FROMGIT: Input: uinput - allow injecting event times

Currently, uinput doesn't use the input_set_timestamp API, so any
event injected using uinput is not accurately timestamped in terms of
measuring when the actual event happened. Hence, call the
input_set_timestamp API from uinput in order to provide a more
accurate sense of time for the event. Propagate only the timestamps
which are a) positive, b) within a pre-defined offset (10 secs) from
the current time, and c) not in the future.

Bug: 271946580
Bug: 277040837
Change-Id: I928be61d0114b78e2098995ee49eeb0376bef2a3
(cherry picked from commit 3a2df60200a03f78173f1fd831aa54c08464dcde
https://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git master)
Signed-off-by: Biswarup Pal <biswarupp@google.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Siarhei Vishniakou <svv@google.com>
Link: https://lore.kernel.org/r/20230427000152.1407471-1-biswarupp@google.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
(cherry picked from commit ee1f5fc55cc7bf1bca78edbb8a1f9d989d4ea03e)
This commit is contained in:
Biswarup Pal 2023-05-01 20:19:19 -07:00 committed by Todd Kjos
parent 0acbae5b32
commit b7ba0d931e

View File

@ -33,6 +33,7 @@
#define UINPUT_NAME "uinput"
#define UINPUT_BUFFER_SIZE 16
#define UINPUT_NUM_REQUESTS 16
#define UINPUT_TIMESTAMP_ALLOWED_OFFSET_SECS 10
enum uinput_state { UIST_NEW_DEVICE, UIST_SETUP_COMPLETE, UIST_CREATED };
@ -569,11 +570,40 @@ static int uinput_setup_device_legacy(struct uinput_device *udev,
return retval;
}
/*
* Returns true if the given timestamp is valid (i.e., if all the following
* conditions are satisfied), false otherwise.
* 1) given timestamp is positive
* 2) it's within the allowed offset before the current time
* 3) it's not in the future
*/
static bool is_valid_timestamp(const ktime_t timestamp)
{
ktime_t zero_time;
ktime_t current_time;
ktime_t min_time;
ktime_t offset;
zero_time = ktime_set(0, 0);
if (ktime_compare(zero_time, timestamp) >= 0)
return false;
current_time = ktime_get();
offset = ktime_set(UINPUT_TIMESTAMP_ALLOWED_OFFSET_SECS, 0);
min_time = ktime_sub(current_time, offset);
if (ktime_after(min_time, timestamp) || ktime_after(timestamp, current_time))
return false;
return true;
}
static ssize_t uinput_inject_events(struct uinput_device *udev,
const char __user *buffer, size_t count)
{
struct input_event ev;
size_t bytes = 0;
ktime_t timestamp;
if (count != 0 && count < input_event_size())
return -EINVAL;
@ -588,6 +618,10 @@ static ssize_t uinput_inject_events(struct uinput_device *udev,
if (input_event_from_user(buffer + bytes, &ev))
return -EFAULT;
timestamp = ktime_set(ev.input_event_sec, ev.input_event_usec * NSEC_PER_USEC);
if (is_valid_timestamp(timestamp))
input_set_timestamp(udev->dev, timestamp);
input_event(udev->dev, ev.type, ev.code, ev.value);
bytes += input_event_size();
cond_resched();