I think this circuit will work for limit switches in an h bridge (the switches need to be NC rather than the shown NO though). With no limit switch tripped, the h bridge operates as usual, when a limit switch is tripped the diodes (which need to be able to take the motor current) block movement in the limit switch direction but allow movement the other way. That said, software failure is probably a low probability event and the software version may be just fine and a lot easier.
edit: corrected the diodes as they were wrong ...
Peter