test_klp_callbacks_demo.c 2.9 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. // Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com>
  3. #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  4. #include <linux/module.h>
  5. #include <linux/kernel.h>
  6. #include <linux/livepatch.h>
  7. static int pre_patch_ret;
  8. module_param(pre_patch_ret, int, 0644);
  9. MODULE_PARM_DESC(pre_patch_ret, "pre_patch_ret (default=0)");
  10. static const char *const module_state[] = {
  11. [MODULE_STATE_LIVE] = "[MODULE_STATE_LIVE] Normal state",
  12. [MODULE_STATE_COMING] = "[MODULE_STATE_COMING] Full formed, running module_init",
  13. [MODULE_STATE_GOING] = "[MODULE_STATE_GOING] Going away",
  14. [MODULE_STATE_UNFORMED] = "[MODULE_STATE_UNFORMED] Still setting it up",
  15. };
  16. static void callback_info(const char *callback, struct klp_object *obj)
  17. {
  18. if (obj->mod)
  19. pr_info("%s: %s -> %s\n", callback, obj->mod->name,
  20. module_state[obj->mod->state]);
  21. else
  22. pr_info("%s: vmlinux\n", callback);
  23. }
  24. /* Executed on object patching (ie, patch enablement) */
  25. static int pre_patch_callback(struct klp_object *obj)
  26. {
  27. callback_info(__func__, obj);
  28. return pre_patch_ret;
  29. }
  30. /* Executed on object unpatching (ie, patch disablement) */
  31. static void post_patch_callback(struct klp_object *obj)
  32. {
  33. callback_info(__func__, obj);
  34. }
  35. /* Executed on object unpatching (ie, patch disablement) */
  36. static void pre_unpatch_callback(struct klp_object *obj)
  37. {
  38. callback_info(__func__, obj);
  39. }
  40. /* Executed on object unpatching (ie, patch disablement) */
  41. static void post_unpatch_callback(struct klp_object *obj)
  42. {
  43. callback_info(__func__, obj);
  44. }
  45. static void patched_work_func(struct work_struct *work)
  46. {
  47. pr_info("%s\n", __func__);
  48. }
  49. static struct klp_func no_funcs[] = {
  50. {}
  51. };
  52. static struct klp_func busymod_funcs[] = {
  53. {
  54. .old_name = "busymod_work_func",
  55. .new_func = patched_work_func,
  56. }, {}
  57. };
  58. static struct klp_object objs[] = {
  59. {
  60. .name = NULL, /* vmlinux */
  61. .funcs = no_funcs,
  62. .callbacks = {
  63. .pre_patch = pre_patch_callback,
  64. .post_patch = post_patch_callback,
  65. .pre_unpatch = pre_unpatch_callback,
  66. .post_unpatch = post_unpatch_callback,
  67. },
  68. }, {
  69. .name = "test_klp_callbacks_mod",
  70. .funcs = no_funcs,
  71. .callbacks = {
  72. .pre_patch = pre_patch_callback,
  73. .post_patch = post_patch_callback,
  74. .pre_unpatch = pre_unpatch_callback,
  75. .post_unpatch = post_unpatch_callback,
  76. },
  77. }, {
  78. .name = "test_klp_callbacks_busy",
  79. .funcs = busymod_funcs,
  80. .callbacks = {
  81. .pre_patch = pre_patch_callback,
  82. .post_patch = post_patch_callback,
  83. .pre_unpatch = pre_unpatch_callback,
  84. .post_unpatch = post_unpatch_callback,
  85. },
  86. }, { }
  87. };
  88. static struct klp_patch patch = {
  89. .mod = THIS_MODULE,
  90. .objs = objs,
  91. };
  92. static int test_klp_callbacks_demo_init(void)
  93. {
  94. return klp_enable_patch(&patch);
  95. }
  96. static void test_klp_callbacks_demo_exit(void)
  97. {
  98. }
  99. module_init(test_klp_callbacks_demo_init);
  100. module_exit(test_klp_callbacks_demo_exit);
  101. MODULE_LICENSE("GPL");
  102. MODULE_INFO(livepatch, "Y");
  103. MODULE_AUTHOR("Joe Lawrence <joe.lawrence@redhat.com>");
  104. MODULE_DESCRIPTION("Livepatch test: livepatch demo");