linux-kernel - Re: [PATCH] atomic: Specify natural alignment for atomic

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

Message-ID: <20250825114136.GX3245006@noisy.programming.kicks-ass.net>
Date: Mon, 25 Aug 2025 13:41:36 +0200
From: Peter Zijlstra <peterz@...radead.org>
To: Finn Thain <fthain@...ux-m68k.org>
Cc: Andrew Morton <akpm@...ux-foundation.org>,
	Lance Yang <lance.yang@...ux.dev>,
	Geert Uytterhoeven <geert@...ux-m68k.org>,
	Masami Hiramatsu <mhiramat@...nel.org>,
	Eero Tamminen <oak@...sinkinet.fi>, Will Deacon <will@...nel.org>,
	stable@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] atomic: Specify natural alignment for atomic_t

On Mon, Aug 25, 2025 at 06:03:23PM +1000, Finn Thain wrote:
> 
> On Mon, 25 Aug 2025, Peter Zijlstra wrote:
> 
> > 
> > And your architecture doesn't trap on unaligned atomic access ?!!?!
> > 
> 
> Right. This port doesn't do SMP.

There is RMW_INSN which seems to imply a compare-and-swap instruction of
sorts. That is happy to work on unaligned storage?

Anyway, it might make sense to add an alignment check to
arch/m68k/include/asm/atomic.h somewhere, perhaps dependent on
some DEBUG flag or other.