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
74 unsigned int state_initialized:1;
75 unsigned int state_in_sysfs:1;
76 unsigned int state_add_uevent_sent:1;
77 unsigned int state_remove_uevent_sent:1;
78 unsigned int uevent_suppress:1;
79
80 #ifdef CONFIG_DEBUG_KOBJECT_RELEASE
81 struct delayed_work release;
82 #endif
83
84 ANDROID_KABI_RESERVE(1);
85 ANDROID_KABI_RESERVE(2);
86 ANDROID_KABI_RESERVE(3);
87 ANDROID_KABI_RESERVE(4);
88 };
89
90 __printf(2, 3) int kobject_set_name(struct kobject *kobj, const char *name, ...);
91 __printf(2, 0) int kobject_set_name_vargs(struct kobject *kobj, const char *fmt, va_list vargs);
92
kobject_name(const struct kobject * kobj)93 static inline const char *kobject_name(const struct kobject *kobj)
94 {
95 return kobj->name;
96 }
97
98 void kobject_init(struct kobject *kobj, const struct kobj_type *ktype);
99 __printf(3, 4) __must_check int kobject_add(struct kobject *kobj,
100 struct kobject *parent,
101 const char *fmt, ...);
102 __printf(4, 5) __must_check int kobject_init_and_add(struct kobject *kobj,
103 const struct kobj_type *ktype,
104 struct kobject *parent,
105 const char *fmt, ...);
106
107 void kobject_del(struct kobject *kobj);
108
109 struct kobject * __must_check kobject_create_and_add(const char *name, struct kobject *parent);
110
111 int __must_check kobject_rename(struct kobject *, const char *new_name);
112 int __must_check kobject_move(struct kobject *, struct kobject *);
113
114 struct kobject *kobject_get(struct kobject *kobj);
115 struct kobject * __must_check kobject_get_unless_zero(struct kobject *kobj);
116 void kobject_put(struct kobject *kobj);
117
118 const void *kobject_namespace(const struct kobject *kobj);
119 void kobject_get_ownership(const struct kobject *kobj, kuid_t *uid, kgid_t *gid);
120 char *kobject_get_path(const struct kobject *kobj, gfp_t flag);
121
122 struct kobj_type {
123 void (*release)(struct kobject *kobj);
124 const struct sysfs_ops *sysfs_ops;
125 const struct attribute_group **default_groups;
126 const struct kobj_ns_type_operations *(*child_ns_type)(const struct kobject *kobj);
127 const void *(*namespace)(const struct kobject *kobj);
128 void (*get_ownership)(const struct kobject *kobj, kuid_t *uid, kgid_t *gid);
129
130 ANDROID_KABI_RESERVE(1);
131 ANDROID_KABI_RESERVE(2);
132 ANDROID_KABI_RESERVE(3);
133 ANDROID_KABI_RESERVE(4);
134 };
135
136 struct kobj_uevent_env {
137 char *argv[3];
138 char *envp[UEVENT_NUM_ENVP];
139 int envp_idx;
140 char buf[UEVENT_BUFFER_SIZE];
141 int buflen;
142 };
143
144 struct kset_uevent_ops {
145 int (* const filter)(const struct kobject *kobj);
146 const char *(* const name)(const struct kobject *kobj);
147 int (* const uevent)(const struct kobject *kobj, struct kobj_uevent_env *env);
148 };
149
150 struct kobj_attribute {
151 struct attribute attr;
152 ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
153 char *buf);
154 ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
155 const char *buf, size_t count);
156 };
157
158 extern const struct sysfs_ops kobj_sysfs_ops;
159
160 struct sock;
161
162 /**
163 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
164 *
165 * A kset defines a group of kobjects. They can be individually
166 * different "types" but overall these kobjects all want to be grouped
167 * together and operated on in the same manner. ksets are used to
168 * define the attribute callbacks and other common events that happen to
169 * a kobject.
170 *
171 * @list: the list of all kobjects for this kset
172 * @list_lock: a lock for iterating over the kobjects
173 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
174 * @uevent_ops: the set of uevent operations for this kset. These are
175 * called whenever a kobject has something happen to it so that the kset
176 * can add new environment variables, or filter out the uevents if so
177 * desired.
178 */
179 struct kset {
180 struct list_head list;
181 spinlock_t list_lock;
182 struct kobject kobj;
183 const struct kset_uevent_ops *uevent_ops;
184
185 ANDROID_KABI_RESERVE(1);
186 ANDROID_KABI_RESERVE(2);
187 ANDROID_KABI_RESERVE(3);
188 ANDROID_KABI_RESERVE(4);
189 } __randomize_layout;
190
191 void kset_init(struct kset *kset);
192 int __must_check kset_register(struct kset *kset);
193 void kset_unregister(struct kset *kset);
194 struct kset * __must_check kset_create_and_add(const char *name, const struct kset_uevent_ops *u,
195 struct kobject *parent_kobj);
196
to_kset(struct kobject * kobj)197 static inline struct kset *to_kset(struct kobject *kobj)
198 {
199 return kobj ? container_of(kobj, struct kset, kobj) : NULL;
200 }
201
kset_get(struct kset * k)202 static inline struct kset *kset_get(struct kset *k)
203 {
204 return k ? to_kset(kobject_get(&k->kobj)) : NULL;
205 }
206
kset_put(struct kset * k)207 static inline void kset_put(struct kset *k)
208 {
209 kobject_put(&k->kobj);
210 }
211
get_ktype(const struct kobject * kobj)212 static inline const struct kobj_type *get_ktype(const struct kobject *kobj)
213 {
214 return kobj->ktype;
215 }
216
217 struct kobject *kset_find_obj(struct kset *, const char *);
218
219 /* The global /sys/kernel/ kobject for people to chain off of */
220 extern struct kobject *kernel_kobj;
221 /* The global /sys/kernel/mm/ kobject for people to chain off of */
222 extern struct kobject *mm_kobj;
223 /* The global /sys/hypervisor/ kobject for people to chain off of */
224 extern struct kobject *hypervisor_kobj;
225 /* The global /sys/power/ kobject for people to chain off of */
226 extern struct kobject *power_kobj;
227 /* The global /sys/firmware/ kobject for people to chain off of */
228 extern struct kobject *firmware_kobj;
229
230 int kobject_uevent(struct kobject *kobj, enum kobject_action action);
231 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
232 char *envp[]);
233 int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count);
234
235 __printf(2, 3)
236 int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
237
238 #endif /* _KOBJECT_H_ */
239