Re: [PATCH 2/4] PCI: pciehp: bail out if pci_hp_add_bridge() fails

On Fri, May 03, 2024 at 09:23:20PM +0200, Nam Cao wrote:

If there is no bus number available for the downstream bus of the hot-plugged bridge, pci_hp_add_bridge() will fail. The driver proceeds regardless, and the kernel crashes.

Abort if pci_hp_add_bridge() fails.

[...]

--- a/drivers/pci/hotplug/pciehp_pci.c +++ b/drivers/pci/hotplug/pciehp_pci.c @@ -58,8 +58,13 @@ int pciehp_configure_device(struct controller *ctrl) goto out; }

• for_each_pci_bridge(dev, parent)

• pci_hp_add_bridge(dev);
  

• for_each_pci_bridge(dev, parent) {

• if (pci_hp_add_bridge(dev)) {
  

• 	pci_stop_and_remove_bus_device(dev);
  

• 	ret = -EINVAL;
  

• 	goto out;
  

• }
  

• }

Is the pci_stop_and_remove_bus_device() really necessary here? Why not just leave the bridge as is, without any child devices?

Thanks,

Lukas