Thread (859 messages) flat view 859 messages, 8 authors, 2021-11-16
STALE1734d REVIEWED: 3 (2M)

2 review trailers (1 from subsystem maintainers).

[PATCH 5.14 349/849] lockdep: Let lock_is_held_type() detect recursive read as read

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-11-16 01:35:55
Also in: lkml
Subsystem: locking primitives, the rest · Maintainers: Peter Zijlstra, Ingo Molnar, Will Deacon, Boqun Feng, Linus Torvalds

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

[ Upstream commit 2507003a1d10917c9158077bf6030719d02c941e ]

lock_is_held_type(, 1) detects acquired read locks. It only recognized
locks acquired with lock_acquire_shared(). Read locks acquired with
lock_acquire_shared_recursive() are not recognized because a `2' is
stored as the read value.

Rework the check to additionally recognise lock's read value one and two
as a read held lock.

Fixes: e918188611f07 ("locking: More accurate annotations for read_lock()")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Boqun Feng <redacted>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lkml.kernel.org/r/20210903084001.lblecrvz4esl4mrr@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/locking/lockdep.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 8a509672a4cc9..d624231eab2bb 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -5366,7 +5366,7 @@ int __lock_is_held(const struct lockdep_map *lock, int read)
 		struct held_lock *hlock = curr->held_locks + i;
 
 		if (match_held_lock(hlock, lock)) {
-			if (read == -1 || hlock->read == read)
+			if (read == -1 || !!hlock->read == read)
 				return LOCK_STATE_HELD;
 
 			return LOCK_STATE_NOT_HELD;
-- 
2.33.0


Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help