diff options
| author | Gustavo A. R. Silva | 2018-02-06 11:53:44 -0500 |
|---|---|---|
| committer | Mauro Carvalho Chehab | 2018-02-26 08:10:27 -0500 |
| commit | fc49d3d7dc26a43f8d3b1874c7ddb975a49e8a8c (patch) | |
| tree | 2b4c9753643c8cdbbc6786eb0b9ccd1240492962 | |
| parent | eb64311ffc693e6e7b646a9b53631194f79b77c3 (diff) | |
media: platform: vivid-cec: use 64-bit arithmetic instead of 32-bit
Add suffix ULL to constant 10 in order to give the compiler complete
information about the proper arithmetic to use. Notice that this
constant is used in a context that expects an expression of type
u64 (64 bits, unsigned).
The expression len * 10 * CEC_TIM_DATA_BIT_TOTAL is currently being
evaluated using 32-bit arithmetic.
Also, remove unnecessary parentheses and add a code comment to make it
clear what is the reason of the code change.
Addresses-Coverity-ID: 1454996 ("Unintentional integer overflow")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
| -rw-r--r-- | drivers/media/platform/vivid/vivid-cec.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/media/platform/vivid/vivid-cec.c b/drivers/media/platform/vivid/vivid-cec.c index 619bd8435b7f..c2c889d6dcf5 100644 --- a/drivers/media/platform/vivid/vivid-cec.c +++ b/drivers/media/platform/vivid/vivid-cec.c @@ -70,8 +70,15 @@ static void vivid_cec_pin_adap_events(struct cec_adapter *adap, ktime_t ts, if (adap == NULL) return; - ts = ktime_sub_us(ts, (CEC_TIM_START_BIT_TOTAL + - len * 10 * CEC_TIM_DATA_BIT_TOTAL)); + + /* + * Suffix ULL on constant 10 makes the expression + * CEC_TIM_START_BIT_TOTAL + 10ULL * len * CEC_TIM_DATA_BIT_TOTAL + * to be evaluated using 64-bit unsigned arithmetic (u64), which + * is what ktime_sub_us expects as second argument. + */ + ts = ktime_sub_us(ts, CEC_TIM_START_BIT_TOTAL + + 10ULL * len * CEC_TIM_DATA_BIT_TOTAL); cec_queue_pin_cec_event(adap, false, ts); ts = ktime_add_us(ts, CEC_TIM_START_BIT_LOW); cec_queue_pin_cec_event(adap, true, ts); |