddset(&t
->pending
.signal
, SIGKILL
);
1025 signal_wake_up(t
, 1);
1030 * Must be called under rcu_read_lock() or with tasklist_lock read-held.
1032 struct sighand_struct
*lock_task_sighand(struct task_struct
*tsk
, unsigned long *flags
)
1034 struct sighand_struct
*sighand
;
1037 sighand
= rcu_dereference(tsk
->sighand
);
1038 if (unlikely(sighand
== NULL
))
1041 spin_lock_irqsave(&sighand
->siglock
, *flags
);
1042 if (likely(sighand
== tsk
->sighand
))
1044 spin_unlock_irqrestore(&sighand
->siglock
, *flags
);
1050 int group_send_sig_info(int sig
, struct siginfo
*info
, struct task_struct
*p
)
1052 unsigned long flags
;
1055 ret
= check_kill_permission(sig
, info
, p
);
1059 if (lock_task_sighand(p
, &flags
)) {
1060 ret
= __group_send_sig_info(sig
, info
, p
);
1061 unlock_task_sighand(p
, &flags
);
1069 * kill_pgrp_info() sends a signal to a process group: this is what the tty
1070 * control characters do (^C, ^Z etc)
1073 int __kill_pgrp_info(int sig
, struct siginfo
*info
, struct pid
*pgrp
)
1075 struct task_struct
*p
= NULL
;
1076 int retval
, success
;
1080 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
1081 int err
= group_send_sig_info(sig
, info
, p
);
1084 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
1085 return success
? 0 : retval
;
1088 int kill_pgrp_info(int sig
, struct siginfo
*info
, struct pid
*pgrp
)
1092 read_lock(&tasklist_lock
);
1093 retval
= __kill_pgrp_info(sig
, info
, pgrp
);
1094 read_unlock(&tasklist_lock
);
1099 int __kill_pg_info(int sig
, struct siginfo
*info
, pid_t pgrp
)
1104 return __kill_pgrp_info(sig
, info
, find_pid(pgrp
));
1108 kill_pg_info(int sig
, struct siginfo
*info
, pid_t pgrp
)
1112 read_lock(&tasklist_lock
);
1113 retval
= __kill_pg_info(sig
, info
, pgrp
);
1114 read_unlock(&tasklist_lock
);
1119 int kill_pid_info(int sig
, struct siginfo
*info
, struct pid
*pid
)
1122 struct task_struct
*p
;
1125 if (unlikely(sig_needs_tasklist(sig
)))
1126 read_lock(&tasklist_lock
);
1128 p
= pid_task(pid
, PIDTYPE_PID
);
1131 error
= group_send_sig_info(sig
, info
, p
);
1133 if (unlikely(sig_needs_tasklist(sig
)))
1134 read_unlock(&tasklist_lock
);
1139 static int kill_proc_info(int sig
, struct siginfo
*info
, pid_t pid
)
1143 error
= kill_pid_info(sig
, info
, find_pid(pid
));
1148 /* like kill_pid_info(), but doesn't use uid/euid of "current" */
1149 int kill_pid_info_as_uid(int sig
, struct siginfo
*info
, struct pid
*pid
,
1150 uid_t uid
, uid_t euid
, u32 secid
)
1153 struct task_struct
*p
;
1155 if (!valid_signal(sig
))
1158 read_lock(&tasklist_lock
);
1159 p
= pid_task(pid
, PIDTYPE_PID
);
1164 if ((info
== SEND_SIG_NOINFO
|| (!is_si_special(info
) && SI_FROMUSER(info
)))
1165 && (euid
!= p
->suid
) && (euid
!= p
->uid
)
1166 && (uid
!= p
->suid
) && (uid
!= p
->uid
)) {
1170 ret
= security_task_kill(p
, info
, sig
, secid
);
1173 if (sig
&& p
->sighand
) {
1174 unsigned long flags
;
1175 spin_lock_irqsave(&p
->sighand
->siglock
, flags
);
1176 ret
= __group_send_sig_info(sig
, info
, p
);
1177 spin_unlock_irqrestore(&p
->sighand
->siglock
, flags
);
1180 read_unlock(&tasklist_lock
);
1183 EXPORT_SYMBOL_GPL(kill_pid_info_as_uid
);
1186 * kill_something_info() interprets pid in interesting ways just like kill(2).
1188 * POSIX specifies that kill(-1,sig) is unspecified, but what we have
1189 * is probably wrong. Should make it like BSD or SYSV.
1192 static int kill_something_info(int sig
, struct siginfo
*info
, int pid
)
1195 return kill_pg_info(sig
, info
, process_group(current
));
1196 } else if (pid
== -1) {
1197 int retval
= 0, count
= 0;
1198 struct task_struct
* p
;
1200 read_lock(&tasklist_lock
);
1201 for_each_process(p
) {
1202 if (p
->pid
> 1 && p
->tgid
!= current
->tgid
) {
1203 int err
= group_send_sig_info(sig
, info
, p
);
1209 read_unlock(&tasklist_lock
);
1210 return count
? retval
: -ESRCH
;
1211 } else if (pid
< 0) {
1212 return kill_pg_info(sig
, info
, -pid
);
1214 return kill_proc_info(sig
, info
, pid
);
1219 * These are for backward compatibility with the rest of the kernel source.
1223 * These two are the most common entry points. They send a signal
1224 * just to the specific thread.
1227 send_sig_info(int sig
, struct siginfo
*info
, struct task_struct
*p
)
1230 unsigned long flags
;
1233 * Make sure legacy kernel users don't send in bad values
1234 * (normal paths check this in check_kill_permission).
1236 if (!valid_signal(sig
))
1240 * We need the tasklist lock even for the specific
1241 * thread case (when we don't need to follow the group
1242 * lists) in order to avoid races with "p->sighand"
1243 * going away or changing from under us.
1245 read_lock(&tasklist_lock
);
1246 spin_lock_irqsave(&p
->sighand
->siglock
, flags
);
1247 ret
= specific_send_sig_info(sig
, info
, p
);
1248 spin_unlock_irqrestore(&p
->sighand
->siglock
, flags
);
1249 read_unlock(&tasklist_lock
);
1253 #define __si_special(priv) \
1254 ((priv) ? SEND_SIG_PRIV : SEND_SIG_NOINFO)
1257 send_sig(int sig
, struct task_struct
*p
, int priv
)
1259 return send_sig_info(sig
, __si_special(priv
), p
);
1263 * This is the entry point for "process-wide" signals.
1264 * They will go to an appropriate thread in the thread group.
1267 send_group_sig_info(int sig
, struct siginfo
*info
, struct task_struct
*p
)
1270 read_lock(&tasklist_lock
);
1271 ret
= group_send_sig_info(sig
, info
, p
);
1272 read_unlock(&tasklist_lock
);
1277 force_sig(int sig
, struct task_struct
*p
)
1279 force_sig_info(sig
, SEND_SIG_PRIV
, p
);
1283 * When things go south during signal handling, we
1284 * will force a SIGSEGV. And if the signal that caused
1285 * the problem was already a SIGSEGV, we'll want to
1286 * make sure we don't even try to deliver the signal..
1289 force_sigsegv(int sig
, struct task_struct
*p
)
1291 if (sig
== SIGSEGV
) {
1292 unsigned long flags
;
1293 spin_lock_irqsave(&p
->sighand
->siglock
, flags
);
1294 p
->sighand
->action
[sig
- 1].sa
.sa_handler
= SIG_DFL
;
1295 spin_unlock_irqrestore(&p
->sighand
->siglock
, flags
);
1297 force_sig(SIGSEGV
, p
);
1301 int kill_pgrp(struct pid
*pid
, int sig
, int priv
)
1303 return kill_pgrp_info(sig
, __si_special(priv
), pid
);
1305 EXPORT_SYMBOL(kill_pgrp
);
1307 int kill_pid(struct pid
*pid
, int sig
, int priv
)
1309 return kill_pid_info(sig
, __si_special(priv
), pid
);
1311 EXPORT_SYMBOL(kill_pid
);
1314 kill_pg(pid_t pgrp
, int sig
, int priv
)
1316 return kill_pg_info(sig
, __si_special(priv
), pgrp
);
1320 kill_proc(pid_t pid
, int sig
, int priv
)
1322 return kill_proc_info(sig
, __si_special(priv
), pid
);
1326 * These functions support sending signals using preallocated sigqueue
1327 * structures. This is needed "because realtime applications cannot
1328 * afford to lose notifications of asynchronous events, like timer
1329 * expirations or I/O completions". In the case of Posix Timers
1330 * we allocate the sigqueue structure from the timer_create. If this
1331 * allocation fails we are able to report the failure to the application
1332 * with an EAGAIN error.
1335 struct sigqueue
*sigqueue_alloc(void)
1339 if ((q
= __sigqueue_alloc(current
, GFP_KERNEL
, 0)))
1340 q
->flags
|= SIGQUEUE_PREALLOC
;
1344 void sigqueue_free(struct sigqueue
*q
)
1346 unsigned long flags
;
1347 BUG_ON(!(q
->flags
& SIGQUEUE_PREALLOC
));
1349 * If the signal is still pending remove it from the
1352 if (unlikely(!list_empty(&q
->list
))) {
1353 spinlock_t
*lock
= ¤t
->sighand
->siglock
;
1354 read_lock(&tasklist_lock
);
1355 spin_lock_irqsave(lock
, flags
);
1356 if (!list_empty(&q
->list
))
1357 list_del_init(&q
->list
);
1358 spin_unlock_irqrestore(lock
, flags
);
1359 read_unlock(&tasklist_lock
);
1361 q
->flags
&= ~SIGQUEUE_PREALLOC
;
1365 int send_sigqueue(int sig
, struct sigqueue
*q
, struct task_struct
*p
)
1367 unsigned long flags
;
1370 BUG_ON(!(q
->flags
& SIGQUEUE_PREALLOC
));
1373 * The rcu based delayed sighand destroy makes it possible to
1374 * run this without tasklist lock held. The task struct itself
1375 * cannot go away as create_timer did get_task_struct().
1377 * We return -1, when the task is marked exiting, so
1378 * posix_timer_event can redirect it to the group leader
1382 if (!likely(lock_task_sighand(p
, &flags
))) {
1387 if (unlikely(!list_empty(&q
->list
))) {
1389 * If an SI_TIMER entry is already queue just increment
1390 * the overrun count.
1392 BUG_ON(q
->info
.si_code
!= SI_TIMER
);
1393 q
->info
.si_overrun
++;
1396 /* Short-circuit ignored signals. */
1397 if (sig_ignored(p
, sig
)) {
1402 list_add_tail(&q
->list
, &p
->pending
.list
);
1403 sigaddset(&p
->pending
.signal
, sig
);
1404 if (!sigismember(&p
->blocked
, sig
))
1405 signal_wake_up(p
, sig
== SIGKILL
);
1408 unlock_task_sighand(p
, &flags
);
1416 send_group_sigqueue(int sig
, struct sigqueue
*q
, struct task_struct
*p
)
1418 unsigned long flags
;
1421 BUG_ON(!(q
->flags
& SIGQUEUE_PREALLOC
));
1423 read_lock(&tasklist_lock
);
1424 /* Since it_lock is held, p->sighand cannot be NULL. */
1425 spin_lock_irqsave(&p
->sighand
->siglock
, flags
);
1426 handle_stop_signal(sig
, p
);
1428 /* Short-circuit ignored signals. */
1429 if (sig_ignored(p
, sig
)) {
1434 if (unlikely(!list_empty(&q
->list
))) {
1436 * If an SI_TIMER entry is already queue just increment
1437 * the overrun count. Other uses should not try to
1438 * send the signal multiple times.
1440 BUG_ON(q
->info
.si_code
!= SI_TIMER
);
1441 q
->info
.si_overrun
++;
1446 * Put this signal on the shared-pending queue.
1447 * We always use the shared queue for process-wide signals,
1448 * to avoid several races.
1450 list_add_tail(&q
->list
, &p
->signal
->shared_pending
.list
);
1451 sigaddset(&p
->signal
->shared_pending
.signal
, sig
);
1453 __group_complete_signal(sig
, p
);
1455 spin_unlock_irqrestore(&p
->sighand
->siglock
, flags
);
1456 read_unlock(&tasklist_lock
);
1461 * Wake up any threads in the parent blocked in wait* syscalls.
1463 static inline void __wake_up_parent(struct task_struct
*p
,
1464 struct task_struct
*parent
)
1466 wake_up_interruptible_sync(&parent
->signal
->wait_chldexit
);
1470 * Let a parent know about the death of a child.
1471 * For a stopped/continued status change, use do_notify_parent_cldstop instead.
1474 void do_notify_parent(struct task_struct
*tsk
, int sig
)
1476 struct siginfo info
;
1477 unsigned long flags
;
1478 struct sighand_struct
*psig
;
1482 /* do_notify_parent_cldstop should have been called instead. */
1483 BUG_ON(tsk
->state
& (TASK_STOPPED
|TASK_TRACED
));
1485 BUG_ON(!tsk
->ptrace
&&
1486 (tsk
->group_leader
!= tsk
|| !thread_group_empty(tsk
)));
1488 info
.si_signo
= sig
;
1490 info
.si_pid
= tsk
->pid
;
1491 info
.si_uid
= tsk
->uid
;
1493 /* FIXME: find out whether or not this is supposed to be c*time. */
1494 info
.si_utime
= cputime_to_jiffies(cputime_add(tsk
->utime
,
1495 tsk
->signal
->utime
));
1496 info
.si_stime
= cputime_to_jiffies(cputime_add(tsk
->stime
,
1497 tsk
->signal
->stime
));
1499 info
.si_status
= tsk
->exit_code
& 0x7f;
1500 if (tsk
->exit_code
& 0x80)
1501 info
.si_code
= CLD_DUMPED
;
1502 else if (tsk
->exit_code
& 0x7f)
1503 info
.si_code
= CLD_KILLED
;
1505 info
.si_code
= CLD_EXITED
;
1506 info
.si_status
= tsk
->exit_code
>> 8;
1509 psig
= tsk
->parent
->sighand
;
1510 spin_lock_irqsave(&psig
->siglock
, flags
);
1511 if (!tsk
->ptrace
&& sig
== SIGCHLD
&&
1512 (psig
->action
[SIGCHLD
-1].sa
.sa_handler
== SIG_IGN
||
1513 (psig
->action
[SIGCHLD
-1].sa
.sa_flags
& SA_NOCLDWAIT
))) {
1515 * We are exiting and our parent doesn't care. POSIX.1
1516 * defines special semantics for setting SIGCHLD to SIG_IGN
1517 * or setting the SA_NOCLDWAIT flag: we should be reaped
1518 * automatically and not left for our parent's wait4 call.
1519 * Rather than having the parent do it as a magic kind of
1520 * signal handler, we just set this to tell do_exit that we
1521 * can be cleaned up without becoming a zombie. Note that
1522 * we still call __wake_up_parent in this case, because a
1523 * blocked sys_wait4 might now return -ECHILD.
1525 * Whether we send SIGCHLD or not for SA_NOCLDWAIT
1526 * is implementation-defined: we do (if you don't want
1527 * it, just use SIG_IGN instead).
1529 tsk
->exit_signal
= -1;
1530 if (psig
->action
[SIGCHLD
-1].sa
.sa_handler
== SIG_IGN
)
1533 if (valid_signal(sig
) && sig
> 0)
1534 __group_send_sig_info(sig
, &info
, tsk
->parent
);
1535 __wake_up_parent(tsk
, tsk
->parent
);
1536 spin_unlock_irqrestore(&psig
->siglock
, flags
);
1539 static void do_notify_parent_cldstop(struct task_struct
*tsk
, int why
)
1541 struct siginfo info
;
1542 unsigned long flags
;
1543 struct task_struct
*parent
;
1544 struct sighand_struct
*sighand
;
1546 if (tsk
->ptrace
& PT_PTRACED
)
1547 parent
= tsk
->parent
;
1549 tsk
= tsk
->group_leader
;
1550 parent
= tsk
->real_parent
;
1553 info
.si_signo
= SIGCHLD
;
1555 info
.si_pid
= tsk
->pid
;
1556 info
.si_uid
= tsk
->uid
;
1558 /* FIXME: find out whether or not this is supposed to be c*time. */
1559 info
.si_utime
= cputime_to_jiffies(tsk
->utime
);
1560 info
.si_stime
= cputime_to_jiffies(tsk
->stime
);
1565 info
.si_status
= SIGCONT
;
1568 info
.si_status
= tsk
->signal
->group_exit_code
& 0x7f;
1571 info
.si_status
= tsk
->exit_code
& 0x7f;
1577 sighand
= parent
->sighand
;
1578 spin_lock_irqsave(&sighand
->siglock
, flags
);
1579 if (sighand
->action
[SIGCHLD
-1].sa
.sa_handler
!= SIG_IGN
&&
1580 !(sighand
->action
[SIGCHLD
-1].sa
.sa_flags
& SA_NOCLDSTOP
))
1581 __group_send_sig_info(SIGCHLD
, &info
, parent
);
1583 * Even if SIGCHLD is not generated, we must wake up wait4 calls.
