lkmpg/examples/hello-1.c

/*
 * hello-1.c - The simplest kernel module.
 */
#include <linux/kernel.h> /* Needed for pr_info() */
#include <linux/module.h> /* Needed by all modules */

int init_module(void)
{
    pr_info("Hello world 1.\n");

    /* A non 0 return means init_module failed; module can't be loaded. */
    return 0;
}

void cleanup_module(void)
{
    pr_info("Goodbye world 1.\n");
}

MODULE_LICENSE("GPL");
Add LaTeX script and sample code 2021-07-22 06:35:24 +08:00			`/*`
Apply editorial changes This patch makes source listing shorter and more compact, that helps when browsing. 2021-08-08 01:24:59 +08:00			`* hello-1.c - The simplest kernel module.`
Add LaTeX script and sample code 2021-07-22 06:35:24 +08:00			`*/`
Mention pr_info() rather than KERN_INFO The latter might have been used along with printk() in an earlier version, but pr_info() is getting used consistently so adjust the #include comments accordingly. For the avoidance of doubt, pr_info() actually comes from printk.h, which gets #include'd by kernel.h. 2021-08-17 03:02:55 +08:00			`#include <linux/kernel.h> /* Needed for pr_info() */`
Enforce the customized style for example code Instead of using tab for indention, the style defaults to 4 spaces for the sake of compact layout. 2021-07-22 06:58:13 +08:00			`#include <linux/module.h> /* Needed by all modules */`
Add LaTeX script and sample code 2021-07-22 06:35:24 +08:00
			`int init_module(void)`
			`{`
			`pr_info("Hello world 1.\n");`

Drop the deprecated init_module() and cleanup_module() 2021-08-08 00:29:24 +08:00			`/* A non 0 return means init_module failed; module can't be loaded. */`
Add LaTeX script and sample code 2021-07-22 06:35:24 +08:00			`return 0;`
			`}`

			`void cleanup_module(void)`
			`{`
			`pr_info("Goodbye world 1.\n");`
			`}`

			`MODULE_LICENSE("GPL");`