pam_tests: Force doing a memory leak check at tests Cleanup

ASAN in go does not catch memory leaks properly at the end of the
test program execution, so force this using a wrapper function that is
called when each test is completed.

Author: 3v1n0

pam/pam_test/module-transaction-dummy_test.go

@@ -26,6 +26,8 @@ func ptrValue[T any](value T) *T {
 
 func TestSetGetItem(t *testing.T) {
 	t.Parallel()
+	t.Cleanup(MaybeDoLeakCheck)
+	t.Cleanup(MaybeDoLeakCheck)
 
 	testCases := map[string]struct {
 		item             pam.Item
@@ -67,6 +69,7 @@ func TestSetGetItem(t *testing.T) {
 		tc := tc
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
+			t.Cleanup(MaybeDoLeakCheck)
 
 			require.True(t, tc.value != nil || tc.expectedValue != nil)
 
@@ -88,6 +91,7 @@ func TestSetGetItem(t *testing.T) {
 
 func TestSetPutEnv(t *testing.T) {
 	t.Parallel()
+	t.Cleanup(MaybeDoLeakCheck)
 
 	testCases := map[string]struct {
 		env              string
@@ -144,6 +148,7 @@ func TestSetPutEnv(t *testing.T) {
 		tc := tc
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
+			t.Cleanup(MaybeDoLeakCheck)
 
 			require.False(t, tc.skipPut && tc.expectedValue == nil)
 
@@ -202,6 +207,7 @@ func TestSetPutEnv(t *testing.T) {
 
 func TestSetGetData(t *testing.T) {
 	t.Parallel()
+	t.Cleanup(MaybeDoLeakCheck)
 
 	testCases := map[string]struct {
 		key              string
@@ -251,6 +257,7 @@ func TestSetGetData(t *testing.T) {
 		tc := tc
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
+			t.Cleanup(MaybeDoLeakCheck)
 
 			require.False(t, tc.skipGet && tc.skipSet)
 
@@ -279,6 +286,7 @@ func TestSetGetData(t *testing.T) {
 
 func TestGetUser(t *testing.T) {
 	t.Parallel()
+	t.Cleanup(MaybeDoLeakCheck)
 
 	testCases := map[string]struct {
 		presetUser    string
@@ -324,6 +332,7 @@ func TestGetUser(t *testing.T) {
 		tc := tc
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
+			t.Cleanup(MaybeDoLeakCheck)
 
 			tx := NewModuleTransactionDummy(tc.convHandler)
 
@@ -342,6 +351,7 @@ func TestGetUser(t *testing.T) {
 
 func TestStartStringConv(t *testing.T) {
 	t.Parallel()
+	t.Cleanup(MaybeDoLeakCheck)
 
 	testCases := map[string]struct {
 		prompt                string
@@ -392,6 +402,7 @@ func TestStartStringConv(t *testing.T) {
 		tc := tc
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
+			t.Cleanup(MaybeDoLeakCheck)
 
 			convFunCalled := false
 			tx := NewModuleTransactionDummy(func() pam.ConversationFunc {
@@ -438,6 +449,7 @@ func TestStartStringConv(t *testing.T) {
 
 func TestStartBinaryConv(t *testing.T) {
 	t.Parallel()
+	t.Cleanup(MaybeDoLeakCheck)
 
 	testCases := map[string]struct {
 		request       []byte
@@ -467,6 +479,7 @@ func TestStartBinaryConv(t *testing.T) {
 		tc := tc
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
+			t.Cleanup(MaybeDoLeakCheck)
 
 			convFunCalled := false
 			var tx pam.ModuleTransaction

pam/pam_test/utils.go

@@ -0,0 +1,34 @@
+// Package pam_test includes Test tools for the PAM module
+package pam_test
+
+/*
+void __lsan_do_leak_check (void) __attribute__ ((weak));
+
+static inline void
+maybe_do_leak_check (void)
+{
+  if (__lsan_do_leak_check != NULL)
+    __lsan_do_leak_check ();
+}
+*/
+import "C"
+
+import (
+	"os"
+	"runtime"
+	"time"
+)
+
+// MaybeDoLeakCheck triggers the garbage collector and if the go program is
+// compiled with -asan flag, do a memory leak check.
+// This is meant to be used as a test Cleanup function, to force Go detecting
+// if allocated resources have been released, e.g. using
+// t.Cleanup(pam_test.MaybeDoLeakCheck)
+func MaybeDoLeakCheck() {
+	if os.Getenv("AUTHD_PAM_SKIP_LEAK_CHECK") != "" {
+		return
+	}
+	runtime.GC()
+	time.Sleep(time.Millisecond * 10)
+	C.maybe_do_leak_check()
+}