From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.bugs Subject: bug#18361: New 'sort' implementation can crash Emacs Date: Fri, 29 Aug 2014 22:22:48 -0700 Organization: UCLA Computer Science Department Message-ID: <54015FA8.5070400@cs.ucla.edu> References: <5400EFA5.6090902@cs.ucla.edu> <540102E5.6040404@yandex.ru> <5401079D.7070505@cs.ucla.edu> <54015C22.5030108@yandex.ru> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1409376264 17911 80.91.229.3 (30 Aug 2014 05:24:24 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 30 Aug 2014 05:24:24 +0000 (UTC) Cc: 18361@debbugs.gnu.org To: Dmitry Antipov Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Sat Aug 30 07:24:18 2014 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1XNb96-0008KV-PS for geb-bug-gnu-emacs@m.gmane.org; Sat, 30 Aug 2014 07:24:16 +0200 Original-Received: from localhost ([::1]:45273 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XNb96-0006AC-8C for geb-bug-gnu-emacs@m.gmane.org; Sat, 30 Aug 2014 01:24:16 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:43947) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XNb8y-0006A7-8C for bug-gnu-emacs@gnu.org; Sat, 30 Aug 2014 01:24:14 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XNb8s-00016e-BN for bug-gnu-emacs@gnu.org; Sat, 30 Aug 2014 01:24:08 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:34150) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XNb8s-00016a-8Z for bug-gnu-emacs@gnu.org; Sat, 30 Aug 2014 01:24:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.80) (envelope-from ) id 1XNb8r-0004Yn-T2 for bug-gnu-emacs@gnu.org; Sat, 30 Aug 2014 01:24:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Paul Eggert Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sat, 30 Aug 2014 05:24:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 18361 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 18361-submit@debbugs.gnu.org id=B18361.140937618517454 (code B ref 18361); Sat, 30 Aug 2014 05:24:01 +0000 Original-Received: (at 18361) by debbugs.gnu.org; 30 Aug 2014 05:23:05 +0000 Original-Received: from localhost ([127.0.0.1]:53947 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1XNb7w-0004XR-IA for submit@debbugs.gnu.org; Sat, 30 Aug 2014 01:23:04 -0400 Original-Received: from smtp.cs.ucla.edu ([131.179.128.62]:55147) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1XNb7t-0004Wq-5U for 18361@debbugs.gnu.org; Sat, 30 Aug 2014 01:23:01 -0400 Original-Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp.cs.ucla.edu (Postfix) with ESMTP id E7DFBA60013; Fri, 29 Aug 2014 22:22:54 -0700 (PDT) X-Virus-Scanned: amavisd-new at smtp.cs.ucla.edu Original-Received: from smtp.cs.ucla.edu ([127.0.0.1]) by localhost (smtp.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id eyCFqvtsBXQE; Fri, 29 Aug 2014 22:22:53 -0700 (PDT) Original-Received: from [192.168.1.9] (pool-71-177-17-123.lsanca.dsl-w.verizon.net [71.177.17.123]) by smtp.cs.ucla.edu (Postfix) with ESMTPSA id BAC15A60002; Fri, 29 Aug 2014 22:22:53 -0700 (PDT) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.0 In-Reply-To: <54015C22.5030108@yandex.ru> X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.15 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 140.186.70.43 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-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:92841 Archived-At: Dmitry Antipov wrote: > > If an undefined behavior doesn't cause crash, Unfortunately undefined behavior in qsort can cause a crash (or an infinite loop, etc., etc.). It's platform-dependent, and on many platforms the problem happens only in unusual cases, so I'm not surprised your tests didn't find it. But it definitely can happen. See, for example, https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42157 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51297 These crash reports are for Solaris qsort, but today I found similar issues in the latest glibc qsort by code inspection (e.g., the path qsort takes when memory is low). These issues are not qsort bugs, since the qsort spec requires a total-order comparison function. It's a bug in the Emacs trunk.