Aaro says:
> With spinlock debugs enabled I get might_sleep() warnings when using
> ptrace.
tracked down to a missing enable_irq before calling do_undefinstr().
Reported-by: Aaro Koskinen <aaro.koskinen@nokia.com> Tested-by: Aaro Koskinen <aaro.koskinen@nokia.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>