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 10371C43441 for ; Wed, 14 Nov 2018 01:55:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C4E402175B for ; Wed, 14 Nov 2018 01:54:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C4E402175B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=cn.fujitsu.com 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 S1731938AbeKNLz6 (ORCPT ); Wed, 14 Nov 2018 06:55:58 -0500 Received: from mail.cn.fujitsu.com ([183.91.158.132]:61453 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726496AbeKNLz6 (ORCPT ); Wed, 14 Nov 2018 06:55:58 -0500 X-IronPort-AV: E=Sophos;i="5.43,368,1503331200"; d="scan'208";a="48047742" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 14 Nov 2018 09:54:55 +0800 Received: from G08CNEXCHPEKD01.g08.fujitsu.local (unknown [10.167.33.80]) by cn.fujitsu.com (Postfix) with ESMTP id EFA774B6260C; Wed, 14 Nov 2018 09:54:53 +0800 (CST) Received: from localhost.localdomain (10.167.225.56) by G08CNEXCHPEKD01.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server (TLS) id 14.3.408.0; Wed, 14 Nov 2018 09:54:59 +0800 Date: Wed, 14 Nov 2018 09:54:50 +0800 From: Chao Fan To: Borislav Petkov CC: , , , , , , , , , , , Subject: Re: [PATCH v11 3/5] x86/boot: Add get_acpi_rsdp() to parse RSDP in cmdlien from kexec Message-ID: <20181114015450.GA2875@localhost.localdomain> References: <20181112094645.4879-1-fanc.fnst@cn.fujitsu.com> <20181112094645.4879-4-fanc.fnst@cn.fujitsu.com> <20181113175150.GK10502@zn.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20181113175150.GK10502@zn.tnic> User-Agent: Mutt/1.10.1 (2018-07-13) X-Originating-IP: [10.167.225.56] X-yoursite-MailScanner-ID: EFA774B6260C.AD457 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: fanc.fnst@cn.fujitsu.com Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 13, 2018 at 06:51:50PM +0100, Borislav Petkov wrote: >On Mon, Nov 12, 2018 at 05:46:43PM +0800, Chao Fan wrote: >> Imitate setup_acpi_rsdp() for the early_param of 'acpi_rsdp'. >> KEXEC writes the RSDP pointer to cmdline for EFI booting. >> So if 'acpi_rsdp' found in cmdline, use it directely. >> >> Since function kstrtoull() is needed, include it in >> arch/x86/boot/string.h. To solve the definition conflict >> problem, set BOOT_STRING tag to expose only kstrtoull() and >> functions used by it. Other functions in lib/kstrtox.c will >> be covered. >> >> Signed-off-by: Chao Fan >> --- >> arch/x86/boot/compressed/acpitb.c | 26 ++++++++++++++++++++++++++ >> arch/x86/boot/string.h | 4 ++++ >> lib/kstrtox.c | 4 ++++ >> 3 files changed, 34 insertions(+) >> >> diff --git a/arch/x86/boot/compressed/acpitb.c b/arch/x86/boot/compressed/acpitb.c >> index 50fa65cf824d..5cfb4efa5a19 100644 >> --- a/arch/x86/boot/compressed/acpitb.c >> +++ b/arch/x86/boot/compressed/acpitb.c >> @@ -8,6 +8,12 @@ >> #include >> #include >> >> +#define STATIC >> +#include >> + >> +#define BOOT_STRING >> +#include "../string.h" >> + >> /* Search EFI table for RSDP table. */ >> static void efi_get_rsdp_addr(acpi_physical_address *rsdp_addr) >> { >> @@ -200,3 +206,23 @@ static void bios_get_rsdp_addr(acpi_physical_address *rsdp_addr) >> *rsdp_addr = (acpi_physical_address)address; >> } >> } >> + >> +static void get_acpi_rsdp(acpi_physical_address *rsdp_addr) >> +{ >> +#ifdef CONFIG_KEXEC > >Ok, why is that CONFIG_KEXEC dependency needed now too? > CONFIG_KEXEC is only needed in this function. When searching RSDP, there are three methods in order: 1. When booting from KEXEC, 'acpi_rsdp' is added to cmdline by KEXEC, so it can be parsed and used. CONFIG_KEXEC is needed here. 2. When booting from EFI, parse EFI table and find RSDP. 3. When booting from BIOS, search memory for RSDP just like acpi_find_root_pointer() in drivers/acpi/acpica/tbxfroot.c did. So, CONFIG_KEXEC is only needed in 1, exactly in this function get_acpi_rsdp() of my PATCH. Thanks, Chao Fan >Ok, let's recap: so far, for your use case you need: > >CONFIG_MEMORY_HOTREMOVE >CONFIG_RANDOMIZE_BASE >and now >CONFIG_KEXEC > >So, you can clean up all that ifdeffery by defining a new config item >CONFIG_EARLY_PARSE_RSDP or so which depends on all those three items and >then you can do > >vmlinux-objs-$(CONFIG_EARLY_PARSE_RSDP) += $(obj)/acpitb.o > >and get rid of the most of the ifdeffery. > >Yes? > >> + unsigned long long res; >> + int len = 0; >> + char *val; >> + >> + val = malloc(19); >> + len = cmdline_find_option("acpi_rsdp", val, 19); >> + > >^ Superfluous newline. > >> + if (len == -1) >> + return; > >That check is not needed since you do > 0 below. > >> + >> + if (len > 0) { >> + val[len] = 0; >> + *rsdp_addr = (acpi_physical_address)kstrtoull(val, 16, &res); >> + } >> +#endif >> +} >> diff --git a/arch/x86/boot/string.h b/arch/x86/boot/string.h >> index 3d78e27077f4..0ff3edb888e4 100644 >> --- a/arch/x86/boot/string.h >> +++ b/arch/x86/boot/string.h >> @@ -30,3 +30,7 @@ extern unsigned long long simple_strtoull(const char *cp, char **endp, >> unsigned int base); >> >> #endif /* BOOT_STRING_H */ >> + >> +#ifdef BOOT_STRING >> +#include "../../../lib/kstrtox.c" >> +#endif >> diff --git a/lib/kstrtox.c b/lib/kstrtox.c >> index 1006bf70bf74..3804db9eed56 100644 >> --- a/lib/kstrtox.c >> +++ b/lib/kstrtox.c >> @@ -126,6 +126,8 @@ int kstrtoull(const char *s, unsigned int base, unsigned long long *res) >> } >> EXPORT_SYMBOL(kstrtoull); > >This needs a comment to explain what is that guard used for. > >> +#ifndef BOOT_STRING >> + >> /** >> * kstrtoll - convert a string to a long long >> * @s: The start of the string. The string must be null-terminated, and may also >> @@ -408,3 +410,5 @@ kstrto_from_user(kstrtou16_from_user, kstrtou16, u16); >> kstrto_from_user(kstrtos16_from_user, kstrtos16, s16); >> kstrto_from_user(kstrtou8_from_user, kstrtou8, u8); >> kstrto_from_user(kstrtos8_from_user, kstrtos8, s8); >> + >> +#endif > >#endif /* BOOT_STRING */ > >-- >Regards/Gruss, > Boris. > >Good mailing practices for 400: avoid top-posting and trim the reply. > >