Line data Source code
1 : /* SPDX-License-Identifier: GPL-2.0 */
2 : /*
3 : * sysfs.h - definitions for the device driver filesystem
4 : *
5 : * Copyright (c) 2001,2002 Patrick Mochel
6 : * Copyright (c) 2004 Silicon Graphics, Inc.
7 : * Copyright (c) 2007 SUSE Linux Products GmbH
8 : * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
9 : *
10 : * Please see Documentation/filesystems/sysfs.rst for more information.
11 : */
12 :
13 : #ifndef _SYSFS_H_
14 : #define _SYSFS_H_
15 :
16 : #include <linux/kernfs.h>
17 : #include <linux/compiler.h>
18 : #include <linux/errno.h>
19 : #include <linux/list.h>
20 : #include <linux/lockdep.h>
21 : #include <linux/kobject_ns.h>
22 : #include <linux/stat.h>
23 : #include <linux/atomic.h>
24 :
25 : struct kobject;
26 : struct module;
27 : struct bin_attribute;
28 : enum kobj_ns_type;
29 :
30 : struct attribute {
31 : const char *name;
32 : umode_t mode;
33 : #ifdef CONFIG_DEBUG_LOCK_ALLOC
34 : bool ignore_lockdep:1;
35 : struct lock_class_key *key;
36 : struct lock_class_key skey;
37 : #endif
38 : };
39 :
40 : /**
41 : * sysfs_attr_init - initialize a dynamically allocated sysfs attribute
42 : * @attr: struct attribute to initialize
43 : *
44 : * Initialize a dynamically allocated struct attribute so we can
45 : * make lockdep happy. This is a new requirement for attributes
46 : * and initially this is only needed when lockdep is enabled.
47 : * Lockdep gives a nice error when your attribute is added to
48 : * sysfs if you don't have this.
49 : */
50 : #ifdef CONFIG_DEBUG_LOCK_ALLOC
51 : #define sysfs_attr_init(attr) \
52 : do { \
53 : static struct lock_class_key __key; \
54 : \
55 : (attr)->key = &__key; \
56 : } while (0)
57 : #else
58 : #define sysfs_attr_init(attr) do {} while (0)
59 : #endif
60 :
61 : /**
62 : * struct attribute_group - data structure used to declare an attribute group.
63 : * @name: Optional: Attribute group name
64 : * If specified, the attribute group will be created in
65 : * a new subdirectory with this name.
66 : * @is_visible: Optional: Function to return permissions associated with an
67 : * attribute of the group. Will be called repeatedly for each
68 : * non-binary attribute in the group. Only read/write
69 : * permissions as well as SYSFS_PREALLOC are accepted. Must
70 : * return 0 if an attribute is not visible. The returned value
71 : * will replace static permissions defined in struct attribute.
72 : * @is_bin_visible:
73 : * Optional: Function to return permissions associated with a
74 : * binary attribute of the group. Will be called repeatedly
75 : * for each binary attribute in the group. Only read/write
76 : * permissions as well as SYSFS_PREALLOC are accepted. Must
77 : * return 0 if a binary attribute is not visible. The returned
78 : * value will replace static permissions defined in
79 : * struct bin_attribute.
80 : * @attrs: Pointer to NULL terminated list of attributes.
81 : * @bin_attrs: Pointer to NULL terminated list of binary attributes.
82 : * Either attrs or bin_attrs or both must be provided.
83 : */
84 : struct attribute_group {
85 : const char *name;
86 : umode_t (*is_visible)(struct kobject *,
87 : struct attribute *, int);
88 : umode_t (*is_bin_visible)(struct kobject *,
89 : struct bin_attribute *, int);
90 : struct attribute **attrs;
91 : struct bin_attribute **bin_attrs;
92 : };
93 :
94 : /*
95 : * Use these macros to make defining attributes easier.
96 : * See include/linux/device.h for examples..
97 : */
98 :
99 : #define SYSFS_PREALLOC 010000
100 :
101 : #define __ATTR(_name, _mode, _show, _store) { \
102 : .attr = {.name = __stringify(_name), \
103 : .mode = VERIFY_OCTAL_PERMISSIONS(_mode) }, \
104 : .show = _show, \
105 : .store = _store, \
106 : }
107 :
108 : #define __ATTR_PREALLOC(_name, _mode, _show, _store) { \
109 : .attr = {.name = __stringify(_name), \
110 : .mode = SYSFS_PREALLOC | VERIFY_OCTAL_PERMISSIONS(_mode) },\
111 : .show = _show, \
112 : .store = _store, \
113 : }
114 :
115 : #define __ATTR_RO(_name) { \
116 : .attr = { .name = __stringify(_name), .mode = 0444 }, \
117 : .show = _name##_show, \
118 : }
119 :
120 : #define __ATTR_RO_MODE(_name, _mode) { \
121 : .attr = { .name = __stringify(_name), \
122 : .mode = VERIFY_OCTAL_PERMISSIONS(_mode) }, \
123 : .show = _name##_show, \
124 : }
125 :
126 : #define __ATTR_RW_MODE(_name, _mode) { \
127 : .attr = { .name = __stringify(_name), \
128 : .mode = VERIFY_OCTAL_PERMISSIONS(_mode) }, \
129 : .show = _name##_show, \
130 : .store = _name##_store, \
131 : }
132 :
133 : #define __ATTR_WO(_name) { \
134 : .attr = { .name = __stringify(_name), .mode = 0200 }, \
135 : .store = _name##_store, \
136 : }
137 :
138 : #define __ATTR_RW(_name) __ATTR(_name, 0644, _name##_show, _name##_store)
139 :
140 : #define __ATTR_NULL { .attr = { .name = NULL } }
141 :
142 : #ifdef CONFIG_DEBUG_LOCK_ALLOC
143 : #define __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) { \
144 : .attr = {.name = __stringify(_name), .mode = _mode, \
145 : .ignore_lockdep = true }, \
146 : .show = _show, \
147 : .store = _store, \
148 : }
149 : #else
150 : #define __ATTR_IGNORE_LOCKDEP __ATTR
151 : #endif
152 :
153 : #define __ATTRIBUTE_GROUPS(_name) \
154 : static const struct attribute_group *_name##_groups[] = { \
155 : &_name##_group, \
156 : NULL, \
157 : }
158 :
159 : #define ATTRIBUTE_GROUPS(_name) \
160 : static const struct attribute_group _name##_group = { \
161 : .attrs = _name##_attrs, \
162 : }; \
163 : __ATTRIBUTE_GROUPS(_name)
164 :
165 : #define BIN_ATTRIBUTE_GROUPS(_name) \
166 : static const struct attribute_group _name##_group = { \
167 : .bin_attrs = _name##_attrs, \
168 : }; \
169 : __ATTRIBUTE_GROUPS(_name)
170 :
171 : struct file;
172 : struct vm_area_struct;
173 : struct address_space;
174 :
175 : struct bin_attribute {
176 : struct attribute attr;
177 : size_t size;
178 : void *private;
179 : struct address_space *(*f_mapping)(void);
180 : ssize_t (*read)(struct file *, struct kobject *, struct bin_attribute *,
181 : char *, loff_t, size_t);
182 : ssize_t (*write)(struct file *, struct kobject *, struct bin_attribute *,
183 : char *, loff_t, size_t);
184 : int (*mmap)(struct file *, struct kobject *, struct bin_attribute *attr,
185 : struct vm_area_struct *vma);
186 : };
187 :
188 : /**
189 : * sysfs_bin_attr_init - initialize a dynamically allocated bin_attribute
190 : * @attr: struct bin_attribute to initialize
191 : *
192 : * Initialize a dynamically allocated struct bin_attribute so we
193 : * can make lockdep happy. This is a new requirement for
194 : * attributes and initially this is only needed when lockdep is
195 : * enabled. Lockdep gives a nice error when your attribute is
196 : * added to sysfs if you don't have this.
