> +struct ib_uverbs_close_xrc_domain { > + __u64 response; > + __u32 xrcd_handle; > + __u64 driver_data[0]; > +}; This creates 32/64 compatibility problems: on a 32-bit architecture, driver_data may only be aligned to 32 bits. We need to insert a __u32 reserved; field after xrcd_handle for alignment.