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Bluetooth: hidp: fix possible might sleep error in hidp_session_thread

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It looks like hidp_session_thread 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@rock-chips.com>
Tested-by: AL Yu-Chen Cho <acho@suse.com>
Tested-by: Rohit Vaswani <rvaswani@nvidia.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This commit is contained in:
Jeffy Chen 2017-06-27 17:34:44 +08:00 committed by Marcel Holtmann
parent f06d977309
commit 5da8e47d84
1 changed files with 22 additions and 11 deletions
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33
net/bluetooth/hidp/core.c
View File

@ -36,6 +36,7 @@
#define VERSION "1.2"
static DECLARE_RWSEM(hidp_session_sem);
static DECLARE_WAIT_QUEUE_HEAD(hidp_session_wq);
static LIST_HEAD(hidp_session_list);
static unsigned char hidp_keycode[256] = {
@ -1068,12 +1069,12 @@ static int hidp_session_start_sync(struct hidp_session *session)
* Wake up session thread and notify it to stop. This is asynchronous and
* returns immediately. Call this whenever a runtime error occurs and you want
* the session to stop.
* Note: wake_up_process() performs any necessary memory-barriers for us.
* Note: wake_up_interruptible() performs any necessary memory-barriers for us.
*/
static void hidp_session_terminate(struct hidp_session *session)
{
atomic_inc(&session->terminate);
wake_up_process(session->task);
wake_up_interruptible(&hidp_session_wq);
}
/*
@ -1180,7 +1181,9 @@ static void hidp_session_run(struct hidp_session *session)
struct sock *ctrl_sk = session->ctrl_sock->sk;
struct sock *intr_sk = session->intr_sock->sk;
struct sk_buff *skb;
DEFINE_WAIT_FUNC(wait, woken_wake_function);
add_wait_queue(&hidp_session_wq, &wait);
for (;;) {
/*
* This thread can be woken up two ways:
@ -1188,12 +1191,10 @@ static void hidp_session_run(struct hidp_session *session)
* session->terminate flag and wakes this thread up.
* - Via modifying the socket state of ctrl/intr_sock. This
* thread is woken up by ->sk_state_changed().
*
* Note: set_current_state() performs any necessary
* memory-barriers for us.
*/
set_current_state(TASK_INTERRUPTIBLE);
/* Ensure session->terminate is updated */
smp_mb__before_atomic();
if (atomic_read(&session->terminate))
break;
@ -1227,11 +1228,22 @@ static void hidp_session_run(struct hidp_session *session)
hidp_process_transmit(session, &session->ctrl_transmit,
session->ctrl_sock);
schedule();
wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
}
remove_wait_queue(&hidp_session_wq, &wait);
atomic_inc(&session->terminate);
set_current_state(TASK_RUNNING);
/* Ensure session->terminate is updated */
smp_mb__after_atomic();
}
static int hidp_session_wake_function(wait_queue_t *wait,
unsigned int mode,
int sync, void *key)
{
wake_up_interruptible(&hidp_session_wq);
return false;
}
/*
@ -1244,7 +1256,8 @@ static void hidp_session_run(struct hidp_session *session)
static int hidp_session_thread(void *arg)
{
struct hidp_session *session = arg;
wait_queue_t ctrl_wait, intr_wait;
DEFINE_WAIT_FUNC(ctrl_wait, hidp_session_wake_function);
DEFINE_WAIT_FUNC(intr_wait, hidp_session_wake_function);
BT_DBG("session %p", session);
@ -1254,8 +1267,6 @@ static int hidp_session_thread(void *arg)
set_user_nice(current, -15);
hidp_set_timer(session);
init_waitqueue_entry(&ctrl_wait, current);
init_waitqueue_entry(&intr_wait, current);
add_wait_queue(sk_sleep(session->ctrl_sock->sk), &ctrl_wait);
add_wait_queue(sk_sleep(session->intr_sock->sk), &intr_wait);
/* This memory barrier is paired with wq_has_sleeper(). See