From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from EUR05-AM6-obe.outbound.protection.outlook.com (mail-am6eur05on2088.outbound.protection.outlook.com [40.107.22.88]) by sourceware.org (Postfix) with ESMTPS id BD0E33858D28 for ; Thu, 5 Jan 2023 14:58:12 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org BD0E33858D28 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=arm.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=armh.onmicrosoft.com; s=selector2-armh-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=3GpJzyUoy0VUrfpVcjAFvJKRqeTxcHmx+sOdl2r+fvI=; b=f2wNnqGmINcc4AtHV548BEtWrAu71nqVrVJHMDHu1H2D9BNdnG+TD6qrjg2IlBpMmzMLGgqZ7t9BGU2E1Q3k4j5Xub9TwXw/RQh/W8KPThKIYbzJ+38nkcoyfk+zt5rv3Q0mNt6mjw19FHSdcuwnzocKs5OIBap3s4RAAxg4Hpg= Received: from AS9PR06CA0733.eurprd06.prod.outlook.com (2603:10a6:20b:487::28) by GV1PR08MB7988.eurprd08.prod.outlook.com (2603:10a6:150:9c::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5986.9; Thu, 5 Jan 2023 14:58:09 +0000 Received: from AM7EUR03FT015.eop-EUR03.prod.protection.outlook.com (2603:10a6:20b:487:cafe::7b) by AS9PR06CA0733.outlook.office365.com (2603:10a6:20b:487::28) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5986.15 via Frontend Transport; Thu, 5 Jan 2023 14:58:09 +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 AM7EUR03FT015.mail.protection.outlook.com (100.127.140.173) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5966.17 via Frontend Transport; Thu, 5 Jan 2023 14:58:09 +0000 Received: ("Tessian outbound b1d3ffe56e73:v132"); Thu, 05 Jan 2023 14:58:09 +0000 X-CheckRecipientChecked: true X-CR-MTA-CID: 88d452a36378935b X-CR-MTA-TID: 64aa7808 Received: from d96df061f432.1 by 64aa7808-outbound-1.mta.getcheckrecipient.com id 7F3C623E-8D88-431D-9041-6E5F2259D16E.1; Thu, 05 Jan 2023 14:57:59 +0000 Received: from EUR01-DB5-obe.outbound.protection.outlook.com by 64aa7808-outbound-1.mta.getcheckrecipient.com with ESMTPS id d96df061f432.1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384); Thu, 05 Jan 2023 14:57:59 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=Swphtt3jdyL52e3kVXGB1YW2oHdkWpXlSB7TztWAkWDNe+uE05A7QcJS1e1AsQb70EMQEFYPXIydO0mxZKNg7ZEA8MojWgYjJc7tRxMzjrak4D3qKN1ntybGn29l7aa/msYab9OcoX78cEV0EMI8dlWb8AYFt7NXJKyDUljEYz2MUy42Ye+b2oGreL+RLjQM6KfzFs7jQItpV89jRH1KCIc5gWEgSS+ozkm5mlVzVTCYAcZrOWx9lZnpJOHbsdFaneKw4ncQ+onnHMu5LE/K6jBYpm6PVijzjTwUzMfrRkcydknuLyKc8LNo5xM1ylWRyll+oLJwHxT/XlTtqLBkPw== 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=3GpJzyUoy0VUrfpVcjAFvJKRqeTxcHmx+sOdl2r+fvI=; b=mXlICNoe20Qi0X5E80PERxv9bQG0XFsiQna3FUmVZDjMXIGbN/bDqj+6EeBoTU4CGnDWWlKz1isYKAa96hPF6yYNK15Af3eB7okZVFOnc9mqwv6mpg1Ya09DjDMyNDO/xA8araesMqRGR2x5sG9b3q5VWsXhU+MgbO3H6UlKmkxb8r1wYPiX04II/G8PfjWBUZYZFW3AZRga5nU5/OJCnH/Xdzi9YvNox12eklblWatxvdyvt/riC2eYdJtiWTdsR9hkhWXG6OWhnp5eEfTBDoZD/GAj6botH5MWfw5HP7ARK8Y9imrQqt8xyuo+7ve9Hrs6/uU9ZG51PzUnq5aCZA== 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 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=armh.onmicrosoft.com; s=selector2-armh-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=3GpJzyUoy0VUrfpVcjAFvJKRqeTxcHmx+sOdl2r+fvI=; b=f2wNnqGmINcc4AtHV548BEtWrAu71nqVrVJHMDHu1H2D9BNdnG+TD6qrjg2IlBpMmzMLGgqZ7t9BGU2E1Q3k4j5Xub9TwXw/RQh/W8KPThKIYbzJ+38nkcoyfk+zt5rv3Q0mNt6mjw19FHSdcuwnzocKs5OIBap3s4RAAxg4Hpg= Authentication-Results-Original: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=arm.com; Received: from DB9PR08MB7179.eurprd08.prod.outlook.com (2603:10a6:10:2cc::19) by AS8PR08MB7912.eurprd08.prod.outlook.com (2603:10a6:20b:52b::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5986.9; Thu, 5 Jan 2023 14:57:55 +0000 Received: from DB9PR08MB7179.eurprd08.prod.outlook.com ([fe80::7e1c:3eb8:a25:50ff]) by DB9PR08MB7179.eurprd08.prod.outlook.com ([fe80::7e1c:3eb8:a25:50ff%5]) with mapi id 15.20.5986.009; Thu, 5 Jan 2023 14:57:55 +0000 Date: Thu, 5 Jan 2023 14:57:41 +0000 From: Szabolcs Nagy To: Wilco Dijkstra Cc: Richard Sandiford , GCC Patches Subject: Re: [PATCH] libgcc: Fix uninitialized RA signing on AArch64 [PR107678] Message-ID: References: Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: LO4P123CA0537.GBRP123.PROD.OUTLOOK.COM (2603:10a6:600:2c5::17) To DB9PR08MB7179.eurprd08.prod.outlook.com (2603:10a6:10:2cc::19) MIME-Version: 1.0 X-MS-TrafficTypeDiagnostic: DB9PR08MB7179:EE_|AS8PR08MB7912:EE_|AM7EUR03FT015:EE_|GV1PR08MB7988:EE_ X-MS-Office365-Filtering-Correlation-Id: 8e77a8e7-f4a6-4001-8540-08daef2d4295 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:DB9PR08MB7179.eurprd08.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230022)(4636009)(366004)(396003)(39860400002)(136003)(346002)(376002)(451199015)(66946007)(5660300002)(8936002)(66476007)(66556008)(8676002)(37006003)(54906003)(2906002)(6862004)(316002)(4326008)(36756003)(6636002)(6486002)(83380400001)(6512007)(2616005)(38100700002)(26005)(186003)(6506007)(41300700001)(86362001)(478600001)(6666004);DIR:OUT;SFP:1101; X-MS-Exchange-Transport-CrossTenantHeadersStamped: AS8PR08MB7912 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: AM7EUR03FT015.eop-EUR03.prod.protection.outlook.com X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id-Prvs: 794d787a-ac64-4184-4708-08daef2d39cc X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: cEzEdnj6oBfT0UPjA4zmaLkGMW85lLmYD2Uwk+ezIr4Dj2WbWvWNxKi9klLHHays7CKHD9XlTu8lwM1FFMsd/xGBYBj0PWMboPq50x8oX1P5ZgiozbVP3fz7oBUVpNpDyvwVHrPF52MVjgVwBCI6Oxbx89Msm/sc0eyz9A5J4QgOuA5CbXjggkwnqkHaJllSJTShxO09FcVWYHZ19B9CZWzxvC6XMcZuLCCVJhOYUGYdKd9sRcpsPr+H86158m5SeK6O46R39nVQkxvV+cZ/4ZEXWIE2gU1Syu/FOoJ9ZrcLF4RBNqIqJH1hFFoVPRschdJCmmxbwV8XE0XQU9Q6014KVtMaPLNBQaXnIFcFFTIfG6aDcdpQhYTY1/5f65wIJM0AEzGIfOBVmdM0igukc1Q7m4y8jrmD0+NstzMEr7ehOzMV1/XtFf37jYy85FJ9qN/LAY1tB1PhVmwFEPWKgNrQ5vo6vusPq6cBZrXiPDe+flKsSKZlgIWLfHOzaWZVZPSlJ0X/ti53h/vzpD2jW4tLl3vitWARIY49PNOrg70XR4p2Cb5MWIG9Pa6OSPupwOo/Yb3GHt9PJF9rTfRR1WQKeI6KEkuWSRgN9RBK5+vHU9KYrP5vp7QfgZA5S45Gxzn7djfZQAukmDZdIBMPBZJ5m/0thkwGlFZVMAaL/noXHtW7yFlLVJGctC7gfGclPs2Al5dfcQZliuon/8Pxqw== 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:(13230022)(4636009)(346002)(376002)(136003)(39860400002)(396003)(451199015)(46966006)(36840700001)(40470700004)(83380400001)(36756003)(82740400003)(5660300002)(41300700001)(6862004)(8936002)(2906002)(47076005)(86362001)(356005)(36860700001)(70206006)(54906003)(6486002)(70586007)(37006003)(6636002)(81166007)(6666004)(336012)(6512007)(478600001)(40480700001)(316002)(4326008)(6506007)(40460700003)(82310400005)(26005)(8676002)(186003)(2616005);DIR:OUT;SFP:1101; X-OriginatorOrg: arm.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 Jan 2023 14:58:09.5383 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 8e77a8e7-f4a6-4001-8540-08daef2d4295 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: AM7EUR03FT015.eop-EUR03.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: GV1PR08MB7988 X-Spam-Status: No, score=-5.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,FORGED_SPF_HELO,KAM_DMARC_NONE,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_NONE,TXREP,UNPARSEABLE_RELAY autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: The 01/03/2023 17:27, Wilco Dijkstra wrote: > > > Also, if I understood correctly, the reason we use REG_UNSAVED is to > > ensure that state from one frame isn't carried across to a parent frame, > > in cases where the parent frame lacks any signing. That is, each frame > > should start out with a zero bit even if a child frame is unwound while > > it has a set bit. > > This works fine since all registers are initialized to REG_UNSAVED every frame. > > In v2 I've removed some clutter and encode the signing state in REG_UNSAVED/ > REG_UNDEFINED. this looks good to me. > @@ -1206,8 +1205,10 @@ execute_cfa_program (const unsigned char *insn_ptr, > /* This CFA is multiplexed with Sparc. On AArch64 it's used to toggle > return address signing status. */ > reg = DWARF_REGNUM_AARCH64_RA_STATE; > - gcc_assert (fs->regs.how[reg] == REG_UNSAVED); > - fs->regs.reg[reg].loc.offset ^= 1; > + if (fs->regs.how[reg] == REG_UNSAVED) > + fs->regs.how[reg] = REG_UNDEFINED; > + else > + fs->regs.how[reg] = REG_UNSAVED; > #else > /* ??? Hardcoded for SPARC register window configuration. */ > if (__LIBGCC_DWARF_FRAME_REGISTERS__ >= 32) i would keep the assert: how[reg] must be either UNSAVED or UNDEFINED here, other how[reg] means the toggle cfi instruction is mixed with incompatible instructions for the pseudo reg. and i would add a comment about this e.g. saying that UNSAVED/UNDEFINED how[reg] is used for tracking the return address signing status and other how[reg] is not allowed here. otherwise the patch looks good.