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 */
37 extern char uevent_helper[];
38 #endif
39
40 /* counter to tag the uevent, read only except for the kobject core */
41 extern atomic64_t 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 */
53 enum 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
64 struct 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
73 unsigned int state_initialized:1;
74 unsigned int state_in_sysfs:1;
75 unsigned int state_add_uevent_sent:1;
76 unsigned int state_remove_uevent_sent:1;
77 unsigned int uevent_suppress:1;
78
79 #ifdef CONFIG_DEBUG_KOBJECT_RELEASE
80 struct delayed_work release;
81 #endif
82 };
83
84 __printf(2, 3) int kobject_set_name(struct kobject *kobj, const char *name, ...);
85 __printf(2, 0) int kobject_set_name_vargs(struct kobject *kobj, const char *fmt, va_list vargs);
86
kobject_name(const struct kobject * kobj)87 static inline const char *kobject_name(const struct kobject *kobj)
88 {
89 return kobj->name;
90 }
91
92 void kobject_init(struct kobject *kobj, const struct kobj_type *ktype);
93 __printf(3, 4) __must_check int kobject_add(struct kobject *kobj,
94 struct kobject *parent,
95 const char *fmt, ...);
96 __printf(4, 5) __must_check int kobject_init_and_add(struct kobject *kobj,
97 const struct kobj_type *ktype,
98 struct kobject *parent,
99 const char *fmt, ...);
100
101 void kobject_del(struct kobject *kobj);
102
103 struct kobject * __must_check kobject_create_and_add(const char *name, struct kobject *parent);
104
105 int __must_check kobject_rename(struct kobject *, const char *new_name);
106 int __must_check kobject_move(struct kobject *, struct kobject *);
107
108 struct kobject *kobject_get(struct kobject *kobj);
109 struct kobject * __must_check kobject_get_unless_zero(struct kobject *kobj);
110 void kobject_put(struct kobject *kobj);
111
112 const void *kobject_namespace(const struct kobject *kobj);
113 void kobject_get_ownership(const struct kobject *kobj, kuid_t *uid, kgid_t *gid);
114 char *kobject_get_path(const struct kobject *kobj, gfp_t flag);
115
116 struct kobj_type {
117 void (*release)(struct kobject *kobj);
118 const struct sysfs_ops *sysfs_ops;
119 const struct attribute_group **default_groups;
120 const struct kobj_ns_type_operations *(*child_ns_type)(const struct kobject *kobj);
121 const void *(*namespace)(const struct kobject *kobj);
122 void (*get_ownership)(const struct kobject *kobj, kuid_t *uid, kgid_t *gid);
123 };
124
125 struct kobj_uevent_env {
126 char *argv[3];
127 char *envp[UEVENT_NUM_ENVP];
128 int envp_idx;
129 char buf[UEVENT_BUFFER_SIZE];
130 int buflen;
131 };
132
133 struct kset_uevent_ops {
134 int (* const filter)(const struct kobject *kobj);
135 const char *(* const name)(const struct kobject *kobj);
136 int (* const uevent)(const struct kobject *kobj, struct kobj_uevent_env *env);
137 };
138
139 struct kobj_attribute {
140 struct attribute attr;
141 ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
142 char *buf);
143 ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
144 const char *buf, size_t count);
145 };
146
147 extern const struct sysfs_ops kobj_sysfs_ops;
148
149 struct sock;
150
151 /**
152 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
153 *
154 * A kset defines a group of kobjects. They can be individually
155 * different "types" but overall these kobjects all want to be grouped
156 * together and operated on in the same manner. ksets are used to
157 * define the attribute callbacks and other common events that happen to
158 * a kobject.
159 *
160 * @list: the list of all kobjects for this kset
161 * @list_lock: a lock for iterating over the kobjects
162 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
163 * @uevent_ops: the set of uevent operations for this kset. These are
164 * called whenever a kobject has something happen to it so that the kset
165 * can add new environment variables, or filter out the uevents if so
166 * desired.
167 */
168 struct kset {
169 struct list_head list;
170 spinlock_t list_lock;
171 struct kobject kobj;
172 const struct kset_uevent_ops *uevent_ops;
173 } __randomize_layout;
174
175 void kset_init(struct kset *kset);
176 int __must_check kset_register(struct kset *kset);
177 void kset_unregister(struct kset *kset);
178 struct kset * __must_check kset_create_and_add(const char *name, const struct kset_uevent_ops *u,
179 struct kobject *parent_kobj);
180
to_kset(struct kobject * kobj)181 static inline struct kset *to_kset(struct kobject *kobj)
182 {
183 return kobj ? container_of(kobj, struct kset, kobj) : NULL;
184 }
185
kset_get(struct kset * k)186 static inline struct kset *kset_get(struct kset *k)
187 {
188 return k ? to_kset(kobject_get(&k->kobj)) : NULL;
189 }
190
kset_put(struct kset * k)191 static inline void kset_put(struct kset *k)
192 {
193 kobject_put(&k->kobj);
194 }
195
get_ktype(const struct kobject * kobj)196 static inline const struct kobj_type *get_ktype(const struct kobject *kobj)
197 {
198 return kobj->ktype;
199 }
200
201 struct kobject *kset_find_obj(struct kset *, const char *);
202
203 /* The global /sys/kernel/ kobject for people to chain off of */
204 extern struct kobject *kernel_kobj;
205 /* The global /sys/kernel/mm/ kobject for people to chain off of */
206 extern struct kobject *mm_kobj;
207 /* The global /sys/hypervisor/ kobject for people to chain off of */
208 extern struct kobject *hypervisor_kobj;
209 /* The global /sys/power/ kobject for people to chain off of */
210 extern struct kobject *power_kobj;
211 /* The global /sys/firmware/ kobject for people to chain off of */
212 extern struct kobject *firmware_kobj;
213
214 int kobject_uevent(struct kobject *kobj, enum kobject_action action);
215 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
216 char *envp[]);
217 int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count);
218
219 __printf(2, 3)
220 int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
221
222 #endif /* _KOBJECT_H_ */
223