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authorJohan Hedberg <johan.hedberg@intel.com>2014-11-12 10:15:50 +0300
committerMarcel Holtmann <marcel@holtmann.org>2014-11-12 12:05:25 +0300
commitf03567040cbf874834c9e3e52b72fdcb672b9bbb (patch)
treef7a18f485dad11dec93bc810aa330407c0943035 /net/bluetooth/l2cap_sock.c
parentc8937a1d112b1a948454f4fa2f9b747fee2a3f66 (diff)
downloadlinux-f03567040cbf874834c9e3e52b72fdcb672b9bbb.tar.xz
Bluetooth: Fix l2cap_sock_teardown_cb lockdep warning
Any code calling bt_accept_dequeue() to get a new child socket from a server socket should use lock_sock_nested to avoid lockdep warnings due to the parent and child sockets being locked at the same time. The l2cap_sock_accept() function is already doing this correctly but a second place calling bt_accept_dequeue() is the code path from l2cap_sock_teardown_cb() that calls l2cap_sock_cleanup_listen(). This patch fixes the proper nested locking annotation and thereby avoids the following style of lockdep warning. [ +0.000224] [ INFO: possible recursive locking detected ] [ +0.000222] 3.17.0+ #1153 Not tainted [ +0.000130] --------------------------------------------- [ +0.000227] l2cap-tester/562 is trying to acquire lock: [ +0.000210] (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+...}, at: [<c1393f47>] bt_accept_dequeue+0x68/0x11b [ +0.000467] but task is already holding lock: [ +0.000186] (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+...}, at: [<c13b949a>] lock_sock+0xa/0xc [ +0.000421] other info that might help us debug this: [ +0.000199] Possible unsafe locking scenario: [ +0.000117] CPU0 [ +0.000000] ---- [ +0.000000] lock(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP); [ +0.000000] lock(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP); [ +0.000000] *** DEADLOCK *** Signed-off-by: Johan Hedberg <johan.hedberg@intel.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'net/bluetooth/l2cap_sock.c')
-rw-r--r--net/bluetooth/l2cap_sock.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index 31f106e61ca2..ad1cf82fee02 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -1246,7 +1246,7 @@ static void l2cap_sock_teardown_cb(struct l2cap_chan *chan, int err)
struct sock *sk = chan->data;
struct sock *parent;
- lock_sock(sk);
+ lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
parent = bt_sk(sk)->parent;