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Diffstat (limited to 'kernel/signal.c')
-rw-r--r--kernel/signal.c34
1 files changed, 17 insertions, 17 deletions
diff --git a/kernel/signal.c b/kernel/signal.c
index 60c737e423a1..6f3a5aa39b09 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -618,20 +618,18 @@ static int __dequeue_signal(struct sigpending *pending, sigset_t *mask,
}
/*
- * Dequeue a signal and return the element to the caller, which is
- * expected to free it.
- *
- * All callers have to hold the siglock.
+ * Try to dequeue a signal. If a deliverable signal is found fill in the
+ * caller provided siginfo and return the signal number. Otherwise return
+ * 0.
*/
-int dequeue_signal(struct task_struct *tsk, sigset_t *mask,
- kernel_siginfo_t *info, enum pid_type *type)
+int dequeue_signal(sigset_t *mask, kernel_siginfo_t *info, enum pid_type *type)
{
+ struct task_struct *tsk = current;
bool resched_timer = false;
int signr;
- /* We only dequeue private signals from ourselves, we don't let
- * signalfd steal them
- */
+ lockdep_assert_held(&tsk->sighand->siglock);
+
*type = PIDTYPE_PID;
signr = __dequeue_signal(&tsk->pending, mask, info, &resched_timer);
if (!signr) {
@@ -1940,10 +1938,11 @@ struct sigqueue *sigqueue_alloc(void)
void sigqueue_free(struct sigqueue *q)
{
- unsigned long flags;
spinlock_t *lock = &current->sighand->siglock;
+ unsigned long flags;
- BUG_ON(!(q->flags & SIGQUEUE_PREALLOC));
+ if (WARN_ON_ONCE(!(q->flags & SIGQUEUE_PREALLOC)))
+ return;
/*
* We must hold ->siglock while testing q->list
* to serialize with collect_signal() or with
@@ -1971,7 +1970,10 @@ int send_sigqueue(struct sigqueue *q, struct pid *pid, enum pid_type type)
unsigned long flags;
int ret, result;
- BUG_ON(!(q->flags & SIGQUEUE_PREALLOC));
+ if (WARN_ON_ONCE(!(q->flags & SIGQUEUE_PREALLOC)))
+ return 0;
+ if (WARN_ON_ONCE(q->info.si_code != SI_TIMER))
+ return 0;
ret = -1;
rcu_read_lock();
@@ -2006,7 +2008,6 @@ int send_sigqueue(struct sigqueue *q, struct pid *pid, enum pid_type type)
* If an SI_TIMER entry is already queue just increment
* the overrun count.
*/
- BUG_ON(q->info.si_code != SI_TIMER);
q->info.si_overrun++;
result = TRACE_SIGNAL_ALREADY_PENDING;
goto out;
@@ -2793,8 +2794,7 @@ relock:
type = PIDTYPE_PID;
signr = dequeue_synchronous_signal(&ksig->info);
if (!signr)
- signr = dequeue_signal(current, &current->blocked,
- &ksig->info, &type);
+ signr = dequeue_signal(&current->blocked, &ksig->info, &type);
if (!signr)
break; /* will return 0 */
@@ -3648,7 +3648,7 @@ static int do_sigtimedwait(const sigset_t *which, kernel_siginfo_t *info,
signotset(&mask);
spin_lock_irq(&tsk->sighand->siglock);
- sig = dequeue_signal(tsk, &mask, info, &type);
+ sig = dequeue_signal(&mask, info, &type);
if (!sig && timeout) {
/*
* None ready, temporarily unblock those we're interested
@@ -3667,7 +3667,7 @@ static int do_sigtimedwait(const sigset_t *which, kernel_siginfo_t *info,
spin_lock_irq(&tsk->sighand->siglock);
__set_task_blocked(tsk, &tsk->real_blocked);
sigemptyset(&tsk->real_blocked);
- sig = dequeue_signal(tsk, &mask, info, &type);
+ sig = dequeue_signal(&mask, info, &type);
}
spin_unlock_irq(&tsk->sighand->siglock);