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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 */
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 memcpy(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 pr_err("%s failed for %s with -EEXIST, don't try to register things with the same name in the same directory.\n",
238 __func__, kobject_name(kobj));
239 else
240 pr_err("%s failed for %s (error: %d parent: %s)\n",
241 __func__, kobject_name(kobj), error,
242 parent ? kobject_name(parent) : "'none'");
243 } else
244 kobj->state_in_sysfs = 1;
245
246 return error;
247}
248
249/**
250 * kobject_set_name_vargs - Set the name of an kobject
251 * @kobj: struct kobject to set the name of
252 * @fmt: format string used to build the name
253 * @vargs: vargs to format the string.
254 */
255int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
256 va_list vargs)
257{
258 const char *s;
259
260 if (kobj->name && !fmt)
261 return 0;
262
263 s = kvasprintf_const(GFP_KERNEL, fmt, vargs);
264 if (!s)
265 return -ENOMEM;
266
267 /*
268 * ewww... some of these buggers have '/' in the name ... If
269 * that's the case, we need to make sure we have an actual
270 * allocated copy to modify, since kvasprintf_const may have
271 * returned something from .rodata.
272 */
273 if (strchr(s, '/')) {
274 char *t;
275
276 t = kstrdup(s, GFP_KERNEL);
277 kfree_const(s);
278 if (!t)
279 return -ENOMEM;
280 strreplace(t, '/', '!');
281 s = t;
282 }
283 kfree_const(kobj->name);
284 kobj->name = s;
285
286 return 0;
287}
288
289/**
290 * kobject_set_name - Set the name of a kobject
291 * @kobj: struct kobject to set the name of
292 * @fmt: format string used to build the name
293 *
294 * This sets the name of the kobject. If you have already added the
295 * kobject to the system, you must call kobject_rename() in order to
296 * change the name of the kobject.
297 */
298int kobject_set_name(struct kobject *kobj, const char *fmt, ...)
299{
300 va_list vargs;
301 int retval;
302
303 va_start(vargs, fmt);
304 retval = kobject_set_name_vargs(kobj, fmt, vargs);
305 va_end(vargs);
306
307 return retval;
308}
309EXPORT_SYMBOL(kobject_set_name);
310
311/**
312 * kobject_init - initialize a kobject structure
313 * @kobj: pointer to the kobject to initialize
314 * @ktype: pointer to the ktype for this kobject.
315 *
316 * This function will properly initialize a kobject such that it can then
317 * be passed to the kobject_add() call.
318 *
319 * After this function is called, the kobject MUST be cleaned up by a call
320 * to kobject_put(), not by a call to kfree directly to ensure that all of
321 * the memory is cleaned up properly.
322 */
323void kobject_init(struct kobject *kobj, struct kobj_type *ktype)
324{
325 char *err_str;
326
327 if (!kobj) {
328 err_str = "invalid kobject pointer!";
329 goto error;
330 }
331 if (!ktype) {
332 err_str = "must have a ktype to be initialized properly!\n";
333 goto error;
334 }
335 if (kobj->state_initialized) {
336 /* do not error out as sometimes we can recover */
337 printk(KERN_ERR "kobject (%p): tried to init an initialized "
338 "object, something is seriously wrong.\n", kobj);
339 dump_stack();
340 }
341
342 kobject_init_internal(kobj);
343 kobj->ktype = ktype;
344 return;
345
346error:
347 printk(KERN_ERR "kobject (%p): %s\n", kobj, err_str);
348 dump_stack();
349}
350EXPORT_SYMBOL(kobject_init);
351
352static __printf(3, 0) int kobject_add_varg(struct kobject *kobj,
353 struct kobject *parent,
354 const char *fmt, va_list vargs)
355{
356 int retval;
357
358 retval = kobject_set_name_vargs(kobj, fmt, vargs);
359 if (retval) {
360 printk(KERN_ERR "kobject: can not set name properly!\n");
361 return retval;
362 }
363 kobj->parent = parent;
364 return kobject_add_internal(kobj);
365}
366
367/**
368 * kobject_add - the main kobject add function
369 * @kobj: the kobject to add
370 * @parent: pointer to the parent of the kobject.
371 * @fmt: format to name the kobject with.
372 *
373 * The kobject name is set and added to the kobject hierarchy in this
374 * function.
375 *
376 * If @parent is set, then the parent of the @kobj will be set to it.
377 * If @parent is NULL, then the parent of the @kobj will be set to the
378 * kobject associated with the kset assigned to this kobject. If no kset
379 * is assigned to the kobject, then the kobject will be located in the
380 * root of the sysfs tree.
381 *
382 * If this function returns an error, kobject_put() must be called to
383 * properly clean up the memory associated with the object.
384 * Under no instance should the kobject that is passed to this function
385 * be directly freed with a call to kfree(), that can leak memory.
386 *
387 * Note, no "add" uevent will be created with this call, the caller should set
388 * up all of the necessary sysfs files for the object and then call
389 * kobject_uevent() with the UEVENT_ADD parameter to ensure that
390 * userspace is properly notified of this kobject's creation.
391 */
392int kobject_add(struct kobject *kobj, struct kobject *parent,
393 const char *fmt, ...)
394{
395 va_list args;
396 int retval;
397
398 if (!kobj)
399 return -EINVAL;
400
401 if (!kobj->state_initialized) {
402 printk(KERN_ERR "kobject '%s' (%p): tried to add an "
403 "uninitialized object, something is seriously wrong.\n",
404 kobject_name(kobj), kobj);
405 dump_stack();
406 return -EINVAL;
407 }
408 va_start(args, fmt);
409 retval = kobject_add_varg(kobj, parent, fmt, args);
410 va_end(args);
411
412 return retval;
413}
414EXPORT_SYMBOL(kobject_add);
415
416/**
417 * kobject_init_and_add - initialize a kobject structure and add it to the kobject hierarchy
418 * @kobj: pointer to the kobject to initialize
419 * @ktype: pointer to the ktype for this kobject.
420 * @parent: pointer to the parent of this kobject.
421 * @fmt: the name of the kobject.
422 *
423 * This function combines the call to kobject_init() and
424 * kobject_add(). The same type of error handling after a call to
425 * kobject_add() and kobject lifetime rules are the same here.
426 */
427int kobject_init_and_add(struct kobject *kobj, struct kobj_type *ktype,
428 struct kobject *parent, const char *fmt, ...)
429{
430 va_list args;
431 int retval;
432
433 kobject_init(kobj, ktype);
434
435 va_start(args, fmt);
436 retval = kobject_add_varg(kobj, parent, fmt, args);
437 va_end(args);
438
439 return retval;
440}
441EXPORT_SYMBOL_GPL(kobject_init_and_add);
442
443/**
444 * kobject_rename - change the name of an object
445 * @kobj: object in question.
446 * @new_name: object's new name
447 *
448 * It is the responsibility of the caller to provide mutual
449 * exclusion between two different calls of kobject_rename
450 * on the same kobject and to ensure that new_name is valid and
451 * won't conflict with other kobjects.
452 */
453int kobject_rename(struct kobject *kobj, const char *new_name)
454{
455 int error = 0;
456 const char *devpath = NULL;
457 const char *dup_name = NULL, *name;
458 char *devpath_string = NULL;
459 char *envp[2];
460
461 kobj = kobject_get(kobj);
462 if (!kobj)
463 return -EINVAL;
464 if (!kobj->parent)
465 return -EINVAL;
466
467 devpath = kobject_get_path(kobj, GFP_KERNEL);
468 if (!devpath) {
469 error = -ENOMEM;
470 goto out;
471 }
472 devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL);
473 if (!devpath_string) {
474 error = -ENOMEM;
475 goto out;
476 }
477 sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);
478 envp[0] = devpath_string;
479 envp[1] = NULL;
480
481 name = dup_name = kstrdup_const(new_name, GFP_KERNEL);
482 if (!name) {
483 error = -ENOMEM;
484 goto out;
485 }
486
487 error = sysfs_rename_dir_ns(kobj, new_name, kobject_namespace(kobj));
488 if (error)
489 goto out;
490
491 /* Install the new kobject name */
492 dup_name = kobj->name;
493 kobj->name = name;
494
495 /* This function is mostly/only used for network interface.
496 * Some hotplug package track interfaces by their name and
497 * therefore want to know when the name is changed by the user. */
498 kobject_uevent_env(kobj, KOBJ_MOVE, envp);
499
500out:
501 kfree_const(dup_name);
502 kfree(devpath_string);
503 kfree(devpath);
504 kobject_put(kobj);
505
506 return error;
507}
508EXPORT_SYMBOL_GPL(kobject_rename);
509
510/**
511 * kobject_move - move object to another parent
512 * @kobj: object in question.
513 * @new_parent: object's new parent (can be NULL)
514 */
515int kobject_move(struct kobject *kobj, struct kobject *new_parent)
516{
517 int error;
518 struct kobject *old_parent;
519 const char *devpath = NULL;
520 char *devpath_string = NULL;
521 char *envp[2];
522
523 kobj = kobject_get(kobj);
524 if (!kobj)
525 return -EINVAL;
526 new_parent = kobject_get(new_parent);
527 if (!new_parent) {
528 if (kobj->kset)
529 new_parent = kobject_get(&kobj->kset->kobj);
530 }
531
532 /* old object path */
533 devpath = kobject_get_path(kobj, GFP_KERNEL);
534 if (!devpath) {
535 error = -ENOMEM;
536 goto out;
537 }
538 devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL);
539 if (!devpath_string) {
540 error = -ENOMEM;
541 goto out;
542 }
543 sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);
544 envp[0] = devpath_string;
545 envp[1] = NULL;
546 error = sysfs_move_dir_ns(kobj, new_parent, kobject_namespace(kobj));
547 if (error)
548 goto out;
549 old_parent = kobj->parent;
550 kobj->parent = new_parent;
551 new_parent = NULL;
552 kobject_put(old_parent);
553 kobject_uevent_env(kobj, KOBJ_MOVE, envp);
554out:
555 kobject_put(new_parent);
556 kobject_put(kobj);
557 kfree(devpath_string);
558 kfree(devpath);
559 return error;
560}
561EXPORT_SYMBOL_GPL(kobject_move);
562
563/**
564 * kobject_del - unlink kobject from hierarchy.
565 * @kobj: object.
566 */
567void kobject_del(struct kobject *kobj)
568{
569 struct kernfs_node *sd;
570
571 if (!kobj)
572 return;
573
574 sd = kobj->sd;
575 sysfs_remove_dir(kobj);
576 sysfs_put(sd);
577
578 kobj->state_in_sysfs = 0;
579 kobj_kset_leave(kobj);
580 kobject_put(kobj->parent);
581 kobj->parent = NULL;
582}
583EXPORT_SYMBOL(kobject_del);
584
585/**
586 * kobject_get - increment refcount for object.
587 * @kobj: object.
588 */
589struct kobject *kobject_get(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_get() is being "
595 "called.\n", kobject_name(kobj), kobj);
596 kref_get(&kobj->kref);
597 }
598 return kobj;
599}
600EXPORT_SYMBOL(kobject_get);
601
602static struct kobject * __must_check kobject_get_unless_zero(struct kobject *kobj)
603{
604 if (!kref_get_unless_zero(&kobj->kref))
605 kobj = NULL;
606 return kobj;
607}
608
609/*
610 * kobject_cleanup - free kobject resources.
611 * @kobj: object to cleanup
612 */
613static void kobject_cleanup(struct kobject *kobj)
614{
615 struct kobj_type *t = get_ktype(kobj);
616 const char *name = kobj->name;
617
618 pr_debug("kobject: '%s' (%p): %s, parent %p\n",
619 kobject_name(kobj), kobj, __func__, kobj->parent);
620
621 if (t && !t->release)
622 pr_debug("kobject: '%s' (%p): does not have a release() "
623 "function, it is broken and must be fixed.\n",
624 kobject_name(kobj), kobj);
625
626 /* send "remove" if the caller did not do it but sent "add" */
627 if (kobj->state_add_uevent_sent && !kobj->state_remove_uevent_sent) {
628 pr_debug("kobject: '%s' (%p): auto cleanup 'remove' event\n",
629 kobject_name(kobj), kobj);
630 kobject_uevent(kobj, KOBJ_REMOVE);
631 }
632
633 /* remove from sysfs if the caller did not do it */
634 if (kobj->state_in_sysfs) {
635 pr_debug("kobject: '%s' (%p): auto cleanup kobject_del\n",
636 kobject_name(kobj), kobj);
637 kobject_del(kobj);
638 }
639
640 if (t && t->release) {
641 pr_debug("kobject: '%s' (%p): calling ktype release\n",
642 kobject_name(kobj), kobj);
643 t->release(kobj);
644 }
645
646 /* free name if we allocated it */
647 if (name) {
648 pr_debug("kobject: '%s': free name\n", name);
649 kfree_const(name);
650 }
651}
652
653#ifdef CONFIG_DEBUG_KOBJECT_RELEASE
654static void kobject_delayed_cleanup(struct work_struct *work)
655{
656 kobject_cleanup(container_of(to_delayed_work(work),
657 struct kobject, release));
658}
659#endif
660
661static void kobject_release(struct kref *kref)
662{
663 struct kobject *kobj = container_of(kref, struct kobject, kref);
664#ifdef CONFIG_DEBUG_KOBJECT_RELEASE
665 unsigned long delay = HZ + HZ * (get_random_int() & 0x3);
666 pr_info("kobject: '%s' (%p): %s, parent %p (delayed %ld)\n",
667 kobject_name(kobj), kobj, __func__, kobj->parent, delay);
668 INIT_DELAYED_WORK(&kobj->release, kobject_delayed_cleanup);
669
670 schedule_delayed_work(&kobj->release, delay);
671#else
672 kobject_cleanup(kobj);
673#endif
674}
675
676/**
677 * kobject_put - decrement refcount for object.
678 * @kobj: object.
679 *
680 * Decrement the refcount, and if 0, call kobject_cleanup().
681 */
682void kobject_put(struct kobject *kobj)
683{
684 if (kobj) {
685 if (!kobj->state_initialized)
686 WARN(1, KERN_WARNING "kobject: '%s' (%p): is not "
687 "initialized, yet kobject_put() is being "
688 "called.\n", kobject_name(kobj), kobj);
689 kref_put(&kobj->kref, kobject_release);
690 }
691}
692EXPORT_SYMBOL(kobject_put);
693
694static void dynamic_kobj_release(struct kobject *kobj)
695{
696 pr_debug("kobject: (%p): %s\n", kobj, __func__);
697 kfree(kobj);
698}
699
700static struct kobj_type dynamic_kobj_ktype = {
701 .release = dynamic_kobj_release,
702 .sysfs_ops = &kobj_sysfs_ops,
703};
704
705/**
706 * kobject_create - create a struct kobject dynamically
707 *
708 * This function creates a kobject structure dynamically and sets it up
709 * to be a "dynamic" kobject with a default release function set up.
710 *
711 * If the kobject was not able to be created, NULL will be returned.
712 * The kobject structure returned from here must be cleaned up with a
713 * call to kobject_put() and not kfree(), as kobject_init() has
714 * already been called on this structure.
715 */
716struct kobject *kobject_create(void)
717{
718 struct kobject *kobj;
719
720 kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
721 if (!kobj)
722 return NULL;
723
724 kobject_init(kobj, &dynamic_kobj_ktype);
725 return kobj;
726}
727
728/**
729 * kobject_create_and_add - create a struct kobject dynamically and register it with sysfs
730 *
731 * @name: the name for the kobject
732 * @parent: the parent kobject of this kobject, if any.
733 *
734 * This function creates a kobject structure dynamically and registers it
735 * with sysfs. When you are finished with this structure, call
736 * kobject_put() and the structure will be dynamically freed when
737 * it is no longer being used.
738 *
739 * If the kobject was not able to be created, NULL will be returned.
740 */
741struct kobject *kobject_create_and_add(const char *name, struct kobject *parent)
742{
743 struct kobject *kobj;
744 int retval;
745
746 kobj = kobject_create();
747 if (!kobj)
748 return NULL;
749
750 retval = kobject_add(kobj, parent, "%s", name);
751 if (retval) {
752 printk(KERN_WARNING "%s: kobject_add error: %d\n",
753 __func__, retval);
754 kobject_put(kobj);
755 kobj = NULL;
756 }
757 return kobj;
758}
759EXPORT_SYMBOL_GPL(kobject_create_and_add);
760
761/**
762 * kset_init - initialize a kset for use
763 * @k: kset
764 */
765void kset_init(struct kset *k)
766{
767 kobject_init_internal(&k->kobj);
768 INIT_LIST_HEAD(&k->list);
769 spin_lock_init(&k->list_lock);
770}
771
772/* default kobject attribute operations */
773static ssize_t kobj_attr_show(struct kobject *kobj, struct attribute *attr,
774 char *buf)
775{
776 struct kobj_attribute *kattr;
777 ssize_t ret = -EIO;
778
779 kattr = container_of(attr, struct kobj_attribute, attr);
780 if (kattr->show)
781 ret = kattr->show(kobj, kattr, buf);
782 return ret;
783}
784
785static ssize_t kobj_attr_store(struct kobject *kobj, struct attribute *attr,
786 const char *buf, size_t count)
787{
788 struct kobj_attribute *kattr;
789 ssize_t ret = -EIO;
790
791 kattr = container_of(attr, struct kobj_attribute, attr);
792 if (kattr->store)
793 ret = kattr->store(kobj, kattr, buf, count);
794 return ret;
795}
796
797const struct sysfs_ops kobj_sysfs_ops = {
798 .show = kobj_attr_show,
799 .store = kobj_attr_store,
800};
801EXPORT_SYMBOL_GPL(kobj_sysfs_ops);
802
803/**
804 * kset_register - initialize and add a kset.
805 * @k: kset.
806 */
807int kset_register(struct kset *k)
808{
809 int err;
810
811 if (!k)
812 return -EINVAL;
813
814 kset_init(k);
815 err = kobject_add_internal(&k->kobj);
816 if (err)
817 return err;
818 kobject_uevent(&k->kobj, KOBJ_ADD);
819 return 0;
820}
821EXPORT_SYMBOL(kset_register);
822
823/**
824 * kset_unregister - remove a kset.
825 * @k: kset.
826 */
827void kset_unregister(struct kset *k)
828{
829 if (!k)
830 return;
831 kobject_del(&k->kobj);
832 kobject_put(&k->kobj);
833}
834EXPORT_SYMBOL(kset_unregister);
835
836/**
837 * kset_find_obj - search for object in kset.
838 * @kset: kset we're looking in.
839 * @name: object's name.
840 *
841 * Lock kset via @kset->subsys, and iterate over @kset->list,
842 * looking for a matching kobject. If matching object is found
843 * take a reference and return the object.
844 */
845struct kobject *kset_find_obj(struct kset *kset, const char *name)
846{
847 struct kobject *k;
848 struct kobject *ret = NULL;
849
850 spin_lock(&kset->list_lock);
851
852 list_for_each_entry(k, &kset->list, entry) {
853 if (kobject_name(k) && !strcmp(kobject_name(k), name)) {
854 ret = kobject_get_unless_zero(k);
855 break;
856 }
857 }
858
859 spin_unlock(&kset->list_lock);
860 return ret;
861}
862EXPORT_SYMBOL_GPL(kset_find_obj);
863
864static void kset_release(struct kobject *kobj)
865{
866 struct kset *kset = container_of(kobj, struct kset, kobj);
867 pr_debug("kobject: '%s' (%p): %s\n",
868 kobject_name(kobj), kobj, __func__);
869 kfree(kset);
870}
871
872static struct kobj_type kset_ktype = {
873 .sysfs_ops = &kobj_sysfs_ops,
874 .release = kset_release,
875};
876
877/**
878 * kset_create - create a struct kset dynamically
879 *
880 * @name: the name for the kset
881 * @uevent_ops: a struct kset_uevent_ops for the kset
882 * @parent_kobj: the parent kobject of this kset, if any.
883 *
884 * This function creates a kset structure dynamically. This structure can
885 * then be registered with the system and show up in sysfs with a call to
886 * kset_register(). When you are finished with this structure, if
887 * kset_register() has been called, call kset_unregister() and the
888 * structure will be dynamically freed when it is no longer being used.
889 *
890 * If the kset was not able to be created, NULL will be returned.
891 */
892static struct kset *kset_create(const char *name,
893 const struct kset_uevent_ops *uevent_ops,
894 struct kobject *parent_kobj)
895{
896 struct kset *kset;
897 int retval;
898
899 kset = kzalloc(sizeof(*kset), GFP_KERNEL);
900 if (!kset)
901 return NULL;
902 retval = kobject_set_name(&kset->kobj, "%s", name);
903 if (retval) {
904 kfree(kset);
905 return NULL;
906 }
907 kset->uevent_ops = uevent_ops;
908 kset->kobj.parent = parent_kobj;
909
910 /*
911 * The kobject of this kset will have a type of kset_ktype and belong to
912 * no kset itself. That way we can properly free it when it is
913 * finished being used.
914 */
915 kset->kobj.ktype = &kset_ktype;
916 kset->kobj.kset = NULL;
917
918 return kset;
919}
920
921/**
922 * kset_create_and_add - create a struct kset dynamically and add it to sysfs
923 *
924 * @name: the name for the kset
925 * @uevent_ops: a struct kset_uevent_ops for the kset
926 * @parent_kobj: the parent kobject of this kset, if any.
927 *
928 * This function creates a kset structure dynamically and registers it
929 * with sysfs. When you are finished with this structure, call
930 * kset_unregister() and the structure will be dynamically freed when it
931 * is no longer being used.
932 *
933 * If the kset was not able to be created, NULL will be returned.
934 */
935struct kset *kset_create_and_add(const char *name,
936 const struct kset_uevent_ops *uevent_ops,
937 struct kobject *parent_kobj)
938{
939 struct kset *kset;
940 int error;
941
942 kset = kset_create(name, uevent_ops, parent_kobj);
943 if (!kset)
944 return NULL;
945 error = kset_register(kset);
946 if (error) {
947 kfree(kset);
948 return NULL;
949 }
950 return kset;
951}
952EXPORT_SYMBOL_GPL(kset_create_and_add);
953
954
955static DEFINE_SPINLOCK(kobj_ns_type_lock);
956static const struct kobj_ns_type_operations *kobj_ns_ops_tbl[KOBJ_NS_TYPES];
957
958int kobj_ns_type_register(const struct kobj_ns_type_operations *ops)
959{
960 enum kobj_ns_type type = ops->type;
961 int error;
962
963 spin_lock(&kobj_ns_type_lock);
964
965 error = -EINVAL;
966 if (type >= KOBJ_NS_TYPES)
967 goto out;
968
969 error = -EINVAL;
970 if (type <= KOBJ_NS_TYPE_NONE)
971 goto out;
972
973 error = -EBUSY;
974 if (kobj_ns_ops_tbl[type])
975 goto out;
976
977 error = 0;
978 kobj_ns_ops_tbl[type] = ops;
979
980out:
981 spin_unlock(&kobj_ns_type_lock);
982 return error;
983}
984
985int kobj_ns_type_registered(enum kobj_ns_type type)
986{
987 int registered = 0;
988
989 spin_lock(&kobj_ns_type_lock);
990 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES))
991 registered = kobj_ns_ops_tbl[type] != NULL;
992 spin_unlock(&kobj_ns_type_lock);
993
994 return registered;
995}
996
997const struct kobj_ns_type_operations *kobj_child_ns_ops(struct kobject *parent)
998{
999 const struct kobj_ns_type_operations *ops = NULL;
1000
1001 if (parent && parent->ktype && parent->ktype->child_ns_type)
1002 ops = parent->ktype->child_ns_type(parent);
1003
1004 return ops;
1005}
1006
1007const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj)
1008{
1009 return kobj_child_ns_ops(kobj->parent);
1010}
1011
1012bool kobj_ns_current_may_mount(enum kobj_ns_type type)
1013{
1014 bool may_mount = true;
1015
1016 spin_lock(&kobj_ns_type_lock);
1017 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1018 kobj_ns_ops_tbl[type])
1019 may_mount = kobj_ns_ops_tbl[type]->current_may_mount();
1020 spin_unlock(&kobj_ns_type_lock);
1021
1022 return may_mount;
1023}
1024
1025void *kobj_ns_grab_current(enum kobj_ns_type type)
1026{
1027 void *ns = NULL;
1028
1029 spin_lock(&kobj_ns_type_lock);
1030 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1031 kobj_ns_ops_tbl[type])
1032 ns = kobj_ns_ops_tbl[type]->grab_current_ns();
1033 spin_unlock(&kobj_ns_type_lock);
1034
1035 return ns;
1036}
1037
1038const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk)
1039{
1040 const void *ns = NULL;
1041
1042 spin_lock(&kobj_ns_type_lock);
1043 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1044 kobj_ns_ops_tbl[type])
1045 ns = kobj_ns_ops_tbl[type]->netlink_ns(sk);
1046 spin_unlock(&kobj_ns_type_lock);
1047
1048 return ns;
1049}
1050
1051const void *kobj_ns_initial(enum kobj_ns_type type)
1052{
1053 const void *ns = NULL;
1054
1055 spin_lock(&kobj_ns_type_lock);
1056 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1057 kobj_ns_ops_tbl[type])
1058 ns = kobj_ns_ops_tbl[type]->initial_ns();
1059 spin_unlock(&kobj_ns_type_lock);
1060
1061 return ns;
1062}
1063
1064void kobj_ns_drop(enum kobj_ns_type type, void *ns)
1065{
1066 spin_lock(&kobj_ns_type_lock);
1067 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1068 kobj_ns_ops_tbl[type] && kobj_ns_ops_tbl[type]->drop_ns)
1069 kobj_ns_ops_tbl[type]->drop_ns(ns);
1070 spin_unlock(&kobj_ns_type_lock);
1071}
1072
generated by cgit at 2024-05-18 14:51:06 (GMT)