--- /dev/null
+++ dyld/dyld-941.4/libdyld/LibSystemHelpers.cpp
@@ -0,0 +1,184 @@
+/*
+ * Copyright (c) 2017 Apple Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+
+#include <string.h>
+#include <stdint.h>
+#include <sys/errno.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <TargetConditionals.h>
+#include <_simple.h>
+#include <mach-o/dyld_priv.h>
+#include <malloc/malloc.h>
+#include <mach-o/dyld.h>
+#include <mach-o/dyld_priv.h>
+#include <dlfcn.h>
+#include <dlfcn_private.h>
+#include <libc_private.h>
+#include <ptrauth.h>
+#if !TARGET_OS_DRIVERKIT
+  #include <vproc_priv.h>
+#endif
+
+// atexit header is missing C++ guards
+extern "C" {
+    #include <System/atexit.h>
+}
+
+// libc is missing header declaration for this
+extern "C" int __cxa_atexit(void (*func)(void*), void* arg, void* dso);
+
+#include "LibSystemHelpers.h"
+#include "DyldProcessConfig.h"
+#include "DyldAPIs.h"
+
+// implemented in assembly
+extern "C" void* tlv_get_addr(dyld3::MachOAnalyzer::TLV_Thunk*);
+
+
+namespace dyld4 {
+
+uintptr_t LibSystemHelpers::version() const
+{
+    return 2;
+}
+
+void* LibSystemHelpers::malloc(size_t size) const
+{
+    return ::malloc(size);
+}
+
+void LibSystemHelpers::free(void* p) const
+{
+    ::free(p);
+}
+
+size_t LibSystemHelpers::malloc_size(const void* p) const
+{
+    return ::malloc_size(p);
+}
+
+kern_return_t LibSystemHelpers::vm_allocate(vm_map_t task, vm_address_t* address, vm_size_t size, int flags) const
+{
+    return ::vm_allocate(task, address, size, flags);
+}
+
+kern_return_t LibSystemHelpers::vm_deallocate(vm_map_t task, vm_address_t address, vm_size_t size) const
+{
+    return ::vm_deallocate(task, address, size);
+}
+
+// Note: driverkit uses a different arm64e ABI, so we cannot call libSystem's pthread_key_create() from dyld
+int LibSystemHelpers::pthread_key_create_free(pthread_key_t* key) const
+{
+    return ::pthread_key_create(key, &::free);
+}
+
+static void finalizeListTLV_thunk(void* list)
+{
+    // Called by pthreads when the current thread is going away
+    gDyld.apis->_finalizeListTLV(list);
+}
+
+// Note: driverkit uses a different arm64e ABI, so we cannot call libSystem's pthread_key_create() from dyld
+int LibSystemHelpers::pthread_key_create_thread_exit(pthread_key_t* key) const
+{
+    return ::pthread_key_create(key, &finalizeListTLV_thunk);
+}
+
+void* LibSystemHelpers::pthread_getspecific(pthread_key_t key) const
+{
+    return ::pthread_getspecific(key);
+}
+
+int LibSystemHelpers::pthread_setspecific(pthread_key_t key, const void* value) const
+{
+    return ::pthread_setspecific(key, value);
+}
+
+void LibSystemHelpers::__cxa_atexit(void (*func)(void*), void* arg, void* dso) const
+{
+#if !__arm64e__
+    // Note: for arm64e driverKit uses a different ABI for function pointers,
+    // but dyld does not support static terminators for arm64e
+    ::__cxa_atexit(func, arg, dso);
+#endif
+}
+
+void LibSystemHelpers::__cxa_finalize_ranges(const __cxa_range_t ranges[], unsigned int count) const
+{
+    ::__cxa_finalize_ranges(ranges, count);
+}
+
+bool LibSystemHelpers::isLaunchdOwned() const
+{
+#if TARGET_OS_DRIVERKIT
+    return false;
+#else
+    // the vproc_swap_integer() call has to be to libSystem.dylib's function - not a static copy in dyld
+    int64_t val = 0;
+    ::vproc_swap_integer(nullptr, VPROC_GSK_IS_MANAGED, nullptr, &val);
+	return ( val != 0 );
+#endif
+}
+
+void LibSystemHelpers::os_unfair_recursive_lock_lock_with_options(os_unfair_recursive_lock_t lock, os_unfair_lock_options_t options) const
+{
+    ::os_unfair_recursive_lock_lock_with_options(lock, options);
+}
+
+void LibSystemHelpers::os_unfair_recursive_lock_unlock(os_unfair_recursive_lock_t lock) const
+{
+    ::os_unfair_recursive_lock_unlock(lock);
+}
+
+void LibSystemHelpers::exit(int result) const
+{
+    ::exit(result);
+}
+
+const char* LibSystemHelpers::getenv(const char* key) const
+{
+    return ::getenv(key);
+}
+
+int LibSystemHelpers::mkstemp(char* templatePath) const
+{
+    return ::mkstemp(templatePath);
+}
+
+LibSystemHelpers::TLVGetAddrFunc LibSystemHelpers::getTLVGetAddrFunc() const
+{
+    return &::tlv_get_addr;
+}
+
+// Added in version 2
+
+void LibSystemHelpers::os_unfair_recursive_lock_unlock_forked_child(os_unfair_recursive_lock_t lock) const
+{
+    ::os_unfair_recursive_lock_unlock_forked_child(lock);
+}
+
+} // namespace dyld4
+