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-rw-r--r--sound/core/control.c272
1 files changed, 218 insertions, 54 deletions
diff --git a/sound/core/control.c b/sound/core/control.c
index 5165741a8400..498e3701514a 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -7,6 +7,7 @@
#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>
@@ -18,8 +19,11 @@
#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 {
@@ -28,10 +32,12 @@ 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_open(struct inode *inode, struct file *file)
{
@@ -182,6 +188,32 @@ void snd_ctl_notify(struct snd_card *card, unsigned int mask,
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);
+ down_read(&snd_ctl_layer_rwsem);
+ for (lops = snd_ctl_layer; lops; lops = lops->next)
+ lops->lnotify(card, mask, kctl, ioff);
+ up_read(&snd_ctl_layer_rwsem);
+}
+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
@@ -250,6 +282,7 @@ struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
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);
@@ -342,7 +375,6 @@ 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;
@@ -376,10 +408,8 @@ static int __snd_ctl_add_replace(struct snd_card *card,
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);
+ for (idx = 0; idx < kcontrol->count; idx++)
+ snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_ADD, kcontrol, idx);
return 0;
}
@@ -462,16 +492,14 @@ EXPORT_SYMBOL(snd_ctl_replace);
*/
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);
+ 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;
}
@@ -537,9 +565,6 @@ static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
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;
@@ -584,11 +609,13 @@ 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);
@@ -1022,7 +1049,8 @@ static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
if (result < 0)
return result;
/* drop internal access flags */
- info.access &= ~SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK;
+ 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;
@@ -1110,25 +1138,34 @@ static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
unsigned int index_offset;
int result;
+ 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)
+ 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;
@@ -1150,9 +1187,7 @@ static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
if (result < 0)
goto error;
- down_write(&card->controls_rwsem);
result = snd_ctl_elem_write(card, file, control);
- up_write(&card->controls_rwsem);
if (result < 0)
goto error;
@@ -1231,6 +1266,12 @@ 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)
{
@@ -1296,12 +1337,12 @@ static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
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;
- struct snd_ctl_elem_id id;
unsigned int mask = 0;
int i;
int change;
@@ -1309,6 +1350,10 @@ static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
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);
@@ -1326,17 +1371,20 @@ 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;
}
@@ -1367,6 +1415,7 @@ 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;
@@ -1374,16 +1423,17 @@ 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)
+ 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);
@@ -1397,14 +1447,27 @@ 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;
+ // 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);
@@ -1418,6 +1481,7 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file,
unsigned int count;
unsigned int access;
long private_size;
+ size_t alloc_size;
struct user_element *ue;
unsigned int offset;
int err;
@@ -1435,13 +1499,6 @@ 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)
@@ -1472,6 +1529,13 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file,
if (info->count < 1)
return -EINVAL;
private_size = value_sizes[info->type] * info->count;
+ alloc_size = compute_user_elem_size(private_size, count);
+
+ down_write(&card->controls_rwsem);
+ if (check_user_elem_overflow(card, alloc_size)) {
+ err = -ENOMEM;
+ goto unlock;
+ }
/*
* Keep memory object for this userspace control. After passing this
@@ -1481,18 +1545,21 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file,
*/
err = snd_ctl_new(&kctl, count, access, file);
if (err < 0)
- return err;
+ goto unlock;
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;
+ err = -ENOMEM;
+ goto unlock;
}
+ 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;
@@ -1502,7 +1569,7 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file,
err = snd_ctl_elem_init_enum_names(ue);
if (err < 0) {
snd_ctl_free_one(kctl);
- return err;
+ goto unlock;
}
}
@@ -1519,7 +1586,6 @@ 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);
@@ -1534,9 +1600,6 @@ 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 err;
@@ -1976,6 +2039,88 @@ 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 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;
+ down_read(&snd_ctl_layer_rwsem);
+ for (lops = snd_ctl_layer; lops; lops = lops->next)
+ if (strcmp(lops->module_name, module_name) == 0)
+ break;
+ up_read(&snd_ctl_layer_rwsem);
+ if (lops)
+ 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;
+
+ down_write(&snd_ctl_layer_rwsem);
+ lops->next = snd_ctl_layer;
+ snd_ctl_layer = lops;
+ up_write(&snd_ctl_layer_rwsem);
+ for (card_number = 0; card_number < SNDRV_CARDS; card_number++) {
+ card = snd_card_ref(card_number);
+ if (card) {
+ down_read(&card->controls_rwsem);
+ lops->lregister(card);
+ up_read(&card->controls_rwsem);
+ 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;
+
+ down_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;
+ }
+ up_write(&snd_ctl_layer_rwsem);
+}
+EXPORT_SYMBOL_GPL(snd_ctl_disconnect_layer);
+
+/*
* INIT PART
*/
@@ -1998,9 +2143,20 @@ static const struct file_operations snd_ctl_f_ops =
static int snd_ctl_dev_register(struct snd_device *device)
{
struct snd_card *card = device->device_data;
+ struct snd_ctl_layer_ops *lops;
+ 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;
+ down_read(&card->controls_rwsem);
+ down_read(&snd_ctl_layer_rwsem);
+ for (lops = snd_ctl_layer; lops; lops = lops->next)
+ lops->lregister(card);
+ up_read(&snd_ctl_layer_rwsem);
+ up_read(&card->controls_rwsem);
+ return 0;
}
/*
@@ -2010,6 +2166,7 @@ static int snd_ctl_dev_disconnect(struct snd_device *device)
{
struct snd_card *card = device->device_data;
struct snd_ctl_file *ctl;
+ struct snd_ctl_layer_ops *lops;
unsigned long flags;
read_lock_irqsave(&card->ctl_files_rwlock, flags);
@@ -2019,6 +2176,13 @@ static int snd_ctl_dev_disconnect(struct snd_device *device)
}
read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
+ down_read(&card->controls_rwsem);
+ down_read(&snd_ctl_layer_rwsem);
+ for (lops = snd_ctl_layer; lops; lops = lops->next)
+ lops->ldisconnect(card);
+ up_read(&snd_ctl_layer_rwsem);
+ up_read(&card->controls_rwsem);
+
return snd_unregister_device(&card->ctl_dev);
}
generated by cgit v1.2.3 (git 2.39.1) at 2025-03-19 22:18:11 +0000