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Bluetooth: Move identity address update behind a workqueue

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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>
This commit is contained in:
Johan Hedberg 2014-09-05 22:19:50 +03:00 committed by Marcel Holtmann
parent 84bc0db53b
commit f3d82d0c8e
3 changed files with 11 additions and 4 deletions
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3
include/net/bluetooth/l2cap.h
View file

@ -633,6 +633,8 @@ struct l2cap_conn {
struct sk_buff_head pending_rx; struct sk_buff_head pending_rx;
struct work_struct pending_rx_work; struct work_struct pending_rx_work;
struct work_struct id_addr_update_work;
__u8 disc_reason; __u8 disc_reason;
struct l2cap_chan *smp; 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_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_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_send_conn_req(struct l2cap_chan *chan);
void l2cap_move_start(struct l2cap_chan *chan); void l2cap_move_start(struct l2cap_chan *chan);
void l2cap_logical_cfm(struct l2cap_chan *chan, struct hci_chan *hchan, void l2cap_logical_cfm(struct l2cap_chan *chan, struct hci_chan *hchan,

10
net/bluetooth/l2cap_core.c
View file

@ -631,9 +631,11 @@ void l2cap_chan_del(struct l2cap_chan *chan, int err)
} }
EXPORT_SYMBOL_GPL(l2cap_chan_del); 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; struct l2cap_chan *chan;
mutex_lock(&conn->chan_lock); 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)) if (work_pending(&conn->pending_rx_work))
cancel_work_sync(&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); l2cap_unregister_all_users(conn);
/* Force the connection to be immediately dropped */ /* 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); skb_queue_head_init(&conn->pending_rx);
INIT_WORK(&conn->pending_rx_work, process_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; conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM;

2
net/bluetooth/smp.c
View file

@ -654,7 +654,7 @@ static void smp_notify_keys(struct l2cap_conn *conn)
*/ */
bacpy(&hcon->dst, &smp->remote_irk->bdaddr); bacpy(&hcon->dst, &smp->remote_irk->bdaddr);
hcon->dst_type = smp->remote_irk->addr_type; 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 /* When receiving an indentity resolving key for
* a remote device that does not use a resolvable * a remote device that does not use a resolvable