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Date:   Sun, 27 Jun 2021 18:12:26 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     Christophe Leroy <christophe.leroy@csgroup.eu>
Cc:     Steven Price <steven.price@arm.com>, linux-mm@kvack.org,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>, dja@axtens.net,
        "Oliver O'Halloran" <oohall@gmail.com>, linux-arch@vger.kernel.org,
        linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] mm: pagewalk: Fix walk for hugepage tables
Message-Id: <20210627181226.983d899cc30c02420e1a6af5@linux-foundation.org>
In-Reply-To: <38d04410700c8d02f28ba37e020b62c55d6f3d2c.1624597695.git.christophe.leroy@csgroup.eu>
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On Fri, 25 Jun 2021 05:10:12 +0000 (UTC) Christophe Leroy <christophe.leroy@csgroup.eu> wrote:

> Pagewalk ignores hugepd entries and walk down the tables
> as if it was traditionnal entries, leading to crazy result.
> 
> Add walk_hugepd_range() and use it to walk hugepage tables.

More details, please?  I assume "crazy result" is userspace visible? 
For how long has this bug existed?  Is a -stable backport needed?  Has
a Fixes: commit been identified?  etcetera!