1585 __wake_up_parent(tsk
, parent
);
1586 spin_unlock_irqrestore(&sighand
->siglock
, flags
);
1589 static inline int may_ptrace_stop(void)
1591 if (!likely(current
->ptrace
& PT_PTRACED
))
1594 if (unlikely(current
->parent
== current
->real_parent
&&
1595 (current
->ptrace
& PT_ATTACHED
)))
1598 if (unlikely(current
->signal
== current
->parent
->signal
) &&
1599 unlikely(current
->signal
->flags
& SIGNAL_GROUP_EXIT
))
1603 * Are we in the middle of do_coredump?
1604 * If so and our tracer is also part of the coredump stopping
1605 * is a deadlock situation, and pointless because our tracer
1606 * is dead so don't allow us to stop.
1607 * If SIGKILL was already sent before the caller unlocked
1608 * ->siglock we must see ->core_waiters != 0. Otherwise it
1609 * is safe to enter schedule().
1611 if (unlikely(current
->mm
->core_waiters
) &&
1612 unlikely(current
->mm
== current
->parent
->mm
))
1619 * This must be called with current->sighand->siglock held.
1621 * This should be the path for all ptrace stops.
1622 * We always set current->last_siginfo while stopped here.
1623 * That makes it a way to test a stopped process for
1624 * being ptrace-stopped vs being job-control-stopped.
1626 * If we actually decide not to stop at all because the tracer is gone,
1627 * we leave nostop_code in current->exit_code.
1629 static void ptrace_stop(int exit_code
, int nostop_code
, siginfo_t
*info
)
1632 * If there is a group stop in progress,
1633 * we must participate in the bookkeeping.
1635 if (current
->signal
->group_stop_count
> 0)
1636 --current
->signal
->group_stop_count
;
1638 current
->last_siginfo
= info
;
1639 current
->exit_code
= exit_code
;
1641 /* Let the debugger run. */
1642 set_current_state(TASK_TRACED
);
1643 spin_unlock_irq(¤t
->sighand
->siglock
);
1645 read_lock(&tasklist_lock
);
1646 if (may_ptrace_stop()) {
1647 do_notify_parent_cldstop(current
, CLD_TRAPPED
);
1648 read_unlock(&tasklist_lock
);
1652 * By the time we got the lock, our tracer went away.
1655 read_unlock(&tasklist_lock
);
1656 set_current_state(TASK_RUNNING
);
1657 current
->exit_code
= nostop_code
;
1661 * We are back. Now reacquire the siglock before touching
1662 * last_siginfo, so that we are sure to have synchronized with
1663 * any signal-sending on another CPU that wants to examine it.
1665 spin_lock_irq(¤t
->sighand
->siglock
);
1666 current
->last_siginfo
= NULL
;
1669 * Queued signals ignored us while we were stopped for tracing.
1670 * So check for any that we should take before resuming user mode.
1672 recalc_sigpending();
1675 void ptrace_notify(int exit_code
)
1679 BUG_ON((exit_code
& (0x7f | ~0xffff)) != SIGTRAP
);
1681 memset(&info
, 0, sizeof info
);
1682 info
.si_signo
= SIGTRAP
;
1683 info
.si_code
= exit_code
;
1684 info
.si_pid
= current
->pid
;
1685 info
.si_uid
= current
->uid
;
1687 /* Let the debugger run. */
1688 spin_lock_irq(¤t
->sighand
->siglock
);
1689 ptrace_stop(exit_code
, 0, &info
);
1690 spin_unlock_irq(¤t
->sighand
->siglock
);
1694 finish_stop(int stop_count
)
1697 * If there are no other threads in the group, or if there is
1698 * a group stop in progress and we are the last to stop,
1699 * report to the parent. When ptraced, every thread reports itself.
1701 if (stop_count
== 0 || (current
->ptrace
& PT_PTRACED
)) {
1702 read_lock(&tasklist_lock
);
1703 do_notify_parent_cldstop(current
, CLD_STOPPED
);
1704 read_unlock(&tasklist_lock
);
1709 } while (try_to_freeze());
1711 * Now we don't run again until continued.
1713 current
->exit_code
= 0;
1717 * This performs the stopping for SIGSTOP and other stop signals.
1718 * We have to stop all threads in the thread group.
1719 * Returns nonzero if we've actually stopped and released the siglock.
1720 * Returns zero if we didn't stop and still hold the siglock.
1722 static int do_signal_stop(int signr
)
1724 struct signal_struct
*sig
= current
->signal
;
1727 if (!likely(sig
->flags
& SIGNAL_STOP_DEQUEUED
))
1730 if (sig
->group_stop_count
> 0) {
1732 * There is a group stop in progress. We don't need to
1733 * start another one.
1735 stop_count
= --sig
->group_stop_count
;
1738 * There is no group stop already in progress.
1739 * We must initiate one now.
1741 struct task_struct
*t
;
1743 sig
->group_exit_code
= signr
;
1746 for (t
= next_thread(current
); t
!= current
; t
= next_thread(t
))
1748 * Setting state to TASK_STOPPED for a group
1749 * stop is always done with the siglock held,
1750 * so this check has no races.
1752 if (!t
->exit_state
&&
1753 !(t
->state
& (TASK_STOPPED
|TASK_TRACED
))) {
1755 signal_wake_up(t
, 0);
1757 sig
->group_stop_count
= stop_count
;
1760 if (stop_count
== 0)
1761 sig
->flags
= SIGNAL_STOP_STOPPED
;
1762 current
->exit_code
= sig
->group_exit_code
;
1763 __set_current_state(TASK_STOPPED
);
1765 spin_unlock_irq(¤t
->sighand
->siglock
);
1766 finish_stop(stop_count
);
1771 * Do appropriate magic when group_stop_count > 0.
1772 * We return nonzero if we stopped, after releasing the siglock.
1773 * We return zero if we still hold the siglock and should look
1774 * for another signal without checking group_stop_count again.
