Why could there be an error?

Question

linux

Hello everyone, I am writing a kernel module, using the kill_pid function, but the following error occurs:

error: implicit declaration of function ‘kill_pid’; did you mean ‘si_pid’? [-Werror=implicit-function-declaration]
   kill_pid(task_pid(current_pr), SIGCONT, 1);

Those who know, tell me what to do, I looked that this function is located in include/linux/sched/signal.h

Answer 1

Add to code
#include <linux/sched/signal.h>