From: Leon Romanovsky <leonro@xxxxxxxxxxxx>
When the refcount is 0 the device is invisible to netlink. However
in the patch below the refcount = 1 was moved to after the device_add().
This creates a race where userspace can issue a netlink query after the
device_add() event and not see the device as visible.
Ensure that no uevent is fired before device is fully registered.
Fixes: d79af7242bb2 ("RDMA/device: Expose ib_device_try_get(()")
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
---
Changelog
v0 -> v1
* Fix comment as suggested by Parav.
---
drivers/infiniband/core/device.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 8ec1ad7b5441..ca1dba5f9ec6 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -1304,6 +1304,11 @@ int ib_register_device(struct ib_device *device, const char *name)
ib_device_register_rdmacg(device);
+ /*
+ * Ensure that ADD uevent is not fired because it
+ * is too early amd device is not initialized yet.
+ */
+ dev_set_uevent_suppress(&device->dev, true);
ret = device_add(&device->dev);
if (ret)
goto cg_cleanup;
@@ -1322,6 +1327,9 @@ int ib_register_device(struct ib_device *device, const char *name)
}
ret = enable_device_and_get(device);
+ dev_set_uevent_suppress(&device->dev, false);
+ /* Mark for userspace that device is ready */
+ kobject_uevent(&device->dev.kobj, KOBJ_ADD);
if (ret) {
void (*dealloc_fn)(struct ib_device *);
@@ -1352,6 +1360,7 @@ int ib_register_device(struct ib_device *device, const char *name)
dev_cleanup:
device_del(&device->dev);
cg_cleanup:
+ dev_set_uevent_suppress(&device->dev, false);
ib_device_unregister_rdmacg(device);
ib_cache_cleanup_one(device);
return ret;
--
2.20.1
