[issue1844] gdb detach from vkernel causes vkernel to die with SIGILL

[Matthew Dillon]

:    This is probably one of the I/O threads used by if_vke and if_vkd.
:    These threads are not counted as 'cpus' and do not have globaldata

    Ah, I think it must be the I/O thread taking a signal due to the GDB
    interactions.  Those I/O threads absolutely cannot take signals, they
    will explode (the signals assume a globaldata context).

    I'm not sure how we can address this.

					-Matt
					Matthew Dillon 
					<dillon at backplane.com>