From patchwork Mon Jun 22 16:21:34 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Claudio Imbrenda X-Patchwork-Id: 11618377 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9FA1A90 for ; Mon, 22 Jun 2020 16:21:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8F33220760 for ; Mon, 22 Jun 2020 16:21:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729655AbgFVQVy (ORCPT ); Mon, 22 Jun 2020 12:21:54 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:21496 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729671AbgFVQVx (ORCPT ); Mon, 22 Jun 2020 12:21:53 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 05MG4VGB102606 for ; Mon, 22 Jun 2020 12:21:53 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 31tysp8tfa-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 22 Jun 2020 12:21:52 -0400 Received: from m0098396.ppops.net (m0098396.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 05MGC0iB140491 for ; Mon, 22 Jun 2020 12:21:52 -0400 Received: from ppma05fra.de.ibm.com (6c.4a.5195.ip4.static.sl-reverse.com [149.81.74.108]) by mx0a-001b2d01.pphosted.com with ESMTP id 31tysp8te6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 22 Jun 2020 12:21:52 -0400 Received: from pps.filterd (ppma05fra.de.ibm.com [127.0.0.1]) by ppma05fra.de.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 05MG1BPv029895; Mon, 22 Jun 2020 16:21:49 GMT Received: from b06cxnps3074.portsmouth.uk.ibm.com (d06relay09.portsmouth.uk.ibm.com [9.149.109.194]) by ppma05fra.de.ibm.com with ESMTP id 31sa37seg5-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 22 Jun 2020 16:21:49 +0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 05MGLggm48824486 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 22 Jun 2020 16:21:42 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 270F952052; Mon, 22 Jun 2020 16:21:42 +0000 (GMT) Received: from ibm-vm.ibmuc.com (unknown [9.145.9.197]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id CBAF15205F; Mon, 22 Jun 2020 16:21:41 +0000 (GMT) From: Claudio Imbrenda To: kvm@vger.kernel.org, pbonzini@redhat.com Cc: frankja@linux.ibm.com, thuth@redhat.com, david@redhat.com Subject: [kvm-unit-tests PATCH v1 1/8] x86/cstart.S: initialize stack before using it Date: Mon, 22 Jun 2020 18:21:34 +0200 Message-Id: <20200622162141.279716-2-imbrenda@linux.ibm.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200622162141.279716-1-imbrenda@linux.ibm.com> References: <20200622162141.279716-1-imbrenda@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.216,18.0.687 definitions=2020-06-22_09:2020-06-22,2020-06-22 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 spamscore=0 lowpriorityscore=0 clxscore=1015 cotscore=-2147483648 impostorscore=0 phishscore=0 mlxlogscore=999 priorityscore=1501 bulkscore=0 suspectscore=0 adultscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006220117 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org It seems the 32-bit initialization code uses the stack before actually initializing it. Probably the boot loader leaves a reasonable value in the stack pointer so this issue has not been noticed before. Signed-off-by: Claudio Imbrenda --- x86/cstart.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/x86/cstart.S b/x86/cstart.S index 38ac19b..fa62e09 100644 --- a/x86/cstart.S +++ b/x86/cstart.S @@ -96,13 +96,13 @@ MSR_GS_BASE = 0xc0000101 .globl start start: + mov $stacktop, %esp push %ebx call setup_multiboot call setup_libcflat mov mb_cmdline(%ebx), %eax mov %eax, __args call __setup_args - mov $stacktop, %esp setup_percpu_area call prepare_32 jmpl $8, $start32