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From:   Andrii Nakryiko <andrii.nakryiko@gmail.com>
Date:   Tue, 31 Mar 2020 12:45:46 -0700
Message-ID: <CAEf4BzadnfAwfa1D0jZb=01Ou783GpK_U7PAYeEJca-L9kdnVA@mail.gmail.com>
Subject: Re: [PATCH] kbuild: disable DEBUG_INFO_SPLIT when BTF is on
To:     Slava Bacherikov <slava@bacher09.org>
Cc:     Masahiro Yamada <yamada.masahiro@socionext.com>,
        Andrii Nakryiko <andriin@fb.com>, bpf <bpf@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>
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On Tue, Mar 31, 2020 at 9:57 AM Slava Bacherikov <slava@bacher09.org> wrote:
>
> Currently turning on DEBUG_INFO_SPLIT when DEBUG_INFO_BTF is also
> enabled will produce invalid btf file, since gen_btf function in
> link-vmlinux.sh script doesn't handle *.dwo files.
>
> Signed-off-by: Slava Bacherikov <slava@bacher09.org>
> ---
>  lib/Kconfig.debug | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index f61d834e02fe..a9429ef5eec8 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -223,6 +223,7 @@ config DEBUG_INFO_DWARF4
>  config DEBUG_INFO_BTF
>         bool "Generate BTF typeinfo"
>         depends on DEBUG_INFO
> +       depends on !DEBUG_INFO_SPLIT

Thanks for following up! This looks good, but I think there are more
DWARF-related configs that should be banned. See [0] and [1]. If you
don't mind, let's use your patch to disable all of them in one go. So
can you please update and disable DEBUG_INFO_REDUCED and
GCC_PLUGIN_RANDSTRUCT? Thanks!

  [0] https://lore.kernel.org/bpf/202003311110.2B08091E@keescook
  [1] https://lore.kernel.org/bpf/a2b1a025-6a70-c3a5-fc19-155f0266946a@fb.com


>         help
>           Generate deduplicated BTF type information from DWARF debug info.
>           Turning this on expects presence of pahole tool, which will convert
> --
> 2.24.1
>