From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f69.google.com (mail-oi0-f69.google.com [209.85.218.69]) by kanga.kvack.org (Postfix) with ESMTP id 8006E6B0005 for ; Tue, 2 Aug 2016 07:00:46 -0400 (EDT) Received: by mail-oi0-f69.google.com with SMTP id w207so356376937oiw.1 for ; Tue, 02 Aug 2016 04:00:46 -0700 (PDT) Received: from EUR01-DB5-obe.outbound.protection.outlook.com (mail-db5eur01on0093.outbound.protection.outlook.com. [104.47.2.93]) by mx.google.com with ESMTPS id p22si1006937otd.125.2016.08.02.04.00.44 for (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 02 Aug 2016 04:00:45 -0700 (PDT) Subject: Re: [PATCHv2 3/6] x86/arch_prctl/vdso: add ARCH_MAP_VDSO_* References: <20160629105736.15017-1-dsafonov@virtuozzo.com> <20160629105736.15017-4-dsafonov@virtuozzo.com> <20160711182654.GA19160@redhat.com> <20160712141446.GB28837@redhat.com> From: Dmitry Safonov Message-ID: Date: Tue, 2 Aug 2016 13:59:40 +0300 MIME-Version: 1.0 In-Reply-To: <20160712141446.GB28837@redhat.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Oleg Nesterov , Andy Lutomirski Cc: Michal Hocko , Vladimir Davydov , "linux-kernel@vger.kernel.org" , Dmitry Safonov <0x7f454c46@gmail.com>, "linux-mm@kvack.org" , Ingo Molnar , Cyrill Gorcunov , xemul@virtuozzo.com, Andy Lutomirski , Thomas Gleixner , "H. Peter Anvin" , X86 ML On 07/12/2016 05:14 PM, Oleg Nesterov wrote: > On 07/11, Andy Lutomirski wrote: >> I'm starting to wonder if we should finally suck it up and give >> special mappings a non-NULL vm_file so we can track them properly. >> Oleg, weren't you thinking of doing that for some other reason? > > Yes, uprobes. Currently we can't probe vdso page(s). So, to make sure, that I've understood correctly, I need to: o add vm_file to vdso/vvar vmas, __install_special_mapping will init them; o place array pages[] inside f_mapping; o create f_inode for each file -- for this we need some mount point, so I'll create something like vdsofs, register this filesystem and mount it in initcall (or like do_basic_setup - as it's done by shmem, i.e). Is this the idea, or I got it wrong? And maybe the idea is to create fake vm_file for just reference counting, but do not treat/init it like file with inode, etc? So with fake file I can also check if vdso is mapped already, but I'm sure the fake file will not help Oleg with uprobes. -- Dmitry -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935097AbcHBO4G (ORCPT ); Tue, 2 Aug 2016 10:56:06 -0400 Received: from mail-db5eur01on0095.outbound.protection.outlook.com ([104.47.2.95]:41556 "EHLO EUR01-DB5-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S934844AbcHBMik (ORCPT ); Tue, 2 Aug 2016 08:38:40 -0400 Authentication-Results: spf=none (sender IP is ) smtp.mailfrom=dsafonov@virtuozzo.com; Subject: Re: [PATCHv2 3/6] x86/arch_prctl/vdso: add ARCH_MAP_VDSO_* To: Oleg Nesterov , Andy Lutomirski References: <20160629105736.15017-1-dsafonov@virtuozzo.com> <20160629105736.15017-4-dsafonov@virtuozzo.com> <20160711182654.GA19160@redhat.com> <20160712141446.GB28837@redhat.com> CC: Michal Hocko , Vladimir Davydov , "linux-kernel@vger.kernel.org" , Dmitry Safonov <0x7f454c46@gmail.com>, "linux-mm@kvack.org" , "Ingo Molnar" , Cyrill Gorcunov , , Andy Lutomirski , Thomas Gleixner , "H. Peter Anvin" , X86 ML From: Dmitry Safonov Message-ID: Date: Tue, 2 Aug 2016 13:59:40 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.1.0 MIME-Version: 1.0 In-Reply-To: <20160712141446.GB28837@redhat.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [195.214.232.10] X-ClientProxiedBy: AM5PR0901CA0009.eurprd09.prod.outlook.com (10.164.186.147) To AM5PR0801MB1731.eurprd08.prod.outlook.com (10.169.247.9) X-MS-Office365-Filtering-Correlation-Id: 26d74e4c-9747-4678-16b6-08d3bac43e73 X-Microsoft-Exchange-Diagnostics: 1;AM5PR0801MB1731;2:KIErmPHoZWhgXeu5p4IpoyMOTzjyGrkr7bLn7+0h6oxpBle3icqJboeesXvmrye+Sp8jPcN/8M5sbmxNNulZ/FeritbAz6xht0XdOf71xOJHVCl7z2W8FtDCbw70KXWE6MoWwBwv2225vlTzTa+nP28XEmU/Hg9hfWgR1jRQiHv0qhcURn//b8ecKakVPudm;3:raxFibuSI7oz7RruDACa5sGogz2rVhS3J0ZHGrjaisvQ7Hkp6L35l0OM1ant+3uecaGrir66EkzVm0EDvX3IAnKm5fUJUVKSSZAfcIVS2qU4bcV39k63n+j66r1dIh5c X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:;SRVR:AM5PR0801MB1731; X-Microsoft-Exchange-Diagnostics: 1;AM5PR0801MB1731;25: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;31:Ocp0fAQvtjXZqpLRzDak4hG2WlxPiAHJ44ihspr3b4/FTJNmcjly5GvNLVi2N+WOapkCEfy1a4rLysKCNJTwetcDMa0FghfqOj4kK03USLWI9Ib6p9/CcGVcR8SNw3XpGM0dDCKkY2SDADvljhtQhsu4I0vs4f2nXULkvVfsNTAJU5aVkP/Wt+d9FUSiQPXlnrn7vLIvDvsd0foFjBsgAYAsX8BiNFq1nO02PMnAfeI= X-Microsoft-Antispam-PRVS: X-Exchange-Antispam-Report-Test: UriScan:(17755550239193); X-Exchange-Antispam-Report-CFA-Test: BCL:0;PCL:0;RULEID:(6040130)(601004)(2401047)(8121501046)(5005006)(3002001)(10201501046)(6041072)(6043046);SRVR:AM5PR0801MB1731;BCL:0;PCL:0;RULEID:;SRVR:AM5PR0801MB1731; X-Microsoft-Exchange-Diagnostics: 1;AM5PR0801MB1731;4:Qru8qwSsiIoXGYIL2vJWP2cyYMA1QnuBJxa66rHj3qgQ8QyZK1tVXMP4RSVhR/JdW9Zi4GVx8ghgYFvLQI/cAx+33BuF3c8o++Wt0WnSJ+yUdJym1gKJqQ3tuPLWtEL+TjA8Cb97iCNRfC41Wi1MuPVzOaG0Pzm5ZH5jP2v8ryOczSvOenAfU1acp9eIExX3i//guENZUmtG999RQurYDeRHnz8Zexf9o8IVJL+IqnMnu29cJiIcLiudI9YOItCGILnNjjtBZNpLxORSQ6gdTK6cvSJujuzlJVCMSQRN9+hCDZftc417Lu257D2pYP/bd9k1HIyRrfkjUZDXfOY4Iwj8cKlLntCwF6OWZyzud/jg/djKqj8msYkJSGvdC1fIGmUS9a0jelxg0xsEDlXGBM+2l566tsNaeatwMCucG/Srj9I86rn3pDuik7BdQH/kEYLT1icki7KV3pa3eTG0Og== X-Forefront-PRVS: 0022134A87 X-Forefront-Antispam-Report: SFV:NSPM;SFS:(10019020)(4630300001)(6009001)(6049001)(7916002)(24454002)(199003)(189002)(377454003)(65806001)(47776003)(31696002)(42186005)(7416002)(65956001)(66066001)(8676002)(230700001)(50466002)(31686004)(2950100001)(2906002)(81166006)(4326007)(81156014)(4001350100001)(5001770100001)(189998001)(6116002)(586003)(77096005)(97736004)(105586002)(3846002)(93886004)(101416001)(68736007)(36756003)(86362001)(50986999)(305945005)(83506001)(33646002)(64126003)(106356001)(7736002)(23746002)(92566002)(7846002)(76176999)(54356999)(65826006);DIR:OUT;SFP:1102;SCL:1;SRVR:AM5PR0801MB1731;H:[10.30.26.154];FPR:;SPF:None;PTR:InfoNoRecords;A:1;MX:1;LANG:en; X-Microsoft-Exchange-Diagnostics: =?Windows-1252?Q?1;AM5PR0801MB1731;23:QO5+bd3kIQ/apJGAlqHS436H/nVTXD/vVjJ?= =?Windows-1252?Q?eUkZ8xTqrx6sWYQc9DWsfNSiUKwElPwT/VL3z4h0kAo12B1ZqvHaWJi4?= =?Windows-1252?Q?8Nz3gh8yVU4u5zYyLdib+bZrhJpQO272tfDfsUpoKKqHhWuJBnwwgL/X?= =?Windows-1252?Q?Uiehao4tvOJyAkoyh3bfLoOUT/d4rNDk2GcwQGDdjP8pmjjhdi0bQZVW?= =?Windows-1252?Q?nqECX0HGAX/4mQrhfYWhFubClVqfkPek0iAN0g9dt4uGVX8qChXylAGF?= =?Windows-1252?Q?Gkl23VhXvErPdAj8dbFQr3TffFSJ6Nr5+DMESWej2ewSbRhXiR+DKEpp?= =?Windows-1252?Q?0xsmIDrgg9awCkLp7rVWuJiYJz41myMBy+6xQejKoqvgP9+IHYlxlc0D?= =?Windows-1252?Q?5Dk1hT5HA+VDy+hZHG+OOs5UBUNY9YZglconMYA+Z+icobFekB66AaJb?= =?Windows-1252?Q?Vumxy0xjQNNa1/31HE80MMsYqWLyFEoJ2Wt7ENrPqzNbAbI2Np2LjUsH?= =?Windows-1252?Q?gYgiAVstUdTrHOQeYQl15fVQh56kfQ6gwh6TaijEJoShs3kAUIUe6KjM?= =?Windows-1252?Q?llRuuKFlb0FJ+NUM0g0SmJqHaVGw21IvBsGEAtIgtcZpUwKLvwlCjy/z?= =?Windows-1252?Q?lN5lUsQVZO+SI8FL7XuBwIqtKspsMfVSo/rdXJxnUHLzR2AyAHKiBT3X?= =?Windows-1252?Q?z2eQFiJDi1xluOmVQkAX5sfzlOLGrZSeS+k2Ym9dxOdZGeYcXrsf7pZz?= =?Windows-1252?Q?0snn1wEEmviAhUOavwS79nxVqd4YqcwYHka4v6Y38CMhvp8I0GfUmwgS?= =?Windows-1252?Q?YhR1aFpOeWCPs7brNrOjjNtIyOfWsU6uU4XotPGAcwmp4TDNrv4DKPwY?= =?Windows-1252?Q?RvRqsHB6ftYu/JOwR8t6nJJKM3glEbEQQS6diI5/YlXVGQn+Pjj+ngSC?= =?Windows-1252?Q?1p7xva9UKtac7hXQ2mlFR4PXOO/gFeXiXejxhPKz/VP5iyDqBNDhJgyD?= =?Windows-1252?Q?W04nO2JRQXtCo5Xk0VwTSMWNzUI3Bbt21tYVt8/TfepPAqSIBSuyBomX?= =?Windows-1252?Q?9nvPwWhwdRDyXabYA7L8pRCCHS2zojpDNbQCGwOEemVQXKqTQwdnbkkJ?= =?Windows-1252?Q?8/CLLCIcyTN4wBfpIUqOoOqDvWwVs6NCaYL6UdItu/zMhwf/ebOmObbL?= =?Windows-1252?Q?/CM0VCxi438rgHLK92B5VHzXoh7EsMsZNyfayOykzSiVC3hP/HwpcTup?