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=-5.2 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 690C6C00A89 for ; Fri, 30 Oct 2020 14:12:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0A6FC20725 for ; Fri, 30 Oct 2020 14:12:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726841AbgJ3OMO (ORCPT ); Fri, 30 Oct 2020 10:12:14 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:43114 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726178AbgJ3OMN (ORCPT ); Fri, 30 Oct 2020 10:12:13 -0400 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 1kYV8U-0006ee-Tl; Fri, 30 Oct 2020 14:12:10 +0000 To: =?UTF-8?Q?Martin_Hundeb=c3=b8ll?= From: Colin Ian King Subject: re: spi: bcm2835: fix gpio cs level inversion Cc: Mark Brown , Florian Fainelli , Ray Jui , Scott Branden , bcm-kernel-feedback-list@broadcom.com, Nicolas Saenz Julienne , Gregory CLEMENT , linux-spi@vger.kernel.org, "moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" Message-ID: Date: Fri, 30 Oct 2020 14:12:10 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.3.2 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Static analysis with coverity on today's linux-next has detected a potential issue in bcm2835_spi_setup() in the following commit: commit 5e31ba0c0543a04483b53151eb5b7413efece94c Author: Martin Hundebøll Date: Wed Oct 14 11:02:30 2020 +0200 spi: bcm2835: fix gpio cs level inversion The analysis is as follows: 1191 static int bcm2835_spi_setup(struct spi_device *spi) 1192 { 1193 struct spi_controller *ctlr = spi->controller; 1194 struct bcm2835_spi *bs = spi_controller_get_devdata(ctlr); 1195 struct gpio_chip *chip; 1. var_decl: Declaring variable lflags without initializer. ... and later on ... Uninitialized scalar variable (UNINIT) 9. uninit_use_in_call: Using uninitialized value lflags when calling gpiochip_request_own_desc. [show details] 1262 spi->cs_gpiod = gpiochip_request_own_desc(chip, 8 - spi->chip_select, 1263 DRV_NAME, 1264 lflags, 1265 GPIOD_OUT_LOW); The call to gpiochip_request_own_desc passes the uninitalized lflags down to gpiod_configure_flags: int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, 3698 unsigned long lflags, enum gpiod_flags dflags) 3699{ 3700 int ret; 3701 3702 if (lflags & GPIO_ACTIVE_LOW) 3703 set_bit(FLAG_ACTIVE_LOW, &desc->flags); 3704 3705 if (lflags & GPIO_OPEN_DRAIN) 3706 set_bit(FLAG_OPEN_DRAIN, &desc->flags); so this looks like lflags needs to be initialized with something legitimate, probably zero? Colin