linux-kernel - Re: [PATCH bpf-next v4 5/8] kbuild: Sync kconfig when PAHOLE

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAEf4Bzb9BnSLmHOj=kdgC6is6_ZXHuHw_OyaMO_7xp+eWdtbPw@mail.gmail.com>
Date: Thu, 18 Dec 2025 13:01:13 -0800
From: Andrii Nakryiko <andrii.nakryiko@...il.com>
To: Ihor Solodrai <ihor.solodrai@...ux.dev>
Cc: Alan Maguire <alan.maguire@...cle.com>, Alexei Starovoitov <ast@...nel.org>, 
	Andrea Righi <arighi@...dia.com>, Andrew Morton <akpm@...ux-foundation.org>, 
	Andrii Nakryiko <andrii@...nel.org>, Bill Wendling <morbo@...gle.com>, Changwoo Min <changwoo@...lia.com>, 
	Daniel Borkmann <daniel@...earbox.net>, David Vernet <void@...ifault.com>, 
	Donglin Peng <dolinux.peng@...il.com>, Eduard Zingerman <eddyz87@...il.com>, Hao Luo <haoluo@...gle.com>, 
	Jiri Olsa <jolsa@...nel.org>, John Fastabend <john.fastabend@...il.com>, 
	Jonathan Corbet <corbet@....net>, Justin Stitt <justinstitt@...gle.com>, KP Singh <kpsingh@...nel.org>, 
	Martin KaFai Lau <martin.lau@...ux.dev>, Nathan Chancellor <nathan@...nel.org>, 
	Nick Desaulniers <nick.desaulniers+lkml@...il.com>, Nicolas Schier <nsc@...nel.org>, 
	Shuah Khan <shuah@...nel.org>, Song Liu <song@...nel.org>, Stanislav Fomichev <sdf@...ichev.me>, 
	Tejun Heo <tj@...nel.org>, Yonghong Song <yonghong.song@...ux.dev>, bpf@...r.kernel.org, 
	dwarves@...r.kernel.org, linux-kbuild@...r.kernel.org, 
	linux-kernel@...r.kernel.org, sched-ext@...ts.linux.dev
Subject: Re: [PATCH bpf-next v4 5/8] kbuild: Sync kconfig when PAHOLE_VERSION changes

On Wed, Dec 17, 2025 at 4:34 PM Ihor Solodrai <ihor.solodrai@...ux.dev> wrote:
>
> This patch implements kconfig re-sync when the pahole version changes
> between builds, similar to how it happens for compiler version change
> via CC_VERSION_TEXT.
>
> Define PAHOLE_VERSION in the top-level Makefile and export it for
> config builds. Set CONFIG_PAHOLE_VERSION default to the exported
> variable.
>
> Kconfig records the PAHOLE_VERSION value in
> include/config/auto.conf.cmd [1].
>
> The Makefile includes auto.conf.cmd, so if PAHOLE_VERSION changes
> between builds, make detects a dependency change and triggers
> syncconfig to update the kconfig [2].
>
> For external module builds, add a warning message in the prepare
> target, similar to the existing compiler version mismatch warning.
>
> Note that if pahole is not installed or available, PAHOLE_VERSION is
> set to 0 by pahole-version.sh, so the (un)installation of pahole is
> treated as a version change.
>
> See previous discussions for context [3].
>
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/scripts/kconfig/preprocess.c?h=v6.18#n91
> [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Makefile?h=v6.18#n815
> [3] https://lore.kernel.org/bpf/8f946abf-dd88-4fac-8bb4-84fcd8d81cf0@oracle.com/
>
> Signed-off-by: Ihor Solodrai <ihor.solodrai@...ux.dev>
> ---
>  Makefile     | 9 ++++++++-
>  init/Kconfig | 2 +-
>  2 files changed, 9 insertions(+), 2 deletions(-)
>

This is great, we should have done that a long time ago :)

[...]