Re: Different roots for each process possible?

[nisse@lysator.liu.se (Niels Möller)]

Roland McGrath <frob@debian.org> writes:

> > Why are root privileges needed for chroot. 
> 
> There is no such requirement in the Hurd.

Hmm. On Unix, the reason why chroot requiers special privileges, is
that if you are inside a chroot prison and is allowed to call chroot,
you can do

  cd /       # Get to the top of the prison.
  mkdir foo
  chroot foo # Lower the ceiling.
  cd ..      # We're above the ceiling, so just fly away.

How does the Hurd handle this problem? Does chroot change both the
root and all ports (possibly including the working directory) that
refer to directories outside of the new root? Or do you keep a stack
of all previous roots?

/Niels