| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * Routines for driver control interface |
| * Copyright (c) by Jaroslav Kysela <perex@perex.cz> |
| */ |
| |
| #include <linux/threads.h> |
| #include <linux/interrupt.h> |
| #include <linux/module.h> |
| #include <linux/moduleparam.h> |
| #include <linux/slab.h> |
| #include <linux/vmalloc.h> |
| #include <linux/time.h> |
| #include <linux/mm.h> |
| #include <linux/math64.h> |
| #include <linux/sched/signal.h> |
| #include <sound/core.h> |
| #include <sound/minors.h> |
| #include <sound/info.h> |
| #include <sound/control.h> |
| |
| // Max allocation size for user controls. |
| static int max_user_ctl_alloc_size = 8 * 1024 * 1024; |
| module_param_named(max_user_ctl_alloc_size, max_user_ctl_alloc_size, int, 0444); |
| MODULE_PARM_DESC(max_user_ctl_alloc_size, "Max allocation size for user controls"); |
| |
| #define MAX_CONTROL_COUNT 1028 |
| |
| struct snd_kctl_ioctl { |
| struct list_head list; /* list of all ioctls */ |
| snd_kctl_ioctl_func_t fioctl; |
| }; |
| |
| static DECLARE_RWSEM(snd_ioctl_rwsem); |
| static DECLARE_RWSEM(snd_ctl_layer_rwsem); |
| static LIST_HEAD(snd_control_ioctls); |
| #ifdef CONFIG_COMPAT |
| static LIST_HEAD(snd_control_compat_ioctls); |
| #endif |
| static struct snd_ctl_layer_ops *snd_ctl_layer; |
| |
| static int snd_ctl_remove_locked(struct snd_card *card, |
| struct snd_kcontrol *kcontrol); |
| |
| static int snd_ctl_open(struct inode *inode, struct file *file) |
| { |
| struct snd_card *card; |
| struct snd_ctl_file *ctl; |
| int i, err; |
| |
| err = stream_open(inode, file); |
| if (err < 0) |
| return err; |
| |
| card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL); |
| if (!card) { |
| err = -ENODEV; |
| goto __error1; |
| } |
| err = snd_card_file_add(card, file); |
| if (err < 0) { |
| err = -ENODEV; |
| goto __error1; |
| } |
| if (!try_module_get(card->module)) { |
| err = -EFAULT; |
| goto __error2; |
| } |
| ctl = kzalloc(sizeof(*ctl), GFP_KERNEL); |
| if (ctl == NULL) { |
| err = -ENOMEM; |
| goto __error; |
| } |
| INIT_LIST_HEAD(&ctl->events); |
| init_waitqueue_head(&ctl->change_sleep); |
| spin_lock_init(&ctl->read_lock); |
| ctl->card = card; |
| for (i = 0; i < SND_CTL_SUBDEV_ITEMS; i++) |
| ctl->preferred_subdevice[i] = -1; |
| ctl->pid = get_pid(task_pid(current)); |
| file->private_data = ctl; |
| scoped_guard(write_lock_irqsave, &card->ctl_files_rwlock) |
| list_add_tail(&ctl->list, &card->ctl_files); |
| snd_card_unref(card); |
| return 0; |
| |
| __error: |
| module_put(card->module); |
| __error2: |
| snd_card_file_remove(card, file); |
| __error1: |
| if (card) |
| snd_card_unref(card); |
| return err; |
| } |
| |
| static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl) |
| { |
| struct snd_kctl_event *cread; |
| |
| guard(spinlock_irqsave)(&ctl->read_lock); |
| while (!list_empty(&ctl->events)) { |
| cread = snd_kctl_event(ctl->events.next); |
| list_del(&cread->list); |
| kfree(cread); |
| } |
| } |
| |
| static int snd_ctl_release(struct inode *inode, struct file *file) |
| { |
| struct snd_card *card; |
| struct snd_ctl_file *ctl; |
| struct snd_kcontrol *control; |
| unsigned int idx; |
| |
| ctl = file->private_data; |
| file->private_data = NULL; |
| card = ctl->card; |
| |
| scoped_guard(write_lock_irqsave, &card->ctl_files_rwlock) |
| list_del(&ctl->list); |
| |
| scoped_guard(rwsem_write, &card->controls_rwsem) { |
| list_for_each_entry(control, &card->controls, list) |
| for (idx = 0; idx < control->count; idx++) |
| if (control->vd[idx].owner == ctl) |
| control->vd[idx].owner = NULL; |
| } |
| |
| snd_fasync_free(ctl->fasync); |
| snd_ctl_empty_read_queue(ctl); |
| put_pid(ctl->pid); |
| kfree(ctl); |
| module_put(card->module); |
| snd_card_file_remove(card, file); |
| return 0; |
| } |
| |
| /** |
| * snd_ctl_notify - Send notification to user-space for a control change |
| * @card: the card to send notification |
| * @mask: the event mask, SNDRV_CTL_EVENT_* |
| * @id: the ctl element id to send notification |
| * |
| * This function adds an event record with the given id and mask, appends |
| * to the list and wakes up the user-space for notification. This can be |
| * called in the atomic context. |
| */ |
| void snd_ctl_notify(struct snd_card *card, unsigned int mask, |
| struct snd_ctl_elem_id *id) |
| { |
| struct snd_ctl_file *ctl; |
| struct snd_kctl_event *ev; |
| |
| if (snd_BUG_ON(!card || !id)) |
| return; |
| if (card->shutdown) |
| return; |
| |
| guard(read_lock_irqsave)(&card->ctl_files_rwlock); |
| #if IS_ENABLED(CONFIG_SND_MIXER_OSS) |
| card->mixer_oss_change_count++; |
| #endif |
| list_for_each_entry(ctl, &card->ctl_files, list) { |
| if (!ctl->subscribed) |
| continue; |
| scoped_guard(spinlock, &ctl->read_lock) { |
| list_for_each_entry(ev, &ctl->events, list) { |
| if (ev->id.numid == id->numid) { |
| ev->mask |= mask; |
| goto _found; |
| } |
| } |
| ev = kzalloc(sizeof(*ev), GFP_ATOMIC); |
| if (ev) { |
| ev->id = *id; |
| ev->mask = mask; |
| list_add_tail(&ev->list, &ctl->events); |
| } else { |
| dev_err(card->dev, "No memory available to allocate event\n"); |
| } |
| _found: |
| wake_up(&ctl->change_sleep); |
| } |
| snd_kill_fasync(ctl->fasync, SIGIO, POLL_IN); |
| } |
| } |
| EXPORT_SYMBOL(snd_ctl_notify); |
| |
| /** |
| * snd_ctl_notify_one - Send notification to user-space for a control change |
| * @card: the card to send notification |
| * @mask: the event mask, SNDRV_CTL_EVENT_* |
| * @kctl: the pointer with the control instance |
| * @ioff: the additional offset to the control index |
| * |
| * This function calls snd_ctl_notify() and does additional jobs |
| * like LED state changes. |
| */ |
| void snd_ctl_notify_one(struct snd_card *card, unsigned int mask, |
| struct snd_kcontrol *kctl, unsigned int ioff) |
| { |
| struct snd_ctl_elem_id id = kctl->id; |
| struct snd_ctl_layer_ops *lops; |
| |
| id.index += ioff; |
| id.numid += ioff; |
| snd_ctl_notify(card, mask, &id); |
| guard(rwsem_read)(&snd_ctl_layer_rwsem); |
| for (lops = snd_ctl_layer; lops; lops = lops->next) |
| lops->lnotify(card, mask, kctl, ioff); |
| } |
| EXPORT_SYMBOL(snd_ctl_notify_one); |
| |
| /** |
| * snd_ctl_new - create a new control instance with some elements |
| * @kctl: the pointer to store new control instance |
| * @count: the number of elements in this control |
| * @access: the default access flags for elements in this control |
| * @file: given when locking these elements |
| * |
| * Allocates a memory object for a new control instance. The instance has |
| * elements as many as the given number (@count). Each element has given |
| * access permissions (@access). Each element is locked when @file is given. |
| * |
| * Return: 0 on success, error code on failure |
| */ |
| static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count, |
| unsigned int access, struct snd_ctl_file *file) |
| { |
| unsigned int idx; |
| |
| if (count == 0 || count > MAX_CONTROL_COUNT) |
| return -EINVAL; |
| |
| *kctl = kzalloc(struct_size(*kctl, vd, count), GFP_KERNEL); |
| if (!*kctl) |
| return -ENOMEM; |
| |
| for (idx = 0; idx < count; idx++) { |
| (*kctl)->vd[idx].access = access; |
| (*kctl)->vd[idx].owner = file; |
| } |
| (*kctl)->count = count; |
| |
| return 0; |
| } |
| |
| /** |
| * snd_ctl_new1 - create a control instance from the template |
| * @ncontrol: the initialization record |
| * @private_data: the private data to set |
| * |
| * Allocates a new struct snd_kcontrol instance and initialize from the given |
| * template. When the access field of ncontrol is 0, it's assumed as |
| * READWRITE access. When the count field is 0, it's assumes as one. |
| * |
| * Return: The pointer of the newly generated instance, or %NULL on failure. |
| */ |
| struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol, |
| void *private_data) |
| { |
| struct snd_kcontrol *kctl; |
| unsigned int count; |
| unsigned int access; |
| int err; |
| |
| if (snd_BUG_ON(!ncontrol || !ncontrol->info)) |
| return NULL; |
| |
| count = ncontrol->count; |
| if (count == 0) |
| count = 1; |
| |
| access = ncontrol->access; |
| if (access == 0) |
| access = SNDRV_CTL_ELEM_ACCESS_READWRITE; |
| access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE | |
| SNDRV_CTL_ELEM_ACCESS_VOLATILE | |
| SNDRV_CTL_ELEM_ACCESS_INACTIVE | |
| SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE | |
| SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND | |
| SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK | |
| SNDRV_CTL_ELEM_ACCESS_LED_MASK | |
| SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK); |
| |
| err = snd_ctl_new(&kctl, count, access, NULL); |
| if (err < 0) |
| return NULL; |
| |
| /* The 'numid' member is decided when calling snd_ctl_add(). */ |
| kctl->id.iface = ncontrol->iface; |
| kctl->id.device = ncontrol->device; |
| kctl->id.subdevice = ncontrol->subdevice; |
| if (ncontrol->name) { |
| strscpy(kctl->id.name, ncontrol->name, sizeof(kctl->id.name)); |
| if (strcmp(ncontrol->name, kctl->id.name) != 0) |
| pr_warn("ALSA: Control name '%s' truncated to '%s'\n", |
| ncontrol->name, kctl->id.name); |
| } |
| kctl->id.index = ncontrol->index; |
| |
| kctl->info = ncontrol->info; |
| kctl->get = ncontrol->get; |
| kctl->put = ncontrol->put; |
| kctl->tlv.p = ncontrol->tlv.p; |
| |
| kctl->private_value = ncontrol->private_value; |
| kctl->private_data = private_data; |
| |
| return kctl; |
| } |
| EXPORT_SYMBOL(snd_ctl_new1); |
| |
| /** |
| * snd_ctl_free_one - release the control instance |
| * @kcontrol: the control instance |
| * |
| * Releases the control instance created via snd_ctl_new() |
| * or snd_ctl_new1(). |
| * Don't call this after the control was added to the card. |
| */ |
| void snd_ctl_free_one(struct snd_kcontrol *kcontrol) |
| { |
| if (kcontrol) { |
| if (kcontrol->private_free) |
| kcontrol->private_free(kcontrol); |
| kfree(kcontrol); |
| } |
| } |
| EXPORT_SYMBOL(snd_ctl_free_one); |
| |
| static bool snd_ctl_remove_numid_conflict(struct snd_card *card, |
| unsigned int count) |
| { |
| struct snd_kcontrol *kctl; |
| |
| /* Make sure that the ids assigned to the control do not wrap around */ |
| if (card->last_numid >= UINT_MAX - count) |
| card->last_numid = 0; |
| |
| list_for_each_entry(kctl, &card->controls, list) { |
| if (kctl->id.numid < card->last_numid + 1 + count && |
| kctl->id.numid + kctl->count > card->last_numid + 1) { |
| card->last_numid = kctl->id.numid + kctl->count - 1; |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| static int snd_ctl_find_hole(struct snd_card *card, unsigned int count) |
| { |
| unsigned int iter = 100000; |
| |
| while (snd_ctl_remove_numid_conflict(card, count)) { |
| if (--iter == 0) { |
| /* this situation is very unlikely */ |
| dev_err(card->dev, "unable to allocate new control numid\n"); |
| return -ENOMEM; |
| } |
| } |
| return 0; |
| } |
| |
| /* check whether the given id is contained in the given kctl */ |
| static bool elem_id_matches(const struct snd_kcontrol *kctl, |
| const struct snd_ctl_elem_id *id) |
| { |
| return kctl->id.iface == id->iface && |
| kctl->id.device == id->device && |
| kctl->id.subdevice == id->subdevice && |
| !strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)) && |
| kctl->id.index <= id->index && |
| kctl->id.index + kctl->count > id->index; |
| } |
| |
| #ifdef CONFIG_SND_CTL_FAST_LOOKUP |
| /* Compute a hash key for the corresponding ctl id |
| * It's for the name lookup, hence the numid is excluded. |
| * The hash key is bound in LONG_MAX to be used for Xarray key. |
| */ |
| #define MULTIPLIER 37 |
| static unsigned long get_ctl_id_hash(const struct snd_ctl_elem_id *id) |
| { |
| int i; |
| unsigned long h; |
| |
| h = id->iface; |
| h = MULTIPLIER * h + id->device; |
| h = MULTIPLIER * h + id->subdevice; |
| for (i = 0; i < SNDRV_CTL_ELEM_ID_NAME_MAXLEN && id->name[i]; i++) |
| h = MULTIPLIER * h + id->name[i]; |
| h = MULTIPLIER * h + id->index; |
| h &= LONG_MAX; |
| return h; |
| } |
| |
| /* add hash entries to numid and ctl xarray tables */ |
| static void add_hash_entries(struct snd_card *card, |
| struct snd_kcontrol *kcontrol) |
| { |
| struct snd_ctl_elem_id id = kcontrol->id; |
| int i; |
| |
| xa_store_range(&card->ctl_numids, kcontrol->id.numid, |
| kcontrol->id.numid + kcontrol->count - 1, |
| kcontrol, GFP_KERNEL); |
| |
| for (i = 0; i < kcontrol->count; i++) { |
| id.index = kcontrol->id.index + i; |
| if (xa_insert(&card->ctl_hash, get_ctl_id_hash(&id), |
| kcontrol, GFP_KERNEL)) { |
| /* skip hash for this entry, noting we had collision */ |
| card->ctl_hash_collision = true; |
| dev_dbg(card->dev, "ctl_hash collision %d:%s:%d\n", |
| id.iface, id.name, id.index); |
| } |
| } |
| } |
| |
| /* remove hash entries that have been added */ |
| static void remove_hash_entries(struct snd_card *card, |
| struct snd_kcontrol *kcontrol) |
| { |
| struct snd_ctl_elem_id id = kcontrol->id; |
| struct snd_kcontrol *matched; |
| unsigned long h; |
| int i; |
| |
| for (i = 0; i < kcontrol->count; i++) { |
| xa_erase(&card->ctl_numids, id.numid); |
| h = get_ctl_id_hash(&id); |
| matched = xa_load(&card->ctl_hash, h); |
| if (matched && (matched == kcontrol || |
| elem_id_matches(matched, &id))) |
| xa_erase(&card->ctl_hash, h); |
| id.index++; |
| id.numid++; |
| } |
| } |
| #else /* CONFIG_SND_CTL_FAST_LOOKUP */ |
| static inline void add_hash_entries(struct snd_card *card, |
| struct snd_kcontrol *kcontrol) |
| { |
| } |
| static inline void remove_hash_entries(struct snd_card *card, |
| struct snd_kcontrol *kcontrol) |
| { |
| } |
| #endif /* CONFIG_SND_CTL_FAST_LOOKUP */ |
| |
| enum snd_ctl_add_mode { |
| CTL_ADD_EXCLUSIVE, CTL_REPLACE, CTL_ADD_ON_REPLACE, |
| }; |
| |
| /* add/replace a new kcontrol object; call with card->controls_rwsem locked */ |
| static int __snd_ctl_add_replace(struct snd_card *card, |
| struct snd_kcontrol *kcontrol, |
| enum snd_ctl_add_mode mode) |
| { |
| struct snd_ctl_elem_id id; |
| unsigned int idx; |
| struct snd_kcontrol *old; |
| int err; |
| |
| lockdep_assert_held_write(&card->controls_rwsem); |
| |
| id = kcontrol->id; |
| if (id.index > UINT_MAX - kcontrol->count) |
| return -EINVAL; |
| |
| old = snd_ctl_find_id_locked(card, &id); |
| if (!old) { |
| if (mode == CTL_REPLACE) |
| return -EINVAL; |
| } else { |
| if (mode == CTL_ADD_EXCLUSIVE) { |
| dev_err(card->dev, |
| "control %i:%i:%i:%s:%i is already present\n", |
| id.iface, id.device, id.subdevice, id.name, |
| id.index); |
| return -EBUSY; |
| } |
| |
| err = snd_ctl_remove_locked(card, old); |
| if (err < 0) |
| return err; |
| } |
| |
| if (snd_ctl_find_hole(card, kcontrol->count) < 0) |
| return -ENOMEM; |
| |
| list_add_tail(&kcontrol->list, &card->controls); |
| card->controls_count += kcontrol->count; |
| kcontrol->id.numid = card->last_numid + 1; |
| card->last_numid += kcontrol->count; |
| |
| add_hash_entries(card, kcontrol); |
| |
| for (idx = 0; idx < kcontrol->count; idx++) |
| snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_ADD, kcontrol, idx); |
| |
| return 0; |
| } |
| |
| static int snd_ctl_add_replace(struct snd_card *card, |
| struct snd_kcontrol *kcontrol, |
| enum snd_ctl_add_mode mode) |
| { |
| int err = -EINVAL; |
| |
| if (! kcontrol) |
| return err; |
| if (snd_BUG_ON(!card || !kcontrol->info)) |
| goto error; |
| |
| scoped_guard(rwsem_write, &card->controls_rwsem) |
| err = __snd_ctl_add_replace(card, kcontrol, mode); |
| |
| if (err < 0) |
| goto error; |
| return 0; |
| |
| error: |
| snd_ctl_free_one(kcontrol); |
| return err; |
| } |
| |
| /** |
| * snd_ctl_add - add the control instance to the card |
| * @card: the card instance |
| * @kcontrol: the control instance to add |
| * |
| * Adds the control instance created via snd_ctl_new() or |
| * snd_ctl_new1() to the given card. Assigns also an unique |
| * numid used for fast search. |
| * |
| * It frees automatically the control which cannot be added. |
| * |
| * Return: Zero if successful, or a negative error code on failure. |
| * |
| */ |
| int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol) |
| { |
| return snd_ctl_add_replace(card, kcontrol, CTL_ADD_EXCLUSIVE); |
| } |
| EXPORT_SYMBOL(snd_ctl_add); |
| |
| /** |
| * snd_ctl_replace - replace the control instance of the card |
| * @card: the card instance |
| * @kcontrol: the control instance to replace |
| * @add_on_replace: add the control if not already added |
| * |
| * Replaces the given control. If the given control does not exist |
| * and the add_on_replace flag is set, the control is added. If the |
| * control exists, it is destroyed first. |
| * |
| * It frees automatically the control which cannot be added or replaced. |
| * |
| * Return: Zero if successful, or a negative error code on failure. |
| */ |
| int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol, |
| bool add_on_replace) |
| { |
| return snd_ctl_add_replace(card, kcontrol, |
| add_on_replace ? CTL_ADD_ON_REPLACE : CTL_REPLACE); |
| } |
| EXPORT_SYMBOL(snd_ctl_replace); |
| |
| static int __snd_ctl_remove(struct snd_card *card, |
| struct snd_kcontrol *kcontrol, |
| bool remove_hash) |
| { |
| unsigned int idx; |
| |
| lockdep_assert_held_write(&card->controls_rwsem); |
| |
| if (snd_BUG_ON(!card || !kcontrol)) |
| return -EINVAL; |
| list_del(&kcontrol->list); |
| |
| if (remove_hash) |
| remove_hash_entries(card, kcontrol); |
| |
| card->controls_count -= kcontrol->count; |
| for (idx = 0; idx < kcontrol->count; idx++) |
| snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_REMOVE, kcontrol, idx); |
| snd_ctl_free_one(kcontrol); |
| return 0; |
| } |
| |
| static inline int snd_ctl_remove_locked(struct snd_card *card, |
| struct snd_kcontrol *kcontrol) |
| { |
| return __snd_ctl_remove(card, kcontrol, true); |
| } |
| |
| /** |
| * snd_ctl_remove - remove the control from the card and release it |
| * @card: the card instance |
| * @kcontrol: the control instance to remove |
| * |
| * Removes the control from the card and then releases the instance. |
| * You don't need to call snd_ctl_free_one(). |
| * Passing NULL to @kcontrol argument is allowed as noop. |
| * |
| * Return: 0 if successful, or a negative error code on failure. |
| * |
| * Note that this function takes card->controls_rwsem lock internally. |
| */ |
| int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol) |
| { |
| if (!kcontrol) |
| return 0; |
| guard(rwsem_write)(&card->controls_rwsem); |
| return snd_ctl_remove_locked(card, kcontrol); |
| } |
| EXPORT_SYMBOL(snd_ctl_remove); |
| |
| /** |
| * snd_ctl_remove_id - remove the control of the given id and release it |
| * @card: the card instance |
| * @id: the control id to remove |
| * |
| * Finds the control instance with the given id, removes it from the |
| * card list and releases it. |
| * |
| * Return: 0 if successful, or a negative error code on failure. |
| */ |
| int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id) |
| { |
| struct snd_kcontrol *kctl; |
| |
| guard(rwsem_write)(&card->controls_rwsem); |
| kctl = snd_ctl_find_id_locked(card, id); |
| if (kctl == NULL) |
| return -ENOENT; |
| return snd_ctl_remove_locked(card, kctl); |
| } |
| EXPORT_SYMBOL(snd_ctl_remove_id); |
| |
| /** |
| * snd_ctl_remove_user_ctl - remove and release the unlocked user control |
| * @file: active control handle |
| * @id: the control id to remove |
| * |
| * Finds the control instance with the given id, removes it from the |
| * card list and releases it. |
| * |
| * Return: 0 if successful, or a negative error code on failure. |
| */ |
| static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file, |
| struct snd_ctl_elem_id *id) |
| { |
| struct snd_card *card = file->card; |
| struct snd_kcontrol *kctl; |
| int idx; |
| |
| guard(rwsem_write)(&card->controls_rwsem); |
| kctl = snd_ctl_find_id_locked(card, id); |
| if (kctl == NULL) |
| return -ENOENT; |
| if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) |
| return -EINVAL; |
| for (idx = 0; idx < kctl->count; idx++) |
| if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) |
| return -EBUSY; |
| return snd_ctl_remove_locked(card, kctl); |
| } |
| |
| /** |
| * snd_ctl_activate_id - activate/inactivate the control of the given id |
| * @card: the card instance |
| * @id: the control id to activate/inactivate |
| * @active: non-zero to activate |
| * |
| * Finds the control instance with the given id, and activate or |
| * inactivate the control together with notification, if changed. |
| * The given ID data is filled with full information. |
| * |
| * Return: 0 if unchanged, 1 if changed, or a negative error code on failure. |
| */ |
| int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id, |
| int active) |
| { |
| struct snd_kcontrol *kctl; |
| struct snd_kcontrol_volatile *vd; |
| unsigned int index_offset; |
| int ret; |
| |
| down_write(&card->controls_rwsem); |
| kctl = snd_ctl_find_id_locked(card, id); |
| if (kctl == NULL) { |
| ret = -ENOENT; |
| goto unlock; |
| } |
| index_offset = snd_ctl_get_ioff(kctl, id); |
| vd = &kctl->vd[index_offset]; |
| ret = 0; |
| if (active) { |
| if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)) |
| goto unlock; |
| vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE; |
| } else { |
| if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE) |
| goto unlock; |
| vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE; |
| } |
| snd_ctl_build_ioff(id, kctl, index_offset); |
| downgrade_write(&card->controls_rwsem); |
| snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_INFO, kctl, index_offset); |
| up_read(&card->controls_rwsem); |
| return 1; |
| |
| unlock: |
| up_write(&card->controls_rwsem); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(snd_ctl_activate_id); |
| |
| /** |
| * snd_ctl_rename_id - replace the id of a control on the card |
| * @card: the card instance |
| * @src_id: the old id |
| * @dst_id: the new id |
| * |
| * Finds the control with the old id from the card, and replaces the |
| * id with the new one. |
| * |
| * The function tries to keep the already assigned numid while replacing |
| * the rest. |
| * |
| * Note that this function should be used only in the card initialization |
| * phase. Calling after the card instantiation may cause issues with |
| * user-space expecting persistent numids. |
| * |
| * Return: Zero if successful, or a negative error code on failure. |
| */ |
| int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id, |
| struct snd_ctl_elem_id *dst_id) |
| { |
| struct snd_kcontrol *kctl; |
| int saved_numid; |
| |
| guard(rwsem_write)(&card->controls_rwsem); |
| kctl = snd_ctl_find_id_locked(card, src_id); |
| if (kctl == NULL) |
| return -ENOENT; |
| saved_numid = kctl->id.numid; |
| remove_hash_entries(card, kctl); |
| kctl->id = *dst_id; |
| kctl->id.numid = saved_numid; |
| add_hash_entries(card, kctl); |
| return 0; |
| } |
| EXPORT_SYMBOL(snd_ctl_rename_id); |
| |
| /** |
| * snd_ctl_rename - rename the control on the card |
| * @card: the card instance |
| * @kctl: the control to rename |
| * @name: the new name |
| * |
| * Renames the specified control on the card to the new name. |
| * |
| * Note that this function takes card->controls_rwsem lock internally. |
| */ |
| void snd_ctl_rename(struct snd_card *card, struct snd_kcontrol *kctl, |
| const char *name) |
| { |
| guard(rwsem_write)(&card->controls_rwsem); |
| remove_hash_entries(card, kctl); |
| |
| if (strscpy(kctl->id.name, name, sizeof(kctl->id.name)) < 0) |
| pr_warn("ALSA: Renamed control new name '%s' truncated to '%s'\n", |
| name, kctl->id.name); |
| |
| add_hash_entries(card, kctl); |
| } |
| EXPORT_SYMBOL(snd_ctl_rename); |
| |
| #ifndef CONFIG_SND_CTL_FAST_LOOKUP |
| static struct snd_kcontrol * |
| snd_ctl_find_numid_slow(struct snd_card *card, unsigned int numid) |
| { |
| struct snd_kcontrol *kctl; |
| |
| list_for_each_entry(kctl, &card->controls, list) { |
| if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid) |
| return kctl; |
| } |
| return NULL; |
| } |
| #endif /* !CONFIG_SND_CTL_FAST_LOOKUP */ |
| |
| /** |
| * snd_ctl_find_numid_locked - find the control instance with the given number-id |
| * @card: the card instance |
| * @numid: the number-id to search |
| * |
| * Finds the control instance with the given number-id from the card. |
| * |
| * The caller must down card->controls_rwsem before calling this function |
| * (if the race condition can happen). |
| * |
| * Return: The pointer of the instance if found, or %NULL if not. |
| */ |
| struct snd_kcontrol * |
| snd_ctl_find_numid_locked(struct snd_card *card, unsigned int numid) |
| { |
| if (snd_BUG_ON(!card || !numid)) |
| return NULL; |
| lockdep_assert_held(&card->controls_rwsem); |
| #ifdef CONFIG_SND_CTL_FAST_LOOKUP |
| return xa_load(&card->ctl_numids, numid); |
| #else |
| return snd_ctl_find_numid_slow(card, numid); |
| #endif |
| } |
| EXPORT_SYMBOL(snd_ctl_find_numid_locked); |
| |
| /** |
| * snd_ctl_find_numid - find the control instance with the given number-id |
| * @card: the card instance |
| * @numid: the number-id to search |
| * |
| * Finds the control instance with the given number-id from the card. |
| * |
| * Return: The pointer of the instance if found, or %NULL if not. |
| * |
| * Note that this function takes card->controls_rwsem lock internally. |
| */ |
| struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, |
| unsigned int numid) |
| { |
| guard(rwsem_read)(&card->controls_rwsem); |
| return snd_ctl_find_numid_locked(card, numid); |
| } |
| EXPORT_SYMBOL(snd_ctl_find_numid); |
| |
| /** |
| * snd_ctl_find_id_locked - find the control instance with the given id |
| * @card: the card instance |
| * @id: the id to search |
| * |
| * Finds the control instance with the given id from the card. |
| * |
| * The caller must down card->controls_rwsem before calling this function |
| * (if the race condition can happen). |
| * |
| * Return: The pointer of the instance if found, or %NULL if not. |
| */ |
| struct snd_kcontrol *snd_ctl_find_id_locked(struct snd_card *card, |
| const struct snd_ctl_elem_id *id) |
| { |
| struct snd_kcontrol *kctl; |
| |
| if (snd_BUG_ON(!card || !id)) |
| return NULL; |
| lockdep_assert_held(&card->controls_rwsem); |
| if (id->numid != 0) |
| return snd_ctl_find_numid_locked(card, id->numid); |
| #ifdef CONFIG_SND_CTL_FAST_LOOKUP |
| kctl = xa_load(&card->ctl_hash, get_ctl_id_hash(id)); |
| if (kctl && elem_id_matches(kctl, id)) |
| return kctl; |
| if (!card->ctl_hash_collision) |
| return NULL; /* we can rely on only hash table */ |
| #endif |
| /* no matching in hash table - try all as the last resort */ |
| list_for_each_entry(kctl, &card->controls, list) |
| if (elem_id_matches(kctl, id)) |
| return kctl; |
| |
| return NULL; |
| } |
| EXPORT_SYMBOL(snd_ctl_find_id_locked); |
| |
| /** |
| * snd_ctl_find_id - find the control instance with the given id |
| * @card: the card instance |
| * @id: the id to search |
| * |
| * Finds the control instance with the given id from the card. |
| * |
| * Return: The pointer of the instance if found, or %NULL if not. |
| * |
| * Note that this function takes card->controls_rwsem lock internally. |
| */ |
| struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card, |
| const struct snd_ctl_elem_id *id) |
| { |
| guard(rwsem_read)(&card->controls_rwsem); |
| return snd_ctl_find_id_locked(card, id); |
| } |
| EXPORT_SYMBOL(snd_ctl_find_id); |
| |
| static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl, |
| unsigned int cmd, void __user *arg) |
| { |
| struct snd_ctl_card_info *info __free(kfree) = NULL; |
| |
| info = kzalloc(sizeof(*info), GFP_KERNEL); |
| if (! info) |
| return -ENOMEM; |
| scoped_guard(rwsem_read, &snd_ioctl_rwsem) { |
| info->card = card->number; |
| strscpy(info->id, card->id, sizeof(info->id)); |
| strscpy(info->driver, card->driver, sizeof(info->driver)); |
| strscpy(info->name, card->shortname, sizeof(info->name)); |
| strscpy(info->longname, card->longname, sizeof(info->longname)); |
| strscpy(info->mixername, card->mixername, sizeof(info->mixername)); |
| strscpy(info->components, card->components, sizeof(info->components)); |
| } |
| if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) |
| return -EFAULT; |
| return 0; |
| } |
| |
| static int snd_ctl_elem_list(struct snd_card *card, |
| struct snd_ctl_elem_list *list) |
| { |
| struct snd_kcontrol *kctl; |
| struct snd_ctl_elem_id id; |
| unsigned int offset, space, jidx; |
| |
| offset = list->offset; |
| space = list->space; |
| |
| guard(rwsem_read)(&card->controls_rwsem); |
| list->count = card->controls_count; |
| list->used = 0; |
| if (!space) |
| return 0; |
| list_for_each_entry(kctl, &card->controls, list) { |
| if (offset >= kctl->count) { |
| offset -= kctl->count; |
| continue; |
| } |
| for (jidx = offset; jidx < kctl->count; jidx++) { |
| snd_ctl_build_ioff(&id, kctl, jidx); |
| if (copy_to_user(list->pids + list->used, &id, sizeof(id))) |
| return -EFAULT; |
| list->used++; |
| if (!--space) |
| return 0; |
| } |
| offset = 0; |
| } |
| return 0; |
| } |
| |
| static int snd_ctl_elem_list_user(struct snd_card *card, |
| struct snd_ctl_elem_list __user *_list) |
| { |
| struct snd_ctl_elem_list list; |
| int err; |
| |
| if (copy_from_user(&list, _list, sizeof(list))) |
| return -EFAULT; |
| err = snd_ctl_elem_list(card, &list); |
| if (err) |
| return err; |
| if (copy_to_user(_list, &list, sizeof(list))) |
| return -EFAULT; |
| |
| return 0; |
| } |
| |
| /* Check whether the given kctl info is valid */ |
| static int snd_ctl_check_elem_info(struct snd_card *card, |
| const struct snd_ctl_elem_info *info) |
| { |
| static const unsigned int max_value_counts[] = { |
| [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = 128, |
| [SNDRV_CTL_ELEM_TYPE_INTEGER] = 128, |
| [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = 128, |
| [SNDRV_CTL_ELEM_TYPE_BYTES] = 512, |
| [SNDRV_CTL_ELEM_TYPE_IEC958] = 1, |
| [SNDRV_CTL_ELEM_TYPE_INTEGER64] = 64, |
| }; |
| |
| if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN || |
| info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64) { |
| if (card) |
| dev_err(card->dev, |
| "control %i:%i:%i:%s:%i: invalid type %d\n", |
| info->id.iface, info->id.device, |
| info->id.subdevice, info->id.name, |
| info->id.index, info->type); |
| return -EINVAL; |
| } |
| if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED && |
| info->value.enumerated.items == 0) { |
| if (card) |
| dev_err(card->dev, |
| "control %i:%i:%i:%s:%i: zero enum items\n", |
| info->id.iface, info->id.device, |
| info->id.subdevice, info->id.name, |
| info->id.index); |
| return -EINVAL; |
| } |
| if (info->count > max_value_counts[info->type]) { |
| if (card) |
| dev_err(card->dev, |
| "control %i:%i:%i:%s:%i: invalid count %d\n", |
| info->id.iface, info->id.device, |
| info->id.subdevice, info->id.name, |
| info->id.index, info->count); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| /* The capacity of struct snd_ctl_elem_value.value.*/ |
| static const unsigned int value_sizes[] = { |
| [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = sizeof(long), |
| [SNDRV_CTL_ELEM_TYPE_INTEGER] = sizeof(long), |
| [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = sizeof(unsigned int), |
| [SNDRV_CTL_ELEM_TYPE_BYTES] = sizeof(unsigned char), |
| [SNDRV_CTL_ELEM_TYPE_IEC958] = sizeof(struct snd_aes_iec958), |
| [SNDRV_CTL_ELEM_TYPE_INTEGER64] = sizeof(long long), |
| }; |
| |
| /* fill the remaining snd_ctl_elem_value data with the given pattern */ |
| static void fill_remaining_elem_value(struct snd_ctl_elem_value *control, |
| struct snd_ctl_elem_info *info, |
| u32 pattern) |
| { |
| size_t offset = value_sizes[info->type] * info->count; |
| |
| offset = DIV_ROUND_UP(offset, sizeof(u32)); |
| memset32((u32 *)control->value.bytes.data + offset, pattern, |
| sizeof(control->value) / sizeof(u32) - offset); |
| } |
| |
| /* check whether the given integer ctl value is valid */ |
| static int sanity_check_int_value(struct snd_card *card, |
| const struct snd_ctl_elem_value *control, |
| const struct snd_ctl_elem_info *info, |
| int i, bool print_error) |
| { |
| long long lval, lmin, lmax, lstep; |
| u64 rem; |
| |
| switch (info->type) { |
| default: |
| case SNDRV_CTL_ELEM_TYPE_BOOLEAN: |
| lval = control->value.integer.value[i]; |
| lmin = 0; |
| lmax = 1; |
| lstep = 0; |
| break; |
| case SNDRV_CTL_ELEM_TYPE_INTEGER: |
| lval = control->value.integer.value[i]; |
| lmin = info->value.integer.min; |
| lmax = info->value.integer.max; |
| lstep = info->value.integer.step; |
| break; |
| case SNDRV_CTL_ELEM_TYPE_INTEGER64: |
| lval = control->value.integer64.value[i]; |
| lmin = info->value.integer64.min; |
| lmax = info->value.integer64.max; |
| lstep = info->value.integer64.step; |
| break; |
| case SNDRV_CTL_ELEM_TYPE_ENUMERATED: |
| lval = control->value.enumerated.item[i]; |
| lmin = 0; |
| lmax = info->value.enumerated.items - 1; |
| lstep = 0; |
| break; |
| } |
| |
| if (lval < lmin || lval > lmax) { |
| if (print_error) |
| dev_err(card->dev, |
| "control %i:%i:%i:%s:%i: value out of range %lld (%lld/%lld) at count %i\n", |
| control->id.iface, control->id.device, |
| control->id.subdevice, control->id.name, |
| control->id.index, lval, lmin, lmax, i); |
| return -EINVAL; |
| } |
| if (lstep) { |
| div64_u64_rem(lval, lstep, &rem); |
| if (rem) { |
| if (print_error) |
| dev_err(card->dev, |
| "control %i:%i:%i:%s:%i: unaligned value %lld (step %lld) at count %i\n", |
| control->id.iface, control->id.device, |
| control->id.subdevice, control->id.name, |
| control->id.index, lval, lstep, i); |
| return -EINVAL; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* check whether the all input values are valid for the given elem value */ |
| static int sanity_check_input_values(struct snd_card *card, |
| const struct snd_ctl_elem_value *control, |
| const struct snd_ctl_elem_info *info, |
| bool print_error) |
| { |
| int i, ret; |
| |
| switch (info->type) { |
| case SNDRV_CTL_ELEM_TYPE_BOOLEAN: |
| case SNDRV_CTL_ELEM_TYPE_INTEGER: |
| case SNDRV_CTL_ELEM_TYPE_INTEGER64: |
| case SNDRV_CTL_ELEM_TYPE_ENUMERATED: |
| for (i = 0; i < info->count; i++) { |
| ret = sanity_check_int_value(card, control, info, i, |
| print_error); |
| if (ret < 0) |
| return ret; |
| } |
| break; |
| default: |
| break; |
| } |
| |
| return 0; |
| } |
| |
| /* perform sanity checks to the given snd_ctl_elem_value object */ |
| static int sanity_check_elem_value(struct snd_card *card, |
| const struct snd_ctl_elem_value *control, |
| const struct snd_ctl_elem_info *info, |
| u32 pattern) |
| { |
| size_t offset; |
| int ret; |
| u32 *p; |
| |
| ret = sanity_check_input_values(card, control, info, true); |
| if (ret < 0) |
| return ret; |
| |
| /* check whether the remaining area kept untouched */ |
| offset = value_sizes[info->type] * info->count; |
| offset = DIV_ROUND_UP(offset, sizeof(u32)); |
| p = (u32 *)control->value.bytes.data + offset; |
| for (; offset < sizeof(control->value) / sizeof(u32); offset++, p++) { |
| if (*p != pattern) { |
| ret = -EINVAL; |
| break; |
| } |
| *p = 0; /* clear the checked area */ |
| } |
| |
| return ret; |
| } |
| |
| static int __snd_ctl_elem_info(struct snd_card *card, |
| struct snd_kcontrol *kctl, |
| struct snd_ctl_elem_info *info, |
| struct snd_ctl_file *ctl) |
| { |
| struct snd_kcontrol_volatile *vd; |
| unsigned int index_offset; |
| int result; |
| |
| #ifdef CONFIG_SND_DEBUG |
| info->access = 0; |
| #endif |
| result = snd_power_ref_and_wait(card); |
| if (!result) |
| result = kctl->info(kctl, info); |
| snd_power_unref(card); |
| if (result >= 0) { |
| snd_BUG_ON(info->access); |
| index_offset = snd_ctl_get_ioff(kctl, &info->id); |
| vd = &kctl->vd[index_offset]; |
| snd_ctl_build_ioff(&info->id, kctl, index_offset); |
| info->access = vd->access; |
| if (vd->owner) { |
| info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK; |
| if (vd->owner == ctl) |
| info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER; |
| info->owner = pid_vnr(vd->owner->pid); |
| } else { |
| info->owner = -1; |
| } |
| if (!snd_ctl_skip_validation(info) && |
| snd_ctl_check_elem_info(card, info) < 0) |
| result = -EINVAL; |
| } |
| return result; |
| } |
| |
| static int snd_ctl_elem_info(struct snd_ctl_file *ctl, |
| struct snd_ctl_elem_info *info) |
| { |
| struct snd_card *card = ctl->card; |
| struct snd_kcontrol *kctl; |
| |
| guard(rwsem_read)(&card->controls_rwsem); |
| kctl = snd_ctl_find_id_locked(card, &info->id); |
| if (!kctl) |
| return -ENOENT; |
| return __snd_ctl_elem_info(card, kctl, info, ctl); |
| } |
| |
| static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl, |
| struct snd_ctl_elem_info __user *_info) |
| { |
| struct snd_ctl_elem_info info; |
| int result; |
| |
| if (copy_from_user(&info, _info, sizeof(info))) |
| return -EFAULT; |
| result = snd_ctl_elem_info(ctl, &info); |
| if (result < 0) |
| return result; |
| /* drop internal access flags */ |
| info.access &= ~(SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK| |
| SNDRV_CTL_ELEM_ACCESS_LED_MASK); |
| if (copy_to_user(_info, &info, sizeof(info))) |
| return -EFAULT; |
| return result; |
| } |
| |
| static int snd_ctl_elem_read(struct snd_card *card, |
| struct snd_ctl_elem_value *control) |
| { |
| struct snd_kcontrol *kctl; |
| struct snd_kcontrol_volatile *vd; |
| unsigned int index_offset; |
| struct snd_ctl_elem_info info; |
| const u32 pattern = 0xdeadbeef; |
| int ret; |
| |
| guard(rwsem_read)(&card->controls_rwsem); |
| kctl = snd_ctl_find_id_locked(card, &control->id); |
| if (!kctl) |
| return -ENOENT; |
| |
| index_offset = snd_ctl_get_ioff(kctl, &control->id); |
| vd = &kctl->vd[index_offset]; |
| if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_READ) || !kctl->get) |
| return -EPERM; |
| |
| snd_ctl_build_ioff(&control->id, kctl, index_offset); |
| |
| #ifdef CONFIG_SND_CTL_DEBUG |
| /* info is needed only for validation */ |
| memset(&info, 0, sizeof(info)); |
| info.id = control->id; |
| ret = __snd_ctl_elem_info(card, kctl, &info, NULL); |
| if (ret < 0) |
| return ret; |
| #endif |
| |
| if (!snd_ctl_skip_validation(&info)) |
| fill_remaining_elem_value(control, &info, pattern); |
| ret = snd_power_ref_and_wait(card); |
| if (!ret) |
| ret = kctl->get(kctl, control); |
| snd_power_unref(card); |
| if (ret < 0) |
| return ret; |
| if (!snd_ctl_skip_validation(&info) && |
| sanity_check_elem_value(card, control, &info, pattern) < 0) { |
| dev_err(card->dev, |
| "control %i:%i:%i:%s:%i: access overflow\n", |
| control->id.iface, control->id.device, |
| control->id.subdevice, control->id.name, |
| control->id.index); |
| return -EINVAL; |
| } |
| return 0; |
| } |
| |
| static int snd_ctl_elem_read_user(struct snd_card *card, |
| struct snd_ctl_elem_value __user *_control) |
| { |
| struct snd_ctl_elem_value *control __free(kfree) = NULL; |
| int result; |
| |
| control = memdup_user(_control, sizeof(*control)); |
| if (IS_ERR(control)) |
| return PTR_ERR(no_free_ptr(control)); |
| |
| result = snd_ctl_elem_read(card, control); |
| if (result < 0) |
| return result; |
| |
| if (copy_to_user(_control, control, sizeof(*control))) |
| return -EFAULT; |
| return result; |
| } |
| |
| static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file, |
| struct snd_ctl_elem_value *control) |
| { |
| struct snd_kcontrol *kctl; |
| struct snd_kcontrol_volatile *vd; |
| unsigned int index_offset; |
| int result; |
| |
| down_write(&card->controls_rwsem); |
| kctl = snd_ctl_find_id_locked(card, &control->id); |
| if (kctl == NULL) { |
| up_write(&card->controls_rwsem); |
| return -ENOENT; |
| } |
| |
| index_offset = snd_ctl_get_ioff(kctl, &control->id); |
| vd = &kctl->vd[index_offset]; |
| if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) || kctl->put == NULL || |
| (file && vd->owner && vd->owner != file)) { |
| up_write(&card->controls_rwsem); |
| return -EPERM; |
| } |
| |
| snd_ctl_build_ioff(&control->id, kctl, index_offset); |
| result = snd_power_ref_and_wait(card); |
| /* validate input values */ |
| if (IS_ENABLED(CONFIG_SND_CTL_INPUT_VALIDATION) && !result) { |
| struct snd_ctl_elem_info info; |
| |
| memset(&info, 0, sizeof(info)); |
| info.id = control->id; |
| result = __snd_ctl_elem_info(card, kctl, &info, NULL); |
| if (!result) |
| result = sanity_check_input_values(card, control, &info, |
| false); |
| } |
| if (!result) |
| result = kctl->put(kctl, control); |
| snd_power_unref(card); |
| if (result < 0) { |
| up_write(&card->controls_rwsem); |
| return result; |
| } |
| |
| if (result > 0) { |
| downgrade_write(&card->controls_rwsem); |
| snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_VALUE, kctl, index_offset); |
| up_read(&card->controls_rwsem); |
| } else { |
| up_write(&card->controls_rwsem); |
| } |
| |
| return 0; |
| } |
| |
| static int snd_ctl_elem_write_user(struct snd_ctl_file *file, |
| struct snd_ctl_elem_value __user *_control) |
| { |
| struct snd_ctl_elem_value *control __free(kfree) = NULL; |
| struct snd_card *card; |
| int result; |
| |
| control = memdup_user(_control, sizeof(*control)); |
| if (IS_ERR(control)) |
| return PTR_ERR(no_free_ptr(control)); |
| |
| card = file->card; |
| result = snd_ctl_elem_write(card, file, control); |
| if (result < 0) |
| return result; |
| |
| if (copy_to_user(_control, control, sizeof(*control))) |
| return -EFAULT; |
| return result; |
| } |
| |
| static int snd_ctl_elem_lock(struct snd_ctl_file *file, |
| struct snd_ctl_elem_id __user *_id) |
| { |
| struct snd_card *card = file->card; |
| struct snd_ctl_elem_id id; |
| struct snd_kcontrol *kctl; |
| struct snd_kcontrol_volatile *vd; |
| |
| if (copy_from_user(&id, _id, sizeof(id))) |
| return -EFAULT; |
| guard(rwsem_write)(&card->controls_rwsem); |
| kctl = snd_ctl_find_id_locked(card, &id); |
| if (!kctl) |
| return -ENOENT; |
| vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)]; |
| if (vd->owner) |
| return -EBUSY; |
| vd->owner = file; |
| return 0; |
| } |
| |
| static int snd_ctl_elem_unlock(struct snd_ctl_file *file, |
| struct snd_ctl_elem_id __user *_id) |
| { |
| struct snd_card *card = file->card; |
| struct snd_ctl_elem_id id; |
| struct snd_kcontrol *kctl; |
| struct snd_kcontrol_volatile *vd; |
| |
| if (copy_from_user(&id, _id, sizeof(id))) |
| return -EFAULT; |
| guard(rwsem_write)(&card->controls_rwsem); |
| kctl = snd_ctl_find_id_locked(card, &id); |
| if (!kctl) |
| return -ENOENT; |
| vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)]; |
| if (!vd->owner) |
| return -EINVAL; |
| if (vd->owner != file) |
| return -EPERM; |
| vd->owner = NULL; |
| return 0; |
| } |
| |
| struct user_element { |
| struct snd_ctl_elem_info info; |
| struct snd_card *card; |
| char *elem_data; /* element data */ |
| unsigned long elem_data_size; /* size of element data in bytes */ |
| void *tlv_data; /* TLV data */ |
| unsigned long tlv_data_size; /* TLV data size */ |
| void *priv_data; /* private data (like strings for enumerated type) */ |
| }; |
| |
| // check whether the addition (in bytes) of user ctl element may overflow the limit. |
| static bool check_user_elem_overflow(struct snd_card *card, ssize_t add) |
| { |
| return (ssize_t)card->user_ctl_alloc_size + add > max_user_ctl_alloc_size; |
| } |
| |
| static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol, |
| struct snd_ctl_elem_info *uinfo) |
| { |
| struct user_element *ue = kcontrol->private_data; |
| unsigned int offset; |
| |
| offset = snd_ctl_get_ioff(kcontrol, &uinfo->id); |
| *uinfo = ue->info; |
| snd_ctl_build_ioff(&uinfo->id, kcontrol, offset); |
| |
| return 0; |
| } |
| |
| static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol, |
| struct snd_ctl_elem_info *uinfo) |
| { |
| struct user_element *ue = kcontrol->private_data; |
| const char *names; |
| unsigned int item; |
| unsigned int offset; |
| |
| item = uinfo->value.enumerated.item; |
| |
| offset = snd_ctl_get_ioff(kcontrol, &uinfo->id); |
| *uinfo = ue->info; |
| snd_ctl_build_ioff(&uinfo->id, kcontrol, offset); |
| |
| item = min(item, uinfo->value.enumerated.items - 1); |
| uinfo->value.enumerated.item = item; |
| |
| names = ue->priv_data; |
| for (; item > 0; --item) |
| names += strlen(names) + 1; |
| strcpy(uinfo->value.enumerated.name, names); |
| |
| return 0; |
| } |
| |
| static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol, |
| struct snd_ctl_elem_value *ucontrol) |
| { |
| struct user_element *ue = kcontrol->private_data; |
| unsigned int size = ue->elem_data_size; |
| char *src = ue->elem_data + |
| snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size; |
| |
| memcpy(&ucontrol->value, src, size); |
| return 0; |
| } |
| |
| static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol, |
| struct snd_ctl_elem_value *ucontrol) |
| { |
| int err, change; |
| struct user_element *ue = kcontrol->private_data; |
| unsigned int size = ue->elem_data_size; |
| char *dst = ue->elem_data + |
| snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size; |
| |
| err = sanity_check_input_values(ue->card, ucontrol, &ue->info, false); |
| if (err < 0) |
| return err; |
| |
| change = memcmp(&ucontrol->value, dst, size) != 0; |
| if (change) |
| memcpy(dst, &ucontrol->value, size); |
| return change; |
| } |
| |
| /* called in controls_rwsem write lock */ |
| static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf, |
| unsigned int size) |
| { |
| struct user_element *ue = kctl->private_data; |
| unsigned int *container; |
| unsigned int mask = 0; |
| int i; |
| int change; |
| |
| lockdep_assert_held_write(&ue->card->controls_rwsem); |
| |
| if (size > 1024 * 128) /* sane value */ |
| return -EINVAL; |
| |
| // does the TLV size change cause overflow? |
| if (check_user_elem_overflow(ue->card, (ssize_t)(size - ue->tlv_data_size))) |
| return -ENOMEM; |
| |
| container = vmemdup_user(buf, size); |
| if (IS_ERR(container)) |
| return PTR_ERR(container); |
| |
| change = ue->tlv_data_size != size; |
| if (!change) |
| change = memcmp(ue->tlv_data, container, size) != 0; |
| if (!change) { |
| kvfree(container); |
| return 0; |
| } |
| |
| if (ue->tlv_data == NULL) { |
| /* Now TLV data is available. */ |
| for (i = 0; i < kctl->count; ++i) |
| kctl->vd[i].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ; |
| mask = SNDRV_CTL_EVENT_MASK_INFO; |
| } else { |
| ue->card->user_ctl_alloc_size -= ue->tlv_data_size; |
| ue->tlv_data_size = 0; |
| kvfree(ue->tlv_data); |
| } |
| |
| ue->tlv_data = container; |
| ue->tlv_data_size = size; |
| // decremented at private_free. |
| ue->card->user_ctl_alloc_size += size; |
| |
| mask |= SNDRV_CTL_EVENT_MASK_TLV; |
| for (i = 0; i < kctl->count; ++i) |
| snd_ctl_notify_one(ue->card, mask, kctl, i); |
| |
| return change; |
| } |
| |
| static int read_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf, |
| unsigned int size) |
| { |
| struct user_element *ue = kctl->private_data; |
| |
| if (ue->tlv_data_size == 0 || ue->tlv_data == NULL) |
| return -ENXIO; |
| |
| if (size < ue->tlv_data_size) |
| return -ENOSPC; |
| |
| if (copy_to_user(buf, ue->tlv_data, ue->tlv_data_size)) |
| return -EFAULT; |
| |
| return 0; |
| } |
| |
| static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kctl, int op_flag, |
| unsigned int size, unsigned int __user *buf) |
| { |
| if (op_flag == SNDRV_CTL_TLV_OP_WRITE) |
| return replace_user_tlv(kctl, buf, size); |
| else |
| return read_user_tlv(kctl, buf, size); |
| } |
| |
| /* called in controls_rwsem write lock */ |
| static int snd_ctl_elem_init_enum_names(struct user_element *ue) |
| { |
| char *names, *p; |
| size_t buf_len, name_len; |
| unsigned int i; |
| const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr; |
| |
| lockdep_assert_held_write(&ue->card->controls_rwsem); |
| |
| buf_len = ue->info.value.enumerated.names_length; |
| if (buf_len > 64 * 1024) |
| return -EINVAL; |
| |
| if (check_user_elem_overflow(ue->card, buf_len)) |
| return -ENOMEM; |
| names = vmemdup_user((const void __user *)user_ptrval, buf_len); |
| if (IS_ERR(names)) |
| return PTR_ERR(names); |
| |
| /* check that there are enough valid names */ |
| p = names; |
| for (i = 0; i < ue->info.value.enumerated.items; ++i) { |
| name_len = strnlen(p, buf_len); |
| if (name_len == 0 || name_len >= 64 || name_len == buf_len) { |
| kvfree(names); |
| return -EINVAL; |
| } |
| p += name_len + 1; |
| buf_len -= name_len + 1; |
| } |
| |
| ue->priv_data = names; |
| ue->info.value.enumerated.names_ptr = 0; |
| // increment the allocation size; decremented again at private_free. |
| ue->card->user_ctl_alloc_size += ue->info.value.enumerated.names_length; |
| |
| return 0; |
| } |
| |
| static size_t compute_user_elem_size(size_t size, unsigned int count) |
| { |
| return sizeof(struct user_element) + size * count; |
| } |
| |
| static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol) |
| { |
| struct user_element *ue = kcontrol->private_data; |
| |
| // decrement the allocation size. |
| ue->card->user_ctl_alloc_size -= compute_user_elem_size(ue->elem_data_size, kcontrol->count); |
| ue->card->user_ctl_alloc_size -= ue->tlv_data_size; |
| if (ue->priv_data) |
| ue->card->user_ctl_alloc_size -= ue->info.value.enumerated.names_length; |
| |
| kvfree(ue->tlv_data); |
| kvfree(ue->priv_data); |
| kfree(ue); |
| } |
| |
| static int snd_ctl_elem_add(struct snd_ctl_file *file, |
| struct snd_ctl_elem_info *info, int replace) |
| { |
| struct snd_card *card = file->card; |
| struct snd_kcontrol *kctl; |
| unsigned int count; |
| unsigned int access; |
| long private_size; |
| size_t alloc_size; |
| struct user_element *ue; |
| unsigned int offset; |
| int err; |
| |
| if (!*info->id.name) |
| return -EINVAL; |
| if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name)) |
| return -EINVAL; |
| |
| /* Delete a control to replace them if needed. */ |
| if (replace) { |
| info->id.numid = 0; |
| err = snd_ctl_remove_user_ctl(file, &info->id); |
| if (err) |
| return err; |
| } |
| |
| /* Check the number of elements for this userspace control. */ |
| count = info->owner; |
| if (count == 0) |
| count = 1; |
| |
| /* Arrange access permissions if needed. */ |
| access = info->access; |
| if (access == 0) |
| access = SNDRV_CTL_ELEM_ACCESS_READWRITE; |
| access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE | |
| SNDRV_CTL_ELEM_ACCESS_INACTIVE | |
| SNDRV_CTL_ELEM_ACCESS_TLV_WRITE); |
| |
| /* In initial state, nothing is available as TLV container. */ |
| if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) |
| access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK; |
| access |= SNDRV_CTL_ELEM_ACCESS_USER; |
| |
| /* |
| * Check information and calculate the size of data specific to |
| * this userspace control. |
| */ |
| /* pass NULL to card for suppressing error messages */ |
| err = snd_ctl_check_elem_info(NULL, info); |
| if (err < 0) |
| return err; |
| /* user-space control doesn't allow zero-size data */ |
| if (info->count < 1) |
| return -EINVAL; |
| private_size = value_sizes[info->type] * info->count; |
| alloc_size = compute_user_elem_size(private_size, count); |
| |
| guard(rwsem_write)(&card->controls_rwsem); |
| if (check_user_elem_overflow(card, alloc_size)) |
| return -ENOMEM; |
| |
| /* |
| * Keep memory object for this userspace control. After passing this |
| * code block, the instance should be freed by snd_ctl_free_one(). |
| * |
| * Note that these elements in this control are locked. |
| */ |
| err = snd_ctl_new(&kctl, count, access, file); |
| if (err < 0) |
| return err; |
| memcpy(&kctl->id, &info->id, sizeof(kctl->id)); |
| ue = kzalloc(alloc_size, GFP_KERNEL); |
| if (!ue) { |
| kfree(kctl); |
| return -ENOMEM; |
| } |
| kctl->private_data = ue; |
| kctl->private_free = snd_ctl_elem_user_free; |
| |
| // increment the allocated size; decremented again at private_free. |
| card->user_ctl_alloc_size += alloc_size; |
| |
| /* Set private data for this userspace control. */ |
| ue->card = card; |
| ue->info = *info; |
| ue->info.access = 0; |
| ue->elem_data = (char *)ue + sizeof(*ue); |
| ue->elem_data_size = private_size; |
| if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) { |
| err = snd_ctl_elem_init_enum_names(ue); |
| if (err < 0) { |
| snd_ctl_free_one(kctl); |
| return err; |
| } |
| } |
| |
| /* Set callback functions. */ |
| if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) |
| kctl->info = snd_ctl_elem_user_enum_info; |
| else |
| kctl->info = snd_ctl_elem_user_info; |
| if (access & SNDRV_CTL_ELEM_ACCESS_READ) |
| kctl->get = snd_ctl_elem_user_get; |
| if (access & SNDRV_CTL_ELEM_ACCESS_WRITE) |
| kctl->put = snd_ctl_elem_user_put; |
| if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) |
| kctl->tlv.c = snd_ctl_elem_user_tlv; |
| |
| /* This function manage to free the instance on failure. */ |
| err = __snd_ctl_add_replace(card, kctl, CTL_ADD_EXCLUSIVE); |
| if (err < 0) { |
| snd_ctl_free_one(kctl); |
| return err; |
| } |
| offset = snd_ctl_get_ioff(kctl, &info->id); |
| snd_ctl_build_ioff(&info->id, kctl, offset); |
| /* |
| * Here we cannot fill any field for the number of elements added by |
| * this operation because there're no specific fields. The usage of |
| * 'owner' field for this purpose may cause any bugs to userspace |
| * applications because the field originally means PID of a process |
| * which locks the element. |
| */ |
| return 0; |
| } |
| |
| static int snd_ctl_elem_add_user(struct snd_ctl_file *file, |
| struct snd_ctl_elem_info __user *_info, int replace) |
| { |
| struct snd_ctl_elem_info info; |
| int err; |
| |
| if (copy_from_user(&info, _info, sizeof(info))) |
| return -EFAULT; |
| err = snd_ctl_elem_add(file, &info, replace); |
| if (err < 0) |
| return err; |
| if (copy_to_user(_info, &info, sizeof(info))) { |
| snd_ctl_remove_user_ctl(file, &info.id); |
| return -EFAULT; |
| } |
| |
| return 0; |
| } |
| |
| static int snd_ctl_elem_remove(struct snd_ctl_file *file, |
| struct snd_ctl_elem_id __user *_id) |
| { |
| struct snd_ctl_elem_id id; |
| |
| if (copy_from_user(&id, _id, sizeof(id))) |
| return -EFAULT; |
| return snd_ctl_remove_user_ctl(file, &id); |
| } |
| |
| static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr) |
| { |
| int subscribe; |
| if (get_user(subscribe, ptr)) |
| return -EFAULT; |
| if (subscribe < 0) { |
| subscribe = file->subscribed; |
| if (put_user(subscribe, ptr)) |
| return -EFAULT; |
| return 0; |
| } |
| if (subscribe) { |
| file->subscribed = 1; |
| return 0; |
| } else if (file->subscribed) { |
| snd_ctl_empty_read_queue(file); |
| file->subscribed = 0; |
| } |
| return 0; |
| } |
| |
| static int call_tlv_handler(struct snd_ctl_file *file, int op_flag, |
| struct snd_kcontrol *kctl, |
| struct snd_ctl_elem_id *id, |
| unsigned int __user *buf, unsigned int size) |
| { |
| static const struct { |
| int op; |
| int perm; |
| } pairs[] = { |
| {SNDRV_CTL_TLV_OP_READ, SNDRV_CTL_ELEM_ACCESS_TLV_READ}, |
| {SNDRV_CTL_TLV_OP_WRITE, SNDRV_CTL_ELEM_ACCESS_TLV_WRITE}, |
| {SNDRV_CTL_TLV_OP_CMD, SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND}, |
| }; |
| struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)]; |
| int i, ret; |
| |
| /* Check support of the request for this element. */ |
| for (i = 0; i < ARRAY_SIZE(pairs); ++i) { |
| if (op_flag == pairs[i].op && (vd->access & pairs[i].perm)) |
| break; |
| } |
| if (i == ARRAY_SIZE(pairs)) |
| return -ENXIO; |
| |
| if (kctl->tlv.c == NULL) |
| return -ENXIO; |
| |
| /* Write and command operations are not allowed for locked element. */ |
| if (op_flag != SNDRV_CTL_TLV_OP_READ && |
| vd->owner != NULL && vd->owner != file) |
| return -EPERM; |
| |
| ret = snd_power_ref_and_wait(file->card); |
| if (!ret) |
| ret = kctl->tlv.c(kctl, op_flag, size, buf); |
| snd_power_unref(file->card); |
| return ret; |
| } |
| |
| static int read_tlv_buf(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id, |
| unsigned int __user *buf, unsigned int size) |
| { |
| struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)]; |
| unsigned int len; |
| |
| if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ)) |
| return -ENXIO; |
| |
| if (kctl->tlv.p == NULL) |
| return -ENXIO; |
| |
| len = sizeof(unsigned int) * 2 + kctl->tlv.p[1]; |
| if (size < len) |
| return -ENOMEM; |
| |
| if (copy_to_user(buf, kctl->tlv.p, len)) |
| return -EFAULT; |
| |
| return 0; |
| } |
| |
| static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file, |
| struct snd_ctl_tlv __user *buf, |
| int op_flag) |
| { |
| struct snd_ctl_tlv header; |
| unsigned int __user *container; |
| unsigned int container_size; |
| struct snd_kcontrol *kctl; |
| struct snd_ctl_elem_id id; |
| struct snd_kcontrol_volatile *vd; |
| |
| lockdep_assert_held(&file->card->controls_rwsem); |
| |
| if (copy_from_user(&header, buf, sizeof(header))) |
| return -EFAULT; |
| |
| /* In design of control core, numerical ID starts at 1. */ |
| if (header.numid == 0) |
| return -EINVAL; |
| |
| /* At least, container should include type and length fields. */ |
| if (header.length < sizeof(unsigned int) * 2) |
| return -EINVAL; |
| container_size = header.length; |
| container = buf->tlv; |
| |
| kctl = snd_ctl_find_numid_locked(file->card, header.numid); |
| if (kctl == NULL) |
| return -ENOENT; |
| |
| /* Calculate index of the element in this set. */ |
| id = kctl->id; |
| snd_ctl_build_ioff(&id, kctl, header.numid - id.numid); |
| vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)]; |
| |
| if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) { |
| return call_tlv_handler(file, op_flag, kctl, &id, container, |
| container_size); |
| } else { |
| if (op_flag == SNDRV_CTL_TLV_OP_READ) { |
| return read_tlv_buf(kctl, &id, container, |
| container_size); |
| } |
| } |
| |
| /* Not supported. */ |
| return -ENXIO; |
| } |
| |
| static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
| { |
| struct snd_ctl_file *ctl; |
| struct snd_card *card; |
| struct snd_kctl_ioctl *p; |
| void __user *argp = (void __user *)arg; |
| int __user *ip = argp; |
| int err; |
| |
| ctl = file->private_data; |
| card = ctl->card; |
| if (snd_BUG_ON(!card)) |
| return -ENXIO; |
| switch (cmd) { |
| case SNDRV_CTL_IOCTL_PVERSION: |
| return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0; |
| case SNDRV_CTL_IOCTL_CARD_INFO: |
| return snd_ctl_card_info(card, ctl, cmd, argp); |
| case SNDRV_CTL_IOCTL_ELEM_LIST: |
| return snd_ctl_elem_list_user(card, argp); |
| case SNDRV_CTL_IOCTL_ELEM_INFO: |
| return snd_ctl_elem_info_user(ctl, argp); |
| case SNDRV_CTL_IOCTL_ELEM_READ: |
| return snd_ctl_elem_read_user(card, argp); |
| case SNDRV_CTL_IOCTL_ELEM_WRITE: |
| return snd_ctl_elem_write_user(ctl, argp); |
| case SNDRV_CTL_IOCTL_ELEM_LOCK: |
| return snd_ctl_elem_lock(ctl, argp); |
| case SNDRV_CTL_IOCTL_ELEM_UNLOCK: |
| return snd_ctl_elem_unlock(ctl, argp); |
| case SNDRV_CTL_IOCTL_ELEM_ADD: |
| return snd_ctl_elem_add_user(ctl, argp, 0); |
| case SNDRV_CTL_IOCTL_ELEM_REPLACE: |
| return snd_ctl_elem_add_user(ctl, argp, 1); |
| case SNDRV_CTL_IOCTL_ELEM_REMOVE: |
| return snd_ctl_elem_remove(ctl, argp); |
| case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS: |
| return snd_ctl_subscribe_events(ctl, ip); |
| case SNDRV_CTL_IOCTL_TLV_READ: |
| scoped_guard(rwsem_read, &ctl->card->controls_rwsem) |
| err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ); |
| return err; |
| case SNDRV_CTL_IOCTL_TLV_WRITE: |
| scoped_guard(rwsem_write, &ctl->card->controls_rwsem) |
| err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE); |
| return err; |
| case SNDRV_CTL_IOCTL_TLV_COMMAND: |
| scoped_guard(rwsem_write, &ctl->card->controls_rwsem) |
| err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD); |
| return err; |
| case SNDRV_CTL_IOCTL_POWER: |
| return -ENOPROTOOPT; |
| case SNDRV_CTL_IOCTL_POWER_STATE: |
| return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0; |
| } |
| |
| guard(rwsem_read)(&snd_ioctl_rwsem); |
| list_for_each_entry(p, &snd_control_ioctls, list) { |
| err = p->fioctl(card, ctl, cmd, arg); |
| if (err != -ENOIOCTLCMD) |
| return err; |
| } |
| dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd); |
| return -ENOTTY; |
| } |
| |
| static ssize_t snd_ctl_read(struct file *file, char __user *buffer, |
| size_t count, loff_t * offset) |
| { |
| struct snd_ctl_file *ctl; |
| int err = 0; |
| ssize_t result = 0; |
| |
| ctl = file->private_data; |
| if (snd_BUG_ON(!ctl || !ctl->card)) |
| return -ENXIO; |
| if (!ctl->subscribed) |
| return -EBADFD; |
| if (count < sizeof(struct snd_ctl_event)) |
| return -EINVAL; |
| spin_lock_irq(&ctl->read_lock); |
| while (count >= sizeof(struct snd_ctl_event)) { |
| struct snd_ctl_event ev; |
| struct snd_kctl_event *kev; |
| while (list_empty(&ctl->events)) { |
| wait_queue_entry_t wait; |
| if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) { |
| err = -EAGAIN; |
| goto __end_lock; |
| } |
| init_waitqueue_entry(&wait, current); |
| add_wait_queue(&ctl->change_sleep, &wait); |
| set_current_state(TASK_INTERRUPTIBLE); |
| spin_unlock_irq(&ctl->read_lock); |
| schedule(); |
| remove_wait_queue(&ctl->change_sleep, &wait); |
| if (ctl->card->shutdown) |
| return -ENODEV; |
| if (signal_pending(current)) |
| return -ERESTARTSYS; |
| spin_lock_irq(&ctl->read_lock); |
| } |
| kev = snd_kctl_event(ctl->events.next); |
| ev.type = SNDRV_CTL_EVENT_ELEM; |
| ev.data.elem.mask = kev->mask; |
| ev.data.elem.id = kev->id; |
| list_del(&kev->list); |
| spin_unlock_irq(&ctl->read_lock); |
| kfree(kev); |
| if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) { |
| err = -EFAULT; |
| goto __end; |
| } |
| spin_lock_irq(&ctl->read_lock); |
| buffer += sizeof(struct snd_ctl_event); |
| count -= sizeof(struct snd_ctl_event); |
| result += sizeof(struct snd_ctl_event); |
| } |
| __end_lock: |
| spin_unlock_irq(&ctl->read_lock); |
| __end: |
| return result > 0 ? result : err; |
| } |
| |
| static __poll_t snd_ctl_poll(struct file *file, poll_table * wait) |
| { |
| __poll_t mask; |
| struct snd_ctl_file *ctl; |
| |
| ctl = file->private_data; |
| if (!ctl->subscribed) |
| return 0; |
| poll_wait(file, &ctl->change_sleep, wait); |
| |
| mask = 0; |
| if (!list_empty(&ctl->events)) |
| mask |= EPOLLIN | EPOLLRDNORM; |
| |
| return mask; |
| } |
| |
| /* |
| * register the device-specific control-ioctls. |
| * called from each device manager like pcm.c, hwdep.c, etc. |
| */ |
| static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists) |
| { |
| struct snd_kctl_ioctl *pn; |
| |
| pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL); |
| if (pn == NULL) |
| return -ENOMEM; |
| pn->fioctl = fcn; |
| guard(rwsem_write)(&snd_ioctl_rwsem); |
| list_add_tail(&pn->list, lists); |
| return 0; |
| } |
| |
| /** |
| * snd_ctl_register_ioctl - register the device-specific control-ioctls |
| * @fcn: ioctl callback function |
| * |
| * called from each device manager like pcm.c, hwdep.c, etc. |
| * |
| * Return: zero if successful, or a negative error code |
| */ |
| int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn) |
| { |
| return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls); |
| } |
| EXPORT_SYMBOL(snd_ctl_register_ioctl); |
| |
| #ifdef CONFIG_COMPAT |
| /** |
| * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat |
| * control-ioctls |
| * @fcn: ioctl callback function |
| * |
| * Return: zero if successful, or a negative error code |
| */ |
| int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn) |
| { |
| return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls); |
| } |
| EXPORT_SYMBOL(snd_ctl_register_ioctl_compat); |
| #endif |
| |
| /* |
| * de-register the device-specific control-ioctls. |
| */ |
| static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn, |
| struct list_head *lists) |
| { |
| struct snd_kctl_ioctl *p; |
| |
| if (snd_BUG_ON(!fcn)) |
| return -EINVAL; |
| guard(rwsem_write)(&snd_ioctl_rwsem); |
| list_for_each_entry(p, lists, list) { |
| if (p->fioctl == fcn) { |
| list_del(&p->list); |
| kfree(p); |
| return 0; |
| } |
| } |
| snd_BUG(); |
| return -EINVAL; |
| } |
| |
| /** |
| * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls |
| * @fcn: ioctl callback function to unregister |
| * |
| * Return: zero if successful, or a negative error code |
| */ |
| int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn) |
| { |
| return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls); |
| } |
| EXPORT_SYMBOL(snd_ctl_unregister_ioctl); |
| |
| #ifdef CONFIG_COMPAT |
| /** |
| * snd_ctl_unregister_ioctl_compat - de-register the device-specific compat |
| * 32bit control-ioctls |
| * @fcn: ioctl callback function to unregister |
| * |
| * Return: zero if successful, or a negative error code |
| */ |
| int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn) |
| { |
| return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls); |
| } |
| EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat); |
| #endif |
| |
| static int snd_ctl_fasync(int fd, struct file * file, int on) |
| { |
| struct snd_ctl_file *ctl; |
| |
| ctl = file->private_data; |
| return snd_fasync_helper(fd, file, on, &ctl->fasync); |
| } |
| |
| /* return the preferred subdevice number if already assigned; |
| * otherwise return -1 |
| */ |
| int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type) |
| { |
| struct snd_ctl_file *kctl; |
| int subdevice = -1; |
| |
| guard(read_lock_irqsave)(&card->ctl_files_rwlock); |
| list_for_each_entry(kctl, &card->ctl_files, list) { |
| if (kctl->pid == task_pid(current)) { |
| subdevice = kctl->preferred_subdevice[type]; |
| if (subdevice != -1) |
| break; |
| } |
| } |
| return subdevice; |
| } |
| EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice); |
| |
| /* |
| * ioctl32 compat |
| */ |
| #ifdef CONFIG_COMPAT |
| #include "control_compat.c" |
| #else |
| #define snd_ctl_ioctl_compat NULL |
| #endif |
| |
| /* |
| * control layers (audio LED etc.) |
| */ |
| |
| /** |
| * snd_ctl_request_layer - request to use the layer |
| * @module_name: Name of the kernel module (NULL == build-in) |
| * |
| * Return: zero if successful, or an error code when the module cannot be loaded |
| */ |
| int snd_ctl_request_layer(const char *module_name) |
| { |
| struct snd_ctl_layer_ops *lops; |
| |
| if (module_name == NULL) |
| return 0; |
| scoped_guard(rwsem_read, &snd_ctl_layer_rwsem) { |
| for (lops = snd_ctl_layer; lops; lops = lops->next) |
| if (strcmp(lops->module_name, module_name) == 0) |
| return 0; |
| } |
| return request_module(module_name); |
| } |
| EXPORT_SYMBOL_GPL(snd_ctl_request_layer); |
| |
| /** |
| * snd_ctl_register_layer - register new control layer |
| * @lops: operation structure |
| * |
| * The new layer can track all control elements and do additional |
| * operations on top (like audio LED handling). |
| */ |
| void snd_ctl_register_layer(struct snd_ctl_layer_ops *lops) |
| { |
| struct snd_card *card; |
| int card_number; |
| |
| scoped_guard(rwsem_write, &snd_ctl_layer_rwsem) { |
| lops->next = snd_ctl_layer; |
| snd_ctl_layer = lops; |
| } |
| for (card_number = 0; card_number < SNDRV_CARDS; card_number++) { |
| card = snd_card_ref(card_number); |
| if (card) { |
| scoped_guard(rwsem_read, &card->controls_rwsem) |
| lops->lregister(card); |
| snd_card_unref(card); |
| } |
| } |
| } |
| EXPORT_SYMBOL_GPL(snd_ctl_register_layer); |
| |
| /** |
| * snd_ctl_disconnect_layer - disconnect control layer |
| * @lops: operation structure |
| * |
| * It is expected that the information about tracked cards |
| * is freed before this call (the disconnect callback is |
| * not called here). |
| */ |
| void snd_ctl_disconnect_layer(struct snd_ctl_layer_ops *lops) |
| { |
| struct snd_ctl_layer_ops *lops2, *prev_lops2; |
| |
| guard(rwsem_write)(&snd_ctl_layer_rwsem); |
| for (lops2 = snd_ctl_layer, prev_lops2 = NULL; lops2; lops2 = lops2->next) { |
| if (lops2 == lops) { |
| if (!prev_lops2) |
| snd_ctl_layer = lops->next; |
| else |
| prev_lops2->next = lops->next; |
| break; |
| } |
| prev_lops2 = lops2; |
| } |
| } |
| EXPORT_SYMBOL_GPL(snd_ctl_disconnect_layer); |
| |
| /* |
| * INIT PART |
| */ |
| |
| static const struct file_operations snd_ctl_f_ops = |
| { |
| .owner = THIS_MODULE, |
| .read = snd_ctl_read, |
| .open = snd_ctl_open, |
| .release = snd_ctl_release, |
| .llseek = no_llseek, |
| .poll = snd_ctl_poll, |
| .unlocked_ioctl = snd_ctl_ioctl, |
| .compat_ioctl = snd_ctl_ioctl_compat, |
| .fasync = snd_ctl_fasync, |
| }; |
| |
| /* call lops under rwsems; called from snd_ctl_dev_*() below() */ |
| #define call_snd_ctl_lops(_card, _op) \ |
| do { \ |
| struct snd_ctl_layer_ops *lops; \ |
| guard(rwsem_read)(&(_card)->controls_rwsem); \ |
| guard(rwsem_read)(&snd_ctl_layer_rwsem); \ |
| for (lops = snd_ctl_layer; lops; lops = lops->next) \ |
| lops->_op(_card); \ |
| } while (0) |
| |
| /* |
| * registration of the control device |
| */ |
| static int snd_ctl_dev_register(struct snd_device *device) |
| { |
| struct snd_card *card = device->device_data; |
| int err; |
| |
| err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1, |
| &snd_ctl_f_ops, card, card->ctl_dev); |
| if (err < 0) |
| return err; |
| call_snd_ctl_lops(card, lregister); |
| return 0; |
| } |
| |
| /* |
| * disconnection of the control device |
| */ |
| static int snd_ctl_dev_disconnect(struct snd_device *device) |
| { |
| struct snd_card *card = device->device_data; |
| struct snd_ctl_file *ctl; |
| |
| scoped_guard(read_lock_irqsave, &card->ctl_files_rwlock) { |
| list_for_each_entry(ctl, &card->ctl_files, list) { |
| wake_up(&ctl->change_sleep); |
| snd_kill_fasync(ctl->fasync, SIGIO, POLL_ERR); |
| } |
| } |
| |
| call_snd_ctl_lops(card, ldisconnect); |
| return snd_unregister_device(card->ctl_dev); |
| } |
| |
| /* |
| * free all controls |
| */ |
| static int snd_ctl_dev_free(struct snd_device *device) |
| { |
| struct snd_card *card = device->device_data; |
| struct snd_kcontrol *control; |
| |
| scoped_guard(rwsem_write, &card->controls_rwsem) { |
| while (!list_empty(&card->controls)) { |
| control = snd_kcontrol(card->controls.next); |
| __snd_ctl_remove(card, control, false); |
| } |
| |
| #ifdef CONFIG_SND_CTL_FAST_LOOKUP |
| xa_destroy(&card->ctl_numids); |
| xa_destroy(&card->ctl_hash); |
| #endif |
| } |
| put_device(card->ctl_dev); |
| return 0; |
| } |
| |
| /* |
| * create control core: |
| * called from init.c |
| */ |
| int snd_ctl_create(struct snd_card *card) |
| { |
| static const struct snd_device_ops ops = { |
| .dev_free = snd_ctl_dev_free, |
| .dev_register = snd_ctl_dev_register, |
| .dev_disconnect = snd_ctl_dev_disconnect, |
| }; |
| int err; |
| |
| if (snd_BUG_ON(!card)) |
| return -ENXIO; |
| if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS)) |
| return -ENXIO; |
| |
| err = snd_device_alloc(&card->ctl_dev, card); |
| if (err < 0) |
| return err; |
| dev_set_name(card->ctl_dev, "controlC%d", card->number); |
| |
| err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops); |
| if (err < 0) |
| put_device(card->ctl_dev); |
| return err; |
| } |
| |
| /* |
| * Frequently used control callbacks/helpers |
| */ |
| |
| /** |
| * snd_ctl_boolean_mono_info - Helper function for a standard boolean info |
| * callback with a mono channel |
| * @kcontrol: the kcontrol instance |
| * @uinfo: info to store |
| * |
| * This is a function that can be used as info callback for a standard |
| * boolean control with a single mono channel. |
| * |
| * Return: Zero (always successful) |
| */ |
| int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol, |
| struct snd_ctl_elem_info *uinfo) |
| { |
| uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN; |
| uinfo->count = 1; |
| uinfo->value.integer.min = 0; |
| uinfo->value.integer.max = 1; |
| return 0; |
| } |
| EXPORT_SYMBOL(snd_ctl_boolean_mono_info); |
| |
| /** |
| * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info |
| * callback with stereo two channels |
| * @kcontrol: the kcontrol instance |
| * @uinfo: info to store |
| * |
| * This is a function that can be used as info callback for a standard |
| * boolean control with stereo two channels. |
| * |
| * Return: Zero (always successful) |
| */ |
| int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol, |
| struct snd_ctl_elem_info *uinfo) |
| { |
| uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN; |
| uinfo->count = 2; |
| uinfo->value.integer.min = 0; |
| uinfo->value.integer.max = 1; |
| return 0; |
| } |
| EXPORT_SYMBOL(snd_ctl_boolean_stereo_info); |
| |
| /** |
| * snd_ctl_enum_info - fills the info structure for an enumerated control |
| * @info: the structure to be filled |
| * @channels: the number of the control's channels; often one |
| * @items: the number of control values; also the size of @names |
| * @names: an array containing the names of all control values |
| * |
| * Sets all required fields in @info to their appropriate values. |
| * If the control's accessibility is not the default (readable and writable), |
| * the caller has to fill @info->access. |
| * |
| * Return: Zero (always successful) |
| */ |
| int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels, |
| unsigned int items, const char *const names[]) |
| { |
| info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED; |
| info->count = channels; |
| info->value.enumerated.items = items; |
| if (!items) |
| return 0; |
| if (info->value.enumerated.item >= items) |
| info->value.enumerated.item = items - 1; |
| WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name), |
| "ALSA: too long item name '%s'\n", |
| names[info->value.enumerated.item]); |
| strscpy(info->value.enumerated.name, |
| names[info->value.enumerated.item], |
| sizeof(info->value.enumerated.name)); |
| return 0; |
| } |
| EXPORT_SYMBOL(snd_ctl_enum_info); |