+ rcu_read_unlock();
+
+ /* /events */
+ ret = config_writer_close_element(writer);
+ if (ret) {
+ ret = LTTNG_ERR_SAVE_IO_FAIL;
+ goto end;
+ }
+
+ ret = LTTNG_OK;
+end:
+ return ret;
+}
+
+/* Return LTTNG_OK on success else a LTTNG_ERR* code. */
+static
+int init_ust_event_from_agent_event(struct ltt_ust_event *ust_event,
+ struct agent_event *agent_event)
+{
+ int ret;
+ enum lttng_ust_loglevel_type ust_loglevel_type;
+
+ ust_event->enabled = agent_event->enabled;
+ ust_event->attr.instrumentation = LTTNG_UST_TRACEPOINT;
+ if (lttng_strncpy(ust_event->attr.name, agent_event->name,
+ LTTNG_SYMBOL_NAME_LEN)) {
+ ret = LTTNG_ERR_INVALID;
+ goto end;
+ }
+ switch (agent_event->loglevel_type) {
+ case LTTNG_EVENT_LOGLEVEL_ALL:
+ ust_loglevel_type = LTTNG_UST_LOGLEVEL_ALL;
+ break;
+ case LTTNG_EVENT_LOGLEVEL_SINGLE:
+ ust_loglevel_type = LTTNG_UST_LOGLEVEL_SINGLE;
+ break;
+ case LTTNG_EVENT_LOGLEVEL_RANGE:
+ ust_loglevel_type = LTTNG_UST_LOGLEVEL_RANGE;
+ break;
+ default:
+ ERR("Invalid agent_event loglevel_type.");
+ ret = LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ ust_event->attr.loglevel_type = ust_loglevel_type;
+ ust_event->attr.loglevel = agent_event->loglevel_value;
+ ust_event->filter_expression = agent_event->filter_expression;
+ ust_event->exclusion = agent_event->exclusion;
+
+ ret = LTTNG_OK;
+end:
+ return ret;
+}
+
+/* Return LTTNG_OK on success else a LTTNG_ERR* code. */
+static
+int save_agent_events(struct config_writer *writer,
+ struct agent *agent)
+{
+ int ret;
+ struct lttng_ht_iter iter;
+ struct lttng_ht_node_str *node;
+
+ ret = config_writer_open_element(writer, config_element_events);
+ if (ret) {
+ ret = LTTNG_ERR_SAVE_IO_FAIL;
+ goto end;
+ }
+
+ rcu_read_lock();
+ cds_lfht_for_each_entry(agent->events->ht, &iter.iter, node, node) {
+ int ret;
+ struct agent_event *agent_event;
+ struct ltt_ust_event fake_event;
+
+ memset(&fake_event, 0, sizeof(fake_event));
+ agent_event = caa_container_of(node, struct agent_event, node);
+
+ /*
+ * Initialize a fake ust event to reuse the same serialization
+ * function since UST and agent events contain the same info
+ * (and one could wonder why they don't reuse the same
+ * structures...).
+ */
+ ret = init_ust_event_from_agent_event(&fake_event, agent_event);
+ if (ret != LTTNG_OK) {
+ rcu_read_unlock();
+ goto end;
+ }
+ ret = save_ust_event(writer, &fake_event);
+ if (ret != LTTNG_OK) {
+ rcu_read_unlock();
+ goto end;
+ }
+ }
+ rcu_read_unlock();
+
+ /* /events */
+ ret = config_writer_close_element(writer);
+ if (ret) {
+ ret = LTTNG_ERR_SAVE_IO_FAIL;
+ goto end;
+ }
+
+ ret = LTTNG_OK;
+end:
+ return ret;
+}
+
+/* Return LTTNG_OK on success else a LTTNG_ERR* code. */
+static
+int save_kernel_context(struct config_writer *writer,
+ struct lttng_kernel_context *ctx)
+{
+ int ret = LTTNG_OK;
+
+ if (!ctx) {
+ goto end;
+ }
+
+ ret = config_writer_open_element(writer, config_element_context);
+ if (ret) {
+ ret = LTTNG_ERR_SAVE_IO_FAIL;
+ goto end;
+ }
+
+ if (ctx->ctx == LTTNG_KERNEL_CONTEXT_PERF_CPU_COUNTER) {
+ ret = config_writer_open_element(writer,
+ config_element_context_perf);
+ if (ret) {
+ ret = LTTNG_ERR_SAVE_IO_FAIL;
+ goto end;
+ }
+
+ ret = config_writer_write_element_unsigned_int(writer,
+ config_element_type, ctx->u.perf_counter.type);
+ if (ret) {
+ ret = LTTNG_ERR_SAVE_IO_FAIL;
+ goto end;
+ }
+
+ ret = config_writer_write_element_unsigned_int(writer,
+ config_element_config, ctx->u.perf_counter.config);
+ if (ret) {
+ ret = LTTNG_ERR_SAVE_IO_FAIL;
+ goto end;
+ }
+
+ ret = config_writer_write_element_string(writer,
+ config_element_name, ctx->u.perf_counter.name);
+ if (ret) {
+ ret = LTTNG_ERR_SAVE_IO_FAIL;
+ goto end;
+ }
+
+ /* /perf */
+ ret = config_writer_close_element(writer);
+ if (ret) {
+ ret = LTTNG_ERR_SAVE_IO_FAIL;
+ goto end;
+ }
+ } else {
+ const char *context_type_string =
+ get_kernel_context_type_string(ctx->ctx);
+
+ if (!context_type_string) {
+ ERR("Unsupported kernel context type.");
+ ret = LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ ret = config_writer_write_element_string(writer,
+ config_element_type, context_type_string);
+ if (ret) {
+ ret = LTTNG_ERR_SAVE_IO_FAIL;
+ goto end;
+ }
+ }
+
+ /* /context */
+ ret = config_writer_close_element(writer);
+ if (ret) {
+ ret = LTTNG_ERR_SAVE_IO_FAIL;
+ goto end;
+ }
+
+ ret = LTTNG_OK;
+end:
+ return ret;
+}
+
+/* Return LTTNG_OK on success else a LTTNG_ERR* code. */
+static
+int save_kernel_contexts(struct config_writer *writer,
+ struct ltt_kernel_channel *kchan)
+{
+ int ret;
+ struct ltt_kernel_context *ctx;
+
+ if (cds_list_empty(&kchan->ctx_list)) {
+ ret = LTTNG_OK;
+ goto end;
+ }
+
+ ret = config_writer_open_element(writer, config_element_contexts);
+ if (ret) {
+ ret = LTTNG_ERR_SAVE_IO_FAIL;
+ goto end;
+ }
+
+ cds_list_for_each_entry(ctx, &kchan->ctx_list, list) {
+ ret = save_kernel_context(writer, &ctx->ctx);
+ if (ret != LTTNG_OK) {
+ goto end;
+ }
+ }
+
+ /* /contexts */
+ ret = config_writer_close_element(writer);
+ if (ret) {
+ ret = LTTNG_ERR_SAVE_IO_FAIL;
+ goto end;
+ }
+
+ ret = LTTNG_OK;
+end:
+ return ret;
+}
+
+/* Return LTTNG_OK on success else a LTTNG_ERR* code. */
+static
+int save_ust_context_perf_thread_counter(struct config_writer *writer,
+ struct ltt_ust_context *ctx)
+{
+ int ret;
+
+ assert(writer);
+ assert(ctx);
+
+ /* Perf contexts are saved as event_perf_context_type */
+ ret = config_writer_open_element(writer, config_element_context_perf);
+ if (ret) {
+ ret = LTTNG_ERR_SAVE_IO_FAIL;
+ goto end;
+ }
+
+ ret = config_writer_write_element_unsigned_int(writer,
+ config_element_type, ctx->ctx.u.perf_counter.type);
+ if (ret) {
+ ret = LTTNG_ERR_SAVE_IO_FAIL;
+ goto end;
+ }
+
+ ret = config_writer_write_element_unsigned_int(writer,
+ config_element_config, ctx->ctx.u.perf_counter.config);
+ if (ret) {
+ ret = LTTNG_ERR_SAVE_IO_FAIL;
+ goto end;
+ }
+
+ ret = config_writer_write_element_string(writer, config_element_name,
+ ctx->ctx.u.perf_counter.name);
+ if (ret) {
+ ret = LTTNG_ERR_SAVE_IO_FAIL;
+ goto end;
+ }