> Its
> rebooting without a panic message / core dump (savecore doesn't come up
> with anything).  It doesn't even try to flush the disks before rebooting -
> the screen just flickers and the boot sequence begins.

I've seen that too, after mistyping some configure commands for a gre tunnel,
looked like a kernel stack overflow. I couldn't reproduce it back then.

If you can attach a serial console put some printfs in the gre code and
capture what happens before the panic.


Martin