Revert "locking/lockdep: Add debug_locks check in __lock_downgrade()"

This reverts commit 0e0f7b30721233ce610bde2395a8e58ff7771475 which was
commit 71492580571467fb7177aade19c18ce7486267f5 upstream.

Tetsuo rightly points out that the backport here is incorrect, as it
touches the __lock_set_class function instead of the intended
__lock_downgrade function.

Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Waiman Long <longman@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 0cbdbbb0729fa3cd43ba20560e527c8c2dc2b446..26b57e24476f19ee9409ee4f90463b9afa7036b0 100644 (file)
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -3567,9 +3567,6 @@ __lock_set_class(struct lockdep_map *lock, const char *name,
        unsigned int depth;
        int i;
 
-       if (unlikely(!debug_locks))
-               return 0;
-
        depth = curr->lockdep_depth;
        /*
         * This function is about (re)setting the class of a held lock,