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=-8.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, 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 ACC40C67839 for ; Wed, 12 Dec 2018 03:11:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7CFCE20873 for ; Wed, 12 Dec 2018 03:11:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7CFCE20873 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 S1726458AbeLLDLn (ORCPT ); Tue, 11 Dec 2018 22:11:43 -0500 Received: from mail.cn.fujitsu.com ([183.91.158.132]:51248 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726418AbeLLDLi (ORCPT ); Tue, 11 Dec 2018 22:11:38 -0500 X-IronPort-AV: E=Sophos;i="5.56,343,1539619200"; d="scan'208";a="49566325" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 12 Dec 2018 11:11:34 +0800 Received: from G08CNEXCHPEKD01.g08.fujitsu.local (unknown [10.167.33.80]) by cn.fujitsu.com (Postfix) with ESMTP id 6A8184B734D7; Wed, 12 Dec 2018 11:11:34 +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; Wed, 12 Dec 2018 11:11:39 +0800 From: Chao Fan To: , , , , , , , , CC: , , Subject: [PATCH v13 6/6] x86/boot/KASLR: Limit KASLR to extracting kernel in immovable memory Date: Wed, 12 Dec 2018 11:10:53 +0800 Message-ID: <20181212031053.1815-7-fanc.fnst@cn.fujitsu.com> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20181212031053.1815-1-fanc.fnst@cn.fujitsu.com> References: <20181212031053.1815-1-fanc.fnst@cn.fujitsu.com> 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: 6A8184B734D7.A8BA8 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 KASLR randomly chooses some positions which may locate in movable memory regions. It will break memory hotplug feature and make the movable memory chosen by KASLR practically immovable. The solution is to limit KASLR to choose memory regions in immovable node according to SRAT tables. When CONFIG_EARLY_PARSE_RSDP is enabled, walk through SRAT to get the information of immovable memory so that KASLR knows where should be chosen for randomization. Rename process_mem_region() as __process_mem_region() and name new function as process_mem_region(). Signed-off-by: Chao Fan --- arch/x86/boot/compressed/kaslr.c | 75 +++++++++++++++++++++++++++----- 1 file changed, 64 insertions(+), 11 deletions(-) diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index b251572e77af..fb2cdddaa81a 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -97,6 +97,11 @@ static bool memmap_too_large; /* Store memory limit specified by "mem=nn[KMG]" or "memmap=nn[KMG]" */ static unsigned long long mem_limit = ULLONG_MAX; +#ifdef CONFIG_EARLY_PARSE_RSDP +/* The immovable memory regions */ +extern struct mem_vector immovable_mem[MAX_NUMNODES*2]; +#endif + enum mem_avoid_index { MEM_AVOID_ZO_RANGE = 0, @@ -413,6 +418,9 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size, /* Mark the memmap regions we need to avoid */ handle_mem_options(); + /* Mark the immovable regions we need to choose */ + get_immovable_mem(); + #ifdef CONFIG_X86_VERBOSE_BOOTUP /* Make sure video RAM can be used. */ add_identity_map(0, PMD_SIZE); @@ -568,9 +576,9 @@ static unsigned long slots_fetch_random(void) return 0; } -static void process_mem_region(struct mem_vector *entry, - unsigned long minimum, - unsigned long image_size) +static void __process_mem_region(struct mem_vector *entry, + unsigned long minimum, + unsigned long image_size) { struct mem_vector region, overlap; unsigned long start_orig, end; @@ -646,6 +654,57 @@ static void process_mem_region(struct mem_vector *entry, } } +static bool process_mem_region(struct mem_vector *region, + unsigned long long minimum, + unsigned long long image_size) +{ + int i; + /* + * If no immovable memory found, or MEMORY_HOTREMOVE disabled, + * walk all the regions, so use region directly. + */ + if (!num_immovable_mem) { + __process_mem_region(region, minimum, image_size); + + if (slot_area_index == MAX_SLOT_AREA) { + debug_putstr("Aborted e820/efi memmap scan (slot_areas full)!\n"); + return 1; + } + return 0; + } + +#ifdef CONFIG_EARLY_PARSE_RSDP + /* + * If immovable memory found, filter the intersection between + * immovable memory and region to __process_mem_region(). + * Otherwise, go on old code. + */ + for (i = 0; i < num_immovable_mem; i++) { + struct mem_vector entry; + unsigned long long start, end, entry_end, region_end; + + if (!mem_overlaps(region, &immovable_mem[i])) + continue; + + start = immovable_mem[i].start; + end = start + immovable_mem[i].size; + region_end = region->start + region->size; + + entry.start = clamp(region->start, start, end); + entry_end = clamp(region_end, start, end); + entry.size = entry_end - entry.start; + + __process_mem_region(&entry, minimum, image_size); + + if (slot_area_index == MAX_SLOT_AREA) { + debug_putstr("Aborted e820/efi memmap scan (slot_areas full)!\n"); + return 1; + } + } + return 0; +#endif +} + #ifdef CONFIG_EFI /* * Returns true if mirror region found (and must have been processed @@ -711,11 +770,8 @@ process_efi_entries(unsigned long minimum, unsigned long image_size) region.start = md->phys_addr; region.size = md->num_pages << EFI_PAGE_SHIFT; - process_mem_region(®ion, minimum, image_size); - if (slot_area_index == MAX_SLOT_AREA) { - debug_putstr("Aborted EFI scan (slot_areas full)!\n"); + if (process_mem_region(®ion, minimum, image_size)) break; - } } return true; } @@ -742,11 +798,8 @@ static void process_e820_entries(unsigned long minimum, continue; region.start = entry->addr; region.size = entry->size; - process_mem_region(®ion, minimum, image_size); - if (slot_area_index == MAX_SLOT_AREA) { - debug_putstr("Aborted e820 scan (slot_areas full)!\n"); + if (process_mem_region(®ion, minimum, image_size)) break; - } } } -- 2.19.2