From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Michael Welsh Duggan Newsgroups: gmane.emacs.bugs Subject: bug#47244: 28.0.50; SIGSEGV in long-runnning Emacs Date: Thu, 18 Mar 2021 12:27:13 -0400 Message-ID: <87wnu4qvfi.fsf@md5i.com> References: <87im5ofp3z.fsf@md5i.com> <87czvwfoys.fsf@md5i.com> <83tup8fo1j.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="32015"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) Cc: 47244@debbugs.gnu.org To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Thu Mar 18 17:41:56 2021 Return-path: Envelope-to: geb-bug-gnu-emacs@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 1lMvid-0008Dr-VM for geb-bug-gnu-emacs@m.gmane-mx.org; Thu, 18 Mar 2021 17:41:55 +0100 Original-Received: from localhost ([::1]:37328 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lMvib-0003Di-96 for geb-bug-gnu-emacs@m.gmane-mx.org; Thu, 18 Mar 2021 12:41:53 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:59480) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lMvVC-0001Pv-5y for bug-gnu-emacs@gnu.org; Thu, 18 Mar 2021 12:28:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:36326) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1lMvVB-0006nx-US for bug-gnu-emacs@gnu.org; Thu, 18 Mar 2021 12:28:01 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1lMvVB-0002Xu-QZ for bug-gnu-emacs@gnu.org; Thu, 18 Mar 2021 12:28:01 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Michael Welsh Duggan Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Thu, 18 Mar 2021 16:28:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 47244 X-GNU-PR-Package: emacs Original-Received: via spool by 47244-submit@debbugs.gnu.org id=B47244.16160848419733 (code B ref 47244); Thu, 18 Mar 2021 16:28:01 +0000 Original-Received: (at 47244) by debbugs.gnu.org; 18 Mar 2021 16:27:21 +0000 Original-Received: from localhost ([127.0.0.1]:47872 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1lMvUX-0002Wv-Ba for submit@debbugs.gnu.org; Thu, 18 Mar 2021 12:27:21 -0400 Original-Received: from md5i.com ([75.151.244.229]:32890) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1lMvUV-0002Wi-4L for 47244@debbugs.gnu.org; Thu, 18 Mar 2021 12:27:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=md5i.com; s=dkim; h=Content-Type:MIME-Version:Message-ID:Date:References:In-Reply-To: Subject:Cc:To:From:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=xdOhoD7o5nTLq4g3pAdpA9ZKhFKm+5vWQ7zuLGaDvFE=; b=dzGMHMtWrV6MuKeSX1MiBt2NIY eJdY+V6d/O+1DsVHd8weNP6IQT9lFVAhbhbaOcL+5BcucWawoZDPVqUWGd05u4/UXxw+wwkV0i2qn XN+D4zpZ80wiQlYV+pyKr15In; Original-Received: from abode.md5i.com ([192.168.177.1] helo=miko) by md5i.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1lMvUP-002khs-Ua; Thu, 18 Mar 2021 12:27:13 -0400 In-Reply-To: <83tup8fo1j.fsf@gnu.org> (Eli Zaretskii's message of "Thu, 18 Mar 2021 18:02:16 +0200") X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:202623 Archived-At: Eli Zaretskii writes: >> From: Michael Welsh Duggan >> Date: Thu, 18 Mar 2021 11:42:19 -0400 >> >> I have managed to catch a SEGFAULT in a long-running Emacs in the >> debugger. I've been unable to recreate this SEGFAULT on demand, but it >> seems to be happening when I am attempting to "reset" gnus after >> switching my work VPN on/off. I will keep the gdb session up an running >> in case there is some more that can be done with this. >> >> >> In GNU Emacs 28.0.50 (build 1, x86_64-pc-linux-gnu, X toolkit, cairo >> version 1.16.0) >> of 2021-03-07 built on miko >> Repository revision: c63d2ef59c511c1c48c69a202907b7edfcbb19b3 >> Repository branch: md5i > > This is a build from several days ago, and on some branch that is > probably a local branch. Do the line numbers still correspond to > what's on the current master? They do match. It is a branch, but the changed things in the branch are extremely unlikely to have caused this problem. (One is a patch to gnus summary-producing that changes how thread sorting is ordered, the other is a patch to .gdbinit that handles running gdb on emacs when running with the --daemon option.) I changed the Repository revision field to match the version of Emacs I was using. It's several days old because it took several days before I was able to re-trigger this problem. >> #0 0x00005555555e1a61 in redisplay_internal () >> at ../../master/src/xdisp.c:15789 > > The line number here corresponds to this in the current sources: > > if (CHARPOS (tlbufpos) > BEGV > && FETCH_BYTE (BYTEPOS (tlbufpos) - 1) != '\n' <<<<<<<<<<<<<<<<< > && (CHARPOS (tlbufpos) == ZV > || FETCH_BYTE (BYTEPOS (tlbufpos)) == '\n')) > > Is that so in your sources as well? If so, I'm not sure I understand > how this could segfault, given that tlbufpos is 127. What is the > value of ZV? And what does the following produce: > > (gdb) p current_buffer->text->beg (gdb) p ZV $6 = 127 (gdb) p current_buffer->text->beg $7 = (unsigned char *) 0x0 -- Michael Welsh Duggan (md5i@md5i.com)