tracing: Update stack trace skipping for ORC unwinder

With the addition of ORC unwinder and FRAME POINTER unwinder, the stack
trace skipping requirements have changed.

I went through the tracing stack trace dumps with ORC and with frame
pointers and recalculated the proper values.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

1 files changed, 36 insertions, 13 deletions

diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 27f7ad12c4b1..b611cd36e22d 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -154,6 +154,24 @@ function_trace_call(unsigned long ip, unsigned long parent_ip,
         preempt_enable_notrace();
 }
 
+#ifdef CONFIG_UNWINDER_ORC
+/*
+ * Skip 2:
+ *
+ *   function_stack_trace_call()
+ *   ftrace_call()
+ */
+#define STACK_SKIP 2
+#else
+/*
+ * Skip 3:
+ *   __trace_stack()
+ *   function_stack_trace_call()
+ *   ftrace_call()
+ */
+#define STACK_SKIP 3
+#endif
+
 static void
 function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
                           struct ftrace_ops *op, struct pt_regs *pt_regs)
@@ -180,15 +198,7 @@ function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
         if (likely(disabled == 1)) {
                 pc = preempt_count();
                 trace_function(tr, ip, parent_ip, flags, pc);
-                /*
-                 * skip over 5 funcs:
-                 *    __ftrace_trace_stack,
-                 *    __trace_stack,
-                 *    function_stack_trace_call
-                 *    ftrace_list_func
-                 *    ftrace_call
-                 */
-                __trace_stack(tr, flags, 5, pc);
+                __trace_stack(tr, flags, STACK_SKIP, pc);
         }
 
         atomic_dec(&data->disabled);
@@ -367,14 +377,27 @@ ftrace_traceoff(unsigned long ip, unsigned long parent_ip,
         tracer_tracing_off(tr);
 }
 
+#ifdef CONFIG_UNWINDER_ORC
 /*
- * Skip 4:
+ * Skip 3:
+ *
+ *   function_trace_probe_call()
+ *   ftrace_ops_assist_func()
+ *   ftrace_call()
+ */
+#define FTRACE_STACK_SKIP 3
+#else
+/*
+ * Skip 5:
+ *
+ *   __trace_stack()
  *   ftrace_stacktrace()
  *   function_trace_probe_call()
- *   ftrace_ops_list_func()
+ *   ftrace_ops_assist_func()
  *   ftrace_call()
  */
-#define STACK_SKIP 4
+#define FTRACE_STACK_SKIP 5
+#endif
 
 static __always_inline void trace_stack(struct trace_array *tr)
 {
@@ -384,7 +407,7 @@ static __always_inline void trace_stack(struct trace_array *tr)
         local_save_flags(flags);
         pc = preempt_count();
 
-        __trace_stack(tr, flags, STACK_SKIP, pc);
+        __trace_stack(tr, flags, FTRACE_STACK_SKIP, pc);
 }
 
 static void