| 1 | /* |
| 2 | * kobject.c - library routines for handling generic kernel objects |
| 3 | * |
| 4 | * Copyright (c) 2002-2003 Patrick Mochel <mochel@osdl.org> |
| 5 | * Copyright (c) 2006-2007 Greg Kroah-Hartman <greg@kroah.com> |
| 6 | * Copyright (c) 2006-2007 Novell Inc. |
| 7 | * |
| 8 | * This file is released under the GPLv2. |
| 9 | * |
| 10 | * |
| 11 | * Please see the file Documentation/kobject.txt for critical information |
| 12 | * about using the kobject interface. |
| 13 | */ |
| 14 | |
| 15 | #include <linux/kobject.h> |
| 16 | #include <linux/string.h> |
| 17 | #include <linux/module.h> |
| 18 | #include <linux/stat.h> |
| 19 | #include <linux/slab.h> |
| 20 | |
| 21 | /* |
| 22 | * populate_dir - populate directory with attributes. |
| 23 | * @kobj: object we're working on. |
| 24 | * |
| 25 | * Most subsystems have a set of default attributes that are associated |
| 26 | * with an object that registers with them. This is a helper called during |
| 27 | * object registration that loops through the default attributes of the |
| 28 | * subsystem and creates attributes files for them in sysfs. |
| 29 | */ |
| 30 | static int populate_dir(struct kobject *kobj) |
| 31 | { |
| 32 | struct kobj_type *t = get_ktype(kobj); |
| 33 | struct attribute *attr; |
| 34 | int error = 0; |
| 35 | int i; |
| 36 | |
| 37 | if (t && t->default_attrs) { |
| 38 | for (i = 0; (attr = t->default_attrs[i]) != NULL; i++) { |
| 39 | error = sysfs_create_file(kobj, attr); |
| 40 | if (error) |
| 41 | break; |
| 42 | } |
| 43 | } |
| 44 | return error; |
| 45 | } |
| 46 | |
| 47 | static int create_dir(struct kobject *kobj) |
| 48 | { |
| 49 | int error = 0; |
| 50 | if (kobject_name(kobj)) { |
| 51 | error = sysfs_create_dir(kobj); |
| 52 | if (!error) { |
| 53 | error = populate_dir(kobj); |
| 54 | if (error) |
| 55 | sysfs_remove_dir(kobj); |
| 56 | } |
| 57 | } |
| 58 | return error; |
| 59 | } |
| 60 | |
| 61 | static int get_kobj_path_length(struct kobject *kobj) |
| 62 | { |
| 63 | int length = 1; |
| 64 | struct kobject *parent = kobj; |
| 65 | |
| 66 | /* walk up the ancestors until we hit the one pointing to the |
| 67 | * root. |
| 68 | * Add 1 to strlen for leading '/' of each level. |
| 69 | */ |
| 70 | do { |
| 71 | if (kobject_name(parent) == NULL) |
| 72 | return 0; |
| 73 | length += strlen(kobject_name(parent)) + 1; |
| 74 | parent = parent->parent; |
| 75 | } while (parent); |
| 76 | return length; |
| 77 | } |
| 78 | |
| 79 | static void fill_kobj_path(struct kobject *kobj, char *path, int length) |
| 80 | { |
| 81 | struct kobject *parent; |
| 82 | |
| 83 | --length; |
| 84 | for (parent = kobj; parent; parent = parent->parent) { |
| 85 | int cur = strlen(kobject_name(parent)); |
| 86 | /* back up enough to print this name with '/' */ |
| 87 | length -= cur; |
| 88 | strncpy(path + length, kobject_name(parent), cur); |
| 89 | *(path + --length) = '/'; |
| 90 | } |
| 91 | |
| 92 | pr_debug("kobject: '%s' (%p): %s: path = '%s'\n", kobject_name(kobj), |
| 93 | kobj, __func__, path); |
| 94 | } |
| 95 | |
| 96 | /** |
| 97 | * kobject_get_path - generate and return the path associated with a given kobj and kset pair. |
| 98 | * |
| 99 | * @kobj: kobject in question, with which to build the path |
| 100 | * @gfp_mask: the allocation type used to allocate the path |
| 101 | * |
| 102 | * The result must be freed by the caller with kfree(). |
| 103 | */ |
| 104 | char *kobject_get_path(struct kobject *kobj, gfp_t gfp_mask) |
| 105 | { |
| 106 | char *path; |
| 107 | int len; |
| 108 | |
| 109 | len = get_kobj_path_length(kobj); |
