Subject: Re: uvm_fault
To: mouss <>
From: Malcolm Herbert <>
List: current-users
Date: 02/22/2006 10:54:43
On Tue, Feb 21, 2006 at 10:16:46PM +0100, mouss wrote:
|>>Hi, I have a script that sets up a chroot environment under /opt/sandbox by
|>>calling 'mount_null' to mount /bin, /sbin, /lib, /usr/bin, /usr/sbin, /usr/lib,
|>>etc under /opt/sandbox. When some of the directories are exported via NFS and I
|>>call this scripts on the server that exports those directories, I get a kernel
|>>panic. This is on a pretty recent NetBSD-current.
|>>uvm_fault(0xcace89a0, 0, 0, 1) -> 0xe
|>>kernel: supervisor trap page fault, code = 0
|>>Stopped in pid 543.1 (mountd) at 0: invalid address

I have a similar setup with chroot and null mounts trying to compile pkgsrc stuff
and got a number of these errors during my last build ... single CPU machine,
NetBSD 3.0, RAIDFrame disks, 512M of memory ... 

Rather than type them out each time I just took a photo - they're at

|> It's been suggested that these are memory errors -- that is, hardware
|> failures -- but I can't see any other evidence that the memory in these
|> systems is bad.  I think we must have some kind of race in the VM system.

That was suggested to me as well.  I have bought new memory to take it to 
1G but haven't tried installed it as yet.

|The faults disappeared after I rebuilt a custom kernel. so the faults
|were caused by one of the removed options, but there are too many
|possibilities to test (and the faults occured unpredictably, so I can't
|just rebuild a new kernel and test...).

ah ... interesting ... I might try building a new kernel on a another machine ... 

incidentally, I recall someone mentioning a utility which scans a booting kernel
dmesg output and builds a config out of what it finds detected ... where can
I get that from?

Malcolm Herbert                                This brain intentionally                                                left blank