From patchwork Mon Nov 9 19:21:24 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Rapoport X-Patchwork-Id: 11892319 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B0CF91130 for ; Mon, 9 Nov 2020 19:21:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 72B9C20789 for ; Mon, 9 Nov 2020 19:21:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="k55R9YcA" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 72B9C20789 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 6F8646B0036; Mon, 9 Nov 2020 14:21:45 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 6A75A6B005C; Mon, 9 Nov 2020 14:21:45 -0500 (EST) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4F97A6B005D; Mon, 9 Nov 2020 14:21:45 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0175.hostedemail.com [216.40.44.175]) by kanga.kvack.org (Postfix) with ESMTP id 219B26B0036 for ; Mon, 9 Nov 2020 14:21:45 -0500 (EST) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id ABE143629 for ; Mon, 9 Nov 2020 19:21:44 +0000 (UTC) X-FDA: 77465849328.12.party46_4d06c7c272ee Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin12.hostedemail.com (Postfix) with ESMTP id 8F9E91800BC44 for ; Mon, 9 Nov 2020 19:21:44 +0000 (UTC) X-Spam-Summary: 1,0,0,91df6616e409bf98,d41d8cd98f00b204,rppt@kernel.org,,RULES_HIT:41:69:355:379:541:800:960:967:973:988:989:1260:1311:1314:1345:1437:1515:1535:1544:1711:1730:1747:1777:1792:1801:2198:2199:2393:2525:2559:2568:2570:2628:2682:2685:2693:2703:2859:2895:2899:2933:2937:2939:2942:2945:2947:2951:2954:3022:3355:3865:3866:3867:3868:3871:3872:3874:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4118:4250:4321:4605:5007:6119:6261:7576:7903:8660:8985:9025:10004:11658:13148:13161:13229:13230,0,RBL:198.145.29.99:@kernel.org:.lbl8.mailshell.net-64.100.201.201 62.2.0.100;04yfx9n3thxq63b1j3reapy73hjtfycbqsn3h187kkc8b3fx5g5akmo3gpcjf1c.bg75q9y5ggm3sn9ou4d16rh687wq677rrb1nuqigbbt8pxshoehcq6pywsxykue.k-lbl8.mailshell.net-223.238.255.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:79,LUA_SUMMARY:none X-HE-Tag: party46_4d06c7c272ee X-Filterd-Recvd-Size: 7678 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf47.hostedemail.com (Postfix) with ESMTP for ; Mon, 9 Nov 2020 19:21:43 +0000 (UTC) Received: from aquarius.haifa.ibm.com (nesher1.haifa.il.ibm.com [195.110.40.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 143A5206D8; Mon, 9 Nov 2020 19:21:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604949702; bh=QGTmizEK1UjKs+M3i5taZOyhlQtuke3SF4xVfj8rMZk=; h=From:To:Cc:Subject:Date:From; b=k55R9YcADr0xJwXvM4j0zAp6vWZk0ETbFSE04MFUnjzJKc9PomPqxRT22PQlapBZi 2IzNzcdBMaDo6ymAx8eH7285ig9SBc7A4oWYDMyBtditNFHUzd3UvkTqLbh6yvgCrf IK7aPEp1dRIjSK4NRfcVZ1/a4WCtbm7eFBu5gmDM= From: Mike Rapoport To: Andrew Morton Cc: Albert Ou , Andy Lutomirski , Benjamin Herrenschmidt , Borislav Petkov , Catalin Marinas , Christian Borntraeger , Christoph Lameter , "David S. Miller" , Dave Hansen , David Hildenbrand , David Rientjes , "Edgecombe, Rick P" , "H. Peter Anvin" , Heiko Carstens , Ingo Molnar , Joonsoo Kim , "Kirill A . Shutemov" , "Kirill A. Shutemov" , Len Brown , Michael Ellerman , Mike Rapoport , Mike Rapoport , Palmer Dabbelt , Paul Mackerras , Paul Walmsley , Pavel Machek , Pekka Enberg , Peter Zijlstra , "Rafael J. Wysocki" , Thomas Gleixner , Vasily Gorbik , Vlastimil Babka , Will Deacon , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-pm@vger.kernel.