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 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
14 | |
15 | #include <linux/kobject.h> |
16 | #include <linux/string.h> |
17 | #include <linux/export.h> |
18 | #include <linux/stat.h> |
19 | #include <linux/slab.h> |
20 | #include <linux/random.h> |
21 | |
22 | /** |
23 | * kobject_namespace() - Return @kobj's namespace tag. |
24 | * @kobj: kobject in question |
25 | * |
26 | * Returns namespace tag of @kobj if its parent has namespace ops enabled |
27 | * and thus @kobj should have a namespace tag associated with it. Returns |
28 | * %NULL otherwise. |
29 | */ |
30 | const void *kobject_namespace(const struct kobject *kobj) |
31 | { |
32 | const struct kobj_ns_type_operations *ns_ops = kobj_ns_ops(kobj); |
33 | |
34 | if (!ns_ops || ns_ops->type == KOBJ_NS_TYPE_NONE) |
35 | return NULL; |
36 | |
37 | return kobj->ktype->namespace(kobj); |
38 | } |
39 | |
40 | /** |
41 | * kobject_get_ownership() - Get sysfs ownership data for @kobj. |
42 | * @kobj: kobject in question |
43 | * @uid: kernel user ID for sysfs objects |
44 | * @gid: kernel group ID for sysfs objects |
45 | * |
46 | * Returns initial uid/gid pair that should be used when creating sysfs |
47 | * representation of given kobject. Normally used to adjust ownership of |
48 | * objects in a container. |
49 | */ |
50 | void kobject_get_ownership(const struct kobject *kobj, kuid_t *uid, kgid_t *gid) |
51 | { |
52 | *uid = GLOBAL_ROOT_UID; |
53 | *gid = GLOBAL_ROOT_GID; |
54 | |
55 | if (kobj->ktype->get_ownership) |
56 | kobj->ktype->get_ownership(kobj, uid, gid); |
57 | } |
58 | |
59 | static bool kobj_ns_type_is_valid(enum kobj_ns_type type) |
60 | { |
61 | if ((type <= KOBJ_NS_TYPE_NONE) || (type >= KOBJ_NS_TYPES)) |
62 | return false; |
63 | |
64 | return true; |
65 | } |
66 | |
67 | static int create_dir(struct kobject *kobj) |
68 | { |
69 | const struct kobj_type *ktype = get_ktype(kobj); |
70 | const struct kobj_ns_type_operations *ops; |
71 | int error; |
72 | |
73 | error = sysfs_create_dir_ns(kobj, ns: kobject_namespace(kobj)); |
74 | if (error) |
75 | return error; |
76 | |
77 | error = sysfs_create_groups(kobj, groups: ktype->default_groups); |
78 | if (error) { |
79 | sysfs_remove_dir(kobj); |
80 | return error; |
81 | } |
82 | |
83 | /* |
84 | * @kobj->sd may be deleted by an ancestor going away. Hold an |
85 | * extra reference so that it stays until @kobj is gone. |
86 | */ |
87 | sysfs_get(kn: kobj->sd); |
88 | |
89 | /* |
90 | * If @kobj has ns_ops, its children need to be filtered based on |
91 | * their namespace tags. Enable namespace support on @kobj->sd. |
92 | */ |
93 | ops = kobj_child_ns_ops(parent: kobj); |
94 | if (ops) { |
95 | BUG_ON(!kobj_ns_type_is_valid(ops->type)); |
96 | BUG_ON(!kobj_ns_type_registered(ops->type)); |
97 | |
98 | sysfs_enable_ns(kn: kobj->sd); |
99 | } |
100 | |
101 | return 0; |
102 | } |
103 | |
104 | static int get_kobj_path_length(const struct kobject *kobj) |
105 | { |
106 | int length = 1; |
107 | const struct kobject *parent = kobj; |
108 | |
109 | /* walk up the ancestors until we hit the one pointing to the |
110 | * root. |
111 | * Add 1 to strlen for leading '/' of each level. |
112 | */ |
113 | do { |
114 | if (kobject_name(kobj: parent) == NULL) |
115 | return 0; |
116 | length += strlen(kobject_name(parent)) + 1; |
117 | parent = parent->parent; |
118 | } while (parent); |
119 | return length; |
120 | } |
121 | |
122 | static int fill_kobj_path(const struct kobject *kobj, char *path, int length) |
123 | { |
124 | const struct kobject *parent; |
125 | |
126 | --length; |
127 | for (parent = kobj; parent; parent = parent->parent) { |
128 | int cur = strlen(kobject_name(parent)); |
129 | /* back up enough to print this name with '/' */ |
130 | length -= cur; |
131 | if (length <= 0) |
132 | return -EINVAL; |
133 | memcpy(path + length, kobject_name(parent), cur); |
134 | *(path + --length) = '/'; |
135 | } |
136 | |
137 | pr_debug("'%s' (%p): %s: path = '%s'\n" , kobject_name(kobj), |
138 | kobj, __func__, path); |
139 | |
140 | return 0; |
141 | } |
142 | |
143 | /** |
144 | * kobject_get_path() - Allocate memory and fill in the path for @kobj. |
145 | * @kobj: kobject in question, with which to build the path |
146 | * @gfp_mask: the allocation type used to allocate the path |
147 | * |
148 | * Return: The newly allocated memory, caller must free with kfree(). |
149 | */ |
150 | char *kobject_get_path(const struct kobject *kobj, gfp_t gfp_mask) |
151 | { |
152 | char *path; |
153 | int len; |
154 | |
155 | retry: |
156 | len = get_kobj_path_length(kobj); |
157 | if (len == 0) |
158 | return NULL; |
159 | path = kzalloc(size: len, flags: gfp_mask); |
160 | if (!path) |
161 | return NULL; |
162 | if (fill_kobj_path(kobj, path, length: len)) { |
163 | kfree(objp: path); |
164 | goto retry; |
165 | } |
166 | |
167 | return path; |
168 | } |
169 | EXPORT_SYMBOL_GPL(kobject_get_path); |
170 | |
171 | /* add the kobject to its kset's list */ |
172 | static void kobj_kset_join(struct kobject *kobj) |
173 | { |
174 | if (!kobj->kset) |
175 | return; |
176 | |
177 | kset_get(k: kobj->kset); |
178 | spin_lock(lock: &kobj->kset->list_lock); |
179 | list_add_tail(new: &kobj->entry, head: &kobj->kset->list); |
180 | spin_unlock(lock: &kobj->kset->list_lock); |
181 | } |
182 | |
183 | /* remove the kobject from its kset's list */ |
184 | static void kobj_kset_leave(struct kobject *kobj) |
185 | { |
186 | if (!kobj->kset) |
187 | return; |
188 | |
189 | spin_lock(lock: &kobj->kset->list_lock); |
190 | list_del_init(entry: &kobj->entry); |
191 | spin_unlock(lock: &kobj->kset->list_lock); |
192 | kset_put(k: kobj->kset); |
193 | } |
194 | |
195 | static void kobject_init_internal(struct kobject *kobj) |
196 | { |
197 | if (!kobj) |
198 | return; |
199 | kref_init(kref: &kobj->kref); |
200 | INIT_LIST_HEAD(list: &kobj->entry); |
201 | kobj->state_in_sysfs = 0; |
202 | kobj->state_add_uevent_sent = 0; |
203 | kobj->state_remove_uevent_sent = 0; |
204 | kobj->state_initialized = 1; |
205 | } |
206 | |
207 | |
208 | static int kobject_add_internal(struct kobject *kobj) |
209 | { |
210 | int error = 0; |
211 | struct kobject *parent; |
212 | |
213 | if (!kobj) |
214 | return -ENOENT; |
215 | |
216 | if (!kobj->name || !kobj->name[0]) { |
217 | WARN(1, |
218 | "kobject: (%p): attempted to be registered with empty name!\n" , |
219 | kobj); |
220 | return -EINVAL; |
221 | } |
222 | |
223 | parent = kobject_get(kobj: kobj->parent); |
224 | |
225 | /* join kset if set, use it as parent if we do not already have one */ |
226 | if (kobj->kset) { |
227 | if (!parent) |
228 | parent = kobject_get(kobj: &kobj->kset->kobj); |
229 | kobj_kset_join(kobj); |
230 | kobj->parent = parent; |
231 | } |
232 | |
233 | pr_debug("'%s' (%p): %s: parent: '%s', set: '%s'\n" , |
234 | kobject_name(kobj), kobj, __func__, |
235 | parent ? kobject_name(parent) : "<NULL>" , |
236 | kobj->kset ? kobject_name(&kobj->kset->kobj) : "<NULL>" ); |
237 | |
238 | error = create_dir(kobj); |
239 | if (error) { |
240 | kobj_kset_leave(kobj); |
241 | kobject_put(kobj: parent); |
242 | kobj->parent = NULL; |
243 | |
244 | /* be noisy on error issues */ |
245 | if (error == -EEXIST) |
246 | pr_err("%s failed for %s with -EEXIST, don't try to register things with the same name in the same directory.\n" , |
247 | __func__, kobject_name(kobj)); |
248 | else |
249 | pr_err("%s failed for %s (error: %d parent: %s)\n" , |
250 | __func__, kobject_name(kobj), error, |
251 | parent ? kobject_name(parent) : "'none'" ); |
252 | } else |
253 | kobj->state_in_sysfs = 1; |
254 | |
255 | return error; |
256 | } |
257 | |
258 | /** |
259 | * kobject_set_name_vargs() - Set the name of a kobject. |
260 | * @kobj: struct kobject to set the name of |
261 | * @fmt: format string used to build the name |
262 | * @vargs: vargs to format the string. |
263 | */ |
264 | int kobject_set_name_vargs(struct kobject *kobj, const char *fmt, |
265 | va_list vargs) |
266 | { |
267 | const char *s; |
268 | |
269 | if (kobj->name && !fmt) |
270 | return 0; |
271 | |
272 | s = kvasprintf_const(GFP_KERNEL, fmt, args: vargs); |
273 | if (!s) |
274 | return -ENOMEM; |
275 | |
276 | /* |
277 | * ewww... some of these buggers have '/' in the name ... If |
278 | * that's the case, we need to make sure we have an actual |
279 | * allocated copy to modify, since kvasprintf_const may have |
280 | * returned something from .rodata. |
281 | */ |
282 | if (strchr(s, '/')) { |
283 | char *t; |
284 | |
285 | t = kstrdup(s, GFP_KERNEL); |
286 | kfree_const(x: s); |
287 | if (!t) |
288 | return -ENOMEM; |
289 | s = strreplace(str: t, old: '/', new: '!'); |
290 | } |
291 | kfree_const(x: kobj->name); |
292 | kobj->name = s; |
293 | |
294 | return 0; |
295 | } |
296 | |
297 | /** |
298 | * kobject_set_name() - Set the name of a kobject. |
299 | * @kobj: struct kobject to set the name of |
300 | * @fmt: format string used to build the name |
301 | * |
302 | * This sets the name of the kobject. If you have already added the |
303 | * kobject to the system, you must call kobject_rename() in order to |
304 | * change the name of the kobject. |
305 | */ |
306 | int kobject_set_name(struct kobject *kobj, const char *fmt, ...) |
307 | { |
308 | va_list vargs; |
309 | int retval; |
310 | |
311 | va_start(vargs, fmt); |
312 | retval = kobject_set_name_vargs(kobj, fmt, vargs); |
313 | va_end(vargs); |
314 | |
315 | return retval; |
316 | } |
317 | EXPORT_SYMBOL(kobject_set_name); |
318 | |
319 | /** |
320 | * kobject_init() - Initialize a kobject structure. |
321 | * @kobj: pointer to the kobject to initialize |
322 | * @ktype: pointer to the ktype for this kobject. |
323 | * |
324 | * This function will properly initialize a kobject such that it can then |
325 | * be passed to the kobject_add() call. |
326 | * |
327 | * After this function is called, the kobject MUST be cleaned up by a call |
328 | * to kobject_put(), not by a call to kfree directly to ensure that all of |
329 | * the memory is cleaned up properly. |
330 | */ |
331 | void kobject_init(struct kobject *kobj, const struct kobj_type *ktype) |
332 | { |
333 | char *err_str; |
334 | |
335 | if (!kobj) { |
336 | err_str = "invalid kobject pointer!" ; |
337 | goto error; |
338 | } |
339 | if (!ktype) { |
340 | err_str = "must have a ktype to be initialized properly!\n" ; |
341 | goto error; |
342 | } |
343 | if (kobj->state_initialized) { |
344 | /* do not error out as sometimes we can recover */ |
345 | pr_err("kobject (%p): tried to init an initialized object, something is seriously wrong.\n" , |
346 | kobj); |
347 | dump_stack_lvl(KERN_ERR); |
348 | } |
349 | |
350 | kobject_init_internal(kobj); |
351 | kobj->ktype = ktype; |
352 | return; |
353 | |
354 | error: |
355 | pr_err("kobject (%p): %s\n" , kobj, err_str); |
356 | dump_stack_lvl(KERN_ERR); |
357 | } |
358 | EXPORT_SYMBOL(kobject_init); |
359 | |
360 | static __printf(3, 0) int kobject_add_varg(struct kobject *kobj, |
361 | struct kobject *parent, |
362 | const char *fmt, va_list vargs) |
363 | { |
364 | int retval; |
365 | |
366 | retval = kobject_set_name_vargs(kobj, fmt, vargs); |
367 | if (retval) { |
368 | pr_err("can not set name properly!\n" ); |
369 | return retval; |
370 | } |
371 | kobj->parent = parent; |
372 | return kobject_add_internal(kobj); |
373 | } |
374 | |
375 | /** |
376 | * kobject_add() - The main kobject add function. |
377 | * @kobj: the kobject to add |
378 | * @parent: pointer to the parent of the kobject. |
379 | * @fmt: format to name the kobject with. |
380 | * |
381 | * The kobject name is set and added to the kobject hierarchy in this |
382 | * function. |
383 | * |
384 | * If @parent is set, then the parent of the @kobj will be set to it. |
385 | * If @parent is NULL, then the parent of the @kobj will be set to the |
386 | * kobject associated with the kset assigned to this kobject. If no kset |
387 | * is assigned to the kobject, then the kobject will be located in the |
388 | * root of the sysfs tree. |
389 | * |
390 | * Note, no "add" uevent will be created with this call, the caller should set |
391 | * up all of the necessary sysfs files for the object and then call |
392 | * kobject_uevent() with the UEVENT_ADD parameter to ensure that |
393 | * userspace is properly notified of this kobject's creation. |
394 | * |
395 | * Return: If this function returns an error, kobject_put() must be |
396 | * called to properly clean up the memory associated with the |
397 | * object. Under no instance should the kobject that is passed |
398 | * to this function be directly freed with a call to kfree(), |
399 | * that can leak memory. |
400 | * |
401 | * If this function returns success, kobject_put() must also be called |
402 | * in order to properly clean up the memory associated with the object. |
403 | * |
404 | * In short, once this function is called, kobject_put() MUST be called |
405 | * when the use of the object is finished in order to properly free |
406 | * everything. |
407 | */ |
408 | int kobject_add(struct kobject *kobj, struct kobject *parent, |
409 | const char *fmt, ...) |
410 | { |
411 | va_list args; |
412 | int retval; |
413 | |
414 | if (!kobj) |
415 | return -EINVAL; |
416 | |
417 | if (!kobj->state_initialized) { |
418 | pr_err("kobject '%s' (%p): tried to add an uninitialized object, something is seriously wrong.\n" , |
419 | kobject_name(kobj), kobj); |
420 | dump_stack_lvl(KERN_ERR); |
421 | return -EINVAL; |
422 | } |
423 | va_start(args, fmt); |
424 | retval = kobject_add_varg(kobj, parent, fmt, vargs: args); |
