Re: [PATCH] virtio_net: Use BUG_ON instead of if condition followed by BUG

[Xianting Tian]

thanks for your comments,
It is a good idea, I think we can follow the similar logic in function 
'receive_buf':
	if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
				  virtio_is_little_endian(vi->vdev))) {
		net_warn_ratelimited("%s: bad gso: type: %u, size:%u\n",
				     dev->name, hdr->hdr.gso_type,
				     hdr->hdr.gso_size);
		goto frame_err;
	}

I will summit a new patch later.


在 2021/5/17 下午10:35, Andrew Lunn 写道:
> On Mon, May 17, 2021 at 09:31:19PM +0800, Xianting Tian wrote:
> > BUG_ON() uses unlikely in if(), which can be optimized at compile time.
> >
> > Signed-off-by: Xianting Tian <xianting.tian@xxxxxxxxxxxxxxxxx>
> > ---
> >   drivers/net/virtio_net.c | 5 ++---
> >   1 file changed, 2 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > index c921ebf3ae82..212d52204884 100644
> > --- a/drivers/net/virtio_net.c
> > +++ b/drivers/net/virtio_net.c
> > @@ -1646,10 +1646,9 @@ static int xmit_skb(struct send_queue *sq, struct
> > sk_buff *skb)
> >   	else
> >   		hdr = skb_vnet_hdr(skb);
> >
> > -	if (virtio_net_hdr_from_skb(skb, &hdr->hdr,
>
> How fatal is it not being able to get the header from the skb? There
> has been push back on the use of BUG() or its variants, since it kills
> the machine dead. Would it be possible to turn this into a WARN_ON and
> return -EPROTO or something?
>
>         Andrew