From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by sourceware.org (Postfix) with ESMTPS id B884C3858D1E for ; Tue, 2 May 2023 00:24:58 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org B884C3858D1E Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=oracle.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=oracle.com Received: from pps.filterd (m0246631.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 341LO3JA003575; Tue, 2 May 2023 00:24:56 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=message-id : date : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding : mime-version; s=corp-2023-03-30; bh=NHYhziTTk+jjR1z000lBMjpz6DhszTOYTq8c4Un0db4=; b=y0gkoFEjshvmv95G/SU91Bfb9ExVHcUAU7dkmhz8GwHST4QeFe4aPO4YZhzlWCwHGvDm 8O19mBFWtkd3KBkvxresYDATKZPRMHBjk3P426urg+xU83D76Xb4F9I7/grpdbYT38Sg UcHvyh0xHHZabiZSj4a+ZyE47Xz63MDpTg/8XdmZLfR4gq94FmsMSekGbJWRKvfIjZ4x S4OlVn0r9zEAq6Oq5IAGP7myzylxjz/TebdOvTY7uuuO9ZKhfXQhbfCbPzgtnDZ59r2t zCvP48ROYNd7oP4pCo6rxHjV7yzNBBNoxdyKVAqaZO7RnbIydDIdp/uDrtYlgFkVH2HH RQ== Received: from phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta02.appoci.oracle.com [147.154.114.232]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3q8t13ufj9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 02 May 2023 00:24:56 +0000 Received: from pps.filterd (phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 341NXQa6003371; Tue, 2 May 2023 00:24:55 GMT Received: from nam10-bn7-obe.outbound.protection.outlook.com (mail-bn7nam10lp2105.outbound.protection.outlook.com [104.47.70.105]) by phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 3q8sp59k2u-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 02 May 2023 00:24:55 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=LchrYCUUG7s3a/csTtDt6C36DKTJccycEnS91aw6V89EMiErPywotcXVxwrvyqLdk8ZcOCGlNcqZAyMu7Pz78vDB3tYoPwDRL2iFRU+2AWNS1MR+n4ZAcoJdaK3f6a5675GEPV0hwiepcdoC7WMLZ2/d0XK54IM+9I1sOPGnnMw9RahZu3r/NkVHGdYxG4fHBiVCJtNkuN3PyJ7g0S56dY2g0Vxf/x6YZqyRmPNEfN7ODFqb8VI+bCHVUUZMOqBJpwAFjuqniDUBCR2QHos9beIOWZKjFmKou9bih7QG7aJPHoZaI8xpffaqFK0KWjsgQC95ZKi1KGkYluRtMOk8vA== 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=NHYhziTTk+jjR1z000lBMjpz6DhszTOYTq8c4Un0db4=; b=Gu6l3eEMBRFDzKpYDMAlPSbLU9s9ulYfvIhvUUUzaQecSZS1kVBFIjIjjVIAc7QwD3/+Kjpd60/rHL5oza0jvqM4ekwLsXJ2p1B04aO5E7duaR1S9QZ0QIEhgU4OAryL6c2GWKYi8HXYHkPS1ZShleLj37JyQsvh+KYeVgBlrUsIqBs44zmJkL44WQKlo0TbsCruROalI/9TVzTwTRpCP/5lupgXsJLKWMCry7F+NUw0CWs+1kOa45S1Vbg3HOQFvjnr6d+asiCQJIHGyXXMIFqxoN/8p2cMyfFipMKDmYDG5YTsPNJXk79EMfPHk7GUDyGDA5EbAm4ZF1AMPIbV9g== 