1 /*
2 * Copyright (c) 2003, 2010, 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 "memory/allocation.hpp"
30 #include "oops/constantPoolOop.hpp"
31 #include "oops/methodOop.hpp"
32 #include "utilities/globalDefinitions.hpp"
33 #ifdef TARGET_ARCH_x86
34 # include "bytes_x86.hpp"
35 #endif
36 #ifdef TARGET_ARCH_sparc
37 # include "bytes_sparc.hpp"
38 #endif
39 #ifdef TARGET_ARCH_zero
40 # include "bytes_zero.hpp"
41 #endif
42
43 class StackMapReader;
44
45 // StackMapTable class is the StackMap table used by type checker
46 class StackMapTable : public StackObj {
47 private:
48 // Logically, the _frame_count (as well as many fields in the StackFrame)
49 // should be a u2, but if we defined the variable as that type it will
50 // be difficult to detect/recover from overflow or underflow conditions.
51 // Widening the type and making it signed will help detect these.
52 int32_t _code_length;
53 int32_t _frame_count; // Stackmap frame count
54 StackMapFrame** _frame_array;
55
56 public:
57 StackMapTable(StackMapReader* reader, StackMapFrame* init_frame,
58 u2 max_locals, u2 max_stack,
59 char* code_data, int code_len, TRAPS);
60
61 inline int32_t get_frame_count() const { return _frame_count; }
62 inline int get_offset(int index) const {
63 return _frame_array[index]->offset();
64 }
65
66 // Match and/or update current_frame to the frame in stackmap table with
67 // specified offset. Return true if the two frames match.
68 bool match_stackmap(
69 StackMapFrame* current_frame, int32_t offset,
70 bool match, bool update, TRAPS) const;
71 // Match and/or update current_frame to the frame in stackmap table with
72 // specified offset and frame index. Return true if the two frames match.
73 bool match_stackmap(
74 StackMapFrame* current_frame, int32_t offset, int32_t frame_index,
75 bool match, bool update, TRAPS) const;
76
77 // Check jump instructions. Make sure there are no uninitialized
78 // instances on backward branch.
79 void check_jump_target(StackMapFrame* frame, int32_t target, TRAPS) const;
80
81 // The following methods are only used inside this class.
82
83 // Returns the frame array index where the frame with offset is stored.
84 int get_index_from_offset(int32_t offset) const;
85
86 // Make sure that there's no uninitialized object exist on backward branch.
87 void check_new_object(
88 const StackMapFrame* frame, int32_t target, TRAPS) const;
89
90 // Debugging
91 void print() const PRODUCT_RETURN;
92 };
93
94 class StackMapStream : StackObj {
95 private:
96 typeArrayHandle _data;
97 int _index;
98 public:
99 StackMapStream(typeArrayHandle ah)
100 : _data(ah), _index(0) {
101 }
102 u1 get_u1(TRAPS) {
103 if (_data == NULL || _index >= _data->length()) {
104 stackmap_format_error("access beyond the end of attribute", CHECK_0);
105 }
106 return _data->byte_at(_index++);
107 }
108 u2 get_u2(TRAPS) {
109 if (_data == NULL || _index >= _data->length() - 1) {
110 stackmap_format_error("access beyond the end of attribute", CHECK_0);
111 }
112 u2 res = Bytes::get_Java_u2((u1*)_data->byte_at_addr(_index));
113 _index += 2;
114 return res;
115 }
116 bool at_end() {
117 return (_data == NULL) || (_index == _data->length());
118 }
119 static void stackmap_format_error(const char* msg, TRAPS);
120 };
121
122 class StackMapReader : StackObj {
123 private:
124 // information about the class and method
125 constantPoolHandle _cp;
126 ClassVerifier* _verifier;
127 StackMapStream* _stream;
128 char* _code_data;
129 int32_t _code_length;
130
131 // information get from the attribute
132 int32_t _frame_count; // frame count
133
134 int32_t chop(VerificationType* locals, int32_t length, int32_t chops);
135 VerificationType parse_verification_type(u1* flags, TRAPS);
136 void check_verification_type_array_size(
137 int32_t size, int32_t max_size, TRAPS) {
138 if (size < 0 || size > max_size) {
139 // Since this error could be caused someone rewriting the method
140 // but not knowing to update the stackmap data, we call the the
141 // verifier's error method, which may not throw an exception and
142 // failover to the old verifier instead.
143 _verifier->class_format_error(
144 "StackMapTable format error: bad type array size");
145 }
146 }
147
148 enum {
149 SAME_LOCALS_1_STACK_ITEM_EXTENDED = 247,
150 SAME_EXTENDED = 251,
151 FULL = 255
152 };
153
154 public:
155 // Constructor
156 StackMapReader(ClassVerifier* v, StackMapStream* stream, char* code_data,
157 int32_t code_len, TRAPS) :
158 _verifier(v), _stream(stream),
159 _code_data(code_data), _code_length(code_len) {
160 methodHandle m = v->method();
161 if (m->has_stackmap_table()) {
162 _cp = constantPoolHandle(THREAD, m->constants());
163 _frame_count = _stream->get_u2(CHECK);
164 } else {
165 // There's no stackmap table present. Frame count and size are 0.
166 _frame_count = 0;
167 }
168 }
169
170 inline int32_t get_frame_count() const { return _frame_count; }
171 StackMapFrame* next(StackMapFrame* pre_frame, bool first,
172 u2 max_locals, u2 max_stack, TRAPS);
173
174 void check_end(TRAPS) {
175 if (!_stream->at_end()) {
176 StackMapStream::stackmap_format_error("wrong attribute size", CHECK);
177 }
178 }
179 };
180
181 #endif // SHARE_VM_CLASSFILE_STACKMAPTABLE_HPP