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,URIBL_BLOCKED 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 5FA6EC4321E for ; Sun, 9 Sep 2018 12:49:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0AFD920865 for ; Sun, 9 Sep 2018 12:49:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0AFD920865 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 S1727016AbeIIRja (ORCPT ); Sun, 9 Sep 2018 13:39:30 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:53800 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726906AbeIIRja (ORCPT ); Sun, 9 Sep 2018 13:39:30 -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 10C5B87A87; Sun, 9 Sep 2018 12:49:54 +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 B7AA3108776; Sun, 9 Sep 2018 12:49:49 +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 1/3] x86/mm/KASLR: Fix the wrong calculation of kalsr region initial size Date: Sun, 9 Sep 2018 20:49:44 +0800 Message-Id: <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 [10.11.55.1]); Sun, 09 Sep 2018 12:49:54 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Sun, 09 Sep 2018 12:49:54 +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 In memory KASLR, __PHYSICAL_MASK_SHIFT is taken to calculate the initial size of the direct mapping region. This is right in the old code where __PHYSICAL_MASK_SHIFT was equal to MAX_PHYSMEM_BITS, 46bit, and only 4-level mode was supported. Later, in commit: b83ce5ee91471d ("x86/mm/64: Make __PHYSICAL_MASK_SHIFT always 52"), __PHYSICAL_MASK_SHIFT was changed to be 52 always, no matter it's 5-level or 4-level. This is wrong for 4-level paging. Then when adapt phyiscal memory region size based on available memory, it will overflow if the amount of system RAM and the padding is bigger than 64TB. In fact, here MAX_PHYSMEM_BITS should be used instead. Fix it by replacing __PHYSICAL_MASK_SHIFT with MAX_PHYSMEM_BITS. Fixes: b83ce5ee9147 ("x86/mm/64: Make __PHYSICAL_MASK_SHIFT always 52") Signed-off-by: Baoquan He Acked-by: Kirill A. Shutemov Reviewed-by: Thomas Garnier --- arch/x86/mm/kaslr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c index 61db77b0eda9..0988971069c9 100644 --- a/arch/x86/mm/kaslr.c +++ b/arch/x86/mm/kaslr.c @@ -93,7 +93,7 @@ void __init kernel_randomize_memory(void) if (!kaslr_memory_enabled()) return; - kaslr_regions[0].size_tb = 1 << (__PHYSICAL_MASK_SHIFT - TB_SHIFT); + kaslr_regions[0].size_tb = 1 << (MAX_PHYSMEM_BITS - TB_SHIFT); kaslr_regions[1].size_tb = VMALLOC_SIZE_TB; /* -- 2.13.6