From: Waiman Long <longman@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>, Will Deacon <will.deacon@arm.com>,
Boqun Feng <boqun.feng@gmail.com>
Cc: linux-kernel@vger.kernel.org, Waiman Long <longman@redhat.com>
Subject: [PATCH] locking/lockdep: Prevent abuse of lockdep subclass
Date: Wed, 9 Apr 2025 10:37:51 -0400 [thread overview]
Message-ID: <20250409143751.2010391-1-longman@redhat.com> (raw)
As I have seen code trying to use a subclass value >=
MAX_LOCKDEP_SUBCLASSES (8), add a DEBUG_LOCKS_WARN_ON() statement to
notify the users that such a large value is not allowed.
Signed-off-by: Waiman Long <longman@redhat.com>
---
kernel/locking/lockdep.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 58d78a33ac65..3fb79d8fecdf 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -5101,6 +5101,9 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
lockevent_inc(lockdep_nocheck);
}
+ if (DEBUG_LOCKS_WARN_ON(subclass >= MAX_LOCKDEP_SUBCLASSES))
+ return 0;
+
if (subclass < NR_LOCKDEP_CACHING_CLASSES)
class = lock->class_cache[subclass];
/*
--
2.48.1
next reply other threads:[~2025-04-09 14:38 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-09 14:37 Waiman Long [this message]
2025-05-04 18:03 ` Boqun Feng
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