[tip:tracing/core] tracing/filters: distinguish between signed and unsigned fields

From: tip-bot for Tom Zanussi
Date: Wed Apr 29 2009 - 08:07:49 EST


Commit-ID: 2d7bd214b4fb1c6fff0307459badfc4632509eb9
Gitweb: http://git.kernel.org/tip/2d7bd214b4fb1c6fff0307459badfc4632509eb9
Author: Tom Zanussi <tzanussi@xxxxxxxxx>
AuthorDate: Tue, 28 Apr 2009 03:04:53 -0500
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Wed, 29 Apr 2009 12:37:55 +0200

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@xxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: fweisbec@xxxxxxxxx
Cc: Li Zefan <lizf@xxxxxxxxxxxxxx>
LKML-Reference: <1240905893.6416.120.camel@tropicana>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>


---
include/linux/ftrace_event.h | 7 ++++---
include/trace/ftrace.h | 16 ++++++++--------
kernel/trace/trace.h | 1 +
kernel/trace/trace_event_types.h | 4 ++--
kernel/trace/trace_events.c | 3 ++-
kernel/trace/trace_export.c | 29 ++++++++++++++++++++++-------
6 files changed, 39 insertions(+), 21 deletions(-)

diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 46a27f2..e61a740 100644
--- 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
--- 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
--- 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
--- 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
--- 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
--- 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; \
\
--
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