X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fkernel.c;h=03a358a0d3f1da9478ef220c3e93309298b469f7;hp=4ee4bea64ff630abae9617624f86ce21cc87950d;hb=e8b1187d0ff0323106069738b2fff5c9e5a7d9bb;hpb=ab5be9fa2eb5ba9600a82cd18fd3cfcbac69169a

diff --git a/src/bin/lttng-sessiond/kernel.c b/src/bin/lttng-sessiond/kernel.c
index 4ee4bea64..03a358a0d 100644
--- a/src/bin/lttng-sessiond/kernel.c
+++ b/src/bin/lttng-sessiond/kernel.c
@@ -15,13 +15,28 @@
 #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 <common/sessiond-comm/sessiond-comm.h>
+#include <common/tracker.h>
+#include <common/utils.h>
+#include <lttng/event.h>
+#include <lttng/lttng-error.h>
+#include <lttng/tracker.h>
+
+#include <lttng/userspace-probe.h>
+#include <lttng/userspace-probe-internal.h>
+#include <lttng/condition/on-event.h>
+#include <lttng/condition/on-event-internal.h>
+#include <lttng/event-rule/event-rule.h>
+#include <lttng/event-rule/event-rule-internal.h>
+#include <lttng/event-rule/userspace-probe-internal.h>
 
 #include "lttng-sessiond.h"
 #include "lttng-syscall.h"
+#include "condition-internal.h"
 #include "consumer.h"
 #include "kernel.h"
 #include "kernel-consumer.h"
@@ -29,6 +44,8 @@
 #include "utils.h"
 #include "rotate.h"
 #include "modprobe.h"
+#include "tracker.h"
+#include "notification-thread-commands.h"
 
 /*
  * Key used to reference a channel between the sessiond and the consumer. This
@@ -39,9 +56,10 @@ static uint64_t next_kernel_channel_key;
 static const char *module_proc_lttng = "/proc/lttng";
 
 static int kernel_tracer_fd = -1;
+static int kernel_tracer_event_notifier_group_fd = -1;
+static int kernel_tracer_event_notifier_group_notification_fd = -1;
+static struct cds_lfht *kernel_token_to_event_notifier_rule_ht;
 
-#include <lttng/userspace-probe.h>
-#include <lttng/userspace-probe-internal.h>
 /*
  * Add context on a kernel channel.
  *
@@ -213,6 +231,51 @@ error:
 	return -1;
 }
 
+/*
+ * Create a kernel event notifier group, register it to the kernel tracer and
+ * add it to the kernel session.
+ */
+static int kernel_create_event_notifier_group(int *event_notifier_group_fd)
+{
+	int ret;
+	int local_fd = -1;
+
+	assert(event_notifier_group_fd);
+
+	/* Kernel event notifier group creation. */
+	ret = kernctl_create_event_notifier_group(kernel_tracer_fd);
+	if (ret < 0) {
+		PERROR("Failed to create kernel event notifier group");
+		ret = -1;
+		goto error;
+	}
+
+	local_fd = ret;
+
+	/* Prevent fd duplication after execlp(). */
+	ret = fcntl(local_fd, F_SETFD, FD_CLOEXEC);
+	if (ret < 0) {
+		PERROR("Failed to set FD_CLOEXEC on kernel event notifier group file descriptor: fd = %d",
+				local_fd);
+		goto error;
+	}
+
+	DBG("Created kernel event notifier group: fd = %d", local_fd);
+	*event_notifier_group_fd = local_fd;
+	local_fd = -1;
+	ret = 0;
+error:
+	if (local_fd >= 0) {
+		ret = close(local_fd);
+		if (ret) {
+			PERROR("Failed to close kernel event notifier group file descriptor: fd = %d",
+					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.
@@ -224,7 +287,7 @@ error:
 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;
@@ -261,8 +324,7 @@ int extract_userspace_probe_offset_function_elf(
 		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);
@@ -286,7 +348,7 @@ end:
 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;
@@ -332,7 +394,7 @@ int extract_userspace_probe_offset_tracepoint_sdt(
 	}
 
 	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);
@@ -353,29 +415,16 @@ end:
 	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;
@@ -388,7 +437,8 @@ int userspace_probe_add_callsites(struct lttng_event *ev,
 		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;
@@ -397,8 +447,7 @@ int userspace_probe_add_callsites(struct lttng_event *ev,
 		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("Failed to add callsite to ELF userspace probe.");
 			ret = LTTNG_ERR_KERN_ENABLE_FAIL;
 			goto end;
 		}
@@ -415,8 +464,8 @@ int userspace_probe_add_callsites(struct lttng_event *ev,
 		 * 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;
@@ -425,8 +474,7 @@ int userspace_probe_add_callsites(struct lttng_event *ev,
 			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("Failed to add callsite to SDT userspace probe");
 				ret = LTTNG_ERR_KERN_ENABLE_FAIL;
 				free(offsets);
 				goto end;
@@ -443,6 +491,75 @@ 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)
+{
+	int ret;
+	const struct lttng_userspace_probe_location *location = NULL;
+
+	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("Failed to add callsite to userspace probe event '%s'",
+				ev->name);
+	}
+
+end:
+	return ret;
+}
+
+/*
+ * Extract the offsets of the instrumentation point for the different look-up
+ * methods.
+ */
+static int userspace_probe_event_rule_add_callsites(
+		const struct lttng_event_rule *rule,
+		const struct lttng_credentials *creds,
+		int fd)
+{
+	int ret;
+	enum lttng_event_rule_status status;
+	enum lttng_event_rule_type event_rule_type;
+	const struct lttng_userspace_probe_location *location = NULL;
+
+	assert(rule);
+	assert(creds);
+
+	event_rule_type = lttng_event_rule_get_type(rule);
+	assert(event_rule_type == LTTNG_EVENT_RULE_TYPE_USERSPACE_PROBE);
+
+	status = lttng_event_rule_userspace_probe_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("Failed to add callsite to user space probe object: fd = %d",
+				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.
@@ -451,7 +568,7 @@ end:
 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;
@@ -512,7 +629,8 @@ int kernel_create_event(struct lttng_event *ev,
 	}
 
