lkml.org 
[lkml]   [2014]   [Apr]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:core/urgent] locking/mutex: Fix debug_mutexes
Commit-ID:  a227960fe0cafcc229a8d6bb8b454a3a0b33719d
Gitweb: http://git.kernel.org/tip/a227960fe0cafcc229a8d6bb8b454a3a0b33719d
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Thu, 10 Apr 2014 16:15:59 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Fri, 11 Apr 2014 10:40:35 +0200

locking/mutex: Fix debug_mutexes

debug_mutex_unlock() would bail when !debug_locks and forgets to
actually unlock.

Reported-by: "Michael L. Semon" <mlsemon35@gmail.com>
Reported-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Reported-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Fixes: 6f008e72cd11 ("locking/mutex: Fix debug checks")
Tested-by: Dave Jones <davej@redhat.com>
Cc: Jason Low <jason.low2@hp.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140410141559.GE13658@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
kernel/locking/mutex-debug.c | 19 +++++++++----------
1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/kernel/locking/mutex-debug.c b/kernel/locking/mutex-debug.c
index e1191c9..5cf6731 100644
--- a/kernel/locking/mutex-debug.c
+++ b/kernel/locking/mutex-debug.c
@@ -71,18 +71,17 @@ void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,

void debug_mutex_unlock(struct mutex *lock)
{
- if (unlikely(!debug_locks))
- return;
+ if (likely(debug_locks)) {
+ DEBUG_LOCKS_WARN_ON(lock->magic != lock);

- DEBUG_LOCKS_WARN_ON(lock->magic != lock);
+ if (!lock->owner)
+ DEBUG_LOCKS_WARN_ON(!lock->owner);
+ else
+ DEBUG_LOCKS_WARN_ON(lock->owner != current);

- if (!lock->owner)
- DEBUG_LOCKS_WARN_ON(!lock->owner);
- else
- DEBUG_LOCKS_WARN_ON(lock->owner != current);
-
- DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next);
- mutex_clear_owner(lock);
+ DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next);
+ mutex_clear_owner(lock);
+ }

/*
* __mutex_slowpath_needs_to_unlock() is explicitly 0 for debug

\
 
 \ /
  Last update: 2014-04-14 15:01    [W:0.170 / U:0.052 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site