diff options
Diffstat (limited to 'sound/core/init.c')
| -rw-r--r-- | sound/core/init.c | 946 |
1 files changed, 559 insertions, 387 deletions
diff --git a/sound/core/init.c b/sound/core/init.c index 6b9087115da2..c372b3228785 100644 --- a/sound/core/init.c +++ b/sound/core/init.c @@ -1,22 +1,7 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* * Initialization routines * Copyright (c) by Jaroslav Kysela <perex@perex.cz> - * - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - * */ #include <linux/init.h> @@ -28,6 +13,9 @@ #include <linux/time.h> #include <linux/ctype.h> #include <linux/pm.h> +#include <linux/debugfs.h> +#include <linux/completion.h> +#include <linux/interrupt.h> #include <sound/core.h> #include <sound/control.h> @@ -48,8 +36,7 @@ static const struct file_operations snd_shutdown_f_ops; /* locked for registering/using */ static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS); -struct snd_card *snd_cards[SNDRV_CARDS]; -EXPORT_SYMBOL(snd_cards); +static struct snd_card *snd_cards[SNDRV_CARDS]; static DEFINE_MUTEX(snd_card_mutex); @@ -63,10 +50,10 @@ MODULE_PARM_DESC(slots, "Module names assigned to the slots."); static int module_slot_match(struct module *module, int idx) { int match = 1; -#ifdef MODULE +#ifdef CONFIG_MODULES const char *s1, *s2; - if (!module || !module->name || !slots[idx]) + if (!module || !*module->name || !slots[idx]) return 0; s1 = module->name; @@ -90,69 +77,103 @@ static int module_slot_match(struct module *module, int idx) if (!c1) break; } -#endif /* MODULE */ +#endif /* CONFIG_MODULES */ return match; } -#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE) +#if IS_ENABLED(CONFIG_SND_MIXER_OSS) int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag); EXPORT_SYMBOL(snd_mixer_oss_notify_callback); #endif -#ifdef CONFIG_PROC_FS -static void snd_card_id_read(struct snd_info_entry *entry, - struct snd_info_buffer *buffer) +static int check_empty_slot(struct module *module, int slot) { - snd_iprintf(buffer, "%s\n", entry->card->id); + return !slots[slot] || !*slots[slot]; } -static inline int init_info_for_card(struct snd_card *card) +/* return an empty slot number (>= 0) found in the given bitmask @mask. + * @mask == -1 == 0xffffffff means: take any free slot up to 32 + * when no slot is available, return the original @mask as is. + */ +static int get_slot_from_bitmask(int mask, int (*check)(struct module *, int), + struct module *module) { - int err; - struct snd_info_entry *entry; - - if ((err = snd_info_card_register(card)) < 0) { - snd_printd("unable to create card info\n"); - return err; - } - if ((entry = snd_info_create_card_entry(card, "id", card->proc_root)) == NULL) { - snd_printd("unable to create card entry\n"); - return err; - } - entry->c.text.read = snd_card_id_read; - if (snd_info_register(entry) < 0) { - snd_info_free_entry(entry); - entry = NULL; + int slot; + + for (slot = 0; slot < SNDRV_CARDS; slot++) { + if (slot < 32 && !(mask & (1U << slot))) + continue; + if (!test_bit(slot, snd_cards_lock)) { + if (check(module, slot)) + return slot; /* found */ + } } - card->proc_id = entry; + return mask; /* unchanged */ +} + +/* the default release callback set in snd_device_alloc() */ +static void default_release_alloc(struct device *dev) +{ + kfree(dev); +} + +/** + * snd_device_alloc - Allocate and initialize struct device for sound devices + * @dev_p: pointer to store the allocated device + * @card: card to assign, optional + * + * For releasing the allocated device, call put_device(). + */ +int snd_device_alloc(struct device **dev_p, struct snd_card *card) +{ + struct device *dev; + + *dev_p = NULL; + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) + return -ENOMEM; + device_initialize(dev); + if (card) + dev->parent = &card->card_dev; + dev->class = &sound_class; + dev->release = default_release_alloc; + *dev_p = dev; return 0; } -#else /* !CONFIG_PROC_FS */ -#define init_info_for_card(card) -#endif +EXPORT_SYMBOL_GPL(snd_device_alloc); + +static int snd_card_init(struct snd_card *card, struct device *parent, + int idx, const char *xid, struct module *module, + size_t extra_size); +static int snd_card_do_free(struct snd_card *card); +static const struct attribute_group card_dev_attr_group; + +static void release_card_device(struct device *dev) +{ + snd_card_do_free(dev_to_snd_card(dev)); +} /** - * snd_card_create - create and initialize a soundcard structure + * snd_card_new - create and initialize a soundcard structure + * @parent: the parent device object * @idx: card index (address) [0 ... (SNDRV_CARDS-1)] * @xid: card identification (ASCII string) * @module: top level module for locking * @extra_size: allocate this extra size after the main soundcard structure * @card_ret: the pointer to store the created card instance * - * Creates and initializes a soundcard structure. - * * The function allocates snd_card instance via kzalloc with the given * space for the driver to use freely. The allocated struct is stored * in the given card_ret pointer. * * Return: Zero if successful or a negative error code. */ -int snd_card_create(int idx, const char *xid, +int snd_card_new(struct device *parent, int idx, const char *xid, struct module *module, int extra_size, struct snd_card **card_ret) { struct snd_card *card; - int err, idx2; + int err; if (snd_BUG_ON(!card_ret)) return -EINVAL; @@ -163,102 +184,220 @@ int snd_card_create(int idx, const char *xid, card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL); if (!card) return -ENOMEM; + + err = snd_card_init(card, parent, idx, xid, module, extra_size); + if (err < 0) + return err; /* card is freed by error handler */ + + *card_ret = card; + return 0; +} +EXPORT_SYMBOL(snd_card_new); + +static void __snd_card_release(struct device *dev, void *data) +{ + snd_card_free(data); +} + +/** + * snd_devm_card_new - managed snd_card object creation + * @parent: the parent device object + * @idx: card index (address) [0 ... (SNDRV_CARDS-1)] + * @xid: card identification (ASCII string) + * @module: top level module for locking + * @extra_size: allocate this extra size after the main soundcard structure + * @card_ret: the pointer to store the created card instance + * + * This function works like snd_card_new() but manages the allocated resource + * via devres, i.e. you don't need to free explicitly. + * + * When a snd_card object is created with this function and registered via + * snd_card_register(), the very first devres action to call snd_card_free() + * is added automatically. In that way, the resource disconnection is assured + * at first, then released in the expected order. + * + * If an error happens at the probe before snd_card_register() is called and + * there have been other devres resources, you'd need to free the card manually + * via snd_card_free() call in the error; otherwise it may lead to UAF due to + * devres call orders. You can use snd_card_free_on_error() helper for + * handling it more easily. + * + * Return: zero if successful, or a negative error code + */ +int snd_devm_card_new(struct device *parent, int idx, const char *xid, + struct module *module, size_t extra_size, + struct snd_card **card_ret) +{ + struct snd_card *card; + int err; + + *card_ret = NULL; + card = devres_alloc(__snd_card_release, sizeof(*card) + extra_size, + GFP_KERNEL); + if (!card) + return -ENOMEM; + card->managed = true; + err = snd_card_init(card, parent, idx, xid, module, extra_size); + if (err < 0) { + devres_free(card); /* in managed mode, we need to free manually */ + return err; + } + + devres_add(parent, card); + *card_ret = card; + return 0; +} +EXPORT_SYMBOL_GPL(snd_devm_card_new); + +/** + * snd_card_free_on_error - a small helper for handling devm probe errors + * @dev: the managed device object + * @ret: the return code from the probe callback + * + * This function handles the explicit snd_card_free() call at the error from + * the probe callback. It's just a small helper for simplifying the error + * handling with the managed devices. + * + * Return: zero if successful, or a negative error code + */ +int snd_card_free_on_error(struct device *dev, int ret) +{ + struct snd_card *card; + + if (!ret) + return 0; + card = devres_find(dev, __snd_card_release, NULL, NULL); + if (card) + snd_card_free(card); + return ret; +} +EXPORT_SYMBOL_GPL(snd_card_free_on_error); + +static int snd_card_init(struct snd_card *card, struct device *parent, + int idx, const char *xid, struct module *module, + size_t extra_size) +{ + int err; + + if (extra_size > 0) + card->private_data = (char *)card + sizeof(struct snd_card); if (xid) - strlcpy(card->id, xid, sizeof(card->id)); + strscpy(card->id, xid, sizeof(card->id)); err = 0; - mutex_lock(&snd_card_mutex); - if (idx < 0) { - for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++) { - /* idx == -1 == 0xffff means: take any free slot */ - if (idx2 < sizeof(int) && !(idx & (1U << idx2))) - continue; - if (!test_bit(idx2, snd_cards_lock)) { - if (module_slot_match(module, idx2)) { - idx = idx2; - break; - } - } + scoped_guard(mutex, &snd_card_mutex) { + if (idx < 0) /* first check the matching module-name slot */ + idx = get_slot_from_bitmask(idx, module_slot_match, module); + if (idx < 0) /* if not matched, assign an empty slot */ + idx = get_slot_from_bitmask(idx, check_empty_slot, module); + if (idx < 0) + err = -ENODEV; + else if (idx < snd_ecards_limit) { + if (test_bit(idx, snd_cards_lock)) + err = -EBUSY; /* invalid */ + } else if (idx >= SNDRV_CARDS) + err = -ENODEV; + if (!err) { + set_bit(idx, snd_cards_lock); /* lock it */ + if (idx >= snd_ecards_limit) + snd_ecards_limit = idx + 1; /* increase the limit */ } } - if (idx < 0) { - for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++) { - /* idx == -1 == 0xffff means: take any free slot */ - if (idx2 < sizeof(int) && !(idx & (1U << idx2))) - continue; - if (!test_bit(idx2, snd_cards_lock)) { - if (!slots[idx2] || !*slots[idx2]) { - idx = idx2; - break; - } - } - } - } - if (idx < 0) - err = -ENODEV; - else if (idx < snd_ecards_limit) { - if (test_bit(idx, snd_cards_lock)) - err = -EBUSY; /* invalid */ - } else if (idx >= SNDRV_CARDS) - err = -ENODEV; if (err < 0) { - mutex_unlock(&snd_card_mutex); - snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i), error: %d\n", - idx, snd_ecards_limit - 1, err); - goto __error; + dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n", + idx, snd_ecards_limit - 1, err); + if (!card->managed) + kfree(card); /* manually free here, as no destructor called */ + return err; } - set_bit(idx, snd_cards_lock); /* lock it */ - if (idx >= snd_ecards_limit) - snd_ecards_limit = idx + 1; /* increase the limit */ - mutex_unlock(&snd_card_mutex); + card->dev = parent; card->number = idx; + WARN_ON(IS_MODULE(CONFIG_SND) && !module); card->module = module; INIT_LIST_HEAD(&card->devices); init_rwsem(&card->controls_rwsem); - rwlock_init(&card->ctl_files_rwlock); + rwlock_init(&card->controls_rwlock); INIT_LIST_HEAD(&card->controls); INIT_LIST_HEAD(&card->ctl_files); +#ifdef CONFIG_SND_CTL_FAST_LOOKUP + xa_init(&card->ctl_numids); + xa_init(&card->ctl_hash); +#endif spin_lock_init(&card->files_lock); INIT_LIST_HEAD(&card->files_list); - init_waitqueue_head(&card->shutdown_sleep); - atomic_set(&card->refcount, 0); + mutex_init(&card->memory_mutex); #ifdef CONFIG_PM - mutex_init(&card->power_lock); init_waitqueue_head(&card->power_sleep); + init_waitqueue_head(&card->power_ref_sleep); + atomic_set(&card->power_ref, 0); #endif + init_waitqueue_head(&card->remove_sleep); + card->sync_irq = -1; + + device_initialize(&card->card_dev); + card->card_dev.parent = parent; + card->card_dev.class = &sound_class; + card->card_dev.release = release_card_device; + card->card_dev.groups = card->dev_groups; + card->dev_groups[0] = &card_dev_attr_group; + err = kobject_set_name(&card->card_dev.kobj, "card%d", idx); + if (err < 0) + goto __error; + + snprintf(card->irq_descr, sizeof(card->irq_descr), "%s:%s", + dev_driver_string(card->dev), dev_name(&card->card_dev)); + /* the control interface cannot be accessed from the user space until */ /* snd_cards_bitmask and snd_cards are set with snd_card_register */ err = snd_ctl_create(card); if (err < 0) { - snd_printk(KERN_ERR "unable to register control minors\n"); + dev_err(parent, "unable to register control minors\n"); goto __error; } err = snd_info_card_create(card); if (err < 0) { - snd_printk(KERN_ERR "unable to create card info\n"); + dev_err(parent, "unable to create card info\n"); goto __error_ctl; } - if (extra_size > 0) - card->private_data = (char *)card + sizeof(struct snd_card); - *card_ret = card; + +#ifdef CONFIG_SND_DEBUG + card->debugfs_root = debugfs_create_dir(dev_name(&card->card_dev), + sound_debugfs_root); +#endif return 0; __error_ctl: - snd_device_free_all(card, SNDRV_DEV_CMD_PRE); + snd_device_free_all(card); __error: - kfree(card); + put_device(&card->card_dev); return err; } -EXPORT_SYMBOL(snd_card_create); + +/** + * snd_card_ref - Get the card object from the index + * @idx: the card index + * + * Returns a card object corresponding to the given index or NULL if not found. + * Release the object via snd_card_unref(). + * + * Return: a card object or NULL + */ +struct snd_card *snd_card_ref(int idx) +{ + struct snd_card *card; + + guard(mutex)(&snd_card_mutex); + card = snd_cards[idx]; + if (card) + get_device(&card->card_dev); + return card; +} +EXPORT_SYMBOL_GPL(snd_card_ref); /* return non-zero if a card is already locked */ int snd_card_locked(int card) { - int locked; - - mutex_lock(&snd_card_mutex); - locked = test_bit(card, snd_cards_lock); - mutex_unlock(&snd_card_mutex); - return locked; + guard(mutex)(&snd_card_mutex); + return test_bit(card, snd_cards_lock); } static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig) @@ -282,15 +421,15 @@ static int snd_disconnect_release(struct inode *inode, struct file *file) { struct snd_monitor_file *df = NULL, *_df; - spin_lock(&shutdown_lock); - list_for_each_entry(_df, &shutdown_files, shutdown_list) { - if (_df->file == file) { - df = _df; - list_del_init(&df->shutdown_list); - break; + scoped_guard(spinlock, &shutdown_lock) { + list_for_each_entry(_df, &shutdown_files, shutdown_list) { + if (_df->file == file) { + df = _df; + list_del_init(&df->shutdown_list); + break; + } } } - spin_unlock(&shutdown_lock); if (likely(df)) { if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync) @@ -301,9 +440,9 @@ static int snd_disconnect_release(struct inode *inode, struct file *file) panic("%s(%p, %p) failed!", __func__, inode, file); } -static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait) +static __poll_t snd_disconnect_poll(struct file * file, poll_table * wait) { - return POLLERR | POLLNVAL; + return EPOLLERR | EPOLLNVAL; } static long snd_disconnect_ioctl(struct file *file, @@ -349,168 +488,185 @@ static const struct file_operations snd_shutdown_f_ops = * Note: The current implementation replaces all active file->f_op with special * dummy file operations (they do nothing except release). */ -int snd_card_disconnect(struct snd_card *card) +void snd_card_disconnect(struct snd_card *card) { struct snd_monitor_file *mfile; - int err; if (!card) - return -EINVAL; + return; - spin_lock(&card->files_lock); - if (card->shutdown) { - spin_unlock(&card->files_lock); - return 0; - } - card->shutdown = 1; - spin_unlock(&card->files_lock); + scoped_guard(spinlock, &card->files_lock) { + if (card->shutdown) + return; + card->shutdown = 1; - /* phase 1: disable fops (user space) operations for ALSA API */ - mutex_lock(&snd_card_mutex); - snd_cards[card->number] = NULL; - clear_bit(card->number, snd_cards_lock); - mutex_unlock(&snd_card_mutex); - - /* phase 2: replace file->f_op with special dummy operations */ - - spin_lock(&card->files_lock); - list_for_each_entry(mfile, &card->files_list, list) { - /* it's critical part, use endless loop */ - /* we have no room to fail */ - mfile->disconnected_f_op = mfile->file->f_op; + /* replace file->f_op with special dummy operations */ + list_for_each_entry(mfile, &card->files_list, list) { + /* it's critical part, use endless loop */ + /* we have no room to fail */ + mfile->disconnected_f_op = mfile->file->f_op; - spin_lock(&shutdown_lock); - list_add(&mfile->shutdown_list, &shutdown_files); - spin_unlock(&shutdown_lock); + scoped_guard(spinlock, &shutdown_lock) + list_add(&mfile->shutdown_list, &shutdown_files); - mfile->file->f_op = &snd_shutdown_f_ops; - fops_get(mfile->file->f_op); + mfile->file->f_op = &snd_shutdown_f_ops; + fops_get(mfile->file->f_op); + } } - spin_unlock(&card->files_lock); - /* phase 3: notify all connected devices about disconnection */ +#ifdef CONFIG_PM + /* wake up sleepers here before other callbacks for avoiding potential + * deadlocks with other locks (e.g. in kctls); + * then this notifies the shutdown and sleepers would abort immediately + */ + wake_up_all(&card->power_sleep); +#endif + + /* notify all connected devices about disconnection */ /* at this point, they cannot respond to any calls except release() */ -#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE) +#if IS_ENABLED(CONFIG_SND_MIXER_OSS) if (snd_mixer_oss_notify_callback) snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT); #endif /* notify all devices that we are disconnected */ - err = snd_device_disconnect_all(card); - if (err < 0) - snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number); + snd_device_disconnect_all(card); + + if (card->sync_irq > 0) + synchronize_irq(card->sync_irq); snd_info_card_disconnect(card); - if (card->card_dev) { - device_unregister(card->card_dev); - card->card_dev = NULL; - } -#ifdef CONFIG_PM - wake_up(&card->power_sleep); +#ifdef CONFIG_SND_DEBUG + debugfs_remove(card->debugfs_root); + card->debugfs_root = NULL; #endif - return 0; -} + if (card->registered) { + device_del(&card->card_dev); + card->registered = false; + } + + /* disable fops (user space) operations for ALSA API */ + scoped_guard(mutex, &snd_card_mutex) { + snd_cards[card->number] = NULL; + clear_bit(card->number, snd_cards_lock); + } + + snd_power_sync_ref(card); +} EXPORT_SYMBOL(snd_card_disconnect); /** - * snd_card_free - frees given soundcard structure - * @card: soundcard structure - * - * This function releases the soundcard structure and the all assigned - * devices automatically. That is, you don't have to release the devices - * by yourself. + * snd_card_disconnect_sync - disconnect card and wait until files get closed + * @card: card object to disconnect * - * Return: Zero. Frees all associated devices and frees the control - * interface associated to given soundcard. + * This calls snd_card_disconnect() for disconnecting all belonging components + * and waits until all pending files get closed. + * It assures that all accesses from user-space finished so that the driver + * can release its resources gracefully. */ +void snd_card_disconnect_sync(struct snd_card *card) +{ + snd_card_disconnect(card); + + guard(spinlock_irq)(&card->files_lock); + wait_event_lock_irq(card->remove_sleep, + list_empty(&card->files_list), + card->files_lock); +} +EXPORT_SYMBOL_GPL(snd_card_disconnect_sync); + static int snd_card_do_free(struct