[RFCv5 00/16] Bluetooth: Change socket lock to l2cap_chan lock

[RFCv5 00/16] Bluetooth: Change socket lock to l2cap_chan lock

[Emeltchenko Andrei]

From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>

This set is still WIP, hope to send PATCH series next week.

Those patches which dealing with locks need to be applied at once,
if needed they can be merged together.

Changes:
	* RFCv5: Fixed locking bug in l2cap_data_channel, added locks in 
	l2cap_sock_shutdown function, fixed several styles issues.
	* RFCv4: Better split patches so they looks more clear and obvious,
	taking coments about naming change and delete unused vars. See diff change
	from the previous version below:
	* RFCv3: Split the big patch to several small (I believe logical) chunks,
	remove unneded locks from cleanup_listen, use the same arguments for
	locked/unlocked socket error functions.
	* RFCv2: Convert l2cap channel list back to mutex from RCU list.

Andrei Emeltchenko (16):
  Bluetooth: trivial: Fix long line
  Bluetooth: Revert to mutexes from RCU list
  Bluetooth: Lock chan list when deleting chan
  Bluetooth: Do not use sk lock in get_chan functions
  Bluetooth: Add l2cap_chan_lock
  Bluetooth: Add locked and unlocked state_change
  Bluetooth: Add socket error function
  Bluetooth: Add unlocked __l2cap_chan_add function
  Bluetooth: Use chan lock in timers
  Bluetooth: Use chan lock in L2CAP sig commands
  Bluetooth: Use chan lock in L2CAP conn start
  Bluetooth: Use chan lock in receiving data
  Bluetooth: Change locking logic for conn/chan ready
  Bluetooth: Change locking logic in security_cfm
  Bluetooth: Use l2cap chan lock in socket connect
  Bluetooth: Remove socket lock check

 include/net/bluetooth/l2cap.h |   11 ++
 net/bluetooth/l2cap_core.c    |  391 +++++++++++++++++++++++++----------------
 net/bluetooth/l2cap_sock.c    |   34 +++-
 3 files changed, 280 insertions(+), 156 deletions(-)

-- 
1.7.9

[RFCv5 01/16] Bluetooth: trivial: Fix long line

[Emeltchenko Andrei]

From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
---
 net/bluetooth/l2cap_core.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 37736c6..63539f9 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -2720,7 +2720,8 @@ static inline int l2cap_connect_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hd
 	result = __le16_to_cpu(rsp->result);
 	status = __le16_to_cpu(rsp->status);
 
-	BT_DBG("dcid 0x%4.4x scid 0x%4.4x result 0x%2.2x status 0x%2.2x", dcid, scid, result, status);
+	BT_DBG("dcid 0x%4.4x scid 0x%4.4x result 0x%2.2x status 0x%2.2x",
+						dcid, scid, result, status);
 
 	if (scid) {
 		chan = l2cap_get_chan_by_scid(conn, scid);
-- 
1.7.9

[RFCv5 02/16] Bluetooth: Revert to mutexes from RCU list

[Emeltchenko Andrei]

From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>

Usage of RCU list looks not reasonalbe for a number of reasons:
our code sleep and we have to use socket spinlocks, some parts
of code are updaters thus we need to use mutexes anyway.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
---
 net/bluetooth/l2cap_core.c |   98 ++++++++++++++++++++-----------------------
 1 files changed, 46 insertions(+), 52 deletions(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 63539f9..109b62d 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -77,36 +77,24 @@ static void l2cap_send_disconn_req(struct l2cap_conn *conn,
 
 static struct l2cap_chan *__l2cap_get_chan_by_dcid(struct l2cap_conn *conn, u16 cid)
 {
-	struct l2cap_chan *c, *r = NULL;
-
-	rcu_read_lock();
+	struct l2cap_chan *c;
 
-	list_for_each_entry_rcu(c, &conn->chan_l, list) {
-		if (c->dcid == cid) {
-			r = c;
-			break;
-		}
+	list_for_each_entry(c, &conn->chan_l, list) {
+		if (c->dcid == cid)
+			return c;
 	}
-
-	rcu_read_unlock();
-	return r;
+	return NULL;
 }
 
 static struct l2cap_chan *__l2cap_get_chan_by_scid(struct l2cap_conn *conn, u16 cid)
 {
-	struct l2cap_chan *c, *r = NULL;
-
-	rcu_read_lock();
+	struct l2cap_chan *c;
 
-	list_for_each_entry_rcu(c, &conn->chan_l, list) {
-		if (c->scid == cid) {
-			r = c;
-			break;
-		}
+	list_for_each_entry(c, &conn->chan_l, list) {
+		if (c->scid == cid)
+			return c;
 	}
-
-	rcu_read_unlock();
-	return r;
+	return NULL;
 }
 
 /* Find channel with given SCID.
@@ -115,36 +103,34 @@ static struct l2cap_chan *l2cap_get_chan_by_scid(struct l2cap_conn *conn, u16 ci
 {
 	struct l2cap_chan *c;
 
+	mutex_lock(&conn->chan_lock);
 	c = __l2cap_get_chan_by_scid(conn, cid);
 	if (c)
 		lock_sock(c->sk);
+	mutex_unlock(&conn->chan_lock);
 	return c;
 }
 
 static struct l2cap_chan *__l2cap_get_chan_by_ident(struct l2cap_conn *conn, u8 ident)
 {
-	struct l2cap_chan *c, *r = NULL;
-
-	rcu_read_lock();
+	struct l2cap_chan *c;
 
-	list_for_each_entry_rcu(c, &conn->chan_l, list) {
-		if (c->ident == ident) {
-			r = c;
-			break;
-		}
+	list_for_each_entry(c, &conn->chan_l, list) {
+		if (c->ident == ident)
+			return c;
 	}
-
-	rcu_read_unlock();
-	return r;
+	return NULL;
 }
 
 static inline struct l2cap_chan *l2cap_get_chan_by_ident(struct l2cap_conn *conn, u8 ident)
 {
 	struct l2cap_chan *c;
 
+	mutex_lock(&conn->chan_lock);
 	c = __l2cap_get_chan_by_ident(conn, ident);
 	if (c)
 		lock_sock(c->sk);
+	mutex_unlock(&conn->chan_lock);
 	return c;
 }
 
@@ -331,7 +317,9 @@ static void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
 
 	l2cap_chan_hold(chan);
 
-	list_add_rcu(&chan->list, &conn->chan_l);
+	mutex_lock(&conn->chan_lock);
+	list_add(&chan->list, &conn->chan_l);
+	mutex_unlock(&conn->chan_lock);
 }
 
 /* Delete channel.
@@ -348,8 +336,7 @@ static void l2cap_chan_del(struct l2cap_chan *chan, int err)
 
 	if (conn) {
 		/* Delete from channel list */
-		list_del_rcu(&chan->list);
-		synchronize_rcu();
+		list_del(&chan->list);
 
 		l2cap_chan_put(chan);
 
@@ -400,10 +387,12 @@ static void l2cap_chan_cleanup_listen(struct sock *parent)
 	/* Close not yet accepted channels */
 	while ((sk = bt_accept_dequeue(parent, NULL))) {
 		struct l2cap_chan *chan = l2cap_pi(sk)->chan;
+
 		__clear_chan_timer(chan);
 		lock_sock(sk);
 		l2cap_chan_close(chan, ECONNRESET);
 		release_sock(sk);
+
 		chan->ops->close(chan->data);
 	}
 }
@@ -718,13 +707,13 @@ static void l2cap_send_disconn_req(struct l2cap_conn *conn, struct l2cap_chan *c
 /* ---- L2CAP connections ---- */
 static void l2cap_conn_start(struct l2cap_conn *conn)
 {
-	struct l2cap_chan *chan;
+	struct l2cap_chan *chan, *tmp;
 
 	BT_DBG("conn %p", conn);
 
-	rcu_read_lock();
+	mutex_lock(&conn->chan_lock);
 
-	list_for_each_entry_rcu(chan, &conn->chan_l, list) {
+	list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
 		struct sock *sk = chan->sk;
 
 		bh_lock_sock(sk);
@@ -804,7 +793,7 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
 		bh_unlock_sock(sk);
 	}
 
-	rcu_read_unlock();
+	mutex_unlock(&conn->chan_lock);
 }
 
 /* Find socket with cid and source bdaddr.
@@ -916,9 +905,9 @@ static void l2cap_conn_ready(struct l2cap_conn *conn)
 	if (conn->hcon->out && conn->hcon->type == LE_LINK)
 		smp_conn_security(conn, conn->hcon->pending_sec_level);
 
-	rcu_read_lock();
+	mutex_lock(&conn->chan_lock);
 
-	list_for_each_entry_rcu(chan, &conn->chan_l, list) {
+	list_for_each_entry(chan, &conn->chan_l, list) {
 		struct sock *sk = chan->sk;
 
 		bh_lock_sock(sk);
@@ -938,7 +927,7 @@ static void l2cap_conn_ready(struct l2cap_conn *conn)
 		bh_unlock_sock(sk);
 	}
 
-	rcu_read_unlock();
+	mutex_unlock(&conn->chan_lock);
 }
 
 /* Notify sockets that we cannot guaranty reliability anymore */
@@ -948,16 +937,16 @@ static void l2cap_conn_unreliable(struct l2cap_conn *conn, int err)
 
 	BT_DBG("conn %p", conn);
 
-	rcu_read_lock();
+	mutex_lock(&conn->chan_lock);
 
-	list_for_each_entry_rcu(chan, &conn->chan_l, list) {
+	list_for_each_entry(chan, &conn->chan_l, list) {
 		struct sock *sk = chan->sk;
 
 		if (test_bit(FLAG_FORCE_RELIABLE, &chan->flags))
 			sk->sk_err = err;
 	}
 
-	rcu_read_unlock();
+	mutex_unlock(&conn->chan_lock);
 }
 
 static void l2cap_info_timeout(struct work_struct *work)
@@ -984,6 +973,8 @@ static void l2cap_conn_del(struct hci_conn *hcon, int err)
 
 	kfree_skb(conn->rx_skb);
 
+	mutex_lock(&conn->chan_lock);
+
 	/* Kill channels */
 	list_for_each_entry_safe(chan, l, &conn->chan_l, list) {
 		sk = chan->sk;
@@ -993,6 +984,8 @@ static void l2cap_conn_del(struct hci_conn *hcon, int err)
 		chan->ops->close(chan->data);
 	}
 
+	mutex_unlock(&conn->chan_lock);
+
 	hci_chan_del(conn->hchan);
 
 	if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)
@@ -1050,6 +1043,7 @@ static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon, u8 status)
 	conn->feat_mask = 0;
 
 	spin_lock_init(&conn->lock);
+	mutex_init(&conn->chan_lock);
 
 	INIT_LIST_HEAD(&conn->chan_l);
 
@@ -1792,9 +1786,9 @@ static void l2cap_raw_recv(struct l2cap_conn *conn, struct sk_buff *skb)
 
 	BT_DBG("conn %p", conn);
 
-	rcu_read_lock();
+	mutex_lock(&conn->chan_lock);
 
-	list_for_each_entry_rcu(chan, &conn->chan_l, list) {
+	list_for_each_entry(chan, &conn->chan_l, list) {
 		struct sock *sk = chan->sk;
 		if (chan->chan_type != L2CAP_CHAN_RAW)
 			continue;
@@ -1810,7 +1804,7 @@ static void l2cap_raw_recv(struct l2cap_conn *conn, struct sk_buff *skb)
 			kfree_skb(nskb);
 	}
 
-	rcu_read_unlock();
+	mutex_unlock(&conn->chan_lock);
 }
 
 /* ---- L2CAP signalling commands ---- */
@@ -4492,9 +4486,9 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
 		cancel_delayed_work(&conn->security_timer);
 	}
 
-	rcu_read_lock();
+	mutex_lock(&conn->chan_lock);
 
-	list_for_each_entry_rcu(chan, &conn->chan_l, list) {
+	list_for_each_entry(chan, &conn->chan_l, list) {
 		struct sock *sk = chan->sk;
 
 		bh_lock_sock(sk);
@@ -4574,7 +4568,7 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
 		bh_unlock_sock(sk);
 	}
 
-	rcu_read_unlock();
+	mutex_unlock(&conn->chan_lock);
 
 	return 0;
 }
-- 
1.7.9

Re: [RFCv5 02/16] Bluetooth: Revert to mutexes from RCU list

[Ulisses Furquim]

Hi Andrei,

On Fri, Feb 17, 2012 at 11:43 AM, Emeltchenko Andrei
<Andrei.Emeltchenko.news@gmail.com> wrote:
> From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
>
> Usage of RCU list looks not reasonalbe for a number of reasons:
> our code sleep and we have to use socket spinlocks, some parts
> of code are updaters thus we need to use mutexes anyway.
>
> Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
> ---
>  net/bluetooth/l2cap_core.c |   98 ++++++++++++++++++++-----------------------
>  1 files changed, 46 insertions(+), 52 deletions(-)
>
> diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
> index 63539f9..109b62d 100644
> --- a/net/bluetooth/l2cap_core.c
> +++ b/net/bluetooth/l2cap_core.c
> @@ -77,36 +77,24 @@ static void l2cap_send_disconn_req(struct l2cap_conn *conn,
>
>  static struct l2cap_chan *__l2cap_get_chan_by_dcid(struct l2cap_conn *conn, u16 cid)
>  {
> -       struct l2cap_chan *c, *r = NULL;
> -
> -       rcu_read_lock();
> +       struct l2cap_chan *c;
>
> -       list_for_each_entry_rcu(c, &conn->chan_l, list) {
> -               if (c->dcid == cid) {
> -                       r = c;
> -                       break;
> -               }
> +       list_for_each_entry(c, &conn->chan_l, list) {
> +               if (c->dcid == cid)
> +                       return c;
>        }
> -
> -       rcu_read_unlock();
> -       return r;
> +       return NULL;
>  }
>
>  static struct l2cap_chan *__l2cap_get_chan_by_scid(struct l2cap_conn *conn, u16 cid)
>  {
> -       struct l2cap_chan *c, *r = NULL;
> -
> -       rcu_read_lock();
> +       struct l2cap_chan *c;
>
> -       list_for_each_entry_rcu(c, &conn->chan_l, list) {
> -               if (c->scid == cid) {
> -                       r = c;
> -                       break;
> -               }
> +       list_for_each_entry(c, &conn->chan_l, list) {
> +               if (c->scid == cid)
> +                       return c;
>        }
> -
> -       rcu_read_unlock();
> -       return r;
> +       return NULL;
>  }
>
>  /* Find channel with given SCID.
> @@ -115,36 +103,34 @@ static struct l2cap_chan *l2cap_get_chan_by_scid(struct l2cap_conn *conn, u16 ci
>  {
>        struct l2cap_chan *c;
>
> +       mutex_lock(&conn->chan_lock);
>        c = __l2cap_get_chan_by_scid(conn, cid);
>        if (c)
>                lock_sock(c->sk);
> +       mutex_unlock(&conn->chan_lock);
>        return c;
>  }
>
>  static struct l2cap_chan *__l2cap_get_chan_by_ident(struct l2cap_conn *conn, u8 ident)
>  {
> -       struct l2cap_chan *c, *r = NULL;
> -
> -       rcu_read_lock();
> +       struct l2cap_chan *c;
>
> -       list_for_each_entry_rcu(c, &conn->chan_l, list) {
> -               if (c->ident == ident) {
> -                       r = c;
> -                       break;
> -               }
> +       list_for_each_entry(c, &conn->chan_l, list) {
> +               if (c->ident == ident)
> +                       return c;
>        }
> -
> -       rcu_read_unlock();
> -       return r;
> +       return NULL;
>  }
>
>  static inline struct l2cap_chan *l2cap_get_chan_by_ident(struct l2cap_conn *conn, u8 ident)
>  {
>        struct l2cap_chan *c;
>
> +       mutex_lock(&conn->chan_lock);
>        c = __l2cap_get_chan_by_ident(conn, ident);
>        if (c)
>                lock_sock(c->sk);
> +       mutex_unlock(&conn->chan_lock);
>        return c;
>  }
>
> @@ -331,7 +317,9 @@ static void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
>
>        l2cap_chan_hold(chan);
>
> -       list_add_rcu(&chan->list, &conn->chan_l);
> +       mutex_lock(&conn->chan_lock);
> +       list_add(&chan->list, &conn->chan_l);
> +       mutex_unlock(&conn->chan_lock);
>  }
>
>  /* Delete channel.
> @@ -348,8 +336,7 @@ static void l2cap_chan_del(struct l2cap_chan *chan, int err)
>
>        if (conn) {
>                /* Delete from channel list */
> -               list_del_rcu(&chan->list);
> -               synchronize_rcu();
> +               list_del(&chan->list);
>
>                l2cap_chan_put(chan);
>
> @@ -400,10 +387,12 @@ static void l2cap_chan_cleanup_listen(struct sock *parent)
>        /* Close not yet accepted channels */
>        while ((sk = bt_accept_dequeue(parent, NULL))) {
>                struct l2cap_chan *chan = l2cap_pi(sk)->chan;
> +
>                __clear_chan_timer(chan);
>                lock_sock(sk);
>                l2cap_chan_close(chan, ECONNRESET);
>                release_sock(sk);
> +
>                chan->ops->close(chan->data);
>        }
>  }
> @@ -718,13 +707,13 @@ static void l2cap_send_disconn_req(struct l2cap_conn *conn, struct l2cap_chan *c
>  /* ---- L2CAP connections ---- */
>  static void l2cap_conn_start(struct l2cap_conn *conn)
>  {
> -       struct l2cap_chan *chan;
> +       struct l2cap_chan *chan, *tmp;
>
>        BT_DBG("conn %p", conn);
>
> -       rcu_read_lock();
> +       mutex_lock(&conn->chan_lock);
>
> -       list_for_each_entry_rcu(chan, &conn->chan_l, list) {
> +       list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
>                struct sock *sk = chan->sk;
>
>                bh_lock_sock(sk);
> @@ -804,7 +793,7 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
>                bh_unlock_sock(sk);
>        }
>
> -       rcu_read_unlock();
> +       mutex_unlock(&conn->chan_lock);
>  }
>
>  /* Find socket with cid and source bdaddr.
> @@ -916,9 +905,9 @@ static void l2cap_conn_ready(struct l2cap_conn *conn)
>        if (conn->hcon->out && conn->hcon->type == LE_LINK)
>                smp_conn_security(conn, conn->hcon->pending_sec_level);
>
> -       rcu_read_lock();
> +       mutex_lock(&conn->chan_lock);
>
> -       list_for_each_entry_rcu(chan, &conn->chan_l, list) {
> +       list_for_each_entry(chan, &conn->chan_l, list) {
>                struct sock *sk = chan->sk;
>
>                bh_lock_sock(sk);
> @@ -938,7 +927,7 @@ static void l2cap_conn_ready(struct l2cap_conn *conn)
>                bh_unlock_sock(sk);
>        }
>
> -       rcu_read_unlock();
> +       mutex_unlock(&conn->chan_lock);
>  }
>
>  /* Notify sockets that we cannot guaranty reliability anymore */
> @@ -948,16 +937,16 @@ static void l2cap_conn_unreliable(struct l2cap_conn *conn, int err)
>
>        BT_DBG("conn %p", conn);
>
> -       rcu_read_lock();
> +       mutex_lock(&conn->chan_lock);
>
> -       list_for_each_entry_rcu(chan, &conn->chan_l, list) {
> +       list_for_each_entry(chan, &conn->chan_l, list) {
>                struct sock *sk = chan->sk;
>
>                if (test_bit(FLAG_FORCE_RELIABLE, &chan->flags))
>                        sk->sk_err = err;
>        }
>
> -       rcu_read_unlock();
> +       mutex_unlock(&conn->chan_lock);
>  }
>
>  static void l2cap_info_timeout(struct work_struct *work)
> @@ -984,6 +973,8 @@ static void l2cap_conn_del(struct hci_conn *hcon, int err)
>
>        kfree_skb(conn->rx_skb);
>
> +       mutex_lock(&conn->chan_lock);
> +
>        /* Kill channels */
>        list_for_each_entry_safe(chan, l, &conn->chan_l, list) {
>                sk = chan->sk;
> @@ -993,6 +984,8 @@ static void l2cap_conn_del(struct hci_conn *hcon, int err)
>                chan->ops->close(chan->data);
>        }
>
> +       mutex_unlock(&conn->chan_lock);
> +
>        hci_chan_del(conn->hchan);
>
>        if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)
> @@ -1050,6 +1043,7 @@ static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon, u8 status)
>        conn->feat_mask = 0;
>
>        spin_lock_init(&conn->lock);
> +       mutex_init(&conn->chan_lock);
>
>        INIT_LIST_HEAD(&conn->chan_l);
>
> @@ -1792,9 +1786,9 @@ static void l2cap_raw_recv(struct l2cap_conn *conn, struct sk_buff *skb)
>
>        BT_DBG("conn %p", conn);
>
> -       rcu_read_lock();
> +       mutex_lock(&conn->chan_lock);
>
> -       list_for_each_entry_rcu(chan, &conn->chan_l, list) {
> +       list_for_each_entry(chan, &conn->chan_l, list) {
>                struct sock *sk = chan->sk;
>                if (chan->chan_type != L2CAP_CHAN_RAW)
>                        continue;
> @@ -1810,7 +1804,7 @@ static void l2cap_raw_recv(struct l2cap_conn *conn, struct sk_buff *skb)
>                        kfree_skb(nskb);
>        }
>
> -       rcu_read_unlock();
> +       mutex_unlock(&conn->chan_lock);
>  }
>
>  /* ---- L2CAP signalling commands ---- */
> @@ -4492,9 +4486,9 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
>                cancel_delayed_work(&conn->security_timer);
>        }
>
> -       rcu_read_lock();
> +       mutex_lock(&conn->chan_lock);
>
> -       list_for_each_entry_rcu(chan, &conn->chan_l, list) {
> +       list_for_each_entry(chan, &conn->chan_l, list) {
>                struct sock *sk = chan->sk;
>
>                bh_lock_sock(sk);
> @@ -4574,7 +4568,7 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
>                bh_unlock_sock(sk);
>        }
>
> -       rcu_read_unlock();
> +       mutex_unlock(&conn->chan_lock);
>
>        return 0;
>  }

