Fri, 12 Nov 2010 09:37:13 -0500
Merge
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 */
25 # include "incls/_precompiled.incl"
26 # include "incls/_stackMapTable.cpp.incl"
28 StackMapTable::StackMapTable(StackMapReader* reader, StackMapFrame* init_frame,
29 u2 max_locals, u2 max_stack,
30 char* code_data, int code_len, TRAPS) {
31 _code_length = code_len;
32 _frame_count = reader->get_frame_count();
33 if (_frame_count > 0) {
34 _frame_array = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD,
35 StackMapFrame*, _frame_count);
36 StackMapFrame* pre_frame = init_frame;
37 for (int32_t i = 0; i < _frame_count; i++) {
38 StackMapFrame* frame = reader->next(
39 pre_frame, i == 0, max_locals, max_stack,
40 CHECK_VERIFY(pre_frame->verifier()));
41 _frame_array[i] = frame;
42 int offset = frame->offset();
43 if (offset >= code_len || code_data[offset] == 0) {
44 frame->verifier()->verify_error("StackMapTable error: bad offset");
45 return;
46 }
47 pre_frame = frame;
48 }
49 }
50 reader->check_end(CHECK);
51 }
53 // This method is only called by method in StackMapTable.
54 int StackMapTable::get_index_from_offset(int32_t offset) const {
55 int i = 0;
56 for (; i < _frame_count; i++) {
57 if (_frame_array[i]->offset() == offset) {
58 return i;
59 }
60 }
61 return i; // frame with offset doesn't exist in the array
62 }
64 bool StackMapTable::match_stackmap(
65 StackMapFrame* frame, int32_t target,
66 bool match, bool update, TRAPS) const {
67 int index = get_index_from_offset(target);
69 return match_stackmap(
70 frame, target, index, match,
71 update, CHECK_VERIFY_(frame->verifier(), false));
72 }
74 // Match and/or update current_frame to the frame in stackmap table with
75 // specified offset and frame index. Return true if the two frames match.
76 //
77 // The values of match and update are: _match__update_
78 //
79 // checking a branch target/exception handler: true false
80 // linear bytecode verification following an
81 // unconditional branch: false true
82 // linear bytecode verification not following an
83 // unconditional branch: true true
84 bool StackMapTable::match_stackmap(
85 StackMapFrame* frame, int32_t target, int32_t frame_index,
86 bool match, bool update, TRAPS) const {
87 if (frame_index < 0 || frame_index >= _frame_count) {
88 frame->verifier()->verify_error(frame->offset(),
89 "Expecting a stackmap frame at branch target %d", target);
90 return false;
91 }
93 bool result = true;
94 StackMapFrame *stackmap_frame = _frame_array[frame_index];
95 if (match) {
96 // Has direct control flow from last instruction, need to match the two
97 // frames.
98 result = frame->is_assignable_to(
99 stackmap_frame, CHECK_VERIFY_(frame->verifier(), false));
100 }
101 if (update) {
102 // Use the frame in stackmap table as current frame
103 int lsize = stackmap_frame->locals_size();
104 int ssize = stackmap_frame->stack_size();
105 if (frame->locals_size() > lsize || frame->stack_size() > ssize) {
106 // Make sure unused type array items are all _bogus_type.
107 frame->reset();
108 }
109 frame->set_locals_size(lsize);
110 frame->copy_locals(stackmap_frame);
111 frame->set_stack_size(ssize);
112 frame->copy_stack(stackmap_frame);
113 frame->set_flags(stackmap_frame->flags());
114 }
115 return result;
116 }
118 void StackMapTable::check_jump_target(
119 StackMapFrame* frame, int32_t target, TRAPS) const {
120 bool match = match_stackmap(
121 frame, target, true, false, CHECK_VERIFY(frame->verifier()));
122 if (!match || (target < 0 || target >= _code_length)) {
123 frame->verifier()->verify_error(frame->offset(),
124 "Inconsistent stackmap frames at branch target %d", target);
125 return;
126 }
127 // check if uninitialized objects exist on backward branches
128 check_new_object(frame, target, CHECK_VERIFY(frame->verifier()));
129 }
131 void StackMapTable::check_new_object(
132 const StackMapFrame* frame, int32_t target, TRAPS) const {
133 if (frame->offset() > target && frame->has_new_object()) {
134 frame->verifier()->verify_error(frame->offset(),
135 "Uninitialized object exists on backward branch %d", target);
136 return;
137 }
138 }
140 #ifndef PRODUCT
142 void StackMapTable::print() const {
143 tty->print_cr("StackMapTable: frame_count = %d", _frame_count);
144 tty->print_cr("table = { ");
145 for (int32_t i = 0; i < _frame_count; i++) {
146 _frame_array[i]->print();
147 }
148 tty->print_cr(" }");
149 }
151 #endif
153 int32_t StackMapReader::chop(
154 VerificationType* locals, int32_t length, int32_t chops) {
155 if (locals == NULL) return -1;
156 int32_t pos = length - 1;
157 for (int32_t i=0; i<chops; i++) {
158 if (locals[pos].is_category2_2nd()) {
159 pos -= 2;
160 } else {
161 pos --;
162 }
163 if (pos<0 && i<(chops-1)) return -1;
164 }
165 return pos+1;
166 }
168 VerificationType StackMapReader::parse_verification_type(u1* flags, TRAPS) {
169 u1 tag = _stream->get_u1(THREAD);
170 if (tag < (u1)ITEM_UninitializedThis) {
171 return VerificationType::from_tag(tag);
172 }
173 if (tag == ITEM_Object) {
174 u2 class_index = _stream->get_u2(THREAD);
175 int nconstants = _cp->length();
176 if ((class_index <= 0 || class_index >= nconstants) ||
177 (!_cp->tag_at(class_index).is_klass() &&
178 !_cp->tag_at(class_index).is_unresolved_klass())) {
179 _stream->stackmap_format_error("bad class index", THREAD);
180 return VerificationType::bogus_type();
181 }
182 return VerificationType::reference_type(
183 symbolHandle(THREAD, _cp->klass_name_at(class_index)));
184 }
185 if (tag == ITEM_UninitializedThis) {
186 if (flags != NULL) {
187 *flags |= FLAG_THIS_UNINIT;
188 }
189 return VerificationType::uninitialized_this_type();
190 }
191 if (tag == ITEM_Uninitialized) {
192 u2 offset = _stream->get_u2(THREAD);
193 if (offset >= _code_length ||
194 _code_data[offset] != ClassVerifier::NEW_OFFSET) {
195 ResourceMark rm(THREAD);
196 _verifier->class_format_error(
197 "StackMapTable format error: bad offset for Uninitialized");
198 return VerificationType::bogus_type();
199 }
200 return VerificationType::uninitialized_type(offset);
201 }
202 _stream->stackmap_format_error("bad verification type", THREAD);
203 return VerificationType::bogus_type();
204 }
206 StackMapFrame* StackMapReader::next(
207 StackMapFrame* pre_frame, bool first, u2 max_locals, u2 max_stack, TRAPS) {
208 StackMapFrame* frame;
209 int offset;
210 VerificationType* locals = NULL;
211 u1 frame_type = _stream->get_u1(THREAD);
212 if (frame_type < 64) {
213 // same_frame
214 if (first) {
215 offset = frame_type;
216 // Can't share the locals array since that is updated by the verifier.
217 if (pre_frame->locals_size() > 0) {
218 locals = NEW_RESOURCE_ARRAY_IN_THREAD(
219 THREAD, VerificationType, pre_frame->locals_size());
220 }
221 } else {
222 offset = pre_frame->offset() + frame_type + 1;
223 locals = pre_frame->locals();
224 }
225 frame = new StackMapFrame(
226 offset, pre_frame->flags(), pre_frame->locals_size(), 0,
227 max_locals, max_stack, locals, NULL, _verifier);
228 if (first && locals != NULL) {
229 frame->copy_locals(pre_frame);
230 }
231 return frame;
232 }
233 if (frame_type < 128) {
234 // same_locals_1_stack_item_frame
235 if (first) {
236 offset = frame_type - 64;
237 // Can't share the locals array since that is updated by the verifier.
