1 /*
   2  * Copyright (c) 2003, 2016, 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), _max_locals(max_locals),
  37                       _max_stack(max_stack), _flags(0), _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 void StackMapFrame::initialize_object(
  58     VerificationType old_object, VerificationType new_object) {
  59   int32_t i;
  60   for (i = 0; i < _max_locals; i++) {
  61     if (_locals[i].equals(old_object)) {
  62       _locals[i] = new_object;
  63     }
  64   }
  65   for (i = 0; i < _stack_size; i++) {
  66     if (_stack[i].equals(old_object)) {
  67       _stack[i] = new_object;
  68     }
  69   }
  70   if (old_object == VerificationType::uninitialized_this_type()) {
  71     // "this" has been initialized - reset flags
  72     _flags = 0;
  73   }
  74 }
  75 
  76 VerificationType StackMapFrame::set_locals_from_arg(
  77     const methodHandle& m, VerificationType thisKlass, TRAPS) {
  78   SignatureStream ss(m->signature());
  79   int init_local_num = 0;
  80   if (!m->is_static()) {
  81     init_local_num++;
  82     // add one extra argument for instance method
  83     if (m->name() == vmSymbols::object_initializer_name() &&
  84        thisKlass.name() != vmSymbols::java_lang_Object()) {
  85       _locals[0] = VerificationType::uninitialized_this_type();
  86       _flags |= FLAG_THIS_UNINIT;
  87     } else {
  88       _locals[0] = thisKlass;
  89     }
  90   }
  91 
  92   // local num may be greater than size of parameters because long/double occupies two slots
  93   while(!ss.at_return_type()) {
  94     init_local_num += _verifier->change_sig_to_verificationType(
  95       &ss, &_locals[init_local_num],
  96       CHECK_VERIFY_(verifier(), VerificationType::bogus_type()));
  97     ss.next();
  98   }
  99   _locals_size = init_local_num;
 100 
 101   switch (ss.type()) {
 102     case T_OBJECT:
 103     case T_ARRAY:
 104     {
 105       Symbol* sig = ss.as_symbol(CHECK_(VerificationType::bogus_type()));
 106       // Create another symbol to save as signature stream unreferences
 107       // this symbol.
 108       Symbol* sig_copy =
 109         verifier()->create_temporary_symbol(sig, 0, sig->utf8_length(),
 110                                  CHECK_(VerificationType::bogus_type()));
 111       assert(sig_copy == sig, "symbols don't match");
 112       return VerificationType::reference_type(sig_copy);
 113     }
 114     case T_INT:     return VerificationType::integer_type();
 115     case T_BYTE:    return VerificationType::byte_type();
 116     case T_CHAR:    return VerificationType::char_type();
 117     case T_SHORT:   return VerificationType::short_type();
 118     case T_BOOLEAN: return VerificationType::boolean_type();
 119     case T_FLOAT:   return VerificationType::float_type();
 120     case T_DOUBLE:  return VerificationType::double_type();
 121     case T_LONG:    return VerificationType::long_type();
 122     case T_VOID:    return VerificationType::bogus_type();
 123     default:
 124       ShouldNotReachHere();
 125   }
 126   return VerificationType::bogus_type();
 127 }
 128 
 129 void StackMapFrame::copy_locals(const StackMapFrame* src) {
 130   int32_t len = src->locals_size() < _locals_size ?
 131     src->locals_size() : _locals_size;
 132   for (int32_t i = 0; i < len; i++) {
 133     _locals[i] = src->locals()[i];
 134   }
 135 }
 136 
 137 void StackMapFrame::copy_stack(const StackMapFrame* src) {
 138   int32_t len = src->stack_size() < _stack_size ?
 139     src->stack_size() : _stack_size;
 140   for (int32_t i = 0; i < len; i++) {
 141     _stack[i] = src->stack()[i];
 142   }
 143 }
 144 
 145 // Returns the location of the first mismatch, or 'len' if there are no
 146 // mismatches
 147 int StackMapFrame::is_assignable_to(
 148     VerificationType* from, VerificationType* to, int32_t len, TRAPS) const {
 149   int32_t i = 0;
 150   for (i = 0; i < len; i++) {
 151     if (!to[i].is_assignable_from(from[i], verifier(), false, THREAD)) {
 152       break;
 153     }
 154   }
 155   return i;
 156 }
 157 
 158 bool StackMapFrame::is_assignable_to(
 159     const StackMapFrame* target, ErrorContext* ctx, TRAPS) const {
 160   if (_max_locals != target->max_locals()) {
 161     *ctx = ErrorContext::locals_size_mismatch(
 162         _offset, (StackMapFrame*)this, (StackMapFrame*)target);
 163     return false;
 164   }
 165   if (_stack_size != target->stack_size()) {
 166     *ctx = ErrorContext::stack_size_mismatch(
 167         _offset, (StackMapFrame*)this, (StackMapFrame*)target);
 168     return false;
 169   }
 170   // Only need to compare type elements up to target->locals() or target->stack().
 171   // The remaining type elements in this state can be ignored because they are
 172   // assignable to bogus type.
 173   int mismatch_loc;
 174   mismatch_loc = is_assignable_to(
 175     _locals, target->locals(), target->locals_size(), THREAD);
 176   if (mismatch_loc != target->locals_size()) {
 177     *ctx = ErrorContext::bad_type(target->offset(),
 178         TypeOrigin::local(mismatch_loc, (StackMapFrame*)this),
 179         TypeOrigin::sm_local(mismatch_loc, (StackMapFrame*)target));
 180     return false;
 181   }
 182   mismatch_loc = is_assignable_to(_stack, target->stack(), _stack_size, THREAD);
 183   if (mismatch_loc != _stack_size) {
 184     *ctx = ErrorContext::bad_type(target->offset(),
 185         TypeOrigin::stack(mismatch_loc, (StackMapFrame*)this),
 186         TypeOrigin::sm_stack(mismatch_loc, (StackMapFrame*)target));
 187     return false;
 188   }
 189 
 190   if ((_flags | target->flags()) == target->flags()) {
 191     return true;
 192   } else {
 193     *ctx = ErrorContext::bad_flags(target->offset(),
 194         (StackMapFrame*)this, (StackMapFrame*)target);
 195     return false;
 196   }
 197 }
 198 
 199 VerificationType StackMapFrame::pop_stack_ex(VerificationType type, TRAPS) {
 200   if (_stack_size <= 0) {
 201     verifier()->verify_error(
 202         ErrorContext::stack_underflow(_offset, this),
 203         "Operand stack underflow");
 204     return VerificationType::bogus_type();
 205   }
 206   VerificationType top = _stack[--_stack_size];
 207   bool subtype = type.is_assignable_from(
 208     top, verifier(), false, CHECK_(VerificationType::bogus_type()));
 209   if (!subtype) {
 210     verifier()->verify_error(
 211         ErrorContext::bad_type(_offset, stack_top_ctx(),
 212             TypeOrigin::implicit(type)),
 213         "Bad type on operand stack");
 214     return VerificationType::bogus_type();
 215   }
 216   return top;
 217 }
 218 
 219 VerificationType StackMapFrame::get_local(
 220     int32_t index, VerificationType type, TRAPS) {
 221   if (index >= _max_locals) {
 222     verifier()->verify_error(
 223         ErrorContext::bad_local_index(_offset, index),
 224         "Local variable table overflow");
 225     return VerificationType::bogus_type();
 226   }
 227   bool subtype = type.is_assignable_from(_locals[index],
 228     verifier(), false, CHECK_(VerificationType::bogus_type()));
 229   if (!subtype) {
 230     verifier()->verify_error(
 231         ErrorContext::bad_type(_offset,
 232           TypeOrigin::local(index, this),
 233           TypeOrigin::implicit(type)),
 234         "Bad local variable type");
 235     return VerificationType::bogus_type();
 236   }
 237   if(index >= _locals_size) { _locals_size = index + 1; }
 238   return _locals[index];
 239 }
 240 
 241 void StackMapFrame::get_local_2(
 242     int32_t index, VerificationType type1, VerificationType type2, TRAPS) {
 243   assert(type1.is_long() || type1.is_double(), "must be long/double");
 244   assert(type2.is_long2() || type2.is_double2(), "must be long/double_2");
 245   if (index >= _locals_size - 1) {
 246     verifier()->verify_error(
 247         ErrorContext::bad_local_index(_offset, index),
 248         "get long/double overflows locals");
 249     return;
 250   }
 251   bool subtype = type1.is_assignable_from(_locals[index], verifier(), false, CHECK);
 252   if (!subtype) {
 253     verifier()->verify_error(
 254         ErrorContext::bad_type(_offset,
 255             TypeOrigin::local(index, this), TypeOrigin::implicit(type1)),
 256         "Bad local variable type");
 257   } else {
 258     subtype = type2.is_assignable_from(_locals[index + 1], verifier(), false, CHECK);
 259     if (!subtype) {
 260       /* Unreachable? All local store routines convert a split long or double
 261        * into a TOP during the store.  So we should never end up seeing an
