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=-0.8 required=3.0 tests=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 4DA03C433F5 for ; Sun, 9 Sep 2018 12:50:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0E94E20865 for ; Sun, 9 Sep 2018 12:50:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0E94E20865 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.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 S1727127AbeIIRjf (ORCPT ); Sun, 9 Sep 2018 13:39:35 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:43668 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726906AbeIIRjf (ORCPT ); Sun, 9 Sep 2018 13:39:35 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 818C28011462; Sun, 9 Sep 2018 12:49:59 +0000 (UTC) Received: from MiWiFi-R3L-srv.redhat.com (ovpn-8-21.pek2.redhat.com [10.72.8.21]) by smtp.corp.redhat.com (Postfix) with ESMTP id DB99D108776; Sun, 9 Sep 2018 12:49:54 +0000 (UTC) From: Baoquan He To: tglx@linutronix.de, mingo@kernel.org, hpa@zytor.com, thgarnie@google.com, kirill.shutemov@linux.intel.com Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Baoquan He Subject: [PATCH v2 2/3] x86/mm/KASLR: Calculate the actual size of vmemmap region Date: Sun, 9 Sep 2018 20:49:45 +0800 Message-Id: <20180909124946.17988-2-bhe@redhat.com> In-Reply-To: <20180909124946.17988-1-bhe@redhat.com> References: <20180909124946.17988-1-bhe@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Sun, 09 Sep 2018 12:49:59 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Sun, 09 Sep 2018 12:49:59 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'bhe@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Vmemmap region has different maximum size depending on paging mode. Now its size is hardcoded as 1TB in memory KASLR, this is not right for 5-level paging mode. It will cause overflow if vmemmap region is randomized to be adjacent to cpu_entry_area region and its actual size is bigger than 1TB. So here calculate how many TB by the actual size of vmemmap region and align up to 1TB boundary. Signed-off-by: Baoquan He --- arch/x86/mm/kaslr.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c index 0988971069c9..1db8e166455e 100644 --- a/arch/x86/mm/kaslr.c +++ b/arch/x86/mm/kaslr.c @@ -51,7 +51,7 @@ static __initdata struct kaslr_memory_region { } kaslr_regions[] = { { &page_offset_base, 0 }, { &vmalloc_base, 0 }, - { &vmemmap_base, 1 }, + { &vmemmap_base, 0 }, }; /* Get size in bytes used by the memory region */ @@ -77,6 +77,7 @@ void __init kernel_randomize_memory(void) unsigned long rand, memory_tb; struct rnd_state rand_state; unsigned long remain_entropy; + unsigned long vmemmap_size; vaddr_start = pgtable_l5_enabled() ? __PAGE_OFFSET_BASE_L5 : __PAGE_OFFSET_BASE_L4; vaddr = vaddr_start; @@ -108,6 +109,14 @@ void __init kernel_randomize_memory(void) if (memory_tb < kaslr_regions[0].size_tb) kaslr_regions[0].size_tb = memory_tb; + /* + * Calculate how many TB vmemmap region needs, and align to + * 1TB boundary. + * */ + vmemmap_size = (kaslr_regions[0].size_tb << (TB_SHIFT - PAGE_SHIFT)) * + sizeof(struct page); + kaslr_regions[2].size_tb = DIV_ROUND_UP(vmemmap_size, 1UL << TB_SHIFT); + /* Calculate entropy available between regions */ remain_entropy = vaddr_end - vaddr_start; for (i = 0; i < ARRAY_SIZE(kaslr_regions); i++) -- 2.13.6