linux/sound/core/info.c
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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 const char * const 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        const char * const *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 proc_ops snd_info_entry_operations =
 286{
 287        .proc_lseek     = snd_info_entry_llseek,
 288        .proc_read      = snd_info_entry_read,
 289        .proc_write     = snd_info_entry_write,
 290        .proc_poll      = snd_info_entry_poll,
 291        .proc_ioctl     = snd_info_entry_ioctl,
 292        .proc_mmap      = snd_info_entry_mmap,
 293        .proc_open      = snd_info_entry_open,
 294        .proc_release   = snd_info_entry_release,
 295};
 296
 297/*
 298 * file ops for text proc files
 299 */
 300static ssize_t snd_info_text_entry_write(struct file *file,
 301                                         const char __user *buffer,
 302                                         size_t count, loff_t *offset)
 303{
 304        struct seq_file *m = file->private_data;
 305        struct snd_info_private_data *data = m->private;
 306        struct snd_info_entry *entry = data->entry;
 307        struct snd_info_buffer *buf;
 308        loff_t pos;
 309        size_t next;
 310        int err = 0;
 311
 312        if (!entry->c.text.write)
 313                return -EIO;
 314        pos = *offset;
 315        if (!valid_pos(pos, count))
 316                return -EIO;
 317        next = pos + count;
 318        /* don't handle too large text inputs */
 319        if (next > 16 * 1024)
 320                return -EIO;
 321        mutex_lock(&entry->access);
 322        buf = data->wbuffer;
 323        if (!buf) {
 324                data->wbuffer = buf = kzalloc(sizeof(*buf), GFP_KERNEL);
 325                if (!buf) {
 326                        err = -ENOMEM;
 327                        goto error;
 328                }
 329        }
 330        if (next > buf->len) {
 331                char *nbuf = kvzalloc(PAGE_ALIGN(next), GFP_KERNEL);
 332                if (!nbuf) {
 333                        err = -ENOMEM;
 334                        goto error;
 335                }
 336                kvfree(buf->buffer);
 337                buf->buffer = nbuf;
 338                buf->len = PAGE_ALIGN(next);
 339        }
 340        if (copy_from_user(buf->buffer + pos, buffer, count)) {
 341                err = -EFAULT;
 342                goto error;
 343        }
 344        buf->size = next;
 345 error:
 346        mutex_unlock(&entry->access);
 347        if (err < 0)
 348                return err;
 349        *offset = next;
 350        return count;
 351}
 352
 353static int snd_info_seq_show(struct seq_file *seq, void *p)
 354{
 355        struct snd_info_private_data *data = seq->private;
 356        struct snd_info_entry *entry = data->entry;
 357
 358        if (!entry->c.text.read) {
 359                return -EIO;
 360        } else {
 361                data->rbuffer->buffer = (char *)seq; /* XXX hack! */
 362                entry->c.text.read(entry, data->rbuffer);
 363        }
 364        return 0;
 365}
 366
 367static int snd_info_text_entry_open(struct inode *inode, struct file *file)
 368{
 369        struct snd_info_entry *entry = PDE_DATA(inode);
 370        struct snd_info_private_data *data;
 371        int err;
 372
 373        mutex_lock(&info_mutex);
 374        err = alloc_info_private(entry, &data);
 375        if (err < 0)
 376                goto unlock;
 377
 378        data->rbuffer = kzalloc(sizeof(*data->rbuffer), GFP_KERNEL);
 379        if (!data->rbuffer) {
 380                err = -ENOMEM;
 381                goto error;
 382        }
 383        if (entry->size)
 384                err = single_open_size(file, snd_info_seq_show, data,
 385                                       entry->size);
 386        else
 387                err = single_open(file, snd_info_seq_show, data);
 388        if (err < 0)
 389                goto error;
 390        mutex_unlock(&info_mutex);
 391        return 0;
 392
 393 error:
 394        kfree(data->rbuffer);
 395        kfree(data);
 396        module_put(entry->module);
 397 unlock:
 398        mutex_unlock(&info_mutex);
 399        return err;
 400}
 401
 402static int snd_info_text_entry_release(struct inode *inode, struct file *file)
 403{
 404        struct seq_file *m = file->private_data;
 405        struct snd_info_private_data *data = m->private;
 406        struct snd_info_entry *entry = data->entry;
 407
 408        if (data->wbuffer && entry->c.text.write)
 409                entry->c.text.write(entry, data->wbuffer);
 410
 411        single_release(inode, file);
 412        kfree(data->rbuffer);
 413        if (data->wbuffer) {
 414                kvfree(data->wbuffer->buffer);
 415                kfree(data->wbuffer);
 416        }
 417
 418        module_put(entry->module);
 419        kfree(data);
 420        return 0;
 421}
 422
 423static const struct proc_ops snd_info_text_entry_ops =
 424{
 425        .proc_open      = snd_info_text_entry_open,
 426        .proc_release   = snd_info_text_entry_release,
 427        .proc_write     = snd_info_text_entry_write,
 428        .proc_lseek     = seq_lseek,
 429        .proc_read      = seq_read,
 430};
 431
 432static struct snd_info_entry *create_subdir(struct module *mod,
 433                                            const char *name)
 434{
 435        struct snd_info_entry *entry;
 436
 437        entry = snd_info_create_module_entry(mod, name, NULL);
 438        if (!entry)
 439                return NULL;
 440        entry->mode = S_IFDIR | 0555;
 441        if (snd_info_register(entry) < 0) {
 442                snd_info_free_entry(entry);
 443                return NULL;
 444        }
 445        return entry;
 446}
 447
 448static struct snd_info_entry *
 449snd_info_create_entry(const char *name, struct snd_info_entry *parent,
 450                      struct module *module);
 451
 452int __init snd_info_init(void)
 453{
 454        snd_proc_root = snd_info_create_entry("asound", NULL, THIS_MODULE);
 455        if (!snd_proc_root)
 456                return -ENOMEM;
 457        snd_proc_root->mode = S_IFDIR | 0555;
 458        snd_proc_root->p = proc_mkdir("asound", NULL);
 459        if (!snd_proc_root->p)
 460                goto error;
 461#ifdef CONFIG_SND_OSSEMUL
 462        snd_oss_root = create_subdir(THIS_MODULE, "oss");
 463        if (!snd_oss_root)
 464                goto error;
 465#endif
 466#if IS_ENABLED(CONFIG_SND_SEQUENCER)
 467        snd_seq_root = create_subdir(THIS_MODULE, "seq");
 468        if (!snd_seq_root)
 469                goto error;
 470#endif
 471        if (snd_info_version_init() < 0 ||
 472            snd_minor_info_init() < 0 ||
 473            snd_minor_info_oss_init() < 0 ||
 474            snd_card_info_init() < 0 ||
 475            snd_info_minor_register() < 0)
 476                goto error;
 477        return 0;
 478
 479 error:
 480        snd_info_free_entry(snd_proc_root);
 481        return -ENOMEM;
 482}
 483
 484int __exit snd_info_done(void)
 485{
 486        snd_info_free_entry(snd_proc_root);
 487        return 0;
 488}
 489
 490static void snd_card_id_read(struct snd_info_entry *entry,
 491                             struct snd_info_buffer *buffer)
 492{
 493        struct snd_card *card = entry->private_data;
 494
 495        snd_iprintf(buffer, "%s\n", card->id);
 496}
 497
 498/*
 499 * create a card proc file
 500 * called from init.c
 501 */
 502int snd_info_card_create(struct snd_card *card)
 503{
 504        char str[8];
 505        struct snd_info_entry *entry;
 506
 507        if (snd_BUG_ON(!card))
 508                return -ENXIO;
 509
 510        sprintf(str, "card%i", card->number);
 511        entry = create_subdir(card->module, str);
 512        if (!entry)
 513                return -ENOMEM;
 514        card->proc_root = entry;
 515
 516        return snd_card_ro_proc_new(card, "id", card, snd_card_id_read);
 517}
 518
 519/*
 520 * register the card proc file
 521 * called from init.c
 522 * can be called multiple times for reinitialization
 523 */
 524int snd_info_card_register(struct snd_card *card)
 525{
 526        struct proc_dir_entry *p;
 527        int err;
 528
 529        if (snd_BUG_ON(!card))
 530                return -ENXIO;
 531
 532        err = snd_info_register(card->proc_root);
 533        if (err < 0)
 534                return err;
 535
 536        if (!strcmp(card->id, card->proc_root->name))
 537                return 0;
 538
 539        if (card->proc_root_link)
 540                return 0;
 541        p = proc_symlink(card->id, snd_proc_root->p, card->proc_root->name);
 542        if (!p)
 543                return -ENOMEM;
 544        card->proc_root_link = p;
 545        return 0;
 546}
 547
 548/*
 549 * called on card->id change
 550 */
 551void snd_info_card_id_change(struct snd_card *card)
 552{
 553        mutex_lock(&info_mutex);
 554        if (card->proc_root_link) {
 555                proc_remove(card->proc_root_link);
 556                card->proc_root_link = NULL;
 557        }
 558        if (strcmp(card->id, card->proc_root->name))
 559                card->proc_root_link = proc_symlink(card->id,
 560                                                    snd_proc_root->p,
 561                                                    card->proc_root->name);
 562        mutex_unlock(&info_mutex);
 563}
 564
 565/*
 566 * de-register the card proc file
 567 * called from init.c
 568 */
 569void snd_info_card_disconnect(struct snd_card *card)
 570{
 571        if (!card)
 572                return;
 573        mutex_lock(&info_mutex);
 574        proc_remove(card->proc_root_link);
 575        card->proc_root_link = NULL;
 576        if (card->proc_root)
 577                snd_info_disconnect(card->proc_root);
 578        mutex_unlock(&info_mutex);
 579}
 580
 581/*
 582 * release the card proc file resources
 583 * called from init.c
 584 */
 585int snd_info_card_free(struct snd_card *card)
 586{
 587        if (!card)
 588                return 0;
 589        snd_info_free_entry(card->proc_root);
 590        card->proc_root = NULL;
 591        return 0;
 592}
 593
 594
 595/**
 596 * snd_info_get_line - read one line from the procfs buffer
 597 * @buffer: the procfs buffer
 598 * @line: the buffer to store
 599 * @len: the max. buffer size
 600 *
 601 * Reads one line from the buffer and stores the string.
 602 *
 603 * Return: Zero if successful, or 1 if error or EOF.
 604 */
 605int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
 606{
 607        int c;
 608
 609        if (snd_BUG_ON(!buffer))
 610                return 1;
 611        if (!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 proc_ops *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}
 915
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