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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D81C2C433F5 for ; Sun, 22 May 2022 09:08:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242785AbiEVJIQ (ORCPT ); Sun, 22 May 2022 05:08:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34338 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240935AbiEVJIN (ORCPT ); Sun, 22 May 2022 05:08:13 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D8C18344EB for ; Sun, 22 May 2022 02:07:59 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 5693DB80ACC for ; Sun, 22 May 2022 09:07:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 52A0EC385AA; Sun, 22 May 2022 09:07:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1653210476; bh=Tnd9k7iRjgfdcQgXzfq2JZ4qYtO5XwbTFBmo19t2jIA=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=S8xXimqwBxzn98bU6z1yaq8fOwEkP+dYMHN4eCURaFRz1fCsgAvfxI9/nsO9Umk+2 SA1sZoI38b6YE61f3Lya/sy7xMavAKqSUYWRuKg3zXQwN9jIf337VBGkqckkyI6Yco gFjd7P1zz1tNPnfmBUGwqel+eI3I5ACsqtRgOrSnpcMl2Jdjh7+joPY4TioEsLFQ// i8+ZpTnOSrNQWUuShcWtDsJuzaS41D/07R1BjG1RnAXK/cpBCEnrasRXZqNAi4iMpU 8ZNZzzXyYbLAEbPAbWYRW0XdJWbCqEIedtT3HnQ4A7UsGV2LLJGCTYJiF4ZSTiQc0a NdZYWnmCuBQjQ== Message-ID: Date: Sun, 22 May 2022 11:07:52 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.8.1 Subject: Re: [Ksummit-discuss] uninitialized variables bugs Content-Language: en-US To: Dan Carpenter , ksummit-discuss@lists.linuxfoundation.org, linux-kernel@vger.kernel.org Cc: Nathan Chancellor , kbuild@lists.01.org, lkp@intel.com References: <20220506091338.GE4031@kadam> From: Krzysztof Kozlowski In-Reply-To: <20220506091338.GE4031@kadam> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/05/2022 11:13, Dan Carpenter wrote: > There is also stuff like this which is harmless: > > uint val; > > ret = read(&val); > *p = val; // <-- uninitialized variable if read() fails > return ret; > > Btw, here is how to run Smatch on your code: > https://staticthinking.wordpress.com/2022/04/25/how-to-run-smatch-on-your-code/ In the topic of suppressing false positives we also have several "fixes", sometimes pointed out incorrectly by Coverity, for missing check for of_device_get_match_data(). Compare: https://elixir.bootlin.com/linux/v5.18-rc7/source/drivers/clk/clk-aspeed.c#L415 https://elixir.bootlin.com/linux/v5.18-rc7/source/drivers/clk/clk-oxnas.c#L216 Although in theory the of_device_get_match_data() can return NULL, in practice it is not possible because driver matches via OF thus there will be always of_device_id->driver data. Coverity screams about it, people fix it by adding checks for NULL, which is pointless. Half of drivers add the !NULL check, half do not... Best regards, Krzysztof