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 <[email protected]> 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 return k ? to_kset(kobject_get(&k->kobj)) : NULL; 187 } 188 189 static inline void kset_put(struct kset *k) 190 { 191 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_ */ 221