Index: lib/sanitizer_common/sanitizer_mac.cc
===================================================================
--- lib/sanitizer_common/sanitizer_mac.cc
+++ lib/sanitizer_common/sanitizer_mac.cc
@@ -59,6 +59,7 @@
 #include <libkern/OSAtomic.h>
 #include <mach-o/dyld.h>
 #include <mach/mach.h>
+#include <mach/mach_time.h>
 #include <mach/vm_statistics.h>
 #include <pthread.h>
 #include <sched.h>
@@ -362,7 +363,9 @@
 }
 
 u64 NanoTime() {
-  return 0;
+  static mach_timebase_info_data_t timebase_info;
+  if (timebase_info.denom == 0) mach_timebase_info(&timebase_info);
+  return (mach_absolute_time() * timebase_info.numer) / timebase_info.denom;
 }
 
 uptr GetTlsSize() {