From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 62840 invoked by alias); 31 Jul 2015 12:51:47 -0000 Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Received: (qmail 62746 invoked by uid 89); 31 Jul 2015 12:51:46 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.5 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.2 X-HELO: out1-smtp.messagingengine.com Received: from out1-smtp.messagingengine.com (HELO out1-smtp.messagingengine.com) (66.111.4.25) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Fri, 31 Jul 2015 12:51:43 +0000 Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailout.nyi.internal (Postfix) with ESMTP id 5D10020D41 for ; Fri, 31 Jul 2015 08:51:41 -0400 (EDT) Received: from frontend1 ([10.202.2.160]) by compute4.internal (MEProxy); Fri, 31 Jul 2015 08:51:41 -0400 Received: from [192.168.1.102] (host86-141-131-77.range86-141.btcentralplus.com [86.141.131.77]) by mail.messagingengine.com (Postfix) with ESMTPA id 89339C00023; Fri, 31 Jul 2015 08:51:40 -0400 (EDT) Subject: Re: Seg Fault in strftime To: cygwin@cygwin.com References: Reply-To: cygwin@cygwin.com Cc: mike@kmcardiff.com From: Jon TURNEY Message-ID: <55BB6F59.8060905@dronecode.org.uk> Date: Fri, 31 Jul 2015 12:51:00 -0000 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2015-07/txt/msg00468.txt.bz2 On 31/07/2015 01:16, Michael Enright wrote: > The tznam is set from the tmzone member and when this happens that > member is garbage. This member is garbage POSSIBLY because of a > configuration option in libmozjs. The calling code is in prmjtime.cpp > fills in a struct tm from Spidermonkey's own broken-down time > structure, 'a', and then if the configuration enables, it makes > *another* struct tm with more fields filled in in order to get > a.tm_zone's proper value. My guess is that the path is not enabled but > the bits delivered to me do not disclose whether this righteous code > path is enabled. __cygwin_gettzname is evidently compiled to expect > the tm_zone member to exist because GDB shows it does exist. Thanks for this investigation and analysis. > So did any aspect of this change recently? The application and library > were getting along okay before I did cygwin updates. The last time I > had tried to run this code was early June, at which time I was running > it dozens of times a day. [1] looks like a highly relevant change and [2] is the associated discussion It would be very helpful if you could tweak the testcase there and produce one which reproduces your problem. [1] https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;a=commitdiff;h=75d5f68aabf62c42884ff935f888b12bbcd00001 [2] https://sourceware.org/ml/newlib/2015/msg00321.html > Also it appears that the tm_zone member is an extension. I haven't > been able to find POSIX guidance about how applications are supposed > use struct tm in compliance in the presence of implementation-defined > fields. POSIX example code shows a usage that does access the 'at > least' fields. The language allows for implementation-defined fields. > No mechanism is provided within POSIX to allow an application to > discover additional fields and take care of them. It seems to me that > an application can then assume that when it provides a struct tm as > input, filling in the time and date reasonably, it is always > sufficient to fill in the 'at least' fields and the implementation is > the one who has to assume that the rest of the fields might not be > filled in. Yeah, this seems a bit of an under-specified area. -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple