extern int FASTCALL(__user_walk(const char __user *, unsigned, struct nameidata *));
extern int FASTCALL(__user_walk_fd(int dfd, const char __user *, unsigned, struct nameidata *));
extern int FASTCALL(__user_walk(const char __user *, unsigned, struct nameidata *));
extern int FASTCALL(__user_walk_fd(int dfd, const char __user *, unsigned, struct nameidata *));