Merge branch 'write-handler-consistent-flow' into for-next

Make all of the write() handlers use a consistent flow

From Jason,

This series unifies all the write handlers to use a flow that is very
similar to the ioctl handler flow, including having the same basic
assumptions about extensible buffer handling and the same handler
function call signature.

Along the way this consolidates all the copy_to/from_user into a small
set of safe buffer accessor functions tailored to the usage here. These
accessors use the new dispatcher-controlled calling convention for ucore
data, and support a placement of the response that does not rely on the
cmd.response value.

Overall this brings in in strong bounds checking to all the write()
handlers and consistent enforcement of the zero-fill/zero-check
methodology for buffer extension.

The end result is a significant complexity reduction for all of the
handlers and creates a high degree of uniformity between the write,
write_ex, and ioctl handlers and dispatch flow.

Thanks

Jason Gunthorpe (12):
  RDMA/uverbs: Remove out_len checks that are now done by the core
  RDMA/uverbs: Use uverbs_attr_bundle to pass ucore for write/write_ex
  RDMA/uverbs: Get rid of the 'callback' scheme in the compat path
  RDMA/uverbs: Use uverbs_response() for remaining response copying
  RDMA/uverbs: Use uverbs_request() for request copying
  RDMA/uverbs: Use uverbs_request() and core for write_ex handlers
  RDMA/uverbs: Fill in the response for IB_USER_VERBS_EX_CMD_MODIFY_QP
  RDMA/uverbs: Simplify ib_uverbs_ex_query_device
  RDMA/uverbs: Add a simple iterator interface for reading the command
  RDMA/uverbs: Use the iterator for ib_uverbs_unmarshall_recv()
  RDMA/uverbs: Do not check the input length on create_cq/qp paths
  RDMA/uverbs: Use only attrs for the write() handler signature

 drivers/infiniband/core/rdma_core.h   |    5 +-
 drivers/infiniband/core/uverbs_cmd.c  | 1165 ++++++++++---------------
 drivers/infiniband/core/uverbs_main.c |   23 +-
 drivers/infiniband/core/uverbs_uapi.c |   23 +-
 include/rdma/uverbs_ioctl.h           |    9 +-
 5 files changed, 479 insertions(+), 746 deletions(-)

Signed-off-by: Doug Ledford <dledford@redhat.com>