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 # include "incls/_precompiled.incl" 26 # include "incls/_stackMapTable.cpp.incl" 27 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 } 52 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 } 63 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); 68 69 return match_stackmap( 70 frame, target, index, match, 71 update, CHECK_VERIFY_(frame->verifier(), false)); 72 } 73 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 } 92 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 } 117 118 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 } 130 131 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 } 139 140 #ifndef PRODUCT 141 142 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 } 150 151 #endif 152 153 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 } 167 168 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 } 205 206 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 } 264 265 u2 offset_delta = _stream->get_u2(THREAD); 266 267 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 } 272 273 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 } 304 305 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 } 424 425 _stream->stackmap_format_error( 426 "reserved frame type", CHECK_VERIFY_(pre_frame->verifier(), NULL)); 427 return NULL; 428 }