[PATCH V5 5/9] USB: OHCI: make ohci-at91 a separate driver

[Alan Stern]

On Fri, 27 Sep 2013, Kevin Hilman wrote:

> Manjunath,
> 
> Manjunath Goudar <manjunath.goudar at linaro.org> writes:
> 
> > Separate the  TI OHCI Atmel host controller driver from ohci-hcd
> > host code so that it can be built as a separate driver module.
> > This work is part of enabling multi-platform kernels on ARM.
> 
> This broke booting on atmel sama5 boards (and likely others with the
> same conversion)...
> 
> [...]
> 
> > +static int __init ohci_at91_init(void)
> > +{
> > +	if (usb_disabled())
> > +		return -ENODEV;
> > +
> > +	pr_info("%s: " DRIVER_DESC "\n", hcd_name);
> > +	ohci_init_driver(&ohci_at91_hc_driver, NULL);
> 
> ohci_init_driver() doesn't have any sanity checks for NULL overrides, so
> it blindly dereferences and faults.
> 
> Some of the other conversions have this same problem (at least omap3).
> Did anyone test this series on hardware?
> 
> I'm not too familiar with OHCI, but something like the patch below is
> probably needed along with this series.
> 
> Kevin
> 
> 
> From a3b5cc90e74038a6449fbd25e0d720ea02884f30 Mon Sep 17 00:00:00 2001
> From: Kevin Hilman <khilman at linaro.org>
> Date: Fri, 27 Sep 2013 08:07:19 -0700
> Subject: [PATCH] USB: OHCI: ohci_init_driver(): sanity check overrides
> 
> Check for non-NULL overrides before dereferencing since platforms may
> pass in NULL overrides.
> 
> Signed-off-by: Kevin Hilman <khilman at linaro.org>
> ---
>  drivers/usb/host/ohci-hcd.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
> index 21d937a..8ada13f 100644
> --- a/drivers/usb/host/ohci-hcd.c
> +++ b/drivers/usb/host/ohci-hcd.c
> @@ -1161,10 +1161,12 @@ void ohci_init_driver(struct hc_driver *drv,
>  	/* Copy the generic table to drv and then apply the overrides */
>  	*drv = ohci_hc_driver;
>  
> -	drv->product_desc = over->product_desc;
> -	drv->hcd_priv_size += over->extra_priv_size;
> -	if (over->reset)
> -		drv->reset = over->reset;
> +	if (over) {
> +		drv->product_desc = over->product_desc;
> +		drv->hcd_priv_size += over->extra_priv_size;
> +		if (over->reset)
> +			drv->reset = over->reset;
> +	}
>  }
>  EXPORT_SYMBOL_GPL(ohci_init_driver);

Yes, this is exactly what ehci-hcd does and it clearly is necessary.

Acked-by: Alan Stern <stern at rowland.harvard.edu>