+}
+
+/*
+ * Called under ust lock.
+ */
+static
+void fixup_lazy_probes(void)
+{
+ struct lttng_probe_desc *iter, *tmp;
+ int ret;
+
+ lazy_nesting++;
+ cds_list_for_each_entry_safe(iter, tmp,
+ &lazy_probe_init, lazy_init_head) {
+ lttng_lazy_probe_register(iter);
+ iter->lazy = 0;
+ cds_list_del(&iter->lazy_init_head);
+ }
+ ret = lttng_fix_pending_events();
+ assert(!ret);
+ lazy_nesting--;
+}
+
+/*
+ * Called under ust lock.
+ */
+struct cds_list_head *lttng_get_probe_list_head(void)
+{
+ if (!lazy_nesting && !cds_list_empty(&lazy_probe_init))
+ fixup_lazy_probes();
+ return &_probe_list;
+}
+
+static
+int check_provider_version(struct lttng_probe_desc *desc)
+{
+ /*
+ * Check tracepoint provider version compatibility.
+ */
+ if (desc->major <= LTTNG_UST_PROVIDER_MAJOR) {
+ DBG("Provider \"%s\" accepted, version %u.%u is compatible "
+ "with LTTng UST provider version %u.%u.",
+ desc->provider, desc->major, desc->minor,
+ LTTNG_UST_PROVIDER_MAJOR,
+ LTTNG_UST_PROVIDER_MINOR);
+ if (desc->major < LTTNG_UST_PROVIDER_MAJOR) {
+ DBG("However, some LTTng UST features might not be "
+ "available for this provider unless it is "
+ "recompiled against a more recent LTTng UST.");
+ }
+ return 1; /* accept */
+ } else {
+ ERR("Provider \"%s\" rejected, version %u.%u is incompatible "
+ "with LTTng UST provider version %u.%u. Please upgrade "
+ "LTTng UST.",
+ desc->provider, desc->major, desc->minor,
+ LTTNG_UST_PROVIDER_MAJOR,
+ LTTNG_UST_PROVIDER_MINOR);
+ return 0; /* reject */
+ }
+}
+
+
+int lttng_probe_register(struct lttng_probe_desc *desc)
+{
+ int ret = 0;
+
+ lttng_ust_fixup_tls();
+
+ /*
+ * If version mismatch, don't register, but don't trigger assert
+ * on caller. The version check just prints an error.
+ */
+ if (!check_provider_version(desc))
+ return 0;
+
+ ust_lock_nocheck();
+
+ cds_list_add(&desc->lazy_init_head, &lazy_probe_init);
+ desc->lazy = 1;
+ DBG("adding probe %s containing %u events to lazy registration list",
+ desc->provider, desc->nr_events);