From: "Justin P. Mattock" <justinmattock@gmail.com>
To: Florian Mickler <florian@mickler.org>
Cc: linux-kernel@vger.kernel.org,
Steven Rostedt <rostedt@goodmis.org>,
Manjunatha Halli <manjunatha_halli@ti.com>,
Mauro Carvalho Chehab <mchehab@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Greg Kroah-Hartman <gregkh@suse.de>
Subject: Re: [BUG] NULL pointer dereference in dev_get_drvdata
Date: Thu, 31 Mar 2011 08:41:53 -0700 [thread overview]
Message-ID: <4D94A0C1.1060608@gmail.com> (raw)
In-Reply-To: <20110331111659.0c77abbe@schatten.dmk.lab>
On 03/31/2011 02:16 AM, Florian Mickler wrote:
> On Wed, 30 Mar 2011 08:47:25 -0700
> "Justin P. Mattock"<justinmattock@gmail.com> wrote:
>
>
>>
>> strange thing with this, is one instance my screen went black, then
>> something similar showed up on screen but then the screen kind of went
>> back to normal(was able to move the mouse, but most of everything was
>> frozen), another instance was shutting down the system pics are here:
>>
>> http://www.flickr.com/photos/44066293@N08/5573957179/
>> http://www.flickr.com/photos/44066293@N08/5574543648/
>> (not the best camara used)
>>
>> this does not fire off all the time, but it does.
>> (I will keep my eye out with this one).
>>
>> Justin P. Mattock
>>
>
> even with that resolution (240x320, that's a joke, right? do I need to
> login or something like that?) I see that your stacktrace is
> different.
yeah... the iphone is only capable of so good of a picture.
>
> The stacktrace is the cascade of function-calls that lead to the
> execution of the current code. A null-pointer in the driver-core
> normally means that someone on the calling site did something wrong.
> So in order to fix the bug, you have to look at the stack trace and
> check how that null pointer got handed down to that function.
>
this was(I think) similar but not the same as dev_get_drvdata
(all I know is this has fired off from time to time).
> If you have 2 drivers. Both seperately calling the same function with a
> nullpointer you have 2 seperate issues that trigger the same thing
> (null pointer exception) in the same function. so it is not sufficient
> to look at where the bug happened, you also need to check what is the
> cause.
>
> Regards,
> Flo
>
two drivers calling the same function(sounds bad!) this would be a race
condition right?
As for this message I will keep my eye out for anything in this area and
report it to you guys.
Justin P. Mattock
next prev parent reply other threads:[~2011-03-31 15:41 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-30 1:28 [BUG] NULL pointer dereference in dev_get_drvdata Steven Rostedt
2011-03-30 1:59 ` Mauro Carvalho Chehab
2011-03-30 2:17 ` Steven Rostedt
2011-03-30 15:47 ` Justin P. Mattock
2011-03-31 9:16 ` Florian Mickler
2011-03-31 15:41 ` Justin P. Mattock [this message]
2011-03-31 17:15 ` Florian Mickler
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