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>

1 files changed, 22 insertions, 7 deletions

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;                                                        \
                                                                         \