arm64: compat: Don't pull syscall number from regs in arm_compat_syscall
[linux/fpc-iii.git] / lib / kobject.c
blob97d86dc17c42bf09c94dcb5149ff669a7a6d49db
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * kobject.c - library routines for handling generic kernel objects
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.
9 * Please see the file Documentation/kobject.txt for critical information
10 * about using the kobject interface.
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>
20 /**
21 * kobject_namespace - return @kobj's namespace tag
22 * @kobj: kobject in question
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.
28 const void *kobject_namespace(struct kobject *kobj)
30 const struct kobj_ns_type_operations *ns_ops = kobj_ns_ops(kobj);
32 if (!ns_ops || ns_ops->type == KOBJ_NS_TYPE_NONE)
33 return NULL;
35 return kobj->ktype->namespace(kobj);
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
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.
48 void kobject_get_ownership(struct kobject *kobj, kuid_t *uid, kgid_t *gid)
50 *uid = GLOBAL_ROOT_UID;
51 *gid = GLOBAL_ROOT_GID;
53 if (kobj->ktype->get_ownership)
54 kobj->ktype->get_ownership(kobj, uid, gid);
58 * populate_dir - populate directory with attributes.
59 * @kobj: object we're working on.
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.
66 static int populate_dir(struct kobject *kobj)
68 struct kobj_type *t = get_ktype(kobj);
69 struct attribute *attr;
70 int error = 0;
71 int i;
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;
80 return error;
83 static int create_dir(struct kobject *kobj)
85 const struct kobj_ns_type_operations *ops;
86 int error;
88 error = sysfs_create_dir_ns(kobj, kobject_namespace(kobj));
89 if (error)
90 return error;
92 error = populate_dir(kobj);
93 if (error) {
94 sysfs_remove_dir(kobj);
95 return error;
99 * @kobj->sd may be deleted by an ancestor going away. Hold an
100 * extra reference so that it stays until @kobj is gone.
102 sysfs_get(kobj->sd);
105 * If @kobj has ns_ops, its children need to be filtered based on
106 * their namespace tags. Enable namespace support on @kobj->sd.
108 ops = kobj_child_ns_ops(kobj);
109 if (ops) {
110 BUG_ON(ops->type <= KOBJ_NS_TYPE_NONE);
111 BUG_ON(ops->type >= KOBJ_NS_TYPES);
112 BUG_ON(!kobj_ns_type_registered(ops->type));
114 sysfs_enable_ns(kobj->sd);
117 return 0;
120 static int get_kobj_path_length(struct kobject *kobj)
122 int length = 1;
123 struct kobject *parent = kobj;
125 /* walk up the ancestors until we hit the one pointing to the
126 * root.
127 * Add 1 to strlen for leading '/' of each level.
129 do {
130 if (kobject_name(parent) == NULL)
131 return 0;
132 length += strlen(kobject_name(parent)) + 1;
133 parent = parent->parent;
134 } while (parent);
135 return length;
138 static void fill_kobj_path(struct kobject *kobj, char *path, int length)
140 struct kobject *parent;
142 --length;
143 for (parent = kobj; parent; parent = parent->parent) {
144 int cur = strlen(kobject_name(parent));
145 /* back up enough to print this name with '/' */
146 length -= cur;
147 memcpy(path + length, kobject_name(parent), cur);
148 *(path + --length) = '/';
151 pr_debug("kobject: '%s' (%p): %s: path = '%s'\n", kobject_name(kobj),
152 kobj, __func__, path);
156 * kobject_get_path - generate and return the path associated with a given kobj and kset pair.
158 * @kobj: kobject in question, with which to build the path
159 * @gfp_mask: the allocation type used to allocate the path
161 * The result must be freed by the caller with kfree().
