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>

diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 46a27f2..e61a740 100644 (file)
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -122,8 +122,9 @@ extern int filter_current_check_discard(struct ftrace_event_call *call,
                                        struct ring_buffer_event *event);
 
 extern 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);
 
+#define is_signed_type(type)   (((type)(-1)) < 0)
 
 /*
  * The double __builtin_constant_p is because gcc will give us an error
@@ -144,10 +145,10 @@ do {                                                                      \
                __trace_printk(ip, fmt, ##args);                        \
 } while (0)
 
-#define __common_field(type, item)                                     \
+#define __common_field(type, item, is_signed)                          \
        ret = trace_define_field(event_call, #type, "common_" #item,    \
                                 offsetof(typeof(field.ent), item),     \
-                                sizeof(field.ent.item));               \
+                                sizeof(field.ent.item), is_signed);    \
        if (ret)                                                        \
                return ret;
 

diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 1e68114..edb02bc 100644 (file)
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -225,7 +225,7 @@ ftrace_format_##call(struct trace_seq *s)                           \
 #define __field(type, item)                                            \
        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;
 
@@ -234,7 +234,7 @@ ftrace_format_##call(struct trace_seq *s)                           \
        BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);                         \
        ret = trace_define_field(event_call, #type "[" #len "]", #item, \
                                 offsetof(typeof(field), item),         \
-                                sizeof(field.item));                   \
+                                sizeof(field.item), 0);                \
        if (ret)                                                        \
                return ret;
 
@@ -242,7 +242,7 @@ ftrace_format_##call(struct trace_seq *s)                           \
 #define __string(item, src)                                                   \
        ret = trace_define_field(event_call, "__str_loc", #item,               \
                                offsetof(typeof(field), __str_loc_##item),     \
-                               sizeof(field.__str_loc_##item));
+                                sizeof(field.__str_loc_##item), 0);
 
 #undef TRACE_EVENT
 #define TRACE_EVENT(call, proto, args, tstruct, func, print)           \
@@ -253,11 +253,11 @@ ftrace_define_fields_##call(void)                                 \
        struct ftrace_event_call *event_call = &event_##call;           \
        int ret;                                                        \
                                                                        \
-       __common_field(int, type);                                      \
-       __common_field(unsigned char, flags);                           \
-       __common_field(unsigned char, preempt_count);                   \
-       __common_field(int, pid);                                       \
-       __common_field(int, tgid);                                      \
+       __common_field(int, type, 1);                                   \
+       __common_field(unsigned char, flags, 0);                        \
+       __common_field(unsigned char, preempt_count, 0);                \
+       __common_field(int, pid, 1);                                    \
+       __common_field(int, tgid, 1);                                   \
                                                                        \
        tstruct;                                                        \
                                                                        \

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 1fb7d6c..866d010 100644 (file)
--- 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 cfcecc4..5e32e37 100644 (file)
--- 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 1cd1f37..bbbea74 100644 (file)
--- 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 0cb1a14..d06cf89 100644 (file)
--- 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;                                                        \
                                                                        \