Re: [PATCH v2] drivers/perf: xgene_pmu: Fix uninitialized resource struct

[Will Deacon]

On Mon, Sep 14, 2020 at 09:13:39AM -0400, Mark Salter wrote:
> On Mon, 2020-09-14 at 12:28 +0100, Will Deacon wrote:
> > On Sun, Sep 13, 2020 at 01:45:36PM -0400, Mark Salter wrote:
> > > @@ -1483,11 +1473,23 @@ xgene_pmu_dev_ctx *acpi_get_pmu_hw_inf(struct xgene_pmu *xgene_pmu,
> > >  		return NULL;
> > >  
> > >  	INIT_LIST_HEAD(&resource_list);
> > > -	rc = acpi_dev_get_resources(adev, &resource_list,
> > > -				    acpi_pmu_dev_add_resource, &res);
> > > +	rc = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
> > > +	if (rc <= 0) {
> > > +		dev_err(dev, "PMU type %d: No resources found\n", type);
> > > +		return NULL;
> > > +	}
> > > +
> > > +	list_for_each_entry(rentry, &resource_list, node) {
> > > +		if (resource_type(rentry->res) == IORESOURCE_MEM) {
> > > +			res = *rentry->res;
> > > +			rentry = NULL;
> > > +			break;
> > > +		}
> > > +	}
> > >  	acpi_dev_free_resource_list(&resource_list);
> > > -	if (rc < 0) {
> > > -		dev_err(dev, "PMU type %d: No resource address found\n", type);
> > > +
> > > +	if (rentry) {
> > 
> > I'm curious as to why you've had to change the failure logic here, setting
> > rentry to NULL instead of checking 'rentry->res' like the TX2 driver (which
> > I don't immediately understand at first glance).
> > 
> > Will
> > 
> 
> I don't fully understand the tx2 logic. I do see there's a memory leak if
> that (!rentry->res) is true. I was going to dig deeper and follow up with
> a patch for tx2. I suspect that rentry->res should never be true. And tx2
> won't detect if no memory resource is in the table.

Ah good, so it wasn't just me then! In which case, please send the two
patches as a series fixing both drivers, and I'll queue them both together.

Ta,

Will