Index: lib/tsan/rtl/tsan_platform.h
===================================================================
--- lib/tsan/rtl/tsan_platform.h
+++ lib/tsan/rtl/tsan_platform.h
@@ -816,6 +816,7 @@
 void WriteMemoryProfile(char *buf, uptr buf_size, uptr nthread, uptr nlive);
 int ExtractResolvFDs(void *state, int *fds, int nfd);
 int ExtractRecvmsgFDs(void *msg, int *fds, int nfd);
+void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size);
 
 int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
     void *abstime), void *c, void *m, void *abstime,
Index: lib/tsan/rtl/tsan_platform_linux.cc
===================================================================
--- lib/tsan/rtl/tsan_platform_linux.cc
+++ lib/tsan/rtl/tsan_platform_linux.cc
@@ -320,6 +320,20 @@
   return res;
 }
 
+void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size) {
+  // Check that the thr object is in tls;
+  const uptr thr_beg = (uptr)thr;
+  const uptr thr_end = (uptr)thr + sizeof(*thr);
+  CHECK_GE(thr_beg, tls_addr);
+  CHECK_LE(thr_beg, tls_addr + tls_size);
+  CHECK_GE(thr_end, tls_addr);
+  CHECK_LE(thr_end, tls_addr + tls_size);
+  // Since the thr object is huge, skip it.
+  MemoryRangeImitateWrite(thr, /*pc=*/ 2, tls_addr, thr_beg - tls_addr);
+  MemoryRangeImitateWrite(thr, /*pc=*/ 2,
+      thr_end, tls_addr + tls_size - thr_end);
+}
+
 // Note: this function runs with async signals enabled,
 // so it must not touch any tsan state.
 int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
Index: lib/tsan/rtl/tsan_platform_mac.cc
===================================================================
--- lib/tsan/rtl/tsan_platform_mac.cc
+++ lib/tsan/rtl/tsan_platform_mac.cc
@@ -240,6 +240,18 @@
 }
 
 #if !SANITIZER_GO
+void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size) {
+  CHECK_EQ(tls_addr, (uptr)pthread_self());
+
+  // We stash a pointer to ThreadState in the tls shadow memory,
+  // make sure we don't clobber it.
+  tls_addr += sizeof(uptr);
+  tls_size -= sizeof(uptr);
+  MemoryRangeImitateWrite(thr, /*pc=*/ 2, tls_addr, tls_size);
+}
+#endif
+
+#if !SANITIZER_GO
 // Note: this function runs with async signals enabled,
 // so it must not touch any tsan state.
 int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
Index: lib/tsan/rtl/tsan_rtl_thread.cc
===================================================================
--- lib/tsan/rtl/tsan_rtl_thread.cc
+++ lib/tsan/rtl/tsan_rtl_thread.cc
@@ -248,19 +248,8 @@
     if (stk_addr && stk_size)
       MemoryRangeImitateWrite(thr, /*pc=*/ 1, stk_addr, stk_size);
 
-    if (tls_addr && tls_size) {
-      // Check that the thr object is in tls;
-      const uptr thr_beg = (uptr)thr;
-      const uptr thr_end = (uptr)thr + sizeof(*thr);
-      CHECK_GE(thr_beg, tls_addr);
-      CHECK_LE(thr_beg, tls_addr + tls_size);
-      CHECK_GE(thr_end, tls_addr);
-      CHECK_LE(thr_end, tls_addr + tls_size);
-      // Since the thr object is huge, skip it.
-      MemoryRangeImitateWrite(thr, /*pc=*/ 2, tls_addr, thr_beg - tls_addr);
-      MemoryRangeImitateWrite(thr, /*pc=*/ 2,
-          thr_end, tls_addr + tls_size - thr_end);
-    }
+    if (tls_addr && tls_size)
+      ImitateTlsWrite(thr, tls_addr, tls_size);
   }
 #endif