linux-kernel - Re: [PATCH v3] riscv: Use Zalrsc extension to implement atomic functions

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <27b23b18-1e69-458c-9874-f704553d4bab@htecgroup.com>
Date: Fri, 19 Sep 2025 13:03:05 +0000
From: Aleksa Paunovic <aleksa.paunovic@...cgroup.com>
To: "devnull+aleksa.paunovic.htecgroup.com@...nel.org"
	<devnull+aleksa.paunovic.htecgroup.com@...nel.org>
CC: Aleksa Paunovic <aleksa.paunovic@...cgroup.com>, "alex@...ti.fr"
	<alex@...ti.fr>, "aou@...s.berkeley.edu" <aou@...s.berkeley.edu>,
	"arikalo@...il.com" <arikalo@...il.com>, "boqun.feng@...il.com"
	<boqun.feng@...il.com>, "cfu@...s.com" <cfu@...s.com>, "charlie@...osinc.com"
	<charlie@...osinc.com>, "conor@...nel.org" <conor@...nel.org>, Djordje
 Todorovic <Djordje.Todorovic@...cgroup.com>, "jrtc27@...c27.com"
	<jrtc27@...c27.com>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>, "linux-riscv@...ts.infradead.org"
	<linux-riscv@...ts.infradead.org>, "linux@...musvillemoes.dk"
	<linux@...musvillemoes.dk>, "mark.rutland@....com" <mark.rutland@....com>,
	"palmer@...belt.com" <palmer@...belt.com>, "paul.walmsley@...ive.com"
	<paul.walmsley@...ive.com>, "peterz@...radead.org" <peterz@...radead.org>,
	"samuel.holland@...ive.com" <samuel.holland@...ive.com>, "will@...nel.org"
	<will@...nel.org>, "yury.norov@...il.com" <yury.norov@...il.com>
Subject: Re: [PATCH v3] riscv: Use Zalrsc extension to implement atomic
 functions

On 9/1/25 12:38, Aleksa Paunovic via B4 Relay wrote:

> From: Chao-ying Fu <cfu@...s.com>
>
> Use only LR/SC instructions to implement atomic functions.
>
> Add config ERRATA_MIPS_P8700_AMO_ZALRSC.
>
> Signed-off-by: Chao-ying Fu <cfu@...s.com>
> Signed-off-by: Aleksandar Rikalo <arikalo@...il.com>
> Co-developed-by: Aleksa Paunovic <aleksa.paunovic@...cgroup.com>
> Signed-off-by: Aleksa Paunovic <aleksa.paunovic@...cgroup.com>
> ---
> This patch depends on [1], which implements errata support for the MIPS p8700.
>
> Changes in v3:
> - Use alternatives to replace AMO instructions with LR/SC
> - Rebase on Alexandre Ghiti's "for-next" branch.
> - Link to v2: https://lore.kernel.org/linux-riscv/20241225082412.36727-1-arikalo@gmail.com/
>
> [1] https://lore.kernel.org/linux-riscv/20250724-p8700-pause-v5-0-a6cbbe1c3412@htecgroup.com/
> ---
>  arch/riscv/Kconfig.errata                    |  11 ++
>  arch/riscv/errata/mips/errata.c              |  13 +-
>  arch/riscv/include/asm/atomic.h              |  29 ++--
>  arch/riscv/include/asm/bitops.h              |  28 ++--
>  arch/riscv/include/asm/cmpxchg.h             |   9 +-
>  arch/riscv/include/asm/errata_list.h         | 215 +++++++++++++++++++++++++++
>  arch/riscv/include/asm/errata_list_vendors.h |   3 +-
>  arch/riscv/include/asm/futex.h               |  41 ++---
>  arch/riscv/kernel/entry.S                    |  10 +-
>  9 files changed, 291 insertions(+), 68 deletions(-)

Gentle ping.

We would appreciate any comments on these changes.  I could split this into multiple patches if that would make it easier to read.

Best regards,
Aleksa