From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Gustavo Padovan Subject: [ 72/80] Bluetooth: Add missing lock nesting notation Date: Wed, 9 Jan 2013 12:36:04 -0800 Message-Id: <20130109201509.642066887@linuxfoundation.org> In-Reply-To: <20130109201500.410171651@linuxfoundation.org> References: <20130109201500.410171651@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Gustavo Padovan 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: [] 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: [] 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 Signed-off-by: Greg Kroah-Hartman --- net/bluetooth/rfcomm/sock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/bluetooth/rfcomm/sock.c +++ b/net/bluetooth/rfcomm/sock.c @@ -485,7 +485,7 @@ static int rfcomm_sock_accept(struct soc long timeo; int err = 0; - lock_sock(sk); + lock_sock_nested(sk, SINGLE_DEPTH_NESTING); if (sk->sk_type != SOCK_STREAM) { err = -EINVAL; @@ -522,7 +522,7 @@ static int rfcomm_sock_accept(struct soc release_sock(sk); timeo = schedule_timeout(timeo); - lock_sock(sk); + lock_sock_nested(sk, SINGLE_DEPTH_NESTING); } __set_current_state(TASK_RUNNING); remove_wait_queue(sk_sleep(sk), &wait);