[GIT PULL] lockdep fix

[Ingo Molnar]

Linus,

Please pull the latest locking-urgent-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 
locking-urgent-for-linus

   # HEAD: 5e351ad106997e06b2dc3da9c6b939b95f67fb88 locking/lockdep: Fix 
possible NULL deref

Fix a possible NULL dereference for the (rare) case when a task doesn't have 
->xhlocks space allocated due to kmalloc() OOM-ing.

 Thanks,

        Ingo

------------------>
Peter Zijlstra (1):
      locking/lockdep: Fix possible NULL deref


 kernel/locking/lockdep.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 9776da8db180..670d8d7d8087 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -4790,7 +4790,8 @@ void lockdep_invariant_state(bool force)
         * Verify the former, enforce the latter.
         */
        WARN_ON_ONCE(!force && current->lockdep_depth);
-       invalidate_xhlock(&xhlock(current->xhlock_idx));
+       if (current->xhlocks)
+               invalidate_xhlock(&xhlock(current->xhlock_idx));
 }
 
 static int cross_lock(struct lockdep_map *lock)