linux-kernel - Re: [PATCH v3 2/4] x86/mm/64: Flush global TLB on boot and AP bringup

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: <YXf7hBEbW0CmwYwz@zn.tnic>
Date:   Tue, 26 Oct 2021 14:58:44 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Joerg Roedel <joro@...tes.org>
Cc:     x86@...nel.org, Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, hpa@...or.com,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Andy Lutomirski <luto@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Joerg Roedel <jroedel@...e.de>,
        Mike Rapoport <rppt@...nel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Brijesh Singh <brijesh.singh@....com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 2/4] x86/mm/64: Flush global TLB on boot and AP bringup

On Tue, Oct 26, 2021 at 11:55:44AM +0200, Borislav Petkov wrote:
> > +	movq	%cr4, %rcx
> > +	movq	%rcx, %rax
> > +	xorq	$X86_CR4_PGE, %rcx
> > +	movq	%rcx, %cr4
> > +	movq	%rax, %cr4

Also, I'm wondering if you could compact this even more by defining a
function toggling the PGE bit and calling it from everywhere, even from
asm.

-- 
Regards/Gruss,
    Boris.

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