From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933450AbXCJJ6P (ORCPT ); Sat, 10 Mar 2007 04:58:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932691AbXCJJ6P (ORCPT ); Sat, 10 Mar 2007 04:58:15 -0500 Received: from mtagate1.de.ibm.com ([195.212.29.150]:64487 "EHLO mtagate1.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751473AbXCJJ6O (ORCPT ); Sat, 10 Mar 2007 04:58:14 -0500 Subject: Re: [PATCH] Complain about missing system calls. From: Martin Schwidefsky Reply-To: schwidefsky@de.ibm.com To: Andi Kleen Cc: David Woodhouse , akpm@osdl.org, linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org, rmk@arm.linux.org.uk, sam@ravnborg.org, linux-arch@vger.kernel.org In-Reply-To: <20070309190051.GA20521@one.firstfloor.org> References: <1173394873.3461.510.camel@pmac.infradead.org> <20070309163805.GV18564@lug-owl.de> <20070309190051.GA20521@one.firstfloor.org> Content-Type: text/plain; charset=ISO-8859-1 Organization: IBM Corporation Date: Sat, 10 Mar 2007 10:58:13 +0100 Message-Id: <1173520693.7128.17.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.6.3 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2007-03-09 at 20:00 +0100, Andi Kleen wrote: > > Not everybody has a simple indexed list of pointers :) For example, > > for vax-linux, we use a struct per syscall with the expected number of > > on-stack longwords for the call. > > > > So if something "new" is coming up, please keep in mind that it should > > be flexible enough to represent that. :) > > Are there plans to merge vax any time soon to mainline? > > Normally we don't care very much about out of tree code, especially > if it adds complexity like this. > > But I suspect s390 would need number of arguments anyways. I can't quite follow that line of thought. Why does s390 need the number of arguments? The wrapper of a compat system call implicitly knows how many arguments a system calls to do the conversion. For a normal system call we just call the function. Random example sys_read: the user space loads the arguments to register %r2, %r3, %r4 and calls the system. The register are not touched until sys_read is reached. Only sys_read cares about the number of arguments in this case. -- blue skies, IBM Deutschland Entwicklung GmbH Martin Vorsitzender des Aufsichtsrats: Johann Weihen Geschäftsführung: Herbert Kircher Martin Schwidefsky Sitz der Gesellschaft: Böblingen Linux on zSeries Registergericht: Amtsgericht Stuttgart, Development HRB 243294 "Reality continues to ruin my life." - Calvin.