RaspberryPi crash/freez random time after ~r253751

[Ian Lepore]

On Sat, 2013-08-03 at 03:40 +0400, Andrey Fesenko wrote:
> On Fri, Aug 2, 2013 at 5:09 PM, Andrey Fesenko <f0andrey at gmail.com> wrote:
> > Hello,
> >
> > System work stable after migration EABI ~r20130716 (+fix build perl port)
> > after make new images r253751 and r253847 system (RPi) freez after
> > random time building ports.
> >
> > got to collect a backtrace log http://pastebin.com/Bbn9ka4N
> >
> >> uname -a
> > FreeBSD raspberry-pi 10.0-CURRENT FreeBSD 10.0-CURRENT #0 r253847M:
> > Thu Aug  1 03:54:07 MSK 2013
> > andrey at my_book.local:/home/andrey/obj/arm.armv6/usr/src/sys/RPI-B-IPv6
> >  arm
> 
> after patch http://people.freebsd.org/~andrew/trapframe_align.diff
> system boot, random time building ports crash system
> bt log http://pastebin.com/jBJFf8Zt

That is a very strange backtrace.  

login: panic: vm_fault: fault on nofault entry, addr: db02d000

The page that faulted was db02d000.  The stack on entry to the exception
handler was db02d008.  The exception handling was able to use the stack
in the previous page without double-faulting -- it counts down into
db02cfxx and lower just fine as the exception handling proceeds.

I don't know what to make of it, but I thought I'd mention the oddity in
case it triggers ideas for someone else.

-- Ian