linux-kernel - Re: [PATCH 4/8] unify paravirt parts of system.h

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]

Date:	Sat, 15 Dec 2007 23:54:19 +0100
From:	Pavel Machek <pavel@....cz>
To:	Andi Kleen <andi@...stfloor.org>
Cc:	Andi Kleen <ak@...e.de>, Avi Kivity <avi@...ranet.com>,
	Glauber de Oliveira Costa <gcosta@...hat.com>,
	linux-kernel@...r.kernel.org, akpm@...ux-foundation.org,
	glommer@...il.com, tglx@...utronix.de, mingo@...e.hu,
	ehabkost@...hat.com, jeremy@...p.org, anthony@...emonkey.ws,
	virtualization@...ts.linux-foundation.org, rusty@...tcorp.com.au,
	chrisw@...s-sol.org, rostedt@...dmis.org, hpa@...or.com,
	"Rafael J. Wysocki" <rjw@...k.pl>
Subject: Re: [PATCH 4/8] unify paravirt parts of system.h

On Sat 2007-12-15 14:26:38, Andi Kleen wrote:
> > It probably is safe to remove... but we currently support '2.8.95
> > kernel loads/resumes 2.6.24 image'... which would break if 2.8 uses
> > cr8.
> 
> No it won't. 2.8 would just restore some random useless value.

Restoring random value seems wrong. Putting random values into cpu
registers can break stuff, right?

Even if 2.6.24 image being restored did not set %cr8 itself, it may
depend on %cr8 to have "sane" value.

> If 2.8 wants to use CR8 it would have to re-initialize it

We are talking "2.8 restores 2.6 image" here.

									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
--
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/