X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fcmd.c;h=cc81906b6267ffc104ee357741d0b099af9fbc3c;hp=9af6d9d4acce64b9b9855e46ed462a624573c693;hb=7802bae326824ecb116cb0d782bb7472eaa6f6e4;hpb=93ec662e687dc15a3601704a1e0c96c51ad228c9

diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index 9af6d9d4a..cc81906b6 100644
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -187,7 +187,14 @@ static int get_ust_runtime_stats(struct ltt_session *session,
 	int ret;
 	struct ltt_ust_session *usess;
 
+	if (!discarded_events || !lost_packets) {
+		ret = -1;
+		goto end;
+	}
+
 	usess = session->ust_session;
+	assert(discarded_events);
+	assert(lost_packets);
 
 	if (!usess || !session->has_been_started) {
 		*discarded_events = 0;
@@ -216,6 +223,7 @@ static int get_ust_runtime_stats(struct ltt_session *session,
 		*lost_packets += uchan->per_pid_closed_app_lost;
 	} else {
 		ERR("Unsupported buffer type");
+		assert(0);
 		ret = -1;
 		goto end;
 	}
@@ -267,9 +275,12 @@ static void list_lttng_channels(enum lttng_domain_type domain,
 		rcu_read_lock();
 		cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
 				&iter.iter, uchan, node.node) {
-			uint64_t discarded_events, lost_packets;
+			uint64_t discarded_events = 0, lost_packets = 0;
 
-			strncpy(channels[i].name, uchan->name, LTTNG_SYMBOL_NAME_LEN);
+			if (lttng_strncpy(channels[i].name, uchan->name,
+					LTTNG_SYMBOL_NAME_LEN)) {
+				break;
+			}
 			channels[i].attr.overwrite = uchan->attr.overwrite;
 			channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
 			channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
@@ -750,12 +761,15 @@ static int add_uri_to_consumer(struct consumer_output *consumer,
 		DBG2("Setting trace directory path from URI to %s", uri->dst.path);
 		memset(consumer->dst.trace_path, 0,
 				sizeof(consumer->dst.trace_path));
-		strncpy(consumer->dst.trace_path, uri->dst.path,
-				sizeof(consumer->dst.trace_path));
+		/* Explicit length checks for strcpy and strcat. */
+		if (strlen(uri->dst.path) + strlen(default_trace_dir)
+				>= sizeof(consumer->dst.trace_path)) {
+			ret = LTTNG_ERR_FATAL;
+			goto error;
+		}
+		strcpy(consumer->dst.trace_path, uri->dst.path);
 		/* Append default trace dir */
-		strncat(consumer->dst.trace_path, default_trace_dir,
-				sizeof(consumer->dst.trace_path) -
-				strlen(consumer->dst.trace_path) - 1);
+		strcat(consumer->dst.trace_path, default_trace_dir);
 		/* Flag consumer as local. */
 		consumer->type = CONSUMER_DST_LOCAL;
 		break;
@@ -1319,16 +1333,6 @@ int cmd_enable_channel(struct ltt_session *session,
 		attr->attr.switch_timer_interval = 0;
 	}
 
-	/*
-	 * The ringbuffer (both in user space and kernel) behave badly in overwrite
-	 * mode and with less than 2 subbuf so block it right away and send back an
-	 * invalid attribute error.
-	 */
-	if (attr->attr.overwrite && attr->attr.num_subbuf < 2) {
-		ret = LTTNG_ERR_INVALID;
-		goto error;
-	}
-
 	switch (domain->type) {
 	case LTTNG_DOMAIN_KERNEL:
 	{
@@ -1802,7 +1806,7 @@ static int _cmd_enable_event(struct ltt_session *session,
 		int wpipe, bool internal_event)
 {
 	int ret, channel_created = 0;
-	struct lttng_channel *attr;
+	struct lttng_channel *attr = NULL;
 
 	assert(session);
 	assert(event);
@@ -1845,15 +1849,16 @@ static int _cmd_enable_event(struct ltt_session *session,
 				ret = LTTNG_ERR_FATAL;
 				goto error;
 			}
-			strncpy(attr->name, channel_name, sizeof(attr->name));
+			if (lttng_strncpy(attr->name, channel_name,
+					sizeof(attr->name))) {
+				ret = LTTNG_ERR_INVALID;
+				goto error;
+			}
 
 			ret = cmd_enable_channel(session, domain, attr, wpipe);
 			if (ret != LTTNG_OK) {
-				free(attr);
 				goto error;
 			}
-			free(attr);
-
 			channel_created = 1;
 		}
 
