From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BEF67C5DF65 for ; Wed, 6 Nov 2019 15:42:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9239C217F5 for ; Wed, 6 Nov 2019 15:42:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=nokia.onmicrosoft.com header.i=@nokia.onmicrosoft.com header.b="pJJSThKd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732089AbfKFPma (ORCPT ); Wed, 6 Nov 2019 10:42:30 -0500 Received: from mail-eopbgr60117.outbound.protection.outlook.com ([40.107.6.117]:21573 "EHLO EUR04-DB3-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727028AbfKFPma (ORCPT ); Wed, 6 Nov 2019 10:42:30 -0500 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=WPXZJgThj7uJcGl2AAmV9wcR7bopU6kzP3BUkjPeowosQyicN+Rc+6z2EMqzWc04zNiMgXkmLsWcYrK1S470eM7lioTnv0amxDG9nWZMSSFoptxS9MgL/Wdckjmdji6JTzty0urnBUuPuLhBA+hbmDjYndbKowVxV2aF7Qwy5Y3eLfSqXaX50d0b3B9T8ptYJ9QMy0KQifalyeU3CjIiJPKxuKdgUoVE+RCsQiPqEidNxTGNJmWYn+FuQ3MkjMk4fZeNKNiGer4Z1n+f88qRfKjnHkhCR82Kh09fLENsM2y/SaznL3OEjV7bkOY6icm9SWgmpFfsdOfXNavL3WEciA== 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=WZvUAGxaLgtGJWb2NDNBjCtddpwg6H2W0+Jv+MklurU=; b=Dg8f0JElqSHdlscl20PoOqt7shFcEcU61OsNj/9aaNKlRm/nI32FV+Zh5/H2As0gynduPCeXzhq5f9w4Txonnu2Mcvyi32RqXa5JZBnnDxsHleTIEClJG+55w5vlmeQMzfRGxBxxBoJeir351mZmuOTYM2rxP/c4E89/fdzlHhP5XK2ZUHGmJBiLuy9u3pHG++gx2SkKsDhX8dfAPuOklFdqhKQxMdTouwD+e8p6N4xZC0l8x2KHpI4hfrGfPgTDF13HU99PtVomkWbT/nfrYWpodoDpbfcxVUIJ5ybiaz+GqEugpL38kbDl8zLehEtzIfS/AnHHl5/ZA/6W3vzGVQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nokia.com; dmarc=pass action=none header.from=nokia.com; dkim=pass header.d=nokia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nokia.onmicrosoft.com; s=selector1-nokia-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=WZvUAGxaLgtGJWb2NDNBjCtddpwg6H2W0+Jv+MklurU=; b=pJJSThKdZR/mwnLQFHfd+gjRIbbSd+s/fdpRCBLtlLThJvi+nP7OkXHUjzH7e/6FpXGomsgNnlZXIpvMWJYx8oRJ9Z6DxX04JwliFYwlqYhrDmQPUyeF6X5PuNmXKuvRUBTqWTn11FPSP7HFNEOIIwnBDIoOv1E+dmmmtbagjKs= Received: from VI1PR07MB5040.eurprd07.prod.outlook.com (20.177.203.20) by VI1PR07MB4287.eurprd07.prod.outlook.com (20.176.5.159) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2430.16; Wed, 6 Nov 2019 15:42:25 +0000 Received: from VI1PR07MB5040.eurprd07.prod.outlook.com ([fe80::ec3b:5048:b5f7:2826]) by VI1PR07MB5040.eurprd07.prod.outlook.com ([fe80::ec3b:5048:b5f7:2826%5]) with mapi id 15.20.2430.020; Wed, 6 Nov 2019 15:42:24 +0000 From: "Sverdlin, Alexander (Nokia - DE/Ulm)" To: "linux-kernel@vger.kernel.org" CC: "Sverdlin, Alexander (Nokia - DE/Ulm)" , Marc Kleine-Budde , "Steven Rostedt (VMware)" , Sasha Levin , "linux-arm-kernel@lists.infradead.org" , "stable@vger.kernel.org" Subject: [PATCH v2] ARM: ftrace/recordmcount: filter relocation types Thread-Topic: [PATCH v2] ARM: ftrace/recordmcount: filter relocation types Thread-Index: AQHVlLjJ3L9/ljk2bEOhhVB0w3EsXA== Date: Wed, 6 Nov 2019 15:42:24 +0000 Message-ID: <20191106154209.118919-1-alexander.sverdlin@nokia.