Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751741Ab3IQAo1 (ORCPT ); Mon, 16 Sep 2013 20:44:27 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:44339 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751697Ab3IQAoX (ORCPT ); Mon, 16 Sep 2013 20:44:23 -0400 Message-ID: <5237A5D5.8010006@canonical.com> Date: Mon, 16 Sep 2013 20:44:05 -0400 From: Joseph Salisbury User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130803 Thunderbird/17.0.8 MIME-Version: 1.0 To: Dan Carpenter CC: thomas@m3y3r.de, Jiri Kosina , list@osuosl.org, Haiyang Zhang , LKML , open@osuosl.org, HID CORE LAYER , devel@linuxdriverproject.org Subject: Re: [v3.11][Regression] HID: hyperv: convert alloc+memcpy to memdup References: <5237430B.5040009@canonical.com> <20130916203824.GP25896@mwanda> <52376ED9.5080208@canonical.com> <20130916210503.GQ25896@mwanda> In-Reply-To: <20130916210503.GQ25896@mwanda> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2059 Lines: 45 On 09/16/2013 05:05 PM, Dan Carpenter wrote: > On Mon, Sep 16, 2013 at 04:49:29PM -0400, Joseph Salisbury wrote: >> On 09/16/2013 04:38 PM, Dan Carpenter wrote: >>> On Mon, Sep 16, 2013 at 01:42:35PM -0400, Joseph Salisbury wrote: >>>> Reverting the patch changes the driver back to useing kzalloc() and >>>> memcpy() instead of kmemdup. Doing so has uncovered another bug, which >>>> causes an oops on memcpy()[1]. We are in the process of bisecting that >>>> one now and will provide the results. >>> The two bugs are the same it's that the code has shifted a little. Mark >>> the commit as buggy and continue with the git bisect. >>> >>> regards, >>> dan carpenter >> Can you explain a little further? Mark commit a4a23f6 as bad? An >> initial bisect already reported that was the first bad commit, so it >> can't be marked bad. The oops on memcpy() happens after commit a4a23f6 >> is reverted. The oops on memcpy() did not happen before a4a23f6 was >> committed, so I assume this new oops was introduced by a change later. >> >> Right now I'm bisecting down the oops on memcpy() by updating the bisect >> with good or bad, depending if the test kernel hit the oops. I then >> revert a4a23f6, so that revert is the HEAD of the tree each time before >> building the kernel again(As long as the commit spit out by bisect is >> after when a4a23f6 was introduced). > Yep. Please continue bisecting the memcpy() oops. > > kmemdup() is just a kzalloc() followed by a memcpy(). When we split it > apart by reverting the patch then we would expect the oops to move to > the memcpy() part. Somehow "desc" is a bogus pointer, but I don't > immediately see how that is possible. > > regards, > dan carpenter Thanks for the details. We'll continue the bisect and let you know how it goes. Thanks again, Joe -- 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/