Re: [PATCH v2 01/24] Input: input_event: fix struct padding on sparc64

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Fri, Dec 13, 2019 at 09:49:10PM +0100, Arnd Bergmann wrote:
> 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.
> 
> Cc: sparclinux@vger.kernel.org
> Cc: "David S. Miller" <davem@davemloft.net>
> Fixes: 141e5dcaa735 ("Input: input_event - fix the CONFIG_SPARC64 mixup")
> Fixes: 2e746942ebac ("Input: input_event - provide override for sparc64")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Applied, thank you.

> ---
>  drivers/input/evdev.c       | 14 +++++++-------
>  drivers/input/misc/uinput.c | 14 +++++++++-----
>  include/uapi/linux/input.h  |  1 +
>  3 files changed, 17 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
> index d7dd6fcf2db0..f918fca9ada3 100644
> --- a/drivers/input/evdev.c
> +++ b/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;
>  	}
> diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c
> index fd253781be71..2dabbe47d43e 100644
> --- a/drivers/input/misc/uinput.c
> +++ b/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);
> diff --git a/include/uapi/linux/input.h b/include/uapi/linux/input.h
> index f056b2a00d5c..9a61c28ed3ae 100644
> --- a/include/uapi/linux/input.h
> +++ b/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
> -- 
> 2.20.0
> 

-- 
Dmitry