Why don't you squash together patches 2, 3 and 4? Is there a reason?
Only with patch 2 the change becomes incomplete and prone to errors.
With patch 3 you add some needed changes but then adds an imbalance of
lock/release sock locks which is only solved in patch 4. Why?

Best regards,

-- 
Ulisses Furquim
ProFUSION embedded systems
http://profusion.mobi
Mobile: +55 19 9250 0942
Skype: ulissesffs

Re: [RFCv5 02/16] Bluetooth: Revert to mutexes from RCU list

[Andrei Emeltchenko]

Hi Ulisses,

On Fri, Feb 17, 2012 at 11:22 PM, Ulisses Furquim
<ulisses@profusion.mobi> wrote:
> Why don't you squash together patches 2, 3 and 4? Is there a reason?

The price of squashing is zero and if there are no other comments I
can do it right away.

> Only with patch 2 the change becomes incomplete and prone to errors.

However I do not think that this makes much difference to the existing code.

> With patch 3 you add some needed changes but then adds an imbalance of
> lock/release sock locks which is only solved in patch 4. Why?

How does patch 4 solves locking? If I did not miss something it shall
not change anything.

Regards,
Andrei

Re: [RFCv5 02/16] Bluetooth: Revert to mutexes from RCU list

[Ulisses Furquim]

Hi Andrei,

On Sun, Feb 19, 2012 at 5:49 PM, Andrei Emeltchenko
<andrei.emeltchenko.news@gmail.com> wrote:
> Hi Ulisses,
>
> On Fri, Feb 17, 2012 at 11:22 PM, Ulisses Furquim
> <ulisses@profusion.mobi> wrote:
>> Why don't you squash together patches 2, 3 and 4? Is there a reason?
>
> The price of squashing is zero and if there are no other comments I
> can do it right away.
>
>> Only with patch 2 the change becomes incomplete and prone to errors.
>
> However I do not think that this makes much difference to the existing code.

We're trying to improve things, right? If the current code is broken
somehow is not an excuse for us to merge patches which we know are
incomplete and will possibly break if someone is doing a bisect, for
instance.

>> With patch 3 you add some needed changes but then adds an imbalance of
>> lock/release sock locks which is only solved in patch 4. Why?
>
> How does patch 4 solves locking? If I did not miss something it shall
> not change anything.

For instance, in patch 3 you replace l2cap_get_chan_by_scid() with __
l2cap_get_chan_by_scid() in l2cap_connect_rsp(). However,  __
l2cap_get_chan_by_scid() doesn't lock_sock() as the other one did and
only in patch 4 you add an explicit lock_sock() to
l2cap_connect_rsp(). Got it? A commit should be self contained as much
as possible so we keep the code bisectable.

Regards,

-- 
Ulisses Furquim
ProFUSION embedded systems
http://profusion.mobi
Mobile: +55 19 9250 0942
Skype: ulissesffs

Re: [RFCv5 02/16] Bluetooth: Revert to mutexes from RCU list

[Andrei Emeltchenko]

Hi Ulisses,

On Mon, Feb 20, 2012 at 09:55:35AM -0200, Ulisses Furquim wrote:
> 
> >> With patch 3 you add some needed changes but then adds an imbalance of
> >> lock/release sock locks which is only solved in patch 4. Why?
> >
> > How does patch 4 solves locking? If I did not miss something it shall
> > not change anything.
> 
> For instance, in patch 3 you replace l2cap_get_chan_by_scid() with __
> l2cap_get_chan_by_scid() in l2cap_connect_rsp(). However,  __
> l2cap_get_chan_by_scid() doesn't lock_sock() as the other one did and
> only in patch 4 you add an explicit lock_sock() to
> l2cap_connect_rsp(). Got it? A commit should be self contained as much
> as possible so we keep the code bisectable.

You are right here, I will squash those mentioned patches since this is
easy way.

Best regards 
Andrei Emeltchenko 

[RFCv5 03/16] Bluetooth: Lock chan list when deleting chan

[Emeltchenko Andrei]

From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>

Locks conn->chan_lock when dealing with chan_del
and chan_close. Use unlocked version of get_chan
inside locked region.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
---
 net/bluetooth/l2cap_core.c |   54 +++++++++++++++++++++++++++++++++++---------
 net/bluetooth/l2cap_sock.c |   10 ++++++++
 2 files changed, 53 insertions(+), 11 deletions(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 109b62d..18a9742 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -214,11 +214,13 @@ static void l2cap_chan_timeout(struct work_struct *work)
 {
 	struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
 							chan_timer.work);
+	struct l2cap_conn *conn = chan->conn;
 	struct sock *sk = chan->sk;
 	int reason;
 
 	BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
 
+	mutex_lock(&conn->chan_lock);
 	lock_sock(sk);
 
 	if (chan->state == BT_CONNECTED || chan->state == BT_CONFIG)
@@ -234,6 +236,8 @@ static void l2cap_chan_timeout(struct work_struct *work)
 	release_sock(sk);
 
 	chan->ops->close(chan->data);
+	mutex_unlock(&conn->chan_lock);
+
 	l2cap_chan_put(chan);
 }
 
@@ -2594,6 +2598,7 @@ static inline int l2cap_connect_req(struct l2cap_conn *conn, struct l2cap_cmd_hd
 
 	parent = pchan->sk;
 
+	mutex_lock(&conn->chan_lock);
 	lock_sock(parent);
 
 	/* Check if the ACL is secure enough (if not SDP) */
@@ -2667,6 +2672,7 @@ static inline int l2cap_connect_req(struct l2cap_conn *conn, struct l2cap_cmd_hd
 
 response:
 	release_sock(parent);
+	mutex_unlock(&conn->chan_lock);
 
 sendresp:
 	rsp.scid   = cpu_to_le16(scid);
@@ -2708,6 +2714,7 @@ static inline int l2cap_connect_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hd
 	struct l2cap_chan *chan;
 	struct sock *sk;
 	u8 req[128];
+	int err;
 
 	scid   = __le16_to_cpu(rsp->scid);
 	dcid   = __le16_to_cpu(rsp->dcid);
@@ -2717,16 +2724,24 @@ static inline int l2cap_connect_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hd
 	BT_DBG("dcid 0x%4.4x scid 0x%4.4x result 0x%2.2x status 0x%2.2x",
 						dcid, scid, result, status);
 
+	mutex_lock(&conn->chan_lock);
+
 	if (scid) {
-		chan = l2cap_get_chan_by_scid(conn, scid);
-		if (!chan)
-			return -EFAULT;
+		chan = __l2cap_get_chan_by_scid(conn, scid);
+		if (!chan) {
+			err = -EFAULT;
+			goto unlock;
+		}
 	} else {
-		chan = l2cap_get_chan_by_ident(conn, cmd->ident);
-		if (!chan)
-			return -EFAULT;
+		chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
+		if (!chan) {
+			err = -EFAULT;
+			goto unlock;
+		}
 	}
 
+	err = 0;
+
 	sk = chan->sk;
 
 	switch (result) {
@@ -2754,7 +2769,10 @@ static inline int l2cap_connect_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hd
 	}
 
 	release_sock(sk);
-	return 0;
+unlock:
+	mutex_unlock(&conn->chan_lock);
+
+	return err;
 }
 
 static inline void set_default_fcs(struct l2cap_chan *chan)
@@ -3000,9 +3018,13 @@ static inline int l2cap_disconnect_req(struct l2cap_conn *conn, struct l2cap_cmd
 
 	BT_DBG("scid 0x%4.4x dcid 0x%4.4x", scid, dcid);
 
-	chan = l2cap_get_chan_by_scid(conn, dcid);
-	if (!chan)
+	mutex_lock(&conn->chan_lock);
+
+	chan = __l2cap_get_chan_by_scid(conn, dcid);
+	if (!chan) {
+		mutex_unlock(&conn->chan_lock);
 		return 0;
+	}
 
 	sk = chan->sk;
 
@@ -3016,6 +3038,9 @@ static inline int l2cap_disconnect_req(struct l2cap_conn *conn, struct l2cap_cmd
 	release_sock(sk);
 
 	chan->ops->close(chan->data);
+
+	mutex_unlock(&conn->chan_lock);
+
 	return 0;
 }
 
@@ -3031,9 +3056,13 @@ static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn, struct l2cap_cmd
 
 	BT_DBG("dcid 0x%4.4x scid 0x%4.4x", dcid, scid);
 
-	chan = l2cap_get_chan_by_scid(conn, scid);
-	if (!chan)
+	mutex_lock(&conn->chan_lock);
+
+	chan = __l2cap_get_chan_by_scid(conn, scid);
+	if (!chan) {
+		mutex_unlock(&conn->chan_lock);
 		return 0;
+	}
 
 	sk = chan->sk;
 
@@ -3041,6 +3070,9 @@ static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn, struct l2cap_cmd
 	release_sock(sk);
 
 	chan->ops->close(chan->data);
+
+	mutex_unlock(&conn->chan_lock);
+
 	return 0;
 }
 
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index b48d6c1..1273fcb 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -796,6 +796,7 @@ static int l2cap_sock_shutdown(struct socket *sock, int how)
 {
 	struct sock *sk = sock->sk;
 	struct l2cap_chan *chan;
+	struct l2cap_conn *conn;
 	int err = 0;
 
 	BT_DBG("sock %p, sk %p", sock, sk);
@@ -804,6 +805,10 @@ static int l2cap_sock_shutdown(struct socket *sock, int how)
 		return 0;
 
 	chan = l2cap_pi(sk)->chan;
+	conn = chan->conn;
+
+	if (conn)
+		mutex_lock(&conn->chan_lock);
 
 	lock_sock(sk);
 	if (!sk->sk_shutdown) {
@@ -811,6 +816,7 @@ static int l2cap_sock_shutdown(struct socket *sock, int how)
 			err = __l2cap_wait_ack(sk);
 
 		sk->sk_shutdown = SHUTDOWN_MASK;
+
 		l2cap_chan_close(chan, 0);
 
 		if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
@@ -822,6 +828,10 @@ static int l2cap_sock_shutdown(struct socket *sock, int how)
 		err = -sk->sk_err;
 
 	release_sock(sk);
+
+	if (conn)
+		mutex_unlock(&conn->chan_lock);
+
 	return err;
 }
 
-- 
1.7.9

[RFCv5 04/16] Bluetooth: Do not use sk lock in get_chan functions

[Emeltchenko Andrei]

From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>

Take explicit lock. This change is needed to get rid of
socket locks in L2CAP core code. Socket locks will be changed
by chan locks in the following patches.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
---
 net/bluetooth/l2cap_core.c |   13 +++++++++----
 1 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 18a9742..90e29ac 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -105,9 +105,8 @@ static struct l2cap_chan *l2cap_get_chan_by_scid(struct l2cap_conn *conn, u16 ci
 
 	mutex_lock(&conn->chan_lock);
 	c = __l2cap_get_chan_by_scid(conn, cid);
-	if (c)
-		lock_sock(c->sk);
 	mutex_unlock(&conn->chan_lock);
+
 	return c;
 }
 
@@ -128,9 +127,8 @@ static inline struct l2cap_chan *l2cap_get_chan_by_ident(struct l2cap_conn *conn
 
 	mutex_lock(&conn->chan_lock);
 	c = __l2cap_get_chan_by_ident(conn, ident);
-	if (c)
-		lock_sock(c->sk);
 	mutex_unlock(&conn->chan_lock);
+
 	return c;
 }
 
@@ -2743,6 +2741,7 @@ static inline int l2cap_connect_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hd
 	err = 0;
 
 	sk = chan->sk;
+	lock_sock(sk);
 
 	switch (result) {
 	case L2CAP_CR_SUCCESS:
@@ -2805,6 +2804,7 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr
 		return -ENOENT;
 
 	sk = chan->sk;
+	lock_sock(sk);
 
 	if (chan->state != BT_CONFIG && chan->state != BT_CONNECT2) {
 		struct l2cap_cmd_rej_cid rej;
@@ -2917,6 +2917,7 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr
 		return 0;
 
 	sk = chan->sk;
+	lock_sock(sk);
 
 	switch (result) {
 	case L2CAP_CONF_SUCCESS:
@@ -3027,6 +3028,7 @@ static inline int l2cap_disconnect_req(struct l2cap_conn *conn, struct l2cap_cmd
 	}
 
 	sk = chan->sk;
+	lock_sock(sk);
 
 	rsp.dcid = cpu_to_le16(chan->scid);
 	rsp.scid = cpu_to_le16(chan->dcid);
@@ -3065,6 +3067,7 @@ static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn, struct l2cap_cmd
 	}
 
 	sk = chan->sk;
+	lock_sock(sk);
 
 	l2cap_chan_del(chan, 0);
 	release_sock(sk);
@@ -4231,6 +4234,7 @@ static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk
 	}
 
 	sk = chan->sk;
+	lock_sock(sk);
 
 	BT_DBG("chan %p, len %d", chan, skb->len);
 
@@ -4661,6 +4665,7 @@ int l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags)
 
 		if (chan && chan->sk) {
 			struct sock *sk = chan->sk;
+			lock_sock(sk);
 
 			if (chan->imtu < len - L2CAP_HDR_SIZE) {
 				BT_ERR("Frame exceeding recv MTU (len %d, "
-- 
1.7.9

[RFCv5 05/16] Bluetooth: Add l2cap_chan_lock

[Emeltchenko Andrei]

From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>

Channel lock will be used to lock L2CAP channels which are locked
currently by socket locks.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
---
 include/net/bluetooth/l2cap.h |   11 +++++++++++
 net/bluetooth/l2cap_core.c    |    2 ++
 2 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index bbb0e21..d6d8ec8 100644
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -497,6 +497,7 @@ struct l2cap_chan {
 
 	void		*data;
 	struct l2cap_ops *ops;
+	struct mutex		lock;
 };
 
 struct l2cap_ops {
@@ -609,6 +610,16 @@ static inline void l2cap_chan_put(struct l2cap_chan *c)
 		kfree(c);
 }
 
