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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 09CB9C433F5 for ; Sat, 8 Sep 2018 13:33:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A8F10206BB for ; Sat, 8 Sep 2018 13:33:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A8F10206BB 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 S1726763AbeIHSTb (ORCPT ); Sat, 8 Sep 2018 14:19:31 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:42642 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726452AbeIHSTb (ORCPT ); Sat, 8 Sep 2018 14:19:31 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 61490804B4BA; Sat, 8 Sep 2018 13:33:42 +0000 (UTC) Received: from localhost (ovpn-8-21.pek2.redhat.com [10.72.8.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 642BB2166BA3; Sat, 8 Sep 2018 13:33:40 +0000 (UTC) Date: Sat, 8 Sep 2018 21:33:37 +0800 From: Baoquan He To: Thomas Gleixner Cc: mingo@kernel.org, hpa@zytor.com, thgarnie@google.com, kirill.shutemov@linux.intel.com, x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] x86/mm/KASLR: Fix the wrong calculation of kalsr region initial size Message-ID: <20180908133337.GT1740@192.168.1.3> References: <20180829021754.21850-1-bhe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.1 (2017-09-22) X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Sat, 08 Sep 2018 13:33:42 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Sat, 08 Sep 2018 13:33:42 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.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 On 09/08/18 at 02:10pm, Thomas Gleixner wrote: > On Wed, 29 Aug 2018, Baoquan He wrote: > > > 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 > > by replacing __PHYSICAL_MASK_SHIFT with MAX_PHYSMEM_BITS. > > > > Signed-off-by: Baoquan He > > This lacks a fixes tag ..... Sure, I will add fix tag in this patch, and arrange a new patchset according to discussion with Kirill after test. Thanks Baoquan