163 char *kobject_get_path(struct kobject *kobj, gfp_t gfp_mask)
165 char *path;
166 int len;
168 len = get_kobj_path_length(kobj);
169 if (len == 0)
170 return NULL;
171 path = kzalloc(len, gfp_mask);
172 if (!path)
173 return NULL;
174 fill_kobj_path(kobj, path, len);
176 return path;
178 EXPORT_SYMBOL_GPL(kobject_get_path);
180 /* add the kobject to its kset's list */
181 static void kobj_kset_join(struct kobject *kobj)
183 if (!kobj->kset)
184 return;
186 kset_get(kobj->kset);
187 spin_lock(&kobj->kset->list_lock);
188 list_add_tail(&kobj->entry, &kobj->kset->list);
189 spin_unlock(&kobj->kset->list_lock);
192 /* remove the kobject from its kset's list */
193 static void kobj_kset_leave(struct kobject *kobj)
195 if (!kobj->kset)
196 return;
198 spin_lock(&kobj->kset->list_lock);
199 list_del_init(&kobj->entry);
200 spin_unlock(&kobj->kset->list_lock);
201 kset_put(kobj->kset);
204 static void kobject_init_internal(struct kobject *kobj)
206 if (!kobj)
207 return;
208 kref_init(&kobj->kref);
209 INIT_LIST_HEAD(&kobj->entry);
210 kobj->state_in_sysfs = 0;
211 kobj->state_add_uevent_sent = 0;
212 kobj->state_remove_uevent_sent = 0;
213 kobj->state_initialized = 1;
217 static int kobject_add_internal(struct kobject *kobj)
219 int error = 0;
220 struct kobject *parent;
222 if (!kobj)
223 return -ENOENT;
225 if (!kobj->name || !kobj->name[0]) {
226 WARN(1,
227 "kobject: (%p): attempted to be registered with empty name!\n",
228 kobj);
229 return -EINVAL;
232 parent = kobject_get(kobj->parent);
234 /* join kset if set, use it as parent if we do not already have one */
235 if (kobj->kset) {
236 if (!parent)
237 parent = kobject_get(&kobj->kset->kobj);
238 kobj_kset_join(kobj);
239 kobj->parent = parent;
242 pr_debug("kobject: '%s' (%p): %s: parent: '%s', set: '%s'\n",
243 kobject_name(kobj), kobj, __func__,
244 parent ? kobject_name(parent) : "<NULL>",
245 kobj->kset ? kobject_name(&kobj->kset->kobj) : "<NULL>");
247 error = create_dir(kobj);
248 if (error) {
249 kobj_kset_leave(kobj);
250 kobject_put(parent);
251 kobj->parent = NULL;
253 /* be noisy on error issues */
254 if (error == -EEXIST)
255 pr_err("%s failed for %s with -EEXIST, don't try to register things with the same name in the same directory.\n",
256 __func__, kobject_name(kobj));
257 else
258 pr_err("%s failed for %s (error: %d parent: %s)\n",
259 __func__, kobject_name(kobj), error,
260 parent ? kobject_name(parent) : "'none'");
261 } else
262 kobj->state_in_sysfs = 1;
264 return error;
268 * kobject_set_name_vargs - Set the name of an kobject
269 * @kobj: struct kobject to set the name of
270 * @fmt: format string used to build the name
271 * @vargs: vargs to format the string.
273 int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
274 va_list vargs)
276 const char *s;
278 if (kobj->name && !fmt)
279 return 0;
281 s = kvasprintf_const(GFP_KERNEL, fmt, vargs);
282 if (!s)
283 return -ENOMEM;
286 * ewww... some of these buggers have '/' in the name ... If
287 * that's the case, we need to make sure we have an actual
288 * allocated copy to modify, since kvasprintf_const may have
289 * returned something from .rodata.
291 if (strchr(s, '/')) {
292 char *t;
294 t = kstrdup(s, GFP_KERNEL);
295 kfree_const(s);
296 if (!t)
297 return -ENOMEM;
298 strreplace(t, '/', '!');
299 s = t;
301 kfree_const(kobj->name);
302 kobj->name = s;
304 return 0;
308 * kobject_set_name - Set the name of a kobject
309 * @kobj: struct kobject to set the name of
310 * @fmt: format string used to build the name
312 * This sets the name of the kobject. If you have already added the
313 * kobject to the system, you must call kobject_rename() in order to
314 * change the name of the kobject.
316 int kobject_set_name(struct kobject *kobj, const char *fmt, ...)
318 va_list vargs;
319 int retval;
321 va_start(vargs, fmt);
322 retval = kobject_set_name_vargs(kobj, fmt, vargs);
323 va_end(vargs);
325 return retval;
327 EXPORT_SYMBOL(kobject_set_name);
330 * kobject_init - initialize a kobject structure
331 * @kobj: pointer to the kobject to initialize
332 * @ktype: pointer to the ktype for this kobject.
334 * This function will properly initialize a kobject such that it can then
335 * be passed to the kobject_add() call.
337 * After this function is called, the kobject MUST be cleaned up by a call
338 * to kobject_put(), not by a call to kfree directly to ensure that all of
339 * the memory is cleaned up properly.
341 void kobject_init(struct kobject *kobj, struct kobj_type *ktype)
343 char *err_str;
345 if (!kobj) {
346 err_str = "invalid kobject pointer!";
347 goto error;
349 if (!ktype) {
350 err_str = "must have a ktype to be initialized properly!\n";
351 goto error;
353 if (kobj->state_initialized) {
354 /* do not error out as sometimes we can recover */
355 pr_err("kobject (%p): tried to init an initialized object, something is seriously wrong.\n",
356 kobj);
357 dump_stack();
360 kobject_init_internal(kobj);
361 kobj->ktype = ktype;
362 return;
364 error:
365 pr_err("kobject (%p): %s\n", kobj, err_str);
366 dump_stack();
368 EXPORT_SYMBOL(kobject_init);
370 static __printf(3, 0) int kobject_add_varg(struct kobject *kobj,
371 struct kobject *parent,
372 const char *fmt, va_list vargs)
374 int retval;
376 retval = kobject_set_name_vargs(kobj, fmt, vargs);
377 if (retval) {
378 pr_err("kobject: can not set name properly!\n");
379 return retval;
381 kobj->parent = parent;
382 return kobject_add_internal(kobj);
386 * kobject_add - the main kobject add function
387 * @kobj: the kobject to add
388 * @parent: pointer to the parent of the kobject.
389 * @fmt: format to name the kobject with.
391 * The kobject name is set and added to the kobject hierarchy in this
392 * function.
394 * If @parent is set, then the parent of the @kobj will be set to it.
395 * If @parent is NULL, then the parent of the @kobj will be set to the
396 * kobject associated with the kset assigned to this kobject. If no kset
397 * is assigned to the kobject, then the kobject will be located in the
398 * root of the sysfs tree.
400 * If this function returns an error, kobject_put() must be called to
401 * properly clean up the memory associated with the object.
402 * Under no instance should the kobject that is passed to this function
403 * be directly freed with a call to kfree(), that can leak memory.
405 * Note, no "add" uevent will be created with this call, the caller should set
406 * up all of the necessary sysfs files for the object and then call
407 * kobject_uevent() with the UEVENT_ADD parameter to ensure that
408 * userspace is properly notified of this kobject's creation.
410 int kobject_add(struct kobject *kobj, struct kobject *parent,
411 const char *fmt, ...)
413 va_list args;
414 int retval;
416 if (!kobj)
417 return -EINVAL;
419 if (!kobj->state_initialized) {
420 pr_err("kobject '%s' (%p): tried to add an uninitialized object, something is seriously wrong.\n",
421 kobject_name(kobj), kobj);
422 dump_stack();
423 return -EINVAL;
425 va_start(args, fmt);
426 retval = kobject_add_varg(kobj, parent, fmt, args);
427 va_end(args);
429 return retval;
431 EXPORT_SYMBOL(kobject_add);
434 * kobject_init_and_add - initialize a kobject structure and add it to the kobject hierarchy
435 * @kobj: pointer to the kobject to initialize
436 * @ktype: pointer to the ktype for this kobject.
