[PATCH 4.14 28/35] uio: Reduce return paths from uio_write()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Hamish Martin <hamish.martin@alliedtelesis.co.nz>

commit 81daa406c2cc97d85eef9409400404efc2a3f756 upstream.

Drive all return paths for uio_write() through a single block at the
end of the function.

Signed-off-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/uio/uio.c |   31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -570,20 +570,29 @@ static ssize_t uio_write(struct file *fi
 	ssize_t retval;
 	s32 irq_on;
 
-	if (!idev->info->irq)
-		return -EIO;
-
-	if (count != sizeof(s32))
-		return -EINVAL;
-
-	if (!idev->info->irqcontrol)
-		return -ENOSYS;
-
-	if (copy_from_user(&irq_on, buf, count))
-		return -EFAULT;
+	if (!idev->info->irq) {
+		retval = -EIO;
+		goto out;
+	}
+
+	if (count != sizeof(s32)) {
+		retval = -EINVAL;
+		goto out;
+	}
+
+	if (!idev->info->irqcontrol) {
+		retval = -ENOSYS;
+		goto out;
+	}
+
+	if (copy_from_user(&irq_on, buf, count)) {
+		retval = -EFAULT;
+		goto out;
+	}
 
 	retval = idev->info->irqcontrol(idev->info, irq_on);
 
+out:
 	return retval ? retval : sizeof(s32);
 }