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=-10.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,MSGID_FROM_MTA_HEADER,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 B935CC433B4 for ; Tue, 13 Apr 2021 04:52:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9A15D6120E for ; Tue, 13 Apr 2021 04:52:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230191AbhDMEwt (ORCPT ); Tue, 13 Apr 2021 00:52:49 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:51668 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230157AbhDMEwp (ORCPT ); Tue, 13 Apr 2021 00:52:45 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 13D4jXvv068137; Tue, 13 Apr 2021 04:52:21 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=to : cc : subject : from : message-id : references : date : in-reply-to : content-type : mime-version; s=corp-2020-01-29; bh=6eq4oEvPiEf9Sf08lZVeJ+920VGVPJTDCpZkBBlVTCs=; b=hmCmsfqr12ImaqTFztY6C5Y3yDg/B6BWgVH4huM5avU6JyKHkwVF0gzCPpUIwwuIoUzJ d1n2NV9WaMGdRla+7sEBJO+9W01/lIosTf1HK6IPVAstyyiAB/wtlg8Tu7S3TZCF6500 ucZpEHESI1Rxg3Vap6bx21ES8++7LKMFshPzhSkjDNJEkzh9C9gu4AJ0WbnRxMUp4fSx PQiQYOCDLjngBwgbGwMZD2M/D08dXS3xH3sFCGBtqKKbUNM4/G/ZnHe8tIkQrr1RO49u bQ7IVHaUbNDNEAFZlyPb/nd5QsJarUkcx7j0iExumnvi7uzatvtO1wmQndjCGGJT8Wyr fg== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2120.oracle.com with ESMTP id 37u4nndqgb-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 13 Apr 2021 04:52:21 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 13D4oJ2Y111959; Tue, 13 Apr 2021 04:52:21 GMT Received: from nam11-bn8-obe.outbound.protection.outlook.com (mail-bn8nam11lp2174.outbound.protection.outlook.com [104.47.58.174]) by userp3030.oracle.com with ESMTP id 37unxwch0t-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 13 Apr 2021 04:52:21 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=QJAmqLvrUoYjhz/8DdSD20vonKzyMzklGA3RLkBSzhpoPKgCbTjOu0wUhdriVdR7PLARaRxONICbCweNK4UYEpTZZTGkQHW5qztl7InNTBo9bJoFmVR2s90csh/gaKRgTcB29RCNZ6ex0D2zbaKL5i2fs69E/7K+oHpzufveBVoGK0v0APoP8PbRyUF84MF8bJYSPRL5kXIE2cvdxxdV6jzjMqYxlCjk+TNHoKiwyoZUZFaeztr/QDix8aFmQUs+Nmn1m8ULSgqH5b+B52DfDRQEv+QWuYgP7U6vTo+7S0Q/b4J3DHiaCtGCHJBPjj/WEte547K4sCqJERU8BzxGqA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=6eq4oEvPiEf9Sf08lZVeJ+920VGVPJTDCpZkBBlVTCs=; b=jMLKs/wSP6MIPhR0NciTRhhtyWl30xzg7yyDuxOjAMKtITx8zQeBUlbvLBow7bn6E9hoW5vMtsOpAg0uyWdDdYF3fmxFbiNjcfFDxvKg5XHB2Ty6QnlzUMi11f052RWJSREN1A6i4wPEF7VxgdJpj44JvYQhKuoI0Db2woBF+Yp7CGmX/0Qu825QH95c332VhB7MkCdBrfi8M0vYSjZNN/mdFffLMEeH0OdXpypcmgWamwrkOQOC2laJLNJtJJT+Bo0Q6MOpukaeU86tfdyM4BsmIsjo5f//xc7KKgM6AiggXWVTyA74Q4Q7tt8PSvcojGTGBFPC+pzobyQR0dJOUg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oracle.com; dmarc=pass action=none header.from=oracle.com; dkim=pass header.d=oracle.