Commit cf027f64 authored by Tom Zanussi's avatar Tom Zanussi Committed by Ingo Molnar
Browse files

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: default avatarTom Zanussi <tzanussi@gmail.com>
Acked-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1237710639.7703.46.camel@charm-linux>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 0cf53ff6
......@@ -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[];
......
......@@ -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;
......
......@@ -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>
......@@ -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) \
}
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment