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=-1.0 required=3.0 tests=FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 90237C46464 for ; Fri, 10 Aug 2018 10:23:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4878A223F9 for ; Fri, 10 Aug 2018 10:23:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4878A223F9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=gmx.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727598AbeHJMw1 (ORCPT ); Fri, 10 Aug 2018 08:52:27 -0400 Received: from mout.gmx.net ([212.227.15.18]:33475 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727258AbeHJMw0 (ORCPT ); Fri, 10 Aug 2018 08:52:26 -0400 Received: from homer.simpson.net ([185.221.150.53]) by mail.gmx.com (mrgmx003 [212.227.17.190]) with ESMTPSA (Nemesis) id 0MhAVV-1faXvr0ICX-00MLKe; Fri, 10 Aug 2018 12:23:02 +0200 Message-ID: <1533896581.5885.16.camel@gmx.de> Subject: Re: [PATCH] x86, kdump: Fix efi=noruntime NULL pointer dereference From: Mike Galbraith To: Dave Young Cc: Baoquan He , Sebastian Andrzej Siewior , lkml Date: Fri, 10 Aug 2018 12:23:01 +0200 In-Reply-To: <20180810084501.GA11901@dhcp-128-65.nay.redhat.com> References: <1533737025.4936.3.camel@gmx.de> <20180810084501.GA11901@dhcp-128-65.nay.redhat.com> Content-Type: text/plain; charset="ISO-8859-15" X-Mailer: Evolution 3.26.6 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Provags-ID: V03:K1:6Cd+EnTG0iXsZ6B6na1gwfdxlOeEzVv9yhkaJdApi2wCuGOpmcu cuHk1UNc/G0g/3QSh775HeqKtDjRMjVPIbWkzgjRZEJW562YB2dDPHB6aIIfSoFYMnGD+7m xpHqvdj89PITFcAgueRcmfFVr9xRMAQqZ3djijgyqOYk2G/zIFprGoaUjlAT2y+eFB3WbY0 QDvLBqtqdMkmGZiqUWt6A== X-UI-Out-Filterresults: notjunk:1;V01:K0:JwI/PJSGPp8=:8rpbeVJpAifWlo8OymzVyz pCJKjsqWw7rXWIdpU4OCsk5L9dWZnvbL4vtUEOaS13g9Hw2M5lT09mZwzimNBMcs7vfNFmRuN 2kSlM1w+9e1HrK+7l9CbVsUho1UgIvnk/0Alm1i6hUDpSbzjyrKf96oCC73fUKkKEoXkxyMWJ W5ipscK43HIQXW9T2IsG4CAf92xphgqSXHH/5yMCPuGI5Z4e+drje8BMpp8Upp+wD35Ryrynn 36RLdXOdSbMcUdQJ74okcwBR5c08sDgnmraKgV/6SveqtYF3wHWT2KGslNTNWaQUSVnRYH1Bn CuYYOSIfrRx0c13hej7iLHViO+IXqHM9I1D2zLYFYvvRXcFkCuSSbF+jhmt2MndwM4j2bDcCk 1Qx3itQq04KgujlCWHCiXVmTGzTewzv+/9nMCRUgS0r6eTN8Ss1WuKYrtBnRNfx3tSOx1qz0c OxDb4KXNwEEL73nc6ieAo0t/lTiXBEEGUWmCL7B4x3hpbdDEQhkgnUGDgUmdUIOaqTKUr6Ez2 7ysTNQJAOHkzwJi7PgUatePchEAKcqCMgq5aEu1J8hdJJRA/p1x+qSVC1oM+gVAM0NrDYAMLu iWfZoNmLm32K8hH0Mch0dggIXeoCwpBtaSswm1kavNt7vaMstwTi2O9YSkqIkgMpxbjyr/mwG sAxevLEbBZykCUUAlKtOTUaacJgetEdmgQW1hT3Xv01iWgrCkVAPAdvsKl/7iG4CLTlJXz8pD lDr2R3sI0l6zFTfgFXcrv9eeborJmVuNpcTtfatOsWj9KxVh5ZPYzyS3MVzRToge9lVjz/nv9 a0IEtCV Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2018-08-10 at 16:45 +0800, Dave Young wrote: > > BTW, this patch only fix the kexec load phase problem, even if kexec > load successfully with the fix, the 2nd kernel can not boot because efi > memmap info is not correct and usable. Hm. I didn't do anything else with kexec, but did crashdump my box both w/wo efi=noruntime. > So we should go with some fix similar to below, and do the cleanup we > mentioned with a separate patch later. Ah, you mean the one I had _just_ built when I saw this :) > Also user space kexec-tools need a similar patch to error out in case > no runtime maps. It would be good to fix both userspace and kernel > load. > > diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c > index 7326078eaa7a..e34ba2f53cfb 100644 > --- a/arch/x86/kernel/kexec-bzimage64.c > +++ b/arch/x86/kernel/kexec-bzimage64.c > @@ -123,7 +123,7 @@ static int setup_efi_info_memmap(struct boot_params *params, > struct efi_info *ei = ¶ms->efi_info; > > if (!efi_map_sz) > - return 0; > + return -EINVAL; > > efi_runtime_map_copy(efi_map, efi_map_sz); > > @@ -166,9 +166,10 @@ setup_efi_state(struct boot_params *params, unsigned long params_load_addr, > { > struct efi_info *current_ei = &boot_params.efi_info; > struct efi_info *ei = ¶ms->efi_info; > + int ret; > > if (!current_ei->efi_memmap_size) > - return 0; > + return -EINVAL; > > /* > * If 1:1 mapping is not enabled, second kernel can not setup EFI > @@ -176,8 +177,8 @@ setup_efi_state(struct boot_params *params, unsigned long params_load_addr, > * acpi_rsdp= on kernel command line to make second kernel boot > * without efi. > */ > - if (efi_enabled(EFI_OLD_MEMMAP)) > - return 0; > + if (efi_enabled(EFI_OLD_MEMMAP) || !efi_enabled(EFI_RUNTIME_SERVICES)) > + return -ENODEV; > > ei->efi_loader_signature = current_ei->efi_loader_signature; > ei->efi_systab = current_ei->efi_systab; > @@ -186,8 +187,10 @@ setup_efi_state(struct boot_params *params, unsigned long params_load_addr, > ei->efi_memdesc_version = current_ei->efi_memdesc_version; > ei->efi_memdesc_size = efi_get_runtime_map_desc_size(); > > - setup_efi_info_memmap(params, params_load_addr, efi_map_offset, > + ret = setup_efi_info_memmap(params, params_load_addr, efi_map_offset, > efi_map_sz); > + if (ret) > + return ret; > prepare_add_efi_setup_data(params, params_load_addr, > efi_setup_data_offset); > return 0; > @@ -250,8 +253,10 @@ setup_boot_parameters(struct kimage *image, struct boot_params *params, > > #ifdef CONFIG_EFI > /* Setup EFI state */ > - setup_efi_state(params, params_load_addr, efi_map_offset, efi_map_sz, > + ret = setup_efi_state(params, params_load_addr, efi_map_offset, efi_map_sz, > efi_setup_data_offset); > + if (ret) > + return ret; > #endif > > /* Setup EDD info */