Re: [PATCH v2 2/3] lib: logic_pio: Reject access to unregistered CPU MMIO regions

[Andy Shevchenko]

On Wed, Mar 20, 2019 at 8:14 PM John Garry <john.garry@xxxxxxxxxx> wrote:
>
> Currently when accessing logical indirect PIO addresses in
> logic_{in, out}{,s}, we first ensure that the region is registered.
>
> However, no such check exists for CPU MMIO regions. The CPU MMIO regions
> would be registered by the PCI host (when PCI_IOBASE is defined) in
> pci_register_io_range().
>
> We have seen scenarios when systems which don't have a PCI host or, they
> do, and the PCI host probe fails, that certain devices attempts to still
> attempt to access PCI IO ports; examples are in [1] and [2].
>
> And even though we would protect against this by ensuring the driver call
> request_{muxed_}region(), some don't do this:
>


>  #if defined(CONFIG_INDIRECT_PIO) && defined(PCI_IOBASE)
> +#define INVALID_RANGE(range) (!range || \
> +                             (range->flags == LOGIC_PIO_CPU_MMIO && !range->ops))

It would be better to read in a form
#define foo(x) \
 (...)

> +               ret = range->ops->in(range->hostdata,                   \
> +                                    addr, sizeof(type));               \

Can it fit one line?

-- 
With Best Regards,
Andy Shevchenko