From patchwork Mon Jul 20 15:20:15 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jan Beulich X-Patchwork-Id: 11674149 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 2066A13B4 for ; Mon, 20 Jul 2020 15:21:30 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 03B0822482 for ; Mon, 20 Jul 2020 15:21:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 03B0822482 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jxXal-0003F1-TK; Mon, 20 Jul 2020 15:20:35 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jxXak-0003Ew-Pv for xen-devel@lists.xenproject.org; Mon, 20 Jul 2020 15:20:34 +0000 X-Inumbo-ID: 8de45cbb-ca9c-11ea-9fc2-12813bfff9fa Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 8de45cbb-ca9c-11ea-9fc2-12813bfff9fa; Mon, 20 Jul 2020 15:20:33 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 0A0AEB893; Mon, 20 Jul 2020 15:20:23 +0000 (UTC) To: "xen-devel@lists.xenproject.org" From: Jan Beulich Subject: [PATCH] x86/S3: put data segment registers into known state upon resume Message-ID: <3cad2798-1a01-7d5e-ea55-ddb9ba6388d9@suse.com> Date: Mon, 20 Jul 2020 17:20:15 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 Content-Language: en-US X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Andrew Cooper , "M. Vefa Bicakci" , Wei Liu , =?utf-8?q?Roger?= =?utf-8?q?_Pau_Monn=C3=A9?= Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" wakeup_32 sets %ds and %es to BOOT_DS, while leaving %fs at what wakeup_start did set it to, and %gs at whatever BIOS did load into it. All of this may end up confusing the first load_segments() to run on the BSP after resume, in particular allowing a non-nul selector value to be left in %fs. Alongside %ss, also put all other data segment registers into the same state that the boot and CPU bringup paths put them in. Reported-by: M. Vefa Bicakci Signed-off-by: Jan Beulich Reviewed-by: Roger Pau Monné --- a/xen/arch/x86/acpi/wakeup_prot.S +++ b/xen/arch/x86/acpi/wakeup_prot.S @@ -52,6 +52,16 @@ ENTRY(s3_resume) mov %eax, %ss mov saved_rsp(%rip), %rsp + /* + * Also put other segment registers into known state, like would + * be done on the boot path. This is in particular necessary for + * the first load_segments() to work as intended. + */ + mov %eax, %ds + mov %eax, %es + mov %eax, %fs + mov %eax, %gs + /* Reload code selector */ pushq $__HYPERVISOR_CS leaq 1f(%rip),%rax