LXR linux/lib/livepatch/test_klp_callbacks

   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 pre_patch_ret;
  11module_param(pre_patch_ret, int, 0644);
  12MODULE_PARM_DESC(pre_patch_ret, "pre_patch_ret (default=0)");
  13
  14static const char *const module_state[] = {
  15        [MODULE_STATE_LIVE]     = "[MODULE_STATE_LIVE] Normal state",
  16        [MODULE_STATE_COMING]   = "[MODULE_STATE_COMING] Full formed, running module_init",
  17        [MODULE_STATE_GOING]    = "[MODULE_STATE_GOING] Going away",
  18        [MODULE_STATE_UNFORMED] = "[MODULE_STATE_UNFORMED] Still setting it up",
  19};
  20
  21static void callback_info(const char *callback, struct klp_object *obj)
  22{
  23        if (obj->mod)
  24                pr_info("%s: %s -> %s\n", callback, obj->mod->name,
  25                        module_state[obj->mod->state]);
  26        else
  27                pr_info("%s: vmlinux\n", callback);
  28}
  29
  30/* Executed on object patching (ie, patch enablement) */
  31static int pre_patch_callback(struct klp_object *obj)
  32{
  33        callback_info(__func__, obj);
  34        return pre_patch_ret;
  35}
  36
  37/* Executed on object unpatching (ie, patch disablement) */
  38static void post_patch_callback(struct klp_object *obj)
  39{
  40        callback_info(__func__, obj);
  41}
  42
  43/* Executed on object unpatching (ie, patch disablement) */
  44static void pre_unpatch_callback(struct klp_object *obj)
  45{
  46        callback_info(__func__, obj);
  47}
  48
  49/* Executed on object unpatching (ie, patch disablement) */
  50static void post_unpatch_callback(struct klp_object *obj)
  51{
  52        callback_info(__func__, obj);
  53}
  54
  55static void patched_work_func(struct work_struct *work)
  56{
  57        pr_info("%s\n", __func__);
  58}
  59
  60static struct klp_func no_funcs[] = {
  61        {}
  62};
  63
  64static struct klp_func busymod_funcs[] = {
  65        {
  66                .old_name = "busymod_work_func",
  67                .new_func = patched_work_func,
  68        }, {}
  69};
  70
  71static struct klp_object objs[] = {
  72        {
  73                .name = NULL,   /* vmlinux */
  74                .funcs = no_funcs,
  75                .callbacks = {
  76                        .pre_patch = pre_patch_callback,
  77                        .post_patch = post_patch_callback,
  78                        .pre_unpatch = pre_unpatch_callback,
  79                        .post_unpatch = post_unpatch_callback,
  80                },
  81        },      {
  82                .name = "test_klp_callbacks_mod",
  83                .funcs = no_funcs,
  84                .callbacks = {
  85                        .pre_patch = pre_patch_callback,
  86                        .post_patch = post_patch_callback,
  87                        .pre_unpatch = pre_unpatch_callback,
  88                        .post_unpatch = post_unpatch_callback,
  89                },
  90        },      {
  91                .name = "test_klp_callbacks_busy",
  92                .funcs = busymod_funcs,
  93                .callbacks = {
  94                        .pre_patch = pre_patch_callback,
  95                        .post_patch = post_patch_callback,
  96                        .pre_unpatch = pre_unpatch_callback,
  97                        .post_unpatch = post_unpatch_callback,
  98                },
  99        }, { }
 100};
 101
 102static struct klp_patch patch = {
 103        .mod = THIS_MODULE,
 104        .objs = objs,
 105};
 106
 107static int test_klp_callbacks_demo_init(void)
 108{
 109        return klp_enable_patch(&patch);
 110}
 111
 112static void test_klp_callbacks_demo_exit(void)
 113{
 114}
 115
 116module_init(test_klp_callbacks_demo_init);
 117module_exit(test_klp_callbacks_demo_exit);
 118MODULE_LICENSE("GPL");
 119MODULE_INFO(livepatch, "Y");
 120MODULE_AUTHOR("Joe Lawrence <joe.lawrence@redhat.com>");
 121MODULE_DESCRIPTION("Livepatch test: livepatch demo");
 122