rtnl_is_locked
extern int rtnl_is_locked(void);
WARN_ONCE(!rtnl_is_locked(), \
return rcu_dereference_protected(gwj->cf_mod, rtnl_is_locked());
if (from_cleanup_net() || rtnl_is_locked())
EXPORT_SYMBOL(rtnl_is_locked);
return rtnl_is_locked() && mutex_is_locked(&net->rtnl_mutex);
WARN_ONCE(!rtnl_is_locked() &&