From owner-freebsd-hackers Sun Oct 20 06:44:22 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id GAA19734 for hackers-outgoing; Sun, 20 Oct 1996 06:44:22 -0700 (PDT) Received: from critter.tfs.com (disn4.cybercity.dk [194.16.57.4]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id GAA19729 for ; Sun, 20 Oct 1996 06:44:17 -0700 (PDT) Received: from critter.tfs.com (localhost.tfs.com [127.0.0.1]) by critter.tfs.com (8.7.5/8.7.3) with ESMTP id PAA23863 for ; Sun, 20 Oct 1996 15:44:30 +0200 (MET DST) To: hackers@freebsd.org Subject: an easy way to help us improve -current Reply-to: phk@freebsd.org Date: Sun, 20 Oct 1996 15:44:29 +0200 Message-ID: <23861.845819069@critter.tfs.com> From: Poul-Henning Kamp Sender: owner-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk If you're looking for an easy way to help us improve FreeBSD, then here's one way you can help: There is undoubtedly still programs that mismanage memory allocated with malloc(3). Many of these will core dump when they make a mistake provided you have set the right options for phkmalloc. So if you don't mind a little bit of a slowdown, try this out: ln -sf AJ /etc/malloc.conf If you suddenly see a program print a warning and core-dump, then use the send-pr program to report the problem to us. Of course we will be doubly happy if you include a fix too :-) Most of these are easy bugs to find, so don't be afraid to take a stab at it. If you find the problem in software from one of our many ports you should direct the report to the original author of the program and the maintainer of the freebsd port. Please make sure that you include the fact that you set malloc.conf to "Junk Abort" somewhere in the PR you send. So what does this actually do ? The 'J' means that memory you get from malloc is always filled with "junk" before it is handed to you, and when you free memory back it will be filled with junk again. This of course slows things down, but not much actually. As default the byte value used for "junk" is 0xd0. There are only a few cases where a pointer 0xd0d0d0d0 is valid, and as integers go 3503345872 doesn't seem too common either, so programs generally choke really fast after they get hold of one of these. The 'A' means that any kind of trouble is reason for a core-dump. Happy hunting! -- Poul-Henning Kamp | phk@FreeBSD.ORG FreeBSD Core-team. http://www.freebsd.org/~phk | phk@login.dknet.dk Private mailbox. whois: [PHK] | phk@ref.tfs.com TRW Financial Systems, Inc. Future will arrive by its own means, progress not so.