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.
Signed-off-by: Jeremy Linton <jeremy.linton@xxxxxxx>
---
include/linux/tracepoint.h | 1 +
include/trace/trace_events.h | 16 ++++++++++++++++
2 files changed, 17 insertions(+)
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index f7b0f55..a26ffbe 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -88,6 +88,7 @@ extern void syscall_unregfunc(void);
#define PARAMS(args...) args
#define TRACE_DEFINE_ENUM(x)
+#define TRACE_DEFINE_SIZEOF(x)
#endif /* _LINUX_TRACEPOINT_H */
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)
--
2.9.4
