[FRIAM] div. zero bugs?

[Marcus G. Daniels]

phil henshaw wrote:
> Are there self-protecting sentinel circuits or routines to catch them 
> in the act and shut them down?  
A couple examples come to mind:

1) floating point hardware knows when calculations have gone bad due to 
underflow, overflow, divide by zero, etc.  The operating system kernel 
can notice these and signal them as exceptions, if the user prefers.  
The sanity checks are in hardware as are the task switching / recovery 
mechanisms for inspecting them.

2) The memory management unit of computer knows about the mapping from 
physical addresses to virtual ones and knows the difference between 
valid and invalid memory addresses.  Addresses can be handed out and 
reclaimed such that bad addresses due to programming mistakes cause 
hardware traps (e.g. the Electric fence malloc library).  A crude form 
of this is for Unix users is the segfault or a bus error signals.