Re: [PATCH v5 13/16] cxl/pci: Add error handler for CXL PCIe Port RAS errors

[Gregory Price <gourry@xxxxxxxxxx>]

On Tue, Jan 07, 2025 at 08:38:49AM -0600, Terry Bowman wrote:
> +static void __iomem *cxl_pci_port_ras(struct pci_dev *pdev)
> +{
> +	struct cxl_port *port;
> +
> +	if (!pdev)
> +		return NULL;
> +
> +	if ((pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT) ||
> +	    (pci_pcie_type(pdev) == PCI_EXP_TYPE_DOWNSTREAM)) {
> +		struct cxl_dport *dport;
> +		void __iomem *ras_base;
> +
> +		port = find_cxl_port(&pdev->dev, &dport);
> +		ras_base = dport ? dport->regs.ras : NULL;

I'm fairly certain dport can come back here uninitialized, you
probably want to put this inside the `if (port)` block and 
pre-initialize dport to NULL.

> +		if (port)
> +			put_device(&port->dev);
> +		return ras_base;

You can probably even simplify this down to something like

		struct_cxl_dport *dport = NULL;

		port = find_cxl_port(&pdev->dev, &dport);
		if (port)
			put_device(&port->dev);

		return dport ? dport->regs.ras : NULL;


~Gregory