X-Git-Url: http://git.cascardo.info/?p=cascardo%2Flinux.git;a=blobdiff_plain;f=arch%2Farm%2Finclude%2Fasm%2Fuaccess.h;h=1f59ea051bab814132074b09f55d3a57c800a471;hp=a93c0f99acf7767c680158cf96acef87d1f0da51;hb=8a1e377e55f2dca5c689926313beeaa8ac2adb22;hpb=d4d24d2d0a7ea3b62efd7336bfc2344e29b36bc5

diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
index a93c0f99acf7..1f59ea051bab 100644
--- a/arch/arm/include/asm/uaccess.h
+++ b/arch/arm/include/asm/uaccess.h
@@ -533,11 +533,12 @@ __clear_user(void __user *addr, unsigned long n)
 
 static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
 {
-	if (access_ok(VERIFY_READ, from, n))
-		n = __copy_from_user(to, from, n);
-	else /* security hole - plug it */
-		memset(to, 0, n);
-	return n;
+	unsigned long res = n;
+	if (likely(access_ok(VERIFY_READ, from, n)))
+		res = __copy_from_user(to, from, n);
+	if (unlikely(res))
+		memset(to + (n - res), 0, res);
+	return res;
 }
 
 static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n)