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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/spinlock.h>
23 : #include <linux/kref.h>
24 : #include <linux/kobject_ns.h>
25 : #include <linux/kernel.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 : 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 9533 : static inline const char *kobject_name(const struct kobject *kobj)
89 : {
90 6581 : return kobj->name;
91 : }
92 :
93 : extern void kobject_init(struct kobject *kobj, 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 : 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(void);
105 : extern struct kobject * __must_check kobject_create_and_add(const char *name,
106 : struct kobject *parent);
107 :
108 : extern int __must_check kobject_rename(struct kobject *, const char *new_name);
109 : extern int __must_check kobject_move(struct kobject *, struct kobject *);
110 :
111 : extern struct kobject *kobject_get(struct kobject *kobj);
112 : extern struct kobject * __must_check kobject_get_unless_zero(
113 : struct kobject *kobj);
114 : extern void kobject_put(struct kobject *kobj);
115 :
116 : extern const void *kobject_namespace(struct kobject *kobj);
117 : extern void kobject_get_ownership(struct kobject *kobj,
118 : kuid_t *uid, kgid_t *gid);
119 : extern char *kobject_get_path(struct kobject *kobj, gfp_t flag);
120 :
121 : /**
122 : * kobject_has_children - Returns whether a kobject has children.
123 : * @kobj: the object to test
124 : *
125 : * This will return whether a kobject has other kobjects as children.
126 : *
127 : * It does NOT account for the presence of attribute files, only sub
128 : * directories. It also assumes there is no concurrent addition or
129 : * removal of such children, and thus relies on external locking.
130 : */
131 0 : static inline bool kobject_has_children(struct kobject *kobj)
132 : {
133 0 : WARN_ON_ONCE(kref_read(&kobj->kref) == 0);
134 :
135 0 : return kobj->sd && kobj->sd->dir.subdirs;
136 : }
137 :
138 : struct kobj_type {
139 : void (*release)(struct kobject *kobj);
140 : const struct sysfs_ops *sysfs_ops;
141 : struct attribute **default_attrs; /* use default_groups instead */
142 : const struct attribute_group **default_groups;
143 : const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj);
144 : const void *(*namespace)(struct kobject *kobj);
145 : void (*get_ownership)(struct kobject *kobj, kuid_t *uid, kgid_t *gid);
146 : };
147 :
148 : struct kobj_uevent_env {
149 : char *argv[3];
150 : char *envp[UEVENT_NUM_ENVP];
151 : int envp_idx;
152 : char buf[UEVENT_BUFFER_SIZE];
153 : int buflen;
154 : };
155 :
156 : struct kset_uevent_ops {
157 : int (* const filter)(struct kset *kset, struct kobject *kobj);
158 : const char *(* const name)(struct kset *kset, struct kobject *kobj);
159 : int (* const uevent)(struct kset *kset, struct kobject *kobj,
160 : struct kobj_uevent_env *env);
161 : };
162 :
163 : struct kobj_attribute {
164 : struct attribute attr;
165 : ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
166 : char *buf);
167 : ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
168 : const char *buf, size_t count);
169 : };
170 :
171 : extern const struct sysfs_ops kobj_sysfs_ops;
172 :
173 : struct sock;
174 :
175 : /**
176 : * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
177 : *
178 : * A kset defines a group of kobjects. They can be individually
179 : * different "types" but overall these kobjects all want to be grouped
180 : * together and operated on in the same manner. ksets are used to
181 : * define the attribute callbacks and other common events that happen to
182 : * a kobject.
183 : *
184 : * @list: the list of all kobjects for this kset
185 : * @list_lock: a lock for iterating over the kobjects
186 : * @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
187 : * @uevent_ops: the set of uevent operations for this kset. These are
188 : * called whenever a kobject has something happen to it so that the kset
189 : * can add new environment variables, or filter out the uevents if so
190 : * desired.
191 : */
192 : struct kset {
193 : struct list_head list;
194 : spinlock_t list_lock;
195 : struct kobject kobj;
196 : const struct kset_uevent_ops *uevent_ops;
197 : } __randomize_layout;
198 :
199 : extern void kset_init(struct kset *kset);
200 : extern int __must_check kset_register(struct kset *kset);
201 : extern void kset_unregister(struct kset *kset);
202 : extern struct kset * __must_check kset_create_and_add(const char *name,
203 : const struct kset_uevent_ops *u,
204 : struct kobject *parent_kobj);
205 :
206 487 : static inline struct kset *to_kset(struct kobject *kobj)
207 : {
208 487 : return kobj ? container_of(kobj, struct kset, kobj) : NULL;
209 : }
210 :
211 487 : static inline struct kset *kset_get(struct kset *k)
212 : {
213 487 : return k ? to_kset(kobject_get(&k->kobj)) : NULL;
214 : }
215 :
216 47 : static inline void kset_put(struct kset *k)
217 : {
218 47 : kobject_put(&k->kobj);
219 17 : }
220 :
221 2071 : static inline struct kobj_type *get_ktype(struct kobject *kobj)
222 : {
223 2071 : return kobj->ktype;
224 : }
225 :
226 : extern struct kobject *kset_find_obj(struct kset *, const char *);
227 :
228 : /* The global /sys/kernel/ kobject for people to chain off of */
229 : extern struct kobject *kernel_kobj;
230 : /* The global /sys/kernel/mm/ kobject for people to chain off of */
231 : extern struct kobject *mm_kobj;
232 : /* The global /sys/hypervisor/ kobject for people to chain off of */
233 : extern struct kobject *hypervisor_kobj;
234 : /* The global /sys/power/ kobject for people to chain off of */
235 : extern struct kobject *power_kobj;
236 : /* The global /sys/firmware/ kobject for people to chain off of */
237 : extern struct kobject *firmware_kobj;
238 :
239 : int kobject_uevent(struct kobject *kobj, enum kobject_action action);
240 : int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
241 : char *envp[]);
242 : int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count);
243 :
244 : __printf(2, 3)
245 : int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
246 :
247 : #endif /* _KOBJECT_H_ */
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