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authorDavid S. Miller <davem@davemloft.net>2017-02-17 16:19:39 -0500
committerDavid S. Miller <davem@davemloft.net>2017-02-17 16:19:39 -0500
commit4c03b862b12f980456f9de92db6d508a4999b788 (patch)
tree1e04c243957386fbd888c5accf4e88e7cc50bf78
parent22f0708a718daea5e79de2d29b4829de016a4ff4 (diff)
downloadlinux-stericsson-4c03b862b12f980456f9de92db6d508a4999b788.tar.gz
irda: Fix lockdep annotations in hashbin_delete().
A nested lock depth was added to the hasbin_delete() code but it doesn't actually work some well and results in tons of lockdep splats. Fix the code instead to properly drop the lock around the operation and just keep peeking the head of the hashbin queue. Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/irda/irqueue.c34
1 files changed, 16 insertions, 18 deletions
diff --git a/net/irda/irqueue.c b/net/irda/irqueue.c
index acbe61c7e683..160dc89335e2 100644
--- a/net/irda/irqueue.c
+++ b/net/irda/irqueue.c
@@ -383,9 +383,6 @@ EXPORT_SYMBOL(hashbin_new);
* for deallocating this structure if it's complex. If not the user can
* just supply kfree, which should take care of the job.
*/
-#ifdef CONFIG_LOCKDEP
-static int hashbin_lock_depth = 0;
-#endif
int hashbin_delete( hashbin_t* hashbin, FREE_FUNC free_func)
{
irda_queue_t* queue;
@@ -396,22 +393,27 @@ int hashbin_delete( hashbin_t* hashbin, FREE_FUNC free_func)
IRDA_ASSERT(hashbin->magic == HB_MAGIC, return -1;);
/* Synchronize */
- if ( hashbin->hb_type & HB_LOCK ) {
- spin_lock_irqsave_nested(&hashbin->hb_spinlock, flags,
- hashbin_lock_depth++);
- }
+ if (hashbin->hb_type & HB_LOCK)
+ spin_lock_irqsave(&hashbin->hb_spinlock, flags);
/*
* Free the entries in the hashbin, TODO: use hashbin_clear when
* it has been shown to work
*/
for (i = 0; i < HASHBIN_SIZE; i ++ ) {
- queue = dequeue_first((irda_queue_t**) &hashbin->hb_queue[i]);
- while (queue ) {
- if (free_func)
- (*free_func)(queue);
- queue = dequeue_first(
- (irda_queue_t**) &hashbin->hb_queue[i]);
+ while (1) {
+ queue = dequeue_first((irda_queue_t**) &hashbin->hb_queue[i]);
+
+ if (!queue)
+ break;
+
+ if (free_func) {
+ if (hashbin->hb_type & HB_LOCK)
+ spin_unlock_irqrestore(&hashbin->hb_spinlock, flags);
+ free_func(queue);
+ if (hashbin->hb_type & HB_LOCK)
+ spin_lock_irqsave(&hashbin->hb_spinlock, flags);
+ }
}
}
@@ -420,12 +422,8 @@ int hashbin_delete( hashbin_t* hashbin, FREE_FUNC free_func)
hashbin->magic = ~HB_MAGIC;
/* Release lock */
- if ( hashbin->hb_type & HB_LOCK) {
+ if (hashbin->hb_type & HB_LOCK)
spin_unlock_irqrestore(&hashbin->hb_spinlock, flags);
-#ifdef CONFIG_LOCKDEP
- hashbin_lock_depth--;
-#endif
- }
/*
* Free the hashbin structure