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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * fs/sysfs/file.c - sysfs regular (text) file implementation
4 *
5 * Copyright (c) 2001-3 Patrick Mochel
6 * Copyright (c) 2007 SUSE Linux Products GmbH
7 * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
8 *
9 * Please see Documentation/filesystems/sysfs.txt for more information.
10 */
11
12#include <linux/module.h>
13#include <linux/kobject.h>
14#include <linux/slab.h>
15#include <linux/list.h>
16#include <linux/mutex.h>
17#include <linux/seq_file.h>
18
19#include "sysfs.h"
20
21/*
22 * Determine ktype->sysfs_ops for the given kernfs_node. This function
23 * must be called while holding an active reference.
24 */
25static const struct sysfs_ops *sysfs_file_ops(struct kernfs_node *kn)
26{
27 struct kobject *kobj = kn->parent->priv;
28
29 if (kn->flags & KERNFS_LOCKDEP)
30 lockdep_assert_held(kn);
31 return kobj->ktype ? kobj->ktype->sysfs_ops : NULL;
32}
33
34/*
35 * Reads on sysfs are handled through seq_file, which takes care of hairy
36 * details like buffering and seeking. The following function pipes
37 * sysfs_ops->show() result through seq_file.
38 */
39static int sysfs_kf_seq_show(struct seq_file *sf, void *v)
40{
41 struct kernfs_open_file *of = sf->private;
42 struct kobject *kobj = of->kn->parent->priv;
43 const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
44 ssize_t count;
45 char *buf;
46
47 /* acquire buffer and ensure that it's >= PAGE_SIZE and clear */
48 count = seq_get_buf(sf, &buf);
49 if (count < PAGE_SIZE) {
50 seq_commit(sf, -1);
51 return 0;
52 }
53 memset(buf, 0, PAGE_SIZE);
54
55 /*
56 * Invoke show(). Control may reach here via seq file lseek even
57 * if @ops->show() isn't implemented.
58 */
59 if (ops->show) {
60 count = ops->show(kobj, of->kn->priv, buf);
61 if (count < 0)
62 return count;
63 }
64
65 /*
66 * The code works fine with PAGE_SIZE return but it's likely to
67 * indicate truncated result or overflow in normal use cases.
68 */
69 if (count >= (ssize_t)PAGE_SIZE) {
70 printk("fill_read_buffer: %pS returned bad count\n",
71 ops->show);
72 /* Try to struggle along */
73 count = PAGE_SIZE - 1;
74 }
75 seq_commit(sf, count);
76 return 0;
77}
78
79static ssize_t sysfs_kf_bin_read(struct kernfs_open_file *of, char *buf,
80 size_t count, loff_t pos)
81{
82 struct bin_attribute *battr = of->kn->priv;
83 struct kobject *kobj = of->kn->parent->priv;
84 loff_t size = file_inode(of->file)->i_size;
85
86 if (!count)
87 return 0;
88
89 if (size) {
90 if (pos >= size)
91 return 0;
92 if (pos + count > size)
93 count = size - pos;
94 }
95
96 if (!battr->read)
97 return -EIO;
98
99 return battr->read(of->file, kobj, battr, buf, pos, count);
100}
101
102/* kernfs read callback for regular sysfs files with pre-alloc */
103static ssize_t sysfs_kf_read(struct kernfs_open_file *of, char *buf,
104 size_t count, loff_t pos)
105{
106 const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
107 struct kobject *kobj = of->kn->parent->priv;
108 ssize_t len;
109
110 /*
111 * If buf != of->prealloc_buf, we don't know how
112 * large it is, so cannot safely pass it to ->show
113 */
114 if (WARN_ON_ONCE(buf != of->prealloc_buf))
115 return 0;
116 len = ops->show(kobj, of->kn->priv, buf);
117 if (len < 0)
118 return len;
119 if (pos) {
120 if (len <= pos)
121 return 0;
122 len -= pos;
123 memmove(buf, buf + pos, len);
124 }
