From owner-freebsd-hackers@FreeBSD.ORG Sat Jun 28 01:59:04 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 C9E887B6 for ; Sat, 28 Jun 2014 01:59:04 +0000 (UTC) Received: from mo69.mail-out.ovh.net (10.mo69.mail-out.ovh.net [46.105.73.241]) by mx1.freebsd.org (Postfix) with ESMTP id 897D4242A for ; Sat, 28 Jun 2014 01:59:03 +0000 (UTC) Received: from mail417.ha.ovh.net (gw6.ovh.net [213.251.189.206]) by mo69.mail-out.ovh.net (Postfix) with SMTP id 43321FF9D0D for ; Sat, 28 Jun 2014 00:21:03 +0200 (CEST) Received: from b0.ovh.net (HELO queueout) (213.186.33.50) by b0.ovh.net with SMTP; 28 Jun 2014 00:20:36 +0200 Received: from user-164-127-95-230.play-internet.pl (HELO starpad.nine) (grzegorz@blach.pl@164.127.95.230) by ns0.ovh.net with SMTP; 28 Jun 2014 00:20:34 +0200 Message-ID: <53ADEE4C.2080804@blach.pl> Date: Sat, 28 Jun 2014 00:21:00 +0200 From: Grzegorz Blach User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Konstantin Belousov Subject: Re: Crash probably in libthr References: <53A95016.3090901@blach.pl> <20140624205420.GZ93733@kib.kiev.ua> In-Reply-To: <20140624205420.GZ93733@kib.kiev.ua> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Ovh-Tracer-Id: 17163781131439136448 X-Ovh-Remote: 164.127.95.230 (user-164-127-95-230.play-internet.pl) X-Ovh-Local: 213.186.33.20 (ns0.ovh.net) X-OVH-SPAMSTATE: OK X-OVH-SPAMSCORE: 0 X-OVH-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrfeejfedrtdejucetufdoteggodetrfcurfhrohhfihhlvgemucfqggfjnecuuegrihhlohhuthemuceftddtnecu X-Spam-Check: DONE|U 0.5/N X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: 0 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrfeejfedrtdejucetufdoteggodetrfcurfhrohhfihhlvgemucfqggfjnecuuegrihhlohhuthemuceftddtnecu X-Mailman-Approved-At: Sat, 28 Jun 2014 03:04:54 +0000 Cc: freebsd-hackers@freebsd.org X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 28 Jun 2014 01:59:04 -0000 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 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."