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=-4.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 63794C2D0A3 for ; Mon, 9 Nov 2020 16:49:34 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D8E1A2074F for ; Mon, 9 Nov 2020 16:49:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="HgDBb7hI"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="2PklhGFO" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D8E1A2074F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=CWlZtdMSSmJ350swrusJ6BQOGKrLUOa/cVdYSjpJvFI=; b=HgDBb7hIpewqMBGDzoNYJPC97 xTTKsEfx3TVHg0P0lhx4amqBhrBTbAlxOSE+hLoglNd95JiWXPrLhoQ90gftupjrx3NM0YDXRYllK A4mmapgewijpBkDP1vrDhFNqHYXTlUk+cNU0yk0iumdd4nWzJ5JpsVQyhqnhsRu/IX+XYuUFKJuf4 LgC7QvDr0mPxs/YFrCn9iKUL3OqdLJ+k91x7xpnj+Y8GjKSl1M/0jOvJqL3z8wCB+0CsRfnhw/WK2 tQMDrYwDnU2Td2Pst7bS2SutX7Qzi3nRb50TT0og0vxJKFEdQ/Rz6K+zF5/1d83JqJ98E6Jc1Oyvt bwT7GfLMQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kcAKy-0005Hn-1O; Mon, 09 Nov 2020 16:48:12 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kcAKt-0005Ff-GZ; Mon, 09 Nov 2020 16:48:10 +0000 Received: from kernel.org (unknown [77.125.7.142]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7C3EA2074F; Mon, 9 Nov 2020 16:47:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604940486; bh=6rn/Is9/mb71Cx8T5OixcswhdKR8Yw8hRoo0YqfjdsY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=2PklhGFO1GSLbrkd4w7eR0OQVXIC9bB/NRFuu0yXJ2cad3g2XWFGm5qY1CfZsxWEJ hIEGvV7DG50YSNEMxKxpw57WvEfw0aU7JllVonG+2csYY0gr4DIxzUIPf5drKxbhRb AQb1wGfM13MfcFzy1XYj4m6UEF/itQaci+zuEFqA= Date: Mon, 9 Nov 2020 18:47:52 +0200 From: Mike Rapoport To: Andrew Morton Subject: Re: [PATCH v6 0/4] arch, mm: improve robustness of direct map manipulation Message-ID: <20201109164752.GF301837@kernel.org> References: <20201109162415.13764-1-rppt@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201109162415.13764-1-rppt@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201109_114807_815822_F20F7F57 X-CRM114-Status: GOOD ( 25.14 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: David Hildenbrand , Peter Zijlstra , Benjamin Herrenschmidt , Dave Hansen , linux-mm@kvack.org, Paul Mackerras , Pavel Machek , "H. Peter Anvin" , sparclinux@vger.kernel.org, Christoph Lameter , Will Deacon , linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, Michael Ellerman , x86@kernel.org, Mike Rapoport , Christian Borntraeger , Ingo Molnar , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Len Brown , Albert Ou , Vasily Gorbik , linux-pm@vger.kernel.org, Heiko Carstens , David Rientjes , Borislav Petkov , Andy Lutomirski , Paul Walmsley , "Kirill A. Shutemov" , Thomas Gleixner , Vlastimil Babka , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, Pekka Enberg , Palmer Dabbelt , Joonsoo Kim , "Edgecombe, Rick P" , linuxppc-dev@lists.ozlabs.org, "David S. Miller" , "Kirill A . Shutemov" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Oops, this one has some rebase errors, I'll send v7 soon. Sorry for the noise. On Mon, Nov 09, 2020 at 06:24:11PM +0200, Mike Rapoport wrote: > 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 > > v6 changes: > * revert slab changes to avoid redundant check of static key > > 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(-) > > -- > 2.28.0 > -- Sincerely yours, Mike. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel