ftrace: Create new ftrace_internal.h header

In order to move function graph infrastructure into its own file (fgraph.h)
it needs to access various functions and variables in ftrace.c that are
currently static. Create a new file called ftrace-internal.h that holds the
function prototypes and the extern declarations of the variables needed by
fgraph.c as well, and make them global in ftrace.c such that they can be
used outside that file.

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

1 files changed, 75 insertions, 0 deletions

diff --git a/kernel/trace/ftrace_internal.h b/kernel/trace/ftrace_internal.h
new file mode 100644
index 000000000000..0515a2096f90
--- /dev/null
+++ b/kernel/trace/ftrace_internal.h
@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_KERNEL_FTRACE_INTERNAL_H
+#define  _LINUX_KERNEL_FTRACE_INTERNAL_H
+
+#ifdef CONFIG_FUNCTION_TRACER
+
+/*
+ * Traverse the ftrace_global_list, invoking all entries.  The reason that we
+ * can use rcu_dereference_raw_notrace() is that elements removed from this list
+ * are simply leaked, so there is no need to interact with a grace-period
+ * mechanism.  The rcu_dereference_raw_notrace() calls are needed to handle
+ * concurrent insertions into the ftrace_global_list.
+ *
+ * Silly Alpha and silly pointer-speculation compiler optimizations!
+ */
+#define do_for_each_ftrace_op(op, list)			\
+	op = rcu_dereference_raw_notrace(list);			\
+	do
+
+/*
+ * Optimized for just a single item in the list (as that is the normal case).
+ */
+#define while_for_each_ftrace_op(op)				\
+	while (likely(op = rcu_dereference_raw_notrace((op)->next)) &&	\
+	       unlikely((op) != &ftrace_list_end))
+
+extern struct ftrace_ops __rcu *ftrace_ops_list;
+extern struct ftrace_ops ftrace_list_end;
+extern struct mutex ftrace_lock;
+extern struct ftrace_ops global_ops;
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+
+int ftrace_startup(struct ftrace_ops *ops, int command);
+int ftrace_shutdown(struct ftrace_ops *ops, int command);
+int ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs);
+
+#else /* !CONFIG_DYNAMIC_FTRACE */
+
+int __register_ftrace_function(struct ftrace_ops *ops);
+int __unregister_ftrace_function(struct ftrace_ops *ops);
+/* Keep as macros so we do not need to define the commands */
+# define ftrace_startup(ops, command)					\
+	({								\
+		int ___ret = __register_ftrace_function(ops);		\
+		if (!___ret)						\
+			(ops)->flags |= FTRACE_OPS_FL_ENABLED;		\
+		___ret;							\
+	})
+# define ftrace_shutdown(ops, command)					\
+	({								\
+		int ___ret = __unregister_ftrace_function(ops);		\
+		if (!___ret)						\
+			(ops)->flags &= ~FTRACE_OPS_FL_ENABLED;		\
+		___ret;							\
+	})
+static inline int
+ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
+{
+	return 1;
+}
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+extern int ftrace_graph_active;
+void update_function_graph_func(void);
+#else /* !CONFIG_FUNCTION_GRAPH_TRACER */
+# define ftrace_graph_active 0
+static inline void update_function_graph_func(void) { }
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+#else /* !CONFIG_FUNCTION_TRACER */
+#endif /* CONFIG_FUNCTION_TRACER */
+
+#endif