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/export.h>
15 #include <linux/init.h>
16 #include <linux/sched/mm.h>
17 #include <linux/sched/user.h>
18 #include <linux/sched/debug.h>
19 #include <linux/sched/task.h>
20 #include <linux/sched/task_stack.h>
21 #include <linux/sched/cputime.h>
23 #include <linux/tty.h>
24 #include <linux/binfmts.h>
25 #include <linux/coredump.h>
26 #include <linux/security.h>
27 #include <linux/syscalls.h>
28 #include <linux/ptrace.h>
29 #include <linux/signal.h>
30 #include <linux/signalfd.h>
31 #include <linux/ratelimit.h>
32 #include <linux/tracehook.h>
33 #include <linux/capability.h>
34 #include <linux/freezer.h>
35 #include <linux/pid_namespace.h>
36 #include <linux/nsproxy.h>
37 #include <linux/user_namespace.h>
38 #include <linux/uprobes.h>
39 #include <linux/compat.h>
40 #include <linux/cn_proc.h>
41 #include <linux/compiler.h>
42 #include <linux/posix-timers.h>
43 #include <linux/livepatch.h>
45 #define CREATE_TRACE_POINTS
46 #include <trace/events/signal.h>
48 #include <asm/param.h>
49 #include <linux/uaccess.h>
50 #include <asm/unistd.h>
51 #include <asm/siginfo.h>
52 #include <asm/cacheflush.h>
53 #include "audit.h" /* audit_signal_info() */
56 * SLAB caches for signal bits.
59 static struct kmem_cache
*sigqueue_cachep
;
61 int print_fatal_signals __read_mostly
;
63 static void __user
*sig_handler(struct task_struct
*t
, int sig
)
65 return t
->sighand
->action
[sig
- 1].sa
.sa_handler
;
68 static inline bool sig_handler_ignored(void __user
*handler
, int sig
)
70 /* Is it explicitly or implicitly ignored? */
71 return handler
== SIG_IGN
||
72 (handler
== SIG_DFL
&& sig_kernel_ignore(sig
));
75 static bool sig_task_ignored(struct task_struct
*t
, int sig
, bool force
)
79 handler
= sig_handler(t
, sig
);
81 /* SIGKILL and SIGSTOP may not be sent to the global init */
82 if (unlikely(is_global_init(t
) && sig_kernel_only(sig
)))
85 if (unlikely(t
->signal
->flags
& SIGNAL_UNKILLABLE
) &&
86 handler
== SIG_DFL
&& !(force
&& sig_kernel_only(sig
)))
89 return sig_handler_ignored(handler
, sig
);
92 static bool sig_ignored(struct task_struct
*t
, int sig
, bool force
)
95 * Blocked signals are never ignored, since the
96 * signal handler may change by the time it is
99 if (sigismember(&t
->blocked
, sig
) || sigismember(&t
->real_blocked
, sig
))
103 * Tracers may want to know about even ignored signal unless it
104 * is SIGKILL which can't be reported anyway but can be ignored
105 * by SIGNAL_UNKILLABLE task.
107 if (t
->ptrace
&& sig
!= SIGKILL
)
110 return sig_task_ignored(t
, sig
, force
);
114 * Re-calculate pending state from the set of locally pending
115 * signals, globally pending signals, and blocked signals.
117 static inline bool has_pending_signals(sigset_t
*signal
, sigset_t
*blocked
)
122 switch (_NSIG_WORDS
) {
124 for (i
= _NSIG_WORDS
, ready
= 0; --i
>= 0 ;)
125 ready
|= signal
->sig
[i
] &~ blocked
->sig
[i
];
128 case 4: ready
= signal
->sig
[3] &~ blocked
->sig
[3];
129 ready
|= signal
->sig
[2] &~ blocked
->sig
[2];
130 ready
|= signal
->sig
[1] &~ blocked
->sig
[1];
131 ready
|= signal
->sig
[0] &~ blocked
->sig
[0];
134 case 2: ready
= signal
->sig
[1] &~ blocked
->sig
[1];
135 ready
|= signal
->sig
[0] &~ blocked
->sig
[0];
138 case 1: ready
= signal
->sig
[0] &~ blocked
->sig
[0];
143 #define PENDING(p,b) has_pending_signals(&(p)->signal, (b))
145 static bool recalc_sigpending_tsk(struct task_struct
*t
)
147 if ((t
->jobctl
& JOBCTL_PENDING_MASK
) ||
148 PENDING(&t
->pending
, &t
->blocked
) ||
149 PENDING(&t
->signal
->shared_pending
, &t
->blocked
)) {
150 set_tsk_thread_flag(t
, TIF_SIGPENDING
);
155 * We must never clear the flag in another thread, or in current
156 * when it's possible the current syscall is returning -ERESTART*.
157 * So we don't clear it here, and only callers who know they should do.
163 * After recalculating TIF_SIGPENDING, we need to make sure the task wakes up.
164 * This is superfluous when called on current, the wakeup is a harmless no-op.
166 void recalc_sigpending_and_wake(struct task_struct
*t
)
168 if (recalc_sigpending_tsk(t
))
169 signal_wake_up(t
, 0);
172 void recalc_sigpending(void)
174 if (!recalc_sigpending_tsk(current
) && !freezing(current
) &&
175 !klp_patch_pending(current
))
176 clear_thread_flag(TIF_SIGPENDING
);
179 EXPORT_SYMBOL(recalc_sigpending
);
181 void calculate_sigpending(void)
183 /* Have any signals or users of TIF_SIGPENDING been delayed
186 spin_lock_irq(¤t
->sighand
->siglock
);
187 set_tsk_thread_flag(current
, TIF_SIGPENDING
);
189 spin_unlock_irq(¤t
->sighand
->siglock
);
192 /* Given the mask, find the first available signal that should be serviced. */
194 #define SYNCHRONOUS_MASK \
195 (sigmask(SIGSEGV) | sigmask(SIGBUS) | sigmask(SIGILL) | \
196 sigmask(SIGTRAP) | sigmask(SIGFPE) | sigmask(SIGSYS))
198 int next_signal(struct sigpending
*pending
, sigset_t
*mask
)
200 unsigned long i
, *s
, *m
, x
;
203 s
= pending
->signal
.sig
;
207 * Handle the first word specially: it contains the
208 * synchronous signals that need to be dequeued first.
212 if (x
& SYNCHRONOUS_MASK
)
213 x
&= SYNCHRONOUS_MASK
;
218 switch (_NSIG_WORDS
) {
220 for (i
= 1; i
< _NSIG_WORDS
; ++i
) {
224 sig
= ffz(~x
) + i
*_NSIG_BPW
+ 1;
233 sig
= ffz(~x
) + _NSIG_BPW
+ 1;
244 static inline void print_dropped_signal(int sig
)
246 static DEFINE_RATELIMIT_STATE(ratelimit_state
, 5 * HZ
, 10);
248 if (!print_fatal_signals
)
251 if (!__ratelimit(&ratelimit_state
))
254 pr_info("%s/%d: reached RLIMIT_SIGPENDING, dropped signal %d\n",
255 current
->comm
, current
->pid
, sig
);
259 * task_set_jobctl_pending - set jobctl pending bits
261 * @mask: pending bits to set
263 * Clear @mask from @task->jobctl. @mask must be subset of
264 * %JOBCTL_PENDING_MASK | %JOBCTL_STOP_CONSUME | %JOBCTL_STOP_SIGMASK |
265 * %JOBCTL_TRAPPING. If stop signo is being set, the existing signo is
266 * cleared. If @task is already being killed or exiting, this function
270 * Must be called with @task->sighand->siglock held.
273 * %true if @mask is set, %false if made noop because @task was dying.
275 bool task_set_jobctl_pending(struct task_struct
*task
, unsigned long mask
)
277 BUG_ON(mask
& ~(JOBCTL_PENDING_MASK
| JOBCTL_STOP_CONSUME
|
278 JOBCTL_STOP_SIGMASK
| JOBCTL_TRAPPING
));
279 BUG_ON((mask
& JOBCTL_TRAPPING
) && !(mask
& JOBCTL_PENDING_MASK
));
281 if (unlikely(fatal_signal_pending(task
) || (task
->flags
& PF_EXITING
)))
284 if (mask
& JOBCTL_STOP_SIGMASK
)
285 task
->jobctl
&= ~JOBCTL_STOP_SIGMASK
;
287 task
->jobctl
|= mask
;
292 * task_clear_jobctl_trapping - clear jobctl trapping bit
295 * If JOBCTL_TRAPPING is set, a ptracer is waiting for us to enter TRACED.
296 * Clear it and wake up the ptracer. Note that we don't need any further
297 * locking. @task->siglock guarantees that @task->parent points to the
301 * Must be called with @task->sighand->siglock held.
303 void task_clear_jobctl_trapping(struct task_struct
*task
)
305 if (unlikely(task
->jobctl
& JOBCTL_TRAPPING
)) {
306 task
->jobctl
&= ~JOBCTL_TRAPPING
;
307 smp_mb(); /* advised by wake_up_bit() */
308 wake_up_bit(&task
->jobctl
, JOBCTL_TRAPPING_BIT
);
313 * task_clear_jobctl_pending - clear jobctl pending bits
315 * @mask: pending bits to clear
317 * Clear @mask from @task->jobctl. @mask must be subset of
318 * %JOBCTL_PENDING_MASK. If %JOBCTL_STOP_PENDING is being cleared, other
319 * STOP bits are cleared together.
321 * If clearing of @mask leaves no stop or trap pending, this function calls
322 * task_clear_jobctl_trapping().
325 * Must be called with @task->sighand->siglock held.
327 void task_clear_jobctl_pending(struct task_struct
*task
, unsigned long mask
)
329 BUG_ON(mask
& ~JOBCTL_PENDING_MASK
);
331 if (mask
& JOBCTL_STOP_PENDING
)
332 mask
|= JOBCTL_STOP_CONSUME
| JOBCTL_STOP_DEQUEUED
;
334 task
->jobctl
&= ~mask
;
336 if (!(task
->jobctl
& JOBCTL_PENDING_MASK
))
337 task_clear_jobctl_trapping(task
);
341 * task_participate_group_stop - participate in a group stop
342 * @task: task participating in a group stop
344 * @task has %JOBCTL_STOP_PENDING set and is participating in a group stop.
345 * Group stop states are cleared and the group stop count is consumed if
346 * %JOBCTL_STOP_CONSUME was set. If the consumption completes the group
347 * stop, the appropriate %SIGNAL_* flags are set.
350 * Must be called with @task->sighand->siglock held.
353 * %true if group stop completion should be notified to the parent, %false
356 static bool task_participate_group_stop(struct task_struct
*task
)
358 struct signal_struct
*sig
= task
->signal
;
359 bool consume
= task
->jobctl
& JOBCTL_STOP_CONSUME
;
361 WARN_ON_ONCE(!(task
->jobctl
& JOBCTL_STOP_PENDING
));
363 task_clear_jobctl_pending(task
, JOBCTL_STOP_PENDING
);
368 if (!WARN_ON_ONCE(sig
->group_stop_count
== 0))
369 sig
->group_stop_count
--;
372 * Tell the caller to notify completion iff we are entering into a
373 * fresh group stop. Read comment in do_signal_stop() for details.
375 if (!sig
->group_stop_count
&& !(sig
->flags
& SIGNAL_STOP_STOPPED
)) {
376 signal_set_stop_flags(sig
, SIGNAL_STOP_STOPPED
);
382 void task_join_group_stop(struct task_struct
*task
)
384 /* Have the new thread join an on-going signal group stop */
385 unsigned long jobctl
= current
->jobctl
;
386 if (jobctl
& JOBCTL_STOP_PENDING
) {
387 struct signal_struct
*sig
= current
->signal
;
388 unsigned long signr
= jobctl
& JOBCTL_STOP_SIGMASK
;
389 unsigned long gstop
= JOBCTL_STOP_PENDING
| JOBCTL_STOP_CONSUME
;
390 if (task_set_jobctl_pending(task
, signr
| gstop
)) {
391 sig
->group_stop_count
++;
397 * allocate a new signal queue record
398 * - this may be called without locks if and only if t == current, otherwise an
399 * appropriate lock must be held to stop the target task from exiting
401 static struct sigqueue
*
402 __sigqueue_alloc(int sig
, struct task_struct
*t
, gfp_t flags
, int override_rlimit
)
404 struct sigqueue
*q
= NULL
;
405 struct user_struct
*user
;
408 * Protect access to @t credentials. This can go away when all
409 * callers hold rcu read lock.
412 user
= get_uid(__task_cred(t
)->user
);
413 atomic_inc(&user
->sigpending
);
416 if (override_rlimit
||
417 atomic_read(&user
->sigpending
) <=
418 task_rlimit(t
, RLIMIT_SIGPENDING
)) {
419 q
= kmem_cache_alloc(sigqueue_cachep
, flags
);
421 print_dropped_signal(sig
);
424 if (unlikely(q
== NULL
)) {
425 atomic_dec(&user
->sigpending
);
428 INIT_LIST_HEAD(&q
->list
);
436 static void __sigqueue_free(struct sigqueue
*q
)
438 if (q
->flags
& SIGQUEUE_PREALLOC
)
440 atomic_dec(&q
->user
->sigpending
);
442 kmem_cache_free(sigqueue_cachep
, q
);
445 void flush_sigqueue(struct sigpending
*queue
)
449 sigemptyset(&queue
->signal
);
450 while (!list_empty(&queue
->list
)) {
451 q
= list_entry(queue
->list
.next
, struct sigqueue
, list
);
452 list_del_init(&q
->list
);
458 * Flush all pending signals for this kthread.
460 void flush_signals(struct task_struct
*t
)
464 spin_lock_irqsave(&t
->sighand
->siglock
, flags
);
465 clear_tsk_thread_flag(t
, TIF_SIGPENDING
);
466 flush_sigqueue(&t
->pending
);
467 flush_sigqueue(&t
->signal
->shared_pending
);
468 spin_unlock_irqrestore(&t
->sighand
->siglock
, flags
);
470 EXPORT_SYMBOL(flush_signals
);
472 #ifdef CONFIG_POSIX_TIMERS
473 static void __flush_itimer_signals(struct sigpending
*pending
)
475 sigset_t signal
, retain
;
476 struct sigqueue
*q
, *n
;
478 signal
= pending
->signal
;
479 sigemptyset(&retain
);
481 list_for_each_entry_safe(q
, n
, &pending
->list
, list
) {
482 int sig
= q
->info
.si_signo
;
484 if (likely(q
->info
.si_code
!= SI_TIMER
)) {
485 sigaddset(&retain
, sig
);
487 sigdelset(&signal
, sig
);
488 list_del_init(&q
->list
);
493 sigorsets(&pending
->signal
, &signal
, &retain
);
496 void flush_itimer_signals(void)
498 struct task_struct
*tsk
= current
;
501 spin_lock_irqsave(&tsk
->sighand
->siglock
, flags
);
502 __flush_itimer_signals(&tsk
->pending
);
503 __flush_itimer_signals(&tsk
->signal
->shared_pending
);
504 spin_unlock_irqrestore(&tsk
->sighand
->siglock
, flags
);
508 void ignore_signals(struct task_struct
*t
)
512 for (i
= 0; i
< _NSIG
; ++i
)
513 t
->sighand
->action
[i
].sa
.sa_handler
= SIG_IGN
;
519 * Flush all handlers for a task.
523 flush_signal_handlers(struct task_struct
*t
, int force_default
)
526 struct k_sigaction
*ka
= &t
->sighand
->action
[0];
527 for (i
= _NSIG
; i
!= 0 ; i
--) {
528 if (force_default
|| ka
->sa
.sa_handler
!= SIG_IGN
)
529 ka
->sa
.sa_handler
= SIG_DFL
;
531 #ifdef __ARCH_HAS_SA_RESTORER
532 ka
->sa
.sa_restorer
= NULL
;
534 sigemptyset(&ka
->sa
.sa_mask
);
539 bool unhandled_signal(struct task_struct
*tsk
, int sig
)
541 void __user
*handler
= tsk
->sighand
->action
[sig
-1].sa
.sa_handler
;
542 if (is_global_init(tsk
))
545 if (handler
!= SIG_IGN
&& handler
!= SIG_DFL
)
548 /* if ptraced, let the tracer determine */
552 static void collect_signal(int sig
, struct sigpending
*list
, kernel_siginfo_t
*info
,
555 struct sigqueue
*q
, *first
= NULL
;
558 * Collect the siginfo appropriate to this signal. Check if
559 * there is another siginfo for the same signal.
561 list_for_each_entry(q
, &list
->list
, list
) {
562 if (q
->info
.si_signo
== sig
) {
569 sigdelset(&list
->signal
, sig
);
573 list_del_init(&first
->list
);
574 copy_siginfo(info
, &first
->info
);
577 (first
->flags
& SIGQUEUE_PREALLOC
) &&
578 (info
->si_code
== SI_TIMER
) &&
579 (info
->si_sys_private
);
581 __sigqueue_free(first
);
584 * Ok, it wasn't in the queue. This must be
585 * a fast-pathed signal or we must have been
586 * out of queue space. So zero out the info.