437 * @parent: pointer to the parent of this kobject.
438 * @fmt: the name of the kobject.
440 * This function combines the call to kobject_init() and
441 * kobject_add(). The same type of error handling after a call to
442 * kobject_add() and kobject lifetime rules are the same here.
444 int kobject_init_and_add(struct kobject *kobj, struct kobj_type *ktype,
445 struct kobject *parent, const char *fmt, ...)
447 va_list args;
448 int retval;
450 kobject_init(kobj, ktype);
452 va_start(args, fmt);
453 retval = kobject_add_varg(kobj, parent, fmt, args);
454 va_end(args);
456 return retval;
458 EXPORT_SYMBOL_GPL(kobject_init_and_add);
461 * kobject_rename - change the name of an object
462 * @kobj: object in question.
463 * @new_name: object's new name
465 * It is the responsibility of the caller to provide mutual
466 * exclusion between two different calls of kobject_rename
467 * on the same kobject and to ensure that new_name is valid and
468 * won't conflict with other kobjects.
470 int kobject_rename(struct kobject *kobj, const char *new_name)
472 int error = 0;
473 const char *devpath = NULL;
474 const char *dup_name = NULL, *name;
475 char *devpath_string = NULL;
476 char *envp[2];
478 kobj = kobject_get(kobj);
479 if (!kobj)
480 return -EINVAL;
481 if (!kobj->parent)
482 return -EINVAL;
484 devpath = kobject_get_path(kobj, GFP_KERNEL);
485 if (!devpath) {
486 error = -ENOMEM;
487 goto out;
489 devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL);
490 if (!devpath_string) {
491 error = -ENOMEM;
492 goto out;
494 sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);
495 envp[0] = devpath_string;
496 envp[1] = NULL;
498 name = dup_name = kstrdup_const(new_name, GFP_KERNEL);
499 if (!name) {
500 error = -ENOMEM;
501 goto out;
504 error = sysfs_rename_dir_ns(kobj, new_name, kobject_namespace(kobj));
505 if (error)
506 goto out;
508 /* Install the new kobject name */
509 dup_name = kobj->name;
510 kobj->name = name;
512 /* This function is mostly/only used for network interface.
513 * Some hotplug package track interfaces by their name and
514 * therefore want to know when the name is changed by the user. */
515 kobject_uevent_env(kobj, KOBJ_MOVE, envp);
517 out:
518 kfree_const(dup_name);
519 kfree(devpath_string);
520 kfree(devpath);
521 kobject_put(kobj);
523 return error;
525 EXPORT_SYMBOL_GPL(kobject_rename);
528 * kobject_move - move object to another parent
529 * @kobj: object in question.
530 * @new_parent: object's new parent (can be NULL)
532 int kobject_move(struct kobject *kobj, struct kobject *new_parent)
534 int error;
535 struct kobject *old_parent;
536 const char *devpath = NULL;
537 char *devpath_string = NULL;
538 char *envp[2];
540 kobj = kobject_get(kobj);
541 if (!kobj)
542 return -EINVAL;
543 new_parent = kobject_get(new_parent);
544 if (!new_parent) {
545 if (kobj->kset)
546 new_parent = kobject_get(&kobj->kset->kobj);
549 /* old object path */
550 devpath = kobject_get_path(kobj, GFP_KERNEL);
551 if (!devpath) {
552 error = -ENOMEM;
553 goto out;
555 devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL);
556 if (!devpath_string) {
557 error = -ENOMEM;
558 goto out;
560 sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);
561 envp[0] = devpath_string;
562 envp[1] = NULL;
563 error = sysfs_move_dir_ns(kobj, new_parent, kobject_namespace(kobj));
564 if (error)
565 goto out;
566 old_parent = kobj->parent;
567 kobj->parent = new_parent;
568 new_parent = NULL;
569 kobject_put(old_parent);
570 kobject_uevent_env(kobj, KOBJ_MOVE, envp);
571 out:
572 kobject_put(new_parent);
573 kobject_put(kobj);
574 kfree(devpath_string);
575 kfree(devpath);
576 return error;
578 EXPORT_SYMBOL_GPL(kobject_move);
581 * kobject_del - unlink kobject from hierarchy.
582 * @kobj: object.
584 void kobject_del(struct kobject *kobj)
586 struct kernfs_node *sd;
588 if (!kobj)
589 return;
591 sd = kobj->sd;
592 sysfs_remove_dir(kobj);
593 sysfs_put(sd);
595 kobj->state_in_sysfs = 0;
596 kobj_kset_leave(kobj);
597 kobject_put(kobj->parent);
598 kobj->parent = NULL;
600 EXPORT_SYMBOL(kobject_del);
603 * kobject_get - increment refcount for object.
604 * @kobj: object.
606 struct kobject *kobject_get(struct kobject *kobj)
608 if (kobj) {
609 if (!kobj->state_initialized)
610 WARN(1, KERN_WARNING
611 "kobject: '%s' (%p): is not initialized, yet kobject_get() is being called.\n",
612 kobject_name(kobj), kobj);
613 kref_get(&kobj->kref);
615 return kobj;
617 EXPORT_SYMBOL(kobject_get);
619 struct kobject * __must_check kobject_get_unless_zero(struct kobject *kobj)
621 if (!kobj)
622 return NULL;
623 if (!kref_get_unless_zero(&kobj->kref))
624 kobj = NULL;
625 return kobj;
627 EXPORT_SYMBOL(kobject_get_unless_zero);
630 * kobject_cleanup - free kobject resources.
631 * @kobj: object to cleanup
633 static void kobject_cleanup(struct kobject *kobj)
635 struct kobj_type *t = get_ktype(kobj);
636 const char *name = kobj->name;
638 pr_debug("kobject: '%s' (%p): %s, parent %p\n",
639 kobject_name(kobj), kobj, __func__, kobj->parent);
641 if (t && !t->release)
642 pr_debug("kobject: '%s' (%p): does not have a release() function, it is broken and must be fixed.\n",
643 kobject_name(kobj), kobj);
645 /* send "remove" if the caller did not do it but sent "add" */
646 if (kobj->state_add_uevent_sent && !kobj->state_remove_uevent_sent) {
647 pr_debug("kobject: '%s' (%p): auto cleanup 'remove' event\n",
648 kobject_name(kobj), kobj);
649 kobject_uevent(kobj, KOBJ_REMOVE);
652 /* remove from sysfs if the caller did not do it */
653 if (kobj->state_in_sysfs) {
654 pr_debug("kobject: '%s' (%p): auto cleanup kobject_del\n",
655 kobject_name(kobj), kobj);
656 kobject_del(kobj);
659 if (t && t->release) {
660 pr_debug("kobject: '%s' (%p): calling ktype release\n",
661 kobject_name(kobj), kobj);
662 t->release(kobj);
665 /* free name if we allocated it */
666 if (name) {
667 pr_debug("kobject: '%s': free name\n", name);
668 kfree_const(name);
672 #ifdef CONFIG_DEBUG_KOBJECT_RELEASE
673 static void kobject_delayed_cleanup(struct work_struct *work)
675 kobject_cleanup(container_of(to_delayed_work(work),
676 struct kobject, release));
678 #endif
680 static void kobject_release(struct kref *kref)
682 struct kobject *kobj = container_of(kref, struct kobject, kref);
683 #ifdef CONFIG_DEBUG_KOBJECT_RELEASE
684 unsigned long delay = HZ + HZ * (get_random_int() & 0x3);
685 pr_info("kobject: '%s' (%p): %s, parent %p (delayed %ld)\n",
686 kobject_name(kobj), kobj, __func__, kobj->parent, delay);
687 INIT_DELAYED_WORK(&kobj->release, kobject_delayed_cleanup);
689 schedule_delayed_work(&kobj->release, delay);
690 #else
691 kobject_cleanup(kobj);
692 #endif
696 * kobject_put - decrement refcount for object.
