Re: [PATCH v7 11/12] vduse: Introduce VDUSE - vDPA Device in Userspace

[Jason Wang <jasowang@xxxxxxxxxx>]

在 2021/5/17 下午5:55, Xie Yongji 写道:
> +
> +static int vduse_dev_msg_sync(struct vduse_dev *dev,
> +			      struct vduse_dev_msg *msg)
> +{
> +	init_waitqueue_head(&msg->waitq);
> +	spin_lock(&dev->msg_lock);
> +	vduse_enqueue_msg(&dev->send_list, msg);
> +	wake_up(&dev->waitq);
> +	spin_unlock(&dev->msg_lock);
> +	wait_event_killable(msg->waitq, msg->completed);


What happens if the userspace(malicous) doesn't give a response forever?

It looks like a DOS. If yes, we need to consider a way to fix that.

Thanks


> +	spin_lock(&dev->msg_lock);
> +	if (!msg->completed) {
> +		list_del(&msg->list);
> +		msg->resp.result = VDUSE_REQUEST_FAILED;
> +	}
> +	spin_unlock(&dev->msg_lock);
> +
> +	return (msg->resp.result == VDUSE_REQUEST_OK) ? 0 : -1;
> +}