1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2017 Joe Lawrence <joe.lawrence@redhat.com>
4 */
5
6/*
7 * livepatch-callbacks-busymod.c - (un)patching callbacks demo support module
8 *
9 *
10 * Purpose
11 * -------
12 *
13 * Simple module to demonstrate livepatch (un)patching callbacks.
14 *
15 *
16 * Usage
17 * -----
18 *
19 * This module is not intended to be standalone. See the "Usage"
20 * section of livepatch-callbacks-mod.c.
21 */
22
23#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24
25#include <linux/module.h>
26#include <linux/kernel.h>
27#include <linux/workqueue.h>
28#include <linux/delay.h>
29
30static int sleep_secs;
31module_param(sleep_secs, int, 0644);
32MODULE_PARM_DESC(sleep_secs, "sleep_secs (default=0)");
33
34static void busymod_work_func(struct work_struct *work);
35static DECLARE_DELAYED_WORK(work, busymod_work_func);
36
37static void busymod_work_func(struct work_struct *work)
38{
39 pr_info("%s, sleeping %d seconds ...\n", __func__, sleep_secs);
40 msleep(msecs: sleep_secs * 1000);
41 pr_info("%s exit\n", __func__);
42}
43
44static int livepatch_callbacks_mod_init(void)
45{
46 pr_info("%s\n", __func__);
47 schedule_delayed_work(dwork: &work,
48 delay: msecs_to_jiffies(m: 1000 * 0));
49 return 0;
50}
51
52static void livepatch_callbacks_mod_exit(void)
53{
54 cancel_delayed_work_sync(dwork: &work);
55 pr_info("%s\n", __func__);
56}
57
58module_init(livepatch_callbacks_mod_init);
59module_exit(livepatch_callbacks_mod_exit);
60MODULE_LICENSE("GPL");
61

source code of linux/samples/livepatch/livepatch-callbacks-busymod.c