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;                                                        \
                                                                         \