Bluetooth: Remove socket lock from l2cap_state_change()

This simplify and make safer the state change handling inside l2cap_core.c.
we got rid of __l2cap_state_change(). And l2cap_state_change() doesn't lock
the socket anymore, instead the socket is locked inside the ops callback for
state change in l2cap_sock.c.

It makes the code safer because in some we were using a unlocked version,
and now we are calls to l2cap_state_change(), when dealing with sockets, use
the locked version.

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 7 insertions, 24 deletions

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 049e1c81d771..c65ddc8e7689 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -223,7 +223,7 @@ static u16 l2cap_alloc_cid(struct l2cap_conn *conn)
         return 0;
 }
 
-static void __l2cap_state_change(struct l2cap_chan *chan, int state)
+static void l2cap_state_change(struct l2cap_chan *chan, int state)
 {
         BT_DBG("chan %p %s -> %s", chan, state_to_string(chan->state),
                state_to_string(state));
@@ -232,33 +232,16 @@ static void __l2cap_state_change(struct l2cap_chan *chan, int state)
         chan->ops->state_change(chan, state, 0);
 }
 
-static void l2cap_state_change(struct l2cap_chan *chan, int state)
-{
-        struct sock *sk = chan->sk;
-
-        lock_sock(sk);
-        __l2cap_state_change(chan, state);
-        release_sock(sk);
-}
-
 static inline void l2cap_state_change_and_error(struct l2cap_chan *chan,
                                                 int state, int err)
 {
-        struct sock *sk = chan->sk;
-
-        lock_sock(sk);
         chan->state = state;
         chan->ops->state_change(chan, chan->state, err);
-        release_sock(sk);
 }
 
 static inline void l2cap_chan_set_err(struct l2cap_chan *chan, int err)
 {
-        struct sock *sk = chan->sk;
-
-        lock_sock(sk);
         chan->ops->state_change(chan, chan->state, err);
-        release_sock(sk);
 }
 
 static void __set_retrans_timer(struct l2cap_chan *chan)
@@ -3787,7 +3770,7 @@ static struct l2cap_chan *l2cap_connect(struct l2cap_conn *conn,
         if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE) {
                 if (l2cap_chan_check_security(chan)) {
                         if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
-                                __l2cap_state_change(chan, BT_CONNECT2);
+                                l2cap_state_change(chan, BT_CONNECT2);
                                 result = L2CAP_CR_PEND;
                                 status = L2CAP_CS_AUTHOR_PEND;
                                 chan->ops->defer(chan);
@@ -3797,21 +3780,21 @@ static struct l2cap_chan *l2cap_connect(struct l2cap_conn *conn,
                                  * physical link is up.
                                  */
                                 if (amp_id == AMP_ID_BREDR) {
-                                        __l2cap_state_change(chan, BT_CONFIG);
+                                        l2cap_state_change(chan, BT_CONFIG);
                                         result = L2CAP_CR_SUCCESS;
                                 } else {
-                                        __l2cap_state_change(chan, BT_CONNECT2);
+                                        l2cap_state_change(chan, BT_CONNECT2);
                                         result = L2CAP_CR_PEND;
                                 }
                                 status = L2CAP_CS_NO_INFO;
                         }
                 } else {
-                        __l2cap_state_change(chan, BT_CONNECT2);
+                        l2cap_state_change(chan, BT_CONNECT2);
                         result = L2CAP_CR_PEND;
                         status = L2CAP_CS_AUTHEN_PEND;
                 }
         } else {
-                __l2cap_state_change(chan, BT_CONNECT2);
+                l2cap_state_change(chan, BT_CONNECT2);
                 result = L2CAP_CR_PEND;
                 status = L2CAP_CS_NO_INFO;
         }
@@ -4738,7 +4721,7 @@ static void l2cap_do_create(struct l2cap_chan *chan, int result,
                                sizeof(rsp), &rsp);
 
                 if (result == L2CAP_CR_SUCCESS) {
-                        __l2cap_state_change(chan, BT_CONFIG);
+                        l2cap_state_change(chan, BT_CONFIG);
                         set_bit(CONF_REQ_SENT, &chan->conf_state);
                         l2cap_send_cmd(chan->conn, l2cap_get_ident(chan->conn),
                                        L2CAP_CONF_REQ,