From: Kienan Stewart <kstewart@efficios.com>
Date: Thu, 8 Jun 2023 15:05:17 +0000 (-0400)
Subject: Tests: Avoid looping on app PIDs during cleanup
X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=c1896e2d809e0d32d2d9b8a840755de6d5d70eaf

Tests: Avoid looping on app PIDs during cleanup

When the list of app PIDs becomes long, eg. in the case for
`tests/regression/ust/nprocesses/test_nprocesses`, then performing the
following type of loop can be quite slow, especially if the apps have
some teardown time internally:

```
for p in ${APP_PIDS} ; do
  kill ${p}
  wait ${p}
done
```

Both `kill` and `wait` take a list of PIDs, so the cleanup is easily
factorable to

```
kill ${APP_PIDS}
wait ${APP_PIDS}
```

In the case of `test_nprocesses`, the test run time drops from ~25s to
~4s. The difference is less important in tests with fewer apps.

Signed-off-by: Kienan Stewart <kstewart@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I9619939b4f1201a99f9666dee3e19551a67c9fb6
---

diff --git a/tests/regression/tools/snapshots/test_ust_streaming b/tests/regression/tools/snapshots/test_ust_streaming
index 3104afb3b..2e04d667e 100755
--- a/tests/regression/tools/snapshots/test_ust_streaming
+++ b/tests/regression/tools/snapshots/test_ust_streaming
@@ -6,24 +6,24 @@
 
 TEST_DESC="Streaming - Snapshot UST tracing"
 
-CURDIR=$(dirname $0)/
-TESTDIR=$CURDIR/../../..
+CURDIR=$(dirname "$0")/
+TESTDIR="$CURDIR/../../.."
 EVENT_NAME="tp:tptest"
 SESSION_NAME=""
 CHANNEL_NAME="chan1"
-BIN_NAME="gen-nevents"
 TESTAPP_PATH="$TESTDIR/utils/testapp"
 TESTAPP_NAME="gen-ust-events"
 TESTAPP_BIN="$TESTAPP_PATH/$TESTAPP_NAME/$TESTAPP_NAME"
 NR_ITER=-1
 NR_USEC_WAIT=100
-APPS_PID=
+APP_PIDS=()
 
 TRACE_PATH=$(mktemp -d -t tmp.test_snapshots_ust_streaming_trace_path.XXXXXX)
 
 NUM_TESTS=85
 
-source $TESTDIR/utils/utils.sh
+# shellcheck source-path=SCRIPTDIR/../../../
+source "$TESTDIR/utils/utils.sh"
 
 if [ ! -x "$TESTAPP_BIN" ]; then
 	BAIL_OUT "No UST events binary detected."
@@ -34,25 +34,42 @@ function snapshot_add_output ()
 	local sess_name=$1
 	local trace_path=$2
 	local name=$3
-	local extra_opt=""
+	local options=()
+	local args=()
 
-	if [ ! -z $name ]; then
-		extra_opt="-n $name"
+	if [ -n "$sess_name" ] ; then
+		options+=(-s "$sess_name")
 	fi
 
-	$TESTDIR/../src/bin/lttng/$LTTNG_BIN snapshot add-output -s $sess_name $extra_opt $trace_path >/dev/null 2>&1
+	if [ -n "$name" ]; then
+		options+=(-n "$name")
+	fi
+
+	# Checking for any other optional arguments that should be passed to the lttng command
+	args=("$@")
+	if [ -n "${args[*]:3}" ] ; then
+		options+=("${args[@]:3}")
+	fi
+
+	# The trace_path is a positional argument and must always come last if it is defined
+	if [ -n "$trace_path" ] ; then
+		options+=("$trace_path")
+	fi
+
+	"$TESTDIR/../src/bin/lttng/$LTTNG_BIN" snapshot add-output "${options[@]}" >/dev/null 2>&1
 	ok $? "Added snapshot output $trace_path"
 }
 
 # Start trace application and return once one event has been hit.
 function start_test_app()
 {
-	local tmp_file=$(mktemp -u -t tmp.test_${FUNCNAME[0]}_tmp_file.XXXXXX)
+	local tmp_file
+	tmp_file=$(mktemp -u -t tmp.test_"${FUNCNAME[0]}"_tmp_file.XXXXXX)
 
 	# Start application with a temporary file.
-	$TESTAPP_BIN -i $NR_ITER -w $NR_USEC_WAIT --sync-after-first-event $tmp_file &
+	$TESTAPP_BIN -i $NR_ITER -w $NR_USEC_WAIT --sync-after-first-event "$tmp_file" &
 	ret=$?
-	APPS_PID="${APPS_PID} ${!}"
+	APP_PIDS+=(${!})
 	ok $ret "Start application to trace"
 
 	# Wait for the application file to appear indicating that at least one
@@ -61,55 +78,51 @@ function start_test_app()
 		sleep 0.5
 	done
 	diag "Removing test app temporary file $tmp_file"
-	rm -f $tmp_file
+	rm -f "$tmp_file"
 }
 
 function stop_test_apps()
 {
 	diag "Stopping $TESTAPP_NAME"
-	for p in ${APPS_PID}; do
-		kill ${p}
-		wait ${p} 2>/dev/null
-	done
-	APPS_PID=
+	kill "${APP_PIDS[@]}"
+	wait "${APP_PIDS[@]}" 2>/dev/null
+	APP_PIDS=()
 }
 
 # Test a snapshot using a default name for the output destination.
 function test_ust_default_name_with_del()
 {
 	diag "Test UST snapshot streaming with default name with delete output"
-	create_lttng_session_no_output $SESSION_NAME
-	enable_lttng_mmap_overwrite_ust_channel $SESSION_NAME $CHANNEL_NAME
-	enable_ust_lttng_event_ok $SESSION_NAME $EVENT_NAME $CHANNEL_NAME
-	start_lttng_tracing_ok $SESSION_NAME
+	create_lttng_session_no_output "$SESSION_NAME"
+	enable_lttng_mmap_overwrite_ust_channel "$SESSION_NAME" $CHANNEL_NAME
+	enable_ust_lttng_event_ok "$SESSION_NAME" $EVENT_NAME $CHANNEL_NAME
+	start_lttng_tracing_ok "$SESSION_NAME"
 
 	start_test_app
 
-	snapshot_add_output $SESSION_NAME "net://localhost"
-	lttng_snapshot_record $SESSION_NAME
+	snapshot_add_output "$SESSION_NAME" "net://localhost"
+	lttng_snapshot_record "$SESSION_NAME"
 
 	# Validate test
 	validate_trace_path_ust_uid_snapshot_network "$TRACE_PATH" "$SESSION_NAME" "snapshot-1" 0
-	validate_trace $EVENT_NAME $TRACE_PATH/$HOSTNAME/$SESSION_NAME*/snapshot-1*
-	if [ $? -ne 0 ]; then
+	if ! validate_trace $EVENT_NAME "$TRACE_PATH/$HOSTNAME/$SESSION_NAME*/snapshot-1*" ; then
 		stop_test_apps
 		return $?
 	fi
 
-	lttng_snapshot_del_output_ok $SESSION_NAME 1
-	snapshot_add_output $SESSION_NAME "net://localhost"
-	lttng_snapshot_record $SESSION_NAME
+	lttng_snapshot_del_output_ok "$SESSION_NAME" 1
+	snapshot_add_output "$SESSION_NAME" "net://localhost"
+	lttng_snapshot_record "$SESSION_NAME"
 
 	# Validate test with the next ID since a del output was done prior.
 	validate_trace_path_ust_uid_snapshot_network "$TRACE_PATH" "$SESSION_NAME" "snapshot-2" 1
-	validate_trace $EVENT_NAME $TRACE_PATH/$HOSTNAME/$SESSION_NAME*/snapshot-2*
-	if [ $? -ne 0 ]; then
+	if ! validate_trace $EVENT_NAME "$TRACE_PATH/$HOSTNAME/$SESSION_NAME*/snapshot-2*" ; then
 		stop_test_apps
 		return $?
 	fi
 
-	stop_lttng_tracing_ok $SESSION_NAME
-	destroy_lttng_session_ok $SESSION_NAME
+	stop_lttng_tracing_ok "$SESSION_NAME"
+	destroy_lttng_session_ok "$SESSION_NAME"
 
 	stop_test_apps
 
@@ -120,20 +133,20 @@ function test_ust_default_name_with_del()
 function test_ust_default_name()
 {
 	diag "Test UST snapshot streaming with default name"
-	create_lttng_session_no_output $SESSION_NAME
-	enable_lttng_mmap_overwrite_ust_channel $SESSION_NAME $CHANNEL_NAME
-	enable_ust_lttng_event_ok $SESSION_NAME $EVENT_NAME $CHANNEL_NAME
-	start_lttng_tracing_ok $SESSION_NAME
+	create_lttng_session_no_output "$SESSION_NAME"
+	enable_lttng_mmap_overwrite_ust_channel "$SESSION_NAME" $CHANNEL_NAME
+	enable_ust_lttng_event_ok "$SESSION_NAME" $EVENT_NAME $CHANNEL_NAME
+	start_lttng_tracing_ok "$SESSION_NAME"
 
 	start_test_app
 
-	snapshot_add_output $SESSION_NAME "net://localhost"
-	lttng_snapshot_record $SESSION_NAME
-	stop_lttng_tracing_ok $SESSION_NAME
-	destroy_lttng_session_ok $SESSION_NAME
+	snapshot_add_output "$SESSION_NAME" "net://localhost"
+	lttng_snapshot_record "$SESSION_NAME"
+	stop_lttng_tracing_ok "$SESSION_NAME"
+	destroy_lttng_session_ok "$SESSION_NAME"
 	# Validate test
 	validate_trace_path_ust_uid_snapshot_network "$TRACE_PATH" "$SESSION_NAME" "snapshot-1" 0
-	validate_trace $EVENT_NAME $TRACE_PATH/$HOSTNAME/$SESSION_NAME*/snapshot-1*
+	validate_trace $EVENT_NAME "$TRACE_PATH/$HOSTNAME/$SESSION_NAME*/snapshot-1*"
 	out=$?
 
 	stop_test_apps
@@ -144,20 +157,20 @@ function test_ust_default_name()
 function test_ust_default_name_custom_uri()
 {
 	diag "Test UST snapshot streaming with default name with custom URL"
-	create_lttng_session_no_output $SESSION_NAME
-	enable_lttng_mmap_overwrite_ust_channel $SESSION_NAME $CHANNEL_NAME
-	enable_ust_lttng_event_ok $SESSION_NAME $EVENT_NAME $CHANNEL_NAME
-	start_lttng_tracing_ok $SESSION_NAME
+	create_lttng_session_no_output "$SESSION_NAME"
+	enable_lttng_mmap_overwrite_ust_channel "$SESSION_NAME" $CHANNEL_NAME
+	enable_ust_lttng_event_ok "$SESSION_NAME" $EVENT_NAME $CHANNEL_NAME
+	start_lttng_tracing_ok "$SESSION_NAME"
 
 	start_test_app
 
-	snapshot_add_output $SESSION_NAME "-C tcp://localhost:5342 -D tcp://localhost:5343"
-	lttng_snapshot_record $SESSION_NAME
-	stop_lttng_tracing_ok $SESSION_NAME
-	destroy_lttng_session_ok $SESSION_NAME
+	snapshot_add_output "$SESSION_NAME" '' '' -C tcp://localhost:5342 -D tcp://localhost:5343
+	lttng_snapshot_record "$SESSION_NAME"
+	stop_lttng_tracing_ok "$SESSION_NAME"
+	destroy_lttng_session_ok "$SESSION_NAME"
 	# Validate test
 	validate_trace_path_ust_uid_snapshot_network "$TRACE_PATH" "$SESSION_NAME" "snapshot-1" 0
-	validate_trace $EVENT_NAME $TRACE_PATH/$HOSTNAME/$SESSION_NAME*/snapshot-1*
+	validate_trace $EVENT_NAME "$TRACE_PATH/$HOSTNAME/$SESSION_NAME*/snapshot-1*"
 	out=$?
 
