From 9a6c0e28e215535b2938c61ded54603b4e5814c5 Mon Sep 17 00:00:00 2001 From: Jason Gerecke Date: Thu, 8 Jun 2023 14:38:28 -0700 Subject: HID: wacom: Use ktime_t rather than int when dealing with timestamps Code which interacts with timestamps needs to use the ktime_t type returned by functions like ktime_get. The int type does not offer enough space to store these values, and attempting to use it is a recipe for problems. In this particular case, overflows would occur when calculating/storing timestamps leading to incorrect values being reported to userspace. In some cases these bad timestamps cause input handling in userspace to appear hung. Link: https://gitlab.freedesktop.org/libinput/libinput/-/issues/901 Fixes: 17d793f3ed53 ("HID: wacom: insert timestamp to packed Bluetooth (BT) events") CC: stable@vger.kernel.org Signed-off-by: Jason Gerecke Reviewed-by: Benjamin Tissoires Link: https://lore.kernel.org/r/20230608213828.2108-1-jason.gerecke@wacom.com Signed-off-by: Benjamin Tissoires --- drivers/hid/wacom_wac.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/hid/wacom_wac.c') diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c index 2ccf83837134..174bf03908d7 100644 --- a/drivers/hid/wacom_wac.c +++ b/drivers/hid/wacom_wac.c @@ -1314,7 +1314,7 @@ static void wacom_intuos_pro2_bt_pen(struct wacom_wac *wacom) struct input_dev *pen_input = wacom->pen_input; unsigned char *data = wacom->data; int number_of_valid_frames = 0; - int time_interval = 15000000; + ktime_t time_interval = 15000000; ktime_t time_packet_received = ktime_get(); int i; @@ -1348,7 +1348,7 @@ static void wacom_intuos_pro2_bt_pen(struct wacom_wac *wacom) if (number_of_valid_frames) { if (wacom->hid_data.time_delayed) time_interval = ktime_get() - wacom->hid_data.time_delayed; - time_interval /= number_of_valid_frames; + time_interval = div_u64(time_interval, number_of_valid_frames); wacom->hid_data.time_delayed = time_packet_received; } @@ -1359,7 +1359,7 @@ static void wacom_intuos_pro2_bt_pen(struct wacom_wac *wacom) bool range = frame[0] & 0x20; bool invert = frame[0] & 0x10; int frames_number_reversed = number_of_valid_frames - i - 1; - int event_timestamp = time_packet_received - frames_number_reversed * time_interval; + ktime_t event_timestamp = time_packet_received - frames_number_reversed * time_interval; if (!valid) continue; -- cgit v1.2.3