If a device attach routine fails during boot and calls bus_teardown_intr(), ithread_remove_handler() may fail to remove the interrupt handler if it decides to let the ithread do the removal.  The problem is that during boot "cold" is set, which causes msleep() to return immediately.  This will cause ithread_remove_handler() to fail to wait for the ithread to do the removal from the handler TAILQ before freeing the handler back to the heap.  Bad things will happen when some other user of the TAILQ, such as ithread_add_handler() or the actual ithread attempts to use the freed handler.  Fix the problem by forcing ithread_remove_handler() to do the actual removal itself if the "cold" flag is set.
If a device attach routine fails during boot and calls bus_teardown_intr(),
ithread_remove_handler() may fail to remove the interrupt handler if
it decides to let the ithread do the removal.  The problem is that during
boot "cold" is set, which causes msleep() to return immediately.  This
will cause ithread_remove_handler() to fail to wait for the ithread
to do the removal from the handler TAILQ before freeing the handler
back to the heap.  Bad things will happen when some other user of the
TAILQ, such as ithread_add_handler() or the actual ithread attempts to use
the freed handler.  Fix the problem by forcing ithread_remove_handler()
to do the actual removal itself if the "cold" flag is set.

Reviewed by:	jhb

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase