[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: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c
index e447651..a6a758d 100644
--- a/net/bluetooth/rfcomm/tty.c
+++ b/net/bluetooth/rfcomm/tty.c
@@ -95,9 +95,10 @@
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 @@
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 @@
{
BT_DBG("dev %p", dev);
- set_bit(RFCOMM_TTY_RELEASED, &dev->flags);
+ 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);
}