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, AssertUnsetFieldTable* initial_strict_fields, 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), _assert_unset_fields(initial_strict_fields), _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 void StackMapFrame::unsatisfied_strict_fields_error(InstanceKlass* klass, int bci) {
51 // Default these to `<Unknown>` as they will be replaced with the correct
52 // values by the `find_unset` lambda as we only call this code when
53 // an error has already been determined. This just provides a safe
54 // obvious fallback value.
55 Symbol* name = vmSymbols::unknown_class_name();
56 Symbol* sig = vmSymbols::unknown_class_name();
57 int num_uninit_fields = 0;
58
59 auto find_unset = [&] (const NameAndSig& key, const bool& value) {
60 if (!value) {
61 name = key._name;
62 sig = key._signature;
63 num_uninit_fields++;
64 }
65 };
66 assert_unset_fields()->iterate_all(find_unset);
67
68 verifier()->verify_error(
69 ErrorContext::bad_strict_fields(bci, this),
70 "All strict final fields must be initialized before super(): %d field(s), %s:%s in %s",
71 num_uninit_fields,
72 name->as_C_string(),
73 sig->as_C_string(),
74 klass->name()->as_C_string()
75 );
76 }
77
78 void StackMapFrame::print_strict_fields(AssertUnsetFieldTable* table) {
79 ResourceMark rm;
80 auto printfields = [&] (const NameAndSig& key, const bool& value) {
81 log_info(verification)("Strict field: %s%s (Satisfied: %s)",
82 key._name->as_C_string(),
83 key._signature->as_C_string(),
84 value ? "true" : "false");
85 };
86 table->iterate_all(printfields);
87 }
88
89 StackMapFrame* StackMapFrame::frame_in_exception_handler(u1 flags) {
90 Thread* thr = _verifier->thread();
91 VerificationType* stack = NEW_RESOURCE_ARRAY_IN_THREAD(thr, VerificationType, 1);
92 StackMapFrame* frame = new StackMapFrame(_offset, flags, _locals_size, 0,
93 _max_locals, _max_stack, _locals, stack,
94 _assert_unset_fields, _verifier);
95 return frame;
96 }
97
98 void StackMapFrame::initialize_object(
99 VerificationType old_object, VerificationType new_object) {
100 int32_t i;
101 for (i = 0; i < _max_locals; i++) {
102 if (_locals[i].equals(old_object)) {
103 _locals[i] = new_object;
104 }
105 }
106 for (i = 0; i < _stack_size; i++) {
107 if (_stack[i].equals(old_object)) {
108 _stack[i] = new_object;
109 }
110 }
111 if (old_object == VerificationType::uninitialized_this_type()) {
112 // "this" has been initialized - reset flags
113 _flags = 0;
114 }
115 }
116
117 VerificationType StackMapFrame::set_locals_from_arg(
118 const methodHandle& m, VerificationType thisKlass) {
119 SignatureStream ss(m->signature());
120 int init_local_num = 0;
121 if (!m->is_static()) {
122 init_local_num++;
123 // add one extra argument for instance method
124 if (m->is_object_constructor() &&
125 thisKlass.name() != vmSymbols::java_lang_Object()) {
126 _locals[0] = VerificationType::uninitialized_this_type();
127 _flags |= FLAG_THIS_UNINIT;
128 } else {
129 _locals[0] = thisKlass;
130 }
131 }
132
133 // local num may be greater than size of parameters because long/double occupies two slots
134 while(!ss.at_return_type()) {
135 init_local_num += _verifier->change_sig_to_verificationType(
136 &ss, &_locals[init_local_num]);
137 ss.next();
138 }
139 _locals_size = init_local_num;
140
141 switch (ss.type()) {
142 case T_OBJECT:
143 case T_ARRAY:
144 {
145 Symbol* sig = ss.as_symbol();
146 if (!sig->is_permanent()) {
147 // Create another symbol to save as signature stream unreferences
148 // this symbol.
149 Symbol *sig_copy =
150 verifier()->create_temporary_symbol(sig);
151 assert(sig_copy == sig, "symbols don't match");
152 sig = sig_copy;
153 }
154 return VerificationType::reference_type(sig);
155 }
156 case T_INT: return VerificationType::integer_type();
157 case T_BYTE: return VerificationType::byte_type();
158 case T_CHAR: return VerificationType::char_type();
159 case T_SHORT: return VerificationType::short_type();
160 case T_BOOLEAN: return VerificationType::boolean_type();
161 case T_FLOAT: return VerificationType::float_type();
162 case T_DOUBLE: return VerificationType::double_type();
163 case T_LONG: return VerificationType::long_type();
164 case T_VOID: return VerificationType::bogus_type();
165 default:
166 ShouldNotReachHere();
167 }
168 return VerificationType::bogus_type();
169 }
170
171 void StackMapFrame::copy_locals(const StackMapFrame* src) {
172 int32_t len = src->locals_size() < _locals_size ?
