1 // SPDX-License-Identifier: GPL-2.0
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/core-api/kobject.rst for critical information
23  * kobject_namespace() - Return @kobj's namespace tag.
34 	if (!ns_ops || ns_ops->type == KOBJ_NS_TYPE_NONE)  in kobject_namespace()
37 	return kobj->ktype->namespace(kobj);  in kobject_namespace()
41  * kobject_get_ownership() - Get sysfs ownership data for @kobj.
48  * objects in a container.
55 	if (kobj->ktype->get_ownership)  in kobject_get_ownership()
56 		kobj->ktype->get_ownership(kobj, uid, gid);  in kobject_get_ownership()
77 	error = sysfs_create_groups(kobj, ktype->default_groups);  in create_dir()
84 	 * @kobj->sd may be deleted by an ancestor going away.  Hold an  in create_dir()
87 	sysfs_get(kobj->sd);  in create_dir()
91 	 * their namespace tags.  Enable namespace support on @kobj->sd.  in create_dir()
95 		BUG_ON(!kobj_ns_type_is_valid(ops->type));  in create_dir()
96 		BUG_ON(!kobj_ns_type_registered(ops->type));  in create_dir()
98 		sysfs_enable_ns(kobj->sd);  in create_dir()
117 		parent = parent->parent;  in get_kobj_path_length()
126 	--length;  in fill_kobj_path()
127 	for (parent = kobj; parent; parent = parent->parent) {  in fill_kobj_path()
130 		length -= cur;  in fill_kobj_path()
132 			return -EINVAL;  in fill_kobj_path()
134 		*(path + --length) = '/';  in fill_kobj_path()
144  * kobject_get_path() - Allocate memory and fill in the path for @kobj.
174 	if (!kobj->kset)  in kobj_kset_join()
177 	kset_get(kobj->kset);  in kobj_kset_join()
178 	spin_lock(&kobj->kset->list_lock);  in kobj_kset_join()
179 	list_add_tail(&kobj->entry, &kobj->kset->list);  in kobj_kset_join()
180 	spin_unlock(&kobj->kset->list_lock);  in kobj_kset_join()
186 	if (!kobj->kset)  in kobj_kset_leave()
189 	spin_lock(&kobj->kset->list_lock);  in kobj_kset_leave()
190 	list_del_init(&kobj->entry);  in kobj_kset_leave()
191 	spin_unlock(&kobj->kset->list_lock);  in kobj_kset_leave()
192 	kset_put(kobj->kset);  in kobj_kset_leave()
199 	kref_init(&kobj->kref);  in kobject_init_internal()
200 	INIT_LIST_HEAD(&kobj->entry);  in kobject_init_internal()
201 	kobj->state_in_sysfs = 0;  in kobject_init_internal()
202 	kobj->state_add_uevent_sent = 0;  in kobject_init_internal()
203 	kobj->state_remove_uevent_sent = 0;  in kobject_init_internal()
204 	kobj->state_initialized = 1;  in kobject_init_internal()
214 		return -ENOENT;  in kobject_add_internal()
216 	if (!kobj->name || !kobj->name[0]) {  in kobject_add_internal()
220 		return -EINVAL;  in kobject_add_internal()
223 	parent = kobject_get(kobj->parent);  in kobject_add_internal()
226 	if (kobj->kset) {  in kobject_add_internal()
228 			parent = kobject_get(&kobj->kset->kobj);  in kobject_add_internal()
230 		kobj->parent = parent;  in kobject_add_internal()
236 		 kobj->kset ? kobject_name(&kobj->kset->kobj) : "<NULL>");  in kobject_add_internal()
242 		kobj->parent = NULL;  in kobject_add_internal()
245 		if (error == -EEXIST)  in kobject_add_internal()
246 …pr_err("%s failed for %s with -EEXIST, don't try to register things with the same name in the same…  in kobject_add_internal()
253 		kobj->state_in_sysfs = 1;  in kobject_add_internal()
259  * kobject_set_name_vargs() - Set the name of a kobject.
269 	if (kobj->name && !fmt)  in kobject_set_name_vargs()
274 		return -ENOMEM;  in kobject_set_name_vargs()
288 			return -ENOMEM;  in kobject_set_name_vargs()
291 	kfree_const(kobj->name);  in kobject_set_name_vargs()
292 	kobj->name = s;  in kobject_set_name_vargs()
298  * kobject_set_name() - Set the name of a kobject.
320  * kobject_init() - Initialize a kobject structure.
343 	if (kobj->state_initialized) {  in kobject_init()
351 	kobj->ktype = ktype;  in kobject_init()
371 	kobj->parent = parent;  in kobject_add_varg()
376  * kobject_add() - The main kobject add function.
415 		return -EINVAL;  in kobject_add()
417 	if (!kobj->state_initialized) {  in kobject_add()
421 		return -EINVAL;  in kobject_add()
432  * kobject_init_and_add() - Initialize a kobject structure and add it to
444  * lifetime rules are the same here.
463  * kobject_rename() - Change the name of an object.
482 		return -EINVAL;  in kobject_rename()
483 	if (!kobj->parent) {  in kobject_rename()
485 		return -EINVAL;  in kobject_rename()
490 		error = -ENOMEM;  in kobject_rename()
495 		error = -ENOMEM;  in kobject_rename()
504 		error = -ENOMEM;  in kobject_rename()
513 	dup_name = kobj->name;  in kobject_rename()
514 	kobj->name = name;  in kobject_rename()
532  * kobject_move() - Move object to another parent.
546 		return -EINVAL;  in kobject_move()
549 		if (kobj->kset)  in kobject_move()
550 			new_parent = kobject_get(&kobj->kset->kobj);  in kobject_move()
556 		error = -ENOMEM;  in kobject_move()
561 		error = -ENOMEM;  in kobject_move()
570 	old_parent = kobj->parent;  in kobject_move()
571 	kobj->parent = new_parent;  in kobject_move()
589 	sd = kobj->sd;  in __kobject_del()
592 	sysfs_remove_groups(kobj, ktype->default_groups);  in __kobject_del()
595 	if (kobj->state_add_uevent_sent && !kobj->state_remove_uevent_sent) {  in __kobject_del()
604 	kobj->state_in_sysfs = 0;  in __kobject_del()
606 	kobj->parent = NULL;  in __kobject_del()
610  * kobject_del() - Unlink kobject from hierarchy.
623 	parent = kobj->parent;  in kobject_del()
630  * kobject_get() - Increment refcount for object.
636 		if (!kobj->state_initialized)  in kobject_get()
640 		kref_get(&kobj->kref);  in kobject_get()
650 	if (!kref_get_unless_zero(&kobj->kref))  in kobject_get_unless_zero()
657  * kobject_cleanup - free kobject resources.
662 	struct kobject *parent = kobj->parent;  in kobject_cleanup()
664 	const char *name = kobj->name;  in kobject_cleanup()
667 		 kobject_name(kobj), kobj, __func__, kobj->parent);  in kobject_cleanup()
670 	if (kobj->state_in_sysfs) {  in kobject_cleanup()
679 	if (t->release) {  in kobject_cleanup()
682 		t->release(kobj);  in kobject_cleanup()
684 …e a release() function, it is broken and must be fixed. See Documentation/core-api/kobject.rst.\n",  in kobject_cleanup()
711 		kobject_name(kobj), kobj, __func__, kobj->parent, delay);  in kobject_release()
712 	INIT_DELAYED_WORK(&kobj->release, kobject_delayed_cleanup);  in kobject_release()
714 	schedule_delayed_work(&kobj->release, delay);  in kobject_release()
721  * kobject_put() - Decrement refcount for object.
729 		if (!kobj->state_initialized)  in kobject_put()
733 		kref_put(&kobj->kref, kobject_release);  in kobject_put()
750  * kobject_create() - Create a struct kobject dynamically.
773  * kobject_create_and_add() - Create a struct kobject dynamically and
805  * kset_init() - Initialize a kset for use.
810 	kobject_init_internal(&k->kobj);  in kset_init()
811 	INIT_LIST_HEAD(&k->list);  in kset_init()
812 	spin_lock_init(&k->list_lock);  in kset_init()
820 	ssize_t ret = -EIO;  in kobj_attr_show()
823 	if (kattr->show)  in kobj_attr_show()
824 		ret = kattr->show(kobj, kattr, buf);  in kobj_attr_show()
832 	ssize_t ret = -EIO;  in kobj_attr_store()
835 	if (kattr->store)  in kobj_attr_store()
836 		ret = kattr->store(kobj, kattr, buf, count);  in kobj_attr_store()
847  * kset_register() - Initialize and add a kset.
858 		return -EINVAL;  in kset_register()
860 	if (!k->kobj.ktype) {  in kset_register()
862 		return -EINVAL;  in kset_register()
866 	err = kobject_add_internal(&k->kobj);  in kset_register()
868 		kfree_const(k->kobj.name);  in kset_register()
870 		k->kobj.name = NULL;  in kset_register()
873 	kobject_uevent(&k->kobj, KOBJ_ADD);  in kset_register()
879  * kset_unregister() - Remove a kset.
886 	kobject_del(&k->kobj);  in kset_unregister()
887 	kobject_put(&k->kobj);  in kset_unregister()
892  * kset_find_obj() - Search for object in kset.
896  * Lock kset via @kset->subsys, and iterate over @kset->list,
905 	spin_lock(&kset->list_lock);  in kset_find_obj()
907 	list_for_each_entry(k, &kset->list, entry) {  in kset_find_obj()
914 	spin_unlock(&kset->list_lock);  in kset_find_obj()
929 	if (kobj->parent)  in kset_get_ownership()
930 		kobject_get_ownership(kobj->parent, uid, gid);  in kset_get_ownership()
940  * kset_create() - Create a struct kset dynamically.
964 	retval = kobject_set_name(&kset->kobj, "%s", name);  in kset_create()
969 	kset->uevent_ops = uevent_ops;  in kset_create()
970 	kset->kobj.parent = parent_kobj;  in kset_create()
977 	kset->kobj.ktype = &kset_ktype;  in kset_create()
978 	kset->kobj.kset = NULL;  in kset_create()
984  * kset_create_and_add() - Create a struct kset dynamically and add it to sysfs.
1022 	enum kobj_ns_type type = ops->type;  in kobj_ns_type_register()
1027 	error = -EINVAL;  in kobj_ns_type_register()
1031 	error = -EBUSY;  in kobj_ns_type_register()
1059 	if (parent && parent->ktype->child_ns_type)  in kobj_child_ns_ops()
1060 		ops = parent->ktype->child_ns_type(parent);  in kobj_child_ns_ops()
1067 	return kobj_child_ns_ops(kobj->parent);  in kobj_ns_ops()
1076 		may_mount = kobj_ns_ops_tbl[type]->current_may_mount();  in kobj_ns_current_may_mount()
1088 		ns = kobj_ns_ops_tbl[type]->grab_current_ns();  in kobj_ns_grab_current()
1101 		ns = kobj_ns_ops_tbl[type]->netlink_ns(sk);  in kobj_ns_netlink()
1113 		ns = kobj_ns_ops_tbl[type]->initial_ns();  in kobj_ns_initial()
1123 	    kobj_ns_ops_tbl[type] && kobj_ns_ops_tbl[type]->drop_ns)  in kobj_ns_drop()
1124 		kobj_ns_ops_tbl[type]->drop_ns(ns);  in kobj_ns_drop()