xref: /linux/tools/perf/util/trace-event.c (revision 93df8a1ed6231727c5db94a80b1a6bd5ee67cec3)
1 
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 <traceevent/event-parse.h>
11 #include "trace-event.h"
12 #include "machine.h"
13 #include "util.h"
14 
15 /*
16  * global trace_event object used by trace_event__tp_format
17  *
18  * TODO There's no cleanup call for this. Add some sort of
19  * __exit function support and call trace_event__cleanup
20  * there.
21  */
22 static struct trace_event tevent;
23 static bool tevent_initialized;
24 
25 int trace_event__init(struct trace_event *t)
26 {
27 	struct pevent *pevent = pevent_alloc();
28 
29 	if (pevent) {
30 		t->plugin_list = traceevent_load_plugins(pevent);
31 		t->pevent  = pevent;
32 	}
33 
34 	return pevent ? 0 : -1;
35 }
36 
37 static int trace_event__init2(void)
38 {
39 	int be = traceevent_host_bigendian();
40 	struct pevent *pevent;
41 
42 	if (trace_event__init(&tevent))
43 		return -1;
44 
45 	pevent = tevent.pevent;
46 	pevent_set_flag(pevent, PEVENT_NSEC_OUTPUT);
47 	pevent_set_file_bigendian(pevent, be);
48 	pevent_set_host_bigendian(pevent, be);
49 	tevent_initialized = true;
50 	return 0;
51 }
52 
53 int trace_event__register_resolver(struct machine *machine,
54 				   pevent_func_resolver_t *func)
55 {
56 	if (!tevent_initialized && trace_event__init2())
57 		return -1;
58 
59 	return pevent_set_function_resolver(tevent.pevent, func, machine);
60 }
61 
62 void trace_event__cleanup(struct trace_event *t)
63 {
64 	traceevent_unload_plugins(t->plugin_list, t->pevent);
65 	pevent_free(t->pevent);
66 }
67 
68 static struct event_format*
69 tp_format(const char *sys, const char *name)
70 {
71 	struct pevent *pevent = tevent.pevent;
72 	struct event_format *event = NULL;
73 	char path[PATH_MAX];
74 	size_t size;
75 	char *data;
76 
77 	scnprintf(path, PATH_MAX, "%s/%s/%s/format",
78 		  tracing_events_path, sys, name);
79 
80 	if (filename__read_str(path, &data, &size))
81 		return NULL;
82 
83 	pevent_parse_format(pevent, &event, data, size, sys);
84 
85 	free(data);
86 	return event;
87 }
88 
89 struct event_format*
90 trace_event__tp_format(const char *sys, const char *name)
91 {
92 	if (!tevent_initialized && trace_event__init2())
93 		return NULL;
94 
95 	return tp_format(sys, name);
96 }
97