1 /* 2 * Copyright (c) 2000, 2015, 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 "oops/oop.inline.hpp" 27 #include "oops/symbol.hpp" 28 #include "prims/jvmtiRedefineClassesTrace.hpp" 29 #include "prims/methodComparator.hpp" 30 #include "runtime/handles.inline.hpp" 31 #include "utilities/globalDefinitions.hpp" 32 33 BytecodeStream *MethodComparator::_s_old; 34 BytecodeStream *MethodComparator::_s_new; 35 ConstantPool* MethodComparator::_old_cp; 36 ConstantPool* MethodComparator::_new_cp; 37 BciMap *MethodComparator::_bci_map; 38 bool MethodComparator::_switchable_test; 39 GrowableArray<int> *MethodComparator::_fwd_jmps; 40 41 bool MethodComparator::methods_EMCP(Method* old_method, Method* new_method) { 42 if (old_method->code_size() != new_method->code_size()) 43 return false; 44 if (check_stack_and_locals_size(old_method, new_method) != 0) { 45 // RC_TRACE macro has an embedded ResourceMark 46 RC_TRACE(0x00800000, ("Methods %s non-comparable with diagnosis %d", 47 old_method->name()->as_C_string(), 48 check_stack_and_locals_size(old_method, new_method))); 49 return false; 50 } 51 52 _old_cp = old_method->constants(); 53 _new_cp = new_method->constants(); 54 BytecodeStream s_old(old_method); 55 BytecodeStream s_new(new_method); 56 _s_old = &s_old; 57 _s_new = &s_new; 58 _switchable_test = false; 59 Bytecodes::Code c_old, c_new; 60 61 while ((c_old = s_old.next()) >= 0) { 62 if ((c_new = s_new.next()) < 0 || c_old != c_new) 63 return false; 64 65 if (! args_same(c_old, c_new)) 66 return false; 67 } 68 return true; 69 } 70 71 72 bool MethodComparator::methods_switchable(Method* old_method, Method* new_method, 73 BciMap &bci_map) { 74 if (old_method->code_size() > new_method->code_size()) 75 // Something has definitely been deleted in the new method, compared to the old one. 76 return false; 77 78 if (! check_stack_and_locals_size(old_method, new_method)) 79 return false; 80 81 _old_cp = old_method->constants(); 82 _new_cp = new_method->constants(); 83 BytecodeStream s_old(old_method); 84 BytecodeStream s_new(new_method); 85 _s_old = &s_old; 86 _s_new = &s_new; 87 _bci_map = &bci_map; 88 _switchable_test = true; 89 GrowableArray<int> fwd_jmps(16); 90 _fwd_jmps = &fwd_jmps; 91 Bytecodes::Code c_old, c_new; 92 93 while ((c_old = s_old.next()) >= 0) { 94 if ((c_new = s_new.next()) < 0) 95 return false; 96 if (! (c_old == c_new && args_same(c_old, c_new))) { 97 int old_bci = s_old.bci(); 98 int new_st_bci = s_new.bci(); 99 bool found_match = false; 100 do { 101 c_new = s_new.next(); 102 if (c_new == c_old && args_same(c_old, c_new)) { 103 found_match = true; 104 break; 105 } 106 } while (c_new >= 0); 107 if (! found_match) 108 return false; 109 int new_end_bci = s_new.bci(); 110 bci_map.store_fragment_location(old_bci, new_st_bci, new_end_bci); 111 } 112 } 113 114 // Now we can test all forward jumps 115 for (int i = 0; i < fwd_jmps.length() / 2; i++) { 116 if (! bci_map.old_and_new_locations_same(fwd_jmps.at(i*2), fwd_jmps.at(i*2+1))) { 117 RC_TRACE(0x00800000, 118 ("Fwd jump miss: old dest = %d, calc new dest = %d, act new dest = %d", 119 fwd_jmps.at(i*2), bci_map.new_bci_for_old(fwd_jmps.at(i*2)), 120 fwd_jmps.at(i*2+1))); 121 return false; 122 } 123 } 124 125 return true; 126 } 127 128 129 bool MethodComparator::args_same(Bytecodes::Code