From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from NAM12-MW2-obe.outbound.protection.outlook.com (mail-mw2nam12on2071.outbound.protection.outlook.com [40.107.244.71]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B8FE9158DCE for ; Mon, 6 May 2024 19:08:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.244.71 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715022536; cv=fail; b=qTCm8u4anx+MPbP+Yw26m/ZyVSiEN3HVEb4JZ/eh5pHxqNHeeVJFRVOgqNp/bkc7Gt2bnLL1AJ1Yoz5EPzavwoROQZ3WoxcXwv6UgR/TiIzccGKZ46gshIL7qoXHdjzDnGGRwETdy99L9LlDDxZpn0dCPMhmFOYzeGavEQ9LbJQ= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715022536; c=relaxed/simple; bh=MHFLc+wkGfCsO/IbofmyO0en7lxERUTnEmrUiVCgPGc=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=nG1H8qgJaFxTkx9pxI26W0txqaG+au+7ngOxbuaHO2MwhjeE6Gd0GsrHo3niK1DecnfLOCJISxXmPl0KKtBg4oKHa1tc7hxO1XL3oOra5exPSpS5o+tdIwvx6bXzP14DYLDl9b9dlLCNHTBfgExtjSqca3/mmIl3VJDYmPTmRHk= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=tYYu7yJS; arc=fail smtp.client-ip=40.107.244.71 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b="tYYu7yJS" ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=MCqkVKUPkBF6sJhP/KeSc31yjQ73/0E290L0PKnuFd4Dp02XVtEWLef4SjJRdTPOUlm6xGIa4oq9+iJ5TRG+KnGH4hyD4GpdUtR3eRxINGIOYM0UKC6jj/xyu4Ak4X17AumVKPHGZBXyd9oJCe/eoK8ElPHR2fihrU6K5UQEYiTWdVPmrHMJnOZOm0X5pbXh37CR/o4XTjba2ytRjPmo+sGFELUT9fKGQ6uehnZB4k6VHlv+h5lUlsTLX64xrSmdWtAi2yhn4gQfPmFTttLRXaBNaF1dTDl5TgfzJJwjokuCRT7Egu7tq0p3x0sWTL37Nc5o1W4Y139tLqT4ni7Mmg== 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=RF6R9Dv58rdqqR0tPk4qRq3YPuNoO3Gre6afZuMBIcw=; b=InykGEOhepajALqYQvueU+NIk/aiqqvk2OFUxSB2ssX0EdagRLmzF8JiY0okxeyYTQcTPZEcqmhi8PU7AZBRkUolk+nG3cU9V5JoQ3fXLbxYpyYHT0LgtQtFmUGQC8jE59d76zuuNOIjX90cdneT4rbvgBcfumxxNupAR/DM98JnuLOnPIM8NdyoV1hFvJD4cMGwcR3DfkK8FrGTzev5KZbDb02OjuLTINVtsTMBFLFV4ncYeQbYlmR0D0sFxQPfVFlgmNyxakgIaRrG8rYpeR6ZyowHqg6Cqh9CVuhmaeBNnsoZX+3qSvPU21G943guz/WzQmoWBQHZ58mTzKVfFw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=RF6R9Dv58rdqqR0tPk4qRq3YPuNoO3Gre6afZuMBIcw=; b=tYYu7yJSf11dyoJmeIFsSkEqygFUec0DapL3anxxdWlWa4obANxXXxCdBVKnPFr28ncZ1GKwRKOYoA7yZbk7URzcFE+2trWpZKaJZf6WFPV7Vk7HBH/hGlLrefa9exqV0u1pDh0NLetfgfVnUEWyCNbD7HHr1U4o2CItSpW8ohkubU1U8T1YNvI7DGFnxa14DVUwlH5nsCvWcWBzwjEQbdipTVNASoYBVUENabir1ixarh8Pr9SPk0Mm9A6qzLG3znfJxHSjCDTbDGBLAnclYeC378oJg2cicwuT3i08t7WFBmwKVnPP5K7NQVC6mzmknMAO5G1aAd+PfVt1AYRzUQ== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from BY5PR12MB4130.namprd12.prod.outlook.com (2603:10b6:a03:20b::16) by SA3PR12MB7880.namprd12.prod.outlook.com (2603:10b6:806:305::18) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7544.41; Mon, 6 May 2024 19:08:51 +0000 Received: from BY5PR12MB4130.namprd12.prod.outlook.com ([fe80::2cf4:5198:354a:cd07]) by BY5PR12MB4130.namprd12.prod.outlook.com ([fe80::2cf4:5198:354a:cd07%4]) with mapi id 15.20.7544.041; Mon, 6 May 2024 19:08:51 +0000 Message-ID: <1ff60e91-ac20-476b-a83e-8f9f2f797eb4@nvidia.com> Date: Mon, 6 May 2024 12:08:41 -0700 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] selftests/exec: build with -fPIE instead of -pie, to make clang happy To: Kees Cook Cc: Shuah Khan , Eric Biederman , Muhammad Usama Anjum , Mark Brown , linux-mm@kvack.org, Valentin Obst , linux-kselftest@vger.kernel.org, LKML , llvm@lists.linux.dev References: <20240504022301.35250-1-jhubbard@nvidia.com> <202405061007.F1A46E89@keescook> Content-Language: en-US From: John Hubbard In-Reply-To: <202405061007.F1A46E89@keescook> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: SJ0PR03CA0184.namprd03.prod.outlook.com (2603:10b6:a03:2ef::9) To BY5PR12MB4130.namprd12.prod.outlook.com (2603:10b6:a03:20b::16) Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BY5PR12MB4130:EE_|SA3PR12MB7880:EE_ X-MS-Office365-Filtering-Correlation-Id: 1afdc90e-200f-4de1-28e1-08dc6dfff71e X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230031|376005|1800799015|366007|7416005; X-Microsoft-Antispam-Message-Info: =?utf-8?B?aFc4Tk1PTjBUQU8wVTVlTDFxejhETnA4NkU3R1ZDaEorV2tnMEN0RytwdzJw?= =?utf-8?B?aW5IWG1kckxoWlNPTnBDYXpUQXBEdStuUndDTXRHVjQybGQ5VWxhbnBiODJG?= =?utf-8?B?MkdaWEM3RVdsWWZOTDU1UUgyQ1ZSemVITXh2clM0SjBVVlV4bk9iUXRkNXNR?= =?utf-8?B?TnF4RDF1SXBUOFRBOVdNd1oyNFZsazlDcDVZaFFPZnY5RVZhMlc3U2VhSnJz?= =?utf-8?B?eEFXZFJYR0xBTkhycDNHY2hyNGJwNXh5WWdwbWZUSnE4RnQvUjVER09Eb3Bt?= =?utf-8?B?OE0reTYwbFlvNjdEWExYMkFuYXI2WjBnRkpYTTlkd3dKTWJlVGNuWWZtWWMz?= =?utf-8?B?RmV1Wkh6S1hGcHlYOUxwa1F2YWNkTUd0Kys5eFpGclJwcmNzeTdEcjEraGx5?= =?utf-8?B?VnNCbzlmd0lWeWY0OGxiaUVnVmdNbnUxNEZGblNESlc3N2kzaGczcVZSbUVP?= =?utf-8?B?MFZpOE5DTEtYSjlFdEdmSDVETTB5MWN3cVFtSHl3ZG95UEJ5VDhieFQ4Mis1?= =?utf-8?B?MUkxdmJQdjJ3Tk9vMlUzbW56Ukp4U0pkUy96Yml2QlBRejRpZnd3bVAxZUFs?= =?utf-8?B?WEwyT1hPRzNPZkVTZ2dRcWJ1KzdLRnpjRlhuQm51NitZZlNXV05HamJTWTNq?= =?utf-8?B?NkhOQmdQcVgrYWNUcE1UQ1k2MGlZZHdzV2VKMUgyL0gxbElpWU5hUTByK0JH?= =?utf-8?B?NXFIaFZ0NWlhVUk5ai92MUlJeFJQd3hzK3haZXZQUkVzMXQ1MlQwVjBuLzNl?= =?utf-8?B?ekN2VFgwY0ZnaHc2UlBCeUIzRXh4K0xLb1R6ZUJpWmJRM0s0ZkNoRmlJYllp?= =?utf-8?B?dkZkbkNJWmpSMjg2R0Z5eFd5RFgrQ1BreEFhdzZkY3FRTTdPQW5zZ0IvWThG?= =?utf-8?B?RFJmY1EraWxIcDZLR21TeE8yaCtqNlJUNlRxc2VRaTBzWkZkZ3dLRE1SSk1P?= =?utf-8?B?YnJHYkhQbHNTQUNiMlZiOUErZWhXcHhGenB1NzloNEMwMXJhdFhualg2OUhj?= =?utf-8?B?NER5WldjMVR6TXhwUTZ6bUhnWU9pSEcreWMxeENFYmc4akVkMDBnaHVpUlFl?= =?utf-8?B?VVFXYjRRWUk4ekYwZTA0c0loUVlMeWVRcWdvS0VMYmdNb2V4RlNqMWRQOHNT?= =?utf-8?B?MEI3aG1YRUlPTmhYZ3h5ZCt4QW44NWFsMHFCaHlCeXhFMlorK1F0cjRRdFpN?= =?utf-8?B?UU1xa2ZXKzZFVWVnc0YxbDRpZ0dxRkRBeEU4QmxjYWlkcXZZN0x1ZHJUcWc1?= =?utf-8?B?T0pBU3lCT1pRUGJpTEFWdTlSU1dCMmp1MWZzMk1JQ2JUMmNUS01EUlpqTjRw?= =?utf-8?B?T3FlMy8wZ0ZQTzViWGt5ODhTR2xTQ29pZUxXQVV5akdQWTBZdW1ZWnAzNUlN?= =?utf-8?B?SUFBa1JQYXdPT2NyNDRyT2I4YXRpM2NrajF1THV4SWVCYVpHRDNWb3locysv?= =?utf-8?B?cU5KdWhCeTB1NXVVWHZ5eXpza3dRdnpTVGE5bGpRRWJSZzk2M0tONVFZcmlZ?= =?utf-8?B?Vi92dmNhTVRtNWFtWXNvdGtZeHRxd2Y1NWFGN1Zsdkg4U3hxUlY0REVrZnZT?= =?utf-8?B?S1VvZEVWMUdVZjJKWU4zZ0ZlVjVtbkJNNTJ6WHJVZmh3N3ZMT2VpelEyZGFm?= =?utf-8?B?V2liYkRhRVF0UWRuM3FiM2NiWEtMZXNyVk1kYndCRU1yK09EYmtYTTYvTjVJ?= =?utf-8?B?NWpJWFJrYlZZbmNqZzFyR1dvRjh0bGsybXB2QXo3blF2T1RvcmllZmRBPT0=?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BY5PR12MB4130.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230031)(376005)(1800799015)(366007)(7416005);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?TXBYbWNUcktJelU0TkRxd0s5YzBiMnJkQ25iNmhUTHdPVHkwVEw0MmpOQk93?= =?utf-8?B?LzRKT0w2SXRZVXorYzhkTWgxVUJnSStSU3NtYXNWOFFMOHVNNFM3RmRLSzJq?= =?utf-8?B?dURLYUloemc3VEVZRVNhOVkyYUVYT0VnMmU5MGZxUitZNEVJb2ZqbmN1UGRu?= =?utf-8?B?TXlrRkVsOUt2Wm9sYlY2OVNnYU5UTzRRcm5KSTlBblQ1QWhORTlwaWtDVXpL?= =?utf-8?B?bjduaWs3ejVFNUhxQ3gzYUJlcVJkSFozTWlEUDdCT2ZvUHJialYrSnVvMkVx?= =?utf-8?B?OFViQUNhSEJHRXM5ZFdRdjRaditWdDVhMzhPM25LSlZJejNjaFMxTFRMek4z?= =?utf-8?B?L3dLeWV0US9XOS9RbEx0THpjQ1BXcm54aUVpdUNQSVBRcDNEbzgzMHhiSkFy?= =?utf-8?B?cjBDYVR2TlY3Z2FQVDQxdU5vcHZQQW9WVWplbU8zM1YySG9xdnp0MkZlU2FZ?= =?utf-8?B?WFRLK3lSeUxmRVpUU0JDZE0rWVMyYlVTQ0JpVWtoQ1BxSXNTVXkyaEdOVmtX?= =?utf-8?B?aGl6aHFYQUQ5Mlo1RWZsM09CU3ArY05YRlZJbmk4ak9sdHdvcURaN3lEbVN6?= =?utf-8?B?K0laSDNsaEFwdFlFcjRwOU12dWRKcDBraG1IWi9GbDlGaGtpdnZuL2cwTnZw?= =?utf-8?B?a2JScGJXWkpBdzBaK1lPUUV4UHc3VmRxVHYwTGEvRVVVR29ESlBWUjlDTzhP?= =?utf-8?B?emVRN1VXbHI2bTBaMG1YSi8zMDdsQXhMUVFudE91ckpiS3BWVElmcHpOU0V5?= =?utf-8?B?S1FMeDZEV0dIem1OcktZRzVobDJOb25EUnUvMWxVazRReVA2M3RzaGVQcGpV?= =?utf-8?B?N2s5YXBNTkpqTHdMVFZBOGE3RXdKMEZqOWpBQXJQd2xVdHRVM0VLMjhUQlNa?= =?utf-8?B?N2xhYVMweVlJMEtPclJwN3VQem8zNzF1RUpFM0RmY3E0WUpOemVyeG5WQndF?= =?utf-8?B?L3VHR3crQTRzbUdGUGNtMmxIZTB4NGZMdHVEbzZ4MmFGN3d6WTNrditXOGgv?= =?utf-8?B?bWkxZUhyckJqdUVWWHNDb0JjS3V2WXc1N2FIVUtubGpKNVdPck5RL29JdUpO?= =?utf-8?B?eFp1WklqZ2xJRUpjc2hBN3ZTWVZBYi9haGtoVTk3UHZoUlRNYnFVZHl4T3hp?= =?utf-8?B?eERJem9rV1hoZUU0MUJQVlRmS1l5dDlQQ2lOYnZ1R1ZVUTZ5dGJ6bVBhcW5Y?= =?utf-8?B?bmEvZnZqMUFsdVd3dFFQdldpZVlqZ2dyWUsveFdDT0FrS2tyQ3MwS04yT0Ey?= =?utf-8?B?SndWZXd0TVFjZ1VzNEpyQmkvUHJsZkU1c2tVamR0azV1RkhPSXRMT1Y3eGpq?= =?utf-8?B?UVlTeVVrWWt4Vk9PZk9UVnFaSDZ1V1p0SlZNYVM3Y3Bob0MzdkVHS2dWOTM1?= =?utf-8?B?My9uc2x0Zk1nbFkxYU5iNHF2eEE3bHZiK1BTTmVnUVBPMmYrQmZHTkFkWVls?= =?utf-8?B?eUZDZjloOGtrcTBSenllOHVudnoraWZBMDRUdzhIQy9xSGdRZWpvM0ZmUG1i?= =?utf-8?B?MzFvdllOdnh3T1hTV09SaDZ1ZmpoR2NVR25kaEZhdEV0Y1lnWkpST0szWVl4?= =?utf-8?B?K2h4bzltRzMxWGt6clVqYXpIdlp1NW82SVduMmNWTVVsWjYrM1hvdjVQYkhw?= =?utf-8?B?YUNDSWdURmx1cURnWk5wOWhkSkQveGh6MDBQUnp1Y3h5ZE16WG00Wk91VU82?= =?utf-8?B?VVNZSksrejV4cVVFT1AydUNHamdZTVNOdCs3bTZTZmdlWVowUjEwWjdXWFht?= =?utf-8?B?V2NWUXh6QUpFRGNNR3U1SHJMYU1tS2hDVzV1Z1ppYTN0ZG5UMjZOSmdMSElK?= =?utf-8?B?OVMwMmhscVRDMis3NisyalRzb054N0tINGdKNVVOZng1akNvRUNnaGYxY3Nm?= =?utf-8?B?dXlvMmwyaUw0dnZjMU1HSUdoMUdKV2NBYTJUbWZJa0diQ1hlSkJ0YmlVQWtI?= =?utf-8?B?UzNxL25pclBIWEs0T1JDZFFiUlNqMld3cmNDak1zSVdzQWw4b0JuN2xRTTFk?= =?utf-8?B?SDUxT3VBY2lJUGxjU01rUnE4S0FMVGRJTXpNUjZmblhjSVEwTU1RMmxDbmNI?= =?utf-8?B?d1AvQzJ2NXM0eXdwTXM3U1hpMTN4NUYzcHB4OEdxVUsvUmVrYkZraThEZVNR?= =?utf-8?B?N0F1aGN2dDdVSUF1SUpKaHF6aWhFbWdXL3ZzZHRPQ2hqdG9OK2NKYW9NbXZt?= =?utf-8?B?K2c9PQ==?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 1afdc90e-200f-4de1-28e1-08dc6dfff71e X-MS-Exchange-CrossTenant-AuthSource: BY5PR12MB4130.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 May 2024 19:08:51.0997 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: a8e56/MZSVPSwLv2++k098BQZeh7ebFsSphCGcMUeBJlzLLVNTvlbMgdtqqO/HiyAF7Xc1xaIoeP7+j6sB+YDg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA3PR12MB7880 On 5/6/24 10:09 AM, Kees Cook wrote: > On Fri, May 03, 2024 at 07:23:01PM -0700, John Hubbard wrote: >> clang doesn't deal well with "-pie -static": it warns that -pie is an >> unused option here. Changing to "-fPIE -static" solves this problem for >> clang, while keeping the gcc results identical. >> >> The problem is visible when building via: >> >> make LLVM=1 -C tools/testing/selftests >> >> Again: gcc 13 produces identical binaries for all of these programs, >> both before and after this commit (using "-pie"), and after (using >> "-fPIE"). >> >> Also, the runtime results are the same for both clang and gcc builds. > > Thanks for this! It got solved differently here: > https://lkml.kernel.org/r/20240416152831.3199999-1-usama.anjum@collabora.com > > Does that work for you as well? > Yes it does. Please drop my patch and let's use yours instead, thanks! (As an aside, outside of the compiler sources themselves, it has proven quite difficult to find any in-depth documentation of linking options and behavior--now, and in the past.) thanks, -- John Hubbard NVIDIA