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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1B6FFC433EF for ; Fri, 18 Feb 2022 06:52:45 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 723476B0085; Fri, 18 Feb 2022 01:52:45 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 6D23F6B0087; Fri, 18 Feb 2022 01:52:45 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 525386B0088; Fri, 18 Feb 2022 01:52:45 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0187.hostedemail.com [216.40.44.187]) by kanga.kvack.org (Postfix) with ESMTP id 415586B0085 for ; Fri, 18 Feb 2022 01:52:45 -0500 (EST) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id EB99B181513A1 for ; Fri, 18 Feb 2022 06:52:44 +0000 (UTC) X-FDA: 79154982648.23.11EA3BB Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by imf08.hostedemail.com (Postfix) with ESMTP id 3420C160004 for ; Fri, 18 Feb 2022 06:52:44 +0000 (UTC) Received: from pps.filterd (m0246630.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 21I40cAo014586; Fri, 18 Feb 2022 06:52:32 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : content-type : in-reply-to : mime-version; s=corp-2021-07-09; bh=JaeNQQbs3Kcj356KJb+QfrR3oTp++/Mw0RtYqcRa1KI=; b=yLk9hf/f7WV5iB8ukJLpnnqwWRPtYnONYi1IHWQ3Fv/nmJp/Nrx5hibiWGcqIhTI2VlG +Wc3p9mK295gA+5r7p87d7998u9okDXxaTbEMDYeF9QhuewUNjuhOrUMKEYmFY3di+V5 /8FsiLeeg7D+TZm+EQucJfGj1eFmyPHpTxKf7Vb3O26ruC3dwTqsiEuBc6JjcNmjYWXU gQvID4R5WFyM8TA0PYek1K+kBOWPlZvA3bIaf2DFgEA1IraiI+5/+k7bo2yDn0bLXHB1 jf8AqsJSVfeA3ao34O6CutnfN/lmvidlfY06yhpXmPNwLKqcSJv7TbMguiHUAtl19bCu GA== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by mx0b-00069f02.pphosted.com with ESMTP id 3e8nb3r239-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 18 Feb 2022 06:52:31 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.1.2/8.16.1.2) with SMTP id 21I6kqpn148138; Fri, 18 Feb 2022 06:52:30 GMT Received: from nam04-bn8-obe.outbound.protection.outlook.com (mail-bn8nam08lp2047.outbound.protection.outlook.com [104.47.74.47]) by userp3020.oracle.com with ESMTP id 3e8n4wysd8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 18 Feb 2022 06:52:30 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=mrnlSO7Mh+RLiOe3GcqPQ0vUXQg8L26/uf2qlrM424ptaw5tGSCupeiNxBTS7kjPkRCPjdlduypsL5XLIvYDGptDb9PpY5zIBThQzol41JGqtu9hVPW+IzOF9TJRatVTvzEtdSkFvNM66+nAYsoZCOnXSdbyJbRmmjP02x/6b+4kGgkOPAgPRmHI5QQlmTkzGJow1o/p3fhta9Z6C4JwxEUEQAJkdA1whLWpGgxAf4MZxrxLHwdo6NOm8dz667eB6SsFgW8iRApYhsIpCkZW4M2uyinxs5VVvMCgzIrOWZbiGSt5T0TYBu8t6bQ/18GOJte3EfPkkKh99MFQ0U0Qbw== 