| Message ID | 1644395873-3937-1-git-send-email-wangqing@vivo.com (mailing list archive) |
|---|---|
| State | Rejected |
| Headers | show |
| Series | iio: use div64_u64() instead of do_div() | expand |
On Wed, 9 Feb 2022 00:37:53 -0800 Qing Wang <wangqing@vivo.com> wrote: > From: Wang Qing <wangqing@vivo.com> > > 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 <wangqing@vivo.com> 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 =
Le 13/02/2022 à 18:59, Jonathan Cameron a écrit : > On Wed, 9 Feb 2022 00:37:53 -0800 > Qing Wang <wangqing@vivo.com> wrote: > >> From: Wang Qing <wangqing@vivo.com> >> >> 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 <wangqing@vivo.com> > 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@pengutronix.de/ > 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 <wangqing-DGpbCiVdSXo@public.gmane.org> wrote: >> >>> From: Wang Qing <wangqing-DGpbCiVdSXo@public.gmane.org> >>> >>> 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 <wangqing-DGpbCiVdSXo@public.gmane.org> >> 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/20211117112559.jix3hmx7uwqmuryg@pengutronix.de/ > > >> 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 <christophe.jaillet@wanadoo.fr> 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 <wangqing-DGpbCiVdSXo@public.gmane.org> wrote: > >> > >>> From: Wang Qing <wangqing-DGpbCiVdSXo@public.gmane.org> > >>> > >>> 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 <wangqing-DGpbCiVdSXo@public.gmane.org> > >> 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/20211117112559.jix3hmx7uwqmuryg@pengutronix.de/ > 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 = > >> > >> > > > > >
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 <Jonathan.Cameron@huawei.com> wrote: > > On Sun, 13 Feb 2022 19:54:01 +0100 > Christophe JAILLET <christophe.jaillet@wanadoo.fr> 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 <wangqing-DGpbCiVdSXo@public.gmane.org> wrote: > > >> > > >>> From: Wang Qing <wangqing-DGpbCiVdSXo@public.gmane.org> > > >>> > > >>> 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 <wangqing-DGpbCiVdSXo@public.gmane.org> > > >> 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/20211117112559.jix3hmx7uwqmuryg@pengutronix.de/ > > > 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 = > > >> > > >> > > > > > > > > >
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 =