/* * This module emits "Hello, world" on printk when loaded. * * It is designed to be used for basic evaluation of the module loading * subsystem (for example when validating module signing/verification). It * lacks any extra dependencies, and will not normally be loaded by the * system unless explicitly requested by name. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/init.h>#include <linux/module.h>#include <linux/printk.h> static int __init test_module_init(void){	pr_warn("Hello, world\n"); 	return 0;} module_init(test_module_init); static void __exit test_module_exit(void){	pr_warn("Goodbye\n");} module_exit(test_module_exit); MODULE_AUTHOR("Kees Cook <keescook@chromium.org>");MODULE_LICENSE("GPL");