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From: Keir Fraser <keir.fraser@eu.citrix.com>
To: "Jan Beulich" <JBeulich@novell.com>, "Pasi Kärkkäinen" <pasik@iki.fi>
Cc: "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
	Joanna Rutkowska <joanna@invisiblethingslab.com>,
	Daniel Stodden <Daniel.Stodden@citrix.com>
Subject: Re: Xen 4.0.0x allows for data corruption in Dom0
Date: Tue, 09 Mar 2010 10:15:45 +0000	[thread overview]
Message-ID: <C7BBD051.C7A6%keir.fraser@eu.citrix.com> (raw)
In-Reply-To: <4B9624FD02000078000336EA@vpn.id2.novell.com>

On 09/03/2010 09:37, "Jan Beulich" <JBeulich@novell.com> wrote:

>> 7dc2000: 5a02 0000 0000 0000 760d d90c c500 0000  Z.......v.......
>> 7dc2010: 3785 8def 8003 0000 1eb2 27b5 ff00 0000  7.........'.....
>> 2dc0d000:7802 0000 0000 0000 ec70 d8eb ce00 0000  x........p......
>> 2dc0d010:6fb9 a66d 8403 0000 1eb2 27b5 ff00 0000  o..m......'.....
> 
> How about these being vcpu_time_info structures? The fields
> appear to all make sense. The only thing not matching this would
> be a few differently looking corruption entries sent earlier by Joanna,
> so this may not be the only thing. But it would explain why with 3.4.2
> the issue is not present.

Pasi, can you try the attached patch (which simply stubs out the new
VCPUOP_register_vcpu_time_memory_area hypercall)? I'm pretty sure this is
it: just look at the implementation of __update_vcpu_system_time: when
v!=current it will write to a virtual address in v, using current's page
tables. This will happen on context switch dom0->domU for example.

A quite suitable fix for 4.0.0 is to leave the hypercall stubbed out imo.

 -- Keir

  parent reply	other threads:[~2010-03-09 10:15 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <C7B7F4C4.C5D8%keir.fraser@eu.citrix.com>
2010-03-06 13:36 ` Xen 4.0.0x allows for data corruption in Dom0 Keir Fraser
2010-03-07 14:36   ` Pasi Kärkkäinen
2010-03-07 14:39     ` Keir Fraser
2010-03-07 16:12       ` Pasi Kärkkäinen
2010-03-08 23:22         ` Daniel Stodden
2010-03-08 23:30           ` Joanna Rutkowska
2010-03-08 23:52             ` Daniel Stodden
2010-03-08 23:56               ` Joanna Rutkowska
2010-03-09  0:33                 ` Daniel Stodden
2010-03-09  8:25           ` Pasi Kärkkäinen
2010-03-09  9:37             ` Jan Beulich
2010-03-09 10:15               ` Jan Beulich
2010-03-09 10:17                 ` Keir Fraser
2010-03-09 10:15               ` Keir Fraser [this message]
2010-03-09 10:25                 ` Pasi Kärkkäinen
2010-03-09 10:43                   ` Keir Fraser
2010-03-09 12:03                     ` Pasi Kärkkäinen
2010-03-09 10:42                 ` Jan Beulich
2010-03-09 23:28                 ` Jeremy Fitzhardinge
2010-03-10  1:33                   ` Dan Magenheimer
2010-03-10 18:02                     ` Jeremy Fitzhardinge
     [not found] <C7B80F95.C5F3%keir.fraser@eu.citrix.com>
2010-03-06 13:37 ` Joanna Rutkowska
2010-03-06 17:18   ` Keir Fraser
     [not found] <4B922A89.2060105@invisiblethingslab.com>
2010-03-08 22:24 ` Jeremy Fitzhardinge
2010-03-08 22:34   ` Joanna Rutkowska
2010-03-08 23:12     ` Jeremy Fitzhardinge
2010-03-08 23:23       ` Joanna Rutkowska
2010-03-08 23:41         ` Jeremy Fitzhardinge
2010-03-08 23:48           ` Joanna Rutkowska
2010-03-09  0:18         ` James Harper
2010-03-09  0:20           ` Joanna Rutkowska
2010-03-08 23:32 ` Daniel Stodden
     [not found]   ` <4B958A42.4000407@invisiblethingslab.com>
2010-03-08 23:46     ` Daniel Stodden

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