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Date:   Wed, 13 Jan 2021 16:07:39 -0700
From:   Nathan Chancellor <natechancellor@gmail.com>
To:     Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc:     Masahiro Yamada <masahiroy@kernel.org>,
        Michal Marek <michal.lkml@markovi.net>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
        Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
        Sedat Dilek <sedat.dilek@gmail.com>
Subject: Re: [PATCH] bpf: Hoise pahole version checks into Kconfig
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On Wed, Jan 13, 2021 at 02:38:27PM -0800, Andrii Nakryiko wrote:
> Hm.. Just saw Linus proposing using $(error-if) in Kconfig for an
> unrelated issue ([0]). If we can make this work, then it would catch
> such issue early on, yet won't have any downsides of hiding
> CONFIG_DEBUG_INFO_BTF if pahole is too old. WDYT?
> 
>   [0] https://lore.kernel.org/lkml/CAHk-=wh-+TMHPTFo1qs-MYyK7tZh-OQovA=pP3=e06aCVp6_kA@mail.gmail.com/

Yes, I think that would be exactly what we want because DEBUG_INFO_BTF
could cause the build to error if PAHOLE_VERSION is not >= 116. I will
try to keep an eye on that thread to see how it goes then respin this
based on anything that comes from it.

Cheers,
Nathan