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authorSteven Rostedt <rostedt@goodmis.org>2014-06-17 08:59:16 -0400
committerSteven Rostedt <rostedt@goodmis.org>2014-06-21 00:18:42 -0400
commit4d4c9cc839a308be3289a361ccba4447ee140552 (patch)
tree404a0a22a3700c16ef3437b69fefe46c06cf5f91
parentea73c79e33c45e1fa0071e216f06fd5682314490 (diff)
downloadlinux-4d4c9cc839a308be3289a361ccba4447ee140552.tar.gz
tracing: Add __field_struct macro for TRACE_EVENT()
Currently the __field() macro in TRACE_EVENT is only good for primitive values, such as integers and pointers, but it fails on complex data types such as structures or unions. This is because the __field() macro determines if the variable is signed or not with the test of: (((type)(-1)) < (type)1) Unfortunately, that fails when type is a structure. Since trace events should support structures as fields a new macro is created for such a case called __field_struct() which acts exactly the same as __field() does but it does not do the signed type check and just uses a constant false for that answer. Cc: Tony Luck <tony.luck@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r--include/trace/ftrace.h33
-rw-r--r--samples/trace_events/trace-events-sample.h3
2 files changed, 35 insertions, 1 deletions
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 0fd06fef9fac..26b4f2e13275 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -44,6 +44,12 @@
#undef __field_ext
#define __field_ext(type, item, filter_type) type item;
+#undef __field_struct
+#define __field_struct(type, item) type item;
+
+#undef __field_struct_ext
+#define __field_struct_ext(type, item, filter_type) type item;
+
#undef __array
#define __array(type, item, len) type item[len];
@@ -122,6 +128,12 @@
#undef __field_ext
#define __field_ext(type, item, filter_type)
+#undef __field_struct
+#define __field_struct(type, item)
+
+#undef __field_struct_ext
+#define __field_struct_ext(type, item, filter_type)
+
#undef __array
#define __array(type, item, len)
@@ -315,9 +327,21 @@ static struct trace_event_functions ftrace_event_type_funcs_##call = { \
if (ret) \
return ret;
+#undef __field_struct_ext
+#define __field_struct_ext(type, item, filter_type) \
+ ret = trace_define_field(event_call, #type, #item, \
+ offsetof(typeof(field), item), \
+ sizeof(field.item), \
+ 0, filter_type); \
+ if (ret) \
+ return ret;
+
#undef __field
#define __field(type, item) __field_ext(type, item, FILTER_OTHER)
+#undef __field_struct
+#define __field_struct(type, item) __field_struct_ext(type, item, FILTER_OTHER)
+
#undef __array
#define __array(type, item, len) \
do { \
@@ -379,6 +403,12 @@ ftrace_define_fields_##call(struct ftrace_event_call *event_call) \
#undef __field_ext
#define __field_ext(type, item, filter_type)
+#undef __field_struct
+#define __field_struct(type, item)
+
+#undef __field_struct_ext
+#define __field_struct_ext(type, item, filter_type)
+
#undef __array
#define __array(type, item, len)
@@ -550,6 +580,9 @@ static inline notrace int ftrace_get_offsets_##call( \
#undef __field
#define __field(type, item)
+#undef __field_struct
+#define __field_struct(type, item)
+
#undef __array
#define __array(type, item, len)
diff --git a/samples/trace_events/trace-events-sample.h b/samples/trace_events/trace-events-sample.h
index 6af373236d73..4b0113f73ee9 100644
--- a/samples/trace_events/trace-events-sample.h
+++ b/samples/trace_events/trace-events-sample.h
@@ -56,7 +56,8 @@
* struct: This defines the way the data will be stored in the ring buffer.
* There are currently two types of elements. __field and __array.
* a __field is broken up into (type, name). Where type can be any
- * type but an array.
+ * primitive type (integer, long or pointer). __field_struct() can
+ * be any static complex data value (struct, union, but not an array).
* For an array. there are three fields. (type, name, size). The
* type of elements in the array, the name of the field and the size
* of the array.