From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.skyhub.de ([2a01:4f8:190:11c2::b:1457]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hHUN7-00015I-HB for kexec@lists.infradead.org; Fri, 19 Apr 2019 14:20:11 +0000 Date: Fri, 19 Apr 2019 16:19:52 +0200 From: Borislav Petkov Subject: [PATCH] x86/boot: Disable RSDP parsing temporarily Message-ID: <20190419141952.GE10324@zn.tnic> References: <20190419101733.GA10324@zn.tnic> <20190419105014.GE11060@MiWiFi-R3L-srv> <20190419113413.GC10324@zn.tnic> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Kairui Song , Thomas Gleixner Cc: Juergen Gross , Tom Lendacky , Chao Fan , indou.takao@jp.fujitsu.com, Kees Cook , Baoquan He , Ard Biesheuvel , "x86@kernel.org" , "kexec@lists.infradead.org" , Linux Kernel Mailing List , Ingo Molnar , Dave Hansen , "H. Peter Anvin" , Junichi Nomura , msys.mizuma@gmail.com, Dave Young , "Kirill A. Shutemov" Ok, thinking about this more, we believe it is too late in the release cycle to keep experimenting so the only thing left to do is the below. This should bring the situation back to what it was before, at 5.0 times, and we'll have plenty of time now to address and properly fix all the outstanding issues. --- From: Borislav Petkov The original intention to move RDSP parsing very early, before KASLR does its ranges selection, was to accommodate movable memory regions machines (CONFIG_MEMORY_HOTREMOVE) to still be able to do memory hotplug. However, that broke kexec'ing a kernel on EFI machines because depending on where the EFI systab was mapped, on at least one machine it isn't present in the kexec mapping of the second kernel, leading to a triple fault in the early code. Fixing this properly requires significantly involved surgery and we cannot allow ourselves to do that, that close to the merge window. So disable the RSDP parsing code temporarily until it is fixed properly in the next release cycle. Signed-off-by: Borislav Petkov Cc: Ard Biesheuvel Cc: Baoquan He Cc: Chao Fan Cc: Dave Hansen Cc: "H. Peter Anvin" Cc: indou.takao@jp.fujitsu.com Cc: Ingo Molnar Cc: Juergen Gross Cc: kasong@redhat.com Cc: Kees Cook Cc: "Kirill A. Shutemov" Cc: msys.mizuma@gmail.com Cc: Thomas Gleixner Cc: Tom Lendacky Cc: x86-ml --- arch/x86/boot/compressed/misc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index c0d6c560df69..5a237e8dbf8d 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -352,7 +352,7 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, boot_params->hdr.loadflags &= ~KASLR_FLAG; /* Save RSDP address for later use. */ - boot_params->acpi_rsdp_addr = get_rsdp_addr(); + /* boot_params->acpi_rsdp_addr = get_rsdp_addr(); */ sanitize_boot_params(boot_params); -- 2.21.0 -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply. _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec 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=-8.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 D33A5C282DA for ; Fri, 19 Apr 2019 19:09:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9D50D2064A for ; Fri, 19 Apr 2019 19:09:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="KvSUr3dZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729801AbfDSTJE (ORCPT ); Fri, 19 Apr 2019 15:09:04 -0400 Received: from mail.skyhub.de ([5.9.137.197]:42186 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727924AbfDSTJC (ORCPT ); Fri, 19 Apr 2019 15:09:02 -0400 Received: from zn.tnic (p200300EC2F112E0081C1838BC39E212C.dip0.t-ipconnect.de [IPv6:2003:ec:2f11:2e00:81c1:838b:c39e:212c]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 261A21EC0513; Fri, 19 Apr 2019 16:19:58 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1555683598; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=eOp/ySOqHIMhpte/mJe3u1Zx4rYSYksGeMB7N2WQHHk=; b=KvSUr3dZjOYEW2cN7Z7qdy1pvJR4XtfLReq6g0Mpo/ceNzhES0cByjesayV3ajJm8IQLsl gc0ul2nUCYDTShPum8+7PY3yANpcrLg5Lul9sM9vN3i70sQuyNUx6m/euxFXQp503333CC He51Jt9MdDESEfOK2c4PtnceiCcCUG8= Date: Fri, 19 Apr 2019 16:19:52 +0200 From: Borislav Petkov To: Kairui Song , Thomas Gleixner Cc: Baoquan He , Linux Kernel Mailing List , Junichi Nomura , Dave Young , Chao Fan , "x86@kernel.org" , "kexec@lists.infradead.org" , Ard Biesheuvel , Dave Hansen , "H. Peter Anvin" , indou.takao@jp.fujitsu.com, Ingo Molnar , Juergen Gross , Kees Cook , "Kirill A. Shutemov" , msys.mizuma@gmail.com, Tom Lendacky Subject: [PATCH] x86/boot: Disable RSDP parsing temporarily Message-ID: <20190419141952.GE10324@zn.tnic> References: <20190419101733.GA10324@zn.tnic> <20190419105014.GE11060@MiWiFi-R3L-srv> <20190419113413.GC10324@zn.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ok, thinking about this more, we believe it is too late in the release cycle to keep experimenting so the only thing left to do is the below. This should bring the situation back to what it was before, at 5.0 times, and we'll have plenty of time now to address and properly fix all the outstanding issues. --- From: Borislav Petkov The original intention to move RDSP parsing very early, before KASLR does its ranges selection, was to accommodate movable memory regions machines (CONFIG_MEMORY_HOTREMOVE) to still be able to do memory hotplug. However, that broke kexec'ing a kernel on EFI machines because depending on where the EFI systab was mapped, on at least one machine it isn't present in the kexec mapping of the second kernel, leading to a triple fault in the early code. Fixing this properly requires significantly involved surgery and we cannot allow ourselves to do that, that close to the merge window. So disable the RSDP parsing code temporarily until it is fixed properly in the next release cycle. Signed-off-by: Borislav Petkov Cc: Ard Biesheuvel Cc: Baoquan He Cc: Chao Fan Cc: Dave Hansen Cc: "H. Peter Anvin" Cc: indou.takao@jp.fujitsu.com Cc: Ingo Molnar Cc: Juergen Gross Cc: kasong@redhat.com Cc: Kees Cook Cc: "Kirill A. Shutemov" Cc: msys.mizuma@gmail.com Cc: Thomas Gleixner Cc: Tom Lendacky Cc: x86-ml --- arch/x86/boot/compressed/misc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index c0d6c560df69..5a237e8dbf8d 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -352,7 +352,7 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, boot_params->hdr.loadflags &= ~KASLR_FLAG; /* Save RSDP address for later use. */ - boot_params->acpi_rsdp_addr = get_rsdp_addr(); + /* boot_params->acpi_rsdp_addr = get_rsdp_addr(); */ sanitize_boot_params(boot_params); -- 2.21.0 -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.