1 /*
2 * Copyright (c) 2003, 2025, 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 #include "classfile/stackMapFrame.hpp"
26 #include "classfile/verifier.hpp"
27 #include "classfile/vmSymbols.hpp"
28 #include "memory/resourceArea.hpp"
29 #include "oops/oop.inline.hpp"
30 #include "oops/symbol.hpp"
31 #include "runtime/handles.inline.hpp"
32 #include "utilities/globalDefinitions.hpp"
33
34 StackMapFrame::StackMapFrame(u2 max_locals, u2 max_stack, ClassVerifier* v) :
35 _offset(0), _locals_size(0), _stack_size(0),
36 _stack_mark(0), _max_locals(max_locals),
37 _max_stack(max_stack), _flags(0), _verifier(v) {
38 Thread* thr = v->thread();
39 _locals = NEW_RESOURCE_ARRAY_IN_THREAD(thr, VerificationType, max_locals);
40 _stack = NEW_RESOURCE_ARRAY_IN_THREAD(thr, VerificationType, max_stack);
41 int32_t i;
42 for(i = 0; i < max_locals; i++) {
43 _locals[i] = VerificationType::bogus_type();
44 }
45 for(i = 0; i < max_stack; i++) {
46 _stack[i] = VerificationType::bogus_type();
47 }
48 }
49
50 StackMapFrame* StackMapFrame::frame_in_exception_handler(u1 flags) {
51 Thread* thr = _verifier->thread();
52 VerificationType* stack = NEW_RESOURCE_ARRAY_IN_THREAD(thr, VerificationType, 1);
53 StackMapFrame* frame = new StackMapFrame(_offset, flags, _locals_size, 0, _max_locals, _max_stack, _locals, stack, _verifier);
54 return frame;
55 }
56
57 void StackMapFrame::initialize_object(
58 VerificationType old_object, VerificationType new_object) {
59 int32_t i;
60 for (i = 0; i < _max_locals; i++) {
61 if (_locals[i].equals(old_object)) {
62 _locals[i] = new_object;
63 }
64 }
65 for (i = 0; i < _stack_size; i++) {
66 if (_stack[i].equals(old_object)) {
67 _stack[i] = new_object;
68 }
69 }
70 if (old_object == VerificationType::uninitialized_this_type()) {
71 // "this" has been initialized - reset flags
72 _flags = 0;
73 }
74 }
75
76 VerificationType StackMapFrame::set_locals_from_arg(
77 const methodHandle& m, VerificationType thisKlass) {
78 SignatureStream ss(m->signature());
79 int init_local_num = 0;
80 if (!m->is_static()) {
81 init_local_num++;
82 // add one extra argument for instance method
83 if (m->name() == vmSymbols::object_initializer_name() &&
84 thisKlass.name() != vmSymbols::java_lang_Object()) {
85 _locals[0] = VerificationType::uninitialized_this_type();
86 _flags |= FLAG_THIS_UNINIT;
87 } else {
88 _locals[0] = thisKlass;
89 }
90 }
91
92 // local num may be greater than size of parameters because long/double occupies two slots
93 while(!ss.at_return_type()) {
94 init_local_num += _verifier->change_sig_to_verificationType(
95 &ss, &_locals[init_local_num]);
96 ss.next();
97 }
98 _locals_size = init_local_num;
99
100 switch (ss.type()) {
101 case T_OBJECT:
102 case T_ARRAY:
103 {
104 Symbol* sig = ss.as_symbol();
105 if (!sig->is_permanent()) {
106 // Create another symbol to save as signature stream unreferences
107 // this symbol.
108 Symbol *sig_copy =
109 verifier()->create_temporary_symbol(sig);
110 assert(sig_copy == sig, "symbols don't match");
111 sig = sig_copy;
112 }
113 return VerificationType::reference_type(sig);
114 }
115 case T_INT: return VerificationType::integer_type();
116 case T_BYTE: return VerificationType::byte_type();
117 case T_CHAR: return VerificationType::char_type();
118 case T_SHORT: return VerificationType::short_type();
119 case T_BOOLEAN: return VerificationType::boolean_type();
120 case T_FLOAT: return VerificationType::float_type();
121 case T_DOUBLE: return VerificationType::double_type();
122 case T_LONG: return VerificationType::long_type();
123 case T_VOID: return VerificationType::bogus_type();
124 default:
125 ShouldNotReachHere();
126 }
127 return VerificationType::bogus_type();
128 }
129
130 void StackMapFrame::copy_locals(const StackMapFrame* src) {
131 int32_t len = src->locals_size() < _locals_size ?
132 src->locals_size() : _locals_size;
133 for (int32_t i = 0; i < len; i++) {
134 _locals[i] = src->locals()[i];
135 }
136 }
137
138 void StackMapFrame::copy_stack(const StackMapFrame* src) {
139 int32_t len = src->stack_size() < _stack_size ?
140 src->stack_size() : _stack_size;
141 for (int32_t i = 0; i < len; i++) {
142 _stack[i] = src->stack()[i];
143 }
144 }
145
146 // Returns the location of the first mismatch, or 'len' if there are no
147 // mismatches
148 int StackMapFrame::is_assignable_to(
149 VerificationType* from, VerificationType* to, int32_t len, TRAPS) const {
150 int32_t i = 0;
151 for (i = 0; i < len; i++) {
152 if (!to[i].is_assignable_from(from[i], verifier(), false, THREAD)) {
153 break;
154 }
155 }
156 return i;
157 }
158
159 bool StackMapFrame::is_assignable_to(
160 const StackMapFrame* target, ErrorContext* ctx, TRAPS) const {
161 if (_max_locals != target->max_locals()) {
162 *ctx = ErrorContext::locals_size_mismatch(
163 _offset, (StackMapFrame*)this, (StackMapFrame*)target);
164 return false;
165 }
166 if (_stack_size != target->stack_size()) {
167 *ctx = ErrorContext::stack_size_mismatch(
168 _offset, (StackMapFrame*)this, (StackMapFrame*)target);
169 return false;
170 }
171 // Only need to compare type elements up to target->locals() or target->stack().
172 // The remaining type elements in this state can be ignored because they are
173 // assignable to bogus type.
174 int mismatch_loc;
175 mismatch_loc = is_assignable_to(
176 _locals, target->locals(), target->locals_size(), THREAD);
177 if (mismatch_loc != target->locals_size()) {
178 *ctx = ErrorContext::bad_type(target->offset(),
179 TypeOrigin::local(mismatch_loc, (StackMapFrame*)this),
180 TypeOrigin::sm_local(mismatch_loc, (StackMapFrame*)target));
181 return false;
182 }
183 mismatch_loc = is_assignable_to(_stack, target->stack(), _stack_size, THREAD);
184 if (mismatch_loc != _stack_size) {
185 *ctx = ErrorContext::bad_type(target->offset(),
186 TypeOrigin::stack(mismatch_loc, (StackMapFrame*)this),
187 TypeOrigin::sm_stack(mismatch_loc, (StackMapFrame*)target));
188 return false;
189 }
190
191 if ((_flags | target->flags()) == target->flags()) {
192 return true;
193 } else {
194 *ctx = ErrorContext::bad_flags(target->offset(),
195 (StackMapFrame*)this, (StackMapFrame*)target);
196 return false;
197 }
198 }
199
200 VerificationType StackMapFrame::pop_stack_ex(VerificationType type, TRAPS) {
201 if (_stack_size <= 0) {
202 verifier()->verify_error(
203 ErrorContext::stack_underflow(_offset, this),
204 "Operand stack underflow");
205 return VerificationType::bogus_type();
206 }
207 VerificationType top = _stack[--_stack_size];
208 bool subtype = type.is_assignable_from(
209 top, verifier(), false, CHECK_(VerificationType::bogus_type()));
210 if (!subtype) {
211 verifier()->verify_error(
212 ErrorContext::bad_type(_offset, stack_top_ctx(),
213 TypeOrigin::implicit(type)),
214 "Bad type on operand stack");
215 return VerificationType::bogus_type();
216 }
217 return top;
218 }
219
220 VerificationType StackMapFrame::get_local(
221 int32_t index, VerificationType type, TRAPS) {
222 if (index >= _max_locals) {
223 verifier()->verify_error(
224 ErrorContext::bad_local_index(_offset, index),
225 "Local variable table overflow");
226 return VerificationType::bogus_type();
227 }
228 bool subtype = type.is_assignable_from(_locals[index],
229 verifier(), false, CHECK_(VerificationType::bogus_type()));
230 if (!subtype) {
231 verifier()->verify_error(
232 ErrorContext::bad_type(_offset,
233 TypeOrigin::local(index, this),
234 TypeOrigin::implicit(type)),
235 "Bad local variable type");
236 return VerificationType::bogus_type();
237 }
238 if(index >= _locals_size) { _locals_size = index + 1; }
239 return _locals[index];
240 }
241
242 void StackMapFrame::get_local_2(
243 int32_t index, VerificationType type1, VerificationType type2, TRAPS) {
244 assert(type1.is_long() || type1.is_double(), "must be long/double");
245 assert(type2.is_long2() || type2.is_double2(), "must be long/double_2");
246 if (index >= _locals_size - 1) {
247 verifier()->verify_error(
