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Commit c2219da5 authored by David S. Miller's avatar David S. Miller Committed by Greg Kroah-Hartman
Browse files

irda: Fix lockdep annotations in hashbin_delete(). 



[ Upstream commit 4c03b862b12f980456f9de92db6d508a4999b788 ]

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: default avatarDmitry Vyukov <dvyukov@google.com>
Tested-by: default avatarDmitry Vyukov <dvyukov@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f23fd87e

net/irda/irqueue.c

+16 −18
Original line number Diff line number Diff line
@@ -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 ++ ) {

		while (1) {

			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]);



			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