Line data Source code
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/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 : */
30 728 : const void *kobject_namespace(struct kobject *kobj)
31 : {
32 : const struct kobj_ns_type_operations *ns_ops = kobj_ns_ops(kobj);
33 :
34 728 : if (!ns_ops || ns_ops->type == KOBJ_NS_TYPE_NONE)
35 : return NULL;
36 :
37 2 : return kobj->ktype->namespace(kobj);
38 : }
39 :
40 : /*
41 : * populate_dir - populate directory with attributes.
42 : * @kobj: object we're working on.
43 : *
44 : * Most subsystems have a set of default attributes that are associated
45 : * with an object that registers with them. This is a helper called during
46 : * object registration that loops through the default attributes of the
47 : * subsystem and creates attributes files for them in sysfs.
48 : */
49 728 : static int populate_dir(struct kobject *kobj)
50 : {
51 : struct kobj_type *t = get_ktype(kobj);
52 : struct attribute *attr;
53 : int error = 0;
54 : int i;
55 :
56 728 : if (t && t->default_attrs) {
57 590 : for (i = 0; (attr = t->default_attrs[i]) != NULL; i++) {
58 : error = sysfs_create_file(kobj, attr);
59 590 : if (error)
60 : break;
61 : }
62 : }
63 728 : return error;
64 : }
65 :
66 728 : static int create_dir(struct kobject *kobj)
67 : {
68 : const struct kobj_ns_type_operations *ops;
69 : int error;
70 :
71 728 : error = sysfs_create_dir_ns(kobj, kobject_namespace(kobj));
72 728 : if (error)
73 : return error;
74 :
75 728 : error = populate_dir(kobj);
76 728 : if (error) {
77 0 : sysfs_remove_dir(kobj);
78 0 : return error;
79 : }
80 :
81 : /*
82 : * @kobj->sd may be deleted by an ancestor going away. Hold an
83 : * extra reference so that it stays until @kobj is gone.
84 : */
85 728 : sysfs_get(kobj->sd);
86 :
87 : /*
88 : * If @kobj has ns_ops, its children need to be filtered based on
89 : * their namespace tags. Enable namespace support on @kobj->sd.
90 : */
91 : ops = kobj_child_ns_ops(kobj);
92 728 : if (ops) {
93 : BUG_ON(ops->type <= KOBJ_NS_TYPE_NONE);
94 : BUG_ON(ops->type >= KOBJ_NS_TYPES);
95 3 : BUG_ON(!kobj_ns_type_registered(ops->type));
96 :
97 3 : sysfs_enable_ns(kobj->sd);
98 : }
99 :
100 : return 0;
101 : }
102 :
103 876 : static int get_kobj_path_length(struct kobject *kobj)
104 : {
105 : int length = 1;
106 3097 : struct kobject *parent = kobj;
107 :
108 : /* walk up the ancestors until we hit the one pointing to the
109 : * root.
110 : * Add 1 to strlen for leading '/' of each level.
111 : */
112 : do {
113 3097 : if (kobject_name(parent) == NULL)
114 : return 0;
115 3097 : length += strlen(kobject_name(parent)) + 1;
116 3097 : parent = parent->parent;
117 3097 : } while (parent);
118 : return length;
119 : }
120 :
121 876 : static void fill_kobj_path(struct kobject *kobj, char *path, int length)
122 : {
123 3097 : struct kobject *parent;
124 :
125 876 : --length;
126 3973 : for (parent = kobj; parent; parent = parent->parent) {
127 3097 : int cur = strlen(kobject_name(parent));
128 : /* back up enough to print this name with '/' */
129 3097 : length -= cur;
130 3097 : strncpy(path + length, kobject_name(parent), cur);
131 3097 : *(path + --length) = '/';
132 : }
133 :
134 : pr_debug("kobject: '%s' (%p): %s: path = '%s'\n", kobject_name(kobj),
135 : kobj, __func__, path);
136 876 : }
137 :
138 : /**
139 : * kobject_get_path - generate and return the path associated with a given kobj and kset pair.
140 : *
141 : * @kobj: kobject in question, with which to build the path
142 : * @gfp_mask: the allocation type used to allocate the path
143 : *
144 : * The result must be freed by the caller with kfree().
145 : */
146 876 : char *kobject_get_path(struct kobject *kobj, gfp_t gfp_mask)
147 : {
148 : char *path;
149 : int len;
150 :
151 876 : len = get_kobj_path_length(kobj);
152 876 : if (len == 0)
153 : return NULL;
154 876 : path = kzalloc(len, gfp_mask);
155 876 : if (!path)
156 : return NULL;
157 876 : fill_kobj_path(kobj, path, len);
158 :
159 876 : return path;
160 : }
161 : EXPORT_SYMBOL_GPL(kobject_get_path);
162 :
163 : /* add the kobject to its kset's list */
164 568 : static void kobj_kset_join(struct kobject *kobj)
165 : {
166 568 : if (!kobj->kset)
167 568 : return;
168 :
169 : kset_get(kobj->kset);
170 : spin_lock(&kobj->kset->list_lock);
171 568 : list_add_tail(&kobj->entry, &kobj->kset->list);
172 : spin_unlock(&kobj->kset->list_lock);
173 : }
174 :
175 : /* remove the kobject from its kset's list */
176 16 : static void kobj_kset_leave(struct kobject *kobj)
177 : {
178 16 : if (!kobj->kset)
179 16 : return;
180 :
181 : spin_lock(&kobj->kset->list_lock);
182 16 : list_del_init(&kobj->entry);
183 : spin_unlock(&kobj->kset->list_lock);
184 16 : kset_put(kobj->kset);
185 : }
186 :
187 : static void kobject_init_internal(struct kobject *kobj)
188 : {
189 862 : if (!kobj)
190 : return;
191 : kref_init(&kobj->kref);
192 862 : INIT_LIST_HEAD(&kobj->entry);
193 862 : kobj->state_in_sysfs = 0;
194 862 : kobj->state_add_uevent_sent = 0;
195 862 : kobj->state_remove_uevent_sent = 0;
196 862 : kobj->state_initialized = 1;
197 : }
198 :
199 :
200 728 : static int kobject_add_internal(struct kobject *kobj)
201 : {
202 : int error = 0;
203 : struct kobject *parent;
204 :
205 728 : if (!kobj)
206 : return -ENOENT;
207 :
208 728 : if (!kobj->name || !kobj->name[0]) {
209 : WARN(1, "kobject: (%p): attempted to be registered with empty "
210 : "name!\n", kobj);
211 : return -EINVAL;
212 : }
213 :
214 728 : parent = kobject_get(kobj->parent);
215 :
216 : /* join kset if set, use it as parent if we do not already have one */
217 728 : if (kobj->kset) {
218 568 : if (!parent)
219 229 : parent = kobject_get(&kobj->kset->kobj);
220 568 : kobj_kset_join(kobj);
221 568 : kobj->parent = parent;
222 : }
223 :
224 : pr_debug("kobject: '%s' (%p): %s: parent: '%s', set: '%s'\n",
225 : kobject_name(kobj), kobj, __func__,
226 : parent ? kobject_name(parent) : "<NULL>",
227 : kobj->kset ? kobject_name(&kobj->kset->kobj) : "<NULL>");
228 :
229 728 : error = create_dir(kobj);
230 728 : if (error) {
231 0 : kobj_kset_leave(kobj);
232 0 : kobject_put(parent);
233 0 : kobj->parent = NULL;
234 :
235 : /* be noisy on error issues */
236 : if (error == -EEXIST)
237 : WARN(1, "%s failed for %s with "
238 : "-EEXIST, don't try to register things with "
239 : "the same name in the same directory.\n",
240 : __func__, kobject_name(kobj));
241 : else
242 : WARN(1, "%s failed for %s (error: %d parent: %s)\n",
243 : __func__, kobject_name(kobj), error,
244 : parent ? kobject_name(parent) : "'none'");
245 : } else
246 728 : kobj->state_in_sysfs = 1;
247 :
248 728 : return error;
249 : }
250 :
251 : /**
252 : * kobject_set_name_vargs - Set the name of an kobject
253 : * @kobj: struct kobject to set the name of
254 : * @fmt: format string used to build the name
255 : * @vargs: vargs to format the string.
256 : */
257 1019 : int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
258 : va_list vargs)
259 : {
260 1019 : const char *old_name = kobj->name;
261 : char *s;
262 :
263 1019 : if (kobj->name && !fmt)
264 : return 0;
265 :
266 744 : kobj->name = kvasprintf(GFP_KERNEL, fmt, vargs);
267 744 : if (!kobj->name) {
268 0 : kobj->name = old_name;
269 0 : return -ENOMEM;
270 : }
271 :
272 : /* ewww... some of these buggers have '/' in the name ... */
273 744 : while ((s = strchr(kobj->name, '/')))
274 0 : s[0] = '!';
275 :
276 744 : kfree(old_name);
277 744 : return 0;
278 : }
279 :
280 : /**
281 : * kobject_set_name - Set the name of a kobject
282 : * @kobj: struct kobject to set the name of
283 : * @fmt: format string used to build the name
284 : *
285 : * This sets the name of the kobject. If you have already added the
286 : * kobject to the system, you must call kobject_rename() in order to
287 : * change the name of the kobject.
