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

Greg Kroah-Hartman
2021-11-16T01:35:55Z

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 <boqun.feng@gmail.com>
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