rfcomm, sched/wait: Fix broken wait construct

rfcomm_run() is a tad broken in that is has a nested wait loop. One
cannot rely on p->state for the outer wait because the inner wait will
overwrite it.

Fix this using the new wait_woken() facility.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Alexander Holler <holler@ahsoftware.de>
Cc: David S. Miller <davem@davemloft.net>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Joe Perches <joe@perches.com>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Libor Pechacek <lpechacek@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Seung-Woo Kim <sw0312.kim@samsung.com>
Cc: Vignesh Raman <Vignesh_Raman@mentor.com>
Cc: linux-bluetooth@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Peter Zijlstra 2014-10-29 16:17:12 +01:00 committed by Ingo Molnar
parent 6b55fc63f4
commit eedf7e47da

View File

@ -101,11 +101,11 @@ static struct rfcomm_session *rfcomm_session_del(struct rfcomm_session *s);
#define __get_rpn_stop_bits(line) (((line) >> 2) & 0x1)
#define __get_rpn_parity(line) (((line) >> 3) & 0x7)
static DECLARE_WAIT_QUEUE_HEAD(rfcomm_wq);
static void rfcomm_schedule(void)
{
if (!rfcomm_thread)
return;
wake_up_process(rfcomm_thread);
wake_up_all(&rfcomm_wq);
}
/* ---- RFCOMM FCS computation ---- */
@ -2086,24 +2086,22 @@ static void rfcomm_kill_listener(void)
static int rfcomm_run(void *unused)
{
DEFINE_WAIT_FUNC(wait, woken_wake_function);
BT_DBG("");
set_user_nice(current, -10);
rfcomm_add_listener(BDADDR_ANY);
while (1) {
set_current_state(TASK_INTERRUPTIBLE);
if (kthread_should_stop())
break;
add_wait_queue(&rfcomm_wq, &wait);
while (!kthread_should_stop()) {
/* Process stuff */
rfcomm_process_sessions();
schedule();
wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
}
__set_current_state(TASK_RUNNING);
remove_wait_queue(&rfcomm_wq, &wait);
rfcomm_kill_listener();