125 return min_t(ssize_t, count, len);
126}
127
128/* kernfs write callback for regular sysfs files */
129static ssize_t sysfs_kf_write(struct kernfs_open_file *of, char *buf,
130 size_t count, loff_t pos)
131{
132 const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
133 struct kobject *kobj = of->kn->parent->priv;
134
135 if (!count)
136 return 0;
137
138 return ops->store(kobj, of->kn->priv, buf, count);
139}
140
141/* kernfs write callback for bin sysfs files */
142static ssize_t sysfs_kf_bin_write(struct kernfs_open_file *of, char *buf,
143 size_t count, loff_t pos)
144{
145 struct bin_attribute *battr = of->kn->priv;
146 struct kobject *kobj = of->kn->parent->priv;
147 loff_t size = file_inode(of->file)->i_size;
148
149 if (size) {
150 if (size <= pos)
151 return -EFBIG;
152 count = min_t(ssize_t, count, size - pos);
153 }
154 if (!count)
155 return 0;
156
157 if (!battr->write)
158 return -EIO;
159
160 return battr->write(of->file, kobj, battr, buf, pos, count);
161}
162
163static int sysfs_kf_bin_mmap(struct kernfs_open_file *of,
164 struct vm_area_struct *vma)
165{
166 struct bin_attribute *battr = of->kn->priv;
167 struct kobject *kobj = of->kn->parent->priv;
168
169 return battr->mmap(of->file, kobj, battr, vma);
170}
171
172void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr)
173{
174 struct kernfs_node *kn = kobj->sd, *tmp;
175
176 if (kn && dir)
177 kn = kernfs_find_and_get(kn, dir);
178 else
179 kernfs_get(kn);
180
181 if (kn && attr) {
182 tmp = kernfs_find_and_get(kn, attr);
183 kernfs_put(kn);
184 kn = tmp;
185 }
186
187 if (kn) {
188 kernfs_notify(kn);
189 kernfs_put(kn);
190 }
191}
192EXPORT_SYMBOL_GPL(sysfs_notify);
193
194static const struct kernfs_ops sysfs_file_kfops_empty = {
195};
196
197static const struct kernfs_ops sysfs_file_kfops_ro = {
198 .seq_show = sysfs_kf_seq_show,
199};
200
201static const struct kernfs_ops sysfs_file_kfops_wo = {
202 .write = sysfs_kf_write,
203};
204
205static const struct kernfs_ops sysfs_file_kfops_rw = {
206 .seq_show = sysfs_kf_seq_show,
207 .write = sysfs_kf_write,
208};
209
210static const struct kernfs_ops sysfs_prealloc_kfops_ro = {
211 .read = sysfs_kf_read,
212 .prealloc = true,
213};
214
215static const struct kernfs_ops sysfs_prealloc_kfops_wo = {
216 .write = sysfs_kf_write,
217 .prealloc = true,
218};
219
220static const struct kernfs_ops sysfs_prealloc_kfops_rw = {
221 .read = sysfs_kf_read,
222 .write = sysfs_kf_write,
223 .prealloc = true,
224};
225
226static const struct kernfs_ops sysfs_bin_kfops_ro = {
227 .read = sysfs_kf_bin_read,
228};
229
230static const struct kernfs_ops sysfs_bin_kfops_wo = {
231 .write = sysfs_kf_bin_write,
232};
233
234static const struct kernfs_ops sysfs_bin_kfops_rw = {
235 .read = sysfs_kf_bin_read,
236 .write = sysfs_kf_bin_write,
237};
238
239static const struct kernfs_ops sysfs_bin_kfops_mmap = {
240 .read = sysfs_kf_bin_read,
241 .write = sysfs_kf_bin_write,
242 .mmap = sysfs_kf_bin_mmap,
243};
244
245int sysfs_add_file_mode_ns(struct kernfs_node *parent,
246 const struct attribute *attr, bool is_bin,
247 umode_t mode, kuid_t uid, kgid_t gid, const void *ns)
248{
249 struct lock_class_key *key = NULL;
250 const struct kernfs_ops *ops;
251 struct kernfs_node *kn;
252 loff_t size;
253
254 if (!is_bin) {
255 struct kobject *kobj = parent->priv;
256 const struct sysfs_ops *sysfs_ops = kobj->ktype->sysfs_ops;
257
258 /* every kobject with an attribute needs a ktype assigned */
259 if (WARN(!sysfs_ops, KERN_ERR
260 "missing sysfs attribute operations for kobject: %s\n",
261 kobject_name(kobj)))
262 return -EINVAL;
263
264 if (sysfs_ops->show && sysfs_ops->store) {
265 if (mode & SYSFS_PREALLOC)
266 ops = &sysfs_prealloc_kfops_rw;
267 else
268 ops = &sysfs_file_kfops_rw;
269 } else if (sysfs_ops->show) {
270 if (mode & SYSFS_PREALLOC)
271 ops = &sysfs_prealloc_kfops_ro;
272 else
273 ops = &sysfs_file_kfops_ro;
274 } else if (sysfs_ops->store) {
275 if (mode & SYSFS_PREALLOC)
276 ops = &sysfs_prealloc_kfops_wo;
277 else
278 ops = &sysfs_file_kfops_wo;
279 } else
280 ops = &sysfs_file_kfops_empty;
281
282 size = PAGE_SIZE;
283 } else {
284 struct bin_attribute *battr = (void *)attr;
285
286 if (battr->mmap)
287 ops = &sysfs_bin_kfops_mmap;
288 else if (battr->read && battr->write)
289 ops = &sysfs_bin_kfops_rw;
290 else if (battr->read)
291 ops = &sysfs_bin_kfops_ro;
292 else if (battr->write)
293 ops = &sysfs_bin_kfops_wo;
294 else
295 ops = &sysfs_file_kfops_empty;
296
297 size = battr->size;
298 }
299
300#ifdef CONFIG_DEBUG_LOCK_ALLOC
301 if (!attr->ignore_lockdep)
302 key = attr->key ?: (struct lock_class_key *)&attr->skey;
303#endif
304
305 kn = __kernfs_create_file(parent, attr->name, mode & 0777, uid, gid,
306 size, ops, (void *)attr, ns, key);
307 if (IS_ERR(kn)) {
308 if (PTR_ERR(kn) == -EEXIST)
309 sysfs_warn_dup(parent, attr->name);
310 return PTR_ERR(kn);
311 }
312 return 0;
313}
314
315/**
316 * sysfs_create_file_ns - create an attribute file for an object with custom ns
317 * @kobj: object we're creating for
318 * @attr: attribute descriptor
319 * @ns: namespace the new file should belong to
320 */
321int sysfs_create_file_ns(struct kobject *kobj, const struct attribute *attr,
322 const void *ns)
323{
324 kuid_t uid;
325 kgid_t gid;
326
327 if (WARN_ON(!kobj || !kobj->sd || !attr))
328 return -EINVAL;
329
330 kobject_get_ownership(kobj, &uid, &gid);
331 return sysfs_add_file_mode_ns(kobj->sd, attr, false, attr->mode,
332 uid, gid, ns);
333
334}
335EXPORT_SYMBOL_GPL(sysfs_create_file_ns);
336
337int sysfs_create_files(struct kobject *kobj, const struct attribute * const *ptr)
338{
339 int err = 0;
340 int i;
341
342 for (i = 0; ptr[i] && !err; i++)
343 err = sysfs_create_file(kobj, ptr[i]);
344 if (err)
345 while (--i >= 0)
346 sysfs_remove_file(kobj, ptr[i]);
347 return err;
348}
349EXPORT_SYMBOL_GPL(sysfs_create_files);
350
351/**
352 * sysfs_add_file_to_group - add an attribute file to a pre-existing group.
353 * @kobj: object we're acting for.
354 * @attr: attribute descriptor.
355 * @group: group name.
356 */
357int sysfs_add_file_to_group(struct kobject *kobj,
358 const struct attribute *attr, const char *group)
359{
360 struct kernfs_node *parent;
361 kuid_t uid;
362 kgid_t gid;
363 int error;
364
365 if (group) {
366 parent = kernfs_find_and_get(kobj->sd, group);
367 } else {
368 parent = kobj->sd;
369 kernfs_get(parent);
370 }
371
372 if (!parent)
373 return -ENOENT;
374
375 kobject_get_ownership(kobj, &uid, &gid);
376 error = sysfs_add_file_mode_ns(parent, attr, false,
377 attr->mode, uid, gid, NULL);
378 kernfs_put(parent);
379
380 return error;
381}
382EXPORT_SYMBOL_GPL(sysfs_add_file_to_group);
383
384/**
385 * sysfs_chmod_file - update the modified mode value on an object attribute.
386 * @kobj: object we're acting for.
387 * @attr: attribute descriptor.
388 * @mode: file permissions.
389 *
390 */
391int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr,
392 umode_t mode)
393{
394 struct kernfs_node *kn;
395 struct iattr newattrs;
396 int rc;
397
398 kn = kernfs_find_and_get(kobj->sd, attr->name);
399 if (!kn)
400 return -ENOENT;
401
402 newattrs.ia_mode = (mode & S_IALLUGO) | (kn->mode & ~S_IALLUGO);
403 newattrs.ia_valid = ATTR_MODE;
404
405 rc = kernfs_setattr(kn, &newattrs);
406
407 kernfs_put(kn);
408 return rc;
409}
410EXPORT_SYMBOL_GPL(sysfs_chmod_file);
411
412/**
413 * sysfs_break_active_protection - break "active" protection
414 * @kobj: The kernel object @attr is associated with.
415 * @attr: The attribute to break the "active" protection for.
416 *
417 * With sysfs, just like kernfs, deletion of an attribute is postponed until
418 * all active .show() and .store() callbacks have finished unless this function
419 * is called. Hence this function is useful in methods that implement self
420 * deletion.
421 */
422struct kernfs_node *sysfs_break_active_protection(struct kobject *kobj,
423 const struct attribute *attr)
424{
425 struct kernfs_node *kn;
426
427 kobject_get(kobj);
428 kn = kernfs_find_and_get(kobj->sd, attr->name);
429 if (kn)
430 kernfs_break_active_protection(kn);
431 return kn;
432}
433EXPORT_SYMBOL_GPL(sysfs_break_active_protection);
434
435/**
436 * sysfs_unbreak_active_protection - restore "active" protection
437 * @kn: Pointer returned by sysfs_break_active_protection().
438 *
439 * Undo the effects of sysfs_break_active_protection(). Since this function
440 * calls kernfs_put() on the kernfs node that corresponds to the 'attr'
441 * argument passed to sysfs_break_active_protection() that attribute may have
442 * been removed between the sysfs_break_active_protection() and
443 * sysfs_unbreak_active_protection() calls, it is not safe to access @kn after
444 * this function has returned.
445 */
446void sysfs_unbreak_active_protection(struct kernfs_node *kn)
447{
448 struct kobject *kobj = kn->parent->priv;
449
450 kernfs_unbreak_active_protection(kn);
451 kernfs_put(kn);
452 kobject_put(kobj);
453}
454EXPORT_SYMBOL_GPL(sysfs_unbreak_active_protection);
455
456/**
457 * sysfs_remove_file_ns - remove an object attribute with a custom ns tag
458 * @kobj: object we're acting for
459 * @attr: attribute descriptor
460 * @ns: namespace tag of the file to remove
461 *
462 * Hash the attribute name and namespace tag and kill the victim.
463 */
464void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr,
465 const void *ns)
466{
467 struct kernfs_node *parent = kobj->sd;
468
469 kernfs_remove_by_name_ns(parent, attr->name, ns);
470}
471EXPORT_SYMBOL_GPL(sysfs_remove_file_ns);
472
473/**
474 * sysfs_remove_file_self - remove an object attribute from its own method
475 * @kobj: object we're acting for
476 * @attr: attribute descriptor
477 *
478 * See kernfs_remove_self() for details.
479 */
480bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr)
481{
482 struct kernfs_node *parent = kobj->sd;
483 struct kernfs_node *kn;
484 bool ret;
485
486 kn = kernfs_find_and_get(parent, attr->name);
487 if (WARN_ON_ONCE(!kn))
488 return false;
489
490 ret = kernfs_remove_self(kn);
491
492 kernfs_put(kn);
493 return ret;
494}
495
496void sysfs_remove_files(struct kobject *kobj, const struct attribute * const *ptr)
497{
498 int i;
499
500 for (i = 0; ptr[i]; i++)
501 sysfs_remove_file(kobj, ptr[i]);
502}
503EXPORT_SYMBOL_GPL(sysfs_remove_files);
504
505/**
506 * sysfs_remove_file_from_group - remove an attribute file from a group.
507 * @kobj: object we're acting for.
508 * @attr: attribute descriptor.
509 * @group: group name.
510 */
511void sysfs_remove_file_from_group(struct kobject *kobj,
512 const struct attribute *attr, const char *group)
513{
514 struct kernfs_node *parent;
515
516 if (group) {
517 parent = kernfs_find_and_get(kobj->sd, group);
518 } else {
519 parent = kobj->sd;
520 kernfs_get(parent);
521 }
522
523 if (parent) {
524 kernfs_remove_by_name(parent, attr->name);
525 kernfs_put(parent);
526 }
527}
528EXPORT_SYMBOL_GPL(sysfs_remove_file_from_group);
529
530/**
531 * sysfs_create_bin_file - create binary file for object.
532 * @kobj: object.
533 * @attr: attribute descriptor.
534 */
535int sysfs_create_bin_file(struct kobject *kobj,
536 const struct bin_attribute *attr)
537{
538 kuid_t uid;
539 kgid_t gid;
540
541 if (WARN_ON(!kobj || !kobj->sd || !attr))
542 return -EINVAL;
543
544 kobject_get_ownership(kobj, &uid, &gid);
545 return sysfs_add_file_mode_ns(kobj->sd, &attr->attr, true,
546 attr->attr.mode, uid, gid, NULL);
547}
548EXPORT_SYMBOL_GPL(sysfs_create_bin_file);
549
550/**
551 * sysfs_remove_bin_file - remove binary file for object.
552 * @kobj: object.
553 * @attr: attribute descriptor.
554 */
555void sysfs_remove_bin_file(struct kobject *kobj,
556 const struct bin_attribute *attr)
557{
558 kernfs_remove_by_name(kobj->sd, attr->attr.name);
559}
560EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * fs/sysfs/file.c - sysfs regular (text) file implementation
4 *
5 * Copyright (c) 2001-3 Patrick Mochel
6 * Copyright (c) 2007 SUSE Linux Products GmbH
7 * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
8 *
9 * Please see Documentation/filesystems/sysfs.txt for more information.
10 */
11
12#include <linux/module.h>
13#include <linux/kobject.h>
14#include <linux/slab.h>
15#include <linux/list.h>
16#include <linux/mutex.h>
17#include <linux/seq_file.h>
18
19#include "sysfs.h"
20#include "../kernfs/kernfs-internal.h"
21
22/*
23 * Determine ktype->sysfs_ops for the given kernfs_node. This function
24 * must be called while holding an active reference.
25 */
26static const struct sysfs_ops *sysfs_file_ops(struct kernfs_node *kn)
27{
28 struct kobject *kobj = kn->parent->priv;
29
30 if (kn->flags & KERNFS_LOCKDEP)
31 lockdep_assert_held(kn);
32 return kobj->ktype ? kobj->ktype->sysfs_ops : NULL;
33}
34
35/*
36 * Reads on sysfs are handled through seq_file, which takes care of hairy
37 * details like buffering and seeking. The following function pipes
38 * sysfs_ops->show() result through seq_file.
39 */
40static int sysfs_kf_seq_show(struct seq_file *sf, void *v)
41{
42 struct kernfs_open_file *of = sf->private;
43 struct kobject *kobj = of->kn->parent->priv;
44 const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
45 ssize_t count;
46 char *buf;
47
48 /* acquire buffer and ensure that it's >= PAGE_SIZE and clear */
49 count = seq_get_buf(sf, &buf);
50 if (count < PAGE_SIZE) {
51 seq_commit(sf, -1);
52 return 0;
53 }
54 memset(buf, 0, PAGE_SIZE);
55
56 /*
57 * Invoke show(). Control may reach here via seq file lseek even
58 * if @ops->show() isn't implemented.
59 */
60 if (ops->show) {
61 count = ops->show(kobj, of->kn->priv, buf);
62 if (count < 0)
63 return count;
64 }
65
66 /*
67 * The code works fine with PAGE_SIZE return but it's likely to
68 * indicate truncated result or overflow in normal use cases.
