X-Recipient:	archive-cygwin AT delorie DOT com
DomainKey-Signature:	a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:subject:to:references:from:message-id:date
	:mime-version:in-reply-to:content-type
	:content-transfer-encoding; q=dns; s=default; b=x5qK8dD7FpD2I3iL
	29yKt004QpafJm5ivk12lVkqTumG+g6pKbiZxaJiVLxVwVDZhswStrkBK5oq4azl
	Xp1MQbgE0mpWVu2LS6kDmgSYwdoNfHjgv2SDK/OKHWkzuFAlY6lICIplm9KSr0Y7
	RWMCL5v1Kq7tMDQd1web9ynWr3c=
DKIM-Signature:	v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:subject:to:references:from:message-id:date
	:mime-version:in-reply-to:content-type
	:content-transfer-encoding; s=default; bh=cXT5QALH8nwnodZ1IazlER
	aDhs0=; b=uQYFPYD9mEI3rZ4iqkMW5z2PWLKH7jseBUEylTSoQG+vBkDEmZsDGE
	DJC+8DcJcx+lxKhJcvbNz0pHCSWT74J/x4SCauCcVX2p4tgrYmasPBogYtZCBBF9
	/ilIVME45hwxtLSAQpQ+VsjEGX3/UBdVgzl3zzHmM4j4Knf7+VLv0=
Mailing-List:	contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id:	<cygwin.cygwin.com>
List-Subscribe:	<mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive:	<http://sourceware.org/ml/cygwin/>
List-Post:	<mailto:cygwin AT cygwin DOT com>
List-Help:	<mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender:	cygwin-owner AT cygwin DOT com
Mail-Followup-To:	cygwin AT cygwin DOT com
Delivered-To:	mailing list cygwin AT cygwin DOT com
Authentication-Results:	sourceware.org; auth=none
X-Virus-Found:	No
X-Spam-SWARE-Status:	No, score=-2.2 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.2 spammy=todays, vmware, today's, VMware
X-HELO:	out2-smtp.messagingengine.com
Subject:	Re: [ANNOUNCEMENT] mesa 11.0.9-2
To:	cygwin AT cygwin DOT com
References:	<announce DOT 201602220900 DOT u1M90xBM023169 AT int-mx11 DOT intmail DOT prod DOT int DOT phx2 DOT redhat DOT com> <570D122B DOT 50307 AT gmail DOT com> <570DAFFA DOT 7020700 AT cygwin DOT com> <b8ee7d32-504d-27d8-51ab-547ea7a51968 AT dronecode DOT org DOT uk>
From:	Jon Turney <jon DOT turney AT dronecode DOT org DOT uk>
Message-ID:	<4311402a-fb7d-c68a-9cb3-954161a37e58@dronecode.org.uk>
Date:	Fri, 3 Jun 2016 18:56:09 +0100
User-Agent:	Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.1.1
MIME-Version:	1.0
In-Reply-To:	<b8ee7d32-504d-27d8-51ab-547ea7a51968@dronecode.org.uk>

On 31/05/2016 18:03, Jon Turney wrote:
> On 13/04/2016 03:33, Yaakov Selkowitz wrote:
>> On 2016-04-12 10:20, Marco Atzeri wrote:
>>> $ cd /usr/lib/mesa-demos
>>> $ ./quad-clip.exe
>>> GL_RENDERER   = Gallium 0.4 on llvmpipe (LLVM 3.7, 256 bits)
>>> GL_VERSION    = 3.0 Mesa 11.0.9
>>> GL_VENDOR     = VMware, Inc.
>>> Segmentation fault (core dumped)
>>
>> I can reproduce this on 32-bit but not 64-bit, and the same happens with
>> 11.1.2.  It may be an issue with LLVM 3.7 (11.0.9-1 was built with 3.5)
>> but without a useful backtrace it will be hard to pin down.
>
> gdb can successfully backtrace this, with today's cygwin snapshot.
>
> Both examples of the crash provided by Marco show very similar symptoms.
>
> Unfortunately, the backtrace stops at llvm_pipeline_generic() calling
> into some JIT-ed code.  The faulting is at an insertps instruction with
> what looks like a bogus absolute address.
>
> So I guess this some is an llvm issue, possibly with some address
> computation which doesn't give the right result on 32 bit?
>
>> # gdb ./quad-clip
>> [...]
>> (gdb) r
>> [...]
>> Program received signal SIGSEGV, Segmentation fault.
>> 0x7fdf00c1 in ?? ()
[...]
>> /usr/src/debug/mesa-demos-8.3.0-1/src/trivial/quad-clip.c:137
>> (gdb) disassemble 0x7fdf00b1,0x7fdf00d2
>> Dump of assembler code from 0x7fdf00b1 to 0x7fdf00d2:
>>    0x7fdf00b1:  insertps $0x10,0x4(%eax,%edi,1),%xmm0
>>    0x7fdf00b9:  insertps $0x20,0x8(%eax,%edi,1),%xmm0
>> => 0x7fdf00c1:  insertps $0x30,0xfffeff34,%xmm0
>>    0x7fdf00cb:  mov    (%esi),%eax
>>    0x7fdf00cd:  mul    %ecx

After staring this a bit more, I see that this is the offset to the data 
to load, apparently being used as an absolute address

This seems to be the case with other addresses in the JIT-ed code,  so 
perhaps there is some problem preventing relocations being applied...


--
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

- Raw text -