/*

 * Copyright 1997-2009 Sun Microsystems, Inc.  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

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 *

 */

# include "incls/_precompiled.incl"

# include "incls/_frame_x86.cpp.incl"

#ifdef ASSERT

void RegisterMap::check_location_valid() {

}

#endif

// Profiling/safepoint support

bool frame::safe_for_sender(JavaThread *thread) {

  address   sp = (address)_sp;

  address   fp = (address)_fp;

  address   unextended_sp = (address)_unextended_sp;

  // sp must be within the stack

  bool sp_safe = (sp <= thread->stack_base()) &&

                 (sp >= thread->stack_base() - thread->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);

  // 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 ) {

    // First check if frame is complete and tester is reliable

    // Unfortunately we can only check frame complete for runtime stubs and nmethod

    // other generic buffer blobs are more problematic so we just assume they are

    // ok. adapter blobs never have a frame complete 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;

      }

    }

    // Entry frame checks

    if (is_entry_frame()) {

      // an entry frame must have a valid fp.

      if (!fp_safe) return false;

      // Validate the JavaCallWrapper an entry frame must have

      address jcw = (address)entry_frame_call_wrapper();

      bool jcw_safe = (jcw <= thread->stack_base()) && ( jcw > fp);

      return jcw_safe;

    }

    intptr_t* sender_sp = NULL;

    address   sender_pc = NULL;

    if (is_interpreted_frame()) {

      // fp must be safe

      if (!fp_safe) {

        return false;

      }

      sender_pc = (address) this->fp()[return_addr_offset];

      sender_sp = (intptr_t*) addr_at(sender_sp_offset);

    } else {

      // must be some sort of compiled/runtime frame

      // fp does not have to be safe (although it could be check for c1?)

      sender_sp = _unextended_sp + _cb->frame_size();

      // On Intel the return_address is always the word on the stack

      sender_pc = (address) *(sender_sp-1);

    }

    // We must always be able to find a recognizable pc

    CodeBlob* sender_blob = CodeCache::find_blob_unsafe(sender_pc);

    if (sender_pc == NULL ||  sender_blob == NULL) {

      return false;

    }

    // If the potential sender is the interpreter then we can do some more checking

    if (Interpreter::contains(sender_pc)) {

      // ebp is always saved in a recognizable place in any code we generate. However

      // only if the sender is interpreted/call_stub (c1 too?) are we certain that the saved ebp

      // is really a frame pointer.

      intptr_t *saved_fp = (intptr_t*)*(sender_sp - frame::sender_sp_offset);

      bool saved_fp_safe = ((address)saved_fp <= thread->stack_base()) && (saved_fp > sender_sp);

      if (!saved_fp_safe) {

        return false;

      }

      // construct the potential sender

      frame sender(sender_sp, saved_fp, sender_pc);

      return sender.is_interpreted_frame_valid(thread);

    }

    // Could just be some random pointer within the codeBlob

    if (!sender_blob->instructions_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;

    }

    // Could be the call_stub

    if (StubRoutines::returns_to_call_stub(sender_pc)) {

      intptr_t *saved_fp = (intptr_t*)*(sender_sp - frame::sender_sp_offset);

      bool saved_fp_safe = ((address)saved_fp <= thread->stack_base()) && (saved_fp > sender_sp);

      if (!saved_fp_safe) {

        return false;

      }

      // construct the potential sender

      frame sender(sender_sp, saved_fp, sender_pc);

      // Validate the JavaCallWrapper an entry frame must have

      address jcw = (address)sender.entry_frame_call_wrapper();

      bool jcw_safe = (jcw <= thread->stack_base()) && ( jcw > (address)sender.fp());

      return jcw_safe;

    }

    // If the frame size is 0 something is bad because every nmethod has a non-zero frame size

    // because the return address counts against the callee's frame.

    if (sender_blob->frame_size() == 0) {

      assert(!sender_blob->is_nmethod(), "should count return address at least");

      return false;

    }

    // We should never be able to see anything here except an nmethod. If something in the

    // code cache (current frame) is called by an entity within the code cache that entity

    // should not be anything but the call stub (already covered), the interpreter (already covered)

    // or an nmethod.

    assert(sender_blob->is_nmethod(), "Impossible call chain");

    // Could put some more validation for the potential non-interpreted sender

    // frame we'd create by calling sender if I could think of any. Wait for next crash in forte...

    // One idea is seeing if the sender_pc we have is one that we'd expect to call to current cb

    // We've validated the potential sender that would be created

    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;

  }

  // Will the pc we fetch be non-zero (which we'll find at the oldest frame)

  if ( (address) this->fp()[return_addr_offset] == NULL) return false;

  // could try and do some more potential verification of native frame if we could think of some...

  return true;

}

void frame::patch_pc(Thread* thread, address pc) {

  if (TracePcPatching) {

    tty->print_cr("patch_pc at address" INTPTR_FORMAT " [" INTPTR_FORMAT " -> " INTPTR_FORMAT "] ",

                  &((address *)sp())[-1], ((address *)sp())[-1], pc);

  }

  ((address *)sp())[-1] = pc;

  _cb = CodeCache::find_blob(pc);

  if (_cb != NULL && _cb->is_nmethod() && ((nmethod*)_cb)->is_deopt_pc(_pc)) {

    address orig = (((nmethod*)_cb)->get_original_pc(this));

    assert(orig == _pc, "expected original to be stored before patching");

    _deopt_state = is_deoptimized;

    // leave _pc as is

  } else {

    _deopt_state = not_deoptimized;

    _pc = pc;

  }

}

bool frame::is_interpreted_frame() const  {

  return Interpreter::contains(pc());

}

int frame::frame_size(RegisterMap* map) const {

  frame sender = this->sender(map);

  return sender.sp() - sp();

}

intptr_t* frame::entry_frame_argument_at(int offset) const {

  // convert offset to index to deal with tsi

  int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);

  // Entry frame's arguments are always in relation to unextended_sp()

  return &unextended_sp()[index];

}

// sender_sp

#ifdef CC_INTERP

intptr_t* frame::interpreter_frame_sender_sp() const {

  assert(is_interpreted_frame(), "interpreted frame expected");

  // QQQ why does this specialize method exist if frame::sender_sp() does same thing?

  // seems odd and if we always know interpreted vs. non then sender_sp() is really

  // doing too much work.

  return get_interpreterState()->sender_sp();

}

// monitor elements

BasicObjectLock* frame::interpreter_frame_monitor_begin() const {

  return get_interpreterState()->monitor_base();

}

BasicObjectLock* frame::interpreter_frame_monitor_end() const {

  return (BasicObjectLock*) get_interpreterState()->stack_base();

}

#else // CC_INTERP

intptr_t* frame::interpreter_frame_sender_sp() const {

  assert(is_interpreted_frame(), "interpreted frame expected");

  return (intptr_t*) at(interpreter_frame_sender_sp_offset);

}

void frame::set_interpreter_frame_sender_sp(intptr_t* sender_sp) {

  assert(is_interpreted_frame(), "interpreted frame expected");

  ptr_at_put(interpreter_frame_sender_sp_offset, (intptr_t) sender_sp);

}

// monitor elements

BasicObjectLock* frame::interpreter_frame_monitor_begin() const {

  return (BasicObjectLock*) addr_at(interpreter_frame_monitor_block_bottom_offset);

}

BasicObjectLock* frame::interpreter_frame_monitor_end() const {

  BasicObjectLock* result = (BasicObjectLock*) *addr_at(interpreter_frame_monitor_block_top_offset);

  // make sure the pointer points inside the frame

  assert((intptr_t) fp() >  (intptr_t) result, "result must <  than frame pointer");

  assert((intptr_t) sp() <= (intptr_t) result, "result must >= than stack pointer");

  return result;

}

void frame::interpreter_frame_set_monitor_end(BasicObjectLock* value) {

  *((BasicObjectLock**)addr_at(interpreter_frame_monitor_block_top_offset)) = value;

}

// Used by template based interpreter deoptimization

void frame::interpreter_frame_set_last_sp(intptr_t* sp) {

    *((intptr_t**)addr_at(interpreter_frame_last_sp_offset)) = sp;

}

#endif // CC_INTERP

frame frame::sender_for_entry_frame(RegisterMap* map) const {

  assert(map != NULL, "map must be set");

  // Java frame called from C; skip all C frames and return top C

  // frame of that chunk as the sender

  JavaFrameAnchor* jfa = entry_frame_call_wrapper()->anchor();

  assert(!entry_frame_is_first(), "next Java fp must be non zero");

  assert(jfa->last_Java_sp() > sp(), "must be above this frame on stack");

  map->clear();

  assert(map->include_argument_oops(), "should be set by clear");

  if (jfa->last_Java_pc() != NULL ) {

    frame fr(jfa->last_Java_sp(), jfa->last_Java_fp(), jfa->last_Java_pc());

    return fr;

  }

  frame fr(jfa->last_Java_sp(), jfa->last_Java_fp());

  return fr;

}

frame frame::sender_for_interpreter_frame(RegisterMap* map) const {

  // sp is the raw sp from the sender after adapter or interpreter extension

  intptr_t* sp = (intptr_t*) addr_at(sender_sp_offset);

  // This is the sp before any possible extension (adapter/locals).

  intptr_t* unextended_sp = interpreter_frame_sender_sp();

  // The interpreter and compiler(s) always save EBP/RBP in a known

  // location on entry. We must record where that location is

  // so this if EBP/RBP was live on callout from c2 we can find

  // the saved copy no matter what it called.

  // Since the interpreter always saves EBP/RBP if we record where it is then

  // we don't have to always save EBP/RBP on entry and exit to c2 compiled

  // code, on entry will be enough.

#ifdef COMPILER2

  if (map->update_map()) {

    map->set_location(rbp->as_VMReg(), (address) addr_at(link_offset));

#ifdef AMD64

    // this is weird "H" ought to be at a higher address however the

    // oopMaps seems to have the "H" regs at the same address and the

    // vanilla register.

    // XXXX make this go away

    if (true) {

      map->set_location(rbp->as_VMReg()->next(), (address)addr_at(link_offset));

    }

#endif // AMD64

  }

#endif /* COMPILER2 */

}

//------------------------------sender_for_compiled_frame-----------------------

frame frame::sender_for_compiled_frame(RegisterMap* map) const {

  assert(map != NULL, "map must be set");

  const bool c1_compiled = _cb->is_compiled_by_c1();

  // frame owned by optimizing compiler

  intptr_t* sender_sp = NULL;

  assert(_cb->frame_size() >= 0, "must have non-zero frame size");

  sender_sp = unextended_sp() + _cb->frame_size();

  // On Intel the return_address is always the word on the stack

  address sender_pc = (address) *(sender_sp-1);

  // This is the saved value of ebp which may or may not really be an fp.

  // it is only an fp if the sender is an interpreter frame (or c1?)

  intptr_t *saved_fp = (intptr_t*)*(sender_sp - frame::sender_sp_offset);

  if (map->update_map()) {

    // Tell GC to use argument oopmaps for some runtime stubs that need it.

    // For C1, the runtime stub might not have oop maps, so set this flag

    // outside of update_register_map.

    map->set_include_argument_oops(_cb->caller_must_gc_arguments(map->thread()));

    if (_cb->oop_maps() != NULL) {

      OopMapSet::update_register_map(this, map);

    }

    // Since the prolog does the save and restore of epb there is no oopmap

    // for it so we must fill in its location as if there was an oopmap entry

    // since if our caller was compiled code there could be live jvm state in it.

    map->set_location(rbp->as_VMReg(), (address) (sender_sp - frame::sender_sp_offset));

#ifdef AMD64

    // this is weird "H" ought to be at a higher address however the

    // oopMaps seems to have the "H" regs at the same address and the

    // vanilla register.

    // XXXX make this go away

    if (true) {

      map->set_location(rbp->as_VMReg()->next(), (address) (sender_sp - frame::sender_sp_offset));

    }

#endif // AMD64

  }

  assert(sender_sp != sp(), "must have changed");

}

frame frame::sender(RegisterMap* map) const {

  // Default is we done have to follow them. The sender_for_xxx will

  // update it accordingly

  map->set_include_argument_oops(false);

  if (is_entry_frame())       return sender_for_entry_frame(map);

  if (is_interpreted_frame()) return sender_for_interpreter_frame(map);

  assert(_cb == CodeCache::find_blob(pc()),"Must be the same");

  if (_cb != NULL) {

    return sender_for_compiled_frame(map);

  }

  // Must be native-compiled frame, i.e. the marshaling code for native

  // methods that exists in the core system.

  return frame(sender_sp(), link(), sender_pc());

}

bool frame::interpreter_frame_equals_unpacked_fp(intptr_t* fp) {

  assert(is_interpreted_frame(), "must be interpreter frame");

  methodOop method = interpreter_frame_method();

  // When unpacking an optimized frame the frame pointer is

  // adjusted with:

  int diff = (method->max_locals() - method->size_of_parameters()) *

             Interpreter::stackElementWords();

  return _fp == (fp - diff);

}

void frame::pd_gc_epilog() {

  // nothing done here now

}

bool frame::is_interpreted_frame_valid(JavaThread* thread) const {

// QQQ

#ifdef CC_INTERP

#else

  assert(is_interpreted_frame(), "Not an interpreted frame");

  // These are reasonable sanity checks

  if (fp() == 0 || (intptr_t(fp()) & (wordSize-1)) != 0) {

    return false;

  }

  if (sp() == 0 || (intptr_t(sp()) & (wordSize-1)) != 0) {

    return false;

  }

  if (fp() + interpreter_frame_initial_sp_offset < sp()) {

    return false;

  }

  // These are hacks to keep us out of trouble.

  // The problem with these is that they mask other problems

  if (fp() <= sp()) {        // this attempts to deal with unsigned comparison above

    return false;

  }

  // do some validation of frame elements

  // first the method

  methodOop m = *interpreter_frame_method_addr();

  // validate the method we'd find in this potential sender

  if (!Universe::heap()->is_valid_method(m)) return false;

  // stack frames shouldn't be much larger than max_stack elements

  if (fp() - sp() > 1024 + m->max_stack()*Interpreter::stackElementSize()) {

    return false;

  }

  // validate bci/bcx

  intptr_t  bcx    = interpreter_frame_bcx();

  if (m->validate_bci_from_bcx(bcx) < 0) {

    return false;

  }

  // validate constantPoolCacheOop

  constantPoolCacheOop cp = *interpreter_frame_cache_addr();

  if (cp == NULL ||

      !Space::is_aligned(cp) ||

      !Universe::heap()->is_permanent((void*)cp)) return false;

  // validate locals

  address locals =  (address) *interpreter_frame_locals_addr();