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=6eq4oEvPiEf9Sf08lZVeJ+920VGVPJTDCpZkBBlVTCs=; b=Di3ZYqbfW9kLsHtYLgViol2oJ2wBYlGZj1oqW11jxfDMnLDUIcbFmXoeVIHhdG49Om7L7CHJDjShXGQJf151c5VeSsbV/pDbouMH2+XU1hgWvGTW1LyKZhdW9RUXtkxVsh5MU5WpqPBgtoZOBFiQFEMahxLpAU8RIrigt/X5fhw= Authentication-Results: chromium.org; dkim=none (message not signed) header.d=none;chromium.org; dmarc=none action=none header.from=oracle.com; Received: from PH0PR10MB4759.namprd10.prod.outlook.com (2603:10b6:510:3d::12) by PH0PR10MB4774.namprd10.prod.outlook.com (2603:10b6:510:3b::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4020.17; Tue, 13 Apr 2021 04:52:19 +0000 Received: from PH0PR10MB4759.namprd10.prod.outlook.com ([fe80::9ce3:6a25:939f:c688]) by PH0PR10MB4759.namprd10.prod.outlook.com ([fe80::9ce3:6a25:939f:c688%4]) with mapi id 15.20.4020.022; Tue, 13 Apr 2021 04:52:19 +0000 To: Kees Cook Cc: "Gustavo A. R. Silva" , Adaptec OEM Raid Solutions , "James E.J. Bottomley" , "Martin K. Petersen" , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH][next] scsi: aacraid: Replace one-element array with flexible-array member From: "Martin K. Petersen" Organization: Oracle Corporation Message-ID: References: <20210304203822.GA102218@embeddedor> <202104071216.5BEA350@keescook> Date: Tue, 13 Apr 2021 00:52:16 -0400 In-Reply-To: <202104071216.5BEA350@keescook> (Kees Cook's message of "Wed, 7 Apr 2021 12:22:52 -0700") Content-Type: text/plain X-Originating-IP: [138.3.200.58] X-ClientProxiedBy: BY5PR20CA0017.namprd20.prod.outlook.com (2603:10b6:a03:1f4::30) To PH0PR10MB4759.namprd10.prod.outlook.com (2603:10b6:510:3d::12) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from ca-mkp.ca.oracle.com (138.3.200.58) by BY5PR20CA0017.namprd20.prod.outlook.com (2603:10b6:a03:1f4::30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4020.17 via Frontend Transport; Tue, 13 Apr 2021 04:52:18 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 5409df9c-b585-441e-0e28-08d8fe37eadb X-MS-TrafficTypeDiagnostic: PH0PR10MB4774: X-MS-Exchange-Transport-Forked: True X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:8882; X-MS-Exchange-SenderADCheck: 1 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PH0PR10MB4759.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(136003)(346002)(396003)(366004)(39860400002)(376002)(26005)(4744005)(478600001)(66556008)(66476007)(55016002)(316002)(66946007)(5660300002)(8676002)(2906002)(38100700002)(16526019)(4326008)(38350700002)(186003)(83380400001)(86362001)(956004)(54906003)(6916009)(52116002)(7696005)(36916002)(8936002);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData: =?us-ascii?Q?pg1blMOHhp5AH/yK9e0+MYNQx8qn3t/A/Xo9/2fBqWQXSQ3xWwcRAZg+sNjt?= =?us-ascii?Q?DmDmGT4rjSCIgSJlZJ2DTYe/tRDDj5mrj8P0lzBBrxxPstr4OqfXyKa3jOWm?= =?us-ascii?Q?JPYUjItiVu/dGpcfB8W0n7tStX/UzU1wEjuLCXERTGMtI9vcvDYZ8YF9/z/H?= =?us-ascii?Q?rmKbcmUJN2W3eGz0x6f3bZ41CYOBKbah+jkEpRx624VHBFrN2eGvAC0MG0qP?= =?us-ascii?Q?HinqBF5r8+sFEIiGJ0vWVxBNLNvcV3Cp1SzP/ue9qYQ4KfGVpGYfIYwn4sis?= =?us-ascii?Q?lJAPxpyb3zGrOSJtLeDKlAwBMOi1UqejsOMUzH35kcZS2UEnYth01vYfqiAD?= =?us-ascii?Q?e7L8h0lYJeHD9DO0Qt9FiET+wxfIe1E6RXgePTEs13FWofc93lw+0aL8vHdk?= =?us-ascii?Q?+AVwT9e4W8xEPi7JpY7hRV0oPLaBhY9p+wk79W2v/UIs055aJrTv5ur9yh5p?= =?us-ascii?Q?TtUxCa7+0WfgfMS8QIKXgK32B9EFe89kdYmWmjupnJ3UsqfwM7MR+vKKDMwb?= =?us-ascii?Q?fCnpDRTIb3eo/qboZAnBGxqy0Z53cHeC8ygjwLqC9vZgukzJQAfdDshyo5OS?