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, 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 36605C43611 for ; Wed, 12 May 2021 20:36:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 19C6A611F0 for ; Wed, 12 May 2021 20:36:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345932AbhELUhW (ORCPT ); Wed, 12 May 2021 16:37:22 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:40109 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241307AbhELUN6 (ORCPT ); Wed, 12 May 2021 16:13:58 -0400 Received: from 1.general.cking.uk.vpn ([10.172.193.212]) by youngberry.canonical.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.93) (envelope-from ) id 1lgvDi-00051o-1p; Wed, 12 May 2021 20:12:38 +0000 To: Yang Li From: Colin Ian King Subject: re: ASoC: q6dsp: q6afe: remove unneeded dead-store initialization Cc: Mark Brown , Srinivas Kandagatla , "Banajit Goswami , Jaroslav Kysela , Takashi Iwai , alsa-devel@alsa-project.org, "linux-kernel@vger.kernel.org" Message-ID: <5935b287-5b74-84ac-3470-3b71fd69c88c@canonical.com> Date: Wed, 12 May 2021 21:12:37 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Static analysis with Coverity on linux-next has detected an issue with the following commit: commit 5f1b95d08de712327e452d082a50fded435ec884 Author: Yang Li Date: Sun Apr 25 18:12:33 2021 +0800 ASoC: q6dsp: q6afe: remove unneeded dead-store initialization the analysis is as follows: 1181 int q6afe_port_stop(struct q6afe_port *port) 1182 { 1183 struct afe_port_cmd_device_stop *stop; 1184 struct q6afe *afe = port->afe; 1185 struct apr_pkt *pkt; 1. var_decl: Declaring variable port_id without initializer. 1186 int port_id; 1187 int ret = 0; 1188 int index, pkt_size; 1189 void *p; 1190 1191 index = port->token; 2. Condition index < 0, taking false branch. 3. Condition index >= 127, taking false branch. 1192 if (index < 0 || index >= AFE_PORT_MAX) { 1193 dev_err(afe->dev, "AFE port index[%d] invalid!\n", index); 1194 return -EINVAL; 1195 } 1196 1197 pkt_size = APR_HDR_SIZE + sizeof(*stop); 1198 p = kzalloc(pkt_size, GFP_KERNEL); 4. Condition !p, taking false branch. 1199 if (!p) 1200 return -ENOMEM; 1201 1202 pkt = p; 1203 stop = p + APR_HDR_SIZE; 1204 1205 pkt->hdr.hdr_field = APR_HDR_FIELD(APR_MSG_TYPE_SEQ_CMD, 1206 APR_HDR_LEN(APR_HDR_SIZE), 1207 APR_PKT_VER); 1208 pkt->hdr.pkt_size = pkt_size; 1209 pkt->hdr.src_port = 0; 1210 pkt->hdr.dest_port = 0; 1211 pkt->hdr.token = index; 1212 pkt->hdr.opcode = AFE_PORT_CMD_DEVICE_STOP; Uninitialized scalar variable (UNINIT) 5. uninit_use: Using uninitialized value port_id. 1213 stop->port_id = port_id; 1214 stop->reserved = 0; the commit removed the initialization of port_id = port->id, and now we have a regression where stop->port_id is being assigned with a garbage uninitialized value in port_id. Perhaps the fix needs reverting. As it stands, I don't know why clang was reporting this as an error. Colin