Re: [PATCH bpf-next v9 3/3] selftests/bpf: add testcase for TRACING with 6+ arguments

[Alexei Starovoitov]

On Wed, Jul 12, 2023 at 1:50 AM <menglong8.dong@xxxxxxxxx> wrote:
>
> From: Menglong Dong <imagedong@xxxxxxxxxxx>
>
> Add fentry_many_args.c and fexit_many_args.c to test the fentry/fexit
> with 7/11 arguments. As this feature is not supported by arm64 yet, we
> disable these testcases for arm64 in DENYLIST.aarch64. We can combine
> them with fentry_test.c/fexit_test.c when arm64 is supported too.
>
> Correspondingly, add bpf_testmod_fentry_test7() and
> bpf_testmod_fentry_test11() to bpf_testmod.c
>
> Meanwhile, add bpf_modify_return_test2() to test_run.c to test the
> MODIFY_RETURN with 7 arguments.
>
> Add bpf_testmod_test_struct_arg_7/bpf_testmod_test_struct_arg_7 in
> bpf_testmod.c to test the struct in the arguments.
>
> And the testcases passed on x86_64:
>
> ./test_progs -t fexit
> Summary: 5/14 PASSED, 0 SKIPPED, 0 FAILED
>
> ./test_progs -t fentry
> Summary: 3/2 PASSED, 0 SKIPPED, 0 FAILED
>
> ./test_progs -t modify_return
> Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED
>
> ./test_progs -t tracing_struct
> Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED
>
> Signed-off-by: Menglong Dong <imagedong@xxxxxxxxxxx>
> Acked-by: Yonghong Song <yhs@xxxxxx>
> ---
> v9:
> - change the way to test fmod_ret
> v8:
> - split the testcases, and add fentry_many_args/fexit_many_args to
>   DENYLIST.aarch64
> v6:
> - add testcases to tracing_struct.c instead of fentry_test.c and
>   fexit_test.c
> v5:
> - add testcases for MODIFY_RETURN
> v4:
> - use different type for args in bpf_testmod_fentry_test{7,12}
> - add testcase for grabage values in ctx
> v3:
> - move bpf_fentry_test{7,12} to bpf_testmod.c and rename them to
>   bpf_testmod_fentry_test{7,12} meanwhile
> - get return value by bpf_get_func_ret() in
>   "fexit/bpf_testmod_fentry_test12", as we don't change ___bpf_ctx_cast()
>   in this version
> ---
>  net/bpf/test_run.c                            | 14 ++++-
>  tools/testing/selftests/bpf/DENYLIST.aarch64  |  2 +
>  .../selftests/bpf/bpf_testmod/bpf_testmod.c   | 49 ++++++++++++++++-
>  .../selftests/bpf/prog_tests/fentry_test.c    | 43 +++++++++++++--
>  .../selftests/bpf/prog_tests/fexit_test.c     | 43 +++++++++++++--
>  .../selftests/bpf/prog_tests/modify_return.c  | 10 ++--
>  .../selftests/bpf/prog_tests/tracing_struct.c | 19 +++++++
>  .../selftests/bpf/progs/fentry_many_args.c    | 39 ++++++++++++++
>  .../selftests/bpf/progs/fexit_many_args.c     | 40 ++++++++++++++
>  .../selftests/bpf/progs/modify_return.c       | 40 ++++++++++++++
>  .../selftests/bpf/progs/tracing_struct.c      | 54 +++++++++++++++++++
>  11 files changed, 340 insertions(+), 13 deletions(-)
>  create mode 100644 tools/testing/selftests/bpf/progs/fentry_many_args.c
>  create mode 100644 tools/testing/selftests/bpf/progs/fexit_many_args.c
>
> diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
> index 63b11f7a5392..7d47f53f20c1 100644
> --- a/net/bpf/test_run.c
> +++ b/net/bpf/test_run.c
> @@ -565,6 +565,13 @@ __bpf_kfunc int bpf_modify_return_test(int a, int *b)
>         return a + *b;
>  }
>
> +__bpf_kfunc int bpf_modify_return_test2(int a, int *b, short c, int d,
> +                                       void *e, char f, int g)
> +{
> +       *b += 1;
> +       return a + *b + c + d + (long)e + f + g;
> +}
> +
>  int noinline bpf_fentry_shadow_test(int a)
>  {
>         return a + 1;
> @@ -600,6 +607,7 @@ __diag_pop();
>
>  BTF_SET8_START(bpf_test_modify_return_ids)
>  BTF_ID_FLAGS(func, bpf_modify_return_test)
> +BTF_ID_FLAGS(func, bpf_modify_return_test2)
>  BTF_ID_FLAGS(func, bpf_fentry_test1, KF_SLEEPABLE)
>  BTF_SET8_END(bpf_test_modify_return_ids)
>
> @@ -667,7 +675,11 @@ int bpf_prog_test_run_tracing(struct bpf_prog *prog,
>         case BPF_MODIFY_RETURN:
>                 ret = bpf_modify_return_test(1, &b);
>                 if (b != 2)
> -                       side_effect = 1;
> +                       side_effect++;
> +               b = 2;
> +               ret += bpf_modify_return_test2(1, &b, 3, 4, (void *)5, 6, 7);
> +               if (b != 2)
> +                       side_effect++;

Looks better, but now two tests are failing:
Error: #85 get_func_args_test
Error: #252 trampoline_count

See BPF CI.

I suspect you haven't rerun the whole test_progs after your changes.
Please do so in the future.