| 110 | if (len == 0) |
| 111 | return NULL; |
| 112 | path = kzalloc(len, gfp_mask); |
| 113 | if (!path) |
| 114 | return NULL; |
| 115 | fill_kobj_path(kobj, path, len); |
| 116 | |
| 117 | return path; |
| 118 | } |
| 119 | EXPORT_SYMBOL_GPL(kobject_get_path); |
| 120 | |
| 121 | /* add the kobject to its kset's list */ |
| 122 | static void kobj_kset_join(struct kobject *kobj) |
| 123 | { |
| 124 | if (!kobj->kset) |
| 125 | return; |
| 126 | |
| 127 | kset_get(kobj->kset); |
| 128 | spin_lock(&kobj->kset->list_lock); |
| 129 | list_add_tail(&kobj->entry, &kobj->kset->list); |
| 130 | spin_unlock(&kobj->kset->list_lock); |
| 131 | } |
| 132 | |
| 133 | /* remove the kobject from its kset's list */ |
| 134 | static void kobj_kset_leave(struct kobject *kobj) |
| 135 | { |
| 136 | if (!kobj->kset) |
| 137 | return; |
| 138 | |
| 139 | spin_lock(&kobj->kset->list_lock); |
| 140 | list_del_init(&kobj->entry); |
| 141 | spin_unlock(&kobj->kset->list_lock); |
| 142 | kset_put(kobj->kset); |
| 143 | } |
| 144 | |
| 145 | static void kobject_init_internal(struct kobject *kobj) |
| 146 | { |
| 147 | if (!kobj) |
| 148 | return; |
| 149 | kref_init(&kobj->kref); |
| 150 | INIT_LIST_HEAD(&kobj->entry); |
| 151 | kobj->state_in_sysfs = 0; |
| 152 | kobj->state_add_uevent_sent = 0; |
| 153 | kobj->state_remove_uevent_sent = 0; |
| 154 | kobj->state_initialized = 1; |
| 155 | } |
| 156 | |
| 157 | |
| 158 | static int kobject_add_internal(struct kobject *kobj) |
| 159 | { |
| 160 | int error = 0; |
| 161 | struct kobject *parent; |
| 162 | |
| 163 | if (!kobj) |
| 164 | return -ENOENT; |
| 165 | |
| 166 | if (!kobj->name || !kobj->name[0]) { |
| 167 | WARN(1, "kobject: (%p): attempted to be registered with empty " |
| 168 | "name!\n", kobj); |
| 169 | return -EINVAL; |
| 170 | } |
| 171 | |
| 172 | parent = kobject_get(kobj->parent); |
| 173 | |
| 174 | /* join kset if set, use it as parent if we do not already have one */ |
| 175 | if (kobj->kset) { |
| 176 | if (!parent) |
| 177 | parent = kobject_get(&kobj->kset->kobj); |
| 178 | kobj_kset_join(kobj); |
| 179 | kobj->parent = parent; |
| 180 | } |
| 181 | |
| 182 | pr_debug("kobject: '%s' (%p): %s: parent: '%s', set: '%s'\n", |
| 183 | kobject_name(kobj), kobj, __func__, |
| 184 | parent ? kobject_name(parent) : "<NULL>", |
| 185 | kobj->kset ? kobject_name(&kobj->kset->kobj) : "<NULL>"); |
| 186 | |
| 187 | error = create_dir(kobj); |
| 188 | if (error) { |
| 189 | kobj_kset_leave(kobj); |
| 190 | kobject_put(parent); |
| 191 | kobj->parent = NULL; |
| 192 | |
| 193 | /* be noisy on error issues */ |
| 194 | if (error == -EEXIST) |
| 195 | printk(KERN_ERR "%s failed for %s with " |
| 196 | "-EEXIST, don't try to register things with " |
| 197 | "the same name in the same directory.\n", |
| 198 | __func__, kobject_name(kobj)); |
| 199 | else |
| 200 | printk(KERN_ERR "%s failed for %s (%d)\n", |
| 201 | __func__, kobject_name(kobj), error); |
| 202 | dump_stack(); |
| 203 | } else |
| 204 | kobj->state_in_sysfs = 1; |
| 205 | |
| 206 | return error; |
| 207 | } |
| 208 | |
| 209 | /** |
| 210 | * kobject_set_name_vargs - Set the name of an kobject |
| 211 | * @kobj: struct kobject to set the name of |
| 212 | * @fmt: format string used to build the name |
| 213 | * @vargs: vargs to format the string. |
| 214 | */ |
| 215 | int kobject_set_name_vargs(struct kobject *kobj, const char *fmt, |
| 216 | va_list vargs) |
| 217 | { |
| 218 | const char *old_name = kobj->name; |
| 219 | char *s; |
| 220 | |
| 221 | if (kobj->name && !fmt) |
| 222 | return 0; |
| 223 | |
| 224 | kobj->name = kvasprintf(GFP_KERNEL, fmt, vargs); |
| 225 | if (!kobj->name) |
| 226 | return -ENOMEM; |
| 227 | |
| 228 | /* ewww... some of these buggers have '/' in the name ... */ |
| 229 | while ((s = strchr(kobj->name, '/'))) |
| 230 | s[0] = '!'; |
| 231 | |
| 232 | kfree(old_name); |
| 233 | return 0; |
| 234 | } |
| 235 | |
| 236 | /** |
| 237 | * kobject_set_name - Set the name of a kobject |
| 238 | * @kobj: struct kobject to set the name of |
| 239 | * @fmt: format string used to build the name |
| 240 | * |
| 241 | * This sets the name of the kobject. If you have already added the |
| 242 | * kobject to the system, you must call kobject_rename() in order to |
| 243 | * change the name of the kobject. |
| 244 | */ |
| 245 | int kobject_set_name(struct kobject *kobj, const char *fmt, ...) |
| 246 | { |
| 247 | va_list vargs; |
| 248 | int retval; |
| 249 | |
| 250 | va_start(vargs, fmt); |
| 251 | retval = kobject_set_name_vargs(kobj, fmt, vargs); |
| 252 | va_end(vargs); |
| 253 | |
| 254 | return retval; |
| 255 | } |
| 256 | EXPORT_SYMBOL(kobject_set_name); |
| 257 | |
| 258 | /** |
| 259 | * kobject_init - initialize a kobject structure |
| 260 | * @kobj: pointer to the kobject to initialize |
| 261 | * @ktype: pointer to the ktype for this kobject. |
| 262 | * |
| 263 | * This function will properly initialize a kobject such that it can then |
| 264 | * be passed to the kobject_add() call. |
| 265 | * |
| 266 | * After this function is called, the kobject MUST be cleaned up by a call |
| 267 | * to kobject_put(), not by a call to kfree directly to ensure that all of |
| 268 | * the memory is cleaned up properly. |
| 269 | */ |
| 270 | void kobject_init(struct kobject *kobj, struct kobj_type *ktype) |
| 271 | { |
| 272 | char *err_str; |
| 273 | |
| 274 | if (!kobj) { |
| 275 | err_str = "invalid kobject pointer!"; |
| 276 | goto error; |
| 277 | } |
| 278 | if (!ktype) { |
| 279 | err_str = "must have a ktype to be initialized properly!\n"; |
| 280 | goto error; |
| 281 | } |
| 282 | if (kobj->state_initialized) { |
| 283 | /* do not error out as sometimes we can recover */ |
| 284 | printk(KERN_ERR "kobject (%p): tried to init an initialized " |
| 285 | "object, something is seriously wrong.\n", kobj); |
| 286 | dump_stack(); |
| 287 | } |
| 288 | |
| 289 | kobject_init_internal(kobj); |
| 290 | kobj->ktype = ktype; |
| 291 | return; |
| 292 | |
| 293 | error: |
| 294 | printk(KERN_ERR "kobject (%p): %s\n", kobj, err_str); |
| 295 | dump_stack(); |
| 296 | } |
| 297 | EXPORT_SYMBOL(kobject_init); |
| 298 | |
| 299 | static int kobject_add_varg(struct kobject *kobj, struct kobject *parent, |
| 300 | const char *fmt, va_list vargs) |
| 301 | { |
| 302 | int retval; |
| 303 | |
| 304 | retval = kobject_set_name_vargs(kobj, fmt, vargs); |
| 305 | if (retval) { |
| 306 | printk(KERN_ERR "kobject: can not set name properly!\n"); |
| 307 | return retval; |
| 308 | } |
| 309 | kobj->parent = parent; |
| 310 | return kobject_add_internal(kobj); |
| 311 | } |
| 312 | |
| 313 | /** |
| 314 | * kobject_add - the main kobject add function |
| 315 | * @kobj: the kobject to add |
| 316 | * @parent: pointer to the parent of the kobject. |
| 317 | * @fmt: format to name the kobject with. |
| 318 | * |
| 319 | * The kobject name is set and added to the kobject hierarchy in this |
| 320 | * function. |
| 321 | * |
| 322 | * If @parent is set, then the parent of the @kobj will be set to it. |
| 323 | * If @parent is NULL, then the parent of the @kobj will be set to the |
| 324 | * kobject associted with the kset assigned to this kobject. If no kset |
