[PATCH v2 1/6] Bluetooth: Hold the lock inside l2cap_get_sock_by_addr()

["Gustavo F. Padovan" <padovan@profusion.mobi>]

It also have to change the name of the function to
l2cap_get_sock_by_addr() because we do hold the lock inside it now.
l2cap_get_sock_by_addr() just read data, so the lock now is
read_lock_bh().

Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
---
 net/bluetooth/l2cap.c |   17 ++++++-----------
 1 files changed, 6 insertions(+), 11 deletions(-)

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index cd8f6ea..2f72b0d 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -728,15 +728,18 @@ static inline void l2cap_chan_add(struct l2cap_conn *conn, struct sock *sk, stru
 }
 
 /* ---- Socket interface ---- */
-static struct sock *__l2cap_get_sock_by_addr(__le16 psm, bdaddr_t *src)
+static struct sock *l2cap_get_sock_by_addr(__le16 psm, bdaddr_t *src)
 {
 	struct sock *sk;
 	struct hlist_node *node;
+
+	read_lock_bh(&l2cap_sk_list.lock);
 	sk_for_each(sk, node, &l2cap_sk_list.head)
 		if (l2cap_pi(sk)->sport == psm && !bacmp(&bt_sk(sk)->src, src))
 			goto found;
 	sk = NULL;
 found:
+	read_unlock_bh(&l2cap_sk_list.lock);
 	return sk;
 }
 
@@ -1024,9 +1027,7 @@ static int l2cap_sock_bind(struct socket *sock, struct sockaddr *addr, int alen)
 		}
 	}
 
-	write_lock_bh(&l2cap_sk_list.lock);
-
-	if (la.l2_psm && __l2cap_get_sock_by_addr(la.l2_psm, &la.l2_bdaddr)) {
+	if (la.l2_psm && l2cap_get_sock_by_addr(la.l2_psm, &la.l2_bdaddr)) {
 		err = -EADDRINUSE;
 	} else {
 		/* Save source address */
@@ -1040,8 +1041,6 @@ static int l2cap_sock_bind(struct socket *sock, struct sockaddr *addr, int alen)
 			l2cap_pi(sk)->sec_level = BT_SECURITY_SDP;
 	}
 
-	write_unlock_bh(&l2cap_sk_list.lock);
-
 done:
 	release_sock(sk);
 	return err;
@@ -1257,18 +1256,14 @@ static int l2cap_sock_listen(struct socket *sock, int backlog)
 
 		err = -EINVAL;
 
-		write_lock_bh(&l2cap_sk_list.lock);
-
 		for (psm = 0x1001; psm < 0x1100; psm += 2)
-			if (!__l2cap_get_sock_by_addr(cpu_to_le16(psm), src)) {
+			if (!l2cap_get_sock_by_addr(cpu_to_le16(psm), src)) {
 				l2cap_pi(sk)->psm   = cpu_to_le16(psm);
 				l2cap_pi(sk)->sport = cpu_to_le16(psm);
 				err = 0;
 				break;
 			}
 
-		write_unlock_bh(&l2cap_sk_list.lock);
-
 		if (err < 0)
 			goto done;
 	}
-- 
1.7.3.1