io_uring: use mem_is_zero to check ring params

mem_is_zero() does the job without hand rolled loops, use that to verify
reserved fields of ring params.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: isilence

io_uring/io_uring.c

@@ -3684,14 +3684,12 @@ static __cold int io_uring_create(struct io_uring_params *p,
 static long io_uring_setup(u32 entries, struct io_uring_params __user *params)
 {
 	struct io_uring_params p;
-	int i;
 
 	if (copy_from_user(&p, params, sizeof(p)))
 		return -EFAULT;
-	for (i = 0; i < ARRAY_SIZE(p.resv); i++) {
-		if (p.resv[i])
-			return -EINVAL;
-	}
+
+	if (!mem_is_zero(&p.resv, sizeof(p.resv)))
+		return -EINVAL;
 
 	if (p.flags & ~IORING_SETUP_FLAGS)
 		return -EINVAL;