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [131.228.32.181] x-mailer: git-send-email 2.23.0 x-clientproxiedby: HE1PR05CA0197.eurprd05.prod.outlook.com (2603:10a6:3:f9::21) To VI1PR07MB5040.eurprd07.prod.outlook.com (2603:10a6:803:9c::20) authentication-results: spf=none (sender IP is ) smtp.mailfrom=alexander.sverdlin@nokia.com; x-ms-exchange-messagesentrepresentingtype: 1 x-ms-publictraffictype: Email x-ms-office365-filtering-ht: Tenant x-ms-office365-filtering-correlation-id: d1790361-7bf5-4f1c-3707-08d762cfeb96 x-ms-traffictypediagnostic: VI1PR07MB4287: x-ms-exchange-purlcount: 2 x-ms-exchange-transport-forked: True x-microsoft-antispam-prvs: x-ms-oob-tlc-oobclassifiers: OLM:8882; x-forefront-prvs: 02135EB356 x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(396003)(376002)(366004)(346002)(39860400002)(136003)(189003)(199004)(54534003)(2351001)(478600001)(5660300002)(6506007)(4326008)(386003)(14454004)(52116002)(966005)(6306002)(2616005)(26005)(486006)(25786009)(36756003)(102836004)(6486002)(316002)(5640700003)(6916009)(6512007)(476003)(54906003)(6436002)(1076003)(99286004)(186003)(81156014)(256004)(14444005)(305945005)(7736002)(2501003)(66476007)(66556008)(64756008)(66446008)(71190400001)(3846002)(71200400001)(6116002)(66946007)(66066001)(8936002)(81166006)(2906002)(86362001)(8676002)(50226002);DIR:OUT;SFP:1102;SCL:1;SRVR:VI1PR07MB4287;H:VI1PR07MB5040.eurprd07.prod.outlook.com;FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;MX:1;A:1; received-spf: None (protection.outlook.com: nokia.com does not designate permitted sender hosts) x-ms-exchange-senderadcheck: 1 x-microsoft-antispam: BCL:0; x-microsoft-antispam-message-info: l1NQYYq1e5RTtgU/GYjCNFsfcwDmCWXFEO+M3LogAep4WGrYcoqtEznIvT7Me+wOH6dxu0LtX7VRX+KnXJMAWFd6M83gyw10SlHmmVxQRDUU4dmFE1YApdUDqFR4gghkRE1gu0UkrCT5Np248nNHykrKO5Mms5ajU+l1Qlwdf2sr5NQLPU+pdJ4YlHNHq8tEzH4YdIWaJbLrPLfljPJDnlFU1l/Ljaq2azqSDFVqaLEyt1W6VmUs+bIlgqsQ+XHNdNw09V+cde0ZghpMxirooUJAWHRtPay1vAoVClFFffgDR7uac7exfPTcKS1hJg2dl/cSQQjk1UXJXW50p6RV4Qn8EuZXADzLSPj10JHr3MpsunFoMFj0BVIBL23COBN2HJUXgp4P4eHZRZN9eAh+D0trIzSD/oDxCtvfh81rxheMMedZYdIm4Ir82AAHgpfQERR1OpCaUaXn69UVzFgO9i4DkswAzHDCWJFEPkrLqOQ= Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: nokia.com X-MS-Exchange-CrossTenant-Network-Message-Id: d1790361-7bf5-4f1c-3707-08d762cfeb96 X-MS-Exchange-CrossTenant-originalarrivaltime: 06 Nov 2019 15:42:24.8176 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 5d471751-9675-428d-917b-70f44f9630b0 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: DgkQj7kYcwdH6ITA7J1wOda9lYIqXDt3gN3SL3Iki0WBEK8auL4JuYKMPYzYi96/XL/UN5j9kKPJm7XogOoPCRXkXIkHWjk/x89Jnb3fEd8= X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR07MB4287 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Alexander Sverdlin Scenario 1, ARMv7 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D