589 info
->si_signo
= sig
;
591 info
->si_code
= SI_USER
;
597 static int __dequeue_signal(struct sigpending
*pending
, sigset_t
*mask
,
598 kernel_siginfo_t
*info
, bool *resched_timer
)
600 int sig
= next_signal(pending
, mask
);
603 collect_signal(sig
, pending
, info
, resched_timer
);
608 * Dequeue a signal and return the element to the caller, which is
609 * expected to free it.
611 * All callers have to hold the siglock.
613 int dequeue_signal(struct task_struct
*tsk
, sigset_t
*mask
, kernel_siginfo_t
*info
)
615 bool resched_timer
= false;
618 /* We only dequeue private signals from ourselves, we don't let
619 * signalfd steal them
621 signr
= __dequeue_signal(&tsk
->pending
, mask
, info
, &resched_timer
);
623 signr
= __dequeue_signal(&tsk
->signal
->shared_pending
,
624 mask
, info
, &resched_timer
);
625 #ifdef CONFIG_POSIX_TIMERS
629 * itimers are process shared and we restart periodic
630 * itimers in the signal delivery path to prevent DoS
631 * attacks in the high resolution timer case. This is
632 * compliant with the old way of self-restarting
633 * itimers, as the SIGALRM is a legacy signal and only
634 * queued once. Changing the restart behaviour to
635 * restart the timer in the signal dequeue path is
636 * reducing the timer noise on heavy loaded !highres
639 if (unlikely(signr
== SIGALRM
)) {
640 struct hrtimer
*tmr
= &tsk
->signal
->real_timer
;
642 if (!hrtimer_is_queued(tmr
) &&
643 tsk
->signal
->it_real_incr
!= 0) {
644 hrtimer_forward(tmr
, tmr
->base
->get_time(),
645 tsk
->signal
->it_real_incr
);
646 hrtimer_restart(tmr
);
656 if (unlikely(sig_kernel_stop(signr
))) {
658 * Set a marker that we have dequeued a stop signal. Our
659 * caller might release the siglock and then the pending
660 * stop signal it is about to process is no longer in the
661 * pending bitmasks, but must still be cleared by a SIGCONT
662 * (and overruled by a SIGKILL). So those cases clear this
663 * shared flag after we've set it. Note that this flag may
664 * remain set after the signal we return is ignored or
665 * handled. That doesn't matter because its only purpose
666 * is to alert stop-signal processing code when another
667 * processor has come along and cleared the flag.
669 current
->jobctl
|= JOBCTL_STOP_DEQUEUED
;
671 #ifdef CONFIG_POSIX_TIMERS
674 * Release the siglock to ensure proper locking order
675 * of timer locks outside of siglocks. Note, we leave
676 * irqs disabled here, since the posix-timers code is
677 * about to disable them again anyway.
679 spin_unlock(&tsk
->sighand
->siglock
);
680 posixtimer_rearm(info
);
681 spin_lock(&tsk
->sighand
->siglock
);
683 /* Don't expose the si_sys_private value to userspace */
684 info
->si_sys_private
= 0;
689 EXPORT_SYMBOL_GPL(dequeue_signal
);
691 static int dequeue_synchronous_signal(kernel_siginfo_t
*info
)
693 struct task_struct
*tsk
= current
;
694 struct sigpending
*pending
= &tsk
->pending
;
695 struct sigqueue
*q
, *sync
= NULL
;
698 * Might a synchronous signal be in the queue?
700 if (!((pending
->signal
.sig
[0] & ~tsk
->blocked
.sig
[0]) & SYNCHRONOUS_MASK
))
704 * Return the first synchronous signal in the queue.
706 list_for_each_entry(q
, &pending
->list
, list
) {
707 /* Synchronous signals have a postive si_code */
708 if ((q
->info
.si_code
> SI_USER
) &&
709 (sigmask(q
->info
.si_signo
) & SYNCHRONOUS_MASK
)) {
717 * Check if there is another siginfo for the same signal.
719 list_for_each_entry_continue(q
, &pending
->list
, list
) {
720 if (q
->info
.si_signo
== sync
->info
.si_signo
)
724 sigdelset(&pending
->signal
, sync
->info
.si_signo
);
727 list_del_init(&sync
->list
);
728 copy_siginfo(info
, &sync
->info
);
729 __sigqueue_free(sync
);
730 return info
->si_signo
;
734 * Tell a process that it has a new active signal..
736 * NOTE! we rely on the previous spin_lock to
737 * lock interrupts for us! We can only be called with
738 * "siglock" held, and the local interrupt must
739 * have been disabled when that got acquired!
741 * No need to set need_resched since signal event passing
742 * goes through ->blocked
744 void signal_wake_up_state(struct task_struct
*t
, unsigned int state
)
746 set_tsk_thread_flag(t
, TIF_SIGPENDING
);
748 * TASK_WAKEKILL also means wake it up in the stopped/traced/killable
749 * case. We don't check t->state here because there is a race with it
750 * executing another processor and just now entering stopped state.
751 * By using wake_up_state, we ensure the process will wake up and
752 * handle its death signal.
754 if (!wake_up_state(t
, state
| TASK_INTERRUPTIBLE
))
759 * Remove signals in mask from the pending set and queue.
760 * Returns 1 if any signals were found.
762 * All callers must be holding the siglock.
764 static void flush_sigqueue_mask(sigset_t
*mask
, struct sigpending
*s
)
766 struct sigqueue
*q
, *n
;
769 sigandsets(&m
, mask
, &s
->signal
);
770 if (sigisemptyset(&m
))
773 sigandnsets(&s
->signal
, &s
->signal
, mask
);
774 list_for_each_entry_safe(q
, n
, &s
->list
, list
) {
775 if (sigismember(mask
, q
->info
.si_signo
)) {
776 list_del_init(&q
->list
);
782 static inline int is_si_special(const struct kernel_siginfo
*info
)
784 return info
<= SEND_SIG_PRIV
;
787 static inline bool si_fromuser(const struct kernel_siginfo
*info
)
789 return info
== SEND_SIG_NOINFO
||
790 (!is_si_special(info
) && SI_FROMUSER(info
));
794 * called with RCU read lock from check_kill_permission()
796 static bool kill_ok_by_cred(struct task_struct
*t
)
798 const struct cred
*cred
= current_cred();
799 const struct cred
*tcred
= __task_cred(t
);
801 return uid_eq(cred
->euid
, tcred
->suid
) ||
802 uid_eq(cred
->euid
, tcred
->uid
) ||
803 uid_eq(cred
->uid
, tcred
->suid
) ||
804 uid_eq(cred
->uid
, tcred
->uid
) ||
805 ns_capable(tcred
->user_ns
, CAP_KILL
);
809 * Bad permissions for sending the signal
810 * - the caller must hold the RCU read lock
812 static int check_kill_permission(int sig
, struct kernel_siginfo
*info
,
813 struct task_struct
*t
)
818 if (!valid_signal(sig
))
821 if (!si_fromuser(info
))
824 error
= audit_signal_info(sig
, t
); /* Let audit system see the signal */
828 if (!same_thread_group(current
, t
) &&
829 !kill_ok_by_cred(t
)) {
832 sid
= task_session(t
);
834 * We don't return the error if sid == NULL. The
835 * task was unhashed, the caller must notice this.
837 if (!sid
|| sid
== task_session(current
))
844 return security_task_kill(t
, info
, sig
, NULL
);
848 * ptrace_trap_notify - schedule trap to notify ptracer
849 * @t: tracee wanting to notify tracer
851 * This function schedules sticky ptrace trap which is cleared on the next
852 * TRAP_STOP to notify ptracer of an event. @t must have been seized by
855 * If @t is running, STOP trap will be taken. If trapped for STOP and
856 * ptracer is listening for events, tracee is woken up so that it can
857 * re-trap for the new event. If trapped otherwise, STOP trap will be
858 * eventually taken without returning to userland after the existing traps
859 * are finished by PTRACE_CONT.
862 * Must be called with @task->sighand->siglock held.
864 static void ptrace_trap_notify(struct task_struct
*t
)
866 WARN_ON_ONCE(!(t
->ptrace
& PT_SEIZED
));
867 assert_spin_locked(&t
->sighand
->siglock
);
869 task_set_jobctl_pending(t
, JOBCTL_TRAP_NOTIFY
);
870 ptrace_signal_wake_up(t
, t
->jobctl
& JOBCTL_LISTENING
);
874 * Handle magic process-wide effects of stop/continue signals. Unlike
875 * the signal actions, these happen immediately at signal-generation
876 * time regardless of blocking, ignoring, or handling. This does the
877 * actual continuing for SIGCONT, but not the actual stopping for stop
878 * signals. The process stop is done as a signal action for SIG_DFL.
880 * Returns true if the signal should be actually delivered, otherwise
881 * it should be dropped.
883 static bool prepare_signal(int sig
, struct task_struct
*p
, bool force
)
885 struct signal_struct
*signal
= p
->signal
;
886 struct task_struct
*t
;
889 if (signal
->flags
& (SIGNAL_GROUP_EXIT
| SIGNAL_GROUP_COREDUMP
)) {
890 if (!(signal
->flags
& SIGNAL_GROUP_EXIT
))
891 return sig
== SIGKILL
;
893 * The process is in the middle of dying, nothing to do.
895 } else if (sig_kernel_stop(sig
)) {
897 * This is a stop signal. Remove SIGCONT from all queues.
899 siginitset(&flush
, sigmask(SIGCONT
));
900 flush_sigqueue_mask(&flush
, &signal
->shared_pending
);
901 for_each_thread(p
, t
)
902 flush_sigqueue_mask(&flush
, &t
->pending
);
903 } else if (sig
== SIGCONT
) {
906 * Remove all stop signals from all queues, wake all threads.
908 siginitset(&flush
, SIG_KERNEL_STOP_MASK
);
909 flush_sigqueue_mask(&flush
, &signal
->shared_pending
);
910 for_each_thread(p
, t
) {
911 flush_sigqueue_mask(&flush
, &t
->pending
);
912 task_clear_jobctl_pending(t
, JOBCTL_STOP_PENDING
);
913 if (likely(!(t
->ptrace
& PT_SEIZED
)))
914 wake_up_state(t
, __TASK_STOPPED
);
916 ptrace_trap_notify(t
);
920 * Notify the parent with CLD_CONTINUED if we were stopped.
922 * If we were in the middle of a group stop, we pretend it
923 * was already finished, and then continued. Since SIGCHLD
924 * doesn't queue we report only CLD_STOPPED, as if the next
925 * CLD_CONTINUED was dropped.
928 if (signal
->flags
& SIGNAL_STOP_STOPPED
)
929 why
|= SIGNAL_CLD_CONTINUED
;
930 else if (signal
->group_stop_count
)
931 why
|= SIGNAL_CLD_STOPPED
;
935 * The first thread which returns from do_signal_stop()
936 * will take ->siglock, notice SIGNAL_CLD_MASK, and
937 * notify its parent. See get_signal().
939 signal_set_stop_flags(signal
, why
| SIGNAL_STOP_CONTINUED
);
940 signal
->group_stop_count
= 0;
941 signal
->group_exit_code
= 0;
945 return !sig_ignored(p
, sig
, force
);
949 * Test if P wants to take SIG. After we've checked all threads with this,
950 * it's equivalent to finding no threads not blocking SIG. Any threads not
951 * blocking SIG were ruled out because they are not running and already
952 * have pending signals. Such threads will dequeue from the shared queue
953 * as soon as they're available, so putting the signal on the shared queue
954 * will be equivalent to sending it to one such thread.
956 static inline bool wants_signal(int sig
, struct task_struct
*p
)
958 if (sigismember(&p
->blocked
, sig
))
961 if (p
->flags
& PF_EXITING
)
967 if (task_is_stopped_or_traced(p
))
970 return task_curr(p
) || !signal_pending(p
);
973 static void complete_signal(int sig
, struct task_struct
*p
, enum pid_type type
)
975 struct signal_struct
*signal
= p
->signal
;
976 struct task_struct
*t
;
979 * Now find a thread we can wake up to take the signal off the queue.
981 * If the main thread wants the signal, it gets first crack.
982 * Probably the least surprising to the average bear.
984 if (wants_signal(sig
, p
))
986 else if ((type
== PIDTYPE_PID
) || thread_group_empty(p
))
988 * There is just one thread and it does not need to be woken.
989 * It will dequeue unblocked signals before it runs again.
994 * Otherwise try to find a suitable thread.
996 t
= signal
->curr_target
;
997 while (!wants_signal(sig
, t
)) {
999 if (t
== signal
->curr_target
)
1001 * No thread needs to be woken.
1002 * Any eligible threads will see
1003 * the signal in the queue soon.
1007 signal
->curr_target
= t
;
1011 * Found a killable thread. If the signal will be fatal,
1012 * then start taking the whole group down immediately.
1014 if (sig_fatal(p
, sig
) &&
1015 !(signal
->flags
& SIGNAL_GROUP_EXIT
) &&
1016 !sigismember(&t
->real_blocked
, sig
) &&
1017 (sig
== SIGKILL
|| !p
->ptrace
)) {
1019 * This signal will be fatal to the whole group.
1021 if (!sig_kernel_coredump(sig
)) {
1023 * Start a group exit and wake everybody up.
1024 * This way we don't have other threads
1025 * running and doing things after a slower
1026 * thread has the fatal signal pending.
1028 signal
->flags
= SIGNAL_GROUP_EXIT
;
1029 signal
->group_exit_code
= sig
;
1030 signal
->group_stop_count
= 0;
1033 task_clear_jobctl_pending(t
, JOBCTL_PENDING_MASK
);
1034 sigaddset(&t
->pending
.signal
, SIGKILL
);
1035 signal_wake_up(t
, 1);
1036 } while_each_thread(p
, t
);
1042 * The signal is already in the shared-pending queue.
1043 * Tell the chosen thread to wake up and dequeue it.
1045 signal_wake_up(t
, sig
== SIGKILL
);
1049 static inline bool legacy_queue(struct sigpending
*signals
, int sig
)
1051 return (sig
< SIGRTMIN
) && sigismember(&signals
->signal
, sig
);
1054 #ifdef CONFIG_USER_NS
1055 static inline void userns_fixup_signal_uid(struct kernel_siginfo
*info
, struct task_struct
*t
)
1057 if (current_user_ns() == task_cred_xxx(t
, user_ns
))
1060 if (SI_FROMKERNEL(info
))
1064 info
->si_uid
= from_kuid_munged(task_cred_xxx(t
, user_ns
),
1065 make_kuid(current_user_ns(), info
->si_uid
));
1069 static inline void userns_fixup_signal_uid(struct kernel_siginfo
*info
, struct task_struct
*t
)
1075 static int __send_signal(int sig
, struct kernel_siginfo
*info
, struct task_struct
*t
,
1076 enum pid_type type
, int from_ancestor_ns
)
1078 struct sigpending
*pending
;
1080 int override_rlimit
;
1081 int ret
= 0, result
;
1083 assert_spin_locked(&t
->sighand
->siglock
);
1085 result
= TRACE_SIGNAL_IGNORED
;
1086 if (!prepare_signal(sig
, t
,
1087 from_ancestor_ns
|| (info
== SEND_SIG_PRIV
)))
1090 pending
= (type
!= PIDTYPE_PID
) ? &t
->signal
->shared_pending
: &t
->pending
;
1092 * Short-circuit ignored signals and support queuing
1093 * exactly one non-rt signal, so that we can get more
1094 * detailed information about the cause of the signal.
1096 result
= TRACE_SIGNAL_ALREADY_PENDING
;
1097 if (legacy_queue(pending
, sig
))
1100 result
= TRACE_SIGNAL_DELIVERED
;
1102 * Skip useless siginfo allocation for SIGKILL and kernel threads.
1104 if ((sig
== SIGKILL
) || (t
->flags
& PF_KTHREAD
))
1108 * Real-time signals must be queued if sent by sigqueue, or
1109 * some other real-time mechanism. It is implementation
1110 * defined whether kill() does so. We attempt to do so, on
1111 * the principle of least surprise, but since kill is not
1112 * allowed to fail with EAGAIN when low on memory we just
1113 * make sure at least one signal gets delivered and don't
1114 * pass on the info struct.
1117 override_rlimit
= (is_si_special(info
) || info
->si_code
>= 0);
1119 override_rlimit
= 0;
1121 q
= __sigqueue_alloc(sig
, t
, GFP_ATOMIC
, override_rlimit
);
1123 list_add_tail(&q
->list
, &pending
->list
);
1124 switch ((unsigned long) info
) {
1125 case (unsigned long) SEND_SIG_NOINFO
:
1126 clear_siginfo(&q
->info
);
1127 q
->info
.si_signo
= sig
;
1128 q
->info
.si_errno
= 0;
1129 q
->info
.si_code
= SI_USER
;
1130 q
->info
.si_pid
= task_tgid_nr_ns(current
,
1131 task_active_pid_ns(t
));
1132 q
->info
.si_uid
= from_kuid_munged(current_user_ns(), current_uid());
1134 case (unsigned long) SEND_SIG_PRIV
:
1135 clear_siginfo(&q
->info
);
1136 q
->info
.si_signo
= sig
;
1137 q
->info
.si_errno
= 0;
1138 q
->info
.si_code
= SI_KERNEL
;
1143 copy_siginfo(&q
->info
, info
);
1144 if (from_ancestor_ns
)
1149 userns_fixup_signal_uid(&q
->info
, t
);
1151 } else if (!is_si_special(info
)) {
1152 if (sig
>= SIGRTMIN
&& info
->si_code
!= SI_USER
) {
1154 * Queue overflow, abort. We may abort if the
1155 * signal was rt and sent by user using something
1156 * other than kill().