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-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=JaeNQQbs3Kcj356KJb+QfrR3oTp++/Mw0RtYqcRa1KI=; b=GQO/5o24lfC2JQbr73P2Cjptle4ZeW2v5Ky88CGBL3najM/owRwyEFeXlDttlxLvSn2vOl48zISYK2Rhp6wlhCnifkg9GGCw4Xjv/oBtnljv7zyL3rEJZcQPtoB9g3kS57vGI4et3BYBpsW3seZfDd4yr2kYwdts9vx/mV9LxPvflQz5gnXdehYk1g0+evPTHw32wx8ak7PoFG0+pkFQ/Tm1Qs1V/M/WTKhwyRitAmxM8d2M/a3/BPv29G7bKGJPx3jUeaETj0B0To+RENZjSmypSmtWIA8PYJK3eg1ZFzmUxO+Jji+xrobCr5CbB+wsoOLWRNfDj9dY6pI68VDgxQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=none; dmarc=none; dkim=none; 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=JaeNQQbs3Kcj356KJb+QfrR3oTp++/Mw0RtYqcRa1KI=; b=DS4KTyw4jXozp7iwCW1sfHJ9gsjCYdzo89bGDBHBSnXOPzL1LuTo70H/P1J7y4jY/WfpwFoT4gSdsOJ6K6sh6QnQjONfEHoKUvlQFyYlvTgH15TLKnShZxZ78JgYhoEZspSa9fYCv3YyIYraPzrp1uD4dIGlzHjZ5nFPDWngq2w= Received: from MWHPR1001MB2365.namprd10.prod.outlook.com (2603:10b6:301:2d::28) by MW5PR10MB5690.namprd10.prod.outlook.com (2603:10b6:303:19b::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4975.15; Fri, 18 Feb 2022 06:52:28 +0000 Received: from MWHPR1001MB2365.namprd10.prod.outlook.com ([fe80::2c3d:92b5:42b3:c1c5]) by MWHPR1001MB2365.namprd10.prod.outlook.com ([fe80::2c3d:92b5:42b3:c1c5%3]) with mapi id 15.20.4975.019; Fri, 18 Feb 2022 06:52:28 +0000 Date: Fri, 18 Feb 2022 09:52:10 +0300 From: Dan Carpenter To: liuyuntao Cc: mike.kravetz@oracle.com, akpm@linux-foundation.org, baolin.wang@linux.alibaba.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, yaozhenguo1@gmail.com Subject: Re: [PATCH] hugetlb: clean up potential spectre issue warnings Message-ID: <20220218065210.GD2467@kadam> References: <20220217234218.192885-1-mike.kravetz@oracle.com> <20220218034025.17687-1-liuyuntao10@huawei.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220218034025.17687-1-liuyuntao10@huawei.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-ClientProxiedBy: JNAP275CA0057.ZAFP275.PROD.OUTLOOK.COM (2603:1086:0:4f::9) To MWHPR1001MB2365.namprd10.prod.outlook.com (2603:10b6:301:2d::28) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: c2843a23-cd51-49a5-2e31-08d9f2ab3a6a X-MS-TrafficTypeDiagnostic: MW5PR10MB5690:EE_ X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:2733; X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 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:MWHPR1001MB2365.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230001)(7916004)(366004)(8676002)(38100700002)(2906002)(44832011)(38350700002)(33716001)(8936002)(5660300002)(33656002)(6666004)(53546011)(52116002)(186003)(86362001)(66476007)(66556008)(66946007)(1076003)(6512007)(26005)(9686003)(4326008)(508600001)(6916009)(316002)(6506007)(6486002)(83380400001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?hogEFMn+VaSAktoIavsTudNloOHnU1Yu0mBBrxKjbeuAYWnAjT/HgwBCRz6D?= =?us-ascii?Q?Tg01nOkZRKRngN+cDvpaI2+HioHC38e14wX8TPFpkwUF6KLeiIqyYMIlbfKb?= =?us-ascii?Q?DwBLfutonMwkRI9i45ERYW5lRhkRAHF53Ag3z/GLHWvwe9YFBzyInjUweLRo?= =?us-ascii?Q?cRpA3JKQ8ty91ghc/VGiPnwh2FapvF5KRs4yfOGuqi06iocuRQsB826kzsPT?= =?us-ascii?Q?rxj2bcWhObds2VXQ09ZAA3po77R6N2WotGBj17/4bIhbTmWmElul22TODLmk?= =?us-ascii?Q?rAJXQhM0vCILZbu+5l0KRiU8efHFyoHHdsijax/z2NZVpnuvo4yM/lyDKM3i?= =?us-ascii?Q?L1Tkc/glVmRfOg1LefhD1BpZpriIn07uT2w+hYfRuKlGxjbJdy3MruSB2ylB?= =?us-ascii?Q?JS0faKmYiTBxnv249zRyAwYtOTiwqMJL15huGIiOA+yA5xEZr8zBAuFcoo05?= =?us-ascii?Q?jcshmTqr6D7WZXx+2DCyHAVTCWBOJ4k9RNzy42msJFEWbkOEOlU3RFKdrS4i?= =?us-ascii?Q?Am2oKO9uoiH820L5Bo36ZJJVVRUIVVcS/mJlTvlsktJFHt6xB9DAS4vZKfgG?= =?us-ascii?Q?50ZYCoMq+q4VWimEIaYX4ZGVK4+EOPwIQAyYXUMoj6otk/78Uuz7/Gfq1pwx?= =?us-ascii?Q?3zncDwyjvRriZ2YHh2HHwGayvVfRhIwBrNUK10t9tMe91lQ0lPVjAhl2WiM5?= =?us-ascii?Q?1zy9SdfgS0SlctiBV5jCvOn8P9txQD+D7fTZvbnfRkHH7vCV1Q1L07nDLM+3?= =?us-ascii?Q?iBzHM7kj3zOPcD8spLvY7X7yJUbg6AopArVdFdfLrFabaTcPI3W45Zce6cMP?= =?us-ascii?Q?VyabkIk2pTjl0syZ/qKqFyS+qoDdVkfV/hHuOWptft6yGNo/Vvmm6xY5mfyu?= =?us-ascii?Q?oJCOCJhuJOmcnJPKPGxqMwNPGdDWB6tHCiJ8CQQjgE07+3NLhkKdnysjooyQ?= =?us-ascii?Q?dhl8wCOIIcyFvJVGGWYcuOO+28C9xUCC+VtyTYYPHIGfBrVje2xQ1SAjxvnZ?= =?us-ascii?Q?6PLtBejGqW61CP5+ovaSZFOZZ4dR56Za5IWTWboTLMnXdEkFVCOT7J1yBjXJ?= =?us-ascii?Q?QNSf5cAi2HYCuYRXkQ0L2nwwWPiBz9Q5OxJMrHAhaSXLC8xaCvPy9hc0IEmf?= =?us-ascii?Q?kuNDYJnDyfIfQAEdp6JUSAHdtKJaKfydf4g5JDzn1n+DChKfuI4mDMACUIYV?= =?us-ascii?Q?/d24aulp22UfGAu43Scf2h1r/uzC8IAYbXwxymhtWcDrtlVXtIewB9AtGutA?= =?us-ascii?Q?NlFWE3It4CqjaV0NbR+skurWINibjDNd/AZ72+nbTudIj60pdzWrjK5oHeLJ?= =?us-ascii?Q?AxvCQy+O/y5MvFMF5x1NQ48uQXGx/y9eLW9FRqoKfFr9XBZ0ceBKhlJ5G5RA?= =?us-ascii?Q?PDaAPwzgk99u+5uBrh3e/c/xzIpNtLgtZxmMDheopNFLeZsZvBoQNXyk8Ya8?= =?us-ascii?Q?VJ4T2jeUTCw+Etv+yizCJWMvzzEJ1vPrHpZg8DRlxGGLpi+gdJHq7CamtYys?= =?us-ascii?Q?8pUxUE8Z6xfmUhgxR1ys4S8Remj79YSRvjQYPnIJmxbrVRSGQ9U4hBj5aZZh?= =?us-ascii?Q?ga7vbNQbthLVUlfQHq2tCVTPBnsEm6rFbkEQao/GbcxNlx9H+h2ylOFyXyAF?= =?us-ascii?Q?NgDn3jeupzC7jDIXTvao2fwp4adKAI1UF7wdhmJqZwLQVqBglQlXpOEedkgF?= =?us-ascii?Q?A1G66w=3D=3D?= X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: c2843a23-cd51-49a5-2e31-08d9f2ab3a6a X-MS-Exchange-CrossTenant-AuthSource: MWHPR1001MB2365.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 18 Feb 2022 06:52:28.5345 (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: Qi0gH3QDaeyOh4qe2P3cCs/3OCc4NNwGMD3MhlS3FyPmjleTUtDQP48daqq1QnxVoAiMTdhUfSrvmVKFOtvzg8Nd0Agmm9uvfIySU9QO3W8= X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW5PR10MB5690 X-Proofpoint-Virus-Version: vendor=nai engine=6300 definitions=10261 signatures=677564 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 suspectscore=0 spamscore=0 phishscore=0 bulkscore=0 mlxlogscore=999 mlxscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2201110000 definitions=main-2202180040 X-Proofpoint-GUID: ZiuUeCTyQwF8MCqYkpw7ghLRXnH8-uzM