1776 static int handle_group_stop(void)
1780 if (current
->signal
->group_exit_task
== current
) {
1782 * Group stop is so we can do a core dump,
1783 * We are the initiating thread, so get on with it.
1785 current
->signal
->group_exit_task
= NULL
;
1789 if (current
->signal
->flags
& SIGNAL_GROUP_EXIT
)
1791 * Group stop is so another thread can do a core dump,
1792 * or else we are racing against a death signal.
1793 * Just punt the stop so we can get the next signal.
1798 * There is a group stop in progress. We stop
1799 * without any associated signal being in our queue.
1801 stop_count
= --current
->signal
->group_stop_count
;
1802 if (stop_count
== 0)
1803 current
->signal
->flags
= SIGNAL_STOP_STOPPED
;
1804 current
->exit_code
= current
->signal
->group_exit_code
;
1805 set_current_state(TASK_STOPPED
);
1806 spin_unlock_irq(¤t
->sighand
->siglock
);
1807 finish_stop(stop_count
);
1811 int get_signal_to_deliver(siginfo_t
*info
, struct k_sigaction
*return_ka
,
1812 struct pt_regs
*regs
, void *cookie
)
1814 sigset_t
*mask
= ¤t
->blocked
;
1820 spin_lock_irq(¤t
->sighand
->siglock
);
1822 struct k_sigaction
*ka
;
1824 if (unlikely(current
->signal
->group_stop_count
> 0) &&
1825 handle_group_stop())
1828 signr
= dequeue_signal(current
, mask
, info
);
1831 break; /* will return 0 */
1833 if ((current
->ptrace
& PT_PTRACED
) && signr
!= SIGKILL
) {
1834 ptrace_signal_deliver(regs
, cookie
);
1836 /* Let the debugger run. */
1837 ptrace_stop(signr
, signr
, info
);
1839 /* We're back. Did the debugger cancel the sig? */
1840 signr
= current
->exit_code
;
1844 current
->exit_code
= 0;
1846 /* Update the siginfo structure if the signal has
1847 changed. If the debugger wanted something
1848 specific in the siginfo structure then it should
1849 have updated *info via PTRACE_SETSIGINFO. */
1850 if (signr
!= info
->si_signo
) {
1851 info
->si_signo
= signr
;
1853 info
->si_code
= SI_USER
;
1854 info
->si_pid
= current
->parent
->pid
;
1855 info
->si_uid
= current
->parent
->uid
;
1858 /* If the (new) signal is now blocked, requeue it. */
1859 if (sigismember(¤t
->blocked
, signr
)) {
1860 specific_send_sig_info(signr
, info
, current
);
1865 ka
= ¤t
->sighand
->action
[signr
-1];
1866 if (ka
->sa
.sa_handler
== SIG_IGN
) /* Do nothing. */
1868 if (ka
->sa
.sa_handler
!= SIG_DFL
) {
1869 /* Run the handler. */
1872 if (ka
->sa
.sa_flags
& SA_ONESHOT
)
1873 ka
->sa
.sa_handler
= SIG_DFL
;
1875 break; /* will return non-zero "signr" value */
1879 * Now we are doing the default action for this signal.
1881 if (sig_kernel_ignore(signr
)) /* Default is nothing. */
1885 * Init of a pid space gets no signals it doesn't want from
1886 * within that pid space. It can of course get signals from
1887 * its parent pid space.
1889 if (current
== child_reaper(current
))
1892 if (sig_kernel_stop(signr
)) {
1894 * The default action is to stop all threads in
1895 * the thread group. The job control signals
1896 * do nothing in an orphaned pgrp, but SIGSTOP
1897 * always works. Note that siglock needs to be
1898 * dropped during the call to is_orphaned_pgrp()
1899 * because of lock ordering with tasklist_lock.
1900 * This allows an intervening SIGCONT to be posted.
1901 * We need to check for that and bail out if necessary.
1903 if (signr
!= SIGSTOP
) {
1904 spin_unlock_irq(¤t
->sighand
->siglock
);
1906 /* signals can be posted during this window */
1908 if (is_orphaned_pgrp(process_group(current
)))
1911 spin_lock_irq(¤t
->sighand
->siglock
);
1914 if (likely(do_signal_stop(signr
))) {
1915 /* It released the siglock. */
1920 * We didn't actually stop, due to a race
1921 * with SIGCONT or something like that.
1926 spin_unlock_irq(¤t
->sighand
->siglock
);
1929 * Anything else is fatal, maybe with a core dump.
1931 current
->flags
|= PF_SIGNALED
;
1932 if (sig_kernel_coredump(signr
)) {
1934 * If it was able to dump core, this kills all
1935 * other threads in the group and synchronizes with
1936 * their demise. If we lost the race with another
1937 * thread getting here, it set group_exit_code
1938 * first and our do_group_exit call below will use
1939 * that value and ignore the one we pass it.
1941 do_coredump((long)signr
, signr
, regs
);
1945 * Death signals, no core dump.
1947 do_group_exit(signr
);
1950 spin_unlock_irq(¤t
->sighand
->siglock
);
1954 EXPORT_SYMBOL(recalc_sigpending
);
1955 EXPORT_SYMBOL_GPL(dequeue_signal
);
1956 EXPORT_SYMBOL(flush_signals
);
1957 EXPORT_SYMBOL(force_sig
);
1958 EXPORT_SYMBOL(kill_pg
);
1959 EXPORT_SYMBOL(kill_proc
);
1960 EXPORT_SYMBOL(ptrace_notify
);
1961 EXPORT_SYMBOL(send_sig
);
1962 EXPORT_SYMBOL(send_sig_info
);
1963 EXPORT_SYMBOL(sigprocmask
);
1964 EXPORT_SYMBOL(block_all_signals
);
1965 EXPORT_SYMBOL(unblock_all_signals
);
1969 * System call entry points.
1972 asmlinkage
long sys_restart_syscall(void)
1974 struct restart_block
*restart
= ¤t_thread_info()->restart_block
;
1975 return restart
->fn(restart
);
1978 long do_no_restart_syscall(struct restart_block
*param
)
1984 * We don't need to get the kernel lock - this is all local to this
1985 * particular thread.. (and that's good, because this is _heavily_
1986 * used by various programs)
1990 * This is also useful for kernel threads that want to temporarily
1991 * (or permanently) block certain signals.
1993 * NOTE! Unlike the user-mode sys_sigprocmask(), the kernel
1994 * interface happily blocks "unblockable" signals like SIGKILL
1997 int sigprocmask(int how
, sigset_t
*set
, sigset_t
*oldset
)
2001 spin_lock_irq(¤t
->sighand
->siglock
);
2003 *oldset
= current
->blocked
;
2008 sigorsets(¤t
->blocked
, ¤t
->blocked
, set
);
2011 signandsets(¤t
->blocked
, ¤t
->blocked
, set
);
2014 current
->blocked
= *set
;
2019 recalc_sigpending();
2020 spin_unlock_irq(¤t
->sighand
->siglock
);
2026 sys_rt_sigprocmask(int how
, sigset_t __user
*set
, sigset_t __user
*oset
, size_t sigsetsize
)
2028 int error
= -EINVAL
;
2029 sigset_t old_set
, new_set
;
2031 /* XXX: Don't preclude handling different sized sigset_t's. */
2032 if (sigsetsize
!= sizeof(sigset_t
))
2037 if (copy_from_user(&new_set
, set
, sizeof(*set
)))
2039 sigdelsetmask(&new_set
, sigmask(SIGKILL
)|sigmask(SIGSTOP
));
2041 error
= sigprocmask(how
, &new_set
, &old_set
);
2047 spin_lock_irq(¤t
->sighand
->siglock
);
2048 old_set
= current
->blocked
;
2049 spin_unlock_irq(¤t
->sighand
->siglock
);
2053 if (copy_to_user(oset
, &old_set
, sizeof(*oset
)))
2061 long do_sigpending(void __user
*set
, unsigned long sigsetsize
)
2063 long error
= -EINVAL
;
2066 if (sigsetsize
> sizeof(sigset_t
))
2069 spin_lock_irq(¤t
->sighand
->siglock
);
2070 sigorsets(&pending
, ¤t
->pending
.signal
,
2071 ¤t
->signal
->shared_pending
.signal
);
2072 spin_unlock_irq(¤t
->sighand
->siglock
);
2074 /* Outside the lock because only this thread touches it. */
2075 sigandsets(&pending
, ¤t
->blocked
, &pending
);
2078 if (!copy_to_user(set
, &pending
, sigsetsize
))
2086 sys_rt_sigpending(sigset_t __user
*set
, size_t sigsetsize
)
2088 return do_sigpending(set
, sigsetsize
);
2091 #ifndef HAVE_ARCH_COPY_SIGINFO_TO_USER
2093 int copy_siginfo_to_user(siginfo_t __user
*to
, siginfo_t
*from
)
2097 if (!access_ok (VERIFY_WRITE
, to
, sizeof(siginfo_t
)))
2099 if (from
->si_code
< 0)
2100 return __copy_to_user(to
, from
, sizeof(siginfo_t
))
2103 * If you change siginfo_t structure, please be sure
2104 * this code is fixed accordingly.
2105 * It should never copy any pad contained in the structure
2106 * to avoid security leaks, but must copy the generic
2107 * 3 ints plus the relevant union member.
2109 err
= __put_user(from
->si_signo
, &to
->si_signo
);
2110 err
|= __put_user(from
->si_errno
, &to
->si_errno
);
2111 err
|= __put_user((short)from
->si_code
, &to
->si_code
);
2112 switch (from
->si_code
& __SI_MASK
) {
2114 err
|= __put_user(from
->si_pid
, &to
->si_pid
);
2115 err
|= __put_user(from
->si_uid
, &to
->si_uid
);
2118 err
|= __put_user(from
->si_tid
, &to
->si_tid
);
2119 err
|= __put_user(from
->si_overrun
, &to
->si_overrun
);
2120 err
|= __put_user(from
->si_ptr
, &to
->si_ptr
);
2123 err
|= __put_user(from
->si_band
, &to
->si_band
);
2124 err
|= __put_user(from
->si_fd
, &to
->si_fd
);
2127 err
|= __put_user(from
->si_addr
, &to
->si_addr
);
2128 #ifdef __ARCH_SI_TRAPNO
2129 err
|= __put_user(from
->si_trapno
, &to
->si_trapno
);
2133 err
|= __put_user(from
->si_pid
, &to
->si_pid
);
2134 err
|= __put_user(from
->si_uid
, &to
->si_uid
);
2135 err
|= __put_user(from
->si_status
, &to
->si_status
);
2136 err
|= __put_user(from
->si_utime
, &to
->si_utime
);
2137 err
|= __put_user(from
->si_stime
, &to
->si_stime
);
2139 case __SI_RT
: /* This is not generated by the kernel as of now. */
2140 case __SI_MESGQ
: /* But this is */
2141 err
|= __put_user(from
->si_pid
, &to
->si_pid
);
2142 err
|= __put_user(from
->si_uid
, &to
->si_uid
);
2143 err
|= __put_user(from
->si_ptr
, &to
->si_ptr
);
2145 default: /* this is just in case for now ... */
2146 err
|= __put_user(from
->si_pid
, &to
->si_pid
);
2147 err
|= __put_user(from
->si_uid
, &to
->si_uid
);
2156 sys_rt_sigtimedwait(const sigset_t __user
*uthese
,
2157 siginfo_t __user
*uinfo
,
2158 const struct timespec __user
*uts
,
2167 /* XXX: Don't preclude handling different sized sigset_t's. */
2168 if (sigsetsize
!= sizeof(sigset_t
))
2171 if (copy_from_user(&these
, uthese
, sizeof(these
)))
2175 * Invert the set of allowed signals to get those we
2178 sigdelsetmask(&these
, sigmask(SIGKILL
)|sigmask(SIGSTOP
));
2182 if (copy_from_user(&ts
, uts
, sizeof(ts
)))
2184 if (ts
.tv_nsec
>= 1000000000L || ts
.tv_nsec
< 0
2189 spin_lock_irq(¤t
->sighand
->siglock
);
2190 sig
= dequeue_signal(current
, &these
, &info
);
2192 timeout
= MAX_SCHEDULE_TIMEOUT
;
2194 timeout
= (timespec_to_jiffies(&ts
)
2195 + (ts
.tv_sec
|| ts
.tv_nsec
));
2198 /* None ready -- temporarily unblock those we're
2199 * interested while we are sleeping in so that we'll
2200 * be awakened when they arrive. */
2201 current
->real_blocked
= current
->blocked
;
2202 sigandsets(¤t
->blocked
, ¤t
->blocked
, &these
);
2203 recalc_sigpending();
2204 spin_unlock_irq(¤t
->sighand
->siglock
);
2206 timeout
= schedule_timeout_interruptible(timeout
);
2208 spin_lock_irq(¤t
->sighand
->siglock
);
2209 sig
= dequeue_signal(current
, &these
, &info
);
2210 current
->blocked
= current
->real_blocked
;
2211 siginitset(¤t
->real_blocked
, 0);
2212 recalc_sigpending();
2215 spin_unlock_irq(¤t
->sighand
->siglock
);
2220 if (copy_siginfo_to_user(uinfo
, &info
))
2233 sys_kill(int pid
, int sig
)
2235 struct siginfo info
;
2237 info
.si_signo
= sig
;
2239 info
.si_code
= SI_USER
;
2240 info
.si_pid
= current
->tgid
;
2241 info
.si_uid
= current
->uid
;
2243 return kill_something_info(sig
, &info
, pid
);
2246 static int do_tkill(int tgid
, int pid
, int sig
)
2249 struct siginfo info
;
2250 struct task_struct
*p
;
2253 info
.si_signo
= sig
;
2255 info
.si_code
= SI_TKILL
;
2256 info
.si_pid
= current
->tgid
;
2257 info
.si_uid
= current
->uid
;
2259 read_lock(&tasklist_lock
);
2260 p
= find_task_by_pid(pid
);
2261 if (p
&& (tgid
<= 0 || p
->tgid
== tgid
)) {
2262 error
= check_kill_permission(sig
, &info
, p
);
2264 * The null signal is a permissions and process existence
2265 * probe. No signal is actually delivered.
2267 if (!error
&& sig
&& p
->sighand
) {
2268 spin_lock_irq(&p
->sighand
->siglock
);
2269 handle_stop_signal(sig
, p
);
2270 error
= specific_send_sig_info(sig
, &info
, p
);
2271 spin_unlock_irq(&p
->sighand
->siglock
);
2274 read_unlock(&tasklist_lock
);
2280 * sys_tgkill - send signal to one specific thread
2281 * @tgid: the thread group ID of the thread
2282 * @pid: the PID of the thread
2283 * @sig: signal to be sent
2285 * This syscall also checks the @tgid and returns -ESRCH even if the PID
2286 * exists but it's not belonging to the target process anymore. This
2287 * method solves the problem of threads exiting and PIDs getting reused.
2289 asmlinkage
long sys_tgkill(int tgid
, int pid
, int sig
)
2291 /* This is only valid for single tasks */
2292 if (pid
<= 0 || tgid
<= 0)
2295 return do_tkill(tgid
, pid
, sig
);
2299 * Send a signal to only one task, even if it's a CLONE_THREAD task.
2302 sys_tkill(int pid
, int sig
)
2304 /* This is only valid for single tasks */
2308 return do_tkill(0, pid
, sig
);
2312 sys_rt_sigqueueinfo(int pid
, int sig
, siginfo_t __user
*uinfo
)
2316 if (copy_from_user(&info
, uinfo
, sizeof(siginfo_t
)))
2319 /* Not even root can pretend to send signals from the kernel.
2320 Nor can they impersonate a kill(), which adds source info. */
2321 if (info
.si_code
>= 0)
2323 info
.si_signo
= sig
;
2325 /* POSIX.1b doesn't mention process groups. */
2326 return kill_proc_info(sig
, &info
, pid
);
2329 int do_sigaction(int sig
, struct k_sigaction
*act
, struct k_sigaction
*oact
)
2331 struct k_sigaction
*k
;
2334 if (!valid_signal(sig
) || sig
< 1 || (act
&& sig_kernel_only(sig
)))
2337 k
= ¤t
->sighand
->action
[sig
-1];
2339 spin_lock_irq(¤t
->sighand
->siglock
);
2340 if (signal_pending(current
)) {
2342 * If there might be a fatal signal pending on multiple
2343 * threads, make sure we take it before changing the action.
2345 spin_unlock_irq(¤t
->sighand
->siglock
);
2346 return -ERESTARTNOINTR
;
2353 sigdelsetmask(&act
->sa
.sa_mask
,
2354 sigmask(SIGKILL
) | sigmask(SIGSTOP
));
2358 * "Setting a signal action to SIG_IGN for a signal that is
2359 * pending shall cause the pending signal to be discarded,
2360 * whether or not it is blocked."
