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[23.128.96.18]) by mx.google.com with ESMTP id dk9si5150483edb.403.2020.04.25.12.34.59; Sat, 25 Apr 2020 12:35:21 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@web.de header.s=dbaedf251592 header.b=lLxRCdNm; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726482AbgDYTar (ORCPT + 99 others); Sat, 25 Apr 2020 15:30:47 -0400 Received: from mout.web.de ([212.227.15.4]:46217 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726203AbgDYTar (ORCPT ); Sat, 25 Apr 2020 15:30:47 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=web.de; s=dbaedf251592; t=1587843026; bh=RwrA069HOzfiE5yqdsD0WFeIg6rPJQx0TsH4TCw5U9A=; h=X-UI-Sender-Class:To:Cc:Subject:From:Date; b=lLxRCdNmxzgg8nbSvTKagYC/6I2n1mkxn59jiYGeXwqYfOtc0kI1GkwuRPx/gGSW7 LHTZtapiw86tHDh2Koy4ZJ6bls0WyXMk766QyTEYPYhZvTexE/UH1CmWGfmJ1uMCtl pL0OAqFKVZjKhwVsn8Z4ACP6pAMla2230ViMuZlU= X-UI-Sender-Class: c548c8c5-30a9-4db5-a2e7-cb6cb037b8f9 Received: from [192.168.1.2] ([78.49.160.204]) by smtp.web.de (mrweb003 [213.165.67.108]) with ESMTPSA (Nemesis) id 0Mhljf-1jpKfi39DX-00Mwio; Sat, 25 Apr 2020 21:30:25 +0200 To: Xiyu Yang , Xin Tan , linux-mmc@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, =?UTF-8?Q?Andreas_F=c3=a4rber?= , Kangjie Lu , Manivannan Sadhasivam , Ulf Hansson , Yuan Zhang Subject: Re: [PATCH] mmc: owl-mmc: Fix dma_chan refcnt leak in owl_mmc_probe() From: Markus Elfring Autocrypt: addr=Markus.Elfring@web.de; prefer-encrypt=mutual; keydata= mQINBFg2+xABEADBJW2hoUoFXVFWTeKbqqif8VjszdMkriilx90WB5c0ddWQX14h6w5bT/A8 +v43YoGpDNyhgA0w9CEhuwfZrE91GocMtjLO67TAc2i2nxMc/FJRDI0OemO4VJ9RwID6ltwt mpVJgXGKkNJ1ey+QOXouzlErVvE2fRh+KXXN1Q7fSmTJlAW9XJYHS3BDHb0uRpymRSX3O+E2 lA87C7R8qAigPDZi6Z7UmwIA83ZMKXQ5stA0lhPyYgQcM7fh7V4ZYhnR0I5/qkUoxKpqaYLp YHBczVP+Zx/zHOM0KQphOMbU7X3c1pmMruoe6ti9uZzqZSLsF+NKXFEPBS665tQr66HJvZvY GMDlntZFAZ6xQvCC1r3MGoxEC1tuEa24vPCC9RZ9wk2sY5Csbva0WwYv3WKRZZBv8eIhGMxs rcpeGShRFyZ/0BYO53wZAPV1pEhGLLxd8eLN/nEWjJE0ejakPC1H/mt5F+yQBJAzz9JzbToU 5jKLu0SugNI18MspJut8AiA1M44CIWrNHXvWsQ+nnBKHDHHYZu7MoXlOmB32ndsfPthR3GSv jN7YD4Ad724H8fhRijmC1+RpuSce7w2JLj5cYj4MlccmNb8YUxsE8brY2WkXQYS8Ivse39MX BE66MQN0r5DQ6oqgoJ4gHIVBUv/ZwgcmUNS5gQkNCFA0dWXznQARAQABtCZNYXJrdXMgRWxm cmluZyA8TWFya3VzLkVsZnJpbmdAd2ViLmRlPokCVAQTAQgAPhYhBHDP0hzibeXjwQ/ITuU9 Figxg9azBQJYNvsQAhsjBQkJZgGABQsJCAcCBhUICQoLAgQWAgMBAh4BAheAAAoJEOU9Figx g9azcyMP/iVihZkZ4VyH3/wlV3nRiXvSreqg+pGPI3c8J6DjP9zvz7QHN35zWM++1yNek7Ar OVXwuKBo18ASlYzZPTFJZwQQdkZSV+atwIzG3US50ZZ4p7VyUuDuQQVVqFlaf6qZOkwHSnk+ CeGxlDz1POSHY17VbJG2CzPuqMfgBtqIU1dODFLpFq4oIAwEOG6fxRa59qbsTLXxyw+PzRaR LIjVOit28raM83Efk07JKow8URb4u1n7k9RGAcnsM5/WMLRbDYjWTx0lJ2WO9zYwPgRykhn2 sOyJVXk9xVESGTwEPbTtfHM+4x0n0gC6GzfTMvwvZ9G6xoM0S4/+lgbaaa9t5tT/PrsvJiob kfqDrPbmSwr2G5mHnSM9M7B+w8odjmQFOwAjfcxoVIHxC4Cl/GAAKsX3KNKTspCHR0Yag78w i8duH/eEd4tB8twcqCi3aCgWoIrhjNS0myusmuA89kAWFFW5z26qNCOefovCx8drdMXQfMYv g5lRk821ZCNBosfRUvcMXoY6lTwHLIDrEfkJQtjxfdTlWQdwr0mM5ye7vd83AManSQwutgpI q+wE8CNY2VN9xAlE7OhcmWXlnAw3MJLW863SXdGlnkA3N+U4BoKQSIToGuXARQ14IMNvfeKX NphLPpUUnUNdfxAHu/S3tPTc/E/oePbHo794dnEm57LuuQINBFg2+xABEADZg/T+4o5qj4cw nd0G5pFy7ACxk28mSrLuva9tyzqPgRZ2bdPiwNXJUvBg1es2u81urekeUvGvnERB/TKekp25 4wU3I2lEhIXj5NVdLc6eU5czZQs4YEZbu1U5iqhhZmKhlLrhLlZv2whLOXRlLwi4jAzXIZAu 76mT813jbczl2dwxFxcT8XRzk9+dwzNTdOg75683uinMgskiiul+dzd6sumdOhRZR7YBT+xC wzfykOgBKnzfFscMwKR0iuHNB+VdEnZw80XGZi4N1ku81DHxmo2HG3icg7CwO1ih2jx8ik0r riIyMhJrTXgR1hF6kQnX7p2mXe6K0s8tQFK0ZZmYpZuGYYsV05OvU8yqrRVL/GYvy4Xgplm3 DuMuC7/A9/BfmxZVEPAS1gW6QQ8vSO4zf60zREKoSNYeiv+tURM2KOEj8tCMZN3k3sNASfoG fMvTvOjT0yzMbJsI1jwLwy5uA2JVdSLoWzBD8awZ2X/eCU9YDZeGuWmxzIHvkuMj8FfX8cK/ 2m437UA877eqmcgiEy/3B7XeHUipOL83gjfq4ETzVmxVswkVvZvR6j2blQVr+MhCZPq83Ota xNB7QptPxJuNRZ49gtT6uQkyGI+2daXqkj/Mot5tKxNKtM1Vbr/3b+AEMA7qLz7QjhgGJcie qp4b0gELjY1Oe9dBAXMiDwARAQABiQI8BBgBCAAmFiEEcM/SHOJt5ePBD8hO5T0WKDGD1rMF Alg2+xACGwwFCQlmAYAACgkQ5T0WKDGD1rOYSw/+P6fYSZjTJDAl9XNfXRjRRyJSfaw6N1pA Ahuu0MIa3djFRuFCrAHUaaFZf5V2iW5xhGnrhDwE1Ksf7tlstSne/G0a+Ef7vhUyeTn6U/0m +/BrsCsBUXhqeNuraGUtaleatQijXfuemUwgB+mE3B0SobE601XLo6MYIhPh8MG32MKO5kOY hB5jzyor7WoN3ETVNQoGgMzPVWIRElwpcXr+yGoTLAOpG7nkAUBBj9n9TPpSdt/npfok9ZfL /Q+ranrxb2Cy4tvOPxeVfR58XveX85ICrW9VHPVq9sJf/a24bMm6+qEg1V/G7u/AM3fM8U2m tdrTqOrfxklZ7beppGKzC1/WLrcr072vrdiN0icyOHQlfWmaPv0pUnW3AwtiMYngT96BevfA qlwaymjPTvH+cTXScnbydfOQW8220JQwykUe+sHRZfAF5TS2YCkQvsyf7vIpSqo/ttDk4+xc Z/wsLiWTgKlih2QYULvW61XU+mWsK8+ZlYUrRMpkauN4CJ5yTpvp+Orcz5KixHQmc5tbkLWf x0n1QFc1xxJhbzN+r9djSGGN/5IBDfUqSANC8cWzHpWaHmSuU3JSAMB/N+yQjIad2ztTckZY pwT6oxng29LzZspTYUEzMz3wK2jQHw+U66qBFk8whA7B2uAU1QdGyPgahLYSOa4XAEGb6wbI FEE= Message-ID: <282da79a-eda7-f534-a6ed-8ac38fcc2c8b@web.de> Date: Sat, 25 Apr 2020 21:30:22 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:fB+rVVZJNRD3ane1aVJusEVoiTDTL4gCWWTmlkGc5gOFMDIwb/d jyMA4Jg2yiogJUGSY6Ah1XiOe1gXcXABJJbTsRQL/UXOoW4xOhM+jUkZF82QvyunQPt5HIT BkdchXYzKXlpCj03eKwyv8+XV9Lbcndu5LZy696IjtdevXepmWc8osEtwzkB1nVFxvhUTzt pWGEGeLz8QyGRbWyj66hw== X-Spam-Flag: NO X-UI-Out-Filterresults: notjunk:1;V03:K0:C24copa4gU4=:BGU01SMQm6FRl7p4kUKNMg 9UTb8ORH7Jvd+UHOY5zUS3RPoPNFVo8wahN6a95Lx0FT9cASiIH/zV5d/C3uRYqP2Yy3P97aL olYXkZllWzdobJ+GBcwoc3P4b8fRBtF68UPY6GE4lmHtefqnEiYiaN1kZTCuDyKnZMeHD7so1 HaBix501yRO0iezCbTeoIbrGL9mfX+WLcGcFNDH2eikzTfcjkZyeWERP9Uxb+kqS/HRnecWOG 5GfxU3Ql313Swnnf6TGVow49gUZ5DFW6lxucp92h7c8pTcv9/yW2cgaKxrtlFjDa2rUcVw5Pi DTqx3duFfImkbNczuZfUdUasS/IJ++YAMCilD9ZycdP+sHStnYpsIHl+Xq3T+xSasvORlLrle flBIeP8oqqzWY2fXraXQwHVmn9Px35bXmo5cTjQcnvlqzplUg69Cp7UQBv8eD2BXu2iZYQ5vx y6bYtrixMXMRIzK8rX/vr9ADX17IeSLRZdNzfz4gVX575mAoTFQLNsfVgi78TOi5I1zFYiljH m4vv/jvzeanm38QYvFJ18JbketMtRzhh2eocskfQ+4801yxf4Y69hdiq3cetHjp7p4ldriRry V3tfdB3j7wC97BKRi+uT3BXbkSutPt2KE4jGjiesgISoOy3hcJ6Zd5mIevxx+/xn4ErVuXDQX H9Ae502UTVcMHglzdUUAT7yi52RhdB8dNocwdJeSIOgiUz+7aya43sYauYP1by9w+sbunsAJn xEYWPj4qTm9uCXDBzUs1dbOhlSplMhIqA1mVEWihD4BOxX9bFRr6WJgCbRUV7gawb4GEpuM0p wiSnJ8EuzPVPXcSQex9tOZ2c33Zkel8bhFSok81+doe130YmRVZBbogHm/PVYJg+joVTVZjuG UCOXuf7+fpqYkHzremuI0MMan7p5I1GpASEGrUpctGMQNSeen9LMpAE9Ibhf6KPiQktLLhdT3 deeUrdzuko4VmqwywJZlxIhFg28k1UbDJeHxetc97h2Vsclwv6dJwadmb6R4JL7ADMzt1Hgw1 jYPCZX4Pfs+/nQ00C74W8jf0m9Fi1OY5cU/DeYsmfaeDreTqh5f3AS7JYXsX/IkZLnw4Wg4/7 dN3Al6nMWJo9MasdMYutUAauwMYNyQBmbU6Jqna5y8jBgZ0wXYQC7Qfo3z7sp42RxgO+tNzYt cZrGDwR7BpTiWH1VbmU8arpQUvvel6Jvt9lAB4FOUi6CZu01fy6XOE+lL5K2Y1LhcDx3Cw8q0 wppaFrAE5PCpEEZJc Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Fix this issue by jumping to "err_put_dma" label when those error > scenarios occur. I suggest to reconsider your jump target selection. =E2=80=A6 > +++ b/drivers/mmc/host/owl-mmc.c =E2=80=A6 > @@ -643,19 +643,22 @@ static int owl_mmc_probe(struct platform_device *p= dev) > return 0; > > +err_put_dma: > + if (owl_host->dma) > + dma_release_channel(owl_host->dma); I interpret the source code in the way that you would like to call this function for the desired exception handling only after a call of the function =E2=80=9Cdma_request_chan=E2=80=9D succeeded. Thus I would expect that the passed pointer will usually be still valid. (Can the proposed null pointer check be omitted then?) How do you think about the following change possibility? +err_release_channel: + dma_release_channel(owl_host->dma); Would you like to add the tag =E2=80=9CFixes=E2=80=9D to the change descri= ption? Regards, Markus