From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from EUR05-VI1-obe.outbound.protection.outlook.com (mail-vi1eur05on2052.outbound.protection.outlook.com [40.107.21.52]) by sourceware.org (Postfix) with ESMTPS id 10E253A07000 for ; Tue, 13 Apr 2021 08:21:12 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 10E253A07000 Received: from AM5PR04CA0018.eurprd04.prod.outlook.com (2603:10a6:206:1::31) by PR3PR08MB5785.eurprd08.prod.outlook.com (2603:10a6:102:89::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4020.17; Tue, 13 Apr 2021 08:21:10 +0000 Received: from AM5EUR03FT039.eop-EUR03.prod.protection.outlook.com (2603:10a6:206:1:cafe::96) by AM5PR04CA0018.outlook.office365.com (2603:10a6:206:1::31) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4020.17 via Frontend Transport; Tue, 13 Apr 2021 08:21:10 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 63.35.35.123) smtp.mailfrom=arm.com; sourceware.org; dkim=pass (signature was verified) header.d=armh.onmicrosoft.com;sourceware.org; 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; Received: from 64aa7808-outbound-1.mta.getcheckrecipient.com (63.35.35.123) by AM5EUR03FT039.mail.protection.outlook.com (10.152.17.185) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4020.17 via Frontend Transport; Tue, 13 Apr 2021 08:21:09 +0000 Received: ("Tessian outbound 47ca92dabae7:v90"); Tue, 13 Apr 2021 08:21:09 +0000 X-CheckRecipientChecked: true X-CR-MTA-CID: 7ad863d819d6974b X-CR-MTA-TID: 64aa7808 Received: from 4115594208e4.1 by 64aa7808-outbound-1.mta.getcheckrecipient.com id A72E30A7-6751-4961-B65B-1647C8817984.1; Tue, 13 Apr 2021 08:20:56 +0000 Received: from EUR05-VI1-obe.outbound.protection.outlook.com by 64aa7808-outbound-1.mta.getcheckrecipient.com with ESMTPS id 4115594208e4.1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384); Tue, 13 Apr 2021 08:20:56 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=cKQQYROvlIvSlHeDNmZUva2W6Kg2L/YqPD957gB98QgCS7vratvUbtCkqLgM3R3lE1N/TKVr/W1JWNVjgE1SYTVsDG3M5JBIpb+8QocDIpa5D9wvox+7c/mVPc480fX7zZ+i8kmaZPTRK4TpeIxtegwEwgugLN6RQZiUx/uViPGVDjVLRvoLARZxVtmYYgcQm4XLqczk6HOXHNY608ltpDTA9nhO0djLFuXHrgPks4iG9TV8WUe8BHwZPGKg3826Y55QgUdwTulKq41FrKiujgraJZhP/izWHF7Mr5DjroLVTR95wR+iRhBvrzglLvo5Z6N6NSxYcipzdeEMSv98KA== 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-SenderADCheck; bh=eI1o7CQWu6VbCUXjEL9eC6+LIz+Gs9bGdp06wUTT0qU=; b=YwVh+F7exUUeBUglXcLq7GErTIjlv0y+/AjCkobhaVmwnkcj7OrRgu++uttl7n6SrIgum8ZiQMFSDAKxpiHvmmNcDjfAujKcoKwpl4ujbTqbx3HFrtHmhStVZvsnIdSrSw126fW/7I6w1BeS/6jK5fY48FpB5D6BxINUTnSyQ8/Jdo8QJEmhE/dyBxUHM2NA4HCk4XSBCg5T24QEdAD9MQJBuqmQ9OWGGIYF6Hsim9CT2q4+XCKcbhIYxJ79/fLz699sJ8F11rEDXc9m2DQ69pOiQMDEllOi8Kk5x73Wuq/mRtM5MKqsMvu87G2QhL0Yu+AP00nqa+SSFJdDFT4YAg== 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: sourceware.org; dkim=none (message not signed) header.d=none;sourceware.org; dmarc=none action=none header.from=arm.com; Received: from PA4PR08MB6320.eurprd08.prod.outlook.com (2603:10a6:102:e5::9) by PAXPR08MB6558.eurprd08.prod.outlook.com (2603:10a6:102:151::10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4020.22; Tue, 13 Apr 2021 08:20:55 +0000 Received: from PA4PR08MB6320.eurprd08.prod.outlook.com ([fe80::c99f:671d:bb2c:f20b]) by PA4PR08MB6320.eurprd08.prod.outlook.com ([fe80::c99f:671d:bb2c:f20b%7]) with mapi id 15.20.4020.022; Tue, 13 Apr 2021 08:20:55 +0000 From: Szabolcs Nagy To: libc-alpha@sourceware.org Subject: [PATCH v2 10/14] i386: Avoid lazy relocation of tlsdesc [BZ #27137] Date: Tue, 13 Apr 2021 09:20:44 +0100 Message-Id: X-Mailer: git-send-email 2.17.1 In-Reply-To: References: Content-Type: text/plain X-Originating-IP: [217.140.106.55] X-ClientProxiedBy: SN4PR0801CA0018.namprd08.prod.outlook.com (2603:10b6:803:29::28) To PA4PR08MB6320.eurprd08.prod.outlook.com (2603:10a6:102:e5::9) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from localhost.localdomain (217.140.106.55) by SN4PR0801CA0018.namprd08.prod.outlook.com (2603:10b6:803:29::28) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4020.16 via Frontend Transport; Tue, 13 Apr 2021 08:20:54 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 72659760-f56a-4a6a-f718-08d8fe5517ad X-MS-TrafficTypeDiagnostic: PAXPR08MB6558:|PR3PR08MB5785: X-Microsoft-Antispam-PRVS: x-checkrecipientrouted: true NoDisclaimer: true X-MS-Oob-TLC-OOBClassifiers: OLM:4714;OLM:4714; X-MS-Exchange-SenderADCheck: 1 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:PA4PR08MB6320.eurprd08.prod.outlook.com; PTR:; CAT:NONE; SFS:(4636009)(366004)(376002)(136003)(39860400002)(346002)(396003)(26005)(69590400012)(66556008)(44832011)(316002)(66476007)(6512007)(16526019)(38100700002)(8676002)(66946007)(38350700002)(52116002)(186003)(478600001)(2616005)(86362001)(2906002)(6666004)(5660300002)(6486002)(956004)(6506007)(6916009)(83380400001)(36756003)(8936002); DIR:OUT; SFP:1101; X-MS-Exchange-AntiSpam-MessageData: =?us-ascii?Q?ZSWYsTh+a2Bd6L7KNnrB89ln1VErpEcKtyZIlGh5BIyeVFKxpR2ZfVAOEPFW?= =?us-ascii?Q?npLrgdKDN5gVx4ONft6PUgF5Q6wpuNqzfr7iQNJSfyDQoCnUy12kisJ2Jsr3?= =?us-ascii?Q?n6qdSjbC97k+0lzxyO2hU3JzeqyyuoGxoxkSXYsEuDwq0Z4/2aN01sRYCPv3?= =?us-ascii?Q?XC48DG3oa9QQEAsZSMjdK1DQeqZ4pibPPj/z5LWnAf4CdGcQ/dA9gYy8tMXv?= =?us-ascii?Q?3hbGx2/piCKn02YrONBCHQfKU5MDMI9AXRT139nFeogXA0K1Q7bszeZHrbwP?= =?us-ascii?Q?f5Kx9oJEcZyesjqX6rejOCtqcfhaE0rWKA9GcvcGj0Dkuk+l83+X9Sx9qHOP?= =?us-ascii?Q?bTirNt444ArnIHSKiXWwfr6EScE6Ic39Nc7pLAekjhq7eWkc3hsV1g4jKE9v?= =?us-ascii?Q?uXrMWKKdAYuDlbTfdHbPsF8WR5SMwgBVGw+N+2QSUcd7cgh7ggE0CvDUd3o2?= =?us-ascii?Q?TpVOEro0pkyyX5HYpKtQ+m/UjTaeJ6I94X4VMdydlegjraQLLICGEA9L6gB+?= =?us-ascii?Q?9mYZHE8iskhPTx2e1UF3ABlF8oDdkolp5EcAIEy4ZHj3RsmX11xUXXYsRw+Q?= =?us-ascii?Q?tdJYMAmoOzIdyaxHIO+8PODYLP5IDoEoSxhmyzW+I0cKRdGAW5QipN6iQT9O?= =?us-ascii?Q?HmHQ9RumifExT/GTVS7Vd7+WnlOQ5XY3MFeCcsQIDL4sHYPplCJbu4BOBGAg?= =?us-ascii?Q?4aHjmx9qntoqtFuDMsh4sysd2aTqXZJ9+MgHt6A2WI4c/06gVyOBW/b3X55F?= =?us-ascii?Q?jYklGD3msT9pUK5C706s94D8TWDzHeyfULx/aJ96pXmHcEjQHkKH5LUkufLo?= =?us-ascii?Q?MHVr2nB2UZ88WM1rgNN5I8T43+hc2+Bs/ytydKPSC1Ujw35on6qkJAvENTY9?= =?us-ascii?Q?z407rrlVh9UsI3fka319cuCAep+IAdEAXCVSIjrb2SpEvEqyZE58m/BNlZgF?= =?us-ascii?Q?EsVLQBz6izQkR+WflcxFcNiIpa/p4vzhayeK/1atrUFSMIs2zEaylz2ldMnm?