| 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * kobject.c - library routines for handling generic kernel objects |
| 4 | * |
| 5 | * Copyright (c) 2002-2003 Patrick Mochel <mochel@osdl.org> |
| 6 | * Copyright (c) 2006-2007 Greg Kroah-Hartman <greg@kroah.com> |
| 7 | * Copyright (c) 2006-2007 Novell Inc. |
| 8 | * |
| 9 | * Please see the file Documentation/core-api/kobject.rst for critical information |
| 10 | * about using the kobject interface. |
| 11 | */ |
| 12 | |
| 13 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 14 | |
| 15 | #include <linux/kobject.h> |
| 16 | #include <linux/string.h> |
| 17 | #include <linux/export.h> |
| 18 | #include <linux/stat.h> |
| 19 | #include <linux/slab.h> |
| 20 | #include <linux/random.h> |
| 21 | |
| 22 | /** |
| 23 | * kobject_namespace() - Return @kobj's namespace tag. |
| 24 | * @kobj: kobject in question |
| 25 | * |
| 26 | * Returns namespace tag of @kobj if its parent has namespace ops enabled |
| 27 | * and thus @kobj should have a namespace tag associated with it. Returns |
| 28 | * %NULL otherwise. |
| 29 | */ |
| 30 | const void *kobject_namespace(const struct kobject *kobj) |
| 31 | { |
| 32 | const struct kobj_ns_type_operations *ns_ops = kobj_ns_ops(kobj); |
| 33 | |
| 34 | if (!ns_ops || ns_ops->type == KOBJ_NS_TYPE_NONE) |
| 35 | return NULL; |
| 36 | |
| 37 | return kobj->ktype->namespace(kobj); |
| 38 | } |
| 39 | |
| 40 | /** |
| 41 | * kobject_get_ownership() - Get sysfs ownership data for @kobj. |
| 42 | * @kobj: kobject in question |
| 43 | * @uid: kernel user ID for sysfs objects |
| 44 | * @gid: kernel group ID for sysfs objects |
| 45 | * |
| 46 | * Returns initial uid/gid pair that should be used when creating sysfs |
| 47 | * representation of given kobject. Normally used to adjust ownership of |
| 48 | * objects in a container. |
| 49 | */ |
| 50 | void kobject_get_ownership(const struct kobject *kobj, kuid_t *uid, kgid_t *gid) |
| 51 | { |
| 52 | *uid = GLOBAL_ROOT_UID; |
| 53 | *gid = GLOBAL_ROOT_GID; |
| 54 | |
| 55 | if (kobj->ktype->get_ownership) |
| 56 | kobj->ktype->get_ownership(kobj, uid, gid); |
| 57 | } |
| 58 | |
| 59 | static bool kobj_ns_type_is_valid(enum kobj_ns_type type) |
| 60 | { |
| 61 | if ((type <= KOBJ_NS_TYPE_NONE) || (type >= KOBJ_NS_TYPES)) |
| 62 | return false; |
| 63 | |
| 64 | return true; |
| 65 | } |
| 66 | |
| 67 | static int create_dir(struct kobject *kobj) |
| 68 | { |
| 69 | const struct kobj_type *ktype = get_ktype(kobj); |
| 70 | const struct kobj_ns_type_operations *ops; |
| 71 | int error; |
| 72 | |
| 73 | error = sysfs_create_dir_ns(kobj, kobject_namespace(kobj)); |
| 74 | if (error) |
| 75 | return error; |
| 76 | |
| 77 | error = sysfs_create_groups(kobj, ktype->default_groups); |
| 78 | if (error) { |
| 79 | sysfs_remove_dir(kobj); |
| 80 | return error; |
| 81 | } |
| 82 | |
| 83 | /* |
| 84 | * @kobj->sd may be deleted by an ancestor going away. Hold an |
| 85 | * extra reference so that it stays until @kobj is gone. |
| 86 | */ |
| 87 | sysfs_get(kobj->sd); |
| 88 | |
| 89 | /* |
| 90 | * If @kobj has ns_ops, its children need to be filtered based on |
| 91 | * their namespace tags. Enable namespace support on @kobj->sd. |
| 92 | */ |
| 93 | ops = kobj_child_ns_ops(kobj); |
| 94 | if (ops) { |
| 95 | BUG_ON(!kobj_ns_type_is_valid(ops->type)); |
| 96 | BUG_ON(!kobj_ns_type_registered(ops->type)); |
| 97 | |
| 98 | sysfs_enable_ns(kobj->sd); |
| 99 | } |
| 100 | |
| 101 | return 0; |
| 102 | } |
| 103 | |
| 104 | static int get_kobj_path_length(const struct kobject *kobj) |
| 105 | { |
| 106 | int length = 1; |
| 107 | const struct kobject *parent = kobj; |
| 108 | |
| 109 | /* walk up the ancestors until we hit the one pointing to the |
| 110 | * root. |
| 111 | * Add 1 to strlen for leading '/' of each level. |
| 112 | */ |
| 113 | do { |
| 114 | if (kobject_name(parent) == NULL) |
| 115 | return 0; |
| 116 | length += strlen(kobject_name(parent)) + 1; |
| 117 | parent = parent->parent; |
| 118 | } while (parent); |
| 119 | return length; |
| 120 | } |
| 121 | |
| 122 | static int fill_kobj_path(const struct kobject *kobj, char *path, int length) |
| 123 | { |
| 124 | const struct kobject *parent; |
| 125 | |
| 126 | --length; |
| 127 | for (parent = kobj; parent; parent = parent->parent) { |
| 128 | int cur = strlen(kobject_name(parent)); |
| 129 | /* back up enough to print this name with '/' */ |
| 130 | length -= cur; |
| 131 | if (length <= 0) |
| 132 | return -EINVAL; |
| 133 | memcpy(path + length, kobject_name(parent), cur); |
| 134 | *(path + --length) = '/'; |
| 135 | } |
| 136 | |
| 137 | pr_debug("'%s' (%p): %s: path = '%s'\n", kobject_name(kobj), |
| 138 | kobj, __func__, path); |
| 139 | |
| 140 | return 0; |
| 141 | } |
| 142 | |
| 143 | /** |
| 144 | * kobject_get_path() - Allocate memory and fill in the path for @kobj. |
| 145 | * @kobj: kobject in question, with which to build the path |
| 146 | * @gfp_mask: the allocation type used to allocate the path |
| 147 | * |
| 148 | * Return: The newly allocated memory, caller must free with kfree(). |
| 149 | */ |
| 150 | char *kobject_get_path(const struct kobject *kobj, gfp_t gfp_mask) |
| 151 | { |
| 152 | char *path; |
| 153 | int len; |
| 154 | |
| 155 | retry: |
| 156 | len = get_kobj_path_length(kobj); |
| 157 | if (len == 0) |
| 158 | return NULL; |
| 159 | path = kzalloc(len, gfp_mask); |
| 160 | if (!path) |
| 161 | return NULL; |
| 162 | if (fill_kobj_path(kobj, path, len)) { |
| 163 | kfree(path); |
| 164 | goto retry; |
| 165 | } |
| 166 | |
| 167 | return path; |
| 168 | } |
| 169 | EXPORT_SYMBOL_GPL(kobject_get_path); |
| 170 | |
| 171 | /* add the kobject to its kset's list */ |
| 172 | static void kobj_kset_join(struct kobject *kobj) |
| 173 | { |
| 174 | if (!kobj->kset) |
| 175 | return; |
| 176 | |
| 177 | kset_get(kobj->kset); |
| 178 | spin_lock(&kobj->kset->list_lock); |
| 179 | list_add_tail(&kobj->entry, &kobj->kset->list); |
| 180 | spin_unlock(&kobj->kset->list_lock); |
| 181 | } |
| 182 | |
| 183 | /* remove the kobject from its kset's list */ |
| 184 | static void kobj_kset_leave(struct kobject *kobj) |
| 185 | { |
| 186 | if (!kobj->kset) |
| 187 | return; |
| 188 | |
| 189 | spin_lock(&kobj->kset->list_lock); |
| 190 | list_del_init(&kobj->entry); |
| 191 | spin_unlock(&kobj->kset->list_lock); |
| 192 | kset_put(kobj->kset); |
| 193 | } |
| 194 | |
| 195 | static void kobject_init_internal(struct kobject *kobj) |
| 196 | { |
| 197 | if (!kobj) |
| 198 | return; |
| 199 | kref_init(&kobj->kref); |
| 200 | INIT_LIST_HEAD(&kobj->entry); |
| 201 | kobj->state_in_sysfs = 0; |
| 202 | kobj->state_add_uevent_sent = 0; |
| 203 | kobj->state_remove_uevent_sent = 0; |
| 204 | kobj->state_initialized = 1; |
| 205 | } |
| 206 | |
| 207 | |
| 208 | static int kobject_add_internal(struct kobject *kobj) |
| 209 | { |
| 210 | int error = 0; |
| 211 | struct kobject *parent; |
| 212 | |
| 213 | if (!kobj) |
| 214 | return -ENOENT; |
| 215 | |
| 216 | if (!kobj->name || !kobj->name[0]) { |
| 217 | WARN(1, |
| 218 | "kobject: (%p): attempted to be registered with empty name!\n", |
| 219 | kobj); |
| 220 | return -EINVAL; |
| 221 | } |
| 222 | |
| 223 | parent = kobject_get(kobj->parent); |
| 224 | |
| 225 | /* join kset if set, use it as parent if we do not already have one */ |
| 226 | if (kobj->kset) { |
| 227 | if (!parent) |
| 228 | parent = kobject_get(&kobj->kset->kobj); |
| 229 | kobj_kset_join(kobj); |
| 230 | kobj->parent = parent; |
| 231 | } |
| 232 | |
| 233 | pr_debug("'%s' (%p): %s: parent: '%s', set: '%s'\n", |
| 234 | kobject_name(kobj), kobj, __func__, |
| 235 | parent ? kobject_name(parent) : "<NULL>", |
| 236 | kobj->kset ? kobject_name(&kobj->kset->kobj) : "<NULL>"); |
| 237 | |
| 238 | error = create_dir(kobj); |
| 239 | if (error) { |
| 240 | kobj_kset_leave(kobj); |
| 241 | kobject_put(parent); |
| 242 | kobj->parent = NULL; |
| 243 | |
| 244 | /* be noisy on error issues */ |
| 245 | if (error == -EEXIST) |
| 246 | pr_err("%s failed for %s with -EEXIST, don't try to register things with the same name in the same directory.\n", |
| 247 | __func__, kobject_name(kobj)); |
| 248 | else |
| 249 | pr_err("%s failed for %s (error: %d parent: %s)\n", |
| 250 | __func__, kobject_name(kobj), error, |
| 251 | parent ? kobject_name(parent) : "'none'"); |
| 252 | } else |
| 253 | kobj->state_in_sysfs = 1; |
| 254 | |
| 255 | return error; |
| 256 | } |
| 257 | |
| 258 | /** |
| 259 | * kobject_set_name_vargs() - Set the name of a kobject. |
| 260 | * @kobj: struct kobject to set the name of |
| 261 | * @fmt: format string used to build the name |
| 262 | * @vargs: vargs to format the string. |
| 263 | */ |
| 264 | int kobject_set_name_vargs(struct kobject *kobj, const char *fmt, |
| 265 | va_list vargs) |
| 266 | { |
| 267 | const char *s; |
| 268 | |
| 269 | if (kobj->name && !fmt) |
| 270 | return 0; |
| 271 | |
| 272 | s = kvasprintf_const(GFP_KERNEL, fmt, vargs); |
| 273 | if (!s) |
| 274 | return -ENOMEM; |
| 275 | |
| 276 | /* |
| 277 | * ewww... some of these buggers have '/' in the name ... If |
| 278 | * that's the case, we need to make sure we have an actual |
| 279 | * allocated copy to modify, since kvasprintf_const may have |
| 280 | * returned something from .rodata. |
| 281 | */ |
| 282 | if (strchr(s, '/')) { |
| 283 | char *t; |
| 284 | |
| 285 | t = kstrdup(s, GFP_KERNEL); |
| 286 | kfree_const(s); |
| 287 | if (!t) |
| 288 | return -ENOMEM; |
| 289 | s = strreplace(t, '/', '!'); |
| 290 | } |
| 291 | kfree_const(kobj->name); |
| 292 | kobj->name = s; |
