linux-kernel - Re: [PATCH v2] x86/mm: fix kern_addr_valid to cope with existing but not present entries

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Message-ID: <YTiV/Sdm/T/jnsHC@zn.tnic>
Date:   Wed, 8 Sep 2021 12:52:45 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Dave Hansen <dave.hansen@...el.com>,
        Mike Rapoport <rppt@...nel.org>
Cc:     x86@...nel.org, Andrew Morton <akpm@...ux-foundation.org>,
        Andy Lutomirski <luto@...nel.org>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        David Hildenbrand <david@...hat.com>,
        Ingo Molnar <mingo@...hat.com>, Jiri Olsa <jolsa@...hat.com>,
        Mike Rapoport <rppt@...ux.ibm.com>,
        Oscar Salvador <osalvador@...e.de>,
        Peter Zijlstra <peterz@...radead.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org,
        stable@...r.kernel.org
Subject: Re: [PATCH v2] x86/mm: fix kern_addr_valid to cope with existing but
 not present entries

On Wed, Sep 08, 2021 at 12:35:21PM +0200, Borislav Petkov wrote:
> So I did stare at this for a while, trying to make sense of it and David
> Hildenbrand asked for a Fixes: tag in v1 review and from doing a bit of
> git archeology I think it should be:
> 
> c40a56a7818c ("x86/mm/init: Remove freed kernel image areas from alias mapping")
> 
> because that thing added the clearing of the Present bit for the high
> kernel image mapping of those areas.
> 
> Right?

Hmm, but that commit is in v4.19. Mike has added

Cc: <stable@...r.kernel.org>    # 4.4+

Mike, why 4.4 and newer?

Hmmm.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette