From owner-freebsd-hackers Mon Sep 24 19:41:20 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from earth.backplane.com (earth-nat-cw.backplane.com [208.161.114.67]) by hub.freebsd.org (Postfix) with ESMTP id 9B34137B41F for ; Mon, 24 Sep 2001 19:41:14 -0700 (PDT) Received: (from dillon@localhost) by earth.backplane.com (8.11.6/8.11.2) id f8P2f2p98637; Mon, 24 Sep 2001 19:41:02 -0700 (PDT) (envelope-from dillon) Date: Mon, 24 Sep 2001 19:41:02 -0700 (PDT) From: Matt Dillon Message-Id: <200109250241.f8P2f2p98637@earth.backplane.com> To: Peter Wemm Cc: Ian Dowse , Julian Elischer , hackers@FreeBSD.ORG Subject: Re: VM Corruption - stumped, anyone have any ideas? References: <20010925012743.43E583808@overcee.netplex.com.au> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG : :I did it as part of the KSE work in 5.x. It would be quite easy to do it :for 4.x as well, but it makes a.out coredumps problematic. : :Also, "options UPAGES=4" is a pretty good defensive measure. : :Cheers, :-Peter :-- :Peter Wemm - peter@FreeBSD.org; peter@yahoo-inc.com; peter@netplex.com.au Well, in 4.x: (kgdb) print p->p_addr $6 = (struct user *) 0xcb7b9000 (kgdb) print &p->p_addr->u_sigacts $7 = (struct sigacts *) 0xcb7b9260 (kgdb) print &p->p_addr->u_stats $8 = (struct pstats *) 0xcb7b9cd0 (kgdb) print &p->p_addr->u_kproc $9 = (struct kinfo_proc *) 0xcb7b9db0 (kgdb) print &p->p_addr->u_md $10 = (struct md_coredump *) 0xcb7ba1d0 (kgdb) print &p->p_addr->u_guard (my new field) $11 = (u_int32_t *) 0xcb7ba1d0 (kgdb) cb7b9000 start of kstack cb7ba1d4 end of struct user cb7bb000 top of kstack Leaving us 3628 bytes for the kernel stack. Something really weird is going on... I added u_guard to the end of the struct user structure and there are two or three processes hitting the guard immediately. All the rest are ok. I'm going to investigate further but this is very odd. Am I missing something about the UAREA? -Matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message