| 293 | |
| 294 | return 0; |
| 295 | } |
| 296 | |
| 297 | /** |
| 298 | * kobject_set_name() - Set the name of a kobject. |
| 299 | * @kobj: struct kobject to set the name of |
| 300 | * @fmt: format string used to build the name |
| 301 | * |
| 302 | * This sets the name of the kobject. If you have already added the |
| 303 | * kobject to the system, you must call kobject_rename() in order to |
| 304 | * change the name of the kobject. |
| 305 | */ |
| 306 | int kobject_set_name(struct kobject *kobj, const char *fmt, ...) |
| 307 | { |
| 308 | va_list vargs; |
| 309 | int retval; |
| 310 | |
| 311 | va_start(vargs, fmt); |
| 312 | retval = kobject_set_name_vargs(kobj, fmt, vargs); |
| 313 | va_end(vargs); |
| 314 | |
| 315 | return retval; |
| 316 | } |
| 317 | EXPORT_SYMBOL(kobject_set_name); |
| 318 | |
| 319 | /** |
| 320 | * kobject_init() - Initialize a kobject structure. |
| 321 | * @kobj: pointer to the kobject to initialize |
| 322 | * @ktype: pointer to the ktype for this kobject. |
| 323 | * |
| 324 | * This function will properly initialize a kobject such that it can then |
| 325 | * be passed to the kobject_add() call. |
| 326 | * |
| 327 | * After this function is called, the kobject MUST be cleaned up by a call |
| 328 | * to kobject_put(), not by a call to kfree directly to ensure that all of |
| 329 | * the memory is cleaned up properly. |
| 330 | */ |
| 331 | void kobject_init(struct kobject *kobj, const struct kobj_type *ktype) |
| 332 | { |
| 333 | char *err_str; |
| 334 | |
| 335 | if (!kobj) { |
| 336 | err_str = "invalid kobject pointer!"; |
| 337 | goto error; |
| 338 | } |
| 339 | if (!ktype) { |
| 340 | err_str = "must have a ktype to be initialized properly!\n"; |
| 341 | goto error; |
| 342 | } |
| 343 | if (kobj->state_initialized) { |
| 344 | /* do not error out as sometimes we can recover */ |
| 345 | pr_err("kobject (%p): tried to init an initialized object, something is seriously wrong.\n", |
| 346 | kobj); |
| 347 | dump_stack_lvl(KERN_ERR); |
| 348 | } |
| 349 | |
| 350 | kobject_init_internal(kobj); |
| 351 | kobj->ktype = ktype; |
| 352 | return; |
| 353 | |
| 354 | error: |
| 355 | pr_err("kobject (%p): %s\n", kobj, err_str); |
| 356 | dump_stack_lvl(KERN_ERR); |
| 357 | } |
| 358 | EXPORT_SYMBOL(kobject_init); |
| 359 | |
| 360 | static __printf(3, 0) int kobject_add_varg(struct kobject *kobj, |
| 361 | struct kobject *parent, |
| 362 | const char *fmt, va_list vargs) |
| 363 | { |
| 364 | int retval; |
| 365 | |
| 366 | retval = kobject_set_name_vargs(kobj, fmt, vargs); |
| 367 | if (retval) { |
| 368 | pr_err("can not set name properly!\n"); |
| 369 | return retval; |
| 370 | } |
| 371 | kobj->parent = parent; |
| 372 | return kobject_add_internal(kobj); |
| 373 | } |
| 374 | |
| 375 | /** |
| 376 | * kobject_add() - The main kobject add function. |
| 377 | * @kobj: the kobject to add |
| 378 | * @parent: pointer to the parent of the kobject. |
| 379 | * @fmt: format to name the kobject with. |
| 380 | * |
| 381 | * The kobject name is set and added to the kobject hierarchy in this |
| 382 | * function. |
| 383 | * |
| 384 | * If @parent is set, then the parent of the @kobj will be set to it. |
| 385 | * If @parent is NULL, then the parent of the @kobj will be set to the |
| 386 | * kobject associated with the kset assigned to this kobject. If no kset |
| 387 | * is assigned to the kobject, then the kobject will be located in the |
| 388 | * root of the sysfs tree. |
| 389 | * |
| 390 | * Note, no "add" uevent will be created with this call, the caller should set |
| 391 | * up all of the necessary sysfs files for the object and then call |
| 392 | * kobject_uevent() with the UEVENT_ADD parameter to ensure that |
| 393 | * userspace is properly notified of this kobject's creation. |
| 394 | * |
| 395 | * Return: If this function returns an error, kobject_put() must be |
| 396 | * called to properly clean up the memory associated with the |
| 397 | * object. Under no instance should the kobject that is passed |
| 398 | * to this function be directly freed with a call to kfree(), |
| 399 | * that can leak memory. |
| 400 | * |
| 401 | * If this function returns success, kobject_put() must also be called |
| 402 | * in order to properly clean up the memory associated with the object. |
| 403 | * |
| 404 | * In short, once this function is called, kobject_put() MUST be called |
| 405 | * when the use of the object is finished in order to properly free |
| 406 | * everything. |
| 407 | */ |
| 408 | int kobject_add(struct kobject *kobj, struct kobject *parent, |
| 409 | const char *fmt, ...) |
| 410 | { |
| 411 | va_list args; |
| 412 | int retval; |
| 413 | |
| 414 | if (!kobj) |
| 415 | return -EINVAL; |
| 416 | |
| 417 | if (!kobj->state_initialized) { |
