From owner-freebsd-hackers@FreeBSD.ORG Sat Aug 16 18:25:18 2014 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 85FEC28E for ; Sat, 16 Aug 2014 18:25:18 +0000 (UTC) Received: from mail-ig0-x231.google.com (mail-ig0-x231.google.com [IPv6:2607:f8b0:4001:c05::231]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 53DFF284F for ; Sat, 16 Aug 2014 18:25:18 +0000 (UTC) Received: by mail-ig0-f177.google.com with SMTP id hn18so4475900igb.16 for ; Sat, 16 Aug 2014 11:25:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type; bh=Wl9WAMfb282By6nZPfzGc84Ng6s/AEyan3tO3Y2dUk8=; b=eX03udALy+uD09aRgDhDEv+HVPpsK98q2IlMCWiNFuADImAqgKPi+W9z4z4NwSKHLR +10QWVT16Ol0lrhXMBKbMXW6j8NLBh3+IzqDirplPkW42Io+MS+2v9xNmAYAFKj3UKtU eideHU6sSItrmTvYIuGs3YlLgDdaMH3BQEuWpV6thMHDomJlMYij8YjYDz1vW9yh+hSw lTwKZ6nLf0zgYz7TfHAr0iB7CWjr94tSnsVT3kbFcMBLYb8/Tff26uKrB2TiBzrlzHoS K+kK1DHSSTuJtYcBciYqaMW+8IDIYSL0EGKL9zbe5xvheoujPiXzBEuTWBlNeUHovoUG E0NA== X-Received: by 10.43.129.74 with SMTP id hh10mr26598153icc.48.1408213517776; Sat, 16 Aug 2014 11:25:17 -0700 (PDT) MIME-Version: 1.0 Received: by 10.107.39.145 with HTTP; Sat, 16 Aug 2014 11:24:47 -0700 (PDT) In-Reply-To: <53ADEE4C.2080804@blach.pl> References: <53A95016.3090901@blach.pl> <20140624205420.GZ93733@kib.kiev.ua> <53ADEE4C.2080804@blach.pl> From: arrowdodger <6yearold@gmail.com> Date: Sat, 16 Aug 2014 22:24:47 +0400 Message-ID: Subject: Re: Crash probably in libthr To: Grzegorz Blach Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.18-1 Cc: freebsd-hackers X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 16 Aug 2014 18:25:18 -0000 On Sat, Jun 28, 2014 at 2:21 AM, Grzegorz Blach wrote: > On 06/24/14 22:54, Konstantin Belousov wrote: > > On Tue, Jun 24, 2014 at 12:16:54PM +0200, Grzegorz Blach wrote: > >> On https://phab.enlightenment.org/T1330 I reported a crash in > >> Enlightenment. After analyzing backtraces from valgrind and gdb we think > >> this might be a bug in libthr. > > And how did you come to this conclusion ? > > > >> Backtrace from valgrind: > >> > https://phab.enlightenment.org/file/data/wlcvu7kmb5blxmgtnk2p/PHID-FILE-dimurhxlz4tvytoxnfup/valgrind2.log > >> Backtrace from gdb: > >> > https://phab.enlightenment.org/file/data/zvbelqzjt4h3ppates6a/PHID-FILE-dsnaw3golsozpzlb7uqe/gdb2.log > >> > >> Have any one known what > >> /usr/src/lib/libthr/arch/amd64/amd64/_umtx_op_err.S:37 does? > > The gdb backtrace you posted reports that the SIGSEGV occured in the > > thread with lwp id 100363. According to the same log, innermost > > frame for the thread is in _op_blend_p_dp_mmx(), which is line 11 > > in the file src/lib/evas/common/./evas_op_blend/op_blend_pixel_i386.c. > > > > umtx_op is the syscall which typically parks thread in the kernel while > > waiting for unblock. It appeared in the log because your process is > > multithreaded and that other thread slept waiting for an event. > > Backtrace from valgrind is completely different than backtrace from gdb. > How do you think that backtrace is more appropriate? > > Also I posted your reply on https://phab.enlightenment.org/T1330 this is > an answer: > > "As I stated before the gdb trace is at least messed up, especially as > the caller to the _op_blend_p_dp_mmx report a lot of impossible > information (all the parameter that int are marked variable: Cannot access memory at address 0x0> or ). I > fail to see how we could believe that nothing is messed up at that point > and that gdb report the problem at the right time." > > _______________________________________________ > freebsd-hackers@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org" > So, what's the status of this? I could lend a hand with debugging/testing this, although my gdb skills are far from expert.