From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-3695087-1523236159-2-6597064065871810675 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.25, MAILING_LIST_MULTI -1, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='com', MailFrom='org', XOriginatingCountry='US' X-Spam-charsets: plain='iso-8859-1' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=fm2; t= 1523236159; b=azLWbyOuJ0Xfa94lhARRsVSiq7N87wYbWtePCQdVsxUuHDmZ/w /zHbpB8lRZyx96q+bdZcVO0bKJwi+Za2yX9NPsiIjh60tosj/z5MjECy6imHwcEL WByIetCNZfvKHDHFHYArsg97KYlRvdLYF7vKNt444p2vlVuxlKGUiUVXvKcx5/nf IsMhukL4vbcwDf8/KkPbB6Clulup0D726mRThucAnGZVr5rgZypbyHpbbrA6Ox2n P5sMX2pKe2EIfi9dDQCk3jSS8Gre3bEmWSMevND4tSg6o6ynAGEtaaFpS78vFr3B Z5n9coRTZ7UXmxIzApPJU1BDFKDO71Rr+qcw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :references:in-reply-to:content-type:content-transfer-encoding :mime-version:sender:list-id; s=fm2; t=1523236159; bh=UR+hyys3eh hCBStH+JzvzUmSoWiuhwbvfRTrqdkSfY0=; b=JKnf5DDoVQ/2kO4L3DwsYJHWi6 TY0roWBx02gIIM4sAB2ZBrGYWKSm5rv8Y3jgdIDSkXWm2vrJzA2U6B1np+uimaB1 7b1npJ7DAnw1JDdArF7zWH5LzbNWtdL7jmhWchyyo3O2A2cTtHYfxRk0efckRdGO 7DNWYsZHtlO8+8OUEkvTCwBLncR+UvogBGk5dCe++Gh0jDVKW6lXJDrFWfdBt7yG NWoEuaTkj5zfQ+OFz7Rf/kBxsEZFgwMzHcQS1iyD5AWypkIVrvpbEfrEUqKaf+Re sLe8UHXoMcuLxaLGFTXUIAvgNvNX7+webdzcKID9G6vsevlUgd1fZj57pLMA== ARC-Authentication-Results: i=1; mx1.messagingengine.com; arc=none (no signatures found); dkim=pass (1024-bit rsa key sha256) header.d=microsoft.com header.i=@microsoft.com header.b=MmH6fEgX x-bits=1024 x-keytype=rsa x-algorithm=sha256 x-selector=selector1; dmarc=pass (p=reject,has-list-id=yes,d=none) header.from=microsoft.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=microsoft.com header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 Authentication-Results: mx1.messagingengine.com; arc=none (no signatures found); dkim=pass (1024-bit rsa key sha256) header.d=microsoft.com header.i=@microsoft.com header.b=MmH6fEgX x-bits=1024 x-keytype=rsa x-algorithm=sha256 x-selector=selector1; dmarc=pass (p=reject,has-list-id=yes,d=none) header.from=microsoft.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=microsoft.com header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 X-ME-VSCategory: clean X-CM-Envelope: MS4wfBs8amLJgAxhl04g4OzoPU2X76hvpe3xcRxcX1z6ea8yPvqP0CsbFu7isQ5qRmDqIqIpcsPzRiO5uuQ1Kib1Tw11d5aiT9Dz8ittz1fgR7nqRJ3yoa9b emp400r1rBZqMTjL+WElAd2t/btrJ3vUy6RYdiCl44WV6oqvNEZLp9Hvi9jjC9mqa/mzGO8qSoSZGVNgepaZt/gw2n+fo7mRwT8tiM9V1kL/5oqDOkG6zber X-CM-Analysis: v=2.3 cv=WaUilXpX c=1 sm=1 tr=0 a=UK1r566ZdBxH71SXbqIOeA==:117 a=UK1r566ZdBxH71SXbqIOeA==:17 a=wRwT6uffUbIA:10 a=t_PdEiP4ckcA:10 a=mw6kJ3eo-EIA:10 a=8nJEP1OIZ-IA:10 a=xqWC_Br6kY4A:10 a=Kd1tUaAdevIA:10 a=Lf-vpJhqX20A:10 a=QyXUC8HyAAAA:8 a=VwQbUJbxAAAA:8 a=20KFwNOVAAAA:8 a=VnNF1IyMAAAA:8 a=7CQSdrXTAAAA:8 a=zAyngx5bAAAA:8 a=J1Y8HTJGAAAA:8 a=oGMlB6cnAAAA:8 a=1XWaLZrsAAAA:8 a=yPCof4ZbAAAA:8 a=WPyIoOwQAAAA:8 a=jIQo8A4GAAAA:8 a=Z4Rwk6OoAAAA:8 a=yMhMjlubAAAA:8 a=hzj1nXxdle4KTAAxqCMA:9 a=pXx8G1reow-gFZz4:21 a=bRviJrUD4RDb5aqL:21 a=wPNLvfGTeEIA:10 a=AjGcO6oz07-iQ99wixmX:22 a=a-qgeE7W1pNrGK8U0ZQC:22 a=4LA4qAFo6bo561LpWNDU:22 a=y1Q9-5lHfBjTkpIzbSAN:22 a=NdAtdrkLVvyUPsUoGJp4:22 a=S-HzPIwwDS8t1QcwSuWs:22 a=Lf5xNeLK5dgiOs8hzIjU:22 a=HkZW87K1Qel5hWWM3VKY:22 X-ME-CMScore: 0 X-ME-CMCategory: none Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755839AbeDIBJO (ORCPT ); Sun, 8 Apr 2018 21:09:14 -0400 Received: from mail-co1nam03on0120.outbound.protection.outlook.com ([104.47.40.120]:40064 "EHLO NAM03-CO1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933028AbeDIAir (ORCPT ); Sun, 8 Apr 2018 20:38:47 -0400 From: Sasha Levin To: "stable@vger.kernel.org" , "linux-kernel@vger.kernel.org" CC: "Kirill A. Shutemov" , Vlastimil Babka , Andrea Arcangeli , Michal Hocko , "Aneesh Kumar K . V" , Catalin Marinas , David Daney , David Miller , "H . Peter Anvin" , Hugh Dickins , Ingo Molnar , Martin Schwidefsky , Nitin Gupta , Ralf Baechle , Thomas Gleixner , Vineet Gupta , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH AUTOSEL for 4.4 141/162] asm-generic: provide generic_pmdp_establish() Thread-Topic: [PATCH AUTOSEL for 4.4 141/162] asm-generic: provide generic_pmdp_establish() Thread-Index: AQHTz5nXr8zZBffnAU+/Ufrota+3Ww== Date: Mon, 9 Apr 2018 00:29:38 +0000 Message-ID: <20180409002738.163941-141-alexander.levin@microsoft.com> References: <20180409002738.163941-1-alexander.levin@microsoft.com> In-Reply-To: <20180409002738.163941-1-alexander.levin@microsoft.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [52.168.54.252] x-ms-publictraffictype: Email x-microsoft-exchange-diagnostics: 1;DM5PR2101MB1125;7:SO/DqMWU/E2edGgG9FHHcDPjCUDOFp+HiFCKJWjam0in0eieE1IpI7kppl2Dus4nYgLuKNXw/J3dPQPNRfWhiXRTNRqh2C/FWkBLaX4mXsKa4ZP6Znp64UP3IGGBrVRgTo+S0VRwhP1kui9n7sFnXAsesOAP7xzwyiF6K3sGB5kEUSSbRUb5LmQ1Ym0hZm9gNvRqgqxTM8A4sTqqTwktSJIbTo6Sfbqx/tWPy7ye/soISwAxhOciK44opzlvXPSg;20:IANdjCCLmu90Wj8s6FFZy4mqd8v5tAf1ynjeuLuJdNjtEBalgrN0DHGP5kZLdtSz20XLHjqBk+TjnqeEzkh4JXLSxW4K1hol8PWuIdXezqKqWWmAs4dOG9IzmuFUlcGFUvtO8Y2wYXLnoXplIYxwI+6+sZJeyyy27rrtU4hY42c= X-MS-Office365-Filtering-Correlation-Id: 44fc20ed-68e5-4bd2-9139-08d59db23ea8 x-ms-office365-filtering-ht: Tenant x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:(7020095)(4652020)(4534165)(4627221)(201703031133081)(201702281549075)(5600026)(4604075)(3008032)(48565401081)(2017052603328)(7193020);SRVR:DM5PR2101MB1125; x-ms-traffictypediagnostic: DM5PR2101MB1125: authentication-results: spf=none (sender IP is ) smtp.mailfrom=Alexander.Levin@microsoft.com; x-microsoft-antispam-prvs: x-exchange-antispam-report-test: UriScan:(28532068793085)(180628864354917)(20558992708506)(89211679590171)(190383065149520)(211936372134217)(42068640409301)(153496737603132)(104084551191319)(146099531331640); x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(8211001083)(61425038)(6040522)(2401047)(8121501046)(5005006)(3231221)(944501327)(52105095)(3002001)(93006095)(93001095)(10201501046)(6055026)(61426038)(61427038)(6041310)(20161123560045)(20161123564045)(20161123558120)(20161123562045)(201703131423095)(201702281528075)(20161123555045)(201703061421075)(201703061406153)(6072148)(201708071742011);SRVR:DM5PR2101MB1125;BCL:0;PCL:0;RULEID:;SRVR:DM5PR2101MB1125; x-forefront-prvs: 0637FCE711 x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(346002)(39860400002)(39380400002)(366004)(376002)(396003)(189003)(199004)(2906002)(25786009)(6512007)(10090500001)(3280700002)(10290500003)(6666003)(6306002)(3660700001)(316002)(110136005)(54906003)(11346002)(107886003)(2616005)(476003)(446003)(36756003)(7416002)(99286004)(86612001)(53936002)(4326008)(486006)(6436002)(3846002)(81156014)(305945005)(966005)(5250100002)(1076002)(102836004)(14454004)(66066001)(7736002)(105586002)(81166006)(59450400001)(106356001)(8676002)(97736004)(6116002)(6506007)(6486002)(5660300001)(186003)(76176011)(22452003)(72206003)(478600001)(2501003)(2900100001)(26005)(86362001)(575784001)(8936002)(68736007)(22906009)(41533002)(217873001);DIR:OUT;SFP:1102;SCL:1;SRVR:DM5PR2101MB1125;H:DM5PR2101MB1032.namprd21.prod.outlook.com;FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;MX:1;A:1; x-microsoft-antispam-message-info: 