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,URIBL_BLOCKED,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 9F684C433E2 for ; Fri, 4 Sep 2020 04:04:23 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5E4A3206CA for ; Fri, 4 Sep 2020 04:04:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5E4A3206CA 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 E14B06B0037; Fri, 4 Sep 2020 00:04:22 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DC5B06B005C; Fri, 4 Sep 2020 00:04:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CDCF36B005D; Fri, 4 Sep 2020 00:04:22 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0106.hostedemail.com [216.40.44.106]) by kanga.kvack.org (Postfix) with ESMTP id B3D096B0037 for ; Fri, 4 Sep 2020 00:04:22 -0400 (EDT) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 7D2C5362C for ; Fri, 4 Sep 2020 04:04:22 +0000 (UTC) X-FDA: 77224036764.20.scale20_2d0623c270af Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin20.hostedemail.com (Postfix) with ESMTP id 522D4180C07AB for ; Fri, 4 Sep 2020 04:04:22 +0000 (UTC) X-HE-Tag: scale20_2d0623c270af X-Filterd-Recvd-Size: 2849 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf36.hostedemail.com (Postfix) with ESMTP for ; Fri, 4 Sep 2020 04:04:21 +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 12BC6101E; Thu, 3 Sep 2020 21:04:21 -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 3B9653F71F; Thu, 3 Sep 2020 21:04:18 -0700 (PDT) Subject: Re: [PATCH v4 03/13] mm/debug_vm_pgtable/ppc64: Avoid setting top bits in radom value To: "Aneesh Kumar K.V" , linux-mm@kvack.org, akpm@linux-foundation.org Cc: mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org References: <20200902114222.181353-1-aneesh.kumar@linux.ibm.com> <20200902114222.181353-4-aneesh.kumar@linux.ibm.com> From: Anshuman Khandual Message-ID: <74b87dca-1c8d-6458-8af6-392b87c0bfc6@arm.com> Date: Fri, 4 Sep 2020 09:33:47 +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: <20200902114222.181353-4-aneesh.kumar@linux.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 522D4180C07AB X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 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 09/02/2020 05:12 PM, Aneesh Kumar K.V wrote: > ppc64 use bit 62 to indicate a pte entry (_PAGE_PTE). Avoid setting > that bit in random value. > > Signed-off-by: Aneesh Kumar K.V > --- > mm/debug_vm_pgtable.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c > index 086309fb9b6f..00649b47f6e0 100644 > --- a/mm/debug_vm_pgtable.c > +++ b/mm/debug_vm_pgtable.c > @@ -44,10 +44,17 @@ > * entry type. But these bits might affect the ability to clear entries with > * pxx_clear() because of how dynamic page table folding works on s390. So > * while loading up the entries do not change the lower 4 bits. It does not > - * have affect any other platform. > + * have affect any other platform. Also avoid the 62nd bit on ppc64 that is > + * used to mark a pte entry. > */ > -#define S390_MASK_BITS 4 > -#define RANDOM_ORVALUE GENMASK(BITS_PER_LONG - 1, S390_MASK_BITS) > +#define S390_SKIP_MASK GENMASK(3, 0) > +#if __BITS_PER_LONG == 64 > +#define PPC64_SKIP_MASK GENMASK(62, 62) > +#else > +#define PPC64_SKIP_MASK 0x0 > +#endif > +#define ARCH_SKIP_MASK (S390_SKIP_MASK | PPC64_SKIP_MASK) > +#define RANDOM_ORVALUE (GENMASK(BITS_PER_LONG - 1, 0) & ~ARCH_SKIP_MASK) > #define RANDOM_NZVALUE GENMASK(7, 0) > > static void __init pte_basic_tests(unsigned long pfn, pgprot_t prot) > Reviewed-by: Anshuman Khandual