From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Mon, 30 Jun 2008 21:59:55 +0100 (BST) Received: from sj-iport-2.cisco.com ([171.71.176.71]:17457 "EHLO sj-iport-2.cisco.com") by ftp.linux-mips.org with ESMTP id S28790551AbYF3U7t (ORCPT ); Mon, 30 Jun 2008 21:59:49 +0100 X-IronPort-AV: E=Sophos;i="4.27,728,1204531200"; d="scan'208";a="61578812" Received: from sj-dkim-3.cisco.com ([171.71.179.195]) by sj-iport-2.cisco.com with ESMTP; 30 Jun 2008 13:59:30 -0700 Received: from sj-core-1.cisco.com (sj-core-1.cisco.com [171.71.177.237]) by sj-dkim-3.cisco.com (8.12.11/8.12.11) with ESMTP id m5UKxTXM008897 for ; Mon, 30 Jun 2008 13:59:29 -0700 Received: from sausatlsmtp2.sciatl.com ([192.133.217.159]) by sj-core-1.cisco.com (8.13.8/8.13.8) with ESMTP id m5UKxTpO014403 for ; Mon, 30 Jun 2008 20:59:29 GMT Received: from default.com ([192.133.217.159]) by sausatlsmtp2.sciatl.com with Microsoft SMTPSVC(6.0.3790.3959); Mon, 30 Jun 2008 16:59:27 -0400 Received: from sausatlbhs01.corp.sa.net ([192.133.216.76]) by sausatlsmtp2.sciatl.com with Microsoft SMTPSVC(6.0.3790.3959); Mon, 30 Jun 2008 16:59:25 -0400 Received: from SAUSCUPEXCH01.corp.sa.net ([64.101.22.160]) by sausatlbhs01.corp.sa.net with Microsoft SMTPSVC(6.0.3790.3959); Mon, 30 Jun 2008 16:59:24 -0400 Received: from [127.0.0.1] ([64.101.20.200]) by SAUSCUPEXCH01.corp.sa.net with Microsoft SMTPSVC(6.0.3790.3959); Mon, 30 Jun 2008 13:59:23 -0700 Message-ID: <48694927.90906@cisco.com> Date: Mon, 30 Jun 2008 13:59:19 -0700 From: David VomLehn User-Agent: Thunderbird 2.0.0.14 (Windows/20080421) MIME-Version: 1.0 To: binutils@sourceware.org, gcc@gcc.gnu.org, linux-mips@linux-mips.org, dan@codesourcery.com, rdsandiford@googlemail.com Subject: Re: RFC: Adding non-PIC executable support to MIPS References: <87y74pxwyl.fsf@firetop.home> In-Reply-To: <87y74pxwyl.fsf@firetop.home> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 30 Jun 2008 20:59:23.0885 (UTC) FILETIME=[2CD151D0:01C8DAF4] X-ST-MF-Message-Resent: 6/30/2008 16:59 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; l=1931; t=1214859569; x=1215723569; c=relaxed/simple; s=sjdkim3002; h=Content-Type:From:Subject:Content-Transfer-Encoding:MIME-Version; d=cisco.com; i=dvomlehn@cisco.com; z=From:=20David=20VomLehn=20 |Subject:=20Re=3A=20RFC=3A=20Adding=20non-PIC=20executable= 20support=20to=20MIPS |Sender:=20; bh=d46fpFyQnkLvWhMuSyP2GJn34oMmpFnBKSSB07c8amQ=; b=a/WTrXH6h8DTPEdZh0YIKnJ4Eh9KXJmDJOPfIL0UGSHWlbXDt4uIZSrGJ9 06F+o23Qm/XclKXdwKGrV9AMjLTClDTmA9qWJJ5cIQUhxMKCWWE6qYHbzg2O eO8oYW7BLN; Authentication-Results: sj-dkim-3; header.From=dvomlehn@cisco.com; dkim=pass ( sig from cisco.com/sjdkim3002 verified; ); Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 19673 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: dvomlehn@cisco.com Precedence: bulk X-list: linux-mips Richard Sandiford wrote: > [Sorry for the 3-way crosspost!] > > One of the big holes in the MIPS ABI has always been the lack of support > for non-PIC executables. ... > I'll describe my implementation > below, then compare it to what I understand CS's version to be. > CS folks: please correct me if I'm wrong. This sounds like really good stuff and, on first reading, it all seems to make sense to me. My only real concern is documentation of these changes. The MIPS ABI (http://math-atlas.sourceforge.net/devel/assembly/mipsabi32.pdf) is currently moribund. The document that describes it hasn't been updated in since 1996 and gcc is not fully conformant (see, for example, the assumptions required for correct stack backtracing). It would take significant work to resurrect this but it certainly would be helpful to have a current document that completely describes the MIPS ABI, or at least the current ELF format, as currently implemented on Linux, especially if it is to be extended. The logical home for something like this would probably be the Linux Standard Base project hosted by the Linux Foundation. -- David VomLehn, dvomlehn@cisco.com The opinions expressed herein are likely mine, but might not be my employer's... - - - - - Cisco - - - - - This e-mail and any attachments may contain information which is confidential, proprietary, privileged or otherwise protected by law. The information is solely intended for the named addressee (or a person responsible for delivering it to the addressee). If you are not the intended recipient of this message, you are not authorized to read, print, retain, copy or disseminate this message or any part of it. If you have received this e-mail in error, please notify the sender immediately by return e-mail and delete it from your computer.