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, 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 16AA4C433ED for ; Tue, 18 May 2021 18:52:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DED9061261 for ; Tue, 18 May 2021 18:52:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351673AbhERSyH (ORCPT ); Tue, 18 May 2021 14:54:07 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:59376 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234553AbhERSyG (ORCPT ); Tue, 18 May 2021 14:54:06 -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 1lj4pj-00005U-AM; Tue, 18 May 2021 18:52:47 +0000 To: Ansuel Smith Cc: Andrew Lunn , "David S. Miller" , "linux-kernel@vger.kernel.org" From: Colin Ian King Subject: re: net: dsa: qca8k: handle error with qca8k_read operation Message-ID: <41e1a058-4c13-479d-68aa-2b017fda95fe@canonical.com> Date: Tue, 18 May 2021 19:52:46 +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 of linux-next with Coverity has found several repeated issues in the following commit: commit 028f5f8ef44fcf87a456772cbb9f0d90a0a22884 Author: Ansuel Smith Date: Fri May 14 22:59:55 2021 +0200 net: dsa: qca8k: handle error with qca8k_read operation The issues are as following: 322 for (i = 0; i < 4; i++) { 323 val = qca8k_read(priv, QCA8K_REG_ATU_DATA0 + (i * 4)); Unsigned compared against 0 (NO_EFFECT) unsigned_compare: This less-than-zero comparison of an unsigned value is never true. val < 0U. 324 if (val < 0) 325 return val; 326 327 reg[i] = val; 328 } ... 397 /* Check for table full violation when adding an entry */ 398 if (cmd == QCA8K_FDB_LOAD) { 399 reg = qca8k_read(priv, QCA8K_REG_ATU_FUNC); Unsigned compared against 0 (NO_EFFECT) unsigned_compare: This less-than-zero comparison of an unsigned value is never true. reg < 0U. 400 if (reg < 0) 401 return reg; 402 if (reg & QCA8K_ATU_FUNC_FULL) 403 return -1; 404 } 478 /* Check for table full violation when adding an entry */ 479 if (cmd == QCA8K_VLAN_LOAD) { 480 reg = qca8k_read(priv, QCA8K_REG_VTU_FUNC1); Unsigned compared against 0 (NO_EFFECT) unsigned_compare: This less-than-zero comparison of an unsigned value is never true. reg < 0U. 481 if (reg < 0) 482 return reg; 483 if (reg & QCA8K_VTU_FUNC1_FULL) 484 return -ENOMEM; 485 } 508 reg = qca8k_read(priv, QCA8K_REG_VTU_FUNC0); Unsigned compared against 0 (NO_EFFECT) unsigned_compare: This less-than-zero comparison of an unsigned value is never true. reg < 0U. 509 if (reg < 0) 510 return reg; and many others too. There similar issues with commit: commit ba5707ec58cfb6853dff41c2aae72deb6a03d389 Author: Ansuel Smith Date: Fri May 14 22:59:54 2021 +0200 net: dsa: qca8k: handle qca8k_set_page errors for example: 162 val = qca8k_set_page(bus, page); Unsigned compared against 0 (NO_EFFECT) unsigned_compare: This less-than-zero comparison of an unsigned value is never true. val < 0U. 163 if (val < 0) 164 goto exit; I suspect there are many others. So perhaps a review of recent patches on this driver would address this unsigned less than zero compare issues. Colin