[PATCH 1/5] PCI: protect restore with device lock to be consistent

Sinan Kaya
2017-09-24T00:17:10Z

Commit b014e96d1abb ("PCI: Protect pci_error_handlers->reset_notify() usage
with device_lock()") added protection around pci_dev_restore() function so
that device specific remove callback does not cause a race condition
against hotplug.

pci_dev_lock() usage has been forgotten in two different places in the
code. Adding locks for pci_slot_restore() and moving pci_dev_restore()
inside the locks for pci_try_reset_function().

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
drivers/pci/pci.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 6078dfc..23681f4 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4344,9 +4344,9 @@ int pci_try_reset_function(struct pci_dev *dev)

pci_dev_save_and_disable(dev);
rc = __pci_reset_function_locked(dev);
+ pci_dev_restore(dev);
pci_dev_unlock(dev);

- pci_dev_restore(dev);
return rc;
}
EXPORT_SYMBOL_GPL(pci_try_reset_function);
@@ -4546,7 +4546,9 @@ static void pci_slot_restore(struct pci_slot *slot)
list_for_each_entry(dev, &slot->bus->devices, bus_list) {
if (!dev->slot || dev->slot != slot)
continue;
+ pci_dev_lock(dev);
pci_dev_restore(dev);
+ pci_dev_unlock(dev);
if (dev->subordinate)
pci_bus_restore(dev->subordinate);
}
--
1.9.1