On Fri, 25 Dec 2009 22:23:51 -0500
Michael Breuer [off-list ref] wrote:

On 12/25/2009 6:22 PM, Stephen Hemminger wrote:

quoted

On Fri, 25 Dec 2009 11:28:55 -0500
Michael Breuer[off-list ref]  wrote:

   

quoted

   More data points - I'm able to reliably recreate this now.
While I thought it was coincidence, each and every time I hit this issue
there is a DHCP renew event immediately before the first error.
The crash occurs while under load - in my case seems that the traffic is
actually IPV6 (hadn't noticed that before).
I ran nethogs on a remote display - the reported rx rate on the IPV6 smb
connection at the time of the lockup was 33889.688 KB/sec on a 1gbit
nic. I've got two events like this - don't recall if the earlier one was
the exact same # - but it was in the ballpark.

On 12/24/2009 2:01 AM, Andrew Morton wrote:
     

quoted

cc's added again.

On Wed, 23 Dec 2009 17:54:27 -0500 Michael Breuer[off-list ref]   wrote:


       

quoted

Ok - not the firmware.  Ran another Windows backup and sky2 went down.

Nothing in dmesg.old - have oops in syslog. System became unresponsive
and watchdog kicked in after a minute.

Also note that I have a similar oops with VT-D disabled (posted here on
12/5). I'm attaching the oops from that below this oops for comparison.
That also happened under similar load.

On the assumption that I can recreate this (although it takes a while)
please let me know how I can help.

What's in my log (starting with an smbd error about 2 min before the
oops (note: the dchpd is not the system doing the backup).

         

This (nastily wordwrapped) oops appers to be quite different from
Berck's one.


       

What is the MTU?
   

1500

quoted

quoted

It looks like the problem only shows up for packets generated by DHCP,
and these come through AF_PACKET. The problem maybe related to how this
packets are fragmented into header and page, in a different way than other
packets confusing the driver or DMA engine.

Does this help?
-----

--- a/drivers/net/sky2.c	2009-12-26 09:50:20.869565022 -0800
+++ b/drivers/net/sky2.c	2009-12-26 09:55:54.620645355 -0800

@@ -1616,6 +1616,13 @@ static netdev_tx_t sky2_xmit_frame(struc
  	if (unlikely(tx_avail(sky2) < tx_le_req(skb)))
   		return NETDEV_TX_BUSY;
 
+	if (!pskb_may_pull(skb, ETH_HLEN)) {
+		if (net_ratelimit())
+			pr_info(PFX "%s: packet missing ether header (%d)?",
+				dev->name, skb->len);
+		goto drop;
+	}
+
 	len = skb_headlen(skb);
 	mapping = pci_map_single(hw->pdev, skb->data, len, PCI_DMA_TODEVICE);
 

@@ -1761,6 +1768,7 @@ mapping_unwind:
 mapping_error:
 	if (net_ratelimit())
 		dev_warn(&hw->pdev->dev, "%s: tx mapping error\n", dev->name);
+drop:
 	dev_kfree_skb(skb);
 	return NETDEV_TX_OK;
 }

--