projects/linux·blob v4.19-rc2 · refs

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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 <[email protected]>
6 * Copyright (c) 2006-2007 Greg Kroah-Hartman <[email protected]>
7 * Copyright (c) 2006-2007 Novell Inc.
8 *
9 * Please see the file Documentation/kobject.txt 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_ns_type_operations *ops;
86 int error;
87
88 error = sysfs_create_dir_ns(kobj, kobject_namespace(kobj));
89 if (error)
90 return error;
91
92 error = populate_dir(kobj);
93 if (error) {
94 sysfs_remove_dir(kobj);
95 return error;
96 }
97
98 /*
99 * @kobj->sd may be deleted by an ancestor going away. Hold an
100 * extra reference so that it stays until @kobj is gone.
101 */
102 sysfs_get(kobj->sd);
103
104 /*
105 * If @kobj has ns_ops, its children need to be filtered based on
106 * their namespace tags. Enable namespace support on @kobj->sd.
107 */
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));
113
114 sysfs_enable_ns(kobj->sd);
115 }
116
117 return 0;
118}
119
120static int get_kobj_path_length(struct kobject *kobj)
121{
122 int length = 1;
123 struct kobject *parent = kobj;
124
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.
128 */
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;
136}
137
138static void fill_kobj_path(struct kobject *kobj, char *path, int length)
139{
140 struct kobject *parent;
141
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) = '/';
149 }
150
151 pr_debug("kobject: '%s' (%p): %s: path = '%s'\n", kobject_name(kobj),
152 kobj, __func__, path);
153}
154
155/**
156 * kobject_get_path - generate and return the path associated with a given kobj and kset pair.
157 *
158 * @kobj: kobject in question, with which to build the path
159 * @gfp_mask: the allocation type used to allocate the path
160 *
161 * The result must be freed by the caller with kfree().
162 */
163char *kobject_get_path(struct kobject *kobj, gfp_t gfp_mask)
164{
165 char *path;
166 int len;
167
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);
175
176 return path;
177}
178EXPORT_SYMBOL_GPL(kobject_get_path);
179
180/* add the kobject to its kset's list */
181static void kobj_kset_join(struct kobject *kobj)
182{
183 if (!kobj->kset)
184 return;
185
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);
190}
191
192/* remove the kobject from its kset's list */
193static void kobj_kset_leave(struct kobject *kobj)
194{
195 if (!kobj->kset)
196 return;
197
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);
202}
203
204static void kobject_init_internal(struct kobject *kobj)
205{
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;
214}
215
216
217static int kobject_add_internal(struct kobject *kobj)
218{
219 int error = 0;
220 struct kobject *parent;
221
222 if (!kobj)
223 return -ENOENT;
224
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;
230 }
231
232 parent = kobject_get(kobj->parent);
233
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;
240 }
241
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>");
246
247 error = create_dir(kobj);
248 if (error) {
249 kobj_kset_leave(kobj);
250 kobject_put(parent);
251 kobj->parent = NULL;
252
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;
263
264 return error;
265}
266
267/**
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.
272 */
273int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
274 va_list vargs)
275{
276 const char *s;
277
278 if (kobj->name && !fmt)
279 return 0;
280
281 s = kvasprintf_const(GFP_KERNEL, fmt, vargs);
282 if (!s)
283 return -ENOMEM;
284
285 /*
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.
290 */
291 if (strchr(s, '/')) {
292 char *t;
293
294 t = kstrdup(s, GFP_KERNEL);
295 kfree_const(s);
296 if (!t)
297 return -ENOMEM;
298 strreplace(t, '/', '!');
299 s = t;
300 }
301 kfree_const(kobj->name);
302 kobj->name = s;
303
304 return 0;
305}
306
307/**
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
311 *
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.
315 */
316int kobject_set_name(struct kobject *kobj, const char *fmt, ...)
317{
318 va_list vargs;
319 int retval;
320
321 va_start(vargs, fmt);
322 retval = kobject_set_name_vargs(kobj, fmt, vargs);
323 va_end(vargs);
324
325 return retval;
326}
327EXPORT_SYMBOL(kobject_set_name);
328
329/**
330 * kobject_init - initialize a kobject structure
331 * @kobj: pointer to the kobject to initialize
332 * @ktype: pointer to the ktype for this kobject.
333 *
334 * This function will properly initialize a kobject such that it can then
335 * be passed to the kobject_add() call.
336 *
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.
340 */
341void kobject_init(struct kobject *kobj, struct kobj_type *ktype)
342{
343 char *err_str;
344
345 if (!kobj) {
346 err_str = "invalid kobject pointer!";
347 goto error;
348 }
349 if (!ktype) {
350 err_str = "must have a ktype to be initialized properly!\n";
351 goto error;
352 }
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();
358 }
359
360 kobject_init_internal(kobj);
361 kobj->ktype = ktype;
362 return;
363
364error:
365 pr_err("kobject (%p): %s\n", kobj, err_str);
366 dump_stack();
367}
368EXPORT_SYMBOL(kobject_init);
369
370static __printf(3, 0) int kobject_add_varg(struct kobject *kobj,
371 struct kobject *parent,
372 const char *fmt, va_list vargs)
373{
374 int retval;
375
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;
380 }
381 kobj->parent = parent;
382 return kobject_add_internal(kobj);
383}
384
385/**
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.
390 *
391 * The kobject name is set and added to the kobject hierarchy in this
392 * function.
393 *
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.
399 *
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.
404 *
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.
409 */
410int kobject_add(struct kobject *kobj, struct kobject *parent,
411 const char *fmt, ...)
412{
413 va_list args;
414 int retval;
415
416 if (!kobj)
417 return -EINVAL;
418
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;
424 }
425 va_start(args, fmt);
426 retval = kobject_add_varg(kobj, parent, fmt, args);
427 va_end(args);
428
429 return retval;
430}
431EXPORT_SYMBOL(kobject_add);
432
433/**
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.
439 *
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.
443 */
444int kobject_init_and_add(struct kobject *kobj, struct kobj_type *ktype,
445 struct kobject *parent, const char *fmt, ...)
446{
447 va_list args;
448 int retval;
449
450 kobject_init(kobj, ktype);
451
452 va_start(args, fmt);
453 retval = kobject_add_varg(kobj, parent, fmt, args);
454 va_end(args);
455
456 return retval;
457}
458EXPORT_SYMBOL_GPL(kobject_init_and_add);
459
460/**
461 * kobject_rename - change the name of an object
462 * @kobj: object in question.
463 * @new_name: object's new name
464 *
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.
469 */
470int kobject_rename(struct kobject *kobj, const char *new_name)
471{
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];
477
478 kobj = kobject_get(kobj);
479 if (!kobj)
480 return -EINVAL;
481 if (!kobj->parent)
482 return -EINVAL;
483
484 devpath = kobject_get_path(kobj, GFP_KERNEL);
485 if (!devpath) {
486 error = -ENOMEM;
487 goto out;
488 }
489 devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL);
490 if (!devpath_string) {
491 error = -ENOMEM;
492 goto out;
493 }
494 sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);
495 envp[0] = devpath_string;
496 envp[1] = NULL;
497
498 name = dup_name = kstrdup_const(new_name, GFP_KERNEL);
499 if (!name) {
500 error = -ENOMEM;
501 goto out;
502 }
503
504 error = sysfs_rename_dir_ns(kobj, new_name, kobject_namespace(kobj));
505 if (error)
506 goto out;
507
508 /* Install the new kobject name */
509 dup_name = kobj->name;
510 kobj->name = name;
511
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);
516
517out:
518 kfree_const(dup_name);
519 kfree(devpath_string);
520 kfree(devpath);
521 kobject_put(kobj);
522
523 return error;
524}
525EXPORT_SYMBOL_GPL(kobject_rename);
526
527/**
528 * kobject_move - move object to another parent
529 * @kobj: object in question.
530 * @new_parent: object's new parent (can be NULL)
531 */
532int kobject_move(struct kobject *kobj, struct kobject *new_parent)
533{
534 int error;
535 struct kobject *old_parent;
536 const char *devpath = NULL;
537 char *devpath_string = NULL;
538 char *envp[2];
539
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);
547 }
548
549 /* old object path */
550 devpath = kobject_get_path(kobj, GFP_KERNEL);
551 if (!devpath) {
552 error = -ENOMEM;
553 goto out;
554 }
555 devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL);
556 if (!devpath_string) {
557 error = -ENOMEM;
558 goto out;
559 }
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);
571out:
572 kobject_put(new_parent);
573 kobject_put(kobj);
574 kfree(devpath_string);
575 kfree(devpath);
576 return error;
577}
578EXPORT_SYMBOL_GPL(kobject_move);
579
580/**
581 * kobject_del - unlink kobject from hierarchy.
582 * @kobj: object.
583 */
584void kobject_del(struct kobject *kobj)
585{
586 struct kernfs_node *sd;
587
588 if (!kobj)
589 return;
590
591 sd = kobj->sd;
592 sysfs_remove_dir(kobj);
593 sysfs_put(sd);
594
595 kobj->state_in_sysfs = 0;
596 kobj_kset_leave(kobj);
597 kobject_put(kobj->parent);
598 kobj->parent = NULL;
599}
600EXPORT_SYMBOL(kobject_del);
601
602/**
603 * kobject_get - increment refcount for object.
604 * @kobj: object.
605 */
606struct kobject *kobject_get(struct kobject *kobj)
607{
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);
614 }
615 return kobj;
616}
617EXPORT_SYMBOL(kobject_get);
618
619struct kobject * __must_check kobject_get_unless_zero(struct kobject *kobj)
620{
621 if (!kobj)
622 return NULL;
623 if (!kref_get_unless_zero(&kobj->kref))
624 kobj = NULL;
625 return kobj;
626}
627EXPORT_SYMBOL(kobject_get_unless_zero);
628
629/*
630 * kobject_cleanup - free kobject resources.
631 * @kobj: object to cleanup
632 */
633static void kobject_cleanup(struct kobject *kobj)
634{
635 struct kobj_type *t = get_ktype(kobj);
636 const char *name = kobj->name;
637
638 pr_debug("kobject: '%s' (%p): %s, parent %p\n",
639 kobject_name(kobj), kobj, __func__, kobj->parent);
640
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);
644
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);
650 }
651
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);
657 }
658
659 if (t && t->release) {
660 pr_debug("kobject: '%s' (%p): calling ktype release\n",
661 kobject_name(kobj), kobj);
662 t->release(kobj);
663 }
664
665 /* free name if we allocated it */
666 if (name) {
667 pr_debug("kobject: '%s': free name\n", name);
668 kfree_const(name);
669 }
670}
671
672#ifdef CONFIG_DEBUG_KOBJECT_RELEASE
673static void kobject_delayed_cleanup(struct work_struct *work)
674{
675 kobject_cleanup(container_of(to_delayed_work(work),
676 struct kobject, release));
677}
678#endif
679
680static void kobject_release(struct kref *kref)
681{
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);
688
689 schedule_delayed_work(&kobj->release, delay);
690#else
691 kobject_cleanup(kobj);
692#endif
693}
694
695/**
696 * kobject_put - decrement refcount for object.
697 * @kobj: object.
698 *
699 * Decrement the refcount, and if 0, call kobject_cleanup().
700 */
701void kobject_put(struct kobject *kobj)
702{
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);
709 }
710}
711EXPORT_SYMBOL(kobject_put);
712
713static void dynamic_kobj_release(struct kobject *kobj)
714{
715 pr_debug("kobject: (%p): %s\n", kobj, __func__);
716 kfree(kobj);
717}
718
719static struct kobj_type dynamic_kobj_ktype = {
720 .release = dynamic_kobj_release,
721 .sysfs_ops = &kobj_sysfs_ops,
722};
723
724/**
725 * kobject_create - create a struct kobject dynamically
726 *
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.