X-Proofpoint-ORIG-GUID: ZiuUeCTyQwF8MCqYkpw7ghLRXnH8-uzM X-Rspamd-Queue-Id: 3420C160004 X-Stat-Signature: ugyd9c8hppgs71kzuse1mryppx4nrimg X-Rspam-User: Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2021-07-09 header.b="yLk9hf/f"; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=DS4KTyw4; spf=none (imf08.hostedemail.com: domain of dan.carpenter@oracle.com has no SPF policy when checking 205.220.177.32) smtp.mailfrom=dan.carpenter@oracle.com; dmarc=pass (policy=none) header.from=oracle.com X-Rspamd-Server: rspam05 X-HE-Tag: 1645167164-587809 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Feb 18, 2022 at 11:40:25AM +0800, liuyuntao wrote: > On 17 Feb 2022 15:42:18 -0800, Mike Kravetz wrote: > > Recently introduced code allows numa nodes to be specified on the > > kernel command line for hugetlb allocations or CMA reservations. The > > node values are user specified and used as indicies into arrays. This > > generated the following smatch warnings: > > > > mm/hugetlb.c:4170 hugepages_setup() warn: potential spectre issue 'default_hugepages_in_node' [w] > > mm/hugetlb.c:4172 hugepages_setup() warn: potential spectre issue 'parsed_hstate->max_huge_pages_node' [w] > > mm/hugetlb.c:6898 cmdline_parse_hugetlb_cma() warn: potential spectre issue 'hugetlb_cma_size_in_node' [w] (local cap) > > > > Clean up by using array_index_nospec to sanitize array indicies. > > > > Signed-off-by: Mike Kravetz > > --- > > mm/hugetlb.c | 7 ++++--- > > 1 file changed, 4 insertions(+), 3 deletions(-) > > > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > > index 1f0cca036f7f..6b14d0791cb4 100644 > > --- a/mm/hugetlb.c > > +++ b/mm/hugetlb.c > > @@ -31,6 +31,7 @@ > > #include > > #include > > #include > > +#include > > > > #include > > #include > > @@ -4161,7 +4162,7 @@ static int __init hugepages_setup(char *s) > > } > > if (tmp >= nr_online_nodes) > > goto invalid; > > - node = tmp; > > + node = array_index_nospec(tmp, nr_online_nodes); > > p += count + 1; > > /* Parse hugepages */ > > if (sscanf(p, "%lu%n", &tmp, &count) != 1) > > @@ -6889,9 +6890,9 @@ static int __init cmdline_parse_hugetlb_cma(char *p) > > break; > > > > if (s[count] == ':') { > > - nid = tmp; > > - if (nid < 0 || nid >= MAX_NUMNODES) > > + if (tmp < 0 || tmp >= MAX_NUMNODES) > > Here tmp is unsigned, no need to check if less than 0. > Do we really have any automated checking? lol > Smatch ignores checks for negative when it's part of a clamp test. In this situation the check for negative is obviously harmless so a warning is a false positive. If you wrote it the other way: if (tmp >= MAX_NUMNODES || tmp < 0) then Smatch would print a warning because I try not to get involved with style debates but I really don't like that style... :P regards, dan carpenter