238 if (pre_frame->locals_size() > 0) {
239 locals = NEW_RESOURCE_ARRAY_IN_THREAD(
240 THREAD, VerificationType, pre_frame->locals_size());
241 }
242 } else {
243 offset = pre_frame->offset() + frame_type - 63;
244 locals = pre_frame->locals();
245 }
246 VerificationType* stack = NEW_RESOURCE_ARRAY_IN_THREAD(
247 THREAD, VerificationType, 2);
248 u2 stack_size = 1;
249 stack[0] = parse_verification_type(NULL, CHECK_VERIFY_(_verifier, NULL));
250 if (stack[0].is_category2()) {
251 stack[1] = stack[0].to_category2_2nd();
252 stack_size = 2;
253 }
254 check_verification_type_array_size(
255 stack_size, max_stack, CHECK_VERIFY_(_verifier, NULL));
256 frame = new StackMapFrame(
257 offset, pre_frame->flags(), pre_frame->locals_size(), stack_size,
258 max_locals, max_stack, locals, stack, _verifier);
259 if (first && locals != NULL) {
260 frame->copy_locals(pre_frame);
261 }
262 return frame;
263 }
265 u2 offset_delta = _stream->get_u2(THREAD);
267 if (frame_type < SAME_LOCALS_1_STACK_ITEM_EXTENDED) {
268 // reserved frame types
269 _stream->stackmap_format_error(
270 "reserved frame type", CHECK_VERIFY_(_verifier, NULL));
271 }
273 if (frame_type == SAME_LOCALS_1_STACK_ITEM_EXTENDED) {
274 // same_locals_1_stack_item_frame_extended
275 if (first) {
276 offset = offset_delta;
277 // Can't share the locals array since that is updated by the verifier.
278 if (pre_frame->locals_size() > 0) {
279 locals = NEW_RESOURCE_ARRAY_IN_THREAD(
280 THREAD, VerificationType, pre_frame->locals_size());
281 }
282 } else {
283 offset = pre_frame->offset() + offset_delta + 1;
284 locals = pre_frame->locals();
285 }
286 VerificationType* stack = NEW_RESOURCE_ARRAY_IN_THREAD(
287 THREAD, VerificationType, 2);
288 u2 stack_size = 1;
289 stack[0] = parse_verification_type(NULL, CHECK_VERIFY_(_verifier, NULL));
290 if (stack[0].is_category2()) {
291 stack[1] = stack[0].to_category2_2nd();
292 stack_size = 2;
293 }
294 check_verification_type_array_size(
295 stack_size, max_stack, CHECK_VERIFY_(_verifier, NULL));
296 frame = new StackMapFrame(
297 offset, pre_frame->flags(), pre_frame->locals_size(), stack_size,
298 max_locals, max_stack, locals, stack, _verifier);
299 if (first && locals != NULL) {
300 frame->copy_locals(pre_frame);
301 }
302 return frame;
303 }
305 if (frame_type <= SAME_EXTENDED) {
306 // chop_frame or same_frame_extended
307 locals = pre_frame->locals();
308 int length = pre_frame->locals_size();
309 int chops = SAME_EXTENDED - frame_type;
310 int new_length = length;
311 u1 flags = pre_frame->flags();
312 if (chops != 0) {
313 new_length = chop(locals, length, chops);
314 check_verification_type_array_size(
315 new_length, max_locals, CHECK_VERIFY_(_verifier, NULL));
316 // Recompute flags since uninitializedThis could have been chopped.
317 flags = 0;
318 for (int i=0; i<new_length; i++) {
319 if (locals[i].is_uninitialized_this()) {
320 flags |= FLAG_THIS_UNINIT;
321 break;
322 }
323 }
324 }
325 if (first) {
326 offset = offset_delta;
327 // Can't share the locals array since that is updated by the verifier.
