[tip: timers/core] signal: Replace BUG_ON()s

["tip-bot2 for Thomas Gleixner" <tip-bot2@xxxxxxxxxxxxx>]

The following commit has been merged into the timers/core branch of tip:

Commit-ID:     7f8af7bac5380f2d95a63a6f19964e22437166e1
Gitweb:        https://git.kernel.org/tip/7f8af7bac5380f2d95a63a6f19964e22437166e1
Author:        Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate:    Mon, 10 Jun 2024 18:42:34 +02:00
Committer:     Frederic Weisbecker <frederic@xxxxxxxxxx>
CommitterDate: Mon, 29 Jul 2024 21:57:35 +02:00

signal: Replace BUG_ON()s

These really can be handled gracefully without killing the machine.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Reviewed-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
 kernel/signal.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index 897765b..6f3a5aa 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1938,10 +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
@@ -1969,7 +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();
@@ -2004,7 +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;