jdk

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/*
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 * Copyright (c) 2008, 2024, Oracle and/or its affiliates. All rights reserved.
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * This code is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License version 2 only, as
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 * published by the Free Software Foundation.
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 *
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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 * version 2 for more details (a copy is included in the LICENSE file that
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 * accompanied this code).
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 *
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 * You should have received a copy of the GNU General Public License version
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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 *
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 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * or visit www.oracle.com if you need additional information or have any
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 * questions.
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 *
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 */
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#include "precompiled.hpp"
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#include "compiler/oopMap.hpp"
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#include "interpreter/interpreter.hpp"
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#include "memory/resourceArea.hpp"
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#include "memory/universe.hpp"
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#include "oops/markWord.hpp"
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#include "oops/method.hpp"
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#include "oops/oop.inline.hpp"
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#include "prims/methodHandles.hpp"
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#include "runtime/frame.inline.hpp"
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#include "runtime/handles.inline.hpp"
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#include "runtime/javaCalls.hpp"
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#include "runtime/monitorChunk.hpp"
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#include "runtime/os.inline.hpp"
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#include "runtime/signature.hpp"
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#include "runtime/stubCodeGenerator.hpp"
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#include "runtime/stubRoutines.hpp"
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#include "vmreg_arm.inline.hpp"
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#ifdef COMPILER1
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#include "c1/c1_Runtime1.hpp"
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#include "runtime/vframeArray.hpp"
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#endif
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#ifdef ASSERT
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void RegisterMap::check_location_valid() {
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}
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#endif
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// Profiling/safepoint support
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bool frame::safe_for_sender(JavaThread *thread) {
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  address   sp = (address)_sp;
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  address   fp = (address)_fp;
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  address   unextended_sp = (address)_unextended_sp;
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  // consider stack guards when trying to determine "safe" stack pointers
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  // sp must be within the usable part of the stack (not in guards)
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  if (!thread->is_in_usable_stack(sp)) {
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    return false;
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  }
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  if (!thread->is_in_stack_range_incl(unextended_sp, sp)) {
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    return false;
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  }
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  // We know sp/unextended_sp are safe. Only fp is questionable here.
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  bool fp_safe = thread->is_in_stack_range_incl(fp, sp);
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  if (_cb != nullptr ) {
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    // First check if frame is complete and tester is reliable
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    // Unfortunately we can only check frame complete for runtime stubs and nmethod
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    // other generic buffer blobs are more problematic so we just assume they are
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    // ok. adapter blobs never have a frame complete and are never ok.
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    if (!_cb->is_frame_complete_at(_pc)) {
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      if (_cb->is_nmethod() || _cb->is_adapter_blob() || _cb->is_runtime_stub()) {
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        return false;
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      }
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    }
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    // Could just be some random pointer within the codeBlob
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    if (!_cb->code_contains(_pc)) {
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      return false;
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    }
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    // Entry frame checks
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    if (is_entry_frame()) {
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      // an entry frame must have a valid fp.
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      return fp_safe && is_entry_frame_valid(thread);
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    }
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    intptr_t* sender_sp = nullptr;
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    address   sender_pc = nullptr;
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    if (is_interpreted_frame()) {
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      // fp must be safe
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      if (!fp_safe) {
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        return false;
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      }
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      sender_pc = (address) this->fp()[return_addr_offset];
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      sender_sp = (intptr_t*) addr_at(sender_sp_offset);
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    } else {
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      // must be some sort of compiled/runtime frame
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      // fp does not have to be safe (although it could be check for c1?)
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      sender_sp = _unextended_sp + _cb->frame_size();
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      // Is sender_sp safe?
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      if (!thread->is_in_full_stack_checked((address)sender_sp)) {
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        return false;
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      }
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      // With our calling conventions, the return_address should
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      // end up being the word on the stack
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      sender_pc = (address) *(sender_sp - sender_sp_offset + return_addr_offset);
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    }
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    // We must always be able to find a recognizable pc
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    CodeBlob* sender_blob = CodeCache::find_blob(sender_pc);
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    if (sender_pc == nullptr || sender_blob == nullptr) {
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      return false;
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    }
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    // If the potential sender is the interpreter then we can do some more checking
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    if (Interpreter::contains(sender_pc)) {
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      // FP is always saved in a recognizable place in any code we generate. However
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      // only if the sender is interpreted/call_stub (c1 too?) are we certain that the saved FP
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      // is really a frame pointer.
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      intptr_t *saved_fp = (intptr_t*)*(sender_sp - frame::sender_sp_offset + link_offset);
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      if (!thread->is_in_stack_range_excl((address)saved_fp, (address)sender_sp)) {
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        return false;
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      }
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      // construct the potential sender
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      frame sender(sender_sp, saved_fp, sender_pc);
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      return sender.is_interpreted_frame_valid(thread);
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    }
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    // Could just be some random pointer within the codeBlob
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    if (!sender_blob->code_contains(sender_pc)) {
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      return false;
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    }
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    // We should never be able to see an adapter if the current frame is something from code cache
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    if (sender_blob->is_adapter_blob()) {
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      return false;
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    }
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    // Could be the call_stub
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    if (StubRoutines::returns_to_call_stub(sender_pc)) {
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      intptr_t *saved_fp = (intptr_t*)*(sender_sp - frame::sender_sp_offset + link_offset);
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      if (!thread->is_in_stack_range_excl((address)saved_fp, (address)sender_sp)) {
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        return false;
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      }
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      // construct the potential sender
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      frame sender(sender_sp, saved_fp, sender_pc);
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      // Validate the JavaCallWrapper an entry frame must have
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      address jcw = (address)sender.entry_frame_call_wrapper();
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      return thread->is_in_stack_range_excl(jcw, (address)sender.fp());
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    }
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    // If the frame size is 0 something (or less) is bad because every nmethod has a non-zero frame size
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    // because the return address counts against the callee's frame.
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    if (sender_blob->frame_size() <= 0) {
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      assert(!sender_blob->is_nmethod(), "should count return address at least");
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      return false;
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    }
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    // We should never be able to see anything here except an nmethod. If something in the
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    // code cache (current frame) is called by an entity within the code cache that entity
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    // should not be anything but the call stub (already covered), the interpreter (already covered)
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    // or an nmethod.
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    if (!sender_blob->is_nmethod()) {
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      return false;
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    }
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    // Could put some more validation for the potential non-interpreted sender
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    // frame we'd create by calling sender if I could think of any. Wait for next crash in forte...
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    // One idea is seeing if the sender_pc we have is one that we'd expect to call to current cb
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    // We've validated the potential sender that would be created
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    return true;
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  }
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  // Must be native-compiled frame. Since sender will try and use fp to find
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  // linkages it must be safe
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  if (!fp_safe) {
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    return false;
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  }
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  // Will the pc we fetch be non-zero (which we'll find at the oldest frame)
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  if ((address) this->fp()[return_addr_offset] == nullptr) return false;
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  // could try and do some more potential verification of native frame if we could think of some...
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  return true;
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}
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void frame::patch_pc(Thread* thread, address pc) {
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  assert(_cb == CodeCache::find_blob(pc), "unexpected pc");
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  address* pc_addr = &((address *)sp())[-sender_sp_offset+return_addr_offset];
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  if (TracePcPatching) {
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    tty->print_cr("patch_pc at address" INTPTR_FORMAT " [" INTPTR_FORMAT " -> " INTPTR_FORMAT "] ",
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                  p2i(pc_addr), p2i(*pc_addr), p2i(pc));
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  }
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  DEBUG_ONLY(address old_pc = _pc;)
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  *pc_addr = pc;
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  _pc = pc; // must be set before call to get_deopt_original_pc
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  address original_pc = get_deopt_original_pc();
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  if (original_pc != nullptr) {
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    assert(original_pc == old_pc, "expected original PC to be stored before patching");
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    _deopt_state = is_deoptimized;
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    // leave _pc as is
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  } else {
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    _deopt_state = not_deoptimized;
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    _pc = pc;
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  }
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}
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bool frame::is_interpreted_frame() const  {
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  return Interpreter::contains(pc());
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}
