X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=lttng-events.c;h=39e04e51dd0918559b03f35f1f4a215726abb95c;hb=refs%2Fheads%2Fstable-2.4;hp=97d82a297b911d9ad945cc6b88e484d87d2d8fb3;hpb=abc0446a8da1fe7cc09a546389cbcc932b265520;p=lttng-modules.git

diff --git a/lttng-events.c b/lttng-events.c
index 97d82a29..39e04e51 100644
--- a/lttng-events.c
+++ b/lttng-events.c
@@ -98,6 +98,8 @@ struct lttng_session *lttng_session_create(void)
 	kref_init(&metadata_cache->refcount);
 	session->metadata_cache = metadata_cache;
 	INIT_LIST_HEAD(&metadata_cache->metadata_stream);
+	memcpy(&metadata_cache->uuid, &session->uuid,
+		sizeof(metadata_cache->uuid));
 	list_add(&session->list, &sessions);
 	mutex_unlock(&sessions_mutex);
 	return session;
@@ -368,7 +370,7 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan,
 
 	mutex_lock(&sessions_mutex);
 	if (chan->free_event_id == -1U) {
-		event = ERR_PTR(-EMFILE);
+		ret = -EMFILE;
 		goto full;
 	}
 	/*
@@ -377,13 +379,13 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan,
 	 */
 	list_for_each_entry(event, &chan->session->events, list) {
 		if (!strcmp(event->desc->name, event_param->name)) {
-			event = ERR_PTR(-EEXIST);
+			ret = -EEXIST;
 			goto exist;
 		}
 	}
 	event = kmem_cache_zalloc(event_cache, GFP_KERNEL);
 	if (!event) {
-		event = ERR_PTR(-ENOMEM);
+		ret = -ENOMEM;
 		goto cache_error;
 	}
 	event->chan = chan;
@@ -397,14 +399,14 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan,
 	case LTTNG_KERNEL_TRACEPOINT:
 		event->desc = lttng_event_get(event_param->name);
 		if (!event->desc) {
-			event = ERR_PTR(-ENOENT);
+			ret = -ENOENT;
 			goto register_error;
 		}
-		ret = kabi_2635_tracepoint_probe_register(event_param->name,
+		ret = kabi_2635_tracepoint_probe_register(event->desc->kname,
 				event->desc->probe_callback,
 				event);
 		if (ret) {
-			event = ERR_PTR(-EINVAL);
+			ret = -EINVAL;
 			goto register_error;
 		}
 		break;
@@ -415,7 +417,7 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan,
 				event_param->u.kprobe.addr,
 				event);
 		if (ret) {
-			event = ERR_PTR(-EINVAL);
+			ret = -EINVAL;
 			goto register_error;
 		}
 		ret = try_module_get(event->desc->owner);
@@ -429,7 +431,7 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan,
 		event_return =
 			kmem_cache_zalloc(event_cache, GFP_KERNEL);
 		if (!event_return) {
-			event = ERR_PTR(-ENOMEM);
+			ret = -ENOMEM;
 			goto register_error;
 		}
 		event_return->chan = chan;
@@ -448,7 +450,7 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan,
 				event, event_return);
 		if (ret) {
 			kmem_cache_free(event_cache, event_return);
-			event = ERR_PTR(-EINVAL);
+			ret = -EINVAL;
 			goto register_error;
 		}
 		/* Take 2 refs on the module: one per event. */
@@ -463,7 +465,6 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan,
 			kmem_cache_free(event_cache, event_return);
 			module_put(event->desc->owner);
 			module_put(event->desc->owner);
-			event = ERR_PTR(ret);
 			goto statedump_error;
 		}
 		list_add(&event_return->list, &chan->session->events);
@@ -474,7 +475,6 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan,
 				event_param->u.ftrace.symbol_name,
 				event);
 		if (ret) {
-			event = ERR_PTR(ret);
 			goto register_error;
 		}
 		ret = try_module_get(event->desc->owner);
@@ -483,19 +483,18 @@ struct lttng_event *lttng_event_create(struct lttng_channel *chan,
 	case LTTNG_KERNEL_NOOP:
 		event->desc = internal_desc;
 		if (!event->desc) {
-			event = ERR_PTR(-EINVAL);
+			ret = -EINVAL;
 			goto register_error;
 		}
 		break;
 	default:
 		WARN_ON_ONCE(1);
-		event = ERR_PTR(-EINVAL);
+		ret = -EINVAL;
 		goto register_error;
 	}
 	ret = _lttng_event_metadata_statedump(chan->session, chan, event);
 	WARN_ON_ONCE(ret > 0);
 	if (ret) {
-		event = ERR_PTR(ret);
 		goto statedump_error;
 	}
 	list_add(&event->list, &chan->session->events);
@@ -510,7 +509,7 @@ cache_error:
 exist:
 full:
 	mutex_unlock(&sessions_mutex);
-	return event;
+	return ERR_PTR(ret);
 }
 
 /*
@@ -522,7 +521,7 @@ int _lttng_event_unregister(struct lttng_event *event)
 
 	switch (event->instrumentation) {
 	case LTTNG_KERNEL_TRACEPOINT:
-		ret = kabi_2635_tracepoint_probe_unregister(event->desc->name,
+		ret = kabi_2635_tracepoint_probe_unregister(event->desc->kname,
 						  event->desc->probe_callback,
 						  event);
 		if (ret)
@@ -600,16 +599,20 @@ int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
 
 	/*
 	 * Ensure we support mutiple get_next / put sequences followed
-	 * by put_next.
+	 * by put_next. The metadata stream lock internally protects
+	 * reading the metadata cache. It can indeed be read
+	 * concurrently by "get_next_subbuf" and "flush" operations on
+	 * the buffer invoked by different processes.
 	 */
+	mutex_lock(&stream->lock);
 	WARN_ON(stream->metadata_in < stream->metadata_out);
 	if (stream->metadata_in != stream->metadata_out)
-		return 0;
+		goto end;
 
 	len = stream->metadata_cache->metadata_written -
 		stream->metadata_in;
 	if (!len)
-		return 0;
+		goto end;
 	reserve_len = min_t(size_t,
 			stream->transport->ops.packet_avail_size(chan),
 			len);
@@ -631,6 +634,7 @@ int lttng_metadata_output_channel(struct lttng_metadata_stream *stream,
 	ret = reserve_len;
 
 end:
+	mutex_unlock(&stream->lock);
 	return ret;
 }
 
@@ -1289,4 +1293,5 @@ MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
 MODULE_DESCRIPTION("LTTng Events");
 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
 	__stringify(LTTNG_MODULES_MINOR_VERSION) "."
-	__stringify(LTTNG_MODULES_PATCHLEVEL_VERSION));
+	__stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
+	LTTNG_MODULES_EXTRAVERSION);