1158 result
= TRACE_SIGNAL_OVERFLOW_FAIL
;
1163 * This is a silent loss of information. We still
1164 * send the signal, but the *info bits are lost.
1166 result
= TRACE_SIGNAL_LOSE_INFO
;
1171 signalfd_notify(t
, sig
);
1172 sigaddset(&pending
->signal
, sig
);
1174 /* Let multiprocess signals appear after on-going forks */
1175 if (type
> PIDTYPE_TGID
) {
1176 struct multiprocess_signals
*delayed
;
1177 hlist_for_each_entry(delayed
, &t
->signal
->multiprocess
, node
) {
1178 sigset_t
*signal
= &delayed
->signal
;
1179 /* Can't queue both a stop and a continue signal */
1181 sigdelsetmask(signal
, SIG_KERNEL_STOP_MASK
);
1182 else if (sig_kernel_stop(sig
))
1183 sigdelset(signal
, SIGCONT
);
1184 sigaddset(signal
, sig
);
1188 complete_signal(sig
, t
, type
);
1190 trace_signal_generate(sig
, info
, t
, type
!= PIDTYPE_PID
, result
);
1194 static int send_signal(int sig
, struct kernel_siginfo
*info
, struct task_struct
*t
,
1197 int from_ancestor_ns
= 0;
1199 #ifdef CONFIG_PID_NS
1200 from_ancestor_ns
= si_fromuser(info
) &&
1201 !task_pid_nr_ns(current
, task_active_pid_ns(t
));
1204 return __send_signal(sig
, info
, t
, type
, from_ancestor_ns
);
1207 static void print_fatal_signal(int signr
)
1209 struct pt_regs
*regs
= signal_pt_regs();
1210 pr_info("potentially unexpected fatal signal %d.\n", signr
);
1212 #if defined(__i386__) && !defined(__arch_um__)
1213 pr_info("code at %08lx: ", regs
->ip
);
1216 for (i
= 0; i
< 16; i
++) {
1219 if (get_user(insn
, (unsigned char *)(regs
->ip
+ i
)))
1221 pr_cont("%02x ", insn
);
1231 static int __init
setup_print_fatal_signals(char *str
)
1233 get_option (&str
, &print_fatal_signals
);
1238 __setup("print-fatal-signals=", setup_print_fatal_signals
);
1241 __group_send_sig_info(int sig
, struct kernel_siginfo
*info
, struct task_struct
*p
)
1243 return send_signal(sig
, info
, p
, PIDTYPE_TGID
);
1246 int do_send_sig_info(int sig
, struct kernel_siginfo
*info
, struct task_struct
*p
,
1249 unsigned long flags
;
1252 if (lock_task_sighand(p
, &flags
)) {
1253 ret
= send_signal(sig
, info
, p
, type
);
1254 unlock_task_sighand(p
, &flags
);
1261 * Force a signal that the process can't ignore: if necessary
1262 * we unblock the signal and change any SIG_IGN to SIG_DFL.
1264 * Note: If we unblock the signal, we always reset it to SIG_DFL,
1265 * since we do not want to have a signal handler that was blocked
1266 * be invoked when user space had explicitly blocked it.
1268 * We don't want to have recursive SIGSEGV's etc, for example,
1269 * that is why we also clear SIGNAL_UNKILLABLE.
1272 force_sig_info(int sig
, struct kernel_siginfo
*info
, struct task_struct
*t
)
1274 unsigned long int flags
;
1275 int ret
, blocked
, ignored
;
1276 struct k_sigaction
*action
;
1278 spin_lock_irqsave(&t
->sighand
->siglock
, flags
);
1279 action
= &t
->sighand
->action
[sig
-1];
1280 ignored
= action
->sa
.sa_handler
== SIG_IGN
;
1281 blocked
= sigismember(&t
->blocked
, sig
);
1282 if (blocked
|| ignored
) {
1283 action
->sa
.sa_handler
= SIG_DFL
;
1285 sigdelset(&t
->blocked
, sig
);
1286 recalc_sigpending_and_wake(t
);
1290 * Don't clear SIGNAL_UNKILLABLE for traced tasks, users won't expect
1291 * debugging to leave init killable.
1293 if (action
->sa
.sa_handler
== SIG_DFL
&& !t
->ptrace
)
1294 t
->signal
->flags
&= ~SIGNAL_UNKILLABLE
;
1295 ret
= send_signal(sig
, info
, t
, PIDTYPE_PID
);
1296 spin_unlock_irqrestore(&t
->sighand
->siglock
, flags
);
1302 * Nuke all other threads in the group.
1304 int zap_other_threads(struct task_struct
*p
)
1306 struct task_struct
*t
= p
;
1309 p
->signal
->group_stop_count
= 0;
1311 while_each_thread(p
, t
) {
1312 task_clear_jobctl_pending(t
, JOBCTL_PENDING_MASK
);
1315 /* Don't bother with already dead threads */
1318 sigaddset(&t
->pending
.signal
, SIGKILL
);
1319 signal_wake_up(t
, 1);
1325 struct sighand_struct
*__lock_task_sighand(struct task_struct
*tsk
,
1326 unsigned long *flags
)
1328 struct sighand_struct
*sighand
;
1332 sighand
= rcu_dereference(tsk
->sighand
);
1333 if (unlikely(sighand
== NULL
))
1337 * This sighand can be already freed and even reused, but
1338 * we rely on SLAB_TYPESAFE_BY_RCU and sighand_ctor() which
1339 * initializes ->siglock: this slab can't go away, it has
1340 * the same object type, ->siglock can't be reinitialized.
1342 * We need to ensure that tsk->sighand is still the same
1343 * after we take the lock, we can race with de_thread() or
1344 * __exit_signal(). In the latter case the next iteration
1345 * must see ->sighand == NULL.
1347 spin_lock_irqsave(&sighand
->siglock
, *flags
);
1348 if (likely(sighand
== tsk
->sighand
))
1350 spin_unlock_irqrestore(&sighand
->siglock
, *flags
);
1358 * send signal info to all the members of a group
1360 int group_send_sig_info(int sig
, struct kernel_siginfo
*info
,
1361 struct task_struct
*p
, enum pid_type type
)
1366 ret
= check_kill_permission(sig
, info
, p
);
1370 ret
= do_send_sig_info(sig
, info
, p
, type
);
1376 * __kill_pgrp_info() sends a signal to a process group: this is what the tty
1377 * control characters do (^C, ^Z etc)
1378 * - the caller must hold at least a readlock on tasklist_lock
1380 int __kill_pgrp_info(int sig
, struct kernel_siginfo
*info
, struct pid
*pgrp
)
1382 struct task_struct
*p
= NULL
;
1383 int retval
, success
;
1387 do_each_pid_task(pgrp
, PIDTYPE_PGID
, p
) {
1388 int err
= group_send_sig_info(sig
, info
, p
, PIDTYPE_PGID
);
1391 } while_each_pid_task(pgrp
, PIDTYPE_PGID
, p
);
1392 return success
? 0 : retval
;
1395 int kill_pid_info(int sig
, struct kernel_siginfo
*info
, struct pid
*pid
)
1398 struct task_struct
*p
;
1402 p
= pid_task(pid
, PIDTYPE_PID
);
1404 error
= group_send_sig_info(sig
, info
, p
, PIDTYPE_TGID
);
1406 if (likely(!p
|| error
!= -ESRCH
))
1410 * The task was unhashed in between, try again. If it
1411 * is dead, pid_task() will return NULL, if we race with
1412 * de_thread() it will find the new leader.
1417 static int kill_proc_info(int sig
, struct kernel_siginfo
*info
, pid_t pid
)
1421 error
= kill_pid_info(sig
, info
, find_vpid(pid
));
1426 static inline bool kill_as_cred_perm(const struct cred
*cred
,
1427 struct task_struct
*target
)
1429 const struct cred
*pcred
= __task_cred(target
);
1431 return uid_eq(cred
->euid
, pcred
->suid
) ||
1432 uid_eq(cred
->euid
, pcred
->uid
) ||
1433 uid_eq(cred
->uid
, pcred
->suid
) ||
1434 uid_eq(cred
->uid
, pcred
->uid
);
1437 /* like kill_pid_info(), but doesn't use uid/euid of "current" */
1438 int kill_pid_info_as_cred(int sig
, struct kernel_siginfo
*info
, struct pid
*pid
,
1439 const struct cred
*cred
)
1442 struct task_struct
*p
;
1443 unsigned long flags
;
1445 if (!valid_signal(sig
))
1449 p
= pid_task(pid
, PIDTYPE_PID
);
1454 if (si_fromuser(info
) && !kill_as_cred_perm(cred
, p
)) {
1458 ret
= security_task_kill(p
, info
, sig
, cred
);
1463 if (lock_task_sighand(p
, &flags
)) {
1464 ret
= __send_signal(sig
, info
, p
, PIDTYPE_TGID
, 0);
1465 unlock_task_sighand(p
, &flags
);
1473 EXPORT_SYMBOL_GPL(kill_pid_info_as_cred
);
1476 * kill_something_info() interprets pid in interesting ways just like kill(2).
1478 * POSIX specifies that kill(-1,sig) is unspecified, but what we have
1479 * is probably wrong. Should make it like BSD or SYSV.
1482 static int kill_something_info(int sig
, struct kernel_siginfo
*info
, pid_t pid
)
1488 ret
= kill_pid_info(sig
, info
, find_vpid(pid
));
1493 /* -INT_MIN is undefined. Exclude this case to avoid a UBSAN warning */
1497 read_lock(&tasklist_lock
);
1499 ret
= __kill_pgrp_info(sig
, info
,
1500 pid
? find_vpid(-pid
) : task_pgrp(current
));
1502 int retval
= 0, count
= 0;
1503 struct task_struct
* p
;
1505 for_each_process(p
) {
1506 if (task_pid_vnr(p
) > 1 &&
1507 !same_thread_group(p
, current
)) {
1508 int err
= group_send_sig_info(sig
, info
, p
,
1515 ret
= count
? retval
: -ESRCH
;
1517 read_unlock(&tasklist_lock
);
1523 * These are for backward compatibility with the rest of the kernel source.
1526 int send_sig_info(int sig
, struct kernel_siginfo
*info
, struct task_struct
*p
)
1529 * Make sure legacy kernel users don't send in bad values
1530 * (normal paths check this in check_kill_permission).
1532 if (!valid_signal(sig
))
1535 return do_send_sig_info(sig
, info
, p
, PIDTYPE_PID
);
1537 EXPORT_SYMBOL(send_sig_info
);
1539 #define __si_special(priv) \
1540 ((priv) ? SEND_SIG_PRIV : SEND_SIG_NOINFO)
1543 send_sig(int sig
, struct task_struct
*p
, int priv
)
1545 return send_sig_info(sig
, __si_special(priv
), p
);
1547 EXPORT_SYMBOL(send_sig
);
1549 void force_sig(int sig
, struct task_struct
*p
)
1551 force_sig_info(sig
, SEND_SIG_PRIV
, p
);
1553 EXPORT_SYMBOL(force_sig
);
1556 * When things go south during signal handling, we
1557 * will force a SIGSEGV. And if the signal that caused
1558 * the problem was already a SIGSEGV, we'll want to
1559 * make sure we don't even try to deliver the signal..
1561 void force_sigsegv(int sig
, struct task_struct
*p
)
1563 if (sig
== SIGSEGV
) {
1564 unsigned long flags
;
1565 spin_lock_irqsave(&p
->sighand
->siglock
, flags
);
1566 p
->sighand
->action
[sig
- 1].sa
.sa_handler
= SIG_DFL
;
1567 spin_unlock_irqrestore(&p
->sighand
->siglock
, flags
);
1569 force_sig(SIGSEGV
, p
);
1572 int force_sig_fault(int sig
, int code
, void __user
*addr
1573 ___ARCH_SI_TRAPNO(int trapno
)
1574 ___ARCH_SI_IA64(int imm
, unsigned int flags
, unsigned long isr
)
1575 , struct task_struct
*t
)
1577 struct kernel_siginfo info
;
1579 clear_siginfo(&info
);
1580 info
.si_signo
= sig
;
1582 info
.si_code
= code
;
1583 info
.si_addr
= addr
;
1584 #ifdef __ARCH_SI_TRAPNO
1585 info
.si_trapno
= trapno
;
1589 info
.si_flags
= flags
;
1592 return force_sig_info(info
.si_signo
, &info
, t
);
1595 int send_sig_fault(int sig
, int code
, void __user
*addr
1596 ___ARCH_SI_TRAPNO(int trapno
)
1597 ___ARCH_SI_IA64(int imm
, unsigned int flags
, unsigned long isr
)
1598 , struct task_struct
*t
)
1600 struct kernel_siginfo info
;
1602 clear_siginfo(&info
);
1603 info
.si_signo
= sig
;
1605 info
.si_code
= code
;
1606 info
.si_addr
= addr
;
1607 #ifdef __ARCH_SI_TRAPNO
1608 info
.si_trapno
= trapno
;
1612 info
.si_flags
= flags
;
1615 return send_sig_info(info
.si_signo
, &info
, t
);
1618 int force_sig_mceerr(int code
, void __user
*addr
, short lsb
, struct task_struct
*t
)
1620 struct kernel_siginfo info
;
1622 WARN_ON((code
!= BUS_MCEERR_AO
) && (code
!= BUS_MCEERR_AR
));
1623 clear_siginfo(&info
);
1624 info
.si_signo
= SIGBUS
;
1626 info
.si_code
= code
;
1627 info
.si_addr
= addr
;
1628 info
.si_addr_lsb
= lsb
;
1629 return force_sig_info(info
.si_signo
, &info
, t
);
1632 int send_sig_mceerr(int code
, void __user
*addr
, short lsb
, struct task_struct
*t
)
1634 struct kernel_siginfo info
;
1636 WARN_ON((code
!= BUS_MCEERR_AO
) && (code
!= BUS_MCEERR_AR
));
1637 clear_siginfo(&info
);
1638 info
.si_signo
= SIGBUS
;
1640 info
.si_code
= code
;
1641 info
.si_addr
= addr
;
1642 info
.si_addr_lsb
= lsb
;
1643 return send_sig_info(info
.si_signo
, &info
, t
);
1645 EXPORT_SYMBOL(send_sig_mceerr
);
1647 int force_sig_bnderr(void __user
*addr
, void __user
*lower
, void __user
*upper
)
1649 struct kernel_siginfo info
;
1651 clear_siginfo(&info
);
1652 info
.si_signo
= SIGSEGV
;
1654 info
.si_code
= SEGV_BNDERR
;
1655 info
.si_addr
= addr
;
1656 info
.si_lower
= lower
;
1657 info
.si_upper
= upper
;
1658 return force_sig_info(info
.si_signo
, &info
, current
);
1662 int force_sig_pkuerr(void __user
*addr
, u32 pkey
)
1664 struct kernel_siginfo info
;
1666 clear_siginfo(&info
);
1667 info
.si_signo
= SIGSEGV
;
1669 info
.si_code
= SEGV_PKUERR
;
1670 info
.si_addr
= addr
;
1671 info
.si_pkey
= pkey
;
1672 return force_sig_info(info
.si_signo
, &info
, current
);
1676 /* For the crazy architectures that include trap information in
1677 * the errno field, instead of an actual errno value.
1679 int force_sig_ptrace_errno_trap(int errno
, void __user
*addr
)
1681 struct kernel_siginfo info
;
1683 clear_siginfo(&info
);
1684 info
.si_signo
= SIGTRAP
;
1685 info
.si_errno
= errno
;
1686 info
.si_code
= TRAP_HWBKPT
;
1687 info
.si_addr
= addr
;
1688 return force_sig_info(info
.si_signo
, &info
, current
);
1691 int kill_pgrp(struct pid
*pid
, int sig
, int priv
)
1695 read_lock(&tasklist_lock
);
1696 ret
= __kill_pgrp_info(sig
, __si_special(priv
), pid
);
1697 read_unlock(&tasklist_lock
);
1701 EXPORT_SYMBOL(kill_pgrp
);
1703 int kill_pid(struct pid
*pid
, int sig
, int priv
)
1705 return kill_pid_info(sig
, __si_special(priv
), pid
);
1707 EXPORT_SYMBOL(kill_pid
);
1710 * These functions support sending signals using preallocated sigqueue
1711 * structures. This is needed "because realtime applications cannot
1712 * afford to lose notifications of asynchronous events, like timer
1713 * expirations or I/O completions". In the case of POSIX Timers
1714 * we allocate the sigqueue structure from the timer_create. If this
1715 * allocation fails we are able to report the failure to the application
1716 * with an EAGAIN error.
