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=-0.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 41E57C76186 for ; Wed, 24 Jul 2019 18:52:58 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9BAFF21841 for ; Wed, 24 Jul 2019 18:52:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="U/B4/BsH"; dkim=pass (1024-bit key) header.d=fb.onmicrosoft.com header.i=@fb.onmicrosoft.com header.b="m/tM6G9W" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9BAFF21841 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=fb.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 130B48E0007; Wed, 24 Jul 2019 14:52:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0E2FD8E0003; Wed, 24 Jul 2019 14:52:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EC56A8E0007; Wed, 24 Jul 2019 14:52:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-yw1-f69.google.com (mail-yw1-f69.google.com [209.85.161.69]) by kanga.kvack.org (Postfix) with ESMTP id CBAA48E0003 for ; Wed, 24 Jul 2019 14:52:56 -0400 (EDT) Received: by mail-yw1-f69.google.com with SMTP id d135so35370576ywd.0 for ; Wed, 24 Jul 2019 11:52:56 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:dkim-signature:from:to:cc:subject :thread-topic:thread-index:date:message-id:references:in-reply-to :accept-language:content-language:content-id :content-transfer-encoding:mime-version; bh=aa1yNHhGub2q5giAEw5YCf3oqlsTy4a2Ha1OCMwoAtU=; b=RnvLP4ySeMIj8n7hyE8n2YA09xi7tYHBl3J/Bdy7xJGEQ9RgXg/zOw10xWu/Q3BVTj GPPJU/3QiW3sAlLKDvw1MozhkA6X60n3VbSw0J5c01WX8DfziRwYurgI3AGOt/QlzLkq 7FYSHbmaQotBq9bUM8qkAGzvpjm2p0RWrqsTOwxH4VDEcyD8quMC+7AreLigfTpwang5 laNSAUpW7NXS+Ic+H7C915Udh9+/KUCdXJdJ30xAb6YErf9nAsa4eKHtnvbcB2cnAame i393ZF8z9Xz2AmvWbDz0TybeKFVd8QT3ljDIfCKO00NLKWoCOnXI7M8FbSppjlWBDRh0 1fkg== X-Gm-Message-State: APjAAAUp9ZMOYUFOE+HJLK7Mql8s0RHE9lRtKG0d7nuDxR1myVhyu9h9 ts2xFDmL9x5QsUfUUff6NVR526Xqb4ttcxAfvZkYFZArUTb9gSmkUYBkDxrkkvM3qlvg8f2NFZ6 gsUKnqKMzZPm5KbpBhUhjmUf0Vmfvpzh52TiFM78E1NhXkRokxs2xtCsHJQge80fWEw== X-Received: by 2002:a05:6902:4e1:: with SMTP id w1mr45353355ybs.247.1563994376467; Wed, 24 Jul 2019 11:52:56 -0700 (PDT) X-Google-Smtp-Source: APXvYqxAJCtS7daJMqss7cbEecE6G1h4awTN7aI6ggKWCwnViP4oKgdY8twbmxRrX1gqW0bEuUCd X-Received: by 2002:a05:6902:4e1:: with SMTP id w1mr45353327ybs.247.1563994375750; Wed, 24 Jul 2019 11:52:55 -0700 (PDT) ARC-Seal: i=2; a=rsa-sha256; t=1563994375; cv=pass; d=google.com; s=arc-20160816; b=yBlfA5T5d8EVcSLRk5bhAHMH0w2Sm/M7LN6BKqri+/DGXaY6XVCkPVxkWPB3ZrPtlc CYtfyecZcByn8Ul9Me2HDgQyO1Zuhm0MvXgiATVE9HdzVIWcPvgnFC+zWzi4vcN8hXG5 m4tHKoPxWnQIM5cuTKVsT6GBN017olv+6dfHMNZPR276wxQTi3ojvmERKSgS4MF+wRED b2sKauYLMWB5jHDGsFFCwzIq2dPtLmXiyCjQRTX8QWQOtRqDwK1/cFd1IhmWJJET3rRv WqY1MWqybI4BvvD7MdoSdjSgwSy7YJqYK8sjQ8xk0CWFrPbsuFQMAtM5ztz2Fdl0JKy5 Bizw== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:content-transfer-encoding:content-id:content-language :accept-language:in-reply-to:references:message-id:date:thread-index :thread-topic:subject:cc:to:from:dkim-signature:dkim-signature; bh=aa1yNHhGub2q5giAEw5YCf3oqlsTy4a2Ha1OCMwoAtU=; b=HBJsCASZMSVHibGbxGCp6qsXJbXGKC9AmwAhqRUfWayWfSpR5GWzIqY9PLY1Q/VPeZ 1OuiUOXq5tP+sP4Ci/gS9Ty3Y5zZthY5eXoFDYe1chXPs7NhsAOhtcjLUeb4P2SDNpY4 