@@ -1982,14 +1987,16 @@ static int _cmd_enable_event(struct ltt_session *session,
 				ret = LTTNG_ERR_FATAL;
 				goto error;
 			}
-			strncpy(attr->name, channel_name, sizeof(attr->name));
+			if (lttng_strncpy(attr->name, channel_name,
+					sizeof(attr->name))) {
+				ret = LTTNG_ERR_INVALID;
+				goto error;
+			}
 
 			ret = cmd_enable_channel(session, domain, attr, wpipe);
 			if (ret != LTTNG_OK) {
-				free(attr);
 				goto error;
 			}
-			free(attr);
 
 			/* Get the newly created channel reference back */
 			uchan = trace_ust_find_channel_by_name(
@@ -2164,6 +2171,7 @@ error:
 	free(filter_expression);
 	free(filter);
 	free(exclusion);
+	free(attr);
 	rcu_read_unlock();
 	return ret;
 }
@@ -2429,7 +2437,15 @@ int cmd_stop_trace(struct ltt_session *session)
 	if (ksession && ksession->active) {
 		DBG("Stop kernel tracing");
 
-		/* Flush metadata if exist */
+		ret = kernel_stop_session(ksession);
+		if (ret < 0) {
+			ret = LTTNG_ERR_KERN_STOP_FAIL;
+			goto error;
+		}
+
+		kernel_wait_quiescent(kernel_tracer_fd);
+
+		/* Flush metadata after stopping (if exists) */
 		if (ksession->metadata_stream_fd >= 0) {
 			ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
 			if (ret < 0) {
@@ -2437,7 +2453,7 @@ int cmd_stop_trace(struct ltt_session *session)
 			}
 		}
 
-		/* Flush all buffers before stopping */
+		/* Flush all buffers after stopping */
 		cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
 			ret = kernel_flush_buffer(kchan);
 			if (ret < 0) {
@@ -2445,14 +2461,6 @@ int cmd_stop_trace(struct ltt_session *session)
 			}
 		}
 
-		ret = kernel_stop_session(ksession);
-		if (ret < 0) {
-			ret = LTTNG_ERR_KERN_STOP_FAIL;
-			goto error;
-		}
-
-		kernel_wait_quiescent(kernel_tracer_fd);
-
 		ksession->active = 0;
 	}
 
@@ -2740,64 +2748,6 @@ int cmd_destroy_session(struct ltt_session *session, int wpipe)
 	return ret;
 }
 
-/*
- * Command LTTNG_CALIBRATE processed by the client thread.
- */
-int cmd_calibrate(enum lttng_domain_type domain,
-		struct lttng_calibrate *calibrate)
-{
-	int ret;
-
-	switch (domain) {
-	case LTTNG_DOMAIN_KERNEL:
-	{
-		struct lttng_kernel_calibrate kcalibrate;
-
-		switch (calibrate->type) {
-		case LTTNG_CALIBRATE_FUNCTION:
-		default:
-			/* Default and only possible calibrate option. */
-			kcalibrate.type = LTTNG_KERNEL_CALIBRATE_KRETPROBE;
-			break;
-		}
-
-		ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
-		if (ret < 0) {
-			ret = LTTNG_ERR_KERN_ENABLE_FAIL;
-			goto error;
-		}
-		break;
-	}
-	case LTTNG_DOMAIN_UST:
-	{
-		struct lttng_ust_calibrate ucalibrate;
-
-		switch (calibrate->type) {
-		case LTTNG_CALIBRATE_FUNCTION:
-		default:
-			/* Default and only possible calibrate option. */
-			ucalibrate.type = LTTNG_UST_CALIBRATE_TRACEPOINT;
-			break;
-		}
-
-		ret = ust_app_calibrate_glb(&ucalibrate);
-		if (ret < 0) {
-			ret = LTTNG_ERR_UST_CALIBRATE_FAIL;
-			goto error;
-		}
-		break;
-	}
-	default:
-		ret = LTTNG_ERR_UND;
-		goto error;
-	}
-
-	ret = LTTNG_OK;
-
-error:
-	return ret;
-}
-
 /*
  * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
  */
@@ -3199,11 +3149,10 @@ int cmd_snapshot_add_output(struct ltt_session *session,
 	DBG("Cmd snapshot add output for session %s", session->name);
 
 	/*
-	 * Permission denied to create an output if the session is not
-	 * set in no output mode.
+	 * Can't create an output if the session is not set in no-output mode.
 	 */
 	if (session->output_traces) {
-		ret = LTTNG_ERR_EPERM;
+		ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
 		goto error;
 	}
 
@@ -3267,7 +3216,7 @@ int cmd_snapshot_del_output(struct ltt_session *session,
 	 * set in no output mode.
 	 */
 	if (session->output_traces) {
-		ret = LTTNG_ERR_EPERM;
+		ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
 		goto error;
 	}
 
@@ -3319,19 +3268,19 @@ ssize_t cmd_snapshot_list_outputs(struct ltt_session *session,
 	 * set in no output mode.
 	 */
 	if (session->output_traces) {
-		ret = -LTTNG_ERR_EPERM;
-		goto error;
+		ret = -LTTNG_ERR_NOT_SNAPSHOT_SESSION;
+		goto end;
 	}
 
 	if (session->snapshot.nb_output == 0) {
 		ret = 0;
-		goto error;
+		goto end;
 	}
 
 	list = zmalloc(session->snapshot.nb_output * sizeof(*list));
 	if (!list) {
 		ret = -LTTNG_ERR_NOMEM;
-		goto error;
+		goto end;
 	}
 
 	/* Copy list from session to the new list object. */
@@ -3341,10 +3290,18 @@ ssize_t cmd_snapshot_list_outputs(struct ltt_session *session,
 		assert(output->consumer);
 		list[idx].id = output->id;
 		list[idx].max_size = output->max_size;
-		strncpy(list[idx].name, output->name, sizeof(list[idx].name));
+		if (lttng_strncpy(list[idx].name, output->name,
+				sizeof(list[idx].name))) {
+			ret = -LTTNG_ERR_INVALID;
+			goto error;
+		}
 		if (output->consumer->type == CONSUMER_DST_LOCAL) {
-			strncpy(list[idx].ctrl_url, output->consumer->dst.trace_path,
-					sizeof(list[idx].ctrl_url));
+			if (lttng_strncpy(list[idx].ctrl_url,
+					output->consumer->dst.trace_path,
+					sizeof(list[idx].ctrl_url))) {
+				ret = -LTTNG_ERR_INVALID;
+				goto error;
+			}
 		} else {
 			/* Control URI. */
 			ret = uri_to_str_url(&output->consumer->dst.net.control,
@@ -3369,8 +3326,9 @@ ssize_t cmd_snapshot_list_outputs(struct ltt_session *session,
 	list = NULL;
 	ret = session->snapshot.nb_output;
 error:
-	free(list);
 	rcu_read_unlock();
+	free(list);
+end:
 	return ret;
 }
 
@@ -3381,7 +3339,7 @@ error:
  * Return 0 if the metadata can be generated, a LTTNG_ERR code otherwise.
  */
 static
-int check_metadata_regenerate_support(struct ltt_session *session)
+int check_regenerate_metadata_support(struct ltt_session *session)
 {
 	int ret;
 
@@ -3420,7 +3378,28 @@ end:
 }
 
 static
-int ust_metadata_regenerate(struct ltt_ust_session *usess)
+int clear_metadata_file(int fd)
+{
+	int ret;
+
+	ret = lseek(fd, 0, SEEK_SET);
+	if (ret < 0) {
+		PERROR("lseek");
+		goto end;
+	}
+
+	ret = ftruncate(fd, 0);
+	if (ret < 0) {
+		PERROR("ftruncate");
+		goto end;
+	}
+
+end:
+	return ret;
+}
+
+static
+int ust_regenerate_metadata(struct ltt_ust_session *usess)
 {
 	int ret = 0;
 	struct buffer_reg_uid *uid_reg = NULL;
@@ -3440,6 +3419,15 @@ int ust_metadata_regenerate(struct ltt_ust_session *usess)
 		memset(registry->metadata, 0, registry->metadata_alloc_len);
 		registry->metadata_len = 0;
 		registry->metadata_version++;
+		if (registry->metadata_fd > 0) {
+			/* Clear the metadata file's content. */
+			ret = clear_metadata_file(registry->metadata_fd);
+			if (ret) {
+				pthread_mutex_unlock(&registry->lock);
+				goto end;
+			}
+		}
+
 		ret = ust_metadata_session_statedump(registry, NULL,
 				registry->major, registry->minor);
 		if (ret) {
@@ -3481,7 +3469,7 @@ end:
 }
 
 /*
- * Command LTTNG_METADATA_REGENERATE from the lttng-ctl library.
+ * Command LTTNG_REGENERATE_METADATA from the lttng-ctl library.
  *
  * Ask the consumer to truncate the existing metadata file(s) and
  * then regenerate the metadata. Live and per-pid sessions are not
@@ -3489,19 +3477,19 @@ end:
  *
  * Return 0 on success or else a LTTNG_ERR code.
  */
-int cmd_metadata_regenerate(struct ltt_session *session)
+int cmd_regenerate_metadata(struct ltt_session *session)
 {
 	int ret;
 
 	assert(session);
 
-	ret = check_metadata_regenerate_support(session);
+	ret = check_regenerate_metadata_support(session);
 	if (ret) {
 		goto end;
 	}
 
 	if (session->kernel_session) {
-		ret = kernctl_session_metadata_regenerate(
+		ret = kernctl_session_regenerate_metadata(
 				session->kernel_session->fd);
 		if (ret < 0) {
 			ERR("Failed to regenerate the kernel metadata");
@@ -3510,7 +3498,7 @@ int cmd_metadata_regenerate(struct ltt_session *session)
 	}
 
 	if (session->ust_session) {
-		ret = ust_metadata_regenerate(session->ust_session);
+		ret = ust_regenerate_metadata(session->ust_session);
 		if (ret < 0) {
 			ERR("Failed to regenerate the UST metadata");
 			goto end;
@@ -3523,6 +3511,60 @@ end:
 	return ret;
 }
 
+/*
+ * Command LTTNG_REGENERATE_STATEDUMP from the lttng-ctl library.
+ *
+ * Ask the tracer to regenerate a new statedump.
+ *
+ * Return 0 on success or else a LTTNG_ERR code.
+ */
+int cmd_regenerate_statedump(struct ltt_session *session)
+{
+	int ret;
+
+	assert(session);
+
+	if (!session->active) {
+		ret = LTTNG_ERR_SESSION_NOT_STARTED;
+		goto end;
+	}
+	ret = 0;
+
+	if (session->kernel_session) {
+		ret = kernctl_session_regenerate_statedump(
+				session->kernel_session->fd);
+		/*
+		 * Currently, the statedump in kernel can only fail if out
+		 * of memory.
+		 */
+		if (ret < 0) {
+			if (ret == -ENOMEM) {
+				ret = LTTNG_ERR_REGEN_STATEDUMP_NOMEM;
+			} else {
+				ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
+			}
+			ERR("Failed to regenerate the kernel statedump");
+			goto end;
+		}
+	}
+
+	if (session->ust_session) {
+		ret = ust_app_regenerate_statedump_all(session->ust_session);
+		/*
+		 * Currently, the statedump in UST always returns 0.
+		 */
+		if (ret < 0) {
+			ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
+			ERR("Failed to regenerate the UST statedump");
+			goto end;
+		}
+	}
+	DBG("Cmd regenerate statedump for session %s", session->name);
+	ret = LTTNG_OK;
+
+end:
+	return ret;
+}
 
 /*
  * Send relayd sockets from snapshot output to consumer. Ignore request if the
@@ -3585,13 +3627,6 @@ static int record_kernel_snapshot(struct ltt_kernel_session *ksess,
 	assert(output);
 	assert(session);
 
-	/* Get the datetime for the snapshot output directory. */
-	ret = utils_get_current_time_str("%Y%m%d-%H%M%S", output->datetime,
-			sizeof(output->datetime));
-	if (!ret) {
-		ret = LTTNG_ERR_INVALID;
-		goto error;
-	}
 
 	/*
 	 * Copy kernel session sockets so we can communicate with the right
@@ -3639,14 +3674,6 @@ static int record_ust_snapshot(struct ltt_ust_session *usess,
 	assert(output);
 	assert(session);
 
