From patchwork Sun Nov 1 17:08:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Rapoport X-Patchwork-Id: 11872225 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 D92C614B2 for ; Sun, 1 Nov 2020 17:08:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C19B722267 for ; Sun, 1 Nov 2020 17:08:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604250510; bh=qoO5B8Xp/14MFZgwPU/jGedaEAFQ4yw8Iy0a70elFZc=; h=From:To:Cc:Subject:Date:List-ID:From; b=gAIyDvPTzKg5eyMVwKhm4AedO+JFk6ErZIbW5E2hUcsrzjN6m91yqFxAV3rbuzD9U aorj+oQ1xW5vLCQ17aVneOMClVRfr3gdcHYf4RjpZhiB5FoUqX51uV9YIjiG3yDIAQ 74NNHqgOgzumgnT72WTXjf86zj0+Xb1UFtV2mIdQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726848AbgKARIa (ORCPT ); Sun, 1 Nov 2020 12:08:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:41434 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726790AbgKARI3 (ORCPT ); Sun, 1 Nov 2020 12:08:29 -0500 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 00EE02225C; Sun, 1 Nov 2020 17:08:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604250509; bh=qoO5B8Xp/14MFZgwPU/jGedaEAFQ4yw8Iy0a70elFZc=; h=From:To:Cc:Subject:Date:From; b=aeXT/OwHW/+BWp6oDUxTK7tVEE2JgNKn8o5RLAeVKF+gGN+y6GvNt66sXz3oUAyoZ vkym2hkg+IlgloGjifAdEzvsQmMYzb9WgOIhPVVzHGB/5j1He/xPl8nns1ugr0qnKd Iu84ZStCPNzsoPu6jktGifijoWUJtUBDfdbfbGOg= 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" , 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 , 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 v3 0/4] arch, mm: improve robustness of direct map manipulation Date: Sun, 1 Nov 2020 19:08:11 +0200 Message-Id: <20201101170815.9795-1-rppt@kernel.org> X-Mailer: git-send-email 2.28.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org 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, it is updated to make direct map accesses there more explicit. [1] https://lore.kernel.org/lkml/2759b4bf-e1e3-d006-7d86-78a40348269d@redhat.com v3 changes: * update arm64 changes to avoid regression, per Rick's comments * fix bisectability 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_pages() helper PM: hibernate: make direct map manipulations more explicit arch, mm: restore dependency of __kernel_map_pages() of 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 | 35 +++++++++++++---------------- include/linux/set_memory.h | 5 +++++ kernel/power/snapshot.c | 30 +++++++++++++++++++++++-- mm/memory_hotplug.c | 3 +-- mm/page_alloc.c | 6 ++--- mm/slab.c | 8 +++---- 20 files changed, 103 insertions(+), 58 deletions(-) Acked-by: Kirill A. Shutemov