consumer: fix: unaligned accesses to index fields

[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 88b687611fc8714675722f8616a85b10fce40baa..17672fb20950e77f5d61d2738ef5109f059a161f 100644 (file)
--- a/src/common/ust-consumer/ust-consumer.c
+++ b/src/common/ust-consumer/ust-consumer.c
@@ -2198,62 +2198,69 @@ static int get_index_values(struct ctf_packet_index *index,
                struct ustctl_consumer_stream *ustream)
 {
        int ret;
+       uint64_t packet_size, content_size, timestamp_begin, timestamp_end,
+                       events_discarded, stream_id, stream_instance_id,
+                       packet_seq_num;
 
-       ret = ustctl_get_timestamp_begin(ustream, &index->timestamp_begin);
+       ret = ustctl_get_timestamp_begin(ustream, &timestamp_begin);
        if (ret < 0) {
                PERROR("ustctl_get_timestamp_begin");
                goto error;
        }
-       index->timestamp_begin = htobe64(index->timestamp_begin);
 
-       ret = ustctl_get_timestamp_end(ustream, &index->timestamp_end);
+       ret = ustctl_get_timestamp_end(ustream, &timestamp_end);
        if (ret < 0) {
                PERROR("ustctl_get_timestamp_end");
                goto error;
        }
-       index->timestamp_end = htobe64(index->timestamp_end);
 
-       ret = ustctl_get_events_discarded(ustream, &index->events_discarded);
+       ret = ustctl_get_events_discarded(ustream, &events_discarded);
        if (ret < 0) {
                PERROR("ustctl_get_events_discarded");
                goto error;
        }
-       index->events_discarded = htobe64(index->events_discarded);
 
-       ret = ustctl_get_content_size(ustream, &index->content_size);
+       ret = ustctl_get_content_size(ustream, &content_size);
        if (ret < 0) {
                PERROR("ustctl_get_content_size");
                goto error;
        }
-       index->content_size = htobe64(index->content_size);
 
-       ret = ustctl_get_packet_size(ustream, &index->packet_size);
+       ret = ustctl_get_packet_size(ustream, &packet_size);
        if (ret < 0) {
                PERROR("ustctl_get_packet_size");
                goto error;
        }
-       index->packet_size = htobe64(index->packet_size);
 
-       ret = ustctl_get_stream_id(ustream, &index->stream_id);
+       ret = ustctl_get_stream_id(ustream, &stream_id);
        if (ret < 0) {
                PERROR("ustctl_get_stream_id");
                goto error;
        }
-       index->stream_id = htobe64(index->stream_id);
 
-       ret = ustctl_get_instance_id(ustream, &index->stream_instance_id);
+       ret = ustctl_get_instance_id(ustream, &stream_instance_id);
        if (ret < 0) {
                PERROR("ustctl_get_instance_id");
                goto error;
        }
-       index->stream_instance_id = htobe64(index->stream_instance_id);
 
-       ret = ustctl_get_sequence_number(ustream, &index->packet_seq_num);
+       ret = ustctl_get_sequence_number(ustream, &packet_seq_num);
        if (ret < 0) {
                PERROR("ustctl_get_sequence_number");
                goto error;
        }
-       index->packet_seq_num = htobe64(index->packet_seq_num);
+
+       *index = (typeof(*index)) {
+               .offset = index->offset,
+               .packet_size = htobe64(packet_size),
+               .content_size = htobe64(content_size),
+               .timestamp_begin = htobe64(timestamp_begin),
+               .timestamp_end = htobe64(timestamp_end),
+               .events_discarded = htobe64(events_discarded),
+               .stream_id = htobe64(stream_id),
+               .stream_instance_id = htobe64(stream_instance_id),
+               .packet_seq_num = htobe64(packet_seq_num),
+       };
 
 error:
        return ret;
@@ -2330,6 +2337,13 @@ int commit_one_metadata_packet(struct lttng_consumer_stream *stream)
                        stream->ust_metadata_pushed);
        ret = write_len;
 
+       /*
+        * Switch packet (but don't open the next one) on every commit of
+        * a metadata packet. Since the subbuffer is fully filled (with padding,
+        * if needed), the stream is "quiescent" after this commit.
+        */
+       ustctl_flush_buffer(stream->ustream, 1);
+       stream->quiescent = true;
 end:
        pthread_mutex_unlock(&stream->chan->metadata_cache->lock);
        return ret;
@@ -2374,7 +2388,6 @@ int lttng_ustconsumer_sync_metadata(struct lttng_consumer_local_data *ctx,
                retry = 1;
        }
 
-       ustctl_flush_buffer(metadata->ustream, 1);
        ret = ustctl_snapshot(metadata->ustream);
        if (ret < 0) {
                if (errno != EAGAIN) {
@@ -2564,7 +2577,6 @@ retry:
                        if (ret <= 0) {
                                goto end;
                        }
-                       ustctl_flush_buffer(stream->ustream, 1);
                        goto retry;
                }