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

Re: [Xen-devel] [PATCH] gdbserver-xen: fix corefile access

To: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] gdbserver-xen: fix corefile access
From: Horms <horms@xxxxxxxxxxxx>
Date: Thu, 2 Mar 2006 21:19:24 +0900
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Thu, 02 Mar 2006 18:13:19 +0000
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <67b15d3e07c51779c332ec14ca9067fb@xxxxxxxxxxxx>
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>
References: <du6abq$cce$1@xxxxxxxxxxxxx> <67b15d3e07c51779c332ec14ca9067fb@xxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.5.11+cvs20060126
On Thu, Mar 02, 2006 at 10:45:02AM +0000, Keir Fraser wrote:
> 
> On 2 Mar 2006, at 08:28, Horms wrote:
> 
> >This patch fixes corefile access by ensuring that the open fd
> >to the corefile (current_domid) is passed to the underlying
> >xc_routines as neccessary. Currently the prevailing pid is passed,
> >which works fine when attaching to a running domain, but fails
> >for the corefile case.
> 
> This is too gross.

Sorry about that.

> The correct fix is to update the xc_ptrace_core() interface to match 
> the xc_ptrace() interface. Kip Macy made the latter SMP aware, but 
> didn't fix up the former.
> 
> It should be easy to do -- note how xc_ptrace() takes a domid on 
> PTRACE_ATTACH, and vcpuid at all other times. xc_ptrace_core() should 
> take a fd on PTRACE_ATTACH, and vcpuid at all other times. Since we 
> don't dump SMP core files right now, vcpuid should either be ignored 
> for the time being, or fail the call if vcpuid!=0.

I didn't notice that, but I should have.

Are you suggesting that xc_ptrace_core() should record the fd passed
to it on PTRACE_ATTACH and use that later, presumably in current_domid?
If so, yes that does look very easy. If not, can you explain a little
further? In any case, I'll look into it tomorrow.

-- 
Horms

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel