1 /*
2 * Copyright (c) 2003, 2014, 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 "precompiled.hpp"
26 #include "classfile/stackMapFrame.hpp"
27 #include "classfile/verifier.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), _flags(0), _max_locals(max_locals),
37 _max_stack(max_stack), _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 // Return true if frame has an uninitialized (new) object that differs
58 // from the target frame's object.
59 bool StackMapFrame::has_unique_new_object(const StackMapFrame *target_frame) const {
60 int32_t i;
61 for (i = 0; i < _max_locals; i++) {
62 if (_locals[i].is_uninitialized() &&
63 !_locals[i].equals(target_frame->_locals[i])) {
64 return true;
65 }
66 }
67 for (i = 0; i < _stack_size; i++) {
68 if (_stack[i].is_uninitialized() &&
69 !_stack[i].equals(target_frame->_stack[i])) {
70 return true;
71 }
72 }
73 return false;
74 }
75
76 void StackMapFrame::initialize_object(
77 VerificationType old_object, VerificationType new_object) {
78 int32_t i;
79 for (i = 0; i < _max_locals; i++) {
80 if (_locals[i].equals(old_object)) {
81 _locals[i] = new_object;
82 }
83 }
84 for (i = 0; i < _stack_size; i++) {
85 if (_stack[i].equals(old_object)) {
86 _stack[i] = new_object;
87 }
88 }
89 if (old_object == VerificationType::uninitialized_this_type()) {
90 // "this" has been initialized - reset flags
91 _flags = 0;
92 }
93 }
94
95 VerificationType StackMapFrame::set_locals_from_arg(
96 const methodHandle m, VerificationType thisKlass, TRAPS) {
97 SignatureStream ss(m->signature());
98 int init_local_num = 0;
99 if (!m->is_static()) {
100 init_local_num++;
101 // add one extra argument for instance method
102 if (m->name() == vmSymbols::object_initializer_name() &&
103 thisKlass.name() != vmSymbols::java_lang_Object()) {
104 _locals[0] = VerificationType::uninitialized_this_type();
105 _flags |= FLAG_THIS_UNINIT;
106 } else {
107 _locals[0] = thisKlass;
108 }
109 }
110
111 // local num may be greater than size of parameters because long/double occupies two slots
112 while(!ss.at_return_type()) {
113 init_local_num += _verifier->change_sig_to_verificationType(
114 &ss, &_locals[init_local_num],
115 CHECK_VERIFY_(verifier(), VerificationType::bogus_type()));
116 ss.next();
117 }
118 _locals_size = init_local_num;
119
120 switch (ss.type()) {
121 case T_OBJECT:
122 case T_ARRAY:
123 {
124 Symbol* sig = ss.as_symbol(CHECK_(VerificationType::bogus_type()));
125 // Create another symbol to save as signature stream unreferences
126 // this symbol.
127 Symbol* sig_copy =
128 verifier()->create_temporary_symbol(sig, 0, sig->utf8_length(),
129 CHECK_(VerificationType::bogus_type()));
130 assert(sig_copy == sig, "symbols don't match");
131 return VerificationType::reference_type(sig_copy);
132 }
133 case T_INT: return VerificationType::integer_type();
134 case T_BYTE: return VerificationType::byte_type();
135 case T_CHAR: return VerificationType::char_type();
136 case T_SHORT: return VerificationType::short_type();
137 case T_BOOLEAN: return VerificationType::boolean_type();
138 case T_FLOAT: return VerificationType::float_type();
139 case T_DOUBLE: return VerificationType::double_type();
140 case T_LONG: return VerificationType::long_type();
141 case T_VOID: return VerificationType::bogus_type();
142 default:
143 ShouldNotReachHere();
144 }
145 return VerificationType::bogus_type();
146 }
147
148 void StackMapFrame::copy_locals(const StackMapFrame* src) {
149 int32_t len = src->locals_size() < _locals_size ?
150 src->locals_size() : _locals_size;
151 for (int32_t i = 0; i < len; i++) {
152 _locals[i] = src->locals()[i];
153 }
154 }
155
156 void StackMapFrame::copy_stack(const StackMapFrame* src) {
157 int32_t len = src->stack_size() < _stack_size ?
158 src->stack_size() : _stack_size;
159 for (int32_t i = 0; i < len; i++) {
160 _stack[i] = src->stack()[i];
161 }
162 }
163
164 // Returns the location of the first mismatch, or 'len' if there are no
165 // mismatches
166 int StackMapFrame::is_assignable_to(
167 VerificationType* from, VerificationType* to, int32_t len, TRAPS) const {
168 int32_t i = 0;
169 for (i = 0; i < len; i++) {
170 if (!to[i].is_assignable_from(from[i], verifier(), THREAD)) {
171 break;
172 }
173 }
174 return i;
175 }
176
177 bool StackMapFrame::has_flag_match_exception(
178 const StackMapFrame* target) const {
179 // We allow flags of {UninitThis} to assign to {} if-and-only-if the
180 // target frame does not depend upon the current type.
181 // This is slightly too strict, as we need only enforce that the
182 // slots that were initialized by the <init> (the things that were
183 // UninitializedThis before initialize_object() converted them) are unused.
184 // However we didn't save that information so we'll enforce this upon
185 // anything that might have been initialized. This is a rare situation
186 // and javac never generates code that would end up here, but some profilers
187 // (such as NetBeans) might, when adding exception handlers in <init>
188 // methods to cover the invokespecial instruction. See 7020118.
189
190 assert(max_locals() == target->max_locals() &&
191 stack_size() == target->stack_size(), "StackMap sizes must match");
192
193 VerificationType top = VerificationType::top_type();
194 VerificationType this_type = verifier()->current_type();
195
196 if (!flag_this_uninit() || target->flags() != 0) {
197 return false;
198 }
199
200 for (int i = 0; i < target->locals_size(); ++i) {
201 if (locals()[i] == this_type && target->locals()[i] != top) {
202 return false;
203 }
204 }
205
206 for (int i = 0; i < target->stack_size(); ++i) {
207 if (stack()[i] == this_type && target->stack()[i] != top) {
208 return false;
209 }
210 }
211
212 return true;
213 }
214
215 bool StackMapFrame::is_assignable_to(
216 const StackMapFrame* target, bool is_exception_handler,
217 ErrorContext* ctx, TRAPS) const {
218 if (_max_locals != target->max_locals()) {
219 *ctx = ErrorContext::locals_size_mismatch(
220 _offset, (StackMapFrame*)this, (StackMapFrame*)target);
221 return false;
222 }
223 if (_stack_size != target->stack_size()) {
224 *ctx = ErrorContext::stack_size_mismatch(
225 _offset, (StackMapFrame*)this, (StackMapFrame*)target);
226 return false;
227 }
228 // Only need to compare type elements up to target->locals() or target->stack().
229 // The remaining type elements in this state can be ignored because they are
230 // assignable to bogus type.
231 int mismatch_loc;
232 mismatch_loc = is_assignable_to(
233 _locals, target->locals(), target->locals_size(), THREAD);
234 if (mismatch_loc != target->locals_size()) {
235 *ctx = ErrorContext::bad_type(target->offset(),
236 TypeOrigin::local(mismatch_loc, (StackMapFrame*)this),
237 TypeOrigin::sm_local(mismatch_loc, (StackMapFrame*)target));
238 return false;
239 }
240 mismatch_loc = is_assignable_to(_stack, target->stack(), _stack_size, THREAD);
241 if (mismatch_loc != _stack_size) {
242 *ctx = ErrorContext::bad_type(target->offset(),
243 TypeOrigin::stack(mismatch_loc, (StackMapFrame*)this),
244 TypeOrigin::sm_stack(mismatch_loc, (StackMapFrame*)target));
245 return false;
246 }
247
248 bool match_flags = (_flags | target->flags()) == target->flags();
249 if (match_flags || is_exception_handler && has_flag_match_exception(target)) {
250 return true;
251 } else {
252 *ctx = ErrorContext::bad_flags(target->offset(),
253 (StackMapFrame*)this, (StackMapFrame*)target);
254 return false;
255 }
256 }
257
258 VerificationType StackMapFrame::pop_stack_ex(VerificationType type, TRAPS) {
259 if (_stack_size <= 0) {
260 verifier()->verify_error(
261 ErrorContext::stack_underflow(_offset, this),
262 "Operand stack underflow");
263 return VerificationType::bogus_type();
264 }
265 VerificationType top = _stack[--_stack_size];
266 bool subtype = type.is_assignable_from(
267 top, verifier(), CHECK_(VerificationType::bogus_type()));
268 if (!subtype) {
269 verifier()->verify_error(
270 ErrorContext::bad_type(_offset, stack_top_ctx(),
271 TypeOrigin::implicit(type)),
272 "Bad type on operand stack");
273 return VerificationType::bogus_type();
274 }
275 return top;
276 }
277
278 VerificationType StackMapFrame::get_local(
279 int32_t index, VerificationType type, TRAPS) {
280 if (index >= _max_locals) {
281 verifier()->verify_error(
282 ErrorContext::bad_local_index(_offset, index),
283 "Local variable table overflow");
284 return VerificationType::bogus_type();
285 }
286 bool subtype = type.is_assignable_from(_locals[index],
287 verifier(), CHECK_(VerificationType::bogus_type()));
288 if (!subtype) {
289 verifier()->verify_error(
290 ErrorContext::bad_type(_offset,
291 TypeOrigin::local(index, this),
292 TypeOrigin::implicit(type)),
293 "Bad local variable type");
294 return VerificationType::bogus_type();
295 }
296 if(index >= _locals_size) { _locals_size = index + 1; }
297 return _locals[index];
298 }
299