1718 struct sigqueue
*sigqueue_alloc(void)
1720 struct sigqueue
*q
= __sigqueue_alloc(-1, current
, GFP_KERNEL
, 0);
1723 q
->flags
|= SIGQUEUE_PREALLOC
;
1728 void sigqueue_free(struct sigqueue
*q
)
1730 unsigned long flags
;
1731 spinlock_t
*lock
= ¤t
->sighand
->siglock
;
1733 BUG_ON(!(q
->flags
& SIGQUEUE_PREALLOC
));
1735 * We must hold ->siglock while testing q->list
1736 * to serialize with collect_signal() or with
1737 * __exit_signal()->flush_sigqueue().
1739 spin_lock_irqsave(lock
, flags
);
1740 q
->flags
&= ~SIGQUEUE_PREALLOC
;
1742 * If it is queued it will be freed when dequeued,
1743 * like the "regular" sigqueue.
1745 if (!list_empty(&q
->list
))
1747 spin_unlock_irqrestore(lock
, flags
);
1753 int send_sigqueue(struct sigqueue
*q
, struct pid
*pid
, enum pid_type type
)
1755 int sig
= q
->info
.si_signo
;
1756 struct sigpending
*pending
;
1757 struct task_struct
*t
;
1758 unsigned long flags
;
1761 BUG_ON(!(q
->flags
& SIGQUEUE_PREALLOC
));
1765 t
= pid_task(pid
, type
);
1766 if (!t
|| !likely(lock_task_sighand(t
, &flags
)))
1769 ret
= 1; /* the signal is ignored */
1770 result
= TRACE_SIGNAL_IGNORED
;
1771 if (!prepare_signal(sig
, t
, false))
1775 if (unlikely(!list_empty(&q
->list
))) {
1777 * If an SI_TIMER entry is already queue just increment
1778 * the overrun count.
1780 BUG_ON(q
->info
.si_code
!= SI_TIMER
);
1781 q
->info
.si_overrun
++;
1782 result
= TRACE_SIGNAL_ALREADY_PENDING
;
1785 q
->info
.si_overrun
= 0;
1787 signalfd_notify(t
, sig
);
1788 pending
= (type
!= PIDTYPE_PID
) ? &t
->signal
->shared_pending
: &t
->pending
;
1789 list_add_tail(&q
->list
, &pending
->list
);
1790 sigaddset(&pending
->signal
, sig
);
1791 complete_signal(sig
, t
, type
);
1792 result
= TRACE_SIGNAL_DELIVERED
;
1794 trace_signal_generate(sig
, &q
->info
, t
, type
!= PIDTYPE_PID
, result
);
1795 unlock_task_sighand(t
, &flags
);
1802 * Let a parent know about the death of a child.
1803 * For a stopped/continued status change, use do_notify_parent_cldstop instead.
1805 * Returns true if our parent ignored us and so we've switched to
1808 bool do_notify_parent(struct task_struct
*tsk
, int sig
)
1810 struct kernel_siginfo info
;
1811 unsigned long flags
;
1812 struct sighand_struct
*psig
;
1813 bool autoreap
= false;
1818 /* do_notify_parent_cldstop should have been called instead. */
1819 BUG_ON(task_is_stopped_or_traced(tsk
));
1821 BUG_ON(!tsk
->ptrace
&&
1822 (tsk
->group_leader
!= tsk
|| !thread_group_empty(tsk
)));
1824 if (sig
!= SIGCHLD
) {
1826 * This is only possible if parent == real_parent.
1827 * Check if it has changed security domain.
1829 if (tsk
->parent_exec_id
!= tsk
->parent
->self_exec_id
)
1833 clear_siginfo(&info
);
1834 info
.si_signo
= sig
;
1837 * We are under tasklist_lock here so our parent is tied to
1838 * us and cannot change.
1840 * task_active_pid_ns will always return the same pid namespace
1841 * until a task passes through release_task.
1843 * write_lock() currently calls preempt_disable() which is the
1844 * same as rcu_read_lock(), but according to Oleg, this is not
1845 * correct to rely on this
1848 info
.si_pid
= task_pid_nr_ns(tsk
, task_active_pid_ns(tsk
->parent
));
1849 info
.si_uid
= from_kuid_munged(task_cred_xxx(tsk
->parent
, user_ns
),
1853 task_cputime(tsk
, &utime
, &stime
);
1854 info
.si_utime
= nsec_to_clock_t(utime
+ tsk
->signal
->utime
);
1855 info
.si_stime
= nsec_to_clock_t(stime
+ tsk
->signal
->stime
);
1857 info
.si_status
= tsk
->exit_code
& 0x7f;
1858 if (tsk
->exit_code
& 0x80)
1859 info
.si_code
= CLD_DUMPED
;
1860 else if (tsk
->exit_code
& 0x7f)
1861 info
.si_code
= CLD_KILLED
;
1863 info
.si_code
= CLD_EXITED
;
1864 info
.si_status
= tsk
->exit_code
>> 8;
1867 psig
= tsk
->parent
->sighand
;
1868 spin_lock_irqsave(&psig
->siglock
, flags
);
1869 if (!tsk
->ptrace
&& sig
== SIGCHLD
&&
1870 (psig
->action
[SIGCHLD
-1].sa
.sa_handler
== SIG_IGN
||
1871 (psig
->action
[SIGCHLD
-1].sa
.sa_flags
& SA_NOCLDWAIT
))) {
1873 * We are exiting and our parent doesn't care. POSIX.1
1874 * defines special semantics for setting SIGCHLD to SIG_IGN
1875 * or setting the SA_NOCLDWAIT flag: we should be reaped
1876 * automatically and not left for our parent's wait4 call.
1877 * Rather than having the parent do it as a magic kind of
1878 * signal handler, we just set this to tell do_exit that we
1879 * can be cleaned up without becoming a zombie. Note that
1880 * we still call __wake_up_parent in this case, because a
1881 * blocked sys_wait4 might now return -ECHILD.
1883 * Whether we send SIGCHLD or not for SA_NOCLDWAIT
1884 * is implementation-defined: we do (if you don't want
1885 * it, just use SIG_IGN instead).
1888 if (psig
->action
[SIGCHLD
-1].sa
.sa_handler
== SIG_IGN
)
1891 if (valid_signal(sig
) && sig
)
1892 __group_send_sig_info(sig
, &info
, tsk
->parent
);
1893 __wake_up_parent(tsk
, tsk
->parent
);
1894 spin_unlock_irqrestore(&psig
->siglock
, flags
);
1900 * do_notify_parent_cldstop - notify parent of stopped/continued state change
1901 * @tsk: task reporting the state change
1902 * @for_ptracer: the notification is for ptracer
1903 * @why: CLD_{CONTINUED|STOPPED|TRAPPED} to report
1905 * Notify @tsk's parent that the stopped/continued state has changed. If
1906 * @for_ptracer is %false, @tsk's group leader notifies to its real parent.
1907 * If %true, @tsk reports to @tsk->parent which should be the ptracer.
1910 * Must be called with tasklist_lock at least read locked.
1912 static void do_notify_parent_cldstop(struct task_struct
*tsk
,
1913 bool for_ptracer
, int why
)
1915 struct kernel_siginfo info
;
1916 unsigned long flags
;
1917 struct task_struct
*parent
;
1918 struct sighand_struct
*sighand
;
1922 parent
= tsk
->parent
;
1924 tsk
= tsk
->group_leader
;
1925 parent
= tsk
->real_parent
;
1928 clear_siginfo(&info
);
1929 info
.si_signo
= SIGCHLD
;
1932 * see comment in do_notify_parent() about the following 4 lines
1935 info
.si_pid
= task_pid_nr_ns(tsk
, task_active_pid_ns(parent
));
1936 info
.si_uid
= from_kuid_munged(task_cred_xxx(parent
, user_ns
), task_uid(tsk
));
1939 task_cputime(tsk
, &utime
, &stime
);
1940 info
.si_utime
= nsec_to_clock_t(utime
);
1941 info
.si_stime
= nsec_to_clock_t(stime
);
1946 info
.si_status
= SIGCONT
;
1949 info
.si_status
= tsk
->signal
->group_exit_code
& 0x7f;
1952 info
.si_status
= tsk
->exit_code
& 0x7f;
1958 sighand
= parent
->sighand
;
1959 spin_lock_irqsave(&sighand
->siglock
, flags
);
1960 if (sighand
->action
[SIGCHLD
-1].sa
.sa_handler
!= SIG_IGN
&&
1961 !(sighand
->action
[SIGCHLD
-1].sa
.sa_flags
& SA_NOCLDSTOP
))
1962 __group_send_sig_info(SIGCHLD
, &info
, parent
);
1964 * Even if SIGCHLD is not generated, we must wake up wait4 calls.
1966 __wake_up_parent(tsk
, parent
);
1967 spin_unlock_irqrestore(&sighand
->siglock
, flags
);
1970 static inline bool may_ptrace_stop(void)
1972 if (!likely(current
->ptrace
))
1975 * Are we in the middle of do_coredump?
1976 * If so and our tracer is also part of the coredump stopping
1977 * is a deadlock situation, and pointless because our tracer
1978 * is dead so don't allow us to stop.
1979 * If SIGKILL was already sent before the caller unlocked
1980 * ->siglock we must see ->core_state != NULL. Otherwise it
1981 * is safe to enter schedule().
1983 * This is almost outdated, a task with the pending SIGKILL can't
1984 * block in TASK_TRACED. But PTRACE_EVENT_EXIT can be reported
1985 * after SIGKILL was already dequeued.
1987 if (unlikely(current
->mm
->core_state
) &&
1988 unlikely(current
->mm
== current
->parent
->mm
))
1995 * Return non-zero if there is a SIGKILL that should be waking us up.
1996 * Called with the siglock held.
1998 static bool sigkill_pending(struct task_struct
*tsk
)
2000 return sigismember(&tsk
->pending
.signal
, SIGKILL
) ||
2001 sigismember(&tsk
->signal
->shared_pending
.signal
, SIGKILL
);
2005 * This must be called with current->sighand->siglock held.
2007 * This should be the path for all ptrace stops.
2008 * We always set current->last_siginfo while stopped here.
2009 * That makes it a way to test a stopped process for
2010 * being ptrace-stopped vs being job-control-stopped.
2012 * If we actually decide not to stop at all because the tracer
2013 * is gone, we keep current->exit_code unless clear_code.
2015 static void ptrace_stop(int exit_code
, int why
, int clear_code
, kernel_siginfo_t
*info
)
2016 __releases(¤t
->sighand
->siglock
)
2017 __acquires(¤t
->sighand
->siglock
)
2019 bool gstop_done
= false;
2021 if (arch_ptrace_stop_needed(exit_code
, info
)) {
2023 * The arch code has something special to do before a
2024 * ptrace stop. This is allowed to block, e.g. for faults
2025 * on user stack pages. We can't keep the siglock while
2026 * calling arch_ptrace_stop, so we must release it now.
2027 * To preserve proper semantics, we must do this before
2028 * any signal bookkeeping like checking group_stop_count.
2029 * Meanwhile, a SIGKILL could come in before we retake the
2030 * siglock. That must prevent us from sleeping in TASK_TRACED.
2031 * So after regaining the lock, we must check for SIGKILL.
2033 spin_unlock_irq(¤t
->sighand
->siglock
);
2034 arch_ptrace_stop(exit_code
, info
);
2035 spin_lock_irq(¤t
->sighand
->siglock
);
2036 if (sigkill_pending(current
))
2040 set_special_state(TASK_TRACED
);
2043 * We're committing to trapping. TRACED should be visible before
2044 * TRAPPING is cleared; otherwise, the tracer might fail do_wait().
2045 * Also, transition to TRACED and updates to ->jobctl should be
2046 * atomic with respect to siglock and should be done after the arch
2047 * hook as siglock is released and regrabbed across it.
2052 * [L] wait_on_bit(JOBCTL_TRAPPING) [S] set_special_state(TRACED)
2054 * set_current_state() smp_wmb();
2056 * wait_task_stopped()
2057 * task_stopped_code()
2058 * [L] task_is_traced() [S] task_clear_jobctl_trapping();
2062 current
->last_siginfo
= info
;
2063 current
->exit_code
= exit_code
;
2066 * If @why is CLD_STOPPED, we're trapping to participate in a group
2067 * stop. Do the bookkeeping. Note that if SIGCONT was delievered
2068 * across siglock relocks since INTERRUPT was scheduled, PENDING
2069 * could be clear now. We act as if SIGCONT is received after
2070 * TASK_TRACED is entered - ignore it.
2072 if (why
== CLD_STOPPED
&& (current
->jobctl
& JOBCTL_STOP_PENDING
))
2073 gstop_done
= task_participate_group_stop(current
);
2075 /* any trap clears pending STOP trap, STOP trap clears NOTIFY */
2076 task_clear_jobctl_pending(current
, JOBCTL_TRAP_STOP
);
2077 if (info
&& info
->si_code
>> 8 == PTRACE_EVENT_STOP
)
2078 task_clear_jobctl_pending(current
, JOBCTL_TRAP_NOTIFY
);
2080 /* entering a trap, clear TRAPPING */
2081 task_clear_jobctl_trapping(current
);
2083 spin_unlock_irq(¤t
->sighand
->siglock
);
2084 read_lock(&tasklist_lock
);
2085 if (may_ptrace_stop()) {
2087 * Notify parents of the stop.
2089 * While ptraced, there are two parents - the ptracer and
2090 * the real_parent of the group_leader. The ptracer should
2091 * know about every stop while the real parent is only
2092 * interested in the completion of group stop. The states
2093 * for the two don't interact with each other. Notify
2094 * separately unless they're gonna be duplicates.
2096 do_notify_parent_cldstop(current
, true, why
);
2097 if (gstop_done
&& ptrace_reparented(current
))
2098 do_notify_parent_cldstop(current
, false, why
);
2101 * Don't want to allow preemption here, because
2102 * sys_ptrace() needs this task to be inactive.
2104 * XXX: implement read_unlock_no_resched().
2107 read_unlock(&tasklist_lock
);
2108 preempt_enable_no_resched();
2109 freezable_schedule();
2112 * By the time we got the lock, our tracer went away.
2113 * Don't drop the lock yet, another tracer may come.
2115 * If @gstop_done, the ptracer went away between group stop
2116 * completion and here. During detach, it would have set
2117 * JOBCTL_STOP_PENDING on us and we'll re-enter
2118 * TASK_STOPPED in do_signal_stop() on return, so notifying
2119 * the real parent of the group stop completion is enough.
2122 do_notify_parent_cldstop(current
, false, why
);
2124 /* tasklist protects us from ptrace_freeze_traced() */
2125 __set_current_state(TASK_RUNNING
);
2127 current
->exit_code
= 0;
2128 read_unlock(&tasklist_lock
);
2132 * We are back. Now reacquire the siglock before touching
2133 * last_siginfo, so that we are sure to have synchronized with
2134 * any signal-sending on another CPU that wants to examine it.
2136 spin_lock_irq(¤t
->sighand
->siglock
);
2137 current
->last_siginfo
= NULL
;
2139 /* LISTENING can be set only during STOP traps, clear it */
2140 current
->jobctl
&= ~JOBCTL_LISTENING
;
2143 * Queued signals ignored us while we were stopped for tracing.
2144 * So check for any that we should take before resuming user mode.
2145 * This sets TIF_SIGPENDING, but never clears it.
2147 recalc_sigpending_tsk(current
);
2150 static void ptrace_do_notify(int signr
, int exit_code
, int why
)
2152 kernel_siginfo_t info
;
2154 clear_siginfo(&info
);
2155 info
.si_signo
= signr
;
2156 info
.si_code
= exit_code
;
2157 info
.si_pid
= task_pid_vnr(current
);
2158 info
.si_uid
= from_kuid_munged(current_user_ns(), current_uid());
2160 /* Let the debugger run. */
2161 ptrace_stop(exit_code
, why
, 1, &info
);
2164 void ptrace_notify(int exit_code
)
2166 BUG_ON((exit_code
& (0x7f | ~0xffff)) != SIGTRAP
);
2167 if (unlikely(current
->task_works
))
2170 spin_lock_irq(¤t
->sighand
->siglock
);
2171 ptrace_do_notify(SIGTRAP
, exit_code
, CLD_TRAPPED
);
2172 spin_unlock_irq(¤t
->sighand
->siglock
);
2176 * do_signal_stop - handle group stop for SIGSTOP and other stop signals
2177 * @signr: signr causing group stop if initiating
2179 * If %JOBCTL_STOP_PENDING is not set yet, initiate group stop with @signr
2180 * and participate in it. If already set, participate in the existing
2181 * group stop. If participated in a group stop (and thus slept), %true is
2182 * returned with siglock released.
2184 * If ptraced, this function doesn't handle stop itself. Instead,
2185 * %JOBCTL_TRAP_STOP is scheduled and %false is returned with siglock
2186 * untouched. The caller must ensure that INTERRUPT trap handling takes
2187 * places afterwards.
2190 * Must be called with @current->sighand->siglock held, which is released
2194 * %false if group stop is already cancelled or ptrace trap is scheduled.
2195 * %true if participated in group stop.
2197 static bool do_signal_stop(int signr
)
2198 __releases(¤t
->sighand
->siglock
)
2200 struct signal_struct
*sig
= current
->signal
;
2202 if (!(current
->jobctl
& JOBCTL_STOP_PENDING
)) {
2203 unsigned long gstop
= JOBCTL_STOP_PENDING
| JOBCTL_STOP_CONSUME
;
2204 struct task_struct
*t
;
2206 /* signr will be recorded in task->jobctl for retries */
2207 WARN_ON_ONCE(signr
& ~JOBCTL_STOP_SIGMASK
);
2209 if (!likely(current
->jobctl
& JOBCTL_STOP_DEQUEUED
) ||
2210 unlikely(signal_group_exit(sig
)))
2213 * There is no group stop already in progress. We must
2216 * While ptraced, a task may be resumed while group stop is
2217 * still in effect and then receive a stop signal and
2218 * initiate another group stop. This deviates from the
2219 * usual behavior as two consecutive stop signals can't
2220 * cause two group stops when !ptraced. That is why we
2221 * also check !task_is_stopped(t) below.
2223 * The condition can be distinguished by testing whether
2224 * SIGNAL_STOP_STOPPED is already set. Don't generate
2225 * group_exit_code in such case.
2227 * This is not necessary for SIGNAL_STOP_CONTINUED because
2228 * an intervening stop signal is required to cause two
2229 * continued events regardless of ptrace.
2231 if (!(sig
->flags
& SIGNAL_STOP_STOPPED
))
2232 sig
->group_exit_code
= signr
;
2234 sig
->group_stop_count
= 0;
2236 if (task_set_jobctl_pending(current
, signr
| gstop
))
2237 sig
->group_stop_count
++;
2240 while_each_thread(current
, t
) {
2242 * Setting state to TASK_STOPPED for a group
2243 * stop is always done with the siglock held,
2244 * so this check has no races.
2246 if (!task_is_stopped(t
) &&
2247 task_set_jobctl_pending(t
, signr
| gstop
)) {
2248 sig
->group_stop_count
++;
2249 if (likely(!(t
->ptrace
& PT_SEIZED
)))
2250 signal_wake_up(t
, 0);
2252 ptrace_trap_notify(t
);
2257 if (likely(!current
->ptrace
)) {
2261 * If there are no other threads in the group, or if there
2262 * is a group stop in progress and we are the last to stop,
2263 * report to the parent.
2265 if (task_participate_group_stop(current
))
2266 notify
= CLD_STOPPED
;
2268 set_special_state(TASK_STOPPED
);
2269 spin_unlock_irq(¤t
->sighand
->siglock
);
2272 * Notify the parent of the group stop completion. Because
2273 * we're not holding either the siglock or tasklist_lock
2274 * here, ptracer may attach inbetween; however, this is for
2275 * group stop and should always be delivered to the real
2276 * parent of the group leader. The new ptracer will get
2277 * its notification when this task transitions into
2281 read_lock(&tasklist_lock
);
2282 do_notify_parent_cldstop(current
, false, notify
);
2283 read_unlock(&tasklist_lock
);
2286 /* Now we don't run again until woken by SIGCONT or SIGKILL */
2287 freezable_schedule();
2291 * While ptraced, group stop is handled by STOP trap.
2292 * Schedule it and let the caller deal with it.
2294 task_set_jobctl_pending(current
, JOBCTL_TRAP_STOP
);
2300 * do_jobctl_trap - take care of ptrace jobctl traps
2302 * When PT_SEIZED, it's used for both group stop and explicit
2303 * SEIZE/INTERRUPT traps. Both generate PTRACE_EVENT_STOP trap with
2304 * accompanying siginfo. If stopped, lower eight bits of exit_code contain
2305 * the stop signal; otherwise, %SIGTRAP.
2307 * When !PT_SEIZED, it's used only for group stop trap with stop signal
2308 * number as exit_code and no siginfo.
2311 * Must be called with @current->sighand->siglock held, which may be
2312 * released and re-acquired before returning with intervening sleep.
2314 static void do_jobctl_trap(void)
2316 struct signal_struct
*signal
= current
->signal
;
2317 int signr
= current
->jobctl
& JOBCTL_STOP_SIGMASK
;
2319 if (current
->ptrace
& PT_SEIZED
) {
2320 if (!signal
->group_stop_count
&&
2321 !(signal
->flags
& SIGNAL_STOP_STOPPED
))
2323 WARN_ON_ONCE(!signr
);
2324 ptrace_do_notify(signr
, signr
| (PTRACE_EVENT_STOP
<< 8),
2327 WARN_ON_ONCE(!signr
);
2328 ptrace_stop(signr
, CLD_STOPPED
, 0, NULL
);
2329 current
->exit_code
= 0;
2333 static int ptrace_signal(int signr
, kernel_siginfo_t
*info
)
2336 * We do not check sig_kernel_stop(signr) but set this marker
2337 * unconditionally because we do not know whether debugger will
2338 * change signr. This flag has no meaning unless we are going
2339 * to stop after return from ptrace_stop(). In this case it will
2340 * be checked in do_signal_stop(), we should only stop if it was
2341 * not cleared by SIGCONT while we were sleeping. See also the
2342 * comment in dequeue_signal().
2344 current
->jobctl
|= JOBCTL_STOP_DEQUEUED
;
2345 ptrace_stop(signr
, CLD_TRAPPED
, 0, info
);
2347 /* We're back. Did the debugger cancel the sig? */
2348 signr
= current
->exit_code
;
2352 current
->exit_code
= 0;
2355 * Update the siginfo structure if the signal has
2356 * changed. If the debugger wanted something
2357 * specific in the siginfo structure then it should
2358 * have updated *info via PTRACE_SETSIGINFO.
2360 if (signr
!= info
->si_signo
) {
2361 clear_siginfo(info
);
2362 info
->si_signo
= signr
;
2364 info
->si_code
= SI_USER
;
2366 info
->si_pid
= task_pid_vnr(current
->parent
);
2367 info
->si_uid
= from_kuid_munged(current_user_ns(),
2368 task_uid(current
->parent
));
2372 /* If the (new) signal is now blocked, requeue it. */
2373 if (sigismember(¤t
->blocked
, signr
)) {
2374 send_signal(signr
, info
, current
, PIDTYPE_PID
);
2381 bool get_signal(struct ksignal
*ksig
)
2383 struct sighand_struct
*sighand
= current
->sighand
;
2384 struct signal_struct
*signal
= current
->signal
;
2387 if (unlikely(current
->task_works
))
2390 if (unlikely(uprobe_deny_signal()))
2394 * Do this once, we can't return to user-mode if freezing() == T.
2395 * do_signal_stop() and ptrace_stop() do freezable_schedule() and
2396 * thus do not need another check after return.
2401 spin_lock_irq(&sighand
->siglock
);
2403 * Every stopped thread goes here after wakeup. Check to see if
2404 * we should notify the parent, prepare_signal(SIGCONT) encodes
2405 * the CLD_ si_code into SIGNAL_CLD_MASK bits.
2407 if (unlikely(signal
->flags
& SIGNAL_CLD_MASK
)) {
2410 if (signal
->flags
& SIGNAL_CLD_CONTINUED
)
2411 why
= CLD_CONTINUED
;
2415 signal
->flags
&= ~SIGNAL_CLD_MASK
;
2417 spin_unlock_irq(&sighand
->siglock
);
2420 * Notify the parent that we're continuing. This event is
2421 * always per-process and doesn't make whole lot of sense
2422 * for ptracers, who shouldn't consume the state via
2423 * wait(2) either, but, for backward compatibility, notify
2424 * the ptracer of the group leader too unless it's gonna be
2427 read_lock(&tasklist_lock
);
2428 do_notify_parent_cldstop(current
, false, why
);
2430 if (ptrace_reparented(current
->group_leader
))
2431 do_notify_parent_cldstop(current
->group_leader
,
2433 read_unlock(&tasklist_lock
);
2438 /* Has this task already been marked for death? */
2439 if (signal_group_exit(signal
)) {
2440 ksig
->info
.si_signo
= signr
= SIGKILL
;
2441 sigdelset(¤t
->pending
.signal
, SIGKILL
);
2442 recalc_sigpending();
2447 struct k_sigaction
*ka
;
2449 if (unlikely(current
->jobctl
& JOBCTL_STOP_PENDING
) &&
2453 if (unlikely(current
->jobctl
& JOBCTL_TRAP_MASK
)) {
2455 spin_unlock_irq(&sighand
->siglock
);
2460 * Signals generated by the execution of an instruction
2461 * need to be delivered before any other pending signals
2462 * so that the instruction pointer in the signal stack
2463 * frame points to the faulting instruction.
2465 signr
= dequeue_synchronous_signal(&ksig
->info
);
2467 signr
= dequeue_signal(current
, ¤t
->blocked
, &ksig
->info
);
2470 break; /* will return 0 */
2472 if (unlikely(current
->ptrace
) && signr
!= SIGKILL
) {
2473 signr
= ptrace_signal(signr
, &ksig
->info
);
2478 ka
= &sighand
->action
[signr
-1];
2480 /* Trace actually delivered signals. */
2481 trace_signal_deliver(signr
, &ksig
->info
, ka
);
2483 if (ka
->sa
.sa_handler
== SIG_IGN
) /* Do nothing. */
2485 if (ka
->sa
.sa_handler
!= SIG_DFL
) {
2486 /* Run the handler. */
2489 if (ka
->sa
.sa_flags
& SA_ONESHOT
)
2490 ka
->sa
.sa_handler
= SIG_DFL
;
2492 break; /* will return non-zero "signr" value */
2496 * Now we are doing the default action for this signal.
2498 if (sig_kernel_ignore(signr
)) /* Default is nothing. */
2502 * Global init gets no signals it doesn't want.
2503 * Container-init gets no signals it doesn't want from same
2506 * Note that if global/container-init sees a sig_kernel_only()
2507 * signal here, the signal must have been generated internally
2508 * or must have come from an ancestor namespace. In either
2509 * case, the signal cannot be dropped.
2511 if (unlikely(signal
->flags
& SIGNAL_UNKILLABLE
) &&
2512 !sig_kernel_only(signr
))
2515 if (sig_kernel_stop(signr
)) {
2517 * The default action is to stop all threads in
2518 * the thread group. The job control signals
2519 * do nothing in an orphaned pgrp, but SIGSTOP
2520 * always works. Note that siglock needs to be
2521 * dropped during the call to is_orphaned_pgrp()
2522 * because of lock ordering with tasklist_lock.
2523 * This allows an intervening SIGCONT to be posted.
2524 * We need to check for that and bail out if necessary.
2526 if (signr
!= SIGSTOP
) {
2527 spin_unlock_irq(&sighand
->siglock
);
2529 /* signals can be posted during this window */
2531 if (is_current_pgrp_orphaned())
2534 spin_lock_irq(&sighand
->siglock
);
2537 if (likely(do_signal_stop(ksig
->info
.si_signo
))) {
2538 /* It released the siglock. */
2543 * We didn't actually stop, due to a race
2544 * with SIGCONT or something like that.
2550 spin_unlock_irq(&sighand
->siglock
);
2553 * Anything else is fatal, maybe with a core dump.
2555 current
->flags
|= PF_SIGNALED
;
2557 if (sig_kernel_coredump(signr
)) {
2558 if (print_fatal_signals
)
2559 print_fatal_signal(ksig
->info
.si_signo
);
2560 proc_coredump_connector(current
);
2562 * If it was able to dump core, this kills all
2563 * other threads in the group and synchronizes with
2564 * their demise. If we lost the race with another
2565 * thread getting here, it set group_exit_code
2566 * first and our do_group_exit call below will use
2567 * that value and ignore the one we pass it.
2569 do_coredump(&ksig
->info
);
2573 * Death signals, no core dump.
2575 do_group_exit(ksig
->info
.si_signo
);
2578 spin_unlock_irq(&sighand
->siglock
);
2581 return ksig
->sig
> 0;
2585 * signal_delivered -
2586 * @ksig: kernel signal struct
2587 * @stepping: nonzero if debugger single-step or block-step in use
2589 * This function should be called when a signal has successfully been
2590 * delivered. It updates the blocked signals accordingly (@ksig->ka.sa.sa_mask
2591 * is always blocked, and the signal itself is blocked unless %SA_NODEFER
2592 * is set in @ksig->ka.sa.sa_flags. Tracing is notified.
2594 static void signal_delivered(struct ksignal
*ksig
, int stepping
)
2598 /* A signal was successfully delivered, and the
2599 saved sigmask was stored on the signal frame,
2600 and will be restored by sigreturn. So we can
2601 simply clear the restore sigmask flag. */
2602 clear_restore_sigmask();
2604 sigorsets(&blocked
, ¤t
->blocked
, &ksig
->ka
.sa
.sa_mask
);
2605 if (!(ksig
->ka
.sa
.sa_flags
& SA_NODEFER
))
2606 sigaddset(&blocked
, ksig
->sig
);
2607 set_current_blocked(&blocked
);
2608 tracehook_signal_handler(stepping
);
2611 void signal_setup_done(int failed
, struct ksignal
*ksig
, int stepping
)
2614 force_sigsegv(ksig
->sig
, current
);
2616 signal_delivered(ksig
, stepping
);
2620 * It could be that complete_signal() picked us to notify about the
2621 * group-wide signal. Other threads should be notified now to take
2622 * the shared signals in @which since we will not.
2624 static void retarget_shared_pending(struct task_struct
*tsk
, sigset_t
*which
)
2627 struct task_struct
*t
;
2629 sigandsets(&retarget
, &tsk
->signal
->shared_pending
.signal
, which
);
2630 if (sigisemptyset(&retarget
))
2634 while_each_thread(tsk
, t
) {
2635 if (t
->flags
& PF_EXITING
)
2638 if (!has_pending_signals(&retarget
, &t
->blocked
))
2640 /* Remove the signals this thread can handle. */
2641 sigandsets(&retarget
, &retarget
, &t
->blocked
);
2643 if (!signal_pending(t
))
2644 signal_wake_up(t
, 0);
2646 if (sigisemptyset(&retarget
))
2651 void exit_signals(struct task_struct
*tsk
)
2657 * @tsk is about to have PF_EXITING set - lock out users which
2658 * expect stable threadgroup.
2660 cgroup_threadgroup_change_begin(tsk
);
2662 if (thread_group_empty(tsk
) || signal_group_exit(tsk
->signal
)) {
2663 tsk
->flags
|= PF_EXITING
;
2664 cgroup_threadgroup_change_end(tsk
);
2668 spin_lock_irq(&tsk
->sighand
->siglock
);
2670 * From now this task is not visible for group-wide signals,
2671 * see wants_signal(), do_signal_stop().
2673 tsk
->flags
|= PF_EXITING
;
2675 cgroup_threadgroup_change_end(tsk
);
2677 if (!signal_pending(tsk
))
2680 unblocked
= tsk
->blocked
;
2681 signotset(&unblocked
);
2682 retarget_shared_pending(tsk
, &unblocked
);
2684 if (unlikely(tsk
->jobctl
& JOBCTL_STOP_PENDING
) &&
2685 task_participate_group_stop(tsk
))
2686 group_stop
= CLD_STOPPED
;
2688 spin_unlock_irq(&tsk
->sighand
->siglock
);
2691 * If group stop has completed, deliver the notification. This
2692 * should always go to the real parent of the group leader.
2694 if (unlikely(group_stop
)) {
2695 read_lock(&tasklist_lock
);
2696 do_notify_parent_cldstop(tsk
, false, group_stop
);
2697 read_unlock(&tasklist_lock
);
2702 * System call entry points.
2706 * sys_restart_syscall - restart a system call
2708 SYSCALL_DEFINE0(restart_syscall
)
2710 struct restart_block
*restart
= ¤t
->restart_block
;
2711 return restart
->fn(restart
);
2714 long do_no_restart_syscall(struct restart_block
*param
)
2719 static void __set_task_blocked(struct task_struct
*tsk
, const sigset_t
*newset
)
2721 if (signal_pending(tsk
) && !thread_group_empty(tsk
)) {
2722 sigset_t newblocked
;
2723 /* A set of now blocked but previously unblocked signals. */
2724 sigandnsets(&newblocked
, newset
, ¤t
->blocked
);
2725 retarget_shared_pending(tsk
, &newblocked
);
2727 tsk
->blocked
= *newset
;
2728 recalc_sigpending();
2732 * set_current_blocked - change current->blocked mask
2735 * It is wrong to change ->blocked directly, this helper should be used
2736 * to ensure the process can't miss a shared signal we are going to block.