66r2XezClPjhjYhPvn1wjhD5Lx7OzzlsxI/I/TCWWwlaVeWabeFXYONzWUngmy5mnfa9Ja7vnnGPRmbG3y5pAHGvqKKzqEhy4HusDkR+MQsRG10NiIIVz5+jiA1QbzcjliCWvctd7K1wo+DeFdqZEWZAtvQcUUGcEK9xCE52Ty3Dg13vqoV5vTAYgd7TzHZdG83+4lPYJq4c/Wh0YQ0DuGvM7tT1oaLH52NyPNgEeAT4ITBFtl2yMJNon1gQ5JOJMxmgAS62pCsjGcSabpKSjru7Zrw0FkWZe49WjcC49QfjgD8F8tSNy+XSelsXa/eSIKMm8FuSwR8h2BSRvKmvFpbRyGqW4iZjX73HvAQ1nWps1D7pYYxRmaMV8dnwi/xIGGxBZnF2hVGIAaP91xS0q8HwkbizgFUNZoGAqccoQ48= spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: microsoft.com X-MS-Exchange-CrossTenant-Network-Message-Id: 44fc20ed-68e5-4bd2-9139-08d59db23ea8 X-MS-Exchange-CrossTenant-originalarrivaltime: 09 Apr 2018 00:29:38.2870 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 72f988bf-86f1-41af-91ab-2d7cd011db47 X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM5PR2101MB1125 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: From: "Kirill A. Shutemov" [ Upstream commit c58f0bb77ed8bf93dfdde762b01cb67eebbdfc29 ] Patch series "Do not lose dirty bit on THP pages", v4. Vlastimil noted that pmdp_invalidate() is not atomic and we can lose dirty and access bits if CPU sets them after pmdp dereference, but before set_pmd_at(). The bug can lead to data loss, but the race window is tiny and I haven't seen any reports that suggested that it happens in reality. So I don't think it worth sending it to stable. Unfortunately, there's no way to address the issue in a generic way. We need to fix all architectures that support THP one-by-one. All architectures that have THP supported have to provide atomic pmdp_invalidate() that returns previous value. If generic implementation of pmdp_invalidate() is used, architecture needs to provide atomic pmdp_estabish(). pmdp_estabish() is not used out-side generic implementation of pmdp_invalidate() so far, but I think this can change in the future. This patch (of 12): This is an implementation of pmdp_establish() that is only suitable for an architecture that doesn't have hardware dirty/accessed bits. In this case we can't race with CPU which sets these bits and non-atomic approach is fine. Link: http://lkml.kernel.org/r/20171213105756.69879-2-kirill.shutemov@linux= .intel.com Signed-off-by: Kirill A. Shutemov Cc: Vlastimil Babka Cc: Andrea Arcangeli Cc: Michal Hocko Cc: Aneesh Kumar K.V Cc: Catalin Marinas Cc: David Daney Cc: David Miller Cc: H. Peter Anvin Cc: Hugh Dickins Cc: Ingo Molnar Cc: Martin Schwidefsky Cc: Nitin Gupta Cc: Ralf Baechle Cc: Thomas Gleixner Cc: Vineet Gupta Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- include/asm-generic/pgtable.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 4814cf971048..25b793325b09 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -237,6 +237,21 @@ extern void pgtable_trans_huge_deposit(struct mm_struc= t *mm, pmd_t *pmdp, extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *= pmdp); #endif =20 +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +/* + * This is an implementation of pmdp_establish() that is only suitable for= an + * architecture that doesn't have hardware dirty/accessed bits. In this ca= se we + * can't race with CPU which sets these bits and non-atomic aproach is fin= e. + */ +static inline pmd_t generic_pmdp_establish(struct vm_area_struct *vma, + unsigned long address, pmd_t *pmdp, pmd_t pmd) +{ + pmd_t old_pmd =3D *pmdp; + set_pmd_at(vma->vm_mm, address, pmdp, pmd); + return old_pmd; +} +#endif + #ifndef __HAVE_ARCH_PMDP_INVALIDATE extern void pmdp_invalidate(struct vm_area_struct *vma, unsigned long addr= ess, pmd_t *pmdp); --=20 2.15.1