69 */
70 if (count >= (ssize_t)PAGE_SIZE) {
71 printk("fill_read_buffer: %pS returned bad count\n",
72 ops->show);
73 /* Try to struggle along */
74 count = PAGE_SIZE - 1;
75 }
76 seq_commit(sf, count);
77 return 0;
78}
79
80static ssize_t sysfs_kf_bin_read(struct kernfs_open_file *of, char *buf,
81 size_t count, loff_t pos)
82{
83 struct bin_attribute *battr = of->kn->priv;
84 struct kobject *kobj = of->kn->parent->priv;
85 loff_t size = file_inode(of->file)->i_size;
86
87 if (!count)
88 return 0;
89
90 if (size) {
91 if (pos >= size)
92 return 0;
93 if (pos + count > size)
94 count = size - pos;
95 }
96
97 if (!battr->read)
98 return -EIO;
99
100 return battr->read(of->file, kobj, battr, buf, pos, count);
101}
102
103/* kernfs read callback for regular sysfs files with pre-alloc */
104static ssize_t sysfs_kf_read(struct kernfs_open_file *of, char *buf,
105 size_t count, loff_t pos)
106{
107 const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
108 struct kobject *kobj = of->kn->parent->priv;
109 ssize_t len;
110
111 /*
112 * If buf != of->prealloc_buf, we don't know how
113 * large it is, so cannot safely pass it to ->show
114 */
115 if (WARN_ON_ONCE(buf != of->prealloc_buf))
116 return 0;
117 len = ops->show(kobj, of->kn->priv, buf);
118 if (len < 0)
119 return len;
120 if (pos) {
121 if (len <= pos)
122 return 0;
123 len -= pos;
124 memmove(buf, buf + pos, len);
125 }
126 return min_t(ssize_t, count, len);
127}
128
129/* kernfs write callback for regular sysfs files */
130static ssize_t sysfs_kf_write(struct kernfs_open_file *of, char *buf,
131 size_t count, loff_t pos)
132{
133 const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
134 struct kobject *kobj = of->kn->parent->priv;
135
136 if (!count)
137 return 0;
138
139 return ops->store(kobj, of->kn->priv, buf, count);
140}
141
142/* kernfs write callback for bin sysfs files */
143static ssize_t sysfs_kf_bin_write(struct kernfs_open_file *of, char *buf,
144 size_t count, loff_t pos)
145{
146 struct bin_attribute *battr = of->kn->priv;
147 struct kobject *kobj = of->kn->parent->priv;
148 loff_t size = file_inode(of->file)->i_size;
149
150 if (size) {
151 if (size <= pos)
152 return -EFBIG;
153 count = min_t(ssize_t, count, size - pos);
154 }
155 if (!count)
156 return 0;
157
158 if (!battr->write)
159 return -EIO;
160
161 return battr->write(of->file, kobj, battr, buf, pos, count);
162}
163
164static int sysfs_kf_bin_mmap(struct kernfs_open_file *of,
165 struct vm_area_struct *vma)
166{
167 struct bin_attribute *battr = of->kn->priv;
168 struct kobject *kobj = of->kn->parent->priv;
169
170 return battr->mmap(of->file, kobj, battr, vma);
171}
172
173void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr)
174{
175 struct kernfs_node *kn = kobj->sd, *tmp;
176
177 if (kn && dir)
178 kn = kernfs_find_and_get(kn, dir);
179 else
180 kernfs_get(kn);
181
182 if (kn && attr) {
183 tmp = kernfs_find_and_get(kn, attr);
184 kernfs_put(kn);
185 kn = tmp;
186 }
187
188 if (kn) {
189 kernfs_notify(kn);
190 kernfs_put(kn);
191 }
192}
193EXPORT_SYMBOL_GPL(sysfs_notify);
194
195static const struct kernfs_ops sysfs_file_kfops_empty = {
196};
197
198static const struct kernfs_ops sysfs_file_kfops_ro = {
199 .seq_show = sysfs_kf_seq_show,
200};
201
202static const struct kernfs_ops sysfs_file_kfops_wo = {
203 .write = sysfs_kf_write,
204};
205
206static const struct kernfs_ops sysfs_file_kfops_rw = {
207 .seq_show = sysfs_kf_seq_show,
208 .write = sysfs_kf_write,
209};
210
211static const struct kernfs_ops sysfs_prealloc_kfops_ro = {
212 .read = sysfs_kf_read,
213 .prealloc = true,
214};
215
216static const struct kernfs_ops sysfs_prealloc_kfops_wo = {
217 .write = sysfs_kf_write,
218 .prealloc = true,
219};
220
221static const struct kernfs_ops sysfs_prealloc_kfops_rw = {
222 .read = sysfs_kf_read,
223 .write = sysfs_kf_write,
224 .prealloc = true,
225};
226
227static const struct kernfs_ops sysfs_bin_kfops_ro = {
228 .read = sysfs_kf_bin_read,
229};
230
231static const struct kernfs_ops sysfs_bin_kfops_wo = {
232 .write = sysfs_kf_bin_write,
233};
234
235static const struct kernfs_ops sysfs_bin_kfops_rw = {
236 .read = sysfs_kf_bin_read,
237 .write = sysfs_kf_bin_write,
238};
239
240static const struct kernfs_ops sysfs_bin_kfops_mmap = {
241 .read = sysfs_kf_bin_read,
242 .write = sysfs_kf_bin_write,
243 .mmap = sysfs_kf_bin_mmap,
244};
245
246int sysfs_add_file_mode_ns(struct kernfs_node *parent,
247 const struct attribute *attr, bool is_bin,
248 umode_t mode, const void *ns)
249{
250 struct lock_class_key *key = NULL;
251 const struct kernfs_ops *ops;
252 struct kernfs_node *kn;
253 loff_t size;
254
255 if (!is_bin) {
256 struct kobject *kobj = parent->priv;
257 const struct sysfs_ops *sysfs_ops = kobj->ktype->sysfs_ops;
258
259 /* every kobject with an attribute needs a ktype assigned */
260 if (WARN(!sysfs_ops, KERN_ERR
261 "missing sysfs attribute operations for kobject: %s\n",
262 kobject_name(kobj)))
263 return -EINVAL;
264
265 if (sysfs_ops->show && sysfs_ops->store) {
266 if (mode & SYSFS_PREALLOC)
267 ops = &sysfs_prealloc_kfops_rw;
268 else
269 ops = &sysfs_file_kfops_rw;
270 } else if (sysfs_ops->show) {
271 if (mode & SYSFS_PREALLOC)
272 ops = &sysfs_prealloc_kfops_ro;
273 else
274 ops = &sysfs_file_kfops_ro;
275 } else if (sysfs_ops->store) {
276 if (mode & SYSFS_PREALLOC)
277 ops = &sysfs_prealloc_kfops_wo;
278 else
279 ops = &sysfs_file_kfops_wo;
280 } else
281 ops = &sysfs_file_kfops_empty;
282
283 size = PAGE_SIZE;
284 } else {
285 struct bin_attribute *battr = (void *)attr;
286
287 if (battr->mmap)
288 ops = &sysfs_bin_kfops_mmap;
289 else if (battr->read && battr->write)
290 ops = &sysfs_bin_kfops_rw;
291 else if (battr->read)
292 ops = &sysfs_bin_kfops_ro;
293 else if (battr->write)
294 ops = &sysfs_bin_kfops_wo;
295 else
296 ops = &sysfs_file_kfops_empty;
297
298 size = battr->size;
299 }
300
301#ifdef CONFIG_DEBUG_LOCK_ALLOC
302 if (!attr->ignore_lockdep)
303 key = attr->key ?: (struct lock_class_key *)&attr->skey;
304#endif
305 kn = __kernfs_create_file(parent, attr->name, mode & 0777, size, ops,
306 (void *)attr, ns, key);
307 if (IS_ERR(kn)) {
308 if (PTR_ERR(kn) == -EEXIST)
309 sysfs_warn_dup(parent, attr->name);
310 return PTR_ERR(kn);
311 }
312 return 0;
313}
314
315int sysfs_add_file(struct kernfs_node *parent, const struct attribute *attr,
316 bool is_bin)
317{
318 return sysfs_add_file_mode_ns(parent, attr, is_bin, attr->mode, NULL);
319}
320
321/**
322 * sysfs_create_file_ns - create an attribute file for an object with custom ns
323 * @kobj: object we're creating for
324 * @attr: attribute descriptor
325 * @ns: namespace the new file should belong to
326 */
327int sysfs_create_file_ns(struct kobject *kobj, const struct attribute *attr,
328 const void *ns)
329{
330 BUG_ON(!kobj || !kobj->sd || !attr);
331
332 return sysfs_add_file_mode_ns(kobj->sd, attr, false, attr->mode, ns);
333
334}
335EXPORT_SYMBOL_GPL(sysfs_create_file_ns);
336
337int sysfs_create_files(struct kobject *kobj, const struct attribute **ptr)
338{
339 int err = 0;
340 int i;
341
342 for (i = 0; ptr[i] && !err; i++)
343 err = sysfs_create_file(kobj, ptr[i]);
344 if (err)
345 while (--i >= 0)
346 sysfs_remove_file(kobj, ptr[i]);
347 return err;
348}
349EXPORT_SYMBOL_GPL(sysfs_create_files);
350
351/**
352 * sysfs_add_file_to_group - add an attribute file to a pre-existing group.
353 * @kobj: object we're acting for.
354 * @attr: attribute descriptor.
355 * @group: group name.
356 */
357int sysfs_add_file_to_group(struct kobject *kobj,
358 const struct attribute *attr, const char *group)
359{
360 struct kernfs_node *parent;
361 int error;
362
363 if (group) {
364 parent = kernfs_find_and_get(kobj->sd, group);
365 } else {
366 parent = kobj->sd;
367 kernfs_get(parent);
368 }
369
370 if (!parent)
371 return -ENOENT;
372
373 error = sysfs_add_file(parent, attr, false);
374 kernfs_put(parent);
375
376 return error;
377}
378EXPORT_SYMBOL_GPL(sysfs_add_file_to_group);
379
380/**
381 * sysfs_chmod_file - update the modified mode value on an object attribute.
382 * @kobj: object we're acting for.
383 * @attr: attribute descriptor.
384 * @mode: file permissions.
385 *
386 */
387int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr,
388 umode_t mode)
389{
390 struct kernfs_node *kn;
391 struct iattr newattrs;
392 int rc;
393
394 kn = kernfs_find_and_get(kobj->sd, attr->name);
395 if (!kn)
396 return -ENOENT;
397
398 newattrs.ia_mode = (mode & S_IALLUGO) | (kn->mode & ~S_IALLUGO);
399 newattrs.ia_valid = ATTR_MODE;
400
401 rc = kernfs_setattr(kn, &newattrs);
402
403 kernfs_put(kn);
404 return rc;
405}
406EXPORT_SYMBOL_GPL(sysfs_chmod_file);
407
408/**
409 * sysfs_remove_file_ns - remove an object attribute with a custom ns tag
410 * @kobj: object we're acting for
411 * @attr: attribute descriptor
412 * @ns: namespace tag of the file to remove
413 *
414 * Hash the attribute name and namespace tag and kill the victim.
415 */
416void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr,
417 const void *ns)
418{
419 struct kernfs_node *parent = kobj->sd;
420
421 kernfs_remove_by_name_ns(parent, attr->name, ns);
422}
423EXPORT_SYMBOL_GPL(sysfs_remove_file_ns);
424
425/**
426 * sysfs_remove_file_self - remove an object attribute from its own method
427 * @kobj: object we're acting for
428 * @attr: attribute descriptor
429 *
430 * See kernfs_remove_self() for details.
431 */
432bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr)
433{
434 struct kernfs_node *parent = kobj->sd;
435 struct kernfs_node *kn;
436 bool ret;
437
438 kn = kernfs_find_and_get(parent, attr->name);
439 if (WARN_ON_ONCE(!kn))
440 return false;
441
442 ret = kernfs_remove_self(kn);
443
444 kernfs_put(kn);
445 return ret;
446}
447
448void sysfs_remove_files(struct kobject *kobj, const struct attribute **ptr)
449{
450 int i;
451 for (i = 0; ptr[i]; i++)
452 sysfs_remove_file(kobj, ptr[i]);
453}
454EXPORT_SYMBOL_GPL(sysfs_remove_files);
455
456/**
457 * sysfs_remove_file_from_group - remove an attribute file from a group.
458 * @kobj: object we're acting for.
459 * @attr: attribute descriptor.
460 * @group: group name.
461 */
462void sysfs_remove_file_from_group(struct kobject *kobj,
463 const struct attribute *attr, const char *group)
464{
465 struct kernfs_node *parent;
466
467 if (group) {
468 parent = kernfs_find_and_get(kobj->sd, group);
469 } else {
470 parent = kobj->sd;
471 kernfs_get(parent);
472 }
473
474 if (parent) {
475 kernfs_remove_by_name(parent, attr->name);
476 kernfs_put(parent);
477 }
478}
479EXPORT_SYMBOL_GPL(sysfs_remove_file_from_group);
480
481/**
482 * sysfs_create_bin_file - create binary file for object.
483 * @kobj: object.
484 * @attr: attribute descriptor.
485 */
486int sysfs_create_bin_file(struct kobject *kobj,
487 const struct bin_attribute *attr)
488{
489 BUG_ON(!kobj || !kobj->sd || !attr);
490
491 return sysfs_add_file(kobj->sd, &attr->attr, true);
492}
493EXPORT_SYMBOL_GPL(sysfs_create_bin_file);
494
495/**
496 * sysfs_remove_bin_file - remove binary file for object.
497 * @kobj: object.
498 * @attr: attribute descriptor.
499 */
500void sysfs_remove_bin_file(struct kobject *kobj,
501 const struct bin_attribute *attr)
502{
503 kernfs_remove_by_name(kobj->sd, attr->attr.name);
504}
505EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);