[PATCH net v2] veth: xdp: use head instead of hard_start

Mao Wenan
2020-03-31T06:04:14Z

xdp.data_hard_start is equal to first address of
struct xdp_frame, which is mentioned in
convert_to_xdp_frame(). But the pointer hard_start
in veth_xdp_rcv_one() is 32 bytes offset of frame,
so it should use head instead of hard_start to
set xdp.data_hard_start. Otherwise, if BPF program
calls helper_function such as bpf_xdp_adjust_head, it
will be confused for xdp_frame_end.

Fixes: 9fc8d518d9d5 ("veth: Handle xdp_frames in xdp napi ring")
Signed-off-by: Mao Wenan <maowenan@huawei.com>
---
v2: add fixes tag, as well as commit log.
drivers/net/veth.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index d4cbb9e8c63f..5ea550884bf8 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -506,7 +506,7 @@ static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
struct xdp_buff xdp;
u32 act;

- xdp.data_hard_start = hard_start;
+ xdp.data_hard_start = head;
xdp.data = frame->data;
xdp.data_end = frame->data + frame->len;
xdp.data_meta = frame->data - frame->metasize;
--
2.20.1