diff options
Diffstat (limited to 'sound/core/control.c')
| -rw-r--r-- | sound/core/control.c | 1320 |
1 files changed, 901 insertions, 419 deletions
diff --git a/sound/core/control.c b/sound/core/control.c index fad7db402443..9c3fd5113a61 100644 --- a/sound/core/control.c +++ b/sound/core/control.c @@ -1,39 +1,29 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* * Routines for driver control interface * 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/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 number of user-defined controls */ -#define MAX_USER_CONTROLS 32 +// 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 { @@ -42,19 +32,23 @@ struct snd_kctl_ioctl { }; 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) { - unsigned long flags; struct snd_card *card; struct snd_ctl_file *ctl; int i, err; - err = nonseekable_open(inode, file); + err = stream_open(inode, file); if (err < 0) return err; @@ -85,9 +79,8 @@ static int snd_ctl_open(struct inode *inode, struct file *file) ctl->preferred_subdevice[i] = -1; ctl->pid = get_pid(task_pid(current)); file->private_data = ctl; - write_lock_irqsave(&card->ctl_files_rwlock, flags); - list_add_tail(&ctl->list, &card->ctl_files); - write_unlock_irqrestore(&card->ctl_files_rwlock, flags); + scoped_guard(write_lock_irqsave, &card->controls_rwlock) + list_add_tail(&ctl->list, &card->ctl_files); snd_card_unref(card); return 0; @@ -103,21 +96,18 @@ static int snd_ctl_open(struct inode *inode, struct file *file) static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl) { - unsigned long flags; struct snd_kctl_event *cread; - spin_lock_irqsave(&ctl->read_lock, flags); + guard(spinlock_irqsave)(&ctl->read_lock); while (!list_empty(&ctl->events)) { cread = snd_kctl_event(ctl->events.next); list_del(&cread->list); kfree(cread); } - spin_unlock_irqrestore(&ctl->read_lock, flags); } static int snd_ctl_release(struct inode *inode, struct file *file) { - unsigned long flags; struct snd_card *card; struct snd_ctl_file *ctl; struct snd_kcontrol *control; @@ -126,15 +116,18 @@ static int snd_ctl_release(struct inode *inode, struct file *file) ctl = file->private_data; file->private_data = NULL; card = ctl->card; - write_lock_irqsave(&card->ctl_files_rwlock, flags); - list_del(&ctl->list); - write_unlock_irqrestore(&card->ctl_files_rwlock, flags); - down_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; - up_write(&card->controls_rwsem); + + scoped_guard(write_lock_irqsave, &card->controls_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); @@ -156,7 +149,6 @@ static int snd_ctl_release(struct inode *inode, struct file *file) void snd_ctl_notify(struct snd_card *card, unsigned int mask, struct snd_ctl_elem_id *id) { - unsigned long flags; struct snd_ctl_file *ctl; struct snd_kctl_event *ev; @@ -164,38 +156,63 @@ void snd_ctl_notify(struct snd_card *card, unsigned int mask, return; if (card->shutdown) return; - read_lock(&card->ctl_files_rwlock); + + guard(read_lock_irqsave)(&card->controls_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; - spin_lock_irqsave(&ctl->read_lock, flags); - list_for_each_entry(ev, &ctl->events, list) { - if (ev->id.numid == id->numid) { - ev->mask |= mask; - goto _found; + 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); } - 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); - spin_unlock_irqrestore(&ctl->read_lock, flags); - kill_fasync(&ctl->fasync, SIGIO, POLL_IN); + snd_kill_fasync(ctl->fasync, SIGIO, POLL_IN); } - read_unlock(&card->ctl_files_rwlock); } 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 @@ -211,24 +228,20 @@ EXPORT_SYMBOL(snd_ctl_notify); static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count, unsigned int access, struct snd_ctl_file *file) { - unsigned int size; unsigned int idx; if (count == 0 || count > MAX_CONTROL_COUNT) return -EINVAL; - size = sizeof(struct snd_kcontrol); - size += sizeof(struct snd_kcontrol_volatile) * count; - - *kctl = kzalloc(size, GFP_KERNEL); + *kctl = kzalloc(struct_size(*kctl, vd, count), GFP_KERNEL); if (!*kctl) return -ENOMEM; + (*kctl)->count = count; for (idx = 0; idx < count; idx++) { (*kctl)->vd[idx].access = access; (*kctl)->vd[idx].owner = file; } - (*kctl)->count = count; return 0; } @@ -267,7 +280,9 @@ struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol, 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_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) @@ -278,7 +293,7 @@ struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol, kctl->id.device = ncontrol->device; kctl->id.subdevice = ncontrol->subdevice; if (ncontrol->name) { - strlcpy(kctl->id.name, ncontrol->name, sizeof(kctl->id.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); @@ -348,6 +363,93 @@ static int snd_ctl_find_hole(struct snd_card *card, unsigned int count) 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, }; @@ -359,10 +461,11 @@ static int __snd_ctl_add_replace(struct snd_card *card, { struct snd_ctl_elem_id id; unsigned int idx; - unsigned int count; 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; @@ -380,7 +483,7 @@ static int __snd_ctl_add_replace(struct snd_card *card, return -EBUSY; } - err = snd_ctl_remove(card, old); + err = snd_ctl_remove_locked(card, old); if (err < 0) return err; } @@ -388,15 +491,17 @@ static int __snd_ctl_add_replace(struct snd_card *card, 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; + scoped_guard(write_lock_irq, &card->controls_rwlock) { + list_add_tail(&kcontrol->list, &card->controls); + card->controls_count += kcontrol->count; + kcontrol->id.numid = card->last_numid + 1; + card->last_numid += kcontrol->count; + } - id = kcontrol->id; - count = kcontrol->count; - for (idx = 0; idx < count; idx++, id.index++, id.numid++) - snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id); + 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; } @@ -412,9 +517,9 @@ static int snd_ctl_add_replace(struct snd_card *card, if (snd_BUG_ON(!card || !kcontrol->info)) goto error; - down_write(&card->controls_rwsem); - err = __snd_ctl_add_replace(card, kcontrol, mode); - up_write(&card->controls_rwsem); + scoped_guard(rwsem_write, &card->controls_rwsem) + err = __snd_ctl_add_replace(card, kcontrol, mode); + if (err < 0) goto error; return 0; @@ -466,31 +571,56 @@ int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol, } 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; + + if (remove_hash) + remove_hash_entries(card, kcontrol); + + scoped_guard(write_lock_irq, &card->controls_rwlock) { + list_del(&kcontrol->list); + 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(). You must be in - * the write lock - down_write(&card->controls_rwsem). + * 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) { - struct snd_ctl_elem_id id; - unsigned int idx; - - if (snd_BUG_ON(!card || !kcontrol)) - return -EINVAL; - list_del(&kcontrol->list); - card->controls_count -= kcontrol->count; - id = kcontrol->id; - for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++) - snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id); - snd_ctl_free_one(kcontrol); - return 0; + if (!kcontrol) + return 0; + guard(rwsem_write)(&card->controls_rwsem); + return snd_ctl_remove_locked(card, kcontrol); } EXPORT_SYMBOL(snd_ctl_remove); @@ -507,17 +637,12 @@ EXPORT_SYMBOL(snd_ctl_remove); int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id) { struct snd_kcontrol *kctl; - int ret; - down_write(&card->controls_rwsem); + guard(rwsem_write)(&card->controls_rwsem); kctl = snd_ctl_find_id(card, id); - if (kctl == NULL) { - up_write(&card->controls_rwsem); + if (kctl == NULL) return -ENOENT; - } - ret = snd_ctl_remove(card, kctl); - up_write(&card->controls_rwsem); - return ret; + return snd_ctl_remove_locked(card, kctl); } EXPORT_SYMBOL(snd_ctl_remove_id); @@ -536,30 +661,18 @@ static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file, { struct snd_card *card = file->card; struct snd_kcontrol *kctl; - int idx, ret; + int idx; - down_write(&card->controls_rwsem); + guard(rwsem_write)(&card->controls_rwsem); kctl = snd_ctl_find_id(card, id); - if (kctl == NULL) { - ret = -ENOENT; - goto error; - } - if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) { - ret = -EINVAL; - goto error; - } + 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) { - ret = -EBUSY; - goto error; - } - ret = snd_ctl_remove(card, kctl); - if (ret < 0) - goto error; - card->user_ctl_count--; -error: - up_write(&card->controls_rwsem); - return ret; + if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) + return -EBUSY; + return snd_ctl_remove_locked(card, kctl); } /** @@ -601,11 +714,13 @@ int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id, vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE; } snd_ctl_build_ioff(id, kctl, index_offset); - ret = 1; + 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); - if (ret > 0) - snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id); return ret; } EXPORT_SYMBOL_GPL(snd_ctl_activate_id); @@ -619,52 +734,96 @@ EXPORT_SYMBOL_GPL(snd_ctl_activate_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; - down_write(&card->controls_rwsem); + guard(rwsem_write)(&card->controls_rwsem); kctl = snd_ctl_find_id(card, src_id); - if (kctl == NULL) { - up_write(&card->controls_rwsem); + if (kctl == NULL) return -ENOENT; - } + saved_numid = kctl->id.numid; + remove_hash_entries(card, kctl); kctl->id = *dst_id; - kctl->id.numid = card->last_numid + 1; - card->last_numid += kctl->count; - up_write(&card->controls_rwsem); + kctl->id.numid = saved_numid; + add_hash_entries(card, kctl); return 0; } EXPORT_SYMBOL(snd_ctl_rename_id); /** - * snd_ctl_find_numid - find the control instance with the given number-id + * snd_ctl_rename - rename the control on the card * @card: the card instance - * @numid: the number-id to search + * @kctl: the control to rename + * @name: the new name * - * 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. + * Renames the specified control on the card to the new name. * + * Note that this function takes card->controls_rwsem lock internally. */ -struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid) +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; - if (snd_BUG_ON(!card || !numid)) - return NULL; + guard(read_lock_irqsave)(&card->controls_rwlock); 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 - 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_rwlock lock internally. + */ +struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, + unsigned int numid) +{ + if (snd_BUG_ON(!card || !numid)) + return NULL; + +#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); /** @@ -674,36 +833,33 @@ EXPORT_SYMBOL(snd_ctl_find_numid); * * 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. * + * Note that this function takes card->controls_rwlock lock internally. */ struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card, - struct snd_ctl_elem_id *id) + const struct snd_ctl_elem_id *id) { struct snd_kcontrol *kctl; if (snd_BUG_ON(!card || !id)) return NULL; + if (id->numid != 0) return snd_ctl_find_numid(card, id->numid); - list_for_each_entry(kctl, &card->controls, list) { - if (kctl->id.iface != id->iface) - continue; - if (kctl->id.device != id->device) - continue; - if (kctl->id.subdevice != id->subdevice) - continue; - if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name))) - continue; - if (kctl->id.index > id->index) - continue; - if (kctl->id.index + kctl->count <= id->index) - continue; +#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 */ + guard(read_lock_irqsave)(&card->controls_rwlock); + list_for_each_entry(kctl, &card->controls, list) + if (elem_id_matches(kctl, id)) + return kctl; + return NULL; } EXPORT_SYMBOL(snd_ctl_find_id); @@ -711,117 +867,270 @@ 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; + struct snd_ctl_card_info *info __free(kfree) = NULL; info = kzalloc(sizeof(*info), GFP_KERNEL); if (! info) return -ENOMEM; - down_read(&snd_ioctl_rwsem); - info->card = card->number; - strlcpy(info->id, card->id, sizeof(info->id)); - strlcpy(info->driver, card->driver, sizeof(info->driver)); - strlcpy(info->name, card->shortname, sizeof(info->name)); - strlcpy(info->longname, card->longname, sizeof(info->longname)); - strlcpy(info->mixername, card->mixername, sizeof(info->mixername)); - strlcpy(info->components, card->components, sizeof(info->components)); - up_read(&snd_ioctl_rwsem); - if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) { - kfree(info); - return -EFAULT; + 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)); } - kfree(info); + 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 __user *_list) + struct snd_ctl_elem_list *list) { - struct snd_ctl_elem_list list; struct snd_kcontrol *kctl; struct snd_ctl_elem_id id; unsigned int offset, space, jidx; - int err = 0; - if (copy_from_user(&list, _list, sizeof(list))) - return -EFAULT; - offset = list.offset; - space = list.space; - - down_read(&card->controls_rwsem); - list.count = card->controls_count; - list.used = 0; - if (space > 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))) { - err = -EFAULT; - goto out; - } - list.used++; - if (!--space) - goto out; - } - offset = 0; + 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; } - out: - up_read(&card->controls_rwsem); - if (!err && copy_to_user(_list, &list, sizeof(list))) - err = -EFAULT; - return err; + return 0; } -static bool validate_element_member_dimension(struct snd_ctl_elem_info *info) +static int snd_ctl_elem_list_user(struct snd_card *card, + struct snd_ctl_elem_list __user *_list) { - unsigned int members; - unsigned int i; + 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; - if (info->dimen.d[0] == 0) - return true; + return 0; +} - members = 1; - for (i = 0; i < ARRAY_SIZE(info->dimen.d); ++i) { - if (info->dimen.d[i] == 0) - break; - members *= info->dimen.d[i]; - - /* - * info->count should be validated in advance, to guarantee - * calculation soundness. - */ - if (members > info->count) - return false; +/* 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), +}; - for (++i; i < ARRAY_SIZE(info->dimen.d); ++i) { - if (info->dimen.d[i] > 0) - return false; +/* 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; } - return members == info->count; + 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; } -static int snd_ctl_elem_info(struct snd_ctl_file *ctl, - struct snd_ctl_elem_info *info) +/* 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_card *card = ctl->card; - struct snd_kcontrol *kctl; struct snd_kcontrol_volatile *vd; unsigned int index_offset; int result; - down_read(&card->controls_rwsem); - kctl = snd_ctl_find_id(card, &info->id); - if (kctl == NULL) { - up_read(&card->controls_rwsem); - return -ENOENT; - } #ifdef CONFIG_SND_DEBUG info->access = 0; #endif @@ -840,25 +1149,45 @@ static int snd_ctl_elem_info(struct snd_ctl_file *ctl, } else { info->owner = -1; } + if (!snd_ctl_skip_validation(info) && + snd_ctl_check_elem_info(card, info) < 0) + result = -EINVAL; } - up_read(&card->controls_rwsem); 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(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_card *card = ctl->card; struct snd_ctl_elem_info info; int result; if (copy_from_user(&info, _info, sizeof(info))) return -EFAULT; - result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0); - if (result < 0) + result = snd_power_ref_and_wait(card); + if (result) return result; result = snd_ctl_elem_info(ctl, &info); + snd_power_unref(card); 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; @@ -870,44 +1199,68 @@ static int snd_ctl_elem_read(struct snd_card *card, 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(card, &control->id); - if (kctl == NULL) + 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 == NULL) + if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_READ) || !kctl->get) return -EPERM; snd_ctl_build_ioff(&control->id, kctl, index_offset); - return kctl->get(kctl, control); + +#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 = kctl->get(kctl, control); + 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; + struct snd_ctl_elem_value *control __free(kfree) = NULL; int result; control = memdup_user(_control, sizeof(*control)); if (IS_ERR(control)) return PTR_ERR(control); - result = snd_power_wait(card, SNDRV_CTL_POWER_D0); - if (result < 0) - goto error; - - down_read(&card->controls_rwsem); + result = snd_power_ref_and_wait(card); + if (result) + return result; result = snd_ctl_elem_read(card, control); - up_read(&card->controls_rwsem); + snd_power_unref(card); if (result < 0) - goto error; + return result; if (copy_to_user(_control, control, sizeof(*control))) - result = -EFAULT; - error: - kfree(control); + return -EFAULT; return result; } @@ -917,27 +1270,48 @@ static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file, struct snd_kcontrol *kctl; struct snd_kcontrol_volatile *vd; unsigned int index_offset; - int result; + int result = 0; + down_write(&card->controls_rwsem); kctl = snd_ctl_find_id(card, &control->id); - if (kctl == NULL) + 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 = kctl->put(kctl, control); - if (result < 0) + /* validate input values */ + if (IS_ENABLED(CONFIG_SND_CTL_INPUT_VALIDATION)) { + 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); + if (result < 0) { + up_write(&card->controls_rwsem); return result; + } if (result > 0) { - struct snd_ctl_elem_id id = control->id; - snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id); + 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; @@ -946,7 +1320,7 @@ static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file, 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; + struct snd_ctl_elem_value *control __free(kfree) = NULL; struct snd_card *card; int result; @@ -955,20 +1329,16 @@ static int snd_ctl_elem_write_user(struct snd_ctl_file *file, return PTR_ERR(control); card = file->card; - result = snd_power_wait(card, SNDRV_CTL_POWER_D0); + result = snd_power_ref_and_wait(card); if (result < 0) - goto error; - - down_write(&card->controls_rwsem); + return result; result = snd_ctl_elem_write(card, file, control); - up_write(&card->controls_rwsem); + snd_power_unref(card); if (result < 0) - goto error; + return result; if (copy_to_user(_control, control, sizeof(*control))) - result = -EFAULT; - error: - kfree(control); + return -EFAULT; return result; } @@ -979,25 +1349,18 @@ static int snd_ctl_elem_lock(struct snd_ctl_file *file, struct snd_ctl_elem_id id; struct snd_kcontrol *kctl; struct snd_kcontrol_volatile *vd; - int result; if (copy_from_user(&id, _id, sizeof(id))) return -EFAULT; - down_write(&card->controls_rwsem); + guard(rwsem_write)(&card->controls_rwsem); kctl = snd_ctl_find_id(card, &id); - if (kctl == NULL) { - result = -ENOENT; - } else { - vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)]; - if (vd->owner != NULL) - result = -EBUSY; - else { - vd->owner = file; - result = 0; - } - } - up_write(&card->controls_rwsem); - return result; + 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, @@ -1007,27 +1370,20 @@ static int snd_ctl_elem_unlock(struct snd_ctl_file *file, struct snd_ctl_elem_id id; struct snd_kcontrol *kctl; struct snd_kcontrol_volatile *vd; - int result; if (copy_from_user(&id, _id, sizeof(id))) return -EFAULT; - down_write(&card->controls_rwsem); + guard(rwsem_write)(&card->controls_rwsem); kctl = snd_ctl_find_id(card, &id); - if (kctl == NULL) { - result = -ENOENT; - } else { - vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)]; - if (vd->owner == NULL) - result = -EINVAL; - else if (vd->owner != file) - result = -EPERM; - else { - vd->owner = NULL; - result = 0; - } - } - up_write(&card->controls_rwsem); - return result; + 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 { @@ -1040,10 +1396,16 @@ struct user_element { 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; + struct user_element *ue = snd_kcontrol_chip(kcontrol); unsigned int offset; offset = snd_ctl_get_ioff(kcontrol, &uinfo->id); @@ -1056,7 +1418,7 @@ static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol, 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; + struct user_element *ue = snd_kcontrol_chip(kcontrol); const char *names; unsigned int item; unsigned int offset; @@ -1073,7 +1435,7 @@ static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol, names = ue->priv_data; for (; item > 0; --item) names += strlen(names) + 1; - strcpy(uinfo->value.enumerated.name, names); + strscpy(uinfo->value.enumerated.name, names); return 0; } @@ -1081,7 +1443,7 @@ static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol, static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol) { - struct user_element *ue = kcontrol->private_data; + struct user_element *ue = snd_kcontrol_chip(kcontrol); unsigned int size = ue->elem_data_size; char *src = ue->elem_data + snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size; @@ -1093,31 +1455,41 @@ static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol, static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol) { - int