From owner-cvs-src@FreeBSD.ORG  Mon Sep 19 14:33:46 2005
Return-Path: <owner-cvs-src@FreeBSD.ORG>
X-Original-To: cvs-src@freebsd.org
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 57FF716A420;
	Mon, 19 Sep 2005 14:33:46 +0000 (GMT) (envelope-from imp@bsdimp.com)
Received: from harmony.bsdimp.com (vc4-2-0-87.dsl.netrack.net [199.45.160.85])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 788DD43D45;
	Mon, 19 Sep 2005 14:33:45 +0000 (GMT) (envelope-from imp@bsdimp.com)
Received: from localhost (localhost.village.org [127.0.0.1] (may be forged))
	by harmony.bsdimp.com (8.13.3/8.13.3) with ESMTP id j8JEVbdD022903;
	Mon, 19 Sep 2005 08:31:37 -0600 (MDT) (envelope-from imp@bsdimp.com)
Date: Mon, 19 Sep 2005 08:31:46 -0600 (MDT)
Message-Id: <20050919.083146.105425670.imp@bsdimp.com>
To: ru@freebsd.org
From: "M. Warner Losh" <imp@bsdimp.com>
In-Reply-To: <20050919055028.GC65954@ip.net.ua>
References: <200509190310.j8J3ALgt095979@repoman.freebsd.org>
	<20050919055028.GC65954@ip.net.ua>
X-Mailer: Mew version 3.3 on Emacs 21.3 / Mule 5.0 (SAKAKI)
Mime-Version: 1.0
Content-Type: Text/Plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-2.0
	(harmony.bsdimp.com [127.0.0.1]);
	Mon, 19 Sep 2005 08:31:37 -0600 (MDT)
Cc: cvs-src@freebsd.org, src-committers@freebsd.org, cvs-all@freebsd.org
Subject: Re: cvs commit: src/sys/dev/an if_an.c src/sys/dev/arl
 if_arl_isa.c src/sys/dev/awi if_awi_pccard.c src/sys/dev/cm if_cm_isa.c
 src/sys/dev/cnw if_cnw.c src/sys/dev/cp if_cp.c src/sys/dev/cs if_cs.c
 src/sys/dev/ed if_ed.c src/sys/dev/em if_em.c ...
X-BeenThere: cvs-src@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: CVS commit messages for the src tree <cvs-src.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/cvs-src>,
	<mailto:cvs-src-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/cvs-src>
List-Post: <mailto:cvs-src@freebsd.org>
List-Help: <mailto:cvs-src-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/cvs-src>,
	<mailto:cvs-src-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 19 Sep 2005 14:33:46 -0000

In message: <20050919055028.GC65954@ip.net.ua>
            Ruslan Ermilov <ru@freebsd.org> writes:
: Hi,
: 
: On Mon, Sep 19, 2005 at 03:10:21AM +0000, Warner Losh wrote:
: > imp         2005-09-19 03:10:21 UTC
: > 
: >   FreeBSD src repository
: > 
: >   Modified files:
: >     sys/dev/an           if_an.c 
: [...]
: >     sys/dev/xe           if_xe_pccard.c 
: >   Log:
: >   Make sure that we call if_free(ifp) after bus_teardown_intr.  Since we
: >   could get an interrupt after we free the ifp, and the interrupt
: >   handler depended on the ifp being still alive, this could, in theory,
: >   cause a crash.  Eliminate this possibility by moving the if_free to
: >   after the bus_teardown_intr() call.
: >   
: I'm going into more details in my other reply to your ed(4) commit,
: but I'm pretty sure you're attacking a wrong problem here.  Most
: drivers don' assume and will behave badly (read: panic) if foo_intr()
: is called after foo_stop() (foo_stop() disables interrupts and
: usually frees some resources needed by code called from foo_intr()).
: A better fix that I had in mind (and that I think jhb@ has suggested)
: would be to return from foo_intr() quickly if IFF_DRV_RUNNING is not
: set.  Can you reproduce the problem that you mention on real hardware?

You can't test IFF_DRV_RUNNING in memory that's already been freed.

Warner