src/cpu/ppc/vm/frame_ppc.cpp

*** 47,64 ****
  }
  #endif // ASSERT
  
  bool frame::safe_for_sender(JavaThread *thread) {
    bool safe = false;
!   address   cursp = (address)sp();
!   address   curfp = (address)fp();
!   if ((cursp != NULL && curfp != NULL &&
!       (cursp <= thread->stack_base() && cursp >= thread->stack_base() - thread->stack_size())) &&
!       (curfp <= thread->stack_base() && curfp >= thread->stack_base() - thread->stack_size())) {
!       safe = true;
    }
!   return safe;
  }
  
  bool frame::is_interpreted_frame() const  {
    return Interpreter::contains(pc());
  }
--- 47,184 ----
  }
  #endif // ASSERT
  
  bool frame::safe_for_sender(JavaThread *thread) {
    bool safe = false;
!   address sp = (address)_sp;
!   address fp = (address)_fp;
!   address unextended_sp = (address)_unextended_sp;
! 
!   // Consider stack guards when trying to determine "safe" stack pointers
!   static size_t stack_guard_size = os::uses_stack_guard_pages() ?
!     thread->stack_red_zone_size() + thread->stack_yellow_zone_size() : 0;
!   size_t usable_stack_size = thread->stack_size() - stack_guard_size;
! 
!   // sp must be within the usable part of the stack (not in guards)
!   bool sp_safe = (sp < thread->stack_base()) &&
!                  (sp >= thread->stack_base() - usable_stack_size);
! 
! 
!   if (!sp_safe) {
!     return false;
!   }
! 
!   // Unextended sp must be within the stack and above or equal sp
!   bool unextended_sp_safe = (unextended_sp < thread->stack_base()) && (unextended_sp >= sp);
! 
!   if (!unextended_sp_safe) {
!     return false;
!   }
! 
!   // An fp must be within the stack and above (but not equal) sp.
!   bool fp_safe = (fp <= thread->stack_base()) &&  (fp > sp);
!   // an interpreter fp must be within the stack and above (but not equal) sp
!   bool fp_interp_safe = (fp <= thread->stack_base()) &&  (fp > sp) &&
!     ((fp - sp) >= (ijava_state_size + top_ijava_frame_abi_size));
! 
!   // We know sp/unextended_sp are safe, only fp is questionable here
! 
!   // If the current frame is known to the code cache then we can attempt to
!   // to construct the sender and do some validation of it. This goes a long way
!   // toward eliminating issues when we get in frame construction code
! 
!   if (_cb != NULL ){
!     // Entry frame checks
!     if (is_entry_frame()) {
!       // An entry frame must have a valid fp.
!       return fp_safe && is_entry_frame_valid(thread);
      }
! 
!     // Now check if the frame is complete and the test is
!     // reliable. Unfortunately we can only check frame completeness for
!     // runtime stubs and nmethods. Other generic buffer blobs are more
!     // problematic so we just assume they are OK. Adapter blobs never have a
!     // complete frame and are never OK
!     if (!_cb->is_frame_complete_at(_pc)) {
!       if (_cb->is_nmethod() || _cb->is_adapter_blob() || _cb->is_runtime_stub()) {
!         return false;
!       }
!     }
! 
!     // Could just be some random pointer within the codeBlob.
!     if (!_cb->code_contains(_pc)) {
!       return false;
!     }
! 
!     if (is_interpreted_frame() && !fp_interp_safe) {
!       return false;
!     }
! 
!     abi_minframe* sender_abi = (abi_minframe*) fp;
!     intptr_t* sender_sp = (intptr_t*) fp;
!     address   sender_pc = (address) sender_abi->lr;;
! 
!     // We must always be able to find a recognizable pc.
!     CodeBlob* sender_blob = CodeCache::find_blob_unsafe(sender_pc);
!     if (sender_blob == NULL) {
!       return false;
!     }
! 
!     // Could be a zombie method
!     if (sender_blob->is_zombie() || sender_blob->is_unloaded()) {
!       return false;
!     }
! 
!     // It should be safe to construct the sender though it might not be valid.
! 
!     frame sender(sender_sp, sender_pc);
! 
!     // Do we have a valid fp?
!     address sender_fp = (address) sender.fp();
! 
!     // sender_fp must be within the stack and above (but not
!     // equal) current frame's fp.
!     if (sender_fp > thread->stack_base() || sender_fp <= fp) {
!         return false;
!     }
! 
!     // If the potential sender is the interpreter then we can do some more checking.
!     if (Interpreter::contains(sender_pc)) {
!       return sender.is_interpreted_frame_valid(thread);
!     }
! 
!     // Could just be some random pointer within the codeBlob.
!     if (!sender.cb()->code_contains(sender_pc)) {
!       return false;
!     }
! 
!     // We should never be able to see an adapter if the current frame is something from code cache.
!     if (sender_blob->is_adapter_blob()) {
!       return false;
!     }
! 
!     if (sender.is_entry_frame()) {
!       return sender.is_entry_frame_valid(thread);
!     }
! 
!     // Frame size is always greater than zero. If the sender frame size is zero or less,
!     // something is really weird and we better give up.
!     if (sender_blob->frame_size() <= 0) {
!       return false;
!     }
! 
!     return true;
!   }
! 
!   // Must be native-compiled frame. Since sender will try and use fp to find
!   // linkages it must be safe
! 
!   if (!fp_safe) {
!     return false;
!   }
! 
!   return true;
  }
  
  bool frame::is_interpreted_frame() const  {
    return Interpreter::contains(pc());
  }