From owner-freebsd-stable@freebsd.org Sat Aug 5 09:54:54 2017 Return-Path: Delivered-To: freebsd-stable@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id C847FDCAB8A for ; Sat, 5 Aug 2017 09:54:54 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 45EC06E854 for ; Sat, 5 Aug 2017 09:54:54 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from tom.home (kib@localhost [127.0.0.1]) by kib.kiev.ua (8.15.2/8.15.2) with ESMTPS id v759snhD064090 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Sat, 5 Aug 2017 12:54:49 +0300 (EEST) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua v759snhD064090 Received: (from kostik@localhost) by tom.home (8.15.2/8.15.2/Submit) id v759snds064089; Sat, 5 Aug 2017 12:54:49 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Sat, 5 Aug 2017 12:54:49 +0300 From: Konstantin Belousov To: Kevin Oberman Cc: FreeBSD-STABLE Mailing List Subject: Re: Program crashes after 320666 Message-ID: <20170805095449.GY1700@kib.kiev.ua> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.8.3 (2017-05-23) X-Spam-Status: No, score=-2.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FROM,NML_ADSP_CUSTOM_MED autolearn=no autolearn_force=no version=3.4.1 X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on tom.home X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 05 Aug 2017 09:54:54 -0000 On Fri, Aug 04, 2017 at 06:10:48PM -0700, Kevin Oberman wrote: > multimedia/avidemux_qt4 has started dumping core with segfaults and other > errors in libthread called from Qt4. I am suspicious that the real problem > is in Qt4 and those errors were previously not detected and usually not > causing a problem. > > The problem shows up with kernels at r320666 and later. The update on July > 5 was: > Add MAP_GUARD and use it for stack protection. So the same userspace and application binaries on pre-r320666 works fine, am I right ? > > Should I open a ticket for the Qt4 or should I spend more effort on whether > it might be a kernel issue. (Pretty sure it's Qt4 at fault.) I might also > look into updating the port to use Qr5 as Qt4 is clearly starting to bitrot > and support for Qt5 has already been added upstream. Regardless of tickets, the only way to know what is going on is to debug the app. Build everything with the debug symbols, crash it under debugger control and obtain - backtraces of all threads - content of registers of the faulted thread - disassembly of the function which faulted - memory map of the application