2738 void set_current_blocked(sigset_t
*newset
)
2740 sigdelsetmask(newset
, sigmask(SIGKILL
) | sigmask(SIGSTOP
));
2741 __set_current_blocked(newset
);
2744 void __set_current_blocked(const sigset_t
*newset
)
2746 struct task_struct
*tsk
= current
;
2749 * In case the signal mask hasn't changed, there is nothing we need
2750 * to do. The current->blocked shouldn't be modified by other task.
2752 if (sigequalsets(&tsk
->blocked
, newset
))
2755 spin_lock_irq(&tsk
->sighand
->siglock
);
2756 __set_task_blocked(tsk
, newset
);
2757 spin_unlock_irq(&tsk
->sighand
->siglock
);
2761 * This is also useful for kernel threads that want to temporarily
2762 * (or permanently) block certain signals.
2764 * NOTE! Unlike the user-mode sys_sigprocmask(), the kernel
2765 * interface happily blocks "unblockable" signals like SIGKILL
2768 int sigprocmask(int how
, sigset_t
*set
, sigset_t
*oldset
)
2770 struct task_struct
*tsk
= current
;
2773 /* Lockless, only current can change ->blocked, never from irq */
2775 *oldset
= tsk
->blocked
;
2779 sigorsets(&newset
, &tsk
->blocked
, set
);
2782 sigandnsets(&newset
, &tsk
->blocked
, set
);
2791 __set_current_blocked(&newset
);
2794 EXPORT_SYMBOL(sigprocmask
);
2797 * The api helps set app-provided sigmasks.
2799 * This is useful for syscalls such as ppoll, pselect, io_pgetevents and
2800 * epoll_pwait where a new sigmask is passed from userland for the syscalls.
2802 int set_user_sigmask(const sigset_t __user
*usigmask
, sigset_t
*set
,
2803 sigset_t
*oldset
, size_t sigsetsize
)
2808 if (sigsetsize
!= sizeof(sigset_t
))
2810 if (copy_from_user(set
, usigmask
, sizeof(sigset_t
)))
2813 *oldset
= current
->blocked
;
2814 set_current_blocked(set
);
2818 EXPORT_SYMBOL(set_user_sigmask
);
2820 #ifdef CONFIG_COMPAT
2821 int set_compat_user_sigmask(const compat_sigset_t __user
*usigmask
,
2822 sigset_t
*set
, sigset_t
*oldset
,
2828 if (sigsetsize
!= sizeof(compat_sigset_t
))
2830 if (get_compat_sigset(set
, usigmask
))
2833 *oldset
= current
->blocked
;
2834 set_current_blocked(set
);
2838 EXPORT_SYMBOL(set_compat_user_sigmask
);
2842 * restore_user_sigmask:
2843 * usigmask: sigmask passed in from userland.
2844 * sigsaved: saved sigmask when the syscall started and changed the sigmask to
2847 * This is useful for syscalls such as ppoll, pselect, io_pgetevents and
2848 * epoll_pwait where a new sigmask is passed in from userland for the syscalls.
2850 void restore_user_sigmask(const void __user
*usigmask
, sigset_t
*sigsaved
)
2856 * When signals are pending, do not restore them here.
2857 * Restoring sigmask here can lead to delivering signals that the above
2858 * syscalls are intended to block because of the sigmask passed in.
2860 if (signal_pending(current
)) {
2861 current
->saved_sigmask
= *sigsaved
;
2862 set_restore_sigmask();
2867 * This is needed because the fast syscall return path does not restore
2868 * saved_sigmask when signals are not pending.
2870 set_current_blocked(sigsaved
);
2872 EXPORT_SYMBOL(restore_user_sigmask
);
2875 * sys_rt_sigprocmask - change the list of currently blocked signals
2876 * @how: whether to add, remove, or set signals
2877 * @nset: stores pending signals
2878 * @oset: previous value of signal mask if non-null
2879 * @sigsetsize: size of sigset_t type
2881 SYSCALL_DEFINE4(rt_sigprocmask
, int, how
, sigset_t __user
*, nset
,
2882 sigset_t __user
*, oset
, size_t, sigsetsize
)
2884 sigset_t old_set
, new_set
;
2887 /* XXX: Don't preclude handling different sized sigset_t's. */
2888 if (sigsetsize
!= sizeof(sigset_t
))
2891 old_set
= current
->blocked
;
2894 if (copy_from_user(&new_set
, nset
, sizeof(sigset_t
)))
2896 sigdelsetmask(&new_set
, sigmask(SIGKILL
)|sigmask(SIGSTOP
));
2898 error
= sigprocmask(how
, &new_set
, NULL
);
2904 if (copy_to_user(oset
, &old_set
, sizeof(sigset_t
)))
2911 #ifdef CONFIG_COMPAT
2912 COMPAT_SYSCALL_DEFINE4(rt_sigprocmask
, int, how
, compat_sigset_t __user
*, nset
,
2913 compat_sigset_t __user
*, oset
, compat_size_t
, sigsetsize
)
2915 sigset_t old_set
= current
->blocked
;
2917 /* XXX: Don't preclude handling different sized sigset_t's. */
2918 if (sigsetsize
!= sizeof(sigset_t
))
2924 if (get_compat_sigset(&new_set
, nset
))
2926 sigdelsetmask(&new_set
, sigmask(SIGKILL
)|sigmask(SIGSTOP
));
2928 error
= sigprocmask(how
, &new_set
, NULL
);
2932 return oset
? put_compat_sigset(oset
, &old_set
, sizeof(*oset
)) : 0;
2936 static void do_sigpending(sigset_t
*set
)
2938 spin_lock_irq(¤t
->sighand
->siglock
);
2939 sigorsets(set
, ¤t
->pending
.signal
,
2940 ¤t
->signal
->shared_pending
.signal
);
2941 spin_unlock_irq(¤t
->sighand
->siglock
);
2943 /* Outside the lock because only this thread touches it. */
2944 sigandsets(set
, ¤t
->blocked
, set
);
2948 * sys_rt_sigpending - examine a pending signal that has been raised
2950 * @uset: stores pending signals
2951 * @sigsetsize: size of sigset_t type or larger
2953 SYSCALL_DEFINE2(rt_sigpending
, sigset_t __user
*, uset
, size_t, sigsetsize
)
2957 if (sigsetsize
> sizeof(*uset
))
2960 do_sigpending(&set
);
2962 if (copy_to_user(uset
, &set
, sigsetsize
))
2968 #ifdef CONFIG_COMPAT
2969 COMPAT_SYSCALL_DEFINE2(rt_sigpending
, compat_sigset_t __user
*, uset
,
2970 compat_size_t
, sigsetsize
)
2974 if (sigsetsize
> sizeof(*uset
))
2977 do_sigpending(&set
);
2979 return put_compat_sigset(uset
, &set
, sigsetsize
);
2983 static const struct {
2984 unsigned char limit
, layout
;
2986 [SIGILL
] = { NSIGILL
, SIL_FAULT
},
2987 [SIGFPE
] = { NSIGFPE
, SIL_FAULT
},
2988 [SIGSEGV
] = { NSIGSEGV
, SIL_FAULT
},
2989 [SIGBUS
] = { NSIGBUS
, SIL_FAULT
},
2990 [SIGTRAP
] = { NSIGTRAP
, SIL_FAULT
},
2992 [SIGEMT
] = { NSIGEMT
, SIL_FAULT
},
2994 [SIGCHLD
] = { NSIGCHLD
, SIL_CHLD
},
2995 [SIGPOLL
] = { NSIGPOLL
, SIL_POLL
},
2996 [SIGSYS
] = { NSIGSYS
, SIL_SYS
},
2999 static bool known_siginfo_layout(unsigned sig
, int si_code
)
3001 if (si_code
== SI_KERNEL
)
3003 else if ((si_code
> SI_USER
)) {
3004 if (sig_specific_sicodes(sig
)) {
3005 if (si_code
<= sig_sicodes
[sig
].limit
)
3008 else if (si_code
<= NSIGPOLL
)
3011 else if (si_code
>= SI_DETHREAD
)
3013 else if (si_code
== SI_ASYNCNL
)
3018 enum siginfo_layout
siginfo_layout(unsigned sig
, int si_code
)
3020 enum siginfo_layout layout
= SIL_KILL
;
3021 if ((si_code
> SI_USER
) && (si_code
< SI_KERNEL
)) {
3022 if ((sig
< ARRAY_SIZE(sig_sicodes
)) &&
3023 (si_code
<= sig_sicodes
[sig
].limit
)) {
3024 layout
= sig_sicodes
[sig
].layout
;
3025 /* Handle the exceptions */
3026 if ((sig
== SIGBUS
) &&
3027 (si_code
>= BUS_MCEERR_AR
) && (si_code
<= BUS_MCEERR_AO
))
3028 layout
= SIL_FAULT_MCEERR
;
3029 else if ((sig
== SIGSEGV
) && (si_code
== SEGV_BNDERR
))
3030 layout
= SIL_FAULT_BNDERR
;
3032 else if ((sig
== SIGSEGV
) && (si_code
== SEGV_PKUERR
))
3033 layout
= SIL_FAULT_PKUERR
;
3036 else if (si_code
<= NSIGPOLL
)
3039 if (si_code
== SI_TIMER
)
3041 else if (si_code
== SI_SIGIO
)
3043 else if (si_code
< 0)
3049 static inline char __user
*si_expansion(const siginfo_t __user
*info
)
3051 return ((char __user
*)info
) + sizeof(struct kernel_siginfo
);
3054 int copy_siginfo_to_user(siginfo_t __user
*to
, const kernel_siginfo_t
*from
)
3056 char __user
*expansion
= si_expansion(to
);
3057 if (copy_to_user(to
, from
, sizeof(struct kernel_siginfo
)))
3059 if (clear_user(expansion
, SI_EXPANSION_SIZE
))
3064 static int post_copy_siginfo_from_user(kernel_siginfo_t
*info
,
3065 const siginfo_t __user
*from
)
3067 if (unlikely(!known_siginfo_layout(info
->si_signo
, info
->si_code
))) {
3068 char __user
*expansion
= si_expansion(from
);
3069 char buf
[SI_EXPANSION_SIZE
];
3072 * An unknown si_code might need more than
3073 * sizeof(struct kernel_siginfo) bytes. Verify all of the
3074 * extra bytes are 0. This guarantees copy_siginfo_to_user
3075 * will return this data to userspace exactly.
3077 if (copy_from_user(&buf
, expansion
, SI_EXPANSION_SIZE
))
3079 for (i
= 0; i
< SI_EXPANSION_SIZE
; i
++) {
3087 static int __copy_siginfo_from_user(int signo
, kernel_siginfo_t
*to
,
3088 const siginfo_t __user
*from
)
3090 if (copy_from_user(to
, from
, sizeof(struct kernel_siginfo
)))
3092 to
->si_signo
= signo
;
3093 return post_copy_siginfo_from_user(to
, from
);
3096 int copy_siginfo_from_user(kernel_siginfo_t
*to
, const siginfo_t __user
*from
)
3098 if (copy_from_user(to
, from
, sizeof(struct kernel_siginfo
)))
3100 return post_copy_siginfo_from_user(to
, from
);
3103 #ifdef CONFIG_COMPAT
3104 int copy_siginfo_to_user32(struct compat_siginfo __user
*to
,
3105 const struct kernel_siginfo
*from
)
3106 #if defined(CONFIG_X86_X32_ABI) || defined(CONFIG_IA32_EMULATION)
3108 return __copy_siginfo_to_user32(to
, from
, in_x32_syscall());
3110 int __copy_siginfo_to_user32(struct compat_siginfo __user
*to
,
3111 const struct kernel_siginfo
*from
, bool x32_ABI
)
3114 struct compat_siginfo
new;
3115 memset(&new, 0, sizeof(new));
3117 new.si_signo
= from
->si_signo
;
3118 new.si_errno
= from
->si_errno
;
3119 new.si_code
= from
->si_code
;
3120 switch(siginfo_layout(from
->si_signo
, from
->si_code
)) {
3122 new.si_pid
= from
->si_pid
;
3123 new.si_uid
= from
->si_uid
;
3126 new.si_tid
= from
->si_tid
;
3127 new.si_overrun
= from
->si_overrun
;
3128 new.si_int
= from
->si_int
;
3131 new.si_band
= from
->si_band
;
3132 new.si_fd
= from
->si_fd
;
3135 new.si_addr
= ptr_to_compat(from
->si_addr
);
3136 #ifdef __ARCH_SI_TRAPNO
3137 new.si_trapno
= from
->si_trapno
;
3140 case SIL_FAULT_MCEERR
:
3141 new.si_addr
= ptr_to_compat(from
->si_addr
);
3142 #ifdef __ARCH_SI_TRAPNO
3143 new.si_trapno
= from
->si_trapno
;
3145 new.si_addr_lsb
= from
->si_addr_lsb
;
3147 case SIL_FAULT_BNDERR
:
3148 new.si_addr
= ptr_to_compat(from
->si_addr
);
3149 #ifdef __ARCH_SI_TRAPNO
3150 new.si_trapno
= from
->si_trapno
;
3152 new.si_lower
= ptr_to_compat(from
->si_lower
);
3153 new.si_upper
= ptr_to_compat(from
->si_upper
);
3155 case SIL_FAULT_PKUERR
:
3156 new.si_addr
= ptr_to_compat(from
->si_addr
);
3157 #ifdef __ARCH_SI_TRAPNO
3158 new.si_trapno
= from
->si_trapno
;
3160 new.si_pkey
= from
->si_pkey
;
3163 new.si_pid
= from
->si_pid
;
3164 new.si_uid
= from
->si_uid
;
3165 new.si_status
= from
->si_status
;
3166 #ifdef CONFIG_X86_X32_ABI
3168 new._sifields
._sigchld_x32
._utime
= from
->si_utime
;
3169 new._sifields
._sigchld_x32
._stime
= from
->si_stime
;
3173 new.si_utime
= from
->si_utime
;
3174 new.si_stime
= from
->si_stime
;
3178 new.si_pid
= from
->si_pid
;
3179 new.si_uid
= from
->si_uid
;
3180 new.si_int
= from
->si_int
;
3183 new.si_call_addr
= ptr_to_compat(from
->si_call_addr
);
3184 new.si_syscall
= from
->si_syscall
;
3185 new.si_arch
= from
->si_arch
;
3189 if (copy_to_user(to
, &new, sizeof(struct compat_siginfo
)))
3195 static int post_copy_siginfo_from_user32(kernel_siginfo_t
*to
,
3196 const struct compat_siginfo
*from
)
3199 to
->si_signo
= from
->si_signo
;
3200 to
->si_errno
= from
->si_errno
;
3201 to
->si_code
= from
->si_code
;
3202 switch(siginfo_layout(from
->si_signo
, from
->si_code
)) {
3204 to
->si_pid
= from
->si_pid
;
3205 to
->si_uid
= from
->si_uid
;
3208 to
->si_tid
= from
->si_tid
;
3209 to
->si_overrun
= from
->si_overrun
;
3210 to
->si_int
= from
->si_int
;
3213 to
->si_band
= from
->si_band
;
3214 to
->si_fd
= from
->si_fd
;
3217 to
->si_addr
= compat_ptr(from
->si_addr
);
3218 #ifdef __ARCH_SI_TRAPNO
3219 to
->si_trapno
= from
->si_trapno
;
3222 case SIL_FAULT_MCEERR
:
3223 to
->si_addr
= compat_ptr(from
->si_addr
);
3224 #ifdef __ARCH_SI_TRAPNO
3225 to
->si_trapno
= from
->si_trapno
;
3227 to
->si_addr_lsb
= from
->si_addr_lsb
;
3229 case SIL_FAULT_BNDERR
:
3230 to
->si_addr
= compat_ptr(from
->si_addr
);
3231 #ifdef __ARCH_SI_TRAPNO
3232 to
->si_trapno
= from
->si_trapno
;
3234 to
->si_lower
= compat_ptr(from
->si_lower
);
3235 to
->si_upper
= compat_ptr(from
->si_upper
);
3237 case SIL_FAULT_PKUERR
:
3238 to
->si_addr
= compat_ptr(from
->si_addr
);
3239 #ifdef __ARCH_SI_TRAPNO
3240 to
->si_trapno
= from
->si_trapno
;
3242 to
->si_pkey
= from
->si_pkey
;
3245 to
->si_pid
= from
->si_pid
;
3246 to
->si_uid
= from
->si_uid
;
3247 to
->si_status
= from
->si_status
;
3248 #ifdef CONFIG_X86_X32_ABI
3249 if (in_x32_syscall()) {
3250 to
->si_utime
= from
->_sifields
._sigchld_x32
._utime
;
3251 to
->si_stime
= from
->_sifields
._sigchld_x32
._stime
;
3255 to
->si_utime
= from
->si_utime
;
3256 to
->si_stime
= from
->si_stime
;
3260 to
->si_pid
= from
->si_pid
;
3261 to
->si_uid
= from
->si_uid
;
3262 to
->si_int
= from
->si_int
;
3265 to
->si_call_addr
= compat_ptr(from
->si_call_addr
);
3266 to
->si_syscall
= from
->si_syscall
;
3267 to
->si_arch
= from
->si_arch
;
3273 static int __copy_siginfo_from_user32(int signo
, struct kernel_siginfo
*to
,
3274 const struct compat_siginfo __user
*ufrom
)
3276 struct compat_siginfo from
;
3278 if (copy_from_user(&from
, ufrom
, sizeof(struct compat_siginfo
)))
3281 from
.si_signo
= signo
;
3282 return post_copy_siginfo_from_user32(to
, &from
);
3285 int copy_siginfo_from_user32(struct kernel_siginfo
*to
,
3286 const struct compat_siginfo __user
*ufrom
)
3288 struct compat_siginfo from
;
3290 if (copy_from_user(&from
, ufrom
, sizeof(struct compat_siginfo
)))
3293 return post_copy_siginfo_from_user32(to
, &from
);
3295 #endif /* CONFIG_COMPAT */
3298 * do_sigtimedwait - wait for queued signals specified in @which
3299 * @which: queued signals to wait for
3300 * @info: if non-null, the signal's siginfo is returned here
3301 * @ts: upper bound on process time suspension
3303 static int do_sigtimedwait(const sigset_t
*which
, kernel_siginfo_t
*info
,
3304 const struct timespec64
*ts
)
3306 ktime_t
*to
= NULL
, timeout
= KTIME_MAX
;
3307 struct task_struct
*tsk
= current
;
3308 sigset_t mask
= *which
;
3312 if (!timespec64_valid(ts
))
3314 timeout
= timespec64_to_ktime(*ts
);
3319 * Invert the set of allowed signals to get those we want to block.
