From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 658BFC4361A for ; Fri, 4 Dec 2020 11:47:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 31ABC22A84 for ; Fri, 4 Dec 2020 11:47:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728962AbgLDLrU (ORCPT ); Fri, 4 Dec 2020 06:47:20 -0500 Received: from mga11.intel.com ([192.55.52.93]:58576 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727100AbgLDLrS (ORCPT ); Fri, 4 Dec 2020 06:47:18 -0500 IronPort-SDR: 6O3PvRfDTG3ErnCOeapQceG0wI9dCTLys2MAn4LnuSnfP83fBmtQgj0EbmaKk6ltubhl4j2thT obkKr8zWry1A== X-IronPort-AV: E=McAfee;i="6000,8403,9824"; a="169857506" X-IronPort-AV: E=Sophos;i="5.78,392,1599548400"; d="scan'208";a="169857506" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Dec 2020 03:45:37 -0800 IronPort-SDR: slZITTdZZgS3TJf6ncwEHOUcWPDqpSd03g7ZcabsatqOfCMNKSDL+aDwvNNYba732ekCMsLipC j1fMqV9PYD6g== X-IronPort-AV: E=Sophos;i="5.78,392,1599548400"; d="scan'208";a="482361261" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Dec 2020 03:45:34 -0800 Received: by paasikivi.fi.intel.com (Postfix, from userid 1000) id 5DF3720676; Fri, 4 Dec 2020 13:45:32 +0200 (EET) Date: Fri, 4 Dec 2020 13:45:32 +0200 From: Sakari Ailus To: Andy Shevchenko Cc: Colin Ian King , Dongchun Zhu , Andy Shevchenko , Mauro Carvalho Chehab , Matthias Brugger , linux-media , "linux-arm-kernel@lists.infradead.org" , "moderated list:ARM/Mediatek SoC support" , "linux-kernel@vger.kernel.org" Subject: Re: media: i2c: add OV02A10 image sensor driver Message-ID: <20201204114532.GT852@paasikivi.fi.intel.com> References: <9af089ea-2532-68ac-5d22-97a669ccec91@canonical.com> <8eb453c7-a221-e741-5fe5-655e59075f34@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 03, 2020 at 08:30:03PM +0200, Andy Shevchenko wrote: > On Thu, Dec 3, 2020 at 8:24 PM Colin Ian King wrote: > > On 03/12/2020 18:10, Andy Shevchenko wrote: > > > On Thu, Dec 3, 2020 at 8:03 PM Colin Ian King wrote: > > > > > >> Static analysis on linux-next with Coverity has detected an issue with > > >> the following commit: > > > > > > If you want to fix it properly, see my comments below... > > > > > >> 529 static int ov02a10_s_stream(struct v4l2_subdev *sd, int on) > > >> 530 { > > >> 531 struct ov02a10 *ov02a10 = to_ov02a10(sd); > > >> 532 struct i2c_client *client = > > >> v4l2_get_subdevdata(&ov02a10->subdev); > > >> > > >> 1. var_decl: Declaring variable ret without initializer. > > >> > > >> 533 int ret; > > >> 534 > > >> 535 mutex_lock(&ov02a10->mutex); > > >> 536 > > >> > > >> 2. Condition ov02a10->streaming == on, taking true branch. > > >> > > >> 537 if (ov02a10->streaming == on) > > >> > > >> 3. Jumping to label unlock_and_return. > > >> > > >> 538 goto unlock_and_return; > > >> 539 > > >> 540 if (on) { > > >> 541 ret = pm_runtime_get_sync(&client->dev); > > >> 542 if (ret < 0) { > > > > > >> 543 pm_runtime_put_noidle(&client->dev); > > >> 544 goto unlock_and_return; > > > > > > Instead of two above: > > > goto err_rpm_put; > > > > > >> 545 } > > >> 546 > > >> 547 ret = __ov02a10_start_stream(ov02a10); > > >> 548 if (ret) { > > >> 549 __ov02a10_stop_stream(ov02a10); > > >> 550 ov02a10->streaming = !on; > > >> 551 goto err_rpm_put; > > >> 552 } > > >> 553 } else { > > >> 554 __ov02a10_stop_stream(ov02a10); > > >> 555 pm_runtime_put(&client->dev); > > >> 556 } > > >> 557 > > >> 558 ov02a10->streaming = on; > > > > > > (1) > > > > > >> 559 mutex_unlock(&ov02a10->mutex); > > >> 560 > > >> 561 return 0; > > >> 562 > > >> 563 err_rpm_put: > > >> 564 pm_runtime_put(&client->dev); > > > > > >> 565 unlock_and_return: > > > > > > Should be moved to (1). > > > > > >> 566 mutex_unlock(&ov02a10->mutex); > > >> 567 > > >> > > >> Uninitialized scalar variable (UNINIT) > > >> 4. uninit_use: Using uninitialized value ret. > > >> > > >> 568 return ret; > > >> 569 } > > >> > > >> Variable ret has not been initialized, so the error return value is a > > >> garbage value. It should be initialized with some appropriate negative > > >> error code, or ret could be removed and the return should return a > > >> literal value of a error code. > > >> > > >> I was unsure what value is appropriate to fix this, so instead I'm > > >> reporting this issue. > > > > > Not sure I fully understand how that fixes it. > > If you are not sure and have no means to test, then don't bother. This > is not the priority driver anyway. Arnd sent a patch to address this: -- Sakari Ailus