 	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;
 		}
@@ -669,281 +787,406 @@ error:
 	return ret;
 }
 
-static struct lttng_tracker_list *get_id_tracker_list(
+/*
+ * Disable a kernel event notifier.
+ */
+static
+int kernel_disable_event_notifier_rule(struct ltt_kernel_event_notifier_rule *event)
+{
+	int ret;
+
+	assert(event);
+
+	rcu_read_lock();
+	cds_lfht_del(kernel_token_to_event_notifier_rule_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("Failed to disable kernel event notifier: fd = %d, token = %" PRIu64,
+					event->fd, event->token);
+			break;
+		}
+		goto error;
+	}
+
+	event->enabled = 0;
+	DBG("Disabled kernel event notifier: fd = %d, token = %" PRIu64,
+			event->fd, event->token);
+
+error:
+	return ret;
+}
+
+static
+struct process_attr_tracker *_kernel_get_process_attr_tracker(
 		struct ltt_kernel_session *session,
-		enum lttng_tracker_type tracker_type)
+		enum lttng_process_attr process_attr)
 {
-	switch (tracker_type) {
-	case LTTNG_TRACKER_PID:
-		return session->tracker_list_pid;
-	case LTTNG_TRACKER_VPID:
-		return session->tracker_list_vpid;
-	case LTTNG_TRACKER_UID:
-		return session->tracker_list_uid;
-	case LTTNG_TRACKER_VUID:
-		return session->tracker_list_vuid;
-	case LTTNG_TRACKER_GID:
-		return session->tracker_list_gid;
-	case LTTNG_TRACKER_VGID:
-		return session->tracker_list_vgid;
+	switch (process_attr) {
+	case LTTNG_PROCESS_ATTR_PROCESS_ID:
+		return session->tracker_pid;
+	case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
+		return session->tracker_vpid;
+	case LTTNG_PROCESS_ATTR_USER_ID:
+		return session->tracker_uid;
+	case LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID:
+		return session->tracker_vuid;
+	case LTTNG_PROCESS_ATTR_GROUP_ID:
+		return session->tracker_gid;
+	case LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID:
+		return session->tracker_vgid;
 	default:
 		return NULL;
 	}
 }
 
-int kernel_track_id(enum lttng_tracker_type tracker_type,
+const struct process_attr_tracker *kernel_get_process_attr_tracker(
 		struct ltt_kernel_session *session,
-		const struct lttng_tracker_id *id)
+		enum lttng_process_attr process_attr)
 {
-	int ret, value;
-	struct lttng_tracker_list *tracker_list;
-	struct lttng_tracker_ids *saved_ids;
+	return (const struct process_attr_tracker *)
+			_kernel_get_process_attr_tracker(session, process_attr);
+}
 
-	ret = lttng_tracker_id_lookup_string(tracker_type, id, &value);
-	if (ret != LTTNG_OK) {
-		return ret;
-	}
+enum lttng_error_code kernel_process_attr_tracker_set_tracking_policy(
+		struct ltt_kernel_session *session,
+		enum lttng_process_attr process_attr,
+		enum lttng_tracking_policy policy)
+{
+	int ret;
+	enum lttng_error_code ret_code = LTTNG_OK;
+	struct process_attr_tracker *tracker =
+			_kernel_get_process_attr_tracker(session, process_attr);
+	enum lttng_tracking_policy previous_policy;
 
-	tracker_list = get_id_tracker_list(session, tracker_type);
-	if (!tracker_list) {
-		return LTTNG_ERR_INVALID;
+	if (!tracker) {
+		ret_code = LTTNG_ERR_INVALID;
+		goto end;
 	}
 
-	/* Save list for restore on error. */
-	ret = lttng_tracker_id_get_list(tracker_list, &saved_ids);
-	if (ret != LTTNG_OK) {
-		return LTTNG_ERR_INVALID;
+	previous_policy = process_attr_tracker_get_tracking_policy(tracker);
+	ret = process_attr_tracker_set_tracking_policy(tracker, policy);
+	if (ret) {
+		ret_code = LTTNG_ERR_UNK;
+		goto end;
 	}
 
-	/* Add to list. */
-	ret = lttng_tracker_list_add(tracker_list, id);
-	if (ret != LTTNG_OK) {
+	if (previous_policy == policy) {
 		goto end;
 	}
 
-	switch (tracker_type) {
-	case LTTNG_TRACKER_PID:
-		DBG("Kernel track PID %d for session id %" PRIu64 ".", value,
-				session->id);
-		ret = kernctl_track_pid(session->fd, value);
-		if (!ret) {
-			ret = LTTNG_OK;
-			goto end;
-		}
-		break;
-	case LTTNG_TRACKER_VPID:
-		DBG("Kernel track VPID %d for session id %" PRIu64 ".", value,
-				session->id);
-		ret = kernctl_track_id(session->fd, LTTNG_TRACKER_VPID, value);
-		if (!ret) {
-			ret = LTTNG_OK;
-			goto end;
-		}
-		break;
-	case LTTNG_TRACKER_UID:
-		DBG("Kernel track UID %d for session id %" PRIu64 ".", value,
-				session->id);
-		ret = kernctl_track_id(session->fd, LTTNG_TRACKER_UID, value);
-		if (!ret) {
-			ret = LTTNG_OK;
-			goto end;
-		}
-		break;
-	case LTTNG_TRACKER_GID:
-		DBG("Kernel track GID %d for session id %" PRIu64 ".", value,
-				session->id);
-		ret = kernctl_track_id(session->fd, LTTNG_TRACKER_GID, value);
-		if (!ret) {
-			ret = LTTNG_OK;
-			goto end;
-		}
-		break;
-	case LTTNG_TRACKER_VUID:
-		DBG("Kernel track VUID %d for session id %" PRIu64 ".", value,
-				session->id);
-		ret = kernctl_track_id(session->fd, LTTNG_TRACKER_VUID, value);
-		if (!ret) {
-			ret = LTTNG_OK;
-			goto end;
+	switch (policy) {
+	case LTTNG_TRACKING_POLICY_INCLUDE_ALL:
+		if (process_attr == LTTNG_PROCESS_ATTR_PROCESS_ID) {
+			/*
+			 * Maintain a special case for the process ID process
+			 * attribute tracker as it was the only supported
+			 * attribute prior to 2.12.
+			 */
+			ret = kernctl_track_pid(session->fd, -1);
+		} else {
+			ret = kernctl_track_id(session->fd, process_attr, -1);
 		}
 		break;
-	case LTTNG_TRACKER_VGID:
-		DBG("Kernel track VGID %d for session id %" PRIu64 ".", value,
-				session->id);
-		ret = kernctl_track_id(session->fd, LTTNG_TRACKER_VGID, value);
-		if (!ret) {
-			ret = LTTNG_OK;
-			goto end;
+	case LTTNG_TRACKING_POLICY_EXCLUDE_ALL:
+	case LTTNG_TRACKING_POLICY_INCLUDE_SET:
+		/* fall-through. */
+		if (process_attr == LTTNG_PROCESS_ATTR_PROCESS_ID) {
+			/*
+			 * Maintain a special case for the process ID process
+			 * attribute tracker as it was the only supported
+			 * attribute prior to 2.12.
+			 */
+			ret = kernctl_untrack_pid(session->fd, -1);
+		} else {
+			ret = kernctl_untrack_id(session->fd, process_attr, -1);
 		}
 		break;
 	default:
-		ret = -EINVAL;
-		break;
+		abort();
 	}
-
-	/* Error handling. */
+	/* kern-ctl error handling */
 	switch (-ret) {
+	case 0:
+		ret_code = LTTNG_OK;
+		break;
 	case EINVAL:
-		ret = LTTNG_ERR_INVALID;
+		ret_code = LTTNG_ERR_INVALID;
 		break;
 	case ENOMEM:
-		ret = LTTNG_ERR_NOMEM;
+		ret_code = LTTNG_ERR_NOMEM;
 		break;
 	case EEXIST:
-		ret = LTTNG_ERR_ID_TRACKED;
+		ret_code = LTTNG_ERR_PROCESS_ATTR_EXISTS;
 		break;
 	default:
-		ret = LTTNG_ERR_UNK;
+		ret_code = LTTNG_ERR_UNK;
 		break;
 	}
-
-	if (lttng_tracker_id_set_list(tracker_list, saved_ids) != LTTNG_OK) {
-		ERR("Error on tracker add error handling.\n");
-	}
 end:
-	lttng_tracker_ids_destroy(saved_ids);
-	return ret;
+	return ret_code;
 }
 
-int kernel_untrack_id(enum lttng_tracker_type tracker_type,
+enum lttng_error_code kernel_process_attr_tracker_inclusion_set_add_value(
 		struct ltt_kernel_session *session,
-		const struct lttng_tracker_id *id)
+		enum lttng_process_attr process_attr,
+		const struct process_attr_value *value)
 {
-	int ret, value;
-	struct lttng_tracker_list *tracker_list;
-	struct lttng_tracker_ids *saved_ids;
-
-	ret = lttng_tracker_id_lookup_string(tracker_type, id, &value);
-	if (ret != LTTNG_OK) {
-		return ret;
-	}
-
-	tracker_list = get_id_tracker_list(session, tracker_type);
-	if (!tracker_list) {
-		return LTTNG_ERR_INVALID;
-	}
-	/* Save list for restore on error. */
-	ret = lttng_tracker_id_get_list(tracker_list, &saved_ids);
-	if (ret != LTTNG_OK) {
-		return LTTNG_ERR_INVALID;
-	}
-	/* Remove from list. */
-	ret = lttng_tracker_list_remove(tracker_list, id);
-	if (ret != LTTNG_OK) {
-		goto end;
-	}
+	int ret, integral_value;
+	enum lttng_error_code ret_code;
+	struct process_attr_tracker *tracker;
+	enum process_attr_tracker_status status;
 
