FreeBSD by Sean Eric Fagan, but a bit different. This makes the checks
in the same places as sef's FreeBSD patch, but does not hardcode the
"kmem" group into the kernel, and also does a check identical to the
(3) and (4) checks in the NetBSD ptrace(2):
(1) it's not owned by you, or is set-id on exec (unless
you're root), or
(2) it's init, which controls the security level of the
entire system, and the system was not compiled with
permanently insecure mode turned on.
