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>,
Arnd Bergmann <arnd@arndb.de>, Ard Biesheuvel <ardb@kernel.org>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH v2] arm64: compat: Fix decrementing LDM/STM alignment emulation
Date: Thu, 27 Aug 2026 16:22:37 +0100 [thread overview]
Message-ID: <178784016455.65228.15282615597317035882.b4-ty@kernel.org> (raw)
In-Reply-To: <20260819222712.81855-1-kmehltretter@gmail.com>
On Thu, 20 Aug 2026 00:27:12 +0200, Karl Mehltretter wrote:
> The compat alignment emulator inherited unsigned long data addresses from
> the 32-bit ARM implementation.
>
> In do_alignment_ldmstm(), nr_regs is an unsigned int holding the transfer
> size. The function uses the same address addition for both transfer
> directions, negating nr_regs first for a decrementing LDM or STM. The
> 32-bit negation wraps before the addition, so the handler adds nearly
> 4 GiB instead of subtracting the transfer size.
> The resulting address lies outside the compat task's address space, so
> decrementing LDM/STM emulation fails, while incrementing forms work.
>
> [...]
Applied to arm64 (for-next/core), thanks!
[1/1] arm64: compat: Fix decrementing LDM/STM alignment emulation
https://git.kernel.org/arm64/c/f5b8b9037df3
Cheers,
--
Will
https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev
prev parent reply other threads:[~2026-08-27 15:22 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-19 22:27 Karl Mehltretter
2026-08-27 15:22 ` Will Deacon [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=178784016455.65228.15282615597317035882.b4-ty@kernel.org \
--to=will@kernel.org \
--cc=ardb@kernel.org \
--cc=arnd@arndb.de \
--cc=catalin.marinas@arm.com \
--cc=kernel-team@android.com \
--cc=kmehltretter@gmail.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®