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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 const void *kobject_namespace(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 * 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 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 if (t && t->default_attrs) {
57 for (i = 0; (attr = t->default_attrs[i]) != NULL; i++) {
58 error = sysfs_create_file(kobj, attr);
59 if (error)
60 break;
61 }
62 }
63 return error;
64 }
65
66 static int create_dir(struct kobject *kobj)
67 {
68 const struct kobj_ns_type_operations *ops;
69 int error;
70
71 error = sysfs_create_dir_ns(kobj, kobject_namespace(kobj));
72 if (error)
73 return error;
74
75 error = populate_dir(kobj);
76 if (error) {
77 sysfs_remove_dir(kobj);
78 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 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 if (ops) {
93 BUG_ON(ops->type <= KOBJ_NS_TYPE_NONE);
94 BUG_ON(ops->type >= KOBJ_NS_TYPES);
95 BUG_ON(!kobj_ns_type_registered(ops->type));
96
97 sysfs_enable_ns(kobj->sd);
98 }
99
100 return 0;
101 }
102
103 static int get_kobj_path_length(struct kobject *kobj)
104 {
105 int length = 1;
106 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 if (kobject_name(parent) == NULL)
114 return 0;
115 length += strlen(kobject_name(parent)) + 1;
116 parent = parent->parent;
117 } while (parent);
118 return length;
119 }
120
121 static void fill_kobj_path(struct kobject *kobj, char *path, int length)
122 {
123 struct kobject *parent;
124
125 --length;
126 for (parent = kobj; parent; parent = parent->parent) {
127 int cur = strlen(kobject_name(parent));
128 /* back up enough to print this name with '/' */
129 length -= cur;
130 strncpy(path + length, kobject_name(parent), cur);
131 *(path + --length) = '/';
132 }
133
134 pr_debug("kobject: '%s' (%p): %s: path = '%s'\n", kobject_name(kobj),
135 kobj, __func__, path);
136 }
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 char *kobject_get_path(struct kobject *kobj, gfp_t gfp_mask)
147 {
148 char *path;
149 int len;
150
151 len = get_kobj_path_length(kobj);
152 if (len == 0)
153 return NULL;
154 path = kzalloc(len, gfp_mask);
155 if (!path)
156 return NULL;
157 fill_kobj_path(kobj, path, len);
158
159 return path;
160 }
161 EXPORT_SYMBOL_GPL(kobject_get_path);
162
163 /* add the kobject to its kset's list */
164 static void kobj_kset_join(struct kobject *kobj)
165 {
166 if (!kobj->kset)
167 return;
168
169 kset_get(kobj->kset);
170 spin_lock(&kobj->kset->list_lock);
171 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 static void kobj_kset_leave(struct kobject *kobj)
177 {
178 if (!kobj->kset)
179 return;
180
181 spin_lock(&kobj->kset->list_lock);
182 list_del_init(&kobj->entry);
183 spin_unlock(&kobj->kset->list_lock);
184 kset_put(kobj->kset);
185 }
186
187 static void kobject_init_internal(struct kobject *kobj)
188 {
189 if (!kobj)
190 return;
191 kref_init(&kobj->kref);
192 INIT_LIST_HEAD(&kobj->entry);
193 kobj->state_in_sysfs = 0;
194 kobj->state_add_uevent_sent = 0;
195 kobj->state_remove_uevent_sent = 0;
196 kobj->state_initialized = 1;
197 }
198
199
200 static int kobject_add_internal(struct kobject *kobj)
201 {
202 int error = 0;
203 struct kobject *parent;
204
205 if (!kobj)
206 return -ENOENT;
207
208 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 parent = kobject_get(kobj->parent);
215
216 /* join kset if set, use it as parent if we do not already have one */
217 if (kobj->kset) {
218 if (!parent)
219 parent = kobject_get(&kobj->kset->kobj);
220 kobj_kset_join(kobj);
221 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 error = create_dir(kobj);
230 if (error) {
231 kobj_kset_leave(kobj);
232 kobject_put(parent);
233 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 kobj->state_in_sysfs = 1;
247
248 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 int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
258 va_list vargs)
259 {
260 char *s;
261
262 if (kobj->name && !fmt)
263 return 0;
264
265 s = kvasprintf(GFP_KERNEL, fmt, vargs);
266 if (!s)
267 return -ENOMEM;
268
269 /* ewww... some of these buggers have '/' in the name ... */
270 strreplace(s, '/', '!');
271 kfree(kobj->name);
272 kobj->name = s;
273
274 return 0;
275 }
276
277 /**
278 * kobject_set_name - Set the name of a kobject
279 * @kobj: struct kobject to set the name of
280 * @fmt: format string used to build the name
281 *
282 * This sets the name of the kobject. If you have already added the
283 * kobject to the system, you must call kobject_rename() in order to
284 * change the name of the kobject.
285 */
286 int kobject_set_name(struct kobject *kobj, const char *fmt, ...)
287 {
288 va_list vargs;
289 int retval;
290
291 va_start(vargs, fmt);
292 retval = kobject_set_name_vargs(kobj, fmt, vargs);
293 va_end(vargs);
294
295 return retval;
296 }
297 EXPORT_SYMBOL(kobject_set_name);
298
299 /**
300 * kobject_init - initialize a kobject structure
301 * @kobj: pointer to the kobject to initialize
302 * @ktype: pointer to the ktype for this kobject.
303 *
304 * This function will properly initialize a kobject such that it can then
305 * be passed to the kobject_add() call.
306 *
307 * After this function is called, the kobject MUST be cleaned up by a call
308 * to kobject_put(), not by a call to kfree directly to ensure that all of
309 * the memory is cleaned up properly.
310 */
311 void kobject_init(struct kobject *kobj, struct kobj_type *ktype)
312 {
313 char *err_str;
314
315 if (!kobj) {
316 err_str = "invalid kobject pointer!";
317 goto error;
318 }
319 if (!ktype) {
320 err_str = "must have a ktype to be initialized properly!\n";
321 goto error;
322 }
323 if (kobj->state_initialized) {
324 /* do not error out as sometimes we can recover */
325 printk(KERN_ERR "kobject (%p): tried to init an initialized "
326 "object, something is seriously wrong.\n", kobj);
327 dump_stack();
328 }
329
330 kobject_init_internal(kobj);
331 kobj->ktype = ktype;
332 return;
333
334 error:
335 printk(KERN_ERR "kobject (%p): %s\n", kobj, err_str);
336 dump_stack();
337 }
338 EXPORT_SYMBOL(kobject_init);
339
340 static __printf(3, 0) int kobject_add_varg(struct kobject *kobj,
341 struct kobject *parent,
342 const char *fmt, va_list vargs)
343 {
344 int retval;
345
346 retval = kobject_set_name_vargs(kobj, fmt, vargs);
347 if (retval) {
348 printk(KERN_ERR "kobject: can not set name properly!\n");
349 return retval;
350 }
351 kobj->parent = parent;
352 return kobject_add_internal(kobj);
353 }
354
355 /**
356 * kobject_add - the main kobject add function
357 * @kobj: the kobject to add
358 * @parent: pointer to the parent of the kobject.
359 * @fmt: format to name the kobject with.
360 *
361 * The kobject name is set and added to the kobject hierarchy in this
362 * function.
363 *
364 * If @parent is set, then the parent of the @kobj will be set to it.
365 * If @parent is NULL, then the parent of the @kobj will be set to the
366 * kobject associated with the kset assigned to this kobject. If no kset
367 * is assigned to the kobject, then the kobject will be located in the
368 * root of the sysfs tree.
369 *
370 * If this function returns an error, kobject_put() must be called to
371 * properly clean up the memory associated with the object.
372 * Under no instance should the kobject that is passed to this function
373 * be directly freed with a call to kfree(), that can leak memory.
374 *
375 * Note, no "add" uevent will be created with this call, the caller should set
376 * up all of the necessary sysfs files for the object and then call
377 * kobject_uevent() with the UEVENT_ADD parameter to ensure that
378 * userspace is properly notified of this kobject's creation.
379 */
380 int kobject_add(struct kobject *kobj, struct kobject *parent,
381 const char *fmt, ...)
382 {
383 va_list args;
384 int retval;
385
386 if (!kobj)
387 return -EINVAL;
388
389 if (!kobj->state_initialized) {
390 printk(KERN_ERR "kobject '%s' (%p): tried to add an "
391 "uninitialized object, something is seriously wrong.\n",
392 kobject_name(kobj), kobj);
393 dump_stack();
394 return -EINVAL;
395 }
396 va_start(args, fmt);
397 retval = kobject_add_varg(kobj, parent, fmt, args);
398 va_end(args);
399
400 return retval;
401 }
402 EXPORT_SYMBOL(kobject_add);
403
404 /**
405 * kobject_init_and_add - initialize a kobject structure and add it to the kobject hierarchy
406 * @kobj: pointer to the kobject to initialize
407 * @ktype: pointer to the ktype for this kobject.
408 * @parent: pointer to the parent of this kobject.
409 * @fmt: the name of the kobject.
410 *
411 * This function combines the call to kobject_init() and
412 * kobject_add(). The same type of error handling after a call to
413 * kobject_add() and kobject lifetime rules are the same here.
414 */
415 int kobject_init_and_add(struct kobject *kobj, struct kobj_type *ktype,
416 struct kobject *parent, const char *fmt, ...)
417 {
418 va_list args;
419 int retval;
420
421 kobject_init(kobj, ktype);
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_GPL(kobject_init_and_add);
430
431 /**
432 * kobject_rename - change the name of an object
433 * @kobj: object in question.
434 * @new_name: object's new name
435 *
436 * It is the responsibility of the caller to provide mutual
437 * exclusion between two different calls of kobject_rename
438 * on the same kobject and to ensure that new_name is valid and
439 * won't conflict with other kobjects.
440 */
441 int kobject_rename(struct kobject *kobj, const char *new_name)
442 {
443 int error = 0;
444 const char *devpath = NULL;
445 const char *dup_name = NULL, *name;
446 char *devpath_string = NULL;
447 char *envp[2];
448
449 kobj = kobject_get(kobj);
450 if (!kobj)
451 return -EINVAL;
452 if (!kobj->parent)
453 return -EINVAL;
454
455 devpath = kobject_get_path(kobj, GFP_KERNEL);
456 if (!devpath) {
457 error = -ENOMEM;
458 goto out;
459 }
460 devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL);
461 if (!devpath_string) {
462 error = -ENOMEM;
463 goto out;
464 }
465 sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);
466 envp[0] = devpath_string;
467 envp[1] = NULL;
468
469 name = dup_name = kstrdup(new_name, GFP_KERNEL);
470 if (!name) {
471 error = -ENOMEM;
472 goto out;
473 }
474
475 error = sysfs_rename_dir_ns(kobj, new_name, kobject_namespace(kobj));
476 if (error)
477 goto out;
478
479 /* Install the new kobject name */
480 dup_name = kobj->name;
481 kobj->name = name;
482
483 /* This function is mostly/only used for network interface.
484 * Some hotplug package track interfaces by their name and
485 * therefore want to know when the name is changed by the user. */
486 kobject_uevent_env(kobj, KOBJ_MOVE, envp);
487
488 out:
489 kfree(dup_name);
490 kfree(devpath_string);
491 kfree(devpath);
492 kobject_put(kobj);
493
494 return error;
495 }
496 EXPORT_SYMBOL_GPL(kobject_rename);
497
498 /**
499 * kobject_move - move object to another parent
500 * @kobj: object in question.
501 * @new_parent: object's new parent (can be NULL)
502 */
503 int kobject_move(struct kobject *kobj, struct kobject *new_parent)
504 {
505 int error;
506 struct kobject *old_parent;
507 const char *devpath = NULL;
508 char *devpath_string = NULL;
509 char *envp[2];
510
511 kobj = kobject_get(kobj);
512 if (!kobj)
513 return -EINVAL;
514 new_parent = kobject_get(new_parent);
515 if (!new_parent) {
516 if (kobj->kset)
517 new_parent = kobject_get(&kobj->kset->kobj);
518 }
519
520 /* old object path */
521 devpath = kobject_get_path(kobj, GFP_KERNEL);
522 if (!devpath) {
523 error = -ENOMEM;
524 goto out;
525 }
526 devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL);
527 if (!devpath_string) {
528 error = -ENOMEM;
529 goto out;
530 }
531 sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);
532 envp[0] = devpath_string;
533 envp[1] = NULL;
534 error = sysfs_move_dir_ns(kobj, new_parent, kobject_namespace(kobj));
535 if (error)
536 goto out;
537 old_parent = kobj->parent;
538 kobj->parent = new_parent;
539 new_parent = NULL;
540 kobject_put(old_parent);
541 kobject_uevent_env(kobj, KOBJ_MOVE, envp);
542 out:
543 kobject_put(new_parent);
544 kobject_put(kobj);
545 kfree(devpath_string);
546 kfree(devpath);
547 return error;
548 }
549 EXPORT_SYMBOL_GPL(kobject_move);
550
551 /**
552 * kobject_del - unlink kobject from hierarchy.
553 * @kobj: object.
554 */
555 void kobject_del(struct kobject *kobj)
556 {
557 struct kernfs_node *sd;
558
559 if (!kobj)
560 return;
561
562 sd = kobj->sd;
563 sysfs_remove_dir(kobj);
564 sysfs_put(sd);
565
566 kobj->state_in_sysfs = 0;
567 kobj_kset_leave(kobj);
568 kobject_put(kobj->parent);
569 kobj->parent = NULL;
570 }
571
572 /**
573 * kobject_get - increment refcount for object.
574 * @kobj: object.
575 */
576 struct kobject *kobject_get(struct kobject *kobj)
577 {
578 if (kobj) {
579 if (!kobj->state_initialized)
580 WARN(1, KERN_WARNING "kobject: '%s' (%p): is not "
581 "initialized, yet kobject_get() is being "
582 "called.\n", kobject_name(kobj), kobj);
583 kref_get(&kobj->kref);
584 }
585 return kobj;
586 }
587
588 static struct kobject * __must_check kobject_get_unless_zero(struct kobject *kobj)
589 {
590 if (!kref_get_unless_zero(&kobj->kref))
591 kobj = NULL;
592 return kobj;
593 }
594
595 /*
596 * kobject_cleanup - free kobject resources.
597 * @kobj: object to cleanup
598 */
599 static void kobject_cleanup(struct kobject *kobj)
600 {
601 struct kobj_type *t = get_ktype(kobj);
602 const char *name = kobj->name;
603
604 pr_debug("kobject: '%s' (%p): %s, parent %p\n",
605 kobject_name(kobj), kobj, __func__, kobj->parent);
606
607 if (t && !t->release)
608 pr_debug("kobject: '%s' (%p): does not have a release() "
609 "function, it is broken and must be fixed.\n",
610 kobject_name(kobj), kobj);
611
612 /* send "remove" if the caller did not do it but sent "add" */
613 if (kobj->state_add_uevent_sent && !kobj->state_remove_uevent_sent) {
614 pr_debug("kobject: '%s' (%p): auto cleanup 'remove' event\n",
615 kobject_name(kobj), kobj);
616 kobject_uevent(kobj, KOBJ_REMOVE);
617 }
618
619 /* remove from sysfs if the caller did not do it */
620 if (kobj->state_in_sysfs) {
621 pr_debug("kobject: '%s' (%p): auto cleanup kobject_del\n",
622 kobject_name(kobj), kobj);
623 kobject_del(kobj);
624 }
625
626 if (t && t->release) {
627 pr_debug("kobject: '%s' (%p): calling ktype release\n",
628 kobject_name(kobj), kobj);
629 t->release(kobj);
630 }
631
632 /* free name if we allocated it */
633 if (name) {
634 pr_debug("kobject: '%s': free name\n", name);
635 kfree(name);
636 }
637 }
638
639 #ifdef CONFIG_DEBUG_KOBJECT_RELEASE
640 static void kobject_delayed_cleanup(struct work_struct *work)
641 {
642 kobject_cleanup(container_of(to_delayed_work(work),
643 struct kobject, release));
644 }
645 #endif
646
647 static void kobject_release(struct kref *kref)
648 {
649 struct kobject *kobj = container_of(kref, struct kobject, kref);
650 #ifdef CONFIG_DEBUG_KOBJECT_RELEASE
651 unsigned long delay = HZ + HZ * (get_random_int() & 0x3);
652 pr_info("kobject: '%s' (%p): %s, parent %p (delayed %ld)\n",
653 kobject_name(kobj), kobj, __func__, kobj->parent, delay);
654 INIT_DELAYED_WORK(&kobj->release, kobject_delayed_cleanup);
655
656 schedule_delayed_work(&kobj->release, delay);
657 #else
658 kobject_cleanup(kobj);
659 #endif
660 }
661
662 /**
663 * kobject_put - decrement refcount for object.
664 * @kobj: object.
665 *
666 * Decrement the refcount, and if 0, call kobject_cleanup().
667 */
668 void kobject_put(struct kobject *kobj)
669 {
670 if (kobj) {
671 if (!kobj->state_initialized)
672 WARN(1, KERN_WARNING "kobject: '%s' (%p): is not "
673 "initialized, yet kobject_put() is being "
674 "called.\n", kobject_name(kobj), kobj);
675 kref_put(&kobj->kref, kobject_release);
676 }
677 }
678
679 static void dynamic_kobj_release(struct kobject *kobj)
680 {
681 pr_debug("kobject: (%p): %s\n", kobj, __func__);
682 kfree(kobj);
683 }
684
685 static struct kobj_type dynamic_kobj_ktype = {
686 .release = dynamic_kobj_release,
687 .sysfs_ops = &kobj_sysfs_ops,
688 };
689
690 /**
691 * kobject_create - create a struct kobject dynamically
692 *
693 * This function creates a kobject structure dynamically and sets it up
694 * to be a "dynamic" kobject with a default release function set up.
695 *
696 * If the kobject was not able to be created, NULL will be returned.
697 * The kobject structure returned from here must be cleaned up with a
698 * call to kobject_put() and not kfree(), as kobject_init() has
699 * already been called on this structure.
700 */
701 struct kobject *kobject_create(void)
702 {
703 struct kobject *kobj;
704
705 kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
706 if (!kobj)
707 return NULL;
708
709 kobject_init(kobj, &dynamic_kobj_ktype);
710 return kobj;
711 }
712
713 /**
714 * kobject_create_and_add - create a struct kobject dynamically and register it with sysfs
715 *
716 * @name: the name for the kobject
717 * @parent: the parent kobject of this kobject, if any.
718 *
719 * This function creates a kobject structure dynamically and registers it
720 * with sysfs. When you are finished with this structure, call
721 * kobject_put() and the structure will be dynamically freed when
722 * it is no longer being used.
723 *
724 * If the kobject was not able to be created, NULL will be returned.
725 */
726 struct kobject *kobject_create_and_add(const char *name, struct kobject *parent)
727 {
728 struct kobject *kobj;
729 int retval;
730
731 kobj = kobject_create();
732 if (!kobj)
733 return NULL;
734
735 retval = kobject_add(kobj, parent, "%s", name);
736 if (retval) {
737 printk(KERN_WARNING "%s: kobject_add error: %d\n",
738 __func__, retval);
739 kobject_put(kobj);
740 kobj = NULL;
741 }
742 return kobj;
743 }
744 EXPORT_SYMBOL_GPL(kobject_create_and_add);
745
746 /**
747 * kset_init - initialize a kset for use
748 * @k: kset
749 */
750 void kset_init(struct kset *k)
751 {
752 kobject_init_internal(&k->kobj);
753 INIT_LIST_HEAD(&k->list);
754 spin_lock_init(&k->list_lock);
755 }
756
757 /* default kobject attribute operations */
758 static ssize_t kobj_attr_show(struct kobject *kobj, struct attribute *attr,
759 char *buf)
760 {
761 struct kobj_attribute *kattr;
762 ssize_t ret = -EIO;
763
764 kattr = container_of(attr, struct kobj_attribute, attr);
765 if (kattr->show)
766 ret = kattr->show(kobj, kattr, buf);
767 return ret;
768 }
769
770 static ssize_t kobj_attr_store(struct kobject *kobj, struct attribute *attr,
771 const char *buf, size_t count)
772 {
773 struct kobj_attribute *kattr;
774 ssize_t ret = -EIO;
775
776 kattr = container_of(attr, struct kobj_attribute, attr);
777 if (kattr->store)
778 ret = kattr->store(kobj, kattr, buf, count);
779 return ret;
780 }
781
782 const struct sysfs_ops kobj_sysfs_ops = {
783 .show = kobj_attr_show,
784 .store = kobj_attr_store,
785 };
786 EXPORT_SYMBOL_GPL(kobj_sysfs_ops);
787
788 /**
789 * kset_register - initialize and add a kset.
790 * @k: kset.
791 */
792 int kset_register(struct kset *k)
793 {
794 int err;
795
796 if (!k)
797 return -EINVAL;
798
799 kset_init(k);
800 err = kobject_add_internal(&k->kobj);
801 if (err)
802 return err;
803 kobject_uevent(&k->kobj, KOBJ_ADD);
804 return 0;
805 }
806
807 /**
808 * kset_unregister - remove a kset.
809 * @k: kset.
810 */
811 void kset_unregister(struct kset *k)
812 {
813 if (!k)
814 return;
815 kobject_del(&k->kobj);
816 kobject_put(&k->kobj);
817 }
818
819 /**
820 * kset_find_obj - search for object in kset.
821 * @kset: kset we're looking in.
822 * @name: object's name.
823 *
824 * Lock kset via @kset->subsys, and iterate over @kset->list,
825 * looking for a matching kobject. If matching object is found
826 * take a reference and return the object.
827 */
828 struct kobject *kset_find_obj(struct kset *kset, const char *name)
829 {
830 struct kobject *k;
831 struct kobject *ret = NULL;
832
833 spin_lock(&kset->list_lock);
834
835 list_for_each_entry(k, &kset->list, entry) {
836 if (kobject_name(k) && !strcmp(kobject_name(k), name)) {
837 ret = kobject_get_unless_zero(k);
838 break;
839 }
840 }
841
842 spin_unlock(&kset->list_lock);
843 return ret;
844 }
845
846 static void kset_release(struct kobject *kobj)
847 {
848 struct kset *kset = container_of(kobj, struct kset, kobj);
849 pr_debug("kobject: '%s' (%p): %s\n",
850 kobject_name(kobj), kobj, __func__);
851 kfree(kset);
852 }
853
854 static struct kobj_type kset_ktype = {
855 .sysfs_ops = &kobj_sysfs_ops,
856 .release = kset_release,
857 };
858
859 /**
860 * kset_create - create a struct kset dynamically
861 *
862 * @name: the name for the kset
863 * @uevent_ops: a struct kset_uevent_ops for the kset
864 * @parent_kobj: the parent kobject of this kset, if any.
865 *
866 * This function creates a kset structure dynamically. This structure can
867 * then be registered with the system and show up in sysfs with a call to
868 * kset_register(). When you are finished with this structure, if
869 * kset_register() has been called, call kset_unregister() and the
870 * structure will be dynamically freed when it is no longer being used.
871 *
872 * If the kset was not able to be created, NULL will be returned.
873 */
874 static struct kset *kset_create(const char *name,
875 const struct kset_uevent_ops *uevent_ops,
876 struct kobject *parent_kobj)
877 {
878 struct kset *kset;
879 int retval;
880
881 kset = kzalloc(sizeof(*kset), GFP_KERNEL);
882 if (!kset)
883 return NULL;
884 retval = kobject_set_name(&kset->kobj, "%s", name);
885 if (retval) {
886 kfree(kset);
887 return NULL;
888 }
889 kset->uevent_ops = uevent_ops;
890 kset->kobj.parent = parent_kobj;
891
892 /*
893 * The kobject of this kset will have a type of kset_ktype and belong to
894 * no kset itself. That way we can properly free it when it is
895 * finished being used.
896 */
897 kset->kobj.ktype = &kset_ktype;
898 kset->kobj.kset = NULL;
899
900 return kset;
901 }
902
903 /**
904 * kset_create_and_add - create a struct kset dynamically and add it to sysfs
905 *
906 * @name: the name for the kset
907 * @uevent_ops: a struct kset_uevent_ops for the kset
908 * @parent_kobj: the parent kobject of this kset, if any.
909 *
910 * This function creates a kset structure dynamically and registers it
911 * with sysfs. When you are finished with this structure, call
912 * kset_unregister() and the structure will be dynamically freed when it
913 * is no longer being used.
914 *
915 * If the kset was not able to be created, NULL will be returned.
916 */
917 struct kset *kset_create_and_add(const char *name,
918 const struct kset_uevent_ops *uevent_ops,
919 struct kobject *parent_kobj)
920 {
921 struct kset *kset;
922 int error;
923
924 kset = kset_create(name, uevent_ops, parent_kobj);
925 if (!kset)
926 return NULL;
927 error = kset_register(kset);
928 if (error) {
929 kfree(kset);
930 return NULL;
931 }
932 return kset;
933 }
934 EXPORT_SYMBOL_GPL(kset_create_and_add);
935
936
937 static DEFINE_SPINLOCK(kobj_ns_type_lock);
938 static const struct kobj_ns_type_operations *kobj_ns_ops_tbl[KOBJ_NS_TYPES];
939
940 int kobj_ns_type_register(const struct kobj_ns_type_operations *ops)
941 {
942 enum kobj_ns_type type = ops->type;
943 int error;
944
945 spin_lock(&kobj_ns_type_lock);
946
947 error = -EINVAL;
948 if (type >= KOBJ_NS_TYPES)
949 goto out;
950
951 error = -EINVAL;
952 if (type <= KOBJ_NS_TYPE_NONE)
953 goto out;
954
955 error = -EBUSY;
956 if (kobj_ns_ops_tbl[type])
957 goto out;
958
959 error = 0;
960 kobj_ns_ops_tbl[type] = ops;
961
962 out:
963 spin_unlock(&kobj_ns_type_lock);
964 return error;
965 }
966
967 int kobj_ns_type_registered(enum kobj_ns_type type)
968 {
969 int registered = 0;
970
971 spin_lock(&kobj_ns_type_lock);
972 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES))
973 registered = kobj_ns_ops_tbl[type] != NULL;
974 spin_unlock(&kobj_ns_type_lock);
975
976 return registered;
977 }
978
979 const struct kobj_ns_type_operations *kobj_child_ns_ops(struct kobject *parent)
980 {
981 const struct kobj_ns_type_operations *ops = NULL;
982
983 if (parent && parent->ktype && parent->ktype->child_ns_type)
984 ops = parent->ktype->child_ns_type(parent);
985
986 return ops;
987 }
988
989 const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj)
990 {
991 return kobj_child_ns_ops(kobj->parent);
992 }
993
994 bool kobj_ns_current_may_mount(enum kobj_ns_type type)
995 {
996 bool may_mount = true;
997
998 spin_lock(&kobj_ns_type_lock);
999 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1000 kobj_ns_ops_tbl[type])
1001 may_mount = kobj_ns_ops_tbl[type]->current_may_mount();
1002 spin_unlock(&kobj_ns_type_lock);
1003
1004 return may_mount;
1005 }
1006
1007 void *kobj_ns_grab_current(enum kobj_ns_type type)
1008 {
1009 void *ns = NULL;
1010
1011 spin_lock(&kobj_ns_type_lock);
1012 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1013 kobj_ns_ops_tbl[type])
1014 ns = kobj_ns_ops_tbl[type]->grab_current_ns();
1015 spin_unlock(&kobj_ns_type_lock);
1016
1017 return ns;
1018 }
1019
1020 const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk)
1021 {
1022 const void *ns = NULL;
1023
1024 spin_lock(&kobj_ns_type_lock);
1025 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1026 kobj_ns_ops_tbl[type])
1027 ns = kobj_ns_ops_tbl[type]->netlink_ns(sk);
1028 spin_unlock(&kobj_ns_type_lock);
1029
1030 return ns;
1031 }
1032
1033 const void *kobj_ns_initial(enum kobj_ns_type type)
1034 {
1035 const void *ns = NULL;
1036
1037 spin_lock(&kobj_ns_type_lock);
1038 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1039 kobj_ns_ops_tbl[type])
1040 ns = kobj_ns_ops_tbl[type]->initial_ns();
1041 spin_unlock(&kobj_ns_type_lock);
1042
1043 return ns;
1044 }
1045
1046 void kobj_ns_drop(enum kobj_ns_type type, void *ns)
1047 {
1048 spin_lock(&kobj_ns_type_lock);
1049 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1050 kobj_ns_ops_tbl[type] && kobj_ns_ops_tbl[type]->drop_ns)
1051 kobj_ns_ops_tbl[type]->drop_ns(ns);
1052 spin_unlock(&kobj_ns_type_lock);
1053 }
1054
1055 EXPORT_SYMBOL(kobject_get);
1056 EXPORT_SYMBOL(kobject_put);
1057 EXPORT_SYMBOL(kobject_del);
1058
1059 EXPORT_SYMBOL(kset_register);
1060 EXPORT_SYMBOL(kset_unregister);