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 */
26 static struct trace_event tevent;
27 static bool tevent_initialized;
28
trace_event__init(struct trace_event * t)29 int 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
trace_event__init2(void)41 static int trace_event__init2(void)
42 {
43 int be = tep_host_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_host_bigendian(pevent, be);
53 tevent_initialized = true;
54 return 0;
55 }
56
trace_event__register_resolver(struct machine * machine,tep_func_resolver_t * func)57 int 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
trace_event__cleanup(struct trace_event * t)66 void 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 */
75 static struct event_format*
tp_format(const char * sys,const char * name)76 tp_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 event_format *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 */
105 struct event_format*
trace_event__tp_format(const char * sys,const char * name)106 trace_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
trace_event__tp_format_id(int id)114 struct event_format *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 }
121
