From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755101Ab0BUAJA (ORCPT ); Sat, 20 Feb 2010 19:09:00 -0500 Received: from mx.treblig.org ([80.68.94.177]:51317 "EHLO mx.treblig.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754131Ab0BUAI7 (ORCPT ); Sat, 20 Feb 2010 19:08:59 -0500 Date: Sun, 21 Feb 2010 00:02:29 +0000 From: "Dr. David Alan Gilbert" To: Andi Kleen Cc: "Nikita V. Youshchenko" , LKML Subject: Re: Extended error reporting to user space? Message-ID: <20100221000229.GA8092@gallifrey> References: <201002161520.26700@zigzag.lvk.cs.msu.su> <87r5ok5gl2.fsf@basil.nowhere.org> <201002171316.49165@zigzag.lvk.cs.msu.su> <20100217103504.GO21783@one.firstfloor.org> <20100217192058.GA8937@gallifrey> <20100217202312.GQ21783@one.firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100217202312.GQ21783@one.firstfloor.org> X-Chocolate: 70 percent or better cocoa solids preferably X-Operating-System: Linux/2.6.31.5-kvm-i386-2009-10-30 (i686) X-Uptime: 23:57:53 up 97 days, 7:07, 1 user, load average: 0.07, 0.02, 0.00 User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Andi Kleen (andi@firstfloor.org) wrote: > > I'd wondered about some form of halfway house where the error > > value is expanded but could be truncated for compatibility - i.e. > > Who would do the truncation? I'd assumed something like the code in entry*.S or equivalent for existing syscalls, but have another entry that would pass it through to a newer libc that new how to handle it. > > if at the moment we had: > > > > return -EINVAL; > > > > it would become: > > > > return ERRORNUM(EINVAL, BADLENGTH); > > x86 only has about 12 bits in the current ABI btw. Ah yes I can see that now, hmm. Dave -- -----Open up your eyes, open up your mind, open up your code ------- / Dr. David Alan Gilbert | Running GNU/Linux on Alpha,68K| Happy \ \ gro.gilbert @ treblig.org | MIPS,x86,ARM,SPARC,PPC & HPPA | In Hex / \ _________________________|_____ http://www.treblig.org |_______/