From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 87772 invoked by alias); 9 Feb 2018 13:11:47 -0000 Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Received: (qmail 87763 invoked by uid 89); 9 Feb 2018 13:11:46 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-101.4 required=5.0 tests=AWL,BAYES_00,GOOD_FROM_CORINNA_CYGWIN,KAM_LAZY_DOMAIN_SECURITY,KAM_NUMSUBJECT,RCVD_IN_DNSWL_LOW,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy=downwards, Apart, reserved X-HELO: drew.franken.de Received: from mail-n.franken.de (HELO drew.franken.de) (193.175.24.27) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 09 Feb 2018 13:11:45 +0000 Received: from aqua.hirmke.de (aquarius.franken.de [193.175.24.89]) (Authenticated sender: aquarius) by mail-n.franken.de (Postfix) with ESMTPSA id E0D10721E280C for ; Fri, 9 Feb 2018 14:11:41 +0100 (CET) Received: from calimero.vinschen.de (calimero.vinschen.de [192.168.129.6]) by aqua.hirmke.de (Postfix) with ESMTP id 98F735E038F for ; Fri, 9 Feb 2018 14:11:41 +0100 (CET) Received: by calimero.vinschen.de (Postfix, from userid 500) id 83610A80865; Fri, 9 Feb 2018 14:11:41 +0100 (CET) Date: Fri, 09 Feb 2018 13:11:00 -0000 From: Corinna Vinschen To: cygwin@cygwin.com Subject: Re: Regression for OCaml introduced by rebase 4.4.4 Message-ID: <20180209131141.GL30794@calimero.vinschen.de> Reply-To: cygwin@cygwin.com Mail-Followup-To: cygwin@cygwin.com References: <000001d3a0d2$9f604860$de20d920$@cl.cam.ac.uk> <20180208151549.GA32555@calimero.vinschen.de> <20180209114048.GK30794@calimero.vinschen.de> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="0z5c7mBtSy1wdr4F" Content-Disposition: inline In-Reply-To: <20180209114048.GK30794@calimero.vinschen.de> User-Agent: Mutt/1.9.1 (2017-09-22) X-SW-Source: 2018-02/txt/msg00097.txt.bz2 --0z5c7mBtSy1wdr4F Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Content-length: 2463 On Feb 9 12:40, Corinna Vinschen wrote: > On Feb 9 11:29, David Allsopp wrote: > > > Apart from that, not only Cygwin DLLs but also the Windows system DLLs > > > are all loaded and relocated to the area beyond 0x1:80000000, so > > > relocation beyond the 32 bit address space is no generic problem in > > > Windows. Why isn't that possible in FlexDLL? I don't understand thi= s. > > > To me this looks like a bug in FlexDLL, not a requirement to let cert= ain > > > DLLs slip through the cracks. > >=20 > > There's a more full explanation of what and why for flexdll here: > > https://github.com/alainfrisch/flexdll/blob/master/README.md. I > > believe it's not unrelated to some of the black magic going on in > > Cygwin's autoload.cc, but without (at least at the moment), quite as > > much self-modifying code. > > [...] > > I guess one can argue over whether that's a bug or a limitation, but > > the problem we face is that we can engineer it so that our DLLs and > > executables are within a 2GB range (having looked again at this in > > even more detail, we could just as readily do this with addresses > > > 0x200000000), but we still run the risk of rebase messing up the DLLs. > >=20 > > However, we'll scratch our heads some more on possible alternative > > solutions, since having a flag for DLLs which says "keep us within a > > 2GB range somewhere" sounds even more less likely to get merged than > > my previous suggestion. >=20 > Two points: >=20 > - You are aware that the main executable of 64 bit Cygwin processes are > loaded to 0x1:00400000, right? The 2 GB offset problem is already > imminent. ...and you must not use the 0x0:80000000 - 0x1:00000000 area because that's reserved for thread stacks. To clarify, the full layout requirements: - 0x0:00000000 - 0x0:80000000 Windows - 0x0:80000000 - 0x1:00000000 Cygwin pthreads (including main thread) - 0x1:00000000 - 0x1:80000000 Executable - 0x1:80000000 - 0x2:00000000 Cygwin DLL - 0x2:00000000 - 0x4:00000000 Rebased DLLs - 0x4:00000000 - 0x6:00000000 Non-rebased DLLs (hashed default addresses generated by binutils ld with -auto-image-based (default on Cygwin)) - 0x6:00000000 Start Address Heap, growing upwards - 0x8:00000000 - 0x700:00000000 Mmaps, allocated downwards - 0x700:00000000 and beyond Windows Corinna --=20 Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Maintainer cygwin AT cygwin DOT com Red Hat --0z5c7mBtSy1wdr4F Content-Type: application/pgp-signature; name="signature.asc" Content-length: 833 -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEoVYPmneWZnwT6kwF9TYGna5ET6AFAlp9ng0ACgkQ9TYGna5E T6Bifg//b2ak7vvqei7/fQLHkpRe1nTVK+z1nenZTlWEqutH0UG7L2oqOqnZy/od dmVaTPKCSGMWfvwrRNsG5C2WLBMT64k5S4XZcmToXEaaq9xrHF08Xh6z00/KPzSZ reayRA+omVzP4aGFOIU7vkAwmjr3Dnqw8K3c2zdn2r6lbREiQp6NdzvtH/X7iGds NEVhJKqxwiOepze9KNII7TfgyGINTsRxVB59yjU2ktfvK64f99IE5wMI2WaTZjFr gKbQCJVLcd32VQGAXeWKec8JY5vte0wLjrAjHt3By2IdDlbs7h2P+uNn2NSGo9R9 4oslK4PZ6iYCUXguHMkGWCwC7mYTbN/byJ8MdkdpWiUvAFLTCiE7OVtrlYrZ1dSl u06bHaQyiCTZIbdyDc3h68SNs9UutyWE3jNF4uCEqARh3PhQvTC8N0UVv/g603Qq p5v5kvjVyG0zrJH++0ODaDHDYRu3k5fCI5n2aH+JCNnWdBSKMO9953SNZDK7+GAb A9RAdQWAV6IFPC+aBEceU/PsY44S4beLI7HS9LSKqOckd4QGWf6BH9/j1MJ/D5Vl 5y9gQrJq1UxFhemkFPHr/WtWgJNTeXyksI2diz3YuLAc8WOYwRXVHn3UjRMMZuRi 4MbWiwwIQ0U8T3WCGx4783Xv2ApLHtZBQFOHO9+fi+IiBPi+uco= =xbKs -----END PGP SIGNATURE----- --0z5c7mBtSy1wdr4F--