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Date: Tue, 21 Mar 2017 14:42:00 +0100
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: dlclose() vs fork()
Message-ID: <20170321134200.GA18800@calimero.vinschen.de>
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References: <1504e7ff-dd60-f55f-d00a-0a1ae5d5e034 AT asokolov DOT org>
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On Mar 21 09:03, Alexey Sokolov wrote:
> Hello,
> If the same DLL is dlopen()ed several times, dlclose() will actually
> unload the DLL only after the same number of calls to dlclose().
>=20
> This works fine in cygwin, until we add fork().
>=20
> It looks like in the child process the counters of inherited DLLs are
> set to 1, so the first dlclose() unloads it, causing segfault for
> subsequent access to the unloaded code.
> https://github.com/znc/znc/issues/1385#issuecomment-288014319 has a
> working minimal example of this behavior.

dlopen/dlclose reference counting was broken.  I applied a fix and
uploaded new dev snapshots to https://cygwin.com/snapshots/

I'm just building a 2.8.0-0.2 test release as well.


Please test.


Thanks,
Corinna

--=20
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

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