From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762583AbXIXQg5 (ORCPT ); Mon, 24 Sep 2007 12:36:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760793AbXIXQ1Q (ORCPT ); Mon, 24 Sep 2007 12:27:16 -0400 Received: from mga07.intel.com ([143.182.124.22]:44815 "EHLO azsmga101.ch.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1760282AbXIXQ1O (ORCPT ); Mon, 24 Sep 2007 12:27:14 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.20,292,1186383600"; d="scan'208";a="285538169" Date: Mon, 24 Sep 2007 09:26:52 -0700 From: Mark Gross To: lkml , usbdev Subject: Re: [patch] usb-skeleton leaking locks on open. Message-ID: <20070924162652.GA5227@linux.intel.com> Reply-To: mgross@linux.intel.com References: <20070924161822.GA4525@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070924161822.GA4525@linux.intel.com> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org forgot to CC greg ... On Mon, Sep 24, 2007 at 09:18:22AM -0700, Mark Gross wrote: > This weekend I was hacking around with a trivial USB driver for talking > to the boot load firmware of a USB Bit Whacker. It's running the > MicroChip Pic18 boot loader firmware and I'm putting together a flash > program for writing new FW to the thing. > > Anyway in my use of the usb-skeleton.c as my starting point I discovered > my test program was getting hung up after attempting to write a buffer. > The application and driver where hung in a way that required me to > reboot to get it to clean up so I could try again. > > It turned out the code path through skel_open can grap the driver's > io_mutex lock and forget to release it. > > The following patch fixes the problem for me. > > --mgross > > Signed-off-by: Mark Gross > > diff -urN -X linux-2.6.23-rc7/Documentation/dontdiff linux-2.6.23-rc7/drivers/usb/usb-skeleton.c linux-2.6.23-rc7-bugfix/drivers/usb/usb-skeleton.c > --- linux-2.6.23-rc7/drivers/usb/usb-skeleton.c 2007-09-24 08:57:54.000000000 -0700 > +++ linux-2.6.23-rc7-bugfix/drivers/usb/usb-skeleton.c 2007-09-24 09:01:43.000000000 -0700 > @@ -125,6 +125,7 @@ > > /* save our object in the file's private structure */ > file->private_data = dev; > + mutex_unlock(&dev->io_mutex); > > exit: > return retval; > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/