tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 tep_handle *pevent = tep_alloc();
32
33 if (pevent) {
34 t->plugin_list = tep_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 = tep_is_bigendian();
44 struct tep_handle *pevent;
45
46 if (trace_event__init(&tevent))
47 return -1;
48
49 pevent = tevent.pevent;
50 tep_set_flag(pevent, TEP_NSEC_OUTPUT);
51 tep_set_file_bigendian(pevent, be);
52 tep_set_local_bigendian(pevent, be);
53 tevent_initialized = true;
54 return 0;
55}
56
57int trace_event__register_resolver(struct machine *machine,
58 tep_func_resolver_t *func)
59{
60 if (!tevent_initialized && trace_event__init2())
61 return -1;
62
63 return tep_set_function_resolver(tevent.pevent, func, machine);
64}
65
66void trace_event__cleanup(struct trace_event *t)
67{
68 tep_unload_plugins(t->plugin_list, t->pevent);
69 tep_free(t->pevent);
70}
71
72/*
73 * Returns pointer with encoded error via <linux/err.h> interface.
74 */
75static struct tep_event*
76tp_format(const char *sys, const char *name)
77{
78 char *tp_dir = get_events_file(sys);
79 struct tep_handle *pevent = tevent.pevent;
80 struct tep_event *event = NULL;
81 char path[PATH_MAX];
82 size_t size;
83 char *data;
84 int err;
85
86 if (!tp_dir)
87 return ERR_PTR(-errno);
88
89 scnprintf(path, PATH_MAX, "%s/%s/format", tp_dir, name);
90 put_events_file(tp_dir);
91
92 err = filename__read_str(path, &data, &size);
93 if (err)
94 return ERR_PTR(err);
95
96 tep_parse_format(pevent, &event, data, size, sys);
97
98 free(data);
99 return event;
100}
101
102/*
103 * Returns pointer with encoded error via <linux/err.h> interface.
104 */
105struct tep_event*
106trace_event__tp_format(const char *sys, const char *name)
107{
108 if (!tevent_initialized && trace_event__init2())
109 return ERR_PTR(-ENOMEM);
110
111 return tp_format(sys, name);
112}
113
114struct tep_event *trace_event__tp_format_id(int id)
115{
116 if (!tevent_initialized && trace_event__init2())
117 return ERR_PTR(-ENOMEM);
118
119 return tep_find_event(tevent.pevent, id);
120}