729 *
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.
734 */
735struct kobject *kobject_create(void)
736{
737 struct kobject *kobj;
738
739 kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
740 if (!kobj)
741 return NULL;
742
743 kobject_init(kobj, &dynamic_kobj_ktype);
744 return kobj;
745}
746
747/**
748 * kobject_create_and_add - create a struct kobject dynamically and register it with sysfs
749 *
750 * @name: the name for the kobject
751 * @parent: the parent kobject of this kobject, if any.
752 *
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.
757 *
758 * If the kobject was not able to be created, NULL will be returned.
759 */
760struct kobject *kobject_create_and_add(const char *name, struct kobject *parent)
761{
762 struct kobject *kobj;
763 int retval;
764
765 kobj = kobject_create();
766 if (!kobj)
767 return NULL;
768
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;
774 }
775 return kobj;
776}
777EXPORT_SYMBOL_GPL(kobject_create_and_add);
778
779/**
780 * kset_init - initialize a kset for use
781 * @k: kset
782 */
783void kset_init(struct kset *k)
784{
785 kobject_init_internal(&k->kobj);
786 INIT_LIST_HEAD(&k->list);
787 spin_lock_init(&k->list_lock);
788}
789
790/* default kobject attribute operations */
791static ssize_t kobj_attr_show(struct kobject *kobj, struct attribute *attr,
792 char *buf)
793{
794 struct kobj_attribute *kattr;
795 ssize_t ret = -EIO;
796
797 kattr = container_of(attr, struct kobj_attribute, attr);
798 if (kattr->show)
799 ret = kattr->show(kobj, kattr, buf);
800 return ret;
801}
802
803static ssize_t kobj_attr_store(struct kobject *kobj, struct attribute *attr,
804 const char *buf, size_t count)
805{
806 struct kobj_attribute *kattr;
807 ssize_t ret = -EIO;
808
809 kattr = container_of(attr, struct kobj_attribute, attr);
810 if (kattr->store)
811 ret = kattr->store(kobj, kattr, buf, count);
812 return ret;
813}
814
815const struct sysfs_ops kobj_sysfs_ops = {
816 .show = kobj_attr_show,
817 .store = kobj_attr_store,
818};
819EXPORT_SYMBOL_GPL(kobj_sysfs_ops);
820
821/**
822 * kset_register - initialize and add a kset.
823 * @k: kset.
824 */
825int kset_register(struct kset *k)
826{
827 int err;
828
829 if (!k)
830 return -EINVAL;
831
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;
838}
839EXPORT_SYMBOL(kset_register);
840
841/**
842 * kset_unregister - remove a kset.
843 * @k: kset.
844 */
845void kset_unregister(struct kset *k)
846{
847 if (!k)
848 return;
849 kobject_del(&k->kobj);
850 kobject_put(&k->kobj);
851}
852EXPORT_SYMBOL(kset_unregister);
853
854/**
855 * kset_find_obj - search for object in kset.
856 * @kset: kset we're looking in.
857 * @name: object's name.
858 *
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.
862 */
863struct kobject *kset_find_obj(struct kset *kset, const char *name)
864{
865 struct kobject *k;
866 struct kobject *ret = NULL;
867
868 spin_lock(&kset->list_lock);
869
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;
874 }
875 }
876
877 spin_unlock(&kset->list_lock);
878 return ret;
879}
880EXPORT_SYMBOL_GPL(kset_find_obj);
881
882static void kset_release(struct kobject *kobj)
883{
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);
888}
889
890void kset_get_ownership(struct kobject *kobj, kuid_t *uid, kgid_t *gid)
891{
892 if (kobj->parent)
893 kobject_get_ownership(kobj->parent, uid, gid);
894}
895
896static struct kobj_type kset_ktype = {
897 .sysfs_ops = &kobj_sysfs_ops,
898 .release = kset_release,
899 .get_ownership = kset_get_ownership,
900};
901
902/**
903 * kset_create - create a struct kset dynamically
904 *
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.
