From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#18410: Use SAFE_ALLOCA etc. to avoid unbounded stack allocation. Date: Mon, 08 Sep 2014 05:35:28 +0300 Message-ID: <83wq9ec00f.fsf@gnu.org> References: <5409536B.5090201@cs.ucla.edu> <540C0741.8090900@cs.ucla.edu> <83bnqrcq7u.fsf@gnu.org> <540CC106.8040705@cs.ucla.edu> Reply-To: Eli Zaretskii NNTP-Posting-Host: plane.gmane.org X-Trace: ger.gmane.org 1410143785 27348 80.91.229.3 (8 Sep 2014 02:36:25 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Mon, 8 Sep 2014 02:36:25 +0000 (UTC) Cc: eggert@cs.ucla.edu, 18410@debbugs.gnu.org To: Stefan Monnier Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Mon Sep 08 04:36:17 2014 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1XQooS-0000bZ-CV for geb-bug-gnu-emacs@m.gmane.org; Mon, 08 Sep 2014 04:36:16 +0200 Original-Received: from localhost ([::1]:40305 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XQooR-0007I9-Np for geb-bug-gnu-emacs@m.gmane.org; Sun, 07 Sep 2014 22:36:15 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:48561) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XQooJ-0007HC-SE for bug-gnu-emacs@gnu.org; Sun, 07 Sep 2014 22:36:12 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XQooE-0004x1-MO for bug-gnu-emacs@gnu.org; Sun, 07 Sep 2014 22:36:07 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:41543) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XQooE-0004wx-Jb for bug-gnu-emacs@gnu.org; Sun, 07 Sep 2014 22:36:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.80) (envelope-from ) id 1XQooE-0000kW-4n for bug-gnu-emacs@gnu.org; Sun, 07 Sep 2014 22:36:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Mon, 08 Sep 2014 02:36:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 18410 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: patch Original-Received: via spool by 18410-submit@debbugs.gnu.org id=B18410.14101437322835 (code B ref 18410); Mon, 08 Sep 2014 02:36:02 +0000 Original-Received: (at 18410) by debbugs.gnu.org; 8 Sep 2014 02:35:32 +0000 Original-Received: from localhost ([127.0.0.1]:33107 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1XQonj-0000je-Tj for submit@debbugs.gnu.org; Sun, 07 Sep 2014 22:35:32 -0400 Original-Received: from mtaout25.012.net.il ([80.179.55.181]:48696) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1XQong-0000jP-OA for 18410@debbugs.gnu.org; Sun, 07 Sep 2014 22:35:30 -0400 Original-Received: from conversion-daemon.mtaout25.012.net.il by mtaout25.012.net.il (HyperSendmail v2007.08) id <0NBK00O009G30O00@mtaout25.012.net.il> for 18410@debbugs.gnu.org; Mon, 08 Sep 2014 05:29:51 +0300 (IDT) Original-Received: from HOME-C4E4A596F7 ([87.69.4.28]) by mtaout25.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0NBK00I9E9LRQY50@mtaout25.012.net.il>; Mon, 08 Sep 2014 05:29:51 +0300 (IDT) In-reply-to: X-012-Sender: halo1@inter.net.il X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.15 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 140.186.70.43 X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:93127 Archived-At: > From: Stefan Monnier > Cc: Eli Zaretskii , 18410@debbugs.gnu.org > Date: Sun, 07 Sep 2014 22:22:23 -0400 > > > Usually MAX_ALLOCA-related code falls back on malloc, and does not exit > > merely because a request was larger. callproc.c's child_setup function is > > MAX_ALLOCA is chosen small so that we can allocate several/many objects > of size MAX_ALLOCA. Whereas in this case, after this alloca we're not > expected to use up the stack much more (we're about to `exec' anyway, > right?). So MAX_ALLOCA is much too conservative for this case. Indeed, I agree. So I think we should increase the limit in callproc.c, especially if we are going to keep the exit with failed status when the limit is exceeded.