DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:reply-to:to:from:subject:message-id:date
	:mime-version:content-type:content-transfer-encoding; q=dns; s=
	default; b=idYpeVDL+HOhHLTnM5xO5MMUnLychgQEzDkzT0Rfu4SxK4V54iqMx
	2xPvAaQy2AmiLsz/sHZeYAbuHhgxSF5VAjDlPFukgMXMDXHALtXB4ylvUNX6OEhP
	Q34QLwJcMO2+P2p+/qWvZsEgSvpLQzN8pohOgzJ+8U+h1D+CyQB1rk=
Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm
Sender: cygwin-owner@cygwin.com
Mail-Followup-To: cygwin@cygwin.com
Reply-To: moss@cs.umass.edu
To: cygwin <cygwin@cygwin.com>
From: Eliot Moss <moss@cs.umass.edu>
Subject: Help debugging a dll issue
Message-ID: <b21c0ab1-341b-d6f5-915b-f73973b8079b@cs.umass.edu>
Date: Thu, 19 May 2016 22:54:29 -0400
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.1.0
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit

Dear Cygwin friends --

I am trying to get pypy to build under cygwin.  (It used to do so, but
has not been maintained.)  I am very close, but there is something quite
odd happening when trying to access the large dll that the system builds:
the first call into that dll goes wild and causes a segfault.  The issue
seems to lie with run-time linking, for I can use dlopen to open the dll
and then dlsym to look up the function, and I get the same bad address.
I see nothing wrong from nm and objdump.  The dll is about 70 million
bytes long, so I can't really post it, but if you want to have a crack
at this, we can find some mutually agreeable place and I can tell you
the entry point I am trying to access.

I have found that if I patch the indirection in the associated .exe file
to refer to the actual address of the function, then the program runs,
so it's just this one linkage that is not working (apparently).  Very
mysterious to me.

Regards -- Eliot Moss

--
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