1// SPDX-License-Identifier: GPL-2.0
2#include <stdio.h>
3#include <unistd.h>
4#include <stdlib.h>
5#include <errno.h>
6#include <sys/types.h>
7#include <sys/stat.h>
8#include <fcntl.h>
9#include <linux/kernel.h>
10#include <linux/err.h>
11#include <traceevent/event-parse.h>
12#include <api/fs/tracing_path.h>
13#include <api/fs/fs.h>
14#include "trace-event.h"
15#include "machine.h"
16
17/*
18 * global trace_event object used by trace_event__tp_format
19 *
20 * TODO There's no cleanup call for this. Add some sort of
21 * __exit function support and call trace_event__cleanup
22 * there.
23 */
24static struct trace_event tevent;
25static bool tevent_initialized;
26
27int trace_event__init(struct trace_event *t)
28{
29	struct tep_handle *pevent = tep_alloc();
30
31	if (pevent) {
32		t->plugin_list = tep_load_plugins(pevent);
33		t->pevent  = pevent;
34	}
35
36	return pevent ? 0 : -1;
37}
38
39static int trace_event__init2(void)
40{
41	int be = tep_is_bigendian();
42	struct tep_handle *pevent;
43
44	if (trace_event__init(&tevent))
45		return -1;
46
47	pevent = tevent.pevent;
48	tep_set_flag(pevent, TEP_NSEC_OUTPUT);
49	tep_set_file_bigendian(pevent, be);
50	tep_set_local_bigendian(pevent, be);
51	tevent_initialized = true;
52	return 0;
53}
54
55int trace_event__register_resolver(struct machine *machine,
56				   tep_func_resolver_t *func)
57{
58	if (!tevent_initialized && trace_event__init2())
59		return -1;
60
61	return tep_set_function_resolver(tevent.pevent, func, machine);
62}
63
64void trace_event__cleanup(struct trace_event *t)
65{
66	tep_unload_plugins(t->plugin_list, t->pevent);
67	tep_free(t->pevent);
68}
69
70/*
71 * Returns pointer with encoded error via <linux/err.h> interface.
72 */
73static struct tep_event*
74tp_format(const char *sys, const char *name)
75{
76	char *tp_dir = get_events_file(sys);
77	struct tep_handle *pevent = tevent.pevent;
78	struct tep_event *event = NULL;
79	char path[PATH_MAX];
80	size_t size;
81	char *data;
82	int err;
83
84	if (!tp_dir)
85		return ERR_PTR(-errno);
86
87	scnprintf(path, PATH_MAX, "%s/%s/format", tp_dir, name);
88	put_events_file(tp_dir);
89
90	err = filename__read_str(path, &data, &size);
91	if (err)
92		return ERR_PTR(err);
93
94	tep_parse_format(pevent, &event, data, size, sys);
95
96	free(data);
97	return event;
98}
99
100/*
101 * Returns pointer with encoded error via <linux/err.h> interface.
102 */
103struct tep_event*
104trace_event__tp_format(const char *sys, const char *name)
105{
106	if (!tevent_initialized && trace_event__init2())
107		return ERR_PTR(-ENOMEM);
108
109	return tp_format(sys, name);
110}
111
112struct tep_event *trace_event__tp_format_id(int id)
113{
114	if (!tevent_initialized && trace_event__init2())
115		return ERR_PTR(-ENOMEM);
116
117	return tep_find_event(tevent.pevent, id);
118}
119