> One could still implement copy-on-write using segmentation.
> Only, instead of duplicating the pages as they are written, the data
> segment needed to be duplicated all at once.
> The only problem would be if the parent process wrote something in the
> memory immediately after the fork().
> (now, thinking about that, it's pretty likely that the parent does
> that)

In fact, it is absolutely certain that both processes will modify their
memory. At some point they will call either exec or exit, which causes
the return address to be pushed on the stack which would trigger a copy.

--
With kind regards,
Erik van der Kouwe