1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun // Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com>
3*4882a593Smuzhiyun
4*4882a593Smuzhiyun #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
5*4882a593Smuzhiyun
6*4882a593Smuzhiyun #include <linux/module.h>
7*4882a593Smuzhiyun #include <linux/kernel.h>
8*4882a593Smuzhiyun #include <linux/livepatch.h>
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun static int replace;
11*4882a593Smuzhiyun module_param(replace, int, 0644);
12*4882a593Smuzhiyun MODULE_PARM_DESC(replace, "replace (default=0)");
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun static const char *const module_state[] = {
15*4882a593Smuzhiyun [MODULE_STATE_LIVE] = "[MODULE_STATE_LIVE] Normal state",
16*4882a593Smuzhiyun [MODULE_STATE_COMING] = "[MODULE_STATE_COMING] Full formed, running module_init",
17*4882a593Smuzhiyun [MODULE_STATE_GOING] = "[MODULE_STATE_GOING] Going away",
18*4882a593Smuzhiyun [MODULE_STATE_UNFORMED] = "[MODULE_STATE_UNFORMED] Still setting it up",
19*4882a593Smuzhiyun };
20*4882a593Smuzhiyun
callback_info(const char * callback,struct klp_object * obj)21*4882a593Smuzhiyun static void callback_info(const char *callback, struct klp_object *obj)
22*4882a593Smuzhiyun {
23*4882a593Smuzhiyun if (obj->mod)
24*4882a593Smuzhiyun pr_info("%s: %s -> %s\n", callback, obj->mod->name,
25*4882a593Smuzhiyun module_state[obj->mod->state]);
26*4882a593Smuzhiyun else
27*4882a593Smuzhiyun pr_info("%s: vmlinux\n", callback);
28*4882a593Smuzhiyun }
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun /* Executed on object patching (ie, patch enablement) */
pre_patch_callback(struct klp_object * obj)31*4882a593Smuzhiyun static int pre_patch_callback(struct klp_object *obj)
32*4882a593Smuzhiyun {
33*4882a593Smuzhiyun callback_info(__func__, obj);
34*4882a593Smuzhiyun return 0;
35*4882a593Smuzhiyun }
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun /* Executed on object unpatching (ie, patch disablement) */
post_patch_callback(struct klp_object * obj)38*4882a593Smuzhiyun static void post_patch_callback(struct klp_object *obj)
39*4882a593Smuzhiyun {
40*4882a593Smuzhiyun callback_info(__func__, obj);
41*4882a593Smuzhiyun }
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun /* Executed on object unpatching (ie, patch disablement) */
pre_unpatch_callback(struct klp_object * obj)44*4882a593Smuzhiyun static void pre_unpatch_callback(struct klp_object *obj)
45*4882a593Smuzhiyun {
46*4882a593Smuzhiyun callback_info(__func__, obj);
47*4882a593Smuzhiyun }
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun /* Executed on object unpatching (ie, patch disablement) */
post_unpatch_callback(struct klp_object * obj)50*4882a593Smuzhiyun static void post_unpatch_callback(struct klp_object *obj)
51*4882a593Smuzhiyun {
52*4882a593Smuzhiyun callback_info(__func__, obj);
53*4882a593Smuzhiyun }
54*4882a593Smuzhiyun
55*4882a593Smuzhiyun static struct klp_func no_funcs[] = {
56*4882a593Smuzhiyun { }
57*4882a593Smuzhiyun };
58*4882a593Smuzhiyun
59*4882a593Smuzhiyun static struct klp_object objs[] = {
60*4882a593Smuzhiyun {
61*4882a593Smuzhiyun .name = NULL, /* vmlinux */
62*4882a593Smuzhiyun .funcs = no_funcs,
63*4882a593Smuzhiyun .callbacks = {
64*4882a593Smuzhiyun .pre_patch = pre_patch_callback,
65*4882a593Smuzhiyun .post_patch = post_patch_callback,
66*4882a593Smuzhiyun .pre_unpatch = pre_unpatch_callback,
67*4882a593Smuzhiyun .post_unpatch = post_unpatch_callback,
68*4882a593Smuzhiyun },
69*4882a593Smuzhiyun }, { }
70*4882a593Smuzhiyun };
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun static struct klp_patch patch = {
73*4882a593Smuzhiyun .mod = THIS_MODULE,
74*4882a593Smuzhiyun .objs = objs,
75*4882a593Smuzhiyun /* set .replace in the init function below for demo purposes */
76*4882a593Smuzhiyun };
77*4882a593Smuzhiyun
test_klp_callbacks_demo2_init(void)78*4882a593Smuzhiyun static int test_klp_callbacks_demo2_init(void)
79*4882a593Smuzhiyun {
80*4882a593Smuzhiyun patch.replace = replace;
81*4882a593Smuzhiyun return klp_enable_patch(&patch);
82*4882a593Smuzhiyun }
83*4882a593Smuzhiyun
test_klp_callbacks_demo2_exit(void)84*4882a593Smuzhiyun static void test_klp_callbacks_demo2_exit(void)
85*4882a593Smuzhiyun {
86*4882a593Smuzhiyun }
87*4882a593Smuzhiyun
88*4882a593Smuzhiyun module_init(test_klp_callbacks_demo2_init);
89*4882a593Smuzhiyun module_exit(test_klp_callbacks_demo2_exit);
90*4882a593Smuzhiyun MODULE_LICENSE("GPL");
91*4882a593Smuzhiyun MODULE_INFO(livepatch, "Y");
92*4882a593Smuzhiyun MODULE_AUTHOR("Joe Lawrence <joe.lawrence@redhat.com>");
93*4882a593Smuzhiyun MODULE_DESCRIPTION("Livepatch test: livepatch demo2");
94