300 void StackMapFrame::get_local_2(
301 int32_t index, VerificationType type1, VerificationType type2, TRAPS) {
302 assert(type1.is_long() || type1.is_double(), "must be long/double");
303 assert(type2.is_long2() || type2.is_double2(), "must be long/double_2");
304 if (index >= _locals_size - 1) {
305 verifier()->verify_error(
306 ErrorContext::bad_local_index(_offset, index),
307 "get long/double overflows locals");
308 return;
309 }
310 bool subtype = type1.is_assignable_from(_locals[index], verifier(), CHECK);
311 if (!subtype) {
312 verifier()->verify_error(
313 ErrorContext::bad_type(_offset,
314 TypeOrigin::local(index, this), TypeOrigin::implicit(type1)),
315 "Bad local variable type");
316 } else {
317 subtype = type2.is_assignable_from(_locals[index + 1], verifier(), CHECK);
318 if (!subtype) {
319 /* Unreachable? All local store routines convert a split long or double
320 * into a TOP during the store. So we should never end up seeing an
321 * orphaned half. */
322 verifier()->verify_error(
323 ErrorContext::bad_type(_offset,
324 TypeOrigin::local(index + 1, this), TypeOrigin::implicit(type2)),
325 "Bad local variable type");
326 }
327 }
328 }
329
330 void StackMapFrame::set_local(int32_t index, VerificationType type, TRAPS) {
331 assert(!type.is_check(), "Must be a real type");
332 if (index >= _max_locals) {
333 verifier()->verify_error(
334 ErrorContext::bad_local_index(_offset, index),
335 "Local variable table overflow");
336 return;
337 }
338 // If type at index is double or long, set the next location to be unusable
339 if (_locals[index].is_double() || _locals[index].is_long()) {
340 assert((index + 1) < _locals_size, "Local variable table overflow");
341 _locals[index + 1] = VerificationType::bogus_type();
342 }
343 // If type at index is double_2 or long_2, set the previous location to be unusable
344 if (_locals[index].is_double2() || _locals[index].is_long2()) {
345 assert(index >= 1, "Local variable table underflow");
346 _locals[index - 1] = VerificationType::bogus_type();
347 }
348 _locals[index] = type;
349 if (index >= _locals_size) {
350 #ifdef ASSERT
351 for (int i=_locals_size; i<index; i++) {
352 assert(_locals[i] == VerificationType::bogus_type(),
353 "holes must be bogus type");
354 }
355 #endif
356 _locals_size = index + 1;
357 }
358 }
359
360 void StackMapFrame::set_local_2(
361 int32_t index, VerificationType type1, VerificationType type2, TRAPS) {
362 assert(type1.is_long() || type1.is_double(), "must be long/double");
363 assert(type2.is_long2() || type2.is_double2(), "must be long/double_2");
364 if (index >= _max_locals - 1) {
365 verifier()->verify_error(
366 ErrorContext::bad_local_index(_offset, index),
367 "Local variable table overflow");
368 return;
369 }
370 // If type at index+1 is double or long, set the next location to be unusable
371 if (_locals[index+1].is_double() || _locals[index+1].is_long()) {
372 assert((index + 2) < _locals_size, "Local variable table overflow");
373 _locals[index + 2] = VerificationType::bogus_type();
374 }
375 // If type at index is double_2 or long_2, set the previous location to be unusable
376 if (_locals[index].is_double2() || _locals[index].is_long2()) {
377 assert(index >= 1, "Local variable table underflow");
378 _locals[index - 1] = VerificationType::bogus_type();
379 }
380 _locals[index] = type1;
381 _locals[index+1] = type2;
382 if (index >= _locals_size - 1) {
383 #ifdef ASSERT
384 for (int i=_locals_size; i<index; i++) {
385 assert(_locals[i] == VerificationType::bogus_type(),
386 "holes must be bogus type");
387 }
388 #endif
389 _locals_size = index + 2;
390 }
391 }
392
393 TypeOrigin StackMapFrame::stack_top_ctx() {
394 return TypeOrigin::stack(_stack_size, this);
395 }
396
397 void StackMapFrame::print_on(outputStream* str) const {
398 str->indent().print_cr("bci: @%d", _offset);
399 str->indent().print_cr("flags: {%s }",
400 flag_this_uninit() ? " flagThisUninit" : "");
401 str->indent().print("locals: {");
402 for (int32_t i = 0; i < _locals_size; ++i) {
403 str->print(" ");
404 _locals[i].print_on(str);
405 if (i != _locals_size - 1) {
406 str->print(",");
407 }
408 }
409 str->print_cr(" }");
410 str->indent().print("stack: {");
411 for (int32_t j = 0; j < _stack_size; ++j) {
412 str->print(" ");
413 _stack[j].print_on(str);
414 if (j != _stack_size - 1) {
415 str->print(",");
416 }
417 }
418 str->print_cr(" }");
419 }