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intptr_t* frame::entry_frame_argument_at(int offset) const {
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  assert(is_entry_frame(), "entry frame expected");
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  // convert offset to index to deal with tsi
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  int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
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  // Entry frame's arguments are always in relation to unextended_sp()
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  return &unextended_sp()[index];
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}
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// locals
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void frame::interpreter_frame_set_locals(intptr_t* locs)  {
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  assert(is_interpreted_frame(), "interpreted frame expected");
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  // set relativized locals
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  ptr_at_put(interpreter_frame_locals_offset, (intptr_t) (locs - fp()));
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}
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// sender_sp
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intptr_t* frame::interpreter_frame_sender_sp() const {
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  assert(is_interpreted_frame(), "interpreted frame expected");
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  return (intptr_t*) at(interpreter_frame_sender_sp_offset);
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}
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void frame::set_interpreter_frame_sender_sp(intptr_t* sender_sp) {
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  assert(is_interpreted_frame(), "interpreted frame expected");
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  ptr_at_put(interpreter_frame_sender_sp_offset, (intptr_t) sender_sp);
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}
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// monitor elements
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BasicObjectLock* frame::interpreter_frame_monitor_begin() const {
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  return (BasicObjectLock*) addr_at(interpreter_frame_monitor_block_bottom_offset);
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}
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BasicObjectLock* frame::interpreter_frame_monitor_end() const {
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  BasicObjectLock* result = (BasicObjectLock*) *addr_at(interpreter_frame_monitor_block_top_offset);
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  // make sure the pointer points inside the frame
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  assert((intptr_t) fp() >  (intptr_t) result, "result must <  than frame pointer");
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  assert((intptr_t) sp() <= (intptr_t) result, "result must >= than stack pointer");
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  return result;
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}
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void frame::interpreter_frame_set_monitor_end(BasicObjectLock* value) {
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  *((BasicObjectLock**)addr_at(interpreter_frame_monitor_block_top_offset)) = value;
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}
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// Used by template based interpreter deoptimization
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void frame::interpreter_frame_set_last_sp(intptr_t* sp) {
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    *((intptr_t**)addr_at(interpreter_frame_last_sp_offset)) = sp;
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}
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frame frame::sender_for_entry_frame(RegisterMap* map) const {
302
  assert(map != nullptr, "map must be set");
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  // Java frame called from C; skip all C frames and return top C
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  // frame of that chunk as the sender
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  JavaFrameAnchor* jfa = entry_frame_call_wrapper()->anchor();
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  assert(!entry_frame_is_first(), "next Java fp must be non zero");
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  assert(jfa->last_Java_sp() > sp(), "must be above this frame on stack");
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  map->clear();
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  assert(map->include_argument_oops(), "should be set by clear");
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  if (jfa->last_Java_pc() != nullptr) {
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    frame fr(jfa->last_Java_sp(), jfa->last_Java_fp(), jfa->last_Java_pc());
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    return fr;
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  }
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  frame fr(jfa->last_Java_sp(), jfa->last_Java_fp());
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  return fr;
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}
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UpcallStub::FrameData* UpcallStub::frame_data_for_frame(const frame& frame) const {
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  ShouldNotCallThis();
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  return nullptr;
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}
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323
bool frame::upcall_stub_frame_is_first() const {
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  ShouldNotCallThis();
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  return false;
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}
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//------------------------------------------------------------------------------
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// frame::verify_deopt_original_pc
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//
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// Verifies the calculated original PC of a deoptimization PC for the
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// given unextended SP.  The unextended SP might also be the saved SP
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// for MethodHandle call sites.
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#ifdef ASSERT
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void frame::verify_deopt_original_pc(nmethod* nm, intptr_t* unextended_sp, bool is_method_handle_return) {
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  frame fr;
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338
  // This is ugly but it's better than to change {get,set}_original_pc
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  // to take an SP value as argument.  And it's only a debugging
340
  // method anyway.
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  fr._unextended_sp = unextended_sp;
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  address original_pc = nm->get_original_pc(&fr);
344
  assert(nm->insts_contains_inclusive(original_pc),
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         "original PC must be in the main code section of the compiled method (or must be immediately following it)");
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  assert(nm->is_method_handle_return(original_pc) == is_method_handle_return, "must be");
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}
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#endif
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//------------------------------------------------------------------------------
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// frame::adjust_unextended_sp
352
void frame::adjust_unextended_sp() {
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  // same as on x86
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  // If we are returning to a compiled MethodHandle call site, the
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  // saved_fp will in fact be a saved value of the unextended SP.  The
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  // simplest way to tell whether we are returning to such a call site
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  // is as follows:
359

360
  nmethod* sender_nm = (_cb == nullptr) ? nullptr : _cb->as_nmethod_or_null();
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  if (sender_nm != nullptr) {
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    // If the sender PC is a deoptimization point, get the original
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    // PC.  For MethodHandle call site the unextended_sp is stored in
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    // saved_fp.
365
    if (sender_nm->is_deopt_mh_entry(_pc)) {
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      DEBUG_ONLY(verify_deopt_mh_original_pc(sender_nm, _fp));
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      _unextended_sp = _fp;
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    }
369
    else if (sender_nm->is_deopt_entry(_pc)) {
370
      DEBUG_ONLY(verify_deopt_original_pc(sender_nm, _unextended_sp));
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    }
372
    else if (sender_nm->is_method_handle_return(_pc)) {
373
      _unextended_sp = _fp;
374
    }
375
  }
376
}
377

378
//------------------------------------------------------------------------------
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// frame::update_map_with_saved_link
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void frame::update_map_with_saved_link(RegisterMap* map, intptr_t** link_addr) {
381
  // see x86 for comments
382
  map->set_location(FP->as_VMReg(), (address) link_addr);
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}
384

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frame frame::sender_for_interpreter_frame(RegisterMap* map) const {
386
  // SP is the raw SP from the sender after adapter or interpreter
387
  // extension.
388
  intptr_t* sender_sp = this->sender_sp();
389

390
  // This is the sp before any possible extension (adapter/locals).
391
  intptr_t* unextended_sp = interpreter_frame_sender_sp();
392

393
#ifdef COMPILER2
394
  if (map->update_map()) {
395
    update_map_with_saved_link(map, (intptr_t**) addr_at(link_offset));
396
  }
397
#endif // COMPILER2
398

399
  return frame(sender_sp, unextended_sp, link(), sender_pc());
400
}
401

402
bool frame::is_interpreted_frame_valid(JavaThread* thread) const {
403
  assert(is_interpreted_frame(), "Not an interpreted frame");
404
  // These are reasonable sanity checks
405
  if (fp() == 0 || (intptr_t(fp()) & (wordSize-1)) != 0) {
406
    return false;
407
  }
408
  if (sp() == 0 || (intptr_t(sp()) & (wordSize-1)) != 0) {
409
    return false;
410
  }
411
  if (fp() + interpreter_frame_initial_sp_offset < sp()) {
412
    return false;
413
  }
414
  // These are hacks to keep us out of trouble.
415
  // The problem with these is that they mask other problems
416
  if (fp() <= sp()) {        // this attempts to deal with unsigned comparison above
417
    return false;
418
  }
419
  // do some validation of frame elements
420

421
  // first the method
422

423
  Method* m = safe_interpreter_frame_method();
424

425
  // validate the method we'd find in this potential sender
426
  if (!Method::is_valid_method(m)) return false;
427

428
  // stack frames shouldn't be much larger than max_stack elements
429

430
  if (fp() - sp() > 1024 + m->max_stack()*Interpreter::stackElementSize) {
431
    return false;
432
  }
433

434
  // validate bci/bcp
435

436
  address bcp = interpreter_frame_bcp();
437
  if (m->validate_bci_from_bcp(bcp) < 0) {
438
    return false;
439
  }
440

441
  // validate ConstantPoolCache*
442
  ConstantPoolCache* cp = *interpreter_frame_cache_addr();
443
  if (MetaspaceObj::is_valid(cp) == false) return false;
444

445
  // validate locals
446

447
  address locals =  (address)interpreter_frame_locals();
448
  return thread->is_in_stack_range_incl(locals, (address)fp());
449
}
450

451
BasicType frame::interpreter_frame_result(oop* oop_result, jvalue* value_result) {
452
  assert(is_interpreted_frame(), "interpreted frame expected");
453
  Method* method = interpreter_frame_method();
454
  BasicType type = method->result_type();
455

456
  intptr_t* res_addr;
457
  if (method->is_native()) {
458
    // Prior to calling into the runtime to report the method_exit both of
459
    // the possible return value registers are saved.
460
    // Return value registers are pushed to the native stack
461
    res_addr = (intptr_t*)sp();
462
#ifdef __ABI_HARD__
463
    // FP result is pushed onto a stack along with integer result registers
464
    if (type == T_FLOAT || type == T_DOUBLE) {
465
      res_addr += 2;
466
    }
467
#endif // __ABI_HARD__
468
  } else {
469
    res_addr = (intptr_t*)interpreter_frame_tos_address();
470
  }
471

472
  switch (type) {
473
    case T_OBJECT  :
474
    case T_ARRAY   : {
475
      oop obj;
476
      if (method->is_native()) {
477
        obj = cast_to_oop(at(interpreter_frame_oop_temp_offset));
478
      } else {
479
        obj = *(oop*)res_addr;
480
      }
481
      assert(Universe::is_in_heap_or_null(obj), "sanity check");
482
      *oop_result = obj;
483
      break;
484
    }
485
    case T_BOOLEAN : value_result->z = *(jboolean*)res_addr; break;
486
    case T_BYTE    : value_result->b = *(jbyte*)res_addr; break;
487
    case T_CHAR    : value_result->c = *(jchar*)res_addr; break;
488
    case T_SHORT   : value_result->s = *(jshort*)res_addr; break;
489
    case T_INT     : value_result->i = *(jint*)res_addr; break;
490
    case T_LONG    : value_result->j = *(jlong*)res_addr; break;
491
    case T_FLOAT   : value_result->f = *(jfloat*)res_addr; break;
492
    case T_DOUBLE  : value_result->d = *(jdouble*)res_addr; break;
493
    case T_VOID    : /* Nothing to do */ break;
494
    default        : ShouldNotReachHere();
495
  }
496

497
  return type;
498
}
499

500
intptr_t* frame::interpreter_frame_tos_at(jint offset) const {
501
  int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
502
  return &interpreter_frame_tos_address()[index];
503
}
504

505
#ifndef PRODUCT
506

507
#define DESCRIBE_FP_OFFSET(name) \
508
  values.describe(frame_no, fp() + frame::name##_offset, #name)
509

510
void frame::describe_pd(FrameValues& values, int frame_no) {
511
  if (is_interpreted_frame()) {
512
    DESCRIBE_FP_OFFSET(interpreter_frame_sender_sp);
513
    DESCRIBE_FP_OFFSET(interpreter_frame_last_sp);
514
    DESCRIBE_FP_OFFSET(interpreter_frame_method);
515
    DESCRIBE_FP_OFFSET(interpreter_frame_mdp);
516
    DESCRIBE_FP_OFFSET(interpreter_frame_cache);
517
    DESCRIBE_FP_OFFSET(interpreter_frame_locals);
518
    DESCRIBE_FP_OFFSET(interpreter_frame_bcp);
519
    DESCRIBE_FP_OFFSET(interpreter_frame_initial_sp);
520
  }
521
}
522

523
// This is a generic constructor which is only used by pns() in debug.cpp.
524
frame::frame(void* sp, void* fp, void* pc) {
525
  init((intptr_t*)sp, (intptr_t*)sp, (intptr_t*)fp, (address)pc);
526
}
527

528
#endif
529

530
intptr_t *frame::initial_deoptimization_info() {
531
  // used to reset the saved FP
532
  return fp();
533
}
534

535
intptr_t* frame::real_fp() const {
536
  if (is_entry_frame()) {
537
    // Work-around: FP (currently) does not conform to the ABI for entry
538
    // frames (see generate_call_stub). Might be worth fixing as another CR.
539
    // Following code assumes (and asserts) this has not yet been fixed.
540
    assert(frame::entry_frame_call_wrapper_offset == 0, "adjust this code");
541
    intptr_t* new_fp = fp();
542
    new_fp += 5; // saved R0,R1,R2,R4,R10
543
#ifndef __SOFTFP__
544
    new_fp += 8*2; // saved D8..D15
545
#endif
546
    return new_fp;
547
  }
548
  if (_cb != nullptr) {
549
    // use the frame size if valid
550
    int size = _cb->frame_size();
551
    if (size > 0) {
552
      return unextended_sp() + size;
553
    }
554
  }
555
  // else rely on fp()
556
  assert(! is_compiled_frame(), "unknown compiled frame size");
557
  return fp();
558
}
559