[tip:tracing/filters] tracing: add run-time field descriptions for event filtering
From: Tom Zanussi
Date: Sun Mar 22 2009 - 15:40:50 EST
Commit-ID: cf027f645e6aee4f0ca6197a6b6a57f327fdb13f
Gitweb: http://git.kernel.org/tip/cf027f645e6aee4f0ca6197a6b6a57f327fdb13f
Author: Tom Zanussi <tzanussi@xxxxxxxxx>
AuthorDate: Sun, 22 Mar 2009 03:30:39 -0500
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Sun, 22 Mar 2009 18:11:22 +0100
tracing: add run-time field descriptions for event filtering
This patch makes the field descriptions defined for event tracing
available at run-time, for the event-filtering mechanism introduced
in a subsequent patch.
The common event fields are prepended with 'common_' in the format
display, allowing them to be distinguished from the other fields
that might internally have same name and can therefore be
unambiguously used in filters.
Signed-off-by: Tom Zanussi <tzanussi@xxxxxxxxx>
Acked-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
LKML-Reference: <1237710639.7703.46.camel@charm-linux>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
kernel/trace/trace.h | 30 ++++++++++++++++-------
kernel/trace/trace_events.c | 40 ++++++++++++++++++++++++++++++-
kernel/trace/trace_events_stage_2.h | 45 +++++++++++++++++++++++++++++++++++
kernel/trace/trace_events_stage_3.h | 2 +
4 files changed, 107 insertions(+), 10 deletions(-)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 7cfb741..9288dc7 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -775,16 +775,26 @@ enum {
TRACE_EVENT_TYPE_RAW = 2,
};
+struct ftrace_event_field {
+ struct list_head link;
+ char *name;
+ char *type;
+ int offset;
+ int size;
+};
+
struct ftrace_event_call {
- char *name;
- char *system;
- struct dentry *dir;
- int enabled;
- int (*regfunc)(void);
- void (*unregfunc)(void);
- int id;
- int (*raw_init)(void);
- int (*show_format)(struct trace_seq *s);
+ char *name;
+ char *system;
+ struct dentry *dir;
+ int enabled;
+ int (*regfunc)(void);
+ void (*unregfunc)(void);
+ int id;
+ int (*raw_init)(void);
+ int (*show_format)(struct trace_seq *s);
+ int (*define_fields)(void);
+ struct list_head fields;
#ifdef CONFIG_EVENT_PROFILE
atomic_t profile_count;
@@ -793,6 +803,8 @@ struct ftrace_event_call {
#endif
};
+int trace_define_field(struct ftrace_event_call *call, char *type,
+ char *name, int offset, int size);
void event_trace_printk(unsigned long ip, const char *fmt, ...);
extern struct ftrace_event_call __start_ftrace_events[];
extern struct ftrace_event_call __stop_ftrace_events[];
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 3047b56..961b057 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -19,6 +19,34 @@
static DEFINE_MUTEX(event_mutex);
+int trace_define_field(struct ftrace_event_call *call, char *type,
+ char *name, int offset, int size)
+{
+ struct ftrace_event_field *field;
+
+ field = kmalloc(sizeof(*field), GFP_KERNEL);
+ if (!field)
+ goto err;
+ field->name = kstrdup(name, GFP_KERNEL);
+ if (!field->name)
+ goto err;
+ field->type = kstrdup(type, GFP_KERNEL);
+ if (!field->type)
+ goto err;
+ field->offset = offset;
+ field->size = size;
+ list_add(&field->link, &call->fields);
+
+ return 0;
+err:
+ if (field) {
+ kfree(field->name);
+ kfree(field->type);
+ }
+ kfree(field);
+ return -ENOMEM;
+}
+
static void ftrace_clear_events(void)
{
struct ftrace_event_call *call = (void *)__start_ftrace_events;
@@ -343,7 +371,8 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
#undef FIELD
#define FIELD(type, name) \
- #type, #name, offsetof(typeof(field), name), sizeof(field.name)
+ #type, "common_" #name, offsetof(typeof(field), name), \
+ sizeof(field.name)
static int trace_write_header(struct trace_seq *s)
{
@@ -581,6 +610,15 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events)
call->name);
}
+ if (call->define_fields) {
+ ret = call->define_fields();
+ if (ret < 0) {
+ pr_warning("Could not initialize trace point"
+ " events/%s\n", call->name);
+ return ret;
+ }
+ }
+
/* A trace may not want to export its format */
if (!call->show_format)
return 0;
diff --git a/kernel/trace/trace_events_stage_2.h b/kernel/trace/trace_events_stage_2.h
index 5117c43..30743f7 100644
--- a/kernel/trace/trace_events_stage_2.h
+++ b/kernel/trace/trace_events_stage_2.h
@@ -129,3 +129,48 @@ ftrace_format_##call(struct trace_seq *s) \
}
#include <trace/trace_event_types.h>
+
+#undef __field
+#define __field(type, item) \
+ ret = trace_define_field(event_call, #type, #item, \
+ offsetof(typeof(field), item), \
+ sizeof(field.item)); \
+ if (ret) \
+ return ret;
+
+#undef __array
+#define __array(type, item, len) \
+ ret = trace_define_field(event_call, #type "[" #len "]", #item, \
+ offsetof(typeof(field), item), \
+ sizeof(field.item)); \
+ if (ret) \
+ return ret;
+
+#define __common_field(type, item) \
+ ret = trace_define_field(event_call, #type, "common_" #item, \
+ offsetof(typeof(field.ent), item), \
+ sizeof(field.ent.item)); \
+ if (ret) \
+ return ret;
+
+#undef TRACE_EVENT
+#define TRACE_EVENT(call, proto, args, tstruct, func, print) \
+int \
+ftrace_define_fields_##call(void) \
+{ \
+ struct ftrace_raw_##call field; \
+ struct ftrace_event_call *event_call = &event_##call; \
+ 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); \
+ \
+ tstruct; \
+ \
+ return ret; \
+}
+
+#include <trace/trace_event_types.h>
diff --git a/kernel/trace/trace_events_stage_3.h b/kernel/trace/trace_events_stage_3.h
index 6b3261c..468938f 100644
--- a/kernel/trace/trace_events_stage_3.h
+++ b/kernel/trace/trace_events_stage_3.h
@@ -252,6 +252,7 @@ static int ftrace_raw_init_event_##call(void) \
if (!id) \
return -ENODEV; \
event_##call.id = id; \
+ INIT_LIST_HEAD(&event_##call.fields); \
return 0; \
} \
\
@@ -264,6 +265,7 @@ __attribute__((section("_ftrace_events"))) event_##call = { \
.regfunc = ftrace_raw_reg_event_##call, \
.unregfunc = ftrace_raw_unreg_event_##call, \
.show_format = ftrace_format_##call, \
+ .define_fields = ftrace_define_fields_##call, \
_TRACE_PROFILE_INIT(call) \
}
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