RIuGWOBc/8xyQL4FTFi+e5U0j6AmAVVughVbvU/NyQBGWRty0rWvxL/JVHaV4tTOan2u a0T0bDElkwF1LE3ooInEFdQuBvLEonPI1W7LPLBB17H91sdr47jAA273hpHiwwmQSPBc gm/oA8QTuMtZ3EbMl8J93O1B0N091bxAHZLz9kBfFFynQrV8MyDIV/EZX1DW5WwX5GtH ipFg== ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@fb.com header.s=facebook header.b="U/B4/BsH"; dkim=pass header.i=@fb.onmicrosoft.com header.s=selector1-fb-onmicrosoft-com header.b="m/tM6G9W"; arc=pass (i=1 spf=pass spfdomain=fb.com dkim=pass dkdomain=fb.com dmarc=pass fromdomain=fb.com); spf=pass (google.com: domain of prvs=21083052e4=songliubraving@fb.com designates 67.231.145.42 as permitted sender) smtp.mailfrom="prvs=21083052e4=songliubraving@fb.com"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=fb.com Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com. [67.231.145.42]) by mx.google.com with ESMTPS id t187si16978610ywd.83.2019.07.24.11.52.55 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 24 Jul 2019 11:52:55 -0700 (PDT) Received-SPF: pass (google.com: domain of prvs=21083052e4=songliubraving@fb.com designates 67.231.145.42 as permitted sender) client-ip=67.231.145.42; Authentication-Results: mx.google.com; dkim=pass header.i=@fb.com header.s=facebook header.b="U/B4/BsH"; dkim=pass header.i=@fb.onmicrosoft.com header.s=selector1-fb-onmicrosoft-com header.b="m/tM6G9W"; arc=pass (i=1 spf=pass spfdomain=fb.com dkim=pass dkdomain=fb.com dmarc=pass fromdomain=fb.com); spf=pass (google.com: domain of prvs=21083052e4=songliubraving@fb.com designates 67.231.145.42 as permitted sender) smtp.mailfrom="prvs=21083052e4=songliubraving@fb.com"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=fb.com Received: from pps.filterd (m0044008.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x6OInMH8026088; Wed, 24 Jul 2019 11:52:22 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : references : in-reply-to : content-type : content-id : content-transfer-encoding : mime-version; s=facebook; bh=aa1yNHhGub2q5giAEw5YCf3oqlsTy4a2Ha1OCMwoAtU=; b=U/B4/BsH+TbZIGHSloph0x+gn8OgEk83PznMCUXCgDhWTQZP1gkOAEGOGsEPm/OFPXRd gtItcoxCEjzA+QiVal1XBJs4hJhRlHGXADi3FoZNALgZwMN0PMfwIM8MGou+651MCbcE nQeS5OsYSh2ggskGMmQpFDGbR5yemRzqOcI= Received: from mail.thefacebook.com (mailout.thefacebook.com [199.201.64.23]) by mx0a-00082601.pphosted.com with ESMTP id 2txr5nh805-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT); Wed, 24 Jul 2019 11:52:22 -0700 Received: from prn-mbx07.TheFacebook.com (2620:10d:c081:6::21) by prn-hub06.TheFacebook.com (2620:10d:c081:35::130) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.1.1713.5; Wed, 24 Jul 2019 11:52:21 -0700 Received: from prn-hub02.TheFacebook.com (2620:10d:c081:35::126) by prn-mbx07.TheFacebook.com (2620:10d:c081:6::21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.1.1713.5; Wed, 24 Jul 2019 11:52:20 -0700 Received: from NAM04-CO1-obe.outbound.protection.outlook.com (192.168.54.28) by o365-in.thefacebook.com (192.168.16.26) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.1.1713.5 via Frontend Transport; Wed, 24 Jul 2019 11:52:20 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=N1VOVF1/xToYqtmwjQr1BbNSIbOR6k//XqrYIrUKeM9OfXuuuMtwaCp2pxnTS5YIcHtna7v+dDk3BH7Yyr6K+2XQZM+rca7RDzkeZPt7kib83xcIm3HihOj4ETMOd5zrDoRu90cDu1OIN2xvzyVHM/XgD2ZH3oc237xele5LKBaigWdgd4RcffvJjn62DviU4oAb2+ev0EFjlzp1LtzcPZ78/+FUfvaRa+TrkM9CiPUtwWKAuZngUg2m3/itcY55vGjidHgo7KphVMCKkBe62FEwD8EzRe9m/Rc5Kp+VQH4VRnXL7eniU4jVpdug33mb85l9XiTySMV314Nxl12qSA== 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=aa1yNHhGub2q5giAEw5YCf3oqlsTy4a2Ha1OCMwoAtU=; b=hBngRUTrvnD3mIhTR+VxeCxP3qAqkKnBcj9fAxBPvTJzCk1XHpRr29FXsvQ8HH+B8EdHFgKqSx1etH24Y5Juaa8gmKYBqu+esOECor213w14JbbiZBY38SK86S1KV58Gw1F2Yfq+WftmCamnKGxw2gKOxJ+IWqEE4baw5iszJUDF0nkHxRm5Z/R11ds8mf3bjfTgqaox0Iq9TWNS0aO+29VoMnPvEaVGAG3otRlZr/IqNJcA2cWXk2y2iO2kjR0CJNbEJF48sy6k3vcoWQA7lvIKSRmOdHSJAg9bIUO4N6kX2KTSHvNBtlWY69oiVSSgdS3mI0UEf4iur6xy1eC8eg== ARC-Authentication-Results: i=1; mx.microsoft.com 1;spf=pass smtp.mailfrom=fb.com;dmarc=pass action=none header.from=fb.com;dkim=pass header.d=fb.com;arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.onmicrosoft.com; s=selector1-fb-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=aa1yNHhGub2q5giAEw5YCf3oqlsTy4a2Ha1OCMwoAtU=; b=m/tM6G9W32ZbdAMbknK1hPp8rYtAhFTNX8j8R/Euqzem/EmEgbeG4PGP8vIXNMELhc/u0jbf5dZW+2C3rgwcwiyJ3S57qnqHchHnsACOIaOLrGaYfOFsm/sfOD3rdqPMELIZf1ZeexGDoreGK1B3/OJdl45nnqxXpHEtdPBLqk4= Received: from MWHPR15MB1165.namprd15.prod.outlook.com (10.175.3.22) by MWHPR15MB1789.namprd15.prod.outlook.com (10.174.96.8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2115.10; Wed, 24 Jul 2019 18:52:20 +0000 Received: from MWHPR15MB1165.namprd15.prod.outlook.com ([fe80::4066:b41c:4397:27b7]) by MWHPR15MB1165.namprd15.prod.outlook.com ([fe80::4066:b41c:4397:27b7%7]) with mapi id 15.20.2094.013; Wed, 24 Jul 2019 18:52:19 +0000 From: Song Liu To: Oleg Nesterov CC: lkml , Linux-MM , Andrew Morton , "matthew.wilcox@oracle.com" , "kirill.shutemov@linux.intel.com" , "peterz@infradead.org" , "rostedt@goodmis.org" , "Kernel Team" , "william.kucharski@oracle.com" Subject: Re: [PATCH v8 2/4] uprobe: use original page when all uprobes are removed Thread-Topic: [PATCH v8 2/4] uprobe: use original page when all uprobes are removed Thread-Index: AQHVQfsnepoAlMhPK0qmuIU0gpphb6bZpE2AgAB5kgA= Date: Wed, 24 Jul 2019 18:52:19 +0000 Message-ID: References: <20190724083600.832091-1-songliubraving@fb.com> <20190724083600.832091-3-songliubraving@fb.com> <20190724113711.GE21599@redhat.com> In-Reply-To: <20190724113711.GE21599@redhat.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-mailer: Apple Mail (2.3445.104.11) x-originating-ip: [2620:10d:c090:180::1:856f] x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: 6f3fbdb3-69ad-42f9-8813-08d710680e4a x-microsoft-antispam: BCL:0;PCL:0;RULEID:(2390118)(7020095)(4652040)(8989299)(4534185)(4627221)(201703031133081)(201702281549075)(8990200)(5600148)(711020)(4605104)(1401327)(2017052603328)(7193020);SRVR:MWHPR15MB1789; x-ms-traffictypediagnostic: MWHPR15MB1789: x-microsoft-antispam-prvs: x-ms-oob-tlc-oobclassifiers: OLM:605; x-forefront-prvs: 0108A997B2 