173 src->locals_size() : _locals_size;
174 for (int32_t i = 0; i < len; i++) {
175 _locals[i] = src->locals()[i];
176 }
177 }
178
179 void StackMapFrame::copy_stack(const StackMapFrame* src) {
180 int32_t len = src->stack_size() < _stack_size ?
181 src->stack_size() : _stack_size;
182 for (int32_t i = 0; i < len; i++) {
183 _stack[i] = src->stack()[i];
184 }
185 }
186
187 // Returns the location of the first mismatch, or 'len' if there are no
188 // mismatches
189 int StackMapFrame::is_assignable_to(
190 VerificationType* from, VerificationType* to, int32_t len, TRAPS) const {
191 int32_t i = 0;
192 for (i = 0; i < len; i++) {
193 if (!to[i].is_assignable_from(from[i], verifier(), false, THREAD)) {
194 break;
195 }
196 }
197 return i;
198 }
199
200 bool StackMapFrame::is_assignable_to(
201 const StackMapFrame* target, ErrorContext* ctx, TRAPS) const {
202 if (_max_locals != target->max_locals()) {
203 *ctx = ErrorContext::locals_size_mismatch(
204 _offset, (StackMapFrame*)this, (StackMapFrame*)target);
205 return false;
206 }
207 if (_stack_size != target->stack_size()) {
208 *ctx = ErrorContext::stack_size_mismatch(
209 _offset, (StackMapFrame*)this, (StackMapFrame*)target);
210 return false;
211 }
212 // Only need to compare type elements up to target->locals() or target->stack().
213 // The remaining type elements in this state can be ignored because they are
214 // assignable to bogus type.
215 int mismatch_loc;
216 mismatch_loc = is_assignable_to(
217 _locals, target->locals(), target->locals_size(), THREAD);
218 if (mismatch_loc != target->locals_size()) {
219 *ctx = ErrorContext::bad_type(target->offset(),
220 TypeOrigin::local(mismatch_loc, (StackMapFrame*)this),
221 TypeOrigin::sm_local(mismatch_loc, (StackMapFrame*)target));
222 return false;
223 }
224 mismatch_loc = is_assignable_to(_stack, target->stack(), _stack_size, THREAD);
225 if (mismatch_loc != _stack_size) {
226 *ctx = ErrorContext::bad_type(target->offset(),
227 TypeOrigin::stack(mismatch_loc, (StackMapFrame*)this),
228 TypeOrigin::sm_stack(mismatch_loc, (StackMapFrame*)target));
229 return false;
230 }
231
232 // Check that assert unset fields are compatible
233 bool compatible = verify_unset_fields_compatibility(target->assert_unset_fields());
234 if (!compatible) {
235 print_strict_fields(assert_unset_fields());
236 print_strict_fields(target->assert_unset_fields());
237 *ctx = ErrorContext::strict_fields_mismatch(target->offset(),
238 (StackMapFrame*)this, (StackMapFrame*)target);
239 return false;
240 }
241
242 if ((_flags | target->flags()) == target->flags()) {
243 return true;
244 } else {
245 *ctx = ErrorContext::bad_flags(target->offset(),
246 (StackMapFrame*)this, (StackMapFrame*)target);
247 return false;
248 }
249 }
250
251 VerificationType StackMapFrame::pop_stack_ex(VerificationType type, TRAPS) {
252 if (_stack_size <= 0) {
253 verifier()->verify_error(
254 ErrorContext::stack_underflow(_offset, this),
255 "Operand stack underflow");
256 return VerificationType::bogus_type();
257 }
258 VerificationType top = _stack[--_stack_size];
259 bool subtype = type.is_assignable_from(
260 top, verifier(), false, CHECK_(VerificationType::bogus_type()));
261 if (!subtype) {
262 verifier()->verify_error(
263 ErrorContext::bad_type(_offset, stack_top_ctx(),
264 TypeOrigin::implicit(type)),
265 "Bad type on operand stack");
266 return VerificationType::bogus_type();
267 }
268 return top;
269 }
270
271 VerificationType StackMapFrame::get_local(
272 int32_t index, VerificationType type, TRAPS) {
273 if (index >= _max_locals) {
274 verifier()->verify_error(
275 ErrorContext::bad_local_index(_offset, index),
276 "Local variable table overflow");
277 return VerificationType::bogus_type();
278 }
279 bool subtype = type.is_assignable_from(_locals[index],
280 verifier(), false, CHECK_(VerificationType::bogus_type()));
281 if (!subtype) {
282 verifier()->verify_error(
283 ErrorContext::bad_type(_offset,
284 TypeOrigin::local(index, this),
285 TypeOrigin::implicit(type)),
286 "Bad local variable type");
287 return VerificationType::bogus_type();
288 }
289 if(index >= _locals_size) { _locals_size = index + 1; }
290 return _locals[index];
291 }
292
293 void StackMapFrame::get_local_2(
294 int32_t index, VerificationType type1, VerificationType type2, TRAPS) {
295 assert(type1.is_long() || type1.is_double(), "must be long/double");
296 assert(type2.is_long2() || type2.is_double2(), "must be long/double_2");
297 if (index >= _locals_size - 1) {
298 verifier()->verify_error(
299 ErrorContext::bad_local_index(_offset, index),
300 "get long/double overflows locals");
301 return;
302 }
303 bool subtype = type1.is_assignable_from(_locals[index], verifier(), false, CHECK);
304 if (!subtype) {
305 verifier()->verify_error(
306 ErrorContext::bad_type(_offset,
307 TypeOrigin::local(index, this), TypeOrigin::implicit(type1)),
308 "Bad local variable type");
309 } else {
310 subtype = type2.is_assignable_from(_locals[index + 1], verifier(), false, CHECK);
311 if (!subtype) {
312 /* Unreachable? All local store routines convert a split long or double
313 * into a TOP during the store. So we should never end up seeing an
314 * orphaned half. */
315 verifier()->verify_error(
316 ErrorContext::bad_type(_offset,
317 TypeOrigin::local(index + 1, this), TypeOrigin::implicit(type2)),
318 "Bad local variable type");
319 }
320 }
321 }
322
323 void StackMapFrame::set_local(int32_t index, VerificationType type, TRAPS) {
324 assert(!type.is_check(), "Must be a real type");
325 if (index >= _max_locals) {
326 verifier()->verify_error(
327 ErrorContext::bad_local_index(_offset, index),
328 "Local variable table overflow");
329 return;
330 }
331 // If type at index is double or long, set the next location to be unusable
332 if (_locals[index].is_double() || _locals[index].is_long()) {
333 assert((index + 1) < _locals_size, "Local variable table overflow");
334 _locals[index + 1] = VerificationType::bogus_type();
335 }
336 // If type at index is double_2 or long_2, set the previous location to be unusable
337 if (_locals[index].is_double2() || _locals[index].is_long2()) {
338 assert(index >= 1, "Local variable table underflow");
339 _locals[index - 1] = VerificationType::bogus_type();
340 }
341 _locals[index] = type;
342 if (index >= _locals_size) {
343 #ifdef ASSERT
344 for (int i=_locals_size; i<index; i++) {
345 assert(_locals[i] == VerificationType::bogus_type(),
346 "holes must be bogus type");
347 }
348 #endif
349 _locals_size = index + 1;
350 }
351 }
352
353 void StackMapFrame::set_local_2(
354 int32_t index, VerificationType type1, VerificationType type2, TRAPS) {
355 assert(type1.is_long() || type1.is_double(), "must be long/double");
356 assert(type2.is_long2() || type2.is_double2(), "must be long/double_2");
357 if (index >= _max_locals - 1) {
358 verifier()->verify_error(
359 ErrorContext::bad_local_index(_offset, index),
360 "Local variable table overflow");
361 return;
362 }
363 // If type at index+1 is double or long, set the next location to be unusable
364 if (_locals[index+1].is_double() || _locals[index+1].is_long()) {
365 assert((index + 2) < _locals_size, "Local variable table overflow");
366 _locals[index + 2] = VerificationType::bogus_type();
367 }
368 // If type at index is double_2 or long_2, set the previous location to be unusable
369 if (_locals[index].is_double2() || _locals[index].is_long2()) {
370 assert(index >= 1, "Local variable table underflow");
371 _locals[index - 1] = VerificationType::bogus_type();
372 }
373 _locals[index] = type1;
374 _locals[index+1] = type2;
375 if (index >= _locals_size - 1) {
376 #ifdef ASSERT
377 for (int i=_locals_size; i<index; i++) {
378 assert(_locals[i] == VerificationType::bogus_type(),
379 "holes must be bogus type");
380 }
381 #endif
382 _locals_size = index + 2;
383 }
384 }
385
386 TypeOrigin StackMapFrame::stack_top_ctx() {
387 return TypeOrigin::stack(_stack_size, this);
388 }
389
390 void StackMapFrame::print_on(outputStream* str) const {
391 str->print_cr("bci: @%d", _offset);
392 str->print_cr("flags: {%s }",
393 flag_this_uninit() ? " flagThisUninit" : "");
394 str->print("locals: {");
395 for (int32_t i = 0; i < _locals_size; ++i) {
396 str->print(" ");
397 _locals[i].print_on(str);
398 if (i != _locals_size - 1) {
399 str->print(",");
400 }
401 }
402 str->print_cr(" }");
403 str->print("stack: {");
404 for (int32_t j = 0; j < _stack_size; ++j) {
405 str->print(" ");
406 _stack[j].print_on(str);
407 if (j != _stack_size - 1) {
408 str->print(",");
409 }
410 }
411 str->print_cr(" }");
412 }