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 DEEC0C021B2 for ; Tue, 25 Feb 2025 17:21:04 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 59912280008; Tue, 25 Feb 2025 12:21:04 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 521AC280003; Tue, 25 Feb 2025 12:21:04 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2FEE6280008; Tue, 25 Feb 2025 12:21:04 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id E886E280003 for ; Tue, 25 Feb 2025 12:21:03 -0500 (EST) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 907DB1618E8 for ; Tue, 25 Feb 2025 17:21:02 +0000 (UTC) X-FDA: 83159132364.06.2454DA7 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.10]) by imf14.hostedemail.com (Postfix) with ESMTP id C4EE1100011 for ; Tue, 25 Feb 2025 17:20:58 +0000 (UTC) Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=B8cOgchV; arc=reject ("signature check failed: fail, {[1] = sig:microsoft.com:reject}"); spf=pass (imf14.hostedemail.com: domain of maciej.wieczor-retman@intel.com designates 198.175.65.10 as permitted sender) smtp.mailfrom=maciej.wieczor-retman@intel.com; dmarc=pass (policy=none) header.from=intel.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1740504059; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=1/cpoIsYVvxpIH7OKvm3BOMOiT0hT9QBOTbltxVXxI4=; b=f1nAw2BGTlBjjzp5VgfY3zRgZgQ9EGcmzDBaVT4j2U00c0ZNgzJyqiTlkJTQpBNLsue3aL oF6Hdv5NdJQND7T8ugVUb5ir86pLxWwAmZWQW+tNyNWNn4Sy1ZTT4VlXWLWv2pUszRSOH4 fYdOaoalejOeeMIz7vKixzUtGf27dpE= ARC-Authentication-Results: i=2; imf14.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=B8cOgchV; arc=reject ("signature check failed: fail, {[1] = sig:microsoft.com:reject}"); spf=pass (imf14.hostedemail.com: domain of maciej.wieczor-retman@intel.com designates 198.175.65.10 as permitted sender) smtp.mailfrom=maciej.wieczor-retman@intel.com; dmarc=pass (policy=none) header.from=intel.com ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1740504059; a=rsa-sha256; cv=fail; b=G2+6pZ7s8KXXohubmE0lmnwRfGSJbnRWzrkZQdgZjwcFgc8s/8qzig+uqO9ESSDfPX7rQK m2ePGVPsgKomZCDsSKEKAEjwS3l73FUcUBAOc6/51k9GOmUspWSvugyLM6z/+EWKpV8acQ QTLLtPHLMAI3k5rjGSca1lnJ0aoRNNY= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1740504059; x=1772040059; h=date:from:to:cc:subject:message-id:references: content-transfer-encoding:in-reply-to:mime-version; bh=zVU+CVh7piZ16jAYzN0dNc5E4Y4V7w7AeoHFT6R72mk=; b=B8cOgchVixgj/0jWsPLjRo41/ORM44HFxlROktjTQQXGS3l74BBZLONM jgohw8WoWZnz9TsQN5TeTwjarl9RGMpmEyJWPDJqc1gwX8cM8aZQ84T0J dE1sAgw8MU/Q/5rRHQzvaGHNRP1yhjVZLQasBEMxMNx2KH5cEUytrrAFI /Gh303T9XOprcNK3m5mej687/6cXbmfUGIRrWwxkQEoZfjka6A1uVhdQw EjEJWLDdLJt0l/PL4XF0Sz75hf7HsiDJinNWEW4MLR9Nd0DfKp/L+2snQ JFoDs05FNRLGy3hieisLbpJtDj4lKAv+we3lZWzMSjHmAeO0Np4IPqIWu A==; X-CSE-ConnectionGUID: mN40xsD6R8eWjUEz38Y0wQ== X-CSE-MsgGUID: B60dC4lrTeKDz+0ttsrkKA== X-IronPort-AV: E=McAfee;i="6700,10204,11356"; a="58743445" X-IronPort-AV: E=Sophos;i="6.13,314,1732608000"; d="scan'208";a="58743445" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by orvoesa102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Feb 2025 09:20:44 -0800 X-CSE-ConnectionGUID: CiLY/ECrSCWQcxz1khAMoQ== X-CSE-MsgGUID: XeqWG7b2TMOsghRHpWtf4Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.12,224,1728975600"; d="scan'208";a="120561981" Received: from orsmsx601.amr.corp.intel.com ([10.22.229.14]) by fmviesa003.fm.intel.com with ESMTP/TLS/AES256-GCM-SHA384; 25 Feb 2025 09:20:38 -0800 Received: from ORSMSX901.amr.corp.intel.com (10.22.229.23) by ORSMSX601.amr.corp.intel.com (10.22.229.14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.44; Tue, 25 Feb 2025 09:20:32 -0800 Received: from orsedg603.ED.cps.intel.com (10.7.248.4) by ORSMSX901.amr.corp.intel.com (10.22.229.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.14 via Frontend Transport; Tue, 25 Feb 2025 09:20:32 -0800 Received: from NAM11-DM6-obe.outbound.protection.outlook.com (104.47.57.171) by edgegateway.intel.com (134.134.137.100) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.44; Tue, 25 Feb 2025 09:20:29 -0800 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=i87VsXYvDW5jbNbxOIC8xS4SlE0mdXcXaFBiYQcPMMgb4rlGxHxegnVlwhfDTBkrNF86mipOuds3el78k1sXfOXhjbF5RF1uFu9kpMYZKnTYlr7krbjf7Q1z1O6jlOvhmiK9scZ10HdkmalITd83ge0K7WWfzCkZBa0+UjizyFFhiQWcv5M0D7Kkj8iO1lGn6+G1lg9ReIFkUrkHlGbOVe0uOAa0awrGumsKAXfRb6Y0YwjaGad1xnBZSUP7I2oX3YQb1toajrqvILQnAYaWnPb1/8+un7f0Ul0IuKXtvTsB7f2Z/6oID7AaEBEqmm092Cf5cPKgxI0PDXURRrqaiw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; 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=1/cpoIsYVvxpIH7OKvm3BOMOiT0hT9QBOTbltxVXxI4=; b=DEgxyAl4+qTdfOJanLuQOkYrobCEILRvDz76Vs/9J/1HxVgMRloTCQj3DF4q/lX4y3Q48Q3+aO3yseQfLxc68FZ9Y2IxFtKqrKrIkHKU7ruBqnqMeDG0lEV8M36nUf333mEKpIQGkwKZzM0YjIzk2X1O7Q2qkoOECE8B0uZahsQIP+vGFDYuMgeKi5LVJggCJZpMhIn5s+JfTW4F1q/GhJH7ZItfIs7vdFbHFHelVy12VbobPh9kdHGSpFzQKcdYzbONG8gDPnM0qij2noTzDJhcmuViXa2YGnaRLVP3IDfIoMBnn8p7qi3vvjHcKBJs5uh2+PrDYpQVCOicqNW65w== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=intel.com; dmarc=pass action=none header.from=intel.com; dkim=pass header.d=intel.com; arc=none Received: from MN0PR11MB6231.namprd11.prod.outlook.com (2603:10b6:208:3c4::15) by IA1PR11MB8864.namprd11.prod.outlook.com (2603:10b6:208:597::11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8466.20; Tue, 25 Feb 2025 17:20:21 +0000 Received: from MN0PR11MB6231.namprd11.prod.outlook.com ([fe80::a137:ffd0:97a3:1db4]) by MN0PR11MB6231.namprd11.prod.outlook.com ([fe80::a137:ffd0:97a3:1db4%4]) with mapi id 15.20.8466.016; Tue, 25 Feb 2025 17:20:21 +0000 Date: Tue, 25 Feb 2025 18:20:08 +0100 From: Maciej Wieczor-Retman To: Andrey Konovalov CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: Re: [PATCH v2 01/14] kasan: sw_tags: Use arithmetic shift for shadow computation Message-ID: References: <168f775c4587f3a1338271390204a9fe16b150dd.1739866028.git.maciej.wieczor-retman@intel.com> Content-Type: text/plain; charset="utf-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-ClientProxiedBy: DUZPR01CA0027.eurprd01.prod.exchangelabs.com (2603:10a6:10:46b::14) To MN0PR11MB6231.namprd11.prod.outlook.com (2603:10b6:208:3c4::15) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: MN0PR11MB6231:EE_|IA1PR11MB8864:EE_ X-MS-Office365-Filtering-Correlation-Id: 5c6b65d1-d4f3-40dd-c950-08dd55c0ae8c X-LD-Processed: 46c98d88-e344-4ed4-8496-4ed7712e255d,ExtAddr X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|1800799024|366016; X-Microsoft-Antispam-Message-Info: =?utf-8?B?Y016VWZOclU1MkNxcG9waGVRM1Z5VVY5eFZRc2lCZjFwZDEzbXRTdFF1U0NG?= =?utf-8?B?YlpieklHVk1RKzY2ZlNvK2JmMkNGTDhraGZSZitZdEhQQVRRNDExdEN4Wnho?= =?utf-8?B?ZGNHTmRzc01CaEo2ZHd5Q2RhVmFmWUhZYlVsME1MbnhvOVlrYVk5YkcrK0VO?= =?utf-8?B?OG9FZkM4M01KNDZiekY1UkNjVDVUZ0h3aDJzSnpVT0pJUnRNNkRJYjZGNXZi?= =?utf-8?B?eTJjZ0VyUklxcHRvb3hvS1dFdXBpdkRvWlcrRGFLMU1zQ1NoYkJGUWUwclQ5?= =?utf-8?B?OG5FVUZwaXpYMDErKzlMVEhubXBTRHQ3TFFETlhrRmRHL0ZGU1VxemY0c2pl?= =?utf-8?B?S3BuaTRVSmllMEtnMFhNODh6WFRVcG9WMFk5Nlcrc1M4a2hQQ1p6VlRqcmNN?= =?utf-8?B?Yzk3d0ZYY3AwaEFaNDBvUzNHMWFPc3RUS3A4SVBuUTNtNkR5K2VHUWw3UFA2?= =?utf-8?B?eUtOMlVBZTNiRWw2YkNlcEQ5Yy9XcVNGNWZHaHdueWw0QkxubE9odm1Ybm1L?= =?utf-8?B?MXZmd1ZqTmkwMkExeWhnWmJWNVR6NzhkMUlGU0NENHFOQ3g4dGhtd1I1eHJN?= =?utf-8?B?QjFha0JZR3lqSVdVSThZY0IzM0N6amVhcTg3TlBYSDdtWUdsazFpM1ZJSXA2?= =?utf-8?B?K0M3d2VKYVk4YTlLS2pqakhyMWE3OWFqR29tV240c2NKd2ZiYXFCT3FwTTlZ?= =?utf-8?B?Qk1GeUJxeDZjTTRXVWozR2hobGloS1pnVUdFMlRnbVh0WTd1Sm9BL0wxbHB5?= =?utf-8?B?eWtxZnprZHpDRkhRTi9naG9mZjRTaXg4NnZtY0lqSmZ4b203RlExYmpRWXJh?= =?utf-8?B?azIzOWRlSFliSE9UUUJIOFAzS2xQanFwL2c4N3V5QjY4YkhiZGNSS1B5QmY0?= =?utf-8?B?bmFZWjdLeEpFa2dMV2R2QmJjNzdjUWZEa1M1N0Vaa2tGYnpBRnZSZnRzeHQw?= =?utf-8?B?cmFZY1d2cWx0S2dYcmcvdWZrOHJHUTZKWGp6RmQ1SmNuOFk3UEkvRHJyWmwr?= =?utf-8?B?RkpGT2pNd28wZ0pCZmkyQkRYNy8xRDdJZG9HL1RQZnRucjBGNEVpUWxVckNY?= =?utf-8?B?UWlmcWh5Z0tDMmkyVTNEbWF4cVA3R1dGNGIyaWZxQlVxdGVkS1lFMC9tRVla?= =?utf-8?B?L0s3Vy9CdzBZR21wZHlUYkp0V3liYUdDdGdDOHRCMjR6bjMyWFBHVWh4VG9B?= =?utf-8?B?UXRVRGhlY240UmsvMzFrVFZNRG1aZzkvRnZZUDIvMlhLNVlhcUFhMnp5YVZJ?= =?utf-8?B?empMcTdpN1d3cHJGeGxKcWJCVFp3L2F3b2NETFdJc0E5WHppSE5pR3d4MzYv?= =?utf-8?B?QmdaZ1VhMzV6TWlCdTRsUWMzemp5MUV4cDVxT0tBbHpHWnBQdWFZU09JWTFZ?= =?utf-8?B?SXRWVVA2blJxTERrdlhHWmxqdTVhazdndStrZGtXWU5FanNFVVh2YkJqMDBs?= =?utf-8?B?bkZFVFl3Rk5KU0w0LzZ6VzhNZ1MzTmY1TUVuQ202cXQ3S25wTEVwbkw2TWtV?= =?utf-8?B?UnpjZGdzV1BTR2dDVHB1RXdqdDlnaTk4NmpXbEprc0dEV0tYbGExV0Q5WWxC?= =?utf-8?B?aDJTT1hQV29sdjlaZUF3ZGFseFh4NUZhSWZ0aGtGOXNUTmloeFVMakNTT3JW?= =?utf-8?B?alkxYkdVU3ZNQXFvUzFoRWhnWUNTVlZkaTN1ZTQzSWxCa1hXdGdTWjU0QXd0?= =?utf-8?B?Q1psbG5YRXlGUGRiS1NVVSs0N1RYdmZPbFRYeVZISFpCUEVQUHJnei9kZjVl?= =?utf-8?B?UFQzeUlkNUQ0Q3lGS2wyNEFyN1M3dVlKeVM0NDV5MUlFbVVqU21ldFBvWnhN?= =?utf-8?B?b21CVWNUNzdXcWZGZ1hxQT09?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:MN0PR11MB6231.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(7416014)(1800799024)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?TTNENHROVlArSmh5WVR6Sm9pa2hWRmRpVjhHN1UvcVNaRG5LRWEvdnNKdlRu?= =?utf-8?B?WFlsZEJCdEJTNzBpNnRJWDNhQStvZDVaNnFJVE0zbnBMWnBmb1h1ZzFYanlE?= =?utf-8?B?TjE4YlEzM1RCcG9SY0s1OGdKSGxKZmJ6YWpvb01aSzVZa0xmcG1MTnFVTisx?= =?utf-8?B?ekV0LzBKc2RZd2gvLzZ0UjU4enNOM1FQaS9sZW5nZDIvUm9ITTczWXAyelp0?= =?utf-8?B?OFMzL2NLOHBIejJ1VHo4cFJPazM1bE55MTAwMmtQVkFYNHNIbVFmRWluQVZv?= =?utf-8?B?VTVETnlWQVlDRndjZnZKZHJwb2J2dFB2VmlRMXZRY21mQWdMcklkNGpBMFJB?= =?utf-8?B?N2w1ZE5reVZvZ2MvMG1iWVNrMzV0WjVoNlB4WWZrTzZsZlpVdXNGMVZLdDFX?= =?utf-8?B?QktvZEdEQXhwUWVpM1k2d01hL2hyL21ZVFhmZU9mWHZpU3N3UlVjdzBoRkE2?= =?utf-8?B?UU1EVUVseFJOOURtWENtclN4dEhzTk1wdHVIOXJlSTFQc3dVSFVhY3RHc1Bm?= =?utf-8?B?OVFodjRhcjNrZ3UwYSt6aE05YXZ3MXNqaWd1Y29tbENIQlpMQ0lxZ1dHemxp?= =?utf-8?B?Q0c3RFByTXVmUmdRSzhPdmxzbXhaaHJtcXVrUzZid0xrd1ZPcy9nRkozSFFP?= =?utf-8?B?K1Z4Q21ETnZJOThvT0w2SUZpS3Q1QUhiQk95U2E5S2tqa3FXbUhJbXBQSWlO?= =?utf-8?B?amlDUDJocW4ydUhmWWwwMGlITHI2M3BRS3FEczBKZituSFRRcTZkYmFYN1VF?= =?utf-8?B?cm9EV29Va1FzUWpSVitHa0pZTlRjeDFvNGZXTWYyWEcxRzZvZ3JMOXhweDdm?= =?utf-8?B?Rm5QMFNlbU5SMjNaYk56OUZiYnFHaHJldjF0OGRaZUxFVDY5VjZWRThkakd1?= =?utf-8?B?N0FTMFJXUllZRlltVUVXNUFiYTJLYTVQaXhYLy9OUVFXekppL3hvRGxYV0Rx?= =?utf-8?B?ZXF5OHBBRC9wNjhrSjRLWUM2bnpxUW4yeFJ3dEZ1Q3E0RHZabS9xUmh2QnJV?= =?utf-8?B?OUhVS3JObU9sMjVsSHBybElXMng3ajUwZm9tZ3gxZlJLNHNyU05WRFVXenE5?= =?utf-8?B?RWwrbUVscDZyY2VraXYrZmtRajJIZlIrVGE3OUZST3krb1FhbVVDczgwblhn?= =?utf-8?B?U2pHT2s5RGw5M1c1ZUwwMWY5THUzZHBJUWwvL0pVcWtCVmhwdDdDVHJ4RG9p?= =?utf-8?B?WHdMSFYvc2tpeW1BQXNBS1JKTXo0WFlrSEgxbFhDTUdnNUtxek5jNUpRZnVK?= =?utf-8?B?eklYdGdPSFNaK2U5RlNRVHpuZzFpNTRBZHp0SVZHblFpbzhyNXhpd2FtWFlW?= =?utf-8?B?c1VKRnlhNnhQWHU5dUdpN0hjUnRXU0Uvb2ZZd2dOMkRxS2lOZ2szekJseEFp?= =?utf-8?B?TU9EMnQvSklGbForVElQTUVHMXhMZGZWc3dLdDNOdFF3WldMczBaOEVBMkRo?= =?utf-8?B?UXhYN253eXBSV0RyRXNmWDFhcVYvS0NXYUhzb24ranRHOGt1dTRuUlNXMTNj?= =?utf-8?B?ZGhaSzhuc3paeTdQYWtzcnMxNU1uZFlQS1pXUjB6ZW1LZk43bGdLKzdyNWh3?= =?utf-8?B?MVVhbVIyRmllL1IxSVFsOE9iN2lWOXZ3cUhWK2NzYy83NjltNGUzaVM4enN5?= =?utf-8?B?NGNkUWNsOHBRaEcwTDE1YnZhdEcvZGx0ZVhqZi9pN1diaGRYVTUyZ1BmS21F?= =?utf-8?B?SE90NGxhUmVLV0FOKzJtTDJ3a3ZkLytjcDRDMnUzR3pJeWR0cDJsUEw5bmZT?= =?utf-8?B?MW1LWS9Wem1OMStUQ1k4Z1hNM0hrUnI1QjE2TGZXMWlMU2NRV0NhcnhiU2l2?= =?utf-8?B?Q1h2Nk5JZUxGaE0wbnh5N2plYTg2U1FONWJFY0t5dXM4Q29DT2ZpSDhBa2pq?= =?utf-8?B?YVFXZ0NOenpBMzZaYTJPN1VnVE1UTUJheDViV0hKT3VDRENGdWpRd3c4cmgr?= =?utf-8?B?VysxOGNBQk5FRmF2QTRDTTg3cFRQVHd2ZlZKSm9LbW55OGo1WlBMR2NEVXB2?= =?utf-8?B?bzBQS2p2aXdUQXRIM0xDRVoydDU0VlpXbFBBWFpMbXRFZEhLNHUxbzhrQ1g4?= =?utf-8?B?SXUrODBhUlhWSkxocjFXRjB6VkhlUklSZ2JEMXgzVEpzVnhaMXl1dHhJc29s?= =?utf-8?B?VnFjTXM2Mlg0OEtVaTRlTHhNdHFnU2tic1luTEloOGg0SC9oTFRZaU9VcEtK?= =?utf-8?Q?RM4ZnlJ/A33qrKZUiFveDoY=3D?= X-MS-Exchange-CrossTenant-Network-Message-Id: 5c6b65d1-d4f3-40dd-c950-08dd55c0ae8c X-MS-Exchange-CrossTenant-AuthSource: MN0PR11MB6231.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 25 Feb 2025 17:20:20.9133 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 8ToOK6jPuWPolHuBPb4Np2/2g6XGwJFJuKdCT+kd8argyyRW7ES65O9vuke2cD0eAWzhzTf0YAvKTYL4rQC/nXQGUEVaV8QV2+pqnVWl5m0= X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA1PR11MB8864 X-OriginatorOrg: intel.com X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: C4EE1100011 X-Stat-Signature: xzhur73creiqnc8hks7b1xep6a7d35bd X-Rspam-User: X-HE-Tag: 1740504058-908310 X-HE-Meta: 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 VkiibFNT 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000002, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 2025-02-22 at 16:06:02 +0100, Andrey Konovalov wrote: >On Fri, Feb 21, 2025 at 2:12 PM Maciej Wieczor-Retman > wrote: >> >> >Is there any reason we need this change for x86 SW_TAGS besides the >> >optimization benefits? >> >> I wanted to have the shadow memory boundries aligned properly, to not waste page >> table entries, so the memory map is more straight forward. This patch helps with >> that, I don't think it would have worked without it. > >Ok, I see - let's add this info into the commit message then. Sure, but if you like the 0xffeffc0000000000 offset I'll just drop this part. > >> >However, I just realized that this check is not entirely precise. When >> >doing the memory-to-shadow mapping, the memory address always has its >> >top byte set to 0xff: both the inlined compiler code and the outline >> >KASAN code do this >> >> Do you mean that non-canonical addresses passed to kasan_mem_to_shadow() will >> map to the same space that the canonical version would map to? > >No, but non-canonical address are never passed to >kasan_mem_to_shadow(): KASAN always resets the tag before calling this >function. > >> What does that? Does the compiler do something more than is in >> kasan_mem_to_shadow() when instrumenting functions? > >Same for the compiler, it always untags the pointer first [1]. > >[1] https://github.com/llvm/llvm-project/blob/llvmorg-20-init/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp#L922 > >> > Thus, the possible values a shadow address can >> >take are the result of the memory-to-shadow mapping applied to >> >[0xff00000000000000, 0xffffffffffffffff], not to the whole address >> >space. So we can make this check more precise. >> >> In case my question above didn't lead to this: what happens to the rest of the >> values if they get plugged into kasan_mem_to_shadow()? > >We will get some invalid addresses. But this should never happen in >the first place. Thanks for letting me know about the tag resets, that should make changing the check in kasan_non_canonical_hook() easier. -- Kind regards Maciej Wieczór-Retman