tracing/filters: distinguish between signed and unsigned fields

The new filter comparison ops need to be able to distinguish between
signed and unsigned field types, so add an is_signed flag/param to the
event field struct/trace_define_fields().  Also define a simple macro,
is_signed_type() to determine the signedness at compile time, used in the
trace macros.  If the is_signed_type() macro won't work with a specific
type, a new slightly modified version of TRACE_FIELD() called
TRACE_FIELD_SIGN(), allows the signedness to be set explicitly.

[ Impact: extend trace-filter code for new feature ]

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: fweisbec@gmail.com
Cc: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <1240905893.6416.120.camel@tropicana>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

4 files changed, 27 insertions, 10 deletions

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 1fb7d6ccadf4..866d0108fd2f 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -729,6 +729,7 @@ struct ftrace_event_field {
 	char			*type;
 	int			offset;
 	int			size;
+	int			is_signed;
 };
 
 struct event_filter {
diff --git a/kernel/trace/trace_event_types.h b/kernel/trace/trace_event_types.h
index cfcecc4fd86d..5e32e375134d 100644
--- a/kernel/trace/trace_event_types.h
+++ b/kernel/trace/trace_event_types.h
@@ -141,8 +141,8 @@ TRACE_EVENT_FORMAT(hw_branch, TRACE_HW_BRANCHES, hw_branch_entry, ignore,
 
 TRACE_EVENT_FORMAT(power, TRACE_POWER, trace_power, ignore,
 	TRACE_STRUCT(
-		TRACE_FIELD(ktime_t, state_data.stamp, stamp)
-		TRACE_FIELD(ktime_t, state_data.end, end)
+		TRACE_FIELD_SIGN(ktime_t, state_data.stamp, stamp, 1)
+		TRACE_FIELD_SIGN(ktime_t, state_data.end, end, 1)
 		TRACE_FIELD(int, state_data.type, type)
 		TRACE_FIELD(int, state_data.state, state)
 	),
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 1cd1f37373dd..bbbea7479371 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -26,7 +26,7 @@ static DEFINE_MUTEX(event_mutex);
 LIST_HEAD(ftrace_events);
 
 int trace_define_field(struct ftrace_event_call *call, char *type,
-		       char *name, int offset, int size)
+		       char *name, int offset, int size, int is_signed)
 {
 	struct ftrace_event_field *field;
 
@@ -44,6 +44,7 @@ int trace_define_field(struct ftrace_event_call *call, char *type,
 
 	field->offset = offset;
 	field->size = size;
+	field->is_signed = is_signed;
 	list_add(&field->link, &call->fields);
 
 	return 0;
diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c
index 0cb1a142c74f..d06cf898dc86 100644
--- a/kernel/trace/trace_export.c
+++ b/kernel/trace/trace_export.c
@@ -50,6 +50,9 @@ extern void __bad_type_size(void);
 	if (!ret)							\
 		return 0;
 
+#undef TRACE_FIELD_SIGN
+#define TRACE_FIELD_SIGN(type, item, assign, is_signed)	\
+	TRACE_FIELD(type, item, assign)
 
 #undef TP_RAW_FMT
 #define TP_RAW_FMT(args...) args
@@ -98,6 +101,10 @@ ftrace_format_##call(struct trace_seq *s)				\
 #define TRACE_FIELD(type, item, assign)\
 	entry->item = assign;
 
+#undef TRACE_FIELD_SIGN
+#define TRACE_FIELD_SIGN(type, item, assign, is_signed)	\
+	TRACE_FIELD(type, item, assign)
+
 #undef TP_CMD
 #define TP_CMD(cmd...)	cmd
 
@@ -149,7 +156,7 @@ __attribute__((section("_ftrace_events"))) event_##call = {		\
 #define TRACE_FIELD(type, item, assign)					\
 	ret = trace_define_field(event_call, #type, #item,		\
 				 offsetof(typeof(field), item),		\
-				 sizeof(field.item));			\
+				 sizeof(field.item), is_signed_type(type));	\
 	if (ret)							\
 		return ret;
 
@@ -157,7 +164,15 @@ __attribute__((section("_ftrace_events"))) event_##call = {		\
 #define TRACE_FIELD_SPECIAL(type, item, len, cmd)			\
 	ret = trace_define_field(event_call, #type "[" #len "]", #item,	\
 				 offsetof(typeof(field), item),		\
-				 sizeof(field.item));			\
+				 sizeof(field.item), 0);		\
+	if (ret)							\
+		return ret;
+
+#undef TRACE_FIELD_SIGN
+#define TRACE_FIELD_SIGN(type, item, assign, is_signed)			\
+	ret = trace_define_field(event_call, #type, #item,		\
+				 offsetof(typeof(field), item),		\
+				 sizeof(field.item), is_signed);	\
 	if (ret)							\
 		return ret;
 
@@ -173,11 +188,11 @@ ftrace_define_fields_##call(void)					\
 	struct args field;						\
 	int ret;							\
 									\
-	__common_field(unsigned char, type);				\
-	__common_field(unsigned char, flags);				\
-	__common_field(unsigned char, preempt_count);			\
-	__common_field(int, pid);					\
-	__common_field(int, tgid);					\
+	__common_field(unsigned char, type, 0);				\
+	__common_field(unsigned char, flags, 0);			\
+	__common_field(unsigned char, preempt_count, 0);		\
+	__common_field(int, pid, 1);					\
+	__common_field(int, tgid, 1);					\
 									\
 	tstruct;							\
 									\