blob: 4436b83fa1bcc89f585bc17f4b1d4653ec9be234 [file] [log] [blame]
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Fri, 9 Sep 2016 19:22:34 -0400
Subject: microblaze: fix copy_from_user()
commit d0cf385160c12abd109746cad1f13e3b3e8b50b8 upstream.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/microblaze/include/asm/uaccess.h | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
--- a/arch/microblaze/include/asm/uaccess.h
+++ b/arch/microblaze/include/asm/uaccess.h
@@ -364,10 +364,13 @@ extern long __user_bad(void);
static inline long copy_from_user(void *to,
const void __user *from, unsigned long n)
{
+ unsigned long res = n;
might_sleep();
- if (access_ok(VERIFY_READ, from, n))
- return __copy_from_user(to, from, n);
- return 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;
}
#define __copy_to_user(to, from, n) \