x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(346002)(366004)(136003)(396003)(376002)(39860400002)(199004)(189003)(71200400001)(71190400001)(36756003)(5660300002)(14444005)(256004)(57306001)(76116006)(66476007)(66946007)(66446008)(66556008)(64756008)(6116002)(33656002)(6506007)(53546011)(229853002)(102836004)(6916009)(186003)(6246003)(54906003)(316002)(4326008)(76176011)(99286004)(14454004)(6486002)(6436002)(25786009)(11346002)(2616005)(446003)(8676002)(6512007)(7736002)(86362001)(68736007)(81156014)(81166006)(8936002)(46003)(476003)(305945005)(478600001)(50226002)(486006)(53936002)(2906002);DIR:OUT;SFP:1102;SCL:1;SRVR:MWHPR15MB1789;H:MWHPR15MB1165.namprd15.prod.outlook.com;FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;A:1;MX:1; received-spf: None (protection.outlook.com: fb.com does not designate permitted sender hosts) x-ms-exchange-senderadcheck: 1 x-microsoft-antispam-message-info: RZX72aB+99LXHP1bXefZKENqiHQ2YcvdUIqmL6a12NlCiFuAjEKTgoLadlF1kNbIC4ywIXgWxoBT0TIDWbaZZofomrU44V+V3dvuzYZlvgblaTYZ78lsMeZP88ulbBKssmTlcz3W5x6zjXFzFAkrXItKQn70edH25yJ9IDr15a6NCimj3/bfag8EehArsS357dlyHi1kz+g7rnq5Z80Zc9SfNzTk+9kehA+K1yBGnIKhERhnO7QQMs5IaYRSZQL38mt3x2Bo1VMWM+2UMalW9GTxNHThS9ge5nAyzQxP7CDj7uIWZtCntUP6xMjJAJqoFS8ff2E9FYruHrEK4MAElpZgQjLSHrEBXlRzjYmokMSDCqAJ5M5uv3hYMXvXHNOsBU7LmsXVs1hC/Rk5quRhicsit0LHHk8j0ddFpn1ol1Q= Content-Type: text/plain; charset="us-ascii" Content-ID: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-MS-Exchange-CrossTenant-Network-Message-Id: 6f3fbdb3-69ad-42f9-8813-08d710680e4a X-MS-Exchange-CrossTenant-originalarrivaltime: 24 Jul 2019 18:52:19.1547 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 8ae927fe-1255-47a7-a2af-5f3a069daaa2 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: songliubraving@fb.com X-MS-Exchange-Transport-CrossTenantHeadersStamped: MWHPR15MB1789 X-OriginatorOrg: fb.com X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-07-24_07:,, signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1907240200 X-FB-Internal: deliver X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: > On Jul 24, 2019, at 4:37 AM, Oleg Nesterov wrote: >=20 > On 07/24, Song Liu wrote: >>=20 >> lock_page(old_page); >> @@ -177,15 +180,24 @@ static int __replace_page(struct vm_area_struct *v= ma, unsigned long addr, >> mmu_notifier_invalidate_range_start(&range); >> err =3D -EAGAIN; >> if (!page_vma_mapped_walk(&pvmw)) { >> - mem_cgroup_cancel_charge(new_page, memcg, false); >> + if (!orig) >> + mem_cgroup_cancel_charge(new_page, memcg, false); >> goto unlock; >> } >> VM_BUG_ON_PAGE(addr !=3D pvmw.address, old_page); >>=20 >> get_page(new_page); >> - page_add_new_anon_rmap(new_page, vma, addr, false); >> - mem_cgroup_commit_charge(new_page, memcg, false, false); >> - lru_cache_add_active_or_unevictable(new_page, vma); >> + if (orig) { >> + lock_page(new_page); /* for page_add_file_rmap() */ >> + page_add_file_rmap(new_page, false); >=20 >=20 > Shouldn't we re-check new_page->mapping after lock_page() ? Or we can't > race with truncate? We can't race with truncate, because the file is open as binary and=20 protected with DENYWRITE (ETXTBSY).=20 >=20 >=20 > and I am worried this code can try to lock the same page twice... > Say, the probed application does MADV_DONTNEED and then writes "int3" > into vma->vm_file at the same address to fool verify_opcode(). >=20 Do you mean the case where old_page =3D=3D new_page? I think this won't=20 happen, because in uprobe_write_opcode() we only do orig_page for=20 !is_register case.=20 Thanks, Song