freebsd stable - Dec 2016 - Is System V IPC namespace still shared across jails?

Regarding installation of PostgreSQL in a FreeBSD jail, the web hold 
plenty of
warnings/advice that each postgres instance should have a unique UID, 
otherwise
they stumble across each other's feet:

| allow.sysvipc
|   A process within the jail has access to System V IPC primitives. In 
the
| current jail implementation, System V primitives share a single 
namespace
| across the host and jail environments, meaning that processes within a 
jail
| would be able to communicate with (and potentially interfere with) 
processes
| outside of the jail, and in other jails.


Is this still the case in FreeBSD 11.0 ???

I remember hearing rumors that the System V namespace
no longer is (will?) be shared across jails.
(Couldn't find it being mentioned in release notes.)

   Mark

With the new jail parameters, new namespaces for SysV IPC are possible
on FreeBSD 11.

For those ezjail users, add something like this to the jail's config
after creating it using 'ezjail-admin create':

 export jail_postgres_parameters="sysvmsg=new sysvsem=new sysvshm=new"

Cheers,

  Christian

---

man 8 jail
>  ...
>
>  allow.sysvipc
>       A process within the jail has access to System V IPC
>       primitives.  This is deprecated in favor of the per-
>       module parameters (see below).  When this parameter is
>       set, it is equivalent to setting sysvmsg, sysvsem, and
>       sysvshm all to ``inherit''.
>
>  ...
>
>    sysvmsg
>       Allow access to SYSV IPC message primitives.  If set to
>       ``inherit'', all IPC objects on the system are visible to
this
>       jail, whether they were created by the jail itself, the base
>       system, or other jails.  If set to ``new'', the jail will
have
>       its own key namespace, and can only see the objects that it has
>       created; the system (or parent jail) has access to the jail's
>       objects, but not to its keys.  If set to ``disable'', the
jail
>       cannot perform any sysvmsg-related system calls.
>
>     sysvsem, sysvshm
>       Allow access to SYSV IPC semaphore and shared memory primitives,
>       in the same manner as sysvmsg.
>
>  ...