3321 sigdelsetmask(&mask
, sigmask(SIGKILL
) | sigmask(SIGSTOP
));
3324 spin_lock_irq(&tsk
->sighand
->siglock
);
3325 sig
= dequeue_signal(tsk
, &mask
, info
);
3326 if (!sig
&& timeout
) {
3328 * None ready, temporarily unblock those we're interested
3329 * while we are sleeping in so that we'll be awakened when
3330 * they arrive. Unblocking is always fine, we can avoid
3331 * set_current_blocked().
3333 tsk
->real_blocked
= tsk
->blocked
;
3334 sigandsets(&tsk
->blocked
, &tsk
->blocked
, &mask
);
3335 recalc_sigpending();
3336 spin_unlock_irq(&tsk
->sighand
->siglock
);
3338 __set_current_state(TASK_INTERRUPTIBLE
);
3339 ret
= freezable_schedule_hrtimeout_range(to
, tsk
->timer_slack_ns
,
3341 spin_lock_irq(&tsk
->sighand
->siglock
);
3342 __set_task_blocked(tsk
, &tsk
->real_blocked
);
3343 sigemptyset(&tsk
->real_blocked
);
3344 sig
= dequeue_signal(tsk
, &mask
, info
);
3346 spin_unlock_irq(&tsk
->sighand
->siglock
);
3350 return ret
? -EINTR
: -EAGAIN
;
3354 * sys_rt_sigtimedwait - synchronously wait for queued signals specified
3356 * @uthese: queued signals to wait for
3357 * @uinfo: if non-null, the signal's siginfo is returned here
3358 * @uts: upper bound on process time suspension
3359 * @sigsetsize: size of sigset_t type
3361 SYSCALL_DEFINE4(rt_sigtimedwait
, const sigset_t __user
*, uthese
,
3362 siginfo_t __user
*, uinfo
,
3363 const struct __kernel_timespec __user
*, uts
,
3367 struct timespec64 ts
;
3368 kernel_siginfo_t info
;
3371 /* XXX: Don't preclude handling different sized sigset_t's. */
3372 if (sigsetsize
!= sizeof(sigset_t
))
3375 if (copy_from_user(&these
, uthese
, sizeof(these
)))
3379 if (get_timespec64(&ts
, uts
))
3383 ret
= do_sigtimedwait(&these
, &info
, uts
? &ts
: NULL
);
3385 if (ret
> 0 && uinfo
) {
3386 if (copy_siginfo_to_user(uinfo
, &info
))
3393 #ifdef CONFIG_COMPAT_32BIT_TIME
3394 SYSCALL_DEFINE4(rt_sigtimedwait_time32
, const sigset_t __user
*, uthese
,
3395 siginfo_t __user
*, uinfo
,
3396 const struct old_timespec32 __user
*, uts
,
3400 struct timespec64 ts
;
3401 kernel_siginfo_t info
;
3404 if (sigsetsize
!= sizeof(sigset_t
))
3407 if (copy_from_user(&these
, uthese
, sizeof(these
)))
3411 if (get_old_timespec32(&ts
, uts
))
3415 ret
= do_sigtimedwait(&these
, &info
, uts
? &ts
: NULL
);
3417 if (ret
> 0 && uinfo
) {
3418 if (copy_siginfo_to_user(uinfo
, &info
))
3426 #ifdef CONFIG_COMPAT
3427 COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait_time64
, compat_sigset_t __user
*, uthese
,
3428 struct compat_siginfo __user
*, uinfo
,
3429 struct __kernel_timespec __user
*, uts
, compat_size_t
, sigsetsize
)
3432 struct timespec64 t
;
3433 kernel_siginfo_t info
;
3436 if (sigsetsize
!= sizeof(sigset_t
))
3439 if (get_compat_sigset(&s
, uthese
))
3443 if (get_timespec64(&t
, uts
))
3447 ret
= do_sigtimedwait(&s
, &info
, uts
? &t
: NULL
);
3449 if (ret
> 0 && uinfo
) {
3450 if (copy_siginfo_to_user32(uinfo
, &info
))
3457 #ifdef CONFIG_COMPAT_32BIT_TIME
3458 COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait
, compat_sigset_t __user
*, uthese
,
3459 struct compat_siginfo __user
*, uinfo
,
3460 struct old_timespec32 __user
*, uts
, compat_size_t
, sigsetsize
)
3463 struct timespec64 t
;
3464 kernel_siginfo_t info
;
3467 if (sigsetsize
!= sizeof(sigset_t
))
3470 if (get_compat_sigset(&s
, uthese
))
3474 if (get_old_timespec32(&t
, uts
))
3478 ret
= do_sigtimedwait(&s
, &info
, uts
? &t
: NULL
);
3480 if (ret
> 0 && uinfo
) {
3481 if (copy_siginfo_to_user32(uinfo
, &info
))
3491 * sys_kill - send a signal to a process
3492 * @pid: the PID of the process
3493 * @sig: signal to be sent
3495 SYSCALL_DEFINE2(kill
, pid_t
, pid
, int, sig
)
3497 struct kernel_siginfo info
;
3499 clear_siginfo(&info
);
3500 info
.si_signo
= sig
;
3502 info
.si_code
= SI_USER
;
3503 info
.si_pid
= task_tgid_vnr(current
);
3504 info
.si_uid
= from_kuid_munged(current_user_ns(), current_uid());
3506 return kill_something_info(sig
, &info
, pid
);
3510 do_send_specific(pid_t tgid
, pid_t pid
, int sig
, struct kernel_siginfo
*info
)
3512 struct task_struct
*p
;
3516 p
= find_task_by_vpid(pid
);
3517 if (p
&& (tgid
<= 0 || task_tgid_vnr(p
) == tgid
)) {
3518 error
= check_kill_permission(sig
, info
, p
);
3520 * The null signal is a permissions and process existence
3521 * probe. No signal is actually delivered.
3523 if (!error
&& sig
) {
3524 error
= do_send_sig_info(sig
, info
, p
, PIDTYPE_PID
);
3526 * If lock_task_sighand() failed we pretend the task
3527 * dies after receiving the signal. The window is tiny,
3528 * and the signal is private anyway.
3530 if (unlikely(error
== -ESRCH
))
3539 static int do_tkill(pid_t tgid
, pid_t pid
, int sig
)
3541 struct kernel_siginfo info
;
3543 clear_siginfo(&info
);
3544 info
.si_signo
= sig
;
3546 info
.si_code
= SI_TKILL
;
3547 info
.si_pid
= task_tgid_vnr(current
);
3548 info
.si_uid
= from_kuid_munged(current_user_ns(), current_uid());
3550 return do_send_specific(tgid
, pid
, sig
, &info
);
3554 * sys_tgkill - send signal to one specific thread
3555 * @tgid: the thread group ID of the thread
3556 * @pid: the PID of the thread
3557 * @sig: signal to be sent
3559 * This syscall also checks the @tgid and returns -ESRCH even if the PID
3560 * exists but it's not belonging to the target process anymore. This
3561 * method solves the problem of threads exiting and PIDs getting reused.
3563 SYSCALL_DEFINE3(tgkill
, pid_t
, tgid
, pid_t
, pid
, int, sig
)
3565 /* This is only valid for single tasks */
3566 if (pid
<= 0 || tgid
<= 0)
3569 return do_tkill(tgid
, pid
, sig
);
3573 * sys_tkill - send signal to one specific task
3574 * @pid: the PID of the task
3575 * @sig: signal to be sent
3577 * Send a signal to only one task, even if it's a CLONE_THREAD task.
3579 SYSCALL_DEFINE2(tkill
, pid_t
, pid
, int, sig
)
3581 /* This is only valid for single tasks */
3585 return do_tkill(0, pid
, sig
);
3588 static int do_rt_sigqueueinfo(pid_t pid
, int sig
, kernel_siginfo_t
*info
)
3590 /* Not even root can pretend to send signals from the kernel.
3591 * Nor can they impersonate a kill()/tgkill(), which adds source info.
3593 if ((info
->si_code
>= 0 || info
->si_code
== SI_TKILL
) &&
3594 (task_pid_vnr(current
) != pid
))
3597 /* POSIX.1b doesn't mention process groups. */
3598 return kill_proc_info(sig
, info
, pid
);
3602 * sys_rt_sigqueueinfo - send signal information to a signal
3603 * @pid: the PID of the thread
3604 * @sig: signal to be sent
3605 * @uinfo: signal info to be sent
3607 SYSCALL_DEFINE3(rt_sigqueueinfo
, pid_t
, pid
, int, sig
,
3608 siginfo_t __user
*, uinfo
)
3610 kernel_siginfo_t info
;
3611 int ret
= __copy_siginfo_from_user(sig
, &info
, uinfo
);
3614 return do_rt_sigqueueinfo(pid
, sig
, &info
);
3617 #ifdef CONFIG_COMPAT
3618 COMPAT_SYSCALL_DEFINE3(rt_sigqueueinfo
,
3621 struct compat_siginfo __user
*, uinfo
)
3623 kernel_siginfo_t info
;
3624 int ret
= __copy_siginfo_from_user32(sig
, &info
, uinfo
);
3627 return do_rt_sigqueueinfo(pid
, sig
, &info
);
3631 static int do_rt_tgsigqueueinfo(pid_t tgid
, pid_t pid
, int sig
, kernel_siginfo_t
*info
)
3633 /* This is only valid for single tasks */
3634 if (pid
<= 0 || tgid
<= 0)
3637 /* Not even root can pretend to send signals from the kernel.
3638 * Nor can they impersonate a kill()/tgkill(), which adds source info.
3640 if ((info
->si_code
>= 0 || info
->si_code
== SI_TKILL
) &&
3641 (task_pid_vnr(current
) != pid
))
3644 return do_send_specific(tgid
, pid
, sig
, info
);
3647 SYSCALL_DEFINE4(rt_tgsigqueueinfo
, pid_t
, tgid
, pid_t
, pid
, int, sig
,
3648 siginfo_t __user
*, uinfo
)
3650 kernel_siginfo_t info
;
3651 int ret
= __copy_siginfo_from_user(sig
, &info
, uinfo
);
3654 return do_rt_tgsigqueueinfo(tgid
, pid
, sig
, &info
);
3657 #ifdef CONFIG_COMPAT
3658 COMPAT_SYSCALL_DEFINE4(rt_tgsigqueueinfo
,
3662 struct compat_siginfo __user
*, uinfo
)
3664 kernel_siginfo_t info
;
3665 int ret
= __copy_siginfo_from_user32(sig
, &info
, uinfo
);
3668 return do_rt_tgsigqueueinfo(tgid
, pid
, sig
, &info
);
3673 * For kthreads only, must not be used if cloned with CLONE_SIGHAND
3675 void kernel_sigaction(int sig
, __sighandler_t action
)
3677 spin_lock_irq(¤t
->sighand
->siglock
);
3678 current
->sighand
->action
[sig
- 1].sa
.sa_handler
= action
;
3679 if (action
== SIG_IGN
) {
3683 sigaddset(&mask
, sig
);
3685 flush_sigqueue_mask(&mask
, ¤t
->signal
->shared_pending
);
3686 flush_sigqueue_mask(&mask
, ¤t
->pending
);
3687 recalc_sigpending();
3689 spin_unlock_irq(¤t
->sighand
->siglock
);
3691 EXPORT_SYMBOL(kernel_sigaction
);
3693 void __weak
sigaction_compat_abi(struct k_sigaction
*act
,
3694 struct k_sigaction
*oact
)
3698 int do_sigaction(int sig
, struct k_sigaction
*act
, struct k_sigaction
*oact
)
3700 struct task_struct
*p
= current
, *t
;
3701 struct k_sigaction
*k
;
3704 if (!valid_signal(sig
) || sig
< 1 || (act
&& sig_kernel_only(sig
)))
3707 k
= &p
->sighand
->action
[sig
-1];
3709 spin_lock_irq(&p
->sighand
->siglock
);
3713 sigaction_compat_abi(act
, oact
);
3716 sigdelsetmask(&act
->sa
.sa_mask
,
3717 sigmask(SIGKILL
) | sigmask(SIGSTOP
));
3721 * "Setting a signal action to SIG_IGN for a signal that is
3722 * pending shall cause the pending signal to be discarded,
3723 * whether or not it is blocked."
3725 * "Setting a signal action to SIG_DFL for a signal that is
3726 * pending and whose default action is to ignore the signal
3727 * (for example, SIGCHLD), shall cause the pending signal to
3728 * be discarded, whether or not it is blocked"
3730 if (sig_handler_ignored(sig_handler(p
, sig
), sig
)) {
3732 sigaddset(&mask
, sig
);
3733 flush_sigqueue_mask(&mask
, &p
->signal
->shared_pending
);
3734 for_each_thread(p
, t
)
3735 flush_sigqueue_mask(&mask
, &t
->pending
);
3739 spin_unlock_irq(&p
->sighand
->siglock
);
3744 do_sigaltstack (const stack_t
*ss
, stack_t
*oss
, unsigned long sp
,
3747 struct task_struct
*t
= current
;
3750 memset(oss
, 0, sizeof(stack_t
));
3751 oss
->ss_sp
= (void __user
*) t
->sas_ss_sp
;
3752 oss
->ss_size
= t
->sas_ss_size
;
3753 oss
->ss_flags
= sas_ss_flags(sp
) |
3754 (current
->sas_ss_flags
& SS_FLAG_BITS
);
3758 void __user
*ss_sp
= ss
->ss_sp
;
3759 size_t ss_size
= ss
->ss_size
;
3760 unsigned ss_flags
= ss
->ss_flags
;
3763 if (unlikely(on_sig_stack(sp
)))
3766 ss_mode
= ss_flags
& ~SS_FLAG_BITS
;
3767 if (unlikely(ss_mode
!= SS_DISABLE
&& ss_mode
!= SS_ONSTACK
&&
3771 if (ss_mode
== SS_DISABLE
) {
3775 if (unlikely(ss_size
< min_ss_size
))
3779 t
->sas_ss_sp
= (unsigned long) ss_sp
;
3780 t
->sas_ss_size
= ss_size
;
3781 t
->sas_ss_flags
= ss_flags
;
3786 SYSCALL_DEFINE2(sigaltstack
,const stack_t __user
*,uss
, stack_t __user
*,uoss
)
3790 if (uss
&& copy_from_user(&new, uss
, sizeof(stack_t
)))
3792 err
= do_sigaltstack(uss
? &new : NULL
, uoss
? &old
: NULL
,
3793 current_user_stack_pointer(),
3795 if (!err
&& uoss
&& copy_to_user(uoss
, &old
, sizeof(stack_t
)))
3800 int restore_altstack(const stack_t __user
*uss
)
3803 if (copy_from_user(&new, uss
, sizeof(stack_t
)))
3805 (void)do_sigaltstack(&new, NULL
, current_user_stack_pointer(),
3807 /* squash all but EFAULT for now */
3811 int __save_altstack(stack_t __user
*uss
, unsigned long sp
)
3813 struct task_struct
*t
= current
;
3814 int err
= __put_user((void __user
*)t
->sas_ss_sp
, &uss
->ss_sp
) |
3815 __put_user(t
->sas_ss_flags
, &uss
->ss_flags
) |
3816 __put_user(t
->sas_ss_size
, &uss
->ss_size
);
3819 if (t
->sas_ss_flags
& SS_AUTODISARM
)
3824 #ifdef CONFIG_COMPAT
3825 static int do_compat_sigaltstack(const compat_stack_t __user
*uss_ptr
,
3826 compat_stack_t __user
*uoss_ptr
)
3832 compat_stack_t uss32
;
3833 if (copy_from_user(&uss32
, uss_ptr
, sizeof(compat_stack_t
)))
3835 uss
.ss_sp
= compat_ptr(uss32
.ss_sp
);
3836 uss
.ss_flags
= uss32
.ss_flags
;
3837 uss
.ss_size
= uss32
.ss_size
;
3839 ret
= do_sigaltstack(uss_ptr
? &uss
: NULL
, &uoss
,
3840 compat_user_stack_pointer(),
3841 COMPAT_MINSIGSTKSZ
);
3842 if (ret
>= 0 && uoss_ptr
) {
3844 memset(&old
, 0, sizeof(old
));
3845 old
.ss_sp
= ptr_to_compat(uoss
.ss_sp
);
3846 old
.ss_flags
= uoss
.ss_flags
;
3847 old
.ss_size
= uoss
.ss_size
;
3848 if (copy_to_user(uoss_ptr
, &old
, sizeof(compat_stack_t
)))
3854 COMPAT_SYSCALL_DEFINE2(sigaltstack
,
3855 const compat_stack_t __user
*, uss_ptr
,
3856 compat_stack_t __user
*, uoss_ptr
)
3858 return do_compat_sigaltstack(uss_ptr
, uoss_ptr
);
3861 int compat_restore_altstack(const compat_stack_t __user
*uss
)
3863 int err
= do_compat_sigaltstack(uss
, NULL
);
3864 /* squash all but -EFAULT for now */
3865 return err
== -EFAULT
? err
: 0;
3868 int __compat_save_altstack(compat_stack_t __user
*uss
, unsigned long sp
)
3871 struct task_struct
*t
= current
;
3872 err
= __put_user(ptr_to_compat((void __user
*)t
->sas_ss_sp
),
3874 __put_user(t
->sas_ss_flags
, &uss
->ss_flags
) |
3875 __put_user(t
->sas_ss_size
, &uss
->ss_size
);
3878 if (t
->sas_ss_flags
& SS_AUTODISARM
)
3884 #ifdef __ARCH_WANT_SYS_SIGPENDING
3887 * sys_sigpending - examine pending signals
3888 * @uset: where mask of pending signal is returned
3890 SYSCALL_DEFINE1(sigpending
, old_sigset_t __user
*, uset
)
3894 if (sizeof(old_sigset_t
) > sizeof(*uset
))
3897 do_sigpending(&set
);
3899 if (copy_to_user(uset
, &set
, sizeof(old_sigset_t
)))
3905 #ifdef CONFIG_COMPAT
3906 COMPAT_SYSCALL_DEFINE1(sigpending
, compat_old_sigset_t __user
*, set32
)
3910 do_sigpending(&set
);
3912 return put_user(set
.sig
[0], set32
);
3918 #ifdef __ARCH_WANT_SYS_SIGPROCMASK
3920 * sys_sigprocmask - examine and change blocked signals
3921 * @how: whether to add, remove, or set signals
3922 * @nset: signals to add or remove (if non-null)
3923 * @oset: previous value of signal mask if non-null
3925 * Some platforms have their own version with special arguments;
3926 * others support only sys_rt_sigprocmask.
