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=-14.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 47DDEC07E95 for ; Tue, 20 Jul 2021 12:53:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 25BFB61019 for ; Tue, 20 Jul 2021 12:53:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231132AbhGTMNL (ORCPT ); Tue, 20 Jul 2021 08:13:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:45924 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229631AbhGTMNE (ORCPT ); Tue, 20 Jul 2021 08:13:04 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (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 29ECD60FE9; Tue, 20 Jul 2021 12:53:42 +0000 (UTC) Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94.2) (envelope-from ) id 1m5pFk-00EVc3-2Y; Tue, 20 Jul 2021 13:53:40 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Tue, 20 Jul 2021 13:53:39 +0100 From: Marc Zyngier To: Will Deacon Cc: linux-kernel@vger.kernel.org, Ard Biesheuvel , Michael Ellerman , Thomas Gleixner , Benjamin Herrenschmidt , Christophe Leroy , Paul Mackerras , Jonathan Marek , Catalin Marinas , Andrew Morton , Mike Rapoport , Mark Rutland , Geert Uytterhoeven , linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 0/2] Fix arm64 boot regression in 5.14 In-Reply-To: <20210720123512.8740-1-will@kernel.org> References: <20210720123512.8740-1-will@kernel.org> User-Agent: Roundcube Webmail/1.4.11 Message-ID: <99c4f35ae22bbc26bcf8bfe5493f2766@kernel.org> X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: will@kernel.org, linux-kernel@vger.kernel.org, ardb@kernel.org, mpe@ellerman.id.au, tglx@linutronix.de, benh@kernel.crashing.org, christophe.leroy@csgroup.eu, paulus@samba.org, jonathan@marek.ca, catalin.marinas@arm.com, akpm@linux-foundation.org, rppt@kernel.org, mark.rutland@arm.com, geert@linux-m68k.org, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-07-20 13:35, Will Deacon wrote: > Hi folks, > > Jonathan reports [1] that commit c742199a014d ("mm/pgtable: add stubs > for {pmd/pub}_{set/clear}_huge") breaks the boot on arm64 when huge > mappings are used to map the kernel linear map but the VA size is > configured such that PUDs are folded. This is because the > non-functional > pud_set_huge() stub is used to create the linear map, which results in > 1GB holes and a fatal data abort when the kernel attemps to access > them. > > Digging further into the issue, it also transpired that huge-vmap is > silently disabled in these configurations as well [2], despite working > correctly in 5.13. The latter issue causes the pgtable selftests to > scream due to a failing consistency check [3]. > > Rather than leave mainline in a terminally broken state for arm64 while > we figure this out, revert the offending commit to get things working > again. Unfortunately, reverting the change in isolation causes a build > breakage for 32-bit PowerPC 8xx machines which recently started relying > on the problematic stubs to support pte-level huge-vmap entries [4]. > Since Christophe is away at the moment, this series first reverts the > PowerPC 8xx change in order to avoid breaking the build. > > I would really like this to land for -rc3 and I can take these via the > arm64 fixes queue if the PowerPC folks are alright with them. > > Cheers, > > Will > > [1] https://lore.kernel.org/r/20210717160118.9855-1-jonathan@marek.ca > [2] https://lore.kernel.org/r/20210719104918.GA6440@willie-the-truck > [3] > https://lore.kernel.org/r/CAMuHMdXShORDox-xxaeUfDW3wx2PeggFSqhVSHVZNKCGK-y_vQ@mail.gmail.com/ > [4] > https://lore.kernel.org/r/8b972f1c03fb6bd59953035f0a3e4d26659de4f8.1620795204.git.christophe.leroy@csgroup.eu/ > > Cc: Ard Biesheuvel > Cc: Michael Ellerman > Cc: Thomas Gleixner > Cc: Benjamin Herrenschmidt > Cc: Christophe Leroy > Cc: Paul Mackerras > Cc: Jonathan Marek > Cc: Catalin Marinas > Cc: Andrew Morton > Cc: Nicholas Piggin Cc: Mike Rapoport > Cc: Mark Rutland > Cc: Geert Uytterhoeven > Cc: Marc Zyngier > Cc: linuxppc-dev@lists.ozlabs.org > Cc: linux-arm-kernel@lists.infradead.org > > --->8 > > Jonathan Marek (1): > Revert "mm/pgtable: add stubs for {pmd/pub}_{set/clear}_huge" > > Will Deacon (1): > Revert "powerpc/8xx: add support for huge pages on VMAP and VMALLOC" > > arch/arm64/mm/mmu.c | 20 ++++----- > arch/powerpc/Kconfig | 2 +- > arch/powerpc/include/asm/nohash/32/mmu-8xx.h | 43 -------------------- > arch/x86/mm/pgtable.c | 34 +++++++--------- > include/linux/pgtable.h | 26 +----------- > 5 files changed, 25 insertions(+), 100 deletions(-) Acked-by: Marc Zyngier M. -- Jazz is not dead. It just smells funny...