Subject: kern/31994: hard kernel crash
To: None <,,>
From: None <>
List: netbsd-bugs
Date: 11/03/2005 17:48:00
>Number:         31994
>Category:       kern
>Synopsis:       hard kernel crash
>Confidential:   no
>Severity:       serious
>Priority:       low
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Nov 03 17:48:00 +0000 2005
>Originator:     Zeljko Vrba
>Release:        NetBSD 2.0.2
	2 CPU system, HT disabled
System: NetBSD 2.0.2 NetBSD 2.0.2 (DMMSL-38) #10: Sun Aug 21 13:04:48 CEST 2005 i386
Architecture: i386
Machine: i386
So the scenario is following:

- become root, mount FAT32 partition
- cd to that partition

I was playing a bit with the p7zip archiver, which is multithreaded and due to
some command-line options ran out of memory, but with a very strange message
(invalid argument to system call).

Then I tried to ktrace it to see which system call is at fault, and the machine
froze on me. Crashed HARD. Today when I came to work I saw the following thing
on the console:

uvm_fault(0xd72a3c0c, 0, 0, 1) -> 0xe

As for kernel DDB, I have these options in the kernel:
options         DDB             # in-kernel debugger
options         DDB_ONPANIC=1   # see also sysctl(8): `ddb.onpanic'

DDB didn't start. I could do just hard reset.

Not sure. I'm using p7zip from the pkgsrc. I copied the following line from
the manual page:

7za a -t7z -m0=lzma -mx=9 -mfb=64 -md=32m -ms=on archive.7z dir1

Added ktrace in front, replaced -md=32m with some higher numbers. Eventually,
I think that it crashed with -md=64m. Everything was done on FAT32 partition,
and dir1 had about 80G of data.