c_old, Bytecodes::Code c_new) { 130 // BytecodeStream returns the correct standard Java bytecodes for various "fast" 131 // bytecode versions, so we don't have to bother about them here.. 132 switch (c_old) { 133 case Bytecodes::_new : // fall through 134 case Bytecodes::_anewarray : // fall through 135 case Bytecodes::_multianewarray : // fall through 136 case Bytecodes::_checkcast : // fall through 137 case Bytecodes::_instanceof : { 138 u2 cpi_old = _s_old->get_index_u2(); 139 u2 cpi_new = _s_new->get_index_u2(); 140 if ((_old_cp->klass_at_noresolve(cpi_old) != _new_cp->klass_at_noresolve(cpi_new))) 141 return false; 142 if (c_old == Bytecodes::_multianewarray && 143 *(jbyte*)(_s_old->bcp() + 3) != *(jbyte*)(_s_new->bcp() + 3)) 144 return false; 145 break; 146 } 147 148 case Bytecodes::_getstatic : // fall through 149 case Bytecodes::_putstatic : // fall through 150 case Bytecodes::_getfield : // fall through 151 case Bytecodes::_putfield : // fall through 152 case Bytecodes::_invokevirtual : // fall through 153 case Bytecodes::_invokespecial : // fall through 154 case Bytecodes::_invokestatic : // fall through 155 case Bytecodes::_invokeinterface : { 156 int cpci_old = _s_old->get_index_u2_cpcache(); 157 int cpci_new = _s_new->get_index_u2_cpcache(); 158 // Check if the names of classes, field/method names and signatures at these indexes 159 // are the same. Indices which are really into constantpool cache (rather than constant 160 // pool itself) are accepted by the constantpool query routines below. 161 if ((_old_cp->klass_ref_at_noresolve(cpci_old) != _new_cp->klass_ref_at_noresolve(cpci_new)) || 162 (_old_cp->name_ref_at(cpci_old) != _new_cp->name_ref_at(cpci_new)) || 163 (_old_cp->signature_ref_at(cpci_old) != _new_cp->signature_ref_at(cpci_new))) 164 return false; 165 break; 166 } 167 case Bytecodes::_invokedynamic: { 168 int cpci_old = _s_old->get_index_u4(); 169 int cpci_new = _s_new->get_index_u4(); 170 171 // Check if the names of classes, field/method names and signatures at these indexes 172 // are the same. Indices which are really into constantpool cache (rather than constant 173 // pool itself) are accepted by the constantpool query routines below. 174 if ((_old_cp->name_ref_at(cpci_old) != _new_cp->name_ref_at(cpci_new)) || 175 (_old_cp->signature_ref_at(cpci_old) != _new_cp->signature_ref_at(cpci_new))) 176 return false; 177 178 // Translate object indexes to constant pool cache indexes. 179 cpci_old = _old_cp->invokedynamic_cp_cache_index(cpci_old); 180 cpci_new = _new_cp->invokedynamic_cp_cache_index(cpci_new); 181 182 int cpi_old = _old_cp->cache()->entry_at(cpci_old)->constant_pool_index(); 183 int cpi_new = _new_cp->cache()->entry_at(cpci_new)->constant_pool_index(); 184 int bsm_old = _old_cp->invoke_dynamic_bootstrap_method_ref_index_at(cpi_old); 185 int bsm_new = _new_cp->invoke_dynamic_bootstrap_method_ref_index_at(cpi_new); 186 if (!pool_constants_same(bsm_old, bsm_new)) 187 return false; 188 int cnt_old = _old_cp->invoke_dynamic_argument_count_at(cpi_old); 189 int cnt_new = _new_cp->invoke_dynamic_argument_count_at(cpi_new); 190 if (cnt_old != cnt_new) 191 return false; 192 for (int arg_i = 0; arg_i < cnt_old; arg_i++) { 193 int idx_old = _old_cp->invoke_dynamic_argument_index_at(cpi_old, arg_i); 