1 files changed, 105 insertions, 91 deletions

diff --git a/sound/core/timer.c b/sound/core/timer.c
index 5c9fbf3f4340..24fed5c78273 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -74,6 +74,9 @@ static LIST_HEAD(snd_timer_slave_list);
 /* lock for slave active lists */
 static DEFINE_SPINLOCK(slave_active_lock);
 
+#define MAX_SLAVE_INSTANCES	1000
+static int num_slaves;
+
 static DEFINE_MUTEX(register_mutex);
 
 static int snd_timer_free(struct snd_timer *timer);
@@ -85,12 +88,11 @@ static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_l
 
 /*
  * create a timer instance with the given owner string.
- * when timer is not NULL, increments the module counter
  */
-static struct snd_timer_instance *snd_timer_instance_new(char *owner,
-							 struct snd_timer *timer)
+struct snd_timer_instance *snd_timer_instance_new(const char *owner)
 {
 	struct snd_timer_instance *timeri;
+
 	timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
 	if (timeri == NULL)
 		return NULL;
@@ -105,15 +107,20 @@ static struct snd_timer_instance *snd_timer_instance_new(char *owner,
 	INIT_LIST_HEAD(&timeri->slave_list_head);
 	INIT_LIST_HEAD(&timeri->slave_active_head);
 
-	timeri->timer = timer;
-	if (timer && !try_module_get(timer->module)) {
+	return timeri;
+}
+EXPORT_SYMBOL(snd_timer_instance_new);
+
+void snd_timer_instance_free(struct snd_timer_instance *timeri)
+{
+	if (timeri) {
+		if (timeri->private_free)
+			timeri->private_free(timeri);
 		kfree(timeri->owner);
 		kfree(timeri);
-		return NULL;
 	}
-
-	return timeri;
 }
+EXPORT_SYMBOL(snd_timer_instance_free);
 
 /*
  * find a timer instance from the given timer id
@@ -160,6 +167,28 @@ static void snd_timer_request(struct snd_timer_id *tid)
 
 #endif
 
+/* move the slave if it belongs to the master; return 1 if match */
+static int check_matching_master_slave(struct snd_timer_instance *master,
+				       struct snd_timer_instance *slave)
+{
+	if (slave->slave_class != master->slave_class ||
+	    slave->slave_id != master->slave_id)
+		return 0;
+	if (master->timer->num_instances >= master->timer->max_instances)
+		return -EBUSY;
+	list_move_tail(&slave->open_list, &master->slave_list_head);
+	master->timer->num_instances++;
+	spin_lock_irq(&slave_active_lock);
+	spin_lock(&master->timer->lock);
+	slave->master = master;
+	slave->timer = master->timer;
+	if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
+		list_add_tail(&slave->active_list, &master->slave_active_head);
+	spin_unlock(&master->timer->lock);
+	spin_unlock_irq(&slave_active_lock);
+	return 1;
+}
+
 /*
  * look for a master instance matching with the slave id of the given slave.
  * when found, relink the open_link of the slave.
@@ -170,27 +199,18 @@ static int snd_timer_check_slave(struct snd_timer_instance *slave)
 {
 	struct snd_timer *timer;
 	struct snd_timer_instance *master;
+	int err = 0;
 
 	/* FIXME: it's really dumb to look up all entries.. */
 	list_for_each_entry(timer, &snd_timer_list, device_list) {
 		list_for_each_entry(master, &timer->open_list_head, open_list) {
-			if (slave->slave_class == master->slave_class &&
-			    slave->slave_id == master->slave_id) {
-				if (master->timer->num_instances >=
-				    master->timer->max_instances)
-					return -EBUSY;
-				list_move_tail(&slave->open_list,
-					       &master->slave_list_head);
-				master->timer->num_instances++;
-				spin_lock_irq(&slave_active_lock);
-				slave->master = master;
-				slave->timer = master->timer;
-				spin_unlock_irq(&slave_active_lock);
-				return 0;
-			}
+			err = check_matching_master_slave(master, slave);
+			if (err != 0) /* match found or error */
+				goto out;
 		}
 	}
-	return 0;
+ out:
+	return err < 0 ? err : 0;
 }
 
 /*
@@ -202,42 +222,30 @@ static int snd_timer_check_slave(struct snd_timer_instance *slave)
 static int snd_timer_check_master(struct snd_timer_instance *master)
 {
 	struct snd_timer_instance *slave, *tmp;
+	int err = 0;
 
 	/* check all pending slaves */
 	list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) {
-		if (slave->slave_class == master->slave_class &&
-		    slave->slave_id == master->slave_id) {
-			if (master->timer->num_instances >=
-			    master->timer->max_instances)
-				return -EBUSY;
-			list_move_tail(&slave->open_list, &master->slave_list_head);
-			master->timer->num_instances++;
-			spin_lock_irq(&slave_active_lock);
-			spin_lock(&master->timer->lock);
-			slave->master = master;
-			slave->timer = master->timer;
-			if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
-				list_add_tail(&slave->active_list,
-					      &master->slave_active_head);
-			spin_unlock(&master->timer->lock);
-			spin_unlock_irq(&slave_active_lock);
-		}
+		err = check_matching_master_slave(master, slave);
+		if (err < 0)
+			break;
 	}
-	return 0;
+	return err < 0 ? err : 0;
 }
 
-static int snd_timer_close_locked(struct snd_timer_instance *timeri);
+static void snd_timer_close_locked(struct snd_timer_instance *timeri,
+				   struct device **card_devp_to_put);
 
 /*
  * open a timer instance
  * when opening a master, the slave id must be here given.
  */
-int snd_timer_open(struct snd_timer_instance **ti,
-		   char *owner, struct snd_timer_id *tid,
+int snd_timer_open(struct snd_timer_instance *timeri,
+		   struct snd_timer_id *tid,
 		   unsigned int slave_id)
 {
 	struct snd_timer *timer;
-	struct snd_timer_instance *timeri = NULL;
+	struct device *card_dev_to_put = NULL;
 	int err;
 
 	mutex_lock(&register_mutex);
@@ -250,21 +258,17 @@ int snd_timer_open(struct snd_timer_instance **ti,
 			err = -EINVAL;
 			goto unlock;
 		}
-		timeri = snd_timer_instance_new(owner, NULL);
-		if (!timeri) {
-			err = -ENOMEM;
+		if (num_slaves >= MAX_SLAVE_INSTANCES) {
+			err = -EBUSY;
 			goto unlock;
 		}
 		timeri->slave_class = tid->dev_sclass;
 		timeri->slave_id = tid->device;
 		timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
 		list_add_tail(&timeri->open_list, &snd_timer_slave_list);
+		num_slaves++;
 		err = snd_timer_check_slave(timeri);
-		if (err < 0) {
-			snd_timer_close_locked(timeri);
-			timeri = NULL;
-		}
-		goto unlock;
+		goto list_added;
 	}
 
 	/* open a master instance */
@@ -282,11 +286,11 @@ int snd_timer_open(struct snd_timer_instance **ti,
 		goto unlock;
 	}
 	if (!list_empty(&timer->open_list_head)) {
-		timeri = list_entry(timer->open_list_head.next,
+		struct snd_timer_instance *t =
+			list_entry(timer->open_list_head.next,
 				    struct snd_timer_instance, open_list);
-		if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
+		if (t->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
 			err = -EBUSY;
-			timeri = NULL;
 			goto unlock;
 		}
 	}
@@ -294,42 +298,40 @@ int snd_timer_open(struct snd_timer_instance **ti,
 		err = -EBUSY;
 		goto unlock;
 	}
-	timeri = snd_timer_instance_new(owner, timer);
-	if (!timeri) {
-		err = -ENOMEM;
+	if (!try_module_get(timer->module)) {
+		err = -EBUSY;
 		goto unlock;
 	}
 	/* take a card refcount for safe disconnection */
-	if (timer->card)
+	if (timer->card) {
 		get_device(&timer->card->card_dev);
-	timeri->slave_class = tid->dev_sclass;
-	timeri->slave_id = slave_id;
+		card_dev_to_put = &timer->card->card_dev;
+	}
 
 	if (list_empty(&timer->open_list_head) && timer->hw.open) {
 		err = timer->hw.open(timer);
 		if (err) {
-			kfree(timeri->owner);
-			kfree(timeri);
-			timeri = NULL;
-
-			if (timer->card)
-				put_device(&timer->card->card_dev);
 			module_put(timer->module);
 			goto unlock;
 		}
 	}
 
+	timeri->timer = timer;
+	timeri->slave_class = tid->dev_sclass;
+	timeri->slave_id = slave_id;
+
 	list_add_tail(&timeri->open_list, &timer->open_list_head);
 	timer->num_instances++;
 	err = snd_timer_check_master(timeri);
-	if (err < 0) {
-		snd_timer_close_locked(timeri);
-		timeri = NULL;
-	}
+list_added:
+	if (err < 0)
+		snd_timer_close_locked(timeri, &card_dev_to_put);
 
  unlock:
 	mutex_unlock(&register_mutex);
-	*ti = timeri;
+	/* put_device() is called after unlock for avoiding deadlock */
+	if (err < 0 && card_dev_to_put)
+		put_device(card_dev_to_put);
 	return err;
 }
 EXPORT_SYMBOL(snd_timer_open);
@@ -338,7 +340,8 @@ EXPORT_SYMBOL(snd_timer_open);
  * close a timer instance
  * call this with register_mutex down.
  */
-static int snd_timer_close_locked(struct snd_timer_instance *timeri)
+static void snd_timer_close_locked(struct snd_timer_instance *timeri,
+				   struct device **card_devp_to_put)
 {
 	struct snd_timer *timer = timeri->timer;
 	struct snd_timer_instance *slave, *tmp;
@@ -349,7 +352,11 @@ static int snd_timer_close_locked(struct snd_timer_instance *timeri)
 		spin_unlock_irq(&timer->lock);
 	}
 
-	list_del(&timeri->open_list);
+	if (!list_empty(&timeri->open_list)) {
+		list_del_init(&timeri->open_list);
+		if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
+			num_slaves--;
+	}
 
 	/* force to stop the timer */
 	snd_timer_stop(timeri);
@@ -368,6 +375,7 @@ static int snd_timer_close_locked(struct snd_timer_instance *timeri)
 		/* remove slave links */
 		spin_lock_irq(&slave_active_lock);
 		spin_lock(&timer->lock);
+		timeri->timer = NULL;
 		list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head,
 					 open_list) {
 			list_move_tail(&slave->open_list, &snd_timer_slave_list);
@@ -385,37 +393,32 @@ static int snd_timer_close_locked(struct snd_timer_instance *timeri)
 			timer = NULL;
 	}
 
-	if (timeri->private_free)
-		timeri->private_free(timeri);
-	kfree(timeri->owner);
-	kfree(timeri);
-
 	if (timer) {
 		if (list_empty(&timer->open_list_head) && timer->hw.close)
 			timer->hw.close(timer);
 		/* release a card refcount for safe disconnection */
 		if (timer->card)
-			put_device(&timer->card->card_dev);
+			*card_devp_to_put = &timer->card->card_dev;
 		module_put(timer->module);
 	}
-
-	return 0;
 }
 
 /*
  * close a timer instance
  */
-int snd_timer_close(struct snd_timer_instance *timeri)
+void snd_timer_close(struct snd_timer_instance *timeri)
 {
-	int err;
+	struct device *card_dev_to_put = NULL;
 
 	if (snd_BUG_ON(!timeri))
-		return -ENXIO;
+		return;
 
 	mutex_lock(&register_mutex);
-	err = snd_timer_close_locked(timeri);
+	snd_timer_close_locked(timeri, &card_dev_to_put);
 	mutex_unlock(&register_mutex);
-	return err;
+	/* put_device() is called after unlock for avoiding deadlock */
+	if (card_dev_to_put)
+		put_device(card_dev_to_put);
 }
 EXPORT_SYMBOL(snd_timer_close);
 
@@ -1464,8 +1467,10 @@ static int snd_timer_user_release(struct inode *inode, struct file *file)
 		tu = file->private_data;
 		file->private_data = NULL;
 		mutex_lock(&tu->ioctl_lock);
-		if (tu->timeri)
+		if (tu->timeri) {
 			snd_timer_close(tu->timeri);
+			snd_timer_instance_free(tu->timeri);
+		}
 		mutex_unlock(&tu->ioctl_lock);
 		kfree(tu->queue);
 		kfree(tu->tqueue);
@@ -1706,6 +1711,7 @@ static int snd_timer_user_tselect(struct file *file,
 	tu = file->private_data;
 	if (tu->timeri) {
 		snd_timer_close(tu->timeri);
+		snd_timer_instance_free(tu->timeri);
 		tu->timeri = NULL;
 	}
 	if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
@@ -1715,9 +1721,11 @@ static int snd_timer_user_tselect(struct file *file,
 	sprintf(str, "application %i", current->pid);
 	if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
 		tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
-	err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid);
-	if (err < 0)
+	tu->timeri = snd_timer_instance_new(str);
+	if (!tu->timeri) {
+		err = -ENOMEM;
 		goto __err;
+	}
 
 	tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
 	tu->timeri->callback = tu->tread
@@ -1726,6 +1734,12 @@ static int snd_timer_user_tselect(struct file *file,
 	tu->timeri->callback_data = (void *)tu;
 	tu->timeri->disconnect = snd_timer_user_disconnect;
 
+	err = snd_timer_open(tu->timeri, &tselect.id, current->pid);
+	if (err < 0) {
+		snd_timer_instance_free(tu->timeri);
+		tu->timeri = NULL;
+	}
+
       __err:
 	return err;
 }