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| author |   Dave Young <hidave.darkstar@gmail.com> | 2008-01-10 22:22:52 -0800 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2008-01-10 22:22:52 -0800 |
| commit | f951375d470c1a20d92c34377991197e6bf17990 (patch) | |
| tree | c479a1b80c14072a9486214f034078ab6f524471 /net/bluetooth | |
| parent | [AX25] af_ax25: Possible circular locking. (diff) | |
| download | linux-dev-f951375d470c1a20d92c34377991197e6bf17990.tar.xz linux-dev-f951375d470c1a20d92c34377991197e6bf17990.zip | |
[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>
Diffstat (limited to 'net/bluetooth')
| -rw-r--r-- | net/bluetooth/rfcomm/tty.c | 22 |
1 files changed, 13 insertions, 9 deletions
diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c index e447651a2dbe..a6a758dd1f7d 100644 --- a/net/bluetooth/rfcomm/tty.c +++ b/net/bluetooth/rfcomm/tty.c @@ -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); - 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); } |