lockdep: Introduce lockdep_assert_held()

Add a lockdep helper to validate that we indeed are the owner
of a lock.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 12aabfcb45f6..a6d5e5e4d084 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -296,6 +296,10 @@ extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 extern void lock_release(struct lockdep_map *lock, int nested,
                          unsigned long ip);
 
+#define lockdep_is_held(lock)   lock_is_held(&(lock)->dep_map)
+
+extern int lock_is_held(struct lockdep_map *lock);
+
 extern void lock_set_class(struct lockdep_map *lock, const char *name,
                            struct lock_class_key *key, unsigned int subclass,
                            unsigned long ip);
@@ -314,6 +318,8 @@ extern void lockdep_trace_alloc(gfp_t mask);
 
 #define lockdep_depth(tsk)      (debug_locks ? (tsk)->lockdep_depth : 0)
 
+#define lockdep_assert_held(l)  WARN_ON(debug_locks && !lockdep_is_held(l))
+
 #else /* !LOCKDEP */
 
 static inline void lockdep_off(void)
@@ -358,6 +364,8 @@ struct lock_class_key { };
 
 #define lockdep_depth(tsk)      (0)
 
+#define lockdep_assert_held(l)                  do { } while (0)
+
 #endif /* !LOCKDEP */
 
 #ifdef CONFIG_LOCK_STAT