> > I asked about the address space! Since the code assumes that the L2 PTE
> > array is contiguous.....
> 
> That sounds like a bug.

On reflection, maybe not.  IIRC the page tables for the current process 
are mapped linearly at PROCESS_PAGE_TBLS_BASE.  So they are there in an 
single array.  What happens if a physical page is missing from that map 
and we try to dereference it, I've no idea.  I hope we won't end up 
mapping one in, just so that we can decide that it doesn't contain a valid 
mapping.

R.