From mboxrd@z Thu Jan 1 00:00:00 1970 Path: main.gmane.org!not-for-mail From: Richard Stallman Newsgroups: gmane.emacs.devel Subject: Re: `exec shield' test in configure too strict? Date: Tue, 12 Oct 2004 04:56:54 -0400 Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Message-ID: References: <20041004212031.GB2219@fencepost> <01c4ab96$Blat.v2.2.2$19340460@zahav.net.il> <05038177-188D-11D9-821D-000D93505B76@swipnet.se> <416A60C2.50408@swipnet.se> Reply-To: rms@gnu.org NNTP-Posting-Host: deer.gmane.org X-Trace: sea.gmane.org 1097572121 13180 80.91.229.6 (12 Oct 2004 09:08:41 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Tue, 12 Oct 2004 09:08:41 +0000 (UTC) Cc: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Tue Oct 12 11:08:35 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 1CHIe2-0006Qi-00 for ; Tue, 12 Oct 2004 11:08:35 +0200 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.33) id 1CHIl1-0001JB-A3 for ged-emacs-devel@m.gmane.org; Tue, 12 Oct 2004 05:15:47 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.33) id 1CHIZz-0007vF-0V for emacs-devel@gnu.org; Tue, 12 Oct 2004 05:04:23 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.33) id 1CHIZx-0007uM-0C for emacs-devel@gnu.org; Tue, 12 Oct 2004 05:04:21 -0400 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.33) id 1CHIZw-0007sy-N1 for emacs-devel@gnu.org; Tue, 12 Oct 2004 05:04:20 -0400 Original-Received: from [199.232.76.164] (helo=fencepost.gnu.org) by monty-python.gnu.org with esmtp (Exim 4.34) id 1CHISl-0007sK-KH for emacs-devel@gnu.org; Tue, 12 Oct 2004 04:56:55 -0400 Original-Received: from rms by fencepost.gnu.org with local (Exim 4.34) id 1CHISk-0003NI-Iu; Tue, 12 Oct 2004 04:56:54 -0400 Original-To: "Jan D." In-reply-to: <416A60C2.50408@swipnet.se> (jan.h.d@swipnet.se) 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:28281 X-Report-Spam: http://spam.gmane.org/gmane.emacs.devel:28281 > Another idea: can `main' contain code to move its heap address to the > desired place, at startup? No, as the desired place is not a mapped memory region, you can not write there. How about mapping a memory region at the desired place, then putting the heap address there? I think this is the most reliable solution, since it doesn't depend on testing the configuration in advance. It will always be there when it is needed. But we could do as described by Camm Maguire, check if the heap is not at the correct place at temacs startup, and if it is not, call personality(LINUX32) and exec() temacs again. That also seems like a good method, perhaps better. It would require testing whether the symbols pertaining to personalites are developed, but that is a test done by compilation, so it should be unproblematical.