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SubjectRe: [PATCH v2 2/3] lib: logic_pio: Reject access to unregistered CPU MMIO regions
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On 23/03/2019 19:15, Andy Shevchenko wrote:
> On Wed, Mar 20, 2019 at 8:14 PM John Garry <john.garry@huawei.com> 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

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