change; - struct user_element *ue = kcontrol->private_data; + int err, change; + struct user_element *ue = snd_kcontrol_chip(kcontrol); 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; + struct user_element *ue = snd_kcontrol_chip(kctl); unsigned int *container; - struct snd_ctl_elem_id id; 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); @@ -1135,17 +1507,20 @@ static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf, 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); } - 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_build_ioff(&id, kctl, i); - snd_ctl_notify(ue->card, mask, &id); - } + for (i = 0; i < kctl->count; ++i) + snd_ctl_notify_one(ue->card, mask, kctl, i); return change; } @@ -1153,7 +1528,7 @@ static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf, static int read_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf, unsigned int size) { - struct user_element *ue = kctl->private_data; + struct user_element *ue = snd_kcontrol_chip(kctl); if (ue->tlv_data_size == 0 || ue->tlv_data == NULL) return -ENXIO; @@ -1176,6 +1551,7 @@ static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kctl, int op_flag, 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; @@ -1183,16 +1559,19 @@ static int snd_ctl_elem_init_enum_names(struct user_element *ue) unsigned int i; const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr; - if (ue->info.value.enumerated.names_length > 64 * 1024) + lockdep_assert_held_write(&ue->card->controls_rwsem); + + buf_len = ue->info.value.enumerated.names_length; + if (buf_len > 64 * 1024) return -EINVAL; - names = vmemdup_user((const void __user *)user_ptrval, - ue->info.value.enumerated.names_length); + 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 */ - buf_len = ue->info.value.enumerated.names_length; p = names; for (i = 0; i < ue->info.value.enumerated.items; ++i) { name_len = strnlen(p, buf_len); @@ -1206,13 +1585,26 @@ static int snd_ctl_elem_init_enum_names(struct user_element *ue) 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; + struct user_element *ue = snd_kcontrol_chip(kcontrol); + + // 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); @@ -1222,28 +1614,12 @@ static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol) static int snd_ctl_elem_add(struct snd_ctl_file *file, struct snd_ctl_elem_info *info, int replace) { - /* 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), - }; - 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, - }; 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; @@ -1261,17 +1637,12 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file, return err; } - /* - * The number of userspace controls are counted control by control, - * not element by element. - */ - if (card->user_ctl_count + 1 > MAX_USER_CONTROLS) - return -ENOMEM; - /* Check the number of elements for this userspace control. */ count = info->owner; if (count == 0) count = 1; + if (count > MAX_CONTROL_COUNT) + return -EINVAL; /* Arrange access permissions if needed. */ access = info->access; @@ -1290,18 +1661,19 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file, * Check information and calculate the size of data specific to * this userspace control. */ - if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN || - info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64) - return -EINVAL; - if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED && - info->value.enumerated.items == 0) - return -EINVAL; - if (info->count < 1 || - info->count > max_value_counts[info->type]) - return -EINVAL; - if (!validate_element_member_dimension(info)) + /* 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 @@ -1313,16 +1685,18 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file, if (err < 0) return err; memcpy(&kctl->id, &info->id, sizeof(kctl->id)); - kctl->private_data = kzalloc(sizeof(struct user_element) + private_size * count, - GFP_KERNEL); - if (kctl->private_data == NULL) { + 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 = (struct user_element *)kctl->private_data; ue->card = card; ue->info = *info; ue->info.access = 0; @@ -1349,11 +1723,10 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file, kctl->tlv.c = snd_ctl_elem_user_tlv; /* This function manage to free the instance on failure. */ - down_write(&card->controls_rwsem); err = __snd_ctl_add_replace(card, kctl, CTL_ADD_EXCLUSIVE); if (err < 0) { snd_ctl_free_one(kctl); - goto unlock; + return err; } offset = snd_ctl_get_ioff(kctl, &info->id); snd_ctl_build_ioff(&info->id, kctl, offset); @@ -1364,11 +1737,6 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file, * applications because the field originally means PID of a process * which locks the element. */ - - card->user_ctl_count++; - - unlock: - up_write(&card->controls_rwsem); return 0; } @@ -1449,8 +1817,9 @@ static int call_tlv_handler(struct snd_ctl_file *file, int op_flag, if (kctl->tlv.c == NULL) return -ENXIO; - /* When locked, this is unavailable. */ - if (vd->owner != NULL && vd->owner != file) + /* 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; return kctl->tlv.c(kctl, op_flag, size, buf); @@ -1489,6 +1858,8 @@ static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file, 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; @@ -1544,7 +1915,7 @@ static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg 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(card, argp); + 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: @@ -1564,38 +1935,41 @@ static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS: return snd_ctl_subscribe_events(ctl, ip); case SNDRV_CTL_IOCTL_TLV_READ: - down_read(&ctl->card->controls_rwsem); - err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ); - up_read(&ctl->card->controls_rwsem); + err = snd_power_ref_and_wait(card); + if (err < 0) + return err; + scoped_guard(rwsem_read, &card->controls_rwsem) + err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ); + snd_power_unref(card); return err; case SNDRV_CTL_IOCTL_TLV_WRITE: - down_write(&ctl->card->controls_rwsem); - err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE); - up_write(&ctl->card->controls_rwsem); + err = snd_power_ref_and_wait(card); + if (err < 0) + return err; + scoped_guard(rwsem_write, &card->controls_rwsem) + err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE); + snd_power_unref(card); return err; case SNDRV_CTL_IOCTL_TLV_COMMAND: - down_write(&ctl->card->controls_rwsem); - err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD); - up_write(&ctl->card->controls_rwsem); + err = snd_power_ref_and_wait(card); + if (err < 0) + return err; + scoped_guard(rwsem_write, &card->controls_rwsem) + err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD); + snd_power_unref(card); return err; case SNDRV_CTL_IOCTL_POWER: return -ENOPROTOOPT; case SNDRV_CTL_IOCTL_POWER_STATE: -#ifdef CONFIG_PM - return put_user(card->power_state, ip) ? -EFAULT : 0; -#else return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0; -#endif } - down_read(&snd_ioctl_rwsem); + + 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) { - up_read(&snd_ioctl_rwsem); + if (err != -ENOIOCTLCMD) return err; - } } - up_read(&snd_ioctl_rwsem); dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd); return -ENOTTY; } @@ -1687,9 +2061,8 @@ static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head * if (pn == NULL) return -ENOMEM; pn->fioctl = fcn; - down_write(&snd_ioctl_rwsem); + guard(rwsem_write)(&snd_ioctl_rwsem); list_add_tail(&pn->list, lists); - up_write(&snd_ioctl_rwsem); return 0; } @@ -1698,6 +2071,8 @@ static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head * * @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) { @@ -1710,6 +2085,8 @@ EXPORT_SYMBOL(snd_ctl_register_ioctl); * 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) { @@ -1728,16 +2105,14 @@ static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn, if (snd_BUG_ON(!fcn)) return -EINVAL; - down_write(&snd_ioctl_rwsem); + guard(rwsem_write)(&snd_ioctl_rwsem); list_for_each_entry(p, lists, list) { if (p->fioctl == fcn) { list_del(&p->list); - up_write(&snd_ioctl_rwsem); kfree(p); return 0; } } - up_write(&snd_ioctl_rwsem); snd_BUG(); return -EINVAL; } @@ -1745,6 +2120,8 @@ static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn, /** * 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) { @@ -1754,9 +2131,11 @@ EXPORT_SYMBOL(snd_ctl_unregister_ioctl); #ifdef CONFIG_COMPAT /** - * snd_ctl_unregister_ioctl - de-register the device-specific compat 32bit - * control-ioctls + * 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) { @@ -1770,7 +2149,7 @@ static int snd_ctl_fasync(int fd, struct file * file, int on) struct snd_ctl_file *ctl; ctl = file->private_data; - return fasync_helper(fd, file, on, &ctl->fasync); + return snd_fasync_helper(fd, file, on, &ctl->fasync); } /* return the preferred subdevice number if already assigned; @@ -1781,7 +2160,7 @@ int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type) struct snd_ctl_file *kctl; int subdevice = -1; - read_lock(&card->ctl_files_rwlock); + guard(read_lock_irqsave)(&card->controls_rwlock); list_for_each_entry(kctl, &card->ctl_files, list) { if (kctl->pid == task_pid(current)) { subdevice = kctl->preferred_subdevice[type]; @@ -1789,7 +2168,6 @@ int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type) break; } } - read_unlock(&card->ctl_files_rwlock); return subdevice; } EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice); @@ -1804,6 +2182,84 @@ EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice); #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 */ @@ -1813,22 +2269,36 @@ static const struct file_operations snd_ctl_f_ops = .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; - return snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1, - &snd_ctl_f_ops, card, &card->ctl_dev); + 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; } /* @@ -1839,14 +2309,15 @@ static int snd_ctl_dev_disconnect(struct snd_device *device) struct snd_card *card = device->device_data; struct snd_ctl_file *ctl; - read_lock(&card->ctl_files_rwlock); - list_for_each_entry(ctl, &card->ctl_files, list) { - wake_up(&ctl->change_sleep); - kill_fasync(&ctl->fasync, SIGIO, POLL_ERR); + scoped_guard(read_lock_irqsave, &card->controls_rwlock) { + list_for_each_entry(ctl, &card->ctl_files, list) { + wake_up(&ctl->change_sleep); + snd_kill_fasync(ctl->fasync, SIGIO, POLL_ERR); + } } - read_unlock(&card->ctl_files_rwlock); - return snd_unregister_device(&card->ctl_dev); + call_snd_ctl_lops(card, ldisconnect); + return snd_unregister_device(card->ctl_dev); } /* @@ -1857,13 +2328,18 @@ static int snd_ctl_dev_free(struct snd_device *device) struct snd_card *card = device->device_data; struct snd_kcontrol *control; - down_write(&card->controls_rwsem); - while (!list_empty(&card->controls)) { - control = snd_kcontrol(card->controls.next); - snd_ctl_remove(card, 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 } - up_write(&card->controls_rwsem); - put_device(&card->ctl_dev); + put_device(card->ctl_dev); return 0; } @@ -1873,7 +2349,7 @@ static int snd_ctl_dev_free(struct snd_device *device) */ int snd_ctl_create(struct snd_card *card) { - static struct snd_device_ops ops = { + 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, @@ -1885,12 +2361,14 @@ int snd_ctl_create(struct snd_card *card) if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS)) return -ENXIO; - snd_device_initialize(&card->ctl_dev, card); - dev_set_name(&card->ctl_dev, "controlC%d", card->number); + 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); + put_device(card->ctl_dev); return err; } @@ -1906,6 +2384,8 @@ int snd_ctl_create(struct snd_card *card) * * 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) @@ -1926,6 +2406,8 @@ EXPORT_SYMBOL(snd_ctl_boolean_mono_info); * * 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) @@ -1949,7 +2431,7 @@ EXPORT_SYMBOL(snd_ctl_boolean_stereo_info); * If the control's accessibility is not the default (readable and writable), * the caller has to fill @info->access. * - * Return: Zero. + * 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[]) @@ -1964,7 +2446,7 @@ int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels, WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name), "ALSA: too long item name '%s'\n", names[info->value.enumerated.item]); - strlcpy(info->value.enumerated.name, + strscpy(info->value.enumerated.name, names[info->value.enumerated.item], sizeof(info->value.enumerated.name)); return 0; |