+/*
+ * Copyright (C) 2020 Francis Deslauriers <francis.deslauriers@efficios.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <urcu/compiler.h>
+
+#include <common/error.h>
+#include <common/hashtable/hashtable.h>
+#include <common/index-allocator.h>
+#include <common/kernel-ctl/kernel-ctl.h>
+#include <lttng/trigger/trigger-internal.h>
+
+#include "event-notifier-error-accounting.h"
+
+#define ERROR_COUNTER_INDEX_HT_INITIAL_SIZE 16
+
+struct index_ht_entry {
+ struct lttng_ht_node_u64 node;
+ uint64_t error_counter_index;
+ struct rcu_head rcu_head;
+};
+
+struct kernel_error_account_entry {
+ int kernel_event_notifier_error_counter_fd;
+};
+
+static struct kernel_error_account_entry kernel_error_accountant;
+
+/* Hashtable mapping event notifier token to index_ht_entry. */
+static struct lttng_ht *error_counter_indexes_ht;
+
+static uint64_t error_counter_size;
+static struct lttng_index_allocator *index_allocator;
+
+static inline
+const char *error_accounting_status_str(
+ enum event_notifier_error_accounting_status status)
+{
+ switch (status) {
+ case EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK:
+ return "OK";
+ case EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_ERR:
+ return "ERROR";
+ case EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_NOT_FOUND:
+ return "NOT_FOUND";
+ case EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_NOMEM:
+ return "NOMEM";
+ case EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_NO_INDEX_AVAILABLE:
+ return "NO_INDEX_AVAILABLE";
+ default:
+ abort();
+ }
+}
+
+enum event_notifier_error_accounting_status
+event_notifier_error_accounting_init(uint64_t nb_bucket)
+{
+ enum event_notifier_error_accounting_status status;
+
+ index_allocator = lttng_index_allocator_create(nb_bucket);
+ if (!index_allocator) {
+ ERR("Failed to allocate event notifier error counter index");
+ status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_NOMEM;
+ goto error_index_allocator;
+ }
+
+ error_counter_indexes_ht = lttng_ht_new(
+ ERROR_COUNTER_INDEX_HT_INITIAL_SIZE, LTTNG_HT_TYPE_U64);
+ if (!error_counter_indexes_ht) {
+ status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_NOMEM;
+ goto error_index_allocator;
+ }
+
+ error_counter_size = nb_bucket;
+
+ status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK;
+
+error_index_allocator:
+ return status;
+}
+
+static
+enum event_notifier_error_accounting_status get_error_counter_index_for_token(
+ uint64_t tracer_token, uint64_t *error_counter_index)
+{
+ struct lttng_ht_node_u64 *node;
+ struct lttng_ht_iter iter;
+ const struct index_ht_entry *index_entry;
+ enum event_notifier_error_accounting_status status;
+
+ rcu_read_lock();
+ lttng_ht_lookup(error_counter_indexes_ht, &tracer_token, &iter);
+ node = lttng_ht_iter_get_node_u64(&iter);
+ if (node) {
+ index_entry = caa_container_of(
+ node, const struct index_ht_entry, node);
+ *error_counter_index = index_entry->error_counter_index;
+ status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK;
+ } else {
+ status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_NOT_FOUND;
+ }
+
+ rcu_read_unlock();
+ return status;
+}
+
+static
+enum event_notifier_error_accounting_status
+event_notifier_error_accounting_kernel_clear(
+ const struct lttng_trigger *trigger)
+{
+ int ret;
+ uint64_t error_counter_index;
+ enum event_notifier_error_accounting_status status;
+ struct lttng_kernel_counter_clear counter_clear = {};
+
+ status = get_error_counter_index_for_token(
+ lttng_trigger_get_tracer_token(trigger),
+ &error_counter_index);
+ if (status != EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK) {
+ uid_t trigger_owner_uid;
+ const char *trigger_name;
+ const enum lttng_trigger_status trigger_status =
+ lttng_trigger_get_owner_uid(
+ trigger, &trigger_owner_uid);
+
+ assert(trigger_status == LTTNG_TRIGGER_STATUS_OK);
+ if (lttng_trigger_get_name(trigger, &trigger_name) !=
+ LTTNG_TRIGGER_STATUS_OK) {
+ trigger_name = "(unnamed)";
+ }
+
+ ERR("Failed to get event notifier error counter index: trigger owner uid = %d, trigger name = '%s'",
+ trigger_owner_uid, trigger_name);
+ goto end;
+ }
+
+ counter_clear.index.number_dimensions = 1;
