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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>
This commit is contained in:
David S. Miller 2017-02-17 16:19:39 -05:00 committed by LuK1337
parent c427bd1895
commit 94fcbc021a
1 changed files with 16 additions and 18 deletions
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34
net/irda/irqueue.c
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@ -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