[bpf-next PATCH] bpf: simplify xdp_convert_ctx_access for xdp_rxq_info

[Jesper Dangaard Brouer]

As pointed out by Daniel Borkmann, using bpf_target_off() is not
necessary for xdp_rxq_info when extracting queue_index and
ifindex, as these members are u32 like BPF_W.

Also fix trivial spelling mistake introduced in same commit.

Fixes: 02dd3291b2f0 ("bpf: finally expose xdp_rxq_info to XDP bpf-programs")
Reported-by: Daniel Borkmann <dan...@iogearbox.net>
Signed-off-by: Jesper Dangaard Brouer <bro...@redhat.com>
---
 include/uapi/linux/bpf.h |    2 +-
 net/core/filter.c        |    7 +++----
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 405317f9c064..395d261948de 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -899,7 +899,7 @@ struct xdp_md {
        __u32 data;
        __u32 data_end;
        __u32 data_meta;
-       /* Below access go though struct xdp_rxq_info */
+       /* Below access go through struct xdp_rxq_info */
        __u32 ingress_ifindex; /* rxq->dev->ifindex */
        __u32 rx_queue_index;  /* rxq->queue_index  */
 };
diff --git a/net/core/filter.c b/net/core/filter.c
index acdb94c0e97f..4ce50306154d 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4312,16 +4312,15 @@ static u32 xdp_convert_ctx_access(enum bpf_access_type 
type,
                                      si->dst_reg, si->dst_reg,
                                      offsetof(struct xdp_rxq_info, dev));
                *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg,
-                                     bpf_target_off(struct net_device,
-                                                    ifindex, 4, target_size));
+                                     offsetof(struct net_device, ifindex));
                break;
        case offsetof(struct xdp_md, rx_queue_index):
                *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct xdp_buff, rxq),
                                      si->dst_reg, si->src_reg,
                                      offsetof(struct xdp_buff, rxq));
                *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg,
-                                     bpf_target_off(struct xdp_rxq_info,
-                                               queue_index, 4, target_size));
+                                     offsetof(struct xdp_rxq_info,
+                                              queue_index));
                break;
        }