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 */
25 static struct trace_event tevent;
26 static bool tevent_initialized;
27
trace_event__init(struct trace_event * t)28 int 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
trace_event__init2(void)40 static 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
trace_event__register_resolver(struct machine * machine,tep_func_resolver_t * func)56 int 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
trace_event__cleanup(struct trace_event * t)65 void 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 */
74 static struct tep_event*
tp_format(const char * sys,const char * name)75 tp_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 */
104 struct tep_event*
trace_event__tp_format(const char * sys,const char * name)105 trace_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
trace_event__tp_format_id(int id)113 struct 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