= =?us-ascii?Q?kQiD5n7ifdSFpPJH9UOu9xuhSH63ZDBCZ3LewTAuqMOiENnm+Z3tT3CuCqsA?= =?us-ascii?Q?vohMITphwAUkzB/GfLGyE/SMVmcJB+z5I4N5864x/crP9kcLen4ru7+xeBbB?= =?us-ascii?Q?FmX0NMg1AppxcpzRJRw4wXMn67qnPf69TkSlB44F0oiGdR86/RSXpGCf2ft9?= =?us-ascii?Q?UKmJ/d0Sdxj6xgB567f7EW8LD7qTFYUpovXjQn6OhkL4UnH2IxFAmo7HAOdJ?= =?us-ascii?Q?MIROlVPDW3T4elbu6VMZwu4aDaTEOZp57Bnz4eXNf3Xw35lcgXCtDR8NAbJD?= =?us-ascii?Q?kr8iuUojiM9BqdwlPBhJn0K7YhMDtoIOwOOwWsNys/NKVsQKgKCep+ylEUUT?= =?us-ascii?Q?v9lRNgQf2vl+z2uaX9hnaK8U1CaZZ8D6jM91hMH+vFNBBkfA1mKGWL8iI1FD?= =?us-ascii?Q?vgcnupneI6EA9ycCjnRNH5UEd8BR24sUpHxKX35Ohhpu0PjQI0bG9QHqKZdl?= =?us-ascii?Q?eDrqO9ygogxRlP/8FWH4/Xz0I9Xy2Ah8IGczMMCx+gdIF8hH9VcSyA1xoPQP?= =?us-ascii?Q?OLge5cMesNrAyezxaK32tudAZjcF4OmAJYfWXeSJb9tgaaJ87HH728CWziWU?= =?us-ascii?Q?DwxZJgSw7k+2+MJfBhVDL8TgMmq9RtFlzdXSgE3sr24v/oxEhicBfdeWexZU?= =?us-ascii?Q?y947OE4hbGjgCCJDuciHBnPIXI6VMBRnZa7T9x8qxiRfIq8NPcGX1vRlgWNG?= =?us-ascii?Q?T4GxqiHE65zu+0d5BBxmlgo/?= X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: 5409df9c-b585-441e-0e28-08d8fe37eadb X-MS-Exchange-CrossTenant-AuthSource: PH0PR10MB4759.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Apr 2021 04:52:19.1468 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: z1txcgvyaTdQaAn7TqwI7oS8VFtn0mGhzlNz6OeHmQ259EZJYtQkg+TKfwrAeCJoJPBUo9nhVdGuWTpr3Np4Yg2RoVfSDXSXoLEtw0XX1As= X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH0PR10MB4774 X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=9952 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxscore=0 bulkscore=0 malwarescore=0 spamscore=0 adultscore=0 phishscore=0 mlxlogscore=999 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104060000 definitions=main-2104130031 X-Proofpoint-ORIG-GUID: GNbMjlXz7ddO4DkzAqjBK_Tmbh1GXETc X-Proofpoint-GUID: GNbMjlXz7ddO4DkzAqjBK_Tmbh1GXETc X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=9952 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 malwarescore=0 phishscore=0 suspectscore=0 mlxlogscore=999 priorityscore=1501 clxscore=1015 lowpriorityscore=0 spamscore=0 impostorscore=0 bulkscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104060000 definitions=main-2104130030 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Kees/Gustavo! >> @@ -4020,7 +4020,8 @@ static int aac_convert_sgraw2(struct aac_raw_io2 *rio2, int pages, int nseg, int >> } >> } >> sge[pos] = rio2->sge[nseg-1]; >> - memcpy(&rio2->sge[1], &sge[1], (nseg_new-1)*sizeof(struct sge_ieee1212)); >> + memcpy(&rio2->sge[1], &sge[1], >> + flex_array_size(rio2, sge, nseg_new - 1)); > > This was hard to validate, ... which is why I didn't apply this patch. I don't like changes which make the reader have to jump through hoops to figure out what the code actually does. I find the original much easier to understand. Silencing analyzer warnings shouldn't be done at the expense of human readers. If it is imperative to switch to flex_array_size() to quiesce checker warnings, please add a comment in the code explaining that the size evaluates to nseg_new-1 sge_ieee1212 structs. -- Martin K. Petersen Oracle Linux Engineering