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: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Acked-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Thadeu Lima de Souza Cascardo 2012-12-28 09:13:19 +00:00 committed by Benjamin Herrenschmidt
parent d35d142404
commit 6a040ce725
4 changed files with 34 additions and 3 deletions

View file

@ -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) { }

View file

@ -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;
}

View file

@ -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);

View file

@ -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