We can simplify the code gracefully with new guard() macro and co for
automatic cleanup of locks.
The lops calls under multiple rwsems are factored out as a simple
macro, so that it can be called easily from snd_ctl_dev_register()
and snd_ctl_dev_disconnect().
There are a few remaining explicit rwsem and spinlock calls, and those
are the places where the lock downgrade happens or where the temporary
unlock/relocking happens -- which guard() doens't cover well yet.
Only the code refactoring, and no functional changes.
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
sound/core/control.c | 429 +++++++++++++++++--------------------------
1 file changed, 171 insertions(+), 258 deletions(-)
diff --git a/sound/core/control.c b/sound/core/control.c
index c8cd70aed6af..d45428dbdfb0 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -44,7 +44,6 @@ static int snd_ctl_remove_locked(struct snd_card *card,
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;
@@ -80,9 +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->ctl_files_rwlock)
+ list_add_tail(&ctl->list, &card->ctl_files);
snd_card_unref(card);
return 0;
@@ -98,21 +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;
@@ -121,15 +116,17 @@ 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->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);
@@ -152,7 +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;
@@ -160,34 +156,34 @@ void snd_ctl_notify(struct snd_card *card, unsigned int mask,
return;
if (card->shutdown)
return;
- read_lock_irqsave(&card->ctl_files_rwlock, flags);
+
+ 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;
- spin_lock(&ctl->read_lock);
- 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(&ctl->read_lock);
snd_kill_fasync(ctl->fasync, SIGIO, POLL_IN);
}
- read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
}
EXPORT_SYMBOL(snd_ctl_notify);
@@ -210,10 +206,9 @@ void snd_ctl_notify_one(struct snd_card *card, unsigned int mask,
id.index += ioff;
id.numid += ioff;
snd_ctl_notify(card, mask, &id);
- down_read(&snd_ctl_layer_rwsem);
+ guard(rwsem_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);
@@ -520,9 +515,9 @@ 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;
@@ -616,12 +611,8 @@ static inline int snd_ctl_remove_locked(struct snd_card *card,
*/
int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
{
- int ret;
-
- down_write(&card->controls_rwsem);
- ret = snd_ctl_remove_locked(card, kcontrol);
- up_write(&card->controls_rwsem);
- return ret;
+ guard(rwsem_write)(&card->controls_rwsem);
+ return snd_ctl_remove_locked(card, kcontrol);
}
EXPORT_SYMBOL(snd_ctl_remove);
@@ -638,17 +629,12 @@ 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_locked(card, id);
- if (kctl == NULL) {
- up_write(&card->controls_rwsem);
+ if (kctl == NULL)
return -ENOENT;
- }
- ret = snd_ctl_remove_locked(card, kctl);
- up_write(&card->controls_rwsem);
- return ret;
+ return snd_ctl_remove_locked(card, kctl);
}
EXPORT_SYMBOL(snd_ctl_remove_id);
@@ -667,27 +653,18 @@ 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_locked(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_locked(card, kctl);
-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);
}
/**
@@ -764,18 +741,15 @@ int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
struct snd_kcontrol *kctl;
int saved_numid;
- down_write(&card->controls_rwsem);
+ guard(rwsem_write)(&card->controls_rwsem);
kctl = snd_ctl_find_id_locked(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 = saved_numid;
add_hash_entries(card, kctl);
- up_write(&card->controls_rwsem);
return 0;
}
EXPORT_SYMBOL(snd_ctl_rename_id);
@@ -793,7 +767,7 @@ EXPORT_SYMBOL(snd_ctl_rename_id);
void snd_ctl_rename(struct snd_card *card, struct snd_kcontrol *kctl,
const char *name)
{
- down_write(&card->controls_rwsem);
+ guard(rwsem_write)(&card->controls_rwsem);
remove_hash_entries(card, kctl);
if (strscpy(kctl->id.name, name, sizeof(kctl->id.name)) < 0)
@@ -801,7 +775,6 @@ void snd_ctl_rename(struct snd_card *card, struct snd_kcontrol *kctl,
name, kctl->id.name);
add_hash_entries(card, kctl);
- up_write(&card->controls_rwsem);
}
EXPORT_SYMBOL(snd_ctl_rename);
@@ -859,12 +832,8 @@ EXPORT_SYMBOL(snd_ctl_find_numid_locked);
struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card,
unsigned int numid)
{
- struct snd_kcontrol *kctl;
-
- down_read(&card->controls_rwsem);
- kctl = snd_ctl_find_numid_locked(card, numid);
- up_read(&card->controls_rwsem);
- return kctl;
+ guard(rwsem_read)(&card->controls_rwsem);
+ return snd_ctl_find_numid_locked(card, numid);
}
EXPORT_SYMBOL(snd_ctl_find_numid);
@@ -920,12 +889,8 @@ EXPORT_SYMBOL(snd_ctl_find_id_locked);
struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
const struct snd_ctl_elem_id *id)
{
- struct snd_kcontrol *kctl;
-
- down_read(&card->controls_rwsem);
- kctl = snd_ctl_find_id_locked(card, id);
- up_read(&card->controls_rwsem);
- return kctl;
+ guard(rwsem_read)(&card->controls_rwsem);
+ return snd_ctl_find_id_locked(card, id);
}
EXPORT_SYMBOL(snd_ctl_find_id);
@@ -937,15 +902,15 @@ static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (! info)
return -ENOMEM;
- down_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));
- up_read(&snd_ioctl_rwsem);
+ 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;
@@ -957,37 +922,31 @@ static int snd_ctl_elem_list(struct snd_card *card,
struct snd_kcontrol *kctl;
struct snd_ctl_elem_id id;
unsigned int offset, space, jidx;
- int err = 0;
offset = list->offset;
space = list->space;
- down_read(&card->controls_rwsem);
+ guard(rwsem_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;
+ 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);
- return err;
+ return 0;
}
static int snd_ctl_elem_list_user(struct snd_card *card,
@@ -1235,16 +1194,12 @@ static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
{
struct snd_card *card = ctl->card;
struct snd_kcontrol *kctl;
- int result;
- down_read(&card->controls_rwsem);
+ guard(rwsem_read)(&card->controls_rwsem);
kctl = snd_ctl_find_id_locked(card, &info->id);
- if (kctl == NULL)
- result = -ENOENT;
- else
- result = __snd_ctl_elem_info(card, kctl, info, ctl);
- up_read(&card->controls_rwsem);
- return result;
+ 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,
@@ -1276,19 +1231,15 @@ static int snd_ctl_elem_read(struct snd_card *card,
const u32 pattern = 0xdeadbeef;
int ret;
- down_read(&card->controls_rwsem);
+ guard(rwsem_read)(&card->controls_rwsem);
kctl = snd_ctl_find_id_locked(card, &control->id);
- if (kctl == NULL) {
- ret = -ENOENT;
- goto unlock;
- }
+ 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) {
- ret = -EPERM;
- goto unlock;
- }
+ if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_READ) || !kctl->get)
+ return -EPERM;
snd_ctl_build_ioff(&control->id, kctl, index_offset);
@@ -1298,7 +1249,7 @@ static int snd_ctl_elem_read(struct snd_card *card,
info.id = control->id;
ret = __snd_ctl_elem_info(card, kctl, &info, NULL);
if (ret < 0)
- goto unlock;
+ return ret;
#endif
if (!snd_ctl_skip_validation(&info))
@@ -1308,7 +1259,7 @@ static int snd_ctl_elem_read(struct snd_card *card,
ret = kctl->get(kctl, control);
snd_power_unref(card);
if (ret < 0)
- goto unlock;
+ return ret;
if (!snd_ctl_skip_validation(&info) &&
sanity_check_elem_value(card, control, &info, pattern) < 0) {
dev_err(card->dev,
@@ -1316,12 +1267,9 @@ static int snd_ctl_elem_read(struct snd_card *card,
control->id.iface, control->id.device,
control->id.subdevice, control->id.name,
control->id.index);
- ret = -EINVAL;
- goto unlock;
+ return -EINVAL;
}
-unlock:
- up_read(&card->controls_rwsem);
- return ret;
+ return 0;
}
static int snd_ctl_elem_read_user(struct snd_card *card,
@@ -1426,25 +1374,18 @@ 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_locked(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,
@@ -1454,27 +1395,20 @@ 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_locked(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 {
@@ -1756,11 +1690,9 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file,
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;
- }
+ 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