194 int idx_new = _new_cp->invoke_dynamic_argument_index_at(cpi_new, arg_i); 195 if (!pool_constants_same(idx_old, idx_new)) 196 return false; 197 } 198 break; 199 } 200 201 case Bytecodes::_ldc : // fall through 202 case Bytecodes::_ldc_w : { 203 Bytecode_loadconstant ldc_old(_s_old->method(), _s_old->bci()); 204 Bytecode_loadconstant ldc_new(_s_new->method(), _s_new->bci()); 205 int cpi_old = ldc_old.pool_index(); 206 int cpi_new = ldc_new.pool_index(); 207 if (!pool_constants_same(cpi_old, cpi_new)) 208 return false; 209 break; 210 } 211 212 case Bytecodes::_ldc2_w : { 213 u2 cpi_old = _s_old->get_index_u2(); 214 u2 cpi_new = _s_new->get_index_u2(); 215 constantTag tag_old = _old_cp->tag_at(cpi_old); 216 constantTag tag_new = _new_cp->tag_at(cpi_new); 217 if (tag_old.value() != tag_new.value()) 218 return false; 219 if (tag_old.is_long()) { 220 if (_old_cp->long_at(cpi_old) != _new_cp->long_at(cpi_new)) 221 return false; 222 } else { 223 // Use jlong_cast to compare the bits rather than numerical values. 224 // This makes a difference for NaN constants. 225 if (jlong_cast(_old_cp->double_at(cpi_old)) != jlong_cast(_new_cp->double_at(cpi_new))) 226 return false; 227 } 228 break; 229 } 230 231 case Bytecodes::_bipush : 232 if (_s_old->bcp()[1] != _s_new->bcp()[1]) 233 return false; 234 break; 235 236 case Bytecodes::_sipush : 237 if (_s_old->get_index_u2() != _s_new->get_index_u2()) 238 return false; 239 break; 240 241 case Bytecodes::_aload : // fall through 242 case Bytecodes::_astore : // fall through 243 case Bytecodes::_dload : // fall through 244 case Bytecodes::_dstore : // fall through 245 case Bytecodes::_fload : // fall through 246 case Bytecodes::_fstore : // fall through 247 case Bytecodes::_iload : // fall through 248 case Bytecodes::_istore : // fall through 249 case Bytecodes::_lload : // fall through 250 case Bytecodes::_lstore : // fall through 251 case Bytecodes::_ret : 252 if (_s_old->is_wide() != _s_new->is_wide()) 253 return false; 254 if (_s_old->get_index() != _s_new->get_index()) 255 return false; 256 break; 257 258 case Bytecodes::_goto : // fall through 259 case Bytecodes::_if_acmpeq : // fall through 260 case Bytecodes::_if_acmpne : // fall through 261 case Bytecodes::_if_icmpeq : // fall through 262 case Bytecodes::_if_icmpne : // fall through 263 case Bytecodes::_if_icmplt : // fall through 264 case Bytecodes::_if_icmpge : // fall through 265 case Bytecodes::_if_icmpgt : // fall through 266 case Bytecodes::_if_icmple : // fall through 267 case Bytecodes::_ifeq : // fall through 268 case Bytecodes::_ifne : // fall through 269 case Bytecodes::_iflt : // fall through 270 case Bytecodes::_ifge : // fall through 271 case Bytecodes::_ifgt : // fall through 272 case Bytecodes::_ifle : // fall through 273 case Bytecodes::_ifnonnull : // fall through 274 case Bytecodes::_ifnull : // fall through 275 case Bytecodes::_jsr : { 276 int old_ofs = _s_old->bytecode().get_offset_s2(c_old); 277 int new_ofs = _s_new->bytecode().get_offset_s2(c_new); 278 if (_switchable_test) { 279 int old_dest = _s_old->bci() + old_ofs; 280 int new_dest = _s_new->bci() + new_ofs; 281 if (old_ofs < 0 && new_ofs < 0) { 282 if (! _bci_map->old_and_new_locations_same(old_dest, new_dest)) 283 return false; 284 } else if (old_ofs > 0 && new_ofs > 0) { 285 _fwd_jmps->append(old_dest); 286 _fwd_jmps->append(new_dest); 287 } else { 288 return false; 289 } 290 } else { 291 if (old_ofs != new_ofs) 292 return false; 293 } 294 break; 295 } 296 297 case Bytecodes::_iinc : 298 if (_s_old->is_wide() != _s_new->is_wide()) 299 return false; 300 if (! _s_old->is_wide()) { 301 // We could use get_index_u1 and get_constant_u1, but it's simpler to grab both bytes at once: 302 if (Bytes::get_Java_u2(_s_old->bcp() + 1) != Bytes::get_Java_u2(_s_new->bcp() + 1)) 303 return false; 304 } else { 305 // We could use get_index_u2 and get_constant_u2, but it's simpler to grab all four bytes at once: 306 if (Bytes::get_Java_u4(_s_old->bcp() + 1) != Bytes::get_Java_u4(_s_new->bcp() + 1)) 307 return false; 308 } 309 break; 310 311 case Bytecodes::_goto_w : // fall through 312 case Bytecodes::_jsr_w : { 313 int old_ofs = _s_old->bytecode().get_offset_s4(c_old); 314 int new_ofs = _s_new->bytecode().get_offset_s4(c_new); 315 if (_switchable_test) { 316 int old_dest = _s_old->bci() + old_ofs; 317 int new_dest = _s_new->bci() + new_ofs; 318 if (old_ofs < 0 && new_ofs < 0) { 319 if (! _bci_map->old_and_new_locations_same(old_dest, new_dest)) 320 return false; 321 } else if (old_ofs > 0 && new_ofs > 0) { 322 _fwd_jmps->append(old_dest); 323 _fwd_jmps->append(new_dest); 324 } else { 325 return false; 326 } 327 } else { 328 if (old_ofs != new_ofs) 329 return false; 330 } 331 break; 332 } 333 334 case Bytecodes::_lookupswitch : // fall through 335 case Bytecodes::_tableswitch : { 336 if (_switchable_test) { 337 address aligned_bcp_old = (address) round_to((intptr_t)_s_old->bcp() + 1, jintSize); 338 address aligned_bcp_new = (address) round_to((intptr_t)_s_new->bcp() + 1, jintSize); 339 int default_old = (int) Bytes::get_Java_u4(aligned_bcp_old); 340 int default_new = (int) Bytes::get_Java_u4(aligned_bcp_new); 341 _fwd_jmps->append(_s_old->bci() + default_old); 342 _fwd_jmps->append(_s_new->bci() + default_new); 343 if (c_old == Bytecodes::_lookupswitch) { 344 int npairs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + jintSize); 345 int npairs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + jintSize); 346 if (npairs_old != npairs_new) 347 return false; 348 for (int i = 0; i < npairs_old; i++) { 349 int match_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (2+2*i)*jintSize); 350 int match_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (2+2*i)*jintSize); 351 if (match_old != match_new) 352 return false; 353 int ofs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (2+2*i+1)*jintSize); 354 int ofs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (2+2*i+1)*jintSize); 355 _fwd_jmps->append(_s_old->bci() + ofs_old); 356 _fwd_jmps->append(_s_new->bci() + ofs_new); 357 } 358 } else if (c_old == Bytecodes::_tableswitch) { 359 int lo_old = (int) Bytes::get_Java_u4(aligned_bcp_old + jintSize); 360 int lo_new = (int) Bytes::get_Java_u4(aligned_bcp_new + jintSize); 361 if (lo_old != lo_new) 362 return false; 363 int hi_old = (int) Bytes::get_Java_u4(aligned_bcp_old + 2*jintSize); 364 int hi_new = (int) Bytes::get_Java_u4(aligned_bcp_new + 2*jintSize); 365 if (hi_old != hi_new) 366 return false; 367 for (int i = 0; i < hi_old - lo_old + 1; i++) { 368 int ofs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (3+i)*jintSize); 369 int ofs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (3+i)*jintSize); 370 _fwd_jmps->append(_s_old->bci() + ofs_old); 371 _fwd_jmps->append(_s_new->bci() + ofs_new); 372 } 373 } 374 } else { // !