FreeBSD 6.2 Crash

[Kris Kennaway]

Atanas Gendov wrote:
> Hi all FreeBSD Hackers! :)
> My FreeBSD auto reboot itself and I got this report by kgdb, but
> actually I'm not a programmer. I don't know how to debug this error.
> Could someone helps with fixing?
> Thanx in advanced!
> 
> FreeBSD xxxx.com 6.2-RELEASE-p8 FreeBSD 6.2-RELEASE-p8 #0: Tue Oct 30
> 22:54:18 EET 2007
> atanas at xxxxxxxxxxxx:/usr/obj/usr/src/sys/THURISAZ  i386
> 
> kgdb kernel.debug /var/crash/vmcore.0
> kgdb: kvm_nlist(_stopped_cpus):
> kgdb: kvm_nlist(_stoppcbs):
> [GDB will not be able to debug user-mode threads:
> /usr/lib/libthread_db.so: Undefined symbol "ps_pglobal_lookup"]
> GNU gdb 6.1.1 [FreeBSD]
> Copyright 2004 Free Software Foundation, Inc.
> GDB is free software, covered by the GNU General Public License, and you are
> welcome to change it and/or distribute copies of it under certain conditions.
> Type "show copying" to see the conditions.
> There is absolutely no warranty for GDB.  Type "show warranty" for details.
> This GDB was configured as "i386-marcel-freebsd".
> 
> Unread portion of the kernel message buffer:
> 
> Fatal double fault:
> eip = 0xc0489471
> esp = 0xd568af78
> ebp = 0xd568b094
> panic: double fault

Do you use the nve driver?  It has a known bug that causes a double 
fault.  Unfortunately kgdb doesn't know how to properly decode double 
fault backtraces, so there isn't any more information about the cause. 
If you are not using nve, can you try to reproduce and then see what DDB 
says about the backtrace?

Kris