Loading...
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/*
2 * Information interface for ALSA driver
3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4 *
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 *
20 */
21
22#include <linux/init.h>
23#include <linux/time.h>
24#include <linux/mm.h>
25#include <linux/slab.h>
26#include <linux/string.h>
27#include <linux/module.h>
28#include <sound/core.h>
29#include <sound/minors.h>
30#include <sound/info.h>
31#include <linux/utsname.h>
32#include <linux/proc_fs.h>
33#include <linux/mutex.h>
34#include <stdarg.h>
35
36int snd_info_check_reserved_words(const char *str)
37{
38 static char *reserved[] =
39 {
40 "version",
41 "meminfo",
42 "memdebug",
43 "detect",
44 "devices",
45 "oss",
46 "cards",
47 "timers",
48 "synth",
49 "pcm",
50 "seq",
51 NULL
52 };
53 char **xstr = reserved;
54
55 while (*xstr) {
56 if (!strcmp(*xstr, str))
57 return 0;
58 xstr++;
59 }
60 if (!strncmp(str, "card", 4))
61 return 0;
62 return 1;
63}
64
65static DEFINE_MUTEX(info_mutex);
66
67struct snd_info_private_data {
68 struct snd_info_buffer *rbuffer;
69 struct snd_info_buffer *wbuffer;
70 struct snd_info_entry *entry;
71 void *file_private_data;
72};
73
74static int snd_info_version_init(void);
75static void snd_info_disconnect(struct snd_info_entry *entry);
76
77/*
78
79 */
80
81static struct snd_info_entry *snd_proc_root;
82struct snd_info_entry *snd_seq_root;
83EXPORT_SYMBOL(snd_seq_root);
84
85#ifdef CONFIG_SND_OSSEMUL
86struct snd_info_entry *snd_oss_root;
87#endif
88
89static int alloc_info_private(struct snd_info_entry *entry,
90 struct snd_info_private_data **ret)
91{
92 struct snd_info_private_data *data;
93
94 if (!entry || !entry->p)
95 return -ENODEV;
96 if (!try_module_get(entry->module))
97 return -EFAULT;
98 data = kzalloc(sizeof(*data), GFP_KERNEL);
99 if (!data) {
100 module_put(entry->module);
101 return -ENOMEM;
102 }
103 data->entry = entry;
104 *ret = data;
105 return 0;
106}
107
108static bool valid_pos(loff_t pos, size_t count)
109{
110 if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
111 return false;
112 if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
113 return false;
114 return true;
115}
116
117/*
118 * file ops for binary proc files
119 */
120static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
121{
122 struct snd_info_private_data *data;
123 struct snd_info_entry *entry;
124 loff_t ret = -EINVAL, size;
125
126 data = file->private_data;
127 entry = data->entry;
128 mutex_lock(&entry->access);
129 if (entry->c.ops->llseek) {
130 offset = entry->c.ops->llseek(entry,
131 data->file_private_data,
132 file, offset, orig);
133 goto out;
134 }
135
136 size = entry->size;
137 switch (orig) {
138 case SEEK_SET:
139 break;
140 case SEEK_CUR:
141 offset += file->f_pos;
142 break;
143 case SEEK_END:
144 if (!size)
145 goto out;
146 offset += size;
147 break;
148 default:
149 goto out;
150 }
151 if (offset < 0)
152 goto out;
153 if (size && offset > size)
154 offset = size;
155 file->f_pos = offset;
156 ret = offset;
157 out:
158 mutex_unlock(&entry->access);
159 return ret;
160}
161
162static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
163 size_t count, loff_t * offset)
164{
165 struct snd_info_private_data *data = file->private_data;
166 struct snd_info_entry *entry = data->entry;
167 size_t size;
168 loff_t pos;
169
170 pos = *offset;
171 if (!valid_pos(pos, count))
172 return -EIO;
173 if (pos >= entry->size)
174 return 0;
175 size = entry->size - pos;
176 size = min(count, size);
177 size = entry->c.ops->read(entry, data->file_private_data,
178 file, buffer, size, pos);
179 if ((ssize_t) size > 0)
180 *offset = pos + size;
181 return size;
182}
183
184static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
185 size_t count, loff_t * offset)
186{
187 struct snd_info_private_data *data = file->private_data;
188 struct snd_info_entry *entry = data->entry;
189 ssize_t size = 0;
190 loff_t pos;
191
192 pos = *offset;
193 if (!valid_pos(pos, count))
194 return -EIO;
195 if (count > 0) {
196 size_t maxsize = entry->size - pos;
197 count = min(count, maxsize);
198 size = entry->c.ops->write(entry, data->file_private_data,
199 file, buffer, count, pos);
200 }
201 if (size > 0)
202 *offset = pos + size;
203 return size;
204}
205
206static unsigned int snd_info_entry_poll(struct file *file, poll_table *wait)
207{
208 struct snd_info_private_data *data = file->private_data;
209 struct snd_info_entry *entry = data->entry;
210 unsigned int mask = 0;
211
212 if (entry->c.ops->poll)
213 return entry->c.ops->poll(entry,
214 data->file_private_data,
215 file, wait);
216 if (entry->c.ops->read)
217 mask |= POLLIN | POLLRDNORM;
218 if (entry->c.ops->write)
219 mask |= POLLOUT | POLLWRNORM;
220 return mask;
221}
222
223static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
224 unsigned long arg)
225{
226 struct snd_info_private_data *data = file->private_data;
227 struct snd_info_entry *entry = data->entry;
228
229 if (!entry->c.ops->ioctl)
230 return -ENOTTY;
231 return entry->c.ops->ioctl(entry, data->file_private_data,
232 file, cmd, arg);
233}
234
235static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
236{
237 struct inode *inode = file_inode(file);
238 struct snd_info_private_data *data;
239 struct snd_info_entry *entry;
240
241 data = file->private_data;
242 if (data == NULL)
243 return 0;
244 entry = data->entry;
245 if (!entry->c.ops->mmap)
246 return -ENXIO;
247 return entry->c.ops->mmap(entry, data->file_private_data,
248 inode, file, vma);
249}
250
251static int snd_info_entry_open(struct inode *inode, struct file *file)
252{
253 struct snd_info_entry *entry = PDE_DATA(inode);
254 struct snd_info_private_data *data;
255 int mode, err;
256
257 mutex_lock(&info_mutex);
258 err = alloc_info_private(entry, &data);
259 if (err < 0)
260 goto unlock;
261
262 mode = file->f_flags & O_ACCMODE;
263 if (((mode == O_RDONLY || mode == O_RDWR) && !entry->c.ops->read) ||
264 ((mode == O_WRONLY || mode == O_RDWR) && !entry->c.ops->write)) {
265 err = -ENODEV;
266 goto error;
267 }
268
269 if (entry->c.ops->open) {
270 err = entry->c.ops->open(entry, mode, &data->file_private_data);
271 if (err < 0)
272 goto error;
273 }
274
275 file->private_data = data;
276 mutex_unlock(&info_mutex);
277 return 0;
278
279 error:
280 kfree(data);
281 module_put(entry->module);
282 unlock:
283 mutex_unlock(&info_mutex);
284 return err;
285}
286
287static int snd_info_entry_release(struct inode *inode, struct file *file)
288{
289 struct snd_info_private_data *data = file->private_data;
290 struct snd_info_entry *entry = data->entry;
291
292 if (entry->c.ops->release)
293 entry->c.ops->release(entry, file->f_flags & O_ACCMODE,
294 data->file_private_data);
295 module_put(entry->module);
296 kfree(data);
297 return 0;
298}
299
300static const struct file_operations snd_info_entry_operations =
301{
302 .owner = THIS_MODULE,
303 .llseek = snd_info_entry_llseek,
304 .read = snd_info_entry_read,
305 .write = snd_info_entry_write,
306 .poll = snd_info_entry_poll,
307 .unlocked_ioctl = snd_info_entry_ioctl,
308 .mmap = snd_info_entry_mmap,
309 .open = snd_info_entry_open,
310 .release = snd_info_entry_release,
311};
312
313/*
314 * file ops for text proc files
315 */
316static ssize_t snd_info_text_entry_write(struct file *file,
317 const char __user *buffer,
318 size_t count, loff_t *offset)
319{
320 struct seq_file *m = file->private_data;
321 struct snd_info_private_data *data = m->private;
322 struct snd_info_entry *entry = data->entry;
323 struct snd_info_buffer *buf;
324 loff_t pos;
325 size_t next;
326 int err = 0;
327
328 if (!entry->c.text.write)
329 return -EIO;
330 pos = *offset;
331 if (!valid_pos(pos, count))
332 return -EIO;
333 next = pos + count;
334 /* don't handle too large text inputs */
335 if (next > 16 * 1024)
336 return -EIO;
337 mutex_lock(&entry->access);
338 buf = data->wbuffer;
339 if (!buf) {
340 data->wbuffer = buf = kzalloc(sizeof(*buf), GFP_KERNEL);
341 if (!buf) {
342 err = -ENOMEM;
343 goto error;
344 }
345 }
346 if (next > buf->len) {
347 char *nbuf = krealloc(buf->buffer, PAGE_ALIGN(next),
348 GFP_KERNEL | __GFP_ZERO);
349 if (!nbuf) {
350 err = -ENOMEM;
351 goto error;
352 }
353 buf->buffer = nbuf;
354 buf->len = PAGE_ALIGN(next);
355 }
356 if (copy_from_user(buf->buffer + pos, buffer, count)) {
357 err = -EFAULT;
358 goto error;
359 }
360 buf->size = next;
361 error:
362 mutex_unlock(&entry->access);
363 if (err < 0)
364 return err;
365 *offset = next;
366 return count;
367}
368
369static int snd_info_seq_show(struct seq_file *seq, void *p)
370{
371 struct snd_info_private_data *data = seq->private;
372 struct snd_info_entry *entry = data->entry;
373
374 if (!entry->c.text.read) {
375 return -EIO;
376 } else {
377 data->rbuffer->buffer = (char *)seq; /* XXX hack! */
378 entry->c.text.read(entry, data->rbuffer);
379 }
380 return 0;
381}
382
383static int snd_info_text_entry_open(struct inode *inode, struct file *file)
384{
385 struct snd_info_entry *entry = PDE_DATA(inode);
386 struct snd_info_private_data *data;
387 int err;
388
389 mutex_lock(&info_mutex);
390 err = alloc_info_private(entry, &data);
391 if (err < 0)
392 goto unlock;
393
394 data->rbuffer = kzalloc(sizeof(*data->rbuffer), GFP_KERNEL);
395 if (!data->rbuffer) {
396 err = -ENOMEM;
397 goto error;
398 }
399 if (entry->size)
400 err = single_open_size(file, snd_info_seq_show, data,
401 entry->size);
402 else
403 err = single_open(file, snd_info_seq_show, data);
404 if (err < 0)
405 goto error;
406 mutex_unlock(&info_mutex);
407 return 0;
408
409 error:
410 kfree(data->rbuffer);
411 kfree(data);
412 module_put(entry->module);
413 unlock:
414 mutex_unlock(&info_mutex);
415 return err;
416}
417
418static int snd_info_text_entry_release(struct inode *inode, struct file *file)
419{
420 struct seq_file *m = file->private_data;
421 struct snd_info_private_data *data = m->private;
422 struct snd_info_entry *entry = data->entry;
423
424 if (data->wbuffer && entry->c.text.write)
425 entry->c.text.write(entry, data->wbuffer);
426
427 single_release(inode, file);
428 kfree(data->rbuffer);
429 if (data->wbuffer) {
430 kfree(data->wbuffer->buffer);
431 kfree(data->wbuffer);
432 }
433
434 module_put(entry->module);
435 kfree(data);
436 return 0;
437}
438
439static const struct file_operations snd_info_text_entry_ops =
440{
441 .owner = THIS_MODULE,
442 .open = snd_info_text_entry_open,
443 .release = snd_info_text_entry_release,
444 .write = snd_info_text_entry_write,
445 .llseek = seq_lseek,
446 .read = seq_read,
447};
448
449static struct snd_info_entry *create_subdir(struct module *mod,
450 const char *name)
451{
452 struct snd_info_entry *entry;
453
454 entry = snd_info_create_module_entry(mod, name, NULL);
455 if (!entry)
456 return NULL;
457 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
458 if (snd_info_register(entry) < 0) {
459 snd_info_free_entry(entry);
460 return NULL;
461 }
462 return entry;
463}
464
465static struct snd_info_entry *
466snd_info_create_entry(const char *name, struct snd_info_entry *parent);
467
468int __init snd_info_init(void)
469{
470 snd_proc_root = snd_info_create_entry("asound", NULL);
471 if (!snd_proc_root)
472 return -ENOMEM;
473 snd_proc_root->mode = S_IFDIR | S_IRUGO | S_IXUGO;
474 snd_proc_root->p = proc_mkdir("asound", NULL);
475 if (!snd_proc_root->p)
476 goto error;
477#ifdef CONFIG_SND_OSSEMUL
478 snd_oss_root = create_subdir(THIS_MODULE, "oss");
479 if (!snd_oss_root)
480 goto error;
481#endif
482#if IS_ENABLED(CONFIG_SND_SEQUENCER)
483 snd_seq_root = create_subdir(THIS_MODULE, "seq");
484 if (!snd_seq_root)
485 goto error;
486#endif
487 if (snd_info_version_init() < 0 ||
488 snd_minor_info_init() < 0 ||
489 snd_minor_info_oss_init() < 0 ||
490 snd_card_info_init() < 0 ||
491 snd_info_minor_register() < 0)
492 goto error;
493 return 0;
494
495 error:
496 snd_info_free_entry(snd_proc_root);
497 return -ENOMEM;
498}
499
500int __exit snd_info_done(void)
501{
502 snd_info_free_entry(snd_proc_root);
503 return 0;
504}
505
506/*
507 * create a card proc file
508 * called from init.c
509 */
510int snd_info_card_create(struct snd_card *card)
511{
512 char str[8];
513 struct snd_info_entry *entry;
514
515 if (snd_BUG_ON(!card))
516 return -ENXIO;
517
518 sprintf(str, "card%i", card->number);
519 entry = create_subdir(card->module, str);
520 if (!entry)
521 return -ENOMEM;
522 card->proc_root = entry;
523 return 0;
524}
525
526/* register all pending info entries */
527static int snd_info_register_recursive(struct snd_info_entry *entry)
528{
529 struct snd_info_entry *p;
530 int err;
531
532 if (!entry->p) {
533 err = snd_info_register(entry);
534 if (err < 0)
535 return err;
536 }
537
538 list_for_each_entry(p, &entry->children, list) {
539 err = snd_info_register_recursive(p);
540 if (err < 0)
541 return err;
542 }
543
544 return 0;
545}
546
547/*
548 * register the card proc file
549 * called from init.c
550 * can be called multiple times for reinitialization
551 */
552int snd_info_card_register(struct snd_card *card)
553{
554 struct proc_dir_entry *p;
555 int err;
556
557 if (snd_BUG_ON(!card))
558 return -ENXIO;
559
560 err = snd_info_register_recursive(card->proc_root);
561 if (err < 0)
562 return err;
563
564 if (!strcmp(card->id, card->proc_root->name))
565 return 0;
566
567 if (card->proc_root_link)
568 return 0;
569 p = proc_symlink(card->id, snd_proc_root->p, card->proc_root->name);
570 if (!p)
571 return -ENOMEM;
572 card->proc_root_link = p;
573 return 0;
574}
575
576/*
577 * called on card->id change
578 */
579void snd_info_card_id_change(struct snd_card *card)
580{
581 mutex_lock(&info_mutex);
582 if (card->proc_root_link) {
583 proc_remove(card->proc_root_link);
584 card->proc_root_link = NULL;
585 }
586 if (strcmp(card->id, card->proc_root->name))
587 card->proc_root_link = proc_symlink(card->id,
588 snd_proc_root->p,
589 card->proc_root->name);
590 mutex_unlock(&info_mutex);
591}
592
593/*
594 * de-register the card proc file
595 * called from init.c
596 */
597void snd_info_card_disconnect(struct snd_card *card)
598{
599 if (!card)
600 return;
601 mutex_lock(&info_mutex);
602 proc_remove(card->proc_root_link);
603 card->proc_root_link = NULL;
604 if (card->proc_root)
605 snd_info_disconnect(card->proc_root);
606 mutex_unlock(&info_mutex);
607}
608
609/*
610 * release the card proc file resources
611 * called from init.c
612 */
613int snd_info_card_free(struct snd_card *card)
614{
615 if (!card)
616 return 0;
617 snd_info_free_entry(card->proc_root);
618 card->proc_root = NULL;
619 return 0;
620}
621
622
623/**
624 * snd_info_get_line - read one line from the procfs buffer
625 * @buffer: the procfs buffer
626 * @line: the buffer to store
627 * @len: the max. buffer size
628 *
629 * Reads one line from the buffer and stores the string.
630 *
631 * Return: Zero if successful, or 1 if error or EOF.
632 */
633int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
634{
635 int c = -1;
636
637 if (snd_BUG_ON(!buffer || !buffer->buffer))
638 return 1;
639 if (len <= 0 || buffer->stop || buffer->error)
640 return 1;
641 while (!buffer->stop) {
642 c = buffer->buffer[buffer->curr++];
643 if (buffer->curr >= buffer->size)
644 buffer->stop = 1;
645 if (c == '\n')
646 break;
647 if (len > 1) {
648 len--;
649 *line++ = c;
650 }
651 }
652 *line = '\0';
653 return 0;
654}
655
656EXPORT_SYMBOL(snd_info_get_line);
657
658/**
659 * snd_info_get_str - parse a string token
660 * @dest: the buffer to store the string token
661 * @src: the original string
662 * @len: the max. length of token - 1
663 *
664 * Parses the original string and copy a token to the given
665 * string buffer.
666 *
667 * Return: The updated pointer of the original string so that
668 * it can be used for the next call.
669 */
670const char *snd_info_get_str(char *dest, const char *src, int len)
671{
672 int c;
673
674 while (*src == ' ' || *src == '\t')
675 src++;
676 if (*src == '"' || *src == '\'') {
677 c = *src++;
678 while (--len > 0 && *src && *src != c) {
679 *dest++ = *src++;
680 }
681 if (*src == c)
682 src++;
683 } else {
684 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
685 *dest++ = *src++;
686 }
687 }
688 *dest = 0;
689 while (*src == ' ' || *src == '\t')
690 src++;
691 return src;
692}
693
694EXPORT_SYMBOL(snd_info_get_str);
695
696/*
697 * snd_info_create_entry - create an info entry
698 * @name: the proc file name
699 * @parent: the parent directory
700 *
701 * Creates an info entry with the given file name and initializes as
702 * the default state.
703 *
704 * Usually called from other functions such as
705 * snd_info_create_card_entry().
706 *
707 * Return: The pointer of the new instance, or %NULL on failure.
708 */
709static struct snd_info_entry *
710snd_info_create_entry(const char *name, struct snd_info_entry *parent)
711{
712 struct snd_info_entry *entry;
713 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
714 if (entry == NULL)
715 return NULL;
716 entry->name = kstrdup(name, GFP_KERNEL);
717 if (entry->name == NULL) {
718 kfree(entry);
719 return NULL;
720 }
721 entry->mode = S_IFREG | S_IRUGO;
722 entry->content = SNDRV_INFO_CONTENT_TEXT;
723 mutex_init(&entry->access);
724 INIT_LIST_HEAD(&entry->children);
725 INIT_LIST_HEAD(&entry->list);
726 entry->parent = parent;
727 if (parent)
728 list_add_tail(&entry->list, &parent->children);
729 return entry;
730}
731
732/**
733 * snd_info_create_module_entry - create an info entry for the given module
734 * @module: the module pointer
735 * @name: the file name
736 * @parent: the parent directory
737 *
738 * Creates a new info entry and assigns it to the given module.
739 *
740 * Return: The pointer of the new instance, or %NULL on failure.
