From mboxrd@z Thu Jan 1 00:00:00 1970 Path: main.gmane.org!not-for-mail From: David PONCE Newsgroups: gmane.emacs.devel Subject: Re: Unable to bootstrap GNU Emacs 21.3 (SOLVED) Date: Mon, 27 Oct 2003 11:47:46 +0100 (CET) Sender: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Message-ID: <26751439.1067251666023.JavaMail.www@wwinf0203> Reply-To: david.ponce@wanadoo.fr NNTP-Posting-Host: deer.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 7bit X-Trace: sea.gmane.org 1067252007 21763 80.91.224.253 (27 Oct 2003 10:53:27 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Mon, 27 Oct 2003 10:53:27 +0000 (UTC) Original-X-From: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Mon Oct 27 11:53:25 2003 Return-path: Original-Received: from quimby.gnus.org ([80.91.224.244]) by deer.gmane.org with esmtp (Exim 3.35 #1 (Debian)) id 1AE501-0000S0-00 for ; Mon, 27 Oct 2003 11:53:25 +0100 Original-Received: from monty-python.gnu.org ([199.232.76.173]) by quimby.gnus.org with esmtp (Exim 3.35 #1 (Debian)) id 1AE501-0005BA-00 for ; Mon, 27 Oct 2003 11:53:25 +0100 Original-Received: from localhost ([127.0.0.1] helo=monty-python.gnu.org) by monty-python.gnu.org with esmtp (Exim 4.24) id 1AE4vN-0003Pd-Ab for emacs-devel@quimby.gnus.org; Mon, 27 Oct 2003 05:48:37 -0500 Original-Received: from list by monty-python.gnu.org with tmda-scanned (Exim 4.24) id 1AE4v6-0003PT-Oj for emacs-devel@gnu.org; Mon, 27 Oct 2003 05:48:20 -0500 Original-Received: from mail by monty-python.gnu.org with spam-scanned (Exim 4.24) id 1AE4uZ-00031A-UA for emacs-devel@gnu.org; Mon, 27 Oct 2003 05:48:19 -0500 Original-Received: from [193.252.22.29] (helo=mwinf0204.wanadoo.fr) by monty-python.gnu.org with esmtp (Exim 4.24) id 1AE4uZ-00030k-H8 for emacs-devel@gnu.org; Mon, 27 Oct 2003 05:47:47 -0500 Original-Received: from wwinf0203 (wwinf0203 [172.22.133.30]) by mwinf0204.wanadoo.fr (SMTP Server) with ESMTP id 0893DA00008B for ; Mon, 27 Oct 2003 11:47:46 +0100 (CET) Original-To: emacs-devel X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.2 Precedence: list List-Id: Emacs development discussions. List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Xref: main.gmane.org gmane.emacs.devel:17457 X-Report-Spam: http://spam.gmane.org/gmane.emacs.devel:17457 Hi All, To solve this annoying problem, I also posted a bug report on the Redhat Fedora mailing list. And I got an explanation on what happened and on how to solve the issue. I think it could be worth to note that somewhere, perhaps in the etc/PROBLEMS file. In fact, in recent Linux kernels, there is a new "Exec-shield" functionality: "[...] Exec-shield is a security-enhancing modification to the Linux kernel that makes large parts of specially-marked programs _ including their stack _ not executable. This can reduce the potential damage of some security holes. Exec-shield is related to the older "non-exec stack patch" but has the potential to provide greater protection. Exec-shield can also randomize the virtual memory addresses at which certain binaries are loaded. This randomized VM mapping makes it more difficult for a malicious application to improperly access code or data based on knowledge of the code or data's virtual address. [...] Exec-shield functionality is available only to binaries that have been built (and marked) using the toolchain (compiler, assembler, linker) available with Fedora [...]" The problem is that Exec-shield enables a different memory layout that breaks the emacs dumper. Notice that this potentially affects all versions of Emacs. On my system building both Emacs 21.3.1 and latest 21.3.50.1 failed with segfault on: temacs --batch --load loadup [dump|bootstrap] There are two solutions to build Emacs: - Turn off Exec-shield: echo 0 > /proc/sys/kernel/exec-shield - Temporarily disable Exec-shield while building Emacs, using the `setarch' command: setarch i386 ./configure ... setarch i386 make ... Hope this will help. David