This patch changes the implementation of strnlen_user in include/asm-generic/uaccess.h.
Originally, it calls strlen() function directly, which may not correctly handle the access of
user space in most mmu-enabled architectures.
New __strnlen_user is added for using as an architecture specific function.
Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
*
* Return 0 on exception, a value greater than N if too long
*/
-#ifndef strnlen_user
+#ifndef __strnlen_user
+#define __strnlen_user strnlen
+#endif
+
static inline long strnlen_user(const char __user *src, long n)
{
if (!access_ok(VERIFY_READ, src, 1))
return 0;
- return strlen((void * __force)src) + 1;
+ return __strnlen_user(src, n);
}
-#endif
static inline long strlen_user(const char __user *src)
{