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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,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 01CCAC433E0 for ; Fri, 19 Jun 2020 11:18:55 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BBEF22080C for ; Fri, 19 Jun 2020 11:18:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BBEF22080C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 5E05C8D0094; Fri, 19 Jun 2020 07:18:54 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 569C68D0089; Fri, 19 Jun 2020 07:18:54 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 40ADB8D0094; Fri, 19 Jun 2020 07:18:54 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0089.hostedemail.com [216.40.44.89]) by kanga.kvack.org (Postfix) with ESMTP id 29F518D0089 for ; Fri, 19 Jun 2020 07:18:54 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 907968245571 for ; Fri, 19 Jun 2020 11:18:53 +0000 (UTC) X-FDA: 76945714146.29.twist05_0c074a126e18 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin29.hostedemail.com (Postfix) with ESMTP id A159E1808C402 for ; Fri, 19 Jun 2020 11:15:53 +0000 (UTC) X-HE-Tag: twist05_0c074a126e18 X-Filterd-Recvd-Size: 2967 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf02.hostedemail.com (Postfix) with ESMTP for ; Fri, 19 Jun 2020 11:15:52 +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 2B12CD6E; Fri, 19 Jun 2020 04:15:52 -0700 (PDT) Received: from [10.163.81.119] (unknown [10.163.81.119]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5B7513F6CF; Fri, 19 Jun 2020 04:15:48 -0700 (PDT) Subject: Re: [PATCH] mm/debug_vm_pgtable: Fix build failure with powerpc 8xx To: Christophe Leroy , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Will Deacon , Andrew Morton , "Peter Zijlstra (Intel)" Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org References: <6ca8c972e6c920dc4ae0d4affbed9703afa4d010.1592490570.git.christophe.leroy@csgroup.eu> From: Anshuman Khandual Message-ID: <7af42230-2707-d35a-d7ff-6c83b2afdbbb@arm.com> Date: Fri, 19 Jun 2020 16:45:39 +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: <6ca8c972e6c920dc4ae0d4affbed9703afa4d010.1592490570.git.christophe.leroy@csgroup.eu> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: A159E1808C402 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 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 06/18/2020 08:01 PM, Christophe Leroy wrote: > Fix it by using the recently added ptep_get() helper. > > Fixes: 9e343b467c70 ("READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses") > Signed-off-by: Christophe Leroy > --- > mm/debug_vm_pgtable.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c > index e45623016aea..61ab16fb2e36 100644 > --- a/mm/debug_vm_pgtable.c > +++ b/mm/debug_vm_pgtable.c > @@ -246,13 +246,13 @@ static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp, > static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep, > unsigned long vaddr) > { > - pte_t pte = READ_ONCE(*ptep); > + pte_t pte = ptep_get(ptep); > > pte = __pte(pte_val(pte) | RANDOM_ORVALUE); > set_pte_at(mm, vaddr, ptep, pte); > barrier(); > pte_clear(mm, vaddr, ptep); > - pte = READ_ONCE(*ptep); > + pte = ptep_get(ptep); > WARN_ON(!pte_none(pte)); > } Tested this on arm64 and x86 platforms after applying the previous series which adds ptep_get() and a follow up patch. https://patchwork.kernel.org/project/linux-mm/list/?series=302949 https://patchwork.kernel.org/patch/11611929/ Build tested on s390 and arc platforms as well. Reviewed-by: Anshuman Khandual