From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754161AbaHNRVd (ORCPT ); Thu, 14 Aug 2014 13:21:33 -0400 Received: from terminus.zytor.com ([198.137.202.10]:41637 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754053AbaHNRVb (ORCPT ); Thu, 14 Aug 2014 13:21:31 -0400 Message-ID: <53ECEFF5.1040800@zytor.com> Date: Thu, 14 Aug 2014 10:20:53 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.7.0 MIME-Version: 1.0 To: Dave Hansen , Frantisek Hrbata , linux-kernel@vger.kernel.org CC: linux-mm@kvack.org, tglx@linutronix.de, mingo@redhat.com, x86@kernel.org, oleg@redhat.com, kamaleshb@in.ibm.com, hechjie@cn.ibm.com, akpm@linux-foundation.org, dvlasenk@redhat.com, prarit@redhat.com, lwoodman@redhat.com, hannsj_uhl@de.ibm.com Subject: Re: [PATCH 1/1] x86: add phys addr validity check for /dev/mem mmap References: <1408025927-16826-1-git-send-email-fhrbata@redhat.com> <1408025927-16826-2-git-send-email-fhrbata@redhat.com> <53ECE573.1030405@intel.com> In-Reply-To: <53ECE573.1030405@intel.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/14/2014 09:36 AM, Dave Hansen wrote: > Thanks for dredging this back up! > > On 08/14/2014 07:18 AM, Frantisek Hrbata wrote: >> +int valid_phys_addr_range(phys_addr_t addr, size_t count) >> +{ >> + return addr + count <= __pa(high_memory); >> +} > > Is this correct on 32-bit? It would limit /dev/mem to memory below 896MB. > Last I checked, /dev/mem was already broken for highmem... which is actually a problem. I would prefer to see it fixed. -hpa