From: Jesper Dangaard Brouer <brouer@redhat.com>
Date: Wed, 27 May 2020 15:44:09 +0200
Subject: mlx5: fix xdp data_meta setup in mlx5e_fill_xdp_buff
Patch-mainline: v5.8-rc1
Git-commit: 56e2287b4110fbb81456a346b1d4c12bee7cf044
References: jsc#SLE-15172

The helper function xdp_set_data_meta_invalid() must be called after
setting xdp->data as it depends on it.

The bug was introduced in the cited patch below, and cause the kernel
to crash when using BPF helper bpf_xdp_adjust_head() on mlx5 driver.

Fixes: 39d6443c8daf ("mlx5, xsk: Migrate to new MEM_TYPE_XSK_BUFF_POOL")
Reported-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_rx.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -1056,8 +1056,8 @@ static void mlx5e_fill_xdp_buff(struct m
 				u32 len, struct xdp_buff *xdp)
 {
 	xdp->data_hard_start = va;
-	xdp_set_data_meta_invalid(xdp);
 	xdp->data = va + headroom;
+	xdp_set_data_meta_invalid(xdp);
 	xdp->data_end = xdp->data + len;
 	xdp->rxq = &rq->xdp_rxq;
 	xdp->frame_sz = rq->buff.frame0_sz;