Re: [PATCH bpf-next v2 17/18] selftests/bpf: add basic testcases for tracing_multi

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

On Thu, Jul 3, 2025 at 5:18 AM Menglong Dong <menglong8.dong@gmail.com> wrote:
>
> +               return true;
> +
> +       /* Following symbols have multi definition in kallsyms, take
> +        * "t_next" for example:
> +        *
> +        *     ffffffff813c10d0 t t_next
> +        *     ffffffff813d31b0 t t_next
> +        *     ffffffff813e06b0 t t_next
> +        *     ffffffff813eb360 t t_next
> +        *     ffffffff81613360 t t_next
> +        *
> +        * but only one of them have corresponding mrecord:
> +        *     ffffffff81613364 t_next
> +        *
> +        * The kernel search the target function address by the symbol
> +        * name "t_next" with kallsyms_lookup_name() during attaching
> +        * and the function "0xffffffff813c10d0" can be matched, which
> +        * doesn't have a corresponding mrecord. And this will make
> +        * the attach failing. Skip the functions like this.
> +        *
> +        * The list maybe not whole, so we still can fail......We need a
> +        * way to make the whole things right. Yes, we need fix it :/
> +        */
> +       if (!strcmp(name, "kill_pid_usb_asyncio"))
> +               return true;
> +       if (!strcmp(name, "t_next"))
> +               return true;
> +       if (!strcmp(name, "t_stop"))
> +               return true;

This looks like pahole bug. It shouldn't emit BTF for static
functions with the same name in different files.
I recall we discussed it in the past and I thought the fix had landed.