linux-kernel - Re: [PATCH] tools/libbpf: add WERROR option

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 for Android: free password hash cracker in your pocket

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

Message-ID: <CAADnVQLjjLoT6v3kPtVseVqPi09SU8n4buP-au2X-4PzQ6We_g@mail.gmail.com>
Date: Sun, 13 Jul 2025 16:03:09 -0700
From: Alexei Starovoitov <alexei.starovoitov@...il.com>
To: Sam James <sam@...too.org>
Cc: Daniel Borkmann <daniel@...earbox.net>, bpf <bpf@...r.kernel.org>, 
	Andrii Nakryiko <andrii@...nel.org>, Eduard Zingerman <eddyz87@...il.com>, 
	Alexei Starovoitov <ast@...nel.org>, Martin KaFai Lau <martin.lau@...ux.dev>, Song Liu <song@...nel.org>, 
	Yonghong Song <yonghong.song@...ux.dev>, John Fastabend <john.fastabend@...il.com>, 
	KP Singh <kpsingh@...nel.org>, Stanislav Fomichev <sdf@...ichev.me>, Hao Luo <haoluo@...gle.com>, 
	Jiri Olsa <jolsa@...nel.org>, Quentin Monnet <qmo@...nel.org>, LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] tools/libbpf: add WERROR option

On Sun, Jul 13, 2025 at 3:58 PM Sam James <sam@...too.org> wrote:
>
> Alexei Starovoitov <alexei.starovoitov@...il.com> writes:
>
> > On Sat, Jul 12, 2025 at 11:24 PM Sam James <sam@...too.org> wrote:
> >>
> >> Daniel Borkmann <daniel@...earbox.net> writes:
> >>
> >> > On 7/5/25 12:43 PM, Sam James wrote:
> >> >> Check the 'WERROR' variable and suppress adding '-Werror' if WERROR=0.
> >> >> This mirrors what tools/perf and other directories in tools do to
> >> >> handle
> >> >> -Werror rather than adding it unconditionally.
> >> >
> >> > Could you also add to the commit desc why you need it? Are there particular
> >> > warnings you specifically need to suppress when building under gentoo?
> >>
> >> Sure. In this case, it was https://bugs.gentoo.org/959293 where I think
> >
> > I don't recall it was reported on bpf mailing list.
> >
> >> it's fixed by
> >> https://github.com/libbpf/libbpf/commit/715808d3e2d8c54f3001ce3d7fcda0844f765969
> >
> > and looks like it was fixed by accident, so..
>
> I'll note that I've sent patches that have been merged for these
> before. It's just that they're sensitive to optimisation level and prone
> to false positives. Especially with e.g. -Og.

Yeah. Compilers do produce false positives and, like any tool,
any warning is not authoritative, but we prefer people reporting
them instead of silencing and moving on.