linux-kernel - Re: [Xen-devel] [PATCH] x86/xen: Initialize cr4 shadow for 64-bit PV(H) guests

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] [day] [month] [year] [list]

Date:	Tue, 03 Mar 2015 13:27:39 -0500
From:	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
To:	"Luis R. Rodriguez" <mcgrof@...e.com>,
	Boris Ostrovsky <boris.ostrovsky@...cle.com>
CC:	David Vrabel <david.vrabel@...rix.com>,
	xen-devel@...ts.xenproject.org,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Andy Lutomirski <luto@...capital.net>,
	Andrey Ryabinin <a.ryabinin@...sung.com>
Subject: Re: [Xen-devel] [PATCH] x86/xen: Initialize cr4 shadow for 64-bit	PV(H) guests

On March 3, 2015 1:15:42 PM EST, "Luis R. Rodriguez" <mcgrof@...e.com> wrote:
>On Tue, Mar 03, 2015 at 09:27:34AM -0500, Boris Ostrovsky wrote:
>> On 03/03/2015 12:35 AM, Luis R. Rodriguez wrote:
>>> On Mon, Feb 23, 2015 at 9:09 AM, David Vrabel
><david.vrabel@...rix.com> wrote:
>>>> On 23/02/15 16:01, Boris Ostrovsky wrote:
>>>>> Commit 1e02ce4cccdc ("x86: Store a per-cpu shadow copy of CR4")
>>>>> introduced CR4 shadows.
>>>>>
>>>>> These shadows are initialized in early boot code. The commit
>missed
>>>>> initialization for 64-bit PV(H) guests that this patch adds.
>>>> Applied to stable/for-linus-4.0, thanks.
>>>>
>>>> Boris, can you kick of a set of tests on this branch, please?
>>> Do we know worst case what should blow up without this commit ?
>>
>> PVH guest will crash.
>
>Oh wow that is serious. And this is a reactive measure to a change
>upstream,
>it might be hard but it'd be nice if we can have a proactive
>architecture
>to address this. Don't mind me though, I realize this seems hard, just 
>thinking out loud right now. Did you find it through code inspection or
>a test?

Boris runs every night on different hardware an regression test against the latest Linux kernel.

>
>  Luis

L
--
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/