From 0a23ecd02763e687d20c1706695ea84fb39f33c4 Mon Sep 17 00:00:00 2001
From: Kuan-Wei Chiu <visitorckw@gmail.com>
Date: Thu, 9 May 2024 01:12:39 +0800
Subject: [PATCH] vinput: Fix incorrect handling on raw_copy_to_user() failure

When raw_copy_to_user() failed in vinput_read(), the function would set
'count' to -EFAULT and then subtract EFAULT from '*offset'. However,
modifying '*offset' on raw_copy_to_user() failure was incorrect. Fix
this behavior by changing count = -EFAULT to return -EFAULT.
---
 examples/vinput.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/vinput.c b/examples/vinput.c
index 51a1396..ff226e2 100644
--- a/examples/vinput.c
+++ b/examples/vinput.c
@@ -106,7 +106,7 @@ static ssize_t vinput_read(struct file *file, char __user *buffer, size_t count,
         count = len - *offset;
 
     if (raw_copy_to_user(buffer, buff + *offset, count))
-        count = -EFAULT;
+        return -EFAULT;
 
     *offset += count;