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a2818ee4 JL |
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(__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(__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(__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(__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"); |