Re: [PATCH bpf-next v2 8/9] libbpf: add support for the multi-link of tracing

[Alexei Starovoitov <alexei.starovoitov@gmail.com>]

On Mon, Mar 11, 2024 at 2:35 AM Menglong Dong
<dongmenglong.8@bytedance.com> wrote:
>
>
> -               err = libbpf_find_attach_btf_id(prog, attach_name, &btf_obj_fd, &btf_type_id);
> +               name_end = strchr(attach_name, ',');
> +               /* for multi-link tracing, use the first target symbol during
> +                * loading.
> +                */
> +               if ((def & SEC_ATTACH_BTF_MULTI) && name_end) {
> +                       int len = name_end - attach_name + 1;
> +                       char *first_tgt;
> +
> +                       first_tgt = malloc(len);
> +                       if (!first_tgt)
> +                               return -ENOMEM;
> +                       strncpy(first_tgt, attach_name, len);
> +                       first_tgt[len - 1] = '\0';
> +                       err = libbpf_find_attach_btf_id(prog, first_tgt, &btf_obj_fd,
> +                                                       &btf_type_id);
> +                       free(first_tgt);
> +               } else {
> +                       err = libbpf_find_attach_btf_id(prog, attach_name, &btf_obj_fd,
> +                                                       &btf_type_id);
> +               }

Pls use glob_match the way [ku]probe multi are doing
instead of exact match.