425 | va_end(args); |
426 | |
427 | return retval; |
428 | } |
429 | EXPORT_SYMBOL(kobject_add); |
430 | |
431 | /** |
432 | * kobject_init_and_add() - Initialize a kobject structure and add it to |
433 | * the kobject hierarchy. |
434 | * @kobj: pointer to the kobject to initialize |
435 | * @ktype: pointer to the ktype for this kobject. |
436 | * @parent: pointer to the parent of this kobject. |
437 | * @fmt: the name of the kobject. |
438 | * |
439 | * This function combines the call to kobject_init() and kobject_add(). |
440 | * |
441 | * If this function returns an error, kobject_put() must be called to |
442 | * properly clean up the memory associated with the object. This is the |
443 | * same type of error handling after a call to kobject_add() and kobject |
444 | * lifetime rules are the same here. |
445 | */ |
446 | int kobject_init_and_add(struct kobject *kobj, const struct kobj_type *ktype, |
447 | struct kobject *parent, const char *fmt, ...) |
448 | { |
449 | va_list args; |
450 | int retval; |
451 | |
452 | kobject_init(kobj, ktype); |
453 | |
454 | va_start(args, fmt); |
455 | retval = kobject_add_varg(kobj, parent, fmt, vargs: args); |
456 | va_end(args); |
457 | |
458 | return retval; |
459 | } |
460 | EXPORT_SYMBOL_GPL(kobject_init_and_add); |
461 | |
462 | /** |
463 | * kobject_rename() - Change the name of an object. |
464 | * @kobj: object in question. |
465 | * @new_name: object's new name |
466 | * |
467 | * It is the responsibility of the caller to provide mutual |
468 | * exclusion between two different calls of kobject_rename |
469 | * on the same kobject and to ensure that new_name is valid and |
470 | * won't conflict with other kobjects. |
471 | */ |
472 | int kobject_rename(struct kobject *kobj, const char *new_name) |
473 | { |
474 | int error = 0; |
475 | const char *devpath = NULL; |
476 | const char *dup_name = NULL, *name; |
477 | char *devpath_string = NULL; |
478 | char *envp[2]; |
479 | |
480 | kobj = kobject_get(kobj); |
481 | if (!kobj) |
482 | return -EINVAL; |
483 | if (!kobj->parent) { |
484 | kobject_put(kobj); |
485 | return -EINVAL; |
486 | } |
487 | |
488 | devpath = kobject_get_path(kobj, GFP_KERNEL); |
489 | if (!devpath) { |
490 | error = -ENOMEM; |
491 | goto out; |
492 | } |
493 | devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL); |
494 | if (!devpath_string) { |
495 | error = -ENOMEM; |
496 | goto out; |
497 | } |
498 | sprintf(buf: devpath_string, fmt: "DEVPATH_OLD=%s" , devpath); |
499 | envp[0] = devpath_string; |
500 | envp[1] = NULL; |
501 | |
502 | name = dup_name = kstrdup_const(s: new_name, GFP_KERNEL); |
503 | if (!name) { |
504 | error = -ENOMEM; |
505 | goto out; |
506 | } |
507 | |
508 | error = sysfs_rename_dir_ns(kobj, new_name, new_ns: kobject_namespace(kobj)); |
509 | if (error) |
510 | goto out; |
511 | |
512 | /* Install the new kobject name */ |
513 | dup_name = kobj->name; |
514 | kobj->name = name; |
515 | |
516 | /* This function is mostly/only used for network interface. |
517 | * Some hotplug package track interfaces by their name and |
518 | * therefore want to know when the name is changed by the user. */ |
519 | kobject_uevent_env(kobj, action: KOBJ_MOVE, envp); |
520 | |
521 | out: |
522 | kfree_const(x: dup_name); |
523 | kfree(objp: devpath_string); |
524 | kfree(objp: devpath); |
525 | kobject_put(kobj); |
526 | |
527 | return error; |
528 | } |
529 | EXPORT_SYMBOL_GPL(kobject_rename); |
530 | |
531 | /** |
532 | * kobject_move() - Move object to another parent. |
533 | * @kobj: object in question. |
534 | * @new_parent: object's new parent (can be NULL) |
535 | */ |
536 | int kobject_move(struct kobject *kobj, struct kobject *new_parent) |
537 | { |
538 | int error; |
539 | struct kobject *old_parent; |
540 | const char *devpath = NULL; |
541 | char *devpath_string = NULL; |
542 | char *envp[2]; |
543 | |
544 | kobj = kobject_get(kobj); |
545 | if (!kobj) |
546 | return -EINVAL; |
547 | new_parent = kobject_get(kobj: new_parent); |
548 | if (!new_parent) { |
549 | if (kobj->kset) |
550 | new_parent = kobject_get(kobj: &kobj->kset->kobj); |
551 | } |
552 | |
553 | /* old object path */ |
554 | devpath = kobject_get_path(kobj, GFP_KERNEL); |
555 | if (!devpath) { |
556 | error = -ENOMEM; |
557 | goto out; |
558 | } |
559 | devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL); |
560 | if (!devpath_string) { |
561 | error = -ENOMEM; |
562 | goto out; |
563 | } |
564 | sprintf(buf: devpath_string, fmt: "DEVPATH_OLD=%s" , devpath); |
565 | envp[0] = devpath_string; |
566 | envp[1] = NULL; |
567 | error = sysfs_move_dir_ns(kobj, new_parent_kobj: new_parent, new_ns: kobject_namespace(kobj)); |
568 | if (error) |
569 | goto out; |
570 | old_parent = kobj->parent; |
571 | kobj->parent = new_parent; |
572 | new_parent = NULL; |
573 | kobject_put(kobj: old_parent); |
574 | kobject_uevent_env(kobj, action: KOBJ_MOVE, envp); |
575 | out: |
576 | kobject_put(kobj: new_parent); |
577 | kobject_put(kobj); |
578 | kfree(objp: devpath_string); |
579 | kfree(objp: devpath); |
580 | return error; |
581 | } |
582 | EXPORT_SYMBOL_GPL(kobject_move); |
583 | |
584 | static void __kobject_del(struct kobject *kobj) |
585 | { |
586 | struct kernfs_node *sd; |
587 | const struct kobj_type *ktype; |
588 | |
589 | sd = kobj->sd; |
590 | ktype = get_ktype(kobj); |
591 | |
592 | sysfs_remove_groups(kobj, groups: ktype->default_groups); |
593 | |
594 | /* send "remove" if the caller did not do it but sent "add" */ |
595 | if (kobj->state_add_uevent_sent && !kobj->state_remove_uevent_sent) { |
596 | pr_debug("'%s' (%p): auto cleanup 'remove' event\n" , |
597 | kobject_name(kobj), kobj); |
598 | kobject_uevent(kobj, action: KOBJ_REMOVE); |
599 | } |
600 | |
601 | sysfs_remove_dir(kobj); |
602 | sysfs_put(kn: sd); |
603 | |
604 | kobj->state_in_sysfs = 0; |
605 | kobj_kset_leave(kobj); |
606 | kobj->parent = NULL; |
607 | } |
608 | |
609 | /** |
610 | * kobject_del() - Unlink kobject from hierarchy. |
611 | * @kobj: object. |
612 | * |
613 | * This is the function that should be called to delete an object |
614 | * successfully added via kobject_add(). |
615 | */ |
616 | void kobject_del(struct kobject *kobj) |
617 | { |
618 | struct kobject *parent; |
619 | |
620 | if (!kobj) |
621 | return; |
622 | |
623 | parent = kobj->parent; |
624 | __kobject_del(kobj); |
625 | kobject_put(kobj: parent); |
626 | } |
627 | EXPORT_SYMBOL(kobject_del); |
628 | |
629 | /** |
630 | * kobject_get() - Increment refcount for object. |
631 | * @kobj: object. |
632 | */ |
633 | struct kobject *kobject_get(struct kobject *kobj) |
634 | { |
635 | if (kobj) { |
636 | if (!kobj->state_initialized) |
637 | WARN(1, KERN_WARNING |
638 | "kobject: '%s' (%p): is not initialized, yet kobject_get() is being called.\n" , |
639 | kobject_name(kobj), kobj); |
640 | kref_get(kref: &kobj->kref); |
641 | } |
642 | return kobj; |
643 | } |
644 | EXPORT_SYMBOL(kobject_get); |
645 | |
646 | struct kobject * __must_check kobject_get_unless_zero(struct kobject *kobj) |
647 | { |
648 | if (!kobj) |
649 | return NULL; |
650 | if (!kref_get_unless_zero(kref: &kobj->kref)) |
651 | kobj = NULL; |
652 | return kobj; |
653 | } |
654 | EXPORT_SYMBOL(kobject_get_unless_zero); |
655 | |
656 | /* |
657 | * kobject_cleanup - free kobject resources. |
658 | * @kobj: object to cleanup |
659 | */ |
660 | static void kobject_cleanup(struct kobject *kobj) |
661 | { |
662 | struct kobject *parent = kobj->parent; |
663 | const struct kobj_type *t = get_ktype(kobj); |
664 | const char *name = kobj->name; |
665 | |
666 | pr_debug("'%s' (%p): %s, parent %p\n" , |
667 | kobject_name(kobj), kobj, __func__, kobj->parent); |
668 | |
669 | /* remove from sysfs if the caller did not do it */ |
670 | if (kobj->state_in_sysfs) { |
671 | pr_debug("'%s' (%p): auto cleanup kobject_del\n" , |
672 | kobject_name(kobj), kobj); |
673 | __kobject_del(kobj); |
674 | } else { |
675 | /* avoid dropping the parent reference unnecessarily */ |
676 | parent = NULL; |
677 | } |
678 | |
679 | if (t->release) { |
680 | pr_debug("'%s' (%p): calling ktype release\n" , |
681 | kobject_name(kobj), kobj); |
682 | t->release(kobj); |
683 | } else { |
684 | pr_debug("'%s' (%p): does not have a release() function, it is broken and must be fixed. See Documentation/core-api/kobject.rst.\n" , |
685 | kobject_name(kobj), kobj); |
686 | } |
687 | |
688 | /* free name if we allocated it */ |
689 | if (name) { |
690 | pr_debug("'%s': free name\n" , name); |
691 | kfree_const(x: name); |
692 | } |
693 | |
694 | kobject_put(kobj: parent); |
695 | } |
696 | |
697 | #ifdef CONFIG_DEBUG_KOBJECT_RELEASE |
698 | static void kobject_delayed_cleanup(struct work_struct *work) |
699 | { |
700 | kobject_cleanup(container_of(to_delayed_work(work), |
701 | struct kobject, release)); |
702 | } |
703 | #endif |
704 | |
705 | static void kobject_release(struct kref *kref) |
706 | { |
707 | struct kobject *kobj = container_of(kref, struct kobject, kref); |
708 | #ifdef CONFIG_DEBUG_KOBJECT_RELEASE |
