From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamie Lokier Subject: Re: 64-syscall args on 32-bit vs syscall() Date: Wed, 17 Mar 2010 09:18:20 +0000 Message-ID: <20100317091820.GA8149@shareable.org> References: <20100315134449.GB1653@linux-mips.org> <4B9E4EB1.9010800@zytor.com> <4B9E59B7.6060405@redhat.com> <20100315.120004.209998642.davem@davemloft.net> <4B9E8D67.8040209@zytor.com> <1268685311.2335.38.camel@pasglop> <1268776570.19726.98.camel@spokane1.rchland.ibm.com> <1268785874.2335.137.camel@pasglop> <4BA06E1B.2040706@redhat.com> <1268816179.2335.187.camel@pasglop> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail2.shareable.org ([80.68.89.115]:38259 "EHLO mail2.shareable.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753818Ab0CQJTF (ORCPT ); Wed, 17 Mar 2010 05:19:05 -0400 Content-Disposition: inline In-Reply-To: <1268816179.2335.187.camel@pasglop> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Benjamin Herrenschmidt Cc: Ulrich Drepper , munroesj@us.ibm.com, "H. Peter Anvin" , David Miller , ralf@linux-mips.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@teksavvy.com, torvalds@linux-foundation.org Benjamin Herrenschmidt wrote: > Hence, apps that use the first form today because it works on x86 would > end up working at least on powerpc where they would have been otherwise > broken unless they used some arch specific #ifdef to do the second form. I think what Ulrich is getting at is your change will break existing code which already does: #ifdef __powerpc__ syscall(SYS_foo, 0, my_64bit_arg); #else syscall(SYS_foo, my_64bit_arg); #endif I don't know of any such code, but it might be out there. -- Jamie