X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fsave.c;h=1a98515fa0c73f0272c82b346aa102ff5f5117f8;hp=851b9ac5b2f27171dd5bc06fb0ec8b7ad4f02e44;hb=9897fbc95aea23f996b7543d86363a3dd72a0c53;hpb=22c34f481f5a4491981e86a57f884852fc324a21

diff --git a/src/bin/lttng-sessiond/save.c b/src/bin/lttng-sessiond/save.c
index 851b9ac5b..1a98515fa 100644
--- a/src/bin/lttng-sessiond/save.c
+++ b/src/bin/lttng-sessiond/save.c
@@ -15,7 +15,6 @@
  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
 #define _LGPL_SOURCE
 #include <assert.h>
 #include <inttypes.h>
@@ -25,7 +24,7 @@
 
 #include <common/defaults.h>
 #include <common/error.h>
-#include <common/config/config.h>
+#include <common/config/session-config.h>
 #include <common/utils.h>
 #include <common/runas.h>
 #include <lttng/save-internal.h>
@@ -35,6 +34,7 @@
 #include "session.h"
 #include "syscall.h"
 #include "trace-ust.h"
+#include "agent.h"
 
 static
 int save_kernel_channel_attributes(struct config_writer *writer,
@@ -261,6 +261,9 @@ const char *get_ust_context_type_string(
 	case LTTNG_UST_CONTEXT_PTHREAD_ID:
 		context_type_string = config_event_context_pthread_id;
 		break;
+	case LTTNG_UST_CONTEXT_APP_CONTEXT:
+		context_type_string = config_event_context_app;
+		break;
 	case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
 		/*
 		 * Error, should not be stored in the XML, perf contexts
@@ -363,6 +366,16 @@ int save_kernel_event(struct config_writer *writer,
 		goto end;
 	}
 
+	if (event->filter_expression) {
+		ret = config_writer_write_element_string(writer,
+				config_element_filter,
+				event->filter_expression);
+		if (ret) {
+			ret = LTTNG_ERR_SAVE_IO_FAIL;
+			goto end;
+		}
+	}
+
 	if (event->event->instrumentation == LTTNG_KERNEL_FUNCTION ||
 		event->event->instrumentation == LTTNG_KERNEL_KPROBE ||
 		event->event->instrumentation == LTTNG_KERNEL_KRETPROBE) {
@@ -489,57 +502,6 @@ end:
 	return ret;
 }
 
-static
-int save_kernel_syscall(struct config_writer *writer,
-		struct ltt_kernel_channel *kchan)
-{
-	int ret, i;
-	ssize_t count;
-	struct lttng_event *events = NULL;
-
-	assert(writer);
-	assert(kchan);
-
-	count = syscall_list_channel(kchan, &events, 0);
-	if (!count) {
-		/* No syscalls, just gracefully return. */
-		ret = 0;
-		goto end;
-	}
-
-	for (i = 0; i < count; i++) {
-		struct ltt_kernel_event *kevent;
-
-		/* Create a temporary kevent in order to save it. */
-		/*
-		 * TODO: struct lttng_event does not really work for a filter,
-		 * but unfortunately, it is exposed as external API (and used as
-		 * internal representation. Using NULL meanwhile.
-		 */
-		kevent = trace_kernel_create_event(&events[i],
-			NULL, NULL);
-		if (!kevent) {
-			ret = -ENOMEM;
-			goto end;
-		}
-		/* Init list in order so the destroy call can del the node. */
-		CDS_INIT_LIST_HEAD(&kevent->list);
-
-		ret = save_kernel_event(writer, kevent);
-		trace_kernel_destroy_event(kevent);
-		if (ret) {
-			goto end;
-		}
-	}
-
-	/* Everything went well */
-	ret = 0;
-
-end:
-	free(events);
-	return ret;
-}
-
 static
 int save_kernel_events(struct config_writer *writer,
 	struct ltt_kernel_channel *kchan)
@@ -560,12 +522,6 @@ int save_kernel_events(struct config_writer *writer,
 		}
 	}
 
-	/* Save syscalls if any. */
-	ret = save_kernel_syscall(writer, kchan);
-	if (ret) {
-		goto end;
-	}
-
 	/* /events */
 	ret = config_writer_close_element(writer);
 	if (ret) {
@@ -632,11 +588,14 @@ int save_ust_event(struct config_writer *writer,
 		goto end;
 	}
 
-	ret = config_writer_write_element_signed_int(writer,
-		config_element_loglevel, event->attr.loglevel);
-	if (ret) {
-		ret = LTTNG_ERR_SAVE_IO_FAIL;
-		goto end;
+	/* The log level is irrelevant if no "filtering" is enabled */
+	if (event->attr.loglevel_type != LTTNG_UST_LOGLEVEL_ALL) {
+		ret = config_writer_write_element_signed_int(writer,
+				config_element_loglevel, event->attr.loglevel);
+		if (ret) {
+			ret = LTTNG_ERR_SAVE_IO_FAIL;
+			goto end;
+		}
 	}
 
 	if (event->filter_expression) {
@@ -661,7 +620,8 @@ int save_ust_event(struct config_writer *writer,
 		for (i = 0; i < event->exclusion->count; i++) {
 			ret = config_writer_write_element_string(writer,
 				config_element_exclusion,
-				&event->exclusion->names[0][i]);
+				LTTNG_EVENT_EXCLUSION_NAME_AT(
+					event->exclusion, i));
 			if (ret) {
 				ret = LTTNG_ERR_SAVE_IO_FAIL;
 				goto end;
@@ -727,6 +687,93 @@ end:
 	return ret;
 }
 
+static
+int init_ust_event_from_agent_event(struct ltt_ust_event *ust_event,
+		struct agent_event *agent_event)
+{
+	int ret = 0;
+	enum lttng_ust_loglevel_type ust_loglevel_type;
+
+	ust_event->enabled = agent_event->enabled;
+	ust_event->attr.instrumentation = LTTNG_UST_TRACEPOINT;
+	strncpy(ust_event->attr.name, agent_event->name, LTTNG_SYMBOL_NAME_LEN);
+	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 = -1;
+		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;
+end:
+	return ret;
+}
+
+static
+int save_agent_events(struct config_writer *writer,
+		struct ltt_ust_channel *chan,
+		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) {
+			rcu_read_unlock();
+			goto end;
+		}
+		ret = save_ust_event(writer, &fake_event);
+		if (ret) {
+			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;
+	}
+end:
+	return ret;
+}
+
 static
 int save_kernel_context(struct config_writer *writer,
 	struct lttng_kernel_context *ctx)
@@ -744,7 +791,8 @@ int save_kernel_context(struct config_writer *writer,
 	}
 
 	if (ctx->ctx == LTTNG_KERNEL_CONTEXT_PERF_CPU_COUNTER) {
-		ret = config_writer_open_element(writer, config_element_perf);
+		ret = config_writer_open_element(writer,
+				config_element_context_perf);
 		if (ret) {
 			ret = LTTNG_ERR_SAVE_IO_FAIL;
 			goto end;
@@ -841,6 +889,124 @@ end:
 	return ret;
 }
 
+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;
+	}
+
+	/* /perf */
+	ret = config_writer_close_element(writer);
+	if (ret) {
+		ret = LTTNG_ERR_SAVE_IO_FAIL;
+		goto end;
+	}
+end:
+	return ret;
+}
+
+static
+int save_ust_context_app_ctx(struct config_writer *writer,
+		struct ltt_ust_context *ctx)
+{
+	int ret;
+
+	assert(writer);
+	assert(ctx);
+
+	/* Application contexts are saved as application_context_type */
+	ret = config_writer_open_element(writer, config_element_context_app);
+	if (ret) {
+		ret = LTTNG_ERR_SAVE_IO_FAIL;
+		goto end;
+	}
+
+	ret = config_writer_write_element_string(writer,
+			config_element_context_app_provider_name,
+			ctx->ctx.u.app_ctx.provider_name);
+	if (ret) {
+		ret = LTTNG_ERR_SAVE_IO_FAIL;
+		goto end;
+	}
+
+	ret = config_writer_write_element_string(writer,
+			config_element_context_app_ctx_name,
+			ctx->ctx.u.app_ctx.ctx_name);
+	if (ret) {
+		ret = LTTNG_ERR_SAVE_IO_FAIL;
+		goto end;
+	}
+
+	/* /app */
+	ret = config_writer_close_element(writer);
+	if (ret) {
+		ret = LTTNG_ERR_SAVE_IO_FAIL;
+		goto end;
+	}
+end:
+	return ret;
+}
+
+static
+int save_ust_context_generic(struct config_writer *writer,
+		struct ltt_ust_context *ctx)
+{
+	int ret;
+	const char *context_type_string;
+
+	assert(writer);
+	assert(ctx);
+
+	/* Save context as event_context_type_type */
+	context_type_string = get_ust_context_type_string(
+			ctx->ctx.ctx);
+	if (!context_type_string) {
+		ERR("Unsupported UST context type.");
+		ret = LTTNG_ERR_SAVE_IO_FAIL;
+		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;
+	}
+end:
+	return ret;
+}
+
 static
 int save_ust_context(struct config_writer *writer,
 	struct cds_list_head *ctx_list)
@@ -858,9 +1024,6 @@ int save_ust_context(struct config_writer *writer,
 	}
 
