--- zzzz-none-000/linux-4.4.60/kernel/pid.c 2017-04-08 07:53:53.000000000 +0000 +++ jet-2400-727/linux-4.4.60/kernel/pid.c 2021-03-17 14:36:41.000000000 +0000 @@ -431,6 +431,7 @@ new->pids[type].pid = old->pids[type].pid; hlist_replace_rcu(&old->pids[type].node, &new->pids[type].node); } +EXPORT_SYMBOL(find_task_by_vpid); struct task_struct *pid_task(struct pid *pid, enum pid_type type) {