4 * Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
6 * Holds LTTng probes registry.
9 #include <linux/module.h>
10 #include <linux/list.h>
11 #include <linux/mutex.h>
12 #include <linux/seq_file.h>
14 #include "ltt-events.h"
16 static LIST_HEAD(probe_list
);
17 static DEFINE_MUTEX(probe_mutex
);
20 const struct lttng_event_desc
*find_event(const char *name
)
22 struct lttng_probe_desc
*probe_desc
;
25 list_for_each_entry(probe_desc
, &probe_list
, head
) {
26 for (i
= 0; i
< probe_desc
->nr_events
; i
++) {
27 if (!strcmp(probe_desc
->event_desc
[i
].name
, name
))
28 return &probe_desc
->event_desc
[i
];
34 int ltt_probe_register(struct lttng_probe_desc
*desc
)
39 mutex_lock(&probe_mutex
);
41 * TODO: This is O(N^2). Turn into a hash table when probe registration
42 * overhead becomes an issue.
44 for (i
= 0; i
< desc
->nr_events
; i
++) {
45 if (find_event(desc
->event_desc
[i
].name
)) {
50 list_add(&desc
->head
, &probe_list
);
52 mutex_unlock(&probe_mutex
);
55 EXPORT_SYMBOL_GPL(ltt_probe_register
);
57 void ltt_probe_unregister(struct lttng_probe_desc
*desc
)
59 mutex_lock(&probe_mutex
);
60 list_del(&desc
->head
);
61 mutex_unlock(&probe_mutex
);
63 EXPORT_SYMBOL_GPL(ltt_probe_unregister
);
65 const struct lttng_event_desc
*ltt_event_get(const char *name
)
67 const struct lttng_event_desc
*event
;
70 mutex_lock(&probe_mutex
);
71 event
= find_event(name
);
72 mutex_unlock(&probe_mutex
);
75 ret
= try_module_get(event
->owner
);
79 EXPORT_SYMBOL_GPL(ltt_event_get
);
81 void ltt_event_put(const struct lttng_event_desc
*event
)
83 module_put(event
->owner
);
85 EXPORT_SYMBOL_GPL(ltt_event_put
);
88 void *tp_list_start(struct seq_file
*m
, loff_t
*pos
)
90 struct lttng_probe_desc
*probe_desc
;
93 mutex_lock(&probe_mutex
);
94 list_for_each_entry(probe_desc
, &probe_list
, head
) {
95 for (i
= 0; i
< probe_desc
->nr_events
; i
++) {
97 return (void *) &probe_desc
->event_desc
[i
];
105 void *tp_list_next(struct seq_file
*m
, void *p
, loff_t
*ppos
)
107 struct lttng_probe_desc
*probe_desc
;
111 list_for_each_entry(probe_desc
, &probe_list
, head
) {
112 for (i
= 0; i
< probe_desc
->nr_events
; i
++) {
114 return (void *) &probe_desc
->event_desc
[i
];
122 void tp_list_stop(struct seq_file
*m
, void *p
)
124 mutex_unlock(&probe_mutex
);
128 int tp_list_show(struct seq_file
*m
, void *p
)
130 const struct lttng_event_desc
*probe_desc
= p
;
133 * Don't export lttng internal events (metadata).
135 if (!strncmp(probe_desc
->name
, "lttng_", sizeof("lttng_") - 1))
137 seq_printf(m
, "event { name = %s; };\n",
143 const struct seq_operations lttng_tracepoint_list_seq_ops
= {
144 .start
= tp_list_start
,
145 .next
= tp_list_next
,
146 .stop
= tp_list_stop
,
147 .show
= tp_list_show
,
151 int lttng_tracepoint_list_open(struct inode
*inode
, struct file
*file
)
153 return seq_open(file
, <tng_tracepoint_list_seq_ops
);
156 const struct file_operations lttng_tracepoint_list_fops
= {
157 .open
= lttng_tracepoint_list_open
,
160 .release
= seq_release
,