-	switch (tracker_type) {
-	case LTTNG_TRACKER_PID:
-		DBG("Kernel untrack PID %d for session id %" PRIu64 ".", value,
-				session->id);
-		ret = kernctl_untrack_pid(session->fd, value);
-		if (!ret) {
-			ret = LTTNG_OK;
-			goto end;
-		}
-		break;
-	case LTTNG_TRACKER_VPID:
-		DBG("Kernel untrack VPID %d for session id %" PRIu64 ".", value,
-				session->id);
-		ret = kernctl_untrack_id(
-				session->fd, LTTNG_TRACKER_VPID, value);
-		if (!ret) {
-			ret = LTTNG_OK;
-			goto end;
-		}
-		break;
-	case LTTNG_TRACKER_UID:
-		DBG("Kernel untrack UID %d for session id %" PRIu64 ".", value,
-				session->id);
-		ret = kernctl_untrack_id(session->fd, LTTNG_TRACKER_UID, value);
-		if (!ret) {
-			ret = LTTNG_OK;
-			goto end;
-		}
-		break;
-	case LTTNG_TRACKER_GID:
-		DBG("Kernel untrack GID %d for session id %" PRIu64 ".", value,
-				session->id);
-		ret = kernctl_untrack_id(session->fd, LTTNG_TRACKER_GID, value);
-		if (!ret) {
-			ret = LTTNG_OK;
-			goto end;
-		}
+	/*
+	 * Convert process attribute tracker value to the integral
+	 * representation required by the kern-ctl API.
+	 */
+	switch (process_attr) {
+	case LTTNG_PROCESS_ATTR_PROCESS_ID:
+	case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
+		integral_value = (int) value->value.pid;
 		break;
-	case LTTNG_TRACKER_VUID:
-		DBG("Kernel untrack VUID %d for session id %" PRIu64 ".", value,
-				session->id);
-		ret = kernctl_untrack_id(
-				session->fd, LTTNG_TRACKER_VUID, value);
-		if (!ret) {
-			ret = LTTNG_OK;
-			goto end;
+	case LTTNG_PROCESS_ATTR_USER_ID:
+	case LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID:
+		if (value->type == LTTNG_PROCESS_ATTR_VALUE_TYPE_USER_NAME) {
+			uid_t uid;
+
+			ret_code = utils_user_id_from_name(
+					value->value.user_name, &uid);
+			if (ret_code != LTTNG_OK) {
+				goto end;
+			}
+			integral_value = (int) uid;
+		} else {
+			integral_value = (int) value->value.uid;
 		}
 		break;
-	case LTTNG_TRACKER_VGID:
-		DBG("Kernel untrack VGID %d for session id %" PRIu64 ".", value,
-				session->id);
-		ret = kernctl_untrack_id(
-				session->fd, LTTNG_TRACKER_VGID, value);
-		if (!ret) {
-			ret = LTTNG_OK;
-			goto end;
+	case LTTNG_PROCESS_ATTR_GROUP_ID:
+	case LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID:
+		if (value->type == LTTNG_PROCESS_ATTR_VALUE_TYPE_GROUP_NAME) {
+			gid_t gid;
+
+			ret_code = utils_group_id_from_name(
+					value->value.group_name, &gid);
+			if (ret_code != LTTNG_OK) {
+				goto end;
+			}
+			integral_value = (int) gid;
+		} else {
+			integral_value = (int) value->value.gid;
 		}
 		break;
 	default:
-		ret = -EINVAL;
-		break;
+		ret_code = LTTNG_ERR_INVALID;
+		goto end;
+	}
+
+	tracker = _kernel_get_process_attr_tracker(session, process_attr);
+	if (!tracker) {
+		ret_code = LTTNG_ERR_INVALID;
+		goto end;
+	}
+
+	status = process_attr_tracker_inclusion_set_add_value(tracker, value);
+	if (status != PROCESS_ATTR_TRACKER_STATUS_OK) {
+		switch (status) {
+		case PROCESS_ATTR_TRACKER_STATUS_EXISTS:
+			ret_code = LTTNG_ERR_PROCESS_ATTR_EXISTS;
+			break;
+		case PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY:
+			ret_code = LTTNG_ERR_PROCESS_ATTR_TRACKER_INVALID_TRACKING_POLICY;
+			break;
+		case PROCESS_ATTR_TRACKER_STATUS_ERROR:
+		default:
+			ret_code = LTTNG_ERR_UNK;
+			break;
+		}
+		goto end;
 	}
 
-	/* Error handling. */
+	DBG("Kernel track %s %d for session id %" PRIu64,
+			lttng_process_attr_to_string(process_attr),
+			integral_value, session->id);
+	if (process_attr == LTTNG_PROCESS_ATTR_PROCESS_ID) {
+		/*
+		 * Maintain a special case for the process ID process attribute
+		 * tracker as it was the only supported attribute prior to 2.12.
+		 */
+		ret = kernctl_track_pid(session->fd, integral_value);
+	} else {
+		ret = kernctl_track_id(
+				session->fd, process_attr, integral_value);
+	}
+	if (ret == 0) {
+		ret_code = LTTNG_OK;
+		goto end;
+	}
+
+	kernel_wait_quiescent();
+
+	/* kern-ctl error handling */
 	switch (-ret) {
+	case 0:
+		ret_code = LTTNG_OK;
+		break;
 	case EINVAL:
-		ret = LTTNG_ERR_INVALID;
+		ret_code = LTTNG_ERR_INVALID;
 		break;
 	case ENOMEM:
-		ret = LTTNG_ERR_NOMEM;
+		ret_code = LTTNG_ERR_NOMEM;
 		break;
 	case EEXIST:
-		ret = LTTNG_ERR_ID_TRACKED;
+		ret_code = LTTNG_ERR_PROCESS_ATTR_EXISTS;
 		break;
 	default:
-		ret = LTTNG_ERR_UNK;
+		ret_code = LTTNG_ERR_UNK;
 		break;
 	}
 
-	if (lttng_tracker_id_set_list(tracker_list, saved_ids) != LTTNG_OK) {
-		ERR("Error on tracker remove error handling.\n");
+	/* Attempt to remove the value from the tracker. */
+	status = process_attr_tracker_inclusion_set_remove_value(
+			tracker, value);
+	if (status != PROCESS_ATTR_TRACKER_STATUS_OK) {
+		ERR("Failed to roll-back the tracking of kernel %s process attribute %d while handling a kern-ctl error",
+				lttng_process_attr_to_string(process_attr),
+				integral_value);
 	}
 end:
-	lttng_tracker_ids_destroy(saved_ids);
-	return ret;
+	return ret_code;
 }
 
-/*
- * Called with session lock held.
- */
-int kernel_list_tracker_ids(enum lttng_tracker_type tracker_type,
+enum lttng_error_code kernel_process_attr_tracker_inclusion_set_remove_value(
 		struct ltt_kernel_session *session,
-		struct lttng_tracker_ids **_ids)
+		enum lttng_process_attr process_attr,
+		const struct process_attr_value *value)
 {
-	int ret = 0;
-	struct lttng_tracker_list *tracker_list;
+	int ret, integral_value;
+	enum lttng_error_code ret_code;
+	struct process_attr_tracker *tracker;
+	enum process_attr_tracker_status status;
 
-	tracker_list = get_id_tracker_list(session, tracker_type);
-	if (!tracker_list) {
-		ret = -LTTNG_ERR_INVALID;
+	/*
+	 * Convert process attribute tracker value to the integral
+	 * representation required by the kern-ctl API.
+	 */
+	switch (process_attr) {
+	case LTTNG_PROCESS_ATTR_PROCESS_ID:
+	case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
+		integral_value = (int) value->value.pid;
+		break;
+	case LTTNG_PROCESS_ATTR_USER_ID:
+	case LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID:
+		if (value->type == LTTNG_PROCESS_ATTR_VALUE_TYPE_USER_NAME) {
+			uid_t uid;
+
+			ret_code = utils_user_id_from_name(
+					value->value.user_name, &uid);
+			if (ret_code != LTTNG_OK) {
+				goto end;
+			}
+			integral_value = (int) uid;
+		} else {
+			integral_value = (int) value->value.uid;
+		}
+		break;
+	case LTTNG_PROCESS_ATTR_GROUP_ID:
+	case LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID:
+		if (value->type == LTTNG_PROCESS_ATTR_VALUE_TYPE_GROUP_NAME) {
+			gid_t gid;
+
+			ret_code = utils_group_id_from_name(
+					value->value.group_name, &gid);
+			if (ret_code != LTTNG_OK) {
+				goto end;
+			}
+			integral_value = (int) gid;
+		} else {
+			integral_value = (int) value->value.gid;
+		}
+		break;
+	default:
+		ret_code = LTTNG_ERR_INVALID;
 		goto end;
 	}
 
-	ret = lttng_tracker_id_get_list(tracker_list, _ids);
-	if (ret != LTTNG_OK) {
-		ret = -LTTNG_ERR_INVALID;
+	tracker = _kernel_get_process_attr_tracker(session, process_attr);
+	if (!tracker) {
+		ret_code = LTTNG_ERR_INVALID;
+		goto end;
+	}
+
+	status = process_attr_tracker_inclusion_set_remove_value(
+			tracker, value);
+	if (status != PROCESS_ATTR_TRACKER_STATUS_OK) {
+		switch (status) {
+		case PROCESS_ATTR_TRACKER_STATUS_MISSING:
+			ret_code = LTTNG_ERR_PROCESS_ATTR_MISSING;
+			break;
+		case PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY:
+			ret_code = LTTNG_ERR_PROCESS_ATTR_TRACKER_INVALID_TRACKING_POLICY;
+			break;
+		case PROCESS_ATTR_TRACKER_STATUS_ERROR:
+		default:
+			ret_code = LTTNG_ERR_UNK;
+			break;
+		}
 		goto end;
 	}
 
+	DBG("Kernel track %s %d for session id %" PRIu64,
+			lttng_process_attr_to_string(process_attr),
+			integral_value, session->id);
+	if (process_attr == LTTNG_PROCESS_ATTR_PROCESS_ID) {
+		/*
+		 * Maintain a special case for the process ID process attribute
+		 * tracker as it was the only supported attribute prior to 2.12.
+		 */
+		ret = kernctl_untrack_pid(session->fd, integral_value);
+	} else {
+		ret = kernctl_untrack_id(
+				session->fd, process_attr, integral_value);
+	}
+	if (ret == 0) {
+		ret_code = LTTNG_OK;
+		goto end;
+	}
+	kernel_wait_quiescent();
+
+	/* kern-ctl error handling */
+	switch (-ret) {
+	case 0:
+		ret_code = LTTNG_OK;
+		break;
+	case EINVAL:
+		ret_code = LTTNG_ERR_INVALID;
+		break;
+	case ENOMEM:
+		ret_code = LTTNG_ERR_NOMEM;
+		break;
+	case ENOENT:
+		ret_code = LTTNG_ERR_PROCESS_ATTR_MISSING;
+		break;
+	default:
+		ret_code = LTTNG_ERR_UNK;
+		break;
+	}
+
+	/* Attempt to add the value to the tracker. */
+	status = process_attr_tracker_inclusion_set_add_value(
+			tracker, value);
+	if (status != PROCESS_ATTR_TRACKER_STATUS_OK) {
+		ERR("Failed to roll-back the tracking of kernel %s process attribute %d while handling a kern-ctl error",
+				lttng_process_attr_to_string(process_attr),
+				integral_value);
+	}
 end:
-	return ret;
+	return ret_code;
 }
 
 /*
@@ -1546,16 +1789,10 @@ int kernel_syscall_mask(int chan_fd, char **syscall_mask, uint32_t *nr_bits)
 	return kernctl_syscall_mask(chan_fd, syscall_mask, nr_bits);
 }
 
-/*
- * Check for the support of the RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS via abi
- * version number.
- *
- * Return 1 on success, 0 when feature is not supported, negative value in case
- * of errors.
- */
-int kernel_supports_ring_buffer_snapshot_sample_positions(void)
+static
+int kernel_tracer_abi_greater_or_equal(unsigned int major, unsigned int minor)
 {
-	int ret = 0; // Not supported by default
+	int ret;
 	struct lttng_kernel_tracer_abi_version abi;
 
 	ret = kernctl_tracer_abi_version(kernel_tracer_fd, &abi);
@@ -1564,18 +1801,24 @@ int kernel_supports_ring_buffer_snapshot_sample_positions(void)
 		goto error;
 	}
 
+	ret = abi.major > major || (abi.major == major && abi.minor >= minor);
+error:
+	return ret;
+}
+
+/*
+ * Check for the support of the RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS via abi
+ * version number.
+ *
+ * Return 1 on success, 0 when feature is not supported, negative value in case
+ * of errors.
+ */
+int kernel_supports_ring_buffer_snapshot_sample_positions(void)
+{
 	/*
 	 * RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS was introduced in 2.3
 	 */
-	if (abi.major >= 2 && abi.minor >= 3) {
-		/* Supported */
-		ret = 1;
-	} else {
-		/* Not supported */
-		ret = 0;
-	}
-error:
-	return ret;
+	return kernel_tracer_abi_greater_or_equal(2, 3);
 }
 
 /*
@@ -1586,28 +1829,25 @@ error:
  */
 int kernel_supports_ring_buffer_packet_sequence_number(void)
 {
-	int ret = 0; // Not supported by default
-	struct lttng_kernel_tracer_abi_version abi;
-
-	ret = kernctl_tracer_abi_version(kernel_tracer_fd, &abi);
-	if (ret < 0) {
-		ERR("Failed to retrieve lttng-modules ABI version");
-		goto error;
-	}
-
 	/*
 	 * Packet sequence number was introduced in LTTng 2.8,
 	 * lttng-modules ABI 2.1.
 	 */
-	if (abi.major >= 2 && abi.minor >= 1) {
-		/* Supported */
-		ret = 1;
-	} else {
-		/* Not supported */
-		ret = 0;
-	}
-error:
-	return ret;
+	return kernel_tracer_abi_greater_or_equal(2, 1);
+}
+
+/*
+ * Check for the support of event notifiers via abi version number.
+ *
+ * Return 1 on success, 0 when feature is not supported, negative value in case
+ * of errors.
+ */
+int kernel_supports_event_notifiers(void)
+{
+	/*
+	 * Event notifiers were introduced in LTTng 2.13, lttng-modules ABI 2.6.
+	 */
+	return kernel_tracer_abi_greater_or_equal(2, 6);
 }
 
 /*
@@ -1639,7 +1879,7 @@ enum lttng_error_code kernel_rotate_session(struct ltt_session *session)
 			socket, node.node) {
 		struct ltt_kernel_channel *chan;
 
-                /* For each channel, ask the consumer to rotate it. */
+		/* For each channel, ask the consumer to rotate it. */
 		cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
 			DBG("Rotate kernel channel %" PRIu64 ", session %s",
 					chan->key, session->name);
@@ -1647,7 +1887,7 @@ enum lttng_error_code kernel_rotate_session(struct ltt_session *session)
 					ksess->uid, ksess->gid, ksess->consumer,
 					/* is_metadata_channel */ false);
 			if (ret < 0) {
-				status = LTTNG_ERR_KERN_CONSUMER_FAIL;
+				status = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
 				goto error;
 			}
 		}
@@ -1659,7 +1899,7 @@ enum lttng_error_code kernel_rotate_session(struct ltt_session *session)
 				ksess->uid, ksess->gid, ksess->consumer,
 				/* is_metadata_channel */ true);
 		if (ret < 0) {
-			status = LTTNG_ERR_KERN_CONSUMER_FAIL;
+			status = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
 			goto error;
 		}
 	}
@@ -1732,35 +1972,81 @@ int init_kernel_tracer(void)
 	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).");
 	}
 
-	DBG("Kernel tracer fd %d", kernel_tracer_fd);
+	ret = kernel_supports_event_notifiers();
+	if (ret < 0) {
+		ERR("Failed to check for kernel tracer event notifier support");
+		goto error_modules;
+	}
+	ret = kernel_create_event_notifier_group(&kernel_tracer_event_notifier_group_fd);
+	if (ret < 0) {
+		/* This is not fatal. */
+		WARN("Failed to create kernel event notifier group");
+		kernel_tracer_event_notifier_group_fd = -1;
+	} else {
+		const enum lttng_error_code error_code_ret =
+				kernel_create_event_notifier_group_notification_fd(
+						&kernel_tracer_event_notifier_group_notification_fd);
+
+		if (error_code_ret != LTTNG_OK) {
+			goto error_modules;
+		}
+
+		kernel_token_to_event_notifier_rule_ht = cds_lfht_new(
+				DEFAULT_HT_SIZE, 1, 0,
+				CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING,
+				NULL);
+		if (!kernel_token_to_event_notifier_rule_ht) {
+			goto error_token_ht;
+		}
+	}
+
+	DBG("Kernel tracer initialized: kernel tracer fd = %d, event notifier group fd = %d, event notifier group notification fd = %d",
+			kernel_tracer_fd, kernel_tracer_event_notifier_group_fd,
+			kernel_tracer_event_notifier_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:
 	modprobe_remove_lttng_control();
 	ret = close(kernel_tracer_fd);
 	if (ret) {
-		PERROR("close");
+		PERROR("Failed to close kernel tracer file descriptor: fd = %d",
+				kernel_tracer_fd);
 	}
 	kernel_tracer_fd = -1;
 	return LTTNG_ERR_KERN_VERSION;
 
+
+error_token_ht:
+	ret = close(kernel_tracer_event_notifier_group_notification_fd);
+	if (ret) {
+		PERROR("Failed to close kernel tracer event notifier group notification file descriptor: fd = %d",
+				kernel_tracer_event_notifier_group_notification_fd);
+	}
+
 error_modules:
+	ret = close(kernel_tracer_event_notifier_group_fd);
+	if (ret) {
+		PERROR("Failed to close kernel tracer event notifier group file descriptor: fd = %d",
+				kernel_tracer_event_notifier_group_fd);
+	}
+
 	ret = close(kernel_tracer_fd);
 	if (ret) {
-		PERROR("close");
+		PERROR("Failed to close kernel tracer file descriptor: fd = %d",
+				kernel_tracer_fd);
 	}
 
 error_open:
@@ -1779,16 +2065,54 @@ error:
 LTTNG_HIDDEN
 void cleanup_kernel_tracer(void)
 {
-	int ret;
+	DBG2("Closing kernel event notifier group notification file descriptor");
+	if (kernel_tracer_event_notifier_group_notification_fd >= 0) {
+		int ret = notification_thread_command_remove_tracer_event_source(
+				notification_thread_handle,
+				kernel_tracer_event_notifier_group_notification_fd);
+		if (ret != LTTNG_OK) {
+			ERR("Failed to remove kernel event notifier notification from notification thread");
+		}
+
+		ret = close(kernel_tracer_event_notifier_group_notification_fd);
+		if (ret) {
+			PERROR("Failed to close kernel event notifier group notification file descriptor: fd = %d",
+					kernel_tracer_event_notifier_group_notification_fd);
+		}
+
+		kernel_tracer_event_notifier_group_notification_fd = -1;
+	}
+
+	if (kernel_token_to_event_notifier_rule_ht) {
+		const int ret = cds_lfht_destroy(
+				kernel_token_to_event_notifier_rule_ht, NULL);
+		assert(ret == 0);
+	}
+
+	DBG2("Closing kernel event notifier group file descriptor");
+	if (kernel_tracer_event_notifier_group_fd >= 0) {
+		const int ret = close(kernel_tracer_event_notifier_group_fd);
+
+		if (ret) {
+			PERROR("Failed to close kernel event notifier group file descriptor: fd = %d",
+					kernel_tracer_event_notifier_group_fd);
+		}
+
+		kernel_tracer_event_notifier_group_fd = -1;
+	}
 
 	DBG2("Closing kernel fd");
 	if (kernel_tracer_fd >= 0) {
-		ret = close(kernel_tracer_fd);
+		const int ret = close(kernel_tracer_fd);
+
 		if (ret) {
-			PERROR("close");
+			PERROR("Failed to close kernel tracer file descriptor: fd = %d",
+					kernel_tracer_fd);
 		}
+
 		kernel_tracer_fd = -1;
 	}
+
 	DBG("Unloading kernel modules");
 	modprobe_remove_lttng_all();
 	free(syscall_table);
@@ -1879,3 +2203,337 @@ end:
 	rcu_read_unlock();
 	return status;
 }
+
+enum lttng_error_code kernel_create_event_notifier_group_notification_fd(
+		int *event_notifier_group_notification_fd)
+{
+	int local_fd = -1, ret;
+	enum lttng_error_code error_code_ret;
+
+	assert(event_notifier_group_notification_fd);
+
+	ret = kernctl_create_event_notifier_group_notification_fd(
+			kernel_tracer_event_notifier_group_fd);
+	if (ret < 0) {
+		PERROR("Failed to create kernel event notifier group notification file descriptor");
+		error_code_ret = LTTNG_ERR_EVENT_NOTIFIER_GROUP_NOTIFICATION_FD;
+		goto error;
+	}
+
+	local_fd = ret;
+
+	/* Prevent fd duplication after execlp(). */
+	ret = fcntl(local_fd, F_SETFD, FD_CLOEXEC);
+	if (ret < 0) {
+		PERROR("Failed to set FD_CLOEXEC on kernel event notifier group notification file descriptor: fd = %d",
+				local_fd);
+		error_code_ret = LTTNG_ERR_EVENT_NOTIFIER_GROUP_NOTIFICATION_FD;
+		goto error;
+	}
+
+	DBG("Created kernel notifier group notification file descriptor: fd = %d",
+			local_fd);
+	error_code_ret = LTTNG_OK;
+	*event_notifier_group_notification_fd = local_fd;
+	local_fd = -1;
+
+error:
+	if (local_fd >= 0) {
+		ret = close(local_fd);
+		if (ret) {
+			PERROR("Failed to close kernel event notifier group notification file descriptor: fd = %d",
+					local_fd);
+		}
+	}
+
+	return error_code_ret;
+}
+
+enum lttng_error_code kernel_destroy_event_notifier_group_notification_fd(
+		int event_notifier_group_notification_fd)
+{
+	enum lttng_error_code ret_code = LTTNG_OK;
+
+	DBG("Closing event notifier group notification file descriptor: fd = %d",
+			event_notifier_group_notification_fd);
+	if (event_notifier_group_notification_fd >= 0) {
+		const int ret = close(event_notifier_group_notification_fd);
+		if (ret) {
+			PERROR("Failed to close event notifier group notification file descriptor: fd = %d",
+					event_notifier_group_notification_fd);
+		}
+	}
+
+	return ret_code;
+}
+
+static
+unsigned long hash_trigger(const 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)
+{
+	const struct ltt_kernel_event_notifier_rule *event_notifier_rule;
+	const struct lttng_trigger *trigger = key;
+
+	event_notifier_rule = caa_container_of(node,
+			const struct ltt_kernel_event_notifier_rule, ht_node);
+
+	return lttng_trigger_is_equal(trigger, event_notifier_rule->trigger);
+}
+
+static enum lttng_error_code kernel_create_event_notifier_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;
+	enum lttng_condition_status condition_status;
+	enum lttng_condition_type condition_type;
+	enum lttng_event_rule_type event_rule_type;
+	struct ltt_kernel_event_notifier_rule *event_notifier_rule;
+	struct lttng_kernel_event_notifier kernel_event_notifier = {};
+	unsigned int capture_bytecode_count = 0, i;
+	const struct lttng_condition *condition = NULL;
+	const struct lttng_event_rule *event_rule = NULL;
+	enum lttng_condition_status cond_status;
+
+	assert(trigger);
+
+	condition = lttng_trigger_get_const_condition(trigger);
+	assert(condition);
+
+	condition_type = lttng_condition_get_type(condition);
+	assert(condition_type == LTTNG_CONDITION_TYPE_ON_EVENT);
+
+	/* Does not acquire a reference. */
+	condition_status = lttng_condition_on_event_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);
+
+	error_code_ret = trace_kernel_create_event_notifier_rule(trigger, token,
+			&event_notifier_rule);
+	if (error_code_ret != LTTNG_OK) {
+		goto error;
+	}
+
+	error_code_ret = trace_kernel_init_event_notifier_from_event_rule(
+			event_rule, &kernel_event_notifier);
+	if (error_code_ret != LTTNG_OK) {
+		goto free_event;
+	}
+
+	kernel_event_notifier.event.token = event_notifier_rule->token;
+
+	fd = kernctl_create_event_notifier(
+			kernel_tracer_event_notifier_group_fd,
+			&kernel_event_notifier);
+	if (fd < 0) {
+		switch (-fd) {
+		case EEXIST:
+			error_code_ret = LTTNG_ERR_KERN_EVENT_EXIST;
+			break;
+		case ENOSYS:
+			WARN("Failed to create kernel event notifier: not notifier type not implemented");
+			error_code_ret = LTTNG_ERR_KERN_EVENT_ENOSYS;
+			break;
+		case ENOENT:
+			WARN("Failed to create kernel event notifier: not found: name = '%s'",
+					kernel_event_notifier.event.name);
+			error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
+			break;
+		default:
+			PERROR("Failed to create kernel event notifier: error code = %d, name = '%s'",
+					fd, kernel_event_notifier.event.name);
+			error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
+		}
+		goto free_event;
+	}
+
+	event_notifier_rule->fd = fd;
+	/* Prevent fd duplication after execlp(). */
+	err = fcntl(event_notifier_rule->fd, F_SETFD, FD_CLOEXEC);
+	if (err < 0) {
+		PERROR("Failed to set FD_CLOEXEC on kernel event notifier file descriptor: fd = %d",
+				fd);
+		error_code_ret = LTTNG_ERR_FATAL;
+		goto set_cloexec_error;
+	}
+
+	if (event_notifier_rule->filter) {
+		err = kernctl_filter(event_notifier_rule->fd, event_notifier_rule->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_USERSPACE_PROBE) {
+		ret = userspace_probe_event_rule_add_callsites(
+				event_rule, creds, event_notifier_rule->fd);
+		if (ret) {
+			error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
+			goto add_callsite_error;
+		}
+	}
+
+	/* Set the capture bytecode if any. */
+	cond_status = lttng_condition_on_event_get_capture_descriptor_count(
+			condition, &capture_bytecode_count);
+	assert(cond_status == LTTNG_CONDITION_STATUS_OK);
+
+	for (i = 0; i < capture_bytecode_count; i++) {
+		const struct lttng_bytecode *capture_bytecode =
+				lttng_condition_on_event_get_capture_bytecode_at_index(
+						condition, i);
+
+		if (capture_bytecode == NULL) {
+			ERR("Unexpected NULL capture bytecode on condition");
+			error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
+			goto capture_error;
+		}
+
+		ret = kernctl_capture(event_notifier_rule->fd, capture_bytecode);
+		if (ret < 0) {
+			ERR("Failed to set capture bytecode on event notifier rule fd: fd = %d",
+					event_notifier_rule->fd);
+			error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
+			goto capture_error;
+		}
+	}
+
+	err = kernctl_enable(event_notifier_rule->fd);
+	if (err < 0) {
+		switch (-err) {
+		case EEXIST:
+			error_code_ret = LTTNG_ERR_KERN_EVENT_EXIST;
+			break;
+		default:
+			PERROR("enable kernel event notifier");
+			error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
+			break;
+		}
+		goto enable_error;
+	}
+
+	/* Add trigger to kernel token mapping in the hash table. */
+	rcu_read_lock();
+	cds_lfht_add(kernel_token_to_event_notifier_rule_ht, hash_trigger(trigger),
+			&event_notifier_rule->ht_node);
+	rcu_read_unlock();
+
+	DBG("Created kernel event notifier: name = '%s', fd = %d",
+			kernel_event_notifier.event.name,
+			event_notifier_rule->fd);
+
+	return LTTNG_OK;
+
+capture_error:
+add_callsite_error:
+enable_error:
+set_cloexec_error:
+filter_error:
+	{
+		const int close_ret = close(event_notifier_rule->fd);
+
+		if (close_ret) {
+			PERROR("Failed to close kernel event notifier file descriptor: fd = %d",
+					event_notifier_rule->fd);
+		}
+	}
+free_event:
+	free(event_notifier_rule);
+error:
+	return error_code_ret;
+}
+
+enum lttng_error_code kernel_register_event_notifier(
+		struct lttng_trigger *trigger,
+		const struct lttng_credentials *cmd_creds)
+{
+	enum lttng_error_code ret;
+	enum lttng_condition_status status;
+	enum lttng_domain_type domain_type;
+	const struct lttng_event_rule *event_rule;
+	const struct lttng_condition *const condition =
+			lttng_trigger_get_const_condition(trigger);
+	const uint64_t token = lttng_trigger_get_tracer_token(trigger);
+
+	assert(condition);
+
+	/* Does not acquire a reference to the event rule. */
+	status = lttng_condition_on_event_get_rule(
+			condition, &event_rule);
+	assert(status == LTTNG_CONDITION_STATUS_OK);
+
+	domain_type = lttng_event_rule_get_domain_type(event_rule);
+	assert(domain_type == LTTNG_DOMAIN_KERNEL);
+
+	ret = kernel_create_event_notifier_rule(trigger, cmd_creds, token);
+	if (ret != LTTNG_OK) {
+		ERR("Failed to create kernel event notifier rule");
+	}
+
+	return ret;
+}
+
+enum lttng_error_code kernel_unregister_event_notifier(
+		const struct lttng_trigger *trigger)
+{
+	struct ltt_kernel_event_notifier_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();
+
+	cds_lfht_lookup(kernel_token_to_event_notifier_rule_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_event_notifier_rule, ht_node);
+
+	ret = kernel_disable_event_notifier_rule(token_event_rule_element);
+	if (ret) {
+		error_code_ret = LTTNG_ERR_FATAL;
+		goto error;
+	}
+
+	trace_kernel_destroy_event_notifier_rule(token_event_rule_element);
+	error_code_ret = LTTNG_OK;
+
+error:
+	rcu_read_unlock();
+
+	return error_code_ret;
+}
+
+int kernel_get_notification_fd(void)
+{
+	return kernel_tracer_event_notifier_group_notification_fd;
+}