Re: [PATCH v5 1/3] uinput: Use monotonic times for uinput timestamps.

From: Dmitry Torokhov
Date: Tue Jan 02 2018 - 01:47:01 EST


On Sun, Dec 17, 2017 at 09:18:42PM -0800, Deepa Dinamani wrote:
> struct timeval which is part of struct input_event to
> maintain the event times is not y2038 safe.
>
> Real time timestamps are also not ideal for input_event
> as this time can go backwards as noted in the patch
> a80b83b7b8 by John Stultz.
>
> The patch switches the timestamps to use monotonic time
> from realtime time. This is assuming no one is using
> absolute times from these timestamps.
>
> The structure to maintain input events will be changed
> in a different patch.
>
> Signed-off-by: Deepa Dinamani <deepa.kernel@xxxxxxxxx>
> Acked-by: Peter Hutterer <peter.hutterer@xxxxxxxxx>

Applied, thank you.

> ---
> drivers/input/misc/uinput.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c
> index 91df0df15e68..9251765645d1 100644
> --- a/drivers/input/misc/uinput.c
> +++ b/drivers/input/misc/uinput.c
> @@ -84,11 +84,14 @@ static int uinput_dev_event(struct input_dev *dev,
> unsigned int type, unsigned int code, int value)
> {
> 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;
> - do_gettimeofday(&udev->buff[udev->head].time);
> + ktime_get_ts64(&ts);
> + udev->buff[udev->head].time.tv_sec = ts.tv_sec;
> + udev->buff[udev->head].time.tv_usec = ts.tv_nsec / NSEC_PER_USEC;
> udev->head = (udev->head + 1) % UINPUT_BUFFER_SIZE;
>
> wake_up_interruptible(&udev->waitq);
> --
> 2.14.1
>

--
Dmitry