From owner-freebsd-hackers@FreeBSD.ORG  Mon Jun 25 19:31:49 2007
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
X-Original-To: freebsd-hackers@freebsd.org
Delivered-To: freebsd-hackers@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
	by hub.freebsd.org (Postfix) with ESMTP id CED4D16A47B;
	Mon, 25 Jun 2007 19:31:49 +0000 (UTC)
	(envelope-from danny@cs.huji.ac.il)
Received: from cs1.cs.huji.ac.il (cs1.cs.huji.ac.il [132.65.16.10])
	by mx1.freebsd.org (Postfix) with ESMTP id 8126B13C44B;
	Mon, 25 Jun 2007 19:31:49 +0000 (UTC)
	(envelope-from danny@cs.huji.ac.il)
Received: from pampa.cs.huji.ac.il ([132.65.80.32])
	by cs1.cs.huji.ac.il with esmtp
	id 1I2uHq-000DkP-E7; Mon, 25 Jun 2007 22:31:46 +0300
X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.2
To: Julian Elischer <julian@elischer.org>
In-reply-to: Your message of Mon, 25 Jun 2007 12:20:06 -0700 .
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Date: Mon, 25 Jun 2007 22:31:46 +0300
From: Danny Braniss <danny@cs.huji.ac.il>
Message-ID: <E1I2uHq-000DkP-E7@cs1.cs.huji.ac.il>
Cc: freebsd-hackers@freebsd.org, freebsd-current@FreeBSD.ORG
Subject: Re: KSE was Re: open/close/ioctl api change? 
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
	<freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>, 
	<mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 25 Jun 2007 19:31:50 -0000

> Danny Braniss wrote:
> >> Danny Braniss wrote:
> >>>> actually it's the struct thread *tp where my problems are,
> >>>> this code works fine under 6.2, and did work till some days ago under current.
> >>>>
> >>>> static int
> >>>> iscsi_open(struct cdev *dev, int flags, int otype, struct thread *td)
> >>>> {
> >>>> ...
> >>>> 	debug(3, "td->td_proc=%p", td->td_proc);
> >>>> 	debug(3, "td->td_proc->p_pid=%d pid=%d",
> >>>> 	   td->td_proc->p_pid, curproc->p_pid);
> >>>> ...
> >>>>
> >>>> the first debug prints out td->td_proc=0 and the next one panics.
> >>> found the problem, 'option KSE' which is defined now in DEFAULTS,
> >>> and i'm compiling a module! which does not include DEFAULTS!
> >>>
> >> even so it shouldnt' happen..
> >>
> > why? I'm compiling outside the source tree.
> > I agree that it shouldn't, specially, since it took me a long
> > time to find the problem :-), but I can't see how config options
> > can be exported. Unless, the make file is made aware of the KERNCONF file.
> 
> there should be no place in the source at any time where a thread 
> that is not on the free list could have a td_proc of NULL.
> it doesn't matter about where a module came from etc.. the fact that
> it happened is a bug somewhere.

Julian,
I compiled the kernel, and DEFAULT contains
	option KSE
then I compiled the loadable module, outside the source tree, where
KSE is not defined, the thread structure has #ifdef KSE ... #endif
so my module sees a different thread structure. The real arguable issue
is that the #ifdef KSE is below the *td_proc, So td->proc should not
be affected by the ifdef. BTW, it was NULL when compiled for i386,
garbage for amd64.

	danny