Fix: Missing RCU read lock in kernel_destroy_session()

[lttng-tools.git] / src / bin / lttng-sessiond / kernel.c

diff --git a/src/bin/lttng-sessiond/kernel.c b/src/bin/lttng-sessiond/kernel.c
index b997a4aeab6b7ac0aac7208fa82bacd6e964ce28..fc95302fccb9336332df0517b32dfec5a02954d5 100644 (file)
--- a/src/bin/lttng-sessiond/kernel.c
+++ b/src/bin/lttng-sessiond/kernel.c
@@ -171,6 +171,7 @@ error:
 /*
  * Create a kernel event, enable it to the kernel tracer and add it to the
  * channel event list of the kernel session.
+ * We own filter_expression and filter.
  */
 int kernel_create_event(struct lttng_event *ev,
                struct ltt_kernel_channel *channel)
@@ -766,6 +767,7 @@ void kernel_destroy_session(struct ltt_kernel_session *ksess)
                struct lttng_ht_iter iter;
 
                /* For each consumer socket. */
+               rcu_read_lock();
                cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
                                socket, node.node) {
                        struct ltt_kernel_channel *chan;
@@ -779,6 +781,7 @@ void kernel_destroy_session(struct ltt_kernel_session *ksess)
                                }
                        }
                }
+               rcu_read_unlock();
        }
 
        /* Close any relayd session */
@@ -823,13 +826,12 @@ void kernel_destroy_channel(struct ltt_kernel_channel *kchan)
  * Return 0 on success or else return a LTTNG_ERR code.
  */
 int kernel_snapshot_record(struct ltt_kernel_session *ksess,
-               struct snapshot_output *output, int wait, unsigned int nb_streams)
+               struct snapshot_output *output, int wait, uint64_t max_size_per_stream)
 {
        int err, ret, saved_metadata_fd;
        struct consumer_socket *socket;
        struct lttng_ht_iter iter;
        struct ltt_kernel_metadata *saved_metadata;
-       uint64_t max_size_per_stream = 0;
 
        assert(ksess);
        assert(ksess->consumer);
@@ -855,10 +857,6 @@ int kernel_snapshot_record(struct ltt_kernel_session *ksess,
                goto error_open_stream;
        }
 
-       if (output->max_size > 0 && nb_streams > 0) {
-               max_size_per_stream = output->max_size / nb_streams;
-       }
-
        /* Send metadata to consumer and snapshot everything. */
        cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
                        socket, node.node) {
@@ -885,17 +883,6 @@ int kernel_snapshot_record(struct ltt_kernel_session *ksess,
 
                /* For each channel, ask the consumer to snapshot it. */
                cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
-                       if (max_size_per_stream &&
-                                       chan->channel->attr.subbuf_size > max_size_per_stream) {
-                               ret = LTTNG_ERR_INVALID;
-                               DBG3("Kernel snapshot record maximum stream size %" PRIu64
-                                               " is smaller than subbuffer size of %" PRIu64,
-                                               max_size_per_stream, chan->channel->attr.subbuf_size);
-                               (void) kernel_consumer_destroy_metadata(socket,
-                                               ksess->metadata);
-                               goto error_consumer;
-                       }
-
                        pthread_mutex_lock(socket->lock);
                        ret = consumer_snapshot_channel(socket, chan->fd, output, 0,
                                        ksess->uid, ksess->gid,