On Tue, Sep 22, 2026 at 11:21:11AM +0000, Bill Wendling wrote: > Annotate the "ch" pointer member of "struct st_sensor_settings" with the > "__counted_by_ptr" attribute. The elements of "ch" are counted by the > "num_ch" member in the same struct. > > All instances of "struct st_sensor_settings" are defined as "static > const" arrays across the ST sensor core drivers. For pressure sensors, > "num_ch" is explicitly initialized with the size of the respective > channel array using "ARRAY_SIZE(...)" during static definition. > > For accelerometer, gyroscope, and magnetometer sensors, "num_ch" is not > explicitly initialized (and thus defaults to 0). This is because those > drivers hardcode the channel count to "ST_SENSORS_NUMBER_ALL_CHANNELS" > rather than using "num_ch" from the settings struct. > > Since these structures are static const, both "ch" and "num_ch" are > fully initialized at compile time and available immediately at boot > time. The only accesses to the "ch" field of "st_sensor_settings" occur > when assigning it to "indio_dev->channels" during device probing. > > Because "sensor_settings->ch" is never dereferenced or accessed as an > array, adding the "__counted_by_ptr" annotation does not cause any > runtime panics or false-positive bounds checks under KASAN or UBSAN. > > Cc: [email protected] > Assisted-by: LLM > Signed-off-by: Bill Wendling <[email protected]> > ---
Reviewed-by: Nuno Sá <[email protected]> > include/linux/iio/common/st_sensors.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/iio/common/st_sensors.h > b/include/linux/iio/common/st_sensors.h > index 1ba496f0fea5..6e914ed49529 100644 > --- a/include/linux/iio/common/st_sensors.h > +++ b/include/linux/iio/common/st_sensors.h > @@ -206,7 +206,7 @@ struct st_sensor_settings { > u8 wai; > u8 wai_addr; > char sensors_supported[ST_SENSORS_MAX_4WAI][ST_SENSORS_MAX_NAME]; > - struct iio_chan_spec *ch; > + struct iio_chan_spec *ch __counted_by_ptr(num_ch); > int num_ch; > struct st_sensor_odr odr; > struct st_sensor_power pw; > -- > 2.55.0.1082.g2b9226bbc0-goog >
