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

Yongji Xie
2021-05-27T04:57:25Z

On Thu, May 27, 2021 at 12:13 PM Jason Wang <jasowang@redhat.com> wrote:
>
>
> 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.
>

How about using wait_event_killable_timeout() instead?

Thanks,
Yongji