futex: arch_futex_atomic_op_inuser() calling conventions change

Move access_ok() in and pagefault_enable()/pagefault_disable() out.
Mechanical conversion only - some instances don't really need
a separate access_ok() at all (e.g. the ones only using
get_user()/put_user(), or architectures where access_ok()
is always true); we'll deal with that in followups.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/powerpc/include/asm/futex.h

@@ -35,8 +35,9 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
 {
 	int oldval = 0, ret;
 
+	if (!access_ok(uaddr, sizeof(u32)))
+		return -EFAULT;
 	allow_read_write_user(uaddr, uaddr, sizeof(*uaddr));
-	pagefault_disable();
 
 	switch (op) {
 	case FUTEX_OP_SET:
@@ -58,8 +59,6 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
 		ret = -ENOSYS;
 	}
 
-	pagefault_enable();
-
 	*oval = oldval;
 
 	prevent_read_write_user(uaddr, uaddr, sizeof(*uaddr));