1 /* 2 * Copyright (C) 2017 Joe Lawrence <joe.lawrence@redhat.com> 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 2 7 * of the License, or (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, see <http://www.gnu.org/licenses/>. 16 */ 17 18 /* 19 * livepatch-callbacks-busymod.c - (un)patching callbacks demo support module 20 * 21 * 22 * Purpose 23 * ------- 24 * 25 * Simple module to demonstrate livepatch (un)patching callbacks. 26 * 27 * 28 * Usage 29 * ----- 30 * 31 * This module is not intended to be standalone. See the "Usage" 32 * section of livepatch-callbacks-mod.c. 33 */ 34 35 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 36 37 #include <linux/module.h> 38 #include <linux/kernel.h> 39 #include <linux/workqueue.h> 40 #include <linux/delay.h> 41 42 static int sleep_secs; 43 module_param(sleep_secs, int, 0644); 44 MODULE_PARM_DESC(sleep_secs, "sleep_secs (default=0)"); 45 46 static void busymod_work_func(struct work_struct *work); 47 static DECLARE_DELAYED_WORK(work, busymod_work_func); 48 49 static void busymod_work_func(struct work_struct *work) 50 { 51 pr_info("%s, sleeping %d seconds ...\n", __func__, sleep_secs); 52 msleep(sleep_secs * 1000); 53 pr_info("%s exit\n", __func__); 54 } 55 56 static int livepatch_callbacks_mod_init(void) 57 { 58 pr_info("%s\n", __func__); 59 schedule_delayed_work(&work, 60 msecs_to_jiffies(1000 * 0)); 61 return 0; 62 } 63 64 static void livepatch_callbacks_mod_exit(void) 65 { 66 cancel_delayed_work_sync(&work); 67 pr_info("%s\n", __func__); 68 } 69 70 module_init(livepatch_callbacks_mod_init); 71 module_exit(livepatch_callbacks_mod_exit); 72 MODULE_LICENSE("GPL"); 73