--- libmalloc/libmalloc-792.60.6/tests/xzone_testing.h
+++ libmalloc/libmalloc-657.60.21/tests/xzone_testing.h
@@ -8,72 +8,6 @@
 #include "tmo_test_defs.h"
 
 #if CONFIG_XZONE_MALLOC
-
-#pragma mark shims
-
-#define TESTING_XZONE_MALLOC 1
-
-// On exclavekit, we only want one copy of the code enclosed here, which we'll
-// arbitrarily build into the metapool tests - they just have to be built into
-// one of them
-
-#if !TARGET_OS_EXCLAVEKIT || defined(TESTING_METAPOOL)
-
-#include "../src/vm.c"
-
-void
-malloc_report(uint32_t flags, const char *fmt, ...)
-{
-	T_LOG("malloc_report(): %s", fmt);
-}
-
-void
-malloc_zone_error(uint32_t flags, bool is_corruption, const char *fmt, ...)
-{
-	__builtin_trap();
-}
-
-#endif // !TARGET_OS_EXCLAVEKIT || defined(TESTING_METAPOOL)
-
-static void test_malloc_lock_lock(_malloc_lock_s *lock) {
-#if MALLOC_HAS_OS_LOCK
-	os_unfair_lock_lock(lock);
-#else
-	T_QUIET; T_ASSERT_EQ(pthread_mutex_lock(lock), 0, "Lock lock");
-#endif // MALLOC_HAS_OS_LOCK
-}
-#define _malloc_lock_lock(lock) test_malloc_lock_lock(lock);
-
-static void test_malloc_lock_unlock(_malloc_lock_s *lock) {
-#if MALLOC_HAS_OS_LOCK
-	os_unfair_lock_unlock(lock);
-#else
-	T_QUIET; T_ASSERT_EQ(pthread_mutex_unlock(lock), 0, "Unlock lock");
-#endif // MALLOC_HAS_OS_LOCK
-}
-#define _malloc_lock_unlock(lock) test_malloc_lock_unlock(lock);
-
-#if !MALLOC_TARGET_EXCLAVES && !defined(TESTING_METAPOOL)
-
-// When not specifically testing the metapool, stub out these functions so that
-// we can build code that uses them.
-
-void *
-xzm_metapool_alloc(xzm_metapool_t mp)
-{
-	__builtin_trap();
-	return NULL;
-}
-
-void
-xzm_metapool_free(xzm_metapool_t mp, void *blockp)
-{
-	__builtin_trap();
-}
-
-#endif // !MALLOC_TARGET_EXCLAVES && !defined(TESTING_METAPOOL)
-
-#pragma mark TMO test helpers
 
 #if defined(_MALLOC_TYPE_ENABLED) && _MALLOC_TYPE_ENABLED
 #define HAVE_MALLOC_TYPE 1
@@ -93,11 +27,7 @@
 	unsigned i = 0;
 
 	malloc_zone_t *zone = malloc_zones[i];
-
-	const char *name = malloc_get_zone_name(zone);
-	if ((zone->version >= 14 &&
-			zone->introspect->zone_type == MALLOC_ZONE_TYPE_PGM) ||
-			(name && !strcmp(name, "ProbGuardMallocZone"))) {
+	if (!strcmp(malloc_get_zone_name(zone), "ProbGuardMallocZone")) {
 		found_pgm = true;
 
