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1/*
2 * fs/sysfs/group.c - Operations for adding/removing multiple files at once.
3 *
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 * Copyright (c) 2013 Greg Kroah-Hartman
7 * Copyright (c) 2013 The Linux Foundation
8 *
9 * This file is released undert the GPL v2.
10 *
11 */
12
13#include <linux/kobject.h>
14#include <linux/module.h>
15#include <linux/dcache.h>
16#include <linux/namei.h>
17#include <linux/err.h>
18#include "sysfs.h"
19
20
21static void remove_files(struct kernfs_node *parent, struct kobject *kobj,
22 const struct attribute_group *grp)
23{
24 struct attribute *const *attr;
25 struct bin_attribute *const *bin_attr;
26
27 if (grp->attrs)
28 for (attr = grp->attrs; *attr; attr++)
29 kernfs_remove_by_name(parent, (*attr)->name);
30 if (grp->bin_attrs)
31 for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++)
32 sysfs_remove_bin_file(kobj, *bin_attr);
33}
34
35static int create_files(struct kernfs_node *parent, struct kobject *kobj,
36 const struct attribute_group *grp, int update)
37{
38 struct attribute *const *attr;
39 struct bin_attribute *const *bin_attr;
40 int error = 0, i;
41
42 if (grp->attrs) {
43 for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) {
44 umode_t mode = 0;
45
46 /*
47 * In update mode, we're changing the permissions or
48 * visibility. Do this by first removing then
49 * re-adding (if required) the file.
50 */
51 if (update)
52 kernfs_remove_by_name(parent, (*attr)->name);
53 if (grp->is_visible) {
54 mode = grp->is_visible(kobj, *attr, i);
55 if (!mode)
56 continue;
57 }
58 error = sysfs_add_file_mode_ns(parent, *attr, false,
59 (*attr)->mode | mode,
60 NULL);
61 if (unlikely(error))
62 break;
63 }
64 if (error) {
65 remove_files(parent, kobj, grp);
66 goto exit;
67 }
68 }
69
70 if (grp->bin_attrs) {
71 for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++) {
72 if (update)
73 kernfs_remove_by_name(parent,
74 (*bin_attr)->attr.name);
75 error = sysfs_add_file_mode_ns(parent,
76 &(*bin_attr)->attr, true,
77 (*bin_attr)->attr.mode, NULL);
78 if (error)
79 break;
80 }
81 if (error)
82 remove_files(parent, kobj, grp);
83 }
84exit:
85 return error;
86}
87
88
89static int internal_create_group(struct kobject *kobj, int update,
90 const struct attribute_group *grp)
91{
92 struct kernfs_node *kn;
93 int error;
94
95 BUG_ON(!kobj || (!update && !kobj->sd));
96
97 /* Updates may happen before the object has been instantiated */
98 if (unlikely(update && !kobj->sd))
99 return -EINVAL;
100 if (!grp->attrs && !grp->bin_attrs) {
101 WARN(1, "sysfs: (bin_)attrs not set by subsystem for group: %s/%s\n",
102 kobj->name, grp->name ? "" : grp->name);
103 return -EINVAL;
104 }
105 if (grp->name) {
106 kn = kernfs_create_dir(kobj->sd, grp->name,
107 S_IRWXU | S_IRUGO | S_IXUGO, kobj);
108 if (IS_ERR(kn)) {
109 if (PTR_ERR(kn) == -EEXIST)
110 sysfs_warn_dup(kobj->sd, grp->name);
111 return PTR_ERR(kn);
112 }
113 } else
114 kn = kobj->sd;
115 kernfs_get(kn);
116 error = create_files(kn, kobj, grp, update);
117 if (error) {
118 if (grp->name)
119 kernfs_remove(kn);
120 }
121 kernfs_put(kn);
122 return error;
123}
124
125/**
126 * sysfs_create_group - given a directory kobject, create an attribute group
127 * @kobj: The kobject to create the group on
128 * @grp: The attribute group to create
129 *
130 * This function creates a group for the first time. It will explicitly
131 * warn and error if any of the attribute files being created already exist.
132 *
133 * Returns 0 on success or error.
134 */
135int sysfs_create_group(struct kobject *kobj,
136 const struct attribute_group *grp)
137{
138 return internal_create_group(kobj, 0, grp);
139}
140EXPORT_SYMBOL_GPL(sysfs_create_group);
141
142/**
143 * sysfs_create_groups - given a directory kobject, create a bunch of attribute groups
144 * @kobj: The kobject to create the group on
145 * @groups: The attribute groups to create, NULL terminated
146 *
147 * This function creates a bunch of attribute groups. If an error occurs when
148 * creating a group, all previously created groups will be removed, unwinding
149 * everything back to the original state when this function was called.
150 * It will explicitly warn and error if any of the attribute files being
151 * created already exist.
152 *
153 * Returns 0 on success or error code from sysfs_create_group on error.
154 */
155int sysfs_create_groups(struct kobject *kobj,
156 const struct attribute_group **groups)
157{
158 int error = 0;
159 int i;
160
161 if (!groups)
162 return 0;
163
164 for (i = 0; groups[i]; i++) {
165 error = sysfs_create_group(kobj, groups[i]);
166 if (error) {
167 while (--i >= 0)
168 sysfs_remove_group(kobj, groups[i]);
169 break;
170 }
171 }
172 return error;
173}
174EXPORT_SYMBOL_GPL(sysfs_create_groups);
175
176/**
177 * sysfs_update_group - given a directory kobject, update an attribute group
178 * @kobj: The kobject to update the group on
179 * @grp: The attribute group to update
180 *
181 * This function updates an attribute group. Unlike
182 * sysfs_create_group(), it will explicitly not warn or error if any
183 * of the attribute files being created already exist. Furthermore,
184 * if the visibility of the files has changed through the is_visible()
185 * callback, it will update the permissions and add or remove the
186 * relevant files.
187 *
188 * The primary use for this function is to call it after making a change
189 * that affects group visibility.
190 *
191 * Returns 0 on success or error.
192 */
193int sysfs_update_group(struct kobject *kobj,
194 const struct attribute_group *grp)
195{
196 return internal_create_group(kobj, 1, grp);
197}
198EXPORT_SYMBOL_GPL(sysfs_update_group);
199
200/**
201 * sysfs_remove_group: remove a group from a kobject
202 * @kobj: kobject to remove the group from
203 * @grp: group to remove
204 *
205 * This function removes a group of attributes from a kobject. The attributes
206 * previously have to have been created for this group, otherwise it will fail.
207 */
208void sysfs_remove_group(struct kobject *kobj,
209 const struct attribute_group *grp)
210{
211 struct kernfs_node *parent = kobj->sd;
212 struct kernfs_node *kn;
213
214 if (grp->name) {
215 kn = kernfs_find_and_get(parent, grp->name);
216 if (!kn) {
217 WARN(!kn, KERN_WARNING
218 "sysfs group %p not found for kobject '%s'\n",
219 grp, kobject_name(kobj));
220 return;
221 }
222 } else {
223 kn = parent;
224 kernfs_get(kn);
225 }
226
227 remove_files(kn, kobj, grp);
228 if (grp->name)
229 kernfs_remove(kn);
230
231 kernfs_put(kn);
232}
233EXPORT_SYMBOL_GPL(sysfs_remove_group);
234
235/**
236 * sysfs_remove_groups - remove a list of groups
237 *
238 * @kobj: The kobject for the groups to be removed from
239 * @groups: NULL terminated list of groups to be removed
240 *
241 * If groups is not NULL, remove the specified groups from the kobject.
242 */
243void sysfs_remove_groups(struct kobject *kobj,
244 const struct attribute_group **groups)
245{
246 int i;
247
248 if (!groups)
249 return;
250 for (i = 0; groups[i]; i++)
251 sysfs_remove_group(kobj, groups[i]);
252}
253EXPORT_SYMBOL_GPL(sysfs_remove_groups);
254
255/**
256 * sysfs_merge_group - merge files into a pre-existing attribute group.
257 * @kobj: The kobject containing the group.
258 * @grp: The files to create and the attribute group they belong to.
259 *
260 * This function returns an error if the group doesn't exist or any of the
261 * files already exist in that group, in which case none of the new files
262 * are created.
263 */
264int sysfs_merge_group(struct kobject *kobj,
265 const struct attribute_group *grp)
266{
267 struct kernfs_node *parent;
268 int error = 0;
269 struct attribute *const *attr;
270 int i;
271
272 parent = kernfs_find_and_get(kobj->sd, grp->name);
273 if (!parent)
274 return -ENOENT;
275
276 for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr))
277 error = sysfs_add_file(parent, *attr, false);
278 if (error) {
279 while (--i >= 0)
280 kernfs_remove_by_name(parent, (*--attr)->name);
281 }
282 kernfs_put(parent);
283
284 return error;
285}
286EXPORT_SYMBOL_GPL(sysfs_merge_group);
287
288/**
289 * sysfs_unmerge_group - remove files from a pre-existing attribute group.
290 * @kobj: The kobject containing the group.
291 * @grp: The files to remove and the attribute group they belong to.
292 */
293void sysfs_unmerge_group(struct kobject *kobj,
294 const struct attribute_group *grp)
295{
296 struct kernfs_node *parent;
297 struct attribute *const *attr;
298
299 parent = kernfs_find_and_get(kobj->sd, grp->name);
300 if (parent) {
301 for (attr = grp->attrs; *attr; ++attr)
302 kernfs_remove_by_name(parent, (*attr)->name);
303 kernfs_put(parent);
304 }
305}
306EXPORT_SYMBOL_GPL(sysfs_unmerge_group);
307
308/**
309 * sysfs_add_link_to_group - add a symlink to an attribute group.
310 * @kobj: The kobject containing the group.
311 * @group_name: The name of the group.
312 * @target: The target kobject of the symlink to create.
313 * @link_name: The name of the symlink to create.
314 */
315int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
316 struct kobject *target, const char *link_name)
317{
318 struct kernfs_node *parent;
319 int error = 0;
320
321 parent = kernfs_find_and_get(kobj->sd, group_name);
322 if (!parent)
323 return -ENOENT;
324
325 error = sysfs_create_link_sd(parent, target, link_name);
326 kernfs_put(parent);
327
328 return error;
329}
330EXPORT_SYMBOL_GPL(sysfs_add_link_to_group);
331
332/**
333 * sysfs_remove_link_from_group - remove a symlink from an attribute group.
334 * @kobj: The kobject containing the group.
335 * @group_name: The name of the group.
336 * @link_name: The name of the symlink to remove.
337 */
338void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
339 const char *link_name)
340{
341 struct kernfs_node *parent;
342
343 parent = kernfs_find_and_get(kobj->sd, group_name);
344 if (parent) {
345 kernfs_remove_by_name(parent, link_name);
346 kernfs_put(parent);
347 }
348}
349EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * fs/sysfs/group.c - Operations for adding/removing multiple files at once.
4 *
5 * Copyright (c) 2003 Patrick Mochel
6 * Copyright (c) 2003 Open Source Development Lab
7 * Copyright (c) 2013 Greg Kroah-Hartman
8 * Copyright (c) 2013 The Linux Foundation
9 */
10
11#include <linux/kobject.h>
12#include <linux/module.h>
13#include <linux/dcache.h>
14#include <linux/namei.h>
15#include <linux/err.h>
16#include "sysfs.h"
17
18
19static void remove_files(struct kernfs_node *parent,
20 const struct attribute_group *grp)
21{
22 struct attribute *const *attr;
23 struct bin_attribute *const *bin_attr;
24
25 if (grp->attrs)
26 for (attr = grp->attrs; *attr; attr++)
27 kernfs_remove_by_name(parent, (*attr)->name);
28 if (grp->bin_attrs)
29 for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++)
30 kernfs_remove_by_name(parent, (*bin_attr)->attr.name);
31}
32
33static int create_files(struct kernfs_node *parent, struct kobject *kobj,
34 const struct attribute_group *grp, int update)
35{
36 struct attribute *const *attr;
37 struct bin_attribute *const *bin_attr;
38 int error = 0, i;
39
40 if (grp->attrs) {
41 for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) {
42 umode_t mode = (*attr)->mode;
43
44 /*
45 * In update mode, we're changing the permissions or
46 * visibility. Do this by first removing then
47 * re-adding (if required) the file.
48 */
49 if (update)
50 kernfs_remove_by_name(parent, (*attr)->name);
51 if (grp->is_visible) {
52 mode = grp->is_visible(kobj, *attr, i);
53 if (!mode)
54 continue;
55 }
56
57 WARN(mode & ~(SYSFS_PREALLOC | 0664),
58 "Attribute %s: Invalid permissions 0%o\n",
59 (*attr)->name, mode);
60
61 mode &= SYSFS_PREALLOC | 0664;
62 error = sysfs_add_file_mode_ns(parent, *attr, false,
63 mode, NULL);
64 if (unlikely(error))
65 break;
66 }
67 if (error) {
68 remove_files(parent, grp);
69 goto exit;
70 }
71 }
72
73 if (grp->bin_attrs) {
74 for (i = 0, bin_attr = grp->bin_attrs; *bin_attr; i++, bin_attr++) {
75 umode_t mode = (*bin_attr)->attr.mode;
76
77 if (update)
78 kernfs_remove_by_name(parent,
79 (*bin_attr)->attr.name);
80 if (grp->is_bin_visible) {
81 mode = grp->is_bin_visible(kobj, *bin_attr, i);
82 if (!mode)
83 continue;
84 }
85
86 WARN(mode & ~(SYSFS_PREALLOC | 0664),
87 "Attribute %s: Invalid permissions 0%o\n",
88 (*bin_attr)->attr.name, mode);
89
90 mode &= SYSFS_PREALLOC | 0664;
91 error = sysfs_add_file_mode_ns(parent,
92 &(*bin_attr)->attr, true,
93 mode, NULL);
94 if (error)
95 break;
96 }
97 if (error)
98 remove_files(parent, grp);
99 }
100exit:
101 return error;
102}
103
104
105static int internal_create_group(struct kobject *kobj, int update,
106 const struct attribute_group *grp)
107{
108 struct kernfs_node *kn;
109 int error;
110
111 BUG_ON(!kobj || (!update && !kobj->sd));
112
113 /* Updates may happen before the object has been instantiated */
114 if (unlikely(update && !kobj->sd))
115 return -EINVAL;
116 if (!grp->attrs && !grp->bin_attrs) {
117 WARN(1, "sysfs: (bin_)attrs not set by subsystem for group: %s/%s\n",
118 kobj->name, grp->name ?: "");
119 return -EINVAL;
120 }
121 if (grp->name) {
122 kn = kernfs_create_dir(kobj->sd, grp->name,
123 S_IRWXU | S_IRUGO | S_IXUGO, kobj);
124 if (IS_ERR(kn)) {
125 if (PTR_ERR(kn) == -EEXIST)
126 sysfs_warn_dup(kobj->sd, grp->name);
127 return PTR_ERR(kn);
128 }
129 } else
130 kn = kobj->sd;
131 kernfs_get(kn);
132 error = create_files(kn, kobj, grp, update);
133 if (error) {
134 if (grp->name)
135 kernfs_remove(kn);
136 }
137 kernfs_put(kn);
138 return error;
139}
140
141/**
142 * sysfs_create_group - given a directory kobject, create an attribute group
143 * @kobj: The kobject to create the group on
144 * @grp: The attribute group to create
145 *
146 * This function creates a group for the first time. It will explicitly
147 * warn and error if any of the attribute files being created already exist.
148 *
149 * Returns 0 on success or error code on failure.
150 */
151int sysfs_create_group(struct kobject *kobj,
152 const struct attribute_group *grp)
153{
154 return internal_create_group(kobj, 0, grp);
155}
156EXPORT_SYMBOL_GPL(sysfs_create_group);
157
158/**
159 * sysfs_create_groups - given a directory kobject, create a bunch of attribute groups
160 * @kobj: The kobject to create the group on
161 * @groups: The attribute groups to create, NULL terminated
162 *
163 * This function creates a bunch of attribute groups. If an error occurs when
164 * creating a group, all previously created groups will be removed, unwinding
165 * everything back to the original state when this function was called.
