Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755676Ab0DVQ71 (ORCPT ); Thu, 22 Apr 2010 12:59:27 -0400 Received: from relay.ihostexchange.net ([66.46.182.52]:28741 "EHLO relay.ihostexchange.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755512Ab0DVQ70 (ORCPT ); Thu, 22 Apr 2010 12:59:26 -0400 X-Greylist: delayed 306 seconds by postgrey-1.27 at vger.kernel.org; Thu, 22 Apr 2010 12:59:26 EDT Message-ID: <4BD07F2A.8080808@VirtualLogix.com> Date: Thu, 22 Apr 2010 18:54:02 +0200 From: Eric Lescouet Reply-To: Eric Lescouet User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.7) Gecko/20100120 Fedora/3.0.1-1.fc11 Thunderbird/3.0.1 MIME-Version: 1.0 To: "linux-kernel@vger.kernel.org" , Greg Kroah-Hartman CC: "usbip-devel@lists.sourceforge.net" Subject: [PATCH]: Fix deadlock in USBIP driver (staging), linux-2.6.34-rc5 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1536 Lines: 42 Hi, When detaching a port from the client side (usbip --detach 0), the event thread, on the server side, is going to deadlock. The "eh" server thread is getting USBIP_EH_RESET event and calls: -> stub_device_reset() -> usb_reset_device() the USB framework is then calling back _in the same "eh" thread_ : -> stub_disconnect() -> usbip_stop_eh() -> wait_for_completion() the "eh" thread is being asleep forever, waiting for its own completion. The patch checks if "eh" is the current thread, in usbip_stop_eh(). Please Cc me in reply, I'm not in the list. b.r. ------------------ diff -Nur linux-2.6.34-rc5/drivers/staging/usbip/usbip_event.c linux-2.6.34-rc5.new/drivers/staging/usbip/usbip_event.c --- linux-2.6.34-rc5/drivers/staging/usbip/usbip_event.c 2010-04-20 01:29:56.000000000 +0200 +++ linux-2.6.34-rc5.new/drivers/staging/usbip/usbip_event.c 2010-04-22 17:07:36.249588273 +0200 @@ -116,6 +116,13 @@ void usbip_stop_eh(struct usbip_device *ud) { struct usbip_task *eh = &ud->eh; + int i_am_eh; + + lock_kernel(); + i_am_eh = (eh->thread == current); + unlock_kernel(); + if (i_am_eh) + return; /* do not wait for myself */ wait_for_completion(&eh->thread_done); usbip_dbg_eh("usbip_eh has finished\n"); -- 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/