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

From: Lukas Wunner
Date: Sat May 04 2024 - 04:54:40 EST


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