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=-13.9 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 0D927C433E2 for ; Fri, 4 Sep 2020 05:42:06 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 642C6206C9 for ; Fri, 4 Sep 2020 05:42:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 642C6206C9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4BjRQ35NsFzDrK5 for ; Fri, 4 Sep 2020 15:42:03 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=arm.com (client-ip=217.140.110.172; helo=foss.arm.com; envelope-from=anshuman.khandual@arm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=arm.com Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lists.ozlabs.org (Postfix) with ESMTP id 4BjRMy5yBvzDrHd for ; Fri, 4 Sep 2020 15:40:13 +1000 (AEST) 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 C5A56101E; Thu, 3 Sep 2020 22:40:11 -0700 (PDT) Received: from [10.163.70.23] (unknown [10.163.70.23]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0B1AB3F71F; Thu, 3 Sep 2020 22:40:09 -0700 (PDT) Subject: Re: [PATCH v4 09/13] mm/debug_vm_pgtable/locks: Take correct page table lock To: "Aneesh Kumar K.V" , linux-mm@kvack.org, akpm@linux-foundation.org References: <20200902114222.181353-1-aneesh.kumar@linux.ibm.com> <20200902114222.181353-10-aneesh.kumar@linux.ibm.com> From: Anshuman Khandual Message-ID: <5dc579c4-1892-e260-19ef-4d26a9641e8d@arm.com> Date: Fri, 4 Sep 2020 11:09:37 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20200902114222.181353-10-aneesh.kumar@linux.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Archived-At: List-Archive: On 09/02/2020 05:12 PM, Aneesh Kumar K.V wrote: > Make sure we call pte accessors with correct lock held. > > Signed-off-by: Aneesh Kumar K.V > --- > mm/debug_vm_pgtable.c | 35 ++++++++++++++++++++++------------- > 1 file changed, 22 insertions(+), 13 deletions(-) > > diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c > index f59cf6a9b05e..2bc1952e5f83 100644 > --- a/mm/debug_vm_pgtable.c > +++ b/mm/debug_vm_pgtable.c > @@ -1035,30 +1035,39 @@ static int __init debug_vm_pgtable(void) > > hugetlb_basic_tests(pte_aligned, prot); > > - pte_clear_tests(mm, ptep, vaddr); > - pmd_clear_tests(mm, pmdp); > - pud_clear_tests(mm, pudp); > - p4d_clear_tests(mm, p4dp); > - pgd_clear_tests(mm, pgdp); > + /* > + * Page table modifying tests. They need to hold > + * proper page table lock. > + */ > > ptl = pte_lockptr(mm, pmdp); > spin_lock(ptl); > - > + pte_clear_tests(mm, ptep, vaddr); > pte_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot); > - pmd_advanced_tests(mm, vma, pmdp, pmd_aligned, vaddr, prot); > - pud_advanced_tests(mm, vma, pudp, pud_aligned, vaddr, prot); > - hugetlb_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot); > - > + pte_unmap_unlock(ptep, ptl); > > + ptl = pmd_lock(mm, pmdp); > + pmd_clear_tests(mm, pmdp); > + pmd_advanced_tests(mm, vma, pmdp, pmd_aligned, vaddr, prot); > pmd_huge_tests(pmdp, pmd_aligned, prot); > + pmd_populate_tests(mm, pmdp, saved_ptep); > + spin_unlock(ptl); > + > + ptl = pud_lock(mm, pudp); > + pud_clear_tests(mm, pudp); > + pud_advanced_tests(mm, vma, pudp, pud_aligned, vaddr, prot); > pud_huge_tests(pudp, pud_aligned, prot); > + pud_populate_tests(mm, pudp, saved_pmdp); > + spin_unlock(ptl); > > - pte_unmap_unlock(ptep, ptl); > + hugetlb_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot); > > - pmd_populate_tests(mm, pmdp, saved_ptep); > - pud_populate_tests(mm, pudp, saved_pmdp); > + spin_lock(&mm->page_table_lock); > + p4d_clear_tests(mm, p4dp); > + pgd_clear_tests(mm, pgdp); > p4d_populate_tests(mm, p4dp, saved_pudp); > pgd_populate_tests(mm, pgdp, saved_p4dp); > + spin_unlock(&mm->page_table_lock); > > p4d_free(mm, saved_p4dp); > pud_free(mm, saved_pudp); > This patch, in itself looks good but will probably require folding with the previous one to prevent the git bisect problem on arm64.