The faults Secure HardFault, Secure MemManage, BusFault and SecureFault may indicate corruption of secure state. They should be given priority less than 0x80 and their handlers implemented to not return, to prevent Non-secure from being able to execute in such a situation.

This is the current default platform behaviour anyway, but implementing it this way in common arch code with documented justification will ensure the right behaviour on all platforms.