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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_MED autolearn=ham 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 D9CEDC4321E for ; Mon, 10 Sep 2018 19:07:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 79C9320855 for ; Mon, 10 Sep 2018 19:07:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amdcloud.onmicrosoft.com header.i=@amdcloud.onmicrosoft.com header.b="HgARmtkj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 79C9320855 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=amd.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728506AbeIKACe (ORCPT ); Mon, 10 Sep 2018 20:02:34 -0400 Received: from mail-eopbgr720059.outbound.protection.outlook.com ([40.107.72.59]:59392 "EHLO NAM05-CO1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728020AbeIKACe (ORCPT ); Mon, 10 Sep 2018 20:02:34 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amdcloud.onmicrosoft.com; s=selector1-amd-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=uycPB46MNyw/n+/CEBpB7zv7VOZU15zsccrZt1ElfhQ=; b=HgARmtkjqLRQzu7ZKn52qSj1ssIvqH7S56oydsnbQdJCpi5/a8hIKnuo6Kj7XVY8OL5T934o6L8ILI2iv920XyfZNs6J3hwK4zZfAInU9b7PRtDbKaCsy0vpKvsv643aSx3WpSo3Zq5hIfBJCD7ogpuLKCaigpIk77j2cIJxvAM= Authentication-Results: spf=none (sender IP is ) smtp.mailfrom=brijesh.singh@amd.com; Received: from [10.236.136.62] (165.204.77.1) by DM6PR12MB2682.namprd12.prod.outlook.com (2603:10b6:5:4a::31) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.1122.16; Mon, 10 Sep 2018 19:07:01 +0000 Cc: brijesh.singh@amd.com, linux-crypto@vger.kernel.org, thomas.lendacky@amd.com, Gary Hook , Herbert Xu , linux-kernel@vger.kernel.org Subject: Re: [PATCH crypto-2.6] crypto: ccp: add timeout support in the SEV command To: Borislav Petkov References: <1534367485-4386-1-git-send-email-brijesh.singh@amd.com> <1534367485-4386-2-git-send-email-brijesh.singh@amd.com> <20180904081151.GC32615@zn.tnic> From: Brijesh Singh Message-ID: Date: Mon, 10 Sep 2018 14:06:57 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20180904081151.GC32615@zn.tnic> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [165.204.77.1] X-ClientProxiedBy: SN4PR0501CA0034.namprd05.prod.outlook.com (2603:10b6:803:40::47) To DM6PR12MB2682.namprd12.prod.outlook.com (2603:10b6:5:4a::31) X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: d54cfff7-987f-482f-ab1a-08d6175096d2 X-MS-Office365-Filtering-HT: Tenant X-Microsoft-Antispam: BCL:0;PCL:0;RULEID:(7020095)(4652040)(8989137)(4534165)(4627221)(201703031133081)(201702281549075)(8990107)(5600074)(711020)(4618075)(2017052603328)(7153060)(7193020);SRVR:DM6PR12MB2682; X-Microsoft-Exchange-Diagnostics: 1;DM6PR12MB2682;3:+eTb7XcDKrKBfvT103wNmZNBZrk3QyxPa6F+ESA4/leY42vVzXh3SCAtt8IVrktpGdHiF48K4vY1nOzLxCN3iMYJM9sNAx2JgLzOfrqEYNW5lb7ioZ8xeto18jZcg00HVsLqLw/5Swc8/YH/aEL6zBkzRCTA+OV7I8EyBbQgc42LCXNY7xk/rbFGaOoayJvS1XNktf2+wLNaQXBKmY8UjyuzG4eENQkjYbAkNH2zA4P5hbublaNrteb0PdbGLXbE;25:EeLliV/ocrk+7yr5e7YxwscQjuXtiQ/stnbjbuaPoN/tN2MhKArhyctiCTeeMYfIClYuZVKimd9xYg2EMNceQOR3DJn2Twxv8ECdwP3xXb8zBGycf1OkJpx3vyBjw/WFT1YxEfDfBtdTVYAGNwAhHP2IiJ/ExZXwPgWVv9gX++qw2Mu9XJ7YSsQeZ0WkWFoeOK7xFLW6E15zMjUbg1NZwE2h/gNZwRZ3BfZLYI+5wNkrk2BCCDNUirBIE/nBa6QhrAd89YqCrP8SWlCpRxigHeeCms2+PnNokVxyCnSAcgmnBlro6RJDvIVPjf4cbAXu3ypPwpRbod7Y8ZxssS1wmA==;31:dup+ZneE+xOv2fsF87xa8oIkxA3s86Bk2WYAj6P60zcsln5x6RSE8aOnsEOCClkiQwQNpTOV5S3Z6a50hvJF5/prPxzj5W2G+VKLimqKOxB/gsRXABpi5AgJTmBgFdqfPay7Phf5eG8aOdSok5vZ93/+JIT6RLZmxsgXyDDvNScRQEbXOcFA6GUgkWYwbuvoE+V6VPuwJBJ5e02g5wqGqmbMxLQRarhAMjS79pgIiik= X-MS-TrafficTypeDiagnostic: DM6PR12MB2682: X-Microsoft-Exchange-Diagnostics: 1;DM6PR12MB2682;20: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;4:XaJx0075oweJX6aLmJeoTyAerYoUujpMBrL5NbzvuFG5hsZQzGEf9gghkz4qlL+Qfvnc+sxFSf8riq+Ze/j2kHvLsCMz+zBSdDJLBfWZzW8y6yH7EANSYytRKPMjIi2kA80lwIy0wWBUFaJ2WWacUnvmZ2CA9jIZ+FU67ABmCCv8mvjpCzMX7nmft2TBkNakrbzp1FUoRfu5C5bMrb7cQxheArI2BMdfbm6QjOuC9dLHHlBWwd4rE+RDmP5I/bwzNrcKIor/TDiYSgr4ccd+PQ== X-Microsoft-Antispam-PRVS: X-Exchange-Antispam-Report-Test: UriScan:; X-MS-Exchange-SenderADCheck: 1 X-Exchange-Antispam-Report-CFA-Test: BCL:0;PCL:0;RULEID:(8211001083)(6040522)(2401047)(5005006)(8121501046)(93006095)(93001095)(3231311)(944501410)(52105095)(3002001)(10201501046)(6055026)(149027)(150027)(6041310)(201703131423095)(201702281528075)(20161123555045)(201703061421075)(201703061406153)(20161123560045)(20161123564045)(20161123562045)(20161123558120)(201708071742011)(7699050);SRVR:DM6PR12MB2682;BCL:0;PCL:0;RULEID:;SRVR:DM6PR12MB2682; X-Forefront-PRVS: 07915F544A X-Forefront-Antispam-Report: SFV:NSPM;SFS:(10009020)(6049001)(366004)(39860400002)(376002)(346002)(396003)(136003)(199004)(189003)(446003)(25786009)(81166006)(956004)(2616005)(8936002)(81156014)(476003)(7736002)(305945005)(65956001)(16576012)(316002)(66066001)(65806001)(36756003)(2906002)(6246003)(97736004)(31696002)(478600001)(44832011)(4326008)(11346002)(8676002)(64126003)(486006)(86362001)(50466002)(5660300001)(31686004)(53936002)(53546011)(67846002)(229853002)(2486003)(186003)(52116002)(16526019)(52146003)(23676004)(54906003)(58126008)(47776003)(76176011)(77096007)(26005)(68736007)(230700001)(105586002)(386003)(6916009)(106356001)(6666003)(65826007)(3846002)(6116002)(6486002);DIR:OUT;SFP:1101;SCL:1;SRVR:DM6PR12MB2682;H:[10.236.136.62];FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;A:1;MX:1; Received-SPF: None (protection.outlook.com: amd.com does not designate permitted sender hosts) X-Microsoft-Exchange-Diagnostics: =?utf-8?B?MTtETTZQUjEyTUIyNjgyOzIzOmNSdnZzSDZtQjJZRmV6RVAzcEJXY1FZbHVD?= =?utf-8?B?ek5tYXB6SW1GVlo3eWFaZVhBQ0Y5c0xmRFFqeHIvaUVWWHFYNytPWHB0UnYy?= =?utf-8?B?cjhrRWdzeEdwVlltTyt0SXpYYTV3UjBGV1dtTGhMbjNpdlZpVWFvUnM0UHpE?= =?utf-8?B?bjJ5cG9Na2QrQzN3aktOU3A5YTZPWFZXRUFqSGFOWnE0bEg5bTZTM0ZYWFpS?= =?utf-8?B?YnVZbVF2U1pPaGc5N1lveVd1bC9zSFhNT2FvRlZvbFNDemg0NVVWR0UwMUVW?= =?utf-8?B?SEEwSnMvNnc2czNiS1BaMmp4K1NqOXVXOG52bHFJU0pDVDFZK3FhM1dXamR4?= =?utf-8?B?aHp6Nm9WS3ZYVE1BcTRRN0xxVlFtZDk3cVZmcXdKMWN3NG9QTHU5ZEtQMVFh?= =?utf-8?B?dU5zb2NKUk9za1RZbzQvTFhGUklzdU52RkV2dWJZeUV3Q0NQWG40ZnRheWpS?= =?utf-8?B?TWNIUTNaSUVNd1ZnVVNRV0tObWVBYjRqSlBXSS9QazlJam9BY2JNOE9qeXlE?= =?utf-8?B?Sys3SUZHaFpxNTZkNVRYWDArZzgyL2hQTnlEU2lKcUNzSjRDTXZ6QURKYzNY?= =?utf-8?B?R2tCbTU1NUcwN0lUY05ObHZ3UWNCSkxPRkZZWUpkTmxVaVZtOVRScTBLc1JE?= =?utf-8?B?bmdjMERHUjRBRmVHUS9UcEZpRk5wTlVJVkp4Q2QyWkpvZWt4MjhVSlZwT1VK?= =?utf-8?B?MElaeXM3aU9ZYUJzR1VGVjJqY0srejlwcUgvUG00NVRBMmlMa2dOUzgrUXI4?= =?utf-8?B?ZkpiUnYzNFJXR2kybExXWXlSRE8vMk9mZlJHYnlLNk9tdGJaY0xtODBUc0RB?= =?utf-8?B?bGVrN0FrQjk4TE1zUjl2T1pLQ21jZmJrYytOeDhEclEyODNrT1BTd2ZLRlRi?= =?utf-8?B?elRVQnBUY01ZM2dwelI1WENsckZjQkV5MUU2V204VWZmcEdHdjIrdzA4NVJh?= =?utf-8?B?MkszOGVXMWRIazYybmlJVnArRVp2YUQ4dXB3UlBZc1dFMTZHN2FaR1RVK0g0?= =?utf-8?B?UDc0Z1RBL0tsTkJzaGR4b3NPWHZobitZVFhzaC9EVEZhNHlhbEZjSjlLd3Ba?= =?utf-8?B?aVpyQThPWFE2eHBUSE5KbGdtTjR0OTZRNERqRm8yS3p0NFlPank2RUhIemRU?= =?utf-8?B?UVpYRU5GR1hSQXYrRkdkTG1EbmxNc2FvZ0RnQTROZWhLTk51eHhvaUtDVFVy?= =?utf-8?B?aUZpQk9VQjhOSldEY29FY3RueHFBcUJscG1TWjJ1c3Y4cjcyWTlnR0ZBNVlJ?= =?utf-8?B?YTRhc1JFYmM1N0tma2V4c3FLdFpCam5LTCs1amdscjFGTXhxNkUzdThJVXdx?= =?utf-8?B?OGhuWXdnT1RtYXBnVGFmQXpuZ3FMRTNGS3ljcVJRTUdPai94TGdablpjdktB?= =?utf-8?B?MXkyVk10TVdyc0lxVXprOHQ3SjkwWTRxYVcwQm9sUkRiRzB3VXk4TlZiK2VX?= =?utf-8?B?VmNSZjVXcG9XZkxFMHNmVmpTbTBCUDdRL0FFVEdSejZ0Yzg5RHNNdzZ0Zzht?= =?utf-8?B?Mjk4VkxNcWdlSUdpcml0OEwzdURXWCtOaHVyWWh3bUhBdXNhWnQrNmkzUFpE?= =?utf-8?B?OENuU1F6WVh1NEtOZGs3YWlPV245UWRRem5vWEpUK0pJZytURklDc01XNlcz?= =?utf-8?B?V1dLNUQyN3puWnVXUGpGZTlkcUNTZTR0azYzL2tPcExHeC9wcXNrNEJTbk4x?= =?utf-8?B?SUJNQkRLMHByc2hvbE9TTjZod0VCSGFUcHQzTEhaOCt3di93cGtiU3hGYzZr?= =?utf-8?B?N2tWOW82Z2UvTU16ME5SYmtMeEQwNy9SbGdNY2RuN3dIdFV3SjdGRjkybW9l?= =?utf-8?B?MFVvdHlEbk0xd3BxZWtQU1ZwL0F6YVlmUnlZV3YzY1l4LzZ4LytybFFHOHk4?= =?utf-8?B?eU9KVC9RQkkwQTNNNVRXcERsbVRBaS9PUW13Q2JOYjUrQXZiU09kYnFHRVBR?= =?utf-8?B?MDJnbUxnc0dWRkwxT05qa0RzWHpjYUlTd21YOHBSL1dLSlpEb1IyQ3RJWkIr?= =?utf-8?Q?SjFXGb?