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=-8.5 required=3.0 tests=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 9E0C8C4360F for ; Thu, 4 Apr 2019 07:32:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6AEFE206DF for ; Thu, 4 Apr 2019 07:32:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727053AbfDDHco (ORCPT ); Thu, 4 Apr 2019 03:32:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45544 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726204AbfDDHco (ORCPT ); Thu, 4 Apr 2019 03:32:44 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6509B44FA1; Thu, 4 Apr 2019 07:32:43 +0000 (UTC) Received: from dhcp-128-65.nay.redhat.com (ovpn-12-97.pek2.redhat.com [10.72.12.97]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 97C8F62669; Thu, 4 Apr 2019 07:32:38 +0000 (UTC) Date: Thu, 4 Apr 2019 15:32:33 +0800 From: Dave Young To: Junichi Nomura Cc: Borislav Petkov , "bhe@redhat.com" , "fanc.fnst@cn.fujitsu.com" , "x86@kernel.org" , "kexec@lists.infradead.org" , "kasong@redhat.com" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v3] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernel Message-ID: <20190404073233.GC5708@dhcp-128-65.nay.redhat.com> References: <20190325122302.GC13160@dhcp-128-65.nay.redhat.com> <20190325123229.GL12016@zn.tnic> <20190325231000.GA9184@jeru.linux.bs1.fc.nec.co.jp> <20190326135714.GG1867@zn.tnic> <20190327014852.GA3659@MiWiFi-R3L-srv> <73322ba9-e436-68db-7863-afd31607d969@ce.jp.nec.com> <20190328064343.GA1877@MiWiFi-R3L-srv> <20190328074337.GA9470@jeru.linux.bs1.fc.nec.co.jp> <20190328155256.GP22720@zn.tnic> <20190402102529.GA21698@jeru.linux.bs1.fc.nec.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190402102529.GA21698@jeru.linux.bs1.fc.nec.co.jp> User-Agent: Mutt/1.11.3 (2019-02-01) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Thu, 04 Apr 2019 07:32:43 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Junichi, While we are still debuggin the bug I reproduced, but for this patch I have still some comments inline. BTW, it would be good to start a new thread when you send V4 :) On 04/02/19 at 10:25am, Junichi Nomura wrote: > Commit 3a63f70bf4c3a ("x86/boot: Early parse RSDP and save it in > boot_params") broke kexec boot on EFI systems. efi_get_rsdp_addr() > in the early parsing code tries to search RSDP from EFI table but > that will crash because the table address is virtual when the kernel > was booted by kexec. > > In the case of kexec, physical address of EFI tables is provided > via efi_setup_data in boot_params, which is set up by kexec(1). > > Factor out the table parsing code and use different pointers depending > on whether the kernel is booted by kexec or not. > > Fixes: 3a63f70bf4c3a ("x86/boot: Early parse RSDP and save it in boot_params") > Signed-off-by: Jun'ichi Nomura > Acked-by: Baoquan He > Tested-by: Chao Fan > Cc: Borislav Petkov > Cc: Dave Young > > -- > v2: Added comments above __efi_get_rsdp_addr() and kexec_get_rsdp_addr() > > v3: Properly ifdef out 64bit-only kexec code to avoid 32bit build warnings > > diff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c > index 0ef4ad5..d9f9abd 100644 > --- a/arch/x86/boot/compressed/acpi.c > +++ b/arch/x86/boot/compressed/acpi.c > @@ -44,17 +44,114 @@ static acpi_physical_address get_acpi_rsdp(void) > return addr; > } > > -/* Search EFI system tables for RSDP. */ > -static acpi_physical_address efi_get_rsdp_addr(void) > +#if defined(CONFIG_EFI) && defined(CONFIG_X86_64) > +static unsigned long efi_get_kexec_setup_data_addr(void) > +{ > + struct setup_data *data; > + u64 pa_data; > + > + pa_data = boot_params->hdr.setup_data; > + while (pa_data) { > + data = (struct setup_data *) pa_data; > + if (data->type == SETUP_EFI) > + return pa_data + sizeof(struct setup_data); > + pa_data = data->next; > + } > + return 0; > +} > +#endif > + > +#ifdef CONFIG_EFI > +/* > + * Search EFI system tables for RSDP. If both ACPI_20_TABLE_GUID and > + * ACPI_TABLE_GUID are found, take the former, which has more features. > + */ > +static acpi_physical_address > +__efi_get_rsdp_addr(unsigned long config_tables, unsigned int nr_tables, > + bool efi_64) > { > acpi_physical_address rsdp_addr = 0; > + int i; > > + /* Get EFI tables from systab. */ > + for (i = 0; i < nr_tables; i++) { > + acpi_physical_address table; > + efi_guid_t guid; > + > + if (efi_64) { > + efi_config_table_64_t *tbl = (efi_config_table_64_t *) config_tables + i; > + > + guid = tbl->guid; > + table = tbl->table; > + > + if (!IS_ENABLED(CONFIG_X86_64) && table >> 32) { > + debug_putstr("Error getting RSDP address: EFI config table located above 4GB.