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 */
24 static struct trace_event tevent;
25 static bool tevent_initialized;
26
27 int 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
39 static 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
55 int 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
64 void 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 */
73 static struct tep_event*
74 tp_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 */
103 struct tep_event*
104 trace_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
112 struct 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
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