 		i++;
@@ -108,22 +38,27 @@
 	}
 
 	T_ASSERT_GE(zone->version, 14, "zone version");
-
-#if CONFIG_SANITIZER
-	if (zone->introspect->zone_type == MALLOC_ZONE_TYPE_SANITIZER &&
-			malloc_sanitizer_is_enabled()) {
+	if (zone->introspect->zone_type != MALLOC_ZONE_TYPE_XZONE) {
+		// Maybe it's nano?
 		i++;
 		if (i == malloc_num_zones) {
-			T_ASSERT_FAIL("didn't find xzone zone");
+			T_ASSERT_FAIL("didn't find xzone xzone");
 		}
-		zone = malloc_zones[i];
+		malloc_zone_t *helper_zone = malloc_zones[i];
+		const char *name = malloc_get_zone_name(helper_zone);
+		if (strcmp(name, "MallocHelperZone") != 0) {
+			T_ASSERT_FAIL("unexpected zone %s", name);
+		}
+
+		found_nano = true;
+
+		zone = helper_zone;
+		T_ASSERT_GE(zone->version, 14, "helper zone version");
+		T_ASSERT_EQ(zone->introspect->zone_type, MALLOC_ZONE_TYPE_XZONE,
+				"helper zone is xzone malloc");
 	}
-#endif
 
-	T_ASSERT_GE(zone->version, 14, "zone version");
-	T_ASSERT_EQ(zone->introspect->zone_type, MALLOC_ZONE_TYPE_XZONE,
-			"zone is xzone malloc");
-
+	bool nano_on_xzone = false;
 	enum {
 		PGM_NO_EXPECTATION,
 		PGM_EXPECTED_ENABLED,
@@ -131,12 +66,17 @@
 	} pgm_expectation = PGM_NO_EXPECTATION;
 
 #if !MALLOC_TARGET_EXCLAVES
+	nano_on_xzone = getenv("MallocNanoOnXzone");
+
 	const char *pgm_env = getenv("MallocProbGuard");
 	if (pgm_env) {
 		pgm_expectation = (*pgm_env == '1' ? PGM_EXPECTED_ENABLED :
 				PGM_EXPECTED_DISABLED);
 	}
 #endif
+
+	T_ASSERT_EQ(nano_on_xzone, found_nano,
+			"Nano state matched expectation (%d)", (int)nano_on_xzone);
 
 	switch (pgm_expectation) {
 	case PGM_NO_EXPECTATION:
@@ -164,7 +104,7 @@
 
 static inline void
 validate_bucket_distribution(xzm_malloc_zone_t zone, const char *expr,
-		void **ptrs, size_t n, bool do_free, bool require_smooth_distribution)
+		void **ptrs, size_t n, bool do_free)
 {
 	size_t counts[XZM_XZONE_DEFAULT_POINTER_BUCKET_COUNT] = { 0 };
 
@@ -210,29 +150,10 @@
 
 	T_LOG("(%s) %zu early allocations", expr, early_count);
 
-	if (require_smooth_distribution) {
-		for (int i = 0; i < XZM_XZONE_DEFAULT_POINTER_BUCKET_COUNT; i++) {
-			T_EXPECT_GT(counts[i], (size_t)0,
-					"(%s) expected nonzero allocations for bucket %d, found %zu",
-					expr, i, counts[i]);
-		}
-	} else {
-		// In practice, we can at least assert that the allocations didn't all
-		// fall into a single bucket.  Although that's theoretically possible,
-		// it's unlikely enough that it's worth flagging as a test failure that
-		// we'll occasionally have to waive so that we can catch cases where the
-		// type descriptor is getting lost entirely
-		int nonzero_counts = 0;
-		for (int i = 0; i < XZM_XZONE_DEFAULT_POINTER_BUCKET_COUNT; i++) {
-			T_LOG("(%s) found %zu allocations for bucket %d", expr, counts[i],
-					i);
-			if (counts[i]) {
-				nonzero_counts++;
-			}
-		}
-		T_EXPECT_GT(nonzero_counts, 1,
-				"(%s) expected at least two buckets with nonzero counts, found %d",
-				expr, nonzero_counts);
+	for (int i = 0; i < XZM_XZONE_DEFAULT_POINTER_BUCKET_COUNT; i++) {
+		T_EXPECT_GT(counts[i], (size_t)0,
+				"(%s) expected nonzero allocations for bucket %d, found %zu",
+				expr, i, counts[i]);
 	}
 }