Actually, this isn't a good idea: linux would have to check why the

protection error happened, and I don't think that is necessary or even

something we want it to do.  The current kernel setup just sees an error

it cannot handle, so it sends a SIGSEGV.  No special cases, no chacks

why it happened etc. 
One good (or at least better) argument for SIGBUS being included (and

one I have been thinking about) is that a 486 actually has an alignment

trap, which under sysv-386 does seem to result in a SIGBUS (not that I

have tried: just read about it somewhere).  I haven't bothered about it,

as I think the alignment trap is disabled under linux anyway.  Besides,

I don't see any reason for an alignment fault unless the processor

really isn't able to handle unaligned transfers - but a 486 is perfectly

capable of doing them, even if they are a bit slower.  And gcc generally

doesn't generate such code anyway. 
                Linus