+ counter_clear.index.dimension_indexes[0] = error_counter_index;
+
+ ret = kernctl_counter_clear(
+ kernel_error_accountant.kernel_event_notifier_error_counter_fd,
+ &counter_clear);
+ if (ret) {
+ ERR("Failed to clear event notifier error counter");
+ status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_ERR;
+ goto end;
+ }
+
+ status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK;
+end:
+ return status;
+}
+
+enum event_notifier_error_accounting_status
+event_notifier_error_accounting_register_kernel(
+ int kernel_event_notifier_group_fd)
+{
+ int error_counter_fd = -1, ret;
+ enum event_notifier_error_accounting_status status;
+ const struct lttng_kernel_counter_conf error_counter_conf = {
+ .arithmetic = LTTNG_KERNEL_COUNTER_ARITHMETIC_MODULAR,
+ .bitness = sizeof(void *) == sizeof(uint32_t) ?
+ LTTNG_KERNEL_COUNTER_BITNESS_32 :
+ LTTNG_KERNEL_COUNTER_BITNESS_64,
+ .global_sum_step = 0,
+ .number_dimensions = 1,
+ .dimensions[0].size = error_counter_size,
+ .dimensions[0].has_underflow = false,
+ .dimensions[0].has_overflow = false,
+ };
+
+ ret = kernctl_create_event_notifier_group_error_counter(
+ kernel_event_notifier_group_fd, &error_counter_conf);
+ if (ret < 0) {
+ PERROR("Failed to create event notifier group error counter through kernel ioctl: kernel_event_notifier_group_fd = %d",
+ kernel_event_notifier_group_fd);
+ status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_ERR;
+ goto error;
+ }
+
+ error_counter_fd = ret;
+
+ /* Prevent fd duplication after execlp(). */
+ ret = fcntl(error_counter_fd, F_SETFD, FD_CLOEXEC);
+ if (ret < 0) {
+ PERROR("Failed to set FD_CLOEXEC flag on event notifier error counter file descriptor: error_counter_fd = %d",
+ error_counter_fd);
+ status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_ERR;
+ goto error;
+ }
+
+ DBG("Created kernel event notifier group error counter: fd = %d",
+ error_counter_fd);
+
+ kernel_error_accountant.kernel_event_notifier_error_counter_fd =
+ error_counter_fd;
+ status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK;
+
+error:
+ return status;
+}
+
+static
+enum event_notifier_error_accounting_status create_error_counter_index_for_token(
+ uint64_t tracer_token, uint64_t *error_counter_index)
+{
+ struct index_ht_entry *index_entry;
+ enum lttng_index_allocator_status index_alloc_status;
+ uint64_t local_error_counter_index;
+ enum event_notifier_error_accounting_status status;
+
+ /* Allocate a new index for that counter. */
+ index_alloc_status = lttng_index_allocator_alloc(index_allocator,
+ &local_error_counter_index);
+ switch (index_alloc_status) {
+ case LTTNG_INDEX_ALLOCATOR_STATUS_EMPTY:
+ DBG("No indices left in the configured event notifier error counter: "
+ "number-of-indices = %"PRIu64,
+ lttng_index_allocator_get_index_count(
+ index_allocator));
+ status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_NO_INDEX_AVAILABLE;
+ goto end;
+ case LTTNG_INDEX_ALLOCATOR_STATUS_OK:
+ break;
+ default:
+ status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_ERR;
+ goto end;
+ }
+
+ index_entry = zmalloc(sizeof(*index_entry));
+ if (index_entry == NULL) {
+ PERROR("Failed to allocate event notifier error counter hash table entry");
+ status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_NOMEM;
+ goto end;
+ }
+
+ index_entry->error_counter_index = local_error_counter_index;
+ lttng_ht_node_init_u64(&index_entry->node, tracer_token);
+ lttng_ht_add_unique_u64(error_counter_indexes_ht, &index_entry->node);
+
+ DBG("Allocated error counter index for tracer token: tracer token = %" PRIu64 ", index = %" PRIu64,
+ tracer_token, local_error_counter_index);
+ *error_counter_index = local_error_counter_index;
+ status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK;
+end:
+ return status;
+}
+
+enum event_notifier_error_accounting_status
+event_notifier_error_accounting_register_event_notifier(
+ const struct lttng_trigger *trigger,
+ uint64_t *error_counter_index)
+{
+ enum event_notifier_error_accounting_status status;
+ uint64_t local_error_counter_index;
+
+ /*
+ * Check if this event notifier already has a error counter index
+ * assigned.
+ */
+ status = get_error_counter_index_for_token(
+ lttng_trigger_get_tracer_token(trigger),
+ &local_error_counter_index);
+ switch (status) {
+ case EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_NOT_FOUND:
+ {
+ uid_t trigger_owner_uid;
+ const char *trigger_name;
+ const enum lttng_trigger_status trigger_status =
+ lttng_trigger_get_owner_uid(
+ trigger, &trigger_owner_uid);
+
+ assert(trigger_status == LTTNG_TRIGGER_STATUS_OK);
+ if (lttng_trigger_get_name(trigger, &trigger_name) !=
+ LTTNG_TRIGGER_STATUS_OK) {
+ trigger_name = "(unnamed)";
+ }
+
+ DBG("Event notifier error counter index not found for tracer token (allocating a new one): trigger owner = %d, trigger name = '%s', tracer token = %" PRIu64,
+ trigger_owner_uid, trigger_name,
+ lttng_trigger_get_tracer_token(trigger));
+ status = create_error_counter_index_for_token(
+ lttng_trigger_get_tracer_token(trigger),
+ &local_error_counter_index);
+ if (status != EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK) {
+ goto end;
+ }
+ /* fall-through. */
+ }
+ case EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK:
+ *error_counter_index = local_error_counter_index;
+ status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK;
+ break;
+ default:
+ break;
+ }
+
+end:
+ return status;
+}
+
+static
+enum event_notifier_error_accounting_status
+event_notifier_error_accounting_kernel_get_count(
+ const struct lttng_trigger *trigger, uint64_t *count)
+{
+ struct lttng_kernel_counter_aggregate counter_aggregate = {};
+ enum event_notifier_error_accounting_status status;
+ uint64_t error_counter_index;
+ int ret;
+
+ status = get_error_counter_index_for_token(
+ lttng_trigger_get_tracer_token(trigger), &error_counter_index);
+ if (status != EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK) {
+ goto end;
+ }
+
+ counter_aggregate.index.number_dimensions = 1;
+ counter_aggregate.index.dimension_indexes[0] = error_counter_index;
+
+ assert(kernel_error_accountant.kernel_event_notifier_error_counter_fd);
+
+ ret = kernctl_counter_get_aggregate_value(
+ kernel_error_accountant.kernel_event_notifier_error_counter_fd,
+ &counter_aggregate);
+ if (ret || counter_aggregate.value.value < 0) {
+ uid_t trigger_owner_uid;
+ const char *trigger_name;
+ const enum lttng_trigger_status trigger_status =
+ lttng_trigger_get_owner_uid(
+ trigger, &trigger_owner_uid);
+
+ assert(trigger_status == LTTNG_TRIGGER_STATUS_OK);
+ if (lttng_trigger_get_name(trigger, &trigger_name) !=
+ LTTNG_TRIGGER_STATUS_OK) {
+ trigger_name = "(unnamed)";
+ }
+
+ if (counter_aggregate.value.value < 0) {
+ ERR("Invalid negative event notifier error counter value: trigger owner = %d, trigger name = '%s', value = %" PRId64,
+ trigger_owner_uid, trigger_name,
+ counter_aggregate.value.value);
+ } else {
+ ERR("Failed to getting event notifier error count: trigger owner = %d, trigger name = '%s', ret = %d",
+ trigger_owner_uid, trigger_name, ret);
+ }
+
+ status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_ERR;
+ goto end;
+ }
+
+ /* Error count can't be negative. */
+ assert(counter_aggregate.value.value >= 0);
+ *count = (uint64_t) counter_aggregate.value.value;
+
+ status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK;
+
+end:
+ return status;
+}
+
+enum event_notifier_error_accounting_status
+event_notifier_error_accounting_get_count(
+ const struct lttng_trigger *trigger, uint64_t *count)
+{
+ switch (lttng_trigger_get_underlying_domain_type_restriction(trigger)) {
+ case LTTNG_DOMAIN_KERNEL:
+ return event_notifier_error_accounting_kernel_get_count(
+ trigger, count);
+ case LTTNG_DOMAIN_UST:
+ return EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK;
+ default:
+ abort();
+ }
+}
+
+static
+enum event_notifier_error_accounting_status
+event_notifier_error_accounting_clear(const struct lttng_trigger *trigger)
+{
+ switch (lttng_trigger_get_underlying_domain_type_restriction(trigger)) {
+ case LTTNG_DOMAIN_KERNEL:
+ return event_notifier_error_accounting_kernel_clear(trigger);
+ case LTTNG_DOMAIN_UST:
+ return EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK;
+ default:
+ abort();
+ }
+}
+
+static void free_index_ht_entry(struct rcu_head *head)
+{
+ struct index_ht_entry *entry = caa_container_of(head,
+ struct index_ht_entry, rcu_head);
+
+ free(entry);
+}
+
+void event_notifier_error_accounting_unregister_event_notifier(
+ const struct lttng_trigger *trigger)
+{
+ struct lttng_ht_iter iter;
+ struct lttng_ht_node_u64 *node;
+ struct index_ht_entry *index_entry;
+ enum event_notifier_error_accounting_status status;
+ enum lttng_index_allocator_status index_alloc_status;
+ uint64_t tracer_token = lttng_trigger_get_tracer_token(trigger);
+
+ status = event_notifier_error_accounting_clear(trigger);
+ if (status != EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK) {
+ ERR("Failed to clear event notifier error counter index");
+ }
+
+ rcu_read_lock();
+ lttng_ht_lookup(error_counter_indexes_ht, &tracer_token, &iter);
+ node = lttng_ht_iter_get_node_u64(&iter);
+ if(node) {
+ index_entry = caa_container_of(node, struct index_ht_entry, node);
+ index_alloc_status = lttng_index_allocator_release(
+ index_allocator,
+ index_entry->error_counter_index);
+ if (index_alloc_status != LTTNG_INDEX_ALLOCATOR_STATUS_OK) {
+ ERR("Failed to release event notifier error counter index: index = %" PRIu64,
+ index_entry->error_counter_index);
+ }
+
+ lttng_ht_del(error_counter_indexes_ht, &iter);
+ call_rcu(&index_entry->rcu_head, free_index_ht_entry);
+ }
+
+ rcu_read_unlock();
+}
+
+void event_notifier_error_accounting_fini(void)
+{
+ lttng_index_allocator_destroy(index_allocator);
+
+ if (kernel_error_accountant.kernel_event_notifier_error_counter_fd) {
+ const int ret = close(kernel_error_accountant.kernel_event_notifier_error_counter_fd);
+
+ if (ret) {
+ PERROR("Failed to close kernel event notifier error counter");
+ }
+ }
+
+ /*
+ * Will assert if some error counters were not released (an internal
+ * error).
+ */
+ lttng_ht_destroy(error_counter_indexes_ht);
+}