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

Hi Marek,

Am 18.04.2016 um 19:16 schrieb Marek Vasut:

On 04/17/2016 12:08 PM, Jonathan Cameron wrote:

quoted

On 14/04/16 21:01, Marek Vasut wrote:

quoted

On 04/14/2016 05:48 PM, Stefan Wahren wrote:

quoted

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 <redacted>
---
 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.

thanks, input_unregister_device already free the memory.

Sorry for the mess :-(

I think it would be the best to remove / revert this patch.

Stefan

quoted

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