| 418 | pr_err("kobject '%s' (%p): tried to add an uninitialized object, something is seriously wrong.\n", |
| 419 | kobject_name(kobj), kobj); |
| 420 | dump_stack_lvl(KERN_ERR); |
| 421 | return -EINVAL; |
| 422 | } |
| 423 | va_start(args, fmt); |
| 424 | retval = kobject_add_varg(kobj, parent, fmt, args); |
| 425 | va_end(args); |
| 426 | |
| 427 | return retval; |
| 428 | } |
| 429 | EXPORT_SYMBOL(kobject_add); |
| 430 | |
| 431 | /** |
| 432 | * kobject_init_and_add() - Initialize a kobject structure and add it to |
| 433 | * the kobject hierarchy. |
| 434 | * @kobj: pointer to the kobject to initialize |
| 435 | * @ktype: pointer to the ktype for this kobject. |
| 436 | * @parent: pointer to the parent of this kobject. |
| 437 | * @fmt: the name of the kobject. |
| 438 | * |
| 439 | * This function combines the call to kobject_init() and kobject_add(). |
| 440 | * |
| 441 | * If this function returns an error, kobject_put() must be called to |
| 442 | * properly clean up the memory associated with the object. This is the |
| 443 | * same type of error handling after a call to kobject_add() and kobject |
| 444 | * lifetime rules are the same here. |
| 445 | */ |
| 446 | int kobject_init_and_add(struct kobject *kobj, const struct kobj_type *ktype, |
| 447 | struct kobject *parent, const char *fmt, ...) |
| 448 | { |
| 449 | va_list args; |
| 450 | int retval; |
| 451 | |
| 452 | kobject_init(kobj, ktype); |
| 453 | |
| 454 | va_start(args, fmt); |
| 455 | retval = kobject_add_varg(kobj, parent, fmt, args); |
| 456 | va_end(args); |
| 457 | |
| 458 | return retval; |
| 459 | } |
| 460 | EXPORT_SYMBOL_GPL(kobject_init_and_add); |
| 461 | |
| 462 | /** |
| 463 | * kobject_rename() - Change the name of an object. |
| 464 | * @kobj: object in question. |
| 465 | * @new_name: object's new name |
| 466 | * |
| 467 | * It is the responsibility of the caller to provide mutual |
| 468 | * exclusion between two different calls of kobject_rename |
| 469 | * on the same kobject and to ensure that new_name is valid and |
| 470 | * won't conflict with other kobjects. |
| 471 | */ |
| 472 | int kobject_rename(struct kobject *kobj, const char *new_name) |
| 473 | { |
| 474 | int error = 0; |
| 475 | const char *devpath = NULL; |
| 476 | const char *dup_name = NULL, *name; |
| 477 | char *devpath_string = NULL; |
| 478 | char *envp[2]; |
| 479 | |
| 480 | kobj = kobject_get(kobj); |
| 481 | if (!kobj) |
| 482 | return -EINVAL; |
| 483 | if (!kobj->parent) { |
| 484 | kobject_put(kobj); |
| 485 | return -EINVAL; |
| 486 | } |
| 487 | |
| 488 | devpath = kobject_get_path(kobj, GFP_KERNEL); |
| 489 | if (!devpath) { |
| 490 | error = -ENOMEM; |
| 491 | goto out; |
| 492 | } |
| 493 | devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL); |
| 494 | if (!devpath_string) { |
| 495 | error = -ENOMEM; |
| 496 | goto out; |
| 497 | } |
| 498 | sprintf(devpath_string, "DEVPATH_OLD=%s", devpath); |
| 499 | envp[0] = devpath_string; |
| 500 | envp[1] = NULL; |
| 501 | |
| 502 | name = dup_name = kstrdup_const(new_name, GFP_KERNEL); |
| 503 | if (!name) { |
| 504 | error = -ENOMEM; |
| 505 | goto out; |
| 506 | } |
| 507 | |
| 508 | error = sysfs_rename_dir_ns(kobj, new_name, kobject_namespace(kobj)); |
| 509 | if (error) |
| 510 | goto out; |
| 511 | |
| 512 | /* Install the new kobject name */ |
| 513 | dup_name = kobj->name; |
| 514 | kobj->name = name; |
| 515 | |
| 516 | /* This function is mostly/only used for network interface. |
| 517 | * Some hotplug package track interfaces by their name and |
| 518 | * therefore want to know when the name is changed by the user. */ |
| 519 | kobject_uevent_env(kobj, KOBJ_MOVE, envp); |
| 520 | |
| 521 | out: |
| 522 | kfree_const(dup_name); |
| 523 | kfree(devpath_string); |
| 524 | kfree(devpath); |
| 525 | kobject_put(kobj); |
| 526 | |
| 527 | return error; |
| 528 | } |
| 529 | EXPORT_SYMBOL_GPL(kobject_rename); |
| 530 | |
| 531 | /** |
| 532 | * kobject_move() - Move object to another parent. |
| 533 | * @kobj: object in question. |
| 534 | * @new_parent: object's new parent (can be NULL) |
| 535 | */ |
| 536 | int kobject_move(struct kobject *kobj, struct kobject *new_parent) |
| 537 | { |
| 538 | int error; |
| 539 | struct kobject *old_parent; |
| 540 | const char *devpath = NULL; |
| 541 | char *devpath_string = NULL; |
| 542 | char *envp[2]; |
| 543 | |
| 544 | kobj = kobject_get(kobj); |
| 545 | if (!kobj) |
| 546 | return -EINVAL; |
| 547 | new_parent = kobject_get(new_parent); |
| 548 | if (!new_parent) { |
| 549 | if (kobj->kset) |
| 550 | new_parent = kobject_get(&kobj->kset->kobj); |
| 551 | } |
| 552 | |
| 553 | /* old object path */ |
| 554 | devpath = kobject_get_path(kobj, GFP_KERNEL); |
| 555 | if (!devpath) { |
| 556 | error = -ENOMEM; |
