parisc: fix copy_from_user()

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2016-08-20 19:03:37 -04:00
parent acb2505d01
commit aace880fee

View file

@ -10,6 +10,7 @@
#include <asm-generic/uaccess-unaligned.h>
#include <linux/bug.h>
#include <linux/string.h>
#define VERIFY_READ 0
#define VERIFY_WRITE 1
@ -221,13 +222,14 @@ static inline unsigned long __must_check copy_from_user(void *to,
unsigned long n)
{
int sz = __compiletime_object_size(to);
int ret = -EFAULT;
unsigned long ret = n;
if (likely(sz == -1 || !__builtin_constant_p(n) || sz >= n))
ret = __copy_from_user(to, from, n);
else
copy_from_user_overflow();
if (unlikely(ret))
memset(to + (n - ret), 0, ret);
return ret;
}