#include <sys/types.h>
#include <common/common.h>
+#include <common/hashtable/utils.h>
#include <common/trace-chunk.h>
#include <common/kernel-ctl/kernel-ctl.h>
#include <common/kernel-ctl/kernel-ioctl.h>
#include <lttng/lttng-error.h>
#include <lttng/tracker.h>
+#include <lttng/userspace-probe.h>
+#include <lttng/userspace-probe-internal.h>
+#include <lttng/condition/event-rule.h>
+#include <lttng/condition/event-rule-internal.h>
+#include <lttng/event-rule/event-rule.h>
+#include <lttng/event-rule/event-rule-internal.h>
+#include <lttng/event-rule/uprobe-internal.h>
+
#include "lttng-sessiond.h"
#include "lttng-syscall.h"
+#include "condition-internal.h"
#include "consumer.h"
#include "kernel.h"
#include "kernel-consumer.h"
#include "kern-modules.h"
+#include "sessiond-config.h"
#include "utils.h"
#include "rotate.h"
#include "modprobe.h"
#include "tracker.h"
+#include "trigger-error-accounting.h"
+#include "notification-thread-commands.h"
/*
* Key used to reference a channel between the sessiond and the consumer. This
static const char *module_proc_lttng = "/proc/lttng";
static int kernel_tracer_fd = -1;
+static int kernel_tracer_trigger_group_fd = -1;
+static int kernel_tracer_trigger_group_notification_fd = -1;
+static struct cds_lfht *kernel_tracer_token_ht;
-#include <lttng/userspace-probe.h>
-#include <lttng/userspace-probe-internal.h>
/*
* Add context on a kernel channel.
*
return -1;
}
+/*
+ * Create a kernel channel, register it to the kernel tracer and add it to the
+ * kernel session.
+ */
+static
+int kernel_create_trigger_group(int *trigger_group_fd)
+{
+ int ret;
+ int local_fd = -1;
+
+ assert(trigger_group_fd);
+
+ /* Kernel tracer channel creation */
+ ret = kernctl_create_trigger_group(kernel_tracer_fd);
+ if (ret < 0) {
+ PERROR("ioctl kernel create trigger group");
+ ret = -1;
+ goto error;
+ }
+
+ /* Store locally */
+ local_fd = ret;
+
+ /* Prevent fd duplication after execlp() */
+ ret = fcntl(local_fd, F_SETFD, FD_CLOEXEC);
+ if (ret < 0) {
+ PERROR("fcntl session fd");
+ }
+
+ DBG("Kernel trigger group created (fd: %d)",
+ local_fd);
+ ret = 0;
+
+error:
+ *trigger_group_fd = local_fd;
+ return ret;
+}
+
/*
* Compute the offset of the instrumentation byte in the binary based on the
* function probe location using the ELF lookup method.
static
int extract_userspace_probe_offset_function_elf(
const struct lttng_userspace_probe_location *probe_location,
- struct ltt_kernel_session *session, uint64_t *offset)
+ uid_t uid, gid_t gid, uint64_t *offset)
{
int fd;
int ret = 0;
goto end;
}
- ret = run_as_extract_elf_symbol_offset(fd, symbol, session->uid,
- session->gid, offset);
+ ret = run_as_extract_elf_symbol_offset(fd, symbol, uid, gid, offset);
if (ret < 0) {
DBG("userspace probe offset calculation failed for "
"function %s", symbol);
static
int extract_userspace_probe_offset_tracepoint_sdt(
const struct lttng_userspace_probe_location *probe_location,
- struct ltt_kernel_session *session, uint64_t **offsets,
+ uid_t uid, gid_t gid, uint64_t **offsets,
uint32_t *offsets_count)
{
enum lttng_userspace_probe_location_lookup_method_type lookup_method_type;
}
ret = run_as_extract_sdt_probe_offsets(fd, provider_name, probe_name,
- session->uid, session->gid, offsets, offsets_count);
+ uid, gid, offsets, offsets_count);
if (ret < 0) {
DBG("userspace probe offset calculation failed for sdt "
"probe %s:%s", provider_name, probe_name);
return ret;
}
-/*
- * Extract the offsets of the instrumentation point for the different lookup
- * methods.
- */
static
-int userspace_probe_add_callsites(struct lttng_event *ev,
- struct ltt_kernel_session *session, int fd)
+int userspace_probe_add_callsite(
+ const struct lttng_userspace_probe_location *location,
+ uid_t uid, gid_t gid, int fd)
{
const struct lttng_userspace_probe_location_lookup_method *lookup_method = NULL;
enum lttng_userspace_probe_location_lookup_method_type type;
- const struct lttng_userspace_probe_location *location = NULL;
int ret;
- assert(ev);
- assert(ev->type == LTTNG_EVENT_USERSPACE_PROBE);
-
- location = lttng_event_get_userspace_probe_location(ev);
- if (!location) {
- ret = -1;
- goto end;
- }
- lookup_method =
- lttng_userspace_probe_location_get_lookup_method(location);
+ lookup_method = lttng_userspace_probe_location_get_lookup_method(location);
if (!lookup_method) {
ret = -1;
goto end;
struct lttng_kernel_event_callsite callsite;
uint64_t offset;
- ret = extract_userspace_probe_offset_function_elf(location, session, &offset);
+ ret = extract_userspace_probe_offset_function_elf(location,
+ uid, gid, &offset);
if (ret) {
ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
goto end;
callsite.u.uprobe.offset = offset;
ret = kernctl_add_callsite(fd, &callsite);
if (ret) {
- WARN("Adding callsite to userspace probe "
- "event %s failed.", ev->name);
+ WARN("Adding callsite to ELF userspace probe failed.");
ret = LTTNG_ERR_KERN_ENABLE_FAIL;
goto end;
}
* This call allocates the offsets buffer. This buffer must be freed
* by the caller
*/
- ret = extract_userspace_probe_offset_tracepoint_sdt(location, session,
- &offsets, &offsets_count);
+ ret = extract_userspace_probe_offset_tracepoint_sdt(location,
+ uid, gid, &offsets, &offsets_count);
if (ret) {
ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
goto end;
callsite.u.uprobe.offset = offsets[i];
ret = kernctl_add_callsite(fd, &callsite);
if (ret) {
- WARN("Adding callsite to userspace probe "
- "event %s failed.", ev->name);
+ WARN("Adding callsite to SDT userspace probe "
+ "failed.");
ret = LTTNG_ERR_KERN_ENABLE_FAIL;
free(offsets);
goto end;
return ret;
}
+/*
+ * Extract the offsets of the instrumentation point for the different lookup
+ * methods.
+ */
+static
+int userspace_probe_event_add_callsites(struct lttng_event *ev,
+ struct ltt_kernel_session *session, int fd)
+{
+ const struct lttng_userspace_probe_location *location = NULL;
+ int ret;
+
+ assert(ev);
+ assert(ev->type == LTTNG_EVENT_USERSPACE_PROBE);
+
+ location = lttng_event_get_userspace_probe_location(ev);
+ if (!location) {
+ ret = -1;
+ goto end;
+ }
+
+ ret = userspace_probe_add_callsite(location, session->uid, session->gid,
+ fd);
+ if (ret) {
+ WARN("Adding callsite to userspace probe event \"%s\" "
+ "failed.", ev->name);
+ }
+
+end:
+ return ret;
+}
+
+/*
+ * Extract the offsets of the instrumentation point for the different lookup
+ * methods.
+ */
+static int userspace_probe_event_rule_add_callsites(
+ const struct lttng_event_rule *rule,
+ const struct lttng_credentials *creds,
+ int fd)
+{
+ const struct lttng_userspace_probe_location *location = NULL;
+ enum lttng_event_rule_status status;
+ int ret;
+
+ assert(rule);
+ assert(creds);
+ assert(lttng_event_rule_get_type(rule) == LTTNG_EVENT_RULE_TYPE_UPROBE);
+
+ status = lttng_event_rule_uprobe_get_location(rule, &location);
+ if (status != LTTNG_EVENT_RULE_STATUS_OK || !location) {
+ ret = -1;
+ goto end;
+ }
+
+ ret = userspace_probe_add_callsite(
+ location, lttng_credentials_get_uid(creds), lttng_credentials_get_gid(creds), fd);
+ if (ret) {
+ WARN("Adding callsite to userspace probe object %d"
+ "failed.", fd);
+ }
+
+end:
+ return ret;
+}
+
/*
* Create a kernel event, enable it to the kernel tracer and add it to the
* channel event list of the kernel session.
int kernel_create_event(struct lttng_event *ev,
struct ltt_kernel_channel *channel,
char *filter_expression,
- struct lttng_filter_bytecode *filter)
+ struct lttng_bytecode *filter)
{
int err, fd;
enum lttng_error_code ret;
}
if (ev->type == LTTNG_EVENT_USERSPACE_PROBE) {
- ret = userspace_probe_add_callsites(ev, channel->session, event->fd);
+ ret = userspace_probe_event_add_callsites(ev, channel->session,
+ event->fd);
if (ret) {
goto add_callsite_error;
}
return ret;
}
+/*
+ * Disable a kernel trigger.
+ */
+static
+int kernel_disable_token_event_rule(struct ltt_kernel_token_event_rule *event)
+{
+ int ret;
+
+ assert(event);
+
+ rcu_read_lock();
+ cds_lfht_del(kernel_tracer_token_ht, &event->ht_node);
+ rcu_read_unlock();
+
+ ret = kernctl_disable(event->fd);
+ if (ret < 0) {
+ switch (-ret) {
+ case EEXIST:
+ ret = LTTNG_ERR_KERN_EVENT_EXIST;
+ break;
+ default:
+ PERROR("disable kernel event");
+ break;
+ }
+ goto error;
+ }
+
+ event->enabled = 0;
+ DBG("Kernel trigger token %" PRIu64" disabled (fd: %d)", event->token, event->fd);
+
+ return 0;
+
+error:
+ return ret;
+}
+
static
struct process_attr_tracker *_kernel_get_process_attr_tracker(
struct ltt_kernel_session *session,
int init_kernel_tracer(void)
{
int ret;
+ enum lttng_error_code error_code_ret;
bool is_root = !getuid();
/* Modprobe lttng kernel modules */
if (ret < 0) {
goto error_modules;
}
-
if (ret < 1) {
WARN("Kernel tracer does not support buffer monitoring. "
"The monitoring timer of channels in the kernel domain "
"will be set to 0 (disabled).");
}
+ ret = kernel_create_trigger_group(&kernel_tracer_trigger_group_fd);
+ if (ret < 0) {
+ /* TODO: error handling if it is not supported etc. */
+ WARN("Failed trigger group creation");
+ kernel_tracer_trigger_group_fd = -1;
+ /* This is not fatal */
+ } else {
+
+ error_code_ret = kernel_create_trigger_group_notification_fd(
+ &kernel_tracer_trigger_group_notification_fd);
+ if (error_code_ret != LTTNG_OK) {
+ goto error_modules;
+ }
+
+ trigger_error_accounting_register_kernel(kernel_tracer_trigger_group_fd);
+ if (ret < 0) {
+ goto error_modules;
+ }
+ }
+
+ kernel_tracer_token_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
+ CDS_LFHT_AUTO_RESIZE|CDS_LFHT_ACCOUNTING, NULL);
+ if (!kernel_tracer_token_ht) {
+ goto error_modules;
+ }
+
DBG("Kernel tracer fd %d", kernel_tracer_fd);
+ DBG("Kernel tracer trigger group fd %d", kernel_tracer_trigger_group_fd);
+ DBG("Kernel tracer trigger group notification fd %d", kernel_tracer_trigger_group_notification_fd);
ret = syscall_init_table(kernel_tracer_fd);
if (ret < 0) {
ERR("Unable to populate syscall table. Syscall tracing won't "
"work for this session daemon.");
}
+
return 0;
error_version:
void cleanup_kernel_tracer(void)
{
int ret;
+ struct cds_lfht_iter iter;
+
+ struct ltt_kernel_token_event_rule *rule = NULL;
+ cds_lfht_for_each_entry(kernel_tracer_token_ht, &iter, rule, ht_node) {
+ kernel_disable_token_event_rule(rule);
+ trace_kernel_destroy_token_event_rule(rule);
+ cds_lfht_del(kernel_tracer_token_ht, &rule->ht_node);
+ }
+
+ DBG2("Closing kernel trigger group notification fd");
+ if (kernel_tracer_trigger_group_notification_fd >= 0) {
+
+ ret = notification_thread_command_remove_application(
+ notification_thread_handle,
+ kernel_tracer_trigger_group_notification_fd);
+ if (ret != LTTNG_OK) {
+ ERR("Failed to remove kernel trigger notification from notification thread");
+ }
+ ret = close(kernel_tracer_trigger_group_notification_fd);
+ if (ret) {
+ PERROR("close");
+ }
+ kernel_tracer_trigger_group_notification_fd = -1;
+ }
+
+ /* TODO: do we iterate over the list to remove all token? */
+ DBG2("Closing kernel trigger group fd");
+ if (kernel_tracer_trigger_group_fd >= 0) {
+ ret = close(kernel_tracer_trigger_group_fd);
+ if (ret) {
+ PERROR("close");
+ }
+ kernel_tracer_trigger_group_fd = -1;
+ }
DBG2("Closing kernel fd");
if (kernel_tracer_fd >= 0) {
}
kernel_tracer_fd = -1;
}
+
DBG("Unloading kernel modules");
modprobe_remove_lttng_all();
free(syscall_table);
rcu_read_unlock();
return status;
}
+
+enum lttng_error_code kernel_create_trigger_group_notification_fd(
+ int *trigger_group_notification_fd)
+{
+ enum lttng_error_code error_code_ret;
+ int local_fd = -1, ret;
+
+ assert(trigger_group_notification_fd);
+
+ ret = kernctl_create_trigger_group_notification_fd(kernel_tracer_trigger_group_fd);
+ if (ret < 0) {
+ PERROR("ioctl kernel create trigger group");
+ error_code_ret = LTTNG_ERR_TRIGGER_GROUP_NOTIFICATION_FD;
+ goto error;
+ }
+
+ /* Store locally */
+ local_fd = ret;
+
+ /* Prevent fd duplication after execlp() */
+ ret = fcntl(local_fd, F_SETFD, FD_CLOEXEC);
+ if (ret < 0) {
+ PERROR("fcntl session fd");
+ error_code_ret = LTTNG_ERR_TRIGGER_GROUP_NOTIFICATION_FD;
+ goto error;
+ }
+
+ DBG("Kernel trigger group notification created (fd: %d)",
+ local_fd);
+ error_code_ret = LTTNG_OK;
+ *trigger_group_notification_fd = local_fd;
+
+error:
+ return error_code_ret;
+}
+
+enum lttng_error_code kernel_create_trigger_group_error_counter(
+ int *error_counter_fd, size_t nb_bucket)
+{
+ enum lttng_error_code error_code_ret;
+ int local_fd = -1, ret;
+ struct lttng_kernel_counter_conf error_counter_conf;
+
+ assert(error_counter_fd);
+
+ error_counter_conf.arithmetic = LTTNG_KERNEL_COUNTER_ARITHMETIC_MODULAR;
+ error_counter_conf.bitness = LTTNG_KERNEL_COUNTER_BITNESS_64BITS;
+ error_counter_conf.global_sum_step = 0;
+ error_counter_conf.number_dimensions = 1;
+ error_counter_conf.dimensions[0].size = nb_bucket;
+ error_counter_conf.dimensions[0].has_underflow = false;
+ error_counter_conf.dimensions[0].has_overflow = false;
+
+ ret = kernctl_create_trigger_group_error_counter(
+ kernel_tracer_trigger_group_fd, &error_counter_conf);
+ if (ret < 0) {
+ PERROR("ioctl kernel create trigger group error counter");
+ error_code_ret = LTTNG_ERR_TRIGGER_GROUP_ERROR_COUNTER;
+ goto error;
+ }
+
+ /* Store locally */
+ local_fd = ret;
+
+ /* Prevent fd duplication after execlp() */
+ ret = fcntl(local_fd, F_SETFD, FD_CLOEXEC);
+ if (ret < 0) {
+ error_code_ret = LTTNG_ERR_TRIGGER_GROUP_ERROR_COUNTER;
+ PERROR("fcntl session fd");
+ }
+
+ DBG("Kernel trigger group error counter (fd: %d)",
+ local_fd);
+ error_code_ret = LTTNG_OK;
+
+error:
+ *error_counter_fd = local_fd;
+ return error_code_ret;
+}
+
+enum lttng_error_code kernel_destroy_trigger_group_notification_fd(
+ int trigger_group_notification_fd)
+{
+ enum lttng_error_code ret = LTTNG_OK;
+ DBG("Closing trigger group notification fd %d", trigger_group_notification_fd);
+ if (trigger_group_notification_fd >= 0) {
+ ret = close(trigger_group_notification_fd);
+ if (ret) {
+ PERROR("close");
+ }
+ }
+ return ret;
+}
+
+static
+unsigned long hash_trigger(struct lttng_trigger *trigger)
+{
+ const struct lttng_condition *condition =
+ lttng_trigger_get_const_condition(trigger);
+ return lttng_condition_hash(condition);
+}
+
+static
+int match_trigger(struct cds_lfht_node *node, const void *key)
+{
+ struct ltt_kernel_token_event_rule *token;
+ const struct lttng_trigger *trigger = key;
+
+ token = caa_container_of(node, struct ltt_kernel_token_event_rule, ht_node);
+
+ return lttng_trigger_is_equal(trigger, token->trigger);
+}
+
+static enum lttng_error_code kernel_create_token_event_rule(struct lttng_trigger *trigger,
+ const struct lttng_credentials *creds, uint64_t token)
+{
+ int err, fd, ret = 0;
+ enum lttng_error_code error_code_ret;
+ struct ltt_kernel_token_event_rule *event;
+ struct lttng_kernel_trigger kernel_trigger = {};
+ unsigned int capture_bytecode_count = 0;
+ struct lttng_condition *condition = NULL;
+ struct lttng_event_rule *event_rule = NULL;
+
+ assert(trigger);
+
+ condition = lttng_trigger_get_condition(trigger);
+ assert(condition);
+ assert(lttng_condition_get_type(condition) == LTTNG_CONDITION_TYPE_EVENT_RULE_HIT);
+
+ lttng_condition_event_rule_get_rule_mutable(condition, &event_rule);
+ assert(event_rule);
+ assert(lttng_event_rule_get_type(event_rule) != LTTNG_EVENT_RULE_TYPE_UNKNOWN);
+
+ error_code_ret = trace_kernel_create_token_event_rule(trigger, token,
+ lttng_trigger_get_error_counter_index(trigger), &event);
+ if (error_code_ret != LTTNG_OK) {
+ goto error;
+ }
+
+ trace_kernel_init_trigger_from_event_rule(event_rule, &kernel_trigger);
+ kernel_trigger.id = event->token;
+ kernel_trigger.error_counter_idx = lttng_trigger_get_error_counter_index(trigger);
+
+ fd = kernctl_create_trigger(kernel_tracer_trigger_group_fd, &kernel_trigger);
+ if (fd < 0) {
+ switch (-fd) {
+ case EEXIST:
+ error_code_ret = LTTNG_ERR_KERN_EVENT_EXIST;
+ break;
+ case ENOSYS:
+ WARN("Trigger type not implemented");
+ error_code_ret = LTTNG_ERR_KERN_EVENT_ENOSYS;
+ break;
+ case ENOENT:
+ WARN("Event %s not found!", kernel_trigger.name);
+ error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
+ break;
+ default:
+ error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
+ PERROR("create trigger ioctl");
+ }
+ goto free_event;
+ }
+
+ event->fd = fd;
+ /* Prevent fd duplication after execlp() */
+ err = fcntl(event->fd, F_SETFD, FD_CLOEXEC);
+ if (err < 0) {
+ PERROR("fcntl session fd");
+ }
+
+ if (event->filter) {
+ err = kernctl_filter(event->fd, event->filter);
+ if (err < 0) {
+ switch (-err) {
+ case ENOMEM:
+ error_code_ret = LTTNG_ERR_FILTER_NOMEM;
+ break;
+ default:
+ error_code_ret = LTTNG_ERR_FILTER_INVAL;
+ break;
+ }
+ goto filter_error;
+ }
+ }
+
+ if (lttng_event_rule_get_type(event_rule) ==
+ LTTNG_EVENT_RULE_TYPE_UPROBE) {
+ ret = userspace_probe_event_rule_add_callsites(
+ event_rule, creds, event->fd);
+ if (ret) {
+ error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
+ goto add_callsite_error;
+ }
+ }
+
+ /* Set the capture bytecode */
+ capture_bytecode_count = lttng_trigger_get_capture_bytecode_count(trigger);
+ for (unsigned int i = 0; i < capture_bytecode_count; i++) {
+ const struct lttng_bytecode *capture_bytecode = lttng_trigger_get_capture_bytecode_at_index(trigger, i);
+ ret = kernctl_capture(event->fd, capture_bytecode);
+ if (ret < 0) {
+ error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
+ goto error;
+ }
+ }
+
+ err = kernctl_enable(event->fd);
+ if (err < 0) {
+ switch (-err) {
+ case EEXIST:
+ error_code_ret = LTTNG_ERR_KERN_EVENT_EXIST;
+ break;
+ default:
+ PERROR("enable kernel trigger");
+ error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
+ break;
+ }
+ goto enable_error;
+ }
+
+ /* Add trigger to kernel token mapping in the hashtable. */
+ cds_lfht_add(kernel_tracer_token_ht, hash_trigger(trigger),
+ &event->ht_node);
+
+ DBG("Trigger %s created (fd: %d)", kernel_trigger.name, event->fd);
+
+ return LTTNG_OK;
+
+add_callsite_error:
+enable_error:
+filter_error:
+ {
+ int closeret;
+
+ closeret = close(event->fd);
+ if (closeret) {
+ PERROR("close event fd");
+ }
+ }
+free_event:
+ free(event);
+error:
+ return error_code_ret;
+}
+
+enum lttng_error_code kernel_register_trigger(struct lttng_trigger *trigger, const struct lttng_credentials *cmd_creds)
+{
+ enum lttng_error_code ret;
+ struct lttng_condition *condition;
+ struct lttng_event_rule *event_rule;
+ uint64_t token;
+
+ /* TODO error handling */
+
+ rcu_read_lock();
+ pthread_mutex_lock(¬ification_trigger_tokens_ht_lock);
+
+ /* TODO: error checking and type checking */
+ token = lttng_trigger_get_tracer_token(trigger);
+ condition = lttng_trigger_get_condition(trigger);
+ (void) lttng_condition_event_rule_get_rule_mutable(condition, &event_rule);
+
+ assert(lttng_event_rule_get_domain_type(event_rule) == LTTNG_DOMAIN_KERNEL);
+
+ ret = kernel_create_token_event_rule(trigger, cmd_creds, token);
+ if (ret != LTTNG_OK) {
+ ERR("Failed to create kernel trigger token.");
+ }
+
+ rcu_read_unlock();
+ pthread_mutex_unlock(¬ification_trigger_tokens_ht_lock);
+ return ret;
+}
+
+enum lttng_error_code kernel_unregister_trigger(struct lttng_trigger *trigger)
+{
+ struct ltt_kernel_token_event_rule *token_event_rule_element;
+ struct cds_lfht_node *node;
+ struct cds_lfht_iter iter;
+ enum lttng_error_code error_code_ret;
+ int ret;
+
+ rcu_read_lock();
+ pthread_mutex_unlock(¬ification_trigger_tokens_ht_lock);
+
+ cds_lfht_lookup(kernel_tracer_token_ht, hash_trigger(trigger),
+ match_trigger, trigger, &iter);
+ node = cds_lfht_iter_get_node(&iter);
+ if (!node) {
+ error_code_ret = LTTNG_ERR_TRIGGER_NOT_FOUND;
+ goto error;
+ }
+
+ token_event_rule_element = caa_container_of(node,
+ struct ltt_kernel_token_event_rule, ht_node);
+
+ ret = kernel_disable_token_event_rule(token_event_rule_element);
+ if (ret) {
+ error_code_ret = LTTNG_ERR_FATAL;
+ goto error;
+ }
+
+ trace_kernel_destroy_token_event_rule(token_event_rule_element);
+
+ rcu_read_unlock();
+ pthread_mutex_unlock(¬ification_trigger_tokens_ht_lock);
+
+ error_code_ret = LTTNG_OK;
+
+error:
+ return error_code_ret;
+}
+
+int kernel_get_notification_fd(void)
+{
+ return kernel_tracer_trigger_group_notification_fd;
+}