Re: [PATCH v2 bpf-next 6/7] libbpf: add BPF_CORE_READ/BPF_CORE_READ_INTO helpers

[Song Liu <liu.song.a23@gmail.com>]

On Wed, Oct 2, 2019 at 3:02 PM Andrii Nakryiko <andriin@fb.com> wrote:
>
> Add few macros simplifying BCC-like multi-level probe reads, while also
> emitting CO-RE relocations for each read.
>
> Acked-by: John Fastabend <john.fastabend@gmail.com>
> Signed-off-by: Andrii Nakryiko <andriin@fb.com>
> ---
>  tools/lib/bpf/bpf_helpers.h | 143 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 143 insertions(+)
>
> diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
> index cb9d4d2224af..847dfd7125e4 100644
> --- a/tools/lib/bpf/bpf_helpers.h
> +++ b/tools/lib/bpf/bpf_helpers.h
> @@ -19,6 +19,10 @@
>   */
>  #define SEC(NAME) __attribute__((section(NAME), used))
>
> +#ifndef __always_inline
> +#define __always_inline __attribute__((always_inline))
> +#endif
> +
>  /* helper functions called from eBPF programs written in C */
>  static void *(*bpf_map_lookup_elem)(void *map, const void *key) =
>         (void *) BPF_FUNC_map_lookup_elem;
> @@ -312,4 +316,143 @@ struct bpf_map_def {
>         bpf_probe_read(dst, sz,                                             \
>                        (const void *)__builtin_preserve_access_index(src))
>
> +/*

nit: extra /*.

Well, I actually don't have a strong preference with this. Just to highlight
we are mixing two styles, which we already do in current bpf_helpers.h.

There are multiple other instances below.

Besides these.

Acked-by: Song Liu <songliubraving@fb.com>