Re: [PATCH V2 3/3] perf/x86/intel/uncore: Validate MMIO address before accessing

[Liang, Kan]

On 5/28/2020 9:33 AM, David Laight wrote:
> From: kan.liang@xxxxxxxxxxxxxxx
> > Sent: 28 May 2020 14:15
> ...
> > +static inline bool is_valid_mmio_offset(struct intel_uncore_box *box,
> > +					unsigned long offset)
>
> You need a better name, needs to start 'uncore_' and 'mmio'
> probably isn't right either.

Sure

> > +{
> > +	if (box->pmu->type->mmio_map_size > offset)
> > +		return true;
>
> Swap over.
> Conditionals always read best if 'variable op constant'.
> So you want:
> 	if (offset < box->pmu->type->mmio_map_size)
> 		return true;

Sure

> > +
> > +	pr_warn_once("perf uncore: Access invalid address of %s.\n",
> > +		     box->pmu->type->name);
>
> Pretty hard to debug without the invalid offset.

I will dump the box->io_addr and offset for debugging.

Thanks,
Kan
> I've no idea what the code is supposed to be doing though.
>
> 	David
>
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