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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Information interface for ALSA driver
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 */
6
7#include <linux/init.h>
8#include <linux/time.h>
9#include <linux/mm.h>
10#include <linux/slab.h>
11#include <linux/string.h>
12#include <linux/module.h>
13#include <sound/core.h>
14#include <sound/minors.h>
15#include <sound/info.h>
16#include <linux/utsname.h>
17#include <linux/proc_fs.h>
18#include <linux/mutex.h>
19#include <stdarg.h>
20
21int snd_info_check_reserved_words(const char *str)
22{
23 static char *reserved[] =
24 {
25 "version",
26 "meminfo",
27 "memdebug",
28 "detect",
29 "devices",
30 "oss",
31 "cards",
32 "timers",
33 "synth",
34 "pcm",
35 "seq",
36 NULL
37 };
38 char **xstr = reserved;
39
40 while (*xstr) {
41 if (!strcmp(*xstr, str))
42 return 0;
43 xstr++;
44 }
45 if (!strncmp(str, "card", 4))
46 return 0;
47 return 1;
48}
49
50static DEFINE_MUTEX(info_mutex);
51
52struct snd_info_private_data {
53 struct snd_info_buffer *rbuffer;
54 struct snd_info_buffer *wbuffer;
55 struct snd_info_entry *entry;
56 void *file_private_data;
57};
58
59static int snd_info_version_init(void);
60static void snd_info_disconnect(struct snd_info_entry *entry);
61
62/*
63
64 */
65
66static struct snd_info_entry *snd_proc_root;
67struct snd_info_entry *snd_seq_root;
68EXPORT_SYMBOL(snd_seq_root);
69
70#ifdef CONFIG_SND_OSSEMUL
71struct snd_info_entry *snd_oss_root;
72#endif
73
74static int alloc_info_private(struct snd_info_entry *entry,
75 struct snd_info_private_data **ret)
76{
77 struct snd_info_private_data *data;
78
79 if (!entry || !entry->p)
80 return -ENODEV;
81 if (!try_module_get(entry->module))
82 return -EFAULT;
83 data = kzalloc(sizeof(*data), GFP_KERNEL);
84 if (!data) {
85 module_put(entry->module);
86 return -ENOMEM;
87 }
88 data->entry = entry;
89 *ret = data;
90 return 0;
91}
92
93static bool valid_pos(loff_t pos, size_t count)
94{
95 if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
96 return false;
97 if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
98 return false;
99 return true;
100}
101
102/*
103 * file ops for binary proc files
104 */
105static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
106{
107 struct snd_info_private_data *data;
108 struct snd_info_entry *entry;
109 loff_t ret = -EINVAL, size;
110
111 data = file->private_data;
112 entry = data->entry;
113 mutex_lock(&entry->access);
114 if (entry->c.ops->llseek) {
115 offset = entry->c.ops->llseek(entry,
116 data->file_private_data,
117 file, offset, orig);
118 goto out;
119 }
120
121 size = entry->size;
122 switch (orig) {
123 case SEEK_SET:
124 break;
125 case SEEK_CUR:
126 offset += file->f_pos;
127 break;
128 case SEEK_END:
129 if (!size)
130 goto out;
131 offset += size;
132 break;
133 default:
134 goto out;
135 }
136 if (offset < 0)
137 goto out;
138 if (size && offset > size)
139 offset = size;
140 file->f_pos = offset;
141 ret = offset;
142 out:
143 mutex_unlock(&entry->access);
144 return ret;
145}
146
147static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
148 size_t count, loff_t * offset)
149{
150 struct snd_info_private_data *data = file->private_data;
151 struct snd_info_entry *entry = data->entry;
152 size_t size;
153 loff_t pos;
154
155 pos = *offset;
156 if (!valid_pos(pos, count))
157 return -EIO;
158 if (pos >= entry->size)
159 return 0;
160 size = entry->size - pos;
161 size = min(count, size);
162 size = entry->c.ops->read(entry, data->file_private_data,
163 file, buffer, size, pos);
164 if ((ssize_t) size > 0)
165 *offset = pos + size;
166 return size;
167}
168
169static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
170 size_t count, loff_t * offset)
171{
172 struct snd_info_private_data *data = file->private_data;
173 struct snd_info_entry *entry = data->entry;
174 ssize_t size = 0;
175 loff_t pos;
176
177 pos = *offset;
178 if (!valid_pos(pos, count))
179 return -EIO;
180 if (count > 0) {
181 size_t maxsize = entry->size - pos;
182 count = min(count, maxsize);
183 size = entry->c.ops->write(entry, data->file_private_data,
184 file, buffer, count, pos);
185 }
186 if (size > 0)
187 *offset = pos + size;
188 return size;
189}
190
191static __poll_t snd_info_entry_poll(struct file *file, poll_table *wait)
192{
193 struct snd_info_private_data *data = file->private_data;
194 struct snd_info_entry *entry = data->entry;
195 __poll_t mask = 0;
196
197 if (entry->c.ops->poll)
198 return entry->c.ops->poll(entry,
199 data->file_private_data,
200 file, wait);
201 if (entry->c.ops->read)
202 mask |= EPOLLIN | EPOLLRDNORM;
203 if (entry->c.ops->write)
204 mask |= EPOLLOUT | EPOLLWRNORM;
205 return mask;
206}
207
208static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
209 unsigned long arg)
210{
211 struct snd_info_private_data *data = file->private_data;
212 struct snd_info_entry *entry = data->entry;
213
214 if (!entry->c.ops->ioctl)
215 return -ENOTTY;
216 return entry->c.ops->ioctl(entry, data->file_private_data,
217 file, cmd, arg);
218}
219
220static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
221{
222 struct inode *inode = file_inode(file);
223 struct snd_info_private_data *data;
224 struct snd_info_entry *entry;
225
226 data = file->private_data;
227 if (data == NULL)
228 return 0;
229 entry = data->entry;
230 if (!entry->c.ops->mmap)
231 return -ENXIO;
232 return entry->c.ops->mmap(entry, data->file_private_data,
233 inode, file, vma);
234}
235
