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Message-ID: <20240610164026.992475995@linutronix.de>
From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Anna-Maria Behnsen <anna-maria@linutronix.de>,
 Frederic Weisbecker <frederic@kernel.org>,
 John Stultz <jstultz@google.com>,
 Peter Zijlstra <peterz@infradead.org>,
 Ingo Molnar <mingo@kernel.org>,
 Stephen Boyd <sboyd@kernel.org>,
 Eric Biederman <ebiederm@xmission.com>,
 Oleg Nesterov <oleg@redhat.com>
Subject: [patch V3 24/51] signal: Replace BUG_ON()s
References: <20240610163452.591699700@linutronix.de>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Date: Mon, 10 Jun 2024 18:42:34 +0200 (CEST)

These really can be handled gracefully without killing the machine.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
---
 kernel/signal.c |   11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1940,10 +1940,11 @@ 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 +1972,10 @@ int send_sigqueue(struct sigqueue *q, st
 	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 +2010,6 @@ int send_sigqueue(struct sigqueue *q, st
 		 * 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;