- struct lttng_kernel_event_notifier *event_notifier;
- struct lttng_kernel_event_notifier_private *event_notifier_priv;
- struct lttng_counter *error_counter;
- const char *event_name;
- struct hlist_head *head;
- int ret;
-
- switch (itype) {
- case LTTNG_KERNEL_ABI_TRACEPOINT:
- event_name = event_desc->event_name;
- break;
-
- case LTTNG_KERNEL_ABI_KPROBE: /* Fall-through */
- case LTTNG_KERNEL_ABI_UPROBE: /* Fall-through */
- case LTTNG_KERNEL_ABI_SYSCALL:
- event_name = event_notifier_param->event.name;
- break;
-
- case LTTNG_KERNEL_ABI_KRETPROBE: /* Fall-through */
- case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
- case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
- default:
- WARN_ON_ONCE(1);
- ret = -EINVAL;
- goto type_error;
- }
-
- head = utils_borrow_hash_table_bucket(event_notifier_group->event_notifiers_ht.table,
- LTTNG_EVENT_NOTIFIER_HT_SIZE, event_name);
- lttng_hlist_for_each_entry(event_notifier_priv, head, hlist) {
- WARN_ON_ONCE(!event_notifier_priv->parent.desc);
- if (!strncmp(event_notifier_priv->parent.desc->event_name, event_name,
- LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1)
- && event_notifier_group == event_notifier_priv->group
- && token == event_notifier_priv->parent.user_token) {
- ret = -EEXIST;
- goto exist;
- }
- }
-
- event_notifier = kmem_cache_zalloc(event_notifier_cache, GFP_KERNEL);
- if (!event_notifier) {
- ret = -ENOMEM;
- goto cache_error;
- }
- event_notifier_priv = kmem_cache_zalloc(event_notifier_private_cache, GFP_KERNEL);
- if (!event_notifier_priv) {
- ret = -ENOMEM;
- goto cache_private_error;
- }
- event_notifier_priv->pub = event_notifier;
- event_notifier_priv->parent.pub = &event_notifier->parent;
- event_notifier->priv = event_notifier_priv;
- event_notifier->parent.priv = &event_notifier_priv->parent;
- event_notifier->parent.type = LTTNG_KERNEL_EVENT_TYPE_NOTIFIER;
-
- event_notifier->priv->group = event_notifier_group;
- event_notifier->priv->parent.user_token = token;
- event_notifier->priv->error_counter_index = error_counter_index;
- event_notifier->priv->num_captures = 0;
- event_notifier->priv->parent.instrumentation = itype;
- event_notifier->notification_send = lttng_event_notifier_notification_send;
- INIT_LIST_HEAD(&event_notifier->priv->parent.filter_bytecode_runtime_head);
- INIT_LIST_HEAD(&event_notifier->priv->parent.enablers_ref_head);
- INIT_LIST_HEAD(&event_notifier->priv->capture_bytecode_runtime_head);
- event_notifier->parent.run_filter = lttng_kernel_interpret_event_filter;
-
- switch (itype) {
- case LTTNG_KERNEL_ABI_TRACEPOINT:
- /* Event will be enabled by enabler sync. */
- event_notifier->parent.enabled = 0;
- event_notifier->priv->parent.registered = 0;
- event_notifier->priv->parent.desc = lttng_event_desc_get(event_name);
- if (!event_notifier->priv->parent.desc) {
- ret = -ENOENT;
- goto register_error;
- }
- /* Populate lttng_event_notifier structure before event registration. */
- smp_wmb();
- break;
-
- case LTTNG_KERNEL_ABI_KPROBE:
- /*
- * Needs to be explicitly enabled after creation, since
- * we may want to apply filters.
- */
- event_notifier->parent.enabled = 0;
- event_notifier->priv->parent.registered = 1;
- /*
- * Populate lttng_event_notifier structure before event
- * registration.
- */
- smp_wmb();
- ret = lttng_kprobes_register_event_notifier(
- event_notifier_param->event.u.kprobe.symbol_name,
- event_notifier_param->event.u.kprobe.offset,
- event_notifier_param->event.u.kprobe.addr,
- event_notifier);
- if (ret) {
- ret = -EINVAL;
- goto register_error;
- }
- ret = try_module_get(event_notifier->priv->parent.desc->owner);
- WARN_ON_ONCE(!ret);
- break;
-
- case LTTNG_KERNEL_ABI_SYSCALL:
- /*
- * Needs to be explicitly enabled after creation, since
- * we may want to apply filters.
- */
- event_notifier->parent.enabled = 0;
- event_notifier->priv->parent.registered = 0;
- event_notifier->priv->parent.desc = event_desc;
- switch (event_notifier_param->event.u.syscall.entryexit) {
- case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
- ret = -EINVAL;
- goto register_error;
- case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
- event_notifier->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_ENTRY;
- break;
- case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
- event_notifier->priv->parent.u.syscall.entryexit = LTTNG_SYSCALL_EXIT;
- break;
- }
- switch (event_notifier_param->event.u.syscall.abi) {
- case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
- ret = -EINVAL;
- goto register_error;
- case LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE:
- event_notifier->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_NATIVE;
- break;
- case LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT:
- event_notifier->priv->parent.u.syscall.abi = LTTNG_SYSCALL_ABI_COMPAT;
- break;
- }
-
- if (!event_notifier->priv->parent.desc) {
- ret = -EINVAL;
- goto register_error;
- }
- break;
-
- case LTTNG_KERNEL_ABI_UPROBE:
- /*
- * Needs to be explicitly enabled after creation, since
- * we may want to apply filters.
- */
- event_notifier->parent.enabled = 0;
- event_notifier->priv->parent.registered = 1;
-
- /*
- * Populate lttng_event_notifier structure before
- * event_notifier registration.
- */
- smp_wmb();
-
- ret = lttng_uprobes_register_event_notifier(
- event_notifier_param->event.name,
- event_notifier_param->event.u.uprobe.fd,
- event_notifier);
- if (ret)
- goto register_error;
- ret = try_module_get(event_notifier->priv->parent.desc->owner);
- WARN_ON_ONCE(!ret);
- break;
-
- case LTTNG_KERNEL_ABI_KRETPROBE: /* Fall-through */
- case LTTNG_KERNEL_ABI_FUNCTION: /* Fall-through */
- case LTTNG_KERNEL_ABI_NOOP: /* Fall-through */
- default:
- WARN_ON_ONCE(1);
- ret = -EINVAL;
- goto register_error;
- }
-
- list_add(&event_notifier->priv->node, &event_notifier_group->event_notifiers_head);
- hlist_add_head(&event_notifier->priv->hlist, head);
-
- /*
- * Clear the error counter bucket. The sessiond keeps track of which
- * bucket is currently in use. We trust it. The session lock
- * synchronizes against concurrent creation of the error
- * counter.
- */
- error_counter = event_notifier_group->error_counter;
- if (error_counter) {
- size_t dimension_index[1];
-
- /*
- * Check that the index is within the boundary of the counter.
- */
- if (event_notifier->priv->error_counter_index >= event_notifier_group->error_counter_len) {
- printk(KERN_INFO "LTTng: event_notifier: Error counter index out-of-bound: counter-len=%zu, index=%llu\n",
- event_notifier_group->error_counter_len, event_notifier->priv->error_counter_index);
- ret = -EINVAL;
- goto register_error;
- }
-
- dimension_index[0] = event_notifier->priv->error_counter_index;
- ret = error_counter->ops->counter_clear(error_counter->counter, dimension_index);
- if (ret) {
- printk(KERN_INFO "LTTng: event_notifier: Unable to clear error counter bucket %llu\n",
- event_notifier->priv->error_counter_index);
- goto register_error;
- }
- }