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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 : __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 :
85 : static inline const char *kobject_name(const struct kobject *kobj)
86 : {
87 : return kobj->name;
88 : }
89 :
90 : void 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 :
99 : void kobject_del(struct kobject *kobj);
100 :
101 : struct kobject * __must_check kobject_create_and_add(const char *name, struct kobject *parent);
102 :
103 : int __must_check kobject_rename(struct kobject *, const char *new_name);
104 : int __must_check kobject_move(struct kobject *, struct kobject *);
105 :
106 : struct kobject *kobject_get(struct kobject *kobj);
107 : struct kobject * __must_check kobject_get_unless_zero(struct kobject *kobj);
108 : void kobject_put(struct kobject *kobj);
109 :
110 : const void *kobject_namespace(const struct kobject *kobj);
111 : void kobject_get_ownership(const struct kobject *kobj, kuid_t *uid, kgid_t *gid);
112 : char *kobject_get_path(const struct kobject *kobj, gfp_t flag);
113 :
114 : struct 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 :
123 : struct 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 :
131 : struct 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 :
137 : struct 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 :
145 : extern const struct sysfs_ops kobj_sysfs_ops;
146 :
147 : struct 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 : */
166 : struct 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 :
173 : void kset_init(struct kset *kset);
174 : int __must_check kset_register(struct kset *kset);
175 : void kset_unregister(struct kset *kset);
176 : struct kset * __must_check kset_create_and_add(const char *name, const struct kset_uevent_ops *u,
177 : struct kobject *parent_kobj);
178 :
179 : static inline struct kset *to_kset(struct kobject *kobj)
180 : {
181 : return kobj ? container_of(kobj, struct kset, kobj) : NULL;
182 : }
183 :
184 : static inline struct kset *kset_get(struct kset *k)
185 : {
186 2796 : return k ? to_kset(kobject_get(&k->kobj)) : NULL;
187 : }
188 :
189 : static inline void kset_put(struct kset *k)
190 : {
191 2127 : kobject_put(&k->kobj);
192 : }
193 :
194 : static inline const struct kobj_type *get_ktype(const struct kobject *kobj)
195 : {
196 : return kobj->ktype;
197 : }
198 :
199 : struct kobject *kset_find_obj(struct kset *, const char *);
200 :
201 : /* The global /sys/kernel/ kobject for people to chain off of */
202 : extern struct kobject *kernel_kobj;
203 : /* The global /sys/kernel/mm/ kobject for people to chain off of */
204 : extern struct kobject *mm_kobj;
205 : /* The global /sys/hypervisor/ kobject for people to chain off of */
206 : extern struct kobject *hypervisor_kobj;
207 : /* The global /sys/power/ kobject for people to chain off of */
208 : extern struct kobject *power_kobj;
209 : /* The global /sys/firmware/ kobject for people to chain off of */
210 : extern struct kobject *firmware_kobj;
211 :
212 : int kobject_uevent(struct kobject *kobj, enum kobject_action action);
213 : int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
214 : char *envp[]);
215 : int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count);
216 :
217 : __printf(2, 3)
218 : int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
219 :
220 : #endif /* _KOBJECT_H_ */
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