From: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Date: Mon, 19 Apr 2021 18:04:53 +0000 (-0400)
Subject: Fix: sessiond: trigger with condition not requiring event notifier cannot be listed
X-Git-Tag: v2.13.0-rc1~38
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=43cee6f9977d1690fe8c3613740af7286985eba9;p=lttng-tools.git

Fix: sessiond: trigger with condition not requiring event notifier cannot be listed

Observed issue
==============

The lttng-sessiond process aborts when an lttng error query is performed
against a trigger that uses a condition other than "event-match".

Cause
=====

The trigger's condition is a LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE
which does not have a "domain type".

This results in the call to `abort()` in
`event_notifier_error_accounting_get_count` of the default case.

Solution
========

Check if the trigger "needs" or at least "depends" on tracer notifier.

Known drawbacks
=========

None

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I3d5f09617f95315060a611b464d1df95cb80c5bd
---

diff --git a/src/bin/lttng-sessiond/event-notifier-error-accounting.c b/src/bin/lttng-sessiond/event-notifier-error-accounting.c
index 02c99b96b..61ba6981e 100644
--- a/src/bin/lttng-sessiond/event-notifier-error-accounting.c
+++ b/src/bin/lttng-sessiond/event-notifier-error-accounting.c
@@ -1042,6 +1042,7 @@ event_notifier_error_accounting_get_count(
 		return event_notifier_error_accounting_ust_get_count(trigger,
 				count);
 #else
+		*count = 0;
 		return EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK;
 #endif /* HAVE_LIBLTTNG_UST_CTL */
 	default:
diff --git a/src/bin/lttng-sessiond/trigger-error-query.c b/src/bin/lttng-sessiond/trigger-error-query.c
index ff8c9ca05..54aeb4149 100644
--- a/src/bin/lttng-sessiond/trigger-error-query.c
+++ b/src/bin/lttng-sessiond/trigger-error-query.c
@@ -29,6 +29,12 @@ enum lttng_trigger_status lttng_trigger_add_error_results(
 			&trigger_owner);
 	assert(status == LTTNG_TRIGGER_STATUS_OK);
 
+	/* Only add discarded tracer messages count for applicable triggers. */
+	if (!lttng_trigger_needs_tracer_notifier(trigger)) {
+		status = LTTNG_TRIGGER_STATUS_OK;
+		goto end;
+	}
+
 	error_accounting_status = event_notifier_error_accounting_get_count(
 			trigger, &discarded_tracer_messages_count);
 	if (error_accounting_status != EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK) {