From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752213AbcHXE27 (ORCPT ); Wed, 24 Aug 2016 00:28:59 -0400 Received: from mail-sn1nam02on0103.outbound.protection.outlook.com ([104.47.36.103]:62394 "EHLO NAM02-SN1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750758AbcHXE26 (ORCPT ); Wed, 24 Aug 2016 00:28:58 -0400 From: "Kani, Toshimitsu" To: Dan Williams CC: "Mulumudi, Abhilash Kumar" , "linux-nvdimm@lists.01.org" , "ard.biesheuvel@linaro.org" , "linux-kernel@vger.kernel.org" , "akpm@linux-foundation.org" , "brian.starkey@arm.com" Subject: RE: [PATCH] memremap: Fix NULL pointer BUG in get_zone_device_page() Thread-Topic: [PATCH] memremap: Fix NULL pointer BUG in get_zone_device_page() Thread-Index: AQHR/W5ZePHh0bI7qkGTM3px2vEum6BXIayAgAAUw4CAAA1fgIAADk3AgAAYaQCAABIWAIAABjvw Date: Wed, 24 Aug 2016 04:28:54 +0000 Message-ID: References: <1471977800-12688-1-git-send-email-toshi.kani@hpe.com> <1471996023.1532.6.camel@hpe.com> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: spf=none (sender IP is ) smtp.mailfrom=toshi.kani@hpe.com; x-originating-ip: [174.51.38.138] x-ms-office365-filtering-correlation-id: 4c06f6ea-7ba4-4164-efc9-08d3cbd72887 x-microsoft-exchange-diagnostics: 1;DF4PR84MB0010;6:jFncMlyqsLfn2EdfQDxiP8xz3aG3M+PJRaEEUGp0opRuPp0e+YaK5EZlm4Sesp4I2Gp2P+7Zq7Ykl56ED4enVzCzk8+LGoITruyLRVYIA0OR60JXMADvl2ByMKfoHW6L5jqsFgEgf5+jkTl8pwLDL/XtfWOLDmvmD8svkBQQYUoho1n0f+DwML0J6TuSZxWgJg9fUXWhrOAbNQ3onJS9cy1R0zJq2hvqrvRjwUzn0naHZY865rSOtu0YfNn1fCGvv/pRXEDnLcDhkLxEp1Lph15SHmJ9qDr17b6UFjZRelbX7k+7rlXDfdBTe7mnZBwGdZZ5CR5hoJ/nq9NVAey+bw==;5:/TMEtqe/71HLksEqtuPBAwBVf6FXcUjSjZr2PLY1tXcCj77OxYRoovKwYQ9ACLVMhAFciymd9i6vtyRszDQWDJuO3MyD0nZXAue1mz6RxTy0qvzGBrS/rHN6GYUCjFZjgfOBhldBLOlL5Fk/dumNaw==;24:7gV53DGq962w/j8CPFTEIfqO1JWYDckp3vwnpGCYBDnY0qJVSHfGYfwXfp/JG8nfyv3/04AooaYh5nu43c2SIkcSsKfgR0bcdrD7on3xHSk=;7:bZysS28HBKtwchG3w7g8iTnYY7+JCgkWiRyiRP0OlH76fbs4GZ3ZhjrRAmhGBxiJnXI5oZXaIJQykr0gvpPB6N9WFbIi1iDOKjj4NtBLRVyQgySIFhgjMX8auAC3YJL/+coxGeKeG136p9HgH0IpJiuZ6lgIyGNZvLYgc23keBTocq1Smjl2/gOh1lR4BsbHSQjU3se2D4OGSuiN4eRVodYCVS37uN+wF70Av/ghZKBaol/xOakOLnKPsMTDNWpI x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:;SRVR:DF4PR84MB0010; x-microsoft-antispam-prvs: x-exchange-antispam-report-test: UriScan:(227479698468861)(228905959029699); x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(6040176)(601004)(2401047)(5005006)(8121501046)(10201501046)(3002001)(6055026);SRVR:DF4PR84MB0010;BCL:0;PCL:0;RULEID:;SRVR:DF4PR84MB0010; x-forefront-prvs: 0044C17179 x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(6009001)(7916002)(189002)(199003)(377454003)(24454002)(305945005)(122556002)(7736002)(3846002)(105586002)(74316002)(6116002)(19580395003)(50986999)(19580405001)(106116001)(2906002)(101416001)(33656002)(76176999)(102836003)(54356999)(5002640100001)(5890100001)(9686002)(586003)(7696003)(7846002)(92566002)(99286002)(106356001)(97736004)(77096005)(81156014)(8936002)(81166006)(93886004)(3660700001)(66066001)(8676002)(87936001)(189998001)(2950100001)(10400500002)(2900100001)(68736007)(4326007)(86362001)(5660300001)(3280700002)(110136002);DIR:OUT;SFP:1102;SCL:1;SRVR:DF4PR84MB0010;H:DF4PR84MB0010.NAMPRD84.PROD.OUTLOOK.COM;FPR:;SPF:None;PTR:InfoNoRecords;MX:1;A:1;LANG:en; spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 X-OriginatorOrg: hpe.com X-MS-Exchange-CrossTenant-originalarrivaltime: 24 Aug 2016 04:28:54.5624 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 105b2061-b669-4b31-92ac-24d304d195dc X-MS-Exchange-Transport-CrossTenantHeadersStamped: DF4PR84MB0010 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id u7O4T4qg027656 > On Tue, Aug 23, 2016 at 7:53 PM, Dan Williams > wrote: > > On Tue, Aug 23, 2016 at 6:29 PM, Kani, Toshimitsu > wrote: > >>> On Tue, Aug 23, 2016 at 4:47 PM, Kani, Toshimitsu > > >>> wrote: : > >> > >> crash> p {struct vmem_altmap} 0xffff88046d045410 > >> $6 = { > >> base_pfn = 0x480000, > >> reserve = 0x2, // PHYS_PFN(SZ_8K) > >> free = 0x101fe, > >> align = 0x1fe, > >> alloc = 0x10000 > >> } > > > > Ah, so, on second look the 0x490200000 data offset looks correct. The > > total size of the address range is 16GB which equates to 256MB needed > > for struct page, plus 2MB more to re-align the data on the next 2MB > > boundary. > > > > The question now is why is the guest faulting on an access to an > > address less than 0x490200000? > > Does the attached patch fix this for you? Yeah, that makes sense. I will test it tomorrow. BTW, why does devm_memremap_pages() put a whole range to pgmap_radix as device memory, but only initialize page->pgmap for its data range? Is there particular reason for this inconsistency? Thanks, -Toshi