tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 <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#include "util.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 */
25static struct trace_event tevent;
26static bool tevent_initialized;
27
28int trace_event__init(struct trace_event *t)
29{
30 struct pevent *pevent = pevent_alloc();
31
32 if (pevent) {
33 t->plugin_list = traceevent_load_plugins(pevent);
34 t->pevent = pevent;
35 }
36
37 return pevent ? 0 : -1;
38}
39
40static int trace_event__init2(void)
41{
42 int be = traceevent_host_bigendian();
43 struct pevent *pevent;
44
45 if (trace_event__init(&tevent))
46 return -1;
47
48 pevent = tevent.pevent;
49 pevent_set_flag(pevent, PEVENT_NSEC_OUTPUT);
50 pevent_set_file_bigendian(pevent, be);
51 pevent_set_host_bigendian(pevent, be);
52 tevent_initialized = true;
53 return 0;
54}
55
56int trace_event__register_resolver(struct machine *machine,
57 pevent_func_resolver_t *func)
58{
59 if (!tevent_initialized && trace_event__init2())
60 return -1;
61
62 return pevent_set_function_resolver(tevent.pevent, func, machine);
63}
64
65void trace_event__cleanup(struct trace_event *t)
66{
67 traceevent_unload_plugins(t->plugin_list, t->pevent);
68 pevent_free(t->pevent);
69}
70
71/*
72 * Returns pointer with encoded error via <linux/err.h> interface.
73 */
74static struct event_format*
75tp_format(const char *sys, const char *name)
76{
77 struct pevent *pevent = tevent.pevent;
78 struct event_format *event = NULL;
79 char path[PATH_MAX];
80 size_t size;
81 char *data;
82 int err;
83
84 scnprintf(path, PATH_MAX, "%s/%s/%s/format",
85 tracing_events_path, sys, name);
86
87 err = filename__read_str(path, &data, &size);
88 if (err)
89 return ERR_PTR(err);
90
91 pevent_parse_format(pevent, &event, data, size, sys);
92
93 free(data);
94 return event;
95}
96
97/*
98 * Returns pointer with encoded error via <linux/err.h> interface.
99 */
100struct event_format*
101trace_event__tp_format(const char *sys, const char *name)
102{
103 if (!tevent_initialized && trace_event__init2())
104 return ERR_PTR(-ENOMEM);
105
106 return tp_format(sys, name);
107}
108
109struct event_format *trace_event__tp_format_id(int id)
110{
111 if (!tevent_initialized && trace_event__init2())
112 return ERR_PTR(-ENOMEM);
113
114 return pevent_find_event(tevent.pevent, id);
115}