linux-kernel-module-cheat/packages/kernel_modules/userland/time_boot.c

/* https://github.com/cirosantilli/linux-kernel-module-cheat#time_boot-out */

#include <stdio.h>
#include <unistd.h>

int main(void) {
    FILE *fp;
    fp = fopen("/dev/kmsg", "w");
	fputs(__FILE__ "\n", fp);
	fclose(fp);
	while (1)
		sleep(0xFFFFFFFF);
}