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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 AA42CC5518A for ; Wed, 22 Apr 2020 09:59:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7DD4020735 for ; Wed, 22 Apr 2020 09:59:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587549587; bh=8dKXULgc9tL7S6NUGH/SYxbtnWrHjv56lU3vacd03ss=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=xABeElXjR+AXQDNoaohp+fPVbh4Bvp5o88ETUE6d6LaXXsbDKGeMsWZhpZf1RSWyU LeQGXOXbyHbLitEIWgQr+h+8VToTPA4Lp+QGP6kM5AhVhiXN1WLl7mXq739PWwzrbI lXv91r5bD9VclbJZDKVPwaoXfGkpXq341WH9QNxQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726520AbgDVJ7q (ORCPT ); Wed, 22 Apr 2020 05:59:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:46342 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726503AbgDVJ7l (ORCPT ); Wed, 22 Apr 2020 05:59:41 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 94B2620735; Wed, 22 Apr 2020 09:59:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587549580; bh=8dKXULgc9tL7S6NUGH/SYxbtnWrHjv56lU3vacd03ss=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iI+HdZ3gPGLRbtcvpqktt5uQRUj78yEBiLOgOMMTHAyq1ncRDs39qrEPjQp22bRQR IA/k29EW2bylYn/vRj1UqFBnOk72LXzmjMYycR3/AJt3FA4007raB5THJpk4cmK/mw EDaCp18r0ZlbL+qLOocsnLqqDrdn4OWUr0URac08= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Arvind Sankar , Ard Biesheuvel , Ingo Molnar , Sasha Levin Subject: [PATCH 4.4 009/100] x86/boot: Use unsigned comparison for addresses Date: Wed, 22 Apr 2020 11:55:39 +0200 Message-Id: <20200422095024.457026835@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095022.476101261@linuxfoundation.org> References: <20200422095022.476101261@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arvind Sankar [ Upstream commit 81a34892c2c7c809f9c4e22c5ac936ae673fb9a2 ] The load address is compared with LOAD_PHYSICAL_ADDR using a signed comparison currently (using jge instruction). When loading a 64-bit kernel using the new efi32_pe_entry() point added by: 97aa276579b2 ("efi/x86: Add true mixed mode entry point into .compat section") using Qemu with -m 3072, the firmware actually loads us above 2Gb, resulting in a very early crash. Use the JAE instruction to perform a unsigned comparison instead, as physical addresses should be considered unsigned. Signed-off-by: Arvind Sankar Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20200301230436.2246909-6-nivedita@alum.mit.edu Link: https://lore.kernel.org/r/20200308080859.21568-14-ardb@kernel.org Signed-off-by: Sasha Levin --- arch/x86/boot/compressed/head_32.S | 2 +- arch/x86/boot/compressed/head_64.S | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S index 0256064da8da3..0eca7f2087b1f 100644 --- a/arch/x86/boot/compressed/head_32.S +++ b/arch/x86/boot/compressed/head_32.S @@ -170,7 +170,7 @@ preferred_addr: notl %eax andl %eax, %ebx cmpl $LOAD_PHYSICAL_ADDR, %ebx - jge 1f + jae 1f #endif movl $LOAD_PHYSICAL_ADDR, %ebx 1: diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index b831e24f7168b..ca8151ef3bfa0 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -104,7 +104,7 @@ ENTRY(startup_32) notl %eax andl %eax, %ebx cmpl $LOAD_PHYSICAL_ADDR, %ebx - jge 1f + jae 1f #endif movl $LOAD_PHYSICAL_ADDR, %ebx 1: @@ -337,7 +337,7 @@ preferred_addr: notq %rax andq %rax, %rbp cmpq $LOAD_PHYSICAL_ADDR, %rbp - jge 1f + jae 1f #endif movq $LOAD_PHYSICAL_ADDR, %rbp 1: -- 2.20.1