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
30 static int sleep_secs;
31 module_param(sleep_secs, int, 0644);
32 MODULE_PARM_DESC(sleep_secs, "sleep_secs (default=0)");
33
34 static void busymod_work_func(struct work_struct *work);
35 static DECLARE_DELAYED_WORK(work, busymod_work_func);
36
busymod_work_func(struct work_struct * work)37 static void busymod_work_func(struct work_struct *work)
38 {
39 pr_info("%s, sleeping %d seconds ...\n", __func__, sleep_secs);
40 msleep(sleep_secs * 1000);
41 pr_info("%s exit\n", __func__);
42 }
43
livepatch_callbacks_mod_init(void)44 static int livepatch_callbacks_mod_init(void)
45 {
46 pr_info("%s\n", __func__);
47 schedule_delayed_work(&work,
48 msecs_to_jiffies(1000 * 0));
49 return 0;
50 }
51
livepatch_callbacks_mod_exit(void)52 static void livepatch_callbacks_mod_exit(void)
53 {
54 cancel_delayed_work_sync(&work);
55 pr_info("%s\n", __func__);
56 }
57
58 module_init(livepatch_callbacks_mod_init);
59 module_exit(livepatch_callbacks_mod_exit);
60 MODULE_LICENSE("GPL");
61