From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762078AbXFDV00 (ORCPT ); Mon, 4 Jun 2007 17:26:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761629AbXFDVZo (ORCPT ); Mon, 4 Jun 2007 17:25:44 -0400 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:49221 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1761615AbXFDVZn (ORCPT ); Mon, 4 Jun 2007 17:25:43 -0400 Date: Mon, 04 Jun 2007 14:25:57 -0700 (PDT) Message-Id: <20070604.142557.68139332.davem@davemloft.net> To: joseph@codesourcery.com Cc: linux-kernel@vger.kernel.org, linux-mips@linux-mips.org, linux-arch@vger.kernel.org Subject: Re: 64-bit syscall ABI issue From: David Miller In-Reply-To: References: X-Mailer: Mew version 5.1.52 on Emacs 21.4 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: "Joseph S. Myers" Date: Mon, 4 Jun 2007 20:56:57 +0000 (UTC) [ added linux-arch which is a great place to discuss these kinds of issues. ] > What should the kernel syscall ABI be in such cases (any case where the > syscall implementations expect arguments narrower than registers, so > mainly 32-bit arguments on 64-bit platforms)? There are two obvious > possibilities: In general we've taken the stance that the syscall dispatch should create the proper calling environment for C code implementing the system calls, and this thus means properly sign and zero extending the arguments as expected by the C calling convention.