Re: [PATCH bpf-next] selftests/bpf: fix compilation failure when CONFIG_NET_FOU!=y

[Daniel Borkmann]

Hi Artem,

On 7/18/24 4:31 PM, Artem Savkov wrote:
> Without CONFIG_NET_FOU bpf selftests are unable to build because of
> missing definitions. Add ___local versions of struct bpf_fou_encap and
> enum bpf_fou_encap_type to fix the issue.
>
> Signed-off-by: Artem Savkov <asavkov@xxxxxxxxxx>

This breaks BPF CI, ptal:

https://github.com/kernel-patches/bpf/actions/runs/9999691294/job/27641198557

  [...]
    CLNG-BPF [test_maps] btf__core_reloc_existence___wrong_field_defs.bpf.o
    CLNG-BPF [test_maps] verifier_bswap.bpf.o
    CLNG-BPF [test_maps] test_core_reloc_existence.bpf.o
    CLNG-BPF [test_maps] test_global_func8.bpf.o
    CLNG-BPF [test_maps] verifier_bitfield_write.bpf.o
    CLNG-BPF [test_maps] local_storage_bench.bpf.o
    CLNG-BPF [test_maps] verifier_runtime_jit.bpf.o
    CLNG-BPF [test_maps] test_pkt_access.bpf.o
  progs/test_tunnel_kern.c:39:5: error: conflicting types for 'bpf_skb_set_fou_encap'
     39 | int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx,
        |     ^
  /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107714:12: note: previous declaration is here
   107714 | extern int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap, int type) __weak __ksym;
          |            ^
  progs/test_tunnel_kern.c:41:5: error: conflicting types for 'bpf_skb_get_fou_encap'
     41 | int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx,
        |     ^
  /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107715:12: note: previous declaration is here
   107715 | extern int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap) __weak __ksym;
          |            ^
    CLNG-BPF [test_maps] verifier_typedef.bpf.o
    CLNG-BPF [test_maps] user_ringbuf_fail.bpf.o
    CLNG-BPF [test_maps] verifier_map_in_map.bpf.o
  progs/test_tunnel_kern.c:782:35: error: incompatible pointer types passing 'struct bpf_fou_encap___local *' to parameter of type 'struct bpf_fou_encap *' [-Werror,-Wincompatible-pointer-types]
    782 |         ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_GUE___local);
        |                                          ^~~~~~
  /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107714:83: note: passing argument to parameter 'encap' here
   107714 | extern int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap, int type) __weak __ksym;
          |                                                                                   ^
  progs/test_tunnel_kern.c:819:35: error: incompatible pointer types passing 'struct bpf_fou_encap___local *' to parameter of type 'struct bpf_fou_encap *' [-Werror,-Wincompatible-pointer-types]
    819 |         ret = bpf_skb_set_fou_encap(skb, &encap, FOU_BPF_ENCAP_FOU___local);
        |                                          ^~~~~~
  /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107714:83: note: passing argument to parameter 'encap' here
   107714 | extern int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap, int type) __weak __ksym;
          |                                                                                   ^
  progs/test_tunnel_kern.c:841:35: error: incompatible pointer types passing 'struct bpf_fou_encap___local *' to parameter of type 'struct bpf_fou_encap *' [-Werror,-Wincompatible-pointer-types]
    841 |         ret = bpf_skb_get_fou_encap(skb, &encap);
        |                                          ^~~~~~
  /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/include/vmlinux.h:107715:83: note: passing argument to parameter 'encap' here
   107715 | extern int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap) __weak __ksym;
          |                                                                                   ^
  5 errors generated.
    CLNG-BPF [test_maps] verifier_bounds_deduction.bpf.o
    CLNG-BPF [test_maps] test_netfilter_link_attach.bpf.o
    CLNG-BPF [test_maps] verifier_jeq_infer_not_null.bpf.o
  make: *** [Makefile:654: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/test_tunnel_kern.bpf.o] Error 1
  make: *** Waiting for unfinished jobs....
  make: Leaving directory '/tmp/work/bpf/bpf/tools/testing/selftests/bpf'
  Error: Process completed with exit code 2.