288 : */
289 111 : int kobject_set_name(struct kobject *kobj, const char *fmt, ...)
290 : {
291 : va_list vargs;
292 : int retval;
293 :
294 111 : va_start(vargs, fmt);
295 111 : retval = kobject_set_name_vargs(kobj, fmt, vargs);
296 111 : va_end(vargs);
297 :
298 111 : return retval;
299 : }
300 : EXPORT_SYMBOL(kobject_set_name);
301 :
302 : /**
303 : * kobject_init - initialize a kobject structure
304 : * @kobj: pointer to the kobject to initialize
305 : * @ktype: pointer to the ktype for this kobject.
306 : *
307 : * This function will properly initialize a kobject such that it can then
308 : * be passed to the kobject_add() call.
309 : *
310 : * After this function is called, the kobject MUST be cleaned up by a call
311 : * to kobject_put(), not by a call to kfree directly to ensure that all of
312 : * the memory is cleaned up properly.
313 : */
314 723 : void kobject_init(struct kobject *kobj, struct kobj_type *ktype)
315 : {
316 : char *err_str;
317 :
318 723 : if (!kobj) {
319 : err_str = "invalid kobject pointer!";
320 : goto error;
321 : }
322 723 : if (!ktype) {
323 : err_str = "must have a ktype to be initialized properly!\n";
324 : goto error;
325 : }
326 723 : if (kobj->state_initialized) {
327 : /* do not error out as sometimes we can recover */
328 0 : printk(KERN_ERR "kobject (%p): tried to init an initialized "
329 : "object, something is seriously wrong.\n", kobj);
330 0 : dump_stack();
331 : }
332 :
333 : kobject_init_internal(kobj);
334 723 : kobj->ktype = ktype;
335 1446 : return;
336 :
337 : error:
338 0 : printk(KERN_ERR "kobject (%p): %s\n", kobj, err_str);
339 0 : dump_stack();
340 : }
341 : EXPORT_SYMBOL(kobject_init);
342 :
343 629 : static int kobject_add_varg(struct kobject *kobj, struct kobject *parent,
344 : const char *fmt, va_list vargs)
345 : {
346 : int retval;
347 :
348 629 : retval = kobject_set_name_vargs(kobj, fmt, vargs);
349 629 : if (retval) {
350 0 : printk(KERN_ERR "kobject: can not set name properly!\n");
351 0 : return retval;
352 : }
353 629 : kobj->parent = parent;
354 629 : return kobject_add_internal(kobj);
355 : }
356 :
357 : /**
358 : * kobject_add - the main kobject add function
359 : * @kobj: the kobject to add
360 : * @parent: pointer to the parent of the kobject.
361 : * @fmt: format to name the kobject with.
362 : *
363 : * The kobject name is set and added to the kobject hierarchy in this
364 : * function.
365 : *
366 : * If @parent is set, then the parent of the @kobj will be set to it.
367 : * If @parent is NULL, then the parent of the @kobj will be set to the
368 : * kobject associated with the kset assigned to this kobject. If no kset
369 : * is assigned to the kobject, then the kobject will be located in the
370 : * root of the sysfs tree.
371 : *
372 : * If this function returns an error, kobject_put() must be called to
373 : * properly clean up the memory associated with the object.
374 : * Under no instance should the kobject that is passed to this function
375 : * be directly freed with a call to kfree(), that can leak memory.
376 : *
377 : * Note, no "add" uevent will be created with this call, the caller should set
378 : * up all of the necessary sysfs files for the object and then call
379 : * kobject_uevent() with the UEVENT_ADD parameter to ensure that
380 : * userspace is properly notified of this kobject's creation.
381 : */
382 461 : int kobject_add(struct kobject *kobj, struct kobject *parent,
383 : const char *fmt, ...)
384 : {
385 : va_list args;
386 : int retval;
387 :
388 461 : if (!kobj)
389 : return -EINVAL;
390 :
391 461 : if (!kobj->state_initialized) {
392 0 : printk(KERN_ERR "kobject '%s' (%p): tried to add an "
393 : "uninitialized object, something is seriously wrong.\n",
394 : kobject_name(kobj), kobj);
395 0 : dump_stack();
396 0 : return -EINVAL;
397 : }
398 461 : va_start(args, fmt);
399 461 : retval = kobject_add_varg(kobj, parent, fmt, args);
400 461 : va_end(args);
401 :
402 461 : return retval;
403 : }
404 : EXPORT_SYMBOL(kobject_add);
405 :
406 : /**
407 : * kobject_init_and_add - initialize a kobject structure and add it to the kobject hierarchy
408 : * @kobj: pointer to the kobject to initialize
409 : * @ktype: pointer to the ktype for this kobject.
410 : * @parent: pointer to the parent of this kobject.
411 : * @fmt: the name of the kobject.
412 : *
413 : * This function combines the call to kobject_init() and
414 : * kobject_add(). The same type of error handling after a call to
415 : * kobject_add() and kobject lifetime rules are the same here.
416 : */
417 168 : int kobject_init_and_add(struct kobject *kobj, struct kobj_type *ktype,
418 : struct kobject *parent, const char *fmt, ...)
419 : {
420 : va_list args;
421 : int retval;
422 :
423 168 : kobject_init(kobj, ktype);
424 :
425 168 : va_start(args, fmt);
426 168 : retval = kobject_add_varg(kobj, parent, fmt, args);
427 168 : va_end(args);
428 :
429 168 : return retval;
430 : }
431 : EXPORT_SYMBOL_GPL(kobject_init_and_add);
432 :
433 : /**
434 : * kobject_rename - change the name of an object
435 : * @kobj: object in question.
436 : * @new_name: object's new name
437 : *
438 : * It is the responsibility of the caller to provide mutual
439 : * exclusion between two different calls of kobject_rename
440 : * on the same kobject and to ensure that new_name is valid and
441 : * won't conflict with other kobjects.
442 : */
443 0 : int kobject_rename(struct kobject *kobj, const char *new_name)
444 : {
445 : int error = 0;
446 : const char *devpath = NULL;
447 : const char *dup_name = NULL, *name;
448 : char *devpath_string = NULL;
449 : char *envp[2];
450 :
451 : kobj = kobject_get(kobj);
452 0 : if (!kobj)
453 : return -EINVAL;
454 0 : if (!kobj->parent)
455 : return -EINVAL;
456 :
457 0 : devpath = kobject_get_path(kobj, GFP_KERNEL);
458 0 : if (!devpath) {
459 : error = -ENOMEM;
460 : goto out;
461 : }
462 0 : devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL);
463 0 : if (!devpath_string) {
464 : error = -ENOMEM;
465 : goto out;
466 : }
467 0 : sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);
468 0 : envp[0] = devpath_string;
469 0 : envp[1] = NULL;
470 :
471 0 : name = dup_name = kstrdup(new_name, GFP_KERNEL);
472 0 : if (!name) {
473 : error = -ENOMEM;
474 : goto out;
475 : }
476 :
477 0 : error = sysfs_rename_dir_ns(kobj, new_name, kobject_namespace(kobj));
478 0 : if (error)
479 : goto out;
480 :
481 : /* Install the new kobject name */
482 0 : dup_name = kobj->name;
483 0 : kobj->name = name;
484 :
485 : /* This function is mostly/only used for network interface.
486 : * Some hotplug package track interfaces by their name and
487 : * therefore want to know when the name is changed by the user. */
488 0 : kobject_uevent_env(kobj, KOBJ_MOVE, envp);
489 :
490 : out:
491 0 : kfree(dup_name);
492 0 : kfree(devpath_string);
493 0 : kfree(devpath);
494 0 : kobject_put(kobj);
495 :
496 0 : return error;
497 : }
498 : EXPORT_SYMBOL_GPL(kobject_rename);
499 :
500 : /**
501 : * kobject_move - move object to another parent
502 : * @kobj: object in question.
503 : * @new_parent: object's new parent (can be NULL)
504 : */
505 0 : int kobject_move(struct kobject *kobj, struct kobject *new_parent)
506 : {
507 : int error;
508 : struct kobject *old_parent;
509 : const char *devpath = NULL;
510 : char *devpath_string = NULL;
511 : char *envp[2];
512 :
513 : kobj = kobject_get(kobj);
514 0 : if (!kobj)
515 : return -EINVAL;
516 : new_parent = kobject_get(new_parent);
517 0 : if (!new_parent) {
518 0 : if (kobj->kset)
519 0 : new_parent = kobject_get(&kobj->kset->kobj);
520 : }
521 :
522 : /* old object path */
523 0 : devpath = kobject_get_path(kobj, GFP_KERNEL);
524 0 : if (!devpath) {
525 : error = -ENOMEM;
526 : goto out;
527 : }
528 0 : devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL);
529 0 : if (!devpath_string) {
530 : error = -ENOMEM;
531 : goto out;
532 : }
533 0 : sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);
534 0 : envp[0] = devpath_string;
535 0 : envp[1] = NULL;
536 0 : error = sysfs_move_dir_ns(kobj, new_parent, kobject_namespace(kobj));
537 0 : if (error)
538 : goto out;
539 0 : old_parent = kobj->parent;
540 0 : kobj->parent = new_parent;
541 : new_parent = NULL;
542 0 : kobject_put(old_parent);
543 0 : kobject_uevent_env(kobj, KOBJ_MOVE, envp);
544 : out:
545 0 : kobject_put(new_parent);
546 0 : kobject_put(kobj);
547 0 : kfree(devpath_string);
548 0 : kfree(devpath);
549 0 : return error;
550 : }
551 :
552 : /**
553 : * kobject_del - unlink kobject from hierarchy.
554 : * @kobj: object.
555 : */
556 16 : void kobject_del(struct kobject *kobj)
557 : {
558 : struct kernfs_node *sd;
559 :
560 16 : if (!kobj)
561 16 : return;
562 :
563 16 : sd = kobj->sd;
564 16 : sysfs_remove_dir(kobj);
565 : sysfs_put(sd);
566 :
567 16 : kobj->state_in_sysfs = 0;
568 16 : kobj_kset_leave(kobj);
569 16 : kobject_put(kobj->parent);
570 16 : kobj->parent = NULL;
571 : }
572 :
573 : /**
574 : * kobject_get - increment refcount for object.
575 : * @kobj: object.
576 : */
577 4337 : struct kobject *kobject_get(struct kobject *kobj)
578 : {
579 5294 : if (kobj)
580 : kref_get(&kobj->kref);
581 4337 : return kobj;
582 : }
583 :
584 : static struct kobject * __must_check kobject_get_unless_zero(struct kobject *kobj)
585 : {
586 187 : if (!kref_get_unless_zero(&kobj->kref))
587 : kobj = NULL;
588 : return kobj;
589 : }
590 :
591 : /*
592 : * kobject_cleanup - free kobject resources.
593 : * @kobj: object to cleanup
594 : */
595 18 : static void kobject_cleanup(struct kobject *kobj)
596 : {
597 : struct kobj_type *t = get_ktype(kobj);
598 18 : const char *name = kobj->name;
599 :
600 : pr_debug("kobject: '%s' (%p): %s, parent %p\n",
601 : kobject_name(kobj), kobj, __func__, kobj->parent);
602 :
603 : if (t && !t->release)
604 : pr_debug("kobject: '%s' (%p): does not have a release() "
605 : "function, it is broken and must be fixed.\n",
606 : kobject_name(kobj), kobj);
607 :
608 : /* send "remove" if the caller did not do it but sent "add" */
609 18 : if (kobj->state_add_uevent_sent && !kobj->state_remove_uevent_sent) {
610 : pr_debug("kobject: '%s' (%p): auto cleanup 'remove' event\n",
611 : kobject_name(kobj), kobj);
612 0 : kobject_uevent(kobj, KOBJ_REMOVE);
613 : }
614 :
615 : /* remove from sysfs if the caller did not do it */
616 18 : if (kobj->state_in_sysfs) {
617 : pr_debug("kobject: '%s' (%p): auto cleanup kobject_del\n",
618 : kobject_name(kobj), kobj);
619 2 : kobject_del(kobj);
620 : }
621 :
622 18 : if (t && t->release) {
623 : pr_debug("kobject: '%s' (%p): calling ktype release\n",
624 : kobject_name(kobj), kobj);
625 18 : t->release(kobj);
626 : }
627 :
628 : /* free name if we allocated it */
629 18 : if (name) {
630 : pr_debug("kobject: '%s': free name\n", name);
631 16 : kfree(name);
632 : }
633 18 : }
634 :
635 : #ifdef CONFIG_DEBUG_KOBJECT_RELEASE
636 : static void kobject_delayed_cleanup(struct work_struct *work)
637 : {
638 : kobject_cleanup(container_of(to_delayed_work(work),
639 : struct kobject, release));
640 : }
641 : #endif
642 :
643 18 : static void kobject_release(struct kref *kref)
644 : {
645 18 : struct kobject *kobj = container_of(kref, struct kobject, kref);
646 : #ifdef CONFIG_DEBUG_KOBJECT_RELEASE
647 : unsigned long delay = HZ + HZ * (get_random_int() & 0x3);
648 : pr_info("kobject: '%s' (%p): %s, parent %p (delayed %ld)\n",
649 : kobject_name(kobj), kobj, __func__, kobj->parent, delay);
650 : INIT_DELAYED_WORK(&kobj->release, kobject_delayed_cleanup);
651 :
652 : schedule_delayed_work(&kobj->release, delay);
653 : #else
654 18 : kobject_cleanup(kobj);
655 : #endif
656 18 : }
657 :
658 : /**
659 : * kobject_put - decrement refcount for object.
660 : * @kobj: object.
661 : *
662 : * Decrement the refcount, and if 0, call kobject_cleanup().
663 : */
664 3146 : void kobject_put(struct kobject *kobj)
665 : {
666 3146 : if (kobj) {
667 : if (!kobj->state_initialized)
668 : WARN(1, KERN_WARNING "kobject: '%s' (%p): is not "
669 : "initialized, yet kobject_put() is being "
670 : "called.\n", kobject_name(kobj), kobj);
671 3146 : kref_put(&kobj->kref, kobject_release);
672 : }
673 3146 : }
674 :
675 0 : static void dynamic_kobj_release(struct kobject *kobj)
676 : {
677 : pr_debug("kobject: (%p): %s\n", kobj, __func__);
678 0 : kfree(kobj);
679 0 : }
680 :
681 : static struct kobj_type dynamic_kobj_ktype = {
682 : .release = dynamic_kobj_release,
683 : .sysfs_ops = &kobj_sysfs_ops,
684 : };
685 :
686 : /**
687 : * kobject_create - create a struct kobject dynamically
688 : *
689 : * This function creates a kobject structure dynamically and sets it up
690 : * to be a "dynamic" kobject with a default release function set up.
691 : *
692 : * If the kobject was not able to be created, NULL will be returned.
693 : * The kobject structure returned from here must be cleaned up with a
694 : * call to kobject_put() and not kfree(), as kobject_init() has
695 : * already been called on this structure.
696 : */
697 90 : struct kobject *kobject_create(void)
698 : {
699 : struct kobject *kobj;
700 :
701 : kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
702 90 : if (!kobj)
703 : return NULL;
704 :
705 90 : kobject_init(kobj, &dynamic_kobj_ktype);
706 90 : return kobj;
707 : }
708 :
709 : /**
710 : * kobject_create_and_add - create a struct kobject dynamically and register it with sysfs
711 : *
712 : * @name: the name for the kobject
713 : * @parent: the parent kobject of this kobject, if any.
714 : *
715 : * This function creates a kobject structure dynamically and registers it
716 : * with sysfs. When you are finished with this structure, call
717 : * kobject_put() and the structure will be dynamically freed when
718 : * it is no longer being used.
719 : *
720 : * If the kobject was not able to be created, NULL will be returned.
721 : */
722 89 : struct kobject *kobject_create_and_add(const char *name, struct kobject *parent)
723 : {
724 : struct kobject *kobj;
725 : int retval;
726 :
727 89 : kobj = kobject_create();
728 89 : if (!kobj)
729 : return NULL;
730 :
731 89 : retval = kobject_add(kobj, parent, "%s", name);
732 89 : if (retval) {
733 0 : printk(KERN_WARNING "%s: kobject_add error: %d\n",
734 : __func__, retval);
735 0 : kobject_put(kobj);
736 : kobj = NULL;
737 : }
738 89 : return kobj;
739 : }
740 : EXPORT_SYMBOL_GPL(kobject_create_and_add);
741 :
742 : /**
743 : * kset_init - initialize a kset for use
744 : * @k: kset
745 : */
746 40 : void kset_init(struct kset *k)
747 : {
748 139 : kobject_init_internal(&k->kobj);
749 139 : INIT_LIST_HEAD(&k->list);
750 : spin_lock_init(&k->list_lock);
751 40 : }
752 :
753 : /* default kobject attribute operations */
754 2 : static ssize_t kobj_attr_show(struct kobject *kobj, struct attribute *attr,
755 : char *buf)
756 : {
757 : struct kobj_attribute *kattr;
758 : ssize_t ret = -EIO;
759 :
760 : kattr = container_of(attr, struct kobj_attribute, attr);
761 2 : if (kattr->show)
762 2 : ret = kattr->show(kobj, kattr, buf);
763 2 : return ret;
764 : }
765 :
766 4 : static ssize_t kobj_attr_store(struct kobject *kobj, struct attribute *attr,
767 : const char *buf, size_t count)
768 : {
769 : struct kobj_attribute *kattr;
770 : ssize_t ret = -EIO;
771 :
772 : kattr = container_of(attr, struct kobj_attribute, attr);
773 4 : if (kattr->store)
774 4 : ret = kattr->store(kobj, kattr, buf, count);
775 4 : return ret;
776 : }
777 :
778 : const struct sysfs_ops kobj_sysfs_ops = {
779 : .show = kobj_attr_show,
780 : .store = kobj_attr_store,
781 : };
782 : EXPORT_SYMBOL_GPL(kobj_sysfs_ops);
783 :
784 : /**
785 : * kset_register - initialize and add a kset.
786 : * @k: kset.
787 : */
788 99 : int kset_register(struct kset *k)
789 : {
790 : int err;
791 :
792 99 : if (!k)
793 : return -EINVAL;
794 :
795 : kset_init(k);
796 99 : err = kobject_add_internal(&k->kobj);
797 99 : if (err)
798 : return err;
799 99 : kobject_uevent(&k->kobj, KOBJ_ADD);
800 99 : return 0;
801 : }
802 :
803 : /**
804 : * kset_unregister - remove a kset.
