From f46a09b37b593b9382e709511523e33244d910c9 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Fri, 23 Dec 2016 22:37:27 +0800 Subject: [PATCH] virtio-net: correctly handle XDP_PASS for linearized packets When XDP_PASS were determined for linearized packets, we try to get new buffers in the virtqueue and build skbs from them. This is wrong, we should create skbs based on existed buffers instead. Fixing them by creating skb based on xdp_page. With this patch "ping 192.168.100.4 -s 3900 -M do" works for XDP_PASS. Cc: John Fastabend Signed-off-by: Jason Wang Acked-by: John Fastabend Signed-off-by: David S. Miller --- drivers/net/virtio_net.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 58ad40e17a74f..470293e2b84d4 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -578,8 +578,14 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, act = do_xdp_prog(vi, rq, xdp_prog, xdp_page, offset, len); switch (act) { case XDP_PASS: - if (unlikely(xdp_page != page)) - __free_pages(xdp_page, 0); + /* We can only create skb based on xdp_page. */ + if (unlikely(xdp_page != page)) { + rcu_read_unlock(); + put_page(page); + head_skb = page_to_skb(vi, rq, xdp_page, + 0, len, PAGE_SIZE); + return head_skb; + } break; case XDP_TX: if (unlikely(xdp_page != page)) -- 2.39.5