On Mon, Jan 28, 2019 at 12:12:23PM +0200, Shamir Rabinovitch wrote: > Helper function to get driver's context out of ib_udata wrapped > in uverbs_attr_bundle for uer objects or NULL for kernel objects. > > Signed-off-by: Shamir Rabinovitch <shamir.rabinovitch@xxxxxxxxxx> > include/rdma/ib_verbs.h | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h > index 94b6e1dd4dab..fb4d078d6db3 100644 > +++ b/include/rdma/ib_verbs.h > @@ -4264,4 +4264,18 @@ static inline struct ib_device *rdma_device_to_ibdev(struct device *device) > */ > #define rdma_device_to_drv_device(dev, drv_dev_struct, ibdev_member) \ > container_of(rdma_device_to_ibdev(dev), drv_dev_struct, ibdev_member) > + > +/** > + * rdma_udata_to_drv_context - Helper macro to get the driver's context out of > + * ib_udata which is embadded in uverbs_attr_bundle. > + * > + * NOTE: This macro return NULL for kernel objects and valid driver context for > + * user objects. Actually at this point I think this just can't fail if udata is set, so lets just say that: /* * If udata is not NULL this cannot fail. Otherwise a NULL udata will result * in a NULL ucontext pointer. Callers can rely on !NULL ucontext to show the * op is being called as part of a user system call. */ #define rdma_udata_to_drv_context(udata, drv_dev_struct, member) \ (udata ? container_of(container_of(udata, struct uverbs_attr_bundle, \ driver_udata) \ ->context, \ drv_dev_struct, member) : \ (drv_dev_struct *)NULL) And get rid of the rdma_get_ucontext helper function, umem can just inspect udata->context itself and fail with EIO if NULL. Jason
