On Tue, 2017-02-14 at 08:55 +0800, Jeffy Chen wrote: > It looks like cmtp_session has same pattern as the issue reported in > old rfcomm: > > while (1) { > set_current_state(TASK_INTERRUPTIBLE); > if (condition) > break; > // may call might_sleep here > schedule(); > } > __set_current_state(TASK_RUNNING); > > Which fixed at: > dfb2fae Bluetooth: Fix nested sleeps > > So let's fix it at the same way, also follow the suggestion of: > https://lwn.net/Articles/628628/ > > Signed-off-by: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx> > Reviewed-by: Brian Norris <briannorris@xxxxxxxxxxxx> > Remove unnecessary memory barrier before wake_up_* functions. Reviewed-by: AL Yu-Chen Cho <acho@xxxxxxxx> > > --- > > Changes in v3: > Add brian's Reviewed-by. > > Changes in v2: None > > net/bluetooth/cmtp/core.c | 17 ++++++++++------- > 1 file changed, 10 insertions(+), 7 deletions(-) > > diff --git a/net/bluetooth/cmtp/core.c b/net/bluetooth/cmtp/core.c > index 9e59b66..1152ce3 100644 > --- a/net/bluetooth/cmtp/core.c > +++ b/net/bluetooth/cmtp/core.c > @@ -280,16 +280,16 @@ static int cmtp_session(void *arg) > struct cmtp_session *session = arg; > struct sock *sk = session->sock->sk; > struct sk_buff *skb; > - wait_queue_t wait; > + DEFINE_WAIT_FUNC(wait, woken_wake_function); > > BT_DBG("session %p", session); > > set_user_nice(current, -15); > > - init_waitqueue_entry(&wait, current); > add_wait_queue(sk_sleep(sk), &wait); > while (1) { > - set_current_state(TASK_INTERRUPTIBLE); > + /* Ensure session->terminate is updated */ > + smp_mb__before_atomic(); > > if (atomic_read(&session->terminate)) > break; > @@ -306,9 +306,8 @@ static int cmtp_session(void *arg) > > cmtp_process_transmit(session); > > - schedule(); > + wait_woken(&wait, TASK_INTERRUPTIBLE, > MAX_SCHEDULE_TIMEOUT); > } > - __set_current_state(TASK_RUNNING); > remove_wait_queue(sk_sleep(sk), &wait); > > down_write(&cmtp_session_sem); > @@ -393,7 +392,7 @@ int cmtp_add_connection(struct cmtp_connadd_req > *req, struct socket *sock) > err = cmtp_attach_device(session); > if (err < 0) { > atomic_inc(&session->terminate); > - wake_up_process(session->task); > + wake_up_interruptible(sk_sleep(session- > >sock->sk)); > up_write(&cmtp_session_sem); > return err; > } > @@ -431,7 +430,11 @@ int cmtp_del_connection(struct cmtp_conndel_req > *req) > > /* Stop session thread */ > atomic_inc(&session->terminate); > - wake_up_process(session->task); > + > + /* Ensure session->terminate is updated */ > + smp_mb__after_atomic(); > + > + wake_up_interruptible(sk_sleep(session->sock->sk)); > } else > err = -ENOENT; > -- 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