linux/tools/perf/util/trace-event.c

117 lines
2.5 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <linux/kernel.h>
#include <linux/err.h>
#include <traceevent/event-parse.h>
#include <api/fs/tracing_path.h>
#include <api/fs/fs.h>
#include "trace-event.h"
#include "machine.h"
#include "util.h"
/*
* global trace_event object used by trace_event__tp_format
*
* TODO There's no cleanup call for this. Add some sort of
* __exit function support and call trace_event__cleanup
* there.
*/
static struct trace_event tevent;
static bool tevent_initialized;
int trace_event__init(struct trace_event *t)
{
struct pevent *pevent = pevent_alloc();
if (pevent) {
t->plugin_list = traceevent_load_plugins(pevent);
t->pevent = pevent;
}
return pevent ? 0 : -1;
}
static int trace_event__init2(void)
{
int be = traceevent_host_bigendian();
struct pevent *pevent;
if (trace_event__init(&tevent))
return -1;
pevent = tevent.pevent;
pevent_set_flag(pevent, PEVENT_NSEC_OUTPUT);
pevent_set_file_bigendian(pevent, be);
pevent_set_host_bigendian(pevent, be);
tevent_initialized = true;
return 0;
}
int trace_event__register_resolver(struct machine *machine,
pevent_func_resolver_t *func)
{
if (!tevent_initialized && trace_event__init2())
return -1;
return pevent_set_function_resolver(tevent.pevent, func, machine);
}
void trace_event__cleanup(struct trace_event *t)
{
traceevent_unload_plugins(t->plugin_list, t->pevent);
pevent_free(t->pevent);
}
/*
* Returns pointer with encoded error via <linux/err.h> interface.
*/
static struct event_format*
tp_format(const char *sys, const char *name)
{
struct pevent *pevent = tevent.pevent;
struct event_format *event = NULL;
char path[PATH_MAX];
size_t size;
char *data;
int err;
scnprintf(path, PATH_MAX, "%s/%s/%s/format",
tracing_events_path, sys, name);
err = filename__read_str(path, &data, &size);
if (err)
return ERR_PTR(err);
pevent_parse_format(pevent, &event, data, size, sys);
free(data);
return event;
}
/*
* Returns pointer with encoded error via <linux/err.h> interface.
*/
struct event_format*
trace_event__tp_format(const char *sys, const char *name)
{
if (!tevent_initialized && trace_event__init2())
return ERR_PTR(-ENOMEM);
return tp_format(sys, name);
}
struct event_format *trace_event__tp_format_id(int id)
{
if (!tevent_initialized && trace_event__init2())
return ERR_PTR(-ENOMEM);
return pevent_find_event(tevent.pevent, id);
}