From owner-svn-src-all@FreeBSD.ORG  Tue Aug 25 16:59:55 2009
Return-Path: <owner-svn-src-all@FreeBSD.ORG>
Delivered-To: svn-src-all@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id A9DB81065690;
	Tue, 25 Aug 2009 16:59:55 +0000 (UTC)
	(envelope-from thompsa@FreeBSD.org)
Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:4f8:fff6::2c])
	by mx1.freebsd.org (Postfix) with ESMTP id 98ECD8FC39;
	Tue, 25 Aug 2009 16:59:55 +0000 (UTC)
Received: from svn.freebsd.org (localhost [127.0.0.1])
	by svn.freebsd.org (8.14.3/8.14.3) with ESMTP id n7PGxtuu034086;
	Tue, 25 Aug 2009 16:59:55 GMT (envelope-from thompsa@svn.freebsd.org)
Received: (from thompsa@localhost)
	by svn.freebsd.org (8.14.3/8.14.3/Submit) id n7PGxtsq034084;
	Tue, 25 Aug 2009 16:59:55 GMT (envelope-from thompsa@svn.freebsd.org)
Message-Id: <200908251659.n7PGxtsq034084@svn.freebsd.org>
From: Andrew Thompson <thompsa@FreeBSD.org>
Date: Tue, 25 Aug 2009 16:59:55 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
	svn-src-head@freebsd.org
X-SVN-Group: head
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Cc: 
Subject: svn commit: r196547 - head/sys/dev/usb
X-BeenThere: svn-src-all@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: "SVN commit messages for the entire src tree \(except for &quot;
	user&quot; and &quot; projects&quot; \)" <svn-src-all.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-all>,
	<mailto:svn-src-all-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-all>
List-Post: <mailto:svn-src-all@freebsd.org>
List-Help: <mailto:svn-src-all-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-all>,
	<mailto:svn-src-all-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 25 Aug 2009 16:59:55 -0000

Author: thompsa
Date: Tue Aug 25 16:59:55 2009
New Revision: 196547
URL: http://svn.freebsd.org/changeset/base/196547

Log:
  It is possible for all the kthreads to exit (hci modules unloaded) which in
  turn ends our usb process. This means the proc pointer becomes invalid and will
  panic if a new kthread is added. Count the number of threads and clear the proc
  pointer on the last one.
  
  Suggested by:	julian
  MFC after:	3 days

Modified:
  head/sys/dev/usb/usb_process.c

Modified: head/sys/dev/usb/usb_process.c
==============================================================================
--- head/sys/dev/usb/usb_process.c	Tue Aug 25 16:56:33 2009	(r196546)
+++ head/sys/dev/usb/usb_process.c	Tue Aug 25 16:59:55 2009	(r196547)
@@ -64,6 +64,7 @@
 
 #if (__FreeBSD_version >= 800000)
 static struct proc *usbproc;
+static int usb_pcount;
 #define	USB_THREAD_CREATE(f, s, p, ...) \
 		kproc_kthread_add((f), (s), &usbproc, (p), RFHIGHPID, \
 		    0, "usb", __VA_ARGS__)
@@ -183,6 +184,11 @@ usb_process(void *arg)
 	up->up_ptr = NULL;
 	cv_signal(&up->up_cv);
 	mtx_unlock(up->up_mtx);
+#if (__FreeBSD_version >= 800000)
+	/* Clear the proc pointer if this is the last thread. */
+	if (--usb_pcount == 0)
+		usbproc = NULL;
+#endif
 
 	USB_THREAD_EXIT(0);
 }
@@ -218,6 +224,9 @@ usb_proc_create(struct usb_process *up, 
 		up->up_ptr = NULL;
 		goto error;
 	}
+#if (__FreeBSD_version >= 800000)
+	usb_pcount++;
+#endif
 	return (0);
 
 error: