1 /* 2 * Copyright (c) 2003, 2011, 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/constantPoolOop.hpp" 32 #include "oops/methodOop.hpp" 33 #include "utilities/globalDefinitions.hpp" 34 #ifdef TARGET_ARCH_x86 35 # include "bytes_x86.hpp" 36 #endif 37 #ifdef TARGET_ARCH_sparc 38 # include "bytes_sparc.hpp" 39 #endif 40 #ifdef TARGET_ARCH_zero 41 # include "bytes_zero.hpp" 42 #endif 43 #ifdef TARGET_ARCH_arm 44 # include "bytes_arm.hpp" 45 #endif 46 #ifdef TARGET_ARCH_ppc 47 # include "bytes_ppc.hpp" 48 #endif 49 50 class StackMapReader; 51 52 // StackMapTable class is the StackMap table used by type checker 53 class StackMapTable : public StackObj { 54 private: 55 // Logically, the _frame_count (as well as many fields in the StackFrame) 56 // should be a u2, but if we defined the variable as that type it will 57 // be difficult to detect/recover from overflow or underflow conditions. 58 // Widening the type and making it signed will help detect these. 59 int32_t _code_length; 60 int32_t _frame_count; // Stackmap frame count 61 StackMapFrame** _frame_array; 62 63 public: 64 StackMapTable(StackMapReader* reader, StackMapFrame* init_frame, 65 u2 max_locals, u2 max_stack, 66 char* code_data, int code_len, TRAPS); 67 68 inline int32_t get_frame_count() const { return _frame_count; } 69 inline int get_offset(int index) const { 70 return _frame_array[index]->offset(); 71 } 72 73 // Match and/or update current_frame to the frame in stackmap table with 74 // specified offset. Return true if the two frames match. 75 bool match_stackmap( 76 StackMapFrame* current_frame, int32_t offset, 77 bool match, bool update, ErrorContext* ctx, TRAPS) const; 78 // Match and/or update current_frame to the frame in stackmap table with 79 // specified offset and frame index. Return true if the two frames match. 80 bool match_stackmap( 81 StackMapFrame* current_frame, int32_t offset, int32_t frame_index, 82 bool match, bool update, ErrorContext* ctx, TRAPS) const; 83 84 // Check jump instructions. Make sure there are no uninitialized 85 // instances on backward branch. 86 void check_jump_target(StackMapFrame* frame, int32_t target, TRAPS) const; 87 88 // The following methods are only used inside this class. 89 90 // Returns the frame array index where the frame with offset is stored. 91 int get_index_from_offset(int32_t offset) const; 92 93 // Make sure that there's no uninitialized object exist on backward branch. 94 void check_new_object( 95 const StackMapFrame* frame, int32_t target, TRAPS) const; 96 97 // Debugging 98 void print(outputStream* str) const; 99 }; 100 101 class StackMapStream : StackObj { 102 private: 103 typeArrayHandle _data; 104 int _index; 105 public: 106 StackMapStream(typeArrayHandle ah) 107 : _data(ah), _index(0) { 108 } 109 u1 get_u1(TRAPS) { 110 if (_data == NULL || _index >= _data->length()) { 111 stackmap_format_error("access beyond the end of attribute", CHECK_0); 112 } 113 return _data->byte_at(_index++); 114 } 115 u2 get_u2(TRAPS) { 116 if (_data == NULL || _index >= _data->length() - 1) { 117 stackmap_format_error("access beyond the end of attribute", CHECK_0); 118 } 119 u2 res = Bytes::get_Java_u2((u1*)_data->byte_at_addr(_index)); 120 _index += 2; 121 return res; 122 } 123 bool at_end() { 124 return (_data == NULL) || (_index == _data->length()); 125 } 126 static void stackmap_format_error(const char* msg, TRAPS); 127 }; 128 129 class StackMapReader : StackObj { 130 private: 131 // information about the class and method 132 constantPoolHandle _cp; 133 ClassVerifier* _verifier; 134 StackMapStream* _stream; 135 char* _code_data; 136 int32_t _code_length; 137 138 // information get from the attribute 139 int32_t _frame_count; // frame count 140 141 int32_t chop(VerificationType* locals, int32_t length, int32_t chops); 142 VerificationType parse_verification_type(u1* flags, TRAPS); 143 void check_verification_type_array_size( 144 int32_t size, int32_t max_size, TRAPS) { 145 if (size < 0 || size > max_size) { 146 // Since this error could be caused someone rewriting the method 147 // but not knowing to update the stackmap data, we call the the 148 // verifier's error method, which may not throw an exception and 149 // failover to the old verifier instead. 150 _verifier->class_format_error( 151 "StackMapTable format error: bad type array size"); 152 } 153 } 154 155 enum { 156 SAME_LOCALS_1_STACK_ITEM_EXTENDED = 247, 157 SAME_EXTENDED = 251, 158 FULL = 255 159 }; 160 161 public: 162 // Constructor 163 StackMapReader(ClassVerifier* v, StackMapStream* stream, char* code_data, 164 int32_t code_len, TRAPS) : 165 _verifier(v), _stream(stream), 166 _code_data(code_data), _code_length(code_len) { 167 methodHandle m = v->method(); 168 if (m->has_stackmap_table()) { 169 _cp = constantPoolHandle(THREAD, m->constants()); 170 _frame_count = _stream->get_u2(CHECK); 171 } else { 172 // There's no stackmap table present. Frame count and size are 0. 173 _frame_count = 0; 174 } 175 } 176 177 inline int32_t get_frame_count() const { return _frame_count; } 178 StackMapFrame* next(StackMapFrame* pre_frame, bool first, 179 u2 max_locals, u2 max_stack, TRAPS); 180 181 void check_end(TRAPS) { 182 if (!_stream->at_end()) { 183 StackMapStream::stackmap_format_error("wrong attribute size", CHECK); 184 } 185 } 186 }; 187 188 #endif // SHARE_VM_CLASSFILE_STACKMAPTABLE_HPP