2362 * "Setting a signal action to SIG_DFL for a signal that is
2363 * pending and whose default action is to ignore the signal
2364 * (for example, SIGCHLD), shall cause the pending signal to
2365 * be discarded, whether or not it is blocked"
2367 if (act
->sa
.sa_handler
== SIG_IGN
||
2368 (act
->sa
.sa_handler
== SIG_DFL
&& sig_kernel_ignore(sig
))) {
2369 struct task_struct
*t
= current
;
2371 sigaddset(&mask
, sig
);
2372 rm_from_queue_full(&mask
, &t
->signal
->shared_pending
);
2374 rm_from_queue_full(&mask
, &t
->pending
);
2375 recalc_sigpending_tsk(t
);
2377 } while (t
!= current
);
2381 spin_unlock_irq(¤t
->sighand
->siglock
);
2386 do_sigaltstack (const stack_t __user
*uss
, stack_t __user
*uoss
, unsigned long sp
)
2392 oss
.ss_sp
= (void __user
*) current
->sas_ss_sp
;
2393 oss
.ss_size
= current
->sas_ss_size
;
2394 oss
.ss_flags
= sas_ss_flags(sp
);
2403 if (!access_ok(VERIFY_READ
, uss
, sizeof(*uss
))
2404 || __get_user(ss_sp
, &uss
->ss_sp
)
2405 || __get_user(ss_flags
, &uss
->ss_flags
)
2406 || __get_user(ss_size
, &uss
->ss_size
))
2410 if (on_sig_stack(sp
))
2416 * Note - this code used to test ss_flags incorrectly
2417 * old code may have been written using ss_flags==0
2418 * to mean ss_flags==SS_ONSTACK (as this was the only
2419 * way that worked) - this fix preserves that older
2422 if (ss_flags
!= SS_DISABLE
&& ss_flags
!= SS_ONSTACK
&& ss_flags
!= 0)
2425 if (ss_flags
== SS_DISABLE
) {
2430 if (ss_size
< MINSIGSTKSZ
)
2434 current
->sas_ss_sp
= (unsigned long) ss_sp
;
2435 current
->sas_ss_size
= ss_size
;
2440 if (copy_to_user(uoss
, &oss
, sizeof(oss
)))
2449 #ifdef __ARCH_WANT_SYS_SIGPENDING
2452 sys_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. */
2464 sys_sigprocmask(int how
, old_sigset_t __user
*set
, 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
2515 sys_rt_sigaction(int sig
,
2516 const struct sigaction __user
*act
,
2517 struct sigaction __user
*oact
,
2520 struct k_sigaction new_sa
, old_sa
;
2523 /* XXX: Don't preclude handling different sized sigset_t's. */
2524 if (sigsetsize
!= sizeof(sigset_t
))
2528 if (copy_from_user(&new_sa
.sa
, act
, sizeof(new_sa
.sa
)))
2532 ret
= do_sigaction(sig
, act
? &new_sa
: NULL
, oact
? &old_sa
: NULL
);
2535 if (copy_to_user(oact
, &old_sa
.sa
, sizeof(old_sa
.sa
)))
2541 #endif /* __ARCH_WANT_SYS_RT_SIGACTION */
2543 #ifdef __ARCH_WANT_SYS_SGETMASK
2546 * For backwards compatibility. Functionality superseded by sigprocmask.
2552 return current
->blocked
.sig
[0];
2556 sys_ssetmask(int newmask
)
2560 spin_lock_irq(¤t
->sighand
->siglock
);
2561 old
= current
->blocked
.sig
[0];
2563 siginitset(¤t
->blocked
, newmask
& ~(sigmask(SIGKILL
)|
2565 recalc_sigpending();
2566 spin_unlock_irq(¤t
->sighand
->siglock
);
2570 #endif /* __ARCH_WANT_SGETMASK */
2572 #ifdef __ARCH_WANT_SYS_SIGNAL
2574 * For backwards compatibility. Functionality superseded by sigaction.
2576 asmlinkage
unsigned long
2577 sys_signal(int sig
, __sighandler_t handler
)
2579 struct k_sigaction new_sa
, old_sa
;
2582 new_sa
.sa
.sa_handler
= handler
;
2583 new_sa
.sa
.sa_flags
= SA_ONESHOT
| SA_NOMASK
;
2584 sigemptyset(&new_sa
.sa
.sa_mask
);
2586 ret
= do_sigaction(sig
, &new_sa
, &old_sa
);
2588 return ret
? ret
: (unsigned long)old_sa
.sa
.sa_handler
;
2590 #endif /* __ARCH_WANT_SYS_SIGNAL */
2592 #ifdef __ARCH_WANT_SYS_PAUSE
2597 current
->state
= TASK_INTERRUPTIBLE
;
2599 return -ERESTARTNOHAND
;
2604 #ifdef __ARCH_WANT_SYS_RT_SIGSUSPEND
2605 asmlinkage
long sys_rt_sigsuspend(sigset_t __user
*unewset
, size_t sigsetsize
)
2609 /* XXX: Don't preclude handling different sized sigset_t's. */
2610 if (sigsetsize
!= sizeof(sigset_t
))
2613 if (copy_from_user(&newset
, unewset
, sizeof(newset
)))
2615 sigdelsetmask(&newset
, sigmask(SIGKILL
)|sigmask(SIGSTOP
));
2617 spin_lock_irq(¤t
->sighand
->siglock
);
2618 current
->saved_sigmask
= current
->blocked
;
2619 current
->blocked
= newset
;
2620 recalc_sigpending();
2621 spin_unlock_irq(¤t
->sighand
->siglock
);
2623 current
->state
= TASK_INTERRUPTIBLE
;
2625 set_thread_flag(TIF_RESTORE_SIGMASK
);
2626 return -ERESTARTNOHAND
;
2628 #endif /* __ARCH_WANT_SYS_RT_SIGSUSPEND */
2630 __attribute__((weak
)) const char *arch_vma_name(struct vm_area_struct
*vma
)
2635 void __init
signals_init(void)
2638 kmem_cache_create("sigqueue",
2639 sizeof(struct sigqueue
),
2640 __alignof__(struct sigqueue
),
2641 SLAB_PANIC
, NULL
, NULL
);