src/hotspot/share/code/nmethod.cpp

*** 1157,1166 ****
--- 1157,1179 ----
    if (PrintCompilation && _state != unloaded) {
      print_on(tty, state_msg);
    }
  }
  
+ void nmethod::unlink_from_method(bool acquire_lock) {
+   // We need to check if both the _code and _from_compiled_code_entry_point
+   // refer to this nmethod because there is a race in setting these two fields
+   // in Method* as seen in bugid 4947125.
+   // If the vep() points to the zombie nmethod, the memory for the nmethod
+   // could be flushed and the compiler and vtable stubs could still call
+   // through it.
+   if (method() != NULL && (method()->code() == this ||
+                            method()->from_compiled_entry() == verified_entry_point())) {
+     method()->clear_code(acquire_lock);
+   }
+ }
+ 
  /**
   * Common functionality for both make_not_entrant and make_zombie
   */
  bool nmethod::make_not_entrant_or_zombie(int state) {
    assert(state == zombie || state == not_entrant, "must be zombie or not_entrant");
***************
*** 1244,1264 ****
  
      // Invalidate while holding the patching lock
      JVMCI_ONLY(maybe_invalidate_installed_code());
  
      // Remove nmethod from method.
!     // We need to check if both the _code and _from_compiled_code_entry_point
!     // refer to this nmethod because there is a race in setting these two fields
!     // in Method* as seen in bugid 4947125.
!     // If the vep() points to the zombie nmethod, the memory for the nmethod
!     // could be flushed and the compiler and vtable stubs could still call
!     // through it.
!     if (method() != NULL && (method()->code() == this ||
!                              method()->from_compiled_entry() == verified_entry_point())) {
!       HandleMark hm;
!       method()->clear_code(false /* already owns Patching_lock */);
!     }
    } // leave critical region under Patching_lock
  
  #ifdef ASSERT
    if (is_osr_method() && method() != NULL) {
      // Make sure osr nmethod is invalidated, i.e. not on the list
--- 1257,1267 ----
  
      // Invalidate while holding the patching lock
      JVMCI_ONLY(maybe_invalidate_installed_code());
  
      // Remove nmethod from method.
!     unlink_from_method(false /* already owns Patching_lock */);
    } // leave critical region under Patching_lock
  
  #ifdef ASSERT
    if (is_osr_method() && method() != NULL) {
      // Make sure osr nmethod is invalidated, i.e. not on the list