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=NHYhziTTk+jjR1z000lBMjpz6DhszTOYTq8c4Un0db4=; b=fiSwNyIVeCRDcIUTADejB7fnFoi8MVB68YwtT5K4+15KVKYin0rRtTvollWOuLkokYk64xpbPnopJRuSGLf7Oq2KTeicfwOPWxjsHfL+MvN9fUU2G4ubSR509MNt/bw+ZTN2nJM6DC8w082qzU0dPgaV3tR9dFIA/tndJIPoVoQ= Received: from MWHPR1001MB2158.namprd10.prod.outlook.com (2603:10b6:301:2d::17) by PH0PR10MB6957.namprd10.prod.outlook.com (2603:10b6:510:285::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6340.30; Tue, 2 May 2023 00:24:53 +0000 Received: from MWHPR1001MB2158.namprd10.prod.outlook.com ([fe80::ff1c:f1fb:8db9:22e2]) by MWHPR1001MB2158.namprd10.prod.outlook.com ([fe80::ff1c:f1fb:8db9:22e2%6]) with mapi id 15.20.6340.030; Tue, 2 May 2023 00:24:53 +0000 Message-ID: <2485551a-9608-e4ff-8d4c-bd7974c6c695@oracle.com> Date: Mon, 1 May 2023 17:24:49 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.8.0 Subject: Re: Missing alignment in SFrame spec Content-Language: en-US To: Florian Weimer Cc: binutils@sourceware.org References: <87ildgbf9g.fsf@oldenburg.str.redhat.com> From: Indu Bhagat In-Reply-To: <87ildgbf9g.fsf@oldenburg.str.redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: MW4PR03CA0278.namprd03.prod.outlook.com (2603:10b6:303:b5::13) To MWHPR1001MB2158.namprd10.prod.outlook.com (2603:10b6:301:2d::17) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: MWHPR1001MB2158:EE_|PH0PR10MB6957:EE_ X-MS-Office365-Filtering-Correlation-Id: ae91912d-2888-46e4-d908-08db4aa3a600 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:MWHPR1001MB2158.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230028)(396003)(366004)(136003)(376002)(346002)(39860400002)(451199021)(5660300002)(8676002)(8936002)(41300700001)(44832011)(316002)(36756003)(31696002)(86362001)(2906002)(38100700002)(31686004)(186003)(2616005)(478600001)(83380400001)(6666004)(53546011)(6486002)(966005)(6512007)(6506007)(4326008)(66946007)(6916009)(66556008)(66476007)(45980500001)(43740500002);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?Vk9SYU1pc0J5SEIvZmhETnloNytSeTZqRUk5SlU4R2QydlBuNjNaWE5aa284?= =?utf-8?B?YnZqb0ZrZHZEMDBUcmhEWUV2VVpYSlBiUktDSGFDZ0NQcjNXcmQ4SFRnckw3?= =?utf-8?B?d3U4QndGTEhIU05Ha0pSWUVjenlDZXhRNW1Ub0txMXJqaXFIS01HN0NqY3R1?= =?utf-8?B?bWZiTDJ5WFRBRWpRZFVXRXo2bC96dVkvU241SElWNEZGeXlJdU02UWlycXhp?= =?utf-8?B?eENzc1RPbjU3RWlJb24wSmVucEQ3dXJuTUFmZ1hKMVVuKzRLQUtTYlVZc29P?= =?utf-8?B?cTVRa1pETStsUnpwZFBwRTFabDZHSFBnOFBIbXFTejRmV3FyVTJDK0kvMWFI?= =?utf-8?B?S0tWKzJIUmJXbzgyODBvZEl6QThLcVBjTnBnUmp3R2VUN2lmTGxWWExaTCtV?= =?utf-8?B?M25iaHUzdmEwcG1PdDBzclMvQ0hnRE00cnUzYXEweW1rS2xSYmNZZkNUWDlz?= =?utf-8?B?KzBhN211WE1zUytHdHp0WGt2TmczazY0c2psc2dwM20xYjc5YjFVbTdwejVM?= =?utf-8?B?RHNoZFgzbElJQWpJbFdFVDUvdEhLMFlBMC9oU01SZ2xPVTcza0ZqbzE0ZVZN?