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: <20231019090733.GR33217@noisy.programming.kicks-ass.net>
Date:   Thu, 19 Oct 2023 11:07:33 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     Linus Torvalds <torvalds@...ux-foundation.org>
Cc:     Uros Bizjak <ubizjak@...il.com>, Nadav Amit <namit@...are.com>,
        the arch/x86 maintainers <x86@...nel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Andy Lutomirski <luto@...nel.org>,
        Brian Gerst <brgerst@...il.com>,
        Denys Vlasenko <dvlasenk@...hat.com>,
        "H . Peter Anvin" <hpa@...or.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Josh Poimboeuf <jpoimboe@...hat.com>,
        Nick Desaulniers <ndesaulniers@...gle.com>
Subject: Re: [PATCH v2 -tip] x86/percpu: Use C for arch_raw_cpu_ptr()

On Wed, Oct 18, 2023 at 03:40:05PM -0700, Linus Torvalds wrote:
> On Wed, 18 Oct 2023 at 14:40, Uros Bizjak <ubizjak@...il.com> wrote:
> >
> > The ones in "raw" form are not IRQ safe and these are implemented
> > without volatile qualifier.
> 
> You are misreading it.
> 
> Both *are* irq safe - on x86.

Stronger, x86 arch code very much relies on them being NMI-safe. Which
makes the generic implementation insufficient. 

They *must* be single RmW instructions on x86.

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