From: Eric Dumazet <eric.dumazet@gmail.com>
To: Robin Holt <holt@sgi.com>
Cc: Sandeep Gopalpet <Sandeep.Kumar@freescale.com>,
"David S. Miller" <davem@davemloft.net>,
netdev@vger.kernel.org
Subject: Re: gianfar.c null pointer deref in gfar_start_xmit().
Date: Tue, 09 Aug 2011 09:10:13 +0200 [thread overview]
Message-ID: <1312873813.2531.54.camel@edumazet-laptop> (raw)
In-Reply-To: <20110809065407.GF3709@sgi.com>
Le mardi 09 août 2011 à 01:54 -0500, Robin Holt a écrit :
> On Tue, Aug 02, 2011 at 09:44:38PM -0500, Robin Holt wrote:
> >
> > While using the v3.0 kernel on a Freescale P1010RDB with 3 minor patches
> > (None which affect gianfar.c), I get a NULL pointer deref at:
> >
> > static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev)
> > {
> > ...
> > regs = tx_queue->grp->regs;
> >
> > I put a BUG_ON(tx_queue->grp) just before this line and it did trip.
> > I have not looked at this any more than that.
> >
> > Any suggestions would be welcome. To reproduce, all I need to do is
> > a few sequences of pings.
>
> I was able to reproduce this with the net-next-2.6 kernel as well.
>
This driver incorrectly assumes a non dense txqueue array is possible
for a netdev, but its not true.
In the meantime, you could force it to use one tx_queue only.
tx_queues = (u32 *)of_get_property(np, "fsl,num_tx_queues", NULL);
num_tx_qs = tx_queues ? *tx_queues : 1;
next prev parent reply other threads:[~2011-08-09 7:10 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-03 2:44 gianfar.c null pointer deref in gfar_start_xmit() Robin Holt
2011-08-09 6:54 ` Robin Holt
2011-08-09 7:10 ` Eric Dumazet [this message]
2011-08-09 13:06 ` Robin Holt
2011-08-10 6:01 ` Eric Dumazet
2011-08-10 9:32 ` Robin Holt
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