Am 21.04.20 um 18:22 schrieb Ard Biesheuvel:
When resizing a BAR, pci_reassign_bridge_resources() is invoked to
bring the bridge windows of parent bridges in line with the new BAR
assignment.
This assumes that the device whose BAR is being resized lives on a
subordinate bus, but this is not necessarily the case. A device may
live on the root bus, in which case dev->bus->self is NULL, and
passing a NULL pci_dev pointer to pci_reassign_bridge_resources()
will cause it to crash.
So let's make the call to pci_reassign_bridge_resources() conditional
on whether dev->bus->self is non-NULL in the first place.
Fixes: 8bb705e3e79d84e7 ("PCI: Add pci_resize_resource() for resizing BARs")
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Sounds like it makes sense, patch is Reviewed-by: Christian König
<christian.koenig@xxxxxxx>.
May I ask where you found that condition?
Thanks,
Christian.
---
drivers/pci/setup-res.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index d8ca40a97693..d21fa04fa44d 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -439,10 +439,11 @@ int pci_resize_resource(struct pci_dev *dev, int resno, int size)
res->end = res->start + pci_rebar_size_to_bytes(size) - 1;
/* Check if the new config works by trying to assign everything. */
- ret = pci_reassign_bridge_resources(dev->bus->self, res->flags);
- if (ret)
- goto error_resize;
-
+ if (dev->bus->self) {
+ ret = pci_reassign_bridge_resources(dev->bus->self, res->flags);
+ if (ret)
+ goto error_resize;
+ }
return 0;
error_resize:
