--- old/src/os/posix/vm/os_posix.hpp	2019-01-28 17:43:07.000000000 +0800
+++ new/src/os/posix/vm/os_posix.hpp	2019-01-28 17:43:06.000000000 +0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -62,6 +62,33 @@
 };
 
 /*
+ * Crash protection utility used by JFR. Wrap the callback
+ * with a sigsetjmp and in case of a SIGSEGV/SIGBUS we siglongjmp
+ * back.
+ * To be able to use this - don't take locks, don't rely on destructors,
+ * don't make OS library calls, don't allocate memory, don't print,
+ * don't call code that could leave the heap / memory in an inconsistent state,
+ * or anything else where we are not in control if we suddenly jump out.
+ */
+class ThreadCrashProtection : public StackObj {
+public:
+  static bool is_crash_protected(Thread* thr) {
+    return _crash_protection != NULL && _protected_thread == thr;
+  }
+
+  ThreadCrashProtection();
+  bool call(os::CrashProtectionCallback& cb);
+
+  static void check_crash_protection(int signal, Thread* thread);
+private:
+  static Thread* _protected_thread;
+  static ThreadCrashProtection* _crash_protection;
+  static volatile intptr_t _crash_mux;
+  void restore();
+  sigjmp_buf _jmpbuf;
+};
+
+/*
  * Crash protection for the watcher thread. Wrap the callback
  * with a sigsetjmp and in case of a SIGSEGV/SIGBUS we siglongjmp
  * back.