805 : * @k: kset.
806 : */
807 0 : void kset_unregister(struct kset *k)
808 : {
809 0 : if (!k)
810 0 : return;
811 0 : kobject_del(&k->kobj);
812 0 : kobject_put(&k->kobj);
813 : }
814 :
815 : /**
816 : * kset_find_obj - search for object in kset.
817 : * @kset: kset we're looking in.
818 : * @name: object's name.
819 : *
820 : * Lock kset via @kset->subsys, and iterate over @kset->list,
821 : * looking for a matching kobject. If matching object is found
822 : * take a reference and return the object.
823 : */
824 282 : struct kobject *kset_find_obj(struct kset *kset, const char *name)
825 : {
826 6178 : struct kobject *k;
827 : struct kobject *ret = NULL;
828 :
829 : spin_lock(&kset->list_lock);
830 :
831 6273 : list_for_each_entry(k, &kset->list, entry) {
832 6178 : if (kobject_name(k) && !strcmp(kobject_name(k), name)) {
833 : ret = kobject_get_unless_zero(k);
834 187 : break;
835 : }
836 : }
837 :
838 : spin_unlock(&kset->list_lock);
839 282 : return ret;
840 : }
841 :
842 0 : static void kset_release(struct kobject *kobj)
843 : {
844 0 : struct kset *kset = container_of(kobj, struct kset, kobj);
845 : pr_debug("kobject: '%s' (%p): %s\n",
846 : kobject_name(kobj), kobj, __func__);
847 0 : kfree(kset);
848 0 : }
849 :
850 : static struct kobj_type kset_ktype = {
851 : .sysfs_ops = &kobj_sysfs_ops,
852 : .release = kset_release,
853 : };
854 :
855 : /**
856 : * kset_create - create a struct kset dynamically
857 : *
858 : * @name: the name for the kset
859 : * @uevent_ops: a struct kset_uevent_ops for the kset
860 : * @parent_kobj: the parent kobject of this kset, if any.
861 : *
862 : * This function creates a kset structure dynamically. This structure can
863 : * then be registered with the system and show up in sysfs with a call to
864 : * kset_register(). When you are finished with this structure, if
865 : * kset_register() has been called, call kset_unregister() and the
866 : * structure will be dynamically freed when it is no longer being used.
867 : *
868 : * If the kset was not able to be created, NULL will be returned.
869 : */
870 43 : static struct kset *kset_create(const char *name,
871 : const struct kset_uevent_ops *uevent_ops,
872 : struct kobject *parent_kobj)
873 : {
874 : struct kset *kset;
875 : int retval;
876 :
877 : kset = kzalloc(sizeof(*kset), GFP_KERNEL);
878 43 : if (!kset)
879 : return NULL;
880 43 : retval = kobject_set_name(&kset->kobj, "%s", name);
881 43 : if (retval) {
882 0 : kfree(kset);
883 0 : return NULL;
884 : }
885 43 : kset->uevent_ops = uevent_ops;
886 43 : kset->kobj.parent = parent_kobj;
887 :
888 : /*
889 : * The kobject of this kset will have a type of kset_ktype and belong to
890 : * no kset itself. That way we can properly free it when it is
891 : * finished being used.
892 : */
893 43 : kset->kobj.ktype = &kset_ktype;
894 43 : kset->kobj.kset = NULL;
895 :
896 43 : return kset;
897 : }
898 :
899 : /**
900 : * kset_create_and_add - create a struct kset dynamically and add it to sysfs
901 : *
902 : * @name: the name for the kset
903 : * @uevent_ops: a struct kset_uevent_ops for the kset
904 : * @parent_kobj: the parent kobject of this kset, if any.
905 : *
906 : * This function creates a kset structure dynamically and registers it
907 : * with sysfs. When you are finished with this structure, call
908 : * kset_unregister() and the structure will be dynamically freed when it
909 : * is no longer being used.
910 : *
911 : * If the kset was not able to be created, NULL will be returned.
