Index: lib/sanitizer_common/sanitizer_stacktrace.h
===================================================================
--- lib/sanitizer_common/sanitizer_stacktrace.h
+++ lib/sanitizer_common/sanitizer_stacktrace.h
@@ -15,6 +15,10 @@
 
 #include "sanitizer_internal_defs.h"
 
+#if SANITIZER_FREEBSD
+#include <osreldate.h>  // for __FreeBSD_version
+#endif
+
 namespace __sanitizer {
 
 static const uptr kStackTraceMax = 256;
@@ -41,14 +45,23 @@
 
   static bool WillUseFastUnwind(bool request_fast_unwind) {
     // Check if fast unwind is available. Fast unwind is the only option on Mac.
-    // It is also the only option on FreeBSD as the slow unwinding that
+    // It is also the only option on FreeBSD 9.2 as the slow unwinding that
     // leverages _Unwind_Backtrace() yields the call stack of the signal's
     // handler and not of the code that raised the signal (as it does on Linux).
-    if (!SANITIZER_CAN_FAST_UNWIND)
-      return false;
-    else if (SANITIZER_MAC != 0 || SANITIZER_FREEBSD != 0)
-      return true;
-    return request_fast_unwind;
+#if !SANITIZER_CAN_FAST_UNWIND
+    const bool UseFastUnwind = false;
+#elif SANITIZER_MAC
+    const bool UseFastUnwind = true;
+#elif SANITIZER_FREEBSD
+# if __FreeBSD_version <= 902001  // v9.2
+    const bool UseFastUnwind = true;
+# else
+    const bool UseFastUnwind = request_fast_unwind;
+# endif
+#else
+    const bool UseFastUnwind = request_fast_unwind;
+#endif
+    return UseFastUnwind;
   }
 
   static uptr GetCurrentPc();