| 557 | goto out; |
| 558 | } |
| 559 | devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL); |
| 560 | if (!devpath_string) { |
| 561 | error = -ENOMEM; |
| 562 | goto out; |
| 563 | } |
| 564 | sprintf(devpath_string, "DEVPATH_OLD=%s", devpath); |
| 565 | envp[0] = devpath_string; |
| 566 | envp[1] = NULL; |
| 567 | error = sysfs_move_dir_ns(kobj, new_parent, kobject_namespace(kobj)); |
| 568 | if (error) |
| 569 | goto out; |
| 570 | old_parent = kobj->parent; |
| 571 | kobj->parent = new_parent; |
| 572 | new_parent = NULL; |
| 573 | kobject_put(old_parent); |
| 574 | kobject_uevent_env(kobj, KOBJ_MOVE, envp); |
| 575 | out: |
| 576 | kobject_put(new_parent); |
| 577 | kobject_put(kobj); |
| 578 | kfree(devpath_string); |
| 579 | kfree(devpath); |
| 580 | return error; |
| 581 | } |
| 582 | EXPORT_SYMBOL_GPL(kobject_move); |
| 583 | |
| 584 | static void __kobject_del(struct kobject *kobj) |
| 585 | { |
| 586 | struct kernfs_node *sd; |
| 587 | const struct kobj_type *ktype; |
| 588 | |
| 589 | sd = kobj->sd; |
| 590 | ktype = get_ktype(kobj); |
| 591 | |
| 592 | sysfs_remove_groups(kobj, ktype->default_groups); |
| 593 | |
| 594 | /* send "remove" if the caller did not do it but sent "add" */ |
| 595 | if (kobj->state_add_uevent_sent && !kobj->state_remove_uevent_sent) { |
| 596 | pr_debug("'%s' (%p): auto cleanup 'remove' event\n", |
| 597 | kobject_name(kobj), kobj); |
| 598 | kobject_uevent(kobj, KOBJ_REMOVE); |
| 599 | } |
| 600 | |
| 601 | sysfs_remove_dir(kobj); |
| 602 | sysfs_put(sd); |
| 603 | |
| 604 | kobj->state_in_sysfs = 0; |
| 605 | kobj_kset_leave(kobj); |
| 606 | kobj->parent = NULL; |
| 607 | } |
| 608 | |
| 609 | /** |
| 610 | * kobject_del() - Unlink kobject from hierarchy. |
| 611 | * @kobj: object. |
| 612 | * |
| 613 | * This is the function that should be called to delete an object |
| 614 | * successfully added via kobject_add(). |
| 615 | */ |
| 616 | void kobject_del(struct kobject *kobj) |
| 617 | { |
| 618 | struct kobject *parent; |
| 619 | |
| 620 | if (!kobj) |
| 621 | return; |
| 622 | |
| 623 | parent = kobj->parent; |
| 624 | __kobject_del(kobj); |
| 625 | kobject_put(parent); |
| 626 | } |
| 627 | EXPORT_SYMBOL(kobject_del); |
| 628 | |
| 629 | /** |
| 630 | * kobject_get() - Increment refcount for object. |
| 631 | * @kobj: object. |
| 632 | */ |
| 633 | struct kobject *kobject_get(struct kobject *kobj) |
| 634 | { |
| 635 | if (kobj) { |
| 636 | if (!kobj->state_initialized) |
| 637 | WARN(1, KERN_WARNING |
| 638 | "kobject: '%s' (%p): is not initialized, yet kobject_get() is being called.\n", |
| 639 | kobject_name(kobj), kobj); |
| 640 | kref_get(&kobj->kref); |
| 641 | } |
| 642 | return kobj; |
| 643 | } |
| 644 | EXPORT_SYMBOL(kobject_get); |
| 645 | |
| 646 | struct kobject * __must_check kobject_get_unless_zero(struct kobject *kobj) |
| 647 | { |
| 648 | if (!kobj) |
| 649 | return NULL; |
| 650 | if (!kref_get_unless_zero(&kobj->kref)) |
| 651 | kobj = NULL; |
| 652 | return kobj; |
| 653 | } |
| 654 | EXPORT_SYMBOL(kobject_get_unless_zero); |
| 655 | |
| 656 | /* |
| 657 | * kobject_cleanup - free kobject resources. |
| 658 | * @kobj: object to cleanup |
| 659 | */ |
| 660 | static void kobject_cleanup(struct kobject *kobj) |
| 661 | { |
| 662 | struct kobject *parent = kobj->parent; |
| 663 | const struct kobj_type *t = get_ktype(kobj); |
| 664 | const char *name = kobj->name; |
| 665 | |
| 666 | pr_debug("'%s' (%p): %s, parent %p\n", |
| 667 | kobject_name(kobj), kobj, __func__, kobj->parent); |
| 668 | |
| 669 | /* remove from sysfs if the caller did not do it */ |
| 670 | if (kobj->state_in_sysfs) { |
| 671 | pr_debug("'%s' (%p): auto cleanup kobject_del\n", |
| 672 | kobject_name(kobj), kobj); |
| 673 | __kobject_del(kobj); |
| 674 | } else { |
| 675 | /* avoid dropping the parent reference unnecessarily */ |
| 676 | parent = NULL; |
| 677 | } |
| 678 | |
| 679 | if (t->release) { |
| 680 | pr_debug("'%s' (%p): calling ktype release\n", |
| 681 | kobject_name(kobj), kobj); |
| 682 | t->release(kobj); |
| 683 | } else { |
| 684 | pr_debug("'%s' (%p): does not have a release() function, it is broken and must be fixed. See Documentation/core-api/kobject.rst.\n", |
| 685 | kobject_name(kobj), kobj); |
| 686 | } |
| 687 | |
| 688 | /* free name if we allocated it */ |
| 689 | if (name) { |
| 690 | pr_debug("'%s': free name\n", name); |
| 691 | kfree_const(name); |
| 692 | } |
| 693 | |
| 694 | kobject_put(parent); |
| 695 | } |
| 696 | |
| 697 | #ifdef CONFIG_DEBUG_KOBJECT_RELEASE |
| 698 | static void kobject_delayed_cleanup(struct work_struct *work) |
| 699 | { |
| 700 | kobject_cleanup(container_of(to_delayed_work(work), |
| 701 | struct kobject, release)); |
| 702 | } |
| 703 | #endif |
| 704 | |
| 705 | static void kobject_release(struct kref *kref) |
| 706 | { |
| 707 | struct kobject *kobj = container_of(kref, struct kobject, kref); |
| 708 | #ifdef CONFIG_DEBUG_KOBJECT_RELEASE |
| 709 | unsigned long delay = HZ + HZ * get_random_u32_below(4); |
| 710 | pr_info("'%s' (%p): %s, parent %p (delayed %ld)\n", |
| 711 | kobject_name(kobj), kobj, __func__, kobj->parent, delay); |
| 712 | INIT_DELAYED_WORK(&kobj->release, kobject_delayed_cleanup); |
| 713 | |
| 714 | schedule_delayed_work(&kobj->release, delay); |
| 715 | #else |
| 716 | kobject_cleanup(kobj); |
| 717 | #endif |
| 718 | } |
| 719 | |
| 720 | /** |
| 721 | * kobject_put() - Decrement refcount for object. |
| 722 | * @kobj: object. |
| 723 | * |
| 724 | * Decrement the refcount, and if 0, call kobject_cleanup(). |
| 725 | */ |
| 726 | void kobject_put(struct kobject *kobj) |
| 727 | { |
| 728 | if (kobj) { |
| 729 | if (!kobj->state_initialized) |
| 730 | WARN(1, KERN_WARNING |
| 731 | "kobject: '%s' (%p): is not initialized, yet kobject_put() is being called.\n", |
| 732 | kobject_name(kobj), kobj); |
| 733 | kref_put(&kobj->kref, kobject_release); |
| 734 | } |
| 735 | } |
| 736 | EXPORT_SYMBOL(kobject_put); |
| 737 | |
| 738 | static void dynamic_kobj_release(struct kobject *kobj) |
| 739 | { |
| 740 | pr_debug("(%p): %s\n", kobj, __func__); |
| 741 | kfree(kobj); |
| 742 | } |
| 743 | |
| 744 | static const struct kobj_type dynamic_kobj_ktype = { |
| 745 | .release = dynamic_kobj_release, |
| 746 | .sysfs_ops = &kobj_sysfs_ops, |
| 747 | }; |
| 748 | |
| 749 | /** |
| 750 | * kobject_create() - Create a struct kobject dynamically. |
| 751 | * |
| 752 | * This function creates a kobject structure dynamically and sets it up |
| 753 | * to be a "dynamic" kobject with a default release function set up. |
| 754 | * |
| 755 | * If the kobject was not able to be created, NULL will be returned. |
| 756 | * The kobject structure returned from here must be cleaned up with a |
| 757 | * call to kobject_put() and not kfree(), as kobject_init() has |
| 758 | * already been called on this structure. |
| 759 | */ |
| 760 | static struct kobject *kobject_create(void) |
| 761 | { |
| 762 | struct kobject *kobj; |
| 763 | |
| 764 | kobj = kzalloc(sizeof(*kobj), GFP_KERNEL); |
| 765 | if (!kobj) |
| 766 | return NULL; |
| 767 | |
| 768 | kobject_init(kobj, &dynamic_kobj_ktype); |
| 769 | return kobj; |
| 770 | } |
| 771 | |
| 772 | /** |
| 773 | * kobject_create_and_add() - Create a struct kobject dynamically and |
| 774 | * register it with sysfs. |
| 775 | * @name: the name for the kobject |
| 776 | * @parent: the parent kobject of this kobject, if any. |
| 777 | * |
| 778 | * This function creates a kobject structure dynamically and registers it |
| 779 | * with sysfs. When you are finished with this structure, call |
| 780 | * kobject_put() and the structure will be dynamically freed when |
| 781 | * it is no longer being used. |
| 782 | * |
| 783 | * If the kobject was not able to be created, NULL will be returned. |
| 784 | */ |
| 785 | struct kobject *kobject_create_and_add(const char *name, struct kobject *parent) |
| 786 | { |
| 787 | struct kobject *kobj; |
| 788 | int retval; |
| 789 | |
| 790 | kobj = kobject_create(); |
| 791 | if (!kobj) |
| 792 | return NULL; |
| 793 | |
| 794 | retval = kobject_add(kobj, parent, "%s", name); |
| 795 | if (retval) { |
| 796 | pr_warn("%s: kobject_add error: %d\n", __func__, retval); |
| 797 | kobject_put(kobj); |
| 798 | kobj = NULL; |
| 799 | } |
| 800 | return kobj; |
| 801 | } |
| 802 | EXPORT_SYMBOL_GPL(kobject_create_and_add); |
| 803 | |
| 804 | /** |
| 805 | * kset_init() - Initialize a kset for use. |
| 806 | * @k: kset |
| 807 | */ |
| 808 | void kset_init(struct kset *k) |
| 809 | { |
| 810 | kobject_init_internal(&k->kobj); |
| 811 | INIT_LIST_HEAD(&k->list); |
| 812 | spin_lock_init(&k->list_lock); |
| 813 | } |
| 814 | |
| 815 | /* default kobject attribute operations */ |
| 816 | static ssize_t kobj_attr_show(struct kobject *kobj, struct attribute *attr, |
| 817 | char *buf) |
| 818 | { |
| 819 | struct kobj_attribute *kattr; |
| 820 | ssize_t ret = -EIO; |
| 821 | |
| 822 | kattr = container_of(attr, struct kobj_attribute, attr); |
| 823 | if (kattr->show) |
| 824 | ret = kattr->show(kobj, kattr, buf); |
| 825 | return ret; |
| 826 | } |
| 827 | |
| 828 | static ssize_t kobj_attr_store(struct kobject *kobj, struct attribute *attr, |
| 829 | const char *buf, size_t count) |
| 830 | { |
| 831 | struct kobj_attribute *kattr; |
| 832 | ssize_t ret = -EIO; |
| 833 | |
| 834 | kattr = container_of(attr, struct kobj_attribute, attr); |
| 835 | if (kattr->store) |
| 836 | ret = kattr->store(kobj, kattr, buf, count); |
| 837 | return ret; |
| 838 | } |
| 839 | |
| 840 | const struct sysfs_ops kobj_sysfs_ops = { |
