--- zzzz-none-000/linux-4.4.271/kernel/pid.c	2021-06-03 06:22:09.000000000 +0000
+++ hawkeye-5590-750/linux-4.4.271/kernel/pid.c	2023-04-19 10:22:30.000000000 +0000
@@ -433,6 +433,7 @@
 	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)
 {