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Commit 6a040ce7 authored by Thadeu Lima de Souza Cascardo's avatar Thadeu Lima de Souza Cascardo Committed by Benjamin Herrenschmidt
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powerpc/eeh: Fix crash when adding a device in a slot with DDW 



The DDW code uses a eeh_dev struct from the pci_dev. However, this is
not set until eeh_add_device_late is called.

Since pci_bus_add_devices is called before eeh_add_device_late, the PCI
devices are added to the bus, making drivers' probe hooks to be called.
These will call set_dma_mask, which will call the DDW code, which will
require the eeh_dev struct from pci_dev. This would result in a crash,
due to a NULL dereference.

Calling eeh_add_device_late after pci_bus_add_devices would make the
system BUG, because device files shouldn't be added to devices there
were not added to the system. So, a new function is needed to add such
files only after pci_bus_add_devices have been called.

Cc: stable@vger.kernel.org
Signed-off-by: default avatarThadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Acked-by: default avatarGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent d35d1424

arch/powerpc/include/asm/eeh.h

+3 −0
Original line number Diff line number Diff line
@@ -201,6 +201,7 @@ int eeh_dev_check_failure(struct eeh_dev *edev); 
void __init eeh_addr_cache_build(void);

void eeh_add_device_tree_early(struct device_node *);

void eeh_add_device_tree_late(struct pci_bus *);

void eeh_add_sysfs_files(struct pci_bus *);

void eeh_remove_bus_device(struct pci_dev *, int);



/**
@@ -240,6 +241,8 @@ static inline void eeh_add_device_tree_early(struct device_node *dn) { } 


static inline void eeh_add_device_tree_late(struct pci_bus *bus) { }



static inline void eeh_add_sysfs_files(struct pci_bus *bus) { }



static inline void eeh_remove_bus_device(struct pci_dev *dev, int purge_pe) { }



static inline void eeh_lock(void) { }

arch/powerpc/kernel/of_platform.c

+3 −0
Original line number Diff line number Diff line
@@ -91,6 +91,9 @@ static int of_pci_phb_probe(struct platform_device *dev) 
	/* Add probed PCI devices to the device model */

	pci_bus_add_devices(phb->bus);



	/* sysfs files should only be added after devices are added */

	eeh_add_sysfs_files(phb->bus);



	return 0;

}

arch/powerpc/kernel/pci-common.c

+5 −2
Original line number Diff line number Diff line
@@ -1477,11 +1477,14 @@ void pcibios_finish_adding_to_bus(struct pci_bus *bus) 
	pcibios_allocate_bus_resources(bus);

	pcibios_claim_one_bus(bus);



	/* Fixup EEH */

	eeh_add_device_tree_late(bus);



	/* Add new devices to global lists.  Register in proc, sysfs. */

	pci_bus_add_devices(bus);



	/* Fixup EEH */

	eeh_add_device_tree_late(bus);

	/* sysfs files should only be added after devices are added */

	eeh_add_sysfs_files(bus);

}

EXPORT_SYMBOL_GPL(pcibios_finish_adding_to_bus);

arch/powerpc/platforms/pseries/eeh.c

+23 −1
Original line number Diff line number Diff line
@@ -788,7 +788,6 @@ static void eeh_add_device_late(struct pci_dev *dev) 
	dev->dev.archdata.edev = edev;



	eeh_addr_cache_insert_dev(dev);

	eeh_sysfs_add_device(dev);

}



/**
@@ -814,6 +813,29 @@ void eeh_add_device_tree_late(struct pci_bus *bus) 
}

EXPORT_SYMBOL_GPL(eeh_add_device_tree_late);



/**

 * eeh_add_sysfs_files - Add EEH sysfs files for the indicated PCI bus

 * @bus: PCI bus

 *

 * This routine must be used to add EEH sysfs files for PCI

 * devices which are attached to the indicated PCI bus. The PCI bus

 * is added after system boot through hotplug or dlpar.

 */

void eeh_add_sysfs_files(struct pci_bus *bus)

{

	struct pci_dev *dev;



	list_for_each_entry(dev, &bus->devices, bus_list) {

		eeh_sysfs_add_device(dev);

		if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {

			struct pci_bus *subbus = dev->subordinate;

			if (subbus)

				eeh_add_sysfs_files(subbus);

		}

	}

}

EXPORT_SYMBOL_GPL(eeh_add_sysfs_files);



/**

 * eeh_remove_device - Undo EEH setup for the indicated pci device

 * @dev: pci device to be removed