From owner-freebsd-ports Fri Oct 3 08:55:29 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id IAA22876 for ports-outgoing; Fri, 3 Oct 1997 08:55:29 -0700 (PDT) Received: from seagull.cdrom.com (cracauer@seagull.cdrom.com [204.216.27.14]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id IAA22858; Fri, 3 Oct 1997 08:55:25 -0700 (PDT) Received: (from cracauer@localhost) by seagull.cdrom.com (8.8.6/8.6.6) id IAA07278 ; Fri, 3 Oct 1997 08:54:35 -0700 (PDT) Message-ID: <19971003175433.64822@cons.org> Date: Fri, 3 Oct 1997 17:54:33 +0200 From: Martin Cracauer To: Matthew Thyer Cc: freebsd-current@FreeBSD.ORG, ports@FreeBSD.ORG Subject: Re: xlock: caught signal 8 while running galaxy mode. References: <34348712.F0962930@dsto.defence.gov.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.81 In-Reply-To: <34348712.F0962930@dsto.defence.gov.au>; from Matthew Thyer on Fri, Oct 03, 1997 at 03:18:02PM +0930 Sender: owner-freebsd-ports@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk In <34348712.F0962930@dsto.defence.gov.au>, Matthew Thyer wrote: > Does anyone else have this problem or can anyone confirm that it > will be solved by a newer incarnation of -CURRENT or a newer > xlockmore ? > > I run xlockmore-4.02 on a somewhat dated FreeBSD 3.0-CURRENT now > (3.0-970618-SNAP). > > I always use the galaxy mode for screen locking (because I love it!) > and it often dies with the following error in my > .xsession-errors file: > > "xlock: caught signal 8 while running galaxy mode." > > Signal 8 appears to be a floating point exception (FPE) according to > kill -l. This has been discusssed several times. FreeBSD defaults to abort a program at a floating point exception while anyone else does not. The default for then is to set the result to IEEE exceptional values (InF, NaN etc.). You can switch all systems to do the other. I tried to convince people that FreeBSD hurts itself here, and the dying screensavers are my primary example how this can hurt users. The solution was to tell the port maintainers to switch FP mode for their ports, which haven't happend for any port, as far as I know. There are bugs in our gcc that make relying on FP exceptions handled right dangerous and Bruce Evans felt it is better to through the signal, so that people get aware of the problem. With all respect to Bruce, I'm still conviced that we should switch to default to set exceptional values and not signal the process. Our gcc isn't that much worse than NetBSD's and Linux and those systems obviously didn't get into trouble, at least not my my applications. I think that a user who maintains a critical floating point program is much more likely to be aware of turning on exceptions for his program than any random user is aware of turning them off for a black-box (for his viewpoint) package like xlockmore. If you want to change the system-wide default, add this to npx.h before building a kernel: undef __INITIAL_NPXCW__ #define __INITIAL_NPXCW__ 0x127f If you come to an educated opinion about the issue a mail to core may be useful. Martin -- %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Martin Cracauer http://www.cons.org/cracauer/ BSD User Group Hamburg/Germany http://www.bsdhh.org/