248 ErrorContext::bad_local_index(_offset, index),
249 "get long/double overflows locals");
250 return;
251 }
252 bool subtype = type1.is_assignable_from(_locals[index], verifier(), false, CHECK);
253 if (!subtype) {
254 verifier()->verify_error(
255 ErrorContext::bad_type(_offset,
256 TypeOrigin::local(index, this), TypeOrigin::implicit(type1)),
257 "Bad local variable type");
258 } else {
259 subtype = type2.is_assignable_from(_locals[index + 1], verifier(), false, CHECK);
260 if (!subtype) {
261 /* Unreachable? All local store routines convert a split long or double
262 * into a TOP during the store. So we should never end up seeing an
263 * orphaned half. */
264 verifier()->verify_error(
265 ErrorContext::bad_type(_offset,
266 TypeOrigin::local(index + 1, this), TypeOrigin::implicit(type2)),
267 "Bad local variable type");
268 }
269 }
270 }
271
272 void StackMapFrame::set_local(int32_t index, VerificationType type, TRAPS) {
273 assert(!type.is_check(), "Must be a real type");
274 if (index >= _max_locals) {
275 verifier()->verify_error(
276 ErrorContext::bad_local_index(_offset, index),
277 "Local variable table overflow");
278 return;
279 }
280 // If type at index is double or long, set the next location to be unusable
281 if (_locals[index].is_double() || _locals[index].is_long()) {
282 assert((index + 1) < _locals_size, "Local variable table overflow");
283 _locals[index + 1] = VerificationType::bogus_type();
284 }
285 // If type at index is double_2 or long_2, set the previous location to be unusable
286 if (_locals[index].is_double2() || _locals[index].is_long2()) {
287 assert(index >= 1, "Local variable table underflow");
288 _locals[index - 1] = VerificationType::bogus_type();
289 }
290 _locals[index] = type;
291 if (index >= _locals_size) {
292 #ifdef ASSERT
293 for (int i=_locals_size; i<index; i++) {
294 assert(_locals[i] == VerificationType::bogus_type(),
295 "holes must be bogus type");
296 }
297 #endif
298 _locals_size = index + 1;
299 }
300 }
301
302 void StackMapFrame::set_local_2(
303 int32_t index, VerificationType type1, VerificationType type2, TRAPS) {
304 assert(type1.is_long() || type1.is_double(), "must be long/double");
305 assert(type2.is_long2() || type2.is_double2(), "must be long/double_2");
306 if (index >= _max_locals - 1) {
307 verifier()->verify_error(
308 ErrorContext::bad_local_index(_offset, index),
309 "Local variable table overflow");
310 return;
311 }
312 // If type at index+1 is double or long, set the next location to be unusable
313 if (_locals[index+1].is_double() || _locals[index+1].is_long()) {
314 assert((index + 2) < _locals_size, "Local variable table overflow");
315 _locals[index + 2] = VerificationType::bogus_type();
316 }
317 // If type at index is double_2 or long_2, set the previous location to be unusable
318 if (_locals[index].is_double2() || _locals[index].is_long2()) {
319 assert(index >= 1, "Local variable table underflow");
320 _locals[index - 1] = VerificationType::bogus_type();
321 }
322 _locals[index] = type1;
323 _locals[index+1] = type2;
324 if (index >= _locals_size - 1) {
325 #ifdef ASSERT
326 for (int i=_locals_size; i<index; i++) {
327 assert(_locals[i] == VerificationType::bogus_type(),
328 "holes must be bogus type");
329 }
330 #endif
331 _locals_size = index + 2;
332 }
333 }
334
335 TypeOrigin StackMapFrame::stack_top_ctx() {
336 return TypeOrigin::stack(_stack_size, this);
337 }
338
339 void StackMapFrame::print_on(outputStream* str) const {
340 str->indent().print_cr("bci: @%d", _offset);
341 str->indent().print_cr("flags: {%s }",
342 flag_this_uninit() ? " flagThisUninit" : "");
343 str->indent().print("locals: {");
344 for (int32_t i = 0; i < _locals_size; ++i) {
345 str->print(" ");
346 _locals[i].print_on(str);
347 if (i != _locals_size - 1) {
348 str->print(",");
349 }
350 }
351 str->print_cr(" }");
352 str->indent().print("stack: {");
353 for (int32_t j = 0; j < _stack_size; ++j) {
354 str->print(" ");
355 _stack[j].print_on(str);
356 if (j != _stack_size - 1) {
357 str->print(",");
358 }
359 }
360 str->print_cr(" }");
361 }