linux-kernel - Re: Regression: x86/mm: new _PTE_SWP_SOFT_DIRTY bit conflicts with existing use

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: <CA+55aFyk6s1t92HJ5rxKZQk6dTfszmhdXz+S=MqUmM-CbMo+DQ@mail.gmail.com>
Date:	Wed, 21 Aug 2013 09:30:03 -0700
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Cyrill Gorcunov <gorcunov@...il.com>
Cc:	"H. Peter Anvin" <hpa@...or.com>,
	David Vrabel <david.vrabel@...rix.com>,
	Andy Lutomirski <luto@...capital.net>,
	Pavel Emelyanov <xemul@...allels.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Ingo Molnar <mingo@...hat.com>, Xen-devel@...ts.xen.org,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
	Boris Ostrovsky <boris.ostrovsky@...cle.com>,
	Jan Beulich <jbeulich@...e.com>
Subject: Re: Regression: x86/mm: new _PTE_SWP_SOFT_DIRTY bit conflicts with
 existing use

On Wed, Aug 21, 2013 at 7:19 AM, Cyrill Gorcunov <gorcunov@...il.com> wrote:
> On Wed, Aug 21, 2013 at 04:11:25PM +0200, H. Peter Anvin wrote:
>>
>> Eep.  This should be reverted, indeed.  This isn't a manifest bug on !Xen but we
>> have gotten requests for WT support which would mean adding in the PAT but again.
>
> Please no, letme fix it. That's what I'm having in mind: don't use pse bit in swap
> entry but always mark page read from swap as dirty one (it's better than having
> no tracker at all and  will be the case on old machines with 32bit ptes only).

Quite frankly, unless I see a patch later today that is

 (a) obvious
 (b) explains what is going on
 (c) tested

I will be reverting the whole soft-dirty mess. I thought the
bit-mapping games it played were already too complicated (the patch to
pgtable-2level.h in commit 41bb3476b361 just makes me want to barf and
came in very late, so I'm not positive about the whole soft-dirty mess
in the first place). I really am not at all inclined to want to play
games in this area any more. It's too damn late in the release window.

            Linus
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/