From: Wang Qing <[email protected]>
do_div() does a 64-by-32 division.
When the divisor is u64, do_div() truncates it to 32 bits, this means it
can test non-zero and be truncated to zero for division.
fix do_div.cocci warning:
do_div() does a 64-by-32 division, please consider using div64_u64 instead.
Signed-off-by: Wang Qing <[email protected]>
---
drivers/iio/common/scmi_sensors/scmi_iio.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/iio/common/scmi_sensors/scmi_iio.c b/drivers/iio/common/scmi_sensors/scmi_iio.c
index d538bf3..d6df5da
--- a/drivers/iio/common/scmi_sensors/scmi_iio.c
+++ b/drivers/iio/common/scmi_sensors/scmi_iio.c
@@ -160,7 +160,7 @@ static int scmi_iio_set_odr_val(struct iio_dev *iio_dev, int val, int val2)
mult = scnprintf(buf, sizeof(buf), "%llu", sf) - 1;
sec = int_pow(10, mult) * UHZ_PER_HZ;
- do_div(sec, uHz);
+ div64_u64(sec, uHz);
if (sec == 0) {
dev_err(&iio_dev->dev,
"Trying to set invalid sensor update value for sensor %s",
@@ -237,10 +237,10 @@ static void convert_ns_to_freq(u64 interval_ns, u64 *hz, u64 *uhz)
u64 rem, freq;
freq = NSEC_PER_SEC;
- rem = do_div(freq, interval_ns);
+ rem = div64_u64(freq, interval_ns);
*hz = freq;
*uhz = rem * 1000000UL;
- do_div(*uhz, interval_ns);
+ div64_u64(*uhz, interval_ns);
}
static int scmi_iio_get_odr_val(struct iio_dev *iio_dev, int *val, int *val2)
@@ -266,7 +266,7 @@ static int scmi_iio_get_odr_val(struct iio_dev *iio_dev, int *val, int *val2)
mult = SCMI_SENS_CFG_GET_UPDATE_EXP(sensor_config);
if (mult < 0) {
sensor_interval_mult = int_pow(10, abs(mult));
- do_div(sensor_update_interval, sensor_interval_mult);
+ div64_u64(sensor_update_interval, sensor_interval_mult);
} else {
sensor_interval_mult = int_pow(10, mult);
sensor_update_interval =
@@ -500,7 +500,7 @@ static u64 scmi_iio_convert_interval_to_ns(u32 val)
mult = SCMI_SENS_INTVL_GET_EXP(val);
if (mult < 0) {
sensor_interval_mult = int_pow(10, abs(mult));
- do_div(sensor_update_interval, sensor_interval_mult);
+ div64_u64(sensor_update_interval, sensor_interval_mult);
} else {
sensor_interval_mult = int_pow(10, mult);
sensor_update_interval =
--
2.7.4
Le 13/02/2022 à 18:59, Jonathan Cameron a écrit :
> On Wed, 9 Feb 2022 00:37:53 -0800
> Qing Wang <[email protected]> wrote:
>
>> From: Wang Qing <[email protected]>
>>
>> do_div() does a 64-by-32 division.
>> When the divisor is u64, do_div() truncates it to 32 bits, this means it
>> can test non-zero and be truncated to zero for division.
>>
>> fix do_div.cocci warning:
>> do_div() does a 64-by-32 division, please consider using div64_u64 instead.
>>
>> Signed-off-by: Wang Qing <[email protected]>
> These look correct to me. Jyoti, please could give these a sanity check?
>
This is wrong.
See [1].
CJ
[1]:
https://lore.kernel.org/linux-kernel/[email protected]/
> Thanks,
>
> Jonathan
>
>> ---
>> drivers/iio/common/scmi_sensors/scmi_iio.c | 10 +++++-----
>> 1 file changed, 5 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/iio/common/scmi_sensors/scmi_iio.c b/drivers/iio/common/scmi_sensors/scmi_iio.c
>> index d538bf3..d6df5da
>> --- a/drivers/iio/common/scmi_sensors/scmi_iio.c
>> +++ b/drivers/iio/common/scmi_sensors/scmi_iio.c
>> @@ -160,7 +160,7 @@ static int scmi_iio_set_odr_val(struct iio_dev *iio_dev, int val, int val2)
>> mult = scnprintf(buf, sizeof(buf), "%llu", sf) - 1;
>>
>> sec = int_pow(10, mult) * UHZ_PER_HZ;
>> - do_div(sec, uHz);
>> + div64_u64(sec, uHz);
>> if (sec == 0) {
>> dev_err(&iio_dev->dev,
>> "Trying to set invalid sensor update value for sensor %s",
>> @@ -237,10 +237,10 @@ static void convert_ns_to_freq(u64 interval_ns, u64 *hz, u64 *uhz)
>> u64 rem, freq;
>>
>> freq = NSEC_PER_SEC;
>> - rem = do_div(freq, interval_ns);
>> + rem = div64_u64(freq, interval_ns);
>> *hz = freq;
>> *uhz = rem * 1000000UL;
>> - do_div(*uhz, interval_ns);
>> + div64_u64(*uhz, interval_ns);
>> }
>>
>> static int scmi_iio_get_odr_val(struct iio_dev *iio_dev, int *val, int *val2)
>> @@ -266,7 +266,7 @@ static int scmi_iio_get_odr_val(struct iio_dev *iio_dev, int *val, int *val2)
>> mult = SCMI_SENS_CFG_GET_UPDATE_EXP(sensor_config);
>> if (mult < 0) {
>> sensor_interval_mult = int_pow(10, abs(mult));
>> - do_div(sensor_update_interval, sensor_interval_mult);
>> + div64_u64(sensor_update_interval, sensor_interval_mult);
>> } else {
>> sensor_interval_mult = int_pow(10, mult);
>> sensor_update_interval =
>> @@ -500,7 +500,7 @@ static u64 scmi_iio_convert_interval_to_ns(u32 val)
>> mult = SCMI_SENS_INTVL_GET_EXP(val);
>> if (mult < 0) {
>> sensor_interval_mult = int_pow(10, abs(mult));
>> - do_div(sensor_update_interval, sensor_interval_mult);
>> + div64_u64(sensor_update_interval, sensor_interval_mult);
>> } else {
>> sensor_interval_mult = int_pow(10, mult);
>> sensor_update_interval =
>
>
Le 13/02/2022 à 19:50, Christophe JAILLET a écrit :
> Le 13/02/2022 à 18:59, Jonathan Cameron a écrit :
>> On Wed, 9 Feb 2022 00:37:53 -0800
>> Qing Wang <[email protected]> wrote:
>>
>>> From: Wang Qing <[email protected]>
>>>
>>> do_div() does a 64-by-32 division.
>>> When the divisor is u64, do_div() truncates it to 32 bits, this means it
>>> can test non-zero and be truncated to zero for division.
>>>
>>> fix do_div.cocci warning:
>>> do_div() does a 64-by-32 division, please consider using div64_u64
>>> instead.
>>>
>>> Signed-off-by: Wang Qing <[email protected]>
>> These look correct to me. Jyoti, please could give these a sanity check?
>>
>
> This is wrong.
>
> See [1].
>
> CJ
>
> [1]:
> https://lore.kernel.org/linux-kernel/20211117112559.jix3hmx7uwqmuryg-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org/
Broken link, sorry:
[1]
https://lore.kernel.org/linux-kernel/[email protected]/
>
>
>> Thanks,
>>
>> Jonathan
>>
>>> ---
>>> drivers/iio/common/scmi_sensors/scmi_iio.c | 10 +++++-----
>>> 1 file changed, 5 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/drivers/iio/common/scmi_sensors/scmi_iio.c
>>> b/drivers/iio/common/scmi_sensors/scmi_iio.c
>>> index d538bf3..d6df5da
>>> --- a/drivers/iio/common/scmi_sensors/scmi_iio.c
>>> +++ b/drivers/iio/common/scmi_sensors/scmi_iio.c
>>> @@ -160,7 +160,7 @@ static int scmi_iio_set_odr_val(struct iio_dev
>>> *iio_dev, int val, int val2)
>>> mult = scnprintf(buf, sizeof(buf), "%llu", sf) - 1;
>>> sec = int_pow(10, mult) * UHZ_PER_HZ;
>>> - do_div(sec, uHz);
>>> + div64_u64(sec, uHz);
>>> if (sec == 0) {
>>> dev_err(&iio_dev->dev,
>>> "Trying to set invalid sensor update value for sensor %s",
>>> @@ -237,10 +237,10 @@ static void convert_ns_to_freq(u64 interval_ns,
>>> u64 *hz, u64 *uhz)
>>> u64 rem, freq;
>>> freq = NSEC_PER_SEC;
>>> - rem = do_div(freq, interval_ns);
>>> + rem = div64_u64(freq, interval_ns);
>>> *hz = freq;
>>> *uhz = rem * 1000000UL;
>>> - do_div(*uhz, interval_ns);
>>> + div64_u64(*uhz, interval_ns);
>>> }
>>> static int scmi_iio_get_odr_val(struct iio_dev *iio_dev, int *val,
>>> int *val2)
>>> @@ -266,7 +266,7 @@ static int scmi_iio_get_odr_val(struct iio_dev
>>> *iio_dev, int *val, int *val2)
>>> mult = SCMI_SENS_CFG_GET_UPDATE_EXP(sensor_config);
>>> if (mult < 0) {
>>> sensor_interval_mult = int_pow(10, abs(mult));
>>> - do_div(sensor_update_interval, sensor_interval_mult);
>>> + div64_u64(sensor_update_interval, sensor_interval_mult);
>>> } else {
>>> sensor_interval_mult = int_pow(10, mult);
>>> sensor_update_interval =
>>> @@ -500,7 +500,7 @@ static u64 scmi_iio_convert_interval_to_ns(u32 val)
>>> mult = SCMI_SENS_INTVL_GET_EXP(val);
>>> if (mult < 0) {
>>> sensor_interval_mult = int_pow(10, abs(mult));
>>> - do_div(sensor_update_interval, sensor_interval_mult);
>>> + div64_u64(sensor_update_interval, sensor_interval_mult);
>>> } else {
>>> sensor_interval_mult = int_pow(10, mult);
>>> sensor_update_interval =
>>
>>
>
>
On Wed, 9 Feb 2022 00:37:53 -0800
Qing Wang <[email protected]> wrote:
> From: Wang Qing <[email protected]>
>
> do_div() does a 64-by-32 division.
> When the divisor is u64, do_div() truncates it to 32 bits, this means it
> can test non-zero and be truncated to zero for division.
>
> fix do_div.cocci warning:
> do_div() does a 64-by-32 division, please consider using div64_u64 instead.
>
> Signed-off-by: Wang Qing <[email protected]>
These look correct to me. Jyoti, please could give these a sanity check?
Thanks,
Jonathan
> ---
> drivers/iio/common/scmi_sensors/scmi_iio.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/iio/common/scmi_sensors/scmi_iio.c b/drivers/iio/common/scmi_sensors/scmi_iio.c
> index d538bf3..d6df5da
> --- a/drivers/iio/common/scmi_sensors/scmi_iio.c
> +++ b/drivers/iio/common/scmi_sensors/scmi_iio.c
> @@ -160,7 +160,7 @@ static int scmi_iio_set_odr_val(struct iio_dev *iio_dev, int val, int val2)
> mult = scnprintf(buf, sizeof(buf), "%llu", sf) - 1;
>
> sec = int_pow(10, mult) * UHZ_PER_HZ;
> - do_div(sec, uHz);
> + div64_u64(sec, uHz);
> if (sec == 0) {
> dev_err(&iio_dev->dev,
> "Trying to set invalid sensor update value for sensor %s",
> @@ -237,10 +237,10 @@ static void convert_ns_to_freq(u64 interval_ns, u64 *hz, u64 *uhz)
> u64 rem, freq;
>
> freq = NSEC_PER_SEC;
> - rem = do_div(freq, interval_ns);
> + rem = div64_u64(freq, interval_ns);
> *hz = freq;
> *uhz = rem * 1000000UL;
> - do_div(*uhz, interval_ns);
> + div64_u64(*uhz, interval_ns);
> }
>
> static int scmi_iio_get_odr_val(struct iio_dev *iio_dev, int *val, int *val2)
> @@ -266,7 +266,7 @@ static int scmi_iio_get_odr_val(struct iio_dev *iio_dev, int *val, int *val2)
> mult = SCMI_SENS_CFG_GET_UPDATE_EXP(sensor_config);
> if (mult < 0) {
> sensor_interval_mult = int_pow(10, abs(mult));
> - do_div(sensor_update_interval, sensor_interval_mult);
> + div64_u64(sensor_update_interval, sensor_interval_mult);
> } else {
> sensor_interval_mult = int_pow(10, mult);
> sensor_update_interval =
> @@ -500,7 +500,7 @@ static u64 scmi_iio_convert_interval_to_ns(u32 val)
> mult = SCMI_SENS_INTVL_GET_EXP(val);
> if (mult < 0) {
> sensor_interval_mult = int_pow(10, abs(mult));
> - do_div(sensor_update_interval, sensor_interval_mult);
> + div64_u64(sensor_update_interval, sensor_interval_mult);
> } else {
> sensor_interval_mult = int_pow(10, mult);
> sensor_update_interval =
yes, this is wrong. Also, the logic would be broken as the two apis
do_div() and div64_u64 return values are completely different.
Thanks,
Jyoti
On Mon, Feb 14, 2022 at 3:01 AM Jonathan Cameron
<[email protected]> wrote:
>
> On Sun, 13 Feb 2022 19:54:01 +0100
> Christophe JAILLET <[email protected]> wrote:
>
> > Le 13/02/2022 à 19:50, Christophe JAILLET a écrit :
> > > Le 13/02/2022 à 18:59, Jonathan Cameron a écrit :
> > >> On Wed, 9 Feb 2022 00:37:53 -0800
> > >> Qing Wang <[email protected]> wrote:
> > >>
> > >>> From: Wang Qing <[email protected]>
> > >>>
> > >>> do_div() does a 64-by-32 division.
> > >>> When the divisor is u64, do_div() truncates it to 32 bits, this means it
> > >>> can test non-zero and be truncated to zero for division.
> > >>>
> > >>> fix do_div.cocci warning:
> > >>> do_div() does a 64-by-32 division, please consider using div64_u64
> > >>> instead.
> > >>>
> > >>> Signed-off-by: Wang Qing <[email protected]>
> > >> These look correct to me. Jyoti, please could give these a sanity check?
> > >>
> > >
> > > This is wrong.
> > >
> > > See [1].
> > >
> > > CJ
> > >
> > > [1]:
> > > https://lore.kernel.org/linux-kernel/20211117112559.jix3hmx7uwqmuryg-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org/
> >
> > Broken link, sorry:
> >
> > [1]
> > https://lore.kernel.org/linux-kernel/[email protected]/
> >
> oops. Thanks for the heads up. I'd forgotten the slightly odd convention
> around do_div
>
> Jonathan
>
>
> > >
> > >
> > >> Thanks,
> > >>
> > >> Jonathan
> > >>
> > >>> ---
> > >>> drivers/iio/common/scmi_sensors/scmi_iio.c | 10 +++++-----
> > >>> 1 file changed, 5 insertions(+), 5 deletions(-)
> > >>>
> > >>> diff --git a/drivers/iio/common/scmi_sensors/scmi_iio.c
> > >>> b/drivers/iio/common/scmi_sensors/scmi_iio.c
> > >>> index d538bf3..d6df5da
> > >>> --- a/drivers/iio/common/scmi_sensors/scmi_iio.c
> > >>> +++ b/drivers/iio/common/scmi_sensors/scmi_iio.c
> > >>> @@ -160,7 +160,7 @@ static int scmi_iio_set_odr_val(struct iio_dev
> > >>> *iio_dev, int val, int val2)
> > >>> mult = scnprintf(buf, sizeof(buf), "%llu", sf) - 1;
> > >>> sec = int_pow(10, mult) * UHZ_PER_HZ;
> > >>> - do_div(sec, uHz);
> > >>> + div64_u64(sec, uHz);
> > >>> if (sec == 0) {
> > >>> dev_err(&iio_dev->dev,
> > >>> "Trying to set invalid sensor update value for sensor %s",
> > >>> @@ -237,10 +237,10 @@ static void convert_ns_to_freq(u64 interval_ns,
> > >>> u64 *hz, u64 *uhz)
> > >>> u64 rem, freq;
> > >>> freq = NSEC_PER_SEC;
> > >>> - rem = do_div(freq, interval_ns);
> > >>> + rem = div64_u64(freq, interval_ns);
> > >>> *hz = freq;
> > >>> *uhz = rem * 1000000UL;
> > >>> - do_div(*uhz, interval_ns);
> > >>> + div64_u64(*uhz, interval_ns);
> > >>> }
> > >>> static int scmi_iio_get_odr_val(struct iio_dev *iio_dev, int *val,
> > >>> int *val2)
> > >>> @@ -266,7 +266,7 @@ static int scmi_iio_get_odr_val(struct iio_dev
> > >>> *iio_dev, int *val, int *val2)
> > >>> mult = SCMI_SENS_CFG_GET_UPDATE_EXP(sensor_config);
> > >>> if (mult < 0) {
> > >>> sensor_interval_mult = int_pow(10, abs(mult));
> > >>> - do_div(sensor_update_interval, sensor_interval_mult);
> > >>> + div64_u64(sensor_update_interval, sensor_interval_mult);
> > >>> } else {
> > >>> sensor_interval_mult = int_pow(10, mult);
> > >>> sensor_update_interval =
> > >>> @@ -500,7 +500,7 @@ static u64 scmi_iio_convert_interval_to_ns(u32 val)
> > >>> mult = SCMI_SENS_INTVL_GET_EXP(val);
> > >>> if (mult < 0) {
> > >>> sensor_interval_mult = int_pow(10, abs(mult));
> > >>> - do_div(sensor_update_interval, sensor_interval_mult);
> > >>> + div64_u64(sensor_update_interval, sensor_interval_mult);
> > >>> } else {
> > >>> sensor_interval_mult = int_pow(10, mult);
> > >>> sensor_update_interval =
> > >>
> > >>
> > >
> > >
> >
>
On Sun, 13 Feb 2022 19:54:01 +0100
Christophe JAILLET <[email protected]> wrote:
> Le 13/02/2022 ? 19:50, Christophe JAILLET a ?crit?:
> > Le 13/02/2022 ? 18:59, Jonathan Cameron a ?crit?:
> >> On Wed,? 9 Feb 2022 00:37:53 -0800
> >> Qing Wang <[email protected]> wrote:
> >>
> >>> From: Wang Qing <[email protected]>
> >>>
> >>> do_div() does a 64-by-32 division.
> >>> When the divisor is u64, do_div() truncates it to 32 bits, this means it
> >>> can test non-zero and be truncated to zero for division.
> >>>
> >>> fix do_div.cocci warning:
> >>> do_div() does a 64-by-32 division, please consider using div64_u64
> >>> instead.
> >>>
> >>> Signed-off-by: Wang Qing <[email protected]>
> >> These look correct to me.? Jyoti, please could give these a sanity check?
