Bluetooth: silence lockdep warning

Since bluetooth uses multiple protocols types, to avoid lockdep
warnings, we need to use different lockdep classes (one for each
protocol type).

This is already done in bt_sock_create but it misses a couple of cases
when new connections are created. This patch corrects that to fix the
following warning:

<4>[ 1864.732366] =======================================================
<4>[ 1864.733030] [ INFO: possible circular locking dependency detected ]
<4>[ 1864.733544] 3.0.16-mid3-00007-gc9a0f62 #3
<4>[ 1864.733883] -------------------------------------------------------
<4>[ 1864.734408] t.android.btclc/4204 is trying to acquire lock:
<4>[ 1864.734869]  (rfcomm_mutex){+.+.+.}, at: [<c14970ea>] rfcomm_dlc_close+0x15/0x30
<4>[ 1864.735541]
<4>[ 1864.735549] but task is already holding lock:
<4>[ 1864.736045]  (sk_lock-AF_BLUETOOTH){+.+.+.}, at: [<c1498bf7>] lock_sock+0xa/0xc
<4>[ 1864.736732]
<4>[ 1864.736740] which lock already depends on the new lock.
<4>[ 1864.736750]
<4>[ 1864.737428]
<4>[ 1864.737437] the existing dependency chain (in reverse order) is:
<4>[ 1864.738016]
<4>[ 1864.738023] -> #1 (sk_lock-AF_BLUETOOTH){+.+.+.}:
<4>[ 1864.738549]        [<c1062273>] lock_acquire+0x104/0x140
<4>[ 1864.738977]        [<c13d35c1>] lock_sock_nested+0x58/0x68
<4>[ 1864.739411]        [<c1493c33>] l2cap_sock_sendmsg+0x3e/0x76
<4>[ 1864.739858]        [<c13d06c3>] __sock_sendmsg+0x50/0x59
<4>[ 1864.740279]        [<c13d0ea2>] sock_sendmsg+0x94/0xa8
<4>[ 1864.740687]        [<c13d0ede>] kernel_sendmsg+0x28/0x37
<4>[ 1864.741106]        [<c14969ca>] rfcomm_send_frame+0x30/0x38
<4>[ 1864.741542]        [<c1496a2a>] rfcomm_send_ua+0x58/0x5a
<4>[ 1864.741959]        [<c1498447>] rfcomm_run+0x441/0xb52
<4>[ 1864.742365]        [<c104f095>] kthread+0x63/0x68
<4>[ 1864.742742]        [<c14d5182>] kernel_thread_helper+0x6/0xd
<4>[ 1864.743187]
<4>[ 1864.743193] -> #0 (rfcomm_mutex){+.+.+.}:
<4>[ 1864.743667]        [<c1061ada>] __lock_acquire+0x988/0xc00
<4>[ 1864.744100]        [<c1062273>] lock_acquire+0x104/0x140
<4>[ 1864.744519]        [<c14d2c70>] __mutex_lock_common+0x3b/0x33f
<4>[ 1864.744975]        [<c14d303e>] mutex_lock_nested+0x2d/0x36
<4>[ 1864.745412]        [<c14970ea>] rfcomm_dlc_close+0x15/0x30
<4>[ 1864.745842]        [<c14990d9>] __rfcomm_sock_close+0x5f/0x6b
<4>[ 1864.746288]        [<c1499114>] rfcomm_sock_shutdown+0x2f/0x62
<4>[ 1864.746737]        [<c13d275d>] sys_socketcall+0x1db/0x422
<4>[ 1864.747165]        [<c14d42f0>] syscall_call+0x7/0xb

Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

diff --git a/include/net/bluetooth/bluetooth.h b/include/net/bluetooth/bluetooth.h
index abaad6ed9b83e7b65da14b7a30ae3a175f2992b4..4a82ca0bb0b209a12c65a83b42138098e6572ad1 100644 (file)
--- a/include/net/bluetooth/bluetooth.h
+++ b/include/net/bluetooth/bluetooth.h
@@ -256,4 +256,6 @@ void l2cap_exit(void);
 int sco_init(void);
 void sco_exit(void);
 
+void bt_sock_reclassify_lock(struct sock *sk, int proto);
+
 #endif /* __BLUETOOTH_H */

diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c
index ef92864ac6258b32ec600ad5791e19d399d0965b..72eb187a5f605f9835d71c2de9f980e1e52d6a4e 100644 (file)
--- a/net/bluetooth/af_bluetooth.c
+++ b/net/bluetooth/af_bluetooth.c
@@ -71,19 +71,16 @@ static const char *const bt_slock_key_strings[BT_MAX_PROTO] = {
        "slock-AF_BLUETOOTH-BTPROTO_AVDTP",
 };
 
-static inline void bt_sock_reclassify_lock(struct socket *sock, int proto)
+void bt_sock_reclassify_lock(struct sock *sk, int proto)
 {
-       struct sock *sk = sock->sk;
-
-       if (!sk)
-               return;
-
+       BUG_ON(!sk);
        BUG_ON(sock_owned_by_user(sk));
 
        sock_lock_init_class_and_name(sk,
                        bt_slock_key_strings[proto], &bt_slock_key[proto],
                                bt_key_strings[proto], &bt_lock_key[proto]);
 }
+EXPORT_SYMBOL(bt_sock_reclassify_lock);
 
 int bt_sock_register(int proto, const struct net_proto_family *ops)
 {
@@ -145,7 +142,8 @@ static int bt_sock_create(struct net *net, struct socket *sock, int proto,
 
        if (bt_proto[proto] && try_module_get(bt_proto[proto]->owner)) {
                err = bt_proto[proto]->create(net, sock, proto, kern);
-               bt_sock_reclassify_lock(sock, proto);
+               if (!err)
+                       bt_sock_reclassify_lock(sock->sk, proto);
                module_put(bt_proto[proto]->owner);
        }
 

diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index c57027f7606f801c9ac3e3b0d9632abeed7e7e11..401d9428ae4c824f6dbe2871d77bb6742ba4688c 100644 (file)
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -849,6 +849,8 @@ static struct l2cap_chan *l2cap_sock_new_connection_cb(void *data)
        if (!sk)
                return NULL;
 
+       bt_sock_reclassify_lock(sk, BTPROTO_L2CAP);
+
        l2cap_sock_init(sk, parent);
 
        return l2cap_pi(sk)->chan;

diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index f066678faeee838efae16243111a1bb51f47c8f3..22169c3f148254c52b991caf64b7c0284a54d7f6 100644 (file)
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -956,6 +956,8 @@ int rfcomm_connect_ind(struct rfcomm_session *s, u8 channel, struct rfcomm_dlc *
        if (!sk)
                goto done;
 
+       bt_sock_reclassify_lock(sk, BTPROTO_RFCOMM);
+
        rfcomm_sock_init(sk, parent);
        bacpy(&bt_sk(sk)->src, &src);
        bacpy(&bt_sk(sk)->dst, &dst);