Index: lib/sanitizer_common/sanitizer_common_interceptors.inc
===================================================================
--- lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -7561,6 +7561,15 @@
 INTERCEPTOR(int, sysctlbyname, char *sname, void *oldp, SIZE_T *oldlenp,
             void *newp, SIZE_T newlen) {
   void *ctx;
+  if (UNLIKELY(COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED)) {
+    // On Darwin iOS simulators `sysctlbyname` gets called early
+    // during init. If we do TSan init now we'll trigger a
+    // call to `__cxa_atexit` which will crash due the implementing
+    // library not being properly initialized. To avoid this simply
+    // don't intercept this function until init has been triggered
+    // from elsewhere.
+    return REAL(sysctlbyname)(sname, oldp, oldlenp, newp, newlen);
+  }
   COMMON_INTERCEPTOR_ENTER(ctx, sysctlbyname, sname, oldp, oldlenp, newp,
                            newlen);
   if (sname)