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=-6.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,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 D2F21C4361A for ; Thu, 3 Dec 2020 18:25:41 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 56266207D0 for ; Thu, 3 Dec 2020 18:25:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 56266207D0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=canonical.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=VK06m+lu+okAi8FGyuLw0OWUm4kacGPvtk36u87hark=; b=iQik/vZVeuqHXcBUN0rUYprwL OqvHy1RKBDdTq44cBArAjFKv2p5LMYgN/aY4t0uS/AezDwXDlPtWv7Mt5isZcYta5rX08f1qm7Znd ghIpN/unrqCdWXPOTLBvyCo3PRLhVjr7di+Z6vO0gSJJhrUHOliLeeYTVycfpoOrBb/rxmxpeo/LF L/GTDaVKxfoUy1va+c/kS3U4UiZNqflHfRnxyznGcg5X1bn8MEaAbNBBN+Okdu3CIHHwB1FdZ93eu eTE7twU86Jch/9rA7mlziRdibV2l9kR4pmBv/Io7F1ga9kjUeSmpWZBe32b1cpb3SQztAQGsOOELm 6/KluOxZg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kktHM-00028X-0z; Thu, 03 Dec 2020 18:24:32 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kktHI-00027H-L9; Thu, 03 Dec 2020 18:24:29 +0000 Received: from 1.general.cking.uk.vpn ([10.172.193.212]) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1kktHG-0000p3-Ro; Thu, 03 Dec 2020 18:24:26 +0000 Subject: Re: media: i2c: add OV02A10 image sensor driver To: Andy Shevchenko References: <9af089ea-2532-68ac-5d22-97a669ccec91@canonical.com> From: Colin Ian King Message-ID: <8eb453c7-a221-e741-5fe5-655e59075f34@canonical.com> Date: Thu, 3 Dec 2020 18:24:26 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201203_132428_829946_1B6C8E03 X-CRM114-Status: GOOD ( 20.34 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mauro Carvalho Chehab , "linux-kernel@vger.kernel.org" , "moderated list:ARM/Mediatek SoC support" , Dongchun Zhu , Sakari Ailus , Matthias Brugger , Andy Shevchenko , "linux-arm-kernel@lists.infradead.org" , linux-media Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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. Given that ret is currently not initialized when we hit: if (ov02a10->streaming == on) goto unlock_and_return; either we initialize ret to 0 at the start of the function, or do: if (ov02a10->streaming == on) { ret = 0; goto unlock_and_return; } (assuming the intention is to return zero for this specific case). Colin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel