linux-kernel - Re: [PATCH] [RFC] x86/cpu: rework instruction set selection

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: <aA0vft1cPuvzdZvJ@gmail.com>
Date: Sat, 26 Apr 2025 21:09:50 +0200
From: Ingo Molnar <mingo@...nel.org>
To: Arnd Bergmann <arnd@...db.de>
Cc: Arnd Bergmann <arnd@...nel.org>, Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
	Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
	"H. Peter Anvin" <hpa@...or.com>, Juergen Gross <jgross@...e.com>,
	Boris Ostrovsky <boris.ostrovsky@...cle.com>,
	Alexander Usyskin <alexander.usyskin@...el.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Mateusz Jończyk <mat.jonczyk@...pl>,
	Mike Rapoport <rppt@...nel.org>, Ard Biesheuvel <ardb@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>, linux-kernel@...r.kernel.org,
	xen-devel@...ts.xenproject.org,
	Linus Torvalds <torvalds@...ux-foundation.org>
Subject: Re: [PATCH] [RFC] x86/cpu: rework instruction set selection


* Arnd Bergmann <arnd@...db.de> wrote:

> CMOV is missing not just on old Socket 5/7 CPUs (Pentium MMX, AMD K6, 
> Cyrix MII) but also newer embedded Via C3, Geode GX and 
> Vortex86DX/MX/EX/DX2. The replacement Nehemiah (2003), GeodeLX (2005) 
> and Vortex86DX3/EX2 (2015!) have CMOV, but the old ones were sold 
> alongside them for years, and some of the 586-class Vortex86 products 
> are still commercially available.

Very few (if any) of the commercially available products will run 
modern 6.16+ kernels, right?

Note that the real danger the 32-bit x86 kernel is going to be facing 
in 2-5 years is total removal due to lack of development interest, but 
I think we can support 686+ reasonably far into the future, and can 
keep it tested reasonably - while covering like 99%+ of the currently 
available 32-bit-only x86 products on the market. The fewer variants, 
the better.

Thanks,

	Ingo