[PATCH] IPC namespace - utils

This patch adds basic IPC namespace functionality to
IPC utils:
- init_ipc_ns
- copy/clone/unshare/free IPC ns
- /proc preparations

Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

kernel/fork.c

@@ -1589,6 +1589,16 @@ static int unshare_semundo(unsigned long unshare_flags, struct sem_undo_list **n
 	return 0;
 }
 
+#ifndef CONFIG_IPC_NS
+static inline int unshare_ipcs(unsigned long flags, struct ipc_namespace **ns)
+{
+	if (flags & CLONE_NEWIPC)
+		return -EINVAL;
+
+	return 0;
+}
+#endif
+
 /*
  * unshare allows a process to 'unshare' part of the process
  * context which was originally shared using clone.  copy_*