From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Richard Stallman Newsgroups: gmane.emacs.devel,gmane.emacs.bugs Subject: Re: mark_object crash in 22.1 and latest CVS (as of tonight) Date: Tue, 13 Nov 2007 00:10:01 -0500 Message-ID: References: <16af2f430711081955j3d5e6745gc0f7a50e02d9a892@mail.gmail.com> <16af2f430711090332x39c8c768gb01d1dc6a0e4f427@mail.gmail.com> <16af2f430711120340q27926877tf976ef397d12df16@mail.gmail.com> Reply-To: rms@gnu.org NNTP-Posting-Host: lo.gmane.org Content-Type: text/plain; charset=ISO-8859-15 X-Trace: ger.gmane.org 1194930648 3646 80.91.229.12 (13 Nov 2007 05:10:48 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 13 Nov 2007 05:10:48 +0000 (UTC) Cc: bug-gnu-emacs@gnu.org, kalman.reti@gmail.com, emacs-devel@gnu.org To: "Kalman Reti" Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Tue Nov 13 06:10:51 2007 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1Iro2x-0005L5-GZ for ged-emacs-devel@m.gmane.org; Tue, 13 Nov 2007 06:10:47 +0100 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Iro2l-00085f-9e for ged-emacs-devel@m.gmane.org; Tue, 13 Nov 2007 00:10:35 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Iro2F-0007hE-K8 for emacs-devel@gnu.org; Tue, 13 Nov 2007 00:10:03 -0500 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Iro2E-0007gR-11 for emacs-devel@gnu.org; Tue, 13 Nov 2007 00:10:03 -0500 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Iro2D-0007gN-TX; Tue, 13 Nov 2007 00:10:01 -0500 Original-Received: from fencepost.gnu.org ([140.186.70.10]) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1Iro2D-0001Jo-IG; Tue, 13 Nov 2007 00:10:01 -0500 Original-Received: from rms by fencepost.gnu.org with local (Exim 4.60) (envelope-from ) id 1Iro2D-0000Hx-AO; Tue, 13 Nov 2007 00:10:01 -0500 In-reply-to: <16af2f430711120340q27926877tf976ef397d12df16@mail.gmail.com> (kalman.reti@gmail.com) X-detected-kernel: by monty-python.gnu.org: Linux 2.6, seldom 2.4 (older, 4) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:83108 gmane.emacs.bugs:16960 Archived-At: I assumed someone would recognize WHAT part of a buffer from the contents of the, list, a mixture of conses with marker-in-no-buffer in the car of some and Lisp_Misc_Free in the car of others, the cdr's being negative numbers of pretty small absolute magnitude. I didn't see that when I looked at the other message. Can anyone guess what data this is? > Once you answer those, you can try to figure out how it happened > that the data structure ended up with a bad pointer. > Maybe GC failed to mark that pointer, so the misc object got freed > even though it was still in use. Are there any tools to help with this, e.g. an allocation trace or GC trace? I'm afraid this is the first time I've looked at the Emacs src code. The x... GDB commands in .gdbinit are useful for examining data structures during GC. `last_marked' and `last_marked_index' keep track of the sequence of data objects that were marked. You can use that to determine precisely how the bad data was reached.