Change the credentials documentation to make it clear that the RCU read lock
must be explicitly held when accessing credentials pointers in some other task
than current. Holding a spinlock does not implicitly hold the RCU read lock.
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
