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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 <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 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 : */
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 : #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 : extern __printf(2, 3)
83 : int kobject_set_name(struct kobject *kobj, const char *name, ...);
84 : extern __printf(2, 0)
85 : int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
86 : va_list vargs);
87 :
88 : static inline const char *kobject_name(const struct kobject *kobj)
89 : {
90 : return kobj->name;
91 : }
92 :
93 : extern void kobject_init(struct kobject *kobj, const struct kobj_type *ktype);
94 : extern __printf(3, 4) __must_check
95 : int kobject_add(struct kobject *kobj, struct kobject *parent,
96 : const char *fmt, ...);
97 : extern __printf(4, 5) __must_check
98 : int kobject_init_and_add(struct kobject *kobj,
99 : const struct kobj_type *ktype, struct kobject *parent,
100 : const char *fmt, ...);
101 :
102 : extern void kobject_del(struct kobject *kobj);
103 :
104 : extern struct kobject * __must_check kobject_create_and_add(const char *name,
105 : struct kobject *parent);
106 :
107 : extern int __must_check kobject_rename(struct kobject *, const char *new_name);
108 : extern int __must_check kobject_move(struct kobject *, struct kobject *);
109 :
110 : extern struct kobject *kobject_get(struct kobject *kobj);
111 : extern struct kobject * __must_check kobject_get_unless_zero(
112 : struct kobject *kobj);
113 : extern void kobject_put(struct kobject *kobj);
114 :
115 : extern const void *kobject_namespace(const struct kobject *kobj);
116 : extern void kobject_get_ownership(const struct kobject *kobj,
117 : kuid_t *uid, kgid_t *gid);
118 : extern char *kobject_get_path(const struct kobject *kobj, gfp_t flag);
119 :
120 : struct kobj_type {
121 : void (*release)(struct kobject *kobj);
122 : const struct sysfs_ops *sysfs_ops;
123 : const struct attribute_group **default_groups;
124 : const struct kobj_ns_type_operations *(*child_ns_type)(const struct kobject *kobj);
125 : const void *(*namespace)(const struct kobject *kobj);
126 : void (*get_ownership)(const struct kobject *kobj, kuid_t *uid, kgid_t *gid);
127 : };
128 :
129 : struct kobj_uevent_env {
130 : char *argv[3];
131 : char *envp[UEVENT_NUM_ENVP];
132 : int envp_idx;
133 : char buf[UEVENT_BUFFER_SIZE];
134 : int buflen;
135 : };
136 :
137 : struct kset_uevent_ops {
138 : int (* const filter)(const struct kobject *kobj);
139 : const char *(* const name)(const struct kobject *kobj);
140 : int (* const uevent)(const struct kobject *kobj, struct kobj_uevent_env *env);
141 : };
142 :
143 : struct kobj_attribute {
144 : struct attribute attr;
145 : ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
146 : char *buf);
147 : ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
148 : const char *buf, size_t count);
149 : };
150 :
151 : extern const struct sysfs_ops kobj_sysfs_ops;
152 :
153 : struct sock;
154 :
155 : /**
156 : * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
157 : *
158 : * A kset defines a group of kobjects. They can be individually
159 : * different "types" but overall these kobjects all want to be grouped
160 : * together and operated on in the same manner. ksets are used to
161 : * define the attribute callbacks and other common events that happen to
162 : * a kobject.
163 : *
164 : * @list: the list of all kobjects for this kset
165 : * @list_lock: a lock for iterating over the kobjects
166 : * @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
167 : * @uevent_ops: the set of uevent operations for this kset. These are
168 : * called whenever a kobject has something happen to it so that the kset
169 : * can add new environment variables, or filter out the uevents if so
170 : * desired.
171 : */
172 : struct kset {
173 : struct list_head list;
174 : spinlock_t list_lock;
175 : struct kobject kobj;
176 : const struct kset_uevent_ops *uevent_ops;
177 : } __randomize_layout;
178 :
179 : extern void kset_init(struct kset *kset);
180 : extern int __must_check kset_register(struct kset *kset);
181 : extern void kset_unregister(struct kset *kset);
182 : extern struct kset * __must_check kset_create_and_add(const char *name,
183 : const struct kset_uevent_ops *u,
184 : struct kobject *parent_kobj);
185 :
186 : static inline struct kset *to_kset(struct kobject *kobj)
187 : {
188 : return kobj ? container_of(kobj, struct kset, kobj) : NULL;
189 : }
190 :
191 : static inline struct kset *kset_get(struct kset *k)
192 : {
193 1116 : return k ? to_kset(kobject_get(&k->kobj)) : NULL;
194 : }
195 :
196 : static inline void kset_put(struct kset *k)
197 : {
198 448 : kobject_put(&k->kobj);
199 : }
200 :
201 : static inline const struct kobj_type *get_ktype(const struct kobject *kobj)
202 : {
203 : return kobj->ktype;
204 : }
205 :
206 : extern struct kobject *kset_find_obj(struct kset *, const char *);
207 :
208 : /* The global /sys/kernel/ kobject for people to chain off of */
209 : extern struct kobject *kernel_kobj;
210 : /* The global /sys/kernel/mm/ kobject for people to chain off of */
211 : extern struct kobject *mm_kobj;
212 : /* The global /sys/hypervisor/ kobject for people to chain off of */
213 : extern struct kobject *hypervisor_kobj;
214 : /* The global /sys/power/ kobject for people to chain off of */
215 : extern struct kobject *power_kobj;
216 : /* The global /sys/firmware/ kobject for people to chain off of */
217 : extern struct kobject *firmware_kobj;
218 :
219 : int kobject_uevent(struct kobject *kobj, enum kobject_action action);
220 : int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
221 : char *envp[]);
222 : int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count);
223 :
224 : __printf(2, 3)
225 : int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
226 :
227 : #endif /* _KOBJECT_H_ */
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