On Wed, Jan 04, 2017 at 11:03:32AM +0800, Jason Wang wrote:

On 2017年01月03日 21:33, Stefan Hajnoczi wrote:

quoted

On Wed, Dec 28, 2016 at 04:09:31PM +0800, Jason Wang wrote:

quoted

+static int tun_rx_batched(struct tun_file *tfile, struct sk_buff *skb,
+			  int more)
+{
+	struct sk_buff_head *queue = &tfile->sk.sk_write_queue;
+	struct sk_buff_head process_queue;
+	int qlen;
+	bool rcv = false;
+
+	spin_lock(&queue->lock);

Should this be spin_lock_bh()?  Below and in tun_get_user() there are
explicit local_bh_disable() calls so I guess BHs can interrupt us here
and this would deadlock.

sk_write_queue were accessed only in this function which runs under process
context, so no need for spin_lock_bh() here.

I see, thanks!

Stefan