On 2022/8/27 6:38, Bjorn Helgaas wrote:
[+cc Arnd, Rob]
On Thu, Aug 25, 2022 at 08:27:52PM +0800, Yang Yingliang wrote:
If device_register() fails in pci_register_host_bridge(), the refcount
of bus device is leaked, so device name that set by dev_set_name() can
not be freed. Fix this by calling put_device() when device_register()
fails, so the device name will be freed in kobject_cleanup().
Fixes: 37d6a0a6f470 ("PCI: Add pci_register_host_bridge() interface")
Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
---
drivers/pci/probe.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index e500eb9d6468..292d9da146ce 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -948,8 +948,17 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
name = dev_name(&bus->dev);
err = device_register(&bus->dev);
- if (err)
- goto unregister;
+ if (err) {
+ /*
+ * release_pcibus_dev() will decrease the refcount of bridge
+ * device and free the memory of bus.
+ * The memory of bus device name will be freed when the refcount
+ * get to zero.
+ */
+ put_device(&bus->dev);
+ device_unregister(&bridge->dev);
+ return err;
+ }
Calling put_device(X) after device_register(X) returns failure doesn't
need explanation because that's the standard pattern. I think that
was just missing before.
In this error case, we previously did called put_device() for the
*bridge* instead of the bus. That was likely a typo and seems like
the important thing here.
put_device() for the bridge will be called in the callback of put for
the bus.
So it doesn't call put bridge device here.
Thanks,
Yang
pcibios_add_bus(bus);
@@ -1025,10 +1034,6 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
return 0;
-unregister:
- put_device(&bridge->dev);
- device_unregister(&bridge->dev);
-
free:
kfree(bus);
return err;
--
2.25.1
.
