From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#40661: Crash in regex search during redisplay Date: Sat, 18 Apr 2020 14:57:16 +0300 Message-ID: <834kthatwj.fsf@gnu.org> References: <83ftd3e92z.fsf@gnu.org> <83d087e6gj.fsf@gnu.org> <421071D0-6D75-4442-AC4B-D091B573B49C@dancol.org> <838siucq7b.fsf@gnu.org> <83tv1iaz7g.fsf@gnu.org> Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="12542"; mail-complaints-to="usenet@ciao.gmane.io" Cc: rcopley@gmail.com, 40661@debbugs.gnu.org To: Stefan Monnier Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Sat Apr 18 13:58:23 2020 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 1jPm74-0003Ao-Tc for geb-bug-gnu-emacs@m.gmane-mx.org; Sat, 18 Apr 2020 13:58:22 +0200 Original-Received: from localhost ([::1]:57108 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jPm73-0005HI-V3 for geb-bug-gnu-emacs@m.gmane-mx.org; Sat, 18 Apr 2020 07:58:21 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:34669) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jPm6n-0005G1-4T for bug-gnu-emacs@gnu.org; Sat, 18 Apr 2020 07:58:06 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jPm6l-000386-7J for bug-gnu-emacs@gnu.org; Sat, 18 Apr 2020 07:58:05 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:58758) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1jPm6k-00037U-De for bug-gnu-emacs@gnu.org; Sat, 18 Apr 2020 07:58:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1jPm6k-0002f2-E7 for bug-gnu-emacs@gnu.org; Sat, 18 Apr 2020 07:58:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sat, 18 Apr 2020 11:58:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 40661 X-GNU-PR-Package: emacs Original-Received: via spool by 40661-submit@debbugs.gnu.org id=B40661.158721105610161 (code B ref 40661); Sat, 18 Apr 2020 11:58:02 +0000 Original-Received: (at 40661) by debbugs.gnu.org; 18 Apr 2020 11:57:36 +0000 Original-Received: from localhost ([127.0.0.1]:42067 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jPm6K-0002dp-BR for submit@debbugs.gnu.org; Sat, 18 Apr 2020 07:57:36 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:47626) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jPm6I-0002dQ-NH for 40661@debbugs.gnu.org; Sat, 18 Apr 2020 07:57:35 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:57374) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1jPm6C-0002eq-7s; Sat, 18 Apr 2020 07:57:29 -0400 Original-Received: from [176.228.60.248] (port=4360 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1jPm6A-00078m-23; Sat, 18 Apr 2020 07:57:26 -0400 In-Reply-To: (message from Stefan Monnier on Fri, 17 Apr 2020 12:00:27 -0400) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.51.188.43 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:178563 Archived-At: > From: Stefan Monnier > Cc: rcopley@gmail.com, dancol@dancol.org, 40661@debbugs.gnu.org > Date: Fri, 17 Apr 2020 12:00:27 -0400 > > >> > Obviously, we cannot allow GC to run while regex routines do their > >> > work, because they are passed C pointers to buffer text. The question > >> > is, where to disable GC? We could do it inside > >> > update_syntax_table_forward, but UPDATE_SYNTAX_TABLE_FORWARD is called > >> > from many places that evidently have no problems with GC. So my > >> > suggestion would be to disable GC inside re_match_2_internal instead. > >> > Comments? > >> Looks fine to me. > > So you prefer disabling GC to setting the inhibit_shrinking flag? > > I tend to agree with Daniel here, FWIW. > > No, what I meant was that I'm fine with doing it "inside > re_match_2_internal" instead of "inside update_syntax_table_forward". > But I prefer if the "it" is setting `inhibit_shrinking` instead of > inhibiting the GC altogether. OK, thank you and Daniel for the feedback, and thanks to Richard for finding this bug in the first place. I installed a fix on the emacs-27 branch, it avoids the crashes in the recipe posted by Richard. Please eyeball the fix, in case I made some stupid mistake (my environment is rather noisy today, so I trust myself even less than I usually do).