tests: avoid sending signals in run_test.sh

Change run_test.sh and .bt script such that bpftrace terminates at the end of target test program. Compare the test output after bpftrace has terminated. Using kill -INT to stop bpftrace may interfere with CI environment, because this signal may be interpreted as a job failure. I tried bpftrace -c [1] to work around this, however it turned out to not work for these tests when there are tracepoints refering to dynamic libraries. This is because the .so is not loaded yet when bpftrace attempts to attach to the child process. [1] https://docs.bpftrace.org/latest#-c-command Signed-off-by: Ihor Solodrai <[email protected]>
libbpf · Jan 23, 2025 · 0e39201 · 0e39201
1 parent 7bd06f6
commit 0e39201
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Showing 2 changed files with 36 additions and 26 deletions.
diff --git a/tests/prepare-bt-script.awk b/tests/prepare-bt-script.awk
@@ -46,6 +46,8 @@
 }
 
 END {
-	if (has_contents)
+	if (has_contents) {
+		printf("uretprobe:%s:main { exit(); }\n", OUTPUT "/" TEST);
 		printf("END { printf(\"DONE!\\n\"); }\n");
+	}
 }
diff --git a/tests/run_test.sh b/tests/run_test.sh
@@ -69,36 +69,44 @@ if [ -s "$TEST_BTSCRIPT" ]; then
 	bt_pid=$!
 	bt_pgid="$(ps -opgid= "$bt_pid" | tr -d ' ')"
 
+	dump_bt_output() {
+		echo "BPFTRACE SCRIPT:"
+		cat "$TEST_BTSCRIPT"
+		echo "BPFTRACE OUTPUT:"
+		cat "$TEST_BTOUT_RAW"
+	}
+
+	wait_for_bpftrace() {
+		local bt_start=$(date +%s)
+		local stop_word="$1"
+		local msg="$2"
+		while true; do
+			local bt_elapsed=$(( $(date +%s) - bt_start ))
+			if grep -q "$stop_word" "$TEST_BTOUT_RAW"; then
+				break
+			elif [ "$bt_elapsed" -ge "$TIMEOUT" ]; then
+				sudo kill -KILL -$bt_pgid 2>/dev/null
+				echo "BPFTRACE ${msg} TIMEOUT!"
+				dump_bt_output
+				exit 1
+			elif ! kill -s 0 "$bt_pid"; then
+				echo "BPFTRACE ${msg} FAILURE!"
+				dump_bt_output
+				exit 1
+			else
+				sleep 0.2
+			fi
+		done
+	}
+
 	# wait for bpftrace to finish attachment
-	bt_start=$(date +%s)
-	while true; do
-		bt_elapsed=$(( $(date +%s) - bt_start ))
-		if grep -q "STARTED!" "$TEST_BTOUT_RAW"; then
-			break
-		elif [ "$bt_elapsed" -ge "$TIMEOUT" ]; then
-			sudo kill -KILL -$bt_pgid 2>/dev/null
-			echo "BPFTRACE STARTUP TIMEOUT!"
-			echo "BPFTRACE SCRIPT:"
-			cat "$TEST_BTSCRIPT"
-			echo "BPFTRACE OUTPUT:"
-			cat "$TEST_BTOUT_RAW"
-			exit 1
-		elif ! kill -s 0 "$bt_pid"; then
-			echo "BPFTRACE STARTUP FAILURE!"
-			echo "BPFTRACE SCRIPT:"
-			cat "$TEST_BTSCRIPT"
-			echo "BPFTRACE OUTPUT:"
-			cat "$TEST_BTOUT_RAW"
-			exit 1
-		else
-			sleep 0.2
-		fi
-	done
+	wait_for_bpftrace "STARTED!" "STARTUP"
 
 	# get test output while bpftrace is attached
 	$TEST_BIN &>"$TEST_OUT"
 
-	sudo kill -INT -$bt_pgid 2>/dev/null
+	# wait for bpftrace to terminate
+	wait_for_bpftrace "DONE!" "RUNNING"
 
 	$awk '/STARTED!/ {flag=1; next} /DONE!/ {flag=0} flag' $TEST_BTOUT_RAW > $TEST_BTOUT
 	if ! $awk -f check-match.awk $TEST_BTOUT_SPEC $TEST_BTOUT; then