> >>
> >
> > This is wrong.
> >
> > See [1].
> >
> > CJ
> >
> > [1]:
> > https://lore.kernel.org/linux-kernel/20211117112559.jix3hmx7uwqmuryg-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org/
>
> Broken link, sorry:
>
> [1]
> https://lore.kernel.org/linux-kernel/[email protected]/
>
oops. Thanks for the heads up. I'd forgotten the slightly odd convention
around do_div
Jonathan
> >
> >
> >> Thanks,
> >>
> >> Jonathan
> >>
> >>> ---
> >>> ? drivers/iio/common/scmi_sensors/scmi_iio.c | 10 +++++-----
> >>> ? 1 file changed, 5 insertions(+), 5 deletions(-)
> >>>
> >>> diff --git a/drivers/iio/common/scmi_sensors/scmi_iio.c
> >>> b/drivers/iio/common/scmi_sensors/scmi_iio.c
> >>> index d538bf3..d6df5da
> >>> --- a/drivers/iio/common/scmi_sensors/scmi_iio.c
> >>> +++ b/drivers/iio/common/scmi_sensors/scmi_iio.c
> >>> @@ -160,7 +160,7 @@ static int scmi_iio_set_odr_val(struct iio_dev
> >>> *iio_dev, int val, int val2)
> >>> ????? mult = scnprintf(buf, sizeof(buf), "%llu", sf) - 1;
> >>> ????? sec = int_pow(10, mult) * UHZ_PER_HZ;
> >>> -??? do_div(sec, uHz);
> >>> +??? div64_u64(sec, uHz);
> >>> ????? if (sec == 0) {
> >>> ????????? dev_err(&iio_dev->dev,
> >>> ????????????? "Trying to set invalid sensor update value for sensor %s",
> >>> @@ -237,10 +237,10 @@ static void convert_ns_to_freq(u64 interval_ns,
> >>> u64 *hz, u64 *uhz)
> >>> ????? u64 rem, freq;
> >>> ????? freq = NSEC_PER_SEC;
> >>> -??? rem = do_div(freq, interval_ns);
> >>> +??? rem = div64_u64(freq, interval_ns);
> >>> ????? *hz = freq;
> >>> ????? *uhz = rem * 1000000UL;
> >>> -??? do_div(*uhz, interval_ns);
> >>> +??? div64_u64(*uhz, interval_ns);
> >>> ? }
> >>> ? static int scmi_iio_get_odr_val(struct iio_dev *iio_dev, int *val,
> >>> int *val2)
> >>> @@ -266,7 +266,7 @@ static int scmi_iio_get_odr_val(struct iio_dev
> >>> *iio_dev, int *val, int *val2)
> >>> ????? mult = SCMI_SENS_CFG_GET_UPDATE_EXP(sensor_config);
> >>> ????? if (mult < 0) {
> >>> ????????? sensor_interval_mult = int_pow(10, abs(mult));
> >>> -??????? do_div(sensor_update_interval, sensor_interval_mult);
> >>> +??????? div64_u64(sensor_update_interval, sensor_interval_mult);
> >>> ????? } else {
> >>> ????????? sensor_interval_mult = int_pow(10, mult);
> >>> ????????? sensor_update_interval =
> >>> @@ -500,7 +500,7 @@ static u64 scmi_iio_convert_interval_to_ns(u32 val)
> >>> ????? mult = SCMI_SENS_INTVL_GET_EXP(val);
> >>> ????? if (mult < 0) {
> >>> ????????? sensor_interval_mult = int_pow(10, abs(mult));
> >>> -??????? do_div(sensor_update_interval, sensor_interval_mult);
> >>> +??????? div64_u64(sensor_update_interval, sensor_interval_mult);
> >>> ????? } else {
> >>> ????????? sensor_interval_mult = int_pow(10, mult);
> >>> ????????? sensor_update_interval =
> >>
> >>
> >
> >
>