+
+ DBG("Kernel metadata opened (fd: %d)", lkm->fd);
+
+ return 0;
+
+error:
+ return ret;
+}
+
+/*
+ * kernel_start_session
+ *
+ * Start tracing session.
+ */
+int kernel_start_session(struct ltt_kernel_session *session)
+{
+ int ret;
+
+ ret = kernctl_start_session(session->fd);
+ if (ret < 0) {
+ goto error;
+ }
+
+ DBG("Kernel session started");
+
+ return 0;
+
+error:
+ return ret;
+}
+
+/*
+ * kernel_stop_session
+ *
+ * Stop tracing session.
+ */
+int kernel_stop_session(struct ltt_kernel_session *session)
+{
+ int ret;
+
+ ret = kernctl_stop_session(session->fd);
+ if (ret < 0) {
+ goto error;
+ }
+
+ DBG("Kernel session stopped");
+
+ return 0;
+
+error:
+ return ret;
+}
+
+/*
+ * kernel_create_channel_stream
+ *
+ * Create a stream for a channel.
+ *
+ * Return the number of created stream. Else, a negative value.
+ */
+int kernel_create_channel_stream(struct ltt_kernel_channel *channel)
+{
+ int ret;
+ struct ltt_kernel_stream *lks;
+
+ while ((ret = kernctl_create_stream(channel->fd)) > 0) {
+ lks = malloc(sizeof(struct ltt_kernel_stream));
+ if (lks == NULL) {
+ perror("kernel create stream malloc");
+ ret = -errno;
+ goto error;
+ }
+
+ lks->fd = ret;
+ ret = asprintf(&lks->pathname, "%s/trace_%d",
+ channel->pathname, channel->stream_count);
+ if (ret < 0) {
+ perror("asprintf kernel create stream");
+ goto error;
+ }
+ lks->state = 0;
+
+ cds_list_add(&lks->list, &channel->stream_list.head);
+ channel->stream_count++;
+ }
+
+ DBG("Kernel channel stream created (num: %d)", channel->stream_count);
+
+ return channel->stream_count;
+
+error:
+ return ret;
+}
+
+/*
+ * kernel_create_metadata_stream
+ *
+ * Create the metadata stream.
+ */
+int kernel_create_metadata_stream(struct ltt_kernel_session *session)
+{
+ int ret;
+
+ ret = kernctl_create_stream(session->metadata->fd);
+ if (ret < 0) {
+ perror("kernel create metadata stream");
+ ret = -errno;
+ goto error;
+ }
+
+ DBG("Kernel metadata stream created (fd: %d)", ret);
+ session->metadata_stream_fd = ret;