X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=ltt-probes.c;h=81dcbd715df08300b6bcfd9973418f853544e8d0;hb=6fb8de4b6c1e8dcc69ff6f67310c5cf29718101a;hp=f8f1ef225b417473fb0c6a69fc969fe4cbac40bd;hpb=dda6a249b86e7f06e82fb18a26e981522d9e852d;p=lttng-modules.git

diff --git a/ltt-probes.c b/ltt-probes.c
index f8f1ef22..81dcbd71 100644
--- a/ltt-probes.c
+++ b/ltt-probes.c
@@ -4,108 +4,161 @@
  * 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, &lttng_tracepoint_list_seq_ops);
 }
+
+const struct file_operations lttng_tracepoint_list_fops = {
+	.owner = THIS_MODULE,
+	.open = lttng_tracepoint_list_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = seq_release,
+};