+static inline void l2cap_chan_lock(struct l2cap_chan *chan)
+{
+	mutex_lock(&chan->lock);
+}
+
+static inline void l2cap_chan_unlock(struct l2cap_chan *chan)
+{
+	mutex_unlock(&chan->lock);
+}
+
 static inline void l2cap_set_timer(struct l2cap_chan *chan,
 					struct delayed_work *work, long timeout)
 {
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 90e29ac..98e116b 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -247,6 +247,8 @@ struct l2cap_chan *l2cap_chan_create(struct sock *sk)
 	if (!chan)
 		return NULL;
 
+	mutex_init(&chan->lock);
+
 	chan->sk = sk;
 
 	write_lock(&chan_list_lock);
-- 
1.7.9

[RFCv5 06/16] Bluetooth: Add locked and unlocked state_change

[Emeltchenko Andrei]

From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>

Split to locked and unlocked versions of l2cap_state_change helping
to remove socket locks from l2cap code.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
---
 net/bluetooth/l2cap_core.c |   41 +++++++++++++++++++++++++----------------
 1 files changed, 25 insertions(+), 16 deletions(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 98e116b..a206a24 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -199,7 +199,7 @@ 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));
@@ -208,6 +208,15 @@ static void l2cap_state_change(struct l2cap_chan *chan, int state)
 	chan->ops->state_change(chan->data, state);
 }
 
+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 void l2cap_chan_timeout(struct work_struct *work)
 {
 	struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
@@ -348,7 +357,7 @@ static void l2cap_chan_del(struct l2cap_chan *chan, int err)
 		hci_conn_put(conn->hcon);
 	}
 
-	l2cap_state_change(chan, BT_CLOSED);
+	__l2cap_state_change(chan, BT_CLOSED);
 	sock_set_flag(sk, SOCK_ZAPPED);
 
 	if (err)
@@ -413,7 +422,7 @@ void l2cap_chan_close(struct l2cap_chan *chan, int reason)
 	case BT_LISTEN:
 		l2cap_chan_cleanup_listen(sk);
 
-		l2cap_state_change(chan, BT_CLOSED);
+		__l2cap_state_change(chan, BT_CLOSED);
 		sock_set_flag(sk, SOCK_ZAPPED);
 		break;
 
@@ -704,7 +713,7 @@ static void l2cap_send_disconn_req(struct l2cap_conn *conn, struct l2cap_chan *c
 	l2cap_send_cmd(conn, l2cap_get_ident(conn),
 			L2CAP_DISCONN_REQ, sizeof(req), &req);
 
-	l2cap_state_change(chan, BT_DISCONN);
+	__l2cap_state_change(chan, BT_DISCONN);
 	sk->sk_err = err;
 }
 
@@ -770,7 +779,7 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
 						parent->sk_data_ready(parent, 0);
 
 				} else {
-					l2cap_state_change(chan, BT_CONFIG);
+					__l2cap_state_change(chan, BT_CONFIG);
 					rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
 					rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
 				}
@@ -873,7 +882,7 @@ static void l2cap_le_conn_ready(struct l2cap_conn *conn)
 
 	__set_chan_timer(chan, sk->sk_sndtimeo);
 
-	l2cap_state_change(chan, BT_CONNECTED);
+	__l2cap_state_change(chan, BT_CONNECTED);
 	parent->sk_data_ready(parent, 0);
 
 clean:
@@ -890,7 +899,7 @@ static void l2cap_chan_ready(struct l2cap_chan *chan)
 	chan->conf_state = 0;
 	__clear_chan_timer(chan);
 
-	l2cap_state_change(chan, BT_CONNECTED);
+	__l2cap_state_change(chan, BT_CONNECTED);
 	sk->sk_state_change(sk);
 
 	if (parent)
@@ -922,7 +931,7 @@ static void l2cap_conn_ready(struct l2cap_conn *conn)
 
 		} else if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
 			__clear_chan_timer(chan);
-			l2cap_state_change(chan, BT_CONNECTED);
+			__l2cap_state_change(chan, BT_CONNECTED);
 			sk->sk_state_change(sk);
 
 		} else if (chan->state == BT_CONNECT)
@@ -1196,14 +1205,14 @@ int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid, bdaddr_t *d
 
 	l2cap_chan_add(conn, chan);
 
-	l2cap_state_change(chan, BT_CONNECT);
+	__l2cap_state_change(chan, BT_CONNECT);
 	__set_chan_timer(chan, sk->sk_sndtimeo);
 
 	if (hcon->state == BT_CONNECTED) {
 		if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
 			__clear_chan_timer(chan);
 			if (l2cap_chan_check_security(chan))
-				l2cap_state_change(chan, BT_CONNECTED);
+				__l2cap_state_change(chan, BT_CONNECTED);
 		} else
 			l2cap_do_start(chan);
 	}
@@ -2650,22 +2659,22 @@ static inline int l2cap_connect_req(struct l2cap_conn *conn, struct l2cap_cmd_hd
 	if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE) {
 		if (l2cap_chan_check_security(chan)) {
 			if (bt_sk(sk)->defer_setup) {
-				l2cap_state_change(chan, BT_CONNECT2);
+				__l2cap_state_change(chan, BT_CONNECT2);
 				result = L2CAP_CR_PEND;
 				status = L2CAP_CS_AUTHOR_PEND;
 				parent->sk_data_ready(parent, 0);
 			} else {
-				l2cap_state_change(chan, BT_CONFIG);
+				__l2cap_state_change(chan, BT_CONFIG);
 				result = L2CAP_CR_SUCCESS;
 				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;
 	}
@@ -4583,12 +4592,12 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
 					if (parent)
 						parent->sk_data_ready(parent, 0);
 				} else {
-					l2cap_state_change(chan, BT_CONFIG);
+					__l2cap_state_change(chan, BT_CONFIG);
 					res = L2CAP_CR_SUCCESS;
 					stat = L2CAP_CS_NO_INFO;
 				}
 			} else {
-				l2cap_state_change(chan, BT_DISCONN);
+				__l2cap_state_change(chan, BT_DISCONN);
 				__set_chan_timer(chan,
 					msecs_to_jiffies(L2CAP_DISC_TIMEOUT));
 				res = L2CAP_CR_SEC_BLOCK;
-- 
1.7.9

[RFCv5 07/16] Bluetooth: Add socket error function

[Emeltchenko Andrei]

From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>

Use locked and unlocked versions to help removing socket
locks from l2cap core functions.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
---
 net/bluetooth/l2cap_core.c |   30 +++++++++++++++++++++---------
 1 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index a206a24..1e3ebc5 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -217,6 +217,22 @@ static void l2cap_state_change(struct l2cap_chan *chan, int state)
 	release_sock(sk);
 }
 
+static inline void __l2cap_chan_set_err(struct l2cap_chan *chan, int err)
+{
+	struct sock *sk = chan->sk;
+
+	sk->sk_err = err;
+}
+
+static inline void l2cap_chan_set_err(struct l2cap_chan *chan, int err)
+{
+	struct sock *sk = chan->sk;
+
+	lock_sock(sk);
+	__l2cap_chan_set_err(chan, err);
+	release_sock(sk);
+}
+
 static void l2cap_chan_timeout(struct work_struct *work)
 {
 	struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
@@ -361,7 +377,7 @@ static void l2cap_chan_del(struct l2cap_chan *chan, int err)
 	sock_set_flag(sk, SOCK_ZAPPED);
 
 	if (err)
-		sk->sk_err = err;
+		__l2cap_chan_set_err(chan, err);
 
 	if (parent) {
 		bt_accept_unlink(sk);
@@ -694,14 +710,11 @@ static inline int l2cap_mode_supported(__u8 mode, __u32 feat_mask)
 
 static void l2cap_send_disconn_req(struct l2cap_conn *conn, struct l2cap_chan *chan, int err)
 {
-	struct sock *sk;
 	struct l2cap_disconn_req req;
 
 	if (!conn)
 		return;
 
-	sk = chan->sk;
-
 	if (chan->mode == L2CAP_MODE_ERTM) {
 		__clear_retrans_timer(chan);
 		__clear_monitor_timer(chan);
@@ -714,7 +727,7 @@ static void l2cap_send_disconn_req(struct l2cap_conn *conn, struct l2cap_chan *c
 			L2CAP_DISCONN_REQ, sizeof(req), &req);
 
 	__l2cap_state_change(chan, BT_DISCONN);
-	sk->sk_err = err;
+	__l2cap_chan_set_err(chan, err);
 }
 
 /* ---- L2CAP connections ---- */
@@ -953,10 +966,8 @@ static void l2cap_conn_unreliable(struct l2cap_conn *conn, int err)
 	mutex_lock(&conn->chan_lock);
 
 	list_for_each_entry(chan, &conn->chan_l, list) {
-		struct sock *sk = chan->sk;
-
 		if (test_bit(FLAG_FORCE_RELIABLE, &chan->flags))
-			sk->sk_err = err;
+			__l2cap_chan_set_err(chan, err);
 	}
 
 	mutex_unlock(&conn->chan_lock);
@@ -2987,7 +2998,8 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr
 		}
 
 	default:
-		sk->sk_err = ECONNRESET;
+		__l2cap_chan_set_err(chan, ECONNRESET);
+
 		__set_chan_timer(chan,
 				msecs_to_jiffies(L2CAP_DISC_REJ_TIMEOUT));
 		l2cap_send_disconn_req(conn, chan, ECONNRESET);
-- 
1.7.9

