projects/linux·blob v4.14 · refs

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1/*
2 * kobject.c - library routines for handling generic kernel objects
3 *
4 * Copyright (c) 2002-2003 Patrick Mochel <[email protected]>
5 * Copyright (c) 2006-2007 Greg Kroah-Hartman <[email protected]>
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 */
30const 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 */
49static 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
66static 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
103static 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
121static 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 */
146char *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}
161EXPORT_SYMBOL_GPL(kobject_get_path);
162
163/* add the kobject to its kset's list */
164static 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 */
176static 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
187static 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
200static 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 */
257int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
258 va_list vargs)
259{
260 const char *s;
261
262 if (kobj->name && !fmt)
263 return 0;
264
265 s = kvasprintf_const(GFP_KERNEL, fmt, vargs);
266 if (!s)
267 return -ENOMEM;
268
269 /*
270 * ewww... some of these buggers have '/' in the name ... If
271 * that's the case, we need to make sure we have an actual
272 * allocated copy to modify, since kvasprintf_const may have
273 * returned something from .rodata.
274 */
275 if (strchr(s, '/')) {
276 char *t;
277
278 t = kstrdup(s, GFP_KERNEL);
279 kfree_const(s);
280 if (!t)
281 return -ENOMEM;
282 strreplace(t, '/', '!');
283 s = t;
284 }
285 kfree_const(kobj->name);
286 kobj->name = s;
287
288 return 0;
289}
290
291/**
292 * kobject_set_name - Set the name of a kobject
293 * @kobj: struct kobject to set the name of
294 * @fmt: format string used to build the name
295 *
296 * This sets the name of the kobject. If you have already added the
297 * kobject to the system, you must call kobject_rename() in order to
298 * change the name of the kobject.
299 */
300int kobject_set_name(struct kobject *kobj, const char *fmt, ...)
301{
302 va_list vargs;
303 int retval;
304
305 va_start(vargs, fmt);
306 retval = kobject_set_name_vargs(kobj, fmt, vargs);
307 va_end(vargs);
308
309 return retval;
310}
311EXPORT_SYMBOL(kobject_set_name);
312
313/**
314 * kobject_init - initialize a kobject structure
315 * @kobj: pointer to the kobject to initialize
316 * @ktype: pointer to the ktype for this kobject.
317 *
318 * This function will properly initialize a kobject such that it can then
319 * be passed to the kobject_add() call.
320 *
321 * After this function is called, the kobject MUST be cleaned up by a call
322 * to kobject_put(), not by a call to kfree directly to ensure that all of
323 * the memory is cleaned up properly.
324 */
325void kobject_init(struct kobject *kobj, struct kobj_type *ktype)
326{
327 char *err_str;
328
329 if (!kobj) {
330 err_str = "invalid kobject pointer!";
331 goto error;
332 }
333 if (!ktype) {
334 err_str = "must have a ktype to be initialized properly!\n";
335 goto error;
336 }
337 if (kobj->state_initialized) {
338 /* do not error out as sometimes we can recover */
339 printk(KERN_ERR "kobject (%p): tried to init an initialized "
340 "object, something is seriously wrong.\n", kobj);
341 dump_stack();
342 }
343
344 kobject_init_internal(kobj);
345 kobj->ktype = ktype;
346 return;
347
348error:
349 printk(KERN_ERR "kobject (%p): %s\n", kobj, err_str);
350 dump_stack();
351}
352EXPORT_SYMBOL(kobject_init);
353
354static __printf(3, 0) int kobject_add_varg(struct kobject *kobj,
355 struct kobject *parent,
356 const char *fmt, va_list vargs)
357{
358 int retval;
359
360 retval = kobject_set_name_vargs(kobj, fmt, vargs);
361 if (retval) {
362 printk(KERN_ERR "kobject: can not set name properly!\n");
363 return retval;
364 }
365 kobj->parent = parent;
366 return kobject_add_internal(kobj);
367}
368
369/**
370 * kobject_add - the main kobject add function
371 * @kobj: the kobject to add
372 * @parent: pointer to the parent of the kobject.
373 * @fmt: format to name the kobject with.
374 *
375 * The kobject name is set and added to the kobject hierarchy in this
376 * function.
377 *
378 * If @parent is set, then the parent of the @kobj will be set to it.
379 * If @parent is NULL, then the parent of the @kobj will be set to the
380 * kobject associated with the kset assigned to this kobject. If no kset
381 * is assigned to the kobject, then the kobject will be located in the
382 * root of the sysfs tree.
