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/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 void print_on(outputStream* str) const;
94 };
95
96 class StackMapStream : StackObj {
97 private:
98 Array<u1>* _data;
99 int _index;
100 public:
101 StackMapStream(Array<u1>* ah)
102 : _data(ah), _index(0) {
103 }
104 u1 get_u1(TRAPS) {
105 if (_data == NULL || _index >= _data->length()) {
106 stackmap_format_error("access beyond the end of attribute", CHECK_0);
107 }
108 return _data->at(_index++);
109 }
110 u2 get_u2(TRAPS) {
111 if (_data == NULL || _index >= _data->length() - 1) {
112 stackmap_format_error("access beyond the end of attribute", CHECK_0);
113 }
114 u2 res = Bytes::get_Java_u2(_data->adr_at(_index));
115 _index += 2;
116 return res;
117 }
118 bool at_end() {
119 return (_data == NULL) || (_index == _data->length());
120 }
121 static void stackmap_format_error(const char* msg, TRAPS);
122 };
123
124 class StackMapReader : StackObj {
125 private:
126 // information about the class and method
127 constantPoolHandle _cp;
128 ClassVerifier* _verifier;
129 StackMapStream* _stream;
130 char* _code_data;
131 int32_t _code_length;
132
133 // information get from the attribute
134 int32_t _frame_count; // frame count
135
136 int32_t chop(VerificationType* locals, int32_t length, int32_t chops);
137 VerificationType parse_verification_type(u1* flags, TRAPS);
138 void check_verification_type_array_size(
139 int32_t size, int32_t max_size, TRAPS) {
140 if (size < 0 || size > max_size) {
141 // Since this error could be caused someone rewriting the method
142 // but not knowing to update the stackmap data, we call the the
143 // verifier's error method, which may not throw an exception and
144 // failover to the old verifier instead.
145 _verifier->class_format_error(
146 "StackMapTable format error: bad type array size");
147 }
148 }
149
150 enum {
151 SAME_LOCALS_1_STACK_ITEM_EXTENDED = 247,
152 SAME_EXTENDED = 251,
153 FULL = 255
154 };
155
156 public:
157 // Constructor
158 StackMapReader(ClassVerifier* v, StackMapStream* stream, char* code_data,
159 int32_t code_len, TRAPS) :
160 _verifier(v), _stream(stream),
161 _code_data(code_data), _code_length(code_len) {
162 methodHandle m = v->method();
163 if (m->has_stackmap_table()) {
164 _cp = constantPoolHandle(THREAD, m->constants());
165 _frame_count = _stream->get_u2(CHECK);
166 } else {
167 // There's no stackmap table present. Frame count and size are 0.
168 _frame_count = 0;
169 }
170 }
171
172 inline int32_t get_frame_count() const { return _frame_count; }
173 StackMapFrame* next(StackMapFrame* pre_frame, bool first,
174 u2 max_locals, u2 max_stack, TRAPS);
175
176 void check_end(TRAPS) {
177 if (!_stream->at_end()) {
178 StackMapStream::stackmap_format_error("wrong attribute size", CHECK);
179 }
180 }
181 };
182
183 #endif // SHARE_VM_CLASSFILE_STACKMAPTABLE_HPP