From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>, Waiman Long <llong@redhat.com>,
linux-kernel@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
Will Deacon <will@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH v3] lockdep: Let lock_is_held_type() detect recursive read as read
Date: Fri, 10 Sep 2021 15:53:12 +0200 [thread overview]
Message-ID: <20210910135312.4axzdxt74rgct2ur@linutronix.de> (raw)
In-Reply-To: <YTiN1HLeHeIhi/nT@hirez.programming.kicks-ass.net>
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>
Acked-by: Waiman Long <longman@redhat.com>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
---
v3: move the !! to the right spot so it actually works.
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 bf1c00c881e48..bfa0a347f27c4 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
next prev parent reply other threads:[~2021-09-10 13:53 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-01 16:22 [PATCH] lockdep: Let lock_is_held_type() detect recursive read as read 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 ` [PATCH v2] " Sebastian Andrzej Siewior
2021-09-08 2:16 ` Boqun Feng
2021-09-08 10:17 ` Peter Zijlstra
2021-09-10 13:53 ` Sebastian Andrzej Siewior [this message]
2021-09-08 14:40 ` 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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