Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761828Ab3DDBOH (ORCPT ); Wed, 3 Apr 2013 21:14:07 -0400 Received: from terminus.zytor.com ([198.137.202.10]:45781 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760560Ab3DDBOG (ORCPT ); Wed, 3 Apr 2013 21:14:06 -0400 Message-ID: <515CD3BF.5010104@zytor.com> Date: Wed, 03 Apr 2013 18:13:35 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130311 Thunderbird/17.0.4 MIME-Version: 1.0 To: Simon Jeons CC: Frantisek Hrbata , linux-kernel@vger.kernel.org, linux-mm@kvack.org, tglx@linutronix.de, mingo@redhat.com, x86@kernel.org, oleg@redhat.com, kamaleshb@in.ibm.com, hechjie@cn.ibm.com Subject: Re: [PATCH] x86: add phys addr validity check for /dev/mem mmap References: <1364905733-23937-1-git-send-email-fhrbata@redhat.com> <515B2802.1050405@zytor.com> <515CD359.40004@gmail.com> In-Reply-To: <515CD359.40004@gmail.com> X-Enigmail-Version: 1.5.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 665 Lines: 20 On 04/03/2013 06:11 PM, Simon Jeons wrote: > > Why we consider boot_cpu_data.x86_phys_bits instead of e820 map here? > Because x86_phys_bits is what controls how much address space the processor has. e820 tells us how much *RAM* the machine has, or specifically, how much RAM the machine had on boot. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/