struct ust_error_accounting_entry {
uid_t uid;
+ struct urcu_ref ref;
struct lttng_ht_node_u64 node;
struct rcu_head rcu_head;
struct ustctl_daemon_counter *daemon_counter;
/*
- * Those `lttng_ust_abi_object_data` are anonymous handles to the counters
- * objects.
+ * Those `lttng_ust_abi_object_data` are anonymous handles to the
+ * counters objects.
* They are only used to be duplicated for each new applications of the
* user. To destroy them, call with the `sock` parameter set to -1.
* e.g. `ustctl_release_object(-1, data)`;
};
struct kernel_error_accounting_entry {
- int kernel_event_notifier_error_counter_fd;
+ int error_counter_fd;
};
-static struct kernel_error_accounting_entry kernel_error_accountant;
+static struct kernel_error_accounting_entry kernel_error_accounting_entry;
/* Hashtable mapping uid to error_account_entry. */
static struct lttng_ht *error_counter_uid_ht;
}
}
+#ifdef HAVE_LIBLTTNG_UST_CTL
+struct event_notifier_counter {
+ pthread_mutex_t lock;
+ long count;
+};
+
+static struct event_notifier_counter the_event_notifier_counter;
+
+static void free_ust_error_accounting_entry(struct rcu_head *head)
+{
+ int i;
+ struct ust_error_accounting_entry *entry =
+ caa_container_of(head, typeof(*entry), rcu_head);
+
+ for (i = 0; i < entry->nr_counter_cpu_fds; i++) {
+ ustctl_release_object(-1, entry->cpu_counters[i]);
+ free(entry->cpu_counters[i]);
+ }
+
+ free(entry->cpu_counters);
+
+ ustctl_release_object(-1, entry->counter);
+ free(entry->counter);
+
+ ustctl_destroy_counter(entry->daemon_counter);
+
+ free(entry);
+}
+
+static
+bool ust_error_accounting_entry_get(struct ust_error_accounting_entry *entry)
+{
+ return urcu_ref_get_unless_zero(&entry->ref);
+}
+
+static
+void ust_error_accounting_entry_release(struct urcu_ref *entry_ref)
+{
+ struct ust_error_accounting_entry *entry =
+ container_of(entry_ref, typeof(*entry), ref);
+
+ rcu_read_lock();
+ cds_lfht_del(error_counter_uid_ht->ht, &entry->node.node);
+ call_rcu(&entry->rcu_head, free_ust_error_accounting_entry);
+ rcu_read_unlock();
+}
+
+
+static
+void ust_error_accounting_entry_put(struct ust_error_accounting_entry *entry)
+{
+ if (!entry) {
+ return;
+ }
+
+ urcu_ref_put(&entry->ref, ust_error_accounting_entry_release);
+}
+
+/*
+ * Put one reference to every UID entries.
+ */
+static
+void put_ref_all_ust_error_accounting_entry(void)
+{
+ struct lttng_ht_iter iter;
+ struct ust_error_accounting_entry *uid_entry;
+
+ ASSERT_LOCKED(the_event_notifier_counter.lock);
+
+ rcu_read_lock();
+ cds_lfht_for_each_entry(error_counter_uid_ht->ht, &iter.iter,
+ uid_entry, node.node) {
+ ust_error_accounting_entry_put(uid_entry);
+ }
+
+ rcu_read_unlock();
+}
+
+/*
+ * Get one reference to every UID entries.
+ */
+static
+void get_ref_all_ust_error_accounting_entry(void)
+{
+ struct lttng_ht_iter iter;
+ struct ust_error_accounting_entry *uid_entry;
+
+ ASSERT_LOCKED(the_event_notifier_counter.lock);
+
+ rcu_read_lock();
+ cds_lfht_for_each_entry(error_counter_uid_ht->ht, &iter.iter,
+ uid_entry, node.node) {
+ ust_error_accounting_entry_get(uid_entry);
+ }
+
+ rcu_read_unlock();
+}
+
+#endif /* HAVE_LIBLTTNG_UST_CTL */
+
static
enum event_notifier_error_accounting_status
init_error_accounting_state(struct error_accounting_state *state,
return status;
}
+/*
+ * Return the error counteur index associated to this event notifier tracer
+ * token. Returns _STATUS_OK if found and _STATUS_NOT_FOUND otherwise.
+ */
static
enum event_notifier_error_accounting_status get_error_counter_index_for_token(
struct error_accounting_state *state, uint64_t tracer_token,
}
#ifdef HAVE_LIBLTTNG_UST_CTL
+/*
+ * Find the entry for this app's UID, the caller acquires a reference if the
+ * entry is found.
+ */
static
-struct ust_error_accounting_entry *get_uid_accounting_entry(const struct ust_app *app)
+struct ust_error_accounting_entry *ust_error_accounting_entry_find(
+ struct lttng_ht *uid_ht, const struct ust_app *app)
{
struct ust_error_accounting_entry *entry;
struct lttng_ht_node_u64 *node;
struct lttng_ht_iter iter;
uint64_t key = app->uid;
- lttng_ht_lookup(error_counter_uid_ht, &key, &iter);
+ lttng_ht_lookup(uid_ht, &key, &iter);
node = lttng_ht_iter_get_node_u64(&iter);
if(node == NULL) {
entry = NULL;
} else {
- entry = caa_container_of(node, struct ust_error_accounting_entry, node);
+ bool got_ref;
+
+ entry = caa_container_of(node,
+ struct ust_error_accounting_entry, node);
+
+ got_ref = ust_error_accounting_entry_get(entry);
+ if (!got_ref) {
+ entry = NULL;
+ }
}
return entry;
}
+/*
+ * Create the entry for this app's UID, the caller acquires a reference to the
+ * entry,
+ */
static
-struct ust_error_accounting_entry *create_uid_accounting_entry(
- const struct ust_app *app)
+struct ust_error_accounting_entry *ust_error_accounting_entry_create(
+ struct lttng_ht *uid_ht, const struct ust_app *app)
{
- int i, ret;
+ int i, ret, *cpu_counter_fds = NULL;
struct ustctl_daemon_counter *daemon_counter;
struct lttng_ust_abi_object_data *counter, **cpu_counters;
- int *cpu_counter_fds = NULL;
struct ust_error_accounting_entry *entry = NULL;
const struct ustctl_counter_dimension dimension = {
.size = ust_state.number_indices,
goto error;
}
+ urcu_ref_init(&entry->ref);
entry->uid = app->uid;
entry->nr_counter_cpu_fds = ustctl_get_nr_cpu_per_counter();
PERROR("Failed to allocate event notifier error counter file descriptors array: application uid = %d, application name = '%s', pid = %d, allocation size = %zu",
(int) app->uid, app->name, (int) app->pid,
entry->nr_counter_cpu_fds * sizeof(*cpu_counter_fds));
- ret = -1;
goto error_counter_cpu_fds_alloc;
}
PERROR("Failed to allocate event notifier error counter lttng_ust_abi_object_data array: application uid = %d, application name = '%s', pid = %d, allocation size = %zu",
(int) app->uid, app->name, (int) app->pid,
entry->nr_counter_cpu_fds * sizeof(struct lttng_ust_abi_object_data *));
- ret = -1;
goto error_counter_cpus_alloc;
}
entry->counter = counter;
entry->cpu_counters = cpu_counters;
- lttng_ht_node_init_u64(&entry->node, app->uid);
+ lttng_ht_node_init_u64(&entry->node, entry->uid);
lttng_ht_add_unique_u64(error_counter_uid_ht, &entry->node);
goto end;
ret = close(cpu_counter_fds[i]);
if (ret) {
- PERROR("Failed to close error counter per-CPU shm file descriptor: fd = %d", cpu_counter_fds[i]);
+ PERROR("Failed to close error counter per-CPU shm file descriptor: fd = %d",
+ cpu_counter_fds[i]);
}
}
}
* app. If not, create one.
*/
rcu_read_lock();
- entry = get_uid_accounting_entry(app);
+ entry = ust_error_accounting_entry_find(error_counter_uid_ht, app);
if (entry == NULL) {
- entry = create_uid_accounting_entry(app);
+ /*
+ * Take the event notifier counter lock before creating the new
+ * entry to ensure that no event notifier is registered between
+ * the the entry creation and event notifier count check.
+ */
+ pthread_mutex_lock(&the_event_notifier_counter.lock);
+
+ entry = ust_error_accounting_entry_create(error_counter_uid_ht,
+ app);
if (!entry) {
status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_ERR;
- goto end;
+ pthread_mutex_unlock(&the_event_notifier_counter.lock);
+ goto error_creating_entry;
+ }
+
+ /*
+ * We just created a new UID entry, If there are event
+ * notifiers already registered, take one reference on their
+ * behalf.
