From: Martin Schwidefsky <schwidefsky@de.ibm.com>
From: Ulrich Weigand <uweigand@de.ibm.com>

s390 core changes:
 - Add signo between signal frame and the signal return instruction on the
   user stack for backtrace over signal handlers.
 - Add hfp floating point exceptions.
 - Use a single function for region, segment and page translation exceptions.
 - Discard SIGTRAP for single stepped instructions if the trapping instruction
   is repeated (normal memory faults) or if another signal is delivered anyway.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>