166 * It will explicitly warn and error if any of the attribute files being
167 * created already exist.
168 *
169 * Returns 0 on success or error code from sysfs_create_group on failure.
170 */
171int sysfs_create_groups(struct kobject *kobj,
172 const struct attribute_group **groups)
173{
174 int error = 0;
175 int i;
176
177 if (!groups)
178 return 0;
179
180 for (i = 0; groups[i]; i++) {
181 error = sysfs_create_group(kobj, groups[i]);
182 if (error) {
183 while (--i >= 0)
184 sysfs_remove_group(kobj, groups[i]);
185 break;
186 }
187 }
188 return error;
189}
190EXPORT_SYMBOL_GPL(sysfs_create_groups);
191
192/**
193 * sysfs_update_group - given a directory kobject, update an attribute group
194 * @kobj: The kobject to update the group on
195 * @grp: The attribute group to update
196 *
197 * This function updates an attribute group. Unlike
198 * sysfs_create_group(), it will explicitly not warn or error if any
199 * of the attribute files being created already exist. Furthermore,
200 * if the visibility of the files has changed through the is_visible()
201 * callback, it will update the permissions and add or remove the
202 * relevant files.
203 *
204 * The primary use for this function is to call it after making a change
205 * that affects group visibility.
206 *
207 * Returns 0 on success or error code on failure.
208 */
209int sysfs_update_group(struct kobject *kobj,
210 const struct attribute_group *grp)
211{
212 return internal_create_group(kobj, 1, grp);
213}
214EXPORT_SYMBOL_GPL(sysfs_update_group);
215
216/**
217 * sysfs_remove_group: remove a group from a kobject
218 * @kobj: kobject to remove the group from
219 * @grp: group to remove
220 *
221 * This function removes a group of attributes from a kobject. The attributes
222 * previously have to have been created for this group, otherwise it will fail.
223 */
224void sysfs_remove_group(struct kobject *kobj,
225 const struct attribute_group *grp)
226{
227 struct kernfs_node *parent = kobj->sd;
228 struct kernfs_node *kn;
229
230 if (grp->name) {
231 kn = kernfs_find_and_get(parent, grp->name);
232 if (!kn) {
233 WARN(!kn, KERN_WARNING
234 "sysfs group '%s' not found for kobject '%s'\n",
235 grp->name, kobject_name(kobj));
236 return;
237 }
238 } else {
239 kn = parent;
240 kernfs_get(kn);
241 }
242
243 remove_files(kn, grp);
244 if (grp->name)
245 kernfs_remove(kn);
246
247 kernfs_put(kn);
248}
249EXPORT_SYMBOL_GPL(sysfs_remove_group);
250
251/**
252 * sysfs_remove_groups - remove a list of groups
253 *
254 * @kobj: The kobject for the groups to be removed from
255 * @groups: NULL terminated list of groups to be removed
256 *
257 * If groups is not NULL, remove the specified groups from the kobject.
258 */
259void sysfs_remove_groups(struct kobject *kobj,
260 const struct attribute_group **groups)
261{
262 int i;
263
264 if (!groups)
265 return;
266 for (i = 0; groups[i]; i++)
267 sysfs_remove_group(kobj, groups[i]);
268}
269EXPORT_SYMBOL_GPL(sysfs_remove_groups);
270
271/**
272 * sysfs_merge_group - merge files into a pre-existing attribute group.
273 * @kobj: The kobject containing the group.
274 * @grp: The files to create and the attribute group they belong to.
275 *
276 * This function returns an error if the group doesn't exist or any of the
277 * files already exist in that group, in which case none of the new files
278 * are created.
279 */
280int sysfs_merge_group(struct kobject *kobj,
281 const struct attribute_group *grp)
282{
283 struct kernfs_node *parent;
284 int error = 0;
285 struct attribute *const *attr;
286 int i;
287
288 parent = kernfs_find_and_get(kobj->sd, grp->name);
289 if (!parent)
290 return -ENOENT;
291
292 for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr))
293 error = sysfs_add_file(parent, *attr, false);
294 if (error) {
295 while (--i >= 0)
296 kernfs_remove_by_name(parent, (*--attr)->name);
297 }
298 kernfs_put(parent);
299
300 return error;
301}
302EXPORT_SYMBOL_GPL(sysfs_merge_group);
303
304/**
305 * sysfs_unmerge_group - remove files from a pre-existing attribute group.
306 * @kobj: The kobject containing the group.
307 * @grp: The files to remove and the attribute group they belong to.
308 */
309void sysfs_unmerge_group(struct kobject *kobj,
310 const struct attribute_group *grp)
311{
312 struct kernfs_node *parent;
313 struct attribute *const *attr;
314
315 parent = kernfs_find_and_get(kobj->sd, grp->name);
316 if (parent) {
317 for (attr = grp->attrs; *attr; ++attr)
318 kernfs_remove_by_name(parent, (*attr)->name);
319 kernfs_put(parent);
320 }
321}
322EXPORT_SYMBOL_GPL(sysfs_unmerge_group);
323
324/**
325 * sysfs_add_link_to_group - add a symlink to an attribute group.
326 * @kobj: The kobject containing the group.
327 * @group_name: The name of the group.
328 * @target: The target kobject of the symlink to create.
329 * @link_name: The name of the symlink to create.
330 */
331int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
332 struct kobject *target, const char *link_name)
333{
334 struct kernfs_node *parent;
335 int error = 0;
336
337 parent = kernfs_find_and_get(kobj->sd, group_name);
338 if (!parent)
339 return -ENOENT;
340
341 error = sysfs_create_link_sd(parent, target, link_name);
342 kernfs_put(parent);
343
344 return error;
345}
346EXPORT_SYMBOL_GPL(sysfs_add_link_to_group);
347
348/**
349 * sysfs_remove_link_from_group - remove a symlink from an attribute group.
350 * @kobj: The kobject containing the group.
351 * @group_name: The name of the group.
352 * @link_name: The name of the symlink to remove.
353 */
354void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
355 const char *link_name)
356{
357 struct kernfs_node *parent;
358
359 parent = kernfs_find_and_get(kobj->sd, group_name);
360 if (parent) {
361 kernfs_remove_by_name(parent, link_name);
362 kernfs_put(parent);
363 }
364}
365EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group);
366
367/**
368 * __compat_only_sysfs_link_entry_to_kobj - add a symlink to a kobject pointing
369 * to a group or an attribute
370 * @kobj: The kobject containing the group.
371 * @target_kobj: The target kobject.
372 * @target_name: The name of the target group or attribute.
373 */
374int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
375 struct kobject *target_kobj,
376 const char *target_name)
377{
378 struct kernfs_node *target;
379 struct kernfs_node *entry;
380 struct kernfs_node *link;
381
382 /*
383 * We don't own @target_kobj and it may be removed at any time.
384 * Synchronize using sysfs_symlink_target_lock. See sysfs_remove_dir()
385 * for details.
386 */
387 spin_lock(&sysfs_symlink_target_lock);
388 target = target_kobj->sd;
389 if (target)
390 kernfs_get(target);
391 spin_unlock(&sysfs_symlink_target_lock);
392 if (!target)
393 return -ENOENT;
394
395 entry = kernfs_find_and_get(target_kobj->sd, target_name);
396 if (!entry) {
397 kernfs_put(target);
398 return -ENOENT;
399 }
400
401 link = kernfs_create_link(kobj->sd, target_name, entry);
402 if (IS_ERR(link) && PTR_ERR(link) == -EEXIST)
403 sysfs_warn_dup(kobj->sd, target_name);
404
405 kernfs_put(entry);
406 kernfs_put(target);
407 return PTR_ERR_OR_ZERO(link);
408}
409EXPORT_SYMBOL_GPL(__compat_only_sysfs_link_entry_to_kobj);