linux-kernel - Re: [PATCH 3/6] x86/cpu: proc - remove "wp" status line in cpuinfo

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Date:   Tue, 14 Feb 2017 17:47:08 +0100
From:   Mathias Krause <minipli@...glemail.com>
To:     Borislav Petkov <bp@...en8.de>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        "David S. Miller" <davem@...emloft.net>,
        Jesper Nilsson <jesper.nilsson@...s.com>,
        Mikael Starvik <starvik@...s.com>,
        Geert Uytterhoeven <geert@...ux-m68k.org>,
        x86-ml <x86@...nel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "H. Peter Anvin" <hpa@...ux.intel.com>
Subject: Re: [PATCH 3/6] x86/cpu: proc - remove "wp" status line in cpuinfo

On 14 February 2017 at 17:20, Borislav Petkov <bp@...en8.de> wrote:
> On Sun, Feb 12, 2017 at 10:12:09PM +0100, Mathias Krause wrote:
>> As of commit a5c2a893dbd4 ("x86, 386 removal: Remove
>> CONFIG_X86_WP_WORKS_OK") the kernel won't boot if CR0.WP isn't working
>> correctly. This makes a process reading this file always see "wp : yes"
>> here -- otherwise there would be no process to begin with ;)
>>
>> As this status line in /proc/cpuinfo serves no purpose for quite some
>> time now, get rid of it.
>
> Right, sure, except /proc/cpuinfo's format is kind of an ABI and scripts
> rely on it, I'm being told.

That's the reason I haven't folded this change into patch 2. I had
similar doubts but it's not documented in Documentation/ and kinda
useless to test anyway -- what would a "wp : no" tell one?

> TBH, I'd remove that wp:-line too but this
> is just me. tip guys' call.
>
> FWIW, for all three:
>
> Acked-by: Borislav Petkov <bp@...e.de>

Thanks,
Mathias