| 325 | * is assigned to the kobject, then the kobject will be located in the |
| 326 | * root of the sysfs tree. |
| 327 | * |
| 328 | * If this function returns an error, kobject_put() must be called to |
| 329 | * properly clean up the memory associated with the object. |
| 330 | * Under no instance should the kobject that is passed to this function |
| 331 | * be directly freed with a call to kfree(), that can leak memory. |
| 332 | * |
| 333 | * Note, no "add" uevent will be created with this call, the caller should set |
| 334 | * up all of the necessary sysfs files for the object and then call |
| 335 | * kobject_uevent() with the UEVENT_ADD parameter to ensure that |
| 336 | * userspace is properly notified of this kobject's creation. |
| 337 | */ |
| 338 | int kobject_add(struct kobject *kobj, struct kobject *parent, |
| 339 | const char *fmt, ...) |
| 340 | { |
| 341 | va_list args; |
| 342 | int retval; |
| 343 | |
| 344 | if (!kobj) |
| 345 | return -EINVAL; |
| 346 | |
| 347 | if (!kobj->state_initialized) { |
| 348 | printk(KERN_ERR "kobject '%s' (%p): tried to add an " |
| 349 | "uninitialized object, something is seriously wrong.\n", |
| 350 | kobject_name(kobj), kobj); |
| 351 | dump_stack(); |
| 352 | return -EINVAL; |
| 353 | } |
| 354 | va_start(args, fmt); |
| 355 | retval = kobject_add_varg(kobj, parent, fmt, args); |
| 356 | va_end(args); |
| 357 | |
| 358 | return retval; |
| 359 | } |
| 360 | EXPORT_SYMBOL(kobject_add); |
| 361 | |
| 362 | /** |
| 363 | * kobject_init_and_add - initialize a kobject structure and add it to the kobject hierarchy |
| 364 | * @kobj: pointer to the kobject to initialize |
| 365 | * @ktype: pointer to the ktype for this kobject. |
| 366 | * @parent: pointer to the parent of this kobject. |
| 367 | * @fmt: the name of the kobject. |
| 368 | * |
| 369 | * This function combines the call to kobject_init() and |
| 370 | * kobject_add(). The same type of error handling after a call to |
| 371 | * kobject_add() and kobject lifetime rules are the same here. |
| 372 | */ |
| 373 | int kobject_init_and_add(struct kobject *kobj, struct kobj_type *ktype, |
| 374 | struct kobject *parent, const char *fmt, ...) |
| 375 | { |
| 376 | va_list args; |
| 377 | int retval; |
| 378 | |
| 379 | kobject_init(kobj, ktype); |
| 380 | |
| 381 | va_start(args, fmt); |
| 382 | retval = kobject_add_varg(kobj, parent, fmt, args); |
| 383 | va_end(args); |
| 384 | |
| 385 | return retval; |
| 386 | } |
| 387 | EXPORT_SYMBOL_GPL(kobject_init_and_add); |
| 388 | |
| 389 | /** |
| 390 | * kobject_rename - change the name of an object |
| 391 | * @kobj: object in question. |
| 392 | * @new_name: object's new name |
| 393 | * |
| 394 | * It is the responsibility of the caller to provide mutual |
| 395 | * exclusion between two different calls of kobject_rename |
| 396 | * on the same kobject and to ensure that new_name is valid and |
| 397 | * won't conflict with other kobjects. |
| 398 | */ |
| 399 | int kobject_rename(struct kobject *kobj, const char *new_name) |
| 400 | { |
| 401 | int error = 0; |
| 402 | const char *devpath = NULL; |
| 403 | const char *dup_name = NULL, *name; |
| 404 | char *devpath_string = NULL; |
| 405 | char *envp[2]; |
| 406 | |
| 407 | kobj = kobject_get(kobj); |
| 408 | if (!kobj) |
| 409 | return -EINVAL; |
| 410 | if (!kobj->parent) |
| 411 | return -EINVAL; |
| 412 | |
| 413 | devpath = kobject_get_path(kobj, GFP_KERNEL); |
| 414 | if (!devpath) { |
| 415 | error = -ENOMEM; |
| 416 | goto out; |
| 417 | } |
| 418 | devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL); |
| 419 | if (!devpath_string) { |