[RFCv5 08/16] Bluetooth: Add unlocked __l2cap_chan_add function

[Emeltchenko Andrei]

From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>


Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
---
 net/bluetooth/l2cap_core.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 1e3ebc5..db1640c 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -300,7 +300,7 @@ void l2cap_chan_destroy(struct l2cap_chan *chan)
 	l2cap_chan_put(chan);
 }
 
-static void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
+void __l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
 {
 	BT_DBG("conn %p, psm 0x%2.2x, dcid 0x%4.4x", conn,
 			chan->psm, chan->dcid);
@@ -346,8 +346,13 @@ static void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
 
 	l2cap_chan_hold(chan);
 
-	mutex_lock(&conn->chan_lock);
 	list_add(&chan->list, &conn->chan_l);
+}
+
+void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
+{
+	mutex_lock(&conn->chan_lock);
+	__l2cap_chan_add(conn, chan);
 	mutex_unlock(&conn->chan_lock);
 }
 
-- 
1.7.9

[RFCv5 09/16] Bluetooth: Use chan lock in timers

[Emeltchenko Andrei]

From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>

Change locking in delayed works to chan lock instead of sk lock.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
---
 net/bluetooth/l2cap_core.c |   26 ++++++++++++++------------
 1 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index db1640c..727a1dd 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -238,13 +238,12 @@ static void l2cap_chan_timeout(struct work_struct *work)
 	struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
 							chan_timer.work);
 	struct l2cap_conn *conn = chan->conn;
-	struct sock *sk = chan->sk;
 	int reason;
 
 	BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
 
 	mutex_lock(&conn->chan_lock);
-	lock_sock(sk);
+	l2cap_chan_lock(chan);
 
 	if (chan->state == BT_CONNECTED || chan->state == BT_CONFIG)
 		reason = ECONNREFUSED;
@@ -256,7 +255,7 @@ static void l2cap_chan_timeout(struct work_struct *work)
 
 	l2cap_chan_close(chan, reason);
 
-	release_sock(sk);
+	l2cap_chan_unlock(chan);
 
 	chan->ops->close(chan->data);
 	mutex_unlock(&conn->chan_lock);
@@ -1277,14 +1276,14 @@ static void l2cap_monitor_timeout(struct work_struct *work)
 {
 	struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
 							monitor_timer.work);
-	struct sock *sk = chan->sk;
 
 	BT_DBG("chan %p", chan);
 
-	lock_sock(sk);
+	l2cap_chan_lock(chan);
+
 	if (chan->retry_count >= chan->remote_max_tx) {
 		l2cap_send_disconn_req(chan->conn, chan, ECONNABORTED);
-		release_sock(sk);
+		l2cap_chan_unlock(chan);
 		return;
 	}
 
@@ -1292,25 +1291,26 @@ static void l2cap_monitor_timeout(struct work_struct *work)
 	__set_monitor_timer(chan);
 
 	l2cap_send_rr_or_rnr(chan, L2CAP_CTRL_POLL);
-	release_sock(sk);
+	l2cap_chan_unlock(chan);
 }
 
 static void l2cap_retrans_timeout(struct work_struct *work)
 {
 	struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
 							retrans_timer.work);
-	struct sock *sk = chan->sk;
 
 	BT_DBG("chan %p", chan);
 
-	lock_sock(sk);
+	l2cap_chan_lock(chan);
+
 	chan->retry_count = 1;
 	__set_monitor_timer(chan);
 
 	set_bit(CONN_WAIT_F, &chan->conn_state);
 
 	l2cap_send_rr_or_rnr(chan, L2CAP_CTRL_POLL);
-	release_sock(sk);
+
+	l2cap_chan_unlock(chan);
 }
 
 static void l2cap_drop_acked_frames(struct l2cap_chan *chan)
@@ -2001,9 +2001,11 @@ static void l2cap_ack_timeout(struct work_struct *work)
 
 	BT_DBG("chan %p", chan);
 
-	lock_sock(chan->sk);
+	l2cap_chan_lock(chan);
+
 	__l2cap_send_ack(chan);
-	release_sock(chan->sk);
+
+	l2cap_chan_unlock(chan);
 
 	l2cap_chan_put(chan);
 }
-- 
1.7.9

[RFCv5 10/16] Bluetooth: Use chan lock in L2CAP sig commands

[Emeltchenko Andrei]

From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>

Convert sk lock to chan lock for L2CAP signalling commands.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
---
 net/bluetooth/l2cap_core.c |   61 +++++++++++++++++++++++++------------------
 net/bluetooth/l2cap_sock.c |    7 +++-
 2 files changed, 40 insertions(+), 28 deletions(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 727a1dd..a36b2c3 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -377,6 +377,8 @@ static void l2cap_chan_del(struct l2cap_chan *chan, int err)
 		hci_conn_put(conn->hcon);
 	}
 
+	lock_sock(sk);
+
 	__l2cap_state_change(chan, BT_CLOSED);
 	sock_set_flag(sk, SOCK_ZAPPED);
 
@@ -389,6 +391,8 @@ static void l2cap_chan_del(struct l2cap_chan *chan, int err)
 	} else
 		sk->sk_state_change(sk);
 
+	release_sock(sk);
+
 	if (!(test_bit(CONF_OUTPUT_DONE, &chan->conf_state) &&
 			test_bit(CONF_INPUT_DONE, &chan->conf_state)))
 		return;
@@ -421,10 +425,10 @@ static void l2cap_chan_cleanup_listen(struct sock *parent)
 	while ((sk = bt_accept_dequeue(parent, NULL))) {
 		struct l2cap_chan *chan = l2cap_pi(sk)->chan;
 
+		l2cap_chan_lock(chan);
 		__clear_chan_timer(chan);
-		lock_sock(sk);
 		l2cap_chan_close(chan, ECONNRESET);
-		release_sock(sk);
+		l2cap_chan_unlock(chan);
 
 		chan->ops->close(chan->data);
 	}
@@ -440,10 +444,12 @@ void l2cap_chan_close(struct l2cap_chan *chan, int reason)
 
 	switch (chan->state) {
 	case BT_LISTEN:
+		lock_sock(sk);
 		l2cap_chan_cleanup_listen(sk);
 
 		__l2cap_state_change(chan, BT_CLOSED);
 		sock_set_flag(sk, SOCK_ZAPPED);
+		release_sock(sk);
 		break;
 
 	case BT_CONNECTED:
@@ -486,7 +492,9 @@ void l2cap_chan_close(struct l2cap_chan *chan, int reason)
 		break;
 
 	default:
+		lock_sock(sk);
 		sock_set_flag(sk, SOCK_ZAPPED);
+		release_sock(sk);
 		break;
 	}
 }
@@ -714,6 +722,7 @@ static inline int l2cap_mode_supported(__u8 mode, __u32 feat_mask)
 
 static void l2cap_send_disconn_req(struct l2cap_conn *conn, struct l2cap_chan *chan, int err)
 {
+	struct sock *sk = chan->sk;
 	struct l2cap_disconn_req req;
 
 	if (!conn)
@@ -730,8 +739,10 @@ static void l2cap_send_disconn_req(struct l2cap_conn *conn, struct l2cap_chan *c
 	l2cap_send_cmd(conn, l2cap_get_ident(conn),
 			L2CAP_DISCONN_REQ, sizeof(req), &req);
 
+	lock_sock(sk);
 	__l2cap_state_change(chan, BT_DISCONN);
 	__l2cap_chan_set_err(chan, err);
+	release_sock(sk);
 }
 
 /* ---- L2CAP connections ---- */
@@ -992,7 +1003,6 @@ static void l2cap_conn_del(struct hci_conn *hcon, int err)
 {
 	struct l2cap_conn *conn = hcon->l2cap_data;
 	struct l2cap_chan *chan, *l;
-	struct sock *sk;
 
 	if (!conn)
 		return;
@@ -1005,10 +1015,12 @@ static void l2cap_conn_del(struct hci_conn *hcon, int err)
 
 	/* Kill channels */
 	list_for_each_entry_safe(chan, l, &conn->chan_l, list) {
-		sk = chan->sk;
-		lock_sock(sk);
+		l2cap_chan_lock(chan);
+
 		l2cap_chan_del(chan, err);
-		release_sock(sk);
+
+		l2cap_chan_unlock(chan);
+
 		chan->ops->close(chan->data);
 	}
 
@@ -2666,7 +2678,7 @@ static inline int l2cap_connect_req(struct l2cap_conn *conn, struct l2cap_cmd_hd
 
 	bt_accept_enqueue(parent, sk);
 
-	l2cap_chan_add(conn, chan);
+	__l2cap_chan_add(conn, chan);
 
 	dcid = chan->scid;
 
@@ -2739,7 +2751,6 @@ static inline int l2cap_connect_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hd
 	struct l2cap_conn_rsp *rsp = (struct l2cap_conn_rsp *) data;
 	u16 scid, dcid, result, status;
 	struct l2cap_chan *chan;
-	struct sock *sk;
 	u8 req[128];
 	int err;
 