 262        * orphaned half.  */
 263       verifier()->verify_error(
 264           ErrorContext::bad_type(_offset,
 265               TypeOrigin::local(index + 1, this), TypeOrigin::implicit(type2)),
 266           "Bad local variable type");
 267     }
 268   }
 269 }
 270 
 271 void StackMapFrame::set_local(int32_t index, VerificationType type, TRAPS) {
 272   assert(!type.is_check(), "Must be a real type");
 273   if (index >= _max_locals) {
 274     verifier()->verify_error(
 275         ErrorContext::bad_local_index(_offset, index),
 276         "Local variable table overflow");
 277     return;
 278   }
 279   // If type at index is double or long, set the next location to be unusable
 280   if (_locals[index].is_double() || _locals[index].is_long()) {
 281     assert((index + 1) < _locals_size, "Local variable table overflow");
 282     _locals[index + 1] = VerificationType::bogus_type();
 283   }
 284   // If type at index is double_2 or long_2, set the previous location to be unusable
 285   if (_locals[index].is_double2() || _locals[index].is_long2()) {
 286     assert(index >= 1, "Local variable table underflow");
 287     _locals[index - 1] = VerificationType::bogus_type();
 288   }
 289   _locals[index] = type;
 290   if (index >= _locals_size) {
 291 #ifdef ASSERT
 292     for (int i=_locals_size; i<index; i++) {
 293       assert(_locals[i] == VerificationType::bogus_type(),
 294              "holes must be bogus type");
 295     }
 296 #endif
 297     _locals_size = index + 1;
 298   }
 299 }
 300 
 301 void StackMapFrame::set_local_2(
 302     int32_t index, VerificationType type1, VerificationType type2, TRAPS) {
 303   assert(type1.is_long() || type1.is_double(), "must be long/double");
 304   assert(type2.is_long2() || type2.is_double2(), "must be long/double_2");
 305   if (index >= _max_locals - 1) {
 306     verifier()->verify_error(
 307         ErrorContext::bad_local_index(_offset, index),
 308         "Local variable table overflow");
 309     return;
 310   }
 311   // If type at index+1 is double or long, set the next location to be unusable
 312   if (_locals[index+1].is_double() || _locals[index+1].is_long()) {
 313     assert((index + 2) < _locals_size, "Local variable table overflow");
 314     _locals[index + 2] = VerificationType::bogus_type();
 315   }
 316   // If type at index is double_2 or long_2, set the previous location to be unusable
 317   if (_locals[index].is_double2() || _locals[index].is_long2()) {
 318     assert(index >= 1, "Local variable table underflow");
 319     _locals[index - 1] = VerificationType::bogus_type();
 320   }
 321   _locals[index] = type1;
 322   _locals[index+1] = type2;
 323   if (index >= _locals_size - 1) {
 324 #ifdef ASSERT
 325     for (int i=_locals_size; i<index; i++) {
 326       assert(_locals[i] == VerificationType::bogus_type(),
 327              "holes must be bogus type");
 328     }
 329 #endif
 330     _locals_size = index + 2;
 331   }
 332 }
 333 
 334 TypeOrigin StackMapFrame::stack_top_ctx() {
 335   return TypeOrigin::stack(_stack_size, this);
 336 }
 337 
 338 void StackMapFrame::print_on(outputStream* str) const {
 339   str->indent().print_cr("bci: @%d", _offset);
 340   str->indent().print_cr("flags: {%s }",
 341       flag_this_uninit() ? " flagThisUninit" : "");
 342   str->indent().print("locals: {");
 343   for (int32_t i = 0; i < _locals_size; ++i) {
 344     str->print(" ");
 345     _locals[i].print_on(str);
 346     if (i != _locals_size - 1) {
 347       str->print(",");
 348     }
 349   }
 350   str->print_cr(" }");
 351   str->indent().print("stack: {");
 352   for (int32_t j = 0; j < _stack_size; ++j) {
 353     str->print(" ");
 354     _stack[j].print_on(str);
 355     if (j != _stack_size - 1) {
 356       str->print(",");
 357     }
 358   }
 359   str->print_cr(" }");
 360 }