X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fcmd.c;h=1a3c22a6c8f87715dc85c878ec5b0c3443d7d1e3;hp=b836f3d8f5a4c71b408731c3dcdfe1e394e3147e;hb=9a699f7bb912d287630c8940459069a4b04d2399;hpb=491d15395b58df09f8a3e7ba7404eb1f46392b79

diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index b836f3d8f..1a3c22a6c 100644
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -34,6 +34,7 @@
 #include <lttng/trigger/trigger-internal.h>
 #include <lttng/condition/condition.h>
 #include <lttng/action/action.h>
+#include <lttng/channel.h>
 #include <lttng/channel-internal.h>
 #include <common/string-utils/string-utils.h>
 
@@ -906,6 +907,8 @@ error:
 
 /*
  * Connect to the relayd using URI and send the socket to the right consumer.
+ *
+ * The consumer socket lock must be held by the caller.
  */
 static int send_consumer_relayd_socket(enum lttng_domain_type domain,
 		unsigned int session_id, struct lttng_uri *relayd_uri,
@@ -919,7 +922,7 @@ static int send_consumer_relayd_socket(enum lttng_domain_type domain,
 	/* Connect to relayd and make version check if uri is the control. */
 	ret = create_connect_relayd(relayd_uri, &rsock, consumer);
 	if (ret != LTTNG_OK) {
-		goto error;
+		goto relayd_comm_error;
 	}
 	assert(rsock);
 
@@ -959,10 +962,6 @@ static int send_consumer_relayd_socket(enum lttng_domain_type domain,
 	 */
 
 close_sock:
-	(void) relayd_close(rsock);
-	free(rsock);
-
-error:
 	if (ret != LTTNG_OK) {
 		/*
 		 * The consumer output for this session should not be used anymore
@@ -971,6 +970,10 @@ error:
 		 */
 		consumer->enabled = 0;
 	}
+	(void) relayd_close(rsock);
+	free(rsock);
+
+relayd_comm_error:
 	return ret;
 }
 
@@ -978,6 +981,8 @@ error:
  * Send both relayd sockets to a specific consumer and domain.  This is a
  * helper function to facilitate sending the information to the consumer for a
  * session.
+ *
+ * The consumer socket lock must be held by the caller.
  */
 static int send_consumer_relayd_sockets(enum lttng_domain_type domain,
 		unsigned int session_id, struct consumer_output *consumer,
@@ -1357,6 +1362,30 @@ int cmd_enable_channel(struct ltt_session *session,
 		attr->attr.switch_timer_interval = 0;
 	}
 
+	/* Check for feature support */
+	switch (domain->type) {
+	case LTTNG_DOMAIN_KERNEL:
+	{
+		if (kernel_supports_ring_buffer_snapshot_sample_positions(kernel_tracer_fd) != 1) {
+			/* Sampling position of buffer is not supported */
+			WARN("Kernel tracer does not support buffer monitoring. "
+					"Setting the monitor interval timer to 0 "
+					"(disabled) for channel '%s' of session '%s'",
+					attr-> name, session->name);
+			lttng_channel_set_monitor_timer_interval(attr, 0);
+		}
+		break;
+	}
+	case LTTNG_DOMAIN_UST:
+	case LTTNG_DOMAIN_JUL:
+	case LTTNG_DOMAIN_LOG4J:
+	case LTTNG_DOMAIN_PYTHON:
+		break;
+	default:
+		ret = LTTNG_ERR_UNKNOWN_DOMAIN;
+		goto error;
+	}
+
 	switch (domain->type) {
 	case LTTNG_DOMAIN_KERNEL:
 	{
@@ -1625,6 +1654,16 @@ int cmd_add_context(struct ltt_session *session, enum lttng_domain_type domain,
 	int ret, chan_kern_created = 0, chan_ust_created = 0;
 	char *app_ctx_provider_name = NULL, *app_ctx_name = NULL;
 
+	/*
+	 * Don't try to add a context if the session has been started at
+	 * some point in time before. The tracer does not allow it and would
+	 * result in a corrupted trace.
+	 */
+	if (session->has_been_started) {
+		ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
+		goto end;
+	}
+
 	if (ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
 		app_ctx_provider_name = ctx->u.app_ctx.provider_name;
 		app_ctx_name = ctx->u.app_ctx.ctx_name;
@@ -3525,7 +3564,6 @@ int cmd_regenerate_statedump(struct ltt_session *session)
 		ret = LTTNG_ERR_SESSION_NOT_STARTED;
 		goto end;
 	}
-	ret = 0;
 
 	if (session->kernel_session) {
 		ret = kernctl_session_regenerate_statedump(
@@ -3682,10 +3720,12 @@ static int set_relayd_for_snapshot(struct consumer_output *consumer,
 	rcu_read_lock();
 	cds_lfht_for_each_entry(snap_output->consumer->socks->ht, &iter.iter,
 			socket, node.node) {
+		pthread_mutex_lock(socket->lock);
 		ret = send_consumer_relayd_sockets(0, session->id,
 				snap_output->consumer, socket,
 				session->name, session->hostname,
 				session->live_timer);
+		pthread_mutex_unlock(socket->lock);
 		if (ret != LTTNG_OK) {
 			rcu_read_unlock();
 			goto error;