The change to detach the threads in zap_other_threads() broke the case
where the non-thread-group-leader is the cause of de_thread().

In this case the group leader will be detached and freed before
switch_exec_pids() is complete and invalid data will be used.  This is a
patch that makes sure that the group leader does not get detached and
reaped.

into home.osdl.org:/home/torvalds/v2.5/linux

into home.osdl.org:/home/torvalds/v2.5/linux

into home.osdl.org:/home/torvalds/v2.5/linux

This is a cleaner fix that avoids having two separate unlock
operations.

This disables the local APIC before reboot.  This fixes BIOS reboot
problems reported by a few people.

disable_local_APIC() now checks if detect_init_APIC() enabled the
local APIC via the APIC_BASE MSR, and if so it now disables APIC_BASE.
Previously we would leave APIC_BASE enabled, and that made some
BIOSen unhappy.

The SMP reboot code calls disable_local_APIC(). On SMP HW there is
no change since detect_init_APIC() isn't called and APIC_BASE isn't
enabled by us. An SMP kernel on UP HW behaves just like an UP_APIC
kernel, so it disables APIC_BASE if we enabled it at boot.

The UP_APIC disable-before-suspend code is simplified since the existing
code to disable APIC_BASE is moved into disable_local_APIC().

(Felix Kühling originally reported the BIOS reboot problem. This is a
fixed-up version of his preliminary patch.)

Again, more work to do here..

Remove prototype. It was wrong anyway.

More to do, but its a beginning.

if ki_users = 1, we don't do the wakeup, which seems wrong.

These copies already did a verify_area above.

- Remove unneeded breaks
- Fix double spin_unlock_irqrestore problem