From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 10493 invoked by alias); 15 Mar 2005 05:48:48 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 10116 invoked from network); 15 Mar 2005 05:48:31 -0000 Received: from unknown (HELO e4.ny.us.ibm.com) (32.97.182.144) by sourceware.org with SMTP; 15 Mar 2005 05:48:31 -0000 Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by e4.ny.us.ibm.com (8.12.11/8.12.11) with ESMTP id j2F5mUpq024761 for ; Tue, 15 Mar 2005 00:48:30 -0500 Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by d01relay04.pok.ibm.com (8.12.10/NCO/VER6.6) with ESMTP id j2F5mU9J209904 for ; Tue, 15 Mar 2005 00:48:30 -0500 Received: from d01av02.pok.ibm.com (loopback [127.0.0.1]) by d01av02.pok.ibm.com (8.12.11/8.12.11) with ESMTP id j2F5mTnF028305 for ; Tue, 15 Mar 2005 00:48:30 -0500 Received: from wks126478wss.in.ibm.com (wks126478wss.in.ibm.com [9.182.14.178]) by d01av02.pok.ibm.com (8.12.11/8.12.11) with ESMTP id j2F5mQdK028265; Tue, 15 Mar 2005 00:48:27 -0500 Subject: Re: [Fastboot] Re: Query: Kdump: Core Image ELF Format From: Vivek Goyal To: "Eric W. Biederman" Cc: Andrew Morton , gdb , Dave Anderson , lkml , fastboot In-Reply-To: References: <1110286210.4195.27.camel@wks126478wss.in.ibm.com> <1110350629.31878.7.camel@wks126478wss.in.ibm.com> <1110430955.3574.11.camel@wks126478wss.in.ibm.com> Content-Type: text/plain Date: Tue, 15 Mar 2005 05:48:00 -0000 Message-Id: <1110865787.3576.7.camel@localhost.localdomain> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-SW-Source: 2005-03/txt/msg00154.txt.bz2 On Wed, 2005-03-09 at 23:56 -0700, Eric W. Biederman wrote: > Vivek Goyal writes: > > > I want to fill the virtual addresses of linearly mapped region. That is > > physical addresses from 0 to MAXMEM (896 MB) are mapped by kernel at > > virtual addresses PAGE_OFFSET to (PAGE_OFFSET + MAXMEM). Values of > > PAGE_OFFSET and MAXMEM are already known and hard-coded. > > PAGE_OFFSET has a common value of 0xc0000000, on x86. However > that value is by no means fixed. The 4G/4G split changes it > as do some other patches floating around at the time. > On x86-64 I don't know how stable those kinds of offsets are. Agreed. Then how about, exporting this information to user space. Probably through sysfs. May be the range of linearly mapped region can be exported. (PAGE_OFFSET to (PAGE_OFFSET + x)). > > > I think I used the terminology kernel virtual address and that is adding > > to the confusion. Kernel virtual addresses are not necessarily linearly > > mapped. What I meant was kernel logical addresses whose associated > > physical addresses differ only by a constant offset. > > I know what you meant. I simply meant that things don't look that > constant to me. Especially in Linux where there are enough people > to try most of the reasonable possibilities. > > I don't even think it is a bad idea. But I do think we have a different > idea of what is constant. > > Eric >