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

[John Garry]

On 23/03/2019 19:15, Andy Shevchenko wrote:
> 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:

Hi Andy,

> >  #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) \

Sure, I can change that if you think it reads better.

>  (...)
>
> > +               ret = range->ops->in(range->hostdata,                   \
> > +                                    addr, sizeof(type));               \
>
> Can it fit one line?

It should be ok. I can shorten some variable names.

>

Thanks for checking,
John