From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932462AbWBGJkz (ORCPT ); Tue, 7 Feb 2006 04:40:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932463AbWBGJky (ORCPT ); Tue, 7 Feb 2006 04:40:54 -0500 Received: from ns1.suse.de ([195.135.220.2]:11198 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S932460AbWBGJkg (ORCPT ); Tue, 7 Feb 2006 04:40:36 -0500 From: Andi Kleen To: "David S. Miller" Subject: Re: [PATCH] compat: add compat functions for *at syscalls Date: Tue, 7 Feb 2006 10:25:39 +0100 User-Agent: KMail/1.8.2 Cc: sfr@canb.auug.org.au, akpm@osdl.org, linux-kernel@vger.kernel.org, torvalds@osdl.org References: <20060207105631.39a1080c.sfr@canb.auug.org.au> <20060206.160140.59716704.davem@davemloft.net> In-Reply-To: <20060206.160140.59716704.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200602071025.40130.ak@suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday 07 February 2006 01:01, David S. Miller wrote: > From: Stephen Rothwell > Date: Tue, 7 Feb 2006 10:56:31 +1100 > > > This adds compat version of all the remaining *at syscalls > > so that the "dfd" arguments can be properly sign extended. > > > > Signed-off-by: Stephen Rothwell > > I do the sign extension with tiny stubs in arch/sparc64/kernel/sys32.S > so that the arg frobbing does not consume a stack frame, which is what > happens if you do this in C code. To be honest - do you really think that matters? Even a Niagara will go through that in no time @) And on x86-64 it should be as efficient as an equivalent assembly function. -Andi