@@ -1770,13 +1702,12 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file,
*/
err = snd_ctl_new(&kctl, count, access, file);
if (err < 0)
- goto unlock;
+ return err;
memcpy(&kctl->id, &info->id, sizeof(kctl->id));
ue = kzalloc(alloc_size, GFP_KERNEL);
if (!ue) {
kfree(kctl);
- err = -ENOMEM;
- goto unlock;
+ return -ENOMEM;
}
kctl->private_data = ue;
kctl->private_free = snd_ctl_elem_user_free;
@@ -1794,7 +1725,7 @@ 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);
- goto unlock;
+ return err;
}
}
@@ -1814,7 +1745,7 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file,
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);
@@ -1825,9 +1756,7 @@ 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.
*/
- unlock:
- up_write(&card->controls_rwsem);
- return err;
+ return 0;
}
static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
@@ -2029,34 +1958,31 @@ 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);
+ scoped_guard(rwsem_read, &ctl->card->controls_rwsem)
+ err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
up_read(&ctl->card->controls_rwsem);
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);
+ scoped_guard(rwsem_write, &ctl->card->controls_rwsem)
+ err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
up_write(&ctl->card->controls_rwsem);
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);
+ 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;
}
- 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;
}
@@ -2148,9 +2074,8 @@ 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;
}
@@ -2193,16 +2118,14 @@ 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;
}
@@ -2249,9 +2172,8 @@ int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type)
{
struct snd_ctl_file *kctl;
int subdevice = -1;
- unsigned long flags;
- read_lock_irqsave(&card->ctl_files_rwlock, flags);
+ 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];
@@ -2259,7 +2181,6 @@ int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type)
break;
}
}
- read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
return subdevice;
}
EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice);
@@ -2289,13 +2210,11 @@ int snd_ctl_request_layer(const char *module_name)
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;
+ 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);
@@ -2312,16 +2231,15 @@ 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);
+ 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) {
- down_read(&card->controls_rwsem);
- lops->lregister(card);
- up_read(&card->controls_rwsem);
+ scoped_guard(rwsem_read, &card->controls_rwsem)
+ lops->lregister(card);
snd_card_unref(card);
}
}
@@ -2340,7 +2258,7 @@ 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);
+ 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)
@@ -2351,7 +2269,6 @@ void snd_ctl_disconnect_layer(struct snd_ctl_layer_ops *lops)
}
prev_lops2 = lops2;
}
- up_write(&snd_ctl_layer_rwsem);
}
EXPORT_SYMBOL_GPL(snd_ctl_disconnect_layer);
@@ -2372,25 +2289,29 @@ static const struct file_operations snd_ctl_f_ops =
.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;
- struct snd_ctl_layer_ops *lops;
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;
- 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);
+ call_snd_ctl_lops(card, lregister);
return 0;
}
@@ -2401,23 +2322,15 @@ 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);
- list_for_each_entry(ctl, &card->ctl_files, list) {
- wake_up(&ctl->change_sleep);
- snd_kill_fasync(ctl->fasync, SIGIO, POLL_ERR);
+ 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);
+ }
}
- 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);
+ call_snd_ctl_lops(card, ldisconnect);
return snd_unregister_device(card->ctl_dev);
}
@@ -2429,17 +2342,17 @@ 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, false);
- }
+ 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);
+ xa_destroy(&card->ctl_numids);
+ xa_destroy(&card->ctl_hash);
#endif
- up_write(&card->controls_rwsem);
+ }
put_device(card->ctl_dev);
return 0;
}
--
2.35.3
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