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, x86@kernel.org Subject: [PATCH v7 0/4] arch, mm: improve robustness of direct map manipulation Date: Mon, 9 Nov 2020 21:21:24 +0200 Message-Id: <20201109192128.960-1-rppt@kernel.org> X-Mailer: git-send-email 2.28.0 MIME-Version: 1.0 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: From: Mike Rapoport Hi, During recent discussion about KVM protected memory, David raised a concern about usage of __kernel_map_pages() outside of DEBUG_PAGEALLOC scope [1]. Indeed, for architectures that define CONFIG_ARCH_HAS_SET_DIRECT_MAP it is possible that __kernel_map_pages() would fail, but since this function is void, the failure will go unnoticed. Moreover, there's lack of consistency of __kernel_map_pages() semantics across architectures as some guard this function with #ifdef DEBUG_PAGEALLOC, some refuse to update the direct map if page allocation debugging is disabled at run time and some allow modifying the direct map regardless of DEBUG_PAGEALLOC settings. This set straightens this out by restoring dependency of __kernel_map_pages() on DEBUG_PAGEALLOC and updating the call sites accordingly. Since currently the only user of __kernel_map_pages() outside DEBUG_PAGEALLOC is hibernation, it is updated to make direct map accesses there more explicit. [1] https://lore.kernel.org/lkml/2759b4bf-e1e3-d006-7d86-78a40348269d@redhat.com v7 changes: * fix a rebase error that sneaked into v6 after removal of slab changes v6 changes: * revert slab changes to avoid redundant check of static key https://lore.kernel.org/lkml/20201109162415.13764-1-rppt@kernel.org v5 changes: * use pairs of _map()/_unmap() functions instead of _map(..., int enable) as Vlastimil suggested https://lore.kernel.org/lkml/20201108065758.1815-1-rppt@kernel.org v4 changes: * s/WARN_ON/pr_warn_once/ per David and Kirill * rebase on v5.10-rc2 * add Acked/Reviewed tags https://lore.kernel.org/lkml/20201103162057.22916-1-rppt@kernel.org v3 changes: * update arm64 changes to avoid regression, per Rick's comments * fix bisectability https://lore.kernel.org/lkml/20201101170815.9795-1-rppt@kernel.org v2 changes: * Rephrase patch 2 changelog to better describe the change intentions and implications * Move removal of kernel_map_pages() from patch 1 to patch 2, per David https://lore.kernel.org/lkml/20201029161902.19272-1-rppt@kernel.org v1: https://lore.kernel.org/lkml/20201025101555.3057-1-rppt@kernel.org Mike Rapoport (4): mm: introduce debug_pagealloc_{map,unmap}_pages() helpers PM: hibernate: make direct map manipulations more explicit arch, mm: restore dependency of __kernel_map_pages() on DEBUG_PAGEALLOC arch, mm: make kernel_page_present() always available arch/Kconfig | 3 +++ arch/arm64/Kconfig | 4 +-- arch/arm64/include/asm/cacheflush.h | 1 + arch/arm64/mm/pageattr.c | 6 +++-- arch/powerpc/Kconfig | 5 +--- arch/riscv/Kconfig | 4 +-- arch/riscv/include/asm/pgtable.h | 2 -- arch/riscv/include/asm/set_memory.h | 1 + arch/riscv/mm/pageattr.c | 31 ++++++++++++++++++++++ arch/s390/Kconfig | 4 +-- arch/sparc/Kconfig | 4 +-- arch/x86/Kconfig | 4 +-- arch/x86/include/asm/set_memory.h | 1 + arch/x86/mm/pat/set_memory.c | 4 +-- include/linux/mm.h | 40 ++++++++++++++--------------- include/linux/set_memory.h | 5 ++++ kernel/power/snapshot.c | 38 +++++++++++++++++++++++++-- mm/memory_hotplug.c | 3 +-- mm/page_alloc.c | 6 ++--- 19 files changed, 113 insertions(+), 53 deletions(-)