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 <greg@kroah.com>
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
15 #ifndef _KOBJECT_H_
16 #define _KOBJECT_H_
17
18 #include <linux/types.h>
19 #include <linux/list.h>
20 #include <linux/sysfs.h>
21 #include <linux/compiler.h>
22 #include <linux/container_of.h>
23 #include <linux/spinlock.h>
24 #include <linux/kref.h>
25 #include <linux/kobject_ns.h>
26 #include <linux/wait.h>
27 #include <linux/atomic.h>
28 #include <linux/workqueue.h>
29 #include <linux/uidgid.h>
30 #include <linux/android_kabi.h>
31
32 #define UEVENT_HELPER_PATH_LEN 256
33 #define UEVENT_NUM_ENVP 64 /* number of env pointers */
34 #define UEVENT_BUFFER_SIZE 2048 /* buffer for the variables */
35
36 #ifdef CONFIG_UEVENT_HELPER
37 /* path to the userspace helper executed on an event */
38 extern char uevent_helper[];
39 #endif
40
41 /* counter to tag the uevent, read only except for the kobject core */
42 extern u64 uevent_seqnum;
43
44 /*
45 * The actions here must match the index to the string array
46 * in lib/kobject_uevent.c
47 *
48 * Do not add new actions here without checking with the driver-core
49 * maintainers. Action strings are not meant to express subsystem
50 * or device specific properties. In most cases you want to send a
51 * kobject_uevent_env(kobj, KOBJ_CHANGE, env) with additional event
52 * specific variables added to the event environment.
53 */
54 enum kobject_action {
55 KOBJ_ADD,
56 KOBJ_REMOVE,
57 KOBJ_CHANGE,
58 KOBJ_MOVE,
59 KOBJ_ONLINE,
60 KOBJ_OFFLINE,
61 KOBJ_BIND,
62 KOBJ_UNBIND,
63 };
64
65 struct kobject {
66 const char *name;
67 struct list_head entry;
68 struct kobject *parent;
69 struct kset *kset;
70 const struct kobj_type *ktype;
71 struct kernfs_node *sd; /* sysfs directory entry */
72 struct kref kref;
73 #ifdef CONFIG_DEBUG_KOBJECT_RELEASE
74 struct delayed_work release;
75 #endif
76 unsigned int state_initialized:1;
77 unsigned int state_in_sysfs:1;
78 unsigned int state_add_uevent_sent:1;
79 unsigned int state_remove_uevent_sent:1;
80 unsigned int uevent_suppress:1;
81
82 ANDROID_KABI_RESERVE(1);
83 ANDROID_KABI_RESERVE(2);
84 ANDROID_KABI_RESERVE(3);
85 ANDROID_KABI_RESERVE(4);
86 };
87
88 extern __printf(2, 3)
89 int kobject_set_name(struct kobject *kobj, const char *name, ...);
90 extern __printf(2, 0)
91 int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
92 va_list vargs);
93
kobject_name(const struct kobject * kobj)94 static inline const char *kobject_name(const struct kobject *kobj)
95 {
96 return kobj->name;
97 }
98
99 extern void kobject_init(struct kobject *kobj, const struct kobj_type *ktype);
100 extern __printf(3, 4) __must_check
101 int kobject_add(struct kobject *kobj, struct kobject *parent,
102 const char *fmt, ...);
103 extern __printf(4, 5) __must_check
104 int kobject_init_and_add(struct kobject *kobj,
105 const struct kobj_type *ktype, struct kobject *parent,
106 const char *fmt, ...);
107
108 extern void kobject_del(struct kobject *kobj);
109
110 extern struct kobject * __must_check kobject_create_and_add(const char *name,
111 struct kobject *parent);
112
113 extern int __must_check kobject_rename(struct kobject *, const char *new_name);
114 extern int __must_check kobject_move(struct kobject *, struct kobject *);
115
116 extern struct kobject *kobject_get(struct kobject *kobj);
117 extern struct kobject * __must_check kobject_get_unless_zero(
118 struct kobject *kobj);
119 extern void kobject_put(struct kobject *kobj);
120
121 extern const void *kobject_namespace(struct kobject *kobj);
122 extern void kobject_get_ownership(struct kobject *kobj,
123 kuid_t *uid, kgid_t *gid);
124 extern char *kobject_get_path(const struct kobject *kobj, gfp_t flag);
125
126 struct kobj_type {
127 void (*release)(struct kobject *kobj);
128 const struct sysfs_ops *sysfs_ops;
129 const struct attribute_group **default_groups;
130 const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj);
