linux-kernel - Re: [PATCH 13/15] x86/cpu: Make CONFIG_X86

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: <956412a3-43c2-4d6e-bea2-2573c98233ae@app.fastmail.com>
Date: Fri, 25 Apr 2025 14:10:27 +0200
From: "Arnd Bergmann" <arnd@...nel.org>
To: "Ingo Molnar" <mingo@...nel.org>, linux-kernel@...r.kernel.org
Cc: "Ahmed S . Darwish" <darwi@...utronix.de>,
 "Andrew Cooper" <andrew.cooper3@...rix.com>,
 "Ard Biesheuvel" <ardb@...nel.org>, "Borislav Petkov" <bp@...en8.de>,
 "Dave Hansen" <dave.hansen@...ux.intel.com>,
 "H. Peter Anvin" <hpa@...or.com>, "John Ogness" <john.ogness@...utronix.de>,
 "Linus Torvalds" <torvalds@...ux-foundation.org>,
 "Peter Zijlstra" <peterz@...radead.org>,
 "Thomas Gleixner" <tglx@...utronix.de>
Subject: Re: [PATCH 13/15] x86/cpu: Make CONFIG_X86_CX8 unconditional

On Fri, Apr 25, 2025, at 10:42, Ingo Molnar wrote:
> @@ -257,7 +256,7 @@ config X86_MINIMUM_CPU_FAMILY
>  	int
>  	default "64" if X86_64
>  	default "6" if X86_32 && (MPENTIUM4 || MPENTIUMM || MPENTIUMIII || 
> MPENTIUMII || M686 || MVIAC3_2 || MVIAC7 || MEFFICEON || MATOM || MK7)
> -	default "5" if X86_32 && X86_CX8
> +	default "5" if X86_32
>  	default "4"
> 

I just noticed this one: the final 'default "4"' is no longer possible
here and can be removed. All the remaining CPUs report family "5" or
higher.

There is an old issue for some rare CPUs (Geode LX and Crusoe) that
support CMOV but report family=6. These to boot a kernel with X86_MINIMUM_CPU_FAMILY=6 because it triggers the boot time check.

     Arnd