@@ -2769,8 +2780,7 @@ static inline int l2cap_connect_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hd
 
 	err = 0;
 
-	sk = chan->sk;
-	lock_sock(sk);
+	l2cap_chan_lock(chan);
 
 	switch (result) {
 	case L2CAP_CR_SUCCESS:
@@ -2796,7 +2806,7 @@ static inline int l2cap_connect_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hd
 		break;
 	}
 
-	release_sock(sk);
+	l2cap_chan_unlock(chan);
 unlock:
 	mutex_unlock(&conn->chan_lock);
 
@@ -2820,7 +2830,6 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr
 	u16 dcid, flags;
 	u8 rsp[64];
 	struct l2cap_chan *chan;
-	struct sock *sk;
 	int len;
 
 	dcid  = __le16_to_cpu(req->dcid);
@@ -2832,8 +2841,7 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr
 	if (!chan)
 		return -ENOENT;
 
-	sk = chan->sk;
-	lock_sock(sk);
+	l2cap_chan_lock(chan);
 
 	if (chan->state != BT_CONFIG && chan->state != BT_CONNECT2) {
 		struct l2cap_cmd_rej_cid rej;
@@ -2922,7 +2930,7 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr
 	}
 
 unlock:
-	release_sock(sk);
+	l2cap_chan_unlock(chan);
 	return 0;
 }
 
@@ -2931,7 +2939,6 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr
 	struct l2cap_conf_rsp *rsp = (struct l2cap_conf_rsp *)data;
 	u16 scid, flags, result;
 	struct l2cap_chan *chan;
-	struct sock *sk;
 	int len = cmd->len - sizeof(*rsp);
 
 	scid   = __le16_to_cpu(rsp->scid);
@@ -2945,8 +2952,7 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr
 	if (!chan)
 		return 0;
 
-	sk = chan->sk;
-	lock_sock(sk);
+	l2cap_chan_lock(chan);
 
 	switch (result) {
 	case L2CAP_CONF_SUCCESS:
@@ -3005,7 +3011,7 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr
 		}
 
 	default:
-		__l2cap_chan_set_err(chan, ECONNRESET);
+		l2cap_chan_set_err(chan, ECONNRESET);
 
 		__set_chan_timer(chan,
 				msecs_to_jiffies(L2CAP_DISC_REJ_TIMEOUT));
@@ -3032,7 +3038,7 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr
 	}
 
 done:
-	release_sock(sk);
+	l2cap_chan_unlock(chan);
 	return 0;
 }
 
@@ -3057,17 +3063,21 @@ static inline int l2cap_disconnect_req(struct l2cap_conn *conn, struct l2cap_cmd
 		return 0;
 	}
 
+	l2cap_chan_lock(chan);
+
 	sk = chan->sk;
-	lock_sock(sk);
 
 	rsp.dcid = cpu_to_le16(chan->scid);
 	rsp.scid = cpu_to_le16(chan->dcid);
 	l2cap_send_cmd(conn, cmd->ident, L2CAP_DISCONN_RSP, sizeof(rsp), &rsp);
 
+	lock_sock(sk);
 	sk->sk_shutdown = SHUTDOWN_MASK;
+	release_sock(sk);
 
 	l2cap_chan_del(chan, ECONNRESET);
-	release_sock(sk);
+
+	l2cap_chan_unlock(chan);
 
 	chan->ops->close(chan->data);
 
@@ -3081,7 +3091,6 @@ static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn, struct l2cap_cmd
 	struct l2cap_disconn_rsp *rsp = (struct l2cap_disconn_rsp *) data;
 	u16 dcid, scid;
 	struct l2cap_chan *chan;
-	struct sock *sk;
 
 	scid = __le16_to_cpu(rsp->scid);
 	dcid = __le16_to_cpu(rsp->dcid);
@@ -3096,11 +3105,11 @@ static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn, struct l2cap_cmd
 		return 0;
 	}
 
-	sk = chan->sk;
-	lock_sock(sk);
+	l2cap_chan_lock(chan);
 
 	l2cap_chan_del(chan, 0);
-	release_sock(sk);
+
+	l2cap_chan_unlock(chan);
 
 	chan->ops->close(chan->data);
 
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index 1273fcb..db38fae 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -809,15 +809,18 @@ static int l2cap_sock_shutdown(struct socket *sock, int how)
 
 	if (conn)
 		mutex_lock(&conn->chan_lock);
-
+	l2cap_chan_lock(chan);
 	lock_sock(sk);
+
 	if (!sk->sk_shutdown) {
 		if (chan->mode == L2CAP_MODE_ERTM)
 			err = __l2cap_wait_ack(sk);
 
 		sk->sk_shutdown = SHUTDOWN_MASK;
 
+		release_sock(sk);
 		l2cap_chan_close(chan, 0);
+		lock_sock(sk);
 
 		if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
 			err = bt_sock_wait_state(sk, BT_CLOSED,
@@ -828,7 +831,7 @@ static int l2cap_sock_shutdown(struct socket *sock, int how)
 		err = -sk->sk_err;
 
 	release_sock(sk);
-
+	l2cap_chan_unlock(chan);
 	if (conn)
 		mutex_unlock(&conn->chan_lock);
 
-- 
1.7.9

[RFCv5 11/16] Bluetooth: Use chan lock in L2CAP conn start

[Emeltchenko Andrei]

From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>

Change sk lock to chan lock in l2cap_conn_start. bh_locks were used
because of being RCU critical section.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
---
 net/bluetooth/l2cap_core.c |   16 ++++++++--------
 1 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index a36b2c3..71c7a08 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -757,10 +757,10 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
 	list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
 		struct sock *sk = chan->sk;
 
-		bh_lock_sock(sk);
+		l2cap_chan_lock(chan);
 
 		if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
-			bh_unlock_sock(sk);
+			l2cap_chan_unlock(chan);
 			continue;
 		}
 
@@ -769,17 +769,15 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
 
 			if (!l2cap_chan_check_security(chan) ||
 					!__l2cap_no_conn_pending(chan)) {
-				bh_unlock_sock(sk);
+				l2cap_chan_unlock(chan);
 				continue;
 			}
 
 			if (!l2cap_mode_supported(chan->mode, conn->feat_mask)
 					&& test_bit(CONF_STATE2_DEVICE,
 					&chan->conf_state)) {
-				/* l2cap_chan_close() calls list_del(chan)
-				 * so release the lock */
 				l2cap_chan_close(chan, ECONNRESET);
-				bh_unlock_sock(sk);
+				l2cap_chan_unlock(chan);
 				continue;
 			}
 
@@ -799,6 +797,7 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
 			rsp.dcid = cpu_to_le16(chan->scid);
 
 			if (l2cap_chan_check_security(chan)) {
+				lock_sock(sk);
 				if (bt_sk(sk)->defer_setup) {
 					struct sock *parent = bt_sk(sk)->parent;
 					rsp.result = cpu_to_le16(L2CAP_CR_PEND);
@@ -811,6 +810,7 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
 					rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
 					rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
 				}
+				release_sock(sk);
 			} else {
 				rsp.result = cpu_to_le16(L2CAP_CR_PEND);
 				rsp.status = cpu_to_le16(L2CAP_CS_AUTHEN_PEND);
@@ -821,7 +821,7 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
 
 			if (test_bit(CONF_REQ_SENT, &chan->conf_state) ||
 					rsp.result != L2CAP_CR_SUCCESS) {
-				bh_unlock_sock(sk);
+				l2cap_chan_unlock(chan);
 				continue;
 			}
 
@@ -831,7 +831,7 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
 			chan->num_conf_req++;
 		}
 
-		bh_unlock_sock(sk);
+		l2cap_chan_unlock(chan);
 	}
 
 	mutex_unlock(&conn->chan_lock);
-- 
1.7.9

[RFCv5 12/16] Bluetooth: Use chan lock in receiving data

[Emeltchenko Andrei]

From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>

Change locking logic when receiving ACL and L2CAP data.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
---
 net/bluetooth/l2cap_core.c |   11 +++++------
 net/bluetooth/l2cap_sock.c |   11 +++++++++--
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 71c7a08..31810d3 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -4261,7 +4261,6 @@ drop:
 static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk_buff *skb)
 {
 	struct l2cap_chan *chan;
-	struct sock *sk = NULL;
 	u32 control;
 	u16 tx_seq;
 	int len;
@@ -4269,11 +4268,12 @@ static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk
 	chan = l2cap_get_chan_by_scid(conn, cid);
 	if (!chan) {
 		BT_DBG("unknown cid 0x%4.4x", cid);
-		goto drop;
+		/* Drop packet and return */
+		kfree(skb);
+		return 0;
 	}
 
-	sk = chan->sk;
-	lock_sock(sk);
+	l2cap_chan_lock(chan);
 
 	BT_DBG("chan %p, len %d", chan, skb->len);
 
@@ -4344,8 +4344,7 @@ drop:
 	kfree_skb(skb);
 
 done:
-	if (sk)
-		release_sock(sk);
+	l2cap_chan_unlock(chan);
 
 	return 0;
 }
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index db38fae..a278858 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -877,8 +877,12 @@ static int l2cap_sock_recv_cb(void *data, struct sk_buff *skb)
 	struct sock *sk = data;
 	struct l2cap_pinfo *pi = l2cap_pi(sk);
 
-	if (pi->rx_busy_skb)
-		return -ENOMEM;
+	lock_sock(sk);
+
+	if (pi->rx_busy_skb) {
+		err = -ENOMEM;
+		goto done;
+	}
 
 	err = sock_queue_rcv_skb(sk, skb);
 
@@ -897,6 +901,9 @@ static int l2cap_sock_recv_cb(void *data, struct sk_buff *skb)
 		err = 0;
 	}
 
+done:
+	release_sock(sk);
+
 	return err;
 }
 
-- 
1.7.9

[RFCv5 13/16] Bluetooth: Change locking logic for conn/chan ready

[Emeltchenko Andrei]

From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>

In l2cap_conn_ready and l2cap_chan_ready change locking logic and
use explicit socket when needed.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
---
 net/bluetooth/l2cap_core.c |   16 ++++++++++++----
 1 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 31810d3..6f28cf5 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -920,7 +920,11 @@ clean:
 static void l2cap_chan_ready(struct l2cap_chan *chan)
 {
 	struct sock *sk = chan->sk;
-	struct sock *parent = bt_sk(sk)->parent;
+	struct sock *parent;
+
+	lock_sock(sk);
+
+	parent = bt_sk(sk)->parent;
 
 	BT_DBG("sk %p, parent %p", sk, parent);
 
@@ -932,6 +936,8 @@ static void l2cap_chan_ready(struct l2cap_chan *chan)
 
 	if (parent)
 		parent->sk_data_ready(parent, 0);
+
+	release_sock(sk);
 }
 
 static void l2cap_conn_ready(struct l2cap_conn *conn)
@@ -949,23 +955,25 @@ static void l2cap_conn_ready(struct l2cap_conn *conn)
 	mutex_lock(&conn->chan_lock);
 
 	list_for_each_entry(chan, &conn->chan_l, list) {
-		struct sock *sk = chan->sk;
 
-		bh_lock_sock(sk);
+		l2cap_chan_lock(chan);
 
 		if (conn->hcon->type == LE_LINK) {
 			if (smp_conn_security(conn, chan->sec_level))
 				l2cap_chan_ready(chan);
 
 		} else if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
+			struct sock *sk = chan->sk;
 			__clear_chan_timer(chan);
+			lock_sock(sk);
 			__l2cap_state_change(chan, BT_CONNECTED);
 			sk->sk_state_change(sk);
+			release_sock(sk);
 
 		} else if (chan->state == BT_CONNECT)
 			l2cap_do_start(chan);
 
-		bh_unlock_sock(sk);
+		l2cap_chan_unlock(chan);
 	}
 
 	mutex_unlock(&conn->chan_lock);
-- 
1.7.9

[RFCv5 14/16] Bluetooth: Change locking logic in security_cfm

[Emeltchenko Andrei]

From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>

Change bh_ locking functions to mutex_locks since we can now sleep.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
---
 net/bluetooth/l2cap_core.c |   17 ++++++++++-------
 1 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 6f28cf5..b117014 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -4571,9 +4571,7 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
 	mutex_lock(&conn->chan_lock);
 
 	list_for_each_entry(chan, &conn->chan_l, list) {
-		struct sock *sk = chan->sk;
-
-		bh_lock_sock(sk);
+		l2cap_chan_lock(chan);
 
 		BT_DBG("chan->scid %d", chan->scid);
 
@@ -4583,19 +4581,19 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
 				l2cap_chan_ready(chan);
 			}
 
-			bh_unlock_sock(sk);
+			l2cap_chan_unlock(chan);
 			continue;
 		}
 
 		if (test_bit(CONF_CONNECT_PEND, &chan->conf_state)) {
-			bh_unlock_sock(sk);
+			l2cap_chan_unlock(chan);
 			continue;
 		}
 
 		if (!status && (chan->state == BT_CONNECTED ||
 						chan->state == BT_CONFIG)) {
 			l2cap_check_encryption(chan, encrypt);
-			bh_unlock_sock(sk);
+			l2cap_chan_unlock(chan);
 			continue;
 		}
 
@@ -4616,9 +4614,12 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
 					msecs_to_jiffies(L2CAP_DISC_TIMEOUT));
 			}
 		} else if (chan->state == BT_CONNECT2) {
+			struct sock *sk = chan->sk;
 			struct l2cap_conn_rsp rsp;
 			__u16 res, stat;
 
+			lock_sock(sk);
+
 			if (!status) {
 				if (bt_sk(sk)->defer_setup) {
 					struct sock *parent = bt_sk(sk)->parent;
@@ -4639,6 +4640,8 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
 				stat = L2CAP_CS_NO_INFO;
 			}
 
+			release_sock(sk);
+
 			rsp.scid   = cpu_to_le16(chan->dcid);
 			rsp.dcid   = cpu_to_le16(chan->scid);
 			rsp.result = cpu_to_le16(res);
@@ -4647,7 +4650,7 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
 							sizeof(rsp), &rsp);
 		}
 
-		bh_unlock_sock(sk);
+		l2cap_chan_unlock(chan);
 	}
 
 	mutex_unlock(&conn->chan_lock);
-- 
1.7.9

[RFCv5 15/16] Bluetooth: Use l2cap chan lock in socket connect

[Emeltchenko Andrei]

From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>

Function l2cap_chan_connect does not return with locked socket
anymore. So we take explicit lock in l2cap_sock_connect.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
---
 net/bluetooth/l2cap_core.c |   18 ++++++++++++++----
 net/bluetooth/l2cap_sock.c |    2 ++
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index b117014..ae4df24 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -1159,7 +1159,7 @@ int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid, bdaddr_t *d
 
 	hci_dev_lock(hdev);
 
-	lock_sock(sk);
+	l2cap_chan_lock(chan);
 
 	/* PSM must be odd and lsb of upper byte must be 0 */
 	if ((__le16_to_cpu(psm) & 0x0101) != 0x0001 && !cid &&
@@ -1186,17 +1186,21 @@ int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid, bdaddr_t *d
 		goto done;
 	}
 
+	lock_sock(sk);
+
 	switch (sk->sk_state) {
 	case BT_CONNECT:
 	case BT_CONNECT2:
 	case BT_CONFIG:
 		/* Already connecting */
 		err = 0;
+		release_sock(sk);
 		goto done;
 
 	case BT_CONNECTED:
 		/* Already connected */
 		err = -EISCONN;
+		release_sock(sk);
 		goto done;
 
 	case BT_OPEN:
@@ -1206,11 +1210,15 @@ int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid, bdaddr_t *d
 
 	default:
 		err = -EBADFD;
+		release_sock(sk);
 		goto done;
 	}
 
 	/* Set destination address and psm */
 	bacpy(&bt_sk(sk)->dst, dst);
+
+	release_sock(sk);
+
 	chan->psm = psm;
 	chan->dcid = cid;
 
@@ -1238,23 +1246,25 @@ int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid, bdaddr_t *d
 	/* Update source addr of the socket */
 	bacpy(src, conn->src);
 
+	l2cap_chan_unlock(chan);
 	l2cap_chan_add(conn, chan);
+	l2cap_chan_lock(chan);
 
-	__l2cap_state_change(chan, BT_CONNECT);
+	l2cap_state_change(chan, BT_CONNECT);
 	__set_chan_timer(chan, sk->sk_sndtimeo);
 
 	if (hcon->state == BT_CONNECTED) {
 		if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
 			__clear_chan_timer(chan);
 			if (l2cap_chan_check_security(chan))
-				__l2cap_state_change(chan, BT_CONNECTED);
+				l2cap_state_change(chan, BT_CONNECTED);
 		} else
 			l2cap_do_start(chan);
 	}
 
 	err = 0;
-
 done:
+	l2cap_chan_unlock(chan);
 	hci_dev_unlock(hdev);
 	hci_dev_put(hdev);
 	return err;
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index a278858..bbc1747 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -127,6 +127,8 @@ static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr, int al
 	if (err)
 		goto done;
 
+	lock_sock(sk);
+
 	err = bt_sock_wait_state(sk, BT_CONNECTED,
 			sock_sndtimeo(sk, flags & O_NONBLOCK));
 done:
-- 
1.7.9

[RFCv5 16/16] Bluetooth: Remove socket lock check

[Emeltchenko Andrei]

From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>

Simplify code so that we do not need to check whether socket is locked.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
---
 net/bluetooth/l2cap_sock.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index bbc1747..e2fc24b 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -125,15 +125,15 @@ static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr, int al
 
 	err = l2cap_chan_connect(chan, la.l2_psm, la.l2_cid, &la.l2_bdaddr);
 	if (err)
-		goto done;
+		return err;
 
 	lock_sock(sk);
 
 	err = bt_sock_wait_state(sk, BT_CONNECTED,
 			sock_sndtimeo(sk, flags & O_NONBLOCK));
-done:
-	if (sock_owned_by_user(sk))
-		release_sock(sk);
+
+	release_sock(sk);
+
 	return err;
 }
 
-- 
1.7.9