linux-kernel - Re: [PATCH v2 bpf-next] bpf: Mark kfuncs as _

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Message-Id: 
 <175870800601.2118298.17627237253886547261.git-patchwork-notify@kernel.org>
Date: Wed, 24 Sep 2025 10:00:06 +0000
From: patchwork-bot+netdevbpf@...nel.org
To: Andrea Righi <arighi@...dia.com>
Cc: ast@...nel.org, daniel@...earbox.net, andrii@...nel.org,
 martin.lau@...ux.dev, eddyz87@...il.com, song@...nel.org,
 yonghong.song@...ux.dev, john.fastabend@...il.com, kpsingh@...nel.org,
 sdf@...ichev.me, haoluo@...gle.com, jolsa@...nel.org, void@...ifault.com,
 alan.maguire@...cle.com, bpf@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 bpf-next] bpf: Mark kfuncs as __noclone

Hello:

This patch was applied to bpf/bpf-next.git (master)
by Alexei Starovoitov <ast@...nel.org>:

On Wed, 24 Sep 2025 10:14:26 +0200 you wrote:
> Some distributions (e.g., CachyOS) support building the kernel with -O3,
> but doing so may break kfuncs, resulting in their symbols not being
> properly exported.
> 
> In fact, with gcc -O3, some kfuncs may be optimized away despite being
> annotated as noinline. This happens because gcc can still clone the
> function during IPA optimizations, e.g., by duplicating or inlining it
> into callers, and then dropping the standalone symbol. This breaks BTF
> ID resolution since resolve_btfids relies on the presence of a global
> symbol for each kfunc.
> 
> [...]

Here is the summary with links:
  - [v2,bpf-next] bpf: Mark kfuncs as __noclone
    https://git.kernel.org/bpf/bpf-next/c/d4680a11e14c

You are awesome, thank you!
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