linux-kernel - Re: [patch V3 43/66] x86/pkru: Provide pkru_write

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Message-ID: <YNH0FbTeHthv8xud@zn.tnic>
Date:   Tue, 22 Jun 2021 16:30:45 +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 43/66] x86/pkru: Provide pkru_write_default()

On Fri, Jun 18, 2021 at 04:19:06PM +0200, Thomas Gleixner wrote:
> Provide a simple and trivial helper which just writes the PKRU default
> value without trying to fiddle with the tasks xsave buffer.

task's

> Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
> ---
>  arch/x86/include/asm/pkru.h |    8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> --- a/arch/x86/include/asm/pkru.h
> +++ b/arch/x86/include/asm/pkru.h
> @@ -60,4 +60,12 @@ static inline void write_pkru(u32 pkru)
>  	fpregs_unlock();
>  }
>  
> +static inline void pkru_write_default(void)
> +{
> +	if (!cpu_feature_enabled(X86_FEATURE_OSPKE))
> +		return;
> +
> +	wrpkru(pkru_get_init_value());
> +}
> +
>  #endif

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

-- 
Regards/Gruss,
    Boris.

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