131 const void *(*namespace)(struct kobject *kobj);
132 void (*get_ownership)(struct kobject *kobj, kuid_t *uid, kgid_t *gid);
133
134 ANDROID_KABI_RESERVE(1);
135 ANDROID_KABI_RESERVE(2);
136 ANDROID_KABI_RESERVE(3);
137 ANDROID_KABI_RESERVE(4);
138 };
139
140 struct kobj_uevent_env {
141 char *argv[3];
142 char *envp[UEVENT_NUM_ENVP];
143 int envp_idx;
144 char buf[UEVENT_BUFFER_SIZE];
145 int buflen;
146 };
147
148 struct kset_uevent_ops {
149 int (* const filter)(struct kobject *kobj);
150 const char *(* const name)(struct kobject *kobj);
151 int (* const uevent)(struct kobject *kobj, struct kobj_uevent_env *env);
152 };
153
154 struct kobj_attribute {
155 struct attribute attr;
156 ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
157 char *buf);
158 ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
159 const char *buf, size_t count);
160 };
161
162 extern const struct sysfs_ops kobj_sysfs_ops;
163
164 struct sock;
165
166 /**
167 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
168 *
169 * A kset defines a group of kobjects. They can be individually
170 * different "types" but overall these kobjects all want to be grouped
171 * together and operated on in the same manner. ksets are used to
172 * define the attribute callbacks and other common events that happen to
173 * a kobject.
174 *
175 * @list: the list of all kobjects for this kset
176 * @list_lock: a lock for iterating over the kobjects
177 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
178 * @uevent_ops: the set of uevent operations for this kset. These are
179 * called whenever a kobject has something happen to it so that the kset
180 * can add new environment variables, or filter out the uevents if so
181 * desired.
182 */
183 struct kset {
184 struct list_head list;
185 spinlock_t list_lock;
186 struct kobject kobj;
187 const struct kset_uevent_ops *uevent_ops;
188
189 ANDROID_KABI_RESERVE(1);
190 ANDROID_KABI_RESERVE(2);
191 ANDROID_KABI_RESERVE(3);
192 ANDROID_KABI_RESERVE(4);
193 } __randomize_layout;
194
195 extern void kset_init(struct kset *kset);
196 extern int __must_check kset_register(struct kset *kset);
197 extern void kset_unregister(struct kset *kset);
198 extern struct kset * __must_check kset_create_and_add(const char *name,
199 const struct kset_uevent_ops *u,
200 struct kobject *parent_kobj);
201
to_kset(struct kobject * kobj)202 static inline struct kset *to_kset(struct kobject *kobj)
203 {
204 return kobj ? container_of(kobj, struct kset, kobj) : NULL;
205 }
206
kset_get(struct kset * k)207 static inline struct kset *kset_get(struct kset *k)
208 {
209 return k ? to_kset(kobject_get(&k->kobj)) : NULL;
210 }
211
kset_put(struct kset * k)212 static inline void kset_put(struct kset *k)
213 {
214 kobject_put(&k->kobj);
215 }
216
get_ktype(struct kobject * kobj)217 static inline const struct kobj_type *get_ktype(struct kobject *kobj)
218 {
219 return kobj->ktype;
220 }
221
222 extern struct kobject *kset_find_obj(struct kset *, const char *);
223
224 /* The global /sys/kernel/ kobject for people to chain off of */
225 extern struct kobject *kernel_kobj;
226 /* The global /sys/kernel/mm/ kobject for people to chain off of */
227 extern struct kobject *mm_kobj;
228 /* The global /sys/hypervisor/ kobject for people to chain off of */
229 extern struct kobject *hypervisor_kobj;
230 /* The global /sys/power/ kobject for people to chain off of */
231 extern struct kobject *power_kobj;
232 /* The global /sys/firmware/ kobject for people to chain off of */
233 extern struct kobject *firmware_kobj;
234
235 int kobject_uevent(struct kobject *kobj, enum kobject_action action);
236 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
237 char *envp[]);
238 int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count);
239
240 __printf(2, 3)
241 int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
242
243 #endif /* _KOBJECT_H_ */
244