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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=no 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 55A4CC5518C for ; Wed, 22 Apr 2020 11:05:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3487F20774 for ; Wed, 22 Apr 2020 11:05:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587553531; bh=4MnyMmkAl/EqqxNgkyGui3OAOBpCB1BjyNAYWxVtRPg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=zV8DcBWlf4SXrnMFinjsibyTe78XXQpWnmzWbjNna/YNrzbC4TdjrwbbpI6Br9rFp INGPn2/r5ESTC5d+EsSLHzazgeMfUEtomZzHGarRsSfWAUujd2DQSzKBzOiQ6rcWec i5dDW99SOcaMHl+5U0xRvIcXCXkMWnwzvZUKAia4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726817AbgDVLFa (ORCPT ); Wed, 22 Apr 2020 07:05:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:39442 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726358AbgDVLF3 (ORCPT ); Wed, 22 Apr 2020 07:05:29 -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 AD5AB2076E; Wed, 22 Apr 2020 11:05:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587553528; bh=4MnyMmkAl/EqqxNgkyGui3OAOBpCB1BjyNAYWxVtRPg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=A/JTGIrWnpiXib7VYLPnVA8Y0FdMixdMiXBEqxIureN5dh5gi/qIJiBbTinXyXwxa 5sxDMeeFyYxJxvmhIN82sdppx+JEjwZixbAuV3FNxOL498wCVv6LXplntqy0Bfei56 sQsz2V3ug7BF5Jylv+qxW5saHwblk1Y1KRBlIR+4= Date: Wed, 22 Apr 2020 13:05:25 +0200 From: Greg Kroah-Hartman To: =?iso-8859-1?Q?J=FCrgen_Gro=DF?= Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Miroslav Benes , Sasha Levin Subject: Re: [PATCH 5.6 096/166] x86/xen: Make the boot CPU idle task reliable Message-ID: <20200422110525.GA3128451@kroah.com> References: <20200422095047.669225321@linuxfoundation.org> <20200422095059.319186761@linuxfoundation.org> <48afe770-83c3-03c0-c21f-334ab2056ea3@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <48afe770-83c3-03c0-c21f-334ab2056ea3@suse.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 22, 2020 at 12:45:32PM +0200, Jürgen Groß wrote: > On 22.04.20 11:57, Greg Kroah-Hartman wrote: > > From: Miroslav Benes > > > > [ Upstream commit 2f62f36e62daec43aa7b9633ef7f18e042a80bed ] > > > > The unwinder reports the boot CPU idle task's stack on XEN PV as > > unreliable, which affects at least live patching. There are two reasons > > for this. First, the task does not follow the x86 convention that its > > stack starts at the offset right below saved pt_regs. It allows the > > unwinder to easily detect the end of the stack and verify it. Second, > > startup_xen() function does not store the return address before jumping > > to xen_start_kernel() which confuses the unwinder. > > > > Amend both issues by moving the starting point of initial stack in > > startup_xen() and storing the return address before the jump, which is > > exactly what call instruction does. > > > > Signed-off-by: Miroslav Benes > > Reviewed-by: Juergen Gross > > Signed-off-by: Juergen Gross > > Signed-off-by: Sasha Levin > > You'll need upstream d6f34f4c6b4a96 ("x86/xen: fix booting 32-bit pv > guest"), too. Thanks for that, now queued up. greg k-h