| 841 | .show = kobj_attr_show, |
| 842 | .store = kobj_attr_store, |
| 843 | }; |
| 844 | EXPORT_SYMBOL_GPL(kobj_sysfs_ops); |
| 845 | |
| 846 | /** |
| 847 | * kset_register() - Initialize and add a kset. |
| 848 | * @k: kset. |
| 849 | * |
| 850 | * NOTE: On error, the kset.kobj.name allocated by() kobj_set_name() |
| 851 | * is freed, it can not be used any more. |
| 852 | */ |
| 853 | int kset_register(struct kset *k) |
| 854 | { |
| 855 | int err; |
| 856 | |
| 857 | if (!k) |
| 858 | return -EINVAL; |
| 859 | |
| 860 | if (!k->kobj.ktype) { |
| 861 | pr_err("must have a ktype to be initialized properly!\n"); |
| 862 | return -EINVAL; |
| 863 | } |
| 864 | |
| 865 | kset_init(k); |
| 866 | err = kobject_add_internal(&k->kobj); |
| 867 | if (err) { |
| 868 | kfree_const(k->kobj.name); |
| 869 | /* Set it to NULL to avoid accessing bad pointer in callers. */ |
| 870 | k->kobj.name = NULL; |
| 871 | return err; |
| 872 | } |
| 873 | kobject_uevent(&k->kobj, KOBJ_ADD); |
| 874 | return 0; |
| 875 | } |
| 876 | EXPORT_SYMBOL(kset_register); |
| 877 | |
| 878 | /** |
| 879 | * kset_unregister() - Remove a kset. |
| 880 | * @k: kset. |
| 881 | */ |
| 882 | void kset_unregister(struct kset *k) |
| 883 | { |
| 884 | if (!k) |
| 885 | return; |
| 886 | kobject_del(&k->kobj); |
| 887 | kobject_put(&k->kobj); |
| 888 | } |
| 889 | EXPORT_SYMBOL(kset_unregister); |
| 890 | |
| 891 | /** |
| 892 | * kset_find_obj() - Search for object in kset. |
| 893 | * @kset: kset we're looking in. |
| 894 | * @name: object's name. |
| 895 | * |
| 896 | * Lock kset via @kset->subsys, and iterate over @kset->list, |
| 897 | * looking for a matching kobject. If matching object is found |
| 898 | * take a reference and return the object. |
| 899 | */ |
| 900 | struct kobject *kset_find_obj(struct kset *kset, const char *name) |
| 901 | { |
| 902 | struct kobject *k; |
| 903 | struct kobject *ret = NULL; |
| 904 | |
| 905 | spin_lock(&kset->list_lock); |
| 906 | |
| 907 | list_for_each_entry(k, &kset->list, entry) { |
| 908 | if (kobject_name(k) && !strcmp(kobject_name(k), name)) { |
| 909 | ret = kobject_get_unless_zero(k); |
| 910 | break; |
| 911 | } |
| 912 | } |
| 913 | |
| 914 | spin_unlock(&kset->list_lock); |
| 915 | return ret; |
| 916 | } |
| 917 | EXPORT_SYMBOL_GPL(kset_find_obj); |
| 918 | |
| 919 | static void kset_release(struct kobject *kobj) |
| 920 | { |
| 921 | struct kset *kset = container_of(kobj, struct kset, kobj); |
| 922 | pr_debug("'%s' (%p): %s\n", |
| 923 | kobject_name(kobj), kobj, __func__); |
| 924 | kfree(kset); |
| 925 | } |
| 926 | |
| 927 | static void kset_get_ownership(const struct kobject *kobj, kuid_t *uid, kgid_t *gid) |
| 928 | { |
| 929 | if (kobj->parent) |
| 930 | kobject_get_ownership(kobj->parent, uid, gid); |
| 931 | } |
| 932 | |
| 933 | static const struct kobj_type kset_ktype = { |
| 934 | .sysfs_ops = &kobj_sysfs_ops, |
| 935 | .release = kset_release, |
| 936 | .get_ownership = kset_get_ownership, |
| 937 | }; |
| 938 | |
| 939 | /** |
| 940 | * kset_create() - Create a struct kset dynamically. |
| 941 | * |
| 942 | * @name: the name for the kset |
| 943 | * @uevent_ops: a struct kset_uevent_ops for the kset |
| 944 | * @parent_kobj: the parent kobject of this kset, if any. |
| 945 | * |
| 946 | * This function creates a kset structure dynamically. This structure can |
| 947 | * then be registered with the system and show up in sysfs with a call to |
| 948 | * kset_register(). When you are finished with this structure, if |
| 949 | * kset_register() has been called, call kset_unregister() and the |
| 950 | * structure will be dynamically freed when it is no longer being used. |
| 951 | * |
| 952 | * If the kset was not able to be created, NULL will be returned. |
| 953 | */ |
| 954 | static struct kset *kset_create(const char *name, |
| 955 | const struct kset_uevent_ops *uevent_ops, |
| 956 | struct kobject *parent_kobj) |
| 957 | { |
| 958 | struct kset *kset; |
| 959 | int retval; |
| 960 | |
| 961 | kset = kzalloc(sizeof(*kset), GFP_KERNEL); |
| 962 | if (!kset) |
| 963 | return NULL; |
| 964 | retval = kobject_set_name(&kset->kobj, "%s", name); |
| 965 | if (retval) { |
| 966 | kfree(kset); |
| 967 | return NULL; |
| 968 | } |
| 969 | kset->uevent_ops = uevent_ops; |
| 970 | kset->kobj.parent = parent_kobj; |
| 971 | |
| 972 | /* |
| 973 | * The kobject of this kset will have a type of kset_ktype and belong to |
| 974 | * no kset itself. That way we can properly free it when it is |
| 975 | * finished being used. |
| 976 | */ |
| 977 | kset->kobj.ktype = &kset_ktype; |
| 978 | kset->kobj.kset = NULL; |
| 979 | |
| 980 | return kset; |
| 981 | } |
| 982 | |
| 983 | /** |
| 984 | * kset_create_and_add() - Create a struct kset dynamically and add it to sysfs. |
| 985 | * |
