Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752686AbYGXDrL (ORCPT ); Wed, 23 Jul 2008 23:47:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751232AbYGXDq4 (ORCPT ); Wed, 23 Jul 2008 23:46:56 -0400 Received: from netrider.rowland.org ([192.131.102.5]:3948 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1750997AbYGXDqz (ORCPT ); Wed, 23 Jul 2008 23:46:55 -0400 Date: Wed, 23 Jul 2008 23:46:55 -0400 (EDT) From: Alan Stern X-X-Sender: stern@netrider.rowland.org To: David Brownell cc: Ingo Molnar , Greg KH , , , "Rafael J. Wysocki" Subject: Re: [USB boot crash, -git] ecm_do_notify(), list_add corruption. prev->next should be next (ffff88003b8f82f8) In-Reply-To: <200807231637.33009.david-b@pacbell.net> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1192 Lines: 32 On Wed, 23 Jul 2008, David Brownell wrote: > So far, the fingers point at dummy_hcd... the merge doesn't > seem to have had problems, and the gadget driver had been > tested with four different peripheral controller drivers > (pre-merge). > But the link state notification (probably using ep-e) message > couldn't be queued (list_add_tail) because of this oopsing: > > > > usb0: qlen 10 > > g_cdc gadget: notify connect false > > list_add corruption. prev->next should be next (ffff88003b8f82f8), but was ffff88003b8f8e80. (prev=ffff88003b8f8e80). > > Now, prev->next == prev is expected here: that list of messages > should be empty. > > What's wrong is that head->prev != head, meaning something > trashed a dummy_hcd data structure. The problem could easily be that dummy-hcd simply isn't list-debugging-safe. I wouldn't be at all surprised if, for example, it adds a node to a list without initializing the node first. Alan Stern -- 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/