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Date:   Fri, 17 Sep 2021 13:17:19 -0000
From:   "tip-bot2 for Sebastian Andrzej Siewior" <tip-bot2@linutronix.de>
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Subject: [tip: locking/core] lockdep: Let lock_is_held_type() detect recursive
 read as read
Cc:     Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
        "Peter Zijlstra (Intel)" <peterz@infradead.org>,
        Boqun Feng <boqun.feng@gmail.com>,
        Waiman Long <longman@redhat.com>, x86@kernel.org,
        linux-kernel@vger.kernel.org
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The following commit has been merged into the locking/core branch of tip:

Commit-ID:     2507003a1d10917c9158077bf6030719d02c941e
Gitweb:        https://git.kernel.org/tip/2507003a1d10917c9158077bf6030719d02c941e
Author:        Sebastian Andrzej Siewior <bigeasy@linutronix.de>
AuthorDate:    Fri, 03 Sep 2021 10:40:01 +02:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Fri, 17 Sep 2021 15:08:44 +02:00

lockdep: Let lock_is_held_type() detect recursive read as read

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
---
 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 bf1c00c..bfa0a34 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;