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=-8.8 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 2B408C4360F for ; Wed, 13 Feb 2019 22:42:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EDCD5222C9 for ; Wed, 13 Feb 2019 22:42:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="AT0rnd8B" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2395171AbfBMWmT (ORCPT ); Wed, 13 Feb 2019 17:42:19 -0500 Received: from mail-wr1-f68.google.com ([209.85.221.68]:37486 "EHLO mail-wr1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2395147AbfBMWmL (ORCPT ); Wed, 13 Feb 2019 17:42:11 -0500 Received: by mail-wr1-f68.google.com with SMTP id c8so4383800wrs.4; Wed, 13 Feb 2019 14:42:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references:reply-to :mime-version:content-transfer-encoding; bh=ziJEcxmH0HELRYpJ/Cx0XBIGaICt7y2RQVCxbSTmAUA=; b=AT0rnd8BnDyFyzfZmtZcyeTBEWOmVhTvPmEu5QNum22iV2TcKjKPwLVNWNeagC0CRy ctLWeeTYC/+F6/tKvEGXpJEyq+9Yz6bCFYiyBbA3twYThdmj5oAWC32/BvKKUsEGEX7o Ld9HklU7c97NPh13SsZ6fCE/5BMVPh9dqK1naXMrYOstuBxbrBxG+SqHXwEloEStPyvR ffmv8EeqFFFoGyKtg14GqIYxFVbRpPQFp2z+rCCaXp+qC/Cyh9Zji9wP1jG6KdtLhlYx p7hNzJkTQdZOgNlQY/A8FTBEwkpMfs3AiT9jAGZANXbmBbnzIfgztEwbiLzC+FwV2x8J VLpg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:reply-to:mime-version:content-transfer-encoding; bh=ziJEcxmH0HELRYpJ/Cx0XBIGaICt7y2RQVCxbSTmAUA=; b=X23Dhvaw4P+Ln+TzVY2QkIdVjOLwETcqmP5tZgrdw8gLUCi0+pkhHytcdSnBRf/26j lpuqqUkWkkT5mDLdnMacdOWY5O82NZUC466Jtg85gTs8Vebo1c+Y0ajBXHc1/vNyyb34 AdZ4DU6pcvTDb7ojVA+NzcruHWNmnMIYxRFOZ3ocGTDlxpwF600ZWPP3atD0VZpeiWC5 1hVHj/mqaIvmK+YBsaFNT46WkvIVpVudNRSX6bMzM2Ut26BcXaoUfCICpNd+9t0IxAFo nppVkrs1MyKzQnkirlcjTPIfnx0/A1fml99UWHXGVTVpULl/dKyQAjmWS0OXn7oXnXKD 7aXg== X-Gm-Message-State: AHQUAuZoWeIC3fsAo/vnkG0Ml+DjeRCh7khBJ7yl1gXc1XVl3a6DR/OO 7jabJgD6VulZxHIMhj20Vjs= X-Google-Smtp-Source: AHgI3IYtU8/AyDQPgRNLGyOtrkGvf7ehC6WRZeZ6D8zc6PNd3G4s/XlOJrLl2q5Ckle3r/z/jdGkyg== X-Received: by 2002:adf:fa0d:: with SMTP id m13mr285795wrr.93.1550097729690; Wed, 13 Feb 2019 14:42:09 -0800 (PST) Received: from localhost.localdomain ([91.75.74.250]) by smtp.gmail.com with ESMTPSA id f196sm780810wme.36.2019.02.13.14.42.06 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 13 Feb 2019 14:42:09 -0800 (PST) From: Igor Stoppa X-Google-Original-From: Igor Stoppa Cc: Igor Stoppa , Andy Lutomirski , Nadav Amit , Matthew Wilcox , Peter Zijlstra , Kees Cook , Dave Hansen , Mimi Zohar , Thiago Jung Bauermann , Ahmed Soliman , linux-integrity@vger.kernel.org, kernel-hardening@lists.openwall.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH v5 04/12] __wr_after_init: x86_64: randomize mapping offset Date: Thu, 14 Feb 2019 00:41:33 +0200 Message-Id: <4f3b363bfd20ec0d79a0b066581d72145bb65883.1550097697.git.igor.stoppa@huawei.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: References: Reply-To: Igor Stoppa MIME-Version: 1.0 Content-Transfer-Encoding: 8bit To: unlisted-recipients:; (no To-header on input) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org x86_64 specialized way of defining the base address for the alternate mapping used by write-rare. Since the kernel address space spans across 64TB and it is mapped into a used address space of 128TB, the kernel address space can be shifted by a random offset that is up to 64TB and page aligned. This is accomplished by providing arch-specific version of the function __init_wr_base() Signed-off-by: Igor Stoppa CC: Andy Lutomirski CC: Nadav Amit CC: Matthew Wilcox CC: Peter Zijlstra CC: Kees Cook CC: Dave Hansen CC: Mimi Zohar CC: Thiago Jung Bauermann CC: Ahmed Soliman CC: linux-integrity@vger.kernel.org CC: kernel-hardening@lists.openwall.com CC: linux-mm@kvack.org CC: linux-kernel@vger.kernel.org --- arch/x86/mm/Makefile | 2 ++ arch/x86/mm/prmem.c (new) | 20 ++++++++++++++++++++ 2 files changed, 22 insertions(+) diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile index 4b101dd6e52f..66652de1e2c7 100644 --- a/arch/x86/mm/Makefile +++ b/arch/x86/mm/Makefile @@ -53,3 +53,5 @@ obj-$(CONFIG_PAGE_TABLE_ISOLATION) += pti.o obj-$(CONFIG_AMD_MEM_ENCRYPT) += mem_encrypt.o obj-$(CONFIG_AMD_MEM_ENCRYPT) += mem_encrypt_identity.o obj-$(CONFIG_AMD_MEM_ENCRYPT) += mem_encrypt_boot.o + +obj-$(CONFIG_PRMEM) += prmem.o diff --git a/arch/x86/mm/prmem.c b/arch/x86/mm/prmem.c new file mode 100644 index 000000000000..b04fc03f92fb --- /dev/null +++ b/arch/x86/mm/prmem.c @@ -0,0 +1,20 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * prmem.c: Memory Protection Library - x86_64 backend + * + * (C) Copyright 2018-2019 Huawei Technologies Co. Ltd. + * Author: Igor Stoppa + */ + +#include +#include + +unsigned long __init __init_wr_base(void) +{ + /* + * Place 64TB of kernel address space within 128TB of user address + * space, at a random page aligned offset. + */ + return (((unsigned long)kaslr_get_random_long("WR Poke")) & + PAGE_MASK) % (64 * _BITUL(40)); +} -- 2.19.1