PIDFD_NS_CGROUP
if (self->nsfds[PIDFD_NS_CGROUP] >= 0 && unshare(CLONE_NEWCGROUP) < 0) {
if (self->nsfds[PIDFD_NS_CGROUP] >= 0 && unshare(CLONE_NEWCGROUP) < 0) {
[PIDFD_NS_CGROUP] = { "cgroup", CLONE_NEWCGROUP, PIDFD_GET_CGROUP_NAMESPACE, },