Input: max77693-haptic - fix potential overflow
Expression haptic->pwm_dev->period * haptic->magnitude is of type
'unsigned int' and may overflow. We need to convert one of the operands
to u64 before multiplying, instead of casting result (potentially
overflown) to u64.
Reported by Coverity: CID 1248753
Acked-by : Jaewon Kim <jaewon02.kim@samsung.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
diff --git a/drivers/input/misc/max77693-haptic.c b/drivers/input/misc/max77693-haptic.c
index 7b1fde9..ef6a9d6 100644
--- a/drivers/input/misc/max77693-haptic.c
+++ b/drivers/input/misc/max77693-haptic.c
@@ -194,7 +194,7 @@
struct ff_effect *effect)
{
struct max77693_haptic *haptic = input_get_drvdata(dev);
- uint64_t period_mag_multi;
+ u64 period_mag_multi;
haptic->magnitude = effect->u.rumble.strong_magnitude;
if (!haptic->magnitude)
@@ -205,8 +205,7 @@
* The formula to convert magnitude to pwm_duty as follows:
* - pwm_duty = (magnitude * pwm_period) / MAX_MAGNITUDE(0xFFFF)
*/
- period_mag_multi = (int64_t)(haptic->pwm_dev->period *
- haptic->magnitude);
+ period_mag_multi = (u64)haptic->pwm_dev->period * haptic->magnitude;
haptic->pwm_duty = (unsigned int)(period_mag_multi >>
MAX_MAGNITUDE_SHIFT);