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=-13.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, 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 DEF31C4338F for ; Sat, 14 Aug 2021 02:58:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B98D460F14 for ; Sat, 14 Aug 2021 02:58:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236771AbhHNC6h (ORCPT ); Fri, 13 Aug 2021 22:58:37 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:55425 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236466AbhHNC6Z (ORCPT ); Fri, 13 Aug 2021 22:58:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1628909875; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SZ/gidsl6OmROeOx/n9lMGdC7WafEvzvYpOK4Q3l9nc=; b=VBiPc7zSU7tXoe0FT9rAT6xHCdjFzLQR5Ndy467kf/gSChMp4szkY1oKgZB3kBHA79jsZq KqRqoHr1gf8287+LbcsR9rGmf2mmp0/Va/TMZeW6cVb+56fpSq6p1i7BTZNoLBVgxpjNRq RDIAr1Xu0iyZ1Gb1JupsOsmJXVIovZQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-20-L-p7VCTxOcq4NrRI9XGaug-1; Fri, 13 Aug 2021 22:57:51 -0400 X-MC-Unique: L-p7VCTxOcq4NrRI9XGaug-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DB61F8030B7; Sat, 14 Aug 2021 02:57:49 +0000 (UTC) Received: from [10.64.54.103] (vpn2-54-103.bne.redhat.com [10.64.54.103]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 2097F5C1A1; Sat, 14 Aug 2021 02:57:41 +0000 (UTC) Reply-To: Gavin Shan Subject: Re: [PATCH v6 00/12] mm/debug_vm_pgtable: Enhancements To: Vineet Gupta , 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> <25018384-acc5-dcf7-5125-378499ab4555@kernel.org> From: Gavin Shan Message-ID: <828d44a7-525f-c507-00d1-8e323c8956bc@redhat.com> Date: Sat, 14 Aug 2021 12:57:38 +1000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.0 MIME-Version: 1.0 In-Reply-To: <25018384-acc5-dcf7-5125-378499ab4555@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Vineet, On 8/14/21 5:43 AM, Vineet Gupta wrote: > On 8/13/21 2:25 AM, Gavin Shan wrote: >> 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. > Sure. >>> >>> 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. > Here is repo with v6 series included. Please help to have a try. https://github.com/gwshan/linux # kvm/arm64_debug I tried to build the cross-compiler with buildroot with following 2 repos. Unfortunately, none of them worked for me. The QEMU binary can be built successfully with the provided repo though. [1] git://github.com/foss-for-synopsys-dwc-arc-processors/buildroot.git (branch: master) There are build errors after choosing little-endian ARM from "make menuconfig" [2] https://github.com/buildroot/buildroot (branch: master) The build is successful, but the kernel can't be built because of the following errors: # make ARCH=arc CROSS_COMPILE=arc-linux- axs103_smp_defconfig # make -j 40 : LD vmlinux.o arc-linux-ld: error: attempting to link /home/gavin/sandbox/buildroot/buildroot.arc/output/host/lib /gcc/arc-buildroot-linux-uclibc/10.2.0/libgcc.a(_muldi3.o) with a binary vmlinux.o of different architecture Thanks, Gavin