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,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 AC0B9C606C1 for ; Mon, 8 Jul 2019 15:30:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7B38C21537 for ; Mon, 8 Jul 2019 15:30:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562599842; bh=IWAfHE3MJdLP/FqmZHno6i2OiWv+r4s+QbncoVw12eo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=xgcytsmdaGxTKcyxJRJqrbrg6u7gt8cO9Jwjc4YM6KyTWNdfqwdocnTfzzybJuCu3 KrlweXjgTye15T4W1IP6OQFHrwiKxIyMixCimm8OE9iImEtmPmdmfzB+hhnbcrc0lC iGTCAymzxBfePUXgtafGqtaqRK8IRZbIM7Lldm8A= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389512AbfGHP3f (ORCPT ); Mon, 8 Jul 2019 11:29:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:58332 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389500AbfGHP3c (ORCPT ); Mon, 8 Jul 2019 11:29:32 -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 7AD6321743; Mon, 8 Jul 2019 15:29:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562599771; bh=IWAfHE3MJdLP/FqmZHno6i2OiWv+r4s+QbncoVw12eo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XP06qAH2RDYGUkSv7oZhIlSEEe7XG80CLHf1iWkOB7ufmgLCZZAL+Co0T0NkMhlCW Da+wpiT/vmybvto9hHcHioY7ekJXsSYJkhuj1oQHPddVjW+JfTgju7Qe124YWGfbpz EpE6onTqGE8Ie1FEJ5v1ICITfxjuIzdaJx6N5fEU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kyle D Pelton , "Kirill A. Shutemov" , Borislav Petkov , dave.hansen@linux.intel.com, "H. Peter Anvin" , Ingo Molnar , Thomas Gleixner , Wei Huang , x86-ml , Sasha Levin Subject: [PATCH 4.19 72/90] x86/boot/compressed/64: Do not corrupt EDX on EFER.LME=1 setting Date: Mon, 8 Jul 2019 17:13:39 +0200 Message-Id: <20190708150525.966995669@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190708150521.829733162@linuxfoundation.org> References: <20190708150521.829733162@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 [ Upstream commit 45b13b424faafb81c8c44541f093a682fdabdefc ] RDMSR in the trampoline code overwrites EDX but that register is used to indicate whether 5-level paging has to be enabled and if clobbered, leads to failure to boot on a 5-level paging machine. Preserve EDX on the stack while we are dealing with EFER. Fixes: b677dfae5aa1 ("x86/boot/compressed/64: Set EFER.LME=1 in 32-bit trampoline before returning to long mode") Reported-by: Kyle D Pelton Signed-off-by: Kirill A. Shutemov Signed-off-by: Borislav Petkov Cc: dave.hansen@linux.intel.com Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Wei Huang Cc: x86-ml Link: https://lkml.kernel.org/r/20190206115253.1907-1-kirill.shutemov@linux.intel.com Signed-off-by: Sasha Levin --- arch/x86/boot/compressed/head_64.S | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index f105ae8651c9..f62e347862cc 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -602,10 +602,12 @@ ENTRY(trampoline_32bit_src) 3: /* Set EFER.LME=1 as a precaution in case hypervsior pulls the rug */ pushl %ecx + pushl %edx movl $MSR_EFER, %ecx rdmsr btsl $_EFER_LME, %eax wrmsr + popl %edx popl %ecx /* Enable PAE and LA57 (if required) paging modes */ -- 2.20.1