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=-5.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 37A28C3A59F for ; Thu, 29 Aug 2019 22:17:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 029702166E for ; Thu, 29 Aug 2019 22:17:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=shutemov-name.20150623.gappssmtp.com header.i=@shutemov-name.20150623.gappssmtp.com header.b="lOLmUE9y" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728143AbfH2WRW (ORCPT ); Thu, 29 Aug 2019 18:17:22 -0400 Received: from mail-ed1-f68.google.com ([209.85.208.68]:36489 "EHLO mail-ed1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727686AbfH2WRV (ORCPT ); Thu, 29 Aug 2019 18:17:21 -0400 Received: by mail-ed1-f68.google.com with SMTP id g24so5767510edu.3 for ; Thu, 29 Aug 2019 15:17:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov-name.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=VaTFhxoCm9hWeOCO0ElTE9V4VLgj8vESshlNLr9lSt8=; b=lOLmUE9y33VatAZwocCWLzD5p0QcedDPRQUx62l97hcFeMqSJqi/P9dFD60pebIFqY Xy6sqfSrR8KfT6Z2s3v0QJzxKssQO82njUFDD728x+m0Jl+BjkOgfNDiRKdXcgKa4a2r XuLdiP/LUwvPyPUcX8Y6FNvOQ2i/Uk6XYxHrVO7mma9ftj9GL7D+V4K5qGdHPaUlhufZ npXFlaOntKEr+Moaf8sCpL6XmOl355INUWSQp+jkxtsRMsPScK9pabEQHw1ahp6HMVAI WtOj1CmHg/pBJCEbiDlM3pKaIbEIkPHEV7d8WLkWqWG8A5h+sMlXmeAHPVVtmvMu/AAl AiNw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=VaTFhxoCm9hWeOCO0ElTE9V4VLgj8vESshlNLr9lSt8=; b=gdbq8yKhJrmgrP4E2xpy6nCtPYw+aDNNOIbVK06WNkNyQVMRxeWU2Yk6jgEG6zsEA/ NGuzSPd4jorUHjz0pB/CaSTyvm1OQhmNBWae7c81kBqHfc0HBRy3T8F+Xa3pR070u6Kr 214sYTjAypHKS6pqsbXh71sGr1QsobLNCJa8srkloBVmlhPREml5mQlhzWT+uc7Fm0HG f53vDF7qMIZoiM7GPvPLh+cTFBN2Gfe7qcUv4jaAS6HaTp8umQOidB1xb2d1bNMam44l jfSupTgc+qmuHfxso+13vOVzY5gLSVMyN64hn4XSum+xQHDBeWrmBk4VKfMT7fSHzXJJ Avxg== X-Gm-Message-State: APjAAAVbXDiwiPm0hMEraaDjzV3JbvfoXK3Zvw7teWKmdqi/fDkl5IVA kvHqrgPfp3QISrl4NEy+2sWrOQ== X-Google-Smtp-Source: APXvYqw52tG87FkxH5gtCxt1n5cfLEGSFeSVwA4DyF85KDHKVvHgE7gEHO1VVWF/TpY4Z8/AugtmRQ== X-Received: by 2002:a50:ef04:: with SMTP id m4mr12624736eds.155.1567117040075; Thu, 29 Aug 2019 15:17:20 -0700 (PDT) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id l27sm543544ejd.31.2019.08.29.15.17.19 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 29 Aug 2019 15:17:19 -0700 (PDT) Received: by box.localdomain (Postfix, from userid 1000) id 287CB10212D; Fri, 30 Aug 2019 01:17:23 +0300 (+03) Date: Fri, 30 Aug 2019 01:17:23 +0300 From: "Kirill A. Shutemov" To: Sasha Levin Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, "Kirill A . Shutemov" , Borislav Petkov , "H. Peter Anvin" , Ingo Molnar , Thomas Gleixner , x86-ml Subject: Re: [PATCH AUTOSEL 5.2 51/76] x86/boot/compressed/64: Fix boot on machines with broken E820 table Message-ID: <20190829221723.eicsws3q7gp6nx37@box> References: <20190829181311.7562-1-sashal@kernel.org> <20190829181311.7562-51-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190829181311.7562-51-sashal@kernel.org> User-Agent: NeoMutt/20180716 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 29, 2019 at 02:12:46PM -0400, Sasha Levin wrote: > From: "Kirill A. Shutemov" > > [ Upstream commit 0a46fff2f9108c2c44218380a43a736cf4612541 ] > > BIOS on Samsung 500C Chromebook reports very rudimentary E820 table that > consists of 2 entries: > > BIOS-e820: [mem 0x0000000000000000-0x0000000000000fff] usable > BIOS-e820: [mem 0x00000000fffff000-0x00000000ffffffff] reserved > > It breaks logic in find_trampoline_placement(): bios_start lands on the > end of the first 4k page and trampoline start gets placed below 0. > > Detect underflow and don't touch bios_start for such cases. It makes > kernel ignore E820 table on machines that doesn't have two usable pages > below BIOS_START_MAX. > > Fixes: 1b3a62643660 ("x86/boot/compressed/64: Validate trampoline placement against E820") > Signed-off-by: Kirill A. Shutemov > Signed-off-by: Borislav Petkov > Cc: "H. Peter Anvin" > Cc: Ingo Molnar > Cc: Thomas Gleixner > Cc: x86-ml > Link: https://bugzilla.kernel.org/show_bug.cgi?id=203463 > Link: https://lkml.kernel.org/r/20190813131654.24378-1-kirill.shutemov@linux.intel.com > Signed-off-by: Sasha Levin Please postpone backporting the patch (and into other trees). There's a fixup for it: http://lore.kernel.org/r/20190826133326.7cxb4vbmiawffv2r@box -- Kirill A. Shutemov