Lockdep is needed for proving the spinlocks and rwlocks work fine on our
platform. It also requires calling the trace_hardirqs_off() and
trace_hardirqs_on() pair of routines when entering and exiting an
interrupt.
For OpenRISC the interrupt stack frame does not support frame pointers,
so to call trace_hardirqs_on() and trace_hardirqs_off() here the macro's
build up a stack frame each time.
There is one necessary small change in _sys_call_handler to move
interrupt enabling later so they can get re-enabled during syscall
restart. This was done to fix lockdep warnings that are now possible due
to this
patch.
Signed-off-by: Stafford Horne <shorne@gmail.com>
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