* Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*
* Holds LTTng probes registry.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
*/
#include <linux/module.h>
#include <linux/list.h>
#include <linux/mutex.h>
-#include <linux/slab.h>
+#include <linux/seq_file.h>
-struct ltt_probe {
- const char *name;
- void *cb;
- struct list_head list;
-};
+#include "ltt-events.h"
static LIST_HEAD(probe_list);
static DEFINE_MUTEX(probe_mutex);
-static struct kmem_cache *probe_cache;
-static struct ltt_probe *find_probe(const char *name)
+static
+const struct lttng_event_desc *find_event(const char *name)
{
- struct ltt_probe *probe;
+ struct lttng_probe_desc *probe_desc;
+ int i;
- list_for_each_entry(probe, &probe_list, list) {
- if (!strcmp(probe->name, name))
- return probe;
+ list_for_each_entry(probe_desc, &probe_list, head) {
+ for (i = 0; i < probe_desc->nr_events; i++) {
+ if (!strcmp(probe_desc->event_desc[i].name, name))
+ return &probe_desc->event_desc[i];
+ }
}
return NULL;
}
-int ltt_probe_register(const char *name, void *cb)
+int ltt_probe_register(struct lttng_probe_desc *desc)
{
- struct ltt_probe *probe;
int ret = 0;
-
- if (!cb)
- return -EPERM;
+ int i;
mutex_lock(&probe_mutex);
- if (find_probe(name)) {
- ret = -EEXIST;
- goto end;
- }
- probe = kmem_cache_zalloc(probe_cache, GFP_KERNEL);
- if (!probe) {
- ret = -ENOMEM;
- goto end;
+ /*
+ * TODO: This is O(N^2). Turn into a hash table when probe registration
+ * overhead becomes an issue.
+ */
+ for (i = 0; i < desc->nr_events; i++) {
+ if (find_event(desc->event_desc[i].name)) {
+ ret = -EEXIST;
+ goto end;
+ }
}
- probe->name = name;
- probe->cb = cb;
- list_add(&probe->list, &probe_list);
+ list_add(&desc->head, &probe_list);
end:
mutex_unlock(&probe_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(ltt_probe_register);
-void ltt_probe_unregister(const char *name)
+void ltt_probe_unregister(struct lttng_probe_desc *desc)
{
- struct ltt_probe *probe;
-
mutex_lock(&probe_mutex);
- probe = find_probe(name);
- WARN_ON_ONCE(!probe);
- list_del(&probe->list);
+ list_del(&desc->head);
mutex_unlock(&probe_mutex);
- kmem_cache_free(probe_cache, probe);
}
EXPORT_SYMBOL_GPL(ltt_probe_unregister);
-void *ltt_probe_get(const char *name)
+const struct lttng_event_desc *ltt_event_get(const char *name)
{
- struct ltt_probe *probe;
- void *cb = NULL;
+ const struct lttng_event_desc *event;
int ret;
mutex_lock(&probe_mutex);
- probe = find_probe(name);
- if (!probe)
- goto end;
- cb = probe->cb;
- ret = try_module_get(__module_text_address((unsigned long) cb));
- WARN_ON_ONCE(!ret);
-end:
+ event = find_event(name);
mutex_unlock(&probe_mutex);
- return cb;
+ if (!event)
+ return NULL;
+ ret = try_module_get(event->owner);
+ WARN_ON_ONCE(!ret);
+ return event;
+}
+EXPORT_SYMBOL_GPL(ltt_event_get);
+
+void ltt_event_put(const struct lttng_event_desc *event)
+{
+ module_put(event->owner);
+}
+EXPORT_SYMBOL_GPL(ltt_event_put);
+
+static
+void *tp_list_start(struct seq_file *m, loff_t *pos)
+{
+ struct lttng_probe_desc *probe_desc;
+ int iter = 0, i;
+
+ mutex_lock(&probe_mutex);
+ list_for_each_entry(probe_desc, &probe_list, head) {
+ for (i = 0; i < probe_desc->nr_events; i++) {
+ if (iter++ >= *pos)
+ return (void *) &probe_desc->event_desc[i];
+ }
+ }
+ /* End of list */
+ return NULL;
}
-EXPORT_SYMBOL_GPL(ltt_probe_get);
-void ltt_probe_put(void *cb)
+static
+void *tp_list_next(struct seq_file *m, void *p, loff_t *ppos)
{
- module_put(__module_text_address((unsigned long) cb));
+ struct lttng_probe_desc *probe_desc;
+ int iter = 0, i;
+
+ (*ppos)++;
+ list_for_each_entry(probe_desc, &probe_list, head) {
+ for (i = 0; i < probe_desc->nr_events; i++) {
+ if (iter++ >= *ppos)
+ return (void *) &probe_desc->event_desc[i];
+ }
+ }
+ /* End of list */
+ return NULL;
}
-EXPORT_SYMBOL_GPL(ltt_probe_put);
-int __init ltt_probes_init(void)
+static
+void tp_list_stop(struct seq_file *m, void *p)
{
- probe_cache = KMEM_CACHE(ltt_probe, 0);
- if (!probe_cache)
- return -ENOMEM;
+ mutex_unlock(&probe_mutex);
+}
+
+static
+int tp_list_show(struct seq_file *m, void *p)
+{
+ const struct lttng_event_desc *probe_desc = p;
+
+ /*
+ * Don't export lttng internal events (metadata).
+ */
+ if (!strncmp(probe_desc->name, "lttng_", sizeof("lttng_") - 1))
+ return 0;
+ seq_printf(m, "event { name = %s; };\n",
+ probe_desc->name);
return 0;
}
-void __exit ltt_probes_exit(void)
+static
+const struct seq_operations lttng_tracepoint_list_seq_ops = {
+ .start = tp_list_start,
+ .next = tp_list_next,
+ .stop = tp_list_stop,
+ .show = tp_list_show,
+};
+
+static
+int lttng_tracepoint_list_open(struct inode *inode, struct file *file)
{
- kmem_cache_destroy(probe_cache);
+ return seq_open(file, <tng_tracepoint_list_seq_ops);
}
+
+const struct file_operations lttng_tracepoint_list_fops = {
+ .open = lttng_tracepoint_list_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
projects / lttng-modules.git / blobdiff