From mboxrd@z Thu Jan 1 00:00:00 1970 From: ludo@gnu.org (Ludovic =?UTF-8?Q?Court=C3=A8s?=) Subject: bug#24703: Store references in 8-byte chunks in compiled code Date: Mon, 24 Oct 2016 22:18:00 +0200 Message-ID: <87insh1oxz.fsf@gnu.org> References: <87mvi5lzqu.fsf@netris.org> <87inssncln.fsf@netris.org> <8737jwnb1c.fsf@netris.org> <87r37gstf6.fsf_-_@netris.org> <87d1j0sl1l.fsf@netris.org> <87a8e4glot.fsf@gnu.org> <8f2024ad-13c1-d4b1-1541-c2a5bddcb403@etorok.net> <87h98bdvng.fsf@gnu.org> <87k2d6qqee.fsf@netris.org> <20161024194022.GA1772@jasmine> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:44881) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1byli7-0004yO-B1 for bug-guix@gnu.org; Mon, 24 Oct 2016 16:19:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1byli2-0005A5-Cd for bug-guix@gnu.org; Mon, 24 Oct 2016 16:19:07 -0400 Received: from debbugs.gnu.org ([208.118.235.43]:39568) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1byli2-00059z-8e for bug-guix@gnu.org; Mon, 24 Oct 2016 16:19:02 -0400 Sender: "Debbugs-submit" Resent-Message-ID: In-Reply-To: <20161024194022.GA1772@jasmine> (Leo Famulari's message of "Mon, 24 Oct 2016 15:40:22 -0400") List-Id: Bug reports for GNU Guix List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-guix-bounces+gcggb-bug-guix=m.gmane.org@gnu.org Sender: "bug-Guix" To: Leo Famulari Cc: 24703@debbugs.gnu.org Leo Famulari skribis: > On Mon, Oct 17, 2016 at 11:36:57PM -0400, Mark H Weaver wrote: >> I've been investigating another approach: to enhance our scanner and >> grafter to handle these 8-byte-chunked references. I believe it is >> feasible, but only if we abandon the ability to change the file names of >> grafts outside of the hash. The reason is that the hash portion of >> store references are surrounded by enough other known characters on both >> sides that the hash portion is almost always contained entirely within >> 8-byte chunks. >>=20 >> To be continued... > > Any progress? I built GCC 5.3 with the patch I posted just to notice that it had no effect (according to =E2=80=98ltrace=E2=80=99 it never goes through the getenv("NIX_STORE") call that the patch adds.) I plan to investigate further Real Soon. > If not, I think we should start making a list of packages affected by > the bug in order to prepare a -fno-builtin-strcpy branch. Yeah it would be nice to identify these packages. I=E2=80=99d prefer the GCC patch over -fno-builtin-strcpy because the latte= r is hacky and potentially misses the issue when it occurs with other builtins. Either way, we=E2=80=99ll have to rebuild a lot of things. Ludo=E2=80=99.