From patchwork Tue Dec 6 14:47:04 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 1712733 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.infradead.org (client-ip=2607:7c80:54:3::133; helo=bombadil.infradead.org; envelope-from=linux-snps-arc-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=PUdU+sjh; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=JzF1BFCX; dkim-atps=neutral Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4NRNZM3Z2Wz23yq for ; Wed, 7 Dec 2022 01:48:09 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=xCqXy2n9/d4/FR98YWvGGfJHDLnf4kct6owbGEyJw3E=; b=PUdU+sjhjJ/0oP xpxM/af2/2oLuOpAE6R0bPdeaEmZQR8SvMwJQ/FGhyvBlbb7SUBoN5+FsDSJyq9BGj5Vc1t7jxdjc PL8RgJcjeXqccJtblMvO5M785iRxj5x32O2z3NEZzXDzm4QqeJFo6CYyn54ikxh8IBR4X0Vnnbsvd 2U5/XJGPOjfKrZjmCpPz+oj73Ldzh7YGaEZzj7ReuFPi66BGGc2pmri2etvNdt9BZcHgu81n2p8cB iZD4E+Qp4Ts8p/DTuUSOJptYj+UqTCUfMjEHObFcn/y+TCE2sgRkHXNp2vGHEHoeyuHioNOxsMgcY F5TLdkhJf22f2Nfk8fJw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1p2ZEp-00BgfA-Ul; Tue, 06 Dec 2022 14:48:03 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1p2ZEm-00BgdV-GP for linux-snps-arc@lists.infradead.org; Tue, 06 Dec 2022 14:48:02 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1670338079; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=iUuXMOHVf03Vb0qMF+Y5euIKjDZHBS53BDQPdht/P5M=; b=JzF1BFCXrs090Cy3I08q9Xzn67hr6Win3sKz4MFPclP3k6RtfEx7aQYKeu6rjtVakc5gT5 2soU6O+zQlFW6+/TlUbXHYuWOdtWoMJZ8rn4hJSsUCEs0DVrguN68QgeRVgRdVEWiwmGgK xJQGDGqrOxgXn5SN6/gZNDgFaiHSwJQ= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-335-3aNaSZDWPJGBU0cwaoxK0w-1; Tue, 06 Dec 2022 09:47:56 -0500 X-MC-Unique: 3aNaSZDWPJGBU0cwaoxK0w-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id D08958027F5; Tue, 6 Dec 2022 14:47:53 +0000 (UTC) Received: from t480s.redhat.com (unknown [10.39.193.173]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6E89C492B04; Tue, 6 Dec 2022 14:47:33 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: Andrew Morton , Hugh Dickins , John Hubbard , Jason Gunthorpe , Mike Rapoport , Yang Shi , Vlastimil Babka , Nadav Amit , Andrea Arcangeli , Peter Xu , linux-mm@kvack.org, x86@kernel.org, linux-alpha@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, loongarch@lists.linux.dev, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, openrisc@lists.librecores.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org, David Hildenbrand , Albert Ou , Anton Ivanov , Borislav Petkov , Brian Cain , Christophe Leroy , Chris Zankel , Dave Hansen , "David S. Miller" , Dinh Nguyen , Geert Uytterhoeven , Greg Ungerer , Guo Ren , Helge Deller , "H. Peter Anvin" , Huacai Chen , Ingo Molnar , Ivan Kokshaysky , "James E.J. Bottomley" , Johannes Berg , Matt Turner , Max Filippov , Michael Ellerman , Michal Simek , Nicholas Piggin , Palmer Dabbelt , Paul Walmsley , Richard Henderson , Richard Weinberger , Rich Felker , Russell King , Stafford Horne , Stefan Kristiansson , Thomas Bogendoerfer , Thomas Gleixner , Vineet Gupta , WANG Xuerui , Yoshinori Sato Subject: [PATCH mm-unstable RFC 00/26] mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs Date: Tue, 6 Dec 2022 15:47:04 +0100 Message-Id: <20221206144730.163732-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221206_064800_631393_2D36D488 X-CRM114-Status: GOOD ( 15.58 ) X-Spam-Score: -0.4 (/) X-Spam-Report: Spam detection software, running on the system "bombadil.infradead.org", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: This is the follow-up on [1]: [PATCH v2 0/8] mm: COW fixes part 3: reliable GUP R/W FOLL_GET of anonymous pages After we implemented __HAVE_ARCH_PTE_SWP_EXCLUSIVE on most prominent enterprise architectures, implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all remaining architectures that support swap PTEs. Content analysis details: (-0.4 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_MSPIKE_H2 RBL: Average reputation (+2) [170.10.129.124 listed in wl.mailspike.net] -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [170.10.129.124 listed in list.dnswl.org] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 0.0 SPF_NONE SPF: sender does not publish an SPF Record -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain -0.2 DKIMWL_WL_HIGH DKIMwl.org - High trust sender X-BeenThere: linux-snps-arc@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux on Synopsys ARC Processors List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-snps-arc" Errors-To: linux-snps-arc-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org This is the follow-up on [1]: [PATCH v2 0/8] mm: COW fixes part 3: reliable GUP R/W FOLL_GET of anonymous pages After we implemented __HAVE_ARCH_PTE_SWP_EXCLUSIVE on most prominent enterprise architectures, implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all remaining architectures that support swap PTEs. This makes sure that exclusive anonymous pages will stay exclusive, even after they were swapped out -- for example, making GUP R/W FOLL_GET of anonymous pages reliable. Details can be found in [1]. This primarily fixes remaining known O_DIRECT memory corruptions that can happen on concurrent swapout, whereby we can lose DMA reads to a page (modifying the user page by writing to it). To verify, there are two test cases (requiring swap space, obviously): (1) The O_DIRECT+swapout test case [2] from Andrea. This test case tries triggering a race condition. (2) My vmsplice() test case [3] that tries to detect if the exclusive marker was lost during swapout, not relying on a race condition. For example, on 32bit x86 (with and without PAE), my test case fails without these patches: $ ./test_swp_exclusive FAIL: page was replaced during COW But succeeds with these patches: $ ./test_swp_exclusive PASS: page was not replaced during COW Why implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE for all architectures, even the ones where swap support might be in a questionable state? This is the first step towards removing "readable_exclusive" migration entries, and instead using pte_swp_exclusive() also with (readable) migration entries instead (as suggested by Peter). The only missing piece for that is supporting pmd_swp_exclusive() on relevant architectures with THP migration support. As all relevant architectures now implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE,, we can drop __HAVE_ARCH_PTE_SWP_EXCLUSIVE in the last patch. RFC because some of the swap PTE layouts are really tricky and I really need some feedback related to deciphering these layouts and "using yet unused PTE bits in swap PTEs". I tried cross-compiling all relevant setups (phew, I might only miss some power/nohash variants), but only tested on x86 so far. CCing arch maintainers only on this cover letter and on the respective patch(es). [1] https://lkml.kernel.org/r/20220329164329.208407-1-david@redhat.com [2] https://gitlab.com/aarcange/kernel-testcases-for-v5.11/-/blob/main/page_count_do_wp_page-swap.c [3] https://gitlab.com/davidhildenbrand/scratchspace/-/blob/main/test_swp_exclusive.c David Hildenbrand (26): mm/debug_vm_pgtable: more pte_swp_exclusive() sanity checks alpha/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE arc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE arm/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE csky/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE hexagon/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE ia64/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE loongarch/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE m68k/mm: remove dummy __swp definitions for nommu m68k/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE microblaze/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE mips/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE nios2/mm: refactor swap PTE layout nios2/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE openrisc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE parisc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE powerpc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on 32bit book3s powerpc/nohash/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE riscv/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE sh/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE sparc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on 32bit sparc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on 64bit um/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE x86/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE also on 32bit xtensa/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE mm: remove __HAVE_ARCH_PTE_SWP_EXCLUSIVE arch/alpha/include/asm/pgtable.h | 40 ++++++++- arch/arc/include/asm/pgtable-bits-arcv2.h | 26 +++++- arch/arm/include/asm/pgtable-2level.h | 3 + arch/arm/include/asm/pgtable-3level.h | 3 + arch/arm/include/asm/pgtable.h | 34 ++++++-- arch/arm64/include/asm/pgtable.h | 1 - arch/csky/abiv1/inc/abi/pgtable-bits.h | 13 ++- arch/csky/abiv2/inc/abi/pgtable-bits.h | 19 ++-- arch/csky/include/asm/pgtable.h | 17 ++++ arch/hexagon/include/asm/pgtable.h | 36 ++++++-- arch/ia64/include/asm/pgtable.h | 31 ++++++- arch/loongarch/include/asm/pgtable-bits.h | 4 + arch/loongarch/include/asm/pgtable.h | 38 +++++++- arch/m68k/include/asm/mcf_pgtable.h | 35 +++++++- arch/m68k/include/asm/motorola_pgtable.h | 37 +++++++- arch/m68k/include/asm/pgtable_no.h | 6 -- arch/m68k/include/asm/sun3_pgtable.h | 38 +++++++- arch/microblaze/include/asm/pgtable.h | 44 +++++++--- arch/mips/include/asm/pgtable-32.h | 86 ++++++++++++++++--- arch/mips/include/asm/pgtable-64.h | 23 ++++- arch/mips/include/asm/pgtable.h | 35 ++++++++ arch/nios2/include/asm/pgtable-bits.h | 3 + arch/nios2/include/asm/pgtable.h | 37 ++++++-- arch/openrisc/include/asm/pgtable.h | 40 +++++++-- arch/parisc/include/asm/pgtable.h | 40 ++++++++- arch/powerpc/include/asm/book3s/32/pgtable.h | 37 ++++++-- arch/powerpc/include/asm/book3s/64/pgtable.h | 1 - arch/powerpc/include/asm/nohash/32/pgtable.h | 22 +++-- arch/powerpc/include/asm/nohash/32/pte-40x.h | 6 +- arch/powerpc/include/asm/nohash/32/pte-44x.h | 18 +--- arch/powerpc/include/asm/nohash/32/pte-85xx.h | 4 +- arch/powerpc/include/asm/nohash/64/pgtable.h | 24 +++++- arch/powerpc/include/asm/nohash/pgtable.h | 15 ++++ arch/powerpc/include/asm/nohash/pte-e500.h | 1 - arch/riscv/include/asm/pgtable-bits.h | 3 + arch/riscv/include/asm/pgtable.h | 28 ++++-- arch/s390/include/asm/pgtable.h | 1 - arch/sh/include/asm/pgtable_32.h | 53 +++++++++--- arch/sparc/include/asm/pgtable_32.h | 26 +++++- arch/sparc/include/asm/pgtable_64.h | 37 +++++++- arch/sparc/include/asm/pgtsrmmu.h | 14 +-- arch/um/include/asm/pgtable.h | 36 +++++++- arch/x86/include/asm/pgtable-2level.h | 26 ++++-- arch/x86/include/asm/pgtable-3level.h | 26 +++++- arch/x86/include/asm/pgtable.h | 3 - arch/xtensa/include/asm/pgtable.h | 31 +++++-- include/linux/pgtable.h | 29 ------- mm/debug_vm_pgtable.c | 25 +++++- mm/memory.c | 4 - mm/rmap.c | 11 --- 50 files changed, 943 insertions(+), 227 deletions(-)