From: Vitaliy Shevtsov v.shevtsov@mt-integration.ru
[ Upstream commit c0c1a6bf80e9075e3f6b81fd542550d8eb91e57a ]
[Why] There are several ns_to_ktime() calls that require using nanoseconds. It is better to replace them with us_to_ktime() to make code clear, getting rid of multiplication by 1000.
Also the timer function code may have an integer wrap-around issue. Since both tx_custom_low_usecs and tx_custom_high_usecs can be set to up to 9999999 from the user space via cec_pin_error_inj_parse_line(), this may cause usecs to be overflowed when adap->monitor_pin_cnt is zero and usecs is multiplied by 1000.
[How] Take advantage of using an appropriate helper func us_to_ktime() instead of ns_to_ktime() to improve readability and to make the code clearer. And this also mitigates possible integer wrap-arounds when usecs value is too large and it is multiplied by 1000.
Found by Linux Verification Center (linuxtesting.org) with Svace.
Signed-off-by: Vitaliy Shevtsov v.shevtsov@mt-integration.ru Signed-off-by: Hans Verkuil hverkuil@xs4all.nl Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/media/cec/core/cec-pin.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/drivers/media/cec/core/cec-pin.c b/drivers/media/cec/core/cec-pin.c index a70451d99ebc9..f232c3df7ee16 100644 --- a/drivers/media/cec/core/cec-pin.c +++ b/drivers/media/cec/core/cec-pin.c @@ -873,19 +873,19 @@ static enum hrtimer_restart cec_pin_timer(struct hrtimer *timer) if (pin->wait_usecs > 150) { pin->wait_usecs -= 100; pin->timer_ts = ktime_add_us(ts, 100); - hrtimer_forward_now(timer, ns_to_ktime(100000)); + hrtimer_forward_now(timer, us_to_ktime(100)); return HRTIMER_RESTART; } if (pin->wait_usecs > 100) { pin->wait_usecs /= 2; pin->timer_ts = ktime_add_us(ts, pin->wait_usecs); hrtimer_forward_now(timer, - ns_to_ktime(pin->wait_usecs * 1000)); + us_to_ktime(pin->wait_usecs)); return HRTIMER_RESTART; } pin->timer_ts = ktime_add_us(ts, pin->wait_usecs); hrtimer_forward_now(timer, - ns_to_ktime(pin->wait_usecs * 1000)); + us_to_ktime(pin->wait_usecs)); pin->wait_usecs = 0; return HRTIMER_RESTART; } @@ -1020,13 +1020,12 @@ static enum hrtimer_restart cec_pin_timer(struct hrtimer *timer) if (!adap->monitor_pin_cnt || usecs <= 150) { pin->wait_usecs = 0; pin->timer_ts = ktime_add_us(ts, usecs); - hrtimer_forward_now(timer, - ns_to_ktime(usecs * 1000)); + hrtimer_forward_now(timer, us_to_ktime(usecs)); return HRTIMER_RESTART; } pin->wait_usecs = usecs - 100; pin->timer_ts = ktime_add_us(ts, 100); - hrtimer_forward_now(timer, ns_to_ktime(100000)); + hrtimer_forward_now(timer, us_to_ktime(100)); return HRTIMER_RESTART; }