kobject.h 7.4 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * kobject.h - generic kernel object infrastructure.
  4. *
  5. * Copyright (c) 2002-2003 Patrick Mochel
  6. * Copyright (c) 2002-2003 Open Source Development Labs
  7. * Copyright (c) 2006-2008 Greg Kroah-Hartman <[email protected]>
  8. * Copyright (c) 2006-2008 Novell Inc.
  9. *
  10. * Please read Documentation/core-api/kobject.rst before using the kobject
  11. * interface, ESPECIALLY the parts about reference counts and object
  12. * destructors.
  13. */
  14. #ifndef _KOBJECT_H_
  15. #define _KOBJECT_H_
  16. #include <linux/types.h>
  17. #include <linux/list.h>
  18. #include <linux/sysfs.h>
  19. #include <linux/compiler.h>
  20. #include <linux/container_of.h>
  21. #include <linux/spinlock.h>
  22. #include <linux/kref.h>
  23. #include <linux/kobject_ns.h>
  24. #include <linux/wait.h>
  25. #include <linux/atomic.h>
  26. #include <linux/workqueue.h>
  27. #include <linux/uidgid.h>
  28. #include <linux/android_kabi.h>
  29. #define UEVENT_HELPER_PATH_LEN 256
  30. #define UEVENT_NUM_ENVP 64 /* number of env pointers */
  31. #define UEVENT_BUFFER_SIZE 2048 /* buffer for the variables */
  32. #ifdef CONFIG_UEVENT_HELPER
  33. /* path to the userspace helper executed on an event */
  34. extern char uevent_helper[];
  35. #endif
  36. /* counter to tag the uevent, read only except for the kobject core */
  37. extern u64 uevent_seqnum;
  38. /*
  39. * The actions here must match the index to the string array
  40. * in lib/kobject_uevent.c
  41. *
  42. * Do not add new actions here without checking with the driver-core
  43. * maintainers. Action strings are not meant to express subsystem
  44. * or device specific properties. In most cases you want to send a
  45. * kobject_uevent_env(kobj, KOBJ_CHANGE, env) with additional event
  46. * specific variables added to the event environment.
  47. */
  48. enum kobject_action {
  49. KOBJ_ADD,
  50. KOBJ_REMOVE,
  51. KOBJ_CHANGE,
  52. KOBJ_MOVE,
  53. KOBJ_ONLINE,
  54. KOBJ_OFFLINE,
  55. KOBJ_BIND,
  56. KOBJ_UNBIND,
  57. };
  58. struct kobject {
  59. const char *name;
  60. struct list_head entry;
  61. struct kobject *parent;
  62. struct kset *kset;
  63. const struct kobj_type *ktype;
  64. struct kernfs_node *sd; /* sysfs directory entry */
  65. struct kref kref;
  66. #ifdef CONFIG_DEBUG_KOBJECT_RELEASE
  67. struct delayed_work release;
  68. #endif
  69. unsigned int state_initialized:1;
  70. unsigned int state_in_sysfs:1;
  71. unsigned int state_add_uevent_sent:1;
  72. unsigned int state_remove_uevent_sent:1;
  73. unsigned int uevent_suppress:1;
  74. ANDROID_KABI_RESERVE(1);
  75. ANDROID_KABI_RESERVE(2);
  76. ANDROID_KABI_RESERVE(3);
  77. ANDROID_KABI_RESERVE(4);
  78. };
  79. extern __printf(2, 3)
  80. int kobject_set_name(struct kobject *kobj, const char *name, ...);
  81. extern __printf(2, 0)
  82. int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
  83. va_list vargs);
  84. static inline const char *kobject_name(const struct kobject *kobj)
  85. {
  86. return kobj->name;
  87. }
  88. extern void kobject_init(struct kobject *kobj, const struct kobj_type *ktype);
  89. extern __printf(3, 4) __must_check
  90. int kobject_add(struct kobject *kobj, struct kobject *parent,
  91. const char *fmt, ...);
  92. extern __printf(4, 5) __must_check
  93. int kobject_init_and_add(struct kobject *kobj,
  94. const struct kobj_type *ktype, struct kobject *parent,
  95. const char *fmt, ...);
  96. extern void kobject_del(struct kobject *kobj);
  97. extern struct kobject * __must_check kobject_create_and_add(const char *name,
  98. struct kobject *parent);
  99. extern int __must_check kobject_rename(struct kobject *, const char *new_name);
  100. extern int __must_check kobject_move(struct kobject *, struct kobject *);
  101. extern struct kobject *kobject_get(struct kobject *kobj);
  102. extern struct kobject * __must_check kobject_get_unless_zero(
  103. struct kobject *kobj);
  104. extern void kobject_put(struct kobject *kobj);
  105. extern const void *kobject_namespace(struct kobject *kobj);
  106. extern void kobject_get_ownership(struct kobject *kobj,
  107. kuid_t *uid, kgid_t *gid);
  108. extern char *kobject_get_path(const struct kobject *kobj, gfp_t flag);
