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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 74C97C2BB1D for ; Fri, 10 Apr 2020 03:51:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4807A215A4 for ; Fri, 10 Apr 2020 03:51:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586490686; bh=TwbeNkf9wh9yqk/pHfVPa0QM9C0aKBP8I7YXCSMXwFk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=spIB7+oHBPLtguLlcHBYNntavWtK7mGnR5Jg3/CMGlSBlaKRzdlr69gzs2JDxGgDY g8mmFt3M4XElUrgu/Bqbdt3BRL31v85EwugCv+iFSakuAJE5TzQjqdoOV9RVySHdMu oMUV4EtRg8jyI3dN8MNOU8LlP520aq+KFhAnsRkk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729183AbgDJDvY (ORCPT ); Thu, 9 Apr 2020 23:51:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:36398 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729150AbgDJDvR (ORCPT ); Thu, 9 Apr 2020 23:51:17 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4BB58206C0; Fri, 10 Apr 2020 03:51:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586490677; bh=TwbeNkf9wh9yqk/pHfVPa0QM9C0aKBP8I7YXCSMXwFk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Z9KKZT6w3qHSUx6xs6oBoP80yfHxZaOHfxOkH10toJjUMNyABfEKFUxu7YBInvjRZ YDkB3kXCFVLwLUYfjFaLeYfimsI/+gBRLSjaQgm8GsLAqnoF4D0gpEPWDDpdfdj5j9 DZhTF7AyWY3F0rDhXs+Qiqv0ZqtYjid8iTsjCHIg= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Arvind Sankar , Ard Biesheuvel , Ingo Molnar , Sasha Levin Subject: [PATCH AUTOSEL 4.9 6/9] x86/boot: Use unsigned comparison for addresses Date: Thu, 9 Apr 2020 23:51:07 -0400 Message-Id: <20200410035111.9938-6-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200410035111.9938-1-sashal@kernel.org> References: <20200410035111.9938-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 fd0b6a272dd5b..7532f6f536774 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 9e3a183561a9a..3fac2d133e4ec 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: @@ -339,7 +339,7 @@ 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