Hi Gustavo
On Sat, Oct 30, 2010 at 12:17 AM, Gustavo F. Padovan
<padovan@xxxxxxxxxxxxxx> wrote:
> Hi Andrei,
>
> * Emeltchenko Andrei <Andrei.Emeltchenko.news@xxxxxxxxx> [2010-10-29 16:43:01 +0300]:
>
>> From: Andrei Emeltchenko <andrei.emeltchenko@xxxxxxxxx>
>>
>> In timer context we might delete l2cap channel used by krfcommd.
>> The check makes sure that sk is not owned. If sk is owned we
>> restart timer for HZ/5.
>>
>> Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@xxxxxxxxx>
>> ---
>> net/bluetooth/l2cap.c | 32 ++++++++++++++++++++------------
>> 1 files changed, 20 insertions(+), 12 deletions(-)
>>
>> diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
>> index b1344d8..c67b3c6 100644
>> --- a/net/bluetooth/l2cap.c
>> +++ b/net/bluetooth/l2cap.c
>> @@ -83,6 +83,18 @@ static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn,
>> static int l2cap_ertm_data_rcv(struct sock *sk, struct sk_buff *skb);
>>
>> /* ---- L2CAP timers ---- */
>> +static void l2cap_sock_set_timer(struct sock *sk, long timeout)
>> +{
>> + BT_DBG("sk %p state %d timeout %ld", sk, sk->sk_state, timeout);
>> + sk_reset_timer(sk, &sk->sk_timer, jiffies + timeout);
>> +}
>> +
>> +static void l2cap_sock_clear_timer(struct sock *sk)
>> +{
>> + BT_DBG("sock %p state %d", sk, sk->sk_state);
>> + sk_stop_timer(sk, &sk->sk_timer);
>> +}
>> +
>> static void l2cap_sock_timeout(unsigned long arg)
>> {
>> struct sock *sk = (struct sock *) arg;
>> @@ -92,6 +104,14 @@ static void l2cap_sock_timeout(unsigned long arg)
>>
>> bh_lock_sock(sk);
>>
>> + if (sock_owned_by_user(sk)) {
>> + /* sk is owned by user. Try again later */
>> + l2cap_sock_set_timer(sk, HZ / 5);
>> + bh_unlock_sock(sk);
>> + sock_put(sk);
>
> You can't do a sock_put() here, you have to keep the referencee to the
> socket while the timer is enabled.
sk_reset_timer is holding sock when timer restarts. The same way done
in TCP code in function:
static void tcp_delack_timer(unsigned long data)
Regards,
Andrei
--
To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