If code in arch/arm/kernel/ftrace.c would operate on mcount() pointer the following may be generated: 00000230 : 230: b5f8 push {r3, r4, r5, r6, r7, lr} 232: b500 push {lr} 234: f7ff fffe bl 0 <__gnu_mcount_nc> 234: R_ARM_THM_CALL __gnu_mcount_nc 238: f240 0600 movw r6, #0 238: R_ARM_THM_MOVW_ABS_NC __gnu_mcount_nc 23c: f8d0 1180 ldr.w r1, [r0, #384] ; 0x180 FTRACE currently is not able to deal with it: WARNING: CPU: 0 PID: 0 at .../kernel/trace/ftrace.c:1979 ftrace_bug+0x1ad/0= x230() ... CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.116-... #1 ... [] (unwind_backtrace) from [] (show_stack+0x11/0x14) [] (show_stack) from [] (dump_stack+0x81/0xa8) [] (dump_stack) from [] (warn_slowpath_common+0x69/0x90= ) [] (warn_slowpath_common) from [] (warn_slowpath_null+0= x17/0x1c) [] (warn_slowpath_null) from [] (ftrace_bug+0x1ad/0x230= ) [] (ftrace_bug) from [] (ftrace_process_locs+0x27d/0x44= 4) [] (ftrace_process_locs) from [] (ftrace_init+0x91/0xe8= ) [] (ftrace_init) from [] (start_kernel+0x34b/0x358) [] (start_kernel) from [<00308095>] (0x308095) ---[ end trace cb88537fdc8fa200 ]--- ftrace failed to modify [] prealloc_fixed_plts+0x8/0x60 actual: 44:f2:e1:36 ftrace record flags: 0 (0) expected tramp: c03143e9 Scenario 2, ARMv4T =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D ftrace: allocating 14435 entries in 43 pages ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/trace/ftrace.c:2029 ftrace_bug+0x204/0x310 CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.5 #1 Hardware name: Cirrus Logic EDB9302 Evaluation Board [] (unwind_backtrace) from [] (show_stack+0x20/0x2c) [] (show_stack) from [] (dump_stack+0x20/0x30) [] (dump_stack) from [] (__warn+0xdc/0x104) [] (__warn) from [] (warn_slowpath_null+0x4c/0x5c) [] (warn_slowpath_null) from [] (ftrace_bug+0x204/0x310= ) [] (ftrace_bug) from [] (ftrace_init+0x3b4/0x4d4) [] (ftrace_init) from [] (start_kernel+0x20c/0x410) [] (start_kernel) from [<00000000>] ( (null)) ---[ end trace 0506a2f5dae6b341 ]--- ftrace failed to modify [] perf_trace_sys_exit+0x5c/0xe8 actual: 1e:ff:2f:e1 Initializing ftrace call sites ftrace record flags: 0 (0) expected tramp: c000fb24 The analysis for this problem has been already performed previously, refer to the link below. Fix the above problems by allowing only selected reloc types in __mcount_loc. The list itself comes from the legacy recordmcount.pl script. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/lkml/56961010.6000806@pengutronix.de/ Fixes: ed60453fa8 ("ARM: 6511/1: ftrace: add ARM support for C version of r= ecordmcount") Signed-off-by: Alexander Sverdlin --- Changelog: v2: Rebased scripts/recordmcount.