\n"); > + return 0; > + } > + } else { > + efi_config_table_32_t *tbl = (efi_config_table_32_t *) config_tables + i; > + > + guid = tbl->guid; > + table = tbl->table; > + } > + > + if (!(efi_guidcmp(guid, ACPI_TABLE_GUID))) > + rsdp_addr = table; > + else if (!(efi_guidcmp(guid, ACPI_20_TABLE_GUID))) > + return table; > + } > + > + return rsdp_addr; > +} > +#endif > + > +/* > + * EFI/kexec support is only added for 64bit. So we don't have to > + * care 32bit case. > + */ > +static acpi_physical_address kexec_get_rsdp_addr(void) > +{ > +#if defined(CONFIG_EFI) && defined(CONFIG_X86_64) > + efi_system_table_64_t *systab; > + struct efi_setup_data *esd; > + struct efi_info *ei; > + char *sig; > + > + esd = (struct efi_setup_data *) efi_get_kexec_setup_data_addr(); > + if (!esd) > + return 0; > + > + if (!esd->tables) { > + debug_putstr("Wrong kexec SETUP_EFI data.\n"); > + return 0; > + } > + > + ei = &boot_params->efi_info; > + sig = (char *)&ei->efi_loader_signature; > + if (strncmp(sig, EFI64_LOADER_SIGNATURE, 4)) { > + debug_putstr("Wrong kexec EFI loader signature.\n"); > + return 0; > + } > + > + /* Get systab from boot params. */ > + systab = (efi_system_table_64_t *) (ei->efi_systab | ((__u64)ei->efi_systab_hi << 32)); > + if (!systab) > + error("EFI system table not found in kexec boot_params."); Instead of hang the system, return 0 should be better > + > + return __efi_get_rsdp_addr((unsigned long) esd->tables, > + systab->nr_tables, true); > +#else > + return 0; > +#endif > +} > + > +static acpi_physical_address efi_get_rsdp_addr(void) > +{ > #ifdef CONFIG_EFI > - unsigned long systab, systab_tables, config_tables; > + unsigned long systab, config_tables; > unsigned int nr_tables; > struct efi_info *ei; > bool efi_64; > - int size, i; > char *sig; > > ei = &boot_params->efi_info; > @@ -88,49 +185,20 @@ static acpi_physical_address efi_get_rsdp_addr(void) > > config_tables = stbl->tables; > nr_tables = stbl->nr_tables; > - size = sizeof(efi_config_table_64_t); > } else { > efi_system_table_32_t *stbl = (efi_system_table_32_t *)systab; > > config_tables = stbl->tables; > nr_tables = stbl->nr_tables; > - size = sizeof(efi_config_table_32_t); > } > > if (!config_tables) > error("EFI config tables not found."); > > - /* Get EFI tables from systab. */ > - for (i = 0; i < nr_tables; i++) { > - acpi_physical_address table; > - efi_guid_t guid; > - > - config_tables += size; > - > - if (efi_64) { > - efi_config_table_64_t *tbl = (efi_config_table_64_t *)config_tables; > - > - guid = tbl->guid; > - table = tbl->table; > - > - if (!IS_ENABLED(CONFIG_X86_64) && table >> 32) { > - debug_putstr("Error getting RSDP address: EFI config table located above 4GB.\n"); > - return 0; > - } > - } else { > - efi_config_table_32_t *tbl = (efi_config_table_32_t *)config_tables; > - > - guid = tbl->guid; > - table = tbl->table; > - } > - > - if (!(efi_guidcmp(guid, ACPI_TABLE_GUID))) > - rsdp_addr = table; > - else if (!(efi_guidcmp(guid, ACPI_20_TABLE_GUID))) > - return table; > - } > + return __efi_get_rsdp_addr(config_tables, nr_tables, efi_64); > +#else > + return 0; > #endif > - return rsdp_addr; > } > > static u8 compute_checksum(u8 *buffer, u32 length) > @@ -221,6 +289,9 @@ acpi_physical_address get_rsdp_addr(void) > pa = boot_params->acpi_rsdp_addr; > > if (!pa) > + pa = kexec_get_rsdp_addr(); > + > + if (!pa) > pa = efi_get_rsdp_addr(); In case kexec_get_rsdp_addr failed, above code will try efi_get.. again, but that will also fail for same issue this patch is fixing. In case kexec we should avoid the efi_get_rsdp_addr. > > if (!pa) > > _______________________________________________ > kexec mailing list > kexec@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec Thanks Dave