908 *
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.
914 *
915 * If the kset was not able to be created, NULL will be returned.
916 */
917static struct kset *kset_create(const char *name,
918 const struct kset_uevent_ops *uevent_ops,
919 struct kobject *parent_kobj)
920{
921 struct kset *kset;
922 int retval;
923
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;
931 }
932 kset->uevent_ops = uevent_ops;
933 kset->kobj.parent = parent_kobj;
934
935 /*
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.
939 */
940 kset->kobj.ktype = &kset_ktype;
941 kset->kobj.kset = NULL;
942
943 return kset;
944}
945
946/**
947 * kset_create_and_add - create a struct kset dynamically and add it to sysfs
948 *
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.
952 *
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.
957 *
958 * If the kset was not able to be created, NULL will be returned.
959 */
960struct kset *kset_create_and_add(const char *name,
961 const struct kset_uevent_ops *uevent_ops,
962 struct kobject *parent_kobj)
963{
964 struct kset *kset;
965 int error;
966
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;
974 }
975 return kset;
976}
977EXPORT_SYMBOL_GPL(kset_create_and_add);
978
979
980static DEFINE_SPINLOCK(kobj_ns_type_lock);
981static const struct kobj_ns_type_operations *kobj_ns_ops_tbl[KOBJ_NS_TYPES];
982
983int kobj_ns_type_register(const struct kobj_ns_type_operations *ops)
984{
985 enum kobj_ns_type type = ops->type;
986 int error;
987
988 spin_lock(&kobj_ns_type_lock);
989
990 error = -EINVAL;
991 if (type >= KOBJ_NS_TYPES)
992 goto out;
993
994 error = -EINVAL;
995 if (type <= KOBJ_NS_TYPE_NONE)
996 goto out;
997
998 error = -EBUSY;
999 if (kobj_ns_ops_tbl[type])
1000 goto out;
1001
1002 error = 0;
1003 kobj_ns_ops_tbl[type] = ops;
1004
1005out:
1006 spin_unlock(&kobj_ns_type_lock);
1007 return error;
1008}
1009
1010int kobj_ns_type_registered(enum kobj_ns_type type)
1011{
1012 int registered = 0;
1013
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);
1018
1019 return registered;
1020}
1021
1022const struct kobj_ns_type_operations *kobj_child_ns_ops(struct kobject *parent)
1023{
1024 const struct kobj_ns_type_operations *ops = NULL;
1025
1026 if (parent && parent->ktype && parent->ktype->child_ns_type)
1027 ops = parent->ktype->child_ns_type(parent);
1028
1029 return ops;
1030}
1031
1032const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj)
1033{
1034 return kobj_child_ns_ops(kobj->parent);
1035}
1036
1037bool kobj_ns_current_may_mount(enum kobj_ns_type type)
1038{
1039 bool may_mount = true;
1040
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);
1046
1047 return may_mount;
1048}
1049
1050void *kobj_ns_grab_current(enum kobj_ns_type type)
1051{
1052 void *ns = NULL;
1053
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);
1059
1060 return ns;
1061}
1062EXPORT_SYMBOL_GPL(kobj_ns_grab_current);
1063
1064const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk)
1065{
1066 const void *ns = NULL;
1067
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);
1073
1074 return ns;
1075}
1076
1077const void *kobj_ns_initial(enum kobj_ns_type type)
1078{
1079 const void *ns = NULL;
1080
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);
1086
1087 return ns;
1088}
1089
1090void kobj_ns_drop(enum kobj_ns_type type, void *ns)
1091{
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);
1097}
1098EXPORT_SYMBOL_GPL(kobj_ns_drop);