+/*
+ * Allocate and initialize a kernel token event rule.
+ *
+ * Return pointer to structure or NULL.
+ */
+enum lttng_error_code trace_kernel_create_event_notifier_rule(
+ struct lttng_trigger *trigger,
+ uint64_t token,
+ struct ltt_kernel_event_notifier_rule **event_notifier_rule)
+{
+ enum lttng_error_code ret = LTTNG_OK;
+ enum lttng_condition_type condition_type;
+ enum lttng_event_rule_type event_rule_type;
+ enum lttng_condition_status condition_status;
+ struct ltt_kernel_event_notifier_rule *local_kernel_token_event_rule;
+ const struct lttng_condition *condition = NULL;
+ const struct lttng_event_rule *event_rule = NULL;
+
+ assert(event_notifier_rule);
+
+ condition = lttng_trigger_get_condition(trigger);
+ assert(condition);
+
+ condition_type = lttng_condition_get_type(condition);
+ assert(condition_type == LTTNG_CONDITION_TYPE_EVENT_RULE_HIT);
+
+ condition_status = lttng_condition_event_rule_get_rule(
+ condition, &event_rule);
+ assert(condition_status == LTTNG_CONDITION_STATUS_OK);
+ assert(event_rule);
+
+ event_rule_type = lttng_event_rule_get_type(event_rule);
+ assert(event_rule_type != LTTNG_EVENT_RULE_TYPE_UNKNOWN);
+
+ local_kernel_token_event_rule =
+ zmalloc(sizeof(struct ltt_kernel_event_notifier_rule));
+ if (local_kernel_token_event_rule == NULL) {
+ PERROR("Failed to allocate ltt_kernel_token_event_rule structure");
+ ret = LTTNG_ERR_NOMEM;
+ goto error;
+ }
+
+ local_kernel_token_event_rule->fd = -1;
+ local_kernel_token_event_rule->enabled = 1;
+ local_kernel_token_event_rule->token = token;
+
+ /* Get the reference of the event rule. */
+ lttng_trigger_get(trigger);
+
+ local_kernel_token_event_rule->trigger = trigger;
+ /* The event rule still owns the filter and bytecode. */
+ local_kernel_token_event_rule->filter =
+ lttng_event_rule_get_filter_bytecode(event_rule);
+
+ DBG3("Created kernel event notifier rule: token = %" PRIu64,
+ local_kernel_token_event_rule->token);
+error:
+ *event_notifier_rule = local_kernel_token_event_rule;
+ return ret;
+}
+
+/*
+ * Initialize a kernel trigger from an event rule.
+ */
+enum lttng_error_code trace_kernel_init_event_notifier_from_event_rule(
+ const struct lttng_event_rule *rule,
+ struct lttng_kernel_event_notifier *kernel_event_notifier)
+{
+ enum lttng_error_code ret_code;
+ const char *name;
+ int strncpy_ret;
+
+ switch (lttng_event_rule_get_type(rule)) {
+ case LTTNG_EVENT_RULE_TYPE_KPROBE:
+ {
+ uint64_t address = 0, offset = 0;
+ const char *symbol_name = NULL;
+ const struct lttng_kernel_probe_location *location = NULL;
+ enum lttng_kernel_probe_location_status k_status;
+ enum lttng_event_rule_status status;
+
+ status = lttng_event_rule_kprobe_get_location(rule, &location);
+ if (status != LTTNG_EVENT_RULE_STATUS_OK) {
+ ret_code = LTTNG_ERR_PROBE_LOCATION_INVAL;
+ goto error;
+ }
+
+ switch (lttng_kernel_probe_location_get_type(location)) {
+ case LTTNG_KERNEL_PROBE_LOCATION_TYPE_ADDRESS:
+ {
+ k_status = lttng_kernel_probe_location_address_get_address(
+ location, &address);
+ assert(k_status == LTTNG_KERNEL_PROBE_LOCATION_STATUS_OK);
+ break;
+ }
+ case LTTNG_KERNEL_PROBE_LOCATION_TYPE_SYMBOL_OFFSET:
+ {
+ k_status = lttng_kernel_probe_location_symbol_get_offset(
+ location, &offset);
+ assert(k_status == LTTNG_KERNEL_PROBE_LOCATION_STATUS_OK);
+ symbol_name = lttng_kernel_probe_location_symbol_get_name(
+ location);
+ break;
+ }
+ default:
+ abort();
+ }
+
+ kernel_event_notifier->event.instrumentation = LTTNG_KERNEL_KPROBE;
+ kernel_event_notifier->event.u.kprobe.addr = address;
+ kernel_event_notifier->event.u.kprobe.offset = offset;
+ if (symbol_name) {
+ strncpy_ret = lttng_strncpy(
+ kernel_event_notifier->event.u.kprobe.symbol_name,
+ symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
+
+ if (strncpy_ret) {
+ ret_code = LTTNG_ERR_INVALID;
+ goto error;
+ }
+ }
+
+ kernel_event_notifier->event.u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
+ status = lttng_event_rule_kprobe_get_name(rule, &name);
+ assert(status == LTTNG_EVENT_RULE_STATUS_OK);
+ ret_code = LTTNG_OK;
+ break;
+ }
+ case LTTNG_EVENT_RULE_TYPE_UPROBE:
+ {
+ const struct lttng_userspace_probe_location* location = NULL;
+ const struct lttng_userspace_probe_location_lookup_method *lookup = NULL;
+ enum lttng_event_rule_status status;
+
+ status = lttng_event_rule_uprobe_get_location(rule, &location);
+ if (status != LTTNG_EVENT_RULE_STATUS_OK) {
+ ret_code = LTTNG_ERR_PROBE_LOCATION_INVAL;
+ goto error;
+ }
+
+ kernel_event_notifier->event.instrumentation = LTTNG_KERNEL_UPROBE;
+
+ lookup = lttng_userspace_probe_location_get_lookup_method(
+ location);
+ if (!lookup) {
+ ret_code = LTTNG_ERR_PROBE_LOCATION_INVAL;
+ goto error;
+ }
+
+ /*
+ * From the kernel tracer's perspective, all userspace probe
+ * event types are all the same: a file and an offset.
+ */
+ switch (lttng_userspace_probe_location_lookup_method_get_type(lookup)) {
+ case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF:
+ /* Get the file descriptor on the target binary. */
+ kernel_event_notifier->event.u.uprobe.fd =
+ lttng_userspace_probe_location_function_get_binary_fd(location);
+
+ break;
+ case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT:
+ /* Get the file descriptor on the target binary. */
+ kernel_event_notifier->event.u.uprobe.fd =
+ lttng_userspace_probe_location_tracepoint_get_binary_fd(location);
+ break;
+ default:
+ abort();
+ }
+
+ status = lttng_event_rule_uprobe_get_name(rule, &name);
+ assert(status == LTTNG_EVENT_RULE_STATUS_OK);
+ ret_code = LTTNG_OK;
+ break;
+ }
+ case LTTNG_EVENT_RULE_TYPE_TRACEPOINT:
+ {
+ const enum lttng_domain_type domain =
+ lttng_event_rule_get_domain_type(rule);
+ const enum lttng_event_rule_status status =
+ lttng_event_rule_tracepoint_get_pattern(
+ rule, &name);
+
+ assert(domain == LTTNG_DOMAIN_KERNEL);
+ assert(status == LTTNG_EVENT_RULE_STATUS_OK);
+ kernel_event_notifier->event.instrumentation =
+ LTTNG_KERNEL_TRACEPOINT;
+
+ ret_code = LTTNG_OK;
+ break;
+ }
+ case LTTNG_EVENT_RULE_TYPE_SYSCALL:
+ {
+ const enum lttng_event_rule_status status =
+ lttng_event_rule_syscall_get_pattern(
+ rule, &name);
+
+ assert(status == LTTNG_EVENT_RULE_STATUS_OK);
+
+ kernel_event_notifier->event.instrumentation =
+ LTTNG_KERNEL_SYSCALL;
+ kernel_event_notifier->event.u.syscall.abi =
+ LTTNG_KERNEL_SYSCALL_ABI_ALL;
+ kernel_event_notifier->event.u.syscall.entryexit =
+ LTTNG_KERNEL_SYSCALL_ENTRY;
+ kernel_event_notifier->event.u.syscall.match =
+ LTTNG_KERNEL_SYSCALL_MATCH_NAME;
+ ret_code = LTTNG_OK;
+ break;
+ }
+ case LTTNG_EVENT_RULE_TYPE_KRETPROBE:
+ default:
+ abort();
+ break;
+ }
+
+ strncpy_ret = lttng_strncpy(kernel_event_notifier->event.name, name,
+ LTTNG_KERNEL_SYM_NAME_LEN);
+ if (strncpy_ret) {
+ ret_code = LTTNG_ERR_INVALID;
+ goto error;
+ }
+
+error:
+ return ret_code;
+}