[PATCH RFT 1/5] iio: mxs-lradc: fix memory leak

[Marek Vasut]

On 04/17/2016 12:08 PM, Jonathan Cameron wrote:
> On 14/04/16 21:01, Marek Vasut wrote:
>> On 04/14/2016 05:48 PM, Stefan Wahren wrote:
>>> After successful touchscreen registration the input device was
>>> never freed. So fix this issue by using devm_input_allocate_device().
>>>
>>> Signed-off-by: Stefan Wahren <stefan.wahren at i2se.com>
>>> ---
>>>  drivers/iio/adc/mxs-lradc.c |    8 ++------
>>>  1 file changed, 2 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/iio/adc/mxs-lradc.c b/drivers/iio/adc/mxs-lradc.c
>>> index 33051b8..0576953 100644
>>> --- a/drivers/iio/adc/mxs-lradc.c
>>> +++ b/drivers/iio/adc/mxs-lradc.c
>>> @@ -1109,12 +1109,11 @@ static int mxs_lradc_ts_register(struct mxs_lradc *lradc)
>>>  {
>>>  	struct input_dev *input;
>>>  	struct device *dev = lradc->dev;
>>> -	int ret;
>>>  
>>>  	if (!lradc->use_touchscreen)
>>>  		return 0;
>>>  
>>> -	input = input_allocate_device();
>>> +	input = devm_input_allocate_device(dev);
>>>  	if (!input)
>>>  		return -ENOMEM;
>>>  
>>> @@ -1134,11 +1133,8 @@ static int mxs_lradc_ts_register(struct mxs_lradc *lradc)
>>>  
>>>  	lradc->ts_input = input;
>>>  	input_set_drvdata(input, lradc);
>>> -	ret = input_register_device(input);
>>> -	if (ret)
>>> -		input_free_device(lradc->ts_input);
>>>  
>>> -	return ret;
>>> +	return input_register_device(input);
>>>  }
>>>  
>>>  static void mxs_lradc_ts_unregister(struct mxs_lradc *lradc)
>>>
>>
>> Nice find.
>>
>> Looks like at91_adc.c and exynos_adc.c suffer from the exact same issue.
>> The leak looks a bit more severe on exynos even, exynos_adc_ts_init()
>> could use a proper fail path. Do you want to send patches or shall I ?
>>
> As this has been there a long time I'm not going to rush it in as a fix.

I did take a proper look today and it seems they do the right thing
afterall. I checked them with kmemleak too to be sure.

> I suspect no platform is probing and removing it enough to get a significant
> amount of memory leaked.
> 
> Good to clear it up though!
> 
> Applied to the togreg branch of iio.git, initially pushed out as testing for
> the autobuilders to play with it.
> 
> Thanks,
> 
> Jonathan
> 


-- 
Best regards,
Marek Vasut