Input: input_event - fix struct padding on sparc64

Going through all uses of timeval, I noticed that we screwed up
input_event in the previous attempts to fix it:

The time fields now match between kernel and user space, but all following
fields are in the wrong place.

Add the required padding that is implied by the glibc timeval definition
to fix the layout, and use a struct initializer to avoid leaking kernel
stack data.

Fixes: 141e5dca ("Input: input_event - fix the CONFIG_SPARC64 mixup")
Fixes: 2e746942 ("Input: input_event - provide override for sparc64")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20191213204936.3643476-2-arnd@arndb.de
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/evdev.c

@@ -224,13 +224,13 @@ static void __pass_event(struct evdev_client *client,
 		 */
 		client->tail = (client->head - 2) & (client->bufsize - 1);
 
-		client->buffer[client->tail].input_event_sec =
-						event->input_event_sec;
-		client->buffer[client->tail].input_event_usec =
-						event->input_event_usec;
-		client->buffer[client->tail].type = EV_SYN;
-		client->buffer[client->tail].code = SYN_DROPPED;
-		client->buffer[client->tail].value = 0;
+		client->buffer[client->tail] = (struct input_event) {
+			.input_event_sec = event->input_event_sec,
+			.input_event_usec = event->input_event_usec,
+			.type = EV_SYN,
+			.code = SYN_DROPPED,
+			.value = 0,
+		};
 
 		client->packet_head = client->tail;
 	}

drivers/input/misc/uinput.c

@@ -74,12 +74,16 @@ static int uinput_dev_event(struct input_dev *dev,
 	struct uinput_device	*udev = input_get_drvdata(dev);
 	struct timespec64	ts;
 
-	udev->buff[udev->head].type = type;
-	udev->buff[udev->head].code = code;
-	udev->buff[udev->head].value = value;
 	ktime_get_ts64(&ts);
-	udev->buff[udev->head].input_event_sec = ts.tv_sec;
-	udev->buff[udev->head].input_event_usec = ts.tv_nsec / NSEC_PER_USEC;
+
+	udev->buff[udev->head] = (struct input_event) {
+		.input_event_sec = ts.tv_sec,
+		.input_event_usec = ts.tv_nsec / NSEC_PER_USEC,
+		.type = type,
+		.code = code,
+		.value = value,
+	};
+
 	udev->head = (udev->head + 1) % UINPUT_BUFFER_SIZE;
 
 	wake_up_interruptible(&udev->waitq);

include/uapi/linux/input.h

@@ -34,6 +34,7 @@ struct input_event {
 	__kernel_ulong_t __sec;
 #if defined(__sparc__) && defined(__arch64__)
 	unsigned int __usec;
+	unsigned int __pad;
 #else
 	__kernel_ulong_t __usec;
 #endif