From: Hugh Dickins <hughd@google.com>
To: David Hildenbrand <david@redhat.com>
Cc: Gavin Guo <gavinguo@igalia.com>,
linux-mm@kvack.org, akpm@linux-foundation.org,
willy@infradead.org, ziy@nvidia.com, linmiaohe@huawei.com,
hughd@google.com, revest@google.com, kernel-dev@igalia.com,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm/huge_memory: fix dereferencing invalid pmd migration entry
Date: Wed, 16 Apr 2025 22:36:22 -0700 (PDT) [thread overview]
Message-ID: <6787d0ea-a1b9-08cf-1f48-e361058eec20@google.com> (raw)
In-Reply-To: <27d13454-280f-4966-b694-d7e58d991547@redhat.com>
On Wed, 16 Apr 2025, David Hildenbrand wrote:
>
> Why not something like
>
> struct folio *entry_folio;
>
> if (folio) {
> if (is_pmd_migration_entry(*pmd))
> entry_folio = pfn_swap_entry_folio(pmd_to_swp_entry(*pmd)));
> else
> entry_folio = pmd_folio(*pmd));
>
> if (folio != entry_folio)
> return;
> }
My own preference is to not add unnecessary code:
if folio and pmd_migration entry, we're not interested in entry_folio.
But yes it could be written in lots of other ways.
Hugh
next prev parent reply other threads:[~2025-04-17 5:36 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-14 7:27 Gavin Guo
2025-04-14 16:50 ` Zi Yan
2025-04-15 10:07 ` Gavin Guo
2025-04-15 15:57 ` Zi Yan
2025-04-17 5:29 ` Hugh Dickins
2025-04-18 13:25 ` Zi Yan
2025-04-17 5:03 ` Hugh Dickins
2025-04-16 16:10 ` David Hildenbrand
2025-04-17 5:36 ` Hugh Dickins [this message]
2025-04-17 7:18 ` David Hildenbrand
2025-04-17 8:07 ` David Hildenbrand
2025-04-17 8:09 ` David Hildenbrand
2025-04-17 8:55 ` Hugh Dickins
2025-04-17 9:04 ` David Hildenbrand
2025-04-17 11:21 ` Gavin Guo
2025-04-17 11:32 ` Zi Yan
2025-04-17 12:02 ` Gavin Guo
2025-04-17 12:10 ` Zi Yan
2025-04-17 12:38 ` Gavin Guo
2025-04-17 11:36 ` David Hildenbrand
2025-04-17 12:05 ` Gavin Guo
2025-04-17 4:38 ` Hugh Dickins
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