lockdep/lib/tests: Test dynamic key registration

Make sure that the lockdep_register_key() and lockdep_unregister_key()
code is tested when running the lockdep tests.

Signed-off-by: Bart Van Assche <[e-mail]>
Signed-off-by: Peter Zijlstra (Intel) <[e-mail]>
Cc: Andrew Morton <[e-mail]>
Cc: Johannes Berg <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Cc: Paul E. McKenney <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: Waiman Long <[e-mail]>
Cc: Will Deacon <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>

tools/lib/lockdep/include/liblockdep/common.h

···
 void lock_release(struct lockdep_map *lock, int nested,
 			unsigned long ip);
 void lockdep_reset_lock(struct lockdep_map *lock);
+void lockdep_register_key(struct lock_class_key *key);
+void lockdep_unregister_key(struct lock_class_key *key);
 extern void debug_check_no_locks_freed(const void *from, unsigned long len);
 
 #define STATIC_LOCKDEP_MAP_INIT(_name, _key) \

tools/lib/lockdep/include/liblockdep/mutex.h

···
 
 struct liblockdep_pthread_mutex {
 	pthread_mutex_t mutex;
+	struct lock_class_key key;
 	struct lockdep_map dep_map;
 };
 
···
 	return pthread_mutex_init(&lock->mutex, __mutexattr);
 }
 
-#define liblockdep_pthread_mutex_init(mutex, mutexattr)		\
-({								\
-	static struct lock_class_key __key;			\
-								\
-	__mutex_init((mutex), #mutex, &__key, (mutexattr));	\
+#define liblockdep_pthread_mutex_init(mutex, mutexattr)			\
+({									\
+	lockdep_register_key(&(mutex)->key);				\
+	__mutex_init((mutex), #mutex, &(mutex)->key, (mutexattr));	\
 })
 
 static inline int liblockdep_pthread_mutex_lock(liblockdep_pthread_mutex_t *lock)
···
 static inline int liblockdep_pthread_mutex_destroy(liblockdep_pthread_mutex_t *lock)
 {
 	lockdep_reset_lock(&lock->dep_map);
+	lockdep_unregister_key(&lock->key);
 	return pthread_mutex_destroy(&lock->mutex);
 }
 

tools/lib/lockdep/tests/ABBA.c

···
 
 	pthread_mutex_destroy(&b);
 	pthread_mutex_destroy(&a);
+
+	pthread_mutex_init(&a, NULL);
+	pthread_mutex_init(&b, NULL);
+
+	LOCK_UNLOCK_2(a, b);
+	LOCK_UNLOCK_2(b, a);
+
+	pthread_mutex_destroy(&b);
+	pthread_mutex_destroy(&a);
 }