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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 477DCE7717D for ; Thu, 12 Dec 2024 03:04:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=XQkmT1yPjCtnHFbt7EIihUB6ImRKXJuV2L2GBasoOjw=; b=aLh0G7jiEJhfpMOqgOR0g1E/vO j18bN1uKId1oW6xfwm5EVA4mFbSaiiCD7dZoCteL4wEUaTY2MV8ZuP1oHBPdXGB4Y+7OvGXyYiz6j TjSUyFqigsNv6U0DT11qk4ptuErmKysXdP7nrT1ZaSL8y7ppvlJzBfZG6QkxDwMIOBwglnNhn7kMs P2blwWX3uxlai36Egr6AeoP8oL/colMa6EKeBZTduJvFmFKKtG9usZ36Ii9kE1gYLCTLf2lFSMc29 GkLL/83qnp72z6PU7Mj3SiUz1US6X0MsV3DVkI5yUsO32ergIT+0LkKiUqLr5zMAIZ0YU4dpOcTRI vI2dZhdQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tLZUy-0000000Gml6-4BLC; Thu, 12 Dec 2024 03:04:20 +0000 Received: from mgamail.intel.com ([198.175.65.10]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tLZUw-0000000Gmkb-2MSf for kexec@lists.infradead.org; Thu, 12 Dec 2024 03:04:19 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1733972659; x=1765508659; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=Hrq+a6WXW51XWWS3wLmGanfVMJdQWcnIUm/Pwg0Okgg=; b=iqmoZF8giKfUG4/mENMCvL8Jd7dtEltH3cXkdSWXZzSeD0lPWlbbAXLS porl4Ongeoi+nevuqYTCXjKglwZ2/6bv9ltLF0YdA8gLPyVbOuAVEcj/A 0MHV+I4xJXC8ojlUZ2EPHlYw/ZxvUnjjZWAJyrnVWYi1wnjedzKE5OpXY Vh7H86iti8sDsRZI/r2JZveh/AGvyb8PX9siI40f/ZDsDq2zzquEprYd0 uq3+gVA0d6Nbkb6cs2GRRZaZXDjf6lx6kFmjYAYon3TRTuleSG6wfwAGD X5rymOFva39aL3EZrf13F0IGYlMxchyChC05Ng9OyHcFA07qRnXfnT03J w==; X-CSE-ConnectionGUID: 9OCgDk5FRo+tVh+VtWXMHg== X-CSE-MsgGUID: 8ZmfQdN+S/2vRFS063WZ3A== X-IronPort-AV: E=McAfee;i="6700,10204,11283"; a="51790973" X-IronPort-AV: E=Sophos;i="6.12,227,1728975600"; d="scan'208";a="51790973" Received: from orviesa007.jf.intel.com ([10.64.159.147]) by orvoesa102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Dec 2024 19:04:17 -0800 X-CSE-ConnectionGUID: galIJQFwT1iXUCWiYm5vaA== X-CSE-MsgGUID: K9ut+D3ZSEGSLA9BXwX4ng== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.12,224,1728975600"; d="scan'208";a="96517966" Received: from unknown (HELO [10.238.1.173]) ([10.238.1.173]) by orviesa007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Dec 2024 19:04:12 -0800 Message-ID: <5bb26488-f5fb-4186-92c3-de6a07631f91@linux.intel.com> Date: Thu, 12 Dec 2024 11:03:59 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 13/20] x86/kexec: Mark relocate_kernel page as ROX instead of RWX To: David Woodhouse , kexec@lists.infradead.org Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , David Woodhouse , "Kirill A. Shutemov" , Kai Huang , Nikolay Borisov , linux-kernel@vger.kernel.org, Simon Horman , Dave Young , Peter Zijlstra , jpoimboe@kernel.org, bsz@amazon.de References: <20241205153343.3275139-1-dwmw2@infradead.org> <20241205153343.3275139-14-dwmw2@infradead.org> Content-Language: en-US From: "Ning, Hongyu" In-Reply-To: <20241205153343.3275139-14-dwmw2@infradead.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241211_190418_686724_6ADCBC28 X-CRM114-Status: GOOD ( 17.77 ) X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org On 2024/12/5 23:05, David Woodhouse wrote: > From: David Woodhouse > > All writes to the page now happen before it gets marked as executable > (or after it's already switched to the identmap page tables where it's > OK to be RWX). > > Signed-off-by: David Woodhouse > --- > arch/x86/kernel/machine_kexec_64.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c > index c9fd60f8f806..9232ad1562c8 100644 > --- a/arch/x86/kernel/machine_kexec_64.c > +++ b/arch/x86/kernel/machine_kexec_64.c > @@ -323,7 +323,7 @@ int machine_kexec_prepare(struct kimage *image) > > __memcpy(control_page, __relocate_kernel_start, reloc_end - reloc_start); > > - set_memory_x((unsigned long)control_page, 1); > + set_memory_rox((unsigned long)control_page, 1); > > return 0; > } > @@ -333,6 +333,7 @@ void machine_kexec_cleanup(struct kimage *image) > void *control_page = page_address(image->control_code_page); > > set_memory_nx((unsigned long)control_page, 1); > + set_memory_rw((unsigned long)control_page, 1); > > free_transition_pgtable(image); > } Hi David, I've hit some kdump/kexec regression issue for guest kernel in KVM/QEMU based VM and reported in https://bugzilla.kernel.org/show_bug.cgi?id=219592. based on further git bisect, it seems to be related with this commit, would you help to take a look?