From owner-freebsd-emulation Fri Jan 15 03:18:43 1999 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id DAA25756 for freebsd-emulation-outgoing; Fri, 15 Jan 1999 03:18:43 -0800 (PST) (envelope-from owner-freebsd-emulation@FreeBSD.ORG) Received: from gaia.euronet.nl (gaia.euronet.nl [194.134.0.10]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id DAA25751 for ; Fri, 15 Jan 1999 03:18:38 -0800 (PST) (envelope-from marcel@scc.nl) Received: from scones.sup.scc.nl (i449.ztm.euronet.nl [194.134.67.170]) by gaia.euronet.nl (8.8.8/8.8.8) with ESMTP id MAA09971; Fri, 15 Jan 1999 12:17:23 +0100 (MET) Received: from scc.nl (scones.sup.scc.nl [192.168.2.4]) by scones.sup.scc.nl (8.9.1/8.9.1) with ESMTP id MAA48373; Fri, 15 Jan 1999 12:16:44 +0100 (CET) (envelope-from marcel@scc.nl) Message-ID: <369F239C.D17CD06D@scc.nl> Date: Fri, 15 Jan 1999 12:16:44 +0100 From: Marcel Moolenaar Organization: SCC vof X-Mailer: Mozilla 4.5 [en] (X11; I; FreeBSD 3.0-CURRENT i386) X-Accept-Language: en MIME-Version: 1.0 To: Brian Feldman CC: Mike Smith , freebsd-emulation@FreeBSD.ORG Subject: Re: sendmsg() not working?! References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-emulation@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Brian Feldman wrote: > > > > You know of course that system call arguments are faulted in from the user > > > stack on int 0x80, so it doesn't change the system call time that much > > > (read: substantially at all) to have a couple more. > > > > Ok; but the copyout changes data in a structure controlled by the program. > > That change is visible by the program. Technically speaking, the Linux > > emulator can change runtime behavior. I know; it is not likely, but possible. > > That's what bothers me about the copyout. > > I suppose you're right, I saw the const struct msghdr * in sednmsg, but I don't > think that necessarily applies to the cmsg, which is just a pointer in msghdr. > We do not make any changes to the const struct msghdr *, so we violate no > rules. Correct :-) > Why would a program ever check if the sendmsg affected cmsghdr? It is not for the kernel/emulator developer to ask such questions, for it will only result in unfounded assumptions. (hmmm, did I just say that? :-) > All it would do from then on is have the corrct value of cmsg_level. Correct for FreeBSD, but not correct for Linux. We are running Linux apps of course. > If it really bothers anyone any serious amount, there's an easy fix. [fix deleted] I know. It is not such a big deal to spend any more time on this discussion. Let's instead make sure the necessary changed get committed. marcel To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-emulation" in the body of the message