  109. struct kobj_type {
  110. void (*release)(struct kobject *kobj);
  111. const struct sysfs_ops *sysfs_ops;
  112. const struct attribute_group **default_groups;
  113. const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj);
  114. const void *(*namespace)(struct kobject *kobj);
  115. void (*get_ownership)(struct kobject *kobj, kuid_t *uid, kgid_t *gid);
  116. ANDROID_KABI_RESERVE(1);
  117. ANDROID_KABI_RESERVE(2);
  118. ANDROID_KABI_RESERVE(3);
  119. ANDROID_KABI_RESERVE(4);
  120. };
  121. struct kobj_uevent_env {
  122. char *argv[3];
  123. char *envp[UEVENT_NUM_ENVP];
  124. int envp_idx;
  125. char buf[UEVENT_BUFFER_SIZE];
  126. int buflen;
  127. };
  128. struct kset_uevent_ops {
  129. int (* const filter)(struct kobject *kobj);
  130. const char *(* const name)(struct kobject *kobj);
  131. int (* const uevent)(struct kobject *kobj, struct kobj_uevent_env *env);
  132. };
  133. struct kobj_attribute {
  134. struct attribute attr;
  135. ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
  136. char *buf);
  137. ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
  138. const char *buf, size_t count);
  139. };
  140. extern const struct sysfs_ops kobj_sysfs_ops;
  141. struct sock;
  142. /**
  143. * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
  144. *
  145. * A kset defines a group of kobjects. They can be individually
  146. * different "types" but overall these kobjects all want to be grouped
  147. * together and operated on in the same manner. ksets are used to
  148. * define the attribute callbacks and other common events that happen to
  149. * a kobject.
  150. *
  151. * @list: the list of all kobjects for this kset
  152. * @list_lock: a lock for iterating over the kobjects
  153. * @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
  154. * @uevent_ops: the set of uevent operations for this kset. These are
  155. * called whenever a kobject has something happen to it so that the kset
  156. * can add new environment variables, or filter out the uevents if so
  157. * desired.
  158. */
  159. struct kset {
  160. struct list_head list;
  161. spinlock_t list_lock;
  162. struct kobject kobj;
  163. const struct kset_uevent_ops *uevent_ops;
  164. ANDROID_KABI_RESERVE(1);
  165. ANDROID_KABI_RESERVE(2);
  166. ANDROID_KABI_RESERVE(3);
  167. ANDROID_KABI_RESERVE(4);
  168. } __randomize_layout;
  169. extern void kset_init(struct kset *kset);
  170. extern int __must_check kset_register(struct kset *kset);
  171. extern void kset_unregister(struct kset *kset);
  172. extern struct kset * __must_check kset_create_and_add(const char *name,
  173. const struct kset_uevent_ops *u,
  174. struct kobject *parent_kobj);
  175. static inline struct kset *to_kset(struct kobject *kobj)
  176. {
  177. return kobj ? container_of(kobj, struct kset, kobj) : NULL;
  178. }
  179. static inline struct kset *kset_get(struct kset *k)
  180. {
  181. return k ? to_kset(kobject_get(&k->kobj)) : NULL;
  182. }
  183. static inline void kset_put(struct kset *k)
  184. {
  185. kobject_put(&k->kobj);
  186. }
  187. static inline const struct kobj_type *get_ktype(struct kobject *kobj)
  188. {
  189. return kobj->ktype;
  190. }
  191. extern struct kobject *kset_find_obj(struct kset *, const char *);
  192. /* The global /sys/kernel/ kobject for people to chain off of */
  193. extern struct kobject *kernel_kobj;
  194. /* The global /sys/kernel/mm/ kobject for people to chain off of */
  195. extern struct kobject *mm_kobj;
  196. /* The global /sys/hypervisor/ kobject for people to chain off of */
  197. extern struct kobject *hypervisor_kobj;
  198. /* The global /sys/power/ kobject for people to chain off of */
  199. extern struct kobject *power_kobj;
  200. /* The global /sys/firmware/ kobject for people to chain off of */
  201. extern struct kobject *firmware_kobj;
  202. int kobject_uevent(struct kobject *kobj, enum kobject_action action);
  203. int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
  204. char *envp[]);
  205. int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count);
  206. __printf(2, 3)
  207. int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
  208. #endif /* _KOBJECT_H_ */