The rcu_assign_pointer() function currently doesn't do any sparse checking
on the assigned-to pointer. So its possible that a pointer that is
not __rcu annotated is assigned with rcu_assign_pointer without sparse
complaints. Because rcu_dereference() already does such checking,
this commit makes rcu_assign_pointer() to do the same. The extra
error could be helpful in cases where an RCU pointer is assigned with
rcu_assign_pointer() but not annotated with __rcu.
This doesn't generate any code in the normal case because __CHECKER__ is
defined only in the context of sparse.
This commit also renames rcu_dereference_sparse() to rcu_check_parse()
since the checking now happens not only during derereferencing but also
during assignment.
Test: Introduced an rcu_assign_pointer in code and checked the output of
sparse with and without this change. The change correctly causes sparse
to throw an error.
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>