Re: kernel panic: uvm_fault

[Thomas Klausner <wiz%NetBSD.org@localhost>]

On Mon, Dec 22, 2014 at 03:29:58PM +0000, Robert Swindells wrote:
> 
> Thomas Klausner wrote:
> >I had a kernel panic today with a amd64/7.99.3 kernel from Dec 20. The
> >last activity I had started was downloading a file from network to an
> >NFS directory mounted from a Synology.
> >
> >last activity I had started was downloading a file from network to an
> >NFS directory mounted from a Synology.
> 
> [snip]
> 
> >#1  0xffffffff808ccb54 in vpanic (fmt=fmt@entry=0xffffffff80ddb08d "trap", ap=ap@entry=0xfffffe813bcb8510) at /archive/foreign/src/sys/kern/subr_prf.c:340
> >#2  0xffffffff808ccc0f in panic (fmt=fmt@entry=0xffffffff80ddb08d "trap") at /archive/foreign/src/sys/kern/subr_prf.c:256
> >#3  0xffffffff8091bd87 in trap (frame=0xfffffe813bcb8630) at /archive/foreign/src/sys/arch/amd64/amd64/trap.c:298
> >#4  0xffffffff8010108e in alltraps ()
> >#5  0xffffffff8028b965 in .Mmbuf_inner_loop ()
> >#6  0xfffffe8349294000 in ?? ()
> >#7  0xfffffe813bcb8758 in ?? ()
> >#8  0xffffffff8058733e in in_delayed_cksum (m=0xffff8003393b8000) at /archive/foreign/src/sys/netinet/ip_output.c:793
> >Backtrace stopped: previous frame inner to this frame (corrupt stack?)
> >(gdb)
> 
> >Is this a valid backtrace? Does it give any useful hints?
> 
> It looks the same as the panic you had back in September to me:
> 
> <http://mail-index.netbsd.org/current-users/2014/09/13/msg025777.html>
> 
> Can you turn on HW checksumming on this machine ?

I've just done that ("ifconfig wm0 tcp4csum ip4csum udp4csum"):

wm0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
	capabilities=7ff80<TSO4,IP4CSUM_Rx,IP4CSUM_Tx,TCP4CSUM_Rx>
	capabilities=7ff80<TCP4CSUM_Tx,UDP4CSUM_Rx,UDP4CSUM_Tx,TCP6CSUM_Rx>
	capabilities=7ff80<TCP6CSUM_Tx,UDP6CSUM_Rx,UDP6CSUM_Tx,TSO6>
	enabled=3f00<IP4CSUM_Rx,IP4CSUM_Tx,TCP4CSUM_Rx,TCP4CSUM_Tx>
	enabled=3f00<UDP4CSUM_Rx,UDP4CSUM_Tx>
	ec_capabilities=7<VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU>
	ec_enabled=0
...

I had in the back of my memory that hardware checksumming was usually
the cause of bugs, not when it's turned off. Am I misremembering?
 Thomas