From: Eric Dumazet <edumazet@xxxxxxxxxx> [ Upstream commit be69483bf4f3abaaca5d5ba460dbb50239463552 ] Use BPF_REG_1 for source and destination of gso_segs read, to exercise "bpf: fix access to skb_shared_info->gso_segs" fix. Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Suggested-by: Stanislav Fomichev <sdf@xxxxxxxxxx> Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- tools/testing/selftests/bpf/verifier/ctx_skb.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/tools/testing/selftests/bpf/verifier/ctx_skb.c b/tools/testing/selftests/bpf/verifier/ctx_skb.c index b0fda2877119c..d438193804b21 100644 --- a/tools/testing/selftests/bpf/verifier/ctx_skb.c +++ b/tools/testing/selftests/bpf/verifier/ctx_skb.c @@ -974,6 +974,17 @@ .result = ACCEPT, .prog_type = BPF_PROG_TYPE_CGROUP_SKB, }, +{ + "read gso_segs from CGROUP_SKB", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_1, + offsetof(struct __sk_buff, gso_segs)), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .prog_type = BPF_PROG_TYPE_CGROUP_SKB, +}, { "write gso_segs from CGROUP_SKB", .insns = { -- 2.20.1