 	cds_list_for_each_entry(ctx, ctx_list, list) {
-		const char *context_type_string;
-
-
 		ret = config_writer_open_element(writer,
 			config_element_context);
 		if (ret) {
@@ -868,61 +1031,19 @@ int save_ust_context(struct config_writer *writer,
 			goto end;
 		}
 
-		if (ctx->ctx.ctx == LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER) {
-			/* Perf contexts are saved as event_perf_context_type */
-			ret = config_writer_open_element(writer,
-				config_element_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;
-			}
-
-			/* /perf */
-			ret = config_writer_close_element(writer);
-			if (ret) {
-				ret = LTTNG_ERR_SAVE_IO_FAIL;
-				goto end;
-			}
-		} else {
-			/* Save context as event_context_type_type */
-			context_type_string = get_ust_context_type_string(
-				ctx->ctx.ctx);
-			if (!context_type_string) {
-				ERR("Unsupported UST 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;
-			}
+		switch (ctx->ctx.ctx) {
+		case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
+			ret = save_ust_context_perf_thread_counter(writer, ctx);
+			break;
+		case LTTNG_UST_CONTEXT_APP_CONTEXT:
+			ret = save_ust_context_app_ctx(writer, ctx);
+			break;
+		default:
+			/* Save generic context. */
+			ret = save_ust_context_generic(writer, ctx);
+		}
+		if (ret) {
+			goto end;
 		}
 
 		/* /context */
@@ -1055,10 +1176,31 @@ int save_ust_channel(struct config_writer *writer,
 		goto end;
 	}
 
-	ret = save_ust_events(writer, ust_chan->events);
-	if (ret) {
-		ret = LTTNG_ERR_SAVE_IO_FAIL;
-		goto end;
+	if (ust_chan->domain == LTTNG_DOMAIN_UST) {
+		ret = save_ust_events(writer, ust_chan->events);
+		if (ret) {
+			goto end;
+		}
+	} else {
+		struct agent *agent = NULL;
+
+		agent = trace_ust_find_agent(session, ust_chan->domain);
+		if (!agent) {
+			ret = LTTNG_ERR_SAVE_IO_FAIL;
+			ERR("Could not find agent associated to UST subdomain");
+			goto end;
+		}
+
+		/*
+		 * Channels associated with a UST sub-domain (such as JUL, Log4j
+		 * or Python) don't have any non-internal events. We retrieve
+		 * the "agent" events associated with this channel and serialize
+		 * them.
+		 */
+		ret = save_agent_events(writer, ust_chan, agent);
+		if (ret) {
+			goto end;
+		}
 	}
 
 	ret = save_ust_context(writer, &ust_chan->ctx_list);
@@ -1126,73 +1268,31 @@ end:
 }
 
 static
-int save_ust_session(struct config_writer *writer,
-	struct ltt_session *session, int save_agent)
+const char *get_config_domain_str(enum lttng_domain_type domain)
 {
-	int ret;
-	struct ltt_ust_channel *ust_chan;
-	const char *buffer_type_string;
-	struct lttng_ht_node_str *node;
-	struct lttng_ht_iter iter;
-
-	assert(writer);
-	assert(session);
-
-	ret = config_writer_write_element_string(writer, config_element_type,
-			save_agent ? config_domain_type_jul : config_domain_type_ust);
-	if (ret) {
-		ret = LTTNG_ERR_SAVE_IO_FAIL;
-		goto end;
-	}
-
-	buffer_type_string = get_buffer_type_string(
-			session->ust_session->buffer_type);
-	if (!buffer_type_string) {
-		ERR("Unsupported buffer type.");
-		ret = LTTNG_ERR_INVALID;
-		goto end;
-	}
-
-	ret = config_writer_write_element_string(writer,
-			config_element_buffer_type, buffer_type_string);
-	if (ret) {
-		ret = LTTNG_ERR_SAVE_IO_FAIL;
-		goto end;
-	}
-
-	ret = config_writer_open_element(writer, config_element_channels);
-	if (ret) {
-		ret = LTTNG_ERR_SAVE_IO_FAIL;
-		goto end;
-	}
-
-	rcu_read_lock();
-	cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
-			&iter.iter, node, node) {
-		int agent_channel;
+	const char *str_dom;
 
-		ust_chan = caa_container_of(node, struct ltt_ust_channel, node);
-		agent_channel = !strcmp(DEFAULT_JUL_CHANNEL_NAME, ust_chan->name) ||
-			!strcmp(DEFAULT_LOG4J_CHANNEL_NAME, ust_chan->name) ||
-			!strcmp(DEFAULT_PYTHON_CHANNEL_NAME, ust_chan->name);
-		if (!(save_agent ^ agent_channel)) {
-			ret = save_ust_channel(writer, ust_chan, session->ust_session);
-			if (ret) {
-				rcu_read_unlock();
-				goto end;
-			}
-		}
+	switch (domain) {
+	case LTTNG_DOMAIN_KERNEL:
+		str_dom = config_domain_type_kernel;
+		break;
+	case LTTNG_DOMAIN_UST:
+		str_dom = config_domain_type_ust;
+		break;
+	case LTTNG_DOMAIN_JUL:
+		str_dom = config_domain_type_jul;
+		break;
+	case LTTNG_DOMAIN_LOG4J:
+		str_dom = config_domain_type_log4j;
+		break;
+	case LTTNG_DOMAIN_PYTHON:
+		str_dom = config_domain_type_python;
+		break;
+	default:
+		assert(0);
 	}
-	rcu_read_unlock();
 
-	/* /channels */
-	ret = config_writer_close_element(writer);
-	if (ret) {
-		ret = LTTNG_ERR_SAVE_IO_FAIL;
-		goto end;
-	}
-end:
-	return ret;
+	return str_dom;
 }
 
 static
@@ -1289,45 +1389,90 @@ end:
 }
 
 static
-int save_domains(struct config_writer *writer, struct ltt_session *session)
+int save_ust_domain(struct config_writer *writer,
+	struct ltt_session *session, enum lttng_domain_type domain)
 {
-	int ret = 0;
+	int ret;
+	struct ltt_ust_channel *ust_chan;
+	const char *buffer_type_string;
+	struct lttng_ht_node_str *node;
+	struct lttng_ht_iter iter;
+	const char *config_domain_name;
 
 	assert(writer);
 	assert(session);
 
-	if (!session->kernel_session && !session->ust_session) {
+	ret = config_writer_open_element(writer,
+			config_element_domain);
+	if (ret) {
+		ret = LTTNG_ERR_SAVE_IO_FAIL;
 		goto end;
 	}
 
-	ret = config_writer_open_element(writer, config_element_domains);
+	config_domain_name = get_config_domain_str(domain);
+	if (!config_domain_name) {
+		ret = LTTNG_ERR_INVALID;
+		goto end;
+	}
+
+	ret = config_writer_write_element_string(writer,
+			config_element_type, config_domain_name);
+	if (ret) {
+		ret = LTTNG_ERR_SAVE_IO_FAIL;
+		goto end;
+	}
+
+	buffer_type_string = get_buffer_type_string(
+			session->ust_session->buffer_type);
+	if (!buffer_type_string) {
+		ERR("Unsupported buffer type.");
+		ret = LTTNG_ERR_INVALID;
+		goto end;
+	}
+
+	ret = config_writer_write_element_string(writer,
+			config_element_buffer_type, buffer_type_string);
 	if (ret) {
 		ret = LTTNG_ERR_SAVE_IO_FAIL;
 		goto end;
 	}
 
+	ret = config_writer_open_element(writer, config_element_channels);
+	if (ret) {
+		ret = LTTNG_ERR_SAVE_IO_FAIL;
+		goto end;
+	}
 
-	if (session->kernel_session) {
-		ret = config_writer_open_element(writer,
-			config_element_domain);
-		if (ret) {
-			ret = LTTNG_ERR_SAVE_IO_FAIL;
-			goto end;
+	rcu_read_lock();
+	cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
+			&iter.iter, node, node) {
+		ust_chan = caa_container_of(node, struct ltt_ust_channel, node);
+		if (domain == ust_chan->domain) {
+			ret = save_ust_channel(writer, ust_chan, session->ust_session);
+			if (ret) {
+				rcu_read_unlock();
+				goto end;
+			}
 		}
+	}
+	rcu_read_unlock();
 
