From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Waiman Long <llong@redhat.com>
Cc: linux-kernel@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>,
Boqun Feng <boqun.feng@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH v2] lockdep: Let lock_is_held_type() detect recursive read as read
Date: Fri, 3 Sep 2021 10:40:01 +0200 [thread overview]
Message-ID: <20210903084001.lblecrvz4esl4mrr@linutronix.de> (raw)
In-Reply-To: <9af2b074-9fcf-5aea-f37d-9b2482146489@redhat.com>
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>
---
v1…v2:
- simplify the read check to !!read as suggested by Waiman Long.
kernel/locking/lockdep.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -5366,7 +5366,7 @@ int __lock_is_held(const struct lockdep_
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;
next prev parent reply other threads:[~2021-09-03 8:40 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-01 16:22 [PATCH] " Sebastian Andrzej Siewior
2021-09-01 16:43 ` Boqun Feng
2021-09-03 10:45 ` Sebastian Andrzej Siewior
2021-09-03 14:15 ` Boqun Feng
2021-09-03 14:30 ` Sebastian Andrzej Siewior
2021-09-01 18:32 ` Waiman Long
2021-09-03 8:40 ` Sebastian Andrzej Siewior [this message]
2021-09-08 2:16 ` [PATCH v2] " Boqun Feng
2021-09-08 10:17 ` Peter Zijlstra
2021-09-10 13:53 ` [PATCH v3] " Sebastian Andrzej Siewior
2021-09-08 14:40 ` [PATCH v2] " Waiman Long
2021-09-08 14:35 ` Waiman Long
2021-09-17 13:17 ` [tip: locking/core] " tip-bot2 for Sebastian Andrzej Siewior
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