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
18/*
19 * global trace_event object used by trace_event__tp_format
20 *
21 * TODO There's no cleanup call for this. Add some sort of
22 * __exit function support and call trace_event__cleanup
23 * there.
24 */
25static struct trace_event tevent;
26static bool tevent_initialized;
27
28int trace_event__init(struct trace_event *t)
29{
30	struct tep_handle *pevent = tep_alloc();
31
32	if (pevent) {
33		t->plugin_list = tep_load_plugins(pevent);
34		t->pevent  = pevent;
35	}
36
37	return pevent ? 0 : -1;
38}
39
40static int trace_event__init2(void)
41{
42	int be = tep_is_bigendian();
43	struct tep_handle *pevent;
44
45	if (trace_event__init(&tevent))
46		return -1;
47
48	pevent = tevent.pevent;
49	tep_set_flag(pevent, TEP_NSEC_OUTPUT);
50	tep_set_file_bigendian(pevent, be);
51	tep_set_local_bigendian(pevent, be);
52	tevent_initialized = true;
53	return 0;
54}
55
56int trace_event__register_resolver(struct machine *machine,
57				   tep_func_resolver_t *func)
58{
59	if (!tevent_initialized && trace_event__init2())
60		return -1;
61
62	return tep_set_function_resolver(tevent.pevent, func, machine);
63}
64
65void trace_event__cleanup(struct trace_event *t)
66{
67	tep_unload_plugins(t->plugin_list, t->pevent);
68	tep_free(t->pevent);
69}
70
71/*
72 * Returns pointer with encoded error via <linux/err.h> interface.
73 */
74static struct tep_event*
75tp_format(const char *sys, const char *name)
76{
77	char *tp_dir = get_events_file(sys);
78	struct tep_handle *pevent = tevent.pevent;
79	struct tep_event *event = NULL;
80	char path[PATH_MAX];
81	size_t size;
82	char *data;
83	int err;
84
85	if (!tp_dir)
86		return ERR_PTR(-errno);
87
88	scnprintf(path, PATH_MAX, "%s/%s/format", tp_dir, name);
89	put_events_file(tp_dir);
90
91	err = filename__read_str(path, &data, &size);
92	if (err)
93		return ERR_PTR(err);
94
95	tep_parse_format(pevent, &event, data, size, sys);
96
97	free(data);
98	return event;
99}
100
101/*
102 * Returns pointer with encoded error via <linux/err.h> interface.
103 */
104struct tep_event*
105trace_event__tp_format(const char *sys, const char *name)
106{
107	if (!tevent_initialized && trace_event__init2())
108		return ERR_PTR(-ENOMEM);
109
110	return tp_format(sys, name);
111}
112
113struct tep_event *trace_event__tp_format_id(int id)
114{
115	if (!tevent_initialized && trace_event__init2())
116		return ERR_PTR(-ENOMEM);
117
118	return tep_find_event(tevent.pevent, id);
119}
120