ftrace: Add cleanup to unregister_ftrace_direct_multi

Adding ops cleanup to unregister_ftrace_direct_multi,
so it can be reused in another register call.

Link: https://lkml.kernel.org/r/[email protected]

Cc: Ingo Molnar <[email protected]>
Cc: Heiko Carstens <[email protected]>
Fixes: f64dd46 ("ftrace: Add multi direct register/unregister interface")
Signed-off-by: Jiri Olsa <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>

Author: Jiri Olsa

kernel/trace/ftrace.c

@@ -5542,6 +5542,10 @@ int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
 	err = unregister_ftrace_function(ops);
 	remove_direct_functions_hash(hash, addr);
 	mutex_unlock(&direct_mutex);
+
+	/* cleanup for possible another register call */
+	ops->func = NULL;
+	ops->trampoline = 0;
 	return err;
 }
 EXPORT_SYMBOL_GPL(unregister_ftrace_direct_multi);