/* * Copyright (C) 2017 Joe Lawrence <joe.lawrence@redhat.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see <http://www.gnu.org/licenses/>. */ /* * livepatch-callbacks-busymod.c - (un)patching callbacks demo support module * * * Purpose * ------- * * Simple module to demonstrate livepatch (un)patching callbacks. * * * Usage * ----- * * This module is not intended to be standalone. See the "Usage" * section of livepatch-callbacks-mod.c. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/module.h> #include <linux/kernel.h> #include <linux/workqueue.h> #include <linux/delay.h> static int sleep_secs; module_param(sleep_secs, int, 0644); MODULE_PARM_DESC(sleep_secs, "sleep_secs (default=0)"); static void busymod_work_func(struct work_struct *work); static DECLARE_DELAYED_WORK(work, busymod_work_func); static void busymod_work_func(struct work_struct *work) { pr_info("%s, sleeping %d seconds ...\n", __func__, sleep_secs); msleep(sleep_secs * 1000); pr_info("%s exit\n", __func__); } static int livepatch_callbacks_mod_init(void) { pr_info("%s\n", __func__); schedule_delayed_work(&work, msecs_to_jiffies(1000 * 0)); return 0; } static void livepatch_callbacks_mod_exit(void) { cancel_delayed_work_sync(&work); pr_info("%s\n", __func__); } module_init(livepatch_callbacks_mod_init); module_exit(livepatch_callbacks_mod_exit); MODULE_LICENSE("GPL");