From: Will Deacon <will@kernel.org>
To: Catalin Marinas <catalin.marinas@arm.com>,
Karl Mehltretter <kmehltretter@gmail.com>
Cc: kernel-team@android.com, Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
David Hildenbrand <david@kernel.org>,
Ryan Roberts <ryan.roberts@arm.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] arm64: mm: Fix the lockless page-table walk in show_pte()
Date: Thu, 3 Sep 2026 14:59:17 +0100 [thread overview]
Message-ID: <178844029253.4160801.11282535964402738710.b4-ty@kernel.org> (raw)
In-Reply-To: <20260828174131.46825-1-kmehltretter@gmail.com>
On Fri, 28 Aug 2026 19:41:31 +0200, Karl Mehltretter wrote:
> show_pte() walks page tables locklessly and can run with interrupts
> enabled. A concurrent teardown can free a table page while it is being
> walked. It can also clear a parent entry after show_pte() checked it; the
> regular pXd_offset() helpers then reread the cleared entry and can derive a
> bogus lower-level pointer and fault again.
>
> Use the lockless offset helpers with the saved parent entries, as
> gup_fast() does, and pass the saved PMD to pte_offset_map().
>
> [...]
Applied to arm64 (for-next/fixes), thanks!
[1/1] arm64: mm: Fix the lockless page-table walk in show_pte()
https://git.kernel.org/arm64/c/a77644d009de
Cheers,
--
Will
https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev
prev parent reply other threads:[~2026-09-03 13:59 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-28 17:41 [PATCH v2] arm64: mm: Fix the lockless page-table walk in show_pte() Karl Mehltretter
2026-09-03 13:59 ` Will Deacon [this message]
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