view src/share/vm/oops/constMethod.hpp @ 3996:f9eb431c3efe

8006005: Fix constant pool index validation and alignment trap for method parameter reflection Summary: This patch addresses an alignment trap due to the storage format of method parameters data in constMethod. It also adds code to validate constant pool indexes for method parameters data. Reviewed-by: jrose, dholmes Contributed-by: eric.mccorkle@oracle.com
author coleenp
date Mon, 14 Jan 2013 11:01:39 -0500
parents ade95d680b42
children 16fb9f942703
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/*
 * Copyright (c) 2003, 2012, 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
 * 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#ifndef SHARE_VM_OOPS_CONSTMETHODOOP_HPP
#define SHARE_VM_OOPS_CONSTMETHODOOP_HPP

#include "oops/oop.hpp"

// An ConstMethod* represents portions of a Java method which
// do not vary.
//
// Memory layout (each line represents a word). Note that most
// applications load thousands of methods, so keeping the size of this
// structure small has a big impact on footprint.
//
// |------------------------------------------------------|
// | header                                               |
// | klass                                                |
// |------------------------------------------------------|
// | fingerprint 1                                        |
// | fingerprint 2                                        |
// | constants                      (oop)                 |
// | stackmap_data                  (oop)                 |
// | constMethod_size                                     |
// | interp_kind  | flags    | code_size                  |
// | name index              | signature index            |
// | method_idnum            | max_stack                  |
// | max_locals              | size_of_parameters         |
// |------------------------------------------------------|
// |                                                      |
// | byte codes                                           |
// |                                                      |
// |------------------------------------------------------|
// | compressed linenumber table                          |
// |  (see class CompressedLineNumberReadStream)          |
// |  (note that length is unknown until decompressed)    |
// |  (access flags bit tells whether table is present)   |
// |  (indexed from start of ConstMethod*)                |
// |  (elements not necessarily sorted!)                  |
// |------------------------------------------------------|
// | localvariable table elements + length (length last)  |
// |  (length is u2, elements are 6-tuples of u2)         |
// |  (see class LocalVariableTableElement)               |
// |  (access flags bit tells whether table is present)   |
// |  (indexed from end of ConstMethod*)                  |
// |------------------------------------------------------|
// | exception table + length (length last)               |
// |  (length is u2, elements are 4-tuples of u2)         |
// |  (see class ExceptionTableElement)                   |
// |  (access flags bit tells whether table is present)   |
// |  (indexed from end of ConstMethod*)                  |
// |------------------------------------------------------|
// | checked exceptions elements + length (length last)   |
// |  (length is u2, elements are u2)                     |
// |  (see class CheckedExceptionElement)                 |
// |  (access flags bit tells whether table is present)   |
// |  (indexed from end of ConstMethod*)                  |
// |------------------------------------------------------|
// | method parameters elements + length (length last)    |
// |  (length is u2, elements are u2, u4 structures)      |
// |  (see class MethodParametersElement)                 |
// |  (access flags bit tells whether table is present)   |
// |  (indexed from end of ConstMethod*)                  |
// |------------------------------------------------------|
// | generic signature index (u2)                         |
// |  (indexed from start of constMethodOop)              |
// |------------------------------------------------------|
//
// IMPORTANT: If anything gets added here, there need to be changes to
// ensure that ServicabilityAgent doesn't get broken as a result!


// Utitily class decribing elements in checked exceptions table inlined in Method*.
class CheckedExceptionElement VALUE_OBJ_CLASS_SPEC {
 public:
  u2 class_cp_index;
};


// Utitily class decribing elements in local variable table inlined in Method*.
class LocalVariableTableElement VALUE_OBJ_CLASS_SPEC {
 public:
  u2 start_bci;
  u2 length;
  u2 name_cp_index;
  u2 descriptor_cp_index;
  u2 signature_cp_index;
  u2 slot;
};

// Utitily class describing elements in exception table
class ExceptionTableElement VALUE_OBJ_CLASS_SPEC {
 public:
  u2 start_pc;
  u2 end_pc;
  u2 handler_pc;
  u2 catch_type_index;
};

// Utility class describing elements in method parameters
class MethodParametersElement VALUE_OBJ_CLASS_SPEC {
 public:
  u2 name_cp_index;
  // This has to happen, otherwise it will cause SIGBUS from a
  // misaligned u4 on some architectures (ie SPARC)
  // because MethodParametersElements are only aligned mod 2
  // within the ConstMethod container  u2 flags_hi;
  u2 flags_hi;
  u2 flags_lo;
};


class ConstMethod : public MetaspaceObj {
  friend class VMStructs;

public:
  typedef enum { NORMAL, OVERPASS } MethodType;

private:
  enum {
    _has_linenumber_table = 1,
    _has_checked_exceptions = 2,
    _has_localvariable_table = 4,
    _has_exception_table = 8,
    _has_generic_signature = 16,
    _has_method_parameters = 32,
    _is_overpass = 64
  };

  // Bit vector of signature
  // Callers interpret 0=not initialized yet and
  // -1=too many args to fix, must parse the slow way.
  // The real initial value is special to account for nonatomicity of 64 bit
  // loads and stores.  This value may updated and read without a lock by
  // multiple threads, so is volatile.
  volatile uint64_t _fingerprint;

  ConstantPool*     _constants;                  // Constant pool

  // Raw stackmap data for the method
  Array<u1>*        _stackmap_data;

  int               _constMethod_size;
  jbyte             _interpreter_kind;
  jbyte             _flags;

  // Size of Java bytecodes allocated immediately after Method*.
  u2                _code_size;
  u2                _name_index;                 // Method name (index in constant pool)
  u2                _signature_index;            // Method signature (index in constant pool)
  u2                _method_idnum;               // unique identification number for the method within the class
                                                 // initially corresponds to the index into the methods array.
                                                 // but this may change with redefinition
  u2                _max_stack;                  // Maximum number of entries on the expression stack
  u2                _max_locals;                 // Number of local variables used by this method
  u2                _size_of_parameters;         // size of the parameter block (receiver + arguments) in words

  // Constructor
  ConstMethod(int byte_code_size,
              int compressed_line_number_size,
              int localvariable_table_length,
              int exception_table_length,
              int checked_exceptions_length,
              int method_parameters_length,
              u2  generic_signature_index,
              MethodType is_overpass,
              int size);
public:

  static ConstMethod* allocate(ClassLoaderData* loader_data,
                               int byte_code_size,
                               int compressed_line_number_size,
                               int localvariable_table_length,
                               int exception_table_length,
                               int checked_exceptions_length,
                               int method_parameters_length,
                               u2  generic_signature_index,
                               MethodType mt,
                               TRAPS);

  bool is_constMethod() const { return true; }

  // Inlined tables
  void set_inlined_tables_length(u2  generic_signature_index,
                                 int checked_exceptions_len,
                                 int compressed_line_number_size,
                                 int localvariable_table_len,
                                 int exception_table_len,
                                 int method_parameters_length);

  bool has_generic_signature() const
    { return (_flags & _has_generic_signature) != 0; }

  bool has_linenumber_table() const
    { return (_flags & _has_linenumber_table) != 0; }

  bool has_checked_exceptions() const
    { return (_flags & _has_checked_exceptions) != 0; }

  bool has_localvariable_table() const
    { return (_flags & _has_localvariable_table) != 0; }

  bool has_exception_handler() const
    { return (_flags & _has_exception_table) != 0; }

  bool has_method_parameters() const
    { return (_flags & _has_method_parameters) != 0; }

  MethodType method_type() const {
    return ((_flags & _is_overpass) == 0) ? NORMAL : OVERPASS;
  }

  void set_method_type(MethodType mt) {
    if (mt == NORMAL) {
      _flags &= ~(_is_overpass);
    } else {
      _flags |= _is_overpass;
    }
  }


  void set_interpreter_kind(int kind)      { _interpreter_kind = kind; }
  int  interpreter_kind(void) const        { return _interpreter_kind; }

  // constant pool
  ConstantPool* constants() const        { return _constants; }
  void set_constants(ConstantPool* c)    { _constants = c; }

  Method* method() const;

  // stackmap table data
  Array<u1>* stackmap_data() const { return _stackmap_data; }
  void set_stackmap_data(Array<u1>* sd) { _stackmap_data = sd; }
  bool has_stackmap_table() const { return _stackmap_data != NULL; }

  void init_fingerprint() {
    const uint64_t initval = CONST64(0x8000000000000000);
    _fingerprint = initval;
  }

  uint64_t fingerprint() const                   {
    // Since reads aren't atomic for 64 bits, if any of the high or low order
    // word is the initial value, return 0.  See init_fingerprint for initval.
    uint high_fp = (uint)(_fingerprint >> 32);
    if ((int) _fingerprint == 0 || high_fp == 0x80000000) {
      return 0L;
    } else {
      return _fingerprint;
    }
  }

  uint64_t set_fingerprint(uint64_t new_fingerprint) {
#ifdef ASSERT
    // Assert only valid if complete/valid 64 bit _fingerprint value is read.
    uint64_t oldfp = fingerprint();
#endif // ASSERT
    _fingerprint = new_fingerprint;
    assert(oldfp == 0L || new_fingerprint == oldfp,
           "fingerprint cannot change");
    assert(((new_fingerprint >> 32) != 0x80000000) && (int)new_fingerprint !=0,
           "fingerprint should call init to set initial value");
    return new_fingerprint;
  }

