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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}