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authorIngo Molnar <mingo@elte.hu>2006-07-03 00:24:53 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-07-03 15:27:04 -0700
commit4ea2176dfa714882e88180b474e4cbcd888b70af (patch)
tree7ff3810f6b8750c226234887bb3063d91e1d71c3 /lib/rwsem-spinlock.c
parenta8f24a3978c5f82419e1c90dc90460731204f46f (diff)
downloadlwn-4ea2176dfa714882e88180b474e4cbcd888b70af.tar.gz
lwn-4ea2176dfa714882e88180b474e4cbcd888b70af.zip
[PATCH] lockdep: prove rwsem locking correctness
Use the lock validator framework to prove rwsem locking correctness. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'lib/rwsem-spinlock.c')
-rw-r--r--lib/rwsem-spinlock.c20
1 files changed, 17 insertions, 3 deletions
diff --git a/lib/rwsem-spinlock.c b/lib/rwsem-spinlock.c
index 03b6097eb04e..db4fed74b940 100644
--- a/lib/rwsem-spinlock.c
+++ b/lib/rwsem-spinlock.c
@@ -20,8 +20,16 @@ struct rwsem_waiter {
/*
* initialise the semaphore
*/
-void fastcall init_rwsem(struct rw_semaphore *sem)
+void __init_rwsem(struct rw_semaphore *sem, const char *name,
+ struct lock_class_key *key)
{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ /*
+ * 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);
+#endif
sem->activity = 0;
spin_lock_init(&sem->wait_lock);
INIT_LIST_HEAD(&sem->wait_list);
@@ -183,7 +191,7 @@ int fastcall __down_read_trylock(struct rw_semaphore *sem)
* get a write lock on the semaphore
* - we increment the waiting count anyway to indicate an exclusive lock
*/
-void fastcall __sched __down_write(struct rw_semaphore *sem)
+void fastcall __sched __down_write_nested(struct rw_semaphore *sem, int subclass)
{
struct rwsem_waiter waiter;
struct task_struct *tsk;
@@ -223,6 +231,11 @@ void fastcall __sched __down_write(struct rw_semaphore *sem)
;
}
+void fastcall __sched __down_write(struct rw_semaphore *sem)
+{
+ __down_write_nested(sem, 0);
+}
+
/*
* trylock for writing -- returns 1 if successful, 0 if contention
*/
@@ -292,9 +305,10 @@ void fastcall __downgrade_write(struct rw_semaphore *sem)
spin_unlock_irqrestore(&sem->wait_lock, flags);
}
-EXPORT_SYMBOL(init_rwsem);
+EXPORT_SYMBOL(__init_rwsem);
EXPORT_SYMBOL(__down_read);
EXPORT_SYMBOL(__down_read_trylock);
+EXPORT_SYMBOL(__down_write_nested);
EXPORT_SYMBOL(__down_write);
EXPORT_SYMBOL(__down_write_trylock);
EXPORT_SYMBOL(__up_read);