  // name
  int name_index() const                         { return _name_index; }
  void set_name_index(int index)                 { _name_index = index; }

  // signature
  int signature_index() const                    { return _signature_index; }
  void set_signature_index(int index)            { _signature_index = index; }

  // generics support
  int generic_signature_index() const            {
    if (has_generic_signature()) {
      return *generic_signature_index_addr();
    } else {
      return 0;
    }
  }
  void set_generic_signature_index(u2 index)    {
    assert(has_generic_signature(), "");
    u2* addr = generic_signature_index_addr();
    *addr = index;
  }

  // Sizing
  static int header_size() {
    return sizeof(ConstMethod)/HeapWordSize;
  }

  // Size needed
  static int size(int code_size, int compressed_line_number_size,
                  int local_variable_table_length,
                  int exception_table_length,
                  int checked_exceptions_length,
                  int method_parameters_length,
                  u2  generic_signature_index);

  int size() const                    { return _constMethod_size;}
  void set_constMethod_size(int size)     { _constMethod_size = size; }

  // code size
  int code_size() const                          { return _code_size; }
  void set_code_size(int size) {
    assert(max_method_code_size < (1 << 16),
           "u2 is too small to hold method code size in general");
    assert(0 <= size && size <= max_method_code_size, "invalid code size");
    _code_size = size;
  }

  // linenumber table - note that length is unknown until decompression,
  // see class CompressedLineNumberReadStream.
  u_char* compressed_linenumber_table() const;         // not preserved by gc
  u2* generic_signature_index_addr() const;
  u2* checked_exceptions_length_addr() const;
  u2* localvariable_table_length_addr() const;
  u2* exception_table_length_addr() const;
  u2* method_parameters_length_addr() const;

  // checked exceptions
  int checked_exceptions_length() const;
  CheckedExceptionElement* checked_exceptions_start() const;

  // localvariable table
  int localvariable_table_length() const;
  LocalVariableTableElement* localvariable_table_start() const;

  // exception table
  int exception_table_length() const;
  ExceptionTableElement* exception_table_start() const;

  // method parameters table
  int method_parameters_length() const;
  MethodParametersElement* method_parameters_start() const;

  // byte codes
  void    set_code(address code) {
    if (code_size() > 0) {
      memcpy(code_base(), code, code_size());
    }
  }
  address code_base() const            { return (address) (this+1); }
  address code_end() const             { return code_base() + code_size(); }
  bool    contains(address bcp) const  { return code_base() <= bcp
                                                     && bcp < code_end(); }
  // Offset to bytecodes
  static ByteSize codes_offset()
                            { return in_ByteSize(sizeof(ConstMethod)); }

  static ByteSize constants_offset()
                            { return byte_offset_of(ConstMethod, _constants); }

  static ByteSize max_stack_offset()
                            { return byte_offset_of(ConstMethod, _max_stack); }
  static ByteSize size_of_locals_offset()
                            { return byte_offset_of(ConstMethod, _max_locals); }
  static ByteSize size_of_parameters_offset()
                            { return byte_offset_of(ConstMethod, _size_of_parameters); }


  // Unique id for the method
  static const u2 MAX_IDNUM;
  static const u2 UNSET_IDNUM;
  u2 method_idnum() const                        { return _method_idnum; }
  void set_method_idnum(u2 idnum)                { _method_idnum = idnum; }

  // max stack
  int  max_stack() const                         { return _max_stack; }
  void set_max_stack(int size)                   { _max_stack = size; }

  // max locals
  int  max_locals() const                        { return _max_locals; }
  void set_max_locals(int size)                  { _max_locals = size; }

  // size of parameters
  int  size_of_parameters() const                { return _size_of_parameters; }
  void set_size_of_parameters(int size)          { _size_of_parameters = size; }

  // Deallocation for RedefineClasses
  void deallocate_contents(ClassLoaderData* loader_data);
  bool is_klass() const { return false; }
  DEBUG_ONLY(bool on_stack() { return false; })

private:
  // Since the size of the compressed line number table is unknown, the
  // offsets of the other variable sized sections are computed backwards
  // from the end of the ConstMethod*.

  // First byte after ConstMethod*
  address constMethod_end() const
                          { return (address)((oop*)this + _constMethod_size); }

  // Last short in ConstMethod*
  u2* last_u2_element() const
                                         { return (u2*)constMethod_end() - 1; }

 public:
  // Printing
  void print_on      (outputStream* st) const;
  void print_value_on(outputStream* st) const;

  const char* internal_name() const { return "{constMethod}"; }

  // Verify
  void verify_on(outputStream* st);
};

#endif // SHARE_VM_OOPS_CONSTMETHODOOP_HPP