From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 3279 invoked by alias); 6 Dec 2007 18:02:30 -0000 Received: (qmail 3249 invoked by uid 22791); 6 Dec 2007 18:02:26 -0000 X-Spam-Status: No, hits=-2.1 required=5.0 tests=AWL,BAYES_00,DK_POLICY_SIGNSOME,FORGED_RCVD_HELO X-Spam-Check-By: sourceware.org Received: from wildebeest.demon.nl (HELO gnu.wildebeest.org) (83.160.170.119) by sourceware.org (qpsmtpd/0.31) with ESMTP; Thu, 06 Dec 2007 18:02:15 +0000 Received: from dijkstra.wildebeest.org ([192.168.1.29]) by gnu.wildebeest.org with esmtp (Exim 4.63) (envelope-from ) id 1J0L32-0002Ym-TZ; Thu, 06 Dec 2007 19:02:11 +0100 Subject: Re: libunwind Cursor.step() return values From: Mark Wielaard To: Phil Muldoon Cc: Frysk Hackers In-Reply-To: <475821DC.3030801@redhat.com> References: <475821DC.3030801@redhat.com> Content-Type: text/plain Date: Thu, 06 Dec 2007 18:02:00 -0000 Message-Id: <1196964128.3065.22.camel@dijkstra.wildebeest.org> Mime-Version: 1.0 X-Mailer: Evolution 2.12.1 (2.12.1-3.fc8) Content-Transfer-Encoding: 7bit X-Spam-Score: -4.4 (----) X-IsSubscribed: yes Mailing-List: contact frysk-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: frysk-owner@sourceware.org X-SW-Source: 2007-q4/txt/msg00210.txt.bz2 Hi Phil, On Thu, 2007-12-06 at 16:22 +0000, Phil Muldoon wrote: > I see that step == 0 means no more or unknown frames. Further down the: > > step = newCursor.step() > > returns -1 in this case. What does that mean in this case? A mixup of error codes... It is the result of an open() call passed around as libunwind error code, which it isn't. I am in the middle of rewriting this code. But -1 could be returned in theory and then would mean: UNW_EUNSPEC, /* unspecified (general) error */ If so a new cursor couldn't be created, but that should still not lead to the closing of fd 0 by some other code. On irc (and a quick pair programming on vnc - that is actually pretty cute) we tried to get the right error code across. Which seems to happen (then -10 UNW_ENOINFO is returned), but that didn't fix bad file descriptor closing. So I think it is unrelated, but actually some code trying to shut down and messing up the tty. Maybe one of the places found in the System.exit() bugzilla? http://sourceware.org/bugzilla/show_bug.cgi?id=4299 Cheers, Mark