On Tue, Jul 08, 2014 at 05:54:24PM +0100, David Drysdale wrote:

quoted

How is this implemented in FreeBSD?  I can't find any references to
O_BENEATH_ONLY except for your patchset.

FreeBSD have the relative-only behaviour for openat() relative to a
Capsicum capability dfd [1], and for a process in capability-mode [2],
but they don't have the O_BENEATH_ONLY as a separately-accessible
openat() flag.  However, it seemed like a more widely useful idea so
separating it out was suggested.

In that case we should make sure to use the same name and semantics for
it.  As far as I'm concerned I'd prefer a less clumsy name like
O_BENEATH.