Hello Jason Gunthorpe,
The patch 921eab1143aa: "RDMA/devices: Re-organize device.c locking"
from Feb 6, 2019, leads to the following static checker warning:
drivers/infiniband/core/device.c:712 add_client_context()
warn: missing error code 'ret'
drivers/infiniband/core/device.c
689 static int add_client_context(struct ib_device *device,
690 struct ib_client *client)
691 {
692 int ret = 0;
693
694 if (!device->kverbs_provider && !client->no_kverbs_req)
695 return 0;
696
697 down_write(&device->client_data_rwsem);
698 /*
699 * So long as the client is registered hold both the client and device
700 * unregistration locks.
701 */
702 if (!refcount_inc_not_zero(&client->uses))
703 goto out_unlock;
704 refcount_inc(&device->refcount);
705
706 /*
707 * Another caller to add_client_context got here first and has already
708 * completely initialized context.
709 */
710 if (xa_get_mark(&device->client_data, client->client_id,
711 CLIENT_DATA_REGISTERED))
--> 712 goto out;
Hard to tell if ret should be zero or negative.
713
714 ret = xa_err(xa_store(&device->client_data, client->client_id, NULL,
715 GFP_KERNEL));
716 if (ret)
717 goto out;
718 downgrade_write(&device->client_data_rwsem);
719 if (client->add) {
720 if (client->add(device)) {
721 /*
722 * If a client fails to add then the error code is
723 * ignored, but we won't call any more ops on this
724 * client.
725 */
726 xa_erase(&device->client_data, client->client_id);
727 up_read(&device->client_data_rwsem);
728 ib_device_put(device);
729 ib_client_put(client);
730 return 0;
731 }
732 }
733
734 /* Readers shall not see a client until add has been completed */
735 xa_set_mark(&device->client_data, client->client_id,
736 CLIENT_DATA_REGISTERED);
737 up_read(&device->client_data_rwsem);
738 return 0;
739
740 out:
741 ib_device_put(device);
742 ib_client_put(client);
743 out_unlock:
744 up_write(&device->client_data_rwsem);
745 return ret;
746 }
regards,
dan carpenter
