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=-10.3 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 29F9AC4338F for ; Fri, 13 Aug 2021 19:44:00 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A0973610A4 for ; Fri, 13 Aug 2021 19:43:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org A0973610A4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id E567A8D0001; Fri, 13 Aug 2021 15:43:58 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E05D46B0071; Fri, 13 Aug 2021 15:43:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CF3638D0001; Fri, 13 Aug 2021 15:43:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0232.hostedemail.com [216.40.44.232]) by kanga.kvack.org (Postfix) with ESMTP id B33DF6B006C for ; Fri, 13 Aug 2021 15:43:58 -0400 (EDT) Received: from smtpin01.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 69D781F357 for ; Fri, 13 Aug 2021 19:43:58 +0000 (UTC) X-FDA: 78471082956.01.8599A18 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf20.hostedemail.com (Postfix) with ESMTP id E92C0D000651 for ; Fri, 13 Aug 2021 19:43:57 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 5501260F21; Fri, 13 Aug 2021 19:43:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1628883836; bh=2hyViBfwHWSQ5FVPojFdRsY2lrOVaSM1RPUsZNslGHQ=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=eH6ijDVTmCJEio8xYt1IYxbLhwyyqK/c56JFiqRI7pUlkpH4Q2o1xaMTKdcwHHWS8 ZDdAABt/RgQb46p7RsfgG2hGUbrm23LjhIRXUFs23ogtZK06CndzUgx02/WfVF0bfo v+uXFhYI118O4LZ/m8gqpZ69vUCnac66PjsiItOc5IPexHpVS0EbxGl3B3PRxz0nru 3p8QSNQd6CWUnTrMFbYJDrSBVU73FBGgritnex+lBgxapsg2DoH14TFFqIc9jLo2m+ LaFy+3q4uRBZehB4A+ZU0WBbfhliAOscw6MLxoxGVtTt4C/jc+04lJfH5G7iEznWCv j3lEpgheHWKig== Subject: Re: [PATCH v6 00/12] mm/debug_vm_pgtable: Enhancements To: Gavin Shan , Anshuman Khandual , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, gerald.schaefer@linux.ibm.com, aneesh.kumar@linux.ibm.com, christophe.leroy@csgroup.eu, cai@lca.pw, catalin.marinas@arm.com, will@kernel.org, akpm@linux-foundation.org, chuhu@redhat.com, shan.gavin@gmail.com, arcml References: <20210809092631.1888748-1-gshan@redhat.com> From: Vineet Gupta Message-ID: <25018384-acc5-dcf7-5125-378499ab4555@kernel.org> Date: Fri, 13 Aug 2021 12:43:55 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US X-Rspamd-Queue-Id: E92C0D000651 Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=eH6ijDVT; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf20.hostedemail.com: domain of vgupta@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=vgupta@kernel.org X-Rspamd-Server: rspam04 X-Stat-Signature: zomiwr74j9b8uq1bjj48u87b1degeoja X-HE-Tag: 1628883837-853139 Content-Transfer-Encoding: quoted-printable 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 8/13/21 2:25 AM, Gavin Shan wrote: > Hi Anshuman and Vineet, > > On 8/12/21 9:11 PM, Anshuman Khandual wrote: >> On 8/9/21 2:56 PM, Gavin Shan wrote: >>> There are couple of issues with current implementations and this seri= es >>> tries to resolve the issues: >>> >>> =C2=A0=C2=A0 (a) All needed information are scattered in variables, p= assed to=20 >>> various >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 test functions. The code is orga= nized in pretty much relaxed=20 >>> fashion. >>> >>> =C2=A0=C2=A0 (b) The page isn't allocated from buddy during page tabl= e entry=20 >>> modifying >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 tests. The page can be invalid, = conflicting to the=20 >>> implementations >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 of set_xxx_at() on ARM64. The ta= rget page is accessed so that=20 >>> the >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 iCache can be flushed when execu= tion permission is given on=20 >>> ARM64. >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 Besides, the target page can be = unmapped and accessing to it=20 >>> causes >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 kernel crash. >>> >>> "struct pgtable_debug_args" is introduced to address issue (a). For=20 >>> issue >>> (b), the used page is allocated from buddy in page table entry=20 >>> modifying >>> tests. The corresponding tets will be skipped if we fail to allocate=20 >>> the >>> (huge) page. For other test cases, the original page around to kernel >>> symbol (@start_kernel) is still used. >>> >>> The patches are organized as below. PATCH[2-10] could be combined to=20 >>> one >>> patch, but it will make the review harder: >>> >>> =C2=A0=C2=A0 PATCH[1] introduces "struct pgtable_debug_args" as place= holder=20 >>> of all >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 ne= eded information. With it, the old and new implementation >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 ca= n coexist. >>> =C2=A0=C2=A0 PATCH[2-10] uses "struct pgtable_debug_args" in various = test=20 >>> functions. >>> =C2=A0=C2=A0 PATCH[11] removes the unused code for old implementation= . >>> =C2=A0=C2=A0 PATCH[12] fixes the issue of corrupted page flag for ARM= 64 >>> >>> Changelog >>> =3D=3D=3D=3D=3D=3D=3D=3D=3D >>> v6: >>> =C2=A0=C2=A0=C2=A0 * Populate saved page table entry pointers after >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 they're allocated in init_args() (Ansh= uman) >>> =C2=A0=C2=A0=C2=A0 * Fix imbalanced preemption count issue by replaci= ng >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pte_alloc_mmap() with pte_alloc() in i= nit_args() (syzbot) >> >> + vgupta@kernel.org Please also keep linux-snps-arc CC'ed for ARC changes. >> >> Hello Gavin/Vineet, >> >> This series still need to be tested on ARC ? >> > > Yes, I'm unable to test ARC as it's not supported by QEMU yet. > It would great if Vineet can give it a try on ARC :) We do have a working QEMU (in the process of being upstreamed) you could = try https://github.com/foss-for-synopsys-dwc-arc-processors/qemu #master Is this code in some shared git repo we can pull - instead of apply 8 fil= es. Thx, -Vineet