|  | // SPDX-License-Identifier: GPL-2.0-only | 
|  | /* | 
|  | * 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"); |