Bluetooth: Add missing lock nesting notation
authorGustavo Padovan <gustavo.padovan@collabora.co.uk>
Wed, 21 Nov 2012 01:25:54 +0000 (23:25 -0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 11 Jan 2013 17:07:17 +0000 (09:07 -0800)
commit7e2741804be03faf0eaba1df228e2ba5c07ecdd7
treee9740f5b6e5a6f93343732adfc8e55b75680de1c
parent2145cea1e0be3262768fef384a87f426ecad06fe
Bluetooth: Add missing lock nesting notation

commit dc2a0e20fbc85a71c63aa4330b496fda33f6bf80 upstream.

This patch fixes the following report, it happens when accepting rfcomm
connections:

[  228.165378] =============================================
[  228.165378] [ INFO: possible recursive locking detected ]
[  228.165378] 3.7.0-rc1-00536-gc1d5dc4 #120 Tainted: G        W
[  228.165378] ---------------------------------------------
[  228.165378] bluetoothd/1341 is trying to acquire lock:
[  228.165378]  (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+...}, at:
[<ffffffffa0000aa0>] bt_accept_dequeue+0xa0/0x180 [bluetooth]
[  228.165378]
[  228.165378] but task is already holding lock:
[  228.165378]  (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+...}, at:
[<ffffffffa0205118>] rfcomm_sock_accept+0x58/0x2d0 [rfcomm]
[  228.165378]
[  228.165378] other info that might help us debug this:
[  228.165378]  Possible unsafe locking scenario:
[  228.165378]
[  228.165378]        CPU0
[  228.165378]        ----
[  228.165378]   lock(sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM);
[  228.165378]   lock(sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM);
[  228.165378]
[  228.165378]  *** DEADLOCK ***
[  228.165378]
[  228.165378]  May be due to missing lock nesting notation

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/bluetooth/rfcomm/sock.c