http://forums.dds6qkxpwdeubwucdiaord2xgbbeyds25rbsgr73tbfpqpt4a6vjwsyd.onion/t/hardened-kernel-vs-lkrg/10827/2
There is one exception for compatibility reasons: Protected process might fork itself and for the security reasons if this ever happens, child must be automatically protected as well. Because mother and child often must communicate with each other, every protected process might interact with each other using official API.