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 replace;
  11module_param(replace, int, 0644);
  12MODULE_PARM_DESC(replace, "replace (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 0;
  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 struct klp_func no_funcs[] = {
  56        { }
  57};
  58
  59static struct klp_object objs[] = {
  60        {
  61                .name = NULL,   /* vmlinux */
  62                .funcs = no_funcs,
  63                .callbacks = {
  64                        .pre_patch = pre_patch_callback,
  65                        .post_patch = post_patch_callback,
  66                        .pre_unpatch = pre_unpatch_callback,
  67                        .post_unpatch = post_unpatch_callback,
  68                },
  69        }, { }
  70};
  71
  72static struct klp_patch patch = {
  73        .mod = THIS_MODULE,
  74        .objs = objs,
  75        /* set .replace in the init function below for demo purposes */
  76};
  77
  78static int test_klp_callbacks_demo2_init(void)
  79{
  80        patch.replace = replace;
  81        return klp_enable_patch(&patch);
  82}
  83
  84static void test_klp_callbacks_demo2_exit(void)
  85{
  86}
  87
  88module_init(test_klp_callbacks_demo2_init);
  89module_exit(test_klp_callbacks_demo2_exit);
  90MODULE_LICENSE("GPL");
  91MODULE_INFO(livepatch, "Y");
  92MODULE_AUTHOR("Joe Lawrence <joe.lawrence@redhat.com>");
  93MODULE_DESCRIPTION("Livepatch test: livepatch demo2");
  94