linux/lib/livepatch/test_klp_atomic_replace.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0
   2// Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com>
   3
   4#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   5
   6#include <linux/module.h>
   7#include <linux/kernel.h>
   8#include <linux/livepatch.h>
   9
  10static int replace;
  11module_param(replace, int, 0644);
  12MODULE_PARM_DESC(replace, "replace (default=0)");
  13
  14#include <linux/seq_file.h>
  15static int livepatch_meminfo_proc_show(struct seq_file *m, void *v)
  16{
  17        seq_printf(m, "%s: %s\n", THIS_MODULE->name,
  18                   "this has been live patched");
  19        return 0;
  20}
  21
  22static struct klp_func funcs[] = {
  23        {
  24                .old_name = "meminfo_proc_show",
  25                .new_func = livepatch_meminfo_proc_show,
  26        }, {}
  27};
  28
  29static struct klp_object objs[] = {
  30        {
  31                /* name being NULL means vmlinux */
  32                .funcs = funcs,
  33        }, {}
  34};
  35
  36static struct klp_patch patch = {
  37        .mod = THIS_MODULE,
  38        .objs = objs,
  39        /* set .replace in the init function below for demo purposes */
  40};
  41
  42static int test_klp_atomic_replace_init(void)
  43{
  44        patch.replace = replace;
  45        return klp_enable_patch(&patch);
  46}
  47
  48static void test_klp_atomic_replace_exit(void)
  49{
  50}
  51
  52module_init(test_klp_atomic_replace_init);
  53module_exit(test_klp_atomic_replace_exit);
  54MODULE_LICENSE("GPL");
  55MODULE_INFO(livepatch, "Y");
  56MODULE_AUTHOR("Joe Lawrence <joe.lawrence@redhat.com>");
  57MODULE_DESCRIPTION("Livepatch test: atomic replace");
  58