709 | unsigned long delay = HZ + HZ * get_random_u32_below(ceil: 4); |
710 | pr_info("'%s' (%p): %s, parent %p (delayed %ld)\n" , |
711 | kobject_name(kobj), kobj, __func__, kobj->parent, delay); |
712 | INIT_DELAYED_WORK(&kobj->release, kobject_delayed_cleanup); |
713 | |
714 | schedule_delayed_work(dwork: &kobj->release, delay); |
715 | #else |
716 | kobject_cleanup(kobj); |
717 | #endif |
718 | } |
719 | |
720 | /** |
721 | * kobject_put() - Decrement refcount for object. |
722 | * @kobj: object. |
723 | * |
724 | * Decrement the refcount, and if 0, call kobject_cleanup(). |
725 | */ |
726 | void kobject_put(struct kobject *kobj) |
727 | { |
728 | if (kobj) { |
729 | if (!kobj->state_initialized) |
730 | WARN(1, KERN_WARNING |
731 | "kobject: '%s' (%p): is not initialized, yet kobject_put() is being called.\n" , |
732 | kobject_name(kobj), kobj); |
733 | kref_put(kref: &kobj->kref, release: kobject_release); |
734 | } |
735 | } |
736 | EXPORT_SYMBOL(kobject_put); |
737 | |
738 | static void dynamic_kobj_release(struct kobject *kobj) |
739 | { |
740 | pr_debug("(%p): %s\n" , kobj, __func__); |
741 | kfree(objp: kobj); |
742 | } |
743 | |
744 | static const struct kobj_type dynamic_kobj_ktype = { |
745 | .release = dynamic_kobj_release, |
746 | .sysfs_ops = &kobj_sysfs_ops, |
747 | }; |
748 | |
749 | /** |
750 | * kobject_create() - Create a struct kobject dynamically. |
751 | * |
752 | * This function creates a kobject structure dynamically and sets it up |
753 | * to be a "dynamic" kobject with a default release function set up. |
754 | * |
755 | * If the kobject was not able to be created, NULL will be returned. |
756 | * The kobject structure returned from here must be cleaned up with a |
757 | * call to kobject_put() and not kfree(), as kobject_init() has |
758 | * already been called on this structure. |
759 | */ |
760 | static struct kobject *kobject_create(void) |
761 | { |
762 | struct kobject *kobj; |
763 | |
764 | kobj = kzalloc(size: sizeof(*kobj), GFP_KERNEL); |
765 | if (!kobj) |
766 | return NULL; |
767 | |
768 | kobject_init(kobj, &dynamic_kobj_ktype); |
769 | return kobj; |
770 | } |
771 | |
772 | /** |
773 | * kobject_create_and_add() - Create a struct kobject dynamically and |
774 | * register it with sysfs. |
775 | * @name: the name for the kobject |
776 | * @parent: the parent kobject of this kobject, if any. |
777 | * |
778 | * This function creates a kobject structure dynamically and registers it |
779 | * with sysfs. When you are finished with this structure, call |
780 | * kobject_put() and the structure will be dynamically freed when |
781 | * it is no longer being used. |
782 | * |
783 | * If the kobject was not able to be created, NULL will be returned. |
784 | */ |
785 | struct kobject *kobject_create_and_add(const char *name, struct kobject *parent) |
786 | { |
787 | struct kobject *kobj; |
788 | int retval; |
789 | |
790 | kobj = kobject_create(); |
791 | if (!kobj) |
792 | return NULL; |
793 | |
794 | retval = kobject_add(kobj, parent, "%s" , name); |
795 | if (retval) { |
796 | pr_warn("%s: kobject_add error: %d\n" , __func__, retval); |
797 | kobject_put(kobj); |
798 | kobj = NULL; |
799 | } |
800 | return kobj; |
801 | } |
802 | EXPORT_SYMBOL_GPL(kobject_create_and_add); |
803 | |
804 | /** |
805 | * kset_init() - Initialize a kset for use. |
806 | * @k: kset |
807 | */ |
808 | void kset_init(struct kset *k) |
809 | { |
810 | kobject_init_internal(kobj: &k->kobj); |
811 | INIT_LIST_HEAD(list: &k->list); |
812 | spin_lock_init(&k->list_lock); |
813 | } |
814 | |
815 | /* default kobject attribute operations */ |
816 | static ssize_t kobj_attr_show(struct kobject *kobj, struct attribute *attr, |
817 | char *buf) |
818 | { |
819 | struct kobj_attribute *kattr; |
820 | ssize_t ret = -EIO; |
821 | |
822 | kattr = container_of(attr, struct kobj_attribute, attr); |
823 | if (kattr->show) |
824 | ret = kattr->show(kobj, kattr, buf); |
825 | return ret; |
826 | } |
827 | |
828 | static ssize_t kobj_attr_store(struct kobject *kobj, struct attribute *attr, |
829 | const char *buf, size_t count) |
830 | { |
831 | struct kobj_attribute *kattr; |
832 | ssize_t ret = -EIO; |
833 | |
834 | kattr = container_of(attr, struct kobj_attribute, attr); |
835 | if (kattr->store) |
836 | ret = kattr->store(kobj, kattr, buf, count); |
837 | return ret; |
838 | } |
839 | |
840 | const struct sysfs_ops kobj_sysfs_ops = { |
841 | .show = kobj_attr_show, |
842 | .store = kobj_attr_store, |
843 | }; |
844 | EXPORT_SYMBOL_GPL(kobj_sysfs_ops); |
845 | |
846 | /** |
847 | * kset_register() - Initialize and add a kset. |
848 | * @k: kset. |
849 | * |
850 | * NOTE: On error, the kset.kobj.name allocated by() kobj_set_name() |
851 | * is freed, it can not be used any more. |
852 | */ |
853 | int kset_register(struct kset *k) |
854 | { |
855 | int err; |
856 | |
857 | if (!k) |
858 | return -EINVAL; |
859 | |
860 | if (!k->kobj.ktype) { |
861 | pr_err("must have a ktype to be initialized properly!\n" ); |
862 | return -EINVAL; |
863 | } |
864 | |
865 | kset_init(k); |
866 | err = kobject_add_internal(kobj: &k->kobj); |
867 | if (err) { |
868 | kfree_const(x: k->kobj.name); |
869 | /* Set it to NULL to avoid accessing bad pointer in callers. */ |
870 | k->kobj.name = NULL; |
871 | return err; |
872 | } |
873 | kobject_uevent(kobj: &k->kobj, action: KOBJ_ADD); |
874 | return 0; |
875 | } |
876 | EXPORT_SYMBOL(kset_register); |
877 | |
878 | /** |
879 | * kset_unregister() - Remove a kset. |
880 | * @k: kset. |
881 | */ |
882 | void kset_unregister(struct kset *k) |
883 | { |
884 | if (!k) |
885 | return; |
886 | kobject_del(&k->kobj); |
887 | kobject_put(&k->kobj); |
888 | } |
889 | EXPORT_SYMBOL(kset_unregister); |
890 | |
891 | /** |
892 | * kset_find_obj() - Search for object in kset. |
893 | * @kset: kset we're looking in. |
894 | * @name: object's name. |
895 | * |
896 | * Lock kset via @kset->subsys, and iterate over @kset->list, |
897 | * looking for a matching kobject. If matching object is found |
898 | * take a reference and return the object. |
899 | */ |
900 | struct kobject *kset_find_obj(struct kset *kset, const char *name) |
901 | { |
902 | struct kobject *k; |
903 | struct kobject *ret = NULL; |
904 | |
905 | spin_lock(lock: &kset->list_lock); |
906 | |
907 | list_for_each_entry(k, &kset->list, entry) { |
908 | if (kobject_name(kobj: k) && !strcmp(kobject_name(kobj: k), name)) { |
909 | ret = kobject_get_unless_zero(k); |
910 | break; |
911 | } |
912 | } |
913 | |
914 | spin_unlock(lock: &kset->list_lock); |
915 | return ret; |
916 | } |
917 | EXPORT_SYMBOL_GPL(kset_find_obj); |
918 | |
919 | static void kset_release(struct kobject *kobj) |
920 | { |
921 | struct kset *kset = container_of(kobj, struct kset, kobj); |
922 | pr_debug("'%s' (%p): %s\n" , |
923 | kobject_name(kobj), kobj, __func__); |
924 | kfree(objp: kset); |
925 | } |
926 | |
927 | static void kset_get_ownership(const struct kobject *kobj, kuid_t *uid, kgid_t *gid) |
928 | { |
929 | if (kobj->parent) |
930 | kobject_get_ownership(kobj: kobj->parent, uid, gid); |
931 | } |
932 | |
933 | static const struct kobj_type kset_ktype = { |
934 | .sysfs_ops = &kobj_sysfs_ops, |
935 | .release = kset_release, |
936 | .get_ownership = kset_get_ownership, |
937 | }; |
938 | |
939 | /** |
940 | * kset_create() - Create a struct kset dynamically. |
941 | * |
942 | * @name: the name for the kset |
943 | * @uevent_ops: a struct kset_uevent_ops for the kset |
944 | * @parent_kobj: the parent kobject of this kset, if any. |
945 | * |
946 | * This function creates a kset structure dynamically. This structure can |
947 | * then be registered with the system and show up in sysfs with a call to |
948 | * kset_register(). When you are finished with this structure, if |
949 | * kset_register() has been called, call kset_unregister() and the |
950 | * structure will be dynamically freed when it is no longer being used. |
951 | * |
952 | * If the kset was not able to be created, NULL will be returned. |
953 | */ |
954 | static struct kset *kset_create(const char *name, |
955 | const struct kset_uevent_ops *uevent_ops, |
956 | struct kobject *parent_kobj) |
957 | { |
958 | struct kset *kset; |
959 | int retval; |
960 | |
961 | kset = kzalloc(size: sizeof(*kset), GFP_KERNEL); |
962 | if (!kset) |
963 | return NULL; |
964 | retval = kobject_set_name(&kset->kobj, "%s" , name); |
965 | if (retval) { |
966 | kfree(objp: kset); |
967 | return NULL; |
968 | } |
969 | kset->uevent_ops = uevent_ops; |
970 | kset->kobj.parent = parent_kobj; |
971 | |
972 | /* |
973 | * The kobject of this kset will have a type of kset_ktype and belong to |
974 | * no kset itself. That way we can properly free it when it is |
975 | * finished being used. |
976 | */ |
977 | kset->kobj.ktype = &kset_ktype; |
978 | kset->kobj.kset = NULL; |
979 | |
980 | return kset; |
981 | } |
982 | |
983 | /** |
984 | * kset_create_and_add() - Create a struct kset dynamically and add it to sysfs. |
985 | * |
986 | * @name: the name for the kset |
987 | * @uevent_ops: a struct kset_uevent_ops for the kset |
988 | * @parent_kobj: the parent kobject of this kset, if any. |
989 | * |
990 | * This function creates a kset structure dynamically and registers it |
991 | * with sysfs. When you are finished with this structure, call |
992 | * kset_unregister() and the structure will be dynamically freed when it |
993 | * is no longer being used. |
994 | * |
995 | * If the kset was not able to be created, NULL will be returned. |
996 | */ |
997 | struct kset *kset_create_and_add(const char *name, |
998 | const struct kset_uevent_ops *uevent_ops, |
999 | struct kobject *parent_kobj) |
1000 | { |
1001 | struct kset *kset; |
1002 | int error; |
1003 | |
1004 | kset = kset_create(name, uevent_ops, parent_kobj); |
1005 | if (!kset) |
1006 | return NULL; |
1007 | error = kset_register(kset); |
1008 | if (error) { |
1009 | kfree(objp: kset); |
1010 | return NULL; |
1011 | } |
1012 | return kset; |
1013 | } |
1014 | EXPORT_SYMBOL_GPL(kset_create_and_add); |
1015 | |
1016 | |
1017 | static DEFINE_SPINLOCK(kobj_ns_type_lock); |
1018 | static const struct kobj_ns_type_operations *kobj_ns_ops_tbl[KOBJ_NS_TYPES]; |
1019 | |
1020 | int kobj_ns_type_register(const struct kobj_ns_type_operations *ops) |
1021 | { |
1022 | enum kobj_ns_type type = ops->type; |
1023 | int error; |
1024 | |
1025 | spin_lock(lock: &kobj_ns_type_lock); |
1026 | |
1027 | error = -EINVAL; |
1028 | if (!kobj_ns_type_is_valid(type)) |
1029 | goto out; |
1030 | |
1031 | error = -EBUSY; |
1032 | if (kobj_ns_ops_tbl[type]) |
1033 | goto out; |
1034 | |
1035 | error = 0; |
1036 | kobj_ns_ops_tbl[type] = ops; |
1037 | |
1038 | out: |
1039 | spin_unlock(lock: &kobj_ns_type_lock); |
1040 | return error; |
1041 | } |
1042 | |
1043 | int kobj_ns_type_registered(enum kobj_ns_type type) |
1044 | { |
1045 | int registered = 0; |
1046 | |
1047 | spin_lock(lock: &kobj_ns_type_lock); |
1048 | if (kobj_ns_type_is_valid(type)) |
1049 | registered = kobj_ns_ops_tbl[type] != NULL; |
1050 | spin_unlock(lock: &kobj_ns_type_lock); |
1051 | |
1052 | return registered; |
1053 | } |
1054 | |
1055 | const struct kobj_ns_type_operations *kobj_child_ns_ops(const struct kobject *parent) |
1056 | { |
1057 | const struct kobj_ns_type_operations *ops = NULL; |
1058 | |
1059 | if (parent && parent->ktype->child_ns_type) |
1060 | ops = parent->ktype->child_ns_type(parent); |
1061 | |
1062 | return ops; |
1063 | } |
1064 | |
1065 | const struct kobj_ns_type_operations *kobj_ns_ops(const struct kobject *kobj) |
1066 | { |
1067 | return kobj_child_ns_ops(parent: kobj->parent); |
1068 | } |
1069 | |
1070 | bool kobj_ns_current_may_mount(enum kobj_ns_type type) |
1071 | { |
1072 | bool may_mount = true; |
1073 | |
1074 | spin_lock(lock: &kobj_ns_type_lock); |
1075 | if (kobj_ns_type_is_valid(type) && kobj_ns_ops_tbl[type]) |
1076 | may_mount = kobj_ns_ops_tbl[type]->current_may_mount(); |
1077 | spin_unlock(lock: &kobj_ns_type_lock); |
1078 | |
1079 | return may_mount; |
1080 | } |
1081 | |
1082 | void *kobj_ns_grab_current(enum kobj_ns_type type) |
1083 | { |
1084 | void *ns = NULL; |
1085 | |
1086 | spin_lock(lock: &kobj_ns_type_lock); |
1087 | if (kobj_ns_type_is_valid(type) && kobj_ns_ops_tbl[type]) |
1088 | ns = kobj_ns_ops_tbl[type]->grab_current_ns(); |
1089 | spin_unlock(lock: &kobj_ns_type_lock); |
1090 | |
1091 | return ns; |
1092 | } |
1093 | EXPORT_SYMBOL_GPL(kobj_ns_grab_current); |
1094 | |
1095 | const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk) |
1096 | { |
1097 | const void *ns = NULL; |
1098 | |
1099 | spin_lock(lock: &kobj_ns_type_lock); |
1100 | if (kobj_ns_type_is_valid(type) && kobj_ns_ops_tbl[type]) |
1101 | ns = kobj_ns_ops_tbl[type]->netlink_ns(sk); |
1102 | spin_unlock(lock: &kobj_ns_type_lock); |
1103 | |
1104 | return ns; |
1105 | } |
1106 | |
1107 | const void *kobj_ns_initial(enum kobj_ns_type type) |
1108 | { |
1109 | const void *ns = NULL; |
1110 | |
1111 | spin_lock(lock: &kobj_ns_type_lock); |
1112 | if (kobj_ns_type_is_valid(type) && kobj_ns_ops_tbl[type]) |
1113 | ns = kobj_ns_ops_tbl[type]->initial_ns(); |
1114 | spin_unlock(lock: &kobj_ns_type_lock); |
1115 | |
1116 | return ns; |
1117 | } |
1118 | |
1119 | void kobj_ns_drop(enum kobj_ns_type type, void *ns) |
1120 | { |
1121 | spin_lock(lock: &kobj_ns_type_lock); |
1122 | if (kobj_ns_type_is_valid(type) && |
1123 | kobj_ns_ops_tbl[type] && kobj_ns_ops_tbl[type]->drop_ns) |
1124 | kobj_ns_ops_tbl[type]->drop_ns(ns); |
1125 | spin_unlock(lock: &kobj_ns_type_lock); |
1126 | } |
1127 | EXPORT_SYMBOL_GPL(kobj_ns_drop); |
1128 | |