| 420 | error = -ENOMEM; |
| 421 | goto out; |
| 422 | } |
| 423 | sprintf(devpath_string, "DEVPATH_OLD=%s", devpath); |
| 424 | envp[0] = devpath_string; |
| 425 | envp[1] = NULL; |
| 426 | |
| 427 | name = dup_name = kstrdup(new_name, GFP_KERNEL); |
| 428 | if (!name) { |
| 429 | error = -ENOMEM; |
| 430 | goto out; |
| 431 | } |
| 432 | |
| 433 | error = sysfs_rename_dir(kobj, new_name); |
| 434 | if (error) |
| 435 | goto out; |
| 436 | |
| 437 | /* Install the new kobject name */ |
| 438 | dup_name = kobj->name; |
| 439 | kobj->name = name; |
| 440 | |
| 441 | /* This function is mostly/only used for network interface. |
| 442 | * Some hotplug package track interfaces by their name and |
| 443 | * therefore want to know when the name is changed by the user. */ |
| 444 | kobject_uevent_env(kobj, KOBJ_MOVE, envp); |
| 445 | |
| 446 | out: |
| 447 | kfree(dup_name); |
| 448 | kfree(devpath_string); |
| 449 | kfree(devpath); |
| 450 | kobject_put(kobj); |
| 451 | |
| 452 | return error; |
| 453 | } |
| 454 | EXPORT_SYMBOL_GPL(kobject_rename); |
| 455 | |
| 456 | /** |
| 457 | * kobject_move - move object to another parent |
| 458 | * @kobj: object in question. |
| 459 | * @new_parent: object's new parent (can be NULL) |
| 460 | */ |
| 461 | int kobject_move(struct kobject *kobj, struct kobject *new_parent) |
| 462 | { |
| 463 | int error; |
| 464 | struct kobject *old_parent; |
| 465 | const char *devpath = NULL; |
| 466 | char *devpath_string = NULL; |
| 467 | char *envp[2]; |
| 468 | |
| 469 | kobj = kobject_get(kobj); |
| 470 | if (!kobj) |
| 471 | return -EINVAL; |
| 472 | new_parent = kobject_get(new_parent); |
| 473 | if (!new_parent) { |
| 474 | if (kobj->kset) |
| 475 | new_parent = kobject_get(&kobj->kset->kobj); |
| 476 | } |
| 477 | /* old object path */ |
| 478 | devpath = kobject_get_path(kobj, GFP_KERNEL); |
| 479 | if (!devpath) { |
| 480 | error = -ENOMEM; |
| 481 | goto out; |
| 482 | } |
| 483 | devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL); |
| 484 | if (!devpath_string) { |
| 485 | error = -ENOMEM; |
| 486 | goto out; |
| 487 | } |
| 488 | sprintf(devpath_string, "DEVPATH_OLD=%s", devpath); |
| 489 | envp[0] = devpath_string; |
| 490 | envp[1] = NULL; |
| 491 | error = sysfs_move_dir(kobj, new_parent); |
| 492 | if (error) |
| 493 | goto out; |
| 494 | old_parent = kobj->parent; |
| 495 | kobj->parent = new_parent; |
| 496 | new_parent = NULL; |
| 497 | kobject_put(old_parent); |
| 498 | kobject_uevent_env(kobj, KOBJ_MOVE, envp); |
| 499 | out: |
| 500 | kobject_put(new_parent); |
| 501 | kobject_put(kobj); |
| 502 | kfree(devpath_string); |
| 503 | kfree(devpath); |
| 504 | return error; |
| 505 | } |
| 506 | |
| 507 | /** |
| 508 | * kobject_del - unlink kobject from hierarchy. |
| 509 | * @kobj: object. |
| 510 | */ |
| 511 | void kobject_del(struct kobject *kobj) |
| 512 | { |
| 513 | if (!kobj) |
| 514 | return; |
| 515 | |
| 516 | sysfs_remove_dir(kobj); |
| 517 | kobj->state_in_sysfs = 0; |
| 518 | kobj_kset_leave(kobj); |
| 519 | kobject_put(kobj->parent); |
| 520 | kobj->parent = NULL; |
| 521 | } |
| 522 | |
| 523 | /** |
| 524 | * kobject_get - increment refcount for object. |
| 525 | * @kobj: object. |
| 526 | */ |
| 527 | struct kobject *kobject_get(struct kobject *kobj) |
| 528 | { |
| 529 | if (kobj) |
| 530 | kref_get(&kobj->kref); |
| 531 | return kobj; |
| 532 | } |
| 533 | |
| 534 | /* |
| 535 | * kobject_cleanup - free kobject resources. |
| 536 | * @kobj: object to cleanup |
| 537 | */ |
| 538 | static void kobject_cleanup(struct kobject *kobj) |
| 539 | { |
