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/kobject.txt 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 32 /* 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 KOBJ_MAX 63 }; 64 65 struct kobject { 66 const char *name; 67 struct list_head entry; 68 struct kobject *parent; 69 struct kset *kset; 70 struct kobj_type *ktype; 71 struct kernfs_node *sd; /* sysfs directory entry */ 72 struct kref kref; 73 #ifdef CONFIG_DEBUG_KOBJECT_RELEASE 74 struct delayed_work release; 75 #endif 76 unsigned int state_initialized:1; 77 unsigned int state_in_sysfs:1; 78 unsigned int state_add_uevent_sent:1; 79 unsigned int state_remove_uevent_sent:1; 80 unsigned int uevent_suppress:1; 81 }; 82 83 extern __printf(2, 3) 84 int kobject_set_name(struct kobject *kobj, const char *name, ...); 85 extern __printf(2, 0) 86 int kobject_set_name_vargs(struct kobject *kobj, const char *fmt, 87 va_list vargs); 88 89 static inline const char *kobject_name(const struct kobject *kobj) 90 { 91 return kobj->name; 92 } 93 94 extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype); 95 extern __printf(3, 4) __must_check 96 int kobject_add(struct kobject *kobj, struct kobject *parent, 97 const char *fmt, ...); 98 extern __printf(4, 5) __must_check 99 int kobject_init_and_add(struct kobject *kobj, 100 struct kobj_type *ktype, struct kobject *parent, 101 const char *fmt, ...); 102 103 extern void kobject_del(struct kobject *kobj); 104 105 extern struct kobject * __must_check kobject_create(void); 106 extern struct kobject * __must_check kobject_create_and_add(const char *name, 107 struct kobject *parent); 108 109 extern int __must_check kobject_rename(struct kobject *, const char *new_name); 110 extern int __must_check kobject_move(struct kobject *, struct kobject *); 111 112 extern struct kobject *kobject_get(struct kobject *kobj); 113 extern struct kobject * __must_check kobject_get_unless_zero( 114 struct kobject *kobj); 115 extern void kobject_put(struct kobject *kobj); 116 117 extern const void *kobject_namespace(struct kobject *kobj); 118 extern void kobject_get_ownership(struct kobject *kobj, 119 kuid_t *uid, kgid_t *gid); 120 extern char *kobject_get_path(struct kobject *kobj, gfp_t flag); 121 122 /** 123 * kobject_has_children - Returns whether a kobject has children. 124 * @kobj: the object to test 125 * 126 * This will return whether a kobject has other kobjects as children. 127 * 128 * It does NOT account for the presence of attribute files, only sub 129 * directories. It also assumes there is no concurrent addition or 130 * removal of such children, and thus relies on external locking. 131 */ 132 static inline bool kobject_has_children(struct kobject *kobj) 133 { 134 WARN_ON_ONCE(kref_read(&kobj->kref) == 0); 135 136 return kobj->sd && kobj->sd->dir.subdirs; 137 } 138 139 struct kobj_type { 140 void (*release)(struct kobject *kobj); 141 const struct sysfs_ops *sysfs_ops; 142 struct attribute **default_attrs; /* use default_groups instead */ 143 const struct attribute_group **default_groups; 144 const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj); 145 const void *(*namespace)(struct kobject *kobj); 146 void (*get_ownership)(struct kobject *kobj, kuid_t *uid, kgid_t *gid); 147 }; 148 149 struct kobj_uevent_env { 150 char *argv[3]; 151 char *envp[UEVENT_NUM_ENVP]; 152 int envp_idx; 153 char buf[UEVENT_BUFFER_SIZE]; 154 int buflen; 155 }; 156 157 struct kset_uevent_ops { 158 int (* const filter)(struct kset *kset, struct kobject *kobj); 159 const char *(* const name)(struct kset *kset, struct kobject *kobj); 160 int (* const uevent)(struct kset *kset, struct kobject *kobj, 161 struct kobj_uevent_env *env); 162 }; 163 164 struct kobj_attribute { 165 struct attribute attr; 166 ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr, 167 char *buf); 168 ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr, 169 const char *buf, size_t count); 170 }; 171 172 extern const struct sysfs_ops kobj_sysfs_ops; 173 174 struct sock; 175 176 /** 177 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem. 178 * 179 * A kset defines a group of kobjects. They can be individually 180 * different "types" but overall these kobjects all want to be grouped 181 * together and operated on in the same manner. ksets are used to 182 * define the attribute callbacks and other common events that happen to 183 * a kobject. 184 * 185 * @list: the list of all kobjects for this kset 186 * @list_lock: a lock for iterating over the kobjects 187 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...) 188 * @uevent_ops: the set of uevent operations for this kset. These are 189 * called whenever a kobject has something happen to it so that the kset 190 * can add new environment variables, or filter out the uevents if so 191 * desired. 192 */ 193 struct kset { 194 struct list_head list; 195 spinlock_t list_lock; 196 struct kobject kobj; 197 const struct kset_uevent_ops *uevent_ops; 198 } __randomize_layout; 199 200 extern void kset_init(struct kset *kset); 201 extern int __must_check kset_register(struct kset *kset); 202 extern void kset_unregister(struct kset *kset); 203 extern struct kset * __must_check kset_create_and_add(const char *name, 204 const struct kset_uevent_ops *u, 205 struct kobject *parent_kobj); 206 207 static inline struct kset *to_kset(struct kobject *kobj) 208 { 209 return kobj ? container_of(kobj, struct kset, kobj) : NULL; 210 } 211 212 static inline struct kset *kset_get(struct kset *k) 213 { 214 return k ? to_kset(kobject_get(&k->kobj)) : NULL; 215 } 216 217 static inline void kset_put(struct kset *k) 218 { 219 kobject_put(&k->kobj); 220 } 221 222 static inline struct kobj_type *get_ktype(struct kobject *kobj) 223 { 224 return kobj->ktype; 225 } 226 227 extern struct kobject *kset_find_obj(struct kset *, const char *); 228 229 /* The global /sys/kernel/ kobject for people to chain off of */ 230 extern struct kobject *kernel_kobj; 231 /* The global /sys/kernel/mm/ kobject for people to chain off of */ 232 extern struct kobject *mm_kobj; 233 /* The global /sys/hypervisor/ kobject for people to chain off of */ 234 extern struct kobject *hypervisor_kobj; 235 /* The global /sys/power/ kobject for people to chain off of */ 236 extern struct kobject *power_kobj; 237 /* The global /sys/firmware/ kobject for people to chain off of */ 238 extern struct kobject *firmware_kobj; 239 240 int kobject_uevent(struct kobject *kobj, enum kobject_action action); 241 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, 242 char *envp[]); 243 int kobject_synth_uevent(struct kobject *kobj, const char *buf, size_t count); 244 245 __printf(2, 3) 246 int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...); 247 248 #endif /* _KOBJECT_H_ */ 249