912 : */
913 43 : struct kset *kset_create_and_add(const char *name,
914 : const struct kset_uevent_ops *uevent_ops,
915 : struct kobject *parent_kobj)
916 : {
917 : struct kset *kset;
918 : int error;
919 :
920 43 : kset = kset_create(name, uevent_ops, parent_kobj);
921 43 : if (!kset)
922 : return NULL;
923 43 : error = kset_register(kset);
924 43 : if (error) {
925 0 : kfree(kset);
926 0 : return NULL;
927 : }
928 : return kset;
929 : }
930 : EXPORT_SYMBOL_GPL(kset_create_and_add);
931 :
932 :
933 : static DEFINE_SPINLOCK(kobj_ns_type_lock);
934 : static const struct kobj_ns_type_operations *kobj_ns_ops_tbl[KOBJ_NS_TYPES];
935 :
936 1 : int kobj_ns_type_register(const struct kobj_ns_type_operations *ops)
937 : {
938 1 : enum kobj_ns_type type = ops->type;
939 : int error;
940 :
941 : spin_lock(&kobj_ns_type_lock);
942 :
943 : error = -EINVAL;
944 1 : if (type >= KOBJ_NS_TYPES)
945 : goto out;
946 :
947 : error = -EINVAL;
948 1 : if (type <= KOBJ_NS_TYPE_NONE)
949 : goto out;
950 :
951 : error = -EBUSY;
952 1 : if (kobj_ns_ops_tbl[type])
953 : goto out;
954 :
955 : error = 0;
956 1 : kobj_ns_ops_tbl[type] = ops;
957 :
958 : out:
959 : spin_unlock(&kobj_ns_type_lock);
960 1 : return error;
961 : }
962 :
963 3 : int kobj_ns_type_registered(enum kobj_ns_type type)
964 : {
965 : int registered = 0;
966 :
967 : spin_lock(&kobj_ns_type_lock);
968 3 : if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES))
969 3 : registered = kobj_ns_ops_tbl[type] != NULL;
970 : spin_unlock(&kobj_ns_type_lock);
971 :
972 3 : return registered;
973 : }
974 :
975 0 : const struct kobj_ns_type_operations *kobj_child_ns_ops(struct kobject *parent)
976 : {
977 : const struct kobj_ns_type_operations *ops = NULL;
978 :
979 1747 : if (parent && parent->ktype && parent->ktype->child_ns_type)
980 432 : ops = parent->ktype->child_ns_type(parent);
981 :
982 0 : return ops;
983 : }
984 :
985 291 : const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj)
986 : {
987 1310 : return kobj_child_ns_ops(kobj->parent);
988 : }
989 :
990 1 : bool kobj_ns_current_may_mount(enum kobj_ns_type type)
991 : {
992 : bool may_mount = true;
993 :
994 : spin_lock(&kobj_ns_type_lock);
995 2 : if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
996 1 : kobj_ns_ops_tbl[type])
997 1 : may_mount = kobj_ns_ops_tbl[type]->current_may_mount();
998 : spin_unlock(&kobj_ns_type_lock);
999 :
1000 1 : return may_mount;
1001 : }
1002 :
1003 1 : void *kobj_ns_grab_current(enum kobj_ns_type type)
1004 : {
1005 : void *ns = NULL;
1006 :
1007 : spin_lock(&kobj_ns_type_lock);
1008 2 : if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1009 1 : kobj_ns_ops_tbl[type])
1010 1 : ns = kobj_ns_ops_tbl[type]->grab_current_ns();
1011 : spin_unlock(&kobj_ns_type_lock);
1012 :
1013 1 : return ns;
1014 : }
1015 :
1016 0 : const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk)
1017 : {
1018 : const void *ns = NULL;
1019 :
1020 : spin_lock(&kobj_ns_type_lock);
1021 0 : if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1022 0 : kobj_ns_ops_tbl[type])
1023 0 : ns = kobj_ns_ops_tbl[type]->netlink_ns(sk);
1024 : spin_unlock(&kobj_ns_type_lock);
1025 :
1026 0 : return ns;
1027 : }
1028 :
1029 0 : const void *kobj_ns_initial(enum kobj_ns_type type)
1030 : {
1031 : const void *ns = NULL;
1032 :
1033 : spin_lock(&kobj_ns_type_lock);
1034 0 : if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1035 0 : kobj_ns_ops_tbl[type])
1036 0 : ns = kobj_ns_ops_tbl[type]->initial_ns();
1037 : spin_unlock(&kobj_ns_type_lock);
1038 :
1039 0 : return ns;
1040 : }
1041 :
1042 0 : void kobj_ns_drop(enum kobj_ns_type type, void *ns)
1043 : {
1044 : spin_lock(&kobj_ns_type_lock);
1045 0 : if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1046 0 : kobj_ns_ops_tbl[type] && kobj_ns_ops_tbl[type]->drop_ns)
1047 0 : kobj_ns_ops_tbl[type]->drop_ns(ns);
1048 : spin_unlock(&kobj_ns_type_lock);
1049 0 : }
1050 :
1051 : EXPORT_SYMBOL(kobject_get);
1052 : EXPORT_SYMBOL(kobject_put);
1053 : EXPORT_SYMBOL(kobject_del);
1054 :
1055 : EXPORT_SYMBOL(kset_register);
1056 : EXPORT_SYMBOL(kset_unregister);
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