On 10/4/19 8:23 AM, Uwe Kleine-König wrote: > Hello, > > On Thu, Oct 03, 2019 at 09:46:49PM -0700, Yizhuo wrote: >> Inside function stm32_pwm_config(), variable "psc" and " arr" >> could be uninitialized if regmap_read() returns -EINVALs. >> However, they are used later in the if statement to decide >> the return value which is potentially unsafe.
Hi Yizhuo, like for the your patch in IIO trigger regmap_read could only failed if the hardware block is no more clocked and in this case we won't return of regmap_read. Testing regmap_read() return value just add code but doesn't provide a valid information. If you really want to log all the possible errors cases please do it in regmap code itself and not in *all* the drivers. Thanks, Benjamin >> >> The same case happens in function stm32_pwm_detect_channels() >> with variable "ccer", but we cannot just return -EINVAL because >> the error code is not acceptable by the caller. Aslo, the variable > s/Aslo/Also/ > >> "ccer" in functionstm32_pwm_detect_complementary() could also be > s/functionstm32_pwm_detect_/function stm32_pwm_detect_/ > >> uninitialized, since stm32_pwm_detect_complementary() returns void, >> the patch is not easy. > active_channels() is also affected. Also there are calls to > regmap_update_bits which should have their return values checked. > > While a patch to fix these all is not trivial it is certainly possible > and I would prefer to fix the problem completely. > > Best regards > Uwe >
