From owner-freebsd-hackers Mon Sep 24 16:23:10 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 3391437B40B for ; Mon, 24 Sep 2001 16:23:08 -0700 (PDT) Received: (from dillon@localhost) by earth.backplane.com (8.11.6/8.11.2) id f8ONMaT97469; Mon, 24 Sep 2001 16:22:36 -0700 (PDT) (envelope-from dillon) Date: Mon, 24 Sep 2001 16:22:36 -0700 (PDT) From: Matt Dillon Message-Id: <200109242322.f8ONMaT97469@earth.backplane.com> To: Ian Dowse Cc: Julian Elischer , hackers@freebsd.org Subject: Re: VM Corruption - stumped, anyone have any ideas? References: <200109250001.aa92227@salmon.maths.tcd.ie> 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 :>The pointers in the last few entries of the vm_page_buckets array got :>corrupted when an agument to a function that manipulated whatever was next :>in ram was 0, and it turned out that it was 0 because :> of some PTE flushing thing (you are the one that found it... remember?) : :I think I've also seen a few reports of programs exiting with :"Profiling timer expired" messages with 4.4. These can be caused :by stack overflows, since the p_timer[] array in struct pstats is :one of the things that I think lives below the per-process kernel :stack. I wonder if they are related? Stack overflows could result :in corruption of local variables, after which anything could happen. : :That said, hardware problems are still a possiblilty. : :Ian Hmm. Do we have a guard page at the base of the per process kernel stack? -Matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message