Return-Path: From: "Gustavo F. Padovan" To: linux-bluetooth@vger.kernel.org Cc: "Gustavo F. Padovan" Subject: [RFC 18/22] Bluetooth: invert locking order in connect path Date: Sat, 17 Dec 2011 19:29:38 -0200 Message-Id: <1324157382-1815-19-git-send-email-padovan@profusion.mobi> In-Reply-To: <1324157382-1815-18-git-send-email-padovan@profusion.mobi> References: <1324157382-1815-1-git-send-email-padovan@profusion.mobi> <1324157382-1815-2-git-send-email-padovan@profusion.mobi> <1324157382-1815-3-git-send-email-padovan@profusion.mobi> <1324157382-1815-4-git-send-email-padovan@profusion.mobi> <1324157382-1815-5-git-send-email-padovan@profusion.mobi> <1324157382-1815-6-git-send-email-padovan@profusion.mobi> <1324157382-1815-7-git-send-email-padovan@profusion.mobi> <1324157382-1815-8-git-send-email-padovan@profusion.mobi> <1324157382-1815-9-git-send-email-padovan@profusion.mobi> <1324157382-1815-10-git-send-email-padovan@profusion.mobi> <1324157382-1815-11-git-send-email-padovan@profusion.mobi> <1324157382-1815-12-git-send-email-padovan@profusion.mobi> <1324157382-1815-13-git-send-email-padovan@profusion.mobi> <1324157382-1815-14-git-send-email-padovan@profusion.mobi> <1324157382-1815-15-git-send-email-padovan@profusion.mobi> <1324157382-1815-16-git-send-email-padovan@profusion.mobi> <1324157382-1815-17-git-send-email-padovan@profusion.mobi> <1324157382-1815-18-git-send-email-padovan@profusion.mobi> Sender: linux-bluetooth-owner@vger.kernel.org List-ID: From: "Gustavo F. Padovan" This move some checking code that was in l2cap_sock_connect() to l2cap_chan_connect(). Thus we can invert the lock calls, i.e., call lock_sock() before hci_dev_lock() to avoid a deadlock scenario. Signed-off-by: Gustavo F. Padovan --- include/net/bluetooth/l2cap.h | 3 +- net/bluetooth/l2cap_core.c | 58 +++++++++++++++++++++++++++++++++++++- net/bluetooth/l2cap_sock.c | 61 ++--------------------------------------- 3 files changed, 61 insertions(+), 61 deletions(-) diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h index f791374..c0d168a 100644 --- a/include/net/bluetooth/l2cap.h +++ b/include/net/bluetooth/l2cap.h @@ -806,7 +806,8 @@ int l2cap_add_scid(struct l2cap_chan *chan, __u16 scid); struct l2cap_chan *l2cap_chan_create(struct sock *sk); void l2cap_chan_close(struct l2cap_chan *chan, int reason); void l2cap_chan_destroy(struct l2cap_chan *chan); -int l2cap_chan_connect(struct l2cap_chan *chan); +inline int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid, + bdaddr_t *dst); int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len, u32 priority); void l2cap_chan_busy(struct l2cap_chan *chan, int busy); diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index a78cdf7..d616519 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -1144,11 +1144,10 @@ static struct l2cap_chan *l2cap_global_chan_by_psm(int state, __le16 psm, bdaddr return c1; } -int l2cap_chan_connect(struct l2cap_chan *chan) +inline int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid, bdaddr_t *dst) { struct sock *sk = chan->sk; bdaddr_t *src = &bt_sk(sk)->src; - bdaddr_t *dst = &bt_sk(sk)->dst; struct l2cap_conn *conn; struct hci_conn *hcon; struct hci_dev *hdev; @@ -1164,6 +1163,61 @@ int l2cap_chan_connect(struct l2cap_chan *chan) hci_dev_lock(hdev); + lock_sock(sk); + + /* PSM must be odd and lsb of upper byte must be 0 */ + if ((__le16_to_cpu(psm) & 0x0101) != 0x0001 && !cid && + chan->chan_type != L2CAP_CHAN_RAW) { + err = -EINVAL; + goto done; + } + + if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED && !(psm || cid)) { + err = -EINVAL; + goto done; + } + + switch (chan->mode) { + case L2CAP_MODE_BASIC: + break; + case L2CAP_MODE_ERTM: + case L2CAP_MODE_STREAMING: + if (!disable_ertm) + break; + /* fall through */ + default: + err = -ENOTSUPP; + goto done; + } + + switch (sk->sk_state) { + case BT_CONNECT: + case BT_CONNECT2: + case BT_CONFIG: + /* Already connecting */ + err = 0; + goto done; + + case BT_CONNECTED: + /* Already connected */ + err = -EISCONN; + goto done; + + case BT_OPEN: + case BT_BOUND: + /* Can connect */ + break; + + default: + err = -EBADFD; + goto done; + } + + /* Set destination address and psm */ + bacpy(&bt_sk(sk)->dst, src); + chan->psm = psm; + chan->dcid = cid; + auth_type = l2cap_get_auth_type(chan); if (chan->dcid == L2CAP_CID_LE_DATA) diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index fbdc8b3..6c7d432 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -121,70 +121,15 @@ static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr, int al if (la.l2_cid && la.l2_psm) return -EINVAL; - lock_sock(sk); - - if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED - && !(la.l2_psm || la.l2_cid)) { - err = -EINVAL; - goto done; - } - - switch (chan->mode) { - case L2CAP_MODE_BASIC: - break; - case L2CAP_MODE_ERTM: - case L2CAP_MODE_STREAMING: - if (!disable_ertm) - break; - /* fall through */ - default: - err = -ENOTSUPP; - goto done; - } - - switch (sk->sk_state) { - case BT_CONNECT: - case BT_CONNECT2: - case BT_CONFIG: - /* Already connecting */ - goto wait; - - case BT_CONNECTED: - /* Already connected */ - err = -EISCONN; - goto done; - - case BT_OPEN: - case BT_BOUND: - /* Can connect */ - break; - - default: - err = -EBADFD; - goto done; - } - - /* PSM must be odd and lsb of upper byte must be 0 */ - if ((__le16_to_cpu(la.l2_psm) & 0x0101) != 0x0001 && !la.l2_cid && - chan->chan_type != L2CAP_CHAN_RAW) { - err = -EINVAL; - goto done; - } - - /* Set destination address and psm */ - bacpy(&bt_sk(sk)->dst, &la.l2_bdaddr); - chan->psm = la.l2_psm; - chan->dcid = la.l2_cid; - - err = l2cap_chan_connect(chan); + err = l2cap_chan_connect(chan, la.l2_psm, la.l2_cid, &la.l2_bdaddr); if (err) goto done; -wait: err = bt_sock_wait_state(sk, BT_CONNECTED, sock_sndtimeo(sk, flags & O_NONBLOCK)); done: - release_sock(sk); + if (sock_owned_by_user(sk)) + release_sock(sk); return err; } -- 1.7.6.4