From owner-cvs-src@FreeBSD.ORG Mon Feb 16 17:37:28 2004 Return-Path: Delivered-To: cvs-src@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id DC3FD16A4CE for ; Mon, 16 Feb 2004 17:37:28 -0800 (PST) Received: from tx3.oucs.ox.ac.uk (tx3.oucs.ox.ac.uk [163.1.2.167]) by mx1.FreeBSD.org (Postfix) with ESMTP id B50B143D31 for ; Mon, 16 Feb 2004 17:37:28 -0800 (PST) (envelope-from colin.percival@wadham.ox.ac.uk) Received: from scan3.oucs.ox.ac.uk ([163.1.2.166] helo=localhost) by tx3.oucs.ox.ac.uk with esmtp (Exim 4.24) id 1AsuAx-0005C4-PU for cvs-src@FreeBSD.org; Tue, 17 Feb 2004 01:37:27 +0000 Received: from rx3.oucs.ox.ac.uk ([163.1.2.165]) by localhost (scan3.oucs.ox.ac.uk [163.1.2.166]) (amavisd-new, port 25) with ESMTP id 19470-09 for ; Tue, 17 Feb 2004 01:37:27 +0000 (GMT) Received: from gateway.wadham.ox.ac.uk ([163.1.161.253]) by rx3.oucs.ox.ac.uk with smtp (Exim 4.24) id 1AsuAx-0005C0-C4 for cvs-src@FreeBSD.org; Tue, 17 Feb 2004 01:37:27 +0000 Received: (qmail 4263 invoked by uid 0); 17 Feb 2004 01:37:26 -0000 Received: from colin.percival@wadham.ox.ac.uk by gateway by uid 71 with qmail-scanner-1.16 (sweep: 2.14/3.71. spamassassin: 2.53. Clear:. Processed in 1.558542 secs); 17 Feb 2004 01:37:26 -0000 X-Qmail-Scanner-Mail-From: colin.percival@wadham.ox.ac.uk via gateway X-Qmail-Scanner: 1.16 (Clear:. Processed in 1.558542 secs) Received: from dhcp1131.wadham.ox.ac.uk (HELO piii600.wadham.ox.ac.uk) (163.1.161.131) by gateway.wadham.ox.ac.uk with SMTP; 17 Feb 2004 01:37:24 -0000 Message-Id: <6.0.1.1.1.20040217013021.03a47a30@imap.sfu.ca> X-Sender: cperciva@imap.sfu.ca (Unverified) X-Mailer: QUALCOMM Windows Eudora Version 6.0.1.1 Date: Tue, 17 Feb 2004 01:37:22 +0000 To: Maxime Henrion From: Colin Percival In-Reply-To: <20040216210503.GC35475@elvis.mu.org> References: <28938.1076959003@critter.freebsd.dk> <20040216210503.GC35475@elvis.mu.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed cc: src-committers@FreeBSD.org cc: cvs-src@FreeBSD.org cc: Scott Long cc: cvs-all@FreeBSD.org cc: Poul-Henning Kamp cc: Robert Watson cc: Dag-Erling Smorgrav Subject: Re: cvs commit: src/sys/vm vm_kern.c X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 17 Feb 2004 01:37:29 -0000 At 21:05 16/02/2004, Maxime Henrion wrote: >I find it very convenient to have a flag to tell malloc() to try as hard >as it can to allocate the memory without crashing on us. Is this really good enough? When I was routinely running my system out of kernel memory by using a large malloc backed md(4), the panic never came from a failed allocation in the md code; rather, md would use up all the available memory, and then some other kernel call (which needed only some small amount of memory) would panic. From a security point of view, I can't see how there's any alternative to using a user-allocated buffer for such requests. Colin Percival