linux-kernel - Re: [PATCH 0/3] x86/mce: Fix more noinstr fun

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Message-ID: <CANpmjNOvf7z4BdPqrJH2iF0KnZmP58uUzSH0fFoc4VNg+2S=hw@mail.gmail.com>
Date:   Fri, 4 Feb 2022 12:24:00 +0100
From:   Marco Elver <elver@...gle.com>
To:     Borislav Petkov <bp@...en8.de>
Cc:     Tony Luck <tony.luck@...el.com>, Jakub Kicinski <kuba@...nel.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        X86 ML <x86@...nel.org>, LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 0/3] x86/mce: Fix more noinstr fun

On Fri, 4 Feb 2022 at 09:30, Borislav Petkov <bp@...en8.de> wrote:
>
> From: Borislav Petkov <bp@...e.de>
>
> Hi all,
>
> here's a second small set of fixes for objtool noinstr validation issues
> in the MCE code.
>
> It goes ontop of tip:locking/core where there are some more commits
> changing generic helpers to be always inlined.
>
> As always, comments and suggestions are appreciated.
>
> Thx.
>
> Borislav Petkov (3):
>   cpumask: Add a x86-specific cpumask_clear_cpu() helper
>   x86/ptrace: Always inline v8086_mode() for instrumentation
>   x86/mce: Use arch atomic and bit helpers

I guess to solve noinstr "calling" something else the only solution is
to make the other function noinstr as well, or __always_inline.

Have you considered making some of these other functions 'noinstr' as
well? I guess __always_inline works, esp. if there's just 1 caller.
And by the looks of it you're getting a net .text reduction, so

Acked-by: Marco Elver <elver@...gle.com>