+ */
+ if (the_event_notifier_counter.count > 0) {
+ ust_error_accounting_entry_get(entry);
}
+
+ pthread_mutex_unlock(&the_event_notifier_counter.lock);
}
/* Duplicate counter object data. */
ERR("Failed to duplicate event notifier error accounting counter for application user: application uid = %d, pid = %d, application name = '%s'",
(int) app->uid, (int) app->pid, app->name);
status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_ERR;
- goto end;
+ goto error_duplicate_counter;
}
status = send_counter_data_to_ust(app, new_counter);
error_send_counter_data:
ustctl_release_object(-1, new_counter);
free(new_counter);
+error_duplicate_counter:
+ ust_error_accounting_entry_put(entry);
+error_creating_entry:
+ app->event_notifier_group.counter = NULL;
end:
rcu_read_unlock();
return status;
int i;
rcu_read_lock();
- entry = get_uid_accounting_entry(app);
+
+ /* If an error occurred during app registration no entry was created. */
+ if (!app->event_notifier_group.counter) {
+ status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK;
+ goto end;
+ }
+
+ entry = ust_error_accounting_entry_find(error_counter_uid_ht, app);
if (entry == NULL) {
ERR("Failed to find event notitifier error accounting entry on application teardown: pid = %d, application name = '%s'",
app->pid, app->name);
status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_ERR;
goto end;
+ } else {
+ /*
+ * Put the entry twice as we acquired a reference from the
+ * `ust_error_accounting_entry_find()` above.
+ */
+ ust_error_accounting_entry_put(entry);
+ ust_error_accounting_entry_put(entry);
}
for (i = 0; i < app->event_notifier_group.nr_counter_cpu; i++) {
get_trigger_info_for_log(trigger, &trigger_name, &trigger_owner_uid);
- /*
- * At the moment, the error counter index is domain wide. This means
- * that if UID 1000 registers a event notifier and is allocated index 0
- * in it's error counter, index zero will be unused in error counter of
- * all other users.
- */
- status = get_error_counter_index_for_token(
- &ust_state,
- tracer_token,
+ status = get_error_counter_index_for_token(&ust_state, tracer_token,
&error_counter_index);
if (status != EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK) {
size_t dimension_index;
const uint64_t tracer_token = lttng_trigger_get_tracer_token(trigger);
- /*
- * Go over all error counters (ignoring uid) as a trigger (and trigger
- * errors) can be generated from any applications that this session
- * daemon is managing.
- */
-
rcu_read_lock();
- status = get_error_counter_index_for_token(
- &ust_state,
- tracer_token,
+ status = get_error_counter_index_for_token(&ust_state, tracer_token,
&error_counter_index);
if (status != EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK) {
uid_t trigger_owner_uid;
dimension_index = error_counter_index;
+ /*
+ * Go over all error counters (ignoring uid) as a trigger (and trigger
+ * errors) can be generated from any applications that this session
+ * daemon is managing.
+ */
cds_lfht_for_each_entry(error_counter_uid_ht->ht, &iter.iter,
uid_entry, node.node) {
const int ret = ustctl_counter_clear(uid_entry->daemon_counter,
enum event_notifier_error_accounting_status status;
struct lttng_kernel_counter_clear counter_clear = {};
- status = get_error_counter_index_for_token(
- &kernel_state,
+ status = get_error_counter_index_for_token(&kernel_state,
lttng_trigger_get_tracer_token(trigger),
&error_counter_index);
if (status != EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK) {
counter_clear.index.dimension_indexes[0] = error_counter_index;
ret = kernctl_counter_clear(
- kernel_error_accountant.kernel_event_notifier_error_counter_fd,
+ kernel_error_accounting_entry.error_counter_fd,
&counter_clear);
if (ret) {
uid_t trigger_owner_uid;
DBG("Created kernel event notifier group error counter: fd = %d",
error_counter_fd);
- kernel_error_accountant.kernel_event_notifier_error_counter_fd =
+ kernel_error_accounting_entry.error_counter_fd =
error_counter_fd;
status = EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK;
break;
}
+#ifdef HAVE_LIBLTTNG_UST_CTL
+ switch (lttng_trigger_get_underlying_domain_type_restriction(trigger)) {
+ case LTTNG_DOMAIN_UST:
+ pthread_mutex_lock(&the_event_notifier_counter.lock);
+ the_event_notifier_counter.count++;
+ if (the_event_notifier_counter.count == 1) {
+ /*
+ * On the first event notifier, we get a reference to
+ * every existing UID entries. This ensures that the
+ * entries are kept around if there are still
+ * registered event notifiers but no apps.
+ */
+ get_ref_all_ust_error_accounting_entry();
+ }
+ pthread_mutex_unlock(&the_event_notifier_counter.lock);
+ break;
+ default:
+ break;
+ }
+#endif /* HAVE_LIBLTTNG_UST_CTL */
+
+
end:
return status;
}
uint64_t error_counter_index;
int ret;
- status = get_error_counter_index_for_token(
- &kernel_state,
+ status = get_error_counter_index_for_token(&kernel_state,
lttng_trigger_get_tracer_token(trigger),
&error_counter_index);
if (status != EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK) {
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);
+ assert(kernel_error_accounting_entry.error_counter_fd);
ret = kernctl_counter_get_aggregate_value(
- kernel_error_accountant.kernel_event_notifier_error_counter_fd,
+ kernel_error_accounting_entry.error_counter_fd,
&counter_aggregate);
if (ret || counter_aggregate.value.value < 0) {
uid_t trigger_owner_uid;
/* Trigger details already logged by callee on error. */
ERR("Failed to clear event notifier error counter during unregistration of event notifier: status = '%s'",
error_accounting_status_str(status));
+ goto end;
}
+ rcu_read_lock();
+
switch (lttng_trigger_get_underlying_domain_type_restriction(trigger)) {
case LTTNG_DOMAIN_KERNEL:
state = &kernel_state;
break;
+#ifdef HAVE_LIBLTTNG_UST_CTL
case LTTNG_DOMAIN_UST:
state = &ust_state;
+
+ pthread_mutex_lock(&the_event_notifier_counter.lock);
+ the_event_notifier_counter.count--;
+ if (the_event_notifier_counter.count == 0) {
+
+ /*
+ * When unregistering the last event notifier, put one
+ * reference to every uid entries on the behalf of all
+ * event notifiers.
+ */
+ put_ref_all_ust_error_accounting_entry();
+ }
+
+ pthread_mutex_unlock(&the_event_notifier_counter.lock);
+
break;
+#endif /* HAVE_LIBLTTNG_UST_CTL */
default:
abort();
}
- rcu_read_lock();
lttng_ht_lookup(state->indices_ht, &tracer_token, &iter);
node = lttng_ht_iter_get_node_u64(&iter);
if (node) {
call_rcu(&index_entry->rcu_head, free_index_ht_entry);
}
+end:
rcu_read_unlock();
}
-#ifdef HAVE_LIBLTTNG_UST_CTL
-static void free_error_account_entry(struct rcu_head *head)
-{
- int i;
- struct ust_error_accounting_entry *entry =
- caa_container_of(head, typeof(*entry), rcu_head);
-
- for (i = 0; i < entry->nr_counter_cpu_fds; i++) {
- ustctl_release_object(-1, entry->cpu_counters[i]);
- free(entry->cpu_counters[i]);
- }
-
- free(entry->cpu_counters);
-
- ustctl_release_object(-1, entry->counter);
- free(entry->counter);
-
- ustctl_destroy_counter(entry->daemon_counter);
-
- free(entry);
-}
-#else
-/* Not called without UST support. */
-static void free_error_account_entry(struct rcu_head *head) {}
-#endif /* HAVE_LIBLTTNG_UST_CTL */
-
void event_notifier_error_accounting_fini(void)
{
- struct lttng_ht_iter iter;
- struct ust_error_accounting_entry *uid_entry;
-
- if (kernel_error_accountant.kernel_event_notifier_error_counter_fd) {
- const int ret = close(kernel_error_accountant.kernel_event_notifier_error_counter_fd);
+ if (kernel_error_accounting_entry.error_counter_fd) {
+ const int ret = close(kernel_error_accounting_entry.error_counter_fd);
if (ret) {
PERROR("Failed to close kernel event notifier error counter");
}
}
- /*
- * FIXME error account entries are not reference-counted and torn
- * down on last use. They exist from the moment of their first use
- * up until the teardown of the session daemon.
- */
- rcu_read_lock();
- cds_lfht_for_each_entry(error_counter_uid_ht->ht, &iter.iter,
- uid_entry, node.node) {
- cds_lfht_del(error_counter_uid_ht->ht, &uid_entry->node.node);
- call_rcu(&uid_entry->rcu_head, free_error_account_entry);
- }
- rcu_read_unlock();
-
lttng_ht_destroy(error_counter_uid_ht);
fini_error_accounting_state(&kernel_state);
FULL_LTTNG_SESSIOND_BIN="${TESTDIR}/../src/bin/lttng-sessiond/lttng-sessiond"
UST_NUM_TESTS=15
-DESTRUCTIVE_TESTS_NUM=8
+DESTRUCTIVE_TESTS_NUM=12
KERNEL_NUM_TESTS=$((14 + $DESTRUCTIVE_TESTS_NUM))
NUM_TESTS=$(($UST_NUM_TESTS + $KERNEL_NUM_TESTS))
# Remove the notifier.
lttng_remove_trigger_ok "$trigger_name"
- # Confirm that no notifier is enabled.
+ # Confirm that no trigger is enabled.
list_triggers_line_count=$("$FULL_LTTNG_BIN" list-triggers | wc -l)
is "$list_triggers_line_count" "0" "No \`event-rule-matches\` userspace notifier enabled as expected"
user_trigger_discarded_nb=$(trigger_get_discarded_notif_number "$user_trigger_name")
isnt $root_trigger_discarded_nb 0 \
- "Root trigger discard notifications number ($root_trigger_discarded_nb) is non-zero"
+ "Root trigger discarded notifications number ($root_trigger_discarded_nb) is non-zero"
isnt $user_trigger_discarded_nb 0 \
- "User trigger discard notifications number ($user_trigger_discarded_nb) is non-zero"
+ "User trigger discarded notifications number ($user_trigger_discarded_nb) is non-zero"
lttng_remove_trigger_ok "$root_trigger_name"
lttng_remove_trigger_ok "$user_trigger_name" --user-id "$new_uid"
rm -f "$list_triggers_stdout"
}
+function test_ust_notifier_discarded_regardless_trigger_owner
+{
+ local sessiond_pipe=()
+ local root_trigger_name="root_trigger"
+ local user_trigger_name="user_trigger"
+ local list_triggers_stdout=$(mktemp -t list_triggers_stdout.XXXXXX)
+ local NR_USEC_WAIT=0
+ local PIPE_SIZE
+ local NR_ITER
+ local new_user="dummy_lttng_test_user"
+
+ PIPE_SIZE=$("$CURDIR"/default_pipe_size_getter)
+ if [ $? -ne 0 ]; then
+ BAIL_OUT "Failed to get system default pipe size"
+ else
+ diag "Default system pipe size: $PIPE_SIZE bytes"
+ fi
+
+ # Find the number of events needed to overflow the event notification
+ # pipe buffer. Each LTTng-UST notification is at least 42 bytes long.
+ # Double that number to ensure enough events are created to overflow
+ # the buffer.
+ NR_ITER=$(( (PIPE_SIZE / 42) * 2 ))
+ diag "Test applications will emit $NR_ITER events"
+
+ diag "UST event notifer error counter persists when a root trigger is present"
+
+ # Create a dummy user to run test apps as.
+ useradd --no-create-home "$new_user"
+ new_uid=$(id -u "$new_user")
+
+ # Used on sessiond launch.
+ LTTNG_SESSIOND_ENV_VARS="LTTNG_TESTPOINT_ENABLE=1 \
+ NOTIFIER_PAUSE_PIPE_PATH=${TESTPOINT_PIPE_PATH} \
+ LD_PRELOAD=${TESTPOINT}"
+
+ start_lttng_sessiond_notap
+
+ # This is needed since the testpoint create a pipe with the sessiond
+ # type suffixed.
+ for f in "$TESTPOINT_BASE_PATH"*; do
+ sessiond_pipe+=("$f")
+ done
+
+ lttng_add_trigger_ok "$root_trigger_name" \
+ --condition on-event --userspace tp:tptest \
+ --action notify
+
+ # Stop consumption of notifier tracer notifications.
+ echo -n 1 > $sessiond_pipe
+
+ su "$new_user" -c "$TESTAPP_BIN -i $NR_ITER -w $NR_USEC_WAIT"
+ ok $? "Generating $NR_ITER tracer notifications as UID: $new_uid"
+
+ root_trigger_discarded_nb=$(trigger_get_discarded_notif_number "$root_trigger_name")
+
+ isnt $root_trigger_discarded_nb 0 \
+ "Root trigger discarded notifications number ($root_trigger_discarded_nb) is non-zero"
+
+ lttng_remove_trigger_ok "$root_trigger_name"
+
+ stop_lttng_sessiond_notap
+
+ unset LTTNG_SESSIOND_ENV_VARS
+
+ userdel "$new_user"
+ rm -f "$list_triggers_stdout"
+}
+
test_ust_notifier_discarded_count
test_ust_notifier_discarded_count_max_bucket
test_kernel_notifier_discarded_count_max_bucket
if destructive_tests_enabled ; then
- # This test adds a new user on the system. Since it's a quite
+ # Those tests add a new user on the system. Since it's a quite
# intrusive change to the system, we decide to only run it when
# the user knows what they are doing.
test_ust_notifier_discarded_count_multi_uid
+ test_ust_notifier_discarded_regardless_trigger_owner
else
skip 0 "You need to set the LTTNG_ENABLE_DESTRUCTIVE_TESTS environment variable to \"will-break-my-system\" to run this test" $DESTRUCTIVE_TESTS_NUM
fi
projects / lttng-tools.git / commitdiff