697 * @kobj: object.
699 * Decrement the refcount, and if 0, call kobject_cleanup().
701 void kobject_put(struct kobject *kobj)
703 if (kobj) {
704 if (!kobj->state_initialized)
705 WARN(1, KERN_WARNING
706 "kobject: '%s' (%p): is not initialized, yet kobject_put() is being called.\n",
707 kobject_name(kobj), kobj);
708 kref_put(&kobj->kref, kobject_release);
711 EXPORT_SYMBOL(kobject_put);
713 static void dynamic_kobj_release(struct kobject *kobj)
715 pr_debug("kobject: (%p): %s\n", kobj, __func__);
716 kfree(kobj);
719 static struct kobj_type dynamic_kobj_ktype = {
720 .release = dynamic_kobj_release,
721 .sysfs_ops = &kobj_sysfs_ops,
725 * kobject_create - create a struct kobject dynamically
727 * This function creates a kobject structure dynamically and sets it up
728 * to be a "dynamic" kobject with a default release function set up.
730 * If the kobject was not able to be created, NULL will be returned.
731 * The kobject structure returned from here must be cleaned up with a
732 * call to kobject_put() and not kfree(), as kobject_init() has
733 * already been called on this structure.
735 struct kobject *kobject_create(void)
737 struct kobject *kobj;
739 kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
740 if (!kobj)
741 return NULL;
743 kobject_init(kobj, &dynamic_kobj_ktype);
744 return kobj;
748 * kobject_create_and_add - create a struct kobject dynamically and register it with sysfs
750 * @name: the name for the kobject
751 * @parent: the parent kobject of this kobject, if any.
753 * This function creates a kobject structure dynamically and registers it
754 * with sysfs. When you are finished with this structure, call
755 * kobject_put() and the structure will be dynamically freed when
756 * it is no longer being used.
758 * If the kobject was not able to be created, NULL will be returned.
760 struct kobject *kobject_create_and_add(const char *name, struct kobject *parent)
762 struct kobject *kobj;
763 int retval;
765 kobj = kobject_create();
766 if (!kobj)
767 return NULL;
769 retval = kobject_add(kobj, parent, "%s", name);
770 if (retval) {
771 pr_warn("%s: kobject_add error: %d\n", __func__, retval);
772 kobject_put(kobj);
773 kobj = NULL;
775 return kobj;
777 EXPORT_SYMBOL_GPL(kobject_create_and_add);
780 * kset_init - initialize a kset for use
781 * @k: kset
783 void kset_init(struct kset *k)
785 kobject_init_internal(&k->kobj);
786 INIT_LIST_HEAD(&k->list);
787 spin_lock_init(&k->list_lock);
790 /* default kobject attribute operations */
791 static ssize_t kobj_attr_show(struct kobject *kobj, struct attribute *attr,
792 char *buf)
794 struct kobj_attribute *kattr;
795 ssize_t ret = -EIO;
797 kattr = container_of(attr, struct kobj_attribute, attr);
798 if (kattr->show)
799 ret = kattr->show(kobj, kattr, buf);
800 return ret;
803 static ssize_t kobj_attr_store(struct kobject *kobj, struct attribute *attr,
804 const char *buf, size_t count)
806 struct kobj_attribute *kattr;
807 ssize_t ret = -EIO;
809 kattr = container_of(attr, struct kobj_attribute, attr);
810 if (kattr->store)
811 ret = kattr->store(kobj, kattr, buf, count);
812 return ret;
815 const struct sysfs_ops kobj_sysfs_ops = {
816 .show = kobj_attr_show,
817 .store = kobj_attr_store,
819 EXPORT_SYMBOL_GPL(kobj_sysfs_ops);
822 * kset_register - initialize and add a kset.
823 * @k: kset.
825 int kset_register(struct kset *k)
827 int err;
829 if (!k)
830 return -EINVAL;
832 kset_init(k);
833 err = kobject_add_internal(&k->kobj);
834 if (err)
835 return err;
836 kobject_uevent(&k->kobj, KOBJ_ADD);
837 return 0;
839 EXPORT_SYMBOL(kset_register);
842 * kset_unregister - remove a kset.
843 * @k: kset.
845 void kset_unregister(struct kset *k)
847 if (!k)
848 return;
849 kobject_del(&k->kobj);
850 kobject_put(&k->kobj);
852 EXPORT_SYMBOL(kset_unregister);
855 * kset_find_obj - search for object in kset.
856 * @kset: kset we're looking in.
857 * @name: object's name.
859 * Lock kset via @kset->subsys, and iterate over @kset->list,
860 * looking for a matching kobject. If matching object is found
861 * take a reference and return the object.
863 struct kobject *kset_find_obj(struct kset *kset, const char *name)
865 struct kobject *k;
866 struct kobject *ret = NULL;
868 spin_lock(&kset->list_lock);
870 list_for_each_entry(k, &kset->list, entry) {
871 if (kobject_name(k) && !strcmp(kobject_name(k), name)) {
872 ret = kobject_get_unless_zero(k);
873 break;
877 spin_unlock(&kset->list_lock);
878 return ret;
880 EXPORT_SYMBOL_GPL(kset_find_obj);
882 static void kset_release(struct kobject *kobj)
884 struct kset *kset = container_of(kobj, struct kset, kobj);
885 pr_debug("kobject: '%s' (%p): %s\n",
886 kobject_name(kobj), kobj, __func__);
887 kfree(kset);
890 void kset_get_ownership(struct kobject *kobj, kuid_t *uid, kgid_t *gid)
892 if (kobj->parent)
893 kobject_get_ownership(kobj->parent, uid, gid);
896 static struct kobj_type kset_ktype = {
897 .sysfs_ops = &kobj_sysfs_ops,
898 .release = kset_release,
899 .get_ownership = kset_get_ownership,
903 * kset_create - create a struct kset dynamically
905 * @name: the name for the kset
906 * @uevent_ops: a struct kset_uevent_ops for the kset
907 * @parent_kobj: the parent kobject of this kset, if any.
909 * This function creates a kset structure dynamically. This structure can
910 * then be registered with the system and show up in sysfs with a call to
911 * kset_register(). When you are finished with this structure, if
912 * kset_register() has been called, call kset_unregister() and the
913 * structure will be dynamically freed when it is no longer being used.
915 * If the kset was not able to be created, NULL will be returned.
917 static struct kset *kset_create(const char *name,
918 const struct kset_uevent_ops *uevent_ops,
919 struct kobject *parent_kobj)
921 struct kset *kset;
922 int retval;
924 kset = kzalloc(sizeof(*kset), GFP_KERNEL);
925 if (!kset)
926 return NULL;
927 retval = kobject_set_name(&kset->kobj, "%s", name);
928 if (retval) {
929 kfree(kset);
930 return NULL;
932 kset->uevent_ops = uevent_ops;
933 kset->kobj.parent = parent_kobj;
936 * The kobject of this kset will have a type of kset_ktype and belong to
937 * no kset itself. That way we can properly free it when it is
938 * finished being used.
940 kset->kobj.ktype = &kset_ktype;
941 kset->kobj.kset = NULL;
943 return kset;
947 * kset_create_and_add - create a struct kset dynamically and add it to sysfs
949 * @name: the name for the kset
950 * @uevent_ops: a struct kset_uevent_ops for the kset
951 * @parent_kobj: the parent kobject of this kset, if any.
953 * This function creates a kset structure dynamically and registers it
954 * with sysfs. When you are finished with this structure, call
955 * kset_unregister() and the structure will be dynamically freed when it
956 * is no longer being used.
958 * If the kset was not able to be created, NULL will be returned.
