在 Kernel 2.4 或以上版本，在編譯模組完成，要進行 load module 之前，你會發現底下訊息：
# insmod hello-3.o
Warning: loading hello-3.o will taint the kernel: no license
See http://www.tux.org/lkml/#export-tainted for information about tainted modules
很顯然這訊息是要您在 kernel module 裡面加上版權宣告，例如："GPL"，"GPL v2"…等來宣告您的 module 並非 open source，利用
MODULE_LICENSE() 巨集來宣告程式 License，同樣的，可以用 MODULE_DESCRIPTION() 來描述此模組或者是 Driver 的功用跟簡介，以及用 MODULE_AUTHOR() 來定義此模組作者，這些巨集都可以在 linux/module.h 裡找到，但是這些並非用於 Kernel 本身，如果大家想看範例程式，可以到 drivers/ 資料夾底下觀看每一個 Driver 程式，底下是簡單 hello world 範例：
#include /* pr_info所需 include 檔案*/
#include
#include /* 所有 module 巨集需要檔案*/
#include
static int __init hello_init(void)
{
pr_info("Hello, world appleboy\n");
pr_info("The process is \"%s\" (pid %i)\n", current->comm, current->pid);
return 0;
}
static void __exit hello_exit(void)
{
printk(KERN_INFO "Goodbye\n");
}
MODULE_DESCRIPTION("Hello World !!");/* 此程式介紹與描述*/
MODULE_AUTHOR("Bo-Yi Wu ");/* 此程式作者*/
MODULE_LICENSE("GPL");/* 程式 License*/
module_init(hello_init);
module_exit(hello_exit);
在 linux/module.h 裡頭，可以找到 MODULE_LICENSE 可定義的 License
/*
* The following license idents are currently accepted as indicating free
* software modules
*
* "GPL" [GNU Public License v2 or later]
* "GPL v2" [GNU Public License v2]
* "GPL and additional rights" [GNU Public License v2 rights and more]
* "Dual BSD/GPL" [GNU Public License v2
* or BSD license choice]
* "Dual MIT/GPL" [GNU Public License v2
* or MIT license choice]
* "Dual MPL/GPL" [GNU Public License v2
* or Mozilla license choice]
*
* The following other idents are available
*
* "Proprietary" [Non free products]
*
* There are dual licensed components, but when running with Linux it is the
* GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
* is a GPL combined work.
*
* This exists for several reasons
* 1. So modinfo can show license info for users wanting to vet their setup
* is free
* 2. So the community can ignore bug reports including proprietary modules
* 3. So vendors can do likewise based on their own policies
*/
巨集 define:
#define MODULE_LICENSE(_license) MODULE_INFO(license, _license)
/*
* Author(s), use "Name " or just "Name", for multiple
* authors use multiple MODULE_AUTHOR() statements/lines.
*/
#define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
/* What your module does. */
#define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
