linux-kernel - Re: [v2 01/13] x86/microcode/intel: Prevent printing updated microcode rev multiple times

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: <Y2Tw2+LCmZe8XBJn@zn.tnic>
Date:   Fri, 4 Nov 2022 12:00:43 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Ashok Raj <ashok.raj@...el.com>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        LKML Mailing List <linux-kernel@...r.kernel.org>,
        X86-kernel <x86@...nel.org>, Tony Luck <tony.luck@...el.com>,
        Dave Hansen <dave.hansen@...el.com>,
        Arjan van de Ven <arjan.van.de.ven@...el.com>,
        Andy Lutomirski <luto@...nel.org>,
        Jacon Jun Pan <jacob.jun.pan@...el.com>,
        Tom Lendacky <thomas.lendacky@....com>,
        Kai Huang <kai.huang@...el.com>,
        Andrew Cooper <andrew.cooper3@...rix.com>
Subject: Re: [v2 01/13] x86/microcode/intel: Prevent printing updated
 microcode rev multiple times

On Thu, Nov 03, 2022 at 05:58:49PM +0000, Ashok Raj wrote:
> @@ -696,8 +697,7 @@ static int collect_cpu_info(int cpu_num, struct cpu_signature *csig)
>  
>  	csig->rev = c->microcode;
>  
> -	/* No extra locking on prev, races are harmless. */
> -	if (csig->sig != prev.sig || csig->pf != prev.pf || csig->rev != prev.rev) {
> +	if (bsp && csig->rev != prev.rev) {

This basically means that the loader is not going to support mixed
steppings microcode.

Yes, no?

If yes, can I remove the patch cache too and use a single buffer for the
current patch?

That would simplify things even more.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette