[PATCH] powerpc/pseries: extract host bridge from pci_bus prior to bus removal

From: Tyrel Datwyler
Date: Thu Feb 11 2021 - 13:28:18 EST


The pci_bus->bridge reference may no longer be valid after
pci_bus_remove() resulting in passing a bad value to device_unregister()
for the associated bridge device.

Store the host_bridge reference in a separate variable prior to
pci_bus_remove().

Fixes: 7340056567e3 ("powerpc/pci: Reorder pci bus/bridge unregistration during PHB removal")
Signed-off-by: Tyrel Datwyler <tyreld@xxxxxxxxxxxxx>
---
arch/powerpc/platforms/pseries/pci_dlpar.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/pseries/pci_dlpar.c b/arch/powerpc/platforms/pseries/pci_dlpar.c
index f9ae17e8a0f4..a8f9140a24fa 100644
--- a/arch/powerpc/platforms/pseries/pci_dlpar.c
+++ b/arch/powerpc/platforms/pseries/pci_dlpar.c
@@ -50,6 +50,7 @@ EXPORT_SYMBOL_GPL(init_phb_dynamic);
int remove_phb_dynamic(struct pci_controller *phb)
{
struct pci_bus *b = phb->bus;
+ struct pci_host_bridge *host_bridge = to_pci_host_bridge(b->bridge);
struct resource *res;
int rc, i;

@@ -76,7 +77,8 @@ int remove_phb_dynamic(struct pci_controller *phb)
/* Remove the PCI bus and unregister the bridge device from sysfs */
phb->bus = NULL;
pci_remove_bus(b);
- device_unregister(b->bridge);
+ host_bridge->bus = NULL;
+ device_unregister(&host_bridge->dev);

/* Now release the IO resource */
if (res->flags & IORESOURCE_IO)
--
2.27.0