cxl: use pcibios_free_controller_deferred() when removing vPHBs (6f38a8b9) · Commits · 戴 / test

When cxl removes a vPHB, it's possible that the pci_controller may be freed before all references to the devices on the vPHB have been released. This in turn causes an invalid memory access when the devices are eventually released, as pcibios_release_device() attempts to call the phb's release_device hook. In cxl_pci_vphb_remove(), remove the existing call to pcibios_free_controller(). Instead, use pcibios_free_controller_deferred() to free the pci_controller after all devices have been released. Export pci_set_host_bridge_release() so we can do this. Cc: stable@vger.kernel.org Signed-off-by:

Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by:

Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by:

Ian Munsie <imunsie@au1.ibm.com> Signed-off-by:

Benjamin Herrenschmidt <benh@kernel.crashing.org>

drivers/misc/cxl/vphb.c

+9 −1

Original line number	Diff line number	Diff line
		@@ -230,6 +230,11 @@ int cxl_pci_vphb_add(struct cxl_afu *afu)
		if (phb->bus == NULL)
		return -ENXIO;

		/* Set release hook on root bus */
		pci_set_host_bridge_release(to_pci_host_bridge(phb->bus->bridge),
		pcibios_free_controller_deferred,
		(void *) phb);

		/* Claim resources. This might need some rework as well depending
		* whether we are doing probe-only or not, like assigning unassigned
		* resources etc...
		@@ -256,7 +261,10 @@ void cxl_pci_vphb_remove(struct cxl_afu *afu)
		afu->phb = NULL;

		pci_remove_root_bus(phb->bus);
		pcibios_free_controller(phb);
		/*
		* We don't free phb here - that's handled by
		* pcibios_free_controller_deferred()
		*/
		}

		static bool _cxl_pci_is_vphb_device(struct pci_controller *phb)

drivers/pci/host-bridge.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -44,6 +44,7 @@ void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
		bridge->release_fn = release_fn;
		bridge->release_data = release_data;
		}
		EXPORT_SYMBOL_GPL(pci_set_host_bridge_release);

		void pcibios_resource_to_bus(struct pci_bus bus, struct pci_bus_region region,
		struct resource *res)

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