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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,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 23F8AC433DF for ; Mon, 8 Jun 2020 12:54:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 05B482076A for ; Mon, 8 Jun 2020 12:54:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729877AbgFHMyu (ORCPT ); Mon, 8 Jun 2020 08:54:50 -0400 Received: from mga07.intel.com ([134.134.136.100]:24195 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729850AbgFHMyg (ORCPT ); Mon, 8 Jun 2020 08:54:36 -0400 IronPort-SDR: snJx6xfWjuoPNWsFzf7tHGIShaueZ2tltCofjzLLzm6y+UgjCNosoFSPv0oY+OjV/rYGKSuug6 Od+7CZt2ATFg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jun 2020 05:54:35 -0700 IronPort-SDR: 1b8quhAFTc0jTTKs/rYqChdSLNXYuK3WRXwZzr9Psx945UHNW9hL4q5aATK7R5VRm2CTBOEsrw gwZgyTA08fxg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,487,1583222400"; d="scan'208";a="270496420" Received: from black.fi.intel.com ([10.237.72.28]) by orsmga003.jf.intel.com with ESMTP; 08 Jun 2020 05:54:31 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id B8D1D25A; Mon, 8 Jun 2020 15:54:30 +0300 (EEST) From: "Kirill A. Shutemov" To: Dave Hansen , Andy Lutomirski , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" Cc: Dan Williams , Tony Luck , x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" , Dave Hansen , stable@vger.kernel.org Subject: [PATCHv2 2/2] x86/boot/KASLR: Fix boot with some memory above MAXMEM Date: Mon, 8 Jun 2020 15:54:24 +0300 Message-Id: <20200608125424.70198-3-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.27.0.rc2 In-Reply-To: <20200608125424.70198-1-kirill.shutemov@linux.intel.com> References: <20200608125424.70198-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A 5-level paging capable machine can have memory above 46-bit in the physical address space. This memory is only addressable in the 5-level paging mode: we don't have enough virtual address space to create direct mapping for such memory in the 4-level paging mode Teach KASLR to avoid memory regions above MAXMEM or truncate the region if the end is above MAXMEM. Signed-off-by: Kirill A. Shutemov Reviewed-by: Dave Hansen Cc: stable@vger.kernel.org # v4.14 --- arch/x86/boot/compressed/kaslr.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index d7408af55738..99db18eeb40e 100644 --- a/arch/x86/boot/compressed/kaslr.c +++ b/arch/x86/boot/compressed/kaslr.c @@ -695,7 +695,18 @@ static bool process_mem_region(struct mem_vector *region, unsigned long long minimum, unsigned long long image_size) { + unsigned long long end; int i; + + /* Cannot access memory region above MAXMEM: skip it. */ + if (region->start >= MAXMEM) + return 0; + + /* Truncate the region if the end is above MAXMEM */ + end = region->start + region->size; + end = min_t(unsigned long long, end, MAXMEM - 1); + region->size = end - region->start; + /* * If no immovable memory found, or MEMORY_HOTREMOVE disabled, * use @region directly. -- 2.26.2