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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 E229EC432BE for ; Thu, 12 Aug 2021 11:11:11 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 72C606103A for ; Thu, 12 Aug 2021 11:11:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 72C606103A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id C158B8D0007; Thu, 12 Aug 2021 07:11:10 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BC5F58D0006; Thu, 12 Aug 2021 07:11:10 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id ADC198D0007; Thu, 12 Aug 2021 07:11:10 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0192.hostedemail.com [216.40.44.192]) by kanga.kvack.org (Postfix) with ESMTP id 94D7D8D0006 for ; Thu, 12 Aug 2021 07:11:10 -0400 (EDT) Received: from smtpin05.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 40FFB1B655 for ; Thu, 12 Aug 2021 11:11:10 +0000 (UTC) X-FDA: 78466161900.05.93E9447 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf05.hostedemail.com (Postfix) with ESMTP id B726B5038F46 for ; Thu, 12 Aug 2021 11:11:09 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A24BE1042; Thu, 12 Aug 2021 04:11:08 -0700 (PDT) Received: from [10.163.68.17] (unknown [10.163.68.17]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E0EAC3F718; Thu, 12 Aug 2021 04:11:04 -0700 (PDT) Subject: Re: [PATCH v6 00/12] mm/debug_vm_pgtable: Enhancements To: Gavin Shan , linux-mm@kvack.org, Vineet Gupta 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, vgupta@synopsys.com, akpm@linux-foundation.org, chuhu@redhat.com, shan.gavin@gmail.com References: <20210809092631.1888748-1-gshan@redhat.com> From: Anshuman Khandual Message-ID: Date: Thu, 12 Aug 2021 16:41:58 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210809092631.1888748-1-gshan@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: B726B5038F46 X-Stat-Signature: oqzoiwhixe4g6arhnrw73semu9d5drs7 Authentication-Results: imf05.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf05.hostedemail.com: domain of anshuman.khandual@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=anshuman.khandual@arm.com X-HE-Tag: 1628766669-728366 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 8/9/21 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 Hello Gavin/Vineet, This series still need to be tested on ARC ? - Anshuman