test: dm: Support memory leak checking as a core feature

Check the state of the malloc() heap before each test is run, so that tests
can verify that all is well at the end. Provide helper functions to mark
the heap and to check that it returns to its initial state.

Signed-off-by: Simon Glass <sjg@chromium.org>

include/dm/test.h

@@ -8,6 +8,7 @@
 #define __DM_TEST_H
 
 #include <dm.h>
+#include <malloc.h>
 
 /**
  * struct dm_test_cdata - configuration data for test instance
@@ -120,6 +121,7 @@ struct dm_test_state {
 	int force_fail_alloc;
 	int skip_post_probe;
 	struct udevice *removed;
+	struct mallinfo start;
 };
 
 /* Test flags for each test */
@@ -178,6 +180,27 @@ int dm_check_operations(struct dm_test_state *dms, struct udevice *dev,
 int dm_check_devices(struct dm_test_state *dms, int num_devices);
 
 /**
+ * dm_leak_check_start() - Prepare to check for a memory leak
+ *
+ * Call this before allocating memory to record the amount of memory being
+ * used.
+ *
+ * @dms: Overall test state
+ */
+void dm_leak_check_start(struct dm_test_state *dms);
+
+/**
+ * dm_leak_check_end() - Check that no memory has leaked
+ *
+ * Call this after dm_leak_check_start() and after you have hopefuilly freed
+ * all the memory that was allocated. This function will print an error if
+ * it sees a different amount of total memory allocated than before.
+ *
+ * @dms: Overall test state
+ */int dm_leak_check_end(struct dm_test_state *dms);
+
+
+/**
  * dm_test_main() - Run all the tests
  *
  * This runs all available driver model tests

test/dm/core.c

@@ -67,6 +67,34 @@ static struct driver_info driver_info_pre_reloc = {
 	.platdata = &test_pdata_manual,
 };
 
+void dm_leak_check_start(struct dm_test_state *dms)
+{
+	dms->start = mallinfo();
+	if (!dms->start.uordblks)
+		puts("Warning: Please add '#define DEBUG' to the top of common/dlmalloc.c\n");
+}
+
+int dm_leak_check_end(struct dm_test_state *dms)
+{
+	struct mallinfo end;
+	int id;
+
+	/* Don't delete the root class, since we started with that */
+	for (id = UCLASS_ROOT + 1; id < UCLASS_COUNT; id++) {
+		struct uclass *uc;
+
+		uc = uclass_find(id);
+		if (!uc)
+			continue;
+		ut_assertok(uclass_destroy(uc));
+	}
+
+	end = mallinfo();
+	ut_asserteq(dms->start.uordblks, end.uordblks);
+
+	return 0;
+}
+
 /* Test that binding with platdata occurs correctly */
 static int dm_test_autobind(struct dm_test_state *dms)
 {
@@ -377,14 +405,11 @@ static int dm_test_leak(struct dm_test_state *dms)
 	int i;
 
 	for (i = 0; i < 2; i++) {
-		struct mallinfo start, end;
 		struct udevice *dev;
 		int ret;
 		int id;
 
-		start = mallinfo();
-		if (!start.uordblks)
-			puts("Warning: Please add '#define DEBUG' to the top of common/dlmalloc.c\n");
+		dm_leak_check_start(dms);
 
 		ut_assertok(dm_scan_platdata(false));
 		ut_assertok(dm_scan_fdt(gd->fdt_blob, false));
@@ -398,18 +423,7 @@ static int dm_test_leak(struct dm_test_state *dms)
 			ut_assertok(ret);
 		}
 
-		/* Don't delete the root class, since we started with that */
-		for (id = UCLASS_ROOT + 1; id < UCLASS_COUNT; id++) {
-			struct uclass *uc;
-
-			uc = uclass_find(id);
-			if (!uc)
-				continue;
-			ut_assertok(uclass_destroy(uc));
-		}
-
-		end = mallinfo();
-		ut_asserteq(start.uordblks, end.uordblks);
+		ut_assertok(dm_leak_check_end(dms));
 	}
 
 	return 0;

test/dm/test-main.c

@@ -7,6 +7,7 @@
 #include <common.h>
 #include <dm.h>
 #include <errno.h>
+#include <malloc.h>
 #include <dm/test.h>
 #include <dm/root.h>
 #include <dm/uclass-internal.h>
@@ -88,6 +89,7 @@ int dm_test_main(void)
 		printf("Test: %s\n", test->name);
 		ut_assertok(dm_test_init(dms));
 
+		dms->start = mallinfo();
 		if (test->flags & DM_TESTF_SCAN_PDATA)
 			ut_assertok(dm_scan_platdata(false));
 		if (test->flags & DM_TESTF_PROBE_TEST)