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From:   Alexander Duyck <alexander.duyck@gmail.com>
Date:   Mon, 18 Jul 2022 08:33:42 -0700
Message-ID: <CAKgT0Uejy66aFAdD+vMPYFtSu2BWRgTxBG0mO+BLayk3nNuQMw@mail.gmail.com>
Subject: Re: Re: [PATCH V3] mm: prevent page_frag_alloc() from corrupting the memory
To:     Maurizio Lombardi <mlombard@redhat.com>
Cc:     Chen Lin <chen45464546@163.com>, Jakub Kicinski <kuba@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-mm <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Netdev <netdev@vger.kernel.org>
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On Mon, Jul 18, 2022 at 8:25 AM Maurizio Lombardi <mlombard@redhat.com> wro=
te:
>
> po 18. 7. 2022 v 16:40 odes=C3=ADlatel Chen Lin <chen45464546@163.com> na=
psal:
> >
> > But the original intention of page frag interface is indeed to allocate=
 memory
> > less than one page. It's not a good idea to  complicate the definition =
of
> > "page fragment".
>
> I see your point, I just don't think it makes much sense to break
> drivers here and there
> when a practically identical 2-lines patch can fix the memory corruption =
bug
> without changing a single line of code in the drivers.
>
> By the way, I will wait for the maintainers to decide on the matter.
>
> Maurizio

I'm good with this smaller approach. If it fails only under memory
pressure I am good with that. The issue with the stricter checking is
that it will add additional overhead that doesn't add much value to
the code.

Thanks,

- Alex