rcu_read_lock();
+ /*
+ * The ringbuffer (both in user space and kernel) behave badly in overwrite
+ * mode and with less than 2 subbuf so block it right away and send back an
+ * invalid attribute error.
+ */
+ if (attr->attr.overwrite && attr->attr.num_subbuf < 2) {
+ ret = LTTNG_ERR_INVALID;
+ goto error;
+ }
+
switch (domain->type) {
case LTTNG_DOMAIN_KERNEL:
{
int cmd_start_trace(struct ltt_session *session)
{
int ret;
+ unsigned long nb_chan = 0;
struct ltt_kernel_session *ksession;
struct ltt_ust_session *usess;
goto error;
}
+ /*
+ * Starting a session without channel is useless since after that it's not
+ * possible to enable channel thus inform the client.
+ */
+ if (usess && usess->domain_global.channels) {
+ nb_chan += lttng_ht_get_count(usess->domain_global.channels);
+ }
+ if (ksession) {
+ nb_chan += ksession->channel_count;
+ }
+ if (!nb_chan) {
+ ret = LTTNG_ERR_NO_CHANNEL;
+ goto error;
+ }
+
session->enabled = 1;
/* Kernel tracing */
{
struct lttng_kernel_calibrate kcalibrate;
- kcalibrate.type = calibrate->type;
+ switch (calibrate->type) {
+ case LTTNG_CALIBRATE_FUNCTION:
+ default:
+ /* Default and only possible calibrate option. */
+ kcalibrate.type = LTTNG_KERNEL_CALIBRATE_KRETPROBE;
+ break;
+ }
+
ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
if (ret < 0) {
ret = LTTNG_ERR_KERN_ENABLE_FAIL;
{
struct lttng_ust_calibrate ucalibrate;
- ucalibrate.type = calibrate->type;
+ switch (calibrate->type) {
+ case LTTNG_CALIBRATE_FUNCTION:
+ default:
+ /* Default and only possible calibrate option. */
+ ucalibrate.type = LTTNG_UST_CALIBRATE_TRACEPOINT;
+ break;
+ }
+
ret = ust_app_calibrate_glb(&ucalibrate);
if (ret < 0) {
ret = LTTNG_ERR_UST_CALIBRATE_FAIL;
if (session->enabled) {
ret = LTTNG_ERR_SESSION_STARTED;
goto error;
+ } else {
+ /*
+ * If stopped, just make sure we've started before else the above call
+ * will always send that there is data pending.
+ *
+ * The consumer assumes that when the data pending command is received,
+ * the trace has been started before or else no output data is written
+ * by the streams which is a condition for data pending. So, this is
+ * *VERY* important that we don't ask the consumer before a start
+ * trace.
+ */
+ if (!session->started) {
+ ret = 0;
+ goto error;
+ }
}
if (ksess && ksess->consumer) {
ret = ust_app_snapshot_record(usess, output, wait, nb_streams);
if (ret < 0) {
- if (ret == -EINVAL) {
+ switch (-ret) {
+ case EINVAL:
ret = LTTNG_ERR_INVALID;
- goto error_snapshot;
+ break;
+ case ENODATA:
+ ret = LTTNG_ERR_SNAPSHOT_NODATA;
+ break;
+ default:
+ ret = LTTNG_ERR_SNAPSHOT_FAIL;
+ break;
}
-
- ret = LTTNG_ERR_SNAPSHOT_FAIL;
goto error_snapshot;
}