From 81daa406c2cc97d85eef9409400404efc2a3f756 Mon Sep 17 00:00:00 2001
From: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
Date: Mon, 14 May 2018 13:32:22 +1200
Subject: [PATCH] uio: Reduce return paths from uio_write()
Git-commit: 81daa406c2cc97d85eef9409400404efc2a3f756
Patch-mainline: v4.18-rc1
References: bsc#1051510

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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/uio/uio.c | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index d9235f30e46d..1883ce620ea9 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -568,20 +568,29 @@ static ssize_t uio_write(struct file *filep, const char __user *buf,
 	ssize_t retval;
 	s32 irq_on;
 
-	if (!idev->info->irq)
-		return -EIO;
+	if (!idev->info->irq) {
+		retval = -EIO;
+		goto out;
+	}
 
-	if (count != sizeof(s32))
-		return -EINVAL;
+	if (count != sizeof(s32)) {
+		retval = -EINVAL;
+		goto out;
+	}
 
-	if (!idev->info->irqcontrol)
-		return -ENOSYS;
+	if (!idev->info->irqcontrol) {
+		retval = -ENOSYS;
+		goto out;
+	}
 
-	if (copy_from_user(&irq_on, buf, count))
-		return -EFAULT;
+	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);
 }
 
-- 
2.16.4