WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

[Xen-devel] Fix 32-bit overflow in 64-bit Xen running 32-bit guest.

To: xen-devel@xxxxxxxxxxxxxxxxxxx, "Woller, Thomas" <thomas.woller@xxxxxxx>
Subject: [Xen-devel] Fix 32-bit overflow in 64-bit Xen running 32-bit guest.
From: "Petersson, Mats" <Mats.Petersson@xxxxxxx>
Date: Wed, 27 Sep 2006 18:52:29 +0200
Delivery-date: Wed, 27 Sep 2006 09:56:16 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: AcbiVVISp9zfR89xQ0qH0OsPjpPW6g==
Thread-topic: Fix 32-bit overflow in 64-bit Xen running 32-bit guest.
One of our clients found a problem trying to start OS/2 - we get an
overflow when running a 64-bit hypervisor and 32-bit guest if the RIP is
"large" - this should result in a 32-bit value that is truncated, but
instead results in a 33-bit value that causes "strange" results and
eventually a crash of the guest. 

Attached is a proposed patch that fixes the overflow. I'm not sure if
it's worth trying to #if _x86_64_ around it to avoid the extra vmcb
accesses - but if that's worth doing, there would be a bigger gain from
moving this function from emulate.c into a header-file and making it
inline... ;-)

Comments and criticisms welcome... 

Patch is based on 11619. 

--
Mats

Attachment: rip2ptr.patch
Description: rip2ptr.patch

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
<Prev in Thread] Current Thread [Next in Thread>
  • [Xen-devel] Fix 32-bit overflow in 64-bit Xen running 32-bit guest., Petersson, Mats <=