Fix: check validity of a stream before invoking ust flush command

[lttng-tools.git] / src / common / ust-consumer / ust-consumer.c

diff --git a/src/common/ust-consumer/ust-consumer.c b/src/common/ust-consumer/ust-consumer.c
index 5b8e9431f9ca15d2dbba787442863650fe343453..88b687611fc8714675722f8616a85b10fce40baa 100644 (file)
--- a/src/common/ust-consumer/ust-consumer.c
+++ b/src/common/ust-consumer/ust-consumer.c
@@ -768,10 +768,19 @@ static int flush_channel(uint64_t chan_key)
                health_code_update();
 
                pthread_mutex_lock(&stream->lock);
+
+               /*
+                * Protect against concurrent teardown of a stream.
+                */
+               if (cds_lfht_is_node_deleted(&stream->node.node)) {
+                       goto next;
+               }
+
                if (!stream->quiescent) {
                        ustctl_flush_buffer(stream->ustream, 0);
                        stream->quiescent = true;
                }
+next:
                pthread_mutex_unlock(&stream->lock);
        }
 error:
@@ -1174,7 +1183,7 @@ static int snapshot_channel(uint64_t key, char *path, uint64_t relayd_id,
                                produced_pos, nb_packets_per_stream,
                                stream->max_sb_size);
 
-               while (consumed_pos < produced_pos) {
+               while ((long) (consumed_pos - produced_pos) < 0) {
                        ssize_t read_len;
                        unsigned long len, padded_len;
 
@@ -2922,7 +2931,7 @@ int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data *ctx,
        request.key = channel->key;
 
        DBG("Sending metadata request to sessiond, session id %" PRIu64
-                       ", per-pid %" PRIu64 ", app UID %u and channek key %" PRIu64,
+                       ", per-pid %" PRIu64 ", app UID %u and channel key %" PRIu64,
                        request.session_id, request.session_id_per_pid, request.uid,
                        request.key);