Fix a verification failure. filter_udphdr() calls bpf_xdp_pull_data(), which will invalidate all pkt pointers. Therefore, all ctx->data loaded before filter_udphdr() cannot be used. Reload it to prevent verification errors. The error may not appear on some compiler versions if they decide to load ctx->data after filter_udphdr() when it is first used. Fixes: efec2e55bdef ("selftests: drv-net: Pull data before parsing headers") Signed-off-by: Amery Hung --- tools/testing/selftests/net/lib/xdp_native.bpf.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/net/lib/xdp_native.bpf.c b/tools/testing/selftests/net/lib/xdp_native.bpf.c index df4eea5c192b..c368fc045f4b 100644 --- a/tools/testing/selftests/net/lib/xdp_native.bpf.c +++ b/tools/testing/selftests/net/lib/xdp_native.bpf.c @@ -420,7 +420,6 @@ static int xdp_adjst_tail_grow_data(struct xdp_md *ctx, __u16 offset) static int xdp_adjst_tail(struct xdp_md *ctx, __u16 port) { - void *data = (void *)(long)ctx->data; struct udphdr *udph = NULL; __s32 *adjust_offset, *val; __u32 key, hdr_len; @@ -432,7 +431,8 @@ static int xdp_adjst_tail(struct xdp_md *ctx, __u16 port) if (!udph) return XDP_PASS; - hdr_len = (void *)udph - data + sizeof(struct udphdr); + hdr_len = (void *)udph - (void *)(long)ctx->data + + sizeof(struct udphdr); key = XDP_ADJST_OFFSET; adjust_offset = bpf_map_lookup_elem(&map_xdp_setup, &key); if (!adjust_offset) @@ -572,8 +572,6 @@ static int xdp_adjst_head_grow_data(struct xdp_md *ctx, __u64 hdr_len, static int xdp_head_adjst(struct xdp_md *ctx, __u16 port) { - void *data_end = (void *)(long)ctx->data_end; - void *data = (void *)(long)ctx->data; struct udphdr *udph_ptr = NULL; __u32 key, size, hdr_len; __s32 *val; @@ -584,7 +582,8 @@ static int xdp_head_adjst(struct xdp_md *ctx, __u16 port) if (!udph_ptr) return XDP_PASS; - hdr_len = (void *)udph_ptr - data + sizeof(struct udphdr); + hdr_len = (void *)udph_ptr - (void *)(long)ctx->data + + sizeof(struct udphdr); key = XDP_ADJST_OFFSET; val = bpf_map_lookup_elem(&map_xdp_setup, &key); -- 2.47.3