tracing: define TRACE_DEFINE_SIZEOF() macro to map sizeof's to their values
Perf has a problem that if sizeof() macros are used within TRACE_EVENT()
macro's they end up in userspace as "sizeof(kernel structure)" which
cannot properly be parsed. Add a macro which can forward this data
through the eval_map for userspace utilization.
Link: http://lkml.kernel.org/r/20170531215653.3240-10-jeremy.linton@arm.com
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index 49cce5f..3976fa1 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -46,6 +46,19 @@ TRACE_MAKE_SYSTEM_STR();
__attribute__((section("_ftrace_eval_map"))) \
*TRACE_SYSTEM##_##a = &__##TRACE_SYSTEM##_##a
+#undef TRACE_DEFINE_SIZEOF
+#define TRACE_DEFINE_SIZEOF(a) \
+ static struct trace_eval_map __used __initdata \
+ __##TRACE_SYSTEM##_##a = \
+ { \
+ .system = TRACE_SYSTEM_STRING, \
+ .eval_string = "sizeof(" #a ")", \
+ .eval_value = sizeof(a) \
+ }; \
+ static struct trace_eval_map __used \
+ __attribute__((section("_ftrace_eval_map"))) \
+ *TRACE_SYSTEM##_##a = &__##TRACE_SYSTEM##_##a
+
/*
* DECLARE_EVENT_CLASS can be used to add a generic function
* handlers for events. That is, if all events have the same
@@ -158,6 +171,9 @@ TRACE_MAKE_SYSTEM_STR();
#undef TRACE_DEFINE_ENUM
#define TRACE_DEFINE_ENUM(a)
+#undef TRACE_DEFINE_SIZEOF
+#define TRACE_DEFINE_SIZEOF(a)
+
#undef __field
#define __field(type, item)
