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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_GIT 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 E5BF1C43441 for ; Thu, 29 Nov 2018 08:16:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AB66E20834 for ; Thu, 29 Nov 2018 08:16:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AB66E20834 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 S1727477AbeK2TV0 (ORCPT ); Thu, 29 Nov 2018 14:21:26 -0500 Received: from mail.cn.fujitsu.com ([183.91.158.132]:27144 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726841AbeK2TVZ (ORCPT ); Thu, 29 Nov 2018 14:21:25 -0500 X-IronPort-AV: E=Sophos;i="5.56,293,1539619200"; d="scan'208";a="48821850" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 29 Nov 2018 16:16:50 +0800 Received: from G08CNEXCHPEKD01.g08.fujitsu.local (unknown [10.167.33.80]) by cn.fujitsu.com (Postfix) with ESMTP id 615104B7348C; Thu, 29 Nov 2018 16:16:50 +0800 (CST) Received: from localhost.local (10.167.225.56) by G08CNEXCHPEKD01.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server (TLS) id 14.3.408.0; Thu, 29 Nov 2018 16:16:56 +0800 From: Chao Fan To: , , , , , , , , CC: , , Subject: [PATCH v12 0/5] x86/boot/KASLR: Parse ACPI table and limit KASLR to choosing immovable memory Date: Thu, 29 Nov 2018 16:16:26 +0800 Message-ID: <20181129081631.11139-1-fanc.fnst@cn.fujitsu.com> X-Mailer: git-send-email 2.19.2 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.167.225.56] X-yoursite-MailScanner-ID: 615104B7348C.A4D60 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 ***Background: People reported that KASLR may randomly choose some positions which are located in movable memory regions. This will break memory hotplug feature and make the movable memory chosen by KASLR can't be removed. ***Solutions: Get the information of memory hot-remove, then KASLR will know the right regions. Information about memory hot-remove is in ACPI tables, which will be parsed after start_kernel(), so that KASLR can't get the information. Somebody suggest to add a kernel parameter to specify the immovable memory so that limit KASLR in these regions. Then I make a patchset. After several versions, Ingo gave a suggestion: https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1634024.html Follow Ingo's suggestion, imitate the ACPI code to parse the ACPI tables, so that the kaslr can get necessary memory information in ACPI tables. I think ACPI code is an independent part, so imitate the codes and functions to 'compressed/' directory, so that kaslr won't influence the initialization of ACPI. PATCH 1/5 Add get_acpi_rsdp() to parse RSDP in cmdline from KEXEC PATCH 2/5 Add efi_get_rsdp_addr() to find RSDP from EFI table when booting from EFI. PATCH 3/5 Add bios_get_rsdp_addr() to search RSDP in memory when EFI table not found. PATCH 4/5 Compute SRAT table from RSDP and walk SRAT table to store the immovable memory regions. PATCH 5/5 Calculate the intersection between memory regions from e820/efi memory table and immovable memory regions. Limit KASLR to choosing these regions for randomization. v1->v2: - Simplify some code. Follow Baoquan He's suggestion: - Reuse the head file of acpi code. v2->v3: - Test in more conditions, so remove the 'RFC' tag. - Change some comments. v3->v4: Follow Thomas Gleixner's suggetsion: - Put the whole efi related function into #define CONFIG_EFI and return false in the other stub. v4->v5: Follow Dou Liyang's suggestion: - Add more comments about some functions based on kernel code. - Change some typo in comments. - Clean useless variable. - Add check for the boundary of array. - Add check for 'movable_node' parameter v5->v6: Follow Baoquan He's suggestion: - Change some log. - Add the check for acpi_rsdp - Change some code logical to make code clear v6->v7: Follow Rafael's suggestion: - Add more comments and patch log. Follow test robot's suggestion: - Add "static" tag for function v7-v8: Follow Kees Cook's suggestion: - Use mem_overlaps() to check memory region. - Use #ifdef in the definition of function. v8-v9: Follow Boris' suggestion: - Change code style. - Splite PATCH 1/3 to more path. - Introduce some new function - Use existing function to rework some code Follow Masayoshi's suggetion: - Make code more readable v9->v10: Follow Baoquan's suggestion: - Change some log - Merge last two patch together. v10->v11: Follow Boris' suggestion: - Link kstrtoull() instead of copying it. - Drop the useless wrapped function. v11->v12: Follow Boris' suggestion: - Change patch log and code comments. - Add 'CONFIG_EARLY_PARSE_RSDP' to make code easy to read - Put strtoull() to misc.c Follow Masa's suggestion: - Remove the detection for 'movable_node' - Change the code logical about cmdline_find_option() Any comments will be welcome. Chao Fan (5): x86/boot: Add get_acpi_rsdp() to parse RSDP in cmdline from KEXEC x86/boot: Add efi_get_rsdp_addr() to find RSDP from EFI table x86/boot: Add bios_get_rsdp_addr() to search RSDP in memory x86/boot: Parse SRAT table from RSDP and store immovable memory x86/boot/KASLR: Limit KASLR to extracting kernel in immovable memory arch/x86/Kconfig | 10 + arch/x86/boot/compressed/Makefile | 2 + arch/x86/boot/compressed/acpitb.c | 322 ++++++++++++++++++++++++++++++ arch/x86/boot/compressed/kaslr.c | 79 ++++++-- arch/x86/boot/compressed/misc.c | 5 + arch/x86/boot/compressed/misc.h | 24 +++ lib/kstrtox.c | 5 + 7 files changed, 432 insertions(+), 15 deletions(-) create mode 100644 arch/x86/boot/compressed/acpitb.c -- 2.19.1