1// SPDX-License-Identifier: GPL-2.0
  2
  3#include <stdio.h>
  4#include <unistd.h>
  5#include <stdlib.h>
  6#include <errno.h>
  7#include <sys/types.h>
  8#include <sys/stat.h>
  9#include <fcntl.h>
 10#include <linux/kernel.h>
 11#include <linux/err.h>
 12#include <traceevent/event-parse.h>
 13#include <api/fs/tracing_path.h>
 14#include <api/fs/fs.h>
 15#include "trace-event.h"
 16#include "machine.h"
 17#include "util.h"
 18
 19/*
 20 * global trace_event object used by trace_event__tp_format
 21 *
 22 * TODO There's no cleanup call for this. Add some sort of
 23 * __exit function support and call trace_event__cleanup
 24 * there.
 25 */
 26static struct trace_event tevent;
 27static bool tevent_initialized;
 28
 29int trace_event__init(struct trace_event *t)
 30{
 31	struct pevent *pevent = pevent_alloc();
 32
 33	if (pevent) {
 34		t->plugin_list = traceevent_load_plugins(pevent);
 35		t->pevent  = pevent;
 36	}
 37
 38	return pevent ? 0 : -1;
 39}
 40
 41static int trace_event__init2(void)
 42{
 43	int be = traceevent_host_bigendian();
 44	struct pevent *pevent;
 45
 46	if (trace_event__init(&tevent))
 47		return -1;
 48
 49	pevent = tevent.pevent;
 50	pevent_set_flag(pevent, PEVENT_NSEC_OUTPUT);
 51	pevent_set_file_bigendian(pevent, be);
 52	pevent_set_host_bigendian(pevent, be);
 53	tevent_initialized = true;
 54	return 0;
 55}
 56
 57int trace_event__register_resolver(struct machine *machine,
 58				   pevent_func_resolver_t *func)
 59{
 60	if (!tevent_initialized && trace_event__init2())
 61		return -1;
 62
 63	return pevent_set_function_resolver(tevent.pevent, func, machine);
 64}
 65
 66void trace_event__cleanup(struct trace_event *t)
 67{
 68	traceevent_unload_plugins(t->plugin_list, t->pevent);
 69	pevent_free(t->pevent);
 70}
 71
 72/*
 73 * Returns pointer with encoded error via <linux/err.h> interface.
 74 */
 75static struct event_format*
 76tp_format(const char *sys, const char *name)
 77{
 78	struct pevent *pevent = tevent.pevent;
 79	struct event_format *event = NULL;
 80	char path[PATH_MAX];
 81	size_t size;
 82	char *data;
 83	int err;
 84
 85	scnprintf(path, PATH_MAX, "%s/%s/%s/format",
 86		  tracing_events_path, sys, name);
 87
 88	err = filename__read_str(path, &data, &size);
 89	if (err)
 90		return ERR_PTR(err);
 91
 92	pevent_parse_format(pevent, &event, data, size, sys);
 93
 94	free(data);
 95	return event;
 96}
 97
 98/*
 99 * Returns pointer with encoded error via <linux/err.h> interface.
100 */
101struct event_format*
102trace_event__tp_format(const char *sys, const char *name)
103{
104	if (!tevent_initialized && trace_event__init2())
105		return ERR_PTR(-ENOMEM);
106
107	return tp_format(sys, name);
108}
109
110struct event_format *trace_event__tp_format_id(int id)
111{
112	if (!tevent_initialized && trace_event__init2())
113		return ERR_PTR(-ENOMEM);
114
115	return pevent_find_event(tevent.pevent, id);
116}