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=-13.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 63B18C432BE for ; Fri, 13 Aug 2021 19:44:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 402D6610CF for ; Fri, 13 Aug 2021 19:44:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233719AbhHMToZ (ORCPT ); Fri, 13 Aug 2021 15:44:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:33550 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229601AbhHMToY (ORCPT ); Fri, 13 Aug 2021 15:44:24 -0400 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-Transfer-Encoding: 8bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 series >>> tries to resolve the issues: >>> >>>    (a) All needed information are scattered in variables, passed to >>> various >>>        test functions. The code is organized in pretty much relaxed >>> fashion. >>> >>>    (b) The page isn't allocated from buddy during page table entry >>> modifying >>>        tests. The page can be invalid, conflicting to the >>> implementations >>>        of set_xxx_at() on ARM64. The target page is accessed so that >>> the >>>        iCache can be flushed when execution permission is given on >>> ARM64. >>>        Besides, the target page can be unmapped and accessing to it >>> causes >>>        kernel crash. >>> >>> "struct pgtable_debug_args" is introduced to address issue (a). For >>> issue >>> (b), the used page is allocated from buddy in page table entry >>> modifying >>> tests. The corresponding tets will be skipped if we fail to allocate >>> 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 >>> one >>> patch, but it will make the review harder: >>> >>>    PATCH[1] introduces "struct pgtable_debug_args" as place holder >>> of all >>>             needed information. With it, the old and new implementation >>>             can coexist. >>>    PATCH[2-10] uses "struct pgtable_debug_args" in various test >>> functions. >>>    PATCH[11] removes the unused code for old implementation. >>>    PATCH[12] fixes the issue of corrupted page flag for ARM64 >>> >>> Changelog >>> ========= >>> v6: >>>     * Populate saved page table entry pointers after >>>       they're allocated in init_args() (Anshuman) >>>     * Fix imbalanced preemption count issue by replacing >>>       pte_alloc_mmap() with pte_alloc() in init_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 files. Thx, -Vineet