960 struct kset *kset_create_and_add(const char *name,
961 const struct kset_uevent_ops *uevent_ops,
962 struct kobject *parent_kobj)
964 struct kset *kset;
965 int error;
967 kset = kset_create(name, uevent_ops, parent_kobj);
968 if (!kset)
969 return NULL;
970 error = kset_register(kset);
971 if (error) {
972 kfree(kset);
973 return NULL;
975 return kset;
977 EXPORT_SYMBOL_GPL(kset_create_and_add);
980 static DEFINE_SPINLOCK(kobj_ns_type_lock);
981 static const struct kobj_ns_type_operations *kobj_ns_ops_tbl[KOBJ_NS_TYPES];
983 int kobj_ns_type_register(const struct kobj_ns_type_operations *ops)
985 enum kobj_ns_type type = ops->type;
986 int error;
988 spin_lock(&kobj_ns_type_lock);
990 error = -EINVAL;
991 if (type >= KOBJ_NS_TYPES)
992 goto out;
994 error = -EINVAL;
995 if (type <= KOBJ_NS_TYPE_NONE)
996 goto out;
998 error = -EBUSY;
999 if (kobj_ns_ops_tbl[type])
1000 goto out;
1002 error = 0;
1003 kobj_ns_ops_tbl[type] = ops;
1005 out:
1006 spin_unlock(&kobj_ns_type_lock);
1007 return error;
1010 int kobj_ns_type_registered(enum kobj_ns_type type)
1012 int registered = 0;
1014 spin_lock(&kobj_ns_type_lock);
1015 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES))
1016 registered = kobj_ns_ops_tbl[type] != NULL;
1017 spin_unlock(&kobj_ns_type_lock);
1019 return registered;
1022 const struct kobj_ns_type_operations *kobj_child_ns_ops(struct kobject *parent)
1024 const struct kobj_ns_type_operations *ops = NULL;
1026 if (parent && parent->ktype && parent->ktype->child_ns_type)
1027 ops = parent->ktype->child_ns_type(parent);
1029 return ops;
1032 const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj)
1034 return kobj_child_ns_ops(kobj->parent);
1037 bool kobj_ns_current_may_mount(enum kobj_ns_type type)
1039 bool may_mount = true;
1041 spin_lock(&kobj_ns_type_lock);
1042 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1043 kobj_ns_ops_tbl[type])
1044 may_mount = kobj_ns_ops_tbl[type]->current_may_mount();
1045 spin_unlock(&kobj_ns_type_lock);
1047 return may_mount;
1050 void *kobj_ns_grab_current(enum kobj_ns_type type)
1052 void *ns = NULL;
1054 spin_lock(&kobj_ns_type_lock);
1055 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1056 kobj_ns_ops_tbl[type])
1057 ns = kobj_ns_ops_tbl[type]->grab_current_ns();
1058 spin_unlock(&kobj_ns_type_lock);
1060 return ns;
1062 EXPORT_SYMBOL_GPL(kobj_ns_grab_current);
1064 const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk)
1066 const void *ns = NULL;
1068 spin_lock(&kobj_ns_type_lock);
1069 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1070 kobj_ns_ops_tbl[type])
1071 ns = kobj_ns_ops_tbl[type]->netlink_ns(sk);
1072 spin_unlock(&kobj_ns_type_lock);
1074 return ns;
1077 const void *kobj_ns_initial(enum kobj_ns_type type)
1079 const void *ns = NULL;
1081 spin_lock(&kobj_ns_type_lock);
1082 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1083 kobj_ns_ops_tbl[type])
1084 ns = kobj_ns_ops_tbl[type]->initial_ns();
1085 spin_unlock(&kobj_ns_type_lock);
1087 return ns;
1090 void kobj_ns_drop(enum kobj_ns_type type, void *ns)
1092 spin_lock(&kobj_ns_type_lock);
1093 if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
1094 kobj_ns_ops_tbl[type] && kobj_ns_ops_tbl[type]->drop_ns)
1095 kobj_ns_ops_tbl[type]->drop_ns(ns);
1096 spin_unlock(&kobj_ns_type_lock);
1098 EXPORT_SYMBOL_GPL(kobj_ns_drop);