linux-kernel - Re: [patch V3 55/66] x86/fpu: Remove PKRU handling from switch_fpu

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Date:   Tue, 22 Jun 2021 19:08:52 +0200
From:   Borislav Petkov <bp@...e.de>
To:     Thomas Gleixner <tglx@...utronix.de>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        Andy Lutomirski <luto@...nel.org>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Fenghua Yu <fenghua.yu@...el.com>,
        Tony Luck <tony.luck@...el.com>,
        Yu-cheng Yu <yu-cheng.yu@...el.com>,
        Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
        Peter Zijlstra <peterz@...radead.org>,
        Kan Liang <kan.liang@...ux.intel.com>
Subject: Re: [patch V3 55/66] x86/fpu: Remove PKRU handling from
 switch_fpu_finish()

On Fri, Jun 18, 2021 at 04:19:18PM +0200, Thomas Gleixner wrote:
> PKRU is already updated and the xstate is not longer the proper source of
> information.
> 
> Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
> ---
>  arch/x86/include/asm/fpu/internal.h |   34 ++++------------------------------
>  1 file changed, 4 insertions(+), 30 deletions(-)
> 
> --- a/arch/x86/include/asm/fpu/internal.h
> +++ b/arch/x86/include/asm/fpu/internal.h
> @@ -549,39 +549,13 @@ static inline void switch_fpu_prepare(st
>   */
>  
>  /*
> - * Load PKRU from the FPU context if available. Delay loading of the
> - * complete FPU state until the return to userland.
> + * Delay loading of the complete FPU state until the return to userland.
> + * PKRU is handled seperately.

separately

With that fixed:

Reviewed-by: Borislav Petkov <bp@...e.de>

-- 
Regards/Gruss,
    Boris.

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