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/scripts/recordmcount.c b/scripts/recordmcount.c index 612268e..6872d26 100644 --- a/scripts/recordmcount.c +++ b/scripts/recordmcount.c @@ -38,6 +38,10 @@ #define R_AARCH64_ABS64 257 #endif =20 +#define R_ARM_PC24 1 +#define R_ARM_THM_CALL 10 +#define R_ARM_CALL 28 + static int fd_map; /* File descriptor for file being modified. */ static int mmap_failed; /* Boolean flag. */ static char gpfx; /* prefix for global symbol name (sometimes '_') */ @@ -418,6 +422,18 @@ static char const *already_has_rel_mcount =3D "success= "; /* our work here is done! #define RECORD_MCOUNT_64 #include "recordmcount.h" =20 +static int arm_is_fake_mcount(Elf32_Rel const *rp) +{ + switch (ELF32_R_TYPE(w(rp->r_info))) { + case R_ARM_THM_CALL: + case R_ARM_CALL: + case R_ARM_PC24: + return 0; + } + + return 1; +} + /* 64-bit EM_MIPS has weird ELF64_Rela.r_info. * http://techpubs.sgi.com/library/manuals/4000/007-4658-001/pdf/007-4658-= 001.pdf * We interpret Table 29 Relocation Operation (Elf64_Rel, Elf64_Rela) [p.4= 0] @@ -523,6 +539,7 @@ static int do_file(char const *const fname) altmcount =3D "__gnu_mcount_nc"; make_nop =3D make_nop_arm; rel_type_nop =3D R_ARM_NONE; + is_fake_mcount32 =3D arm_is_fake_mcount; gpfx =3D 0; break; case EM_AARCH64: --=20 2.4.6 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 01534C5DF63 for ; Wed, 6 Nov 2019 15:42:38 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C774721848 for ; Wed, 6 Nov 2019 15:42:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="hWclwSxr"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=nokia.onmicrosoft.com header.i=@nokia.onmicrosoft.com header.b="pJJSThKd" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C774721848 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nokia.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=wIJUeyKseoABUEKH7iCR/kOzLOuBOknF4q5oRLApbaA=; b=hWclwSxr51zcBR ekHAzcjwFGKt+ZwKNAPxw03wIatPOopg4sCuKLtvy7G0P9LDYz47Rt9UJHAGafL9kvgAcZUtLQfT1 KPN41nOpZ8F7DioInu4ORma8oTP+ThZl12d4lGge9inWuARNbaiLFGu9BLgM3qTpG4YOTOwZXvzKd SqjzR9KHWRjU07w4R+O2xfgBh4d+JqTyCHiw0Z4CZDKQwl3/gq5R5a7ECkqTWK+pU4jneVJ7MK9T8 S0NZRQ2aP5hbqL83c9m0Ru2F1ZIqWSIHCjVVDUofKaChvhawsDrrauu/KPVaf/ovD58/IFIdLCcra cxPjwX8BSNKQI0DK+aZA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iSNS8-0001IM-TU; Wed, 06 Nov 2019 15:42:36 +0000 Received: from mail-eopbgr60112.outbound.protection.outlook.com ([40.107.6.112] helo=EUR04-DB3-obe.outbound.protection.outlook.com) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iSNS4-00015w-Hl for linux-arm-kernel@lists.infradead.org; Wed, 06 Nov 2019 15:42:34 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=WPXZJgThj7uJcGl2AAmV9wcR7bopU6kzP3BUkjPeowosQyicN+Rc+6z2EMqzWc04zNiMgXkmLsWcYrK1S470eM7lioTnv0amxDG9nWZMSSFoptxS9MgL/Wdckjmdji6JTzty0urnBUuPuLhBA+hbmDjYndbKowVxV2aF7Qwy5Y3eLfSqXaX50d0b3B9T8ptYJ9QMy0KQifalyeU3CjIiJPKxuKdgUoVE+RCsQiPqEidNxTGNJmWYn+FuQ3MkjMk4fZeNKNiGer4Z1n+f88qRfKjnHkhCR82Kh09fLENsM2y/SaznL3OEjV7bkOY6icm9SWgmpFfsdOfXNavL3WEciA== 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=WZvUAGxaLgtGJWb2NDNBjCtddpwg6H2W0+Jv+MklurU=; b=Dg8f0JElqSHdlscl20PoOqt7shFcEcU61OsNj/9aaNKlRm/nI32FV+Zh5/H2As0gynduPCeXzhq5f9w4Txonnu2Mcvyi32RqXa5JZBnnDxsHleTIEClJG+55w5vlmeQMzfRGxBxxBoJeir351mZmuOTYM2rxP/c4E89/fdzlHhP5XK2ZUHGmJBiLuy9u3pHG++gx2SkKsDhX8dfAPuOklFdqhKQxMdTouwD+e8p6N4xZC0l8x2KHpI4hfrGfPgTDF13HU99PtVomkWbT/nfrYWpodoDpbfcxVUIJ5ybiaz+GqEugpL38kbDl8zLehEtzIfS/AnHHl5/ZA/6W3vzGVQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nokia.com; dmarc=pass action=none header.from=nokia.com; dkim=pass header.d=nokia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nokia.onmicrosoft.com; s=selector1-nokia-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=WZvUAGxaLgtGJWb2NDNBjCtddpwg6H2W0+Jv+MklurU=; b=pJJSThKdZR/mwnLQFHfd+gjRIbbSd+s/fdpRCBLtlLThJvi+nP7OkXHUjzH7e/6FpXGomsgNnlZXIpvMWJYx8oRJ9Z6DxX04JwliFYwlqYhrDmQPUyeF6X5PuNmXKuvRUBTqWTn11FPSP7HFNEOIIwnBDIoOv1E+dmmmtbagjKs= Received: from VI1PR07MB5040.eurprd07.prod.outlook.com (20.177.203.20) by VI1PR07MB4287.eurprd07.prod.outlook.com (20.176.5.159) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2430.16; Wed, 6 Nov 2019 15:42:25 +0000 Received: from VI1PR07MB5040.eurprd07.prod.outlook.com ([fe80::ec3b:5048:b5f7:2826]) by VI1PR07MB5040.eurprd07.prod.outlook.com ([fe80::ec3b:5048:b5f7:2826%5]) with mapi id 15.20.2430.020; Wed, 6 Nov 2019 15:42:24 +0000 From: "Sverdlin, Alexander (Nokia - DE/Ulm)" To: "linux-kernel@vger.kernel.org" Subject: [PATCH v2] ARM: ftrace/recordmcount: filter relocation types Thread-Topic: [PATCH v2] ARM: ftrace/recordmcount: filter relocation types Thread-Index: AQHVlLjJ3L9/ljk2bEOhhVB0w3EsXA== Date: Wed, 6 Nov 2019 15:42:24 +0000 Message-ID: <20191106154209.118919-1-alexander.sverdlin@nokia.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [131.228.32.181] x-mailer: git-send-email 2.23.0 x-clientproxiedby: HE1PR05CA0197.eurprd05.prod.outlook.com (2603:10a6:3:f9::21) To VI1PR07MB5040.eurprd07.prod.outlook.com (2603:10a6:803:9c::20) authentication-results: spf=none (sender IP is ) smtp.mailfrom=alexander.sverdlin@nokia.com; x-ms-exchange-messagesentrepresentingtype: 1 x-ms-publictraffictype: Email x-ms-office365-filtering-ht: Tenant x-ms-office365-filtering-correlation-id: d1790361-7bf5-4f1c-3707-08d762cfeb96 x-ms-traffictypediagnostic: VI1PR07MB4287: x-ms-exchange-purlcount: 2 x-ms-exchange-transport-forked: True x-microsoft-antispam-prvs: x-ms-oob-tlc-oobclassifiers: OLM:8882; x-forefront-prvs: 02135EB356 x-forefront-antispam-report: SFV:NSPM; SFS:(10019020)(396003)(376002)(366004)(346002)(39860400002)(136003)(189003)(199004)(54534003)(2351001)(478600001)(5660300002)(6506007)(4326008)(386003)(14454004)(52116002)(966005)(6306002)(2616005)(26005)(486006)(25786009)(36756003)(102836004)(6486002)(316002)(5640700003)(6916009)(6512007)(476003)(54906003)(6436002)(1076003)(99286004)(186003)(81156014)(256004)(14444005)(305945005)(7736002)(2501003)(66476007)(66556008)(64756008)(66446008)(71190400001)(3846002)(71200400001)(6116002)(66946007)(66066001)(8936002)(81166006)(2906002)(86362001)(8676002)(50226002); DIR:OUT; SFP:1102; SCL:1; SRVR:VI1PR07MB4287; H:VI1PR07MB5040.eurprd07.prod.outlook.com; FPR:; SPF:None; LANG:en; PTR:InfoNoRecords; MX:1; A:1; received-spf: None (protection.outlook.com: nokia.com does not designate permitted sender hosts) x-ms-exchange-senderadcheck: 1 x-microsoft-antispam: BCL:0; x-microsoft-antispam-message-info: l1NQYYq1e5RTtgU/GYjCNFsfcwDmCWXFEO+M3LogAep4WGrYcoqtEznIvT7Me+wOH6dxu0LtX7VRX+KnXJMAWFd6M83gyw10SlHmmVxQRDUU4dmFE1YApdUDqFR4gghkRE1gu0UkrCT5Np248nNHykrKO5Mms5ajU+l1Qlwdf2sr5NQLPU+pdJ4YlHNHq8tEzH4YdIWaJbLrPLfljPJDnlFU1l/Ljaq2azqSDFVqaLEyt1W6VmUs+bIlgqsQ+XHNdNw09V+cde0ZghpMxirooUJAWHRtPay1vAoVClFFffgDR7uac7exfPTcKS1hJg2dl/cSQQjk1UXJXW50p6RV4Qn8EuZXADzLSPj10JHr3MpsunFoMFj0BVIBL23COBN2HJUXgp4P4eHZRZN9eAh+D0trIzSD/oDxCtvfh81rxheMMedZYdIm4Ir82AAHgpfQERR1OpCaUaXn69UVzFgO9i4DkswAzHDCWJFEPkrLqOQ= MIME-Version: 1.0 X-OriginatorOrg: nokia.com X-MS-Exchange-CrossTenant-Network-Message-Id: d1790361-7bf5-4f1c-3707-08d762cfeb96 X-MS-Exchange-CrossTenant-originalarrivaltime: 06 Nov 2019 15:42:24.8176 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 5d471751-9675-428d-917b-70f44f9630b0 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: DgkQj7kYcwdH6ITA7J1wOda9lYIqXDt3gN3SL3Iki0WBEK8auL4JuYKMPYzYi96/XL/UN5j9kKPJm7XogOoPCRXkXIkHWjk/x89Jnb3fEd8= X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR07MB4287 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191106_074232_606445_C520191B X-CRM114-Status: GOOD ( 11.23 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "stable@vger.kernel.org" , Sasha Levin , Marc Kleine-Budde , "Steven Rostedt \(VMware\)" , "Sverdlin, Alexander \(Nokia - DE/Ulm\)" , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Alexander Sverdlin Scenario 1, ARMv7 ================= If code in arch/arm/kernel/ftrace.c would operate on mcount() pointer the following may be generated: 00000230 : 230: b5f8 push {r3, r4, r5, r6, r7, lr} 232: b500 push {lr} 234: f7ff fffe bl 0 <__gnu_mcount_nc> 234: R_ARM_THM_CALL __gnu_mcount_nc 238: f240 0600 movw r6, #0 238: R_ARM_THM_MOVW_ABS_NC __gnu_mcount_nc 23c: f8d0 1180 ldr.w r1, [r0, #384] ; 0x180 FTRACE currently is not able to deal with it: WARNING: CPU: 0 PID: 0 at .../kernel/trace/ftrace.c:1979 ftrace_bug+0x1ad/0x230() ... CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.116-... #1 ... [] (unwind_backtrace) from [] (show_stack+0x11/0x14) [] (show_stack) from [] (dump_stack+0x81/0xa8) [] (dump_stack) from [] (warn_slowpath_common+0x69/0x90) [] (warn_slowpath_common) from [] (warn_slowpath_null+0x17/0x1c) [] (warn_slowpath_null) from [] (ftrace_bug+0x1ad/0x230) [] (ftrace_bug) from [] (ftrace_process_locs+0x27d/0x444) [] (ftrace_process_locs) from [] (ftrace_init+0x91/0xe8) [] (ftrace_init) from [] (start_kernel+0x34b/0x358) [] (start_kernel) from [<00308095>] (0x308095) ---[ end trace cb88537fdc8fa200 ]--- ftrace failed to modify [] prealloc_fixed_plts+0x8/0x60 actual: 44:f2:e1:36 ftrace record flags: 0 (0) expected tramp: c03143e9 Scenario 2, ARMv4T ================== ftrace: allocating 14435 entries in 43 pages ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/trace/ftrace.c:2029 ftrace_bug+0x204/0x310 CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.5 #1 Hardware name: Cirrus Logic EDB9302 Evaluation Board [] (unwind_backtrace) from [] (show_stack+0x20/0x2c) [] (show_stack) from [] (dump_stack+0x20/0x30) [] (dump_stack) from [] (__warn+0xdc/0x104) [] (__warn) from [] (warn_slowpath_null+0x4c/0x5c) [] (warn_slowpath_null) from [] (ftrace_bug+0x204/0x310) [] (ftrace_bug) from [] (ftrace_init+0x3b4/0x4d4) [] (ftrace_init) from [] (start_kernel+0x20c/0x410) [] (start_kernel) from [<00000000>] ( (null)) ---[ end trace 0506a2f5dae6b341 ]--- ftrace failed to modify [] perf_trace_sys_exit+0x5c/0xe8 actual: 1e:ff:2f:e1 Initializing ftrace call sites ftrace record flags: 0 (0) expected tramp: c000fb24 The analysis for this problem has been already performed previously, refer to the link below. Fix the above problems by allowing only selected reloc types in __mcount_loc. The list itself comes from the legacy recordmcount.pl script. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/lkml/56961010.6000806@pengutronix.de/ Fixes: ed60453fa8 ("ARM: 6511/1: ftrace: add ARM support for C version of recordmcount") Signed-off-by: Alexander Sverdlin --- Changelog: v2: Rebased scripts/recordmcount.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/scripts/recordmcount.c b/scripts/recordmcount.c index 612268e..6872d26 100644 --- a/scripts/recordmcount.c +++ b/scripts/recordmcount.c @@ -38,6 +38,10 @@ #define R_AARCH64_ABS64 257 #endif +#define R_ARM_PC24 1 +#define R_ARM_THM_CALL 10 +#define R_ARM_CALL 28 + static int fd_map; /* File descriptor for file being modified. */ static int mmap_failed; /* Boolean flag. */ static char gpfx; /* prefix for global symbol name (sometimes '_') */ @@ -418,6 +422,18 @@ static char const *already_has_rel_mcount = "success"; /* our work here is done! #define RECORD_MCOUNT_64 #include "recordmcount.h" +static int arm_is_fake_mcount(Elf32_Rel const *rp) +{ + switch (ELF32_R_TYPE(w(rp->r_info))) { + case R_ARM_THM_CALL: + case R_ARM_CALL: + case R_ARM_PC24: + return 0; + } + + return 1; +} + /* 64-bit EM_MIPS has weird ELF64_Rela.r_info. * http://techpubs.sgi.com/library/manuals/4000/007-4658-001/pdf/007-4658-001.pdf * We interpret Table 29 Relocation Operation (Elf64_Rel, Elf64_Rela) [p.40] @@ -523,6 +539,7 @@ static int do_file(char const *const fname) altmcount = "__gnu_mcount_nc"; make_nop = make_nop_arm; rel_type_nop = R_ARM_NONE; + is_fake_mcount32 = arm_is_fake_mcount; gpfx = 0; break; case EM_AARCH64: -- 2.4.6 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel