A potential data race in drivers/iio/adc/berlin2-adc.ko

From: Pavel Andrianov
Date: Thu Mar 18 2021 - 04:07:58 EST


Hi,

berlin2_adc_probe [1] registers two interrupt handlers: berlin2_adc_irq [2]
and berlin2_adc_tsen_irq [3]. The interrupt handlers operate with the same data, for example, modify
priv->data with different masks:

priv->data &= BERLIN2_SM_ADC_MASK;
and
priv->data &= BERLIN2_SM_TSEN_MASK;

If the two interrupt handlers are executed simultaneously, a potential data race takes place. So, the question is if the situation is possible. For example, in the case of the handlers are executed on different CPU cores.

Best regards,
Pavel

[1] https://elixir.bootlin.com/linux/latest/source/drivers/iio/adc/berlin2-adc.c#L283
[2] https://elixir.bootlin.com/linux/latest/source/drivers/iio/adc/berlin2-adc.c#L239
[3] https://elixir.bootlin.com/linux/latest/source/drivers/iio/adc/berlin2-adc.c#L259