linux-kernel - Re: [PATCH v9 3/5] x86/cpuid: Make clearcpuid an early param

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Date:   Thu, 12 Oct 2017 10:09:14 +0200
From:   Ingo Molnar <mingo@...nel.org>
To:     Andi Kleen <andi@...stfloor.org>
Cc:     x86@...nel.org, linux-kernel@...r.kernel.org,
        Andi Kleen <ak@...ux.intel.com>,
        Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [PATCH v9 3/5] x86/cpuid: Make clearcpuid an early param


* Andi Kleen <andi@...stfloor.org> wrote:

> From: Andi Kleen <ak@...ux.intel.com>
> 
> Make clearcpuid= an early param, to make sure it is parsed
> before the XSAVE initialization. This allows to modify
> XSAVE state by clearing specific CPUID bits.
> 
> Reviewed-by: Thomas Gleixner <tglx@...utronix.de>
> Signed-off-by: Andi Kleen <ak@...ux.intel.com>
> ---
>  arch/x86/kernel/cpu/common.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
> index fd47692e5ce9..ff51c61d2df0 100644
> --- a/arch/x86/kernel/cpu/common.c
> +++ b/arch/x86/kernel/cpu/common.c
> @@ -1310,7 +1310,7 @@ static __init int setup_disablecpuid(char *arg)
>  
>  	return 1;
>  }
> -__setup("clearcpuid=", setup_disablecpuid);
> +early_param("clearcpuid", setup_disablecpuid);

Yeah, so there's pre-existing bad naming here that should be fixed before we add 
new complexity to the code: why is the option named 'clearcpuid' while the 
function name is 'disablecpuid'?

Thanks,

	Ingo