DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:from:to:subject:date:message-id:references
	:in-reply-to:content-type:content-id:content-transfer-encoding
	:mime-version; q=dns; s=default; b=JDGX5nifBE3DiaP99ZY+y/xzGJr+N
	FhQkVcwfMZ9bhdDBeASKjfz4Pai6nNdA3oi85YjsHOySzVo/BdjqhUg7N/OhUf/5
	7Ev18sVEpbmpFJGb1c87mQZg+KiB2ZOojkMvhQKfA72MF9x0Uk+MTFHxjpMDHCkI
	joQox/7qqEZC3E=
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
From: Ken Brown <kbrown AT cornell DOT edu>
To: "cygwin AT cygwin DOT com" <cygwin AT cygwin DOT com>
Subject: Re: program exit code, "at exit" handler and explicit close of shared objects
Date: Tue, 29 Oct 2019 15:30:57 +0000
Message-ID: <1805e95e-6733-7a73-56fe-8493389ae367@cornell.edu>
References: <a24efbf6-872e-1e5b-017a-b14c59d84550 AT roumenpetrov DOT info> <20754eea-2b5e-dbbb-6027-2643be062e41 AT cornell DOT edu>
In-Reply-To: <20754eea-2b5e-dbbb-6027-2643be062e41@cornell.edu>
user-agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0
received-spf: None (protection.outlook.com: cornell.edu does not designate permitted sender hosts)
Content-Type: text/plain; charset="Windows-1252"
Content-ID: <5E4CBEBA51B807429F2E7CA3DAFB5432 AT namprd04 DOT prod DOT outlook DOT com>
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-userprincipalname: v8Z84lOlmR0Dcqw6mLLZNa1jljfcDGWV/NH01fl1qZ+HB+EdXL9a30EilKYE9uEJDqOCmLVUEF5J2kp/fIoLKg==
X-IsSubscribed: yes
Content-Transfer-Encoding: 8bit
X-MIME-Autoconverted: from quoted-printable to 8bit by delorie.com id x9TFViD5006557

On 10/29/2019 10:53 AM, Ken Brown wrote:
> On 10/26/2019 11:07 AM, Roumen Petrov wrote:
>>
>> After additional tests (research) I was able to isolate issues to simple test
>> case. Please find attached "test-dlclose.c" and "Makefile".
>> First test is as is:
>>
>> $ make
>> cc -g -Wall -Wextra    test-dlclose.c   -o test-dlclose
>> ./test-dlclose
>> exit with code 33
>> make: [Makefile:4: all] Error 33 (ignored)
>>
>> For next test change test-dlclose.c to define DLCLOSE_ATEXIT ( s/#if 0/#if 1/ ):
>> $ make
>> cc -g -Wall -Wextra    test-dlclose.c   -o test-dlclose
>> ./test-dlclose
>> exit with code 33
> 
> I ran this second version of test-dlclose (with DLCLOSE_ATEXIT defined) under
> strace and got the following:
> 
> $ strace -o trace.out ./test-dlclose.exe
> exit with code 33
> Segmentation fault
> 
> The strace output ends with
> 
>      30   30143 [main] test-dlclose 847 write: 18 = write(1, 0x600061E20, 18)
> --- Process 33456 (pid: 847) unloaded DLL at 00000003e7930000
> --- Process 33456 (pid: 847), exception c0000005 at 00000003e7931080
> --- Process 33456 (pid: 847) thread 26088 exited with status 0xc0000005
> --- Process 33456 (pid: 847) thread 33544 exited with status 0xc0000005
> --- Process 33456 (pid: 847) thread 36020 exited with status 0xc0000005
> --- Process 33456 exited with status 0xc0000005
> 
> The address 00000003e7930000 seems to be in /usr/bin/cygz.dll, which is the DLL

Sorry, I meant to say 00000003e7931080; 00000003e7930000 is the start of cygz.dll.

> that got unloaded.  After installing zlib-debuginfo, I ran addr2line to see
> where the crash occurred, and this too crashed:
> 
> $ addr2line -C -f -i -p -e /usr/bin/cygz.dll 0x3e7931080
> Segmentation fault (core dumped)
> 
> That's as far as I've gotten.
> 
> Ken
> 
> --
> 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
> 

--
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