328 if (new_length > 0) {
329 locals = NEW_RESOURCE_ARRAY_IN_THREAD(
330 THREAD, VerificationType, new_length);
331 } else {
332 locals = NULL;
333 }
334 } else {
335 offset = pre_frame->offset() + offset_delta + 1;
336 }
337 frame = new StackMapFrame(
338 offset, flags, new_length, 0, max_locals, max_stack,
339 locals, NULL, _verifier);
340 if (first && locals != NULL) {
341 frame->copy_locals(pre_frame);
342 }
343 return frame;
344 } else if (frame_type < SAME_EXTENDED + 4) {
345 // append_frame
346 int appends = frame_type - SAME_EXTENDED;
347 int real_length = pre_frame->locals_size();
348 int new_length = real_length + appends*2;
349 locals = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, VerificationType, new_length);
350 VerificationType* pre_locals = pre_frame->locals();
351 int i;
352 for (i=0; i<pre_frame->locals_size(); i++) {
353 locals[i] = pre_locals[i];
354 }
355 u1 flags = pre_frame->flags();
356 for (i=0; i<appends; i++) {
357 locals[real_length] = parse_verification_type(&flags, THREAD);
358 if (locals[real_length].is_category2()) {
359 locals[real_length + 1] = locals[real_length].to_category2_2nd();
360 ++real_length;
361 }
362 ++real_length;
363 }
364 check_verification_type_array_size(
365 real_length, max_locals, CHECK_VERIFY_(_verifier, NULL));
366 if (first) {
367 offset = offset_delta;
368 } else {
369 offset = pre_frame->offset() + offset_delta + 1;
370 }
371 frame = new StackMapFrame(
372 offset, flags, real_length, 0, max_locals,
373 max_stack, locals, NULL, _verifier);
374 return frame;
375 }
376 if (frame_type == FULL) {
377 // full_frame
378 u1 flags = 0;
379 u2 locals_size = _stream->get_u2(THREAD);
380 int real_locals_size = 0;
381 if (locals_size > 0) {
382 locals = NEW_RESOURCE_ARRAY_IN_THREAD(
383 THREAD, VerificationType, locals_size*2);
384 }
385 int i;
386 for (i=0; i<locals_size; i++) {
387 locals[real_locals_size] = parse_verification_type(&flags, THREAD);
388 if (locals[real_locals_size].is_category2()) {
389 locals[real_locals_size + 1] =
390 locals[real_locals_size].to_category2_2nd();
391 ++real_locals_size;
392 }
393 ++real_locals_size;
394 }
395 check_verification_type_array_size(
396 real_locals_size, max_locals, CHECK_VERIFY_(_verifier, NULL));
397 u2 stack_size = _stream->get_u2(THREAD);
398 int real_stack_size = 0;
399 VerificationType* stack = NULL;
400 if (stack_size > 0) {
401 stack = NEW_RESOURCE_ARRAY_IN_THREAD(
402 THREAD, VerificationType, stack_size*2);
403 }
404 for (i=0; i<stack_size; i++) {
405 stack[real_stack_size] = parse_verification_type(NULL, THREAD);
406 if (stack[real_stack_size].is_category2()) {
407 stack[real_stack_size + 1] = stack[real_stack_size].to_category2_2nd();
408 ++real_stack_size;
409 }
410 ++real_stack_size;
411 }
412 check_verification_type_array_size(
413 real_stack_size, max_stack, CHECK_VERIFY_(_verifier, NULL));
414 if (first) {
415 offset = offset_delta;
416 } else {
417 offset = pre_frame->offset() + offset_delta + 1;
418 }
419 frame = new StackMapFrame(
420 offset, flags, real_locals_size, real_stack_size,
421 max_locals, max_stack, locals, stack, _verifier);
422 return frame;
423 }
425 _stream->stackmap_format_error(
426 "reserved frame type", CHECK_VERIFY_(pre_frame->verifier(), NULL));
427 return NULL;
428 }