From patchwork Wed Mar 10 08:43:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joerg Roedel X-Patchwork-Id: 12127303 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,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 AA9AFC4332E for ; Wed, 10 Mar 2021 08:45:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 911ED6500B for ; Wed, 10 Mar 2021 08:45:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232450AbhCJIod (ORCPT ); Wed, 10 Mar 2021 03:44:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40952 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231899AbhCJIn6 (ORCPT ); Wed, 10 Mar 2021 03:43:58 -0500 Received: from theia.8bytes.org (8bytes.org [IPv6:2a01:238:4383:600:38bc:a715:4b6d:a889]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4197EC061761; Wed, 10 Mar 2021 00:43:54 -0800 (PST) Received: from cap.home.8bytes.org (p549adcf6.dip0.t-ipconnect.de [84.154.220.246]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by theia.8bytes.org (Postfix) with ESMTPSA id 4FADD3A9; Wed, 10 Mar 2021 09:43:52 +0100 (CET) From: Joerg Roedel To: x86@kernel.org Cc: Joerg Roedel , Joerg Roedel , hpa@zytor.com, Andy Lutomirski , Dave Hansen , Peter Zijlstra , Jiri Slaby , Dan Williams , Tom Lendacky , Juergen Gross , Kees Cook , David Rientjes , Cfir Cohen , Erdem Aktas , Masami Hiramatsu , Mike Stunes , Sean Christopherson , Martin Radev , Arvind Sankar , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: [PATCH v2 2/7] x86/boot/compressed/64: Reload CS in startup_32 Date: Wed, 10 Mar 2021 09:43:20 +0100 Message-Id: <20210310084325.12966-3-joro@8bytes.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210310084325.12966-1-joro@8bytes.org> References: <20210310084325.12966-1-joro@8bytes.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Joerg Roedel Exception handling in the startup_32 boot path requires the CS selector to be correctly set up. Reload it from the current GDT. Signed-off-by: Joerg Roedel --- arch/x86/boot/compressed/head_64.S | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index e94874f4bbc1..c59c80ca546d 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -107,9 +107,16 @@ SYM_FUNC_START(startup_32) movl %eax, %gs movl %eax, %ss -/* setup a stack and make sure cpu supports long mode. */ + /* Setup a stack and load CS from current GDT */ leal rva(boot_stack_end)(%ebp), %esp + pushl $__KERNEL32_CS + leal rva(1f)(%ebp), %eax + pushl %eax + lretl +1: + + /* Make sure cpu supports long mode. */ call verify_cpu testl %eax, %eax jnz .Lno_longmode