Re: S2R resume crash in 2.6.33-rc7 - NULL pointer dereference indev_get_drvdata() for usbhid

From: Jiri Kosina
Date: Wed Feb 17 2010 - 08:24:20 EST


On Sat, 13 Feb 2010, Bruno PrÃmont wrote:

> > > This lets me guess that hid_add_device() is doing something wrong
> > > here when report parsing fails... (as that one is the only one which
> > > could be doing the initialization of usbhid which does work for the
> > > first interface announced by my keyboard)
> >
> > I don't know about doing anything wrong... However it does appear
> > that in this case the interface is registered on the HID bus but
> > doesn't get bound to a driver. Jiri will know whether or not that's
> > the desired outcome.
> >
> > On the other hand, I don't think there would be anything wrong with
> > moving the
> >
> > usbhid->intf = intf;
> > usbhid->ifnum = interface->desc.bInterfaceNumber;
> >
> > lines from usbhid_start() to usbhid_probe(), just before the call to
> > hid_add_device(). It should fix the bug, and those lines do belong in
> > the probe routine. Jiri, any problems with doing this?
>
> With the below patch (which is only half of the move work) I don't
> get crashes anymore. Though I wonder if other initialization steps
> (like the spin_lock_init() right before setting usbhid->intf) would
> need to be moved as well.
>
> Bruno
>
> diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
> index e2997a8..690ca75 100644
> --- a/drivers/hid/usbhid/hid-core.c
> +++ b/drivers/hid/usbhid/hid-core.c
> @@ -1154,6 +1154,8 @@ static int usbhid_probe(struct usb_interface *intf, const struct usb_device_id *
>
> hid->driver_data = usbhid;
> usbhid->hid = hid;
> + usbhid->intf = intf;
> + usbhid->ifnum = interface->desc.bInterfaceNumber;
>
> ret = hid_add_device(hid);
> if (ret) {
>

Thanks for beating me with looking into this guys.

I have pushed fix for this into for-next branch, so it should appear in
tomorrow linux-next pile. If you still experience the problem, please let
me know.

Thanks,

--
Jiri Kosina
SUSE Labs, Novell Inc.
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