linux-kernel - Re: [RFC v2 4/9] x86/mm: Introduce X86_FEATURE

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: <bdf83ab6f5149678ba08cfc52ef806ed705aa283.camel@surriel.com>
Date: Wed, 21 May 2025 12:06:59 -0400
From: Rik van Riel <riel@...riel.com>
To: Borislav Petkov <bp@...en8.de>
Cc: linux-kernel@...r.kernel.org, linux-mm@...ck.org, x86@...nel.org, 
	kernel-team@...a.com, dave.hansen@...ux.intel.com, luto@...nel.org, 
	peterz@...radead.org, tglx@...utronix.de, mingo@...hat.com, hpa@...or.com, 
	nadav.amit@...il.com, Rik van Riel <riel@...com>, Yu-cheng Yu
	 <yu-cheng.yu@...el.com>
Subject: Re: [RFC v2 4/9] x86/mm: Introduce X86_FEATURE_RAR

On Wed, 2025-05-21 at 16:53 +0200, Borislav Petkov wrote:
> On Wed, May 21, 2025 at 09:57:52AM -0400, Rik van Riel wrote:
> > I had the same thought, and tried that already.
> > 
> > It didn't work.
> 
> Care to share why?
> 
It resulted in RAR not being properly initialized,
and the system hanging when trying to use RAR to
flush the TLB.

I don't remember exactly what sequence of events
was happening here, maybe something with the
boot CPU per-cpu RAR initialization being called
(or not, due to X86_FEATURE_RAR not being set)
before the systemwide initialization?

-- 
All Rights Reversed.