From owner-freebsd-current@FreeBSD.ORG  Fri Jul 13 22:14:38 2007
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
X-Original-To: current@FreeBSD.org
Delivered-To: freebsd-current@FreeBSD.ORG
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
	by hub.freebsd.org (Postfix) with ESMTP id B2D4116A401;
	Fri, 13 Jul 2007 22:14:38 +0000 (UTC) (envelope-from imp@bsdimp.com)
Received: from harmony.bsdimp.com (bsdimp.com [199.45.160.85])
	by mx1.freebsd.org (Postfix) with ESMTP id 7337F13C481;
	Fri, 13 Jul 2007 22:14:38 +0000 (UTC) (envelope-from imp@bsdimp.com)
Received: from localhost (localhost [127.0.0.1])
	by harmony.bsdimp.com (8.13.8/8.13.4) with ESMTP id l6DMBqOK066616;
	Fri, 13 Jul 2007 16:11:52 -0600 (MDT) (envelope-from imp@bsdimp.com)
Date: Fri, 13 Jul 2007 16:11:45 -0600 (MDT)
Message-Id: <20070713.161145.1324584079.imp@bsdimp.com>
To: attilio@FreeBSD.org
From: "M. Warner Losh" <imp@bsdimp.com>
In-Reply-To: <46972B28.1010409@FreeBSD.org>
References: <46970DF7.3000803@elischer.org>
	<46972B28.1010409@FreeBSD.org>
X-Mailer: Mew version 5.2 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]);
	Fri, 13 Jul 2007 16:11:53 -0600 (MDT)
Cc: julian@elischer.org, current@FreeBSD.org
Subject: Re: crash in tty code in 6.1.. fixed since?
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>, 
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 13 Jul 2007 22:14:38 -0000

In message: <46972B28.1010409@FreeBSD.org>
            Attilio Rao <attilio@FreeBSD.org> writes:
: I think it has been fixed some months ago IIRC.
: The problem here, should be that if sx_slock() let thread sleep, Giant 
: is released before to sleep and tp->t_session can be accessed in racy way.
: Another nice side-effect about having tty Giant :)

I've been having crashes right and left in cblock code.  I've had good
luck converting it to using a mutext.  However, someone else was
telling me they had big problems going all the way and locking the
entire TTY subsystem.  The evidence is in p4...

Warner