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

source code of linux/include/linux/kobject.h