 	stop_test_apps
@@ -172,23 +185,23 @@ function test_ust_custom_name()
 	local name="asnapshotname"
 
 	diag "Test UST snapshot streaming with custom name"
-	create_lttng_session_no_output $SESSION_NAME
-	enable_lttng_mmap_overwrite_ust_channel $SESSION_NAME $CHANNEL_NAME
-	enable_ust_lttng_event_ok $SESSION_NAME $EVENT_NAME $CHANNEL_NAME
-	start_lttng_tracing_ok $SESSION_NAME
+	create_lttng_session_no_output "$SESSION_NAME"
+	enable_lttng_mmap_overwrite_ust_channel "$SESSION_NAME" $CHANNEL_NAME
+	enable_ust_lttng_event_ok "$SESSION_NAME" $EVENT_NAME $CHANNEL_NAME
+	start_lttng_tracing_ok "$SESSION_NAME"
 
 	start_test_app
 
-	snapshot_add_output $SESSION_NAME "net://localhost" $name
-	lttng_snapshot_record $SESSION_NAME
-	stop_lttng_tracing_ok $SESSION_NAME
-	destroy_lttng_session_ok $SESSION_NAME
+	snapshot_add_output "$SESSION_NAME" "net://localhost" $name
+	lttng_snapshot_record "$SESSION_NAME"
+	stop_lttng_tracing_ok "$SESSION_NAME"
+	destroy_lttng_session_ok "$SESSION_NAME"
 
-	if ls $TRACE_PATH/$HOSTNAME/$SESSION_NAME*/$name* &> /dev/null; then
+	if ls "$TRACE_PATH/$HOSTNAME/$SESSION_NAME"*/"$name"* &> /dev/null; then
 		ok 0 "Custom name snapshot exists"
 		# Validate test
 		validate_trace_path_ust_uid_snapshot_network "$TRACE_PATH" "$SESSION_NAME" "$name" 0
-		validate_trace $EVENT_NAME $TRACE_PATH/$HOSTNAME/$SESSION_NAME*/$name-*
+		validate_trace $EVENT_NAME "$TRACE_PATH/$HOSTNAME/$SESSION_NAME*/$name-*"
 		out=$?
 	else
 		fail "No custom name snapshot found"
@@ -203,27 +216,26 @@ function test_ust_custom_name()
 function test_ust_n_snapshot()
 {
 	diag "Test ust snapshot streaming multiple consecutive snapshot"
-	create_lttng_session_no_output $SESSION_NAME
-	enable_lttng_mmap_overwrite_ust_channel $SESSION_NAME $CHANNEL_NAME
-	enable_ust_lttng_event_ok $SESSION_NAME $EVENT_NAME $CHANNEL_NAME
-	snapshot_add_output $SESSION_NAME "net://localhost"
+	create_lttng_session_no_output "$SESSION_NAME"
+	enable_lttng_mmap_overwrite_ust_channel "$SESSION_NAME" $CHANNEL_NAME
+	enable_ust_lttng_event_ok "$SESSION_NAME" $EVENT_NAME $CHANNEL_NAME
+	snapshot_add_output "$SESSION_NAME" "net://localhost"
 	start_test_app
 	for i in {0..4};
 	do
-		start_lttng_tracing_ok $SESSION_NAME
-		lttng_snapshot_record $SESSION_NAME
-		stop_lttng_tracing_ok $SESSION_NAME
-		validate_trace_path_ust_uid_snapshot_network "$TRACE_PATH" "$SESSION_NAME" "snapshot-1" $i
-		validate_trace $EVENT_NAME $TRACE_PATH/$HOSTNAME/$SESSION_NAME*/snapshot-1*
-		if [ $? -ne 0 ]; then
+		start_lttng_tracing_ok "$SESSION_NAME"
+		lttng_snapshot_record "$SESSION_NAME"
+		stop_lttng_tracing_ok "$SESSION_NAME"
+		validate_trace_path_ust_uid_snapshot_network "$TRACE_PATH" "$SESSION_NAME" "snapshot-1" "$i"
+		if ! validate_trace $EVENT_NAME "$TRACE_PATH/$HOSTNAME/$SESSION_NAME*/snapshot-1*" ; then
 			return 1
 		fi
 		set -u
-		rm -rf $TRACE_PATH/$HOSTNAME
+		rm -rf "${TRACE_PATH:?}/${HOSTNAME}"
 		set +u
 	done
 
-	destroy_lttng_session_ok $SESSION_NAME
+	destroy_lttng_session_ok "$SESSION_NAME"
 	stop_test_apps
 	return 0
 }
@@ -234,13 +246,8 @@ print_test_banner "$TEST_DESC"
 
 bail_out_if_no_babeltrace
 
-if [ "$(id -u)" == "0" ]; then
-	isroot=1
-else
-	isroot=0
-fi
-
 start_lttng_relayd "-o $TRACE_PATH"
+# shellcheck disable=SC2119
 start_lttng_sessiond
 
 tests=( test_ust_default_name_with_del
@@ -250,17 +257,18 @@ tests=( test_ust_default_name_with_del
 	test_ust_n_snapshot
 )
 
-for fct_test in ${tests[@]};
+for fct_test in "${tests[@]}";
 do
 	SESSION_NAME=$(randstring 16 0)
-	${fct_test}
-	if [ $? -eq 0 ]; then
+	if ${fct_test} ; then
 		# Only delete if successful
-		rm -rf $TRACE_PATH
+		rm -rf "$TRACE_PATH"
 	else
 		break
 	fi
 done
 
+# shellcheck disable=SC2119
 stop_lttng_sessiond
+# shellcheck disable=SC2119
 stop_lttng_relayd
diff --git a/tests/regression/tools/snapshots/ust_test b/tests/regression/tools/snapshots/ust_test
index 9cd5a48c9..5188c2b5b 100755
--- a/tests/regression/tools/snapshots/ust_test
+++ b/tests/regression/tools/snapshots/ust_test
@@ -6,42 +6,44 @@
 
 TEST_DESC="Snapshots - UST tracing"
 
-CURDIR=$(dirname $0)/
-TESTDIR=$CURDIR/../../..
+CURDIR=$(dirname "$0")/
+TESTDIR="$CURDIR/../../.."
 EVENT_NAME="tp:tptest"
 SESSION_NAME=""
 CHANNEL_NAME="snapchan"
 TESTAPP_PATH="$TESTDIR/utils/testapp"
 TESTAPP_NAME="gen-ust-events"
 TESTAPP_BIN="$TESTAPP_PATH/$TESTAPP_NAME/$TESTAPP_NAME"
-APPS_PID=
+APPS_PID=()
 
 NUM_TESTS=104
 
 TRACE_PATH=$(mktemp -d -t tmp.test_snapshots_ust_trace_path.XXXXXX)
 
-source $TESTDIR/utils/utils.sh
+# shellcheck source-path=SCRIPTDIR/../../../
+source "$TESTDIR/utils/utils.sh"
 
 if [ ! -x "$TESTAPP_BIN" ]; then
 	BAIL_OUT "No UST events binary detected"
 fi
 
 # Need the number of snapshot to do.
-if [ -z $1 ]; then
+if [ -z "$1" ]; then
 	BAIL_OUT "A number of snapshot is needed"
 fi
 NR_SNAPSHOT=$1
 
-NUM_TESTS=$(($NUM_TESTS + ($NR_SNAPSHOT * 3)))
+NUM_TESTS=$((NUM_TESTS + (NR_SNAPSHOT * 3)))
 
 function start_test_app()
 {
-	local tmp_file=$(mktemp -u -t "tmp.${FUNCNAME[0]}_tmp_file.XXXXXX")
+	local tmp_file
+	tmp_file=$(mktemp -u -t "tmp.${FUNCNAME[0]}_tmp_file.XXXXXX")
 
 	# Start application with a temporary file.
-	$TESTAPP_BIN -i $NR_ITER -w $NR_USEC_WAIT --sync-after-first-event $tmp_file &
+	$TESTAPP_BIN -i "$NR_ITER" -w "$NR_USEC_WAIT" --sync-after-first-event "$tmp_file" &
 	ret=$?
-	APPS_PID="${APPS_PID} ${!}"
+	APPS_PID+=(${!})
 	ok $ret "Start application to trace"
 
 	# Wait for the application file to appear indicating that at least one
@@ -50,25 +52,21 @@ function start_test_app()
 		sleep 0.5
 	done
 	diag "Removing test app temporary file $tmp_file"
-	rm -f $tmp_file
+	rm -f "$tmp_file"
 }
 
 function wait_test_apps()
 {
 	diag "Waiting for $TESTAPP_NAME"
-	for p in ${APPS_PID}; do
-		wait ${p} 2>/dev/null
-	done
+	wait "${APPS_PID[@]}" 2>/dev/null
 }
 
 function stop_test_apps()
 {
 	diag "Stopping $TESTAPP_NAME"
-	for p in ${APPS_PID}; do
-		kill ${p}
-		wait ${p} 2>/dev/null
-	done
-	APPS_PID=
+	kill "${APPS_PID[@]}"
+	wait "${APPS_PID[@]}"
+	APPS_PID=()
 }
 
 function snapshot_add_output ()
@@ -77,20 +75,20 @@ function snapshot_add_output ()
 	local trace_path=$2
 	local name=$3
 	local max_size=$4
-	local extra_opt=""
+	local extra_opt=()
 
-	if [ ! -z $name ]; then
-		extra_opt+=" -n $name "
+	if [ -n "$name" ]; then
+		extra_opt+=(-n "$name")
 	fi
 
-	if [ ! -z $max_size ]; then
-		extra_opt+=" -m $max_size "
+	if [ -n "$max_size" ]; then
+		extra_opt+=(-m "$max_size")
 	fi
 
-	$TESTDIR/../src/bin/lttng/$LTTNG_BIN snapshot add-output \
-		-s $sess_name $extra_opt $trace_path > /dev/null 2>&1
+	"$TESTDIR/../src/bin/lttng/$LTTNG_BIN" snapshot add-output \
+		-s "$sess_name" "${extra_opt[@]}" "$trace_path" > /dev/null 2>&1
 
