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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * kobject.c - library routines for handling generic kernel objects
4 *
5 * Copyright (c) 2002-2003 Patrick Mochel <mochel@osdl.org>
6 * Copyright (c) 2006-2007 Greg Kroah-Hartman <greg@kroah.com>
7 * Copyright (c) 2006-2007 Novell Inc.
8 *
9 * Please see the file Documentation/core-api/kobject.rst for critical information
10 * about using the kobject interface.
11 */
12
13#include <linux/kobject.h>
14#include <linux/string.h>
15#include <linux/export.h>
16#include <linux/stat.h>
17#include <linux/slab.h>
18#include <linux/random.h>
19
20/**
21 * kobject_namespace() - Return @kobj's namespace tag.
22 * @kobj: kobject in question
23 *
24 * Returns namespace tag of @kobj if its parent has namespace ops enabled
25 * and thus @kobj should have a namespace tag associated with it. Returns
26 * %NULL otherwise.
27 */
28const void *kobject_namespace(struct kobject *kobj)
29{
30 const struct kobj_ns_type_operations *ns_ops = kobj_ns_ops(kobj);
31
32 if (!ns_ops || ns_ops->type == KOBJ_NS_TYPE_NONE)
33 return NULL;
34
35 return kobj->ktype->namespace(kobj);
36}
37
38/**
39 * kobject_get_ownership() - Get sysfs ownership data for @kobj.
40 * @kobj: kobject in question
41 * @uid: kernel user ID for sysfs objects
42 * @gid: kernel group ID for sysfs objects
43 *
44 * Returns initial uid/gid pair that should be used when creating sysfs
45 * representation of given kobject. Normally used to adjust ownership of
46 * objects in a container.
47 */
48void kobject_get_ownership(struct kobject *kobj, kuid_t *uid, kgid_t *gid)
49{
50 *uid = GLOBAL_ROOT_UID;
51 *gid = GLOBAL_ROOT_GID;
52
53 if (kobj->ktype->get_ownership)
54 kobj->ktype->get_ownership(kobj, uid, gid);
55}
56
57/*
58 * populate_dir - populate directory with attributes.
59 * @kobj: object we're working on.
60 *
61 * Most subsystems have a set of default attributes that are associated
62 * with an object that registers with them. This is a helper called during
63 * object registration that loops through the default attributes of the
64 * subsystem and creates attributes files for them in sysfs.
65 */
66static int populate_dir(struct kobject *kobj)
67{
68 struct kobj_type *t = get_ktype(kobj);
69 struct attribute *attr;
70 int error = 0;
71 int i;
72
73 if (t && t->default_attrs) {
74 for (i = 0; (attr = t->default_attrs[i]) != NULL; i++) {
75 error = sysfs_create_file(kobj, attr);
76 if (error)
77 break;
78 }
79 }
80 return error;
81}
82
83static int create_dir(struct kobject *kobj)
84{
85 const struct kobj_type *ktype = get_ktype(kobj);
86 const struct kobj_ns_type_operations *ops;
87 int error;
88
89 error = sysfs_create_dir_ns(kobj, kobject_namespace(kobj));
90 if (error)
91 return error;
92
93 error = populate_dir(kobj);
94 if (error) {
95 sysfs_remove_dir(kobj);
96 return error;
97 }
98
99 if (ktype) {
100 error = sysfs_create_groups(kobj, ktype->default_groups);
101 if (error) {
102 sysfs_remove_dir(kobj);
103 return error;
104 }
105 }
106
107 /*
108 * @kobj->sd may be deleted by an ancestor going away. Hold an
109 * extra reference so that it stays until @kobj is gone.
110 */
111 sysfs_get(kobj->sd);
112
113 /*
114 * If @kobj has ns_ops, its children need to be filtered based on
115 * their namespace tags. Enable namespace support on @kobj->sd.
116 */
117 ops = kobj_child_ns_ops(kobj);
118 if (ops) {
119 BUG_ON(ops->type <= KOBJ_NS_TYPE_NONE);
120 BUG_ON(ops->type >= KOBJ_NS_TYPES);
121 BUG_ON(!kobj_ns_type_registered(ops->type));
122
123 sysfs_enable_ns(kobj->sd);
124 }
125
126 return 0;
127}
128
129static int get_kobj_path_length(struct kobject *kobj)
130{
131 int length = 1;
132 struct kobject *parent = kobj;
133
134 /* walk up the ancestors until we hit the one pointing to the
135 * root.
136 * Add 1 to strlen for leading '/' of each level.
137 */
138 do {
139 if (kobject_name(parent) == NULL)
140 return 0;
141 length += strlen(kobject_name(parent)) + 1;
142 parent = parent->parent;
143 } while (parent);
144 return length;
145}
146
147static void fill_kobj_path(struct kobject *kobj, char *path, int length)
148{
149 struct kobject *parent;
150
151 --length;
152 for (parent = kobj; parent; parent = parent->parent) {
153 int cur = strlen(kobject_name(parent));
154 /* back up enough to print this name with '/' */
155 length -= cur;
156 memcpy(path + length, kobject_name(parent), cur);
157 *(path + --length) = '/';
158 }
159
160 pr_debug("kobject: '%s' (%p): %s: path = '%s'\n", kobject_name(kobj),
161 kobj, __func__, path);
162}
163
164/**
165 * kobject_get_path() - Allocate memory and fill in the path for @kobj.
166 * @kobj: kobject in question, with which to build the path
167 * @gfp_mask: the allocation type used to allocate the path
168 *
169 * Return: The newly allocated memory, caller must free with kfree().
170 */
171char *kobject_get_path(struct kobject *kobj, gfp_t gfp_mask)
172{
173 char *path;
174 int len;
175
176 len = get_kobj_path_length(kobj);
177 if (len == 0)
178 return NULL;
179 path = kzalloc(len, gfp_mask);
180 if (!path)
181 return NULL;
182 fill_kobj_path(kobj, path, len);
183
184 return path;
185}
186EXPORT_SYMBOL_GPL(kobject_get_path);
187
188/* add the kobject to its kset's list */
189static void kobj_kset_join(struct kobject *kobj)
190{
191 if (!kobj->kset)
192 return;
193
194 kset_get(kobj->kset);
195 spin_lock(&kobj->kset->list_lock);
196 list_add_tail(&kobj->entry, &kobj->kset->list);
197 spin_unlock(&kobj->kset->list_lock);
198}
199
200/* remove the kobject from its kset's list */
201static void kobj_kset_leave(struct kobject *kobj)
202{
203 if (!kobj->kset)
204 return;
205
206 spin_lock(&kobj->kset->list_lock);
207 list_del_init(&kobj->entry);
208 spin_unlock(&kobj->kset->list_lock);
209 kset_put(kobj->kset);
210}
211
212static void kobject_init_internal(struct kobject *kobj)
213{
214 if (!kobj)
215 return;
216 kref_init(&kobj->kref);
217 INIT_LIST_HEAD(&kobj->entry);
218 kobj->state_in_sysfs = 0;
219 kobj->state_add_uevent_sent = 0;
220 kobj->state_remove_uevent_sent = 0;
221 kobj->state_initialized = 1;
222}
223
224
225static int kobject_add_internal(struct kobject *kobj)
226{
227 int error = 0;
228 struct kobject *parent;
229
230 if (!kobj)
231 return -ENOENT;
232
233 if (!kobj->name || !kobj->name[0]) {
234 WARN(1,
235 "kobject: (%p): attempted to be registered with empty name!\n",
236 kobj);
237 return -EINVAL;
238 }
239
240 parent = kobject_get(kobj->parent);
241
242 /* join kset if set, use it as parent if we do not already have one */
243 if (kobj->kset) {
244 if (!parent)
245 parent = kobject_get(&kobj->kset->kobj);
246 kobj_kset_join(kobj);
247 kobj->parent = parent;
248 }
249
250 pr_debug("kobject: '%s' (%p): %s: parent: '%s', set: '%s'\n",
251 kobject_name(kobj), kobj, __func__,
252 parent ? kobject_name(parent) : "<NULL>",
253 kobj->kset ? kobject_name(&kobj->kset->kobj) : "<NULL>");
254
255 error = create_dir(kobj);
256 if (error) {
257 kobj_kset_leave(kobj);
258 kobject_put(parent);
259 kobj->parent = NULL;
260
261 /* be noisy on error issues */
262 if (error == -EEXIST)
263 pr_err("%s failed for %s with -EEXIST, don't try to register things with the same name in the same directory.\n",
264 __func__, kobject_name(kobj));
265 else
266 pr_err("%s failed for %s (error: %d parent: %s)\n",
267 __func__, kobject_name(kobj), error,
268 parent ? kobject_name(parent) : "'none'");
269 } else
270 kobj->state_in_sysfs = 1;
271
272 return error;
273}
274
275/**
276 * kobject_set_name_vargs() - Set the name of a kobject.
277 * @kobj: struct kobject to set the name of
278 * @fmt: format string used to build the name
279 * @vargs: vargs to format the string.
280 */
281int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
282 va_list vargs)
283{
284 const char *s;
285
286 if (kobj->name && !fmt)
287 return 0;
288
289 s = kvasprintf_const(GFP_KERNEL, fmt, vargs);
290 if (!s)
291 return -ENOMEM;
292
293 /*
294 * ewww... some of these buggers have '/' in the name ... If
295 * that's the case, we need to make sure we have an actual
296 * allocated copy to modify, since kvasprintf_const may have
297 * returned something from .rodata.
298 */
299 if (strchr(s, '/')) {
300 char *t;
301
302 t = kstrdup(s, GFP_KERNEL);
303 kfree_const(s);
304 if (!t)
305 return -ENOMEM;
306 strreplace(t, '/', '!');
307 s = t;
308 }
309 kfree_const(kobj->name);
310 kobj->name = s;
311
312 return 0;
313}
314
315/**
316 * kobject_set_name() - Set the name of a kobject.
317 * @kobj: struct kobject to set the name of
318 * @fmt: format string used to build the name
319 *
320 * This sets the name of the kobject. If you have already added the
321 * kobject to the system, you must call kobject_rename() in order to
322 * change the name of the kobject.
323 */
324int kobject_set_name(struct kobject *kobj, const char *fmt, ...)
325{
326 va_list vargs;
327 int retval;
328
329 va_start(vargs, fmt);
330 retval = kobject_set_name_vargs(kobj, fmt, vargs);
331 va_end(vargs);
332
333 return retval;
334}
335EXPORT_SYMBOL(kobject_set_name);
336
337/**
338 * kobject_init() - Initialize a kobject structure.
339 * @kobj: pointer to the kobject to initialize
340 * @ktype: pointer to the ktype for this kobject.
341 *
342 * This function will properly initialize a kobject such that it can then
343 * be passed to the kobject_add() call.
344 *
345 * After this function is called, the kobject MUST be cleaned up by a call
346 * to kobject_put(), not by a call to kfree directly to ensure that all of
347 * the memory is cleaned up properly.
348 */
349void kobject_init(struct kobject *kobj, struct kobj_type *ktype)
350{
351 char *err_str;
352
353 if (!kobj) {
354 err_str = "invalid kobject pointer!";
355 goto error;
356 }
357 if (!ktype) {
358 err_str = "must have a ktype to be initialized properly!\n";
359 goto error;
360 }
361 if (kobj->state_initialized) {
362 /* do not error out as sometimes we can recover */
363 pr_err("kobject (%p): tried to init an initialized object, something is seriously wrong.\n",
364 kobj);
365 dump_stack();
366 }
367
368 kobject_init_internal(kobj);
369 kobj->ktype = ktype;
370 return;
371
372error:
373 pr_err("kobject (%p): %s\n", kobj, err_str);
374 dump_stack();
375}
376EXPORT_SYMBOL(kobject_init);
377
378static __printf(3, 0) int kobject_add_varg(struct kobject *kobj,
379 struct kobject *parent,
380 const char *fmt, va_list vargs)
381{
382 int retval;
383
384 retval = kobject_set_name_vargs(kobj, fmt, vargs);
385 if (retval) {
386 pr_err("kobject: can not set name properly!\n");
387 return retval;
388 }
389 kobj->parent = parent;
390 return kobject_add_internal(kobj);
391}
392
393/**
394 * kobject_add() - The main kobject add function.
395 * @kobj: the kobject to add
396 * @parent: pointer to the parent of the kobject.
397 * @fmt: format to name the kobject with.
398 *
399 * The kobject name is set and added to the kobject hierarchy in this
400 * function.
401 *
402 * If @parent is set, then the parent of the @kobj will be set to it.
403 * If @parent is NULL, then the parent of the @kobj will be set to the
404 * kobject associated with the kset assigned to this kobject. If no kset
405 * is assigned to the kobject, then the kobject will be located in the
406 * root of the sysfs tree.
407 *
408 * Note, no "add" uevent will be created with this call, the caller should set
409 * up all of the necessary sysfs files for the object and then call
410 * kobject_uevent() with the UEVENT_ADD parameter to ensure that
411 * userspace is properly notified of this kobject's creation.
412 *
413 * Return: If this function returns an error, kobject_put() must be
414 * called to properly clean up the memory associated with the
415 * object. Under no instance should the kobject that is passed
416 * to this function be directly freed with a call to kfree(),
417 * that can leak memory.
418 *
419 * If this function returns success, kobject_put() must also be called
420 * in order to properly clean up the memory associated with the object.
421 *
422 * In short, once this function is called, kobject_put() MUST be called
423 * when the use of the object is finished in order to properly free
424 * everything.
425 */
426int kobject_add(struct kobject *kobj, struct kobject *parent,
427 const char *fmt, ...)
428{
429 va_list args;
430 int retval;
431
432 if (!kobj)
433 return -EINVAL;
434
435 if (!kobj->state_initialized) {
436 pr_err("kobject '%s' (%p): tried to add an uninitialized object, something is seriously wrong.\n",
437 kobject_name(kobj), kobj);
438 dump_stack();
439 return -EINVAL;
440 }
441 va_start(args, fmt);
442 retval = kobject_add_varg(kobj, parent, fmt, args);
443 va_end(args);
444
445 return retval;
446}
447EXPORT_SYMBOL(kobject_add);
448
449/**
450 * kobject_init_and_add() - Initialize a kobject structure and add it to
451 * the kobject hierarchy.
452 * @kobj: pointer to the kobject to initialize
453 * @ktype: pointer to the ktype for this kobject.
454 * @parent: pointer to the parent of this kobject.
455 * @fmt: the name of the kobject.
456 *
457 * This function combines the call to kobject_init() and kobject_add().
458 *
459 * If this function returns an error, kobject_put() must be called to
460 * properly clean up the memory associated with the object. This is the
461 * same type of error handling after a call to kobject_add() and kobject
462 * lifetime rules are the same here.
463 */
464int kobject_init_and_add(struct kobject *kobj, struct kobj_type *ktype,
465 struct kobject *parent, const char *fmt, ...)
466{
467 va_list args;
468 int retval;
469
470 kobject_init(kobj, ktype);
471
472 va_start(args, fmt);
473 retval = kobject_add_varg(kobj, parent, fmt, args);
474 va_end(args);
475
476 return retval;
477}
478EXPORT_SYMBOL_GPL(kobject_init_and_add);
479
480/**
481 * kobject_rename() - Change the name of an object.
482 * @kobj: object in question.
483 * @new_name: object's new name
484 *
485 * It is the responsibility of the caller to provide mutual
486 * exclusion between two different calls of kobject_rename
487 * on the same kobject and to ensure that new_name is valid and
488 * won't conflict with other kobjects.
489 */
490int kobject_rename(struct kobject *kobj, const char *new_name)
491{
492 int error = 0;
493 const char *devpath = NULL;
494 const char *dup_name = NULL, *name;
495 char *devpath_string = NULL;
496 char *envp[2];
497
498 kobj = kobject_get(kobj);
499 if (!kobj)
500 return -EINVAL;
501 if (!kobj->parent) {
502 kobject_put(kobj);
503 return -EINVAL;
504 }
505
506 devpath = kobject_get_path(kobj, GFP_KERNEL);
507 if (!devpath) {
508 error = -ENOMEM;
509 goto out;
510 }
511 devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL);
512 if (!devpath_string) {
513 error = -ENOMEM;
514 goto out;
515 }
516 sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);
517 envp[0] = devpath_string;
518 envp[1] = NULL;
519
520 name = dup_name = kstrdup_const(new_name, GFP_KERNEL);
521 if (!name) {
522 error = -ENOMEM;
523 goto out;
524 }
525
526 error = sysfs_rename_dir_ns(kobj, new_name, kobject_namespace(kobj));
527 if (error)
528 goto out;
529
530 /* Install the new kobject name */
531 dup_name = kobj->name;
532 kobj->name = name;
533
534 /* This function is mostly/only used for network interface.
535 * Some hotplug package track interfaces by their name and
536 * therefore want to know when the name is changed by the user. */
537 kobject_uevent_env(kobj, KOBJ_MOVE, envp);
538
539out:
540 kfree_const(dup_name);
541 kfree(devpath_string);
542 kfree(devpath);
543 kobject_put(kobj);
544
545 return error;
546}
547EXPORT_SYMBOL_GPL(kobject_rename);
548
549/**
550 * kobject_move() - Move object to another parent.
551 * @kobj: object in question.
552 * @new_parent: object's new parent (can be NULL)
553 */
554int kobject_move(struct kobject *kobj, struct kobject *new_parent)
555{
556 int error;
557 struct kobject *old_parent;
558 const char *devpath = NULL;
559 char *devpath_string = NULL;
560 char *envp[2];
561
562 kobj = kobject_get(kobj);
563 if (!kobj)
564 return -EINVAL;
565 new_parent = kobject_get(new_parent);
566 if (!new_parent) {
567 if (kobj->kset)
568 new_parent = kobject_get(&kobj->kset->kobj);
569 }
570
571 /* old object path */
572 devpath = kobject_get_path(kobj, GFP_KERNEL);
573 if (!devpath) {
574 error = -ENOMEM;
575 goto out;
576 }
577 devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL);
578 if (!devpath_string) {
579 error = -ENOMEM;
580 goto out;
581 }
582 sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);
583 envp[0] = devpath_string;
584 envp[1] = NULL;
585 error = sysfs_move_dir_ns(kobj, new_parent, kobject_namespace(kobj));
586 if (error)
587 goto out;
588 old_parent = kobj->parent;
589 kobj->parent = new_parent;
590 new_parent = NULL;
591 kobject_put(old_parent);
592 kobject_uevent_env(kobj, KOBJ_MOVE, envp);
593out:
594 kobject_put(new_parent);
595 kobject_put(kobj);
596 kfree(devpath_string);
597 kfree(devpath);
598 return error;
599}
600EXPORT_SYMBOL_GPL(kobject_move);
601
602static void __kobject_del(struct kobject *kobj)
603{
604 struct kernfs_node *sd;
605 const struct kobj_type *ktype;
606
607 sd = kobj->sd;
608 ktype = get_ktype(kobj);
609
610 if (ktype)
611 sysfs_remove_groups(kobj, ktype->default_groups);
612
613 /* send "remove" if the caller did not do it but sent "add" */
614 if (kobj->state_add_uevent_sent && !kobj->state_remove_uevent_sent) {
615 pr_debug("kobject: '%s' (%p): auto cleanup 'remove' event\n",
616 kobject_name(kobj), kobj);
617 kobject_uevent(kobj, KOBJ_REMOVE);
618 }
619
620 sysfs_remove_dir(kobj);
621 sysfs_put(sd);
622
623 kobj->state_in_sysfs = 0;
624 kobj_kset_leave(kobj);
625 kobj->parent = NULL;
626}
627
628/**
629 * kobject_del() - Unlink kobject from hierarchy.
630 * @kobj: object.
631 *
632 * This is the function that should be called to delete an object
633 * successfully added via kobject_add().
634 */
635void kobject_del(struct kobject *kobj)
636{
637 struct kobject *parent;
638
639 if (!kobj)
640 return;
641
642 parent = kobj->parent;
643 __kobject_del(kobj);
644 kobject_put(parent);
645}
646EXPORT_SYMBOL(kobject_del);
647
648/**
649 * kobject_get() - Increment refcount for object.
650 * @kobj: object.
651 */
652struct kobject *kobject_get(struct kobject *kobj)
653{
654 if (kobj) {
655 if (!kobj->state_initialized)
656 WARN(1, KERN_WARNING
657 "kobject: '%s' (%p): is not initialized, yet kobject_get() is being called.\n",
658 kobject_name(kobj), kobj);
659 kref_get(&kobj->kref);
660 }
661 return kobj;
662}
663EXPORT_SYMBOL(kobject_get);
664
665struct kobject * __must_check kobject_get_unless_zero(struct kobject *kobj)
666{
667 if (!kobj)
668 return NULL;
669 if (!kref_get_unless_zero(&kobj->kref))
670 kobj = NULL;
671 return kobj;
672}
673EXPORT_SYMBOL(kobject_get_unless_zero);
674
675/*
676 * kobject_cleanup - free kobject resources.
677 * @kobj: object to cleanup
678 */
679static void kobject_cleanup(struct kobject *kobj)
680{
681 struct kobject *parent = kobj->parent;
682 struct kobj_type *t = get_ktype(kobj);
683 const char *name = kobj->name;
684
685 pr_debug("kobject: '%s' (%p): %s, parent %p\n",
686 kobject_name(kobj), kobj, __func__, kobj->parent);
687
688 if (t && !t->release)
689 pr_debug("kobject: '%s' (%p): does not have a release() function, it is broken and must be fixed. See Documentation/core-api/kobject.rst.\n",
690 kobject_name(kobj), kobj);
691
692 /* remove from sysfs if the caller did not do it */
693 if (kobj->state_in_sysfs) {
694 pr_debug("kobject: '%s' (%p): auto cleanup kobject_del\n",
695 kobject_name(kobj), kobj);
696 __kobject_del(kobj);
697 } else {
698 /* avoid dropping the parent reference unnecessarily */
699 parent = NULL;
700 }
701
702 if (t && t->release) {
703 pr_debug("kobject: '%s' (%p): calling ktype release\n",
704 kobject_name(kobj), kobj);
705 t->release(kobj);
706 }
707
708 /* free name if we allocated it */
709 if (name) {
710 pr_debug("kobject: '%s': free name\n", name);
711 kfree_const(name);
712 }
713
714 kobject_put(parent);
715}
716
717#ifdef CONFIG_DEBUG_KOBJECT_RELEASE
718static void kobject_delayed_cleanup(struct work_struct *work)
719{
720 kobject_cleanup(container_of(to_delayed_work(work),
721 struct kobject, release));
722}
723#endif
724
725static void kobject_release(struct kref *kref)
726{
727 struct kobject *kobj = container_of(kref, struct kobject, kref);
728#ifdef CONFIG_DEBUG_KOBJECT_RELEASE
729 unsigned long delay = HZ + HZ * (get_random_int() & 0x3);
730 pr_info("kobject: '%s' (%p): %s, parent %p (delayed %ld)\n",
731 kobject_name(kobj), kobj, __func__, kobj->parent, delay);
732 INIT_DELAYED_WORK(&kobj->release, kobject_delayed_cleanup);
733
734 schedule_delayed_work(&kobj->release, delay);
735#else
736 kobject_cleanup(kobj);
737#endif
738}
739
740/**
741 * kobject_put() - Decrement refcount for object.
742 * @kobj: object.
743 *
744 * Decrement the refcount, and if 0, call kobject_cleanup().
745 */
746void kobject_put(struct kobject *kobj)
747{
748 if (kobj) {
749 if (!kobj->state_initialized)
750 WARN(1, KERN_WARNING
751 "kobject: '%s' (%p): is not initialized, yet kobject_put() is being called.\n",
752 kobject_name(kobj), kobj);
753 kref_put(&kobj->kref, kobject_release);
754 }
755}
756EXPORT_SYMBOL(kobject_put);
757
758static void dynamic_kobj_release(struct kobject *kobj)
759{
760 pr_debug("kobject: (%p): %s\n", kobj, __func__);
761 kfree(kobj);
762}
763
764static struct kobj_type dynamic_kobj_ktype = {
765 .release = dynamic_kobj_release,
766 .sysfs_ops = &kobj_sysfs_ops,
767};
768
769/**
770 * kobject_create() - Create a struct kobject dynamically.
771 *
772 * This function creates a kobject structure dynamically and sets it up
773 * to be a "dynamic" kobject with a default release function set up.
774 *
775 * If the kobject was not able to be created, NULL will be returned.
776 * The kobject structure returned from here must be cleaned up with a
777 * call to kobject_put() and not kfree(), as kobject_init() has
778 * already been called on this structure.
779 */
780struct kobject *kobject_create(void)
781{
782 struct kobject *kobj;
783
784 kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
785 if (!kobj)
786 return NULL;
787
788 kobject_init(kobj, &dynamic_kobj_ktype);
789 return kobj;
790}
791
792/**
793 * kobject_create_and_add() - Create a struct kobject dynamically and
794 * register it with sysfs.
795 * @name: the name for the kobject
796 * @parent: the parent kobject of this kobject, if any.
797 *
798 * This function creates a kobject structure dynamically and registers it
799 * with sysfs. When you are finished with this structure, call
800 * kobject_put() and the structure will be dynamically freed when
801 * it is no longer being used.
802 *
803 * If the kobject was not able to be created, NULL will be returned.
804 */
805struct kobject *kobject_create_and_add(const char *name, struct kobject *parent)
806{
807 struct kobject *kobj;
808 int retval;
809
810 kobj = kobject_create();
811 if (!kobj)
812 return NULL;
813
814 retval = kobject_add(kobj, parent, "%s", name);
815 if (retval) {
816 pr_warn("%s: kobject_add error: %d\n", __func__, retval);
817 kobject_put(kobj);
818 kobj = NULL;
819 }
820 return kobj;
821}
822EXPORT_SYMBOL_GPL(kobject_create_and_add);
823
824/**
825 * kset_init() - Initialize a kset for use.
826 * @k: kset
827 */
828void kset_init(struct kset *k)
829{
830 kobject_init_internal(&k->kobj);
831 INIT_LIST_HEAD(&k->list);
832 spin_lock_init(&k->list_lock);
833}
834
835/* default kobject attribute operations */
836static ssize_t kobj_attr_show(struct kobject *kobj, struct attribute *attr,
837 char *buf)
838{
839 struct kobj_attribute *kattr;
840 ssize_t ret = -EIO;
841
842 kattr = container_of(attr, struct kobj_attribute, attr);
843 if (kattr->show)
844 ret = kattr->show(kobj, kattr, buf);
845 return ret;
846}
847
848static ssize_t kobj_attr_store(struct kobject *kobj, struct attribute *attr,
849 const char *buf, size_t count)
850{
851 struct kobj_attribute *kattr;
852 ssize_t ret = -EIO;
853
854 kattr = container_of(attr, struct kobj_attribute, attr);
855 if (kattr->store)
856 ret = kattr->store(kobj, kattr, buf, count);
857 return ret;
858}
859
860const struct sysfs_ops kobj_sysfs_ops = {
861 .show = kobj_attr_show,
862 .store = kobj_attr_store,
863};
864EXPORT_SYMBOL_GPL(kobj_sysfs_ops);
865
866/**
867 * kset_register() - Initialize and add a kset.
868 * @k: kset.
869 */
870int kset_register(struct kset *k)
871{
872 int err;
873
874 if (!k)
875 return -EINVAL;
876
877 kset_init(k);
878 err = kobject_add_internal(&k->kobj);
879 if (err)
880 return err;
881 kobject_uevent(&k->kobj, KOBJ_ADD);
882 return 0;
883}
884EXPORT_SYMBOL(kset_register);
885
886/**
887 * kset_unregister() - Remove a kset.
888 * @k: kset.
889 */
890void kset_unregister(struct kset *k)
891{
892 if (!k)
893 return;
894 kobject_del(&k->kobj);
895 kobject_put(&k->kobj);
896}
897EXPORT_SYMBOL(kset_unregister);
898
899/**
900 * kset_find_obj() - Search for object in kset.
901 * @kset: kset we're looking in.
902 * @name: object's name.
903 *
904 * Lock kset via @kset->subsys, and iterate over @kset->list,
905 * looking for a matching kobject. If matching object is found
906 * take a reference and return the object.
907 */
908struct kobject *kset_find_obj(struct kset *kset, const char *name)
909{
910 struct kobject *k;
911 struct kobject *ret = NULL;
912
913 spin_lock(&kset->list_lock);
914
915 list_for_each_entry(k, &kset->list, entry) {
916 if (kobject_name(k) && !strcmp(kobject_name(k), name)) {
917 ret = kobject_get_unless_zero(k);
918 break;
919 }
920 }
921
922 spin_unlock(&kset->list_lock);
923 return ret;
924}
925EXPORT_SYMBOL_GPL(kset_find_obj);
926
927static void kset_release(struct kobject *kobj)
928{
929 struct kset *kset = container_of(kobj, struct kset, kobj);
930 pr_debug("kobject: '%s' (%p): %s\n",
931 kobject_name(kobj), kobj, __func__);
932 kfree(kset);
933}
934
935static void kset_get_ownership(struct kobject *kobj, kuid_t *uid, kgid_t *gid)
936{
937 if (kobj->parent)
938 kobject_get_ownership(kobj->parent, uid, gid);
939}
940
941static struct kobj_type kset_ktype = {
942 .sysfs_ops = &kobj_sysfs_ops,
943 .release = kset_release,
944 .get_ownership = kset_get_ownership,
945};
946
947/**
948 * kset_create() - Create a struct kset dynamically.
949 *
950 * @name: the name for the kset
951 * @uevent_ops: a struct kset_uevent_ops for the kset
952 * @parent_kobj: the parent kobject of this kset, if any.
953 *
954 * This function creates a kset structure dynamically. This structure can
955 * then be registered with the system and show up in sysfs with a call to
956 * kset_register(). When you are finished with this structure, if
957 * kset_register() has been called, call kset_unregister() and the
958 * structure will be dynamically freed when it is no longer being used.
959 *
960 * If the kset was not able to be created, NULL will be returned.
961 */
962static struct kset *kset_create(const char *name,
963 const struct kset_uevent_ops *uevent_ops,
964 struct kobject *parent_kobj)
965{
966 struct kset *kset;
967 int retval;
968
969 kset = kzalloc(sizeof(*kset), GFP_KERNEL);
970 if (!kset)
971 return NULL;
972 retval = kobject_set_name(&kset->kobj, "%s", name);
973 if (retval) {
974 kfree(kset);
975 return NULL;
976 }
977 kset->uevent_ops = uevent_ops;
978 kset->kobj.parent = parent_kobj;
979
980 /*
981 * The kobject of this kset will have a type of kset_ktype and belong to
982 * no kset itself. That way we can properly free it when it is
983 * finished being used.
984 */
985 kset->kobj.ktype = &kset_ktype;
986 kset->kobj.kset = NULL;
987
988 return kset;
989}
990
991/**
992 * kset_create_and_add() - Create a struct kset dynamically and add it to sysfs.
993 *
994 * @name: the name for the kset
995 * @uevent_ops: a struct kset_uevent_ops for the kset
996 * @parent_kobj: the parent kobject of this kset, if any.
997 *
998 * This function creates a kset structure dynamically and registers it
999 * with sysfs. When you are finished with this structure, call
1000 * kset_unregister() and the structure will be dynamically freed when it
1001 * is no longer being used.
1002 *
1003 * If the kset was not able to be created, NULL will be returned.
1004 */
1005struct kset *kset_create_and_add(const char *name,
1006 const struct kset_uevent_ops *uevent_ops,
1007 struct kobject *parent_kobj)
1008{
1009 struct kset *kset;
1010 int error;
1011
1012 kset = kset_create(name, uevent_ops, parent_kobj);
1013 if (!kset)
1014 return NULL;
1015 error = kset_register(kset);
1016 if (error) {
1017 kfree(kset);
1018 return NULL;
1019 }
1020 return kset;
1021}
1022EXPORT_SYMBOL_GPL(kset_create_and_add);
1023
1024
1025static DEFINE_SPINLOCK(kobj_ns_type_lock);
1026static const struct kobj_ns_type_operations *kobj_ns_ops_tbl[KOBJ_NS_TYPES];
1027
1028int kobj_ns_type_register(const struct kobj_ns_type_operations *ops)
1029{
1030 enum kobj_ns_type type = ops->type;
1031 int error;
1032
1033 spin_lock(&kobj_ns_type_lock);
1034
1035 error = -EINVAL;
1036 if (type >= KOBJ_NS_TYPES)
1037 goto out;
1038
1039 error = -EINVAL;
1040 if (type <= KOBJ_NS_TYPE_NONE)
1041 goto out;
1042
1043 error = -EBUSY;
1044 if (kobj_ns_ops_tbl[type])
1045 goto out;
1046
1047 error = 0;
1048 kobj_ns_ops_tbl[type] = ops;
1049
1050out:
1051 spin_unlock(&kobj_ns_type_lock);
1052 return error;
1053}
1054
1055int kobj_ns_type_registered(enum kobj_ns_type type)
1056{
1057 int registered = 0;
1058
1059 spin_lock(&kobj_ns_type_lock);
1060 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES))
1061 registered = kobj_ns_ops_tbl[type] != NULL;
1062 spin_unlock(&kobj_ns_type_lock);
1063
1064 return registered;
1065}
1066
1067const struct kobj_ns_type_operations *kobj_child_ns_ops(struct kobject *parent)
1068{
1069 const struct kobj_ns_type_operations *ops = NULL;
1070
1071 if (parent && parent->ktype && parent->ktype->child_ns_type)
1072 ops = parent->ktype->child_ns_type(parent);
1073
1074 return ops;
1075}
1076
1077const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj)
1078{
1079 return kobj_child_ns_ops(kobj->parent);
1080}
1081
1082bool kobj_ns_current_may_mount(enum kobj_ns_type type)
1083{
1084 bool may_mount = true;
1085
1086 spin_lock(&kobj_ns_type_lock);
1087 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1088 kobj_ns_ops_tbl[type])
1089 may_mount = kobj_ns_ops_tbl[type]->current_may_mount();
1090 spin_unlock(&kobj_ns_type_lock);
1091
1092 return may_mount;
1093}
1094
1095void *kobj_ns_grab_current(enum kobj_ns_type type)
1096{
1097 void *ns = NULL;
1098
1099 spin_lock(&kobj_ns_type_lock);
1100 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1101 kobj_ns_ops_tbl[type])
1102 ns = kobj_ns_ops_tbl[type]->grab_current_ns();
1103 spin_unlock(&kobj_ns_type_lock);
1104
1105 return ns;
1106}
1107EXPORT_SYMBOL_GPL(kobj_ns_grab_current);
1108
1109const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk)
1110{
1111 const void *ns = NULL;
1112
1113 spin_lock(&kobj_ns_type_lock);
1114 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1115 kobj_ns_ops_tbl[type])
1116 ns = kobj_ns_ops_tbl[type]->netlink_ns(sk);
1117 spin_unlock(&kobj_ns_type_lock);
1118
1119 return ns;
1120}
1121
1122const void *kobj_ns_initial(enum kobj_ns_type type)
1123{
1124 const void *ns = NULL;
1125
1126 spin_lock(&kobj_ns_type_lock);
1127 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1128 kobj_ns_ops_tbl[type])
1129 ns = kobj_ns_ops_tbl[type]->initial_ns();
1130 spin_unlock(&kobj_ns_type_lock);
1131
1132 return ns;
1133}
1134
1135void kobj_ns_drop(enum kobj_ns_type type, void *ns)
1136{
1137 spin_lock(&kobj_ns_type_lock);
1138 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1139 kobj_ns_ops_tbl[type] && kobj_ns_ops_tbl[type]->drop_ns)
1140 kobj_ns_ops_tbl[type]->drop_ns(ns);
1141 spin_unlock(&kobj_ns_type_lock);
1142}
1143EXPORT_SYMBOL_GPL(kobj_ns_drop);
1/*
2 * kobject.c - library routines for handling generic kernel objects
3 *
4 * Copyright (c) 2002-2003 Patrick Mochel <mochel@osdl.org>
5 * Copyright (c) 2006-2007 Greg Kroah-Hartman <greg@kroah.com>
6 * Copyright (c) 2006-2007 Novell Inc.
7 *
8 * This file is released under the GPLv2.
9 *
10 *
11 * Please see the file Documentation/kobject.txt for critical information
12 * about using the kobject interface.
13 */
14
15#include <linux/kobject.h>
16#include <linux/string.h>
17#include <linux/module.h>
18#include <linux/stat.h>
19#include <linux/slab.h>
20
21/*
22 * populate_dir - populate directory with attributes.
23 * @kobj: object we're working on.
24 *
25 * Most subsystems have a set of default attributes that are associated
26 * with an object that registers with them. This is a helper called during
27 * object registration that loops through the default attributes of the
28 * subsystem and creates attributes files for them in sysfs.
29 */
30static int populate_dir(struct kobject *kobj)
31{
32 struct kobj_type *t = get_ktype(kobj);
33 struct attribute *attr;
34 int error = 0;
35 int i;
36
37 if (t && t->default_attrs) {
38 for (i = 0; (attr = t->default_attrs[i]) != NULL; i++) {
39 error = sysfs_create_file(kobj, attr);
40 if (error)
41 break;
42 }
43 }
44 return error;
45}
46
47static int create_dir(struct kobject *kobj)
48{
49 int error = 0;
50 if (kobject_name(kobj)) {
51 error = sysfs_create_dir(kobj);
52 if (!error) {
53 error = populate_dir(kobj);
54 if (error)
55 sysfs_remove_dir(kobj);
56 }
57 }
58 return error;
59}
60
61static int get_kobj_path_length(struct kobject *kobj)
62{
63 int length = 1;
64 struct kobject *parent = kobj;
65
66 /* walk up the ancestors until we hit the one pointing to the
67 * root.
68 * Add 1 to strlen for leading '/' of each level.
69 */
70 do {
71 if (kobject_name(parent) == NULL)
72 return 0;
73 length += strlen(kobject_name(parent)) + 1;
74 parent = parent->parent;
75 } while (parent);
76 return length;
77}
78
79static void fill_kobj_path(struct kobject *kobj, char *path, int length)
80{
81 struct kobject *parent;
82
83 --length;
84 for (parent = kobj; parent; parent = parent->parent) {
85 int cur = strlen(kobject_name(parent));
86 /* back up enough to print this name with '/' */
87 length -= cur;
88 strncpy(path + length, kobject_name(parent), cur);
89 *(path + --length) = '/';
90 }
91
92 pr_debug("kobject: '%s' (%p): %s: path = '%s'\n", kobject_name(kobj),
93 kobj, __func__, path);
94}
95
96/**
97 * kobject_get_path - generate and return the path associated with a given kobj and kset pair.
98 *
99 * @kobj: kobject in question, with which to build the path
100 * @gfp_mask: the allocation type used to allocate the path
101 *
102 * The result must be freed by the caller with kfree().
103 */
104char *kobject_get_path(struct kobject *kobj, gfp_t gfp_mask)
105{
106 char *path;
107 int len;
108
109 len = get_kobj_path_length(kobj);
110 if (len == 0)
111 return NULL;
112 path = kzalloc(len, gfp_mask);
113 if (!path)
114 return NULL;
115 fill_kobj_path(kobj, path, len);
116
117 return path;
118}
119EXPORT_SYMBOL_GPL(kobject_get_path);
120
121/* add the kobject to its kset's list */
122static void kobj_kset_join(struct kobject *kobj)
123{
124 if (!kobj->kset)
125 return;
126
127 kset_get(kobj->kset);
128 spin_lock(&kobj->kset->list_lock);
129 list_add_tail(&kobj->entry, &kobj->kset->list);
130 spin_unlock(&kobj->kset->list_lock);
131}
132
133/* remove the kobject from its kset's list */
134static void kobj_kset_leave(struct kobject *kobj)
135{
136 if (!kobj->kset)
137 return;
138
139 spin_lock(&kobj->kset->list_lock);
140 list_del_init(&kobj->entry);
141 spin_unlock(&kobj->kset->list_lock);
142 kset_put(kobj->kset);
143}
144
145static void kobject_init_internal(struct kobject *kobj)
146{
147 if (!kobj)
148 return;
149 kref_init(&kobj->kref);
150 INIT_LIST_HEAD(&kobj->entry);
151 kobj->state_in_sysfs = 0;
152 kobj->state_add_uevent_sent = 0;
153 kobj->state_remove_uevent_sent = 0;
154 kobj->state_initialized = 1;
155}
156
157
158static int kobject_add_internal(struct kobject *kobj)
159{
160 int error = 0;
161 struct kobject *parent;
162
163 if (!kobj)
164 return -ENOENT;
165
166 if (!kobj->name || !kobj->name[0]) {
167 WARN(1, "kobject: (%p): attempted to be registered with empty "
168 "name!\n", kobj);
169 return -EINVAL;
170 }
171
172 parent = kobject_get(kobj->parent);
173
174 /* join kset if set, use it as parent if we do not already have one */
175 if (kobj->kset) {
176 if (!parent)
177 parent = kobject_get(&kobj->kset->kobj);
178 kobj_kset_join(kobj);
179 kobj->parent = parent;
180 }
181
182 pr_debug("kobject: '%s' (%p): %s: parent: '%s', set: '%s'\n",
183 kobject_name(kobj), kobj, __func__,
184 parent ? kobject_name(parent) : "<NULL>",
185 kobj->kset ? kobject_name(&kobj->kset->kobj) : "<NULL>");
186
187 error = create_dir(kobj);
188 if (error) {
189 kobj_kset_leave(kobj);
190 kobject_put(parent);
191 kobj->parent = NULL;
192
193 /* be noisy on error issues */
194 if (error == -EEXIST)
195 printk(KERN_ERR "%s failed for %s with "
196 "-EEXIST, don't try to register things with "
197 "the same name in the same directory.\n",
198 __func__, kobject_name(kobj));
199 else
200 printk(KERN_ERR "%s failed for %s (%d)\n",
201 __func__, kobject_name(kobj), error);
202 dump_stack();
203 } else
204 kobj->state_in_sysfs = 1;
205
206 return error;
207}
208
209/**
210 * kobject_set_name_vargs - Set the name of an kobject
211 * @kobj: struct kobject to set the name of
212 * @fmt: format string used to build the name
213 * @vargs: vargs to format the string.
214 */
215int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
216 va_list vargs)
217{
218 const char *old_name = kobj->name;
219 char *s;
220
221 if (kobj->name && !fmt)
222 return 0;
223
224 kobj->name = kvasprintf(GFP_KERNEL, fmt, vargs);
225 if (!kobj->name)
226 return -ENOMEM;
227
228 /* ewww... some of these buggers have '/' in the name ... */
229 while ((s = strchr(kobj->name, '/')))
230 s[0] = '!';
231
232 kfree(old_name);
233 return 0;
234}
235
236/**
237 * kobject_set_name - Set the name of a kobject
238 * @kobj: struct kobject to set the name of
239 * @fmt: format string used to build the name
240 *
241 * This sets the name of the kobject. If you have already added the
242 * kobject to the system, you must call kobject_rename() in order to
243 * change the name of the kobject.
244 */
245int kobject_set_name(struct kobject *kobj, const char *fmt, ...)
246{
247 va_list vargs;
248 int retval;
249
250 va_start(vargs, fmt);
251 retval = kobject_set_name_vargs(kobj, fmt, vargs);
252 va_end(vargs);
253
254 return retval;
255}
256EXPORT_SYMBOL(kobject_set_name);
257
258/**
259 * kobject_init - initialize a kobject structure
260 * @kobj: pointer to the kobject to initialize
261 * @ktype: pointer to the ktype for this kobject.
262 *
263 * This function will properly initialize a kobject such that it can then
264 * be passed to the kobject_add() call.
265 *
266 * After this function is called, the kobject MUST be cleaned up by a call
267 * to kobject_put(), not by a call to kfree directly to ensure that all of
268 * the memory is cleaned up properly.
269 */
270void kobject_init(struct kobject *kobj, struct kobj_type *ktype)
271{
272 char *err_str;
273
274 if (!kobj) {
275 err_str = "invalid kobject pointer!";
276 goto error;
277 }
278 if (!ktype) {
279 err_str = "must have a ktype to be initialized properly!\n";
280 goto error;
281 }
282 if (kobj->state_initialized) {
283 /* do not error out as sometimes we can recover */
284 printk(KERN_ERR "kobject (%p): tried to init an initialized "
285 "object, something is seriously wrong.\n", kobj);
286 dump_stack();
287 }
288
289 kobject_init_internal(kobj);
290 kobj->ktype = ktype;
291 return;
292
293error:
294 printk(KERN_ERR "kobject (%p): %s\n", kobj, err_str);
295 dump_stack();
296}
297EXPORT_SYMBOL(kobject_init);
298
299static int kobject_add_varg(struct kobject *kobj, struct kobject *parent,
300 const char *fmt, va_list vargs)
301{
302 int retval;
303
304 retval = kobject_set_name_vargs(kobj, fmt, vargs);
305 if (retval) {
306 printk(KERN_ERR "kobject: can not set name properly!\n");
307 return retval;
308 }
309 kobj->parent = parent;
310 return kobject_add_internal(kobj);
311}
312
313/**
314 * kobject_add - the main kobject add function
315 * @kobj: the kobject to add
316 * @parent: pointer to the parent of the kobject.
317 * @fmt: format to name the kobject with.
318 *
319 * The kobject name is set and added to the kobject hierarchy in this
320 * function.
321 *
322 * If @parent is set, then the parent of the @kobj will be set to it.
323 * If @parent is NULL, then the parent of the @kobj will be set to the
324 * kobject associted with the kset assigned to this kobject. If no kset
325 * is assigned to the kobject, then the kobject will be located in the
326 * root of the sysfs tree.
327 *
328 * If this function returns an error, kobject_put() must be called to
329 * properly clean up the memory associated with the object.
330 * Under no instance should the kobject that is passed to this function
331 * be directly freed with a call to kfree(), that can leak memory.
332 *
333 * Note, no "add" uevent will be created with this call, the caller should set
334 * up all of the necessary sysfs files for the object and then call
335 * kobject_uevent() with the UEVENT_ADD parameter to ensure that
336 * userspace is properly notified of this kobject's creation.
337 */
338int kobject_add(struct kobject *kobj, struct kobject *parent,
339 const char *fmt, ...)
340{
341 va_list args;
342 int retval;
343
344 if (!kobj)
345 return -EINVAL;
346
347 if (!kobj->state_initialized) {
348 printk(KERN_ERR "kobject '%s' (%p): tried to add an "
349 "uninitialized object, something is seriously wrong.\n",
350 kobject_name(kobj), kobj);
351 dump_stack();
352 return -EINVAL;
353 }
354 va_start(args, fmt);
355 retval = kobject_add_varg(kobj, parent, fmt, args);
356 va_end(args);
357
358 return retval;
359}
360EXPORT_SYMBOL(kobject_add);
361
362/**
363 * kobject_init_and_add - initialize a kobject structure and add it to the kobject hierarchy
364 * @kobj: pointer to the kobject to initialize
365 * @ktype: pointer to the ktype for this kobject.
366 * @parent: pointer to the parent of this kobject.
367 * @fmt: the name of the kobject.
368 *
369 * This function combines the call to kobject_init() and
370 * kobject_add(). The same type of error handling after a call to
371 * kobject_add() and kobject lifetime rules are the same here.
372 */
373int kobject_init_and_add(struct kobject *kobj, struct kobj_type *ktype,
374 struct kobject *parent, const char *fmt, ...)
375{
376 va_list args;
377 int retval;
378
379 kobject_init(kobj, ktype);
380
381 va_start(args, fmt);
382 retval = kobject_add_varg(kobj, parent, fmt, args);
383 va_end(args);
384
385 return retval;
386}
387EXPORT_SYMBOL_GPL(kobject_init_and_add);
388
389/**
390 * kobject_rename - change the name of an object
391 * @kobj: object in question.
392 * @new_name: object's new name
393 *
394 * It is the responsibility of the caller to provide mutual
395 * exclusion between two different calls of kobject_rename
396 * on the same kobject and to ensure that new_name is valid and
397 * won't conflict with other kobjects.
398 */
399int kobject_rename(struct kobject *kobj, const char *new_name)
400{
401 int error = 0;
402 const char *devpath = NULL;
403 const char *dup_name = NULL, *name;
404 char *devpath_string = NULL;
405 char *envp[2];
406
407 kobj = kobject_get(kobj);
408 if (!kobj)
409 return -EINVAL;
410 if (!kobj->parent)
411 return -EINVAL;
412
413 devpath = kobject_get_path(kobj, GFP_KERNEL);
414 if (!devpath) {
415 error = -ENOMEM;
416 goto out;
417 }
418 devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL);
419 if (!devpath_string) {
420 error = -ENOMEM;
421 goto out;
422 }
423 sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);
424 envp[0] = devpath_string;
425 envp[1] = NULL;
426
427 name = dup_name = kstrdup(new_name, GFP_KERNEL);
428 if (!name) {
429 error = -ENOMEM;
430 goto out;
431 }
432
433 error = sysfs_rename_dir(kobj, new_name);
434 if (error)
435 goto out;
436
437 /* Install the new kobject name */
438 dup_name = kobj->name;
439 kobj->name = name;
440
441 /* This function is mostly/only used for network interface.
442 * Some hotplug package track interfaces by their name and
443 * therefore want to know when the name is changed by the user. */
444 kobject_uevent_env(kobj, KOBJ_MOVE, envp);
445
446out:
447 kfree(dup_name);
448 kfree(devpath_string);
449 kfree(devpath);
450 kobject_put(kobj);
451
452 return error;
453}
454EXPORT_SYMBOL_GPL(kobject_rename);
455
456/**
457 * kobject_move - move object to another parent
458 * @kobj: object in question.
459 * @new_parent: object's new parent (can be NULL)
460 */
461int kobject_move(struct kobject *kobj, struct kobject *new_parent)
462{
463 int error;
464 struct kobject *old_parent;
465 const char *devpath = NULL;
466 char *devpath_string = NULL;
467 char *envp[2];
468
469 kobj = kobject_get(kobj);
470 if (!kobj)
471 return -EINVAL;
472 new_parent = kobject_get(new_parent);
473 if (!new_parent) {
474 if (kobj->kset)
475 new_parent = kobject_get(&kobj->kset->kobj);
476 }
477 /* old object path */
478 devpath = kobject_get_path(kobj, GFP_KERNEL);
479 if (!devpath) {
480 error = -ENOMEM;
481 goto out;
482 }
483 devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL);
484 if (!devpath_string) {
485 error = -ENOMEM;
486 goto out;
487 }
488 sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);
489 envp[0] = devpath_string;
490 envp[1] = NULL;
491 error = sysfs_move_dir(kobj, new_parent);
492 if (error)
493 goto out;
494 old_parent = kobj->parent;
495 kobj->parent = new_parent;
496 new_parent = NULL;
497 kobject_put(old_parent);
498 kobject_uevent_env(kobj, KOBJ_MOVE, envp);
499out:
500 kobject_put(new_parent);
501 kobject_put(kobj);
502 kfree(devpath_string);
503 kfree(devpath);
504 return error;
505}
506
507/**
508 * kobject_del - unlink kobject from hierarchy.
509 * @kobj: object.
510 */
511void kobject_del(struct kobject *kobj)
512{
513 if (!kobj)
514 return;
515
516 sysfs_remove_dir(kobj);
517 kobj->state_in_sysfs = 0;
518 kobj_kset_leave(kobj);
519 kobject_put(kobj->parent);
520 kobj->parent = NULL;
521}
522
523/**
524 * kobject_get - increment refcount for object.
525 * @kobj: object.
526 */
527struct kobject *kobject_get(struct kobject *kobj)
528{
529 if (kobj)
530 kref_get(&kobj->kref);
531 return kobj;
532}
533
534/*
535 * kobject_cleanup - free kobject resources.
536 * @kobj: object to cleanup
537 */
538static void kobject_cleanup(struct kobject *kobj)
539{
540 struct kobj_type *t = get_ktype(kobj);
541 const char *name = kobj->name;
542
543 pr_debug("kobject: '%s' (%p): %s\n",
544 kobject_name(kobj), kobj, __func__);
545
546 if (t && !t->release)
547 pr_debug("kobject: '%s' (%p): does not have a release() "
548 "function, it is broken and must be fixed.\n",
549 kobject_name(kobj), kobj);
550
551 /* send "remove" if the caller did not do it but sent "add" */
552 if (kobj->state_add_uevent_sent && !kobj->state_remove_uevent_sent) {
553 pr_debug("kobject: '%s' (%p): auto cleanup 'remove' event\n",
554 kobject_name(kobj), kobj);
555 kobject_uevent(kobj, KOBJ_REMOVE);
556 }
557
558 /* remove from sysfs if the caller did not do it */
559 if (kobj->state_in_sysfs) {
560 pr_debug("kobject: '%s' (%p): auto cleanup kobject_del\n",
561 kobject_name(kobj), kobj);
562 kobject_del(kobj);
563 }
564
565 if (t && t->release) {
566 pr_debug("kobject: '%s' (%p): calling ktype release\n",
567 kobject_name(kobj), kobj);
568 t->release(kobj);
569 }
570
571 /* free name if we allocated it */
572 if (name) {
573 pr_debug("kobject: '%s': free name\n", name);
574 kfree(name);
575 }
576}
577
578static void kobject_release(struct kref *kref)
579{
580 kobject_cleanup(container_of(kref, struct kobject, kref));
581}
582
583/**
584 * kobject_put - decrement refcount for object.
585 * @kobj: object.
586 *
587 * Decrement the refcount, and if 0, call kobject_cleanup().
588 */
589void kobject_put(struct kobject *kobj)
590{
591 if (kobj) {
592 if (!kobj->state_initialized)
593 WARN(1, KERN_WARNING "kobject: '%s' (%p): is not "
594 "initialized, yet kobject_put() is being "
595 "called.\n", kobject_name(kobj), kobj);
596 kref_put(&kobj->kref, kobject_release);
597 }
598}
599
600static void dynamic_kobj_release(struct kobject *kobj)
601{
602 pr_debug("kobject: (%p): %s\n", kobj, __func__);
603 kfree(kobj);
604}
605
606static struct kobj_type dynamic_kobj_ktype = {
607 .release = dynamic_kobj_release,
608 .sysfs_ops = &kobj_sysfs_ops,
609};
610
611/**
612 * kobject_create - create a struct kobject dynamically
613 *
614 * This function creates a kobject structure dynamically and sets it up
615 * to be a "dynamic" kobject with a default release function set up.
616 *
617 * If the kobject was not able to be created, NULL will be returned.
618 * The kobject structure returned from here must be cleaned up with a
619 * call to kobject_put() and not kfree(), as kobject_init() has
620 * already been called on this structure.
621 */
622struct kobject *kobject_create(void)
623{
624 struct kobject *kobj;
625
626 kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
627 if (!kobj)
628 return NULL;
629
630 kobject_init(kobj, &dynamic_kobj_ktype);
631 return kobj;
632}
633
634/**
635 * kobject_create_and_add - create a struct kobject dynamically and register it with sysfs
636 *
637 * @name: the name for the kset
638 * @parent: the parent kobject of this kobject, if any.
639 *
640 * This function creates a kobject structure dynamically and registers it
641 * with sysfs. When you are finished with this structure, call
642 * kobject_put() and the structure will be dynamically freed when
643 * it is no longer being used.
644 *
645 * If the kobject was not able to be created, NULL will be returned.
646 */
647struct kobject *kobject_create_and_add(const char *name, struct kobject *parent)
648{
649 struct kobject *kobj;
650 int retval;
651
652 kobj = kobject_create();
653 if (!kobj)
654 return NULL;
655
656 retval = kobject_add(kobj, parent, "%s", name);
657 if (retval) {
658 printk(KERN_WARNING "%s: kobject_add error: %d\n",
659 __func__, retval);
660 kobject_put(kobj);
661 kobj = NULL;
662 }
663 return kobj;
664}
665EXPORT_SYMBOL_GPL(kobject_create_and_add);
666
667/**
668 * kset_init - initialize a kset for use
669 * @k: kset
670 */
671void kset_init(struct kset *k)
672{
673 kobject_init_internal(&k->kobj);
674 INIT_LIST_HEAD(&k->list);
675 spin_lock_init(&k->list_lock);
676}
677
678/* default kobject attribute operations */
679static ssize_t kobj_attr_show(struct kobject *kobj, struct attribute *attr,
680 char *buf)
681{
682 struct kobj_attribute *kattr;
683 ssize_t ret = -EIO;
684
685 kattr = container_of(attr, struct kobj_attribute, attr);
686 if (kattr->show)
687 ret = kattr->show(kobj, kattr, buf);
688 return ret;
689}
690
691static ssize_t kobj_attr_store(struct kobject *kobj, struct attribute *attr,
692 const char *buf, size_t count)
693{
694 struct kobj_attribute *kattr;
695 ssize_t ret = -EIO;
696
697 kattr = container_of(attr, struct kobj_attribute, attr);
698 if (kattr->store)
699 ret = kattr->store(kobj, kattr, buf, count);
700 return ret;
701}
702
703const struct sysfs_ops kobj_sysfs_ops = {
704 .show = kobj_attr_show,
705 .store = kobj_attr_store,
706};
707
708/**
709 * kset_register - initialize and add a kset.
710 * @k: kset.
711 */
712int kset_register(struct kset *k)
713{
714 int err;
715
716 if (!k)
717 return -EINVAL;
718
719 kset_init(k);
720 err = kobject_add_internal(&k->kobj);
721 if (err)
722 return err;
723 kobject_uevent(&k->kobj, KOBJ_ADD);
724 return 0;
725}
726
727/**
728 * kset_unregister - remove a kset.
729 * @k: kset.
730 */
731void kset_unregister(struct kset *k)
732{
733 if (!k)
734 return;
735 kobject_put(&k->kobj);
736}
737
738/**
739 * kset_find_obj - search for object in kset.
740 * @kset: kset we're looking in.
741 * @name: object's name.
742 *
743 * Lock kset via @kset->subsys, and iterate over @kset->list,
744 * looking for a matching kobject. If matching object is found
745 * take a reference and return the object.
746 */
747struct kobject *kset_find_obj(struct kset *kset, const char *name)
748{
749 return kset_find_obj_hinted(kset, name, NULL);
750}
751
752/**
753 * kset_find_obj_hinted - search for object in kset given a predecessor hint.
754 * @kset: kset we're looking in.
755 * @name: object's name.
756 * @hint: hint to possible object's predecessor.
757 *
758 * Check the hint's next object and if it is a match return it directly,
759 * otherwise, fall back to the behavior of kset_find_obj(). Either way
760 * a reference for the returned object is held and the reference on the
761 * hinted object is released.
762 */
763struct kobject *kset_find_obj_hinted(struct kset *kset, const char *name,
764 struct kobject *hint)
765{
766 struct kobject *k;
767 struct kobject *ret = NULL;
768
769 spin_lock(&kset->list_lock);
770
771 if (!hint)
772 goto slow_search;
773
774 /* end of list detection */
775 if (hint->entry.next == kset->list.next)
776 goto slow_search;
777
778 k = container_of(hint->entry.next, struct kobject, entry);
779 if (!kobject_name(k) || strcmp(kobject_name(k), name))
780 goto slow_search;
781
782 ret = kobject_get(k);
783 goto unlock_exit;
784
785slow_search:
786 list_for_each_entry(k, &kset->list, entry) {
787 if (kobject_name(k) && !strcmp(kobject_name(k), name)) {
788 ret = kobject_get(k);
789 break;
790 }
791 }
792
793unlock_exit:
794 spin_unlock(&kset->list_lock);
795
796 if (hint)
797 kobject_put(hint);
798
799 return ret;
800}
801
802static void kset_release(struct kobject *kobj)
803{
804 struct kset *kset = container_of(kobj, struct kset, kobj);
805 pr_debug("kobject: '%s' (%p): %s\n",
806 kobject_name(kobj), kobj, __func__);
807 kfree(kset);
808}
809
810static struct kobj_type kset_ktype = {
811 .sysfs_ops = &kobj_sysfs_ops,
812 .release = kset_release,
813};
814
815/**
816 * kset_create - create a struct kset dynamically
817 *
818 * @name: the name for the kset
819 * @uevent_ops: a struct kset_uevent_ops for the kset
820 * @parent_kobj: the parent kobject of this kset, if any.
821 *
822 * This function creates a kset structure dynamically. This structure can
823 * then be registered with the system and show up in sysfs with a call to
824 * kset_register(). When you are finished with this structure, if
825 * kset_register() has been called, call kset_unregister() and the
826 * structure will be dynamically freed when it is no longer being used.
827 *
828 * If the kset was not able to be created, NULL will be returned.
829 */
830static struct kset *kset_create(const char *name,
831 const struct kset_uevent_ops *uevent_ops,
832 struct kobject *parent_kobj)
833{
834 struct kset *kset;
835 int retval;
836
837 kset = kzalloc(sizeof(*kset), GFP_KERNEL);
838 if (!kset)
839 return NULL;
840 retval = kobject_set_name(&kset->kobj, name);
841 if (retval) {
842 kfree(kset);
843 return NULL;
844 }
845 kset->uevent_ops = uevent_ops;
846 kset->kobj.parent = parent_kobj;
847
848 /*
849 * The kobject of this kset will have a type of kset_ktype and belong to
850 * no kset itself. That way we can properly free it when it is
851 * finished being used.
852 */
853 kset->kobj.ktype = &kset_ktype;
854 kset->kobj.kset = NULL;
855
856 return kset;
857}
858
859/**
860 * kset_create_and_add - create a struct kset dynamically and add it to sysfs
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 and registers it
867 * with sysfs. When you are finished with this structure, call
868 * kset_unregister() and the structure will be dynamically freed when it
869 * is no longer being used.
870 *
871 * If the kset was not able to be created, NULL will be returned.
872 */
873struct kset *kset_create_and_add(const char *name,
874 const struct kset_uevent_ops *uevent_ops,
875 struct kobject *parent_kobj)
876{
877 struct kset *kset;
878 int error;
879
880 kset = kset_create(name, uevent_ops, parent_kobj);
881 if (!kset)
882 return NULL;
883 error = kset_register(kset);
884 if (error) {
885 kfree(kset);
886 return NULL;
887 }
888 return kset;
889}
890EXPORT_SYMBOL_GPL(kset_create_and_add);
891
892
893static DEFINE_SPINLOCK(kobj_ns_type_lock);
894static const struct kobj_ns_type_operations *kobj_ns_ops_tbl[KOBJ_NS_TYPES];
895
896int kobj_ns_type_register(const struct kobj_ns_type_operations *ops)
897{
898 enum kobj_ns_type type = ops->type;
899 int error;
900
901 spin_lock(&kobj_ns_type_lock);
902
903 error = -EINVAL;
904 if (type >= KOBJ_NS_TYPES)
905 goto out;
906
907 error = -EINVAL;
908 if (type <= KOBJ_NS_TYPE_NONE)
909 goto out;
910
911 error = -EBUSY;
912 if (kobj_ns_ops_tbl[type])
913 goto out;
914
915 error = 0;
916 kobj_ns_ops_tbl[type] = ops;
917
918out:
919 spin_unlock(&kobj_ns_type_lock);
920 return error;
921}
922
923int kobj_ns_type_registered(enum kobj_ns_type type)
924{
925 int registered = 0;
926
927 spin_lock(&kobj_ns_type_lock);
928 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES))
929 registered = kobj_ns_ops_tbl[type] != NULL;
930 spin_unlock(&kobj_ns_type_lock);
931
932 return registered;
933}
934
935const struct kobj_ns_type_operations *kobj_child_ns_ops(struct kobject *parent)
936{
937 const struct kobj_ns_type_operations *ops = NULL;
938
939 if (parent && parent->ktype->child_ns_type)
940 ops = parent->ktype->child_ns_type(parent);
941
942 return ops;
943}
944
945const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj)
946{
947 return kobj_child_ns_ops(kobj->parent);
948}
949
950
951void *kobj_ns_grab_current(enum kobj_ns_type type)
952{
953 void *ns = NULL;
954
955 spin_lock(&kobj_ns_type_lock);
956 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
957 kobj_ns_ops_tbl[type])
958 ns = kobj_ns_ops_tbl[type]->grab_current_ns();
959 spin_unlock(&kobj_ns_type_lock);
960
961 return ns;
962}
963
964const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk)
965{
966 const void *ns = NULL;
967
968 spin_lock(&kobj_ns_type_lock);
969 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
970 kobj_ns_ops_tbl[type])
971 ns = kobj_ns_ops_tbl[type]->netlink_ns(sk);
972 spin_unlock(&kobj_ns_type_lock);
973
974 return ns;
975}
976
977const void *kobj_ns_initial(enum kobj_ns_type type)
978{
979 const void *ns = NULL;
980
981 spin_lock(&kobj_ns_type_lock);
982 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
983 kobj_ns_ops_tbl[type])
984 ns = kobj_ns_ops_tbl[type]->initial_ns();
985 spin_unlock(&kobj_ns_type_lock);
986
987 return ns;
988}
989
990void kobj_ns_drop(enum kobj_ns_type type, void *ns)
991{
992 spin_lock(&kobj_ns_type_lock);
993 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
994 kobj_ns_ops_tbl[type] && kobj_ns_ops_tbl[type]->drop_ns)
995 kobj_ns_ops_tbl[type]->drop_ns(ns);
996 spin_unlock(&kobj_ns_type_lock);
997}
998
999EXPORT_SYMBOL(kobject_get);
1000EXPORT_SYMBOL(kobject_put);
1001EXPORT_SYMBOL(kobject_del);
1002
1003EXPORT_SYMBOL(kset_register);
1004EXPORT_SYMBOL(kset_unregister);