mm: added last_pagefault handling when mm_space_t is unmapped
mm: fixed styling inconsistencies, fixed last pagefault range removal
mm: fix unitialized last_pagefault member in slab data
mm_fork_context() currently maps shared chdev mappings 1:1 when forking
a range. The issue with this approach is that chdev mappings are not
guaranteed to be backed by physical memory, and thus cannot safely be
refcounted. This can lead to issues on devices with more complex buffer
lifetimes.
To allow for internal book-keeping, do not map shared chdev memory on
fork and instead allow it to go through the entire fault-in process
again.
Matheus