Commit f951375d authored by Dave Young's avatar Dave Young Committed by David S. Miller
Browse files

[BLUETOOTH]: rfcomm tty BUG_ON() code fix 



1) In tty.c the BUG_ON at line 115 will never be called, because the the
   before list_del_init in this same function.
	115          BUG_ON(!list_empty(&dev->list));
   So move the list_del_init to rfcomm_dev_del 

2) The rfcomm_dev_del could be called from diffrent path
   (rfcomm_tty_hangup/rfcomm_dev_state_change/rfcomm_release_dev),

   So add another BUG_ON when the rfcomm_dev_del is called more than
   one time.

Signed-off-by: default avatarDave Young <hidave.darkstar@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ecd2ebde

net/bluetooth/rfcomm/tty.c

+13 −9
Original line number Diff line number Diff line
@@ -95,9 +95,10 @@ static void rfcomm_dev_destruct(struct rfcomm_dev *dev) 


	BT_DBG("dev %p dlc %p", dev, dlc);



	write_lock_bh(&rfcomm_dev_lock);

	list_del_init(&dev->list);

	write_unlock_bh(&rfcomm_dev_lock);

	/* Refcount should only hit zero when called from rfcomm_dev_del()

	   which will have taken us off the list. Everything else are

	   refcounting bugs. */

	BUG_ON(!list_empty(&dev->list));



	rfcomm_dlc_lock(dlc);

	/* Detach DLC if it's owned by this dev */
@@ -109,11 +110,6 @@ static void rfcomm_dev_destruct(struct rfcomm_dev *dev) 


	tty_unregister_device(rfcomm_tty_driver, dev->id);



	/* Refcount should only hit zero when called from rfcomm_dev_del()

	   which will have taken us off the list. Everything else are

	   refcounting bugs. */

	BUG_ON(!list_empty(&dev->list));



	kfree(dev);



	/* It's safe to call module_put() here because socket still
@@ -313,7 +309,15 @@ static void rfcomm_dev_del(struct rfcomm_dev *dev) 
{

	BT_DBG("dev %p", dev);



	if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags))

		BUG_ON(1);

	else

		set_bit(RFCOMM_TTY_RELEASED, &dev->flags);



	write_lock_bh(&rfcomm_dev_lock);

	list_del_init(&dev->list);

	write_unlock_bh(&rfcomm_dev_lock);



	rfcomm_dev_put(dev);

}

CRA Git | Maintained and supported by SUSTech CRA and CCSE