Commit 4dfbb9d8 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Dmitry Torokhov
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Lockdep: add lockdep_set_class_and_subclass() and lockdep_set_subclass()



This annotation makes it possible to assign a subclass on lock init. This
annotation is meant to reduce the _nested() annotations by assigning a
default subclass.

One could do without this annotation and rely on lockdep_set_class()
exclusively, but that would require a manual stack of struct lock_class_key
objects.
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarDmitry Torokhov <dtor@mail.ru>
parent 86255d9d
......@@ -202,7 +202,7 @@ extern int lockdep_internal(void);
*/
extern void lockdep_init_map(struct lockdep_map *lock, const char *name,
struct lock_class_key *key);
struct lock_class_key *key, int subclass);
/*
* Reinitialize a lock key - for cases where there is special locking or
......@@ -211,9 +211,14 @@ extern void lockdep_init_map(struct lockdep_map *lock, const char *name,
* or they are too narrow (they suffer from a false class-split):
*/
#define lockdep_set_class(lock, key) \
lockdep_init_map(&(lock)->dep_map, #key, key)
lockdep_init_map(&(lock)->dep_map, #key, key, 0)
#define lockdep_set_class_and_name(lock, key, name) \
lockdep_init_map(&(lock)->dep_map, name, key)
lockdep_init_map(&(lock)->dep_map, name, key, 0)
#define lockdep_set_class_and_subclass(lock, key, sub) \
lockdep_init_map(&(lock)->dep_map, #key, key, sub)
#define lockdep_set_subclass(lock, sub) \
lockdep_init_map(&(lock)->dep_map, #lock, \
(lock)->dep_map.key, sub)
/*
* Acquire a lock.
......@@ -257,10 +262,12 @@ static inline int lockdep_internal(void)
# define lock_release(l, n, i) do { } while (0)
# define lockdep_init() do { } while (0)
# define lockdep_info() do { } while (0)
# define lockdep_init_map(lock, name, key) do { (void)(key); } while (0)
# define lockdep_init_map(lock, name, key, sub) do { (void)(key); } while (0)
# define lockdep_set_class(lock, key) do { (void)(key); } while (0)
# define lockdep_set_class_and_name(lock, key, name) \
do { (void)(key); } while (0)
#define lockdep_set_class_and_subclass(lock, key, sub) \
do { (void)(key); } while (0)
# define INIT_LOCKDEP
# define lockdep_reset() do { debug_locks = 1; } while (0)
# define lockdep_free_key_range(start, size) do { } while (0)
......
......@@ -1177,7 +1177,7 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
* itself, so actual lookup of the hash should be once per lock object.
*/
static inline struct lock_class *
register_lock_class(struct lockdep_map *lock, unsigned int subclass)
register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
{
struct lockdep_subclass_key *key;
struct list_head *hash_head;
......@@ -1249,7 +1249,7 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass)
out_unlock_set:
__raw_spin_unlock(&hash_lock);
if (!subclass)
if (!subclass || force)
lock->class_cache = class;
DEBUG_LOCKS_WARN_ON(class->subclass != subclass);
......@@ -1937,7 +1937,7 @@ void trace_softirqs_off(unsigned long ip)
* Initialize a lock instance's lock-class mapping info:
*/
void lockdep_init_map(struct lockdep_map *lock, const char *name,
struct lock_class_key *key)
struct lock_class_key *key, int subclass)
{
if (unlikely(!debug_locks))
return;
......@@ -1957,6 +1957,8 @@ void lockdep_init_map(struct lockdep_map *lock, const char *name,
lock->name = name;
lock->key = key;
lock->class_cache = NULL;
if (subclass)
register_lock_class(lock, subclass, 1);
}
EXPORT_SYMBOL_GPL(lockdep_init_map);
......@@ -1995,7 +1997,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
* Not cached yet or subclass?
*/
if (unlikely(!class)) {
class = register_lock_class(lock, subclass);
class = register_lock_class(lock, subclass, 0);
if (!class)
return 0;
}
......
......@@ -91,7 +91,7 @@ void debug_mutex_init(struct mutex *lock, const char *name,
* Make sure we are not reinitializing a held lock:
*/
debug_check_no_locks_freed((void *)lock, sizeof(*lock));
lockdep_init_map(&lock->dep_map, name, key);
lockdep_init_map(&lock->dep_map, name, key, 0);
#endif
lock->owner = NULL;
lock->magic = lock;
......
......@@ -28,7 +28,7 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name,
* Make sure we are not reinitializing a held semaphore:
*/
debug_check_no_locks_freed((void *)sem, sizeof(*sem));
lockdep_init_map(&sem->dep_map, name, key);
lockdep_init_map(&sem->dep_map, name, key, 0);
#endif
sem->activity = 0;
spin_lock_init(&sem->wait_lock);
......
......@@ -19,7 +19,7 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name,
* Make sure we are not reinitializing a held semaphore:
*/
debug_check_no_locks_freed((void *)sem, sizeof(*sem));
lockdep_init_map(&sem->dep_map, name, key);
lockdep_init_map(&sem->dep_map, name, key, 0);
#endif
sem->count = RWSEM_UNLOCKED_VALUE;
spin_lock_init(&sem->wait_lock);
......
......@@ -20,7 +20,7 @@ void __spin_lock_init(spinlock_t *lock, const char *name,
* Make sure we are not reinitializing a held lock:
*/
debug_check_no_locks_freed((void *)lock, sizeof(*lock));
lockdep_init_map(&lock->dep_map, name, key);
lockdep_init_map(&lock->dep_map, name, key, 0);
#endif
lock->raw_lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
lock->magic = SPINLOCK_MAGIC;
......@@ -38,7 +38,7 @@ void __rwlock_init(rwlock_t *lock, const char *name,
* Make sure we are not reinitializing a held lock:
*/
debug_check_no_locks_freed((void *)lock, sizeof(*lock));
lockdep_init_map(&lock->dep_map, name, key);
lockdep_init_map(&lock->dep_map, name, key, 0);
#endif
lock->raw_lock = (raw_rwlock_t) __RAW_RW_LOCK_UNLOCKED;
lock->magic = RWLOCK_MAGIC;
......
......@@ -823,7 +823,7 @@ static void inline sock_lock_init(struct sock *sk)
af_family_slock_key_strings[sk->sk_family]);
lockdep_init_map(&sk->sk_lock.dep_map,
af_family_key_strings[sk->sk_family],
af_family_keys + sk->sk_family);
af_family_keys + sk->sk_family, 0);
}
/**
......
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