197 : */
198 : #define sysfs_bin_attr_init(bin_attr) sysfs_attr_init(&(bin_attr)->attr)
199 :
200 : /* macros to create static binary attributes easier */
201 : #define __BIN_ATTR(_name, _mode, _read, _write, _size) { \
202 : .attr = { .name = __stringify(_name), .mode = _mode }, \
203 : .read = _read, \
204 : .write = _write, \
205 : .size = _size, \
206 : }
207 :
208 : #define __BIN_ATTR_RO(_name, _size) { \
209 : .attr = { .name = __stringify(_name), .mode = 0444 }, \
210 : .read = _name##_read, \
211 : .size = _size, \
212 : }
213 :
214 : #define __BIN_ATTR_WO(_name, _size) { \
215 : .attr = { .name = __stringify(_name), .mode = 0200 }, \
216 : .write = _name##_write, \
217 : .size = _size, \
218 : }
219 :
220 : #define __BIN_ATTR_RW(_name, _size) \
221 : __BIN_ATTR(_name, 0644, _name##_read, _name##_write, _size)
222 :
223 : #define __BIN_ATTR_NULL __ATTR_NULL
224 :
225 : #define BIN_ATTR(_name, _mode, _read, _write, _size) \
226 : struct bin_attribute bin_attr_##_name = __BIN_ATTR(_name, _mode, _read, \
227 : _write, _size)
228 :
229 : #define BIN_ATTR_RO(_name, _size) \
230 : struct bin_attribute bin_attr_##_name = __BIN_ATTR_RO(_name, _size)
231 :
232 : #define BIN_ATTR_WO(_name, _size) \
233 : struct bin_attribute bin_attr_##_name = __BIN_ATTR_WO(_name, _size)
234 :
235 : #define BIN_ATTR_RW(_name, _size) \
236 : struct bin_attribute bin_attr_##_name = __BIN_ATTR_RW(_name, _size)
237 :
238 :
239 : #define __BIN_ATTR_ADMIN_RO(_name, _size) { \
240 : .attr = { .name = __stringify(_name), .mode = 0400 }, \
241 : .read = _name##_read, \
242 : .size = _size, \
243 : }
244 :
245 : #define __BIN_ATTR_ADMIN_RW(_name, _size) \
246 : __BIN_ATTR(_name, 0600, _name##_read, _name##_write, _size)
247 :
248 : #define BIN_ATTR_ADMIN_RO(_name, _size) \
249 : struct bin_attribute bin_attr_##_name = __BIN_ATTR_ADMIN_RO(_name, _size)
250 :
251 : #define BIN_ATTR_ADMIN_RW(_name, _size) \
252 : struct bin_attribute bin_attr_##_name = __BIN_ATTR_ADMIN_RW(_name, _size)
253 :
254 : struct sysfs_ops {
255 : ssize_t (*show)(struct kobject *, struct attribute *, char *);
256 : ssize_t (*store)(struct kobject *, struct attribute *, const char *, size_t);
257 : };
258 :
259 : #ifdef CONFIG_SYSFS
260 :
261 : int __must_check sysfs_create_dir_ns(struct kobject *kobj, const void *ns);
262 : void sysfs_remove_dir(struct kobject *kobj);
263 : int __must_check sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name,
264 : const void *new_ns);
265 : int __must_check sysfs_move_dir_ns(struct kobject *kobj,
266 : struct kobject *new_parent_kobj,
267 : const void *new_ns);
268 : int __must_check sysfs_create_mount_point(struct kobject *parent_kobj,
269 : const char *name);
270 : void sysfs_remove_mount_point(struct kobject *parent_kobj,
271 : const char *name);
272 :
273 : int __must_check sysfs_create_file_ns(struct kobject *kobj,
274 : const struct attribute *attr,
275 : const void *ns);
276 : int __must_check sysfs_create_files(struct kobject *kobj,
277 : const struct attribute * const *attr);
278 : int __must_check sysfs_chmod_file(struct kobject *kobj,
279 : const struct attribute *attr, umode_t mode);
280 : struct kernfs_node *sysfs_break_active_protection(struct kobject *kobj,
281 : const struct attribute *attr);
282 : void sysfs_unbreak_active_protection(struct kernfs_node *kn);
283 : void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr,
284 : const void *ns);
285 : bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr);
286 : void sysfs_remove_files(struct kobject *kobj, const struct attribute * const *attr);
287 :
288 : int __must_check sysfs_create_bin_file(struct kobject *kobj,
289 : const struct bin_attribute *attr);
290 : void sysfs_remove_bin_file(struct kobject *kobj,
291 : const struct bin_attribute *attr);
292 :
293 : int __must_check sysfs_create_link(struct kobject *kobj, struct kobject *target,
294 : const char *name);
295 : int __must_check sysfs_create_link_nowarn(struct kobject *kobj,
296 : struct kobject *target,
297 : const char *name);
298 : void sysfs_remove_link(struct kobject *kobj, const char *name);
299 :
300 : int sysfs_rename_link_ns(struct kobject *kobj, struct kobject *target,
301 : const char *old_name, const char *new_name,
302 : const void *new_ns);
303 :
304 : void sysfs_delete_link(struct kobject *dir, struct kobject *targ,
305 : const char *name);
306 :
307 : int __must_check sysfs_create_group(struct kobject *kobj,
308 : const struct attribute_group *grp);
309 : int __must_check sysfs_create_groups(struct kobject *kobj,
310 : const struct attribute_group **groups);
311 : int __must_check sysfs_update_groups(struct kobject *kobj,
312 : const struct attribute_group **groups);
313 : int sysfs_update_group(struct kobject *kobj,
314 : const struct attribute_group *grp);
315 : void sysfs_remove_group(struct kobject *kobj,
316 : const struct attribute_group *grp);
317 : void sysfs_remove_groups(struct kobject *kobj,
318 : const struct attribute_group **groups);
319 : int sysfs_add_file_to_group(struct kobject *kobj,
320 : const struct attribute *attr, const char *group);
321 : void sysfs_remove_file_from_group(struct kobject *kobj,
322 : const struct attribute *attr, const char *group);
323 : int sysfs_merge_group(struct kobject *kobj,
324 : const struct attribute_group *grp);
325 : void sysfs_unmerge_group(struct kobject *kobj,
326 : const struct attribute_group *grp);
327 : int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
328 : struct kobject *target, const char *link_name);
329 : void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
330 : const char *link_name);
331 : int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
332 : struct kobject *target_kobj,
333 : const char *target_name,
334 : const char *symlink_name);
335 :
336 : void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr);
337 :
338 : int __must_check sysfs_init(void);
339 :
340 : static inline void sysfs_enable_ns(struct kernfs_node *kn)
341 : {
342 0 : return kernfs_enable_ns(kn);
343 : }
344 :
345 : int sysfs_file_change_owner(struct kobject *kobj, const char *name, kuid_t kuid,
346 : kgid_t kgid);
347 : int sysfs_change_owner(struct kobject *kobj, kuid_t kuid, kgid_t kgid);
348 : int sysfs_link_change_owner(struct kobject *kobj, struct kobject *targ,
349 : const char *name, kuid_t kuid, kgid_t kgid);
350 : int sysfs_groups_change_owner(struct kobject *kobj,
351 : const struct attribute_group **groups,
352 : kuid_t kuid, kgid_t kgid);
353 : int sysfs_group_change_owner(struct kobject *kobj,
354 : const struct attribute_group *groups, kuid_t kuid,
355 : kgid_t kgid);
356 : __printf(2, 3)
357 : int sysfs_emit(char *buf, const char *fmt, ...);
358 : __printf(3, 4)
359 : int sysfs_emit_at(char *buf, int at, const char *fmt, ...);
360 :
361 : #else /* CONFIG_SYSFS */
362 :
363 : static inline int sysfs_create_dir_ns(struct kobject *kobj, const void *ns)
364 : {
365 : return 0;
366 : }
367 :
368 : static inline void sysfs_remove_dir(struct kobject *kobj)
369 : {
370 : }
371 :
372 : static inline int sysfs_rename_dir_ns(struct kobject *kobj,
373 : const char *new_name, const void *new_ns)
374 : {
375 : return 0;
376 : }
377 :
378 : static inline int sysfs_move_dir_ns(struct kobject *kobj,
379 : struct kobject *new_parent_kobj,
380 : const void *new_ns)
381 : {
382 : return 0;
383 : }
384 :
385 : static inline int sysfs_create_mount_point(struct kobject *parent_kobj,
386 : const char *name)
387 : {
388 : return 0;
389 : }
390 :
391 : static inline void sysfs_remove_mount_point(struct kobject *parent_kobj,
392 : const char *name)
393 : {
394 : }
395 :
396 : static inline int sysfs_create_file_ns(struct kobject *kobj,
397 : const struct attribute *attr,
398 : const void *ns)
399 : {
400 : return 0;
401 : }
402 :
403 : static inline int sysfs_create_files(struct kobject *kobj,
404 : const struct attribute * const *attr)
405 : {
406 : return 0;
407 : }
408 :
409 : static inline int sysfs_chmod_file(struct kobject *kobj,
410 : const struct attribute *attr, umode_t mode)
411 : {
412 : return 0;
413 : }
414 :
415 : static inline struct kernfs_node *
416 : sysfs_break_active_protection(struct kobject *kobj,
417 : const struct attribute *attr)
418 : {
419 : return NULL;
420 : }
421 :
422 : static inline void sysfs_unbreak_active_protection(struct kernfs_node *kn)
423 : {
424 : }
425 :
426 : static inline void sysfs_remove_file_ns(struct kobject *kobj,
427 : const struct attribute *attr,
428 : const void *ns)
429 : {
430 : }
431 :
432 : static inline bool sysfs_remove_file_self(struct kobject *kobj,
433 : const struct attribute *attr)
434 : {
435 : return false;
436 : }
437 :
438 : static inline void sysfs_remove_files(struct kobject *kobj,
439 : const struct attribute * const *attr)
440 : {
441 : }
442 :
443 : static inline int sysfs_create_bin_file(struct kobject *kobj,
444 : const struct bin_attribute *attr)
445 : {
446 : return 0;
447 : }
448 :
449 : static inline void sysfs_remove_bin_file(struct kobject *kobj,
450 : const struct bin_attribute *attr)
451 : {
452 : }
453 :
454 : static inline int sysfs_create_link(struct kobject *kobj,
455 : struct kobject *target, const char *name)
456 : {
457 : return 0;
458 : }
459 :
460 : static inline int sysfs_create_link_nowarn(struct kobject *kobj,
461 : struct kobject *target,
462 : const char *name)
463 : {
464 : return 0;
465 : }
466 :
467 : static inline void sysfs_remove_link(struct kobject *kobj, const char *name)
468 : {
469 : }
470 :
471 : static inline int sysfs_rename_link_ns(struct kobject *k, struct kobject *t,
472 : const char *old_name,
473 : const char *new_name, const void *ns)
474 : {
475 : return 0;
476 : }
477 :
478 : static inline void sysfs_delete_link(struct kobject *k, struct kobject *t,
479 : const char *name)
480 : {
481 : }
482 :
483 : static inline int sysfs_create_group(struct kobject *kobj,
484 : const struct attribute_group *grp)
485 : {
486 : return 0;
487 : }
488 :
489 : static inline int sysfs_create_groups(struct kobject *kobj,
490 : const struct attribute_group **groups)
491 : {
492 : return 0;
493 : }
494 :
495 : static inline int sysfs_update_groups(struct kobject *kobj,
496 : const struct attribute_group **groups)
497 : {
498 : return 0;
499 : }
500 :
501 : static inline int sysfs_update_group(struct kobject *kobj,
502 : const struct attribute_group *grp)
503 : {
504 : return 0;
505 : }
506 :
507 : static inline void sysfs_remove_group(struct kobject *kobj,
508 : const struct attribute_group *grp)
509 : {
510 : }
511 :
512 : static inline void sysfs_remove_groups(struct kobject *kobj,
513 : const struct attribute_group **groups)
514 : {
515 : }
516 :
517 : static inline int sysfs_add_file_to_group(struct kobject *kobj,
518 : const struct attribute *attr, const char *group)
519 : {
520 : return 0;
521 : }
522 :
523 : static inline void sysfs_remove_file_from_group(struct kobject *kobj,
524 : const struct attribute *attr, const char *group)
525 : {
526 : }
527 :
528 : static inline int sysfs_merge_group(struct kobject *kobj,
529 : const struct attribute_group *grp)
530 : {
531 : return 0;
532 : }
533 :
534 : static inline void sysfs_unmerge_group(struct kobject *kobj,
535 : const struct attribute_group *grp)
536 : {
537 : }
538 :
539 : static inline int sysfs_add_link_to_group(struct kobject *kobj,
540 : const char *group_name, struct kobject *target,
541 : const char *link_name)
542 : {
543 : return 0;
544 : }
545 :
546 : static inline void sysfs_remove_link_from_group(struct kobject *kobj,
547 : const char *group_name, const char *link_name)
548 : {
549 : }
550 :
551 : static inline int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
552 : struct kobject *target_kobj,
553 : const char *target_name,
554 : const char *symlink_name)
555 : {
556 : return 0;
557 : }
558 :
559 : static inline void sysfs_notify(struct kobject *kobj, const char *dir,
560 : const char *attr)
561 : {
562 : }
563 :
564 : static inline int __must_check sysfs_init(void)
565 : {
566 : return 0;
567 : }
568 :
569 : static inline void sysfs_enable_ns(struct kernfs_node *kn)
570 : {
571 : }
572 :
573 : static inline int sysfs_file_change_owner(struct kobject *kobj,
574 : const char *name, kuid_t kuid,
575 : kgid_t kgid)
576 : {
577 : return 0;
578 : }
579 :
580 : static inline int sysfs_link_change_owner(struct kobject *kobj,
581 : struct kobject *targ,
582 : const char *name, kuid_t kuid,
583 : kgid_t kgid)
584 : {
585 : return 0;
586 : }
587 :
588 : static inline int sysfs_change_owner(struct kobject *kobj, kuid_t kuid, kgid_t kgid)
589 : {
590 : return 0;
591 : }
592 :
593 : static inline int sysfs_groups_change_owner(struct kobject *kobj,
594 : const struct attribute_group **groups,
595 : kuid_t kuid, kgid_t kgid)
596 : {
597 : return 0;
598 : }
599 :
600 : static inline int sysfs_group_change_owner(struct kobject *kobj,
601 : const struct attribute_group *groups,
602 : kuid_t kuid, kgid_t kgid)
603 : {
604 : return 0;
605 : }
606 :
607 : __printf(2, 3)
608 : static inline int sysfs_emit(char *buf, const char *fmt, ...)
609 : {
610 : return 0;
611 : }
612 :
613 : __printf(3, 4)
614 : static inline int sysfs_emit_at(char *buf, int at, const char *fmt, ...)
615 : {
616 : return 0;
617 : }
618 : #endif /* CONFIG_SYSFS */
619 :
620 : static inline int __must_check sysfs_create_file(struct kobject *kobj,
621 : const struct attribute *attr)
622 : {
623 1241 : return sysfs_create_file_ns(kobj, attr, NULL);
624 : }
625 :
626 : static inline void sysfs_remove_file(struct kobject *kobj,
627 : const struct attribute *attr)
628 : {
629 206 : sysfs_remove_file_ns(kobj, attr, NULL);
630 : }
631 :
632 : static inline int sysfs_rename_link(struct kobject *kobj, struct kobject *target,
633 : const char *old_name, const char *new_name)
634 : {
635 : return sysfs_rename_link_ns(kobj, target, old_name, new_name, NULL);
636 : }
637 :
638 : static inline void sysfs_notify_dirent(struct kernfs_node *kn)
639 : {
640 : kernfs_notify(kn);
641 : }
642 :
643 : static inline struct kernfs_node *sysfs_get_dirent(struct kernfs_node *parent,
644 : const char *name)
645 : {
646 : return kernfs_find_and_get(parent, name);
647 : }
648 :
649 : static inline struct kernfs_node *sysfs_get(struct kernfs_node *kn)
650 : {
651 739 : kernfs_get(kn);
652 : return kn;
653 : }
654 :
655 : static inline void sysfs_put(struct kernfs_node *kn)
656 : {
657 47 : kernfs_put(kn);
658 : }
659 :
660 : #endif /* _SYSFS_H_ */
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