-		ret = save_kernel_session(writer, session);
-		if (ret) {
-			goto end;
-		}
+	/* /channels */
+	ret = config_writer_close_element(writer);
+	if (ret) {
+		ret = LTTNG_ERR_SAVE_IO_FAIL;
+		goto end;
+	}
 
+	if (domain == LTTNG_DOMAIN_UST) {
 		ret = config_writer_open_element(writer,
-			config_element_trackers);
+				config_element_trackers);
 		if (ret) {
 			ret = LTTNG_ERR_SAVE_IO_FAIL;
 			goto end;
 		}
 
-		ret = save_pid_tracker(writer, session, LTTNG_DOMAIN_KERNEL);
+		ret = save_pid_tracker(writer, session, LTTNG_DOMAIN_UST);
 		if (ret) {
 			goto end;
 		}
@@ -1335,20 +1480,41 @@ int save_domains(struct config_writer *writer, struct ltt_session *session)
 		/* /trackers */
 		ret = config_writer_close_element(writer);
 		if (ret) {
-			ret = LTTNG_ERR_SAVE_IO_FAIL;
-			goto end;
-		}
-		/* /domain */
-		ret = config_writer_close_element(writer);
-		if (ret) {
-			ret = LTTNG_ERR_SAVE_IO_FAIL;
 			goto end;
 		}
 	}
 
-	if (session->ust_session) {
-		unsigned long agent_count;
+	/* /domain */
+	ret = config_writer_close_element(writer);
+	if (ret) {
+		ret = LTTNG_ERR_SAVE_IO_FAIL;
+		goto end;
+	}
+
+end:
+	return ret;
+}
+
+static
+int save_domains(struct config_writer *writer, struct ltt_session *session)
+{
+	int ret = 0;
+
+	assert(writer);
+	assert(session);
 
+	if (!session->kernel_session && !session->ust_session) {
+		goto end;
+	}
+
+	ret = config_writer_open_element(writer, config_element_domains);
+	if (ret) {
+		ret = LTTNG_ERR_SAVE_IO_FAIL;
+		goto end;
+	}
+
+
+	if (session->kernel_session) {
 		ret = config_writer_open_element(writer,
 			config_element_domain);
 		if (ret) {
@@ -1356,7 +1522,7 @@ int save_domains(struct config_writer *writer, struct ltt_session *session)
 			goto end;
 		}
 
-		ret = save_ust_session(writer, session, 0);
+		ret = save_kernel_session(writer, session);
 		if (ret) {
 			goto end;
 		}
@@ -1368,7 +1534,7 @@ int save_domains(struct config_writer *writer, struct ltt_session *session)
 			goto end;
 		}
 
-		ret = save_pid_tracker(writer, session, LTTNG_DOMAIN_UST);
+		ret = save_pid_tracker(writer, session, LTTNG_DOMAIN_KERNEL);
 		if (ret) {
 			goto end;
 		}
@@ -1385,27 +1551,27 @@ int save_domains(struct config_writer *writer, struct ltt_session *session)
 			ret = LTTNG_ERR_SAVE_IO_FAIL;
 			goto end;
 		}
+	}
 
-		agent_count = lttng_ht_get_count(session->ust_session->agents);
-		if (agent_count > 0) {
-			ret = config_writer_open_element(writer,
-				config_element_domain);
-			if (ret) {
-				ret = LTTNG_ERR_SAVE_IO_FAIL;
-				goto end;
-			}
+	if (session->ust_session) {
+		ret = save_ust_domain(writer, session, LTTNG_DOMAIN_UST);
+		if (ret) {
+			goto end;
+		}
 
-			ret = save_ust_session(writer, session, 1);
-			if (ret) {
-				goto end;
-			}
+		ret = save_ust_domain(writer, session, LTTNG_DOMAIN_JUL);
+		if (ret) {
+			goto end;
+		}
 
-			/* /domain */
-			ret = config_writer_close_element(writer);
-			if (ret) {
-				ret = LTTNG_ERR_SAVE_IO_FAIL;
-				goto end;
-			}
+		ret = save_ust_domain(writer, session, LTTNG_DOMAIN_LOG4J);
+		if (ret) {
+			goto end;
+		}
+
+		ret = save_ust_domain(writer, session, LTTNG_DOMAIN_PYTHON);
+		if (ret) {
+			goto end;
 		}
 	}