LXR linux/samples/livepatch/livepatch-callbacks-busymod.c

   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(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(&work,
  48                msecs_to_jiffies(1000 * 0));
  49        return 0;
  50}
  51
  52static void livepatch_callbacks_mod_exit(void)
  53{
  54        cancel_delayed_work_sync(&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