2 * Kernel module for testing static keys.
4 * Copyright 2015 Akamai Technologies Inc. All Rights Reserved
7 * Jason Baron <jbaron@akamai.com>
9 * This software is licensed under the terms of the GNU General Public
10 * License version 2, as published by the Free Software Foundation, and
11 * may be copied, distributed, and modified under those terms.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
19 #include <linux/module.h>
20 #include <linux/jump_label.h>
23 struct static_key old_true_key = STATIC_KEY_INIT_TRUE;
24 struct static_key old_false_key = STATIC_KEY_INIT_FALSE;
27 DEFINE_STATIC_KEY_TRUE(true_key);
28 DEFINE_STATIC_KEY_FALSE(false_key);
31 extern struct static_key base_old_true_key;
32 extern struct static_key base_inv_old_true_key;
33 extern struct static_key base_old_false_key;
34 extern struct static_key base_inv_old_false_key;
37 extern struct static_key_true base_true_key;
38 extern struct static_key_true base_inv_true_key;
39 extern struct static_key_false base_false_key;
40 extern struct static_key_false base_inv_false_key;
45 struct static_key *key;
46 bool (*test_key)(void);
49 #define test_key_func(key, branch) \
50 ({bool func(void) { return branch(key); } func; })
52 static void invert_key(struct static_key *key)
54 if (static_key_enabled(key))
55 static_key_disable(key);
57 static_key_enable(key);
60 static void invert_keys(struct test_key *keys, int size)
62 struct static_key *previous = NULL;
65 for (i = 0; i < size; i++) {
66 if (previous != keys[i].key) {
67 invert_key(keys[i].key);
68 previous = keys[i].key;
73 static int verify_keys(struct test_key *keys, int size, bool invert)
78 for (i = 0; i < size; i++) {
79 ret = static_key_enabled(keys[i].key);
80 init = keys[i].init_state;
81 if (ret != (invert ? !init : init))
83 ret = keys[i].test_key();
84 if (static_key_enabled(keys[i].key)) {
95 static int __init test_static_key_init(void)
100 struct test_key static_key_tests[] = {
101 /* internal keys - old keys */
104 .key = &old_true_key,
105 .test_key = test_key_func(&old_true_key, static_key_true),
109 .key = &old_false_key,
110 .test_key = test_key_func(&old_false_key, static_key_false),
112 /* internal keys - new keys */
115 .key = &true_key.key,
116 .test_key = test_key_func(&true_key, static_branch_likely),
120 .key = &true_key.key,
121 .test_key = test_key_func(&true_key, static_branch_unlikely),
125 .key = &false_key.key,
126 .test_key = test_key_func(&false_key, static_branch_likely),
130 .key = &false_key.key,
131 .test_key = test_key_func(&false_key, static_branch_unlikely),
133 /* external keys - old keys */
136 .key = &base_old_true_key,
137 .test_key = test_key_func(&base_old_true_key, static_key_true),
141 .key = &base_inv_old_true_key,
142 .test_key = test_key_func(&base_inv_old_true_key, static_key_true),
146 .key = &base_old_false_key,
147 .test_key = test_key_func(&base_old_false_key, static_key_false),
151 .key = &base_inv_old_false_key,
152 .test_key = test_key_func(&base_inv_old_false_key, static_key_false),
154 /* external keys - new keys */
157 .key = &base_true_key.key,
158 .test_key = test_key_func(&base_true_key, static_branch_likely),
162 .key = &base_true_key.key,
163 .test_key = test_key_func(&base_true_key, static_branch_unlikely),
167 .key = &base_inv_true_key.key,
168 .test_key = test_key_func(&base_inv_true_key, static_branch_likely),
172 .key = &base_inv_true_key.key,
173 .test_key = test_key_func(&base_inv_true_key, static_branch_unlikely),
177 .key = &base_false_key.key,
178 .test_key = test_key_func(&base_false_key, static_branch_likely),
182 .key = &base_false_key.key,
183 .test_key = test_key_func(&base_false_key, static_branch_unlikely),
187 .key = &base_inv_false_key.key,
188 .test_key = test_key_func(&base_inv_false_key, static_branch_likely),
192 .key = &base_inv_false_key.key,
193 .test_key = test_key_func(&base_inv_false_key, static_branch_unlikely),
197 size = ARRAY_SIZE(static_key_tests);
199 ret = verify_keys(static_key_tests, size, false);
203 invert_keys(static_key_tests, size);
204 ret = verify_keys(static_key_tests, size, true);
208 invert_keys(static_key_tests, size);
209 ret = verify_keys(static_key_tests, size, false);
217 static void __exit test_static_key_exit(void)
221 module_init(test_static_key_init);
222 module_exit(test_static_key_exit);
224 MODULE_AUTHOR("Jason Baron <jbaron@akamai.com>");
225 MODULE_LICENSE("GPL");