From owner-cvs-all@FreeBSD.ORG Fri Jan 21 18:09:17 2005 Return-Path: Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 76D1616A4CE; Fri, 21 Jan 2005 18:09:17 +0000 (GMT) Received: from repoman.freebsd.org (repoman.freebsd.org [216.136.204.115]) by mx1.FreeBSD.org (Postfix) with ESMTP id 5A61243D39; Fri, 21 Jan 2005 18:09:17 +0000 (GMT) (envelope-from bmilekic@FreeBSD.org) Received: from repoman.freebsd.org (localhost [127.0.0.1]) by repoman.freebsd.org (8.13.1/8.13.1) with ESMTP id j0LI9H1F092620; Fri, 21 Jan 2005 18:09:17 GMT (envelope-from bmilekic@repoman.freebsd.org) Received: (from bmilekic@localhost) by repoman.freebsd.org (8.13.1/8.13.1/Submit) id j0LI9Hh3092619; Fri, 21 Jan 2005 18:09:17 GMT (envelope-from bmilekic) Message-Id: <200501211809.j0LI9Hh3092619@repoman.freebsd.org> From: Bosko Milekic Date: Fri, 21 Jan 2005 18:09:17 +0000 (UTC) To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org X-FreeBSD-CVS-Branch: HEAD Subject: cvs commit: src/sys/conf NOTES files options src/sys/kern kern_malloc.c src/sys/vm memguard.c memguard.h X-BeenThere: cvs-all@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the entire tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 21 Jan 2005 18:09:17 -0000 bmilekic 2005-01-21 18:09:17 UTC FreeBSD src repository Modified files: sys/conf NOTES files options sys/kern kern_malloc.c Added files: sys/vm memguard.c memguard.h Log: Bring in MemGuard, a very simple and small replacement allocator designed to help detect tamper-after-free scenarios, a problem more and more common and likely with multithreaded kernels where race conditions are more prevalent. Currently MemGuard can only take over malloc()/realloc()/free() for particular (a) malloc type(s) and the code brought in with this change manually instruments it to take over M_SUBPROC allocations as an example. If you are planning to use it, for now you must: 1) Put "options DEBUG_MEMGUARD" in your kernel config. 2) Edit src/sys/kern/kern_malloc.c manually, look for "XXX CHANGEME" and replace the M_SUBPROC comparison with the appropriate malloc type (this might require additional but small/simple code modification if, say, the malloc type is declared out of scope). 3) Build and install your kernel. Tune vm.memguard_divisor boot-time tunable which is used to scale how much of kmem_map you want to allott for MemGuard's use. The default is 10, so kmem_size/10. ToDo: 1) Bring in a memguard(9) man page. 2) Better instrumentation (e.g., boot-time) of MemGuard taking over malloc types. 3) Teach UMA about MemGuard to allow MemGuard to override zone allocations too. 4) Improve MemGuard if necessary. This work is partly based on some old patches from Ian Dowse. Revision Changes Path 1.1296 +7 -0 src/sys/conf/NOTES 1.985 +1 -0 src/sys/conf/files 1.490 +3 -0 src/sys/conf/options 1.138 +53 -0 src/sys/kern/kern_malloc.c 1.1 +222 -0 src/sys/vm/memguard.c (new) 1.1 +31 -0 src/sys/vm/memguard.h (new)