Re: [PATCH] virtio_net: Remove BUG() to aviod machine dead

thanks, I submit the patch as commented by Andrew 
https://lkml.org/lkml/2021/5/18/256

Actually, if xmit_skb() returns error, below code will give a warning 
with error code.

	/* Try to transmit */
	err = xmit_skb(sq, skb);

	/* This should not happen! */
	if (unlikely(err)) {
		dev->stats.tx_fifo_errors++;
		if (net_ratelimit())
			dev_warn(&dev->dev,
				 "Unexpected TXQ (%d) queue failure: %d\n",
				 qnum, err);
		dev->stats.tx_dropped++;
		dev_kfree_skb_any(skb);
		return NETDEV_TX_OK;
	}





在 2021/5/18 下午5:54, Michael S. Tsirkin 写道:

typo in subject

On Tue, May 18, 2021 at 05:46:56PM +0800, Xianting Tian wrote:

quoted

When met error, we output a print to avoid a BUG().

Signed-off-by: Xianting Tian <redacted>
---
  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..a66174d13e81 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c

@@ -1647,9 +1647,8 @@ static int xmit_skb(struct send_queue *sq, struct

sk_buff *skb)
  		hdr = skb_vnet_hdr(skb);

  	if (virtio_net_hdr_from_skb(skb, &hdr->hdr,
-				    virtio_is_little_endian(vi->vdev), false,
-				    0))
-		BUG();
+				virtio_is_little_endian(vi->vdev), false, 0))
+		return -EPROTO;

why EPROTO? can you add some comments to explain what is going on pls?

is this related to a malicious hypervisor thing?

don't we want at least a WARN_ON? Or _ONCE?

quoted

  	if (vi->mergeable_rx_bufs)
  		hdr->num_buffers = 0;
-- 
2.17.1