ftrace/direct: Fix lockup in modify_ftrace_direct_multi

We can't call unregister_ftrace_function under ftrace_lock.

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

Fixes: ed29271 ("ftrace/direct: Do not disable when switching direct callers")
Signed-off-by: Jiri Olsa <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>

Author: Jiri Olsa

kernel/trace/ftrace.c

@@ -5602,10 +5602,11 @@ int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
 		}
 	}
 
+	mutex_unlock(&ftrace_lock);
+
 	/* Removing the tmp_ops will add the updated direct callers to the functions */
 	unregister_ftrace_function(&tmp_ops);
 
-	mutex_unlock(&ftrace_lock);
  out_direct:
 	mutex_unlock(&direct_mutex);
 	return err;