Re: [PATCH 1/2] x86: Fix typo preventing msr_set/clear_bit from having an effect

From: Borislav Petkov
Date: Fri May 09 2014 - 03:55:01 EST


On Fri, May 09, 2014 at 03:29:16AM +0200, Andres Freund wrote:
> Due to a typo the msr accessor function introduced in
> 22085a66c2fab6cf9b9393c056a3600a6b4735de didn't have any lasting
> effects because they accidentally wrote the old value back.
>
> After c0a639ad0bc6b178b46996bd1f821a04643e2bde this at the very least
> this causes cpuid limits not to be lifted on some cpus leading to
> missing capabilities for those.
>
> Signed-off-by: Andres Freund <andres@xxxxxxxxxxx>
> Cc: Borislav Petkov <bp@xxxxxxx>
> Cc: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> ---
> arch/x86/lib/msr.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/lib/msr.c b/arch/x86/lib/msr.c
> index db9db44..4362373 100644
> --- a/arch/x86/lib/msr.c
> +++ b/arch/x86/lib/msr.c
> @@ -76,7 +76,7 @@ static inline int __flip_bit(u32 msr, u8 bit, bool set)
> if (m1.q == m.q)
> return 0;
>
> - err = msr_write(msr, &m);
> + err = msr_write(msr, &m1);
> if (err)
> return err;

Good catch, thanks, and sorry about the screwup! :-[

Acked-by: Borislav Petkov <bp@xxxxxxx>

--
Regards/Gruss,
Boris.

Sent from a fat crate under my desk. Formatting is fine.
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