Subject: kern/1503: kernel trap (i386) on NFS mount
To: None <gnats-bugs@gnats.netbsd.org>
From: Giles Lean <giles@nemeton.com.au>
List: netbsd-bugs
Date: 09/25/1995 08:08:30
>Number:         1503
>Category:       kern
>Synopsis:       NFS mount can cause kernel to trap and dump
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    kern-bug-people (Kernel Bug People)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Sep 25 11:50:01 1995
>Last-Modified:
>Originator:     Giles Lean
>Organization:
Giles Lean                                             Nemeton Pty Ltd
<giles@nemeton.com.au>                           phone: +61 3 480 2118        
>Release:        September 22 1995
>Environment:
	
System: NetBSD topaz.nemeton.com.au 1.0A NetBSD 1.0A (TOPAZ) #10: Sun Sep 24 16:55:33 EST 1995 giles@topaz.nemeton.com.au:/usr/src/sys/arch/i386/compile/TOPAZ i386


>Description:
	There is a problem mounting a remote NFS filesystem on a
	mount point that appears in /etc/exports on the client
	system.

>How-To-Repeat:
	Server: NetBSD-1.0/i386		'topaz'
	Client: NetBSD-current/i386	'nemeton'

	The client machine also exports filesystems:

	$ cat /etc/exports
	/usr
	/mnt

	Note that there is no filesystem on /mnt:

	$ mount
	/dev/wd0a on / type ufs (NFS exported, local)
	/dev/wd0e on /usr type ufs (NFS exported, local)
	kernfs on /kern type kernfs (local)
	mfs:16 on /tmp type mfs (asynchronous, local)

	Now, dump the box:

	# mount nemeton:/home /mnt

>Fix:
	First catch your dump.  I have dumps from kernels built
	with and without -g, but don't get a backtrace.  I'll
	build a kernel with DDB and try to get more information.

	(The client machine is crash and burn -- if anyone wants
	more information just ask and I'll crash it again. :-)
>Audit-Trail:
>Unformatted: