On Tue, 23 Sep 2003, Chuck Silvers wrote:

> what's the actual problem with the fault handler if stack vm_map entries
> are merged with non-stack ones?  it would seem better to just remove
> assumptions about vm_map layout from the fault-handler code, then
> merging stack and non-stack entries would be fine.  I'd rather not
> special-case this if it's not necessary.

If I'm understanding Andrew right, the difference is that stack mappings
have different growth semanitcs from non-stack mappings. The former (well
the lowest one) can grow when the stack hits its bottom. The latter can
only grow as a result of explicit system calls to map more memory. Thus if
you access just below a mapping, you either want to grow it or return an
error, depending on if it's a stack or not.

This assumes I'm understanding Andrew right. :-)

Take care,

Bill