-	ok $? "Added snapshot output $trace_path ($extra_opt)"
+	ok $? "Added snapshot output $trace_path (${extra_opt[*]})"
 }
 
 function snapshot_del_output ()
@@ -98,8 +96,8 @@ function snapshot_del_output ()
 	local sess_name=$1
 	local name=$2
 
-	$TESTDIR/../src/bin/lttng/$LTTNG_BIN snapshot del-output \
-		-s $sess_name $name > /dev/null 2>&1
+	"$TESTDIR/../src/bin/lttng/$LTTNG_BIN" snapshot del-output \
+		-s "$sess_name" "$name" > /dev/null 2>&1
 
 	ok $? "Deleted snapshot output named $name"
 }
@@ -111,10 +109,10 @@ function enable_mmap_overwrite_subbuf_ust_channel ()
 	local subbuf_size=$3
 	local subbuf_count=$4
 
-	$TESTDIR/../src/bin/lttng/$LTTNG_BIN enable-channel -s $sess_name \
-		$chan_name -u --output mmap --overwrite \
-		--num-subbuf=$subbuf_count \
-		--subbuf-size $subbuf_size > /dev/null 2>&1
+	"$TESTDIR/../src/bin/lttng/$LTTNG_BIN" enable-channel -s "$sess_name" \
+		"$chan_name" -u --output mmap --overwrite \
+		--num-subbuf="$subbuf_count" \
+		--subbuf-size "$subbuf_size" > /dev/null 2>&1
 
 	ok $? "Enable channel $channel_name for session $sess_name with subbuf size $subbuf_size"
 }
@@ -124,9 +122,9 @@ function enable_mmap_small_discard_ust_channel ()
 	local sess_name=$1
 	local chan_name=$2
 
-	$TESTDIR/../src/bin/lttng/$LTTNG_BIN enable-channel -s $sess_name \
-		$chan_name -u --output mmap --discard \
-		--subbuf-size $(getconf PAGE_SIZE) --num-subbuf 2 \
+	"$TESTDIR/../src/bin/lttng/$LTTNG_BIN" enable-channel -s "$sess_name" \
+		"$chan_name" -u --output mmap --discard \
+		--subbuf-size "$(getconf PAGE_SIZE)" --num-subbuf 2 \
 		> /dev/null 2>&1
 
 	ok $? "Enable channel $channel_name for session $sess_name with small discard buffers"
@@ -137,9 +135,9 @@ function enable_mmap_small_overwrite_ust_channel ()
 	local sess_name=$1
 	local chan_name=$2
 
-	$TESTDIR/../src/bin/lttng/$LTTNG_BIN enable-channel -s $sess_name \
-		$chan_name -u --output mmap --overwrite \
-		--subbuf-size $(getconf PAGE_SIZE) --num-subbuf 2 \
+	"$TESTDIR/../src/bin/lttng/$LTTNG_BIN" enable-channel -s "$sess_name" \
+		"$chan_name" -u --output mmap --overwrite \
+		--subbuf-size "$(getconf PAGE_SIZE)" --num-subbuf 2 \
 		> /dev/null 2>&1
 
 	ok $? "Enable channel $channel_name for session $sess_name with small discard buffers"
@@ -150,29 +148,29 @@ function test_ust_list_output ()
 	output_names=("randomname" "somesnapshot")
 
 	diag "Test UST snapshot output listing"
-	create_lttng_session_no_output $SESSION_NAME
-	enable_lttng_mmap_overwrite_ust_channel $SESSION_NAME $CHANNEL_NAME
-	enable_ust_lttng_event_ok $SESSION_NAME $EVENT_NAME $CHANNEL_NAME
+	create_lttng_session_no_output "$SESSION_NAME"
+	enable_lttng_mmap_overwrite_ust_channel "$SESSION_NAME" $CHANNEL_NAME
+	enable_ust_lttng_event_ok "$SESSION_NAME" $EVENT_NAME $CHANNEL_NAME
 
-	start_lttng_tracing_ok $SESSION_NAME
+	start_lttng_tracing_ok "$SESSION_NAME"
 
-	snapshot_add_output $SESSION_NAME "file://$TRACE_PATH" ${output_names[0]}
+	snapshot_add_output "$SESSION_NAME" "file://$TRACE_PATH" "${output_names[0]}"
 
-	$TESTDIR/../src/bin/lttng/$LTTNG_BIN snapshot list-output \
-		-s $SESSION_NAME 2>&1 | grep ${output_names[0]} > /dev/null
+	"$TESTDIR/../src/bin/lttng/$LTTNG_BIN" snapshot list-output \
+		-s "$SESSION_NAME" 2>&1 | grep "${output_names[0]}" > /dev/null
 	ok $? "Snapshot named ${output_names[0]} present in list-output listing"
 
-	snapshot_del_output $SESSION_NAME ${output_names[0]}
+	snapshot_del_output "$SESSION_NAME" "${output_names[0]}"
 
-	snapshot_add_output $SESSION_NAME "file://$TRACE_PATH" ${output_names[1]}
+	snapshot_add_output "$SESSION_NAME" "file://$TRACE_PATH" "${output_names[1]}"
 
-	$TESTDIR/../src/bin/lttng/$LTTNG_BIN snapshot list-output \
-		-s $SESSION_NAME 2>&1 | grep ${output_names[1]} > /dev/null
+	"$TESTDIR/../src/bin/lttng/$LTTNG_BIN" snapshot list-output \
+		-s "$SESSION_NAME" 2>&1 | grep "${output_names[1]}" > /dev/null
 
 	ok $? "Snapshot named ${output_names[1]} present in list-output listing"
 
-	stop_lttng_tracing_ok $SESSION_NAME
-	destroy_lttng_session_ok $SESSION_NAME
+	stop_lttng_tracing_ok "$SESSION_NAME"
+	destroy_lttng_session_ok "$SESSION_NAME"
 }
 
 function test_ust_local_snapshot ()
@@ -181,25 +179,24 @@ function test_ust_local_snapshot ()
 	NR_USEC_WAIT=100
 
 	diag "Test local UST snapshots"
-	create_lttng_session_no_output $SESSION_NAME
-	enable_lttng_mmap_overwrite_ust_channel $SESSION_NAME $CHANNEL_NAME
-	enable_ust_lttng_event_ok $SESSION_NAME $EVENT_NAME $CHANNEL_NAME
-	start_lttng_tracing_ok $SESSION_NAME
-	lttng_snapshot_add_output_ok $SESSION_NAME file://$TRACE_PATH
+	create_lttng_session_no_output "$SESSION_NAME"
+	enable_lttng_mmap_overwrite_ust_channel "$SESSION_NAME" $CHANNEL_NAME
+	enable_ust_lttng_event_ok "$SESSION_NAME" $EVENT_NAME $CHANNEL_NAME
+	start_lttng_tracing_ok "$SESSION_NAME"
+	lttng_snapshot_add_output_ok "$SESSION_NAME" "file://$TRACE_PATH"
 
 	# Returns once the application has at least fired ONE tracepoint.
 	start_test_app
 
-	lttng_snapshot_record $SESSION_NAME
-	stop_lttng_tracing_ok $SESSION_NAME
-	destroy_lttng_session_ok $SESSION_NAME
+	lttng_snapshot_record "$SESSION_NAME"
+	stop_lttng_tracing_ok "$SESSION_NAME"
+	destroy_lttng_session_ok "$SESSION_NAME"
 
 	# Validate test
 	validate_trace_path_ust_uid_snapshot "$TRACE_PATH" "" "snapshot-1" 0
-	validate_trace $EVENT_NAME $TRACE_PATH/
-	if [ $? -eq 0 ]; then
+	if validate_trace $EVENT_NAME "$TRACE_PATH/" ; then
 		# Only delete if successful
-		rm -rf $TRACE_PATH
+		rm -rf "$TRACE_PATH"
 	fi
 
 	stop_test_apps
@@ -213,31 +210,31 @@ function test_ust_local_snapshot_small_discard_buffers ()
 
 	diag "Test local UST snapshots with small discard buffers"
 	taskset -c "$(get_any_available_cpu)" -p $$ 1>/dev/null 2>&1
-	create_lttng_session_no_output $SESSION_NAME
-	enable_mmap_small_discard_ust_channel $SESSION_NAME $CHANNEL_NAME
-	enable_ust_lttng_event_ok $SESSION_NAME $EVENT_NAME $CHANNEL_NAME
-	start_lttng_tracing_ok $SESSION_NAME
-	lttng_snapshot_add_output_ok $SESSION_NAME file://$TRACE_PATH
+	create_lttng_session_no_output "$SESSION_NAME"
+	enable_mmap_small_discard_ust_channel "$SESSION_NAME" $CHANNEL_NAME
+	enable_ust_lttng_event_ok "$SESSION_NAME" $EVENT_NAME $CHANNEL_NAME
+	start_lttng_tracing_ok "$SESSION_NAME"
+	lttng_snapshot_add_output_ok "$SESSION_NAME" "file://$TRACE_PATH"
 
 	# Run test apps, wait for them to complete.
 	start_test_app
 	wait_test_apps
 
 	# Take first snapshot, remember first line.
-	lttng_snapshot_record $SESSION_NAME
-	FIRST_LINE="$(trace_first_line $TRACE_PATH/)"
+	lttng_snapshot_record "$SESSION_NAME"
+	FIRST_LINE="$(trace_first_line "$TRACE_PATH/")"
 	diag "First line (1st snapshot): $FIRST_LINE"
-	rm -rf $TRACE_PATH/
+	rm -rf "${TRACE_PATH:?}/"
 
 	# Run test apps, wait for them to complete.
 	start_test_app
 	wait_test_apps
 
 	# Take second snapshot, remember first line.
-	lttng_snapshot_record $SESSION_NAME
-	FIRST_LINE_2="$(trace_first_line $TRACE_PATH/)"
+	lttng_snapshot_record "$SESSION_NAME"
+	FIRST_LINE_2="$(trace_first_line "$TRACE_PATH/")"
 	diag "First line (2nd snapshot): $FIRST_LINE_2"
-	rm -rf $TRACE_PATH/
+	rm -rf "${TRACE_PATH:?}/"
 
 	if [ x"$FIRST_LINE" != x"$FIRST_LINE_2" ]; then
 		fail "First snapshot event do not match"
@@ -245,9 +242,9 @@ function test_ust_local_snapshot_small_discard_buffers ()
 		pass "First snapshot event match"
 	fi
 
-	stop_lttng_tracing_ok $SESSION_NAME
-	destroy_lttng_session_ok $SESSION_NAME
-	taskset -p $OLDCPUSET $$ 1>/dev/null 2>&1
+	stop_lttng_tracing_ok "$SESSION_NAME"
+	destroy_lttng_session_ok "$SESSION_NAME"
+	taskset -p "$OLDCPUSET" $$ 1>/dev/null 2>&1
 }
 
 function test_ust_local_snapshot_small_overwrite_buffers ()
@@ -258,31 +255,31 @@ function test_ust_local_snapshot_small_overwrite_buffers ()
 
 	diag "Test local UST snapshots with small overwrite buffers"
 	taskset -p "$(get_any_available_cpu)" $$ 1>/dev/null 2>&1
-	create_lttng_session_no_output $SESSION_NAME
-	enable_mmap_small_overwrite_ust_channel $SESSION_NAME $CHANNEL_NAME
-	enable_ust_lttng_event_ok $SESSION_NAME $EVENT_NAME $CHANNEL_NAME
-	start_lttng_tracing_ok $SESSION_NAME
-	lttng_snapshot_add_output_ok $SESSION_NAME file://$TRACE_PATH
+	create_lttng_session_no_output "$SESSION_NAME"
+	enable_mmap_small_overwrite_ust_channel "$SESSION_NAME" $CHANNEL_NAME
+	enable_ust_lttng_event_ok "$SESSION_NAME" $EVENT_NAME $CHANNEL_NAME
+	start_lttng_tracing_ok "$SESSION_NAME"
+	lttng_snapshot_add_output_ok "$SESSION_NAME" "file://$TRACE_PATH"
 
 	# Run test apps, wait for them to complete.
 	start_test_app
 	wait_test_apps
 
 	# Take first snapshot, remember first line.
-	lttng_snapshot_record $SESSION_NAME
-	FIRST_LINE="$(trace_first_line $TRACE_PATH/)"
+	lttng_snapshot_record "$SESSION_NAME"
+	FIRST_LINE="$(trace_first_line "$TRACE_PATH/")"
 	diag "First line (1st snapshot): $FIRST_LINE"
-	rm -rf $TRACE_PATH/
+	rm -rf "${TRACE_PATH:?}/"
 
 	# Run test apps, wait for them to complete.
 	start_test_app
 	wait_test_apps
 
 	# Take second snapshot, remember first line.
-	lttng_snapshot_record $SESSION_NAME
-	FIRST_LINE_2="$(trace_first_line $TRACE_PATH/)"
+	lttng_snapshot_record "$SESSION_NAME"
+	FIRST_LINE_2="$(trace_first_line "$TRACE_PATH/")"
 	diag "First line (2nd snapshot): $FIRST_LINE_2"
-	rm -rf $TRACE_PATH/
+	rm -rf "${TRACE_PATH:?}/"
 
 	if [ x"$FIRST_LINE" != x"$FIRST_LINE_2" ]; then
 		pass "First snapshot event do not match"
@@ -290,9 +287,9 @@ function test_ust_local_snapshot_small_overwrite_buffers ()
 		fail "First snapshot event match"
 	fi
 
-	stop_lttng_tracing_ok $SESSION_NAME
-	destroy_lttng_session_ok $SESSION_NAME
-	taskset -p $OLDCPUSET $$ 1>/dev/null 2>&1
+	stop_lttng_tracing_ok "$SESSION_NAME"
+	destroy_lttng_session_ok "$SESSION_NAME"
+	taskset -p "$OLDCPUSET" $$ 1>/dev/null 2>&1
 }
 
 function test_ust_local_snapshot_max_size ()
@@ -371,23 +368,22 @@ function test_ust_local_snapshot_large_metadata ()
 	LM_BIN="$LM_PATH/$LM_NAME/$LM_NAME"
 
 	diag "Test local UST snapshots with > 4kB metadata"
-	create_lttng_session_no_output $SESSION_NAME
-	enable_lttng_mmap_overwrite_ust_channel $SESSION_NAME $CHANNEL_NAME
-	enable_ust_lttng_event_ok $SESSION_NAME $LM_EVENT $CHANNEL_NAME
-	start_lttng_tracing_ok $SESSION_NAME
-	lttng_snapshot_add_output_ok $SESSION_NAME file://$TRACE_PATH
+	create_lttng_session_no_output "$SESSION_NAME"
+	enable_lttng_mmap_overwrite_ust_channel "$SESSION_NAME" $CHANNEL_NAME
+	enable_ust_lttng_event_ok "$SESSION_NAME" $LM_EVENT $CHANNEL_NAME
+	start_lttng_tracing_ok "$SESSION_NAME"
+	lttng_snapshot_add_output_ok "$SESSION_NAME" "file://$TRACE_PATH"
 	$LM_BIN --iter 1 --wait 1
 	ok $? "Start application to trace"
-	lttng_snapshot_record $SESSION_NAME
-	stop_lttng_tracing_ok $SESSION_NAME
-	destroy_lttng_session_ok $SESSION_NAME
+	lttng_snapshot_record "$SESSION_NAME"
+	stop_lttng_tracing_ok "$SESSION_NAME"
+	destroy_lttng_session_ok "$SESSION_NAME"
 
 	# Validate test
 	validate_trace_path_ust_uid_snapshot "$TRACE_PATH" "" "snapshot-1" 0
-	validate_trace $LM_EVENT $TRACE_PATH/
-	if [ $? -eq 0 ]; then
+	if validate_trace $LM_EVENT "$TRACE_PATH/" ; then
 		# Only delete if successful
-		rm -rf $TRACE_PATH
+		rm -rf "${TRACE_PATH:?}/"
 	fi
 }
 
@@ -396,7 +392,7 @@ function enable_channel_per_uid_mmap_overwrite()
 	sess_name=$1
 	channel_name=$2
 
-	$TESTDIR/../src/bin/lttng/$LTTNG_BIN enable-channel --buffers-uid -u $channel_name -s $sess_name --output mmap --overwrite >/dev/null 2>&1
+	"$TESTDIR/../src/bin/lttng/$LTTNG_BIN" enable-channel --buffers-uid -u "$channel_name" -s "$sess_name" --output mmap --overwrite >/dev/null 2>&1
 	ok $? "Enable channel $channel_name per UID for session $sess_name"
 }
 
@@ -405,25 +401,24 @@ function test_ust_per_uid_local_snapshot ()
 	NR_ITER=-1
 	NR_USEC_WAIT=100
 	diag "Test per-uid local UST snapshots"
-	create_lttng_session_no_output $SESSION_NAME
-	enable_channel_per_uid_mmap_overwrite $SESSION_NAME $CHANNEL_NAME
-	enable_ust_lttng_event_ok $SESSION_NAME $EVENT_NAME $CHANNEL_NAME
-	start_lttng_tracing_ok $SESSION_NAME
-	lttng_snapshot_add_output_ok $SESSION_NAME file://$TRACE_PATH
+	create_lttng_session_no_output "$SESSION_NAME"
+	enable_channel_per_uid_mmap_overwrite "$SESSION_NAME" $CHANNEL_NAME
+	enable_ust_lttng_event_ok "$SESSION_NAME" $EVENT_NAME $CHANNEL_NAME
+	start_lttng_tracing_ok "$SESSION_NAME"
+	lttng_snapshot_add_output_ok "$SESSION_NAME" "file://$TRACE_PATH"
 
 	# Returns once the application has at least fired ONE tracepoint.
 	start_test_app
 
-	lttng_snapshot_record $SESSION_NAME
-	stop_lttng_tracing_ok $SESSION_NAME
-	destroy_lttng_session_ok $SESSION_NAME
+	lttng_snapshot_record "$SESSION_NAME"
+	stop_lttng_tracing_ok "$SESSION_NAME"
+	destroy_lttng_session_ok "$SESSION_NAME"
 
 	# Validate test
 	validate_trace_path_ust_uid_snapshot "$TRACE_PATH" "" "snapshot-1" 0
-	validate_trace $EVENT_NAME $TRACE_PATH/
-	if [ $? -eq 0 ]; then
+	if validate_trace $EVENT_NAME "$TRACE_PATH/" ; then
 		# Only delete if successful
-		rm -rf $TRACE_PATH
+		rm -rf "${TRACE_PATH:?}/"
 	fi
 
 	stop_test_apps
@@ -435,26 +430,25 @@ function test_ust_per_uid_local_snapshot_post_mortem ()
 	NR_USEC_WAIT=100
 
 	diag "Test local UST snapshots post-mortem"
-	create_lttng_session_no_output $SESSION_NAME
-	enable_channel_per_uid_mmap_overwrite $SESSION_NAME $CHANNEL_NAME
-	enable_ust_lttng_event_ok $SESSION_NAME $EVENT_NAME $CHANNEL_NAME
-	start_lttng_tracing_ok $SESSION_NAME
-	lttng_snapshot_add_output_ok $SESSION_NAME file://$TRACE_PATH
+	create_lttng_session_no_output "$SESSION_NAME"
+	enable_channel_per_uid_mmap_overwrite "$SESSION_NAME" $CHANNEL_NAME
+	enable_ust_lttng_event_ok "$SESSION_NAME" $EVENT_NAME $CHANNEL_NAME
+	start_lttng_tracing_ok "$SESSION_NAME"
+	lttng_snapshot_add_output_ok "$SESSION_NAME" "file://$TRACE_PATH"
 
 	# Returns once the application has at least fired ONE tracepoint.
 	start_test_app
 	stop_test_apps
 
-	lttng_snapshot_record $SESSION_NAME
-	stop_lttng_tracing_ok $SESSION_NAME
-	destroy_lttng_session_ok $SESSION_NAME
+	lttng_snapshot_record "$SESSION_NAME"
+	stop_lttng_tracing_ok "$SESSION_NAME"
+	destroy_lttng_session_ok "$SESSION_NAME"
 
 	# Validate test
 	validate_trace_path_ust_uid_snapshot "$TRACE_PATH" "" "snapshot-1" 0
-	validate_trace $EVENT_NAME $TRACE_PATH/
-	if [ $? -eq 0 ]; then
+	if validate_trace $EVENT_NAME "$TRACE_PATH/" ; then
 		# Only delete if successful
-		rm -rf $TRACE_PATH
+		rm -rf "${TRACE_PATH:?}/"
 	fi
 }
 
@@ -464,29 +458,28 @@ function test_ust_local_snapshots ()
 	NR_USEC_WAIT=100
 
 	diag "Test $NR_SNAPSHOT local UST snapshots"
-	create_lttng_session_no_output $SESSION_NAME
-	enable_lttng_mmap_overwrite_ust_channel $SESSION_NAME $CHANNEL_NAME
-	enable_ust_lttng_event_ok $SESSION_NAME $EVENT_NAME $CHANNEL_NAME
-	start_lttng_tracing_ok $SESSION_NAME
-	lttng_snapshot_add_output_ok $SESSION_NAME file://$TRACE_PATH
+	create_lttng_session_no_output "$SESSION_NAME"
+	enable_lttng_mmap_overwrite_ust_channel "$SESSION_NAME" $CHANNEL_NAME
+	enable_ust_lttng_event_ok "$SESSION_NAME" $EVENT_NAME $CHANNEL_NAME
+	start_lttng_tracing_ok "$SESSION_NAME"
+	lttng_snapshot_add_output_ok "$SESSION_NAME" "file://$TRACE_PATH"
 
 	# Returns once the application has at least fired ONE tracepoint.
 	start_test_app
 
-	for i in $(seq 1 $NR_SNAPSHOT); do
+	for i in $(seq 1 "$NR_SNAPSHOT"); do
 		diag "Snapshot $i/$NR_SNAPSHOT"
-		rm -rf $TRACE_PATH/snapshot/* 2>/dev/null
-		lttng_snapshot_record $SESSION_NAME
+		rm -rf "$TRACE_PATH/snapshot/*" 2>/dev/null
+		lttng_snapshot_record "$SESSION_NAME"
 		# Validate test
 		validate_trace_path_ust_uid_snapshot "$TRACE_PATH" "" "snapshot-1" $((i - 1))
-		validate_trace $EVENT_NAME $TRACE_PATH/
-		if [ $? -eq 0 ]; then
+		if validate_trace $EVENT_NAME "$TRACE_PATH/" ; then
 			# Only delete if successful
-			rm -rf $TRACE_PATH
+			rm -rf "${TRACE_PATH:?}/"
 		fi
 	done
-	stop_lttng_tracing_ok $SESSION_NAME
-	destroy_lttng_session_ok $SESSION_NAME
+	stop_lttng_tracing_ok "$SESSION_NAME"
+	destroy_lttng_session_ok "$SESSION_NAME"
 
 	stop_test_apps
 }
@@ -497,6 +490,7 @@ print_test_banner "$TEST_DESC"
 
 bail_out_if_no_babeltrace
 
+# shellcheck disable=SC2119
 start_lttng_sessiond
 tests=( test_ust_list_output
 	test_ust_local_snapshot
@@ -509,10 +503,11 @@ tests=( test_ust_list_output
 	test_ust_local_snapshot_small_overwrite_buffers
 )
 
-for fct_test in ${tests[@]};
+for fct_test in "${tests[@]}";
 do
 	SESSION_NAME=$(randstring 16 0)
 	${fct_test}
 done
 
+# shellcheck disable=SC2119
 stop_lttng_sessiond
diff --git a/tests/regression/ust/nprocesses/test_nprocesses b/tests/regression/ust/nprocesses/test_nprocesses
index 5e16164e5..cd897d42b 100755
--- a/tests/regression/ust/nprocesses/test_nprocesses
+++ b/tests/regression/ust/nprocesses/test_nprocesses
@@ -7,20 +7,20 @@
 NUM_PROCESS=30
 TEST_DESC="UST tracer - Generate $NUM_PROCESS process"
 
-CURDIR=$(dirname $0)/
+CURDIR=$(dirname "$0")/
 TESTDIR=$CURDIR/../../..
-NR_ITER=-1	# infinite loop
+NR_ITER=-1 # infinite loop
 NR_USEC_WAIT=1000000
 TESTAPP_PATH="$TESTDIR/utils/testapp"
 TESTAPP_NAME="gen-ust-events"
 TESTAPP_BIN="$TESTAPP_PATH/$TESTAPP_NAME/$TESTAPP_NAME"
 SESSION_NAME="ust-nprocesses"
 EVENT_NAME="tp:tptest"
-TEST_WAIT_SEC=5
 NUM_TESTS=9
-APPS_PID=
+APP_PIDS=()
 
-source $TESTDIR/utils/utils.sh
+# shellcheck source-path=SCRIPTDIR/../../../
+source "${TESTDIR}/utils/utils.sh"
 
 if [ ! -x "$TESTAPP_BIN" ]; then
 	BAIL_OUT "No UST $TESTAPP_BIN binary detected."
@@ -32,6 +32,7 @@ plan_tests $NUM_TESTS
 
 print_test_banner "$TEST_DESC"
 
+# shellcheck disable=SC2119
 start_lttng_sessiond
 
 # Start tests. Each is an infinite tracing loop.
@@ -40,32 +41,33 @@ file_sync_after_first=$(mktemp -u -t tmp.test_nprocesses_sync_after_first.XXXXXX
 file_sync_before_last=$(mktemp -u -t tmp.test_nprocesses_sync_before_last.XXXXXX)
 
 diag "Starting $NUM_PROCESS test applications"
-for i in `seq 1 $NUM_PROCESS`
+# shellcheck disable=SC2034
+for i in $(seq 1 $NUM_PROCESS)
 do
 	$TESTAPP_BIN -i $NR_ITER -w $NR_USEC_WAIT \
-		--sync-after-first-event ${file_sync_after_first} \
-		--sync-before-last-event ${file_sync_before_last} >/dev/null 2>&1 &
-	APPS_PID="${APPS_PID} ${!}"
+		--sync-after-first-event "${file_sync_after_first}" \
+		--sync-before-last-event "${file_sync_before_last}" >/dev/null 2>&1 &
+	APP_PIDS+=(${!})
 done
 
 diag "Waiting for applications to be registered to sessiond"
 
 reg_app_count=0
 while [ $reg_app_count -ne $NUM_PROCESS ]; do
-	listing=$($TESTDIR/../src/bin/lttng/$LTTNG_BIN list -u)
-	reg_app_count=$(echo -n $listing | sed "s#$TESTAPP_BIN#$TESTAPP_BIN\n#g" | grep "$TESTAPP_BIN" | wc -l)
+	listing=$("${TESTDIR}/../src/bin/lttng/${LTTNG_BIN}" list -u)
+	reg_app_count=$(echo -n "${listing}" | sed "s#$TESTAPP_BIN#$TESTAPP_BIN\n#g" | grep -c "$TESTAPP_BIN")
 done
 
 pass "All applications are registered to sessiond"
 
 TRACE_PATH=$(mktemp -d -t tmp.test_nprocesses_trace_path.XXXXXX)
 
-create_lttng_session_ok $SESSION_NAME $TRACE_PATH
+create_lttng_session_ok $SESSION_NAME "${TRACE_PATH}"
 
 enable_ust_lttng_event_ok $SESSION_NAME $EVENT_NAME
 start_lttng_tracing_ok $SESSION_NAME
 
-touch ${file_sync_before_last}
+touch "${file_sync_before_last}"
 
 # We don't validate whether the applications have traced here, rather
 # just that they registered to sessiond (above).
@@ -75,17 +77,16 @@ destroy_lttng_session_ok $SESSION_NAME
 
 #TODO: add trace validation.
 
-rm -rf $TRACE_PATH
+rm -rf "${TRACE_PATH}"
 
 diag "Stopping all spawned applications"
-for p in ${APPS_PID}; do
-	kill ${p}
-	wait ${p} 2>/dev/null
-done
-APPS_PID=
+kill "${APP_PIDS[@]}"
+wait "${APP_PIDS[@]}" 2>/dev/null
+APP_PIDS=()
 pass "Stopped all spawned applications"
 
-rm -f ${file_sync_after_first}
-rm -f ${file_sync_before_last}
+rm -f "${file_sync_after_first}"
+rm -f "${file_sync_before_last}"
 
+# shellcheck disable=SC2119
 stop_lttng_sessiond
diff --git a/tests/regression/ust/periodical-metadata-flush/test_periodical_metadata_flush b/tests/regression/ust/periodical-metadata-flush/test_periodical_metadata_flush
index 56c23ff40..f1132c2e4 100755
--- a/tests/regression/ust/periodical-metadata-flush/test_periodical_metadata_flush
+++ b/tests/regression/ust/periodical-metadata-flush/test_periodical_metadata_flush
@@ -6,8 +6,8 @@
 
 TEST_DESC="UST tracer - Tracing with per UID buffers and periodical flush"
 
-CURDIR=$(dirname $0)/
-TESTDIR=$CURDIR/../../..
+CURDIR=$(dirname "$0")/
+TESTDIR="$CURDIR/../../.."
 NR_ITER=100
 NR_USEC_WAIT=100000
 TESTAPP_PATH="$TESTDIR/utils/testapp"
@@ -15,12 +15,12 @@ TESTAPP_NAME="gen-ust-events"
 TESTAPP_BIN="$TESTAPP_PATH/$TESTAPP_NAME/$TESTAPP_NAME"
 SESSION_NAME="periodical-flush"
 EVENT_NAME="tp:tptest"
-BIN_NAME="gen-nevents"
 NUM_TESTS=38
 APP_TMP_FILE=$(mktemp -u -t tmp.test_periodical_metadata_flush_ust_app_tmp_file.XXXXXX)
-APPS_PID=
+APP_PIDS=()
 
-source $TESTDIR/utils/utils.sh
+# shellcheck source-path=SCRIPTDIR/../../../
+source "$TESTDIR/utils/utils.sh"
 
 if [ ! -x "$TESTAPP_BIN" ]; then
 	BAIL_OUT "No UST events binary detected."
@@ -33,7 +33,7 @@ function enable_channel_per_uid()
 	local sess_name=$1
 	local channel_name=$2
 
-	$TESTDIR/../src/bin/lttng/$LTTNG_BIN enable-channel --buffers-uid -u $channel_name -s $sess_name --switch-timer 100000 >/dev/null 2>&1
+	"$TESTDIR/../src/bin/lttng/$LTTNG_BIN" enable-channel --buffers-uid -u "$channel_name" -s "$sess_name" --switch-timer 100000 >/dev/null 2>&1
 	ok $? "Enable channel $channel_name per UID for session $sess_name"
 }
 
@@ -42,7 +42,7 @@ function enable_channel_per_pid()
 	local sess_name=$1
 	local channel_name=$2
 
-	$TESTDIR/../src/bin/lttng/$LTTNG_BIN enable-channel --buffers-pid -u $channel_name -s $sess_name --switch-timer 100000 >/dev/null 2>&1
+	"$TESTDIR/../src/bin/lttng/$LTTNG_BIN" enable-channel --buffers-pid -u "$channel_name" -s "$sess_name" --switch-timer 100000 >/dev/null 2>&1
 	ok $? "Enable channel $channel_name per UID for session $sess_name"
 }
 
@@ -51,7 +51,7 @@ function enable_metadata_per_uid()
 	local sess_name=$1
 	local channel_name="metadata"
 
-	$TESTDIR/../src/bin/lttng/$LTTNG_BIN enable-channel --buffers-uid -u $channel_name -s $sess_name --switch-timer 200000 >/dev/null 2>&1
+	"$TESTDIR/../src/bin/lttng/$LTTNG_BIN" enable-channel --buffers-uid -u "$channel_name" -s "$sess_name" --switch-timer 200000  2>&1
 	ok $? "Enable channel $channel_name per UID for session $sess_name"
 }
 
@@ -60,7 +60,7 @@ function enable_metadata_per_pid()
 	local sess_name=$1
 	local channel_name="metadata"
 
-	$TESTDIR/../src/bin/lttng/$LTTNG_BIN enable-channel --buffers-pid -u $channel_name -s $sess_name --switch-timer 200000 >/dev/null 2>&1
+	"$TESTDIR/../src/bin/lttng/$LTTNG_BIN" enable-channel --buffers-pid -u "$channel_name" -s "$sess_name" --switch-timer 200000 >/dev/null 2>&1
 	ok $? "Enable channel $channel_name per PID for session $sess_name"
 }
 
@@ -68,8 +68,8 @@ function validate_trace()
 {
 	local out
 
-	out=$("$BABELTRACE_BIN" $TRACE_PATH | grep $EVENT_NAME | wc -l)
-	if [ $out -eq 0 ]; then
+	out=$("$BABELTRACE_BIN" "$TRACE_PATH" | grep -c $EVENT_NAME)
+	if [ "$out" -eq 0 ]; then
 		fail "Trace validation"
 		diag "No event(s) found. We are supposed to have at least one."
 		out=1
@@ -90,15 +90,15 @@ function check_app_tmp_file()
 		sleep 0.5
 	done
 	diag "Removing test app temporary file $APP_TMP_FILE"
-	rm -f $APP_TMP_FILE
+	rm -f "$APP_TMP_FILE"
 }
 
 function start_trace_app()
 {
 	# Start application with a temporary file.
-	$TESTAPP_BIN -i $NR_ITER -w $NR_USEC_WAIT --sync-after-first-event $APP_TMP_FILE &
+	$TESTAPP_BIN -i $NR_ITER -w $NR_USEC_WAIT --sync-after-first-event "$APP_TMP_FILE" &
 	ret=$?
-	APPS_PID="${APPS_PID} ${!}"
+	APP_PIDS+=(${!})
 	ok $ret "Start application to trace"
 }
 
@@ -111,20 +111,18 @@ function start_check_trace_app()
 
 function wait_trace_apps()
 {
-	for p in ${APPS_PID}; do
-		wait ${p} 2>/dev/null
-	done
-	APPS_PID=
+	wait "${APP_PIDS[@]}" 2> /dev/null
+	APP_PIDS=()
 }
 
 test_after_app_pid() {
 	local out
 
-	APPS_PID=
+	APP_PIDS=()
 
 	diag "Start application AFTER tracing is started"
 
-	create_lttng_session_ok $SESSION_NAME $TRACE_PATH
+	create_lttng_session_ok $SESSION_NAME "$TRACE_PATH"
 	enable_metadata_per_pid $SESSION_NAME
 	enable_channel_per_pid $SESSION_NAME "channel0"
 	enable_ust_lttng_event_ok $SESSION_NAME $EVENT_NAME "channel0"
@@ -137,20 +135,17 @@ test_after_app_pid() {
 	# Make sure the application does not generate any more data,
 	# thus ensuring that we are not flushing a packet concurrently
 	# with validate_trace.
-	for p in ${APPS_PID}; do
-		kill -s SIGSTOP ${p}
-	done
+	kill -s SIGSTOP "${APP_PIDS[@]}"
 
 	# Give time to the consumer to write inflight data.
 	sleep 2
 
+	# shellcheck disable=SC2119
 	validate_trace
 	out=$?
 
-	for p in ${APPS_PID}; do
-		kill -s SIGKILL ${p}
-		wait ${p} 2>/dev/null
-	done
+	kill -s SIGKILL "${APP_PIDS[@]}"
+	wait "${APP_PIDS[@]}" 2>/dev/null
 	stop_lttng_tracing_ok $SESSION_NAME
 	destroy_lttng_session_ok $SESSION_NAME
 
@@ -161,16 +156,15 @@ test_after_app_pid() {
 
 test_before_app_pid() {
 	local out
-	local tmp_file="/tmp/lttng_test_ust.42.file"
 
-	APPS_PID=
+	APP_PIDS=()
 
 	diag "Start application BEFORE tracing is started"
 
 	start_trace_app
 
 	# Start application before tracing
-	create_lttng_session_ok $SESSION_NAME $TRACE_PATH
+	create_lttng_session_ok $SESSION_NAME "$TRACE_PATH"
 	enable_metadata_per_pid $SESSION_NAME
 	enable_channel_per_pid $SESSION_NAME "channel0"
 	enable_ust_lttng_event_ok $SESSION_NAME $EVENT_NAME "channel0"
@@ -183,20 +177,17 @@ test_before_app_pid() {
 	# Make sure the application does not generate any more data,
 	# thus ensuring that we are not flushing a packet concurrently
 	# with validate_trace.
-	for p in ${APPS_PID}; do
-		kill -s SIGSTOP ${p}
-	done
+	kill -s SIGSTOP "${APP_PIDS[@]}"
 
 	# Give time to the consumer to write inflight data.
 	sleep 2
 
+	# shellcheck disable=SC2119
 	validate_trace
 	out=$?
 
-	for p in ${APPS_PID}; do
-		kill -s SIGKILL ${p}
-		wait ${p} 2>/dev/null
-	done
+	kill -s SIGKILL "${APP_PIDS[@]}"
+	wait "${APP_PIDS[@]}" 2>/dev/null
 
 	stop_lttng_tracing_ok $SESSION_NAME
 	destroy_lttng_session_ok $SESSION_NAME
@@ -209,11 +200,11 @@ test_before_app_pid() {
 test_after_app_uid() {
 	local out
 
-	APPS_PID=
+	APP_PIDS=()
 
 	diag "Start application AFTER tracing is started"
 
-	create_lttng_session_ok $SESSION_NAME $TRACE_PATH
+	create_lttng_session_ok $SESSION_NAME "$TRACE_PATH"
 	enable_metadata_per_uid $SESSION_NAME
 	enable_channel_per_uid $SESSION_NAME "channel0"
 	enable_ust_lttng_event_ok $SESSION_NAME $EVENT_NAME "channel0"
@@ -226,21 +217,17 @@ test_after_app_uid() {
 	# Make sure the application does not generate any more data,
 	# thus ensuring that we are not flushing a packet concurrently
 	# with validate_trace.
-	for p in ${APPS_PID}; do
-		kill -s SIGSTOP ${p}
-	done
-
+	kill -s SIGSTOP "${APP_PIDS[@]}"
 
 	# Give time to the consumer to write inflight data.
 	sleep 2
 
+	# shellcheck disable=SC2119
 	validate_trace
 	out=$?
 
-	for p in ${APPS_PID}; do
-		kill -s SIGKILL ${p}
-		wait ${p} 2>/dev/null
-	done
+	kill -s SIGKILL "${APP_PIDS[@]}"
+	wait "${APP_PIDS[@]}"
 	stop_lttng_tracing_ok $SESSION_NAME
 	destroy_lttng_session_ok $SESSION_NAME
 
@@ -252,14 +239,14 @@ test_after_app_uid() {
 test_before_app_uid() {
 	local out
 
-	APPS_PID=
+	APP_PIDS=()
 
 	diag "Start application BEFORE tracing is started"
 
 	# Start application before tracing
 	start_trace_app
 
-	create_lttng_session_ok $SESSION_NAME $TRACE_PATH
+	create_lttng_session_ok $SESSION_NAME "$TRACE_PATH"
 	enable_metadata_per_uid $SESSION_NAME
 	enable_channel_per_uid $SESSION_NAME "channel0"
 	enable_ust_lttng_event_ok $SESSION_NAME $EVENT_NAME "channel0"
@@ -272,20 +259,17 @@ test_before_app_uid() {
 	# Make sure the application does not generate any more data,
 	# thus ensuring that we are not flushing a packet concurrently
 	# with validate_trace.
-	for p in ${APPS_PID}; do
-		kill -s SIGSTOP ${p}
-	done
+	kill -s SIGSTOP "${APP_PIDS[@]}"
 
 	# Give time to the consumer to write inflight data.
 	sleep 2
 
+	# shellcheck disable=SC2119
 	validate_trace
 	out=$?
 
-	for p in ${APPS_PID}; do
-		kill -s SIGKILL ${p}
-		wait ${p} 2>/dev/null
-	done
+	kill -s SIGKILL "${APP_PIDS[@]}"
+	wait "${APP_PIDS[@]}"
 	stop_lttng_tracing_ok $SESSION_NAME
 	destroy_lttng_session_ok $SESSION_NAME
 
@@ -310,13 +294,15 @@ TESTS=(
 TEST_COUNT=${#TESTS[@]}
 i=0
 
+# shellcheck disable=SC2119
 start_lttng_sessiond
 
-while [ $i -lt $TEST_COUNT ]; do
+while [ $i -lt "$TEST_COUNT" ]; do
 	TRACE_PATH=$(mktemp -d -t tmp.test_periodical_metadata_flush_ust_trace_path.XXXXXX)
 	${TESTS[$i]}
-	rm -rf $TRACE_PATH
-	let "i++"
+	rm -rf "$TRACE_PATH"
+	(( "i++" ))
 done
 
+# shellcheck disable=SC2119
 stop_lttng_sessiond
diff --git a/tests/stress/test_multi_sessions_per_uid_10app b/tests/stress/test_multi_sessions_per_uid_10app
index 68cfc4572..5ddc6be64 100755
--- a/tests/stress/test_multi_sessions_per_uid_10app
+++ b/tests/stress/test_multi_sessions_per_uid_10app
@@ -5,8 +5,8 @@
 # SPDX-License-Identifier: LGPL-2.1-only
 #
 
-CURDIR=$(dirname $0)/
-TESTDIR=$CURDIR/..
+CURDIR=$(dirname "$0")/
+TESTDIR="$CURDIR/.."
 LAUNCH_APP="launch_ust_app"
 SESSION_NAME="stress"
 EVENT_NAME="tp:tptest"
@@ -17,32 +17,34 @@ NR_APP=10
 NR_SESSION=5
 NR_LOOP=1000
 COREDUMP_FILE=$(cat /proc/sys/kernel/core_pattern)
-APPS_PID=
+APP_PIDS=()
 
 TEST_DESC="Stress test - $NR_SESSION sessions per UID with $NR_APP apps"
 
-source $TESTDIR/utils/utils.sh
+# shellcheck source-path=SCRIPTDIR/../
+source "$TESTDIR/utils/utils.sh"
 
 # MUST set TESTDIR before calling those functions
 
 function enable_channel_per_uid()
 {
-    local sess_name=$1
-    local channel_name=$2
+	local sess_name=$1
+	local channel_name=$2
 
-    $TESTDIR/../src/bin/lttng/$LTTNG_BIN enable-channel --buffers-uid -u $channel_name -s $sess_name >/dev/null 2>&1
-    ok $? "Enable channel $channel_name per UID for session $sess_name"
+	"$TESTDIR/../src/bin/lttng/$LTTNG_BIN" enable-channel --buffers-uid -u "$channel_name" -s "$sess_name" >/dev/null 2>&1
+	ok $? "Enable channel $channel_name per UID for session $sess_name"
 }
 
 function check_sessiond()
 {
-	if [ -z "$(lttng_pgrep lt-lttng-sessiond)" ]; then
-		local str_date=$(date +%H%M%S-%d%m%Y)
+	local str_date=''
+	if [ -z "$(lttng_pgrep lttng-sessiond)" ]; then
+		str_date=$(date +%H%M%S-%d%m%Y)
 
 		diag "!!!The session daemon died unexpectedly!!!"
-		mv $LOG_FILE $LOG_FILE-$str_date
-		if [ -e $COREDUMP_FILE ]; then
-			mv $COREDUMP_FILE $COREDUMP_FILE-$str_date
+		mv $LOG_FILE "$LOG_FILE-$str_date"
+		if [ -e "$COREDUMP_FILE" ]; then
+			mv "$COREDUMP_FILE" "$COREDUMP_FILE-$str_date"
 		fi
 		exit 1
 	fi
@@ -50,16 +52,15 @@ function check_sessiond()
 
 function start_sessiond()
 {
-	validate_kernel_version
-	if [ $? -ne 0 ]; then
+	if ! validate_kernel_version ; then
 		fail "Start session daemon"
 		BAIL_OUT "*** Kernel too old for session daemon tests ***"
 	fi
 
-	if [ -z $(lttng_pgrep lt-$SESSIOND_BIN) ]; then
+	if [ -z "$(lttng_pgrep $SESSIOND_BIN)" ]; then
 		# We have to start it like this so the ulimit -c is used by this
 		# process. Also, we collect any error message printed out.
-		$TESTDIR/../src/bin/lttng-sessiond/$SESSIOND_BIN --quiet --background --consumerd32-path="$TESTDIR/../src/bin/lttng-consumerd/lttng-consumerd" --consumerd64-path="$TESTDIR/../src/bin/lttng-consumerd/lttng-consumerd" >$LOG_FILE 2>&1
+		"$TESTDIR/../src/bin/lttng-sessiond/$SESSIOND_BIN" --quiet --background --consumerd32-path="$TESTDIR/../src/bin/lttng-consumerd/lttng-consumerd" --consumerd64-path="$TESTDIR/../src/bin/lttng-consumerd/lttng-consumerd" >$LOG_FILE 2>&1
 		status=$?
 		ok $status "Start session daemon"
 	fi
@@ -67,22 +68,23 @@ function start_sessiond()
 
 test_stress()
 {
+	# shellcheck disable=SC2034
 	for b in $(seq 1 $NR_LOOP); do
 		for a in $(seq 1 $NR_SESSION); do
-			create_lttng_session_ok $SESSION_NAME-$a $TRACE_PATH
+			create_lttng_session_ok $SESSION_NAME-"$a" "$TRACE_PATH"
 			check_sessiond
-			enable_channel_per_uid $SESSION_NAME-$a $CHANNEL_NAME
+			enable_channel_per_uid $SESSION_NAME-"$a" $CHANNEL_NAME
 			check_sessiond
-			enable_ust_lttng_event_ok $SESSION_NAME-$a $EVENT_NAME
+			enable_ust_lttng_event_ok $SESSION_NAME-"$a" $EVENT_NAME
 			check_sessiond
-			start_lttng_tracing_ok $SESSION_NAME-$a
+			start_lttng_tracing_ok $SESSION_NAME-"$a"
 			check_sessiond
 		done
 
 		for a in $(seq 1 $NR_SESSION); do
-			stop_lttng_tracing_ok $SESSION_NAME-$a
+			stop_lttng_tracing_ok $SESSION_NAME-"$a"
 			check_sessiond
-			destroy_lttng_session_ok $SESSION_NAME-$a
+			destroy_lttng_session_ok $SESSION_NAME-"$a"
 			check_sessiond
 		done
 	done
@@ -93,18 +95,17 @@ test_stress()
 function cleanup()
 {
 	diag "Cleaning up!"
-	for p in ${APPS_PID}; do
-		kill -s SIGKILL ${p}
-		wait ${p} 2>/dev/null
-	done
-	APPS_PID=
+	kill -s SIGKILL "${APP_PIDS[@]}"
+	wait "${APP_PIDS[@]}" 2>/dev/null
+	APP_PIDS=()
+	# shellcheck disable=SC2119
 	stop_lttng_sessiond
 }
 
 function sighandler()
 {
 	cleanup
-	rm $LOG_FILE
+	rm "$LOG_FILE"
 	full_cleanup
 }
 
@@ -123,8 +124,8 @@ start_sessiond
 diag "Starting applications"
 
 # Start NR_APP applications script that will spawn apps non stop.
-./$TESTDIR/stress/$LAUNCH_APP $NR_APP &
-APPS_PID="${APPS_PID} ${!}"
+"./$TESTDIR/stress/$LAUNCH_APP" $NR_APP &
+APP_PIDS+=(${!})
 
 TRACE_PATH=$(mktemp -d -t tmp.test_multi_sess_per_uid_10app.XXXXXX)
 
@@ -136,6 +137,6 @@ if [ $out -ne 0 ]; then
 fi
 
 cleanup
-rm -rf $TRACE_PATH
+rm -rf "${TRACE_PATH:?}/"
 rm $LOG_FILE
 exit 0
diff --git a/tests/stress/test_multi_sessions_per_uid_5app_streaming b/tests/stress/test_multi_sessions_per_uid_5app_streaming
index d1d192c02..8800f6f23 100755
--- a/tests/stress/test_multi_sessions_per_uid_5app_streaming
+++ b/tests/stress/test_multi_sessions_per_uid_5app_streaming
@@ -5,8 +5,8 @@
 # SPDX-License-Identifier: LGPL-2.1-only
 #
 
-CURDIR=$(dirname $0)/
-TESTDIR=$CURDIR/..
+CURDIR=$(dirname "$0")/
+TESTDIR="$CURDIR/.."
 LAUNCH_APP="launch_ust_app"
 SESSION_NAME="stress"
 EVENT_NAME="tp:tptest"
@@ -18,32 +18,34 @@ NR_SESSION=5
 NR_LOOP=1000
 COREDUMP_FILE=$(cat /proc/sys/kernel/core_pattern)
 NUM_TESTS=16
-APPS_PID=
+APP_PIDS=()
 
 TEST_DESC="Stress test - $NR_SESSION sessions per UID streaming with $NR_APP apps"
 
-source $TESTDIR/utils/utils.sh
+# shellcheck source-path=SCRIPTDIR/../
+source "$TESTDIR/utils/utils.sh"
 
 # MUST set TESTDIR before calling those functions
 
 function enable_channel_per_uid()
 {
-    local sess_name=$1
-    local channel_name=$2
+	local sess_name=$1
+	local channel_name=$2
 
-    $TESTDIR/../src/bin/lttng/$LTTNG_BIN enable-channel --buffers-uid -u $channel_name -s $sess_name >/dev/null 2>&1
-    ok $? "Enable channel $channel_name per UID for session $sess_name"
+	"$TESTDIR/../src/bin/lttng/$LTTNG_BIN" enable-channel --buffers-uid -u "$channel_name" -s "$sess_name" >/dev/null 2>&1
+	ok $? "Enable channel $channel_name per UID for session $sess_name"
 }
 
 function check_sessiond()
 {
-	if [ -z "$(lttng_pgrep lt-lttng-sessiond)" ]; then
-		local str_date=$(date +%H%M%S-%d%m%Y)
+	local str_date
+	if [ -z "$(lttng_pgrep lttng-sessiond)" ]; then
+		str_date=$(date +%H%M%S-%d%m%Y)
 
 		diag "!!!The session daemon died unexpectedly!!!"
-		mv $LOG_FILE_SESSIOND $LOG_FILE_SESSIOND-$str_date
-		if [ -e $COREDUMP_FILE ]; then
-			mv $COREDUMP_FILE $COREDUMP_FILE-$str_date
+		mv $LOG_FILE_SESSIOND "$LOG_FILE_SESSIOND-$str_date"
+		if [ -e "$COREDUMP_FILE" ]; then
+			mv "$COREDUMP_FILE" "$COREDUMP_FILE-$str_date"
 		fi
 		exit 1
 	fi
@@ -51,13 +53,14 @@ function check_sessiond()
 
 function check_relayd()
 {
-	if [ -z "$(lttng_pgrep lt-lttng-relayd)" ]; then
-		local str_date=$(date +%H%M%S-%d%m%Y)
+	local str_date
+	if [ -z "$(lttng_pgrep lttng-relayd)" ]; then
+		str_date=$(date +%H%M%S-%d%m%Y)
 
 		diag "!!!The relay daemon died unexpectedly!!!"
-		mv $LOG_FILE_RELAYD $LOG_FILE_RELAYD-$str_date
-		if [ -e $COREDUMP_FILE ]; then
-			mv $COREDUMP_FILE $COREDUMP_FILE-$str_date
+		mv $LOG_FILE_RELAYD "$LOG_FILE_RELAYD-$str_date"
+		if [ -e "$COREDUMP_FILE" ]; then
+			mv "$COREDUMP_FILE" "$COREDUMP_FILE-$str_date"
 		fi
 		exit 1
 	fi
@@ -65,16 +68,15 @@ function check_relayd()
 
 function start_sessiond()
 {
-	validate_kernel_version
-	if [ $? -ne 0 ]; then
+	if ! validate_kernel_version ; then
 		fail "Start session daemon"
 		BAIL_OUT "*** Kernel too old for session daemon tests ***"
 	fi
 
-	if [ -z $(lttng_pgrep lt-$SESSIOND_BIN) ]; then
+	if [ -z "$(lttng_pgrep lt-$SESSIOND_BIN)" ]; then
 		# We have to start it like this so the ulimit -c is used by this
 		# process. Also, we collect any error message printed out.
-		$TESTDIR/../src/bin/lttng-sessiond/$SESSIOND_BIN --quiet --background --consumerd32-path="$TESTDIR/../src/bin/lttng-consumerd/lttng-consumerd" --consumerd64-path="$TESTDIR/../src/bin/lttng-consumerd/lttng-consumerd" >$LOG_FILE_SESSIOND 2>&1
+		"$TESTDIR/../src/bin/lttng-sessiond/$SESSIOND_BIN" --quiet --background --consumerd32-path="$TESTDIR/../src/bin/lttng-consumerd/lttng-consumerd" --consumerd64-path="$TESTDIR/../src/bin/lttng-consumerd/lttng-consumerd" >$LOG_FILE_SESSIOND 2>&1
 		status=$?
 		ok $status "Start session daemon"
 	fi
@@ -84,35 +86,36 @@ function start_relayd
 {
 	local opt=$1
 
-	if [ -z $(lttng_pgrep lt-$RELAYD_BIN) ]; then
-		$TESTDIR/../src/bin/lttng-relayd/$RELAYD_BIN $opt >$LOG_FILE_RELAYD 2>&1 &
+	if [ -z "$(lttng_pgrep lt-$RELAYD_BIN)" ]; then
+		"$TESTDIR/../src/bin/lttng-relayd/$RELAYD_BIN" "$opt" >"$LOG_FILE_RELAYD" 2>&1 &
 		ok $? "Start lttng-relayd (opt: \"$opt\")"
 	fi
 }
 
 test_stress()
 {
+	# shellcheck disable=SC2034
 	for b in $(seq 1 $NR_LOOP); do
 		for a in $(seq 1 $NR_SESSION); do
-			create_lttng_session_uri $SESSION_NAME-$a net://localhost
+			create_lttng_session_uri $SESSION_NAME-"$a" net://localhost
 			check_sessiond
 			check_relayd
-			enable_channel_per_uid $SESSION_NAME-$a $CHANNEL_NAME
+			enable_channel_per_uid $SESSION_NAME-"$a" $CHANNEL_NAME
 			check_sessiond
 			check_relayd
-			enable_ust_lttng_event_ok $SESSION_NAME-$a $EVENT_NAME
+			enable_ust_lttng_event_ok $SESSION_NAME-"$a" $EVENT_NAME
 			check_sessiond
 			check_relayd
-			start_lttng_tracing_ok $SESSION_NAME-$a
+			start_lttng_tracing_ok $SESSION_NAME-"$a"
 			check_sessiond
 			check_relayd
 		done
 
 		for a in $(seq 1 $NR_SESSION); do
-			stop_lttng_tracing_ok $SESSION_NAME-$a
+			stop_lttng_tracing_ok $SESSION_NAME-"$a"
 			check_sessiond
 			check_relayd
-			destroy_lttng_session_ok $SESSION_NAME-$a
+			destroy_lttng_session_ok $SESSION_NAME-"$a"
 			check_sessiond
 			check_relayd
 		done
@@ -124,12 +127,12 @@ test_stress()
 function cleanup()
 {
 	diag "Cleaning up!"
-	for p in ${APPS_PID}; do
-		kill -s SIGKILL ${p}
-		wait ${p} 2>/dev/null
-	done
-	APPS_PID=
+	kill -s SIGKILL "${APP_PIDS[@]}"
+	wait "${APP_PIDS[@]}" 2>/dev/null
+	APP_PIDS=()
+	# shellcheck disable=SC2119
 	stop_lttng_sessiond
+	# shellcheck disable=SC2119
 	stop_lttng_relayd
 }
 
@@ -158,8 +161,8 @@ start_sessiond
 diag "Starting applications launcher"
 
 # Start NR_APP applications script that will spawn apps non stop.
-./$TESTDIR/stress/$LAUNCH_APP $NR_APP &
-APPS_PID="${APPS_PID} ${!}"
+"./$TESTDIR/stress/$LAUNCH_APP" $NR_APP &
+APP_PIDS+=(${!})
 
 test_stress
 out=$?
@@ -169,6 +172,6 @@ if [ $out -ne 0 ]; then
 fi
 
 cleanup
-rm -rf $TRACE_PATH
+rm -rf "${TRACE_PATH:?}/"
 rm $LOG_FILE_SESSIOND $LOG_FILE_RELAYD
 exit 0
diff --git a/tests/stress/test_multi_sessions_per_uid_5app_streaming_kill_relayd b/tests/stress/test_multi_sessions_per_uid_5app_streaming_kill_relayd
index 53411cb6d..3d5da8f84 100755
--- a/tests/stress/test_multi_sessions_per_uid_5app_streaming_kill_relayd
+++ b/tests/stress/test_multi_sessions_per_uid_5app_streaming_kill_relayd
@@ -5,8 +5,8 @@
 # SPDX-License-Identifier: LGPL-2.1-only
 #
 
-CURDIR=$(dirname $0)/
-TESTDIR=$CURDIR/..
+CURDIR=$(dirname "$0")/
+TESTDIR="$CURDIR/.."
 LAUNCH_APP="launch_ust_app"
 KILL_RELAYD_HELPER="kill_relayd"
 SESSION_NAME="stress"
@@ -19,32 +19,34 @@ NR_SESSION=5
 NR_LOOP=100000
 COREDUMP_FILE=$(cat /proc/sys/kernel/core_pattern)
 NUM_TESTS=16
-APPS_PID=
+APP_PIDS=()
 
 TEST_DESC="Stress test - $NR_SESSION sessions per UID streaming with $NR_APP apps. The relayd is killed sporadically"
 
-source $TESTDIR/utils/utils.sh
+# shellcheck source-path=SCRIPTDIR/../
+source "$TESTDIR/utils/utils.sh"
 
 # MUST set TESTDIR before calling those functions
 
 function enable_channel_per_uid()
 {
-    local sess_name=$1
-    local channel_name=$2
+	local sess_name=$1
+	local channel_name=$2
 
-    $TESTDIR/../src/bin/lttng/$LTTNG_BIN enable-channel --buffers-uid -u $channel_name -s $sess_name >/dev/null 2>&1
-    ok $? "Enable channel $channel_name per UID for session $sess_name"
+	"$TESTDIR/../src/bin/lttng/$LTTNG_BIN" enable-channel --buffers-uid -u "$channel_name" -s "$sess_name" >/dev/null 2>&1
+	ok $? "Enable channel $channel_name per UID for session $sess_name"
 }
 
 function check_sessiond()
 {
-	if [ -z "$(lttng_pgrep lt-lttng-sessiond)" ]; then
-		local str_date=$(date +%H%M%S-%d%m%Y)
+	local str_date
+	if [ -z "$(lttng_pgrep lttng-sessiond)" ]; then
+		str_date=$(date +%H%M%S-%d%m%Y)
 
 		diag "!!!The session daemon died unexpectedly!!!"
-		mv $LOG_FILE_SESSIOND $LOG_FILE_SESSIOND-$str_date
-		if [ -e $COREDUMP_FILE ]; then
-			mv $COREDUMP_FILE $COREDUMP_FILE-$str_date
+		mv $LOG_FILE_SESSIOND "$LOG_FILE_SESSIOND-$str_date"
+		if [ -e "$COREDUMP_FILE" ]; then
+			mv "$COREDUMP_FILE" "$COREDUMP_FILE-$str_date"
 		fi
 		exit 1
 	fi
@@ -52,17 +54,16 @@ function check_sessiond()
 
 function start_sessiond()
 {
-	validate_kernel_version
-	if [ $? -ne 0 ]; then
+	if ! validate_kernel_version ; then
 		fail "Start session daemon"
 		BAIL_OUT "*** Kernel too old for session daemon tests ***"
 	fi
 
-	if [ -z $(lttng_pgrep lt-$SESSIOND_BIN) ]; then
+	if [ -z "$(lttng_pgrep $SESSIOND_BIN)" ]; then
 		# We have to start it like this so the ulimit -c is used by this
 		# process. Also, we collect any error message printed out.
 		#$TESTDIR/../src/bin/lttng-sessiond/$SESSIOND_BIN --quiet --background --consumerd32-path="$TESTDIR/../src/bin/lttng-consumerd/lttng-consumerd" --consumerd64-path="$TESTDIR/../src/bin/lttng-consumerd/lttng-consumerd" >$LOG_FILE_SESSIOND 2>&1
-		$TESTDIR/../src/bin/lttng-sessiond/$SESSIOND_BIN --verbose-consumer -vvv --background --consumerd32-path="$TESTDIR/../src/bin/lttng-consumerd/lttng-consumerd" --consumerd64-path="$TESTDIR/../src/bin/lttng-consumerd/lttng-consumerd" >$LOG_FILE_SESSIOND 2>&1
+		"$TESTDIR/../src/bin/lttng-sessiond/$SESSIOND_BIN" --verbose-consumer -vvv --background --consumerd32-path="$TESTDIR/../src/bin/lttng-consumerd/lttng-consumerd" --consumerd64-path="$TESTDIR/../src/bin/lttng-consumerd/lttng-consumerd" >$LOG_FILE_SESSIOND 2>&1
 		#$TESTDIR/../src/bin/lttng-sessiond/$SESSIOND_BIN --background --consumerd32-path="$TESTDIR/../src/bin/lttng-consumerd/lttng-consumerd" --consumerd64-path="$TESTDIR/../src/bin/lttng-consumerd/lttng-consumerd" >$LOG_FILE_SESSIOND 2>&1
 		status=$?
 		ok $status "Start session daemon"
@@ -73,20 +74,21 @@ function start_relayd
 {
 	local opt=$1
 
-	if [ -z $(lttng_pgrep lt-$RELAYD_BIN) ]; then
-		$TESTDIR/../src/bin/lttng-relayd/$RELAYD_BIN $opt >$LOG_FILE_RELAYD 2>&1 &
+	if [ -z "$(lttng_pgrep $RELAYD_BIN)" ]; then
+		"$TESTDIR/../src/bin/lttng-relayd/$RELAYD_BIN" "$opt" >$LOG_FILE_RELAYD 2>&1 &
 		ok $? "Start lttng-relayd (opt: \"$opt\")"
 	fi
 }
 
 function check_relayd()
 {
-	if [ -z "$(lttng_pgrep lt-lttng-relayd)" ]; then
-		local str_date=$(date +%H%M%S-%d%m%Y)
+	local str_date
+	if [ -z "$(lttng_pgrep lttng-relayd)" ]; then
+		str_date=$(date +%H%M%S-%d%m%Y)
 
 		#diag "Relay daemon died. Starting it again"
-		if [ -e $COREDUMP_FILE ]; then
-			mv $COREDUMP_FILE $COREDUMP_FILE-$str_date
+		if [ -e "$COREDUMP_FILE" ]; then
+			mv "$COREDUMP_FILE" "$COREDUMP_FILE-$str_date"
 		fi
 		start_relayd
 	fi
@@ -94,27 +96,28 @@ function check_relayd()
 
 test_stress()
 {
+	# shellcheck disable=SC2034
 	for b in $(seq 1 $NR_LOOP); do
 		for a in $(seq 1 $NR_SESSION); do
-			create_lttng_session_uri $SESSION_NAME-$a net://localhost
+			create_lttng_session_uri $SESSION_NAME-"$a" net://localhost
 			check_sessiond
 			check_relayd
-			enable_channel_per_uid $SESSION_NAME-$a $CHANNEL_NAME
+			enable_channel_per_uid $SESSION_NAME-"$a" $CHANNEL_NAME
 			check_sessiond
 			check_relayd
-			enable_ust_lttng_event_ok $SESSION_NAME-$a $EVENT_NAME
+			enable_ust_lttng_event_ok $SESSION_NAME-"$a" $EVENT_NAME
 			check_sessiond
 			check_relayd
-			start_lttng_tracing_ok $SESSION_NAME-$a
+			start_lttng_tracing_ok $SESSION_NAME-"$a"
 			check_sessiond
 			check_relayd
 		done
 
 		for a in $(seq 1 $NR_SESSION); do
-			stop_lttng_tracing_ok $SESSION_NAME-$a
+			stop_lttng_tracing_ok $SESSION_NAME-"$a"
 			check_sessiond
 			check_relayd
-			destroy_lttng_session_ok $SESSION_NAME-$a
+			destroy_lttng_session_ok $SESSION_NAME-"$a"
 			check_sessiond
 			check_relayd
 		done
@@ -126,12 +129,12 @@ test_stress()
 function cleanup()
 {
 	diag "Cleaning up!"
-	for p in ${APPS_PID}; do
-		kill ${p}
-		wait ${p} 2>/dev/null
-	done
-	APPS_PID=
+	kill "${APP_PIDS[@]}"
+	wait "${APP_PIDS[@]}" 2>/dev/null
+	APP_PIDS=()
+	# shellcheck disable=SC2119
 	stop_lttng_sessiond
+	# shellcheck disable=SC2119
 	stop_lttng_relayd
 }
 
@@ -160,12 +163,12 @@ start_sessiond
 diag "Starting applications launcher"
 
 # Start NR_APP applications script that will spawn apps non stop.
-./$TESTDIR/stress/$LAUNCH_APP $NR_APP &
-APPS_PID="${APPS_PID} ${!}"
+"./$TESTDIR/stress/$LAUNCH_APP" $NR_APP &
+APP_PIDS+=(${!})
 
 # Launch the helper script that will randomly kill the relayd at vitam eternam.
-./$TESTDIR/stress/$KILL_RELAYD_HELPER 1 1 &
-APPS_PID="${APPS_PID} ${!}"
+"./$TESTDIR/stress/$KILL_RELAYD_HELPER" 1 1 &
+APP_PIDS+=(${!})
 
 test_stress
 out=$?
@@ -175,6 +178,6 @@ if [ $out -ne 0 ]; then
 fi
 
 cleanup
-rm -rf $TRACE_PATH
+rm -rf "${TRACE_PATH:?}/"
 rm $LOG_FILE_SESSIOND $LOG_FILE_RELAYD
 exit 0