--- libmalloc/libmalloc-166.251.2/src/platform.h
+++ libmalloc/libmalloc-409.60.6/src/platform.h
@@ -24,11 +24,11 @@
 #ifndef __PLATFORM_H
 #define __PLATFORM_H
 
-#if TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR
+#if (TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR) || (TARGET_OS_DRIVERKIT && !MALLOC_TARGET_DK_OSX)
 #define MALLOC_TARGET_IOS 1
-#else // TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR
+#else // (TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR) || (TARGET_OS_DRIVERKIT && !MALLOC_TARGET_DK_OSX)
 #define MALLOC_TARGET_IOS 0
-#endif // TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR
+#endif // (TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR) || (TARGET_OS_DRIVERKIT && !MALLOC_TARGET_DK_OSX)
 
 #ifdef __LP64__
 #define MALLOC_TARGET_64BIT 1
@@ -44,12 +44,13 @@
 #endif // MALLOC_TARGET_IOS
 
 // <rdar://problem/12596555>
+#define CONFIG_RECIRC_DEPOT 1
+#define CONFIG_AGGRESSIVE_MADVISE 1
+
 #if MALLOC_TARGET_IOS
-# define CONFIG_RECIRC_DEPOT 1
-# define CONFIG_AGGRESSIVE_MADVISE 1
+# define DEFAULT_AGGRESSIVE_MADVISE_ENABLED true
 #else // MALLOC_TARGET_IOS
-# define CONFIG_RECIRC_DEPOT 1
-# define CONFIG_AGGRESSIVE_MADVISE 0
+# define DEFAULT_AGGRESSIVE_MADVISE_ENABLED false
 #endif // MALLOC_TARGET_IOS
 
 // <rdar://problem/10397726>
@@ -69,6 +70,15 @@
 // enable nano checking for corrupt free list
 #define NANO_FREE_DEQUEUE_DILIGENCE 1
 
+// Conditional behaviour depends on MallocSpaceEfficient being set by
+// JetsamProperties which isn't true on iOS
+#if MALLOC_TARGET_IOS || TARGET_OS_DRIVERKIT
+#define NANOV2_DEFAULT_MODE NANO_ENABLED
+#else
+#define NANOV2_DEFAULT_MODE NANO_CONDITIONAL
+#endif
+
+
 // This governs a last-free cache of 1 that bypasses the free-list for each region size
 #define CONFIG_TINY_CACHE 1
 #define CONFIG_SMALL_CACHE 1
@@ -79,18 +89,40 @@
 #if MALLOC_TARGET_IOS
 #define CONFIG_MEDIUM_ALLOCATOR 0
 #else // MALLOC_TARGET_IOS
-#define CONFIG_MEDIUM_ALLOCATOR 0
+#define CONFIG_MEDIUM_ALLOCATOR 1
 #endif // MALLOC_TARGET_IOS
 #else // MALLOC_TARGET_64BIT
 #define CONFIG_MEDIUM_ALLOCATOR 0
 #endif // MALLOC_TARGET_64BIT
 
 // The large last-free cache (aka. death row cache)
-#if MALLOC_TARGET_IOS
+#if TARGET_OS_IOS || TARGET_OS_SIMULATOR || TARGET_OS_DRIVERKIT
+// sdk=iphoneos, simulator, sdk=driverkit
+#define CONFIG_LARGE_CACHE 1
+#elif MALLOC_TARGET_IOS
+// all other embedded
 #define CONFIG_LARGE_CACHE 0
 #else
+// Mac
 #define CONFIG_LARGE_CACHE 1
 #endif
+
+#if CONFIG_LARGE_CACHE
+
+#if MALLOC_TARGET_IOS && MALLOC_TARGET_64BIT
+#define DEFAULT_LARGE_CACHE_ENABLED false
+#define CONFIG_DEFERRED_RECLAIM 1
+
+#elif TARGET_OS_SIMULATOR || (MALLOC_TARGET_IOS && !MALLOC_TARGET_64BIT)
+#define DEFAULT_LARGE_CACHE_ENABLED false
+#define CONFIG_DEFERRED_RECLAIM 0
+
+#else // TARGET_OS_SIMULATOR || (MALLOC_TARGET_IOS && !MALLOC_TARGET_64BIT)
+#define DEFAULT_LARGE_CACHE_ENABLED true
+#define CONFIG_DEFERRED_RECLAIM 0
+
+#endif // TARGET_OS_SIMULATOR || (MALLOC_TARGET_IOS && !MALLOC_TARGET_64BIT)
+#endif // CONFIG_LARGE_CACHE
 
 #if MALLOC_TARGET_IOS
 // The VM system on iOS forces malloc-tagged memory to never be marked as
@@ -108,6 +140,19 @@
 #define ENABLE_MEMORY_RESOURCE_EXCEPTION_HANDLING 1
 #endif
 
+#if !TARGET_OS_DRIVERKIT && (!TARGET_OS_OSX || MALLOC_TARGET_64BIT)
+#define CONFIG_FEATUREFLAGS_SIMPLE 1
+#else
+#define CONFIG_FEATUREFLAGS_SIMPLE 0
+#endif
+
+// Quarantine zone, only useful on macOS (+ DriverKit, 64-bit simulators).
+#if (TARGET_OS_OSX || TARGET_OS_DRIVERKIT || TARGET_OS_SIMULATOR) && MALLOC_TARGET_64BIT
+#define CONFIG_QUARANTINE 1
+#else
+#define CONFIG_QUARANTINE 0
+#endif
+
 // presence of commpage memsize
 #define CONFIG_HAS_COMMPAGE_MEMSIZE 1
 
@@ -119,4 +164,16 @@
 #define CONFIG_TINY_USES_HYPER_SHIFT 0
 #define CONFIG_SMALL_USES_HYPER_SHIFT 0
 
+// FIXME: limit number of malloc_create_zone() wrapper zones for watchOS to remove this
+#if TARGET_OS_OSX || TARGET_OS_IOS
+#define CONFIG_PGM_WRAP_CUSTOM_ZONES 1
+#else
+#define CONFIG_PGM_WRAP_CUSTOM_ZONES 0
+#endif
+
+
+#ifndef MALLOC_ZERO_POLICY_DEFAULT
+#define MALLOC_ZERO_POLICY_DEFAULT MALLOC_ZERO_ON_FREE
+#endif
+
 #endif // __PLATFORM_H