From: Greg KH <greg@kroah.com>
To: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Wilco Beekhuizen <wilcobeekhuizen@gmail.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Missing usb_find_device symbol from usb.c
Date: Thu, 24 Jan 2008 09:20:49 -0800 [thread overview]
Message-ID: <20080124172049.GA9665@kroah.com> (raw)
In-Reply-To: <84144f020801240906l7e018a95wfd4ad7736851dd63@mail.gmail.com>
On Thu, Jan 24, 2008 at 07:06:39PM +0200, Pekka Enberg wrote:
> Hi Greg,
>
> On Jan 24, 2008 6:44 PM, Greg KH <greg@kroah.com> wrote:
> > No, that's not the problem. The code should just be using
> > usb_register_driver() and then doing what it needs to do in the probe()
> > callback, like any other USB driver.
> >
> > By calling usb_find_device() it allows more than one driver to talk to
> > the device at the same time, setting it up for some very bad things to
> > possibly happen to the device.
> >
> > So a simple code change should be all that is needed to properly fix
> > this.
> >
> > If you want, I can make up a patch, just point me at the version you
> > wish me to modify.
>
> As I already mentioned in private, the code is here:
>
> http://www.init0.nl/iriverfs-r0.1.0.1-linux-2.6.23.patch.bz2
>
> It's basically abusing the USB driver stack with a ->probe() function
> that returns -ENODEV and doing device discovery at mount time. That,
> however, is also broken as it assumes there's only one device plugged
> in (we're not passing any device identifier to sys_mount).
By returning -ENODEV, that still allows some other driver or user
through usbfs to come in and start talking to the device, while this
"driver" also touches it. Not nice.
> So it's not a simple code change at all.
Just create a root directory for every device that is seen in the
probe() function. That should be pretty simple to do.
thanks,
greg k-h
next prev parent reply other threads:[~2008-01-24 17:35 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-22 19:18 [PATCH] Missing usb_find_device symbol from usb.c Wilco Beekhuizen
2008-01-22 22:08 ` Adrian Bunk
2008-01-24 1:37 ` Greg KH
2008-01-24 10:05 ` Wilco Beekhuizen
2008-01-24 11:19 ` Pekka Enberg
2008-01-24 11:49 ` Oliver Neukum
2008-01-24 11:52 ` Pekka Enberg
2008-01-24 12:24 ` Oliver Neukum
2008-01-24 12:34 ` Pekka Enberg
2008-01-24 12:58 ` Oliver Neukum
2008-01-24 13:14 ` Pekka Enberg
2008-01-24 16:44 ` Greg KH
2008-01-24 17:06 ` Pekka Enberg
2008-01-24 17:20 ` Greg KH [this message]
2008-01-24 17:42 ` Pekka Enberg
2008-01-24 18:03 ` Greg KH
2008-01-24 19:25 ` Pekka J Enberg
2008-01-24 19:57 ` Oliver Neukum
2008-01-24 20:10 ` Pekka Enberg
2008-01-24 20:00 ` Oliver Neukum
2008-01-24 20:26 ` Pekka Enberg
2008-01-24 20:28 ` Greg KH
2008-01-25 8:58 ` Oliver Neukum
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