snd_card *card) { -#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE) + card->releasing = true; +#if IS_ENABLED(CONFIG_SND_MIXER_OSS) if (snd_mixer_oss_notify_callback) snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE); #endif - if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) { - snd_printk(KERN_ERR "unable to free all devices (pre)\n"); - /* Fatal, but this situation should never occur */ - } - if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) { - snd_printk(KERN_ERR "unable to free all devices (normal)\n"); - /* Fatal, but this situation should never occur */ - } - if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) { - snd_printk(KERN_ERR "unable to free all devices (post)\n"); - /* Fatal, but this situation should never occur */ - } + snd_device_free_all(card); if (card->private_free) card->private_free(card); - snd_info_free_entry(card->proc_id); if (snd_info_card_free(card) < 0) { - snd_printk(KERN_WARNING "unable to free card info\n"); + dev_warn(card->dev, "unable to free card info\n"); /* Not fatal error */ } - kfree(card); + if (card->release_completion) + complete(card->release_completion); + if (!card->managed) + kfree(card); return 0; } /** - * snd_card_unref - release the reference counter - * @card: the card instance + * snd_card_free_when_closed - Disconnect the card, free it later eventually + * @card: soundcard structure * - * Decrements the reference counter. When it reaches to zero, wake up - * the sleeper and call the destructor if needed. + * Unlike snd_card_free(), this function doesn't try to release the card + * resource immediately, but tries to disconnect at first. When the card + * is still in use, the function returns before freeing the resources. + * The card resources will be freed when the refcount gets to zero. + * + * Return: zero if successful, or a negative error code */ -void snd_card_unref(struct snd_card *card) +void snd_card_free_when_closed(struct snd_card *card) { - if (atomic_dec_and_test(&card->refcount)) { - wake_up(&card->shutdown_sleep); - if (card->free_on_last_close) - snd_card_do_free(card); - } -} -EXPORT_SYMBOL(snd_card_unref); - -int snd_card_free_when_closed(struct snd_card *card) -{ - int ret; - - atomic_inc(&card->refcount); - ret = snd_card_disconnect(card); - if (ret) { - atomic_dec(&card->refcount); - return ret; - } + if (!card) + return; - card->free_on_last_close = 1; - if (atomic_dec_and_test(&card->refcount)) - snd_card_do_free(card); - return 0; + snd_card_disconnect(card); + put_device(&card->card_dev); + return; } - EXPORT_SYMBOL(snd_card_free_when_closed); -int snd_card_free(struct snd_card *card) +/** + * snd_card_free - frees given soundcard structure + * @card: soundcard structure + * + * This function releases the soundcard structure and the all assigned + * devices automatically. That is, you don't have to release the devices + * by yourself. + * + * This function waits until the all resources are properly released. + * + * Return: Zero. Frees all associated devices and frees the control + * interface associated to given soundcard. + */ +void snd_card_free(struct snd_card *card) { - int ret = snd_card_disconnect(card); - if (ret) - return ret; + DECLARE_COMPLETION_ONSTACK(released); + + /* The call of snd_card_free() is allowed from various code paths; + * a manual call from the driver and the call via devres_free, and + * we need to avoid double-free. Moreover, the release via devres + * may call snd_card_free() twice due to its nature, we need to have + * the check here at the beginning. + */ + if (card->releasing) + return; + + card->release_completion = &released; + snd_card_free_when_closed(card); /* wait, until all devices are ready for the free operation */ - wait_event(card->shutdown_sleep, !atomic_read(&card->refcount)); - snd_card_do_free(card); - return 0; + wait_for_completion(&released); } - EXPORT_SYMBOL(snd_card_free); +/* check, if the character is in the valid ASCII range */ +static inline bool safe_ascii_char(char c) +{ + return isascii(c) && isalnum(c); +} + /* retrieve the last word of shortname or longname */ static const char *retrieve_id_from_card_name(const char *name) { const char *spos = name; while (*name) { - if (isspace(*name) && isalnum(name[1])) + if (isspace(*name) && safe_ascii_char(name[1])) spos = name + 1; name++; } @@ -537,12 +693,12 @@ static void copy_valid_id_string(struct snd_card *card, const char *src, { char *id = card->id; - while (*nid && !isalnum(*nid)) + while (*nid && !safe_ascii_char(*nid)) nid++; if (isdigit(*nid)) *id++ = isalpha(*src) ? *src : 'D'; while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) { - if (isalnum(*nid)) + if (safe_ascii_char(*nid)) *id++ = *nid; nid++; } @@ -567,27 +723,25 @@ static void snd_card_set_id_no_lock(struct snd_card *card, const char *src, * ("card" conflicts with proc directories) */ if (!*id || !strncmp(id, "card", 4)) { - strcpy(id, "Default"); + strscpy(card->id, "Default"); is_default = true; } len = strlen(id); for (loops = 0; loops < SNDRV_CARDS; loops++) { - char *spos; char sfxstr[5]; /* "_012" */ - int sfxlen; + int sfxlen, slen; if (card_id_ok(card, id)) return; /* OK */ /* Add _XYZ suffix */ - sprintf(sfxstr, "_%X", loops + 1); - sfxlen = strlen(sfxstr); + sfxlen = scnprintf(sfxstr, sizeof(sfxstr), "_%X", loops + 1); if (len + sfxlen >= sizeof(card->id)) - spos = id + sizeof(card->id) - sfxlen - 1; + slen = sizeof(card->id) - sfxlen - 1; else - spos = id + len; - strcpy(spos, sfxstr); + slen = len; + strscpy(id + slen, sfxstr, sizeof(card->id) - slen); } /* fallback to the default id */ if (!is_default) { @@ -595,9 +749,9 @@ static void snd_card_set_id_no_lock(struct snd_card *card, const char *src, goto again; } /* last resort... */ - snd_printk(KERN_ERR "unable to set card id (%s)\n", id); + dev_err(card->dev, "unable to set card id (%s)\n", id); if (card->proc_root->name) - strcpy(card->id, card->proc_root->name); + strscpy(card->id, card->proc_root->name, sizeof(card->id)); } /** @@ -613,25 +767,22 @@ void snd_card_set_id(struct snd_card *card, const char *nid) /* check if user specified own card->id */ if (card->id[0] != '\0') return; - mutex_lock(&snd_card_mutex); + guard(mutex)(&snd_card_mutex); snd_card_set_id_no_lock(card, nid, nid); - mutex_unlock(&snd_card_mutex); } EXPORT_SYMBOL(snd_card_set_id); -static ssize_t -card_id_show_attr(struct device *dev, - struct device_attribute *attr, char *buf) +static ssize_t id_show(struct device *dev, + struct device_attribute *attr, char *buf) { - struct snd_card *card = dev_get_drvdata(dev); - return snprintf(buf, PAGE_SIZE, "%s\n", card ? card->id : "(null)"); + struct snd_card *card = container_of(dev, struct snd_card, card_dev); + return sysfs_emit(buf, "%s\n", card->id); } -static ssize_t -card_id_store_attr(struct device *dev, struct device_attribute *attr, - const char *buf, size_t count) +static ssize_t id_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) { - struct snd_card *card = dev_get_drvdata(dev); + struct snd_card *card = container_of(dev, struct snd_card, card_dev); char buf1[sizeof(card->id)]; size_t copy = count > sizeof(card->id) - 1 ? sizeof(card->id) - 1 : count; @@ -640,36 +791,70 @@ card_id_store_attr(struct device *dev, struct device_attribute *attr, for (idx = 0; idx < copy; idx++) { c = buf[idx]; - if (!isalnum(c) && c != '_' && c != '-') + if (!safe_ascii_char(c) && c != '_' && c != '-') return -EINVAL; } memcpy(buf1, buf, copy); buf1[copy] = '\0'; - mutex_lock(&snd_card_mutex); - if (!card_id_ok(NULL, buf1)) { - mutex_unlock(&snd_card_mutex); + guard(mutex)(&snd_card_mutex); + if (!card_id_ok(NULL, buf1)) return -EEXIST; - } - strcpy(card->id, buf1); + strscpy(card->id, buf1); snd_info_card_id_change(card); - mutex_unlock(&snd_card_mutex); return count; } -static struct device_attribute card_id_attrs = - __ATTR(id, S_IRUGO | S_IWUSR, card_id_show_attr, card_id_store_attr); +static DEVICE_ATTR_RW(id); + +static ssize_t number_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct snd_card *card = container_of(dev, struct snd_card, card_dev); + return sysfs_emit(buf, "%i\n", card->number); +} + +static DEVICE_ATTR_RO(number); + +static struct attribute *card_dev_attrs[] = { + &dev_attr_id.attr, + &dev_attr_number.attr, + NULL +}; + +static const struct attribute_group card_dev_attr_group = { + .attrs = card_dev_attrs, +}; -static ssize_t -card_number_show_attr(struct device *dev, - struct device_attribute *attr, char *buf) +/** + * snd_card_add_dev_attr - Append a new sysfs attribute group to card + * @card: card instance + * @group: attribute group to append + * + * Return: zero if successful, or a negative error code + */ +int snd_card_add_dev_attr(struct snd_card *card, + const struct attribute_group *group) { - struct snd_card *card = dev_get_drvdata(dev); - return snprintf(buf, PAGE_SIZE, "%i\n", card ? card->number : -1); + int i; + + /* loop for (arraysize-1) here to keep NULL at the last entry */ + for (i = 0; i < ARRAY_SIZE(card->dev_groups) - 1; i++) { + if (!card->dev_groups[i]) { + card->dev_groups[i] = group; + return 0; + } + } + + dev_err(card->dev, "Too many groups assigned\n"); + return -ENOSPC; } +EXPORT_SYMBOL_GPL(snd_card_add_dev_attr); -static struct device_attribute card_number_attrs = - __ATTR(number, S_IRUGO, card_number_show_attr, NULL); +static void trigger_card_free(void *data) +{ + snd_card_free(data); +} /** * snd_card_register - register the soundcard @@ -689,58 +874,59 @@ int snd_card_register(struct snd_card *card) if (snd_BUG_ON(!card)) return -EINVAL; - if (!card->card_dev) { - card->card_dev = device_create(sound_class, card->dev, - MKDEV(0, 0), card, - "card%i", card->number); - if (IS_ERR(card->card_dev)) - card->card_dev = NULL; + if (!card->registered) { + err = device_add(&card->card_dev); + if (err < 0) + return err; + card->registered = true; + } else { + if (card->managed) + devm_remove_action(card->dev, trigger_card_free, card); } - if ((err = snd_device_register_all(card)) < 0) + if (card->managed) { + err = devm_add_action(card->dev, trigger_card_free, card); + if (err < 0) + return err; + } + + err = snd_device_register_all(card); + if (err < 0) return err; - mutex_lock(&snd_card_mutex); - if (snd_cards[card->number]) { - /* already registered */ - mutex_unlock(&snd_card_mutex); - return 0; + scoped_guard(mutex, &snd_card_mutex) { + if (snd_cards[card->number]) { + /* already registered */ + return snd_info_card_register(card); /* register pending info */ + } + if (*card->id) { + /* make a unique id name from the given string */ + char tmpid[sizeof(card->id)]; + + memcpy(tmpid, card->id, sizeof(card->id)); + snd_card_set_id_no_lock(card, tmpid, tmpid); + } else { + /* create an id from either shortname or longname */ + const char *src; + + src = *card->shortname ? card->shortname : card->longname; + snd_card_set_id_no_lock(card, src, + retrieve_id_from_card_name(src)); + } + snd_cards[card->number] = card; } - if (*card->id) { - /* make a unique id name from the given string */ - char tmpid[sizeof(card->id)]; - memcpy(tmpid, card->id, sizeof(card->id)); - snd_card_set_id_no_lock(card, tmpid, tmpid); - } else { - /* create an id from either shortname or longname */ - const char *src; - src = *card->shortname ? card->shortname : card->longname; - snd_card_set_id_no_lock(card, src, - retrieve_id_from_card_name(src)); - } - snd_cards[card->number] = card; - mutex_unlock(&snd_card_mutex); - init_info_for_card(card); -#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE) + err = snd_info_card_register(card); + if (err < 0) + return err; + +#if IS_ENABLED(CONFIG_SND_MIXER_OSS) if (snd_mixer_oss_notify_callback) snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER); #endif - if (card->card_dev) { - err = device_create_file(card->card_dev, &card_id_attrs); - if (err < 0) - return err; - err = device_create_file(card->card_dev, &card_number_attrs); - if (err < 0) - return err; - } - return 0; } - EXPORT_SYMBOL(snd_card_register); -#ifdef CONFIG_PROC_FS -static struct snd_info_entry *snd_card_info_entry; - +#ifdef CONFIG_SND_PROC_FS static void snd_card_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer) { @@ -748,8 +934,9 @@ static void snd_card_info_read(struct snd_info_entry *entry, struct snd_card *card; for (idx = count = 0; idx < SNDRV_CARDS; idx++) { - mutex_lock(&snd_card_mutex); - if ((card = snd_cards[idx]) != NULL) { + guard(mutex)(&snd_card_mutex); + card = snd_cards[idx]; + if (card) { count++; snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n", idx, @@ -759,26 +946,24 @@ static void snd_card_info_read(struct snd_info_entry *entry, snd_iprintf(buffer, " %s\n", card->longname); } - mutex_unlock(&snd_card_mutex); } if (!count) snd_iprintf(buffer, "--- no soundcards ---\n"); } #ifdef CONFIG_SND_OSSEMUL - void snd_card_info_read_oss(struct snd_info_buffer *buffer) { int idx, count; struct snd_card *card; for (idx = count = 0; idx < SNDRV_CARDS; idx++) { - mutex_lock(&snd_card_mutex); - if ((card = snd_cards[idx]) != NULL) { + guard(mutex)(&snd_card_mutex); + card = snd_cards[idx]; + if (card) { count++; snd_iprintf(buffer, "%s\n", card->longname); } - mutex_unlock(&snd_card_mutex); } if (!count) { snd_iprintf(buffer, "--- no soundcards ---\n"); @@ -787,8 +972,7 @@ void snd_card_info_read_oss(struct snd_info_buffer *buffer) #endif -#ifdef MODULE -static struct snd_info_entry *snd_card_module_info_entry; +#ifdef CONFIG_MODULES static void snd_card_module_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer) { @@ -796,11 +980,11 @@ static void snd_card_module_info_read(struct snd_info_entry *entry, struct snd_card *card; for (idx = 0; idx < SNDRV_CARDS; idx++) { - mutex_lock(&snd_card_mutex); - if ((card = snd_cards[idx]) != NULL) + guard(mutex)(&snd_card_mutex); + card = snd_cards[idx]; + if (card) snd_iprintf(buffer, "%2i %s\n", idx, card->module->name); - mutex_unlock(&snd_card_mutex); } } #endif @@ -813,36 +997,21 @@ int __init snd_card_info_init(void) if (! entry) return -ENOMEM; entry->c.text.read = snd_card_info_read; - if (snd_info_register(entry) < 0) { - snd_info_free_entry(entry); - return -ENOMEM; - } - snd_card_info_entry = entry; + if (snd_info_register(entry) < 0) + return -ENOMEM; /* freed in error path */ -#ifdef MODULE +#ifdef CONFIG_MODULES entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL); - if (entry) { - entry->c.text.read = snd_card_module_info_read; - if (snd_info_register(entry) < 0) - snd_info_free_entry(entry); - else - snd_card_module_info_entry = entry; - } + if (!entry) + return -ENOMEM; + entry->c.text.read = snd_card_module_info_read; + if (snd_info_register(entry) < 0) + return -ENOMEM; /* freed in error path */ #endif return 0; } - -int __exit snd_card_info_done(void) -{ - snd_info_free_entry(snd_card_info_entry); -#ifdef MODULE - snd_info_free_entry(snd_card_module_info_entry); -#endif - return 0; -} - -#endif /* CONFIG_PROC_FS */ +#endif /* CONFIG_SND_PROC_FS */ /** * snd_component_add - add a component string @@ -874,7 +1043,6 @@ int snd_component_add(struct snd_card *card, const char *component) strcat(card->components, component); return 0; } - EXPORT_SYMBOL(snd_component_add); /** @@ -898,18 +1066,15 @@ int snd_card_file_add(struct snd_card *card, struct file *file) mfile->file = file; mfile->disconnected_f_op = NULL; INIT_LIST_HEAD(&mfile->shutdown_list); - spin_lock(&card->files_lock); + guard(spinlock)(&card->files_lock); if (card->shutdown) { - spin_unlock(&card->files_lock); kfree(mfile); return -ENODEV; } list_add(&mfile->list, &card->files_list); - atomic_inc(&card->refcount); - spin_unlock(&card->files_lock); + get_device(&card->card_dev); return 0; } - EXPORT_SYMBOL(snd_card_file_add); /** @@ -929,68 +1094,75 @@ int snd_card_file_remove(struct snd_card *card, struct file *file) { struct snd_monitor_file *mfile, *found = NULL; - spin_lock(&card->files_lock); - list_for_each_entry(mfile, &card->files_list, list) { - if (mfile->file == file) { - list_del(&mfile->list); - spin_lock(&shutdown_lock); - list_del(&mfile->shutdown_list); - spin_unlock(&shutdown_lock); - if (mfile->disconnected_f_op) - fops_put(mfile->disconnected_f_op); - found = mfile; - break; + scoped_guard(spinlock, &card->files_lock) { + list_for_each_entry(mfile, &card->files_list, list) { + if (mfile->file == file) { + list_del(&mfile->list); + scoped_guard(spinlock, &shutdown_lock) + list_del(&mfile->shutdown_list); + if (mfile->disconnected_f_op) + fops_put(mfile->disconnected_f_op); + found = mfile; + break; + } } + if (list_empty(&card->files_list)) + wake_up_all(&card->remove_sleep); } - spin_unlock(&card->files_lock); if (!found) { - snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file); + dev_err(card->dev, "card file remove problem (%p)\n", file); return -ENOENT; } kfree(found); - snd_card_unref(card); + put_device(&card->card_dev); return 0; } - EXPORT_SYMBOL(snd_card_file_remove); #ifdef CONFIG_PM /** - * snd_power_wait - wait until the power-state is changed. - * @card: soundcard structure - * @power_state: expected power state + * snd_power_ref_and_wait - wait until the card gets powered up + * @card: soundcard structure * - * Waits until the power-state is changed. + * Take the power_ref reference count of the given card, and + * wait until the card gets powered up to SNDRV_CTL_POWER_D0 state. + * The refcount is down again while sleeping until power-up, hence this + * function can be used for syncing the floating control ops accesses, + * typically around calling control ops. * - * Return: Zero if successful, or a negative error code. + * The caller needs to pull down the refcount via snd_power_unref() later + * no matter whether the error is returned from this function or not. * - * Note: the power lock must be active before call. + * Return: Zero if successful, or a negative error code. */ -int snd_power_wait(struct snd_card *card, unsigned int power_state) +int snd_power_ref_and_wait(struct snd_card *card) { - wait_queue_t wait; - int result = 0; - - /* fastpath */ - if (snd_power_get_state(card) == power_state) + snd_power_ref(card); + if (snd_power_get_state(card) == SNDRV_CTL_POWER_D0) return 0; - init_waitqueue_entry(&wait, current); - add_wait_queue(&card->power_sleep, &wait); - while (1) { - if (card->shutdown) { - result = -ENODEV; - break; - } - if (snd_power_get_state(card) == power_state) - break; - set_current_state(TASK_UNINTERRUPTIBLE); - snd_power_unlock(card); - schedule_timeout(30 * HZ); - snd_power_lock(card); - } - remove_wait_queue(&card->power_sleep, &wait); - return result; + wait_event_cmd(card->power_sleep, + card->shutdown || + snd_power_get_state(card) == SNDRV_CTL_POWER_D0, + snd_power_unref(card), snd_power_ref(card)); + return card->shutdown ? -ENODEV : 0; } +EXPORT_SYMBOL_GPL(snd_power_ref_and_wait); + +/** + * snd_power_wait - wait until the card gets powered up (old form) + * @card: soundcard structure + * + * Wait until the card gets powered up to SNDRV_CTL_POWER_D0 state. + * + * Return: Zero if successful, or a negative error code. + */ +int snd_power_wait(struct snd_card *card) +{ + int ret; + ret = snd_power_ref_and_wait(card); + snd_power_unref(card); + return ret; +} EXPORT_SYMBOL(snd_power_wait); #endif /* CONFIG_PM */ |