[PATCH 2/4] tracing/filters: add TRACE_EVENT_FORMAT_NOFILTER event macro

From: Steven Rostedt
Date: Thu Apr 02 2009 - 01:35:53 EST


From: Tom Zanussi <tzanussi@xxxxxxxxx>

Frederic Weisbecker suggested that the trace_special event shouldn't be
filterable; this patch adds a TRACE_EVENT_FORMAT_NOFILTER event macro
that allows an event format to be exported without having a filter
attached, and removes filtering from the trace_special event.

Signed-off-by: Tom Zanussi <tzanussi@xxxxxxxxx>
Signed-off-by: Steven Rostedt <srostedt@xxxxxxxxxx>
---
kernel/trace/trace.c | 2 --
kernel/trace/trace.h | 2 ++
kernel/trace/trace_event_types.h | 2 +-
kernel/trace/trace_export.c | 33 +++++++++++++++++++++++++++++++++
4 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 9a10af0..8c27ac4 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1073,7 +1073,6 @@ ftrace_trace_special(void *__tr,
unsigned long arg1, unsigned long arg2, unsigned long arg3,
int pc)
{
- struct ftrace_event_call *call = &event_special;
struct ring_buffer_event *event;
struct trace_array *tr = __tr;
struct special_entry *entry;
@@ -1086,7 +1085,6 @@ ftrace_trace_special(void *__tr,
entry->arg1 = arg1;
entry->arg2 = arg2;
entry->arg3 = arg3;
- filter_check_discard(call, entry, event);
trace_buffer_unlock_commit(tr, event, 0, pc);
}

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index e1615d9..12316e3 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -907,6 +907,8 @@ do { \
#undef TRACE_EVENT_FORMAT
#define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt) \
extern struct ftrace_event_call event_##call;
+#undef TRACE_EVENT_FORMAT_NOFILTER
+#define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct, tpfmt)
#include "trace_event_types.h"

#endif /* _LINUX_KERNEL_TRACE_H */
diff --git a/kernel/trace/trace_event_types.h b/kernel/trace/trace_event_types.h
index 95b147a..cfcecc4 100644
--- a/kernel/trace/trace_event_types.h
+++ b/kernel/trace/trace_event_types.h
@@ -57,7 +57,7 @@ TRACE_EVENT_FORMAT(context_switch, TRACE_CTX, ctx_switch_entry, ignore,
TP_RAW_FMT("%u:%u:%u ==+ %u:%u:%u [%03u]")
);

-TRACE_EVENT_FORMAT(special, TRACE_SPECIAL, special_entry, ignore,
+TRACE_EVENT_FORMAT_NOFILTER(special, TRACE_SPECIAL, special_entry, ignore,
TRACE_STRUCT(
TRACE_FIELD(unsigned long, arg1, arg1)
TRACE_FIELD(unsigned long, arg2, arg2)
diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c
index 47989be..a16a29d 100644
--- a/kernel/trace/trace_export.c
+++ b/kernel/trace/trace_export.c
@@ -65,6 +65,22 @@ ftrace_format_##call(struct trace_seq *s) \
return ret; \
}

+#undef TRACE_EVENT_FORMAT_NOFILTER
+#define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct, \
+ tpfmt) \
+static int \
+ftrace_format_##call(struct trace_seq *s) \
+{ \
+ struct args field; \
+ int ret; \
+ \
+ tstruct; \
+ \
+ trace_seq_printf(s, "\nprint fmt: \"%s\"\n", tpfmt); \
+ \
+ return ret; \
+}
+
#include "trace_event_types.h"

#undef TRACE_ZERO_CHAR
@@ -109,6 +125,19 @@ static int ftrace_raw_init_event_##call(void) \
return 0; \
} \

+#undef TRACE_EVENT_FORMAT_NOFILTER
+#define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct, \
+ tpfmt) \
+ \
+struct ftrace_event_call __used \
+__attribute__((__aligned__(4))) \
+__attribute__((section("_ftrace_events"))) event_##call = { \
+ .name = #call, \
+ .id = proto, \
+ .system = __stringify(TRACE_SYSTEM), \
+ .show_format = ftrace_format_##call, \
+};
+
#include "trace_event_types.h"

#undef TRACE_FIELD
@@ -150,4 +179,8 @@ ftrace_define_fields_##call(void) \
return ret; \
}

+#undef TRACE_EVENT_FORMAT_NOFILTER
+#define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct, \
+ tpfmt)
+
#include "trace_event_types.h"
--
1.6.2.1

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