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=-9.9 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY, 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 E70A9C433E2 for ; Tue, 8 Sep 2020 05:14:52 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 70C5E21897 for ; Tue, 8 Sep 2020 05:14:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 70C5E21897 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=csgroup.eu Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id A9C016B0002; Tue, 8 Sep 2020 01:14:51 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A23A76B0037; Tue, 8 Sep 2020 01:14:51 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 912786B0055; Tue, 8 Sep 2020 01:14:51 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0087.hostedemail.com [216.40.44.87]) by kanga.kvack.org (Postfix) with ESMTP id 776AA6B0002 for ; Tue, 8 Sep 2020 01:14:51 -0400 (EDT) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 34DE83626 for ; Tue, 8 Sep 2020 05:14:51 +0000 (UTC) X-FDA: 77238729582.07.trail98_1d022bc270d2 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin07.hostedemail.com (Postfix) with ESMTP id 0AD741803F9B3 for ; Tue, 8 Sep 2020 05:14:51 +0000 (UTC) X-HE-Tag: trail98_1d022bc270d2 X-Filterd-Recvd-Size: 6551 Received: from pegase1.c-s.fr (pegase1.c-s.fr [93.17.236.30]) by imf26.hostedemail.com (Postfix) with ESMTP for ; Tue, 8 Sep 2020 05:14:50 +0000 (UTC) Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4Bltcl5vwGz9tyfC; Tue, 8 Sep 2020 07:14:47 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id CHegWz2Zqd7i; Tue, 8 Sep 2020 07:14:47 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 4Bltcl4S93z9tyfB; Tue, 8 Sep 2020 07:14:47 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 4FA238B78F; Tue, 8 Sep 2020 07:14:48 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id p7u0ZX_PNhu5; Tue, 8 Sep 2020 07:14:48 +0200 (CEST) Received: from [192.168.4.90] (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id E7EF18B768; Tue, 8 Sep 2020 07:14:45 +0200 (CEST) Subject: Re: [RFC PATCH v2 2/3] mm: make pXd_addr_end() functions page-table entry aware To: Gerald Schaefer , Jason Gunthorpe , John Hubbard Cc: Peter Zijlstra , Dave Hansen , linux-mm , Paul Mackerras , linux-sparc , Alexander Gordeev , Claudio Imbrenda , Will Deacon , linux-arch , linux-s390 , Vasily Gorbik , Richard Weinberger , linux-x86 , Russell King , Christian Borntraeger , Ingo Molnar , Catalin Marinas , Andrey Ryabinin , Heiko Carstens , Arnd Bergmann , Jeff Dike , linux-um , Borislav Petkov , Andy Lutomirski , Thomas Gleixner , linux-arm , linux-power , LKML , Andrew Morton , Linus Torvalds , Mike Rapoport References: <20200907180058.64880-1-gerald.schaefer@linux.ibm.com> <20200907180058.64880-3-gerald.schaefer@linux.ibm.com> From: Christophe Leroy Message-ID: <31dfb3ed-a0cc-3024-d389-ab9bd19e881f@csgroup.eu> Date: Tue, 8 Sep 2020 07:14:38 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <20200907180058.64880-3-gerald.schaefer@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr X-Rspamd-Queue-Id: 0AD741803F9B3 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 Content-Transfer-Encoding: quoted-printable 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: Le 07/09/2020 =C3=A0 20:00, Gerald Schaefer a =C3=A9crit=C2=A0: > From: Alexander Gordeev >=20 > Unlike all other page-table abstractions pXd_addr_end() do not take > into account a particular table entry in which context the functions > are called. On architectures with dynamic page-tables folding that > might lead to lack of necessary information that is difficult to > obtain other than from the table entry itself. That already led to > a subtle memory corruption issue on s390. >=20 > By letting pXd_addr_end() functions know about the page-table entry > we allow archs not only make extra checks, but also optimizations. >=20 > As result of this change the pXd_addr_end_folded() functions used > in gup_fast traversal code become unnecessary and get replaced with > universal pXd_addr_end() variants. >=20 > The arch-specific updates not only add dereferencing of page-table > entry pointers, but also small changes to the code flow to make those > dereferences possible, at least for x86 and powerpc. Also for arm64, > but in way that should not have any impact. >=20 [...] >=20 > Signed-off-by: Alexander Gordeev > Signed-off-by: Gerald Schaefer > --- > arch/arm/include/asm/pgtable-2level.h | 2 +- > arch/arm/mm/idmap.c | 6 ++-- > arch/arm/mm/mmu.c | 8 ++--- > arch/arm64/kernel/hibernate.c | 16 ++++++---- > arch/arm64/kvm/mmu.c | 16 +++++----- > arch/arm64/mm/kasan_init.c | 8 ++--- > arch/arm64/mm/mmu.c | 25 +++++++-------- > arch/powerpc/mm/book3s64/radix_pgtable.c | 7 ++--- > arch/powerpc/mm/hugetlbpage.c | 6 ++-- You forgot arch/powerpc/mm/book3s64/subpage_prot.c it seems. > arch/s390/include/asm/pgtable.h | 8 ++--- > arch/s390/mm/page-states.c | 8 ++--- > arch/s390/mm/pageattr.c | 8 ++--- > arch/s390/mm/vmem.c | 8 ++--- > arch/sparc/mm/hugetlbpage.c | 6 ++-- > arch/um/kernel/tlb.c | 8 ++--- > arch/x86/mm/init_64.c | 15 ++++----- > arch/x86/mm/kasan_init_64.c | 16 +++++----- > include/asm-generic/pgtable-nop4d.h | 2 +- > include/asm-generic/pgtable-nopmd.h | 2 +- > include/asm-generic/pgtable-nopud.h | 2 +- > include/linux/pgtable.h | 26 ++++----------- > mm/gup.c | 8 ++--- > mm/ioremap.c | 8 ++--- > mm/kasan/init.c | 17 +++++----- > mm/madvise.c | 4 +-- > mm/memory.c | 40 ++++++++++++-----------= - > mm/mlock.c | 18 ++++++++--- > mm/mprotect.c | 8 ++--- > mm/pagewalk.c | 8 ++--- > mm/swapfile.c | 8 ++--- > mm/vmalloc.c | 16 +++++----- > 31 files changed, 165 insertions(+), 173 deletions(-) Christophe