Re: [PATCH v3] x86: clear incorrectly forced X86_FEATURE_LAHF_LMflag

From: Borislav Petkov
Date: Tue Aug 11 2009 - 08:00:52 EST


On Mon, Aug 10, 2009 at 07:56:45PM -0300, Kevin Winchester wrote:
> Due to an erratum with certain AMD Athlon 64 processors, the BIOS may
> need to force enable the LAHF_LM capability. Unfortunately, in at
> least one case, the BIOS does this even for processors that do not
> support the functionality.
>
> Add a specific check that will clear the feature bit for processors
> known not to support the LAHF/SAHF instructions.
>
> Signed-off-by: Kevin Winchester <kjwinchester@xxxxxxxxx>

Acked-by: Borislav Petkov <borislav.petkov@xxxxxxx>

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