236static int snd_info_entry_open(struct inode *inode, struct file *file)
237{
238 struct snd_info_entry *entry = PDE_DATA(inode);
239 struct snd_info_private_data *data;
240 int mode, err;
241
242 mutex_lock(&info_mutex);
243 err = alloc_info_private(entry, &data);
244 if (err < 0)
245 goto unlock;
246
247 mode = file->f_flags & O_ACCMODE;
248 if (((mode == O_RDONLY || mode == O_RDWR) && !entry->c.ops->read) ||
249 ((mode == O_WRONLY || mode == O_RDWR) && !entry->c.ops->write)) {
250 err = -ENODEV;
251 goto error;
252 }
253
254 if (entry->c.ops->open) {
255 err = entry->c.ops->open(entry, mode, &data->file_private_data);
256 if (err < 0)
257 goto error;
258 }
259
260 file->private_data = data;
261 mutex_unlock(&info_mutex);
262 return 0;
263
264 error:
265 kfree(data);
266 module_put(entry->module);
267 unlock:
268 mutex_unlock(&info_mutex);
269 return err;
270}
271
272static int snd_info_entry_release(struct inode *inode, struct file *file)
273{
274 struct snd_info_private_data *data = file->private_data;
275 struct snd_info_entry *entry = data->entry;
276
277 if (entry->c.ops->release)
278 entry->c.ops->release(entry, file->f_flags & O_ACCMODE,
279 data->file_private_data);
280 module_put(entry->module);
281 kfree(data);
282 return 0;
283}
284
285static const struct file_operations snd_info_entry_operations =
286{
287 .owner = THIS_MODULE,
288 .llseek = snd_info_entry_llseek,
289 .read = snd_info_entry_read,
290 .write = snd_info_entry_write,
291 .poll = snd_info_entry_poll,
292 .unlocked_ioctl = snd_info_entry_ioctl,
293 .mmap = snd_info_entry_mmap,
294 .open = snd_info_entry_open,
295 .release = snd_info_entry_release,
296};
297
298/*
299 * file ops for text proc files
300 */
301static ssize_t snd_info_text_entry_write(struct file *file,
302 const char __user *buffer,
303 size_t count, loff_t *offset)
304{
305 struct seq_file *m = file->private_data;
306 struct snd_info_private_data *data = m->private;
307 struct snd_info_entry *entry = data->entry;
308 struct snd_info_buffer *buf;
309 loff_t pos;
310 size_t next;
311 int err = 0;
312
313 if (!entry->c.text.write)
314 return -EIO;
315 pos = *offset;
316 if (!valid_pos(pos, count))
317 return -EIO;
318 next = pos + count;
319 /* don't handle too large text inputs */
320 if (next > 16 * 1024)
321 return -EIO;
322 mutex_lock(&entry->access);
323 buf = data->wbuffer;
324 if (!buf) {
325 data->wbuffer = buf = kzalloc(sizeof(*buf), GFP_KERNEL);
326 if (!buf) {
327 err = -ENOMEM;
328 goto error;
329 }
330 }
331 if (next > buf->len) {
332 char *nbuf = kvzalloc(PAGE_ALIGN(next), GFP_KERNEL);
333 if (!nbuf) {
334 err = -ENOMEM;
335 goto error;
336 }
337 kvfree(buf->buffer);
338 buf->buffer = nbuf;
339 buf->len = PAGE_ALIGN(next);
340 }
341 if (copy_from_user(buf->buffer + pos, buffer, count)) {
342 err = -EFAULT;
343 goto error;
344 }
345 buf->size = next;
346 error:
347 mutex_unlock(&entry->access);
348 if (err < 0)
349 return err;
350 *offset = next;
351 return count;
352}
353
354static int snd_info_seq_show(struct seq_file *seq, void *p)
355{
356 struct snd_info_private_data *data = seq->private;
357 struct snd_info_entry *entry = data->entry;
358
359 if (!entry->c.text.read) {
360 return -EIO;
361 } else {
362 data->rbuffer->buffer = (char *)seq; /* XXX hack! */
363 entry->c.text.read(entry, data->rbuffer);
364 }
365 return 0;
366}
367
368static int snd_info_text_entry_open(struct inode *inode, struct file *file)
369{
370 struct snd_info_entry *entry = PDE_DATA(inode);
371 struct snd_info_private_data *data;
372 int err;
373
374 mutex_lock(&info_mutex);
375 err = alloc_info_private(entry, &data);
376 if (err < 0)
377 goto unlock;
378
379 data->rbuffer = kzalloc(sizeof(*data->rbuffer), GFP_KERNEL);
380 if (!data->rbuffer) {
381 err = -ENOMEM;
382 goto error;
383 }
384 if (entry->size)
385 err = single_open_size(file, snd_info_seq_show, data,
386 entry->size);
387 else
388 err = single_open(file, snd_info_seq_show, data);
389 if (err < 0)
390 goto error;
391 mutex_unlock(&info_mutex);
392 return 0;
393
394 error:
395 kfree(data->rbuffer);
396 kfree(data);
397 module_put(entry->module);
398 unlock:
399 mutex_unlock(&info_mutex);
400 return err;
401}
402
403static int snd_info_text_entry_release(struct inode *inode, struct file *file)
404{
405 struct seq_file *m = file->private_data;
406 struct snd_info_private_data *data = m->private;
407 struct snd_info_entry *entry = data->entry;
408
409 if (data->wbuffer && entry->c.text.write)
410 entry->c.text.write(entry, data->wbuffer);
411
412 single_release(inode, file);
413 kfree(data->rbuffer);
414 if (data->wbuffer) {
415 kvfree(data->wbuffer->buffer);
416 kfree(data->wbuffer);
417 }
418
419 module_put(entry->module);
420 kfree(data);
421 return 0;
422}
423
424static const struct file_operations snd_info_text_entry_ops =
425{
426 .owner = THIS_MODULE,
427 .open = snd_info_text_entry_open,
428 .release = snd_info_text_entry_release,
429 .write = snd_info_text_entry_write,
430 .llseek = seq_lseek,
431 .read = seq_read,
432};
433
434static struct snd_info_entry *create_subdir(struct module *mod,
435 const char *name)
436{
437 struct snd_info_entry *entry;
438
439 entry = snd_info_create_module_entry(mod, name, NULL);
440 if (!entry)
441 return NULL;
442 entry->mode = S_IFDIR | 0555;
443 if (snd_info_register(entry) < 0) {
444 snd_info_free_entry(entry);
445 return NULL;
446 }
447 return entry;
448}
449
450static struct snd_info_entry *
451snd_info_create_entry(const char *name, struct snd_info_entry *parent,
452 struct module *module);
453
454int __init snd_info_init(void)
455{
456 snd_proc_root = snd_info_create_entry("asound", NULL, THIS_MODULE);
457 if (!snd_proc_root)
458 return -ENOMEM;
459 snd_proc_root->mode = S_IFDIR | 0555;
460 snd_proc_root->p = proc_mkdir("asound", NULL);
461 if (!snd_proc_root->p)
462 goto error;
463#ifdef CONFIG_SND_OSSEMUL
464 snd_oss_root = create_subdir(THIS_MODULE, "oss");
465 if (!snd_oss_root)
466 goto error;
467#endif
468#if IS_ENABLED(CONFIG_SND_SEQUENCER)
469 snd_seq_root = create_subdir(THIS_MODULE, "seq");
470 if (!snd_seq_root)
471 goto error;
472#endif
473 if (snd_info_version_init() < 0 ||
474 snd_minor_info_init() < 0 ||
475 snd_minor_info_oss_init() < 0 ||
476 snd_card_info_init() < 0 ||
477 snd_info_minor_register() < 0)
478 goto error;
479 return 0;
480
481 error:
482 snd_info_free_entry(snd_proc_root);
483 return -ENOMEM;
484}
485
486int __exit snd_info_done(void)
487{
488 snd_info_free_entry(snd_proc_root);
489 return 0;
490}
491
492static void snd_card_id_read(struct snd_info_entry *entry,
493 struct snd_info_buffer *buffer)
494{
495 struct snd_card *card = entry->private_data;
496
497 snd_iprintf(buffer, "%s\n", card->id);
498}
499
500/*
501 * create a card proc file
502 * called from init.c
503 */
504int snd_info_card_create(struct snd_card *card)
505{
506 char str[8];
507 struct snd_info_entry *entry;
508
509 if (snd_BUG_ON(!card))
510 return -ENXIO;
511
512 sprintf(str, "card%i", card->number);
513 entry = create_subdir(card->module, str);
514 if (!entry)
515 return -ENOMEM;
516 card->proc_root = entry;
517
518 return snd_card_ro_proc_new(card, "id", card, snd_card_id_read);
519}
520
521/*
522 * register the card proc file
523 * called from init.c
524 * can be called multiple times for reinitialization
525 */
526int snd_info_card_register(struct snd_card *card)
527{
528 struct proc_dir_entry *p;
529 int err;
530
531 if (snd_BUG_ON(!card))
532 return -ENXIO;
533
534 err = snd_info_register(card->proc_root);
535 if (err < 0)
536 return err;
537
538 if (!strcmp(card->id, card->proc_root->name))
539 return 0;
540
541 if (card->proc_root_link)
542 return 0;
543 p = proc_symlink(card->id, snd_proc_root->p, card->proc_root->name);
544 if (!p)
545 return -ENOMEM;
546 card->proc_root_link = p;
547 return 0;
548}
549
550/*
551 * called on card->id change
552 */
553void snd_info_card_id_change(struct snd_card *card)
554{
555 mutex_lock(&info_mutex);
556 if (card->proc_root_link) {
557 proc_remove(card->proc_root_link);
558 card->proc_root_link = NULL;
559 }
560 if (strcmp(card->id, card->proc_root->name))
561 card->proc_root_link = proc_symlink(card->id,
562 snd_proc_root->p,
563 card->proc_root->name);
564 mutex_unlock(&info_mutex);
565}
566
567/*
568 * de-register the card proc file
569 * called from init.c
570 */
571void snd_info_card_disconnect(struct snd_card *card)
572{
573 if (!card)
574 return;
575 mutex_lock(&info_mutex);
576 proc_remove(card->proc_root_link);
577 card->proc_root_link = NULL;
578 if (card->proc_root)
579 snd_info_disconnect(card->proc_root);
580 mutex_unlock(&info_mutex);
581}
582
583/*
584 * release the card proc file resources
585 * called from init.c
586 */
587int snd_info_card_free(struct snd_card *card)
588{
589 if (!card)
590 return 0;
591 snd_info_free_entry(card->proc_root);
592 card->proc_root = NULL;
593 return 0;
594}
595
596
597/**
598 * snd_info_get_line - read one line from the procfs buffer
599 * @buffer: the procfs buffer
600 * @line: the buffer to store
601 * @len: the max. buffer size
602 *
603 * Reads one line from the buffer and stores the string.
604 *
605 * Return: Zero if successful, or 1 if error or EOF.
606 */
607int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
608{
609 int c = -1;
610
611 if (snd_BUG_ON(!buffer || !buffer->buffer))
612 return 1;
613 if (len <= 0 || buffer->stop || buffer->error)
614 return 1;
615 while (!buffer->stop) {
616 c = buffer->buffer[buffer->curr++];
617 if (buffer->curr >= buffer->size)
618 buffer->stop = 1;
619 if (c == '\n')
620 break;
621 if (len > 1) {
622 len--;
623 *line++ = c;
624 }
625 }
626 *line = '\0';
627 return 0;
628}
629EXPORT_SYMBOL(snd_info_get_line);
630
631/**
632 * snd_info_get_str - parse a string token
633 * @dest: the buffer to store the string token
634 * @src: the original string
635 * @len: the max. length of token - 1
636 *
637 * Parses the original string and copy a token to the given
638 * string buffer.
639 *
640 * Return: The updated pointer of the original string so that
641 * it can be used for the next call.
642 */
643const char *snd_info_get_str(char *dest, const char *src, int len)
644{
645 int c;
646
647 while (*src == ' ' || *src == '\t')
648 src++;
649 if (*src == '"' || *src == '\'') {
650 c = *src++;
651 while (--len > 0 && *src && *src != c) {
652 *dest++ = *src++;
653 }
654 if (*src == c)
655 src++;
656 } else {
657 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
658 *dest++ = *src++;
659 }
660 }
661 *dest = 0;
662 while (*src == ' ' || *src == '\t')
663 src++;
664 return src;
665}
666EXPORT_SYMBOL(snd_info_get_str);
667
668/*
669 * snd_info_create_entry - create an info entry
670 * @name: the proc file name
671 * @parent: the parent directory
672 *
673 * Creates an info entry with the given file name and initializes as
674 * the default state.
675 *
676 * Usually called from other functions such as
677 * snd_info_create_card_entry().
678 *
679 * Return: The pointer of the new instance, or %NULL on failure.
680 */
681static struct snd_info_entry *
682snd_info_create_entry(const char *name, struct snd_info_entry *parent,
683 struct module *module)
684{
685 struct snd_info_entry *entry;
686 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
687 if (entry == NULL)
688 return NULL;
689 entry->name = kstrdup(name, GFP_KERNEL);
690 if (entry->name == NULL) {
691 kfree(entry);
692 return NULL;
693 }
694 entry->mode = S_IFREG | 0444;
695 entry->content = SNDRV_INFO_CONTENT_TEXT;
696 mutex_init(&entry->access);
697 INIT_LIST_HEAD(&entry->children);
698 INIT_LIST_HEAD(&entry->list);
699 entry->parent = parent;
700 entry->module = module;
701 if (parent) {
702 mutex_lock(&parent->access);
703 list_add_tail(&entry->list, &parent->children);
704 mutex_unlock(&parent->access);
705 }
706 return entry;
707}
708
709/**
710 * snd_info_create_module_entry - create an info entry for the given module
711 * @module: the module pointer
712 * @name: the file name
713 * @parent: the parent directory
714 *
715 * Creates a new info entry and assigns it to the given module.
716 *
717 * Return: The pointer of the new instance, or %NULL on failure.
718 */
719struct snd_info_entry *snd_info_create_module_entry(struct module * module,
720 const char *name,
721 struct snd_info_entry *parent)
722{
723 if (!parent)
724 parent = snd_proc_root;
725 return snd_info_create_entry(name, parent, module);
726}
727EXPORT_SYMBOL(snd_info_create_module_entry);
728
729/**
730 * snd_info_create_card_entry - create an info entry for the given card
731 * @card: the card instance
732 * @name: the file name
733 * @parent: the parent directory
734 *
735 * Creates a new info entry and assigns it to the given card.
736 *
737 * Return: The pointer of the new instance, or %NULL on failure.
738 */
739struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
740 const char *name,
741 struct snd_info_entry * parent)
742{
743 if (!parent)
744 parent = card->proc_root;
745 return snd_info_create_entry(name, parent, card->module);
746}
747EXPORT_SYMBOL(snd_info_create_card_entry);
748
749static void snd_info_disconnect(struct snd_info_entry *entry)
750{
751 struct snd_info_entry *p;
752
753 if (!entry->p)
754 return;
755 list_for_each_entry(p, &entry->children, list)
756 snd_info_disconnect(p);
757 proc_remove(entry->p);
758 entry->p = NULL;
759}
760
761/**
762 * snd_info_free_entry - release the info entry
763 * @entry: the info entry
764 *
765 * Releases the info entry.
766 */
767void snd_info_free_entry(struct snd_info_entry * entry)
768{
769 struct snd_info_entry *p, *n;
770
771 if (!entry)
772 return;
773 if (entry->p) {
774 mutex_lock(&info_mutex);
775 snd_info_disconnect(entry);
776 mutex_unlock(&info_mutex);
777 }
778
779 /* free all children at first */
780 list_for_each_entry_safe(p, n, &entry->children, list)
781 snd_info_free_entry(p);
782
783 p = entry->parent;
784 if (p) {
785 mutex_lock(&p->access);
786 list_del(&entry->list);
787 mutex_unlock(&p->access);
788 }
789 kfree(entry->name);
790 if (entry->private_free)
791 entry->private_free(entry);
792 kfree(entry);
793}
794EXPORT_SYMBOL(snd_info_free_entry);
795
796static int __snd_info_register(struct snd_info_entry *entry)
797{
798 struct proc_dir_entry *root, *p = NULL;
799
800 if (snd_BUG_ON(!entry))
801 return -ENXIO;
802 root = entry->parent == NULL ? snd_proc_root->p : entry->parent->p;
803 mutex_lock(&info_mutex);
804 if (entry->p || !root)
805 goto unlock;
806 if (S_ISDIR(entry->mode)) {
807 p = proc_mkdir_mode(entry->name, entry->mode, root);
808 if (!p) {
809 mutex_unlock(&info_mutex);
810 return -ENOMEM;
811 }
812 } else {
813 const struct file_operations *ops;
814 if (entry->content == SNDRV_INFO_CONTENT_DATA)
815 ops = &snd_info_entry_operations;
816 else
817 ops = &snd_info_text_entry_ops;
818 p = proc_create_data(entry->name, entry->mode, root,
819 ops, entry);
820 if (!p) {
821 mutex_unlock(&info_mutex);
822 return -ENOMEM;
823 }
824 proc_set_size(p, entry->size);
825 }
826 entry->p = p;
827 unlock:
828 mutex_unlock(&info_mutex);
829 return 0;
830}
831
832/**
833 * snd_info_register - register the info entry
834 * @entry: the info entry
835 *
836 * Registers the proc info entry.
837 * The all children entries are registered recursively.
838 *
839 * Return: Zero if successful, or a negative error code on failure.
840 */
841int snd_info_register(struct snd_info_entry *entry)
842{
843 struct snd_info_entry *p;
844 int err;
845
846 if (!entry->p) {
847 err = __snd_info_register(entry);
848 if (err < 0)
849 return err;
850 }
851
852 list_for_each_entry(p, &entry->children, list) {
853 err = snd_info_register(p);
854 if (err < 0)
855 return err;
856 }
857
858 return 0;
859}
860EXPORT_SYMBOL(snd_info_register);
861
862/**
863 * snd_card_rw_proc_new - Create a read/write text proc file entry for the card
864 * @card: the card instance
865 * @name: the file name
866 * @private_data: the arbitrary private data
867 * @read: the read callback
868 * @write: the write callback, NULL for read-only
869 *
870 * This proc file entry will be registered via snd_card_register() call, and
871 * it will be removed automatically at the card removal, too.
872 */
873int snd_card_rw_proc_new(struct snd_card *card, const char *name,
874 void *private_data,
875 void (*read)(struct snd_info_entry *,
876 struct snd_info_buffer *),
877 void (*write)(struct snd_info_entry *entry,
878 struct snd_info_buffer *buffer))
879{
880 struct snd_info_entry *entry;
881
882 entry = snd_info_create_card_entry(card, name, card->proc_root);
883 if (!entry)
884 return -ENOMEM;
885 snd_info_set_text_ops(entry, private_data, read);
886 if (write) {
887 entry->mode |= 0200;
888 entry->c.text.write = write;
889 }
890 return 0;
891}
892EXPORT_SYMBOL_GPL(snd_card_rw_proc_new);
893
894/*
895
896 */
897
898static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
899{
900 snd_iprintf(buffer,
901 "Advanced Linux Sound Architecture Driver Version k%s.\n",
902 init_utsname()->release);
903}
904
905static int __init snd_info_version_init(void)
906{
907 struct snd_info_entry *entry;
908
909 entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
910 if (entry == NULL)
911 return -ENOMEM;
912 entry->c.text.read = snd_info_version_read;
913 return snd_info_register(entry); /* freed in error path */
914}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Information interface for ALSA driver
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 */
6
7#include <linux/init.h>
8#include <linux/time.h>
9#include <linux/mm.h>
10#include <linux/slab.h>
11#include <linux/string.h>
12#include <linux/module.h>
13#include <sound/core.h>
14#include <sound/minors.h>
15#include <sound/info.h>
16#include <linux/utsname.h>
17#include <linux/proc_fs.h>
18#include <linux/mutex.h>
19
20int snd_info_check_reserved_words(const char *str)
21{
22 static const char * const reserved[] =
23 {
24 "version",
25 "meminfo",
26 "memdebug",
27 "detect",
28 "devices",
29 "oss",
30 "cards",
31 "timers",
32 "synth",
33 "pcm",
34 "seq",
35 NULL
36 };
37 const char * const *xstr = reserved;
38
39 while (*xstr) {
40 if (!strcmp(*xstr, str))
41 return 0;
42 xstr++;
43 }
44 if (!strncmp(str, "card", 4))
45 return 0;
46 return 1;
47}
48
49static DEFINE_MUTEX(info_mutex);
50
51struct snd_info_private_data {
52 struct snd_info_buffer *rbuffer;
53 struct snd_info_buffer *wbuffer;
54 struct snd_info_entry *entry;
55 void *file_private_data;
56};
57
58static int snd_info_version_init(void);
59static void snd_info_clear_entries(struct snd_info_entry *entry);
60
61/*
62
63 */
64
65static struct snd_info_entry *snd_proc_root;
66struct snd_info_entry *snd_seq_root;
67EXPORT_SYMBOL(snd_seq_root);
68
69#ifdef CONFIG_SND_OSSEMUL
70struct snd_info_entry *snd_oss_root;
71#endif
72
73static int alloc_info_private(struct snd_info_entry *entry,
74 struct snd_info_private_data **ret)
75{
76 struct snd_info_private_data *data;
77
78 if (!entry || !entry->p)
79 return -ENODEV;
80 if (!try_module_get(entry->module))
81 return -EFAULT;
82 data = kzalloc(sizeof(*data), GFP_KERNEL);
83 if (!data) {
84 module_put(entry->module);
85 return -ENOMEM;
86 }
87 data->entry = entry;
88 *ret = data;
89 return 0;
90}
91
92static bool valid_pos(loff_t pos, size_t count)
93{
94 if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
95 return false;
96 if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
97 return false;
98 return true;
99}
100
101/*
102 * file ops for binary proc files
103 */
104static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
105{
106 struct snd_info_private_data *data;
107 struct snd_info_entry *entry;
108 loff_t ret = -EINVAL, size;
109
110 data = file->private_data;
111 entry = data->entry;
112 mutex_lock(&entry->access);
113 if (entry->c.ops->llseek) {
114 ret = entry->c.ops->llseek(entry,
115 data->file_private_data,
116 file, offset, orig);
117 goto out;
118 }
119
120 size = entry->size;
121 switch (orig) {
122 case SEEK_SET:
123 break;
124 case SEEK_CUR:
125 offset += file->f_pos;
126 break;
127 case SEEK_END:
128 if (!size)
129 goto out;
130 offset += size;
131 break;
132 default:
133 goto out;
134 }
135 if (offset < 0)
136 goto out;
137 if (size && offset > size)
138 offset = size;
139 file->f_pos = offset;
140 ret = offset;
141 out:
142 mutex_unlock(&entry->access);
143 return ret;
144}
145
146static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
147 size_t count, loff_t * offset)
148{
149 struct snd_info_private_data *data = file->private_data;
150 struct snd_info_entry *entry = data->entry;
151 size_t size;
152 loff_t pos;
153
154 pos = *offset;
155 if (!valid_pos(pos, count))
156 return -EIO;
157 if (pos >= entry->size)
158 return 0;
159 size = entry->size - pos;
160 size = min(count, size);
161 size = entry->c.ops->read(entry, data->file_private_data,
162 file, buffer, size, pos);
163 if ((ssize_t) size > 0)
164 *offset = pos + size;
165 return size;
166}
167
168static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
169 size_t count, loff_t * offset)
170{
171 struct snd_info_private_data *data = file->private_data;
172 struct snd_info_entry *entry = data->entry;
173 ssize_t size = 0;
174 loff_t pos;
175
176 pos = *offset;
177 if (!valid_pos(pos, count))
178 return -EIO;
179 if (count > 0) {
180 size_t maxsize = entry->size - pos;
181 count = min(count, maxsize);
182 size = entry->c.ops->write(entry, data->file_private_data,
183 file, buffer, count, pos);
184 }
185 if (size > 0)
186 *offset = pos + size;
187 return size;
188}
189
190static __poll_t snd_info_entry_poll(struct file *file, poll_table *wait)
191{
192 struct snd_info_private_data *data = file->private_data;
193 struct snd_info_entry *entry = data->entry;
194 __poll_t mask = 0;
195
196 if (entry->c.ops->poll)
197 return entry->c.ops->poll(entry,
198 data->file_private_data,
199 file, wait);
200 if (entry->c.ops->read)
201 mask |= EPOLLIN | EPOLLRDNORM;
202 if (entry->c.ops->write)
203 mask |= EPOLLOUT | EPOLLWRNORM;
204 return mask;
205}
206
207static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
208 unsigned long arg)
209{
210 struct snd_info_private_data *data = file->private_data;
211 struct snd_info_entry *entry = data->entry;
212
213 if (!entry->c.ops->ioctl)
214 return -ENOTTY;
215 return entry->c.ops->ioctl(entry, data->file_private_data,
216 file, cmd, arg);
217}
218
219static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
220{
221 struct inode *inode = file_inode(file);
222 struct snd_info_private_data *data;
223 struct snd_info_entry *entry;
224
225 data = file->private_data;
226 if (data == NULL)
227 return 0;
228 entry = data->entry;
229 if (!entry->c.ops->mmap)
230 return -ENXIO;
231 return entry->c.ops->mmap(entry, data->file_private_data,
232 inode, file, vma);
233}
234
235static int snd_info_entry_open(struct inode *inode, struct file *file)
236{
237 struct snd_info_entry *entry = pde_data(inode);
238 struct snd_info_private_data *data;
239 int mode, err;
240
241 mutex_lock(&info_mutex);
242 err = alloc_info_private(entry, &data);
243 if (err < 0)
244 goto unlock;
245
246 mode = file->f_flags & O_ACCMODE;
247 if (((mode == O_RDONLY || mode == O_RDWR) && !entry->c.ops->read) ||
248 ((mode == O_WRONLY || mode == O_RDWR) && !entry->c.ops->write)) {
249 err = -ENODEV;
250 goto error;
251 }
252
253 if (entry->c.ops->open) {
254 err = entry->c.ops->open(entry, mode, &data->file_private_data);
255 if (err < 0)
256 goto error;
257 }
258
259 file->private_data = data;
260 mutex_unlock(&info_mutex);
261 return 0;
262
263 error:
264 kfree(data);
265 module_put(entry->module);
266 unlock:
267 mutex_unlock(&info_mutex);
268 return err;
269}
270
271static int snd_info_entry_release(struct inode *inode, struct file *file)
272{
273 struct snd_info_private_data *data = file->private_data;
274 struct snd_info_entry *entry = data->entry;
275
276 if (entry->c.ops->release)
277 entry->c.ops->release(entry, file->f_flags & O_ACCMODE,
278 data->file_private_data);
279 module_put(entry->module);
280 kfree(data);
281 return 0;
282}
283
284static const struct proc_ops snd_info_entry_operations =
285{
286 .proc_lseek = snd_info_entry_llseek,
287 .proc_read = snd_info_entry_read,
288 .proc_write = snd_info_entry_write,
289 .proc_poll = snd_info_entry_poll,
290 .proc_ioctl = snd_info_entry_ioctl,
291 .proc_mmap = snd_info_entry_mmap,
292 .proc_open = snd_info_entry_open,
293 .proc_release = snd_info_entry_release,
294};
295
296/*
297 * file ops for text proc files
298 */
299static ssize_t snd_info_text_entry_write(struct file *file,
300 const char __user *buffer,
301 size_t count, loff_t *offset)
302{
303 struct seq_file *m = file->private_data;
304 struct snd_info_private_data *data = m->private;
305 struct snd_info_entry *entry = data->entry;
306 struct snd_info_buffer *buf;
307 loff_t pos;
308 size_t next;
309 int err = 0;
310
311 if (!entry->c.text.write)
312 return -EIO;
313 pos = *offset;
314 if (!valid_pos(pos, count))
315 return -EIO;
316 next = pos + count;
317 /* don't handle too large text inputs */
318 if (next > 16 * 1024)
319 return -EIO;
320 mutex_lock(&entry->access);
321 buf = data->wbuffer;
322 if (!buf) {
323 data->wbuffer = buf = kzalloc(sizeof(*buf), GFP_KERNEL);
324 if (!buf) {
325 err = -ENOMEM;
326 goto error;
327 }
328 }
329 if (next > buf->len) {
330 char *nbuf = kvzalloc(PAGE_ALIGN(next), GFP_KERNEL);
331 if (!nbuf) {
332 err = -ENOMEM;
333 goto error;
334 }
335 kvfree(buf->buffer);
336 buf->buffer = nbuf;
337 buf->len = PAGE_ALIGN(next);
338 }
339 if (copy_from_user(buf->buffer + pos, buffer, count)) {
340 err = -EFAULT;
341 goto error;
342 }
343 buf->size = next;
344 error:
345 mutex_unlock(&entry->access);
346 if (err < 0)
347 return err;
348 *offset = next;
349 return count;
350}
351
352static int snd_info_seq_show(struct seq_file *seq, void *p)
353{
354 struct snd_info_private_data *data = seq->private;
355 struct snd_info_entry *entry = data->entry;
356
357 if (!entry->c.text.read) {
358 return -EIO;
359 } else {
360 data->rbuffer->buffer = (char *)seq; /* XXX hack! */
361 entry->c.text.read(entry, data->rbuffer);
362 }
363 return 0;
364}
365
366static int snd_info_text_entry_open(struct inode *inode, struct file *file)
367{
368 struct snd_info_entry *entry = pde_data(inode);
369 struct snd_info_private_data *data;
370 int err;
371
372 mutex_lock(&info_mutex);
373 err = alloc_info_private(entry, &data);
374 if (err < 0)
375 goto unlock;
376
377 data->rbuffer = kzalloc(sizeof(*data->rbuffer), GFP_KERNEL);
378 if (!data->rbuffer) {
379 err = -ENOMEM;
380 goto error;
381 }
382 if (entry->size)
383 err = single_open_size(file, snd_info_seq_show, data,
384 entry->size);
385 else
386 err = single_open(file, snd_info_seq_show, data);
387 if (err < 0)
388 goto error;
389 mutex_unlock(&info_mutex);
390 return 0;
391
392 error:
393 kfree(data->rbuffer);
394 kfree(data);
395 module_put(entry->module);
396 unlock:
397 mutex_unlock(&info_mutex);
398 return err;
399}
400
401static int snd_info_text_entry_release(struct inode *inode, struct file *file)
402{
403 struct seq_file *m = file->private_data;
404 struct snd_info_private_data *data = m->private;
405 struct snd_info_entry *entry = data->entry;
406
407 if (data->wbuffer && entry->c.text.write)
408 entry->c.text.write(entry, data->wbuffer);
409
410 single_release(inode, file);
411 kfree(data->rbuffer);
412 if (data->wbuffer) {
413 kvfree(data->wbuffer->buffer);
414 kfree(data->wbuffer);
415 }
416
417 module_put(entry->module);
418 kfree(data);
419 return 0;
420}
421
422static const struct proc_ops snd_info_text_entry_ops =
423{
424 .proc_open = snd_info_text_entry_open,
425 .proc_release = snd_info_text_entry_release,
426 .proc_write = snd_info_text_entry_write,
427 .proc_lseek = seq_lseek,
428 .proc_read = seq_read,
429};
430
431static struct snd_info_entry *create_subdir(struct module *mod,
432 const char *name)
433{
434 struct snd_info_entry *entry;
435
436 entry = snd_info_create_module_entry(mod, name, NULL);
