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| author | David S. Miller <davem@davemloft.net> | 2017-02-17 16:19:39 -0500 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2017-06-20 14:04:21 +0200 |
| commit | 5988be39d31cb1ab9cc21d86254f2082ff8a9d25 (patch) | |
| tree | 1914bfaebca60644033ec2212761e3ec0f27e87b /net | |
| parent | 296a1ab22e2a153f428d8b3c7c47fc4076c05760 (diff) | |
| download | linux-5988be39d31cb1ab9cc21d86254f2082ff8a9d25.tar.gz linux-5988be39d31cb1ab9cc21d86254f2082ff8a9d25.tar.bz2 linux-5988be39d31cb1ab9cc21d86254f2082ff8a9d25.zip | |
irda: Fix lockdep annotations in hashbin_delete().
commit 4c03b862b12f980456f9de92db6d508a4999b788 upstream.
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>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Diffstat (limited to 'net')
| -rw-r--r-- | net/irda/irqueue.c | 34 |
1 files changed, 16 insertions, 18 deletions
diff --git a/net/irda/irqueue.c b/net/irda/irqueue.c index 7152624ed5f1..26ccd65cdcab 100644 --- a/net/irda/irqueue.c +++ b/net/irda/irqueue.c @@ -385,9 +385,6 @@ 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; @@ -398,22 +395,27 @@ 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); + } } } @@ -422,12 +424,8 @@ 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 |