From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joseph Salisbury Subject: Re: [v3.11][Regression] HID: hyperv: convert alloc+memcpy to memdup Date: Wed, 25 Sep 2013 13:45:54 -0400 Message-ID: <52432152.3030100@canonical.com> References: <5237430B.5040009@canonical.com> <20130916203824.GP25896@mwanda> <52376ED9.5080208@canonical.com> <20130916210503.GQ25896@mwanda> <5237A5D5.8010006@canonical.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Jiri Kosina Cc: Dan Carpenter , thomas@m3y3r.de, list@osuosl.org, Haiyang Zhang , LKML , open@osuosl.org, HID CORE LAYER , devel@linuxdriverproject.org List-Id: linux-input@vger.kernel.org On 09/24/2013 05:29 AM, Jiri Kosina wrote: > On Mon, 16 Sep 2013, Joseph Salisbury wrote: > >>>> 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. > Did this please yield any useful result? > > Thanks, > After further testing reverting the following commit does in fact resolve the bug: commit b1a1442a23776756b254b69786848a94d92445ba Author: Jiri Kosina Date: Mon Jun 3 11:27:48 2013 +0200 HID: core: fix reporting of raw events Reverting this commit in v3.12-rc2 prevents the system from locking up, which happens when connecting a bluetooth trackpad. Jiri, do you think we should revert this patch, or is there some further debugging/data collecting you would like to do? Thanks, Joe