Re: mmap'ing /dev/null

[Thomas Bushnell, BSG]

"Jamie Gennis" <jgennis@mindspring.com> writes:

> I'm new to the hurd and have been browsing around the source tree
> trying to become familiar with how things work in there.  I came
> across an "/* XXX should work! */" in trans/null.c's S_io_map() and
> thought this might be a good place to start coding something.
> However, I'm not sure what the behavior for mmap'ing /dev/null
> should be, and Marcus said to ask here.

Well, that's part of the problem, and why it should work but doesn't!

Each different mapper of /dev/null should get a different memory
object which maps anonymous memory.  That requires adding a new
interface to the default pager to allow the creation of anonymous
objects.  (There is an interface now; maybe it would work.)