741 */
742struct snd_info_entry *snd_info_create_module_entry(struct module * module,
743 const char *name,
744 struct snd_info_entry *parent)
745{
746 struct snd_info_entry *entry = snd_info_create_entry(name, parent);
747 if (entry)
748 entry->module = module;
749 return entry;
750}
751
752EXPORT_SYMBOL(snd_info_create_module_entry);
753
754/**
755 * snd_info_create_card_entry - create an info entry for the given card
756 * @card: the card instance
757 * @name: the file name
758 * @parent: the parent directory
759 *
760 * Creates a new info entry and assigns it to the given card.
761 *
762 * Return: The pointer of the new instance, or %NULL on failure.
763 */
764struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
765 const char *name,
766 struct snd_info_entry * parent)
767{
768 struct snd_info_entry *entry = snd_info_create_entry(name, parent);
769 if (entry) {
770 entry->module = card->module;
771 entry->card = card;
772 }
773 return entry;
774}
775
776EXPORT_SYMBOL(snd_info_create_card_entry);
777
778static void snd_info_disconnect(struct snd_info_entry *entry)
779{
780 struct snd_info_entry *p;
781
782 if (!entry->p)
783 return;
784 list_for_each_entry(p, &entry->children, list)
785 snd_info_disconnect(p);
786 proc_remove(entry->p);
787 entry->p = NULL;
788}
789
790/**
791 * snd_info_free_entry - release the info entry
792 * @entry: the info entry
793 *
794 * Releases the info entry.
795 */
796void snd_info_free_entry(struct snd_info_entry * entry)
797{
798 struct snd_info_entry *p, *n;
799
800 if (!entry)
801 return;
802 if (entry->p) {
803 mutex_lock(&info_mutex);
804 snd_info_disconnect(entry);
805 mutex_unlock(&info_mutex);
806 }
807
808 /* free all children at first */
809 list_for_each_entry_safe(p, n, &entry->children, list)
810 snd_info_free_entry(p);
811
812 list_del(&entry->list);
813 kfree(entry->name);
814 if (entry->private_free)
815 entry->private_free(entry);
816 kfree(entry);
817}
818
819EXPORT_SYMBOL(snd_info_free_entry);
820
821/**
822 * snd_info_register - register the info entry
823 * @entry: the info entry
824 *
825 * Registers the proc info entry.
826 *
827 * Return: Zero if successful, or a negative error code on failure.
828 */
829int snd_info_register(struct snd_info_entry * entry)
830{
831 struct proc_dir_entry *root, *p = NULL;
832
833 if (snd_BUG_ON(!entry))
834 return -ENXIO;
835 root = entry->parent == NULL ? snd_proc_root->p : entry->parent->p;
836 mutex_lock(&info_mutex);
837 if (S_ISDIR(entry->mode)) {
838 p = proc_mkdir_mode(entry->name, entry->mode, root);
839 if (!p) {
840 mutex_unlock(&info_mutex);
841 return -ENOMEM;
842 }
843 } else {
844 const struct file_operations *ops;
845 if (entry->content == SNDRV_INFO_CONTENT_DATA)
846 ops = &snd_info_entry_operations;
847 else
848 ops = &snd_info_text_entry_ops;
849 p = proc_create_data(entry->name, entry->mode, root,
850 ops, entry);
851 if (!p) {
852 mutex_unlock(&info_mutex);
853 return -ENOMEM;
854 }
855 proc_set_size(p, entry->size);
856 }
857 entry->p = p;
858 mutex_unlock(&info_mutex);
859 return 0;
860}
861
862EXPORT_SYMBOL(snd_info_register);
863
864/*
865
866 */
867
868static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
869{
870 snd_iprintf(buffer,
871 "Advanced Linux Sound Architecture Driver Version k%s.\n",
872 init_utsname()->release);
873}
874
875static int __init snd_info_version_init(void)
876{
877 struct snd_info_entry *entry;
878
879 entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
880 if (entry == NULL)
881 return -ENOMEM;
882 entry->c.text.read = snd_info_version_read;
883 return snd_info_register(entry); /* freed in error path */
884}