383 *
384 * If this function returns an error, kobject_put() must be called to
385 * properly clean up the memory associated with the object.
386 * Under no instance should the kobject that is passed to this function
387 * be directly freed with a call to kfree(), that can leak memory.
388 *
389 * Note, no "add" uevent will be created with this call, the caller should set
390 * up all of the necessary sysfs files for the object and then call
391 * kobject_uevent() with the UEVENT_ADD parameter to ensure that
392 * userspace is properly notified of this kobject's creation.
393 */
394int kobject_add(struct kobject *kobj, struct kobject *parent,
395 const char *fmt, ...)
396{
397 va_list args;
398 int retval;
399
400 if (!kobj)
401 return -EINVAL;
402
403 if (!kobj->state_initialized) {
404 printk(KERN_ERR "kobject '%s' (%p): tried to add an "
405 "uninitialized object, something is seriously wrong.\n",
406 kobject_name(kobj), kobj);
407 dump_stack();
408 return -EINVAL;
409 }
410 va_start(args, fmt);
411 retval = kobject_add_varg(kobj, parent, fmt, args);
412 va_end(args);
413
414 return retval;
415}
416EXPORT_SYMBOL(kobject_add);
417
418/**
419 * kobject_init_and_add - initialize a kobject structure and add it to the kobject hierarchy
420 * @kobj: pointer to the kobject to initialize
421 * @ktype: pointer to the ktype for this kobject.
422 * @parent: pointer to the parent of this kobject.
423 * @fmt: the name of the kobject.
424 *
425 * This function combines the call to kobject_init() and
426 * kobject_add(). The same type of error handling after a call to
427 * kobject_add() and kobject lifetime rules are the same here.
428 */
429int kobject_init_and_add(struct kobject *kobj, struct kobj_type *ktype,
430 struct kobject *parent, const char *fmt, ...)
431{
432 va_list args;
433 int retval;
434
435 kobject_init(kobj, ktype);
436
437 va_start(args, fmt);
438 retval = kobject_add_varg(kobj, parent, fmt, args);
439 va_end(args);
440
441 return retval;
442}
443EXPORT_SYMBOL_GPL(kobject_init_and_add);
444
445/**
446 * kobject_rename - change the name of an object
447 * @kobj: object in question.
448 * @new_name: object's new name
449 *
450 * It is the responsibility of the caller to provide mutual
451 * exclusion between two different calls of kobject_rename
452 * on the same kobject and to ensure that new_name is valid and
453 * won't conflict with other kobjects.
454 */
455int kobject_rename(struct kobject *kobj, const char *new_name)
456{
457 int error = 0;
458 const char *devpath = NULL;
459 const char *dup_name = NULL, *name;
460 char *devpath_string = NULL;
461 char *envp[2];
462
463 kobj = kobject_get(kobj);
464 if (!kobj)
465 return -EINVAL;
466 if (!kobj->parent)
467 return -EINVAL;
468
469 devpath = kobject_get_path(kobj, GFP_KERNEL);
470 if (!devpath) {
471 error = -ENOMEM;
472 goto out;
473 }
474 devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL);
475 if (!devpath_string) {
476 error = -ENOMEM;
477 goto out;
478 }
479 sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);
480 envp[0] = devpath_string;
481 envp[1] = NULL;
482
483 name = dup_name = kstrdup_const(new_name, GFP_KERNEL);
484 if (!name) {
485 error = -ENOMEM;
486 goto out;
487 }
488
489 error = sysfs_rename_dir_ns(kobj, new_name, kobject_namespace(kobj));
490 if (error)
491 goto out;
492
493 /* Install the new kobject name */
494 dup_name = kobj->name;
495 kobj->name = name;
496
497 /* This function is mostly/only used for network interface.
498 * Some hotplug package track interfaces by their name and
499 * therefore want to know when the name is changed by the user. */
500 kobject_uevent_env(kobj, KOBJ_MOVE, envp);
501
502out:
503 kfree_const(dup_name);
504 kfree(devpath_string);
505 kfree(devpath);
506 kobject_put(kobj);
507
508 return error;
509}
510EXPORT_SYMBOL_GPL(kobject_rename);
511
512/**
513 * kobject_move - move object to another parent
514 * @kobj: object in question.
515 * @new_parent: object's new parent (can be NULL)
516 */
517int kobject_move(struct kobject *kobj, struct kobject *new_parent)
518{
519 int error;
520 struct kobject *old_parent;
521 const char *devpath = NULL;
522 char *devpath_string = NULL;
523 char *envp[2];
524
525 kobj = kobject_get(kobj);
526 if (!kobj)
527 return -EINVAL;
528 new_parent = kobject_get(new_parent);
529 if (!new_parent) {
530 if (kobj->kset)
531 new_parent = kobject_get(&kobj->kset->kobj);
532 }
533
534 /* old object path */
535 devpath = kobject_get_path(kobj, GFP_KERNEL);
536 if (!devpath) {
537 error = -ENOMEM;
538 goto out;
539 }
540 devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL);
541 if (!devpath_string) {
542 error = -ENOMEM;
543 goto out;
544 }
545 sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);
546 envp[0] = devpath_string;
547 envp[1] = NULL;
548 error = sysfs_move_dir_ns(kobj, new_parent, kobject_namespace(kobj));
549 if (error)
550 goto out;
551 old_parent = kobj->parent;
552 kobj->parent = new_parent;
553 new_parent = NULL;
554 kobject_put(old_parent);
555 kobject_uevent_env(kobj, KOBJ_MOVE, envp);
556out:
557 kobject_put(new_parent);
558 kobject_put(kobj);
559 kfree(devpath_string);
560 kfree(devpath);
561 return error;
562}
563EXPORT_SYMBOL_GPL(kobject_move);
564
565/**
566 * kobject_del - unlink kobject from hierarchy.
567 * @kobj: object.
568 */
569void kobject_del(struct kobject *kobj)
570{
571 struct kernfs_node *sd;
572
573 if (!kobj)
574 return;
575
576 sd = kobj->sd;
577 sysfs_remove_dir(kobj);
578 sysfs_put(sd);
579
580 kobj->state_in_sysfs = 0;
581 kobj_kset_leave(kobj);
582 kobject_put(kobj->parent);
583 kobj->parent = NULL;
584}
585EXPORT_SYMBOL(kobject_del);
586
587/**
588 * kobject_get - increment refcount for object.
589 * @kobj: object.
590 */
591struct kobject *kobject_get(struct kobject *kobj)
592{
593 if (kobj) {
594 if (!kobj->state_initialized)
595 WARN(1, KERN_WARNING "kobject: '%s' (%p): is not "
596 "initialized, yet kobject_get() is being "
597 "called.\n", kobject_name(kobj), kobj);
598 kref_get(&kobj->kref);
599 }
600 return kobj;
601}
602EXPORT_SYMBOL(kobject_get);
603
604struct kobject * __must_check kobject_get_unless_zero(struct kobject *kobj)
605{
606 if (!kobj)
607 return NULL;
608 if (!kref_get_unless_zero(&kobj->kref))
609 kobj = NULL;
610 return kobj;
611}
612EXPORT_SYMBOL(kobject_get_unless_zero);
613
614/*
615 * kobject_cleanup - free kobject resources.
616 * @kobj: object to cleanup
617 */
618static void kobject_cleanup(struct kobject *kobj)
619{
620 struct kobj_type *t = get_ktype(kobj);
621 const char *name = kobj->name;
622
623 pr_debug("kobject: '%s' (%p): %s, parent %p\n",
624 kobject_name(kobj), kobj, __func__, kobj->parent);
625
626 if (t && !t->release)
627 pr_debug("kobject: '%s' (%p): does not have a release() "
628 "function, it is broken and must be fixed.\n",
629 kobject_name(kobj), kobj);
630
631 /* send "remove" if the caller did not do it but sent "add" */
632 if (kobj->state_add_uevent_sent && !kobj->state_remove_uevent_sent) {
633 pr_debug("kobject: '%s' (%p): auto cleanup 'remove' event\n",
634 kobject_name(kobj), kobj);
635 kobject_uevent(kobj, KOBJ_REMOVE);
636 }
637
638 /* remove from sysfs if the caller did not do it */
639 if (kobj->state_in_sysfs) {
640 pr_debug("kobject: '%s' (%p): auto cleanup kobject_del\n",
641 kobject_name(kobj), kobj);
642 kobject_del(kobj);
643 }
644
645 if (t && t->release) {
646 pr_debug("kobject: '%s' (%p): calling ktype release\n",
647 kobject_name(kobj), kobj);
648 t->release(kobj);
649 }
650
651 /* free name if we allocated it */
652 if (name) {
653 pr_debug("kobject: '%s': free name\n", name);
654 kfree_const(name);
655 }
656}
657
658#ifdef CONFIG_DEBUG_KOBJECT_RELEASE
659static void kobject_delayed_cleanup(struct work_struct *work)
660{
661 kobject_cleanup(container_of(to_delayed_work(work),
662 struct kobject, release));
663}
664#endif
665
666static void kobject_release(struct kref *kref)
667{
668 struct kobject *kobj = container_of(kref, struct kobject, kref);
669#ifdef CONFIG_DEBUG_KOBJECT_RELEASE
670 unsigned long delay = HZ + HZ * (get_random_int() & 0x3);
671 pr_info("kobject: '%s' (%p): %s, parent %p (delayed %ld)\n",
672 kobject_name(kobj), kobj, __func__, kobj->parent, delay);
673 INIT_DELAYED_WORK(&kobj->release, kobject_delayed_cleanup);
674
675 schedule_delayed_work(&kobj->release, delay);
676#else
677 kobject_cleanup(kobj);
678#endif
679}
680
681/**
682 * kobject_put - decrement refcount for object.
683 * @kobj: object.
684 *
685 * Decrement the refcount, and if 0, call kobject_cleanup().
686 */
687void kobject_put(struct kobject *kobj)
688{
689 if (kobj) {
690 if (!kobj->state_initialized)
691 WARN(1, KERN_WARNING "kobject: '%s' (%p): is not "
692 "initialized, yet kobject_put() is being "
693 "called.\n", kobject_name(kobj), kobj);
694 kref_put(&kobj->kref, kobject_release);
695 }
696}
697EXPORT_SYMBOL(kobject_put);
698
699static void dynamic_kobj_release(struct kobject *kobj)
700{
701 pr_debug("kobject: (%p): %s\n", kobj, __func__);
702 kfree(kobj);
703}
704
705static struct kobj_type dynamic_kobj_ktype = {
706 .release = dynamic_kobj_release,
707 .sysfs_ops = &kobj_sysfs_ops,
708};
709
710/**
711 * kobject_create - create a struct kobject dynamically
712 *
713 * This function creates a kobject structure dynamically and sets it up
714 * to be a "dynamic" kobject with a default release function set up.
715 *
716 * If the kobject was not able to be created, NULL will be returned.
717 * The kobject structure returned from here must be cleaned up with a
718 * call to kobject_put() and not kfree(), as kobject_init() has
719 * already been called on this structure.
720 */
721struct kobject *kobject_create(void)
722{
723 struct kobject *kobj;
724
725 kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
726 if (!kobj)
727 return NULL;
728
729 kobject_init(kobj, &dynamic_kobj_ktype);
730 return kobj;
731}
732
733/**
734 * kobject_create_and_add - create a struct kobject dynamically and register it with sysfs
735 *
736 * @name: the name for the kobject
737 * @parent: the parent kobject of this kobject, if any.
738 *
739 * This function creates a kobject structure dynamically and registers it
740 * with sysfs. When you are finished with this structure, call
741 * kobject_put() and the structure will be dynamically freed when
742 * it is no longer being used.
743 *
744 * If the kobject was not able to be created, NULL will be returned.
745 */
746struct kobject *kobject_create_and_add(const char *name, struct kobject *parent)
747{
748 struct kobject *kobj;
749 int retval;
750
751 kobj = kobject_create();
752 if (!kobj)
753 return NULL;
754
755 retval = kobject_add(kobj, parent, "%s", name);
756 if (retval) {
757 printk(KERN_WARNING "%s: kobject_add error: %d\n",
758 __func__, retval);
759 kobject_put(kobj);
760 kobj = NULL;
761 }
762 return kobj;
763}
764EXPORT_SYMBOL_GPL(kobject_create_and_add);
765
766/**
767 * kset_init - initialize a kset for use
768 * @k: kset
769 */
770void kset_init(struct kset *k)
771{
772 kobject_init_internal(&k->kobj);
773 INIT_LIST_HEAD(&k->list);
774 spin_lock_init(&k->list_lock);
775}
776
777/* default kobject attribute operations */
778static ssize_t kobj_attr_show(struct kobject *kobj, struct attribute *attr,
779 char *buf)
780{
781 struct kobj_attribute *kattr;
782 ssize_t ret = -EIO;
783
784 kattr = container_of(attr, struct kobj_attribute, attr);
785 if (kattr->show)
786 ret = kattr->show(kobj, kattr, buf);
787 return ret;
788}
789
790static ssize_t kobj_attr_store(struct kobject *kobj, struct attribute *attr,
791 const char *buf, size_t count)
792{
793 struct kobj_attribute *kattr;
794 ssize_t ret = -EIO;
795
796 kattr = container_of(attr, struct kobj_attribute, attr);
797 if (kattr->store)
798 ret = kattr->store(kobj, kattr, buf, count);
799 return ret;
800}
801
802const struct sysfs_ops kobj_sysfs_ops = {
803 .show = kobj_attr_show,
804 .store = kobj_attr_store,
805};
806EXPORT_SYMBOL_GPL(kobj_sysfs_ops);
807
808/**
809 * kset_register - initialize and add a kset.
810 * @k: kset.
811 */
812int kset_register(struct kset *k)
813{
814 int err;
815
816 if (!k)
817 return -EINVAL;
818
819 kset_init(k);
820 err = kobject_add_internal(&k->kobj);
821 if (err)
822 return err;
823 kobject_uevent(&k->kobj, KOBJ_ADD);
824 return 0;
825}
826EXPORT_SYMBOL(kset_register);
827
828/**
829 * kset_unregister - remove a kset.
830 * @k: kset.
831 */
832void kset_unregister(struct kset *k)
833{
834 if (!k)
835 return;
836 kobject_del(&k->kobj);
837 kobject_put(&k->kobj);
838}
839EXPORT_SYMBOL(kset_unregister);
840
841/**
842 * kset_find_obj - search for object in kset.
843 * @kset: kset we're looking in.
844 * @name: object's name.
845 *
846 * Lock kset via @kset->subsys, and iterate over @kset->list,
847 * looking for a matching kobject. If matching object is found
848 * take a reference and return the object.
849 */
850struct kobject *kset_find_obj(struct kset *kset, const char *name)
851{
852 struct kobject *k;
853 struct kobject *ret = NULL;
854
855 spin_lock(&kset->list_lock);
856
857 list_for_each_entry(k, &kset->list, entry) {
858 if (kobject_name(k) && !strcmp(kobject_name(k), name)) {
859 ret = kobject_get_unless_zero(k);
860 break;
861 }
862 }
863
864 spin_unlock(&kset->list_lock);
865 return ret;
866}
867EXPORT_SYMBOL_GPL(kset_find_obj);
868
869static void kset_release(struct kobject *kobj)
870{
871 struct kset *kset = container_of(kobj, struct kset, kobj);
872 pr_debug("kobject: '%s' (%p): %s\n",
873 kobject_name(kobj), kobj, __func__);
874 kfree(kset);
875}
876
877static struct kobj_type kset_ktype = {
878 .sysfs_ops = &kobj_sysfs_ops,
879 .release = kset_release,
880};
881
882/**
883 * kset_create - create a struct kset dynamically
884 *
885 * @name: the name for the kset
886 * @uevent_ops: a struct kset_uevent_ops for the kset
887 * @parent_kobj: the parent kobject of this kset, if any.
888 *
889 * This function creates a kset structure dynamically. This structure can
890 * then be registered with the system and show up in sysfs with a call to
891 * kset_register(). When you are finished with this structure, if
892 * kset_register() has been called, call kset_unregister() and the
893 * structure will be dynamically freed when it is no longer being used.
894 *
895 * If the kset was not able to be created, NULL will be returned.
896 */
897static struct kset *kset_create(const char *name,
898 const struct kset_uevent_ops *uevent_ops,
899 struct kobject *parent_kobj)
900{
901 struct kset *kset;
902 int retval;
903
904 kset = kzalloc(sizeof(*kset), GFP_KERNEL);
905 if (!kset)
906 return NULL;
907 retval = kobject_set_name(&kset->kobj, "%s", name);
908 if (retval) {
909 kfree(kset);
910 return NULL;
911 }
912 kset->uevent_ops = uevent_ops;
913 kset->kobj.parent = parent_kobj;
914
915 /*
916 * The kobject of this kset will have a type of kset_ktype and belong to
917 * no kset itself. That way we can properly free it when it is
918 * finished being used.
919 */
920 kset->kobj.ktype = &kset_ktype;
921 kset->kobj.kset = NULL;
922
923 return kset;
924}
925
926/**
927 * kset_create_and_add - create a struct kset dynamically and add it to sysfs
928 *
929 * @name: the name for the kset
930 * @uevent_ops: a struct kset_uevent_ops for the kset
931 * @parent_kobj: the parent kobject of this kset, if any.
932 *
933 * This function creates a kset structure dynamically and registers it
934 * with sysfs. When you are finished with this structure, call
935 * kset_unregister() and the structure will be dynamically freed when it
936 * is no longer being used.
937 *
938 * If the kset was not able to be created, NULL will be returned.
939 */
940struct kset *kset_create_and_add(const char *name,
941 const struct kset_uevent_ops *uevent_ops,
942 struct kobject *parent_kobj)
943{
944 struct kset *kset;
945 int error;
946
947 kset = kset_create(name, uevent_ops, parent_kobj);
948 if (!kset)
949 return NULL;
950 error = kset_register(kset);
951 if (error) {
952 kfree(kset);
953 return NULL;
954 }
955 return kset;
956}
957EXPORT_SYMBOL_GPL(kset_create_and_add);
958
959
960static DEFINE_SPINLOCK(kobj_ns_type_lock);
961static const struct kobj_ns_type_operations *kobj_ns_ops_tbl[KOBJ_NS_TYPES];
962
963int kobj_ns_type_register(const struct kobj_ns_type_operations *ops)
964{
965 enum kobj_ns_type type = ops->type;
966 int error;
967
968 spin_lock(&kobj_ns_type_lock);
969
970 error = -EINVAL;
971 if (type >= KOBJ_NS_TYPES)
972 goto out;
973
974 error = -EINVAL;
975 if (type <= KOBJ_NS_TYPE_NONE)
976 goto out;
977
978 error = -EBUSY;
979 if (kobj_ns_ops_tbl[type])
980 goto out;
981
982 error = 0;
983 kobj_ns_ops_tbl[type] = ops;
984
985out:
986 spin_unlock(&kobj_ns_type_lock);
987 return error;
988}
989
990int kobj_ns_type_registered(enum kobj_ns_type type)
991{
992 int registered = 0;
993
994 spin_lock(&kobj_ns_type_lock);
995 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES))
996 registered = kobj_ns_ops_tbl[type] != NULL;
997 spin_unlock(&kobj_ns_type_lock);
998
999 return registered;
1000}
1001
1002const struct kobj_ns_type_operations *kobj_child_ns_ops(struct kobject *parent)
1003{
1004 const struct kobj_ns_type_operations *ops = NULL;
1005
1006 if (parent && parent->ktype && parent->ktype->child_ns_type)
1007 ops = parent->ktype->child_ns_type(parent);
1008
1009 return ops;
1010}
1011
1012const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj)
1013{
1014 return kobj_child_ns_ops(kobj->parent);
1015}
1016
1017bool kobj_ns_current_may_mount(enum kobj_ns_type type)
1018{
1019 bool may_mount = true;
1020
1021 spin_lock(&kobj_ns_type_lock);
1022 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1023 kobj_ns_ops_tbl[type])
1024 may_mount = kobj_ns_ops_tbl[type]->current_may_mount();
1025 spin_unlock(&kobj_ns_type_lock);
1026
1027 return may_mount;
1028}
1029
1030void *kobj_ns_grab_current(enum kobj_ns_type type)
1031{
1032 void *ns = NULL;
1033
1034 spin_lock(&kobj_ns_type_lock);
1035 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1036 kobj_ns_ops_tbl[type])
1037 ns = kobj_ns_ops_tbl[type]->grab_current_ns();
1038 spin_unlock(&kobj_ns_type_lock);
1039
1040 return ns;
1041}
1042
1043const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk)
1044{
1045 const void *ns = NULL;
1046
1047 spin_lock(&kobj_ns_type_lock);
1048 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1049 kobj_ns_ops_tbl[type])
1050 ns = kobj_ns_ops_tbl[type]->netlink_ns(sk);
1051 spin_unlock(&kobj_ns_type_lock);
1052
1053 return ns;
1054}
1055
1056const void *kobj_ns_initial(enum kobj_ns_type type)
1057{
1058 const void *ns = NULL;
1059
1060 spin_lock(&kobj_ns_type_lock);
1061 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1062 kobj_ns_ops_tbl[type])
1063 ns = kobj_ns_ops_tbl[type]->initial_ns();
1064 spin_unlock(&kobj_ns_type_lock);
1065
1066 return ns;
1067}
1068
1069void kobj_ns_drop(enum kobj_ns_type type, void *ns)
1070{
1071 spin_lock(&kobj_ns_type_lock);
1072 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1073 kobj_ns_ops_tbl[type] && kobj_ns_ops_tbl[type]->drop_ns)
1074 kobj_ns_ops_tbl[type]->drop_ns(ns);
1075 spin_unlock(&kobj_ns_type_lock);
1076}