= =?us-ascii?Q?6Kad5ZrNhIfp1QjE4EuIwVOcPSFm0+I/kEnHcxlN66jQg/un5CCL4t5t8kx6?= =?us-ascii?Q?yunnc59mwvcC9HZJxcdaohyUIi8sBXj/KgI4RxjmOnpSo+MAJnzxDAHhCCU1?= =?us-ascii?Q?2zewL6IAO3PEIvGM8evAcpKqezLTZ9x/GLPOyvp3P79vOufGQ8qbNY/WYTCu?= =?us-ascii?Q?xgOToL0olaz+iRiObpiKDEUCMens2WuU3I0bUPFyxLTqgX7VqJaXjhDVTOiA?= =?us-ascii?Q?ppdor4G0o1UHK+Bij7UuFCgEZkpKrioVheyTs94rjpr+IJUkOaSQ5/Ip3Tra?= =?us-ascii?Q?/Sho4k0sybpNINGQkZNHxVI+?= X-MS-Exchange-Transport-CrossTenantHeadersStamped: PAXPR08MB6558 Original-Authentication-Results: sourceware.org; dkim=none (message not signed) header.d=none; sourceware.org; dmarc=none action=none header.from=arm.com; X-EOPAttributedMessage: 0 X-MS-Exchange-Transport-CrossTenantHeadersStripped: AM5EUR03FT039.eop-EUR03.prod.protection.outlook.com X-MS-Office365-Filtering-Correlation-Id-Prvs: 834bacea-a65e-4f0e-f1cd-08d8fe550f4f 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:(4636009)(396003)(39860400002)(346002)(376002)(136003)(46966006)(36840700001)(36860700001)(26005)(70206006)(8676002)(478600001)(86362001)(6512007)(2906002)(44832011)(82740400003)(6486002)(356005)(336012)(47076005)(6506007)(36756003)(956004)(81166007)(70586007)(16526019)(2616005)(316002)(8936002)(83380400001)(5660300002)(6666004)(6916009)(82310400003)(186003)(69590400012); DIR:OUT; SFP:1101; X-OriginatorOrg: arm.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Apr 2021 08:21:09.5343 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 72659760-f56a-4a6a-f718-08d8fe5517ad 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: AM5EUR03FT039.eop-EUR03.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: PR3PR08MB5785 X-Spam-Status: No, score=-13.8 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, GIT_PATCH_0, MSGID_FROM_MTA_HEADER, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_PASS, SPF_PASS, TXREP, UNPARSEABLE_RELAY autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 13 Apr 2021 08:21:14 -0000 Lazy tlsdesc relocation is racy because the static tls optimization and tlsdesc management operations are done without holding the dlopen lock. This similar to the commit b7cf203b5c17dd6d9878537d41e0c7cc3d270a67 for aarch64, but it fixes a different race: bug 27137. On i386 the code is a bit more complicated than on x86_64 because both rel and rela relocs are supported. --- sysdeps/i386/dl-machine.h | 76 ++++++++++++++++++--------------------- 1 file changed, 34 insertions(+), 42 deletions(-) diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h index 23e9cc3bfb..590b41d8d7 100644 --- a/sysdeps/i386/dl-machine.h +++ b/sysdeps/i386/dl-machine.h @@ -688,50 +688,32 @@ elf_machine_lazy_rel (struct link_map *map, } else if (__glibc_likely (r_type == R_386_TLS_DESC)) { - struct tlsdesc volatile * __attribute__((__unused__)) td = - (struct tlsdesc volatile *)reloc_addr; - - /* Handle relocations that reference the local *ABS* in a simple - way, so as to preserve a potential addend. */ - if (ELF32_R_SYM (reloc->r_info) == 0) - td->entry = _dl_tlsdesc_resolve_abs_plus_addend; - /* Given a known-zero addend, we can store a pointer to the - reloc in the arg position. */ - else if (td->arg == 0) - { - td->arg = (void*)reloc; - td->entry = _dl_tlsdesc_resolve_rel; - } - else - { - /* We could handle non-*ABS* relocations with non-zero addends - by allocating dynamically an arg to hold a pointer to the - reloc, but that sounds pointless. */ - const Elf32_Rel *const r = reloc; - /* The code below was borrowed from elf_dynamic_do_rel(). */ - const ElfW(Sym) *const symtab = - (const void *) D_PTR (map, l_info[DT_SYMTAB]); + const Elf32_Rel *const r = reloc; + /* The code below was borrowed from elf_dynamic_do_rel(). */ + const ElfW(Sym) *const symtab = + (const void *) D_PTR (map, l_info[DT_SYMTAB]); + /* Always initialize TLS descriptors completely at load time, in + case static TLS is allocated for it that requires locking. */ # ifdef RTLD_BOOTSTRAP - /* The dynamic linker always uses versioning. */ - assert (map->l_info[VERSYMIDX (DT_VERSYM)] != NULL); + /* The dynamic linker always uses versioning. */ + assert (map->l_info[VERSYMIDX (DT_VERSYM)] != NULL); # else - if (map->l_info[VERSYMIDX (DT_VERSYM)]) + if (map->l_info[VERSYMIDX (DT_VERSYM)]) # endif - { - const ElfW(Half) *const version = - (const void *) D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]); - ElfW(Half) ndx = version[ELFW(R_SYM) (r->r_info)] & 0x7fff; - elf_machine_rel (map, r, &symtab[ELFW(R_SYM) (r->r_info)], - &map->l_versions[ndx], - (void *) (l_addr + r->r_offset), skip_ifunc); - } + { + const ElfW(Half) *const version = + (const void *) D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]); + ElfW(Half) ndx = version[ELFW(R_SYM) (r->r_info)] & 0x7fff; + elf_machine_rel (map, r, &symtab[ELFW(R_SYM) (r->r_info)], + &map->l_versions[ndx], + (void *) (l_addr + r->r_offset), skip_ifunc); + } # ifndef RTLD_BOOTSTRAP - else - elf_machine_rel (map, r, &symtab[ELFW(R_SYM) (r->r_info)], NULL, - (void *) (l_addr + r->r_offset), skip_ifunc); + else + elf_machine_rel (map, r, &symtab[ELFW(R_SYM) (r->r_info)], NULL, + (void *) (l_addr + r->r_offset), skip_ifunc); # endif - } } else if (__glibc_unlikely (r_type == R_386_IRELATIVE)) { @@ -758,11 +740,21 @@ elf_machine_lazy_rela (struct link_map *map, ; else if (__glibc_likely (r_type == R_386_TLS_DESC)) { - struct tlsdesc volatile * __attribute__((__unused__)) td = - (struct tlsdesc volatile *)reloc_addr; + const Elf_Symndx symndx = ELFW (R_SYM) (reloc->r_info); + const ElfW (Sym) *symtab = (const void *)D_PTR (map, l_info[DT_SYMTAB]); + const ElfW (Sym) *sym = &symtab[symndx]; + const struct r_found_version *version = NULL; + + if (map->l_info[VERSYMIDX (DT_VERSYM)] != NULL) + { + const ElfW (Half) *vernum = + (const void *)D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]); + version = &map->l_versions[vernum[symndx] & 0x7fff]; + } - td->arg = (void*)reloc; - td->entry = _dl_tlsdesc_resolve_rela; + /* Always initialize TLS descriptors completely at load time, in + case static TLS is allocated for it that requires locking. */ + elf_machine_rela (map, reloc, sym, version, reloc_addr, skip_ifunc); } else if (__glibc_unlikely (r_type == R_386_IRELATIVE)) { -- 2.17.1