--- libmalloc/libmalloc-166.200.60/src/internal.h
+++ libmalloc/libmalloc-317.40.8/src/internal.h
@@ -24,7 +24,10 @@
 #ifndef __INTERNAL_H
 #define __INTERNAL_H
 
-#define __OS_EXPOSE_INTERNALS__ 1
+// Toggles for fixes for specific Radars. If we get enough of these, we
+// probably should create a separate header file for them.
+#define RDAR_48993662 1
+#define OS_ATOMIC_CONFIG_MEMORY_ORDER_DEPENDENCY 1
 
 #include <Availability.h>
 #include <TargetConditionals.h>
@@ -36,7 +39,6 @@
 #include <assert.h>
 #include <crt_externs.h>
 #include <dirent.h>
-#include <dlfcn.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <libc.h>
@@ -54,12 +56,19 @@
 #include <mach/vm_page_size.h>
 #include <mach/vm_param.h>
 #include <mach/vm_statistics.h>
-#include <os/internal/internal_shared.h>
+#include <machine/cpu_capabilities.h>
+#include <os/atomic_private.h>
+#include <os/crashlog_private.h>
 #include <os/lock_private.h>
 #include <os/once_private.h>
 #include <os/overflow.h>
+#if !TARGET_OS_DRIVERKIT
+# include <os/feature_private.h>
+#endif
 #include <os/tsd.h>
 #include <paths.h>
+#include <pthread/private.h>  // _pthread_threadid_self_np_direct()
+#include <pthread/tsd_private.h>  // TSD keys
 #include <signal.h>
 #include <stdarg.h>
 #include <stdbool.h>
@@ -75,18 +84,18 @@
 #include <sys/random.h>
 #include <sys/types.h>
 #include <sys/vmparam.h>
+#include <thread_stack_pcs.h>
 #include <unistd.h>
 #include <xlocale.h>
 
 #include "dtrace.h"
-
 #include "base.h"
 #include "trace.h"
 #include "platform.h"
 #include "debug.h"
 #include "locking.h"
 #include "bitarray.h"
-#include "malloc.h"
+#include "malloc/malloc.h"
 #include "printf.h"
 #include "frozen_malloc.h"
 #include "legacy_malloc.h"
@@ -95,28 +104,31 @@
 #include "nano_malloc_common.h"
 #include "nano_malloc.h"
 #include "nanov2_malloc.h"
+#include "pguard_malloc.h"
 #include "purgeable_malloc.h"
 #include "malloc_private.h"
-#include "stack_logging.h"
-#include "stack_logging_internal.h"
 #include "thresholds.h"
 #include "vm.h"
-
 #include "magazine_rack.h"
 #include "magazine_zone.h"
 #include "nano_zone_common.h"
 #include "nano_zone.h"
 #include "nanov2_zone.h"
-
 #include "magazine_inline.h"
-
-extern uint64_t malloc_entropy[2];
+#include "stack_logging.h"
+#include "malloc_implementation.h"
 
 MALLOC_NOEXPORT
-extern boolean_t malloc_tracing_enabled;
+extern bool malloc_tracing_enabled;
 
 MALLOC_NOEXPORT
 extern unsigned malloc_debug_flags;
+
+MALLOC_NOEXPORT
+extern bool malloc_space_efficient_enabled;
+
+MALLOC_NOEXPORT
+extern bool malloc_medium_space_efficient_enabled;
 
 MALLOC_NOEXPORT MALLOC_NOINLINE
 void
@@ -126,7 +138,31 @@
 int
 malloc_gdb_po_unsafe(void);
 
-MALLOC_NOEXPORT
-extern uint64_t max_lite_mallocs;
+MALLOC_NOEXPORT __attribute__((always_inline, const))
+static inline bool
+malloc_traced(void)
+{
+	return malloc_tracing_enabled;
+}
+
+/*
+  * Copies the malloc library's _malloc_msl_lite_hooks_t structure to a given
+  * location. Size is passed to allow the structure to  grow. Since this is
+  * a temporary arrangement, we don't need to worry about
+  * pointer authentication here or in the _malloc_msl_lite_hooks_t structure
+  * itself.
+  */
+struct _malloc_msl_lite_hooks_s;
+typedef void (*set_msl_lite_hooks_callout_t) (struct _malloc_msl_lite_hooks_s *hooksp, size_t size);
+void set_msl_lite_hooks(set_msl_lite_hooks_callout_t callout);
+
+
+// pthread reserves 5 TSD keys for libmalloc
+#define __TSD_MALLOC_PGUARD_SAMPLE_COUNTER __PTK_LIBMALLOC_KEY0
+#define __TSD_MALLOC_UNUSED1               __PTK_LIBMALLOC_KEY1
+#define __TSD_MALLOC_UNUSED2               __PTK_LIBMALLOC_KEY2
+#define __TSD_MALLOC_UNUSED3               __PTK_LIBMALLOC_KEY3
+#define __TSD_MALLOC_UNUSED4               __PTK_LIBMALLOC_KEY4
+
 
 #endif // __INTERNAL_H