Bluetooth: Move identity address update behind a workqueue

The identity address update of all channels for an l2cap_conn needs to
take the lock for each channel, i.e. it's safest to do this by a
separate workqueue callback.

Previously this was partially solved by moving the entire SMP key
distribution behind a workqueue. However, if we want SMP context locking
to be correct and safe we should always use the l2cap_chan lock when
accessing it, meaning even smp_distribute_keys needs to take that lock
which would once again create a dead lock when updating the identity
address.

The simplest way to solve this is to have l2cap_conn manage the deferred
work which is what this patch does. A subsequent patch will remove the
now unnecessary SMP key distribution work struct.

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

diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index be25eddea615e849b62fbb4cd2d9f58658766d3e..ead99f032f7ab381a0559cf5f4ee23600632d479 100644 (file)
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -633,6 +633,8 @@ struct l2cap_conn {
        struct sk_buff_head     pending_rx;
        struct work_struct      pending_rx_work;
 
+       struct work_struct      id_addr_update_work;
+
        __u8                    disc_reason;
 
        struct l2cap_chan       *smp;
@@ -937,7 +939,6 @@ int l2cap_ertm_init(struct l2cap_chan *chan);
 void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan);
 void __l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan);
 void l2cap_chan_del(struct l2cap_chan *chan, int err);
-void l2cap_conn_update_id_addr(struct hci_conn *hcon);
 void l2cap_send_conn_req(struct l2cap_chan *chan);
 void l2cap_move_start(struct l2cap_chan *chan);
 void l2cap_logical_cfm(struct l2cap_chan *chan, struct hci_chan *hchan,

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index ab405f0e53cbf17b9f992eb377309e0fab31ce58..b71430caab4a26316ff15dc28afbd68c85caeabf 100644 (file)
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -631,9 +631,11 @@ void l2cap_chan_del(struct l2cap_chan *chan, int err)
 }
 EXPORT_SYMBOL_GPL(l2cap_chan_del);
 
-void l2cap_conn_update_id_addr(struct hci_conn *hcon)
+static void l2cap_conn_update_id_addr(struct work_struct *work)
 {
-       struct l2cap_conn *conn = hcon->l2cap_data;
+       struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
+                                              id_addr_update_work);
+       struct hci_conn *hcon = conn->hcon;
        struct l2cap_chan *chan;
 
        mutex_lock(&conn->chan_lock);
@@ -1635,6 +1637,9 @@ static void l2cap_conn_del(struct hci_conn *hcon, int err)
        if (work_pending(&conn->pending_rx_work))
                cancel_work_sync(&conn->pending_rx_work);
 
+       if (work_pending(&conn->id_addr_update_work))
+               cancel_work_sync(&conn->id_addr_update_work);
+
        l2cap_unregister_all_users(conn);
 
        /* Force the connection to be immediately dropped */
@@ -6927,6 +6932,7 @@ static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon)
 
        skb_queue_head_init(&conn->pending_rx);
        INIT_WORK(&conn->pending_rx_work, process_pending_rx);
+       INIT_WORK(&conn->id_addr_update_work, l2cap_conn_update_id_addr);
 
        conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM;
 

diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index 9accb47394882d44d849a452b4f96875451f3a6a..795c603bed30bf6ea96039a8d768149d4b5fabba 100644 (file)
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -654,7 +654,7 @@ static void smp_notify_keys(struct l2cap_conn *conn)
                 */
                bacpy(&hcon->dst, &smp->remote_irk->bdaddr);
                hcon->dst_type = smp->remote_irk->addr_type;
-               l2cap_conn_update_id_addr(hcon);
+               queue_work(hdev->workqueue, &conn->id_addr_update_work);
 
                /* When receiving an indentity resolving key for
                 * a remote device that does not use a resolvable