From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#25178: 26.0.50; Crash when pressing C-g in TTY mode Date: Wed, 14 Dec 2016 05:39:38 +0200 Message-ID: <83y3zj9o1x.fsf@gnu.org> References: <83bmwhccib.fsf@gnu.org> <838trjbrcq.fsf@gnu.org> Reply-To: Eli Zaretskii NNTP-Posting-Host: blaine.gmane.org X-Trace: blaine.gmane.org 1481686879 19690 195.159.176.226 (14 Dec 2016 03:41:19 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 14 Dec 2016 03:41:19 +0000 (UTC) Cc: 25178@debbugs.gnu.org To: Elias Martenson Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Wed Dec 14 04:41:14 2016 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cH0RM-0003IO-QF for geb-bug-gnu-emacs@m.gmane.org; Wed, 14 Dec 2016 04:41:13 +0100 Original-Received: from localhost ([::1]:45330 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cH0RM-00012R-3H for geb-bug-gnu-emacs@m.gmane.org; Tue, 13 Dec 2016 22:41:12 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:35917) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cH0RF-0000sI-VH for bug-gnu-emacs@gnu.org; Tue, 13 Dec 2016 22:41:06 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cH0RB-0000Bg-V3 for bug-gnu-emacs@gnu.org; Tue, 13 Dec 2016 22:41:06 -0500 Original-Received: from debbugs.gnu.org ([208.118.235.43]:54107) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cH0RB-0000BW-Rk for bug-gnu-emacs@gnu.org; Tue, 13 Dec 2016 22:41:01 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1cH0RB-0002Pb-LZ for bug-gnu-emacs@gnu.org; Tue, 13 Dec 2016 22:41:01 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Wed, 14 Dec 2016 03:41:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 25178 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 25178-submit@debbugs.gnu.org id=B25178.14816868349219 (code B ref 25178); Wed, 14 Dec 2016 03:41:01 +0000 Original-Received: (at 25178) by debbugs.gnu.org; 14 Dec 2016 03:40:34 +0000 Original-Received: from localhost ([127.0.0.1]:41272 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cH0Qk-0002Ob-Fs for submit@debbugs.gnu.org; Tue, 13 Dec 2016 22:40:34 -0500 Original-Received: from eggs.gnu.org ([208.118.235.92]:44895) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cH0Qi-0002OM-9b for 25178@debbugs.gnu.org; Tue, 13 Dec 2016 22:40:32 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cH0QY-0008RE-VA for 25178@debbugs.gnu.org; Tue, 13 Dec 2016 22:40:27 -0500 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:55232) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cH0QY-0008R4-SF; Tue, 13 Dec 2016 22:40:22 -0500 Original-Received: from 84.94.185.246.cable.012.net.il ([84.94.185.246]:3255 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1cH0QX-00063U-VX; Tue, 13 Dec 2016 22:40:22 -0500 In-reply-to: (message from Elias Martenson on Wed, 14 Dec 2016 11:09:12 +0800) 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: 208.118.235.43 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.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.org gmane.emacs.bugs:127023 Archived-At: > From: Elias Martenson > CC: <25178@debbugs.gnu.org> > Date: Wed, 14 Dec 2016 11:09:12 +0800 > > > Strangely, I don't see this on the GNU/Linux system to which I have > > access, although Emacs definitely calls pthread_mutex_unlock twice in > > a row in the scenario of this bug report. Is this some change in > > latest versions of glibc? > > Calling pthread_mutex_unlock() twice has to be undefined behaviour. In > fact, it can never work. Imagine what would happen if a different thread > called pthread_mutex_lock() on the mutex between two the two unlock > calls. In that case, you'd be unlocking a mutex help by a different > thread which is obviously very dangerous. I'm not asking if this is undefined behavior; it clearly is. I'm asking whether the second of these two calls is actually the one that crashes Emacs with SIGSEGV. IOW, does the crash happen inside the second call to pthread_mutex_unlock? And the next question would be why doesn't it crash for me on another GNU/Linux system? Thanks.