| 986 | * @name: the name for the kset |
| 987 | * @uevent_ops: a struct kset_uevent_ops for the kset |
| 988 | * @parent_kobj: the parent kobject of this kset, if any. |
| 989 | * |
| 990 | * This function creates a kset structure dynamically and registers it |
| 991 | * with sysfs. When you are finished with this structure, call |
| 992 | * kset_unregister() and the structure will be dynamically freed when it |
| 993 | * is no longer being used. |
| 994 | * |
| 995 | * If the kset was not able to be created, NULL will be returned. |
| 996 | */ |
| 997 | struct kset *kset_create_and_add(const char *name, |
| 998 | const struct kset_uevent_ops *uevent_ops, |
| 999 | struct kobject *parent_kobj) |
| 1000 | { |
| 1001 | struct kset *kset; |
| 1002 | int error; |
| 1003 | |
| 1004 | kset = kset_create(name, uevent_ops, parent_kobj); |
| 1005 | if (!kset) |
| 1006 | return NULL; |
| 1007 | error = kset_register(kset); |
| 1008 | if (error) { |
| 1009 | kfree(kset); |
| 1010 | return NULL; |
| 1011 | } |
| 1012 | return kset; |
| 1013 | } |
| 1014 | EXPORT_SYMBOL_GPL(kset_create_and_add); |
| 1015 | |
| 1016 | |
| 1017 | static DEFINE_SPINLOCK(kobj_ns_type_lock); |
| 1018 | static const struct kobj_ns_type_operations *kobj_ns_ops_tbl[KOBJ_NS_TYPES]; |
| 1019 | |
| 1020 | int kobj_ns_type_register(const struct kobj_ns_type_operations *ops) |
| 1021 | { |
| 1022 | enum kobj_ns_type type = ops->type; |
| 1023 | int error; |
| 1024 | |
| 1025 | spin_lock(&kobj_ns_type_lock); |
| 1026 | |
| 1027 | error = -EINVAL; |
| 1028 | if (!kobj_ns_type_is_valid(type)) |
| 1029 | goto out; |
| 1030 | |
| 1031 | error = -EBUSY; |
| 1032 | if (kobj_ns_ops_tbl[type]) |
| 1033 | goto out; |
| 1034 | |
| 1035 | error = 0; |
| 1036 | kobj_ns_ops_tbl[type] = ops; |
| 1037 | |
| 1038 | out: |
| 1039 | spin_unlock(&kobj_ns_type_lock); |
| 1040 | return error; |
| 1041 | } |
| 1042 | |
| 1043 | int kobj_ns_type_registered(enum kobj_ns_type type) |
| 1044 | { |
| 1045 | int registered = 0; |
| 1046 | |
| 1047 | spin_lock(&kobj_ns_type_lock); |
| 1048 | if (kobj_ns_type_is_valid(type)) |
| 1049 | registered = kobj_ns_ops_tbl[type] != NULL; |
| 1050 | spin_unlock(&kobj_ns_type_lock); |
| 1051 | |
| 1052 | return registered; |
| 1053 | } |
| 1054 | |
| 1055 | const struct kobj_ns_type_operations *kobj_child_ns_ops(const struct kobject *parent) |
| 1056 | { |
| 1057 | const struct kobj_ns_type_operations *ops = NULL; |
| 1058 | |
| 1059 | if (parent && parent->ktype->child_ns_type) |
| 1060 | ops = parent->ktype->child_ns_type(parent); |
| 1061 | |
| 1062 | return ops; |
| 1063 | } |
| 1064 | |
| 1065 | const struct kobj_ns_type_operations *kobj_ns_ops(const struct kobject *kobj) |
| 1066 | { |
| 1067 | return kobj_child_ns_ops(kobj->parent); |
| 1068 | } |
| 1069 | |
| 1070 | bool kobj_ns_current_may_mount(enum kobj_ns_type type) |
| 1071 | { |
| 1072 | bool may_mount = true; |
| 1073 | |
| 1074 | spin_lock(&kobj_ns_type_lock); |
| 1075 | if (kobj_ns_type_is_valid(type) && kobj_ns_ops_tbl[type]) |
| 1076 | may_mount = kobj_ns_ops_tbl[type]->current_may_mount(); |
| 1077 | spin_unlock(&kobj_ns_type_lock); |
| 1078 | |
| 1079 | return may_mount; |
| 1080 | } |
| 1081 | |
| 1082 | void *kobj_ns_grab_current(enum kobj_ns_type type) |
| 1083 | { |
| 1084 | void *ns = NULL; |
| 1085 | |
| 1086 | spin_lock(&kobj_ns_type_lock); |
| 1087 | if (kobj_ns_type_is_valid(type) && kobj_ns_ops_tbl[type]) |
| 1088 | ns = kobj_ns_ops_tbl[type]->grab_current_ns(); |
| 1089 | spin_unlock(&kobj_ns_type_lock); |
| 1090 | |
| 1091 | return ns; |
| 1092 | } |
| 1093 | EXPORT_SYMBOL_GPL(kobj_ns_grab_current); |
| 1094 | |
| 1095 | const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk) |
| 1096 | { |
| 1097 | const void *ns = NULL; |
| 1098 | |
| 1099 | spin_lock(&kobj_ns_type_lock); |
| 1100 | if (kobj_ns_type_is_valid(type) && kobj_ns_ops_tbl[type]) |
| 1101 | ns = kobj_ns_ops_tbl[type]->netlink_ns(sk); |
| 1102 | spin_unlock(&kobj_ns_type_lock); |
| 1103 | |
| 1104 | return ns; |
| 1105 | } |
| 1106 | |
| 1107 | const void *kobj_ns_initial(enum kobj_ns_type type) |
| 1108 | { |
| 1109 | const void *ns = NULL; |
| 1110 | |
| 1111 | spin_lock(&kobj_ns_type_lock); |
| 1112 | if (kobj_ns_type_is_valid(type) && kobj_ns_ops_tbl[type]) |
| 1113 | ns = kobj_ns_ops_tbl[type]->initial_ns(); |
| 1114 | spin_unlock(&kobj_ns_type_lock); |
| 1115 | |
| 1116 | return ns; |
| 1117 | } |
| 1118 | |
| 1119 | void kobj_ns_drop(enum kobj_ns_type type, void *ns) |
| 1120 | { |
| 1121 | spin_lock(&kobj_ns_type_lock); |
| 1122 | if (kobj_ns_type_is_valid(type) && |
| 1123 | kobj_ns_ops_tbl[type] && kobj_ns_ops_tbl[type]->drop_ns) |
| 1124 | kobj_ns_ops_tbl[type]->drop_ns(ns); |
| 1125 | spin_unlock(&kobj_ns_type_lock); |
| 1126 | } |
| 1127 | EXPORT_SYMBOL_GPL(kobj_ns_drop); |