From owner-freebsd-hackers Mon Aug 12 20:39:18 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id UAA12353 for hackers-outgoing; Mon, 12 Aug 1996 20:39:18 -0700 (PDT) Received: from genesis.atrad.adelaide.edu.au (genesis.atrad.adelaide.edu.au [129.127.96.120]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id UAA12346; Mon, 12 Aug 1996 20:39:10 -0700 (PDT) Received: from msmith@localhost by genesis.atrad.adelaide.edu.au (8.6.12/8.6.9) id NAA19491; Tue, 13 Aug 1996 13:24:06 +0930 From: Michael Smith Message-Id: <199608130354.NAA19491@genesis.atrad.adelaide.edu.au> Subject: Re: machine crashing, what panic: free means? To: lmcsato@lmc.ericsson.se (Samy Touati) Date: Tue, 13 Aug 1996 13:24:05 +0930 (CST) Cc: terry@lambert.org, gpalmer@FreeBSD.ORG, hackers@FreeBSD.ORG In-Reply-To: from "Samy Touati" at Aug 12, 96 10:41:26 pm MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk Samy Touati stands accused of saying: > > Reading symbols from kernel.debug...done. > (kgdb) exec-file /var/crash/kernel.1 > (kgdb) core-file /var/crash/vmcore.1 > IdlePTD 1c9000 > current pcb at 1b5ff8 > panic: free: multiple frees > #0 boot (howto=256) at ../../i386/i386/machdep.c:892 > 892 dumppcb.pcb_ptd = rcr3(); > (kgdb) where > #0 boot (howto=256) at ../../i386/i386/machdep.c:892 > #1 0xf0112a73 in panic (fmt=0xf010baa2 "free: multiple frees") > at ../../kern/subr_prf.c:124 > #2 0xf010bb83 in free (addr=0xf05c4b80, type=1) > at ../../kern/kern_malloc.c:337 > #3 0xf0138aca in pppstart (tp=0xf01b52e8) at ../../net/if_ppp.c:1042 > #4 0xf019ed7b in siopoll () at ../../i386/isa/sio.c:1554 > #5 0xf0187067 in doreti_swi () > #6 0xf018f25c in cpu_switch () > > > After browsing through the sources, it seems that the problem is related > to the sio port being saturated. It has nothing at all to do with that; the problem looks like it's to do with a corrupted mbuf chain. (1042 is near an MFREE() macro). There was a nasty buffer overflow bug in the ppp code in 2.1 that has subsequently been fixed. This may be your culprit. > Right now I'm using a 486DX 33, will a DX66 help? No. > I don't have 2.1.5 yet, does anybody knows if sio.c has been changed to > address this problem? sio.c has nothing to do with this. > I'm going to reduce the spped of the serial port to 112000 bauds and see > if this helps. It won't solve the basic problem. And you can't set a port to 112000. > Samy -- ]] Mike Smith, Software Engineer msmith@atrad.adelaide.edu.au [[ ]] Genesis Software genesis@atrad.adelaide.edu.au [[ ]] High-speed data acquisition and (GSM mobile) 0411-222-496 [[ ]] realtime instrument control (ph/fax) +61-8-267-3039 [[ ]] Collector of old Unix hardware. "Where are your PEZ?" The Tick [[