test_static_keys.c 5.6 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Kernel module for testing static keys.
  4. *
  5. * Copyright 2015 Akamai Technologies Inc. All Rights Reserved
  6. *
  7. * Authors:
  8. * Jason Baron <jbaron@akamai.com>
  9. */
  10. #include <linux/module.h>
  11. #include <linux/jump_label.h>
  12. /* old keys */
  13. struct static_key old_true_key = STATIC_KEY_INIT_TRUE;
  14. struct static_key old_false_key = STATIC_KEY_INIT_FALSE;
  15. /* new api */
  16. DEFINE_STATIC_KEY_TRUE(true_key);
  17. DEFINE_STATIC_KEY_FALSE(false_key);
  18. /* external */
  19. extern struct static_key base_old_true_key;
  20. extern struct static_key base_inv_old_true_key;
  21. extern struct static_key base_old_false_key;
  22. extern struct static_key base_inv_old_false_key;
  23. /* new api */
  24. extern struct static_key_true base_true_key;
  25. extern struct static_key_true base_inv_true_key;
  26. extern struct static_key_false base_false_key;
  27. extern struct static_key_false base_inv_false_key;
  28. struct test_key {
  29. bool init_state;
  30. struct static_key *key;
  31. bool (*test_key)(void);
  32. };
  33. #define test_key_func(key, branch) \
  34. static bool key ## _ ## branch(void) \
  35. { \
  36. return branch(&key); \
  37. }
  38. static void invert_key(struct static_key *key)
  39. {
  40. if (static_key_enabled(key))
  41. static_key_disable(key);
  42. else
  43. static_key_enable(key);
  44. }
  45. static void invert_keys(struct test_key *keys, int size)
  46. {
  47. struct static_key *previous = NULL;
  48. int i;
  49. for (i = 0; i < size; i++) {
  50. if (previous != keys[i].key) {
  51. invert_key(keys[i].key);
  52. previous = keys[i].key;
  53. }
  54. }
  55. }
  56. static int verify_keys(struct test_key *keys, int size, bool invert)
  57. {
  58. int i;
  59. bool ret, init;
  60. for (i = 0; i < size; i++) {
  61. ret = static_key_enabled(keys[i].key);
  62. init = keys[i].init_state;
  63. if (ret != (invert ? !init : init))
  64. return -EINVAL;
  65. ret = keys[i].test_key();
  66. if (static_key_enabled(keys[i].key)) {
  67. if (!ret)
  68. return -EINVAL;
  69. } else {
  70. if (ret)
  71. return -EINVAL;
  72. }
  73. }
  74. return 0;
  75. }
  76. test_key_func(old_true_key, static_key_true)
  77. test_key_func(old_false_key, static_key_false)
  78. test_key_func(true_key, static_branch_likely)
  79. test_key_func(true_key, static_branch_unlikely)
  80. test_key_func(false_key, static_branch_likely)
  81. test_key_func(false_key, static_branch_unlikely)
  82. test_key_func(base_old_true_key, static_key_true)
  83. test_key_func(base_inv_old_true_key, static_key_true)
  84. test_key_func(base_old_false_key, static_key_false)
  85. test_key_func(base_inv_old_false_key, static_key_false)
  86. test_key_func(base_true_key, static_branch_likely)
  87. test_key_func(base_true_key, static_branch_unlikely)
  88. test_key_func(base_inv_true_key, static_branch_likely)
  89. test_key_func(base_inv_true_key, static_branch_unlikely)
  90. test_key_func(base_false_key, static_branch_likely)
  91. test_key_func(base_false_key, static_branch_unlikely)
  92. test_key_func(base_inv_false_key, static_branch_likely)
  93. test_key_func(base_inv_false_key, static_branch_unlikely)
  94. static int __init test_static_key_init(void)
  95. {
  96. int ret;
  97. int size;
  98. struct test_key static_key_tests[] = {
  99. /* internal keys - old keys */
  100. {
  101. .init_state = true,
  102. .key = &old_true_key,
  103. .test_key = &old_true_key_static_key_true,
  104. },
  105. {
  106. .init_state = false,
  107. .key = &old_false_key,
  108. .test_key = &old_false_key_static_key_false,
  109. },
  110. /* internal keys - new keys */
  111. {
  112. .init_state = true,
  113. .key = &true_key.key,
  114. .test_key = &true_key_static_branch_likely,
  115. },
  116. {
  117. .init_state = true,
  118. .key = &true_key.key,
  119. .test_key = &true_key_static_branch_unlikely,
  120. },
  121. {
  122. .init_state = false,
  123. .key = &false_key.key,
  124. .test_key = &false_key_static_branch_likely,
  125. },
  126. {
  127. .init_state = false,
  128. .key = &false_key.key,
  129. .test_key = &false_key_static_branch_unlikely,
  130. },
  131. /* external keys - old keys */
  132. {
  133. .init_state = true,
  134. .key = &base_old_true_key,
  135. .test_key = &base_old_true_key_static_key_true,
  136. },
  137. {
  138. .init_state = false,
  139. .key = &base_inv_old_true_key,
  140. .test_key = &base_inv_old_true_key_static_key_true,
  141. },
  142. {
  143. .init_state = false,
  144. .key = &base_old_false_key,
  145. .test_key = &base_old_false_key_static_key_false,
  146. },
  147. {
  148. .init_state = true,
  149. .key = &base_inv_old_false_key,
  150. .test_key = &base_inv_old_false_key_static_key_false,
  151. },
  152. /* external keys - new keys */
  153. {
  154. .init_state = true,
  155. .key = &base_true_key.key,
  156. .test_key = &base_true_key_static_branch_likely,
  157. },
  158. {
  159. .init_state = true,
  160. .key = &base_true_key.key,
  161. .test_key = &base_true_key_static_branch_unlikely,
  162. },
  163. {
  164. .init_state = false,
  165. .key = &base_inv_true_key.key,
  166. .test_key = &base_inv_true_key_static_branch_likely,
  167. },
  168. {
  169. .init_state = false,
  170. .key = &base_inv_true_key.key,
  171. .test_key = &base_inv_true_key_static_branch_unlikely,
  172. },
  173. {
  174. .init_state = false,
  175. .key = &base_false_key.key,
  176. .test_key = &base_false_key_static_branch_likely,
  177. },
  178. {
  179. .init_state = false,
  180. .key = &base_false_key.key,
  181. .test_key = &base_false_key_static_branch_unlikely,
  182. },
  183. {
  184. .init_state = true,
  185. .key = &base_inv_false_key.key,
  186. .test_key = &base_inv_false_key_static_branch_likely,
  187. },
  188. {
  189. .init_state = true,
  190. .key = &base_inv_false_key.key,
  191. .test_key = &base_inv_false_key_static_branch_unlikely,
  192. },
  193. };
  194. size = ARRAY_SIZE(static_key_tests);
  195. ret = verify_keys(static_key_tests, size, false);
  196. if (ret)
  197. goto out;
  198. invert_keys(static_key_tests, size);
  199. ret = verify_keys(static_key_tests, size, true);
  200. if (ret)
  201. goto out;
  202. invert_keys(static_key_tests, size);
  203. ret = verify_keys(static_key_tests, size, false);
  204. if (ret)
  205. goto out;
  206. return 0;
  207. out:
  208. return ret;
  209. }
  210. static void __exit test_static_key_exit(void)
  211. {
  212. }
  213. module_init(test_static_key_init);
  214. module_exit(test_static_key_exit);
  215. MODULE_AUTHOR("Jason Baron <jbaron@akamai.com>");
  216. MODULE_LICENSE("GPL");