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 B9955C433E7 for ; Thu, 15 Oct 2020 03:00:11 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1C24B2222B for ; Thu, 15 Oct 2020 03:00:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1C24B2222B Authentication-Results: mail.kernel.org; dmarc=fail (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 4718B6B0068; Wed, 14 Oct 2020 23:00:10 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 422316B0070; Wed, 14 Oct 2020 23:00:10 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 31236900002; Wed, 14 Oct 2020 23:00:10 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0050.hostedemail.com [216.40.44.50]) by kanga.kvack.org (Postfix) with ESMTP id 051656B0068 for ; Wed, 14 Oct 2020 23:00:09 -0400 (EDT) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 9C25E8249980 for ; Thu, 15 Oct 2020 03:00:09 +0000 (UTC) X-FDA: 77372655738.04.mint65_1202f8827211 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin04.hostedemail.com (Postfix) with ESMTP id 7D8988007951 for ; Thu, 15 Oct 2020 03:00:09 +0000 (UTC) X-HE-Tag: mint65_1202f8827211 X-Filterd-Recvd-Size: 2908 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf22.hostedemail.com (Postfix) with ESMTP for ; Thu, 15 Oct 2020 03:00:08 +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 EE6F831B; Wed, 14 Oct 2020 20:00:07 -0700 (PDT) Received: from [192.168.0.130] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2459F3F719; Wed, 14 Oct 2020 20:00:05 -0700 (PDT) Subject: Re: [PATCH v4 00/13] mm/debug_vm_pgtable fixes To: Andrew Morton , "Aneesh Kumar K.V" Cc: linux-mm@kvack.org, mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org References: <20200902114222.181353-1-aneesh.kumar@linux.ibm.com> <20201013135858.f4a7f0c5f3b0a69a2a304cfe@linux-foundation.org> <034db663-a5bd-fd5e-b7f6-3ec31310e8e5@linux.ibm.com> <20201014133607.fbf63d060e331fcd6007b624@linux-foundation.org> From: Anshuman Khandual Message-ID: <6669114f-8522-c0cf-8b99-53f064b5b946@arm.com> Date: Thu, 15 Oct 2020 08:29:25 +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: <20201014133607.fbf63d060e331fcd6007b624@linux-foundation.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit 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 10/15/2020 02:06 AM, Andrew Morton wrote: > On Wed, 14 Oct 2020 08:45:16 +0530 "Aneesh Kumar K.V" wrote: > >>> Against mm-debug_vm_pgtable-avoid-none-pte-in-pte_clear_test.patch: >>> >>> https://lkml.kernel.org/r/87zh5wx51b.fsf@linux.ibm.com >> >> >> yes this one we should get fixed. I was hoping someone familiar with >> Riscv pte updates rules would pitch in. IIUC we need to update >> RANDON_ORVALUE similar to how we updated it for s390 and ppc64. >> >> >> Alternatively we can do this >> >> modified mm/debug_vm_pgtable.c >> @@ -548,7 +548,7 @@ static void __init pte_clear_tests(struct mm_struct >> *mm, pte_t *ptep, >> pte_t pte = pfn_pte(pfn, prot); >> >> pr_debug("Validating PTE clear\n"); >> - pte = __pte(pte_val(pte) | RANDOM_ORVALUE); >> +// pte = __pte(pte_val(pte) | RANDOM_ORVALUE); >> set_pte_at(mm, vaddr, ptep, pte); >> barrier(); >> pte_clear(mm, vaddr, ptep); >> >> till we get that feedback from RiscV team? > > Would it be better to do > > #ifdef CONFIG_S390 > pte = __pte(pte_val(pte) | RANDOM_ORVALUE); > #endif I would suggest just dropping RANDOM_ORVALUE from pte_clear_tests() possibly with a comment saying it needs to be fixed on RISCV before being added back later. pte = __pte(pte_val(pte)); OR Disable RANDOM_ORVALUE only for RISCV. #ifndef CONFIG_RISCV pte = __pte(pte_val(pte) | RANDOM_ORVALUE); #endif