From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265412AbUEUHct (ORCPT ); Fri, 21 May 2004 03:32:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265346AbUEUHct (ORCPT ); Fri, 21 May 2004 03:32:49 -0400 Received: from cpe-24-221-190-179.ca.sprintbbd.net ([24.221.190.179]:43648 "EHLO myware.akkadia.org") by vger.kernel.org with ESMTP id S265412AbUEUHcJ (ORCPT ); Fri, 21 May 2004 03:32:09 -0400 Message-ID: <40ADACAB.5070907@redhat.com> Date: Fri, 21 May 2004 00:15:55 -0700 From: Ulrich Drepper Organization: Red Hat, Inc. User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8a) Gecko/20040519 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Andrew Morton CC: jakub@redhat.com, linux-kernel@vger.kernel.org, mingo@redhat.com Subject: Re: [PATCH] Add FUTEX_CMP_REQUEUE futex op References: <20040520093817.GX30909@devserv.devel.redhat.com> <20040520155217.7afad53b.akpm@osdl.org> <40AD9C5E.1020603@redhat.com> <20040520233639.126125ef.akpm@osdl.org> In-Reply-To: <20040520233639.126125ef.akpm@osdl.org> X-Enigmail-Version: 0.84.0.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton wrote: > and we're expecting the a's and b's to line up across all architectures and > compiler options. I thought that on some architectures that only works out > if the function has a vararg declaration. I never heard that. > Does it do the right thing on stack-grows-up machines? Would be only HP/PA and I don't see this to be a problem. > If the compiler passes the first few args via registers and the rest on the > stack, are we sure that it won't at some level of complexity decide to pass > _all_ the args on the stack? It's free to do so, I think. This is not how the calling conventions are designed. If registers are used they happens unconditional of the remainder of the parameter list. The stack is used as an overflow. > I have a vague memory of getting bitten by this trick once... I don't and, as Ingo mentioned, we already did it before. -- ➧ Ulrich Drepper ➧ Red Hat, Inc. ➧ 444 Castro St ➧ Mountain View, CA ❖