= =?Windows-1252?Q?ulMwWRxkomRyMSIvdg6suVBLR9UQzo9PbYxWDUoTGvSS+U/g9LUO72EM?= =?Windows-1252?Q?Ou4gybSmcDgZrUvTC9NyGv13CKWUfvwRp5S4MhYpv/dNn2batTf0bBhS?= =?Windows-1252?Q?Khx/7TgsFJTUC?= X-Microsoft-Exchange-Diagnostics: 1;AM5PR0801MB1731;6:0EL+EyPh2DAVg2j8f0yKhxJGuDkMhY2+Uce2U+7Ta+KScKenetPR23EzonLlEhejlb6Fc474SHshUbYSYTx3uCc/HzO6bIWma3iM5NjlWgVPIqBWgNHuTmL8ZAYt4BoN2/d1ceAe6VfNN9mfYD5SJNxsWr+E4aX1Mub+GPTDj2BRJvyAdmGQNAJbj5AJoHqammJ2wjLg3Q6/rEgMomRWewwzyr7lddG55iaJFF4XZztBODzMujJg1nSMSwSa8uksYIZf+Nq7euh62EH69f6euvrSQsVph0CMCUbJV4hgK42OaugnKhjMOlE6f9qadqQ4;5:XVXENLseRVj6umUKygFg3Cc7r61Msz5FQgjIngiPM+sCXSq2bBo9SrVPnwcrGLO4zxy/YNPhiLo58B5Tb8eYcHBLNQGz9n2H6Z1hQlXa3BlyP0U5mLIdcDdFFPpN10oax6PYHaaMfrfEOH8jLgShHA==;24:DPU9sfE/m90jMp3czcXtvdYa5M8LM0KA/eJTOcnZeQh+odfcvEbFgkYZVdSPYIFz8Gu2uqf6AutNqa2ITyJ/Q1aEXJMFzo15+vvgfIlqryc=;7:jKKuhmvgzq5pOloQfNBPzNyQzzHHlhjDHLh/29swkAwvjPBwBCD0jENXaZVR461T6qqM3OZ3qpV+BelJjmPsBjWL4unwIrrrvU3vABmWb2STbsgpjvB3MpT+wfkD/K6RgMIs47gf7JB15EO5TJ0O7ly6v94N5r575ryWIy1fLYpfuavAx3mysQ14zMVTw5JMmIx+AdNYOyRMaSuRTzjdX87R5NyVrL4w1iyDTd+R+81JR39Ufqh2QF7lPs9KuUDr SpamDiagnosticOutput: 1:99 SpamDiagnosticMetadata: NSPM X-Microsoft-Exchange-Diagnostics: 1;AM5PR0801MB1731;20:pReirmNucR3uSBqTJh3zOgWVJO2DU6Ldf9JNyM7JylpKVMzxQtwhRXzfofCZC3iDx5idaahlxqzNc6iFovObCoT8IYxN5fAZ7c1s+bnH2zM80MEWSFPHzjy/ROI+8mnlqt8bRtLn8nwXfHaCaqhG6H/EEDsKBNwFHoqgF9rNV8E= X-OriginatorOrg: virtuozzo.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 Aug 2016 11:00:40.4991 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM5PR0801MB1731 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/12/2016 05:14 PM, Oleg Nesterov wrote: > On 07/11, Andy Lutomirski wrote: >> I'm starting to wonder if we should finally suck it up and give >> special mappings a non-NULL vm_file so we can track them properly. >> Oleg, weren't you thinking of doing that for some other reason? > > Yes, uprobes. Currently we can't probe vdso page(s). So, to make sure, that I've understood correctly, I need to: o add vm_file to vdso/vvar vmas, __install_special_mapping will init them; o place array pages[] inside f_mapping; o create f_inode for each file -- for this we need some mount point, so I'll create something like vdsofs, register this filesystem and mount it in initcall (or like do_basic_setup - as it's done by shmem, i.e). Is this the idea, or I got it wrong? And maybe the idea is to create fake vm_file for just reference counting, but do not treat/init it like file with inode, etc? So with fake file I can also check if vdso is mapped already, but I'm sure the fake file will not help Oleg with uprobes. -- Dmitry