437 if (!entry)
438 return NULL;
439 entry->mode = S_IFDIR | 0555;
440 if (snd_info_register(entry) < 0) {
441 snd_info_free_entry(entry);
442 return NULL;
443 }
444 return entry;
445}
446
447static struct snd_info_entry *
448snd_info_create_entry(const char *name, struct snd_info_entry *parent,
449 struct module *module);
450
451int __init snd_info_init(void)
452{
453 snd_proc_root = snd_info_create_entry("asound", NULL, THIS_MODULE);
454 if (!snd_proc_root)
455 return -ENOMEM;
456 snd_proc_root->mode = S_IFDIR | 0555;
457 snd_proc_root->p = proc_mkdir("asound", NULL);
458 if (!snd_proc_root->p)
459 goto error;
460#ifdef CONFIG_SND_OSSEMUL
461 snd_oss_root = create_subdir(THIS_MODULE, "oss");
462 if (!snd_oss_root)
463 goto error;
464#endif
465#if IS_ENABLED(CONFIG_SND_SEQUENCER)
466 snd_seq_root = create_subdir(THIS_MODULE, "seq");
467 if (!snd_seq_root)
468 goto error;
469#endif
470 if (snd_info_version_init() < 0 ||
471 snd_minor_info_init() < 0 ||
472 snd_minor_info_oss_init() < 0 ||
473 snd_card_info_init() < 0 ||
474 snd_info_minor_register() < 0)
475 goto error;
476 return 0;
477
478 error:
479 snd_info_free_entry(snd_proc_root);
480 return -ENOMEM;
481}
482
483int __exit snd_info_done(void)
484{
485 snd_info_free_entry(snd_proc_root);
486 return 0;
487}
488
489static void snd_card_id_read(struct snd_info_entry *entry,
490 struct snd_info_buffer *buffer)
491{
492 struct snd_card *card = entry->private_data;
493
494 snd_iprintf(buffer, "%s\n", card->id);
495}
496
497/*
498 * create a card proc file
499 * called from init.c
500 */
501int snd_info_card_create(struct snd_card *card)
502{
503 char str[8];
504 struct snd_info_entry *entry;
505
506 if (snd_BUG_ON(!card))
507 return -ENXIO;
508
509 sprintf(str, "card%i", card->number);
510 entry = create_subdir(card->module, str);
511 if (!entry)
512 return -ENOMEM;
513 card->proc_root = entry;
514
515 return snd_card_ro_proc_new(card, "id", card, snd_card_id_read);
516}
517
518/*
519 * register the card proc file
520 * called from init.c
521 * can be called multiple times for reinitialization
522 */
523int snd_info_card_register(struct snd_card *card)
524{
525 struct proc_dir_entry *p;
526 int err;
527
528 if (snd_BUG_ON(!card))
529 return -ENXIO;
530
531 err = snd_info_register(card->proc_root);
532 if (err < 0)
533 return err;
534
535 if (!strcmp(card->id, card->proc_root->name))
536 return 0;
537
538 if (card->proc_root_link)
539 return 0;
540 p = proc_symlink(card->id, snd_proc_root->p, card->proc_root->name);
541 if (!p)
542 return -ENOMEM;
543 card->proc_root_link = p;
544 return 0;
545}
546
547/*
548 * called on card->id change
549 */
550void snd_info_card_id_change(struct snd_card *card)
551{
552 mutex_lock(&info_mutex);
553 if (card->proc_root_link) {
554 proc_remove(card->proc_root_link);
555 card->proc_root_link = NULL;
556 }
557 if (strcmp(card->id, card->proc_root->name))
558 card->proc_root_link = proc_symlink(card->id,
559 snd_proc_root->p,
560 card->proc_root->name);
561 mutex_unlock(&info_mutex);
562}
563
564/*
565 * de-register the card proc file
566 * called from init.c
567 */
568void snd_info_card_disconnect(struct snd_card *card)
569{
570 if (!card)
571 return;
572
573 proc_remove(card->proc_root_link);
574 if (card->proc_root)
575 proc_remove(card->proc_root->p);
576
577 mutex_lock(&info_mutex);
578 if (card->proc_root)
579 snd_info_clear_entries(card->proc_root);
580 card->proc_root_link = NULL;
581 card->proc_root = NULL;
582 mutex_unlock(&info_mutex);
583}
584
585/*
586 * release the card proc file resources
587 * called from init.c
588 */
589int snd_info_card_free(struct snd_card *card)
590{
591 if (!card)
592 return 0;
593 snd_info_free_entry(card->proc_root);
594 card->proc_root = NULL;
595 return 0;
596}
597
598
599/**
600 * snd_info_get_line - read one line from the procfs buffer
601 * @buffer: the procfs buffer
602 * @line: the buffer to store
603 * @len: the max. buffer size
604 *
605 * Reads one line from the buffer and stores the string.
606 *
607 * Return: Zero if successful, or 1 if error or EOF.
608 */
609int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
610{
611 int c;
612
613 if (snd_BUG_ON(!buffer))
614 return 1;
615 if (!buffer->buffer)
616 return 1;
617 if (len <= 0 || buffer->stop || buffer->error)
618 return 1;
619 while (!buffer->stop) {
620 c = buffer->buffer[buffer->curr++];
621 if (buffer->curr >= buffer->size)
622 buffer->stop = 1;
623 if (c == '\n')
624 break;
625 if (len > 1) {
626 len--;
627 *line++ = c;
628 }
629 }
630 *line = '\0';
631 return 0;
632}
633EXPORT_SYMBOL(snd_info_get_line);
634
635/**
636 * snd_info_get_str - parse a string token
637 * @dest: the buffer to store the string token
638 * @src: the original string
639 * @len: the max. length of token - 1
640 *
641 * Parses the original string and copy a token to the given
642 * string buffer.
643 *
644 * Return: The updated pointer of the original string so that
645 * it can be used for the next call.
646 */
647const char *snd_info_get_str(char *dest, const char *src, int len)
648{
649 int c;
650
651 while (*src == ' ' || *src == '\t')
652 src++;
653 if (*src == '"' || *src == '\'') {
654 c = *src++;
655 while (--len > 0 && *src && *src != c) {
656 *dest++ = *src++;
657 }
658 if (*src == c)
659 src++;
660 } else {
661 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
662 *dest++ = *src++;
663 }
664 }
665 *dest = 0;
666 while (*src == ' ' || *src == '\t')
667 src++;
668 return src;
669}
670EXPORT_SYMBOL(snd_info_get_str);
671
672/*
673 * snd_info_create_entry - create an info entry
674 * @name: the proc file name
675 * @parent: the parent directory
676 *
677 * Creates an info entry with the given file name and initializes as
678 * the default state.
679 *
680 * Usually called from other functions such as
681 * snd_info_create_card_entry().
682 *
683 * Return: The pointer of the new instance, or %NULL on failure.
684 */
685static struct snd_info_entry *
686snd_info_create_entry(const char *name, struct snd_info_entry *parent,
687 struct module *module)
688{
689 struct snd_info_entry *entry;
690 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
691 if (entry == NULL)
692 return NULL;
693 entry->name = kstrdup(name, GFP_KERNEL);
694 if (entry->name == NULL) {
695 kfree(entry);
696 return NULL;
697 }
698 entry->mode = S_IFREG | 0444;
699 entry->content = SNDRV_INFO_CONTENT_TEXT;
700 mutex_init(&entry->access);
701 INIT_LIST_HEAD(&entry->children);
702 INIT_LIST_HEAD(&entry->list);
703 entry->parent = parent;
704 entry->module = module;
705 if (parent) {
706 mutex_lock(&parent->access);
707 list_add_tail(&entry->list, &parent->children);
708 mutex_unlock(&parent->access);
709 }
710 return entry;
711}
712
713/**
714 * snd_info_create_module_entry - create an info entry for the given module
715 * @module: the module pointer
716 * @name: the file name
717 * @parent: the parent directory
718 *
719 * Creates a new info entry and assigns it to the given module.
720 *
721 * Return: The pointer of the new instance, or %NULL on failure.
722 */
723struct snd_info_entry *snd_info_create_module_entry(struct module * module,
724 const char *name,
725 struct snd_info_entry *parent)
726{
727 if (!parent)
728 parent = snd_proc_root;
729 return snd_info_create_entry(name, parent, module);
730}
731EXPORT_SYMBOL(snd_info_create_module_entry);
732
733/**
734 * snd_info_create_card_entry - create an info entry for the given card
735 * @card: the card instance
736 * @name: the file name
737 * @parent: the parent directory
738 *
739 * Creates a new info entry and assigns it to the given card.
740 *
741 * Return: The pointer of the new instance, or %NULL on failure.
742 */
743struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
744 const char *name,
745 struct snd_info_entry * parent)
746{
747 if (!parent)
748 parent = card->proc_root;
749 return snd_info_create_entry(name, parent, card->module);
750}
751EXPORT_SYMBOL(snd_info_create_card_entry);
752
753static void snd_info_clear_entries(struct snd_info_entry *entry)
754{
755 struct snd_info_entry *p;
756
757 if (!entry->p)
758 return;
759 list_for_each_entry(p, &entry->children, list)
760 snd_info_clear_entries(p);
761 entry->p = NULL;
762}
763
764/**
765 * snd_info_free_entry - release the info entry
766 * @entry: the info entry
767 *
768 * Releases the info entry.
769 */
770void snd_info_free_entry(struct snd_info_entry * entry)
771{
772 struct snd_info_entry *p, *n;
773
774 if (!entry)
775 return;
776 if (entry->p) {
777 proc_remove(entry->p);
778 mutex_lock(&info_mutex);
779 snd_info_clear_entries(entry);
780 mutex_unlock(&info_mutex);
781 }
782
783 /* free all children at first */
784 list_for_each_entry_safe(p, n, &entry->children, list)
785 snd_info_free_entry(p);
786
787 p = entry->parent;
788 if (p) {
789 mutex_lock(&p->access);
790 list_del(&entry->list);
791 mutex_unlock(&p->access);
792 }
793 kfree(entry->name);
794 if (entry->private_free)
795 entry->private_free(entry);
796 kfree(entry);
797}
798EXPORT_SYMBOL(snd_info_free_entry);
799
800static int __snd_info_register(struct snd_info_entry *entry)
801{
802 struct proc_dir_entry *root, *p = NULL;
803
804 if (snd_BUG_ON(!entry))
805 return -ENXIO;
806 root = entry->parent == NULL ? snd_proc_root->p : entry->parent->p;
807 mutex_lock(&info_mutex);
808 if (entry->p || !root)
809 goto unlock;
810 if (S_ISDIR(entry->mode)) {
811 p = proc_mkdir_mode(entry->name, entry->mode, root);
812 if (!p) {
813 mutex_unlock(&info_mutex);
814 return -ENOMEM;
815 }
816 } else {
817 const struct proc_ops *ops;
818 if (entry->content == SNDRV_INFO_CONTENT_DATA)
819 ops = &snd_info_entry_operations;
820 else
821 ops = &snd_info_text_entry_ops;
822 p = proc_create_data(entry->name, entry->mode, root,
823 ops, entry);
824 if (!p) {
825 mutex_unlock(&info_mutex);
826 return -ENOMEM;
827 }
828 proc_set_size(p, entry->size);
829 }
830 entry->p = p;
831 unlock:
832 mutex_unlock(&info_mutex);
833 return 0;
834}
835
836/**
837 * snd_info_register - register the info entry
838 * @entry: the info entry
839 *
840 * Registers the proc info entry.
841 * The all children entries are registered recursively.
842 *
843 * Return: Zero if successful, or a negative error code on failure.
844 */
845int snd_info_register(struct snd_info_entry *entry)
846{
847 struct snd_info_entry *p;
848 int err;
849
850 if (!entry->p) {
851 err = __snd_info_register(entry);
852 if (err < 0)
853 return err;
854 }
855
856 list_for_each_entry(p, &entry->children, list) {
857 err = snd_info_register(p);
858 if (err < 0)
859 return err;
860 }
861
862 return 0;
863}
864EXPORT_SYMBOL(snd_info_register);
865
866/**
867 * snd_card_rw_proc_new - Create a read/write text proc file entry for the card
868 * @card: the card instance
869 * @name: the file name
870 * @private_data: the arbitrary private data
871 * @read: the read callback
872 * @write: the write callback, NULL for read-only
873 *
874 * This proc file entry will be registered via snd_card_register() call, and
875 * it will be removed automatically at the card removal, too.
876 *
877 * Return: zero if successful, or a negative error code
878 */
879int snd_card_rw_proc_new(struct snd_card *card, const char *name,
880 void *private_data,
881 void (*read)(struct snd_info_entry *,
882 struct snd_info_buffer *),
883 void (*write)(struct snd_info_entry *entry,
884 struct snd_info_buffer *buffer))
885{
886 struct snd_info_entry *entry;
887
888 entry = snd_info_create_card_entry(card, name, card->proc_root);
889 if (!entry)
890 return -ENOMEM;
891 snd_info_set_text_ops(entry, private_data, read);
892 if (write) {
893 entry->mode |= 0200;
894 entry->c.text.write = write;
895 }
896 return 0;
897}
898EXPORT_SYMBOL_GPL(snd_card_rw_proc_new);
899
900/*
901
902 */
903
904static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
905{
906 snd_iprintf(buffer,
907 "Advanced Linux Sound Architecture Driver Version k%s.\n",
908 init_utsname()->release);
909}
910
911static int __init snd_info_version_init(void)
912{
913 struct snd_info_entry *entry;
914
915 entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
916 if (entry == NULL)
917 return -ENOMEM;
918 entry->c.text.read = snd_info_version_read;
919 return snd_info_register(entry); /* freed in error path */
920}