On Fri, 27 Sep 2013, Kevin Hilman wrote:
> Manjunath,
>
> Manjunath Goudar <manjunath.goudar@xxxxxxxxxx> 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@xxxxxxxxxx>
> 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@xxxxxxxxxx>
> ---
> 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@xxxxxxxxxxxxxxxxxxx>
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