= =?utf-8?B?MWpYc2xlbkdpS2UyVjgwMC9xTXg5di9TemVoekprS1E3YTl0YXJ3cW8rRUR4?= =?utf-8?B?MmRNenNZMDh6ZEZWS0FvbWVEeEpDeDN4NUhISmtHNWJLWlFRSnFOTHF1blc0?= =?utf-8?B?TU5xRnFpSzFMYWc5K3ozUGlLWUsvbkp3THY5c2hqZmR5ZFg3VEJaNTZpZWpt?= =?utf-8?B?STB3NjZjVVI5emZYTjlzcnBFeG01Y2tkOEZyUDFCZW1ERG9NUnByOE0rK09p?= =?utf-8?B?bk4xOTBEVlgwWHl2OXdzc3htMWlITTd2NFQ2eUdkMEMxMUttZE9EdGFEWlA0?= =?utf-8?B?aW1jSjBxR2Q4YTdsUElHd0ZudzhxZWh1ZGJqT0lBMnZRZUxBaEZzU3IyZ3J1?= =?utf-8?B?R1RIdk9TRWhEdk5WY1pQSjRRUGg5c3p0UVhRcnY3SDU1VExjVFVtdHU4L09Z?= =?utf-8?B?R0dXNFJadnFFc2phVjFnV3Jua3h2N3ozd2JjWGpWbkQwSzRNQ1RhSHd3MHFR?= =?utf-8?B?VGhJS3pRc080eXJtTEx0NElpcFRxamJ1blYwTU5UZCs4WEZ2NjdMNUJLeVc0?= =?utf-8?B?Y09GTDFVb3EvaExuWTRGV2dEZ05kbEt1aTZmZlpNVlErQ0JtYTU4R1AzazZs?= =?utf-8?B?M1B1UDBkZHRsRmo1TzVKM3k4ckxvVUwveU8xQUtzcXZ1L1FXY2ZPblY3dHd5?= =?utf-8?B?ektMR0Z5aHVTOWZiTnpmT0oycDh5WWsxWGZZaEJKa01LNmkwaG9DbS9wQ3Jl?= =?utf-8?B?V3Q2Y054OFBidGFwVTVpTFZCNXhxbHlsemJwN3l0eldqWmxhS1RFL3JsQ3U1?= =?utf-8?B?N21BSUNCRlZxRFNUcC9xV011UWxHdXlTSER4QVFGeld5Mk0vcFFjN1JaWjQy?= =?utf-8?B?ZjVCUzFoY1B4WUxianRzM21NYUxYVzJFTzZZMFhuQ2hqZzJOd3h5QTl5a0Uw?= =?utf-8?B?MS9hSnFiaWV4WVZMb244Z2hZTEpmY0FBTVlXNmc0UUtyZWZ0Rk8wY0NlQVBv?= =?utf-8?B?bzJ4cW5kTHpZcGFyVnBIdGFSeHpSUzRMeVYxclRFYkgvVEs3WVhXV0FsVWdj?= =?utf-8?B?L0JJeGI4QlpYSHRUWjkwVG1NUU9tTUQ1Nm40ZThVMjh5cGhrOTkvWGEwTGpB?= =?utf-8?B?NVVVOERMMkxTajVZdlVBUy9IcHFaeCtZcGthVDFhSzZpNng3VS9pQkJvV2Rx?= =?utf-8?B?VzJuY0RtelMvajJxZ3drU0h2RFR3SHJHVWhnM05FTzN5NTZZTk1yYW5vanJp?= =?utf-8?B?Rm8yU0JtN2NGaW0xOEFhdVRZT1FiUTJDRzJycUNHV1Rxbng1QW1DcDlmZ1Ja?= =?utf-8?B?WmNzeFhISDFWcjEzUGZQMERGUXl5SWV6MTZjNGJZRnVjcy81SXZ0cklzZkk3?= =?utf-8?B?M1FLYXJhelE4ZnFKRk10aktpUzFoekxpakhmSFJzbytYenRHbnd5bE5hZjZS?= =?utf-8?B?bmUwK0prMXg2VkFtSk4wSGhCQlluNnk2UVprMnFLbVdLRWh5NEJ6SnZnZW5t?= =?utf-8?B?cUowbWxSOWw4eE9tZ3ducjVTZGpNN2FDZXp0Q0RCd21FUi82ZWF4Um10UHJD?= =?utf-8?B?cTh0d2MwckpkaDF5Nm5lZVNwRSs3N1FaRVdTRjNmR2lpeXE5TTAydk1FNGhv?= =?utf-8?Q?ev461KJy9Ou4qrpLRlDLzRY=3D?= X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 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 X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: ae91912d-2888-46e4-d908-08db4aa3a600 X-MS-Exchange-CrossTenant-AuthSource: MWHPR1001MB2158.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 May 2023 00:24:53.0559 (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: ro31pphWZhqaW5c14O8lAt/VMZK/N+r0UCl1+E2UwVaBSgY5YMgNh2vK8sQfwtmyozaMDQ1dNLOd60w+QOx3rg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH0PR10MB6957 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-05-01_16,2023-04-27_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 mlxlogscore=999 spamscore=0 phishscore=0 adultscore=0 mlxscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2303200000 definitions=main-2305020001 X-Proofpoint-GUID: vKZEZ20TRKGFDuB5aDXK1yKNKTwBHMxj X-Proofpoint-ORIG-GUID: vKZEZ20TRKGFDuB5aDXK1yKNKTwBHMxj X-Spam-Status: No, score=-7.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_DNSWL_LOW,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On 4/28/23 01:08, Florian Weimer wrote: > The SFrame specification does not say anything explict about alignment. > It uses ATTRIBUTE_PACKED, which strongly suggests alignment 1, but > looking at the structures themselves, I think what you actually want is > 4-byte alignment. > > Thanks, > Florian > Hi Florian, SFrame stack trace format is an unaligned on-disk format. IIUC, you suggest 4 byte alignment for all structs in SFrame format? Yes, current SFrame FDE and SFrame FRE are 1-byte aligned. I had reasoned about unaligned accesses previously when a bug showed up. Memory READ side: ------------------ So far, we ran into some unaligned memory access issues earlier https://sourceware.org/bugzilla/show_bug.cgi?id=29856, but were fixable in libsframe, because the latter provides SFrame FREs via an in-memory abstraction sframe_frame_row_entry defined in include/sframe-api.h. The members of sframe_frame_row_entry are naturally aligned. PR 29856 was about issues on the the memory READ side of SFrame FREs (Frame Row Entry). Now, I had also expected to see unaligned access when READ access to SFrame FDEs (sframe_func_desc_entry.sfde_func_start_address) was done by GNU ld/objdump. But when fixing the above bug, I did not see them. But I have it noted down to get to this sometime soon. Memory WRITE side: ------------------ As for the accesses to SFrame header and its members, these should all be aligned memory accesses - both READ and WRITE. This is because SFrame header is the first entity in the section. Its members have natural alignment. On the WRITE side, GAS does a byte by byte write IIRC (GAS does not use libsframe APIs to write SFrame section). And as for GNU ld WRITE side, I checked (mentally) that unaligned accesses are either taken care of in libsframe or not present due to usage of memcpy. So bottomline: I _think_ we are okay on the GNU as/ld READ and WRITE side as far as unaligned memory accesses are concerned. *EXCEPT*, SFrame Function Descriptor Entries (FDEs): there is an open item around access to sframe_func_desc_entry.sfde_func_start_address (and following members should exhibit the same problem), which I will check soon. I will double check for both READ and WRITE access to all SFrame FDE members when I do get to this. Thank you for bringing it up. Does the above make sense ? Indu