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diff --git a/lib/sanitizer_common/sanitizer_tls_get_addr.h b/lib/sanitizer_common/sanitizer_tls_get_addr.h
new file mode 100644
index 000000000000..0fc9a2257c68
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+++ b/lib/sanitizer_common/sanitizer_tls_get_addr.h
@@ -0,0 +1,60 @@
+//===-- sanitizer_tls_get_addr.h --------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Handle the __tls_get_addr call.
+//
+// All this magic is specific to glibc and is required to workaround
+// the lack of interface that would tell us about the Dynamic TLS (DTLS).
+// https://sourceware.org/bugzilla/show_bug.cgi?id=16291
+//
+// The matters get worse because the glibc implementation changed between
+// 2.18 and 2.19:
+// https://groups.google.com/forum/#!topic/address-sanitizer/BfwYD8HMxTM
+//
+// Before 2.19, every DTLS chunk is allocated with __libc_memalign,
+// which we intercept and thus know where is the DTLS.
+// Since 2.19, DTLS chunks are allocated with __signal_safe_memalign,
+// which is an internal function that wraps a mmap call, neither of which
+// we can intercept. Luckily, __signal_safe_memalign has a simple parseable
+// header which we can use.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SANITIZER_TLS_GET_ADDR_H
+#define SANITIZER_TLS_GET_ADDR_H
+
+#include "sanitizer_common.h"
+
+namespace __sanitizer {
+
+struct DTLS {
+  // Array of DTLS chunks for the current Thread.
+  // If beg == 0, the chunk is unused.
+  struct DTV {
+    uptr beg, size;
+  };
+
+  uptr dtv_size;
+  DTV *dtv;  // dtv_size elements, allocated by MmapOrDie.
+
+  // Auxiliary fields, don't access them outside sanitizer_tls_get_addr.cc
+  uptr last_memalign_size;
+  uptr last_memalign_ptr;
+};
+
+// Returns pointer and size of a linker-allocated TLS block.
+// Each block is returned exactly once.
+DTLS::DTV *DTLS_on_tls_get_addr(void *arg, void *res);
+void DTLS_on_libc_memalign(void *ptr, uptr size);
+DTLS *DTLS_Get();
+void DTLS_Destroy();  // Make sure to call this before the thread is destroyed.
+
+}  // namespace __sanitizer
+
+#endif  // SANITIZER_TLS_GET_ADDR_H