From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: Boqun Feng <boqun.feng@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>,
Waiman Long <longman@redhat.com>
Cc: LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH v2] lockdep: report name and key when look_up_lock_class() got confused
Date: Mon, 19 Sep 2022 09:52:13 +0900 [thread overview]
Message-ID: <bd99391e-f787-efe9-5ec6-3c6dc4c587b0@I-love.SAKURA.ne.jp> (raw)
In-Reply-To: <YydkEtcVc0GtCizz@boqun-archlinux>
Printing this information will be helpful.
------------[ cut here ]------------
Looking for class "l2tp_sock" with key l2tp_socket_class, but found a different class "slock-AF_INET6" with the same key
WARNING: CPU: 1 PID: 14195 at kernel/locking/lockdep.c:940 look_up_lock_class+0xcc/0x140
Modules linked in:
CPU: 1 PID: 14195 Comm: a.out Not tainted 6.0.0-rc6-dirty #863
Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
RIP: 0010:look_up_lock_class+0xcc/0x140
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
---
Changes in v2:
Make message more human readable, suggested by Boqun Feng <boqun.feng@gmail.com>.
kernel/locking/lockdep.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 64a13eb56078..e3375bc40dad 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -934,8 +934,10 @@ look_up_lock_class(const struct lockdep_map *lock, unsigned int subclass)
* Huh! same key, different name? Did someone trample
* on some memory? We're most confused.
*/
- WARN_ON_ONCE(class->name != lock->name &&
- lock->key != &__lockdep_no_validate__);
+ WARN_ONCE(class->name != lock->name &&
+ lock->key != &__lockdep_no_validate__,
+ "Looking for class \"%s\" with key %ps, but found a different class \"%s\" with the same key\n",
+ lock->name, lock->key, class->name);
return class;
}
}
--
2.34.1
next prev parent reply other threads:[~2022-09-19 0:54 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-18 15:01 [PATCH] lockdep: report name and key when look_up_lock_class() got confused Tetsuo Handa
2022-09-18 18:31 ` Boqun Feng
2022-09-19 0:52 ` Tetsuo Handa [this message]
2022-09-19 10:48 ` [PATCH v2] " Peter Zijlstra
2022-09-19 13:44 ` Tetsuo Handa
2022-09-21 8:01 ` [tip: locking/core] locking/lockdep: Print more debug information - " tip-bot2 for Tetsuo Handa
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