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 | |
10 | static int pre_patch_ret; |
11 | module_param(pre_patch_ret, int, 0644); |
12 | MODULE_PARM_DESC(pre_patch_ret, "pre_patch_ret (default=0)" ); |
13 | |
14 | static 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 | |
21 | static 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) */ |
31 | static int pre_patch_callback(struct klp_object *obj) |
32 | { |
33 | callback_info(callback: __func__, obj); |
34 | return pre_patch_ret; |
35 | } |
36 | |
37 | /* Executed on object unpatching (ie, patch disablement) */ |
38 | static void post_patch_callback(struct klp_object *obj) |
39 | { |
40 | callback_info(callback: __func__, obj); |
41 | } |
42 | |
43 | /* Executed on object unpatching (ie, patch disablement) */ |
44 | static void pre_unpatch_callback(struct klp_object *obj) |
45 | { |
46 | callback_info(callback: __func__, obj); |
47 | } |
48 | |
49 | /* Executed on object unpatching (ie, patch disablement) */ |
50 | static void post_unpatch_callback(struct klp_object *obj) |
51 | { |
52 | callback_info(callback: __func__, obj); |
53 | } |
54 | |
55 | static void patched_work_func(struct work_struct *work) |
56 | { |
57 | pr_info("%s\n" , __func__); |
58 | } |
59 | |
60 | static struct klp_func no_funcs[] = { |
61 | {} |
62 | }; |
63 | |
64 | static struct klp_func busymod_funcs[] = { |
65 | { |
66 | .old_name = "busymod_work_func" , |
67 | .new_func = patched_work_func, |
68 | }, {} |
69 | }; |
70 | |
71 | static 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 | |
102 | static struct klp_patch patch = { |
103 | .mod = THIS_MODULE, |
104 | .objs = objs, |
105 | }; |
106 | |
107 | static int test_klp_callbacks_demo_init(void) |
108 | { |
109 | return klp_enable_patch(&patch); |
110 | } |
111 | |
112 | static void test_klp_callbacks_demo_exit(void) |
113 | { |
114 | } |
115 | |
116 | module_init(test_klp_callbacks_demo_init); |
117 | module_exit(test_klp_callbacks_demo_exit); |
118 | MODULE_LICENSE("GPL" ); |
119 | MODULE_INFO(livepatch, "Y" ); |
120 | MODULE_AUTHOR("Joe Lawrence <joe.lawrence@redhat.com>" ); |
121 | MODULE_DESCRIPTION("Livepatch test: livepatch demo" ); |
122 | |