linux-kernel - Re: [PATCH] x86/microcode: Add an option to reload microcode even if revision is unchanged

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: <20190905202019.GA3649@otc-nc-03>
Date:   Thu, 5 Sep 2019 13:20:19 -0700
From:   "Raj, Ashok" <ashok.raj@...el.com>
To:     Borislav Petkov <bp@...en8.de>
Cc:     Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        Mihai Carabas <mihai.carabas@...cle.com>,
        "H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...hat.com>,
        Jon Grimm <Jon.Grimm@....com>, kanth.ghatraju@...cle.com,
        konrad.wilk@...cle.com, patrick.colp@...cle.com,
        Thomas Gleixner <tglx@...utronix.de>,
        Tom Lendacky <thomas.lendacky@....com>,
        x86-ml <x86@...nel.org>, linux-kernel@...r.kernel.org,
        Ashok Raj <ashok.raj@...el.com>
Subject: Re: [PATCH] x86/microcode: Add an option to reload microcode even if
 revision is unchanged

On Thu, Sep 05, 2019 at 09:49:50PM +0200, Borislav Petkov wrote:
> On Thu, Sep 05, 2019 at 12:40:44PM -0700, Raj, Ashok wrote:
> > The original description said to load a new microcode file, the content
> > could have changed, but revision in the header hasn't increased.
> 
> How does the hardware even accept a revision which is the same as the
> one already loaded?

Hardware will allow a reload as long as the loaded ucode svn <= the version being updated.