linux-kernel - Re: [PATCH v2 1/2] mm/migrate: Fix read-only page got writable when recover pte

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Date:   Tue, 15 Nov 2022 19:16:35 +0100
From:   David Hildenbrand <david@...hat.com>
To:     Peter Xu <peterx@...hat.com>
Cc:     linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        Andrea Arcangeli <aarcange@...hat.com>,
        Axel Rasmussen <axelrasmussen@...gle.com>,
        Ives van Hoorne <ives@...esandbox.io>,
        Nadav Amit <nadav.amit@...il.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Mike Rapoport <rppt@...ux.vnet.ibm.com>, stable@...r.kernel.org
Subject: Re: [PATCH v2 1/2] mm/migrate: Fix read-only page got writable when
 recover pte

On 15.11.22 19:11, Peter Xu wrote:
> On Tue, Nov 15, 2022 at 06:54:09PM +0100, David Hildenbrand wrote:
>> No it isn't natural. But sneaking such a change into your fix seems wrong.
>> Touching !uffd-wp code should be separate, if we want to do this at all (as
>> we discussed, maybe the better/cleaner approach is to eliminate writable
>> migration entries if possible).
> 
> If you see I made the subject as mm/migrate, because I took it as a
> migration change, not uffd-wp specific.  I also added the Fixes to the uffd
> patch because afaict that's the only thing that it affects, but I can't
> tell either.
> 
> As I said, I'm trying to follow the rule where we have read entry I want to
> make sure write bit removed.

I really don't think we should do that generic change.

-- 
Thanks,

David / dhildenb