_switchable_test, can use fast rough compare 375 int len_old = _s_old->instruction_size(); 376 int len_new = _s_new->instruction_size(); 377 if (len_old != len_new) 378 return false; 379 if (memcmp(_s_old->bcp(), _s_new->bcp(), len_old) != 0) 380 return false; 381 } 382 break; 383 } 384 } 385 386 return true; 387 } 388 389 bool MethodComparator::pool_constants_same(int cpi_old, int cpi_new) { 390 constantTag tag_old = _old_cp->tag_at(cpi_old); 391 constantTag tag_new = _new_cp->tag_at(cpi_new); 392 if (tag_old.is_int() || tag_old.is_float()) { 393 if (tag_old.value() != tag_new.value()) 394 return false; 395 if (tag_old.is_int()) { 396 if (_old_cp->int_at(cpi_old) != _new_cp->int_at(cpi_new)) 397 return false; 398 } else { 399 // Use jint_cast to compare the bits rather than numerical values. 400 // This makes a difference for NaN constants. 401 if (jint_cast(_old_cp->float_at(cpi_old)) != jint_cast(_new_cp->float_at(cpi_new))) 402 return false; 403 } 404 } else if (tag_old.is_string() && tag_new.is_string()) { 405 if (strcmp(_old_cp->string_at_noresolve(cpi_old), 406 _new_cp->string_at_noresolve(cpi_new)) != 0) 407 return false; 408 if (_old_cp->is_pseudo_string_at(cpi_old) || _new_cp->is_pseudo_string_at(cpi_new)) 409 return (_old_cp->is_pseudo_string_at(cpi_old) == _new_cp->is_pseudo_string_at(cpi_new)); 410 } else if (tag_old.is_klass() || tag_old.is_unresolved_klass()) { 411 // tag_old should be klass - 4881222 412 if (! (tag_new.is_unresolved_klass() || tag_new.is_klass())) 413 return false; 414 if (_old_cp->klass_at_noresolve(cpi_old) != 415 _new_cp->klass_at_noresolve(cpi_new)) 416 return false; 417 } else if (tag_old.is_method_type() && tag_new.is_method_type()) { 418 int mti_old = _old_cp->method_type_index_at(cpi_old); 419 int mti_new = _new_cp->method_type_index_at(cpi_new); 420 if ((_old_cp->symbol_at(mti_old) != _new_cp->symbol_at(mti_new))) 421 return false; 422 } else if (tag_old.is_method_handle() && tag_new.is_method_handle()) { 423 if (_old_cp->method_handle_ref_kind_at(cpi_old) != 424 _new_cp->method_handle_ref_kind_at(cpi_new)) 425 return false; 426 int mhi_old = _old_cp->method_handle_index_at(cpi_old); 427 int mhi_new = _new_cp->method_handle_index_at(cpi_new); 428 if ((_old_cp->uncached_klass_ref_at_noresolve(mhi_old) != _new_cp->uncached_klass_ref_at_noresolve(mhi_new)) || 429 (_old_cp->uncached_name_ref_at(mhi_old) != _new_cp->uncached_name_ref_at(mhi_new)) || 430 (_old_cp->uncached_signature_ref_at(mhi_old) != _new_cp->uncached_signature_ref_at(mhi_new))) 431 return false; 432 } else { 433 return false; // unknown tag 434 } 435 return true; 436 } 437 438 439 int MethodComparator::check_stack_and_locals_size(Method* old_method, Method* new_method) { 440 if (old_method->max_stack() != new_method->max_stack()) { 441 return 1; 442 } else if (old_method->max_locals() != new_method->max_locals()) { 443 return 2; 444 } else if (old_method->size_of_parameters() != new_method->size_of_parameters()) { 445 return 3; 446 } else return 0; 447 }