-	/* Get the datetime for the snapshot output directory. */
-	ret = utils_get_current_time_str("%Y%m%d-%H%M%S", output->datetime,
-			sizeof(output->datetime));
-	if (!ret) {
-		ret = LTTNG_ERR_INVALID;
-		goto error;
-	}
-
 	/*
 	 * Copy UST session sockets so we can communicate with the right
 	 * consumer for the snapshot record command.
@@ -3668,9 +3695,6 @@ static int record_ust_snapshot(struct ltt_ust_session *usess,
 		case EINVAL:
 			ret = LTTNG_ERR_INVALID;
 			break;
-		case ENODATA:
-			ret = LTTNG_ERR_SNAPSHOT_NODATA;
-			break;
 		default:
 			ret = LTTNG_ERR_SNAPSHOT_FAIL;
 			break;
@@ -3788,18 +3812,27 @@ int cmd_snapshot_record(struct ltt_session *session,
 	unsigned int use_tmp_output = 0;
 	struct snapshot_output tmp_output;
 	unsigned int snapshot_success = 0;
+	char datetime[16];
 
 	assert(session);
 	assert(output);
 
 	DBG("Cmd snapshot record for session %s", session->name);
 
+	/* Get the datetime for the snapshot output directory. */
+	ret = utils_get_current_time_str("%Y%m%d-%H%M%S", datetime,
+			sizeof(datetime));
+	if (!ret) {
+		ret = LTTNG_ERR_INVALID;
+		goto error;
+	}
+
 	/*
 	 * Permission denied to create an output if the session is not
 	 * set in no output mode.
 	 */
 	if (session->output_traces) {
-		ret = LTTNG_ERR_EPERM;
+		ret = LTTNG_ERR_NOT_SNAPSHOT_SESSION;
 		goto error;
 	}
 
@@ -3824,138 +3857,104 @@ int cmd_snapshot_record(struct ltt_session *session,
 		}
 		/* Use the global session count for the temporary snapshot. */
 		tmp_output.nb_snapshot = session->snapshot.nb_snapshot;
+
+		/* Use the global datetime */
+		memcpy(tmp_output.datetime, datetime, sizeof(datetime));
 		use_tmp_output = 1;
 	}
 
-	if (session->kernel_session) {
-		struct ltt_kernel_session *ksess = session->kernel_session;
+	if (use_tmp_output) {
+		int64_t nb_packets_per_stream;
 
-		if (use_tmp_output) {
-			int64_t nb_packets_per_stream;
+		nb_packets_per_stream = get_session_nb_packets_per_stream(session,
+				tmp_output.max_size);
+		if (nb_packets_per_stream < 0) {
+			ret = LTTNG_ERR_MAX_SIZE_INVALID;
+			goto error;
+		}
 
-			nb_packets_per_stream = get_session_nb_packets_per_stream(session,
-					tmp_output.max_size);
-			if (nb_packets_per_stream < 0) {
-				ret = LTTNG_ERR_MAX_SIZE_INVALID;
+		if (session->kernel_session) {
+			ret = record_kernel_snapshot(session->kernel_session,
+					&tmp_output, session,
+					wait, nb_packets_per_stream);
+			if (ret != LTTNG_OK) {
 				goto error;
 			}
-			ret = record_kernel_snapshot(ksess, &tmp_output, session,
+		}
+
+		if (session->ust_session) {
+			ret = record_ust_snapshot(session->ust_session,
+					&tmp_output, session,
 					wait, nb_packets_per_stream);
 			if (ret != LTTNG_OK) {
 				goto error;
 			}
-			snapshot_success = 1;
-		} else {
-			struct snapshot_output *sout;
-			struct lttng_ht_iter iter;
-
-			rcu_read_lock();
-			cds_lfht_for_each_entry(session->snapshot.output_ht->ht,
-					&iter.iter, sout, node.node) {
-				int64_t nb_packets_per_stream;
-
-				/*
-				 * Make a local copy of the output and assign the possible
-				 * temporary value given by the caller.
-				 */
-				memset(&tmp_output, 0, sizeof(tmp_output));
-				memcpy(&tmp_output, sout, sizeof(tmp_output));
-
-				if (output->max_size != (uint64_t) -1ULL) {
-					tmp_output.max_size = output->max_size;
-				}
+		}
 
-				nb_packets_per_stream = get_session_nb_packets_per_stream(session,
-						tmp_output.max_size);
-				if (nb_packets_per_stream < 0) {
-					ret = LTTNG_ERR_MAX_SIZE_INVALID;
-					goto error;
-				}
+		snapshot_success = 1;
+	} else {
+		struct snapshot_output *sout;
+		struct lttng_ht_iter iter;
 
-				/* Use temporary name. */
-				if (*output->name != '\0') {
-					strncpy(tmp_output.name, output->name,
-							sizeof(tmp_output.name));
-				}
+		rcu_read_lock();
+		cds_lfht_for_each_entry(session->snapshot.output_ht->ht,
+				&iter.iter, sout, node.node) {
+			int64_t nb_packets_per_stream;
 
-				tmp_output.nb_snapshot = session->snapshot.nb_snapshot;
+			/*
+			 * Make a local copy of the output and assign the possible
+			 * temporary value given by the caller.
+			 */
+			memset(&tmp_output, 0, sizeof(tmp_output));
+			memcpy(&tmp_output, sout, sizeof(tmp_output));
 
-				ret = record_kernel_snapshot(ksess, &tmp_output,
-						session, wait, nb_packets_per_stream);
-				if (ret != LTTNG_OK) {
-					rcu_read_unlock();
-					goto error;
-				}
-				snapshot_success = 1;
+			if (output->max_size != (uint64_t) -1ULL) {
+				tmp_output.max_size = output->max_size;
 			}
-			rcu_read_unlock();
-		}
-	}
-
-	if (session->ust_session) {
-		struct ltt_ust_session *usess = session->ust_session;
-
-		if (use_tmp_output) {
-			int64_t nb_packets_per_stream;
 
 			nb_packets_per_stream = get_session_nb_packets_per_stream(session,
 					tmp_output.max_size);
 			if (nb_packets_per_stream < 0) {
 				ret = LTTNG_ERR_MAX_SIZE_INVALID;
+				rcu_read_unlock();
 				goto error;
 			}
-			ret = record_ust_snapshot(usess, &tmp_output, session,
-					wait, nb_packets_per_stream);
-			if (ret != LTTNG_OK) {
-				goto error;
-			}
-			snapshot_success = 1;
-		} else {
-			struct snapshot_output *sout;
-			struct lttng_ht_iter iter;
-
-			rcu_read_lock();
-			cds_lfht_for_each_entry(session->snapshot.output_ht->ht,
-					&iter.iter, sout, node.node) {
-				int64_t nb_packets_per_stream;
 
-				/*
-				 * Make a local copy of the output and assign the possible
-				 * temporary value given by the caller.
-				 */
-				memset(&tmp_output, 0, sizeof(tmp_output));
-				memcpy(&tmp_output, sout, sizeof(tmp_output));
-
-				if (output->max_size != (uint64_t) -1ULL) {
-					tmp_output.max_size = output->max_size;
-				}
-
-				nb_packets_per_stream = get_session_nb_packets_per_stream(session,
-						tmp_output.max_size);
-				if (nb_packets_per_stream < 0) {
-					ret = LTTNG_ERR_MAX_SIZE_INVALID;
+			/* Use temporary name. */
+			if (*output->name != '\0') {
+				if (lttng_strncpy(tmp_output.name, output->name,
+						sizeof(tmp_output.name))) {
+					ret = LTTNG_ERR_INVALID;
 					rcu_read_unlock();
 					goto error;
 				}
+			}
 
-				/* Use temporary name. */
-				if (*output->name != '\0') {
-					strncpy(tmp_output.name, output->name,
-							sizeof(tmp_output.name));
-				}
+			tmp_output.nb_snapshot = session->snapshot.nb_snapshot;
+			memcpy(tmp_output.datetime, datetime, sizeof(datetime));
 
-				tmp_output.nb_snapshot = session->snapshot.nb_snapshot;
+			if (session->kernel_session) {
+				ret = record_kernel_snapshot(session->kernel_session,
+						&tmp_output, session,
+						wait, nb_packets_per_stream);
+				if (ret != LTTNG_OK) {
+					rcu_read_unlock();
+					goto error;
+				}
+			}
 
-				ret = record_ust_snapshot(usess, &tmp_output, session,
+			if (session->ust_session) {
+				ret = record_ust_snapshot(session->ust_session,
+						&tmp_output, session,
 						wait, nb_packets_per_stream);
 				if (ret != LTTNG_OK) {
 					rcu_read_unlock();
 					goto error;
 				}
-				snapshot_success = 1;
 			}
-			rcu_read_unlock();
+			snapshot_success = 1;
 		}
+		rcu_read_unlock();
 	}
 
 	if (snapshot_success) {