1 /* 2 * Copyright (c) 2003, 2016, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_VM_CLASSFILE_STACKMAPTABLE_HPP 26 #define SHARE_VM_CLASSFILE_STACKMAPTABLE_HPP 27 28 #include "classfile/stackMapFrame.hpp" 29 #include "classfile/verifier.hpp" 30 #include "memory/allocation.hpp" 31 #include "oops/constantPool.hpp" 32 #include "oops/method.hpp" 33 #include "utilities/bytes.hpp" 34 #include "utilities/globalDefinitions.hpp" 35 36 class StackMapReader; 37 38 // StackMapTable class is the StackMap table used by type checker 39 class StackMapTable : public StackObj { 40 private: 41 // Logically, the _frame_count (as well as many fields in the StackFrame) 42 // should be a u2, but if we defined the variable as that type it will 43 // be difficult to detect/recover from overflow or underflow conditions. 44 // Widening the type and making it signed will help detect these. 45 int32_t _code_length; 46 int32_t _frame_count; // Stackmap frame count 47 StackMapFrame** _frame_array; 48 49 public: 50 StackMapTable(StackMapReader* reader, StackMapFrame* init_frame, 51 u2 max_locals, u2 max_stack, 52 char* code_data, int code_len, TRAPS); 53 get_frame_count() const54 inline int32_t get_frame_count() const { return _frame_count; } get_offset(int index) const55 inline int get_offset(int index) const { 56 return _frame_array[index]->offset(); 57 } 58 59 // Match and/or update current_frame to the frame in stackmap table with 60 // specified offset. Return true if the two frames match. 61 bool match_stackmap( 62 StackMapFrame* current_frame, int32_t offset, 63 bool match, bool update, ErrorContext* ctx, TRAPS) const; 64 // Match and/or update current_frame to the frame in stackmap table with 65 // specified offset and frame index. Return true if the two frames match. 66 bool match_stackmap( 67 StackMapFrame* current_frame, int32_t offset, int32_t frame_index, 68 bool match, bool update, ErrorContext* ctx, TRAPS) const; 69 70 // Check jump instructions. Make sure there are no uninitialized 71 // instances on backward branch. 72 void check_jump_target(StackMapFrame* frame, int32_t target, TRAPS) const; 73 74 // The following methods are only used inside this class. 75 76 // Returns the frame array index where the frame with offset is stored. 77 int get_index_from_offset(int32_t offset) const; 78 79 void print_on(outputStream* str) const; 80 }; 81 82 class StackMapStream : StackObj { 83 private: 84 Array<u1>* _data; 85 int _index; 86 public: StackMapStream(Array<u1> * ah)87 StackMapStream(Array<u1>* ah) 88 : _data(ah), _index(0) { 89 } get_u1(TRAPS)90 u1 get_u1(TRAPS) { 91 if (_data == NULL || _index >= _data->length()) { 92 stackmap_format_error("access beyond the end of attribute", CHECK_0); 93 } 94 return _data->at(_index++); 95 } get_u2(TRAPS)96 u2 get_u2(TRAPS) { 97 if (_data == NULL || _index >= _data->length() - 1) { 98 stackmap_format_error("access beyond the end of attribute", CHECK_0); 99 } 100 u2 res = Bytes::get_Java_u2(_data->adr_at(_index)); 101 _index += 2; 102 return res; 103 } at_end()104 bool at_end() { 105 return (_data == NULL) || (_index == _data->length()); 106 } 107 static void stackmap_format_error(const char* msg, TRAPS); 108 }; 109 110 class StackMapReader : StackObj { 111 private: 112 // information about the class and method 113 constantPoolHandle _cp; 114 ClassVerifier* _verifier; 115 StackMapStream* _stream; 116 char* _code_data; 117 int32_t _code_length; 118 119 // information get from the attribute 120 int32_t _frame_count; // frame count 121 122 int32_t chop(VerificationType* locals, int32_t length, int32_t chops); 123 VerificationType parse_verification_type(u1* flags, TRAPS); check_verification_type_array_size(int32_t size,int32_t max_size,TRAPS)124 void check_verification_type_array_size( 125 int32_t size, int32_t max_size, TRAPS) { 126 if (size < 0 || size > max_size) { 127 // Since this error could be caused someone rewriting the method 128 // but not knowing to update the stackmap data, we call the the 129 // verifier's error method, which may not throw an exception and 130 // failover to the old verifier instead. 131 _verifier->class_format_error( 132 "StackMapTable format error: bad type array size"); 133 } 134 } 135 136 enum { 137 SAME_LOCALS_1_STACK_ITEM_EXTENDED = 247, 138 SAME_EXTENDED = 251, 139 FULL = 255 140 }; 141 142 public: 143 // Constructor 144 StackMapReader(ClassVerifier* v, StackMapStream* stream, char* code_data, 145 int32_t code_len, TRAPS); 146 get_frame_count() const147 inline int32_t get_frame_count() const { return _frame_count; } 148 StackMapFrame* next(StackMapFrame* pre_frame, bool first, 149 u2 max_locals, u2 max_stack, TRAPS); 150 check_end(TRAPS)151 void check_end(TRAPS) { 152 if (!_stream->at_end()) { 153 StackMapStream::stackmap_format_error("wrong attribute size", CHECK); 154 } 155 } 156 }; 157 158 #endif // SHARE_VM_CLASSFILE_STACKMAPTABLE_HPP 159