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]> --- 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
