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=-15.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 1B9B4C07E95 for ; Tue, 20 Jul 2021 12:35:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EE85760E0C for ; Tue, 20 Jul 2021 12:35:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237691AbhGTLzM (ORCPT ); Tue, 20 Jul 2021 07:55:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:38880 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229659AbhGTLzB (ORCPT ); Tue, 20 Jul 2021 07:55:01 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B6E0860E0C; Tue, 20 Jul 2021 12:35:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626784539; bh=asA6l4h5KrepX/z50UVRSC8Q3OvPiGjAUceJKgcJbl0=; h=From:To:Cc:Subject:Date:From; b=YvNKATWOtShf7swN0mmf2C6ONDPu8XOlH7q70SOroQM5S/MpCDM0YB8g1cad/xpAt DZdsiQnk9tGg0td/isJJ2XQ1/izSNXzsQN45DxDXpz3NNJvEIbKKxsa5dpOtaaE+8a CdUdXNFjOfsTHCg3WDra+78eNlhSkoOiYmB+mUHEqgyNu/swwAMbVxkpPUHjFZxtCn vLm4cfaJXBXxlkBtTY64lP3t/wN/Yd0rcIjowQ8w8CxqZOrgoc7dZgOU7csRBpJ8Qp XwqCbdeJMFNQXPGd6+z/3CyrU8g1IAnFcjFSPbUNOMUwmLmsvloD6mVhIG+b4t3vXa Qo/vh5hYZ98XQ== From: Will Deacon To: linux-kernel@vger.kernel.org Cc: Will Deacon , Ard Biesheuvel , Michael Ellerman , Thomas Gleixner , Benjamin Herrenschmidt , Christophe Leroy , Paul Mackerras , Jonathan Marek , Catalin Marinas , Andrew Morton , Mike Rapoport , Mark Rutland , Geert Uytterhoeven , Marc Zyngier , linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH 0/2] Fix arm64 boot regression in 5.14 Date: Tue, 20 Jul 2021 13:35:10 +0100 Message-Id: <20210720123512.8740-1-will@kernel.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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: 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(-) -- 2.32.0.402.g57bb445576-goog