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