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Date:   Mon, 14 Sep 2020 12:28:04 +0100
From:   Will Deacon <will@kernel.org>
To:     Mark Salter <msalter@redhat.com>
Cc:     Mark Rutland <mark.rutland@arm.com>,
        Khuong Dinh <khuong@os.amperecomputing.com>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] drivers/perf: xgene_pmu: Fix uninitialized resource
 struct
Message-ID: <20200914112803.GA24312@willie-the-truck>
References: <20200913174536.207265-1-msalter@redhat.com>
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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