| 540 | struct kobj_type *t = get_ktype(kobj); |
| 541 | const char *name = kobj->name; |
| 542 | |
| 543 | pr_debug("kobject: '%s' (%p): %s\n", |
| 544 | kobject_name(kobj), kobj, __func__); |
| 545 | |
| 546 | if (t && !t->release) |
| 547 | pr_debug("kobject: '%s' (%p): does not have a release() " |
| 548 | "function, it is broken and must be fixed.\n", |
| 549 | kobject_name(kobj), kobj); |
| 550 | |
| 551 | /* send "remove" if the caller did not do it but sent "add" */ |
| 552 | if (kobj->state_add_uevent_sent && !kobj->state_remove_uevent_sent) { |
| 553 | pr_debug("kobject: '%s' (%p): auto cleanup 'remove' event\n", |
| 554 | kobject_name(kobj), kobj); |
| 555 | kobject_uevent(kobj, KOBJ_REMOVE); |
| 556 | } |
| 557 | |
| 558 | /* remove from sysfs if the caller did not do it */ |
| 559 | if (kobj->state_in_sysfs) { |
| 560 | pr_debug("kobject: '%s' (%p): auto cleanup kobject_del\n", |
| 561 | kobject_name(kobj), kobj); |
| 562 | kobject_del(kobj); |
| 563 | } |
| 564 | |
| 565 | if (t && t->release) { |
| 566 | pr_debug("kobject: '%s' (%p): calling ktype release\n", |
| 567 | kobject_name(kobj), kobj); |
| 568 | t->release(kobj); |
| 569 | } |
| 570 | |
| 571 | /* free name if we allocated it */ |
| 572 | if (name) { |
| 573 | pr_debug("kobject: '%s': free name\n", name); |
| 574 | kfree(name); |
| 575 | } |
| 576 | } |
| 577 | |
| 578 | static void kobject_release(struct kref *kref) |
| 579 | { |
| 580 | kobject_cleanup(container_of(kref, struct kobject, kref)); |
| 581 | } |
| 582 | |
| 583 | /** |
| 584 | * kobject_put - decrement refcount for object. |
| 585 | * @kobj: object. |
| 586 | * |
| 587 | * Decrement the refcount, and if 0, call kobject_cleanup(). |
| 588 | */ |
| 589 | void kobject_put(struct kobject *kobj) |
| 590 | { |
| 591 | if (kobj) { |
| 592 | if (!kobj->state_initialized) |
| 593 | WARN(1, KERN_WARNING "kobject: '%s' (%p): is not " |
| 594 | "initialized, yet kobject_put() is being " |
| 595 | "called.\n", kobject_name(kobj), kobj); |
| 596 | kref_put(&kobj->kref, kobject_release); |
| 597 | } |
| 598 | } |
| 599 | |
| 600 | static void dynamic_kobj_release(struct kobject *kobj) |
| 601 | { |
| 602 | pr_debug("kobject: (%p): %s\n", kobj, __func__); |
| 603 | kfree(kobj); |
| 604 | } |
| 605 | |
| 606 | static struct kobj_type dynamic_kobj_ktype = { |
| 607 | .release = dynamic_kobj_release, |
| 608 | .sysfs_ops = &kobj_sysfs_ops, |
| 609 | }; |
| 610 | |
| 611 | /** |
| 612 | * kobject_create - create a struct kobject dynamically |
| 613 | * |
| 614 | * This function creates a kobject structure dynamically and sets it up |
| 615 | * to be a "dynamic" kobject with a default release function set up. |
| 616 | * |
| 617 | * If the kobject was not able to be created, NULL will be returned. |
| 618 | * The kobject structure returned from here must be cleaned up with a |
| 619 | * call to kobject_put() and not kfree(), as kobject_init() has |
| 620 | * already been called on this structure. |
| 621 | */ |
| 622 | struct kobject *kobject_create(void) |
| 623 | { |
| 624 | struct kobject *kobj; |
| 625 | |
| 626 | kobj = kzalloc(sizeof(*kobj), GFP_KERNEL); |
| 627 | if (!kobj) |
| 628 | return NULL; |
| 629 | |
| 630 | kobject_init(kobj, &dynamic_kobj_ktype); |
| 631 | return kobj; |
| 632 | } |
| 633 | |
| 634 | /** |
| 635 | * kobject_create_and_add - create a struct kobject dynamically and register it with sysfs |
| 636 | * |
| 637 | * @name: the name for the kset |
| 638 | * @parent: the parent kobject of this kobject, if any. |
| 639 | * |
| 640 | * This function creates a kobject structure dynamically and registers it |
