From mboxrd@z Thu Jan 1 00:00:00 1970 Path: main.gmane.org!not-for-mail From: Camm Maguire Newsgroups: gmane.emacs.devel,gmane.lisp.gcl.devel Subject: Re: `exec shield' test in configure too strict? Date: 07 Oct 2004 11:44:48 -0400 Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Message-ID: <54acuyfs7j.fsf@intech19.enhanced.com> References: <20041004212031.GB2219@fencepost> <01c4ab96$Blat.v2.2.2$19340460@zahav.net.il> <437506D2-178C-11D9-BCD2-000D93505B76@swipnet.se> NNTP-Posting-Host: deer.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: sea.gmane.org 1097163960 4755 80.91.229.6 (7 Oct 2004 15:46:00 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Thu, 7 Oct 2004 15:46:00 +0000 (UTC) Cc: Eli Zaretskii , emacs-devel@gnu.org, gcl-devel@gnu.org, miles@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Oct 07 17:45:47 2004 Return-path: Original-Received: from lists.gnu.org ([199.232.76.165]) by deer.gmane.org with esmtp (Exim 3.35 #1 (Debian)) id 1CFaSh-0006Fk-00 for ; Thu, 07 Oct 2004 17:45:47 +0200 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.33) id 1CFaZR-000218-JJ for ged-emacs-devel@m.gmane.org; Thu, 07 Oct 2004 11:52:45 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.33) id 1CFaZK-00020d-60 for emacs-devel@gnu.org; Thu, 07 Oct 2004 11:52:38 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.33) id 1CFaZJ-00020E-9H for emacs-devel@gnu.org; Thu, 07 Oct 2004 11:52:37 -0400 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.33) id 1CFaZJ-00020B-3w; Thu, 07 Oct 2004 11:52:37 -0400 Original-Received: from [66.134.96.17] (helo=intech19.enhanced.com) by monty-python.gnu.org with esmtp (Exim 4.34) id 1CFaRp-0001hk-Uc; Thu, 07 Oct 2004 11:44:54 -0400 Original-Received: from camm by intech19.enhanced.com with local (Exim 3.35 #1 (Debian)) id 1CFaRk-0001gH-00; Thu, 07 Oct 2004 11:44:48 -0400 Original-To: "Jan D." In-Reply-To: <437506D2-178C-11D9-BCD2-000D93505B76@swipnet.se> Original-Lines: 46 User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.2 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: main.gmane.org gmane.emacs.devel:28036 gmane.lisp.gcl.devel:4657 X-Report-Spam: http://spam.gmane.org/gmane.emacs.devel:28036 Greetings! "Jan D." writes: > >> I have checked in a test that runs a program and sees if the heap > >> start > >> address is random. > > > > Doesn't this harm cross-building Emacs? I always thought that running > > a test program at configure time should be avoided, and that tests > > that only compile or link programs should be peferred. > > When cross compiling the test obviously can not be run, so configure > assumes > that the heap start address is not random. Come to think of it, the old > test (checking /proc/sys/kernel/exec-shield) was worse, as it did not > handle > cross compiling. > GCL also checks for a randomized sbrk a configure time, and builds into main a personality switch followed by a re-exec to work around the fedora security issues. I'm hoping this avenue won't be going away soon, as I feel there are benefits to the current sbrk-expanding contiguous heap design of these systems. Don't know if there is any answer to the cross-compiling. Take care, > Jan D. > > > > _______________________________________________ > Emacs-devel mailing list > Emacs-devel@gnu.org > http://lists.gnu.org/mailman/listinfo/emacs-devel > > > -- Camm Maguire camm@enhanced.com ========================================================================== "The earth is but one country, and mankind its citizens." -- Baha'u'llah