tracing/fgraph: Have wakeup and irqsoff tracers ignore graph functions too

Currently both the wakeup and irqsoff traces do not handle set_graph_notrace
well. The ftrace infrastructure will ignore the return paths of all
functions leaving them hanging without an end:

  # echo '*spin*' > set_graph_notrace
  # cat trace
  [...]
          _raw_spin_lock() {
            preempt_count_add() {
            do_raw_spin_lock() {
          update_rq_clock();

Where the '*spin*' functions should have looked like this:

          _raw_spin_lock() {
            preempt_count_add();
            do_raw_spin_lock();
          }
          update_rq_clock();

Instead, have the wakeup and irqsoff tracers ignore the functions that are
set by the set_graph_notrace like the function_graph tracer does. Move
the logic in the function_graph tracer into a header to allow wakeup and
irqsoff tracers to use it as well.

Cc: Namhyung Kim <namhyung.kim@lge.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 37602e722336..c2234494f40c 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -846,6 +846,17 @@ static inline int ftrace_graph_notrace_addr(unsigned long addr)
 	return 0;
 }
 #endif /* CONFIG_DYNAMIC_FTRACE */
+
+extern unsigned int fgraph_max_depth;
+
+static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
+{
+	/* trace it when it is-nested-in or is a function enabled. */
+	return !(trace->depth || ftrace_graph_addr(trace->func)) ||
+		(trace->depth < 0) ||
+		(fgraph_max_depth && trace->depth >= fgraph_max_depth);
+}
+
 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
 static inline enum print_line_t
 print_graph_function_flags(struct trace_iterator *iter, u32 flags)