From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from EUR05-AM6-obe.outbound.protection.outlook.com (mail-am6eur05on2083.outbound.protection.outlook.com [40.107.22.83]) by sourceware.org (Postfix) with ESMTPS id E4BDF3836E55 for ; Mon, 6 Jun 2022 14:15:23 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org E4BDF3836E55 ARC-Seal: i=2; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=pass; b=J9pBZMjd9Hxz/Sel8jJcHWps8/APl6FynFUVm9xOCGPPPUyWVdvzhenJ6CNoLeI6Hd3njiUBT/cR+cx5hfwbpfEtNEqfgk5Y3J66m7/2gzJxk+lf4cJNcwDGICx8AOCwFjbZh9MyOefuIph3s/C5PA7PcrHRaT0zfW4kkpGHNzRq8e7qTKVHxiRn5oMsUkWZTtS7PR63L+0acp4jdmXHDWZARHgjezEltSvZHJYOZo+yyDGagw/jAJDDtFZvIxcT7aEMfrML946ESxnDtevVSPMFMdi8MmSPFUxK37VdNGDFolHUYJJUuuimetIIZNVAdxRz+5nqaCfd/M8Rky6qCg== ARC-Message-Signature: i=2; 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=nYwKJ3AyZZbKqWGajPa+NxEk3YusVo4S2yGFDAG1B6s=; b=RbzxCLNbX9sDEoDyzDCA3SJFZR+LEjW+t2yODCt0aAhqQlMxh1LliiKqSW0Z5poJFY4QnjznNdnWAnvceXte1Hj0cvAYiyUov3G+rY9z3MNqOwIcz6O4UdOwWBoF6sbFmuPUTmrG/5DBrxUEHtpnSaLr7xUIzQNWalnbZAlN3UDJiq5Nbd9xQE9JCZ+4GXBdQ4wwSSi1zO95J123/dm9sUNLzCmLg3XO30QJDWPZUJN4XnLJBXIshedUpj8Pf5NHHCTXRdOcuG7sZFr27BK3X53xYjIXfNFfsawvqP6ANuBo3ZWf/ccjpkYJ7AUyNwH1FM0f6mKbUocU6L7XPQd7Sg== ARC-Authentication-Results: i=2; mx.microsoft.com 1; spf=pass (sender ip is 63.35.35.123) smtp.rcpttodomain=gcc.gnu.org smtp.mailfrom=arm.com; dmarc=pass (p=none sp=none pct=100) action=none header.from=arm.com; dkim=pass (signature was verified) header.d=armh.onmicrosoft.com; arc=pass (0 oda=1 ltdi=1 spf=[1,1,smtp.mailfrom=arm.com] dkim=[1,1,header.d=arm.com] dmarc=[1,1,header.from=arm.com]) Received: from DB6PR0402CA0022.eurprd04.prod.outlook.com (2603:10a6:4:91::32) by AM0PR08MB4100.eurprd08.prod.outlook.com (2603:10a6:208:130::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5314.13; Mon, 6 Jun 2022 14:15:20 +0000 Received: from DBAEUR03FT064.eop-EUR03.prod.protection.outlook.com (2603:10a6:4:91:cafe::e1) by DB6PR0402CA0022.outlook.office365.com (2603:10a6:4:91::32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5314.19 via Frontend Transport; Mon, 6 Jun 2022 14:15:20 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 63.35.35.123) smtp.mailfrom=arm.com; dkim=pass (signature was verified) header.d=armh.onmicrosoft.com;dmarc=pass action=none header.from=arm.com; Received-SPF: Pass (protection.outlook.com: domain of arm.com designates 63.35.35.123 as permitted sender) receiver=protection.outlook.com; client-ip=63.35.35.123; helo=64aa7808-outbound-1.mta.getcheckrecipient.com; pr=C Received: from 64aa7808-outbound-1.mta.getcheckrecipient.com (63.35.35.123) by DBAEUR03FT064.mail.protection.outlook.com (100.127.143.3) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5314.12 via Frontend Transport; Mon, 6 Jun 2022 14:15:19 +0000 Received: ("Tessian outbound ff2e13d26e0f:v120"); Mon, 06 Jun 2022 14:15:19 +0000 X-CheckRecipientChecked: true X-CR-MTA-CID: b4015e27307b333a X-CR-MTA-TID: 64aa7808 Received: from 1d0b8f2dd632.1 by 64aa7808-outbound-1.mta.getcheckrecipient.com id 52A8A584-4BDE-44DF-BD82-CE9F14744AE1.1; Mon, 06 Jun 2022 14:15:12 +0000 Received: from EUR05-AM6-obe.outbound.protection.outlook.com by 64aa7808-outbound-1.mta.getcheckrecipient.com with ESMTPS id 1d0b8f2dd632.1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384); Mon, 06 Jun 2022 14:15:12 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=Ei5O+TjqjdRrZVO0QmMEw0+jMmgFEAIN/KfPnhCgfiZA2ApVqVMrVU8GWsZNpas876zloaLvieskjmmvQIzoLWeD3eszf/fKLCXbf/V9VJ9Dpof6sz5Q5G+/eKxs5MalZeoA4kDQfbfJfOMLDu18IpeO1M8kfNc85DjUNg6QWv7AoELdXOmFGA0Pa/l7X9U2FwFJThT/dU5M7vVF3g3tT/U9C3jSb3l0QOtlFqXpY8Sb1mvaANOIEXDqzQGtBDVrSuORqo9kGm9FTPKTUipVZ46AUO4GQPFzJEd3zjTfWYQ27MOHnZf4H+nxpZXhkOBWWj4yd1aXu/hib2Hp8WQ36Q== 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=nYwKJ3AyZZbKqWGajPa+NxEk3YusVo4S2yGFDAG1B6s=; b=lCfHLRdsfPjJEDL/HLYeMeS8nlNh/JOiGqAj6vvTs+PaToGQDMZ27IzDP6u6UaybDf3KhTdlruA6aFd2+GK3fhjMUR3VRrySmqH3v1orS2GTZ1yIxRQF5EbkH85BG0jjDQADVNxoYxZY2vpritl2QXKaod3e5G8DX1s5l0Ypj2TAd7MNjxLHBe8d+9AXEDtMpMvjJ6dPmtvp3Ajd6LTP0q/WPUoMmPX2sqhGakndiKOKai3kWbMYdPMHQoW4Kb4QHnHH2b+p+h0GkR/bQ6SPlPu9vcfGQL22BslLuYvZ1rnRzYDpYcugQ+mLcI83+sYhdjqaBKZXkGY3UyyE3+Yjjg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=arm.com; dmarc=pass action=none header.from=arm.com; dkim=pass header.d=arm.com; arc=none Authentication-Results-Original: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=arm.com; Received: from PAXPR08MB6848.eurprd08.prod.outlook.com (2603:10a6:102:132::19) by AM6PR08MB5220.eurprd08.prod.outlook.com (2603:10a6:20b:c3::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5314.12; Mon, 6 Jun 2022 14:15:11 +0000 Received: from PAXPR08MB6848.eurprd08.prod.outlook.com ([fe80::e47b:9ff6:56b8:5b65]) by PAXPR08MB6848.eurprd08.prod.outlook.com ([fe80::e47b:9ff6:56b8:5b65%8]) with mapi id 15.20.5314.019; Mon, 6 Jun 2022 14:15:11 +0000 Message-ID: <7f637a14-4045-76b3-c8cd-3de18856ecf5@arm.com> Date: Mon, 6 Jun 2022 15:15:09 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 From: Matthew Malcomson Subject: Re: .eh_frame augmentation character for MTE stack tagging To: Richard Earnshaw , Florian Mayer , gcc@gcc.gnu.org Cc: Evgenii Stepanov , Fangrui Song References: <00728f04-2b84-13a3-2ebb-34f5953d28a5@foss.arm.com> Content-Language: en-US In-Reply-To: <00728f04-2b84-13a3-2ebb-34f5953d28a5@foss.arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: LO2P265CA0416.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:a0::20) To PAXPR08MB6848.eurprd08.prod.outlook.com (2603:10a6:102:132::19) MIME-Version: 1.0 X-MS-Office365-Filtering-Correlation-Id: 11179177-1b26-42aa-d45a-08da47c6fcd9 X-MS-TrafficTypeDiagnostic: AM6PR08MB5220:EE_|DBAEUR03FT064:EE_|AM0PR08MB4100:EE_ X-Microsoft-Antispam-PRVS: x-checkrecipientrouted: true NoDisclaimer: true X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam-Untrusted: BCL:0; X-Microsoft-Antispam-Message-Info-Original: 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 X-Forefront-Antispam-Report-Untrusted: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:PAXPR08MB6848.eurprd08.prod.outlook.com; PTR:; CAT:NONE; SFS:(13230001)(4636009)(366004)(44832011)(6506007)(53546011)(66556008)(4326008)(508600001)(2906002)(86362001)(6486002)(966005)(186003)(2616005)(8676002)(38100700002)(31696002)(8936002)(110136005)(36756003)(66476007)(31686004)(54906003)(26005)(6512007)(316002)(5660300002)(66946007)(45980500001)(43740500002); DIR:OUT; SFP:1101; X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM6PR08MB5220 Original-Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=arm.com; X-EOPAttributedMessage: 0 X-MS-Exchange-Transport-CrossTenantHeadersStripped: DBAEUR03FT064.eop-EUR03.prod.protection.outlook.com X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id-Prvs: 51ce8757-89a5-4a79-17e8-08da47c6f77a X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:63.35.35.123; CTRY:IE; LANG:en; SCL:1; SRV:; IPV:CAL; SFV:NSPM; H:64aa7808-outbound-1.mta.getcheckrecipient.com; PTR:ec2-63-35-35-123.eu-west-1.compute.amazonaws.com; CAT:NONE; SFS:(13230001)(4636009)(40470700004)(46966006)(36840700001)(82310400005)(336012)(47076005)(2906002)(8676002)(70206006)(107886003)(2616005)(40460700003)(26005)(6512007)(54906003)(316002)(186003)(6506007)(53546011)(81166007)(110136005)(31686004)(70586007)(508600001)(31696002)(36860700001)(5660300002)(8936002)(4326008)(36756003)(356005)(44832011)(6486002)(966005)(86362001)(43740500002); DIR:OUT; SFP:1101; X-OriginatorOrg: arm.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Jun 2022 14:15:19.7577 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 11179177-1b26-42aa-d45a-08da47c6fcd9 X-MS-Exchange-CrossTenant-Id: f34e5979-57d9-4aaa-ad4d-b122a662184d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=f34e5979-57d9-4aaa-ad4d-b122a662184d; Ip=[63.35.35.123]; Helo=[64aa7808-outbound-1.mta.getcheckrecipient.com] X-MS-Exchange-CrossTenant-AuthSource: DBAEUR03FT064.eop-EUR03.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM0PR08MB4100 X-Spam-Status: No, score=-8.5 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, FORGED_SPF_HELO, KAM_DMARC_NONE, NICE_REPLY_A, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_PASS, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE, UNPARSEABLE_RELAY autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: gcc@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 06 Jun 2022 14:15:26 -0000 Hi there, Just to mention that this decision has been included in the Arm ABI project. https://github.com/ARM-software/abi-aa/blob/main/aadwarf64/aadwarf64.rst#id22 MM On 6/6/22 12:00, Richard Earnshaw via Gcc wrote: > > > On 04/06/2022 00:52, Florian Mayer via Gcc wrote: >> Hey! >> >> We are in the process of implementing MTE (Memory Tagging Extension) >> stack tagging in LLVM. To support stack tagging in combination with >> exceptions, we need to make sure that the unwinder will untag stack >> frames, to avoid leaving behind stale tags. As such, we need some way >> to communicate to the unwinder to do that. >> >> In a discussion on llvm-dev [1], it was decided the best way to go >> forward with this would be to add a new character ('G' for taG, as the >> MTE instructions stg etc.) to the eh_frame augmentation string, and >> then handle that in libunwind by clearing the tags of the respective >> frame. >> >> How does that sound? Would that be a good course of action for GCC as >> well? >> >> Thanks, >> Florian >> >> [1]: https://lists.llvm.org/pipermail/llvm-dev/2020-May/141345.html > > Hi Florian, > > This is something that needs to be specified in the ABI, not just agreed > between a couple of compilers. So while the community input is helpful, > it isn't enough. > > The correct place to do this is in the ABI project here: > https://github.com/ARM-software/abi-aa > > R.