 Home |
Products |
Support |
Community |
News |
xen-devel
Re: [Xen-devel] [PATCH] x86: usercopy assembly constraints
| To: | Jan Beulich <jbeulich@xxxxxxxxxx> |
|---|---|
| Subject: | Re: [Xen-devel] [PATCH] x86: usercopy assembly constraints |
| From: | Keir Fraser <Keir.Fraser@xxxxxxxxxxxx> |
| Date: | Wed, 14 Nov 2007 11:10:01 +0000 |
| Cc: | xen-devel@xxxxxxxxxxxxxxxxxxx |
| Delivery-date: | Wed, 14 Nov 2007 03:11:13 -0800 |
| Envelope-to: | www-data@xxxxxxxxxxxxxxxxxx |
| In-reply-to: | <473AB3AD.76E4.0078.0@xxxxxxxxxx> |
| 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: | AcgmruZMJNuAHJKiEdypyAAX8io7RQ== |
| Thread-topic: | [Xen-devel] [PATCH] x86: usercopy assembly constraints |
| User-agent: | Microsoft-Entourage/11.3.6.070618 |
On 14/11/07 07:37, "Jan Beulich" <jbeulich@xxxxxxxxxx> wrote: >> What's the bug? Does some gcc allocate the 4th output parameter into one of >> the other used registers (cx,si,di) if we don't use '=&'? > > No, the effect is an 'impossible constraint' error, so there's not much reason > to be afraid I think. But as said, the constraint was wrong. I thought '&' was an extra constraint, so I'm surprised it could fix an 'impossible constraint' problem. But anyway, yes, the code is saner and more consistent with your patch. -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel |
| <Prev in Thread] | Current Thread | [Next in Thread> |
|---|---|---|
| ||
| Previous by Date: | [Xen-devel] In VMCS, HOST_CR0.TS is always set 1. Why?, Cui, Dexuan |
|---|---|
| Next by Date: | Re: [Xen-devel] Unable to include xen/sched.h, Keir Fraser |
| Previous by Thread: | Re: [Xen-devel] [PATCH] x86: usercopy assembly constraints, Jan Beulich |
| Next by Thread: | [Xen-devel] [PATCH] fix header dependencies, Jan Beulich |
| Indexes: | [Date] [Thread] [Top] [All Lists] |