= X-Microsoft-Antispam-Message-Info: luDzmn4CChqHlTByt1q3zsBzZaFQ9f5e5KpDtP5A0MbfiMFyVN3CqVB3R5y4gIL8vN3vdOjWHquJ7AKTTd3LtPB1bawBGkXD5fyQaoLCPtkufdosA1ccdB/TBFPpLrAll4Wx+JmmcTlw53KmTRwYc+8xck6cP9+FjBaysZt97CH4u83+p0JGfPExthywa00sG0yv597/1sZKBaC2OOVT7qeszTAmyO+UI+NIGtYSM3lmX9d4gNGJB0Alzl2jaW5M2V/GwWEy8A4NR9L39PfLNkbu9wLnwW/pqR++oksrOP3NfON6ojO0ORjux9ovMZT2SRtwkCQdjP+WLCkjXVE7YMLwSCQ4TR8PTfm9R65jIwQ= X-Microsoft-Exchange-Diagnostics: 1;DM6PR12MB2682;6:sGyP5POPR9kHsaQcBAdzvsyFCgrTqshHBGUdtRgawz4j/FjUsplpuCfDbwmS+QYruOBZvZpWOAIzzML/xccp7dxaZod7W6fkmmCYjeX1gokZmm38cgnJipBzrZMwrp2djtAYOK5vNl+fQmHOgSD9O5jkOs6hX0iLVoSpLZO8qXLB5KRhs3+aHC5l6XeGVYJogqGFkKls4DFS9Zgi4DddrzpzBWc3CrDY3Nh0aS2GNwsUZJ06LystXAnkqUcKFuEXikkzkSn2xNuqGeuYtGjcS7woYzvJ2ZOVlCpY1i68Eg50tvDMNfcUStdiV5B2tl6ShR87Q0w7WlWbgQ0jg3stTa2MUvpJMWsY6hxqUo8J8XAvBFRczgREcW4rf/aikWxjl0gxPrbqnCQDUzV0SIcQYLY71xmDIY+2zPEO/Kf4ev7fAIByzUeNV12BW95A6AGmuEjuYuEUBD49yik1SRbzLA==;5:PZ41VnpT77VzyGyuZzkG9xdDX8owyOMqBzIIRPWU/rwsyoaYPFM9Ggh6Jgqbk0mj1RD4rdyUtLL43g6nekrHJOzlZTx6cIR2i2P5Nf5iebv/R/BFSSVMlOhQ8JV8HTWoxZMkqJRyB8MmxFz7nxKVwCi3keZ5dvu29Y5VfGI1/e4=;7:XUBKi2cZnJY7aIroz/uhZcrSdvDpOH6RTVL5qusXjeE+cbg7sAxmltEcSXDTr2wvBJTBhAZSYzc5SC7S6Q5zIgoV6u1/vVzUI8UeOElkXLVrsYKz65gy6gJxYCvaUe+ECU/x9Qa3IL058FCMPrNL6uljJ8kOnELkJ7BNogfKrlwxM7AbThnCbo4SsULhLRu6CQIPdlsZ9u7GfEVfV7MHS+lBh6FSC5Z1vqTFdhWZlhOVymwkoA7TSpDxB0gn7zy3 SpamDiagnosticOutput: 1:99 SpamDiagnosticMetadata: NSPM X-Microsoft-Exchange-Diagnostics: 1;DM6PR12MB2682;20:iGVZ2MoWXLjPQlO5Y8CaqIF+hKQfvpko2W/ELnfAIMuigIKajMTPhZfiJOTcEiNkb7C8Ki3WFTP8Uo6cvRjrSPul/dVXLPjr1m7MB2CbYQMWTNPC0/lqTs41Bmvw1AKAmiSeTu2Z9GfnNI86o/2sCF9ZraN5s42wnt0u/chhIS3dpYbPOvGgkAAk8Zfm0vx+MRO5gOxVOLItR/aLWsx/98ndYw42Ffe7qc8TiJHC2W8dnbMYyfZluGjQ0ksicyJe X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Sep 2018 19:07:01.0322 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: d54cfff7-987f-482f-ab1a-08d6175096d2 X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR12MB2682 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Boris, On 09/04/2018 03:11 AM, Borislav Petkov wrote: ... >> + >> +static int psp_probe_timeout = 5; >> +module_param(psp_probe_timeout, int, 0644); >> +MODULE_PARM_DESC(psp_probe_timeout, " default timeout value, in seconds, during PSP device probe"); > > Just a question: what prevents the user from supplying non-sensical > values here? > > I think we should clamp them to only allowed values because I don't want > to be debugging some strange bugs due to that. > Nothing prevent user from supplying a bogus number. The main question is, clamp with what number ? IMO, if user is overriding the default timeout number then its possible that user is dealing with a buggy firmware which does not work with default timeout and silently clamping the value will not help them. - Brijesh