Fatal trap 18

[Jeremy Chadwick]

On Tue, Nov 02, 2010 at 11:30:28PM -0600, Dan Allen wrote:
> FreeBSD 8.1-STABLE sometime after 10/28/2010 has caused a fatal boot error on my Toshiba U205, 1.8 GHz Core Duo laptop.
> 
> Many times every week I sync with STABLE and build everything.  I have been doing this for years.
> 
> I sync'd (via csup) and built on 10/28/2010 and everything was fine.
> 
> Then I sync'd yesterday 11/1/2010 and it crashes on boot.  The diagnostics print out the following:
> 
> ---
> 
> Fatal trap 18: integer divide fault while in kernel mode
> 
> kdb_backtrace
> panic
> trap_fatal
> trap
> calltrap
> topo_probe
> cpu_topo
> smp_topo
> sched_setup
> mi_startup
> 
> ---
> 
> I reverted at the loader via boot /boot/kernel.old, resync'd today, rebuilt, and things are still broken.
> 
> Any ideas?

This looks like it could be related to the Intel CPU topology change
that was recently MFC'd:

http://freshbsd.org/2010/11/01/08/20/14

Can you please roll your source code back to a date prior to the above
commit, rebuild, and re-try?  You can accomplish this using the "date"
option in your cvsup/csup file.  See csup(1) for details.  I would
recommend also chopping off an additional hour "just in case".

-- 
| Jeremy Chadwick                                   jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.              PGP: 4BD6C0CB |