diff options
| author | Eric Dumazet <edumazet@google.com> | 2021-04-20 13:01:44 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-04-20 16:54:40 -0700 |
| commit | f5d7872a8b8a3176e65dc6f7f0705ce7e9a699e6 (patch) | |
| tree | 91e6eeebf094dc150d16a3ff053dd7ef89611e14 /drivers/net/virtio_net.c | |
| parent | b8c55ce266dee09b0e359ff9af885eb94e11480a (diff) | |
virtio-net: restrict build_skb() use to some arches
build_skb() is supposed to be followed by
skb_reserve(skb, NET_IP_ALIGN), so that IP headers are word-aligned.
(Best practice is to reserve NET_IP_ALIGN+NET_SKB_PAD, but the NET_SKB_PAD
part is only a performance optimization if tunnel encaps are added.)
Unfortunately virtio_net has not provisioned this reserve.
We can only use build_skb() for arches where NET_IP_ALIGN == 0
We might refine this later, with enough testing.
Fixes: fb32856b16ad ("virtio-net: page_to_skb() use build_skb when there's sufficient tailroom")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/virtio_net.c')
| -rw-r--r-- | drivers/net/virtio_net.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 8cd76037c724..0c84b9f2c5e9 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -415,7 +415,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, shinfo_size = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); - if (len > GOOD_COPY_LEN && tailroom >= shinfo_size) { + if (!NET_IP_ALIGN && len > GOOD_COPY_LEN && tailroom >= shinfo_size) { skb = build_skb(p, truesize); if (unlikely(!skb)) return NULL; |