| 641 | * with sysfs. When you are finished with this structure, call |
| 642 | * kobject_put() and the structure will be dynamically freed when |
| 643 | * it is no longer being used. |
| 644 | * |
| 645 | * If the kobject was not able to be created, NULL will be returned. |
| 646 | */ |
| 647 | struct kobject *kobject_create_and_add(const char *name, struct kobject *parent) |
| 648 | { |
| 649 | struct kobject *kobj; |
| 650 | int retval; |
| 651 | |
| 652 | kobj = kobject_create(); |
| 653 | if (!kobj) |
| 654 | return NULL; |
| 655 | |
| 656 | retval = kobject_add(kobj, parent, "%s", name); |
| 657 | if (retval) { |
| 658 | printk(KERN_WARNING "%s: kobject_add error: %d\n", |
| 659 | __func__, retval); |
| 660 | kobject_put(kobj); |
| 661 | kobj = NULL; |
| 662 | } |
| 663 | return kobj; |
| 664 | } |
| 665 | EXPORT_SYMBOL_GPL(kobject_create_and_add); |
| 666 | |
| 667 | /** |
| 668 | * kset_init - initialize a kset for use |
| 669 | * @k: kset |
| 670 | */ |
| 671 | void kset_init(struct kset *k) |
| 672 | { |
| 673 | kobject_init_internal(&k->kobj); |
| 674 | INIT_LIST_HEAD(&k->list); |
| 675 | spin_lock_init(&k->list_lock); |
| 676 | } |
| 677 | |
| 678 | /* default kobject attribute operations */ |
| 679 | static ssize_t kobj_attr_show(struct kobject *kobj, struct attribute *attr, |
| 680 | char *buf) |
| 681 | { |
| 682 | struct kobj_attribute *kattr; |
| 683 | ssize_t ret = -EIO; |
| 684 | |
| 685 | kattr = container_of(attr, struct kobj_attribute, attr); |
| 686 | if (kattr->show) |
| 687 | ret = kattr->show(kobj, kattr, buf); |
| 688 | return ret; |
| 689 | } |
| 690 | |
| 691 | static ssize_t kobj_attr_store(struct kobject *kobj, struct attribute *attr, |
| 692 | const char *buf, size_t count) |
| 693 | { |
| 694 | struct kobj_attribute *kattr; |
| 695 | ssize_t ret = -EIO; |
| 696 | |
| 697 | kattr = container_of(attr, struct kobj_attribute, attr); |
| 698 | if (kattr->store) |
| 699 | ret = kattr->store(kobj, kattr, buf, count); |
| 700 | return ret; |
| 701 | } |
| 702 | |
| 703 | struct sysfs_ops kobj_sysfs_ops = { |
| 704 | .show = kobj_attr_show, |
| 705 | .store = kobj_attr_store, |
| 706 | }; |
| 707 | |
| 708 | /** |
| 709 | * kset_register - initialize and add a kset. |
| 710 | * @k: kset. |
| 711 | */ |
| 712 | int kset_register(struct kset *k) |
| 713 | { |
| 714 | int err; |
| 715 | |
| 716 | if (!k) |
| 717 | return -EINVAL; |
| 718 | |
| 719 | kset_init(k); |
| 720 | err = kobject_add_internal(&k->kobj); |
| 721 | if (err) |
| 722 | return err; |
| 723 | kobject_uevent(&k->kobj, KOBJ_ADD); |
| 724 | return 0; |
| 725 | } |
| 726 | |
| 727 | /** |
| 728 | * kset_unregister - remove a kset. |
| 729 | * @k: kset. |
| 730 | */ |
| 731 | void kset_unregister(struct kset *k) |
| 732 | { |
| 733 | if (!k) |
| 734 | return; |
| 735 | kobject_put(&k->kobj); |
| 736 | } |
| 737 | |
| 738 | /** |
| 739 | * kset_find_obj - search for object in kset. |
| 740 | * @kset: kset we're looking in. |
| 741 | * @name: object's name. |
| 742 | * |
| 743 | * Lock kset via @kset->subsys, and iterate over @kset->list, |
| 744 | * looking for a matching kobject. If matching object is found |
| 745 | * take a reference and return the object. |
| 746 | */ |
| 747 | struct kobject *kset_find_obj(struct kset *kset, const char *name) |
| 748 | { |
| 749 | struct kobject *k; |
| 750 | struct kobject *ret = NULL; |
| 751 | |
| 752 | spin_lock(&kset->list_lock); |
| 753 | list_for_each_entry(k, &kset->list, entry) { |
| 754 | if (kobject_name(k) && !strcmp(kobject_name(k), name)) { |
| 755 | ret = kobject_get(k); |
| 756 | break; |
| 757 | } |
| 758 | } |
| 759 | spin_unlock(&kset->list_lock); |
| 760 | return ret; |
| 761 | } |
| 762 | |
| 763 | static void kset_release(struct kobject *kobj) |
| 764 | { |
| 765 | struct kset *kset = container_of(kobj, struct kset, kobj); |
| 766 | pr_debug("kobject: '%s' (%p): %s\n", |
| 767 | kobject_name(kobj), kobj, __func__); |
| 768 | kfree(kset); |
| 769 | } |
| 770 | |
| 771 | static struct kobj_type kset_ktype = { |
| 772 | .sysfs_ops = &kobj_sysfs_ops, |
| 773 | .release = kset_release, |
| 774 | }; |
| 775 | |
| 776 | /** |
| 777 | * kset_create - create a struct kset dynamically |
| 778 | * |
| 779 | * @name: the name for the kset |
| 780 | * @uevent_ops: a struct kset_uevent_ops for the kset |
| 781 | * @parent_kobj: the parent kobject of this kset, if any. |
| 782 | * |
| 783 | * This function creates a kset structure dynamically. This structure can |
| 784 | * then be registered with the system and show up in sysfs with a call to |
| 785 | * kset_register(). When you are finished with this structure, if |
| 786 | * kset_register() has been called, call kset_unregister() and the |
| 787 | * structure will be dynamically freed when it is no longer being used. |
| 788 | * |
| 789 | * If the kset was not able to be created, NULL will be returned. |
| 790 | */ |
| 791 | static struct kset *kset_create(const char *name, |
| 792 | struct kset_uevent_ops *uevent_ops, |
| 793 | struct kobject *parent_kobj) |
| 794 | { |
| 795 | struct kset *kset; |
| 796 | int retval; |
| 797 | |
| 798 | kset = kzalloc(sizeof(*kset), GFP_KERNEL); |
| 799 | if (!kset) |
| 800 | return NULL; |
| 801 | retval = kobject_set_name(&kset->kobj, name); |
| 802 | if (retval) { |
| 803 | kfree(kset); |
| 804 | return NULL; |
| 805 | } |
| 806 | kset->uevent_ops = uevent_ops; |
| 807 | kset->kobj.parent = parent_kobj; |
| 808 | |
| 809 | /* |
| 810 | * The kobject of this kset will have a type of kset_ktype and belong to |
| 811 | * no kset itself. That way we can properly free it when it is |
| 812 | * finished being used. |
| 813 | */ |
| 814 | kset->kobj.ktype = &kset_ktype; |
| 815 | kset->kobj.kset = NULL; |
| 816 | |
| 817 | return kset; |
| 818 | } |
| 819 | |
| 820 | /** |
| 821 | * kset_create_and_add - create a struct kset dynamically and add it to sysfs |
| 822 | * |
| 823 | * @name: the name for the kset |
| 824 | * @uevent_ops: a struct kset_uevent_ops for the kset |
| 825 | * @parent_kobj: the parent kobject of this kset, if any. |
| 826 | * |
| 827 | * This function creates a kset structure dynamically and registers it |
| 828 | * with sysfs. When you are finished with this structure, call |
| 829 | * kset_unregister() and the structure will be dynamically freed when it |
| 830 | * is no longer being used. |
| 831 | * |
| 832 | * If the kset was not able to be created, NULL will be returned. |
| 833 | */ |
| 834 | struct kset *kset_create_and_add(const char *name, |
| 835 | struct kset_uevent_ops *uevent_ops, |
| 836 | struct kobject *parent_kobj) |
| 837 | { |
| 838 | struct kset *kset; |
| 839 | int error; |
| 840 | |
| 841 | kset = kset_create(name, uevent_ops, parent_kobj); |
| 842 | if (!kset) |
| 843 | return NULL; |
| 844 | error = kset_register(kset); |
| 845 | if (error) { |
| 846 | kfree(kset); |
| 847 | return NULL; |
| 848 | } |
| 849 | return kset; |
| 850 | } |
| 851 | EXPORT_SYMBOL_GPL(kset_create_and_add); |
| 852 | |
| 853 | EXPORT_SYMBOL(kobject_get); |
| 854 | EXPORT_SYMBOL(kobject_put); |
| 855 | EXPORT_SYMBOL(kobject_del); |
| 856 | |
| 857 | EXPORT_SYMBOL(kset_register); |
| 858 | EXPORT_SYMBOL(kset_unregister); |