PCI/AER: Restore pci_ops pointer while calling original pci_ops
The aer_inject module intercepts config space accesses by replacing the
bus->ops pointer. If it forwards accesses to the original pci_ops, and
those original ops use bus->ops, they see the aer_pci_ops instead of their
own pci_ops, which can cause a crash.
For example, pci_generic_config_read() uses the bus->ops->map_bus pointer.
If bus->ops is set to aer_pci_ops, which doesn't supply .map_bus,
pci_generic_config_read() will dereference an invalid pointer and cause a
crash.
Temporarily restore the original bus->ops pointer while calling ops->read()
or ops->write(). Callers of these functions already hold pci_lock, which
prevents other users of bus->ops until we're finished.
[bhelgaas: changelog]
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
1 file changed