X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=ltt-events.c;h=9c4ba27bc2300012ebbfa1a631451e01d0f3db18;hb=950f5c99af3e6cc7be0c852df714d30ae1326bca;hp=e9e076d802238bc07e1aef14e0bb4f1e2914df6b;hpb=a864fb02d6918ad014596afef779c964e061c127;p=lttng-modules.git

diff --git a/ltt-events.c b/ltt-events.c
index e9e076d8..9c4ba27b 100644
--- a/ltt-events.c
+++ b/ltt-events.c
@@ -196,7 +196,7 @@ struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 				       unsigned int read_timer_interval)
 {
 	struct ltt_channel *chan;
-	struct ltt_transport *transport;
+	struct ltt_transport *transport = NULL;
 
 	mutex_lock(&sessions_mutex);
 	if (session->been_active)
@@ -207,6 +207,10 @@ struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 		       transport_name);
 		goto notransport;
 	}
+	if (!try_module_get(transport->owner)) {
+		printk(KERN_WARNING "LTT : Can't lock transport module.\n");
+		goto notransport;
+	}
 	chan = kzalloc(sizeof(struct ltt_channel), GFP_KERNEL);
 	if (!chan)
 		goto nomem;
@@ -224,6 +228,7 @@ struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 		goto create_error;
 	chan->enabled = 1;
 	chan->ops = &transport->ops;
+	chan->transport = transport;
 	list_add(&chan->list, &session->chan);
 	mutex_unlock(&sessions_mutex);
 	return chan;
@@ -231,6 +236,8 @@ struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 create_error:
 	kfree(chan);
 nomem:
+	if (transport)
+		module_put(transport->owner);
 notransport:
 active:
 	mutex_unlock(&sessions_mutex);
@@ -244,6 +251,7 @@ static
 void _ltt_channel_destroy(struct ltt_channel *chan)
 {
 	chan->ops->channel_destroy(chan->chan);
+	module_put(chan->transport->owner);
 	list_del(&chan->list);
 	lttng_destroy_context(chan->ctx);
 	kfree(chan);
@@ -301,6 +309,49 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan,
 		ret = try_module_get(event->desc->owner);
 		WARN_ON_ONCE(!ret);
 		break;
+	case LTTNG_KERNEL_KRETPROBE:
+	{
+		struct ltt_event *event_return;
+
+		/* kretprobe defines 2 events */
+		event_return =
+			kmem_cache_zalloc(event_cache, GFP_KERNEL);
+		if (!event_return)
+			goto register_error;
+		event_return->chan = chan;
+		event_return->filter = filter;
+		event_return->id = chan->free_event_id++;
+		event_return->enabled = 1;
+		event_return->instrumentation = event_param->instrumentation;
+		/*
+		 * Populate ltt_event structure before kretprobe registration.
+		 */
+		smp_wmb();
+		ret = lttng_kretprobes_register(event_param->name,
+				event_param->u.kretprobe.symbol_name,
+				event_param->u.kretprobe.offset,
+				event_param->u.kretprobe.addr,
+				event, event_return);
+		if (ret) {
+			kmem_cache_free(event_cache, event_return);
+			goto register_error;
+		}
+		/* Take 2 refs on the module: one per event. */
+		ret = try_module_get(event->desc->owner);
+		WARN_ON_ONCE(!ret);
+		ret = try_module_get(event->desc->owner);
+		WARN_ON_ONCE(!ret);
+		ret = _ltt_event_metadata_statedump(chan->session, chan,
+						    event_return);
+		if (ret) {
+			kmem_cache_free(event_cache, event_return);
+			module_put(event->desc->owner);
+			module_put(event->desc->owner);
+			goto statedump_error;
+		}
+		list_add(&event_return->list, &chan->session->events);
+		break;
+	}
 	case LTTNG_KERNEL_FUNCTION:
 		ret = lttng_ftrace_register(event_param->name,
 				event_param->u.ftrace.symbol_name,
@@ -353,6 +404,10 @@ int _ltt_event_unregister(struct ltt_event *event)
 		lttng_kprobes_unregister(event);
 		ret = 0;
 		break;
+	case LTTNG_KERNEL_KRETPROBE:
+		lttng_kretprobes_unregister(event);
+		ret = 0;
+		break;
 	case LTTNG_KERNEL_FUNCTION:
 		lttng_ftrace_unregister(event);
 		ret = 0;
@@ -377,6 +432,10 @@ void _ltt_event_destroy(struct ltt_event *event)
 		module_put(event->desc->owner);
 		lttng_kprobes_destroy_private(event);
 		break;
+	case LTTNG_KERNEL_KRETPROBE:
+		module_put(event->desc->owner);
+		lttng_kretprobes_destroy_private(event);
+		break;
 	case LTTNG_KERNEL_FUNCTION:
 		module_put(event->desc->owner);
 		lttng_ftrace_destroy_private(event);