Linux-libre 4.8.2-gnupck-4.8.2-gnu

1 files changed, 16 insertions, 3 deletions

diff --git a/drivers/iio/industrialio-event.c b/drivers/iio/industrialio-event.c
index cae332b1d..0ebfc923a 100644
--- a/drivers/iio/industrialio-event.c
+++ b/drivers/iio/industrialio-event.c
@@ -44,6 +44,11 @@ struct iio_event_interface {
 	struct mutex		read_lock;
 };
 
+bool iio_event_enabled(const struct iio_event_interface *ev_int)
+{
+	return !!test_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
+}
+
 /**
  * iio_push_event() - try to add event to the list for userspace reading
  * @indio_dev:		IIO device structure
@@ -60,7 +65,7 @@ int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp)
 	int copied;
 
 	/* Does anyone care? */
-	if (test_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
+	if (iio_event_enabled(ev_int)) {
 
 		ev.id = ev_code;
 		ev.timestamp = timestamp;
@@ -180,8 +185,14 @@ int iio_event_getfd(struct iio_dev *indio_dev)
 	if (ev_int == NULL)
 		return -ENODEV;
 
-	if (test_and_set_bit(IIO_BUSY_BIT_POS, &ev_int->flags))
-		return -EBUSY;
+	fd = mutex_lock_interruptible(&indio_dev->mlock);
+	if (fd)
+		return fd;
+
+	if (test_and_set_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
+		fd = -EBUSY;
+		goto unlock;
+	}
 
 	iio_device_get(indio_dev);
 
@@ -194,6 +205,8 @@ int iio_event_getfd(struct iio_dev *indio_dev)
 		kfifo_reset_out(&ev_int->det_events);
 	}
 
+unlock:
+	mutex_unlock(&indio_dev->mlock);
 	return fd;
 }