From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-out.m-online.net ([212.18.0.9]:42597 "EHLO mail-out.m-online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753680AbcDSUKx (ORCPT ); Tue, 19 Apr 2016 16:10:53 -0400 Message-ID: <57168737.1070904@denx.de> Date: Tue, 19 Apr 2016 21:29:59 +0200 From: Marek Vasut MIME-Version: 1.0 To: Stefan Wahren , Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler CC: Ksenija Stanojevic , Fabio Estevam , Juergen Borleis , Alexandre Belloni , linux-iio@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Greg Kroah-Hartman Subject: Re: [PATCH RFT 1/5] iio: mxs-lradc: fix memory leak References: <1460648909-2657-1-git-send-email-stefan.wahren@i2se.com> <1460648909-2657-2-git-send-email-stefan.wahren@i2se.com> <570FF70F.3000501@denx.de> <571360A3.3060809@kernel.org> <57151652.4020709@denx.de> <5715D12D.1020303@i2se.com> <57160937.6000903@denx.de> <5716348F.70200@i2se.com> In-Reply-To: <5716348F.70200@i2se.com> Content-Type: text/plain; charset=utf-8 Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On 04/19/2016 03:37 PM, Stefan Wahren wrote: > Hi Marek, > > Am 19.04.2016 um 12:32 schrieb Marek Vasut: >> On 04/19/2016 08:33 AM, Stefan Wahren wrote: >>> Hi Marek, >>> >>> Am 18.04.2016 um 19:16 schrieb 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 >>>>>>> --- >>>>>>> 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. >> This one? Why exactly? Please elaborate some more, so it's possible to >> understand the reasoning :) >> >> > > as you already pointed out this is not a memory leak, because > input_unregister_device free the input device. So the commit message is > incorrect. I see, yes, it's not a memleak. > This commit also simplifies the code but in this case we should also > remove input_unregister_device. This matches the explanation in drivers/input/input.c above input_register_device() , agreed. > Regards > Stefan > -- Best regards, Marek Vasut From mboxrd@z Thu Jan 1 00:00:00 1970 From: marex@denx.de (Marek Vasut) Date: Tue, 19 Apr 2016 21:29:59 +0200 Subject: [PATCH RFT 1/5] iio: mxs-lradc: fix memory leak In-Reply-To: <5716348F.70200@i2se.com> References: <1460648909-2657-1-git-send-email-stefan.wahren@i2se.com> <1460648909-2657-2-git-send-email-stefan.wahren@i2se.com> <570FF70F.3000501@denx.de> <571360A3.3060809@kernel.org> <57151652.4020709@denx.de> <5715D12D.1020303@i2se.com> <57160937.6000903@denx.de> <5716348F.70200@i2se.com> Message-ID: <57168737.1070904@denx.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 04/19/2016 03:37 PM, Stefan Wahren wrote: > Hi Marek, > > Am 19.04.2016 um 12:32 schrieb Marek Vasut: >> On 04/19/2016 08:33 AM, Stefan Wahren wrote: >>> Hi Marek, >>> >>> Am 18.04.2016 um 19:16 schrieb 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 >>>>>>> --- >>>>>>> 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. >> This one? Why exactly? Please elaborate some more, so it's possible to >> understand the reasoning :) >> >> > > as you already pointed out this is not a memory leak, because > input_unregister_device free the input device. So the commit message is > incorrect. I see, yes, it's not a memleak. > This commit also simplifies the code but in this case we should also > remove input_unregister_device. This matches the explanation in drivers/input/input.c above input_register_device() , agreed. > Regards > Stefan > -- Best regards, Marek Vasut