Fix: consumer relay sender RCU usage

[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 1cd39ef34b7e957bf9cfa95ac93e7fb40374fb9c..4cd6972125dccba26fcfadee133b7438d91c5eeb 100644 (file)
--- a/src/common/ust-consumer/ust-consumer.c
+++ b/src/common/ust-consumer/ust-consumer.c
@@ -56,10 +56,14 @@ ssize_t lttng_ustconsumer_on_read_subbuffer_mmap(
        uint64_t metadata_id;
        struct consumer_relayd_sock_pair *relayd = NULL;
 
+       /* RCU lock for the relayd pointer */
+       rcu_read_lock();
+
        /* Flag that the current stream if set for network streaming. */
        if (stream->net_seq_idx != -1) {
                relayd = consumer_find_relayd(stream->net_seq_idx);
                if (relayd == NULL) {
+                       ERR("Cannot find relay for network stream\n");
                        goto end;
                }
        }
@@ -139,6 +143,7 @@ end:
        if (relayd && stream->metadata_flag) {
                pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
        }
+       rcu_read_unlock();
        return written;
 }
 
@@ -210,6 +215,9 @@ int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
                return -ENOENT;
        }
 
+       /* relayd need RCU read-side lock */
+       rcu_read_lock();
+
        switch (msg.cmd_type) {
        case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
        {
@@ -433,6 +441,7 @@ end:
                ret = write(ctx->consumer_poll_pipe[1], "", 1);
        } while (ret < 0 && errno == EINTR);
 end_nosignal:
+       rcu_read_unlock();
        return 0;
 }