3929 SYSCALL_DEFINE3(sigprocmask
, int, how
, old_sigset_t __user
*, nset
,
3930 old_sigset_t __user
*, oset
)
3932 old_sigset_t old_set
, new_set
;
3933 sigset_t new_blocked
;
3935 old_set
= current
->blocked
.sig
[0];
3938 if (copy_from_user(&new_set
, nset
, sizeof(*nset
)))
3941 new_blocked
= current
->blocked
;
3945 sigaddsetmask(&new_blocked
, new_set
);
3948 sigdelsetmask(&new_blocked
, new_set
);
3951 new_blocked
.sig
[0] = new_set
;
3957 set_current_blocked(&new_blocked
);
3961 if (copy_to_user(oset
, &old_set
, sizeof(*oset
)))
3967 #endif /* __ARCH_WANT_SYS_SIGPROCMASK */
3969 #ifndef CONFIG_ODD_RT_SIGACTION
3971 * sys_rt_sigaction - alter an action taken by a process
3972 * @sig: signal to be sent
3973 * @act: new sigaction
3974 * @oact: used to save the previous sigaction
3975 * @sigsetsize: size of sigset_t type
3977 SYSCALL_DEFINE4(rt_sigaction
, int, sig
,
3978 const struct sigaction __user
*, act
,
3979 struct sigaction __user
*, oact
,
3982 struct k_sigaction new_sa
, old_sa
;
3985 /* XXX: Don't preclude handling different sized sigset_t's. */
3986 if (sigsetsize
!= sizeof(sigset_t
))
3989 if (act
&& copy_from_user(&new_sa
.sa
, act
, sizeof(new_sa
.sa
)))
3992 ret
= do_sigaction(sig
, act
? &new_sa
: NULL
, oact
? &old_sa
: NULL
);
3996 if (oact
&& copy_to_user(oact
, &old_sa
.sa
, sizeof(old_sa
.sa
)))
4001 #ifdef CONFIG_COMPAT
4002 COMPAT_SYSCALL_DEFINE4(rt_sigaction
, int, sig
,
4003 const struct compat_sigaction __user
*, act
,
4004 struct compat_sigaction __user
*, oact
,
4005 compat_size_t
, sigsetsize
)
4007 struct k_sigaction new_ka
, old_ka
;
4008 #ifdef __ARCH_HAS_SA_RESTORER
4009 compat_uptr_t restorer
;
4013 /* XXX: Don't preclude handling different sized sigset_t's. */
4014 if (sigsetsize
!= sizeof(compat_sigset_t
))
4018 compat_uptr_t handler
;
4019 ret
= get_user(handler
, &act
->sa_handler
);
4020 new_ka
.sa
.sa_handler
= compat_ptr(handler
);
4021 #ifdef __ARCH_HAS_SA_RESTORER
4022 ret
|= get_user(restorer
, &act
->sa_restorer
);
4023 new_ka
.sa
.sa_restorer
= compat_ptr(restorer
);
4025 ret
|= get_compat_sigset(&new_ka
.sa
.sa_mask
, &act
->sa_mask
);
4026 ret
|= get_user(new_ka
.sa
.sa_flags
, &act
->sa_flags
);
4031 ret
= do_sigaction(sig
, act
? &new_ka
: NULL
, oact
? &old_ka
: NULL
);
4033 ret
= put_user(ptr_to_compat(old_ka
.sa
.sa_handler
),
4035 ret
|= put_compat_sigset(&oact
->sa_mask
, &old_ka
.sa
.sa_mask
,
4036 sizeof(oact
->sa_mask
));
4037 ret
|= put_user(old_ka
.sa
.sa_flags
, &oact
->sa_flags
);
4038 #ifdef __ARCH_HAS_SA_RESTORER
4039 ret
|= put_user(ptr_to_compat(old_ka
.sa
.sa_restorer
),
4040 &oact
->sa_restorer
);
4046 #endif /* !CONFIG_ODD_RT_SIGACTION */
4048 #ifdef CONFIG_OLD_SIGACTION
4049 SYSCALL_DEFINE3(sigaction
, int, sig
,
4050 const struct old_sigaction __user
*, act
,
4051 struct old_sigaction __user
*, oact
)
4053 struct k_sigaction new_ka
, old_ka
;
4058 if (!access_ok(act
, sizeof(*act
)) ||
4059 __get_user(new_ka
.sa
.sa_handler
, &act
->sa_handler
) ||
4060 __get_user(new_ka
.sa
.sa_restorer
, &act
->sa_restorer
) ||
4061 __get_user(new_ka
.sa
.sa_flags
, &act
->sa_flags
) ||
4062 __get_user(mask
, &act
->sa_mask
))
4064 #ifdef __ARCH_HAS_KA_RESTORER
4065 new_ka
.ka_restorer
= NULL
;
4067 siginitset(&new_ka
.sa
.sa_mask
, mask
);
4070 ret
= do_sigaction(sig
, act
? &new_ka
: NULL
, oact
? &old_ka
: NULL
);
4073 if (!access_ok(oact
, sizeof(*oact
)) ||
4074 __put_user(old_ka
.sa
.sa_handler
, &oact
->sa_handler
) ||
4075 __put_user(old_ka
.sa
.sa_restorer
, &oact
->sa_restorer
) ||
4076 __put_user(old_ka
.sa
.sa_flags
, &oact
->sa_flags
) ||
4077 __put_user(old_ka
.sa
.sa_mask
.sig
[0], &oact
->sa_mask
))
4084 #ifdef CONFIG_COMPAT_OLD_SIGACTION
4085 COMPAT_SYSCALL_DEFINE3(sigaction
, int, sig
,
4086 const struct compat_old_sigaction __user
*, act
,
4087 struct compat_old_sigaction __user
*, oact
)
4089 struct k_sigaction new_ka
, old_ka
;
4091 compat_old_sigset_t mask
;
4092 compat_uptr_t handler
, restorer
;
4095 if (!access_ok(act
, sizeof(*act
)) ||
4096 __get_user(handler
, &act
->sa_handler
) ||
4097 __get_user(restorer
, &act
->sa_restorer
) ||
4098 __get_user(new_ka
.sa
.sa_flags
, &act
->sa_flags
) ||
4099 __get_user(mask
, &act
->sa_mask
))
4102 #ifdef __ARCH_HAS_KA_RESTORER
4103 new_ka
.ka_restorer
= NULL
;
4105 new_ka
.sa
.sa_handler
= compat_ptr(handler
);
4106 new_ka
.sa
.sa_restorer
= compat_ptr(restorer
);
4107 siginitset(&new_ka
.sa
.sa_mask
, mask
);
4110 ret
= do_sigaction(sig
, act
? &new_ka
: NULL
, oact
? &old_ka
: NULL
);
4113 if (!access_ok(oact
, sizeof(*oact
)) ||
4114 __put_user(ptr_to_compat(old_ka
.sa
.sa_handler
),
4115 &oact
->sa_handler
) ||
4116 __put_user(ptr_to_compat(old_ka
.sa
.sa_restorer
),
4117 &oact
->sa_restorer
) ||
4118 __put_user(old_ka
.sa
.sa_flags
, &oact
->sa_flags
) ||
4119 __put_user(old_ka
.sa
.sa_mask
.sig
[0], &oact
->sa_mask
))
4126 #ifdef CONFIG_SGETMASK_SYSCALL
4129 * For backwards compatibility. Functionality superseded by sigprocmask.
4131 SYSCALL_DEFINE0(sgetmask
)
4134 return current
->blocked
.sig
[0];
4137 SYSCALL_DEFINE1(ssetmask
, int, newmask
)
4139 int old
= current
->blocked
.sig
[0];
4142 siginitset(&newset
, newmask
);
4143 set_current_blocked(&newset
);
4147 #endif /* CONFIG_SGETMASK_SYSCALL */
4149 #ifdef __ARCH_WANT_SYS_SIGNAL
4151 * For backwards compatibility. Functionality superseded by sigaction.
4153 SYSCALL_DEFINE2(signal
, int, sig
, __sighandler_t
, handler
)
4155 struct k_sigaction new_sa
, old_sa
;
4158 new_sa
.sa
.sa_handler
= handler
;
4159 new_sa
.sa
.sa_flags
= SA_ONESHOT
| SA_NOMASK
;
4160 sigemptyset(&new_sa
.sa
.sa_mask
);
4162 ret
= do_sigaction(sig
, &new_sa
, &old_sa
);
4164 return ret
? ret
: (unsigned long)old_sa
.sa
.sa_handler
;
4166 #endif /* __ARCH_WANT_SYS_SIGNAL */
4168 #ifdef __ARCH_WANT_SYS_PAUSE
4170 SYSCALL_DEFINE0(pause
)
4172 while (!signal_pending(current
)) {
4173 __set_current_state(TASK_INTERRUPTIBLE
);
4176 return -ERESTARTNOHAND
;
4181 static int sigsuspend(sigset_t
*set
)
4183 current
->saved_sigmask
= current
->blocked
;
4184 set_current_blocked(set
);
4186 while (!signal_pending(current
)) {
4187 __set_current_state(TASK_INTERRUPTIBLE
);
4190 set_restore_sigmask();
4191 return -ERESTARTNOHAND
;
4195 * sys_rt_sigsuspend - replace the signal mask for a value with the
4196 * @unewset value until a signal is received
4197 * @unewset: new signal mask value
4198 * @sigsetsize: size of sigset_t type
4200 SYSCALL_DEFINE2(rt_sigsuspend
, sigset_t __user
*, unewset
, size_t, sigsetsize
)
4204 /* XXX: Don't preclude handling different sized sigset_t's. */
4205 if (sigsetsize
!= sizeof(sigset_t
))
4208 if (copy_from_user(&newset
, unewset
, sizeof(newset
)))
4210 return sigsuspend(&newset
);
4213 #ifdef CONFIG_COMPAT
4214 COMPAT_SYSCALL_DEFINE2(rt_sigsuspend
, compat_sigset_t __user
*, unewset
, compat_size_t
, sigsetsize
)
4218 /* XXX: Don't preclude handling different sized sigset_t's. */
4219 if (sigsetsize
!= sizeof(sigset_t
))
4222 if (get_compat_sigset(&newset
, unewset
))
4224 return sigsuspend(&newset
);
4228 #ifdef CONFIG_OLD_SIGSUSPEND
4229 SYSCALL_DEFINE1(sigsuspend
, old_sigset_t
, mask
)
4232 siginitset(&blocked
, mask
);
4233 return sigsuspend(&blocked
);
4236 #ifdef CONFIG_OLD_SIGSUSPEND3
4237 SYSCALL_DEFINE3(sigsuspend
, int, unused1
, int, unused2
, old_sigset_t
, mask
)
4240 siginitset(&blocked
, mask
);
4241 return sigsuspend(&blocked
);
4245 __weak
const char *arch_vma_name(struct vm_area_struct
*vma
)
4250 static inline void siginfo_buildtime_checks(void)
4252 BUILD_BUG_ON(sizeof(struct siginfo
) != SI_MAX_SIZE
);
4254 /* Verify the offsets in the two siginfos match */
4255 #define CHECK_OFFSET(field) \
4256 BUILD_BUG_ON(offsetof(siginfo_t, field) != offsetof(kernel_siginfo_t, field))
4259 CHECK_OFFSET(si_pid
);
4260 CHECK_OFFSET(si_uid
);
4263 CHECK_OFFSET(si_tid
);
4264 CHECK_OFFSET(si_overrun
);
4265 CHECK_OFFSET(si_value
);
4268 CHECK_OFFSET(si_pid
);
4269 CHECK_OFFSET(si_uid
);
4270 CHECK_OFFSET(si_value
);
4273 CHECK_OFFSET(si_pid
);
4274 CHECK_OFFSET(si_uid
);
4275 CHECK_OFFSET(si_status
);
4276 CHECK_OFFSET(si_utime
);
4277 CHECK_OFFSET(si_stime
);
4280 CHECK_OFFSET(si_addr
);
4281 CHECK_OFFSET(si_addr_lsb
);
4282 CHECK_OFFSET(si_lower
);
4283 CHECK_OFFSET(si_upper
);
4284 CHECK_OFFSET(si_pkey
);
4287 CHECK_OFFSET(si_band
);
4288 CHECK_OFFSET(si_fd
);
4291 CHECK_OFFSET(si_call_addr
);
4292 CHECK_OFFSET(si_syscall
);
4293 CHECK_OFFSET(si_arch
);
4297 void __init
signals_init(void)
4299 siginfo_buildtime_checks();
4301 sigqueue_cachep
= KMEM_CACHE(sigqueue
, SLAB_PANIC
);
4304 #ifdef CONFIG_KGDB_KDB
4305 #include <linux/kdb.h>
4307 * kdb_send_sig - Allows kdb to send signals without exposing
4308 * signal internals. This function checks if the required locks are
4309 * available before calling the main signal code, to avoid kdb
4312 void kdb_send_sig(struct task_struct
*t
, int sig
)
4314 static struct task_struct
*kdb_prev_t
;
4316 if (!spin_trylock(&t
->sighand
->siglock
)) {
4317 kdb_printf("Can't do kill command now.\n"
4318 "The sigmask lock is held somewhere else in "
4319 "kernel, try again later\n");
4322 new_t
= kdb_prev_t
!= t
;
4324 if (t
->state
!= TASK_RUNNING
&& new_t
) {
4325 spin_unlock(&t
->sighand
->siglock
);
4326 kdb_printf("Process is not RUNNING, sending a signal from "
4327 "kdb risks deadlock\n"
4328 "on the run queue locks. "
4329 "The signal has _not_ been sent.\n"
4330 "Reissue the kill command if you want to risk "
4334 ret
= send_signal(sig
, SEND_SIG_PRIV
, t
, PIDTYPE_PID
);
4335 spin_unlock(&t
->sighand
->siglock
);
4337 kdb_printf("Fail to deliver Signal %d to process %d.\n",
4340 kdb_printf("Signal %d is sent to process %d.\n", sig
, t
->pid
);
4342 #endif /* CONFIG_KGDB_KDB */