From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: [scratch/igc] 985247b6bee crash on Linux, KDE, Wayland Date: Sat, 07 Sep 2024 08:57:34 +0300 Message-ID: <861q1w0zw1.fsf@gnu.org> References: <8734mezkgo.fsf@gmail.com> <875xrani8k.fsf@gmail.com> <86bk122azc.fsf@gnu.org> <87v7zagcal.fsf@gmail.com> <867cbp3nw7.fsf@gnu.org> <87v7z9msrl.fsf@gmail.com> <874j6tqxyg.fsf@gmail.com> <87jzfpfhmf.fsf@protonmail.com> <87o751z3zr.fsf@gmail.com> <87v7z8eg2y.fsf@protonmail.com> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="40065"; mail-complaints-to="usenet@ciao.gmane.io" Cc: execvy@gmail.com, gerd.moellmann@gmail.com, emacs-devel@gnu.org To: Pip Cet Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sat Sep 07 07:58:20 2024 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1smoSh-000AGi-Cu for ged-emacs-devel@m.gmane-mx.org; Sat, 07 Sep 2024 07:58:19 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1smoS6-0002yy-RK; Sat, 07 Sep 2024 01:57:42 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1smoS4-0002yi-Dd for emacs-devel@gnu.org; Sat, 07 Sep 2024 01:57:40 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1smoS3-0003nX-5z; Sat, 07 Sep 2024 01:57:39 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=References:Subject:In-Reply-To:To:From:Date: mime-version; bh=XlDDt0FUA0NTpFyvYRa84iHsWH9ch+BUDpHuACbEPQE=; b=LkUIJhdjXC5k SzgGJCksyKnoOphSIS87G4y5/hsxxnFrrCf/RQwKXGPB0ZSq6yRWhdoBX/DA80qubPsFM1vpOVsGo XiyQnQ12Y1Jic3RZpkuNFsV4o/xwsneY8hAdkU8NX/oNPvo7TsRrWYDMX6cEMdLdrvwqapPKQoi/X 5D6JwrmG4UiYDUFI+edcwIuiFLIenzYi6Ml2J6x7zWt2SFvqDUHw7swqVs5dwSSWyjtA++nX2KrSq yBZ/gJJkr5XSl6M8K+Hv0tKNxD52XTpGK4PoYW2Dddaz30TUIpd6RgeGOtF9d6MM67UvBxmePMA+7 M2DEfQCm9JekPKjhTqMSlw==; In-Reply-To: <87v7z8eg2y.fsf@protonmail.com> (message from Pip Cet on Fri, 06 Sep 2024 19:29:28 +0000) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:323483 Archived-At: > Date: Fri, 06 Sep 2024 19:29:28 +0000 > From: Pip Cet > Cc: Eli Zaretskii , gerd.moellmann@gmail.com, emacs-devel@gnu.org > > So we can decode those to three interleaved lists reading, in part: > > (nil font-lock-face (:foreground ...)) > (rear-nonsticky t ...) > (nil font-lock-face (...)) > > is a pointer to what looks like the nursery generation, but > one which we must have failed to trace (presumably the symbol was either > uninterned and freed or interned and moved to an older generation) and > which was subsequently reused for cons cells by composite.c > > Going back to the original report, I notice that it was trying to print > an "error in process filter: " message while handling what looks like a > (long) sequence of terminal escape codes. Were you using M-x term at > the time? Did you notice such error messages? > > I'll have another look at the process filter/longjmp code, but I suspect > we're going to have to wait for further crashes to get to the bottom of > this. What data is missing to get to the bottom of this, and how can we change the code and/or add some .gdbinit magic to provide that data? In general, our current facilities to investigate igc-related crashes are clearly insufficient. The old GC has the last_marked[] array, which could be used to trace back any bad values which caused a GC-related crash, and I used that on several occasions. But there's nothing similar in igc.c, which makes the investigation basically a guesswork. How can we improve this situation? I expect this kind of trouble to happen a lot in the near future, so having efficient tools for debugging is crucial, IMO.