[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] netback crash with xen3.0.3


  • To: Ian Pratt <m+Ian.Pratt@xxxxxxxxxxxx>
  • From: Jacob Gorm Hansen <jacobg@xxxxxxx>
  • Date: Mon, 27 Nov 2006 12:36:12 +0100
  • Cc: xen-devel <Xen-devel@xxxxxxxxxxxxxxxxxxx>, Jacob Gorm Hansen <jacobg@xxxxxxx>
  • Delivery-date: Mon, 27 Nov 2006 03:36:25 -0800
  • Domainkey-signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:date:from:to:cc:subject:message-id:references:mime-version:content-type:content-disposition:in-reply-to:user-agent:sender; b=VB+O2KImEIfM/DQ9COe96hdcszLr6iA7zKnxz48jYIWVWJNiRxxXzjxKiHRRDy3UjjZWAN9l7Jif4fFvy7joi1VNUD4FpQCVaTClEtRxDpNKrlNQXrgUpFWnL99O4ZuhkLbswPqrQ6q27rPsvlgtt5fBP4/EGbpSp9AbC9f/PWc=
  • List-id: Xen developer discussion <xen-devel.lists.xensource.com>

On Fri, Nov 24, 2006 at 07:16:13PM -0000, Ian Pratt wrote:

> > I am working on a network driver for mini-os, and after creating a lot
> > of semi-broken test domains, and a lot of vifs (80 or so), I got dom0
> to
> > crash like below.
> > 
> > I have no idea how to reproduce this, just wanted to let people know
> > there is a some bug in netback somewhere.
> 
> Please could you try and look at the disassembly and figure out which
> pointer dereference is causing the problem. Are you using rx-copy or
> rx-flip?

hi,

I am using rx-copy. The bug seems to stem from the first DPRINTK in
netbk_check_gop, where gop may be used unitialized. Actually, gcc already warns
about this, and since most people will not have this printk, it is probably 
harmless in real life.

Jacob

===============

static int netbk_check_gop(int nr_frags, domid_t domid,
               struct netrx_pending_operations *npo)
{
    multicall_entry_t *mcl;
    gnttab_transfer_t *gop;
    gnttab_copy_t     *copy_op;
    int status = NETIF_RSP_OKAY;
    int i;

    for (i = 0; i <= nr_frags; i++) {
        if (npo->meta[npo->meta_cons + i].copy) {
            copy_op = npo->copy + npo->copy_cons++;
            if (copy_op->status != GNTST_okay) {
                DPRINTK("Bad status %d from copy to DOM%d.\n",
                    gop->status, domid);
                status = NETIF_RSP_ERROR;
            }
        } else {

...

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


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.