Re: [PATCH v2.1 02/23] x86/mmx_32: Remove X86_USE_3DNOW

[Borislav Petkov]

On Mon, Nov 15, 2021 at 05:54:37PM +0100, Peter Zijlstra wrote:
> 
> 
> The alternative (har har) for this patch is the below, which seems
> favoured by Boris.
> 
> ---
> Subject: x86/mmx_32: Remove X86_USE_3DNOW
> From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Date: Mon Nov 15 17:46:39 CET 2021
> 
> This code puts an exception table entry on the PREFETCH instruction to
> overwrite it with a JMP.d8 when it triggers an exception. Except of
> course, our code is no longer writable, also SMP.
> 
> Instead of fixing this broken mess, simply take it out.
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> ---
>  arch/x86/Kconfig                               |    2 
>  arch/x86/Kconfig.cpu                           |    4 
>  arch/x86/include/asm/mmx.h                     |   15 
>  arch/x86/include/asm/page_32.h                 |   14 
>  arch/x86/include/asm/required-features.h       |    4 
>  arch/x86/include/asm/string_32.h               |   33 --
>  arch/x86/lib/Makefile                          |    1 
>  arch/x86/lib/memcpy_32.c                       |    4 
>  arch/x86/lib/mmx_32.c                          |  388 -------------------------
>  arch/x86/lib/usercopy_32.c                     |    1 
>  tools/arch/x86/include/asm/required-features.h |    4 
>  11 files changed, 1 insertion(+), 469 deletions(-)

Acked-by: Borislav Petkov <bp@xxxxxxx>

Obviously. :-)

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette