1 /*
  2  * Copyright (c) 2003, 2025, 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 "classfile/stackMapFrame.hpp"
 26 #include "classfile/verifier.hpp"
 27 #include "classfile/vmSymbols.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, AssertUnsetFieldTable* initial_strict_fields, 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), _assert_unset_fields(initial_strict_fields), _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 void StackMapFrame::unsatisfied_strict_fields_error(InstanceKlass* klass, int bci) {
 51   // Default these to `<Unknown>` as they will be replaced with the correct
 52   // values by the `find_unset` lambda as we only call this code when
 53   // an error has already been determined.  This just provides a safe
 54   // obvious fallback value.
 55   Symbol* name = vmSymbols::unknown_class_name();
 56   Symbol* sig = vmSymbols::unknown_class_name();
 57   int num_uninit_fields = 0;
 58 
 59   auto find_unset = [&] (const NameAndSig& key, const bool& value) {
 60     if (!value) {
 61       name = key._name;
 62       sig = key._signature;
 63       num_uninit_fields++;
 64     }
 65   };
 66   assert_unset_fields()->iterate_all(find_unset);
 67 
 68   verifier()->verify_error(
 69     ErrorContext::bad_strict_fields(bci, this),
 70     "All strict final fields must be initialized before super(): %d field(s), %s:%s in %s",
 71     num_uninit_fields,
 72     name->as_C_string(),
 73     sig->as_C_string(),
 74     klass->name()->as_C_string()
 75   );
 76 }
 77 
 78 void StackMapFrame::print_strict_fields(AssertUnsetFieldTable* table) {
 79   ResourceMark rm;
 80   auto printfields = [&] (const NameAndSig& key, const bool& value) {
 81     log_info(verification)("Strict field: %s%s (Satisfied: %s)",
 82                            key._name->as_C_string(),
 83                            key._signature->as_C_string(),
 84                            value ? "true" : "false");
 85   };
 86   table->iterate_all(printfields);
 87 }
 88 
 89 StackMapFrame* StackMapFrame::frame_in_exception_handler(u1 flags) {
 90   Thread* thr = _verifier->thread();
 91   VerificationType* stack = NEW_RESOURCE_ARRAY_IN_THREAD(thr, VerificationType, 1);
 92   StackMapFrame* frame = new StackMapFrame(_offset, flags, _locals_size, 0,
 93                                            _max_locals, _max_stack, _locals, stack,
 94                                            _assert_unset_fields, _verifier);
 95   return frame;
 96 }
 97 
 98 void StackMapFrame::initialize_object(
 99     VerificationType old_object, VerificationType new_object) {
100   int32_t i;
101   for (i = 0; i < _max_locals; i++) {
102     if (_locals[i].equals(old_object)) {
103       _locals[i] = new_object;
104     }
105   }
106   for (i = 0; i < _stack_size; i++) {
107     if (_stack[i].equals(old_object)) {
108       _stack[i] = new_object;
109     }
110   }
111   if (old_object == VerificationType::uninitialized_this_type()) {
112     // "this" has been initialized - reset flags
113     _flags = 0;
114   }
115 }
116 
117 VerificationType StackMapFrame::set_locals_from_arg(
118     const methodHandle& m, VerificationType thisKlass) {
119   SignatureStream ss(m->signature());
120   int init_local_num = 0;
121   if (!m->is_static()) {
122     init_local_num++;
123     // add one extra argument for instance method
124     if (m->is_object_constructor() &&
125        thisKlass.name() != vmSymbols::java_lang_Object()) {
126       _locals[0] = VerificationType::uninitialized_this_type();
127       _flags |= FLAG_THIS_UNINIT;
128     } else {
129       _locals[0] = thisKlass;
130     }
131   }
132 
133   // local num may be greater than size of parameters because long/double occupies two slots
134   while(!ss.at_return_type()) {
135     init_local_num += _verifier->change_sig_to_verificationType(
136       &ss, &_locals[init_local_num]);
137     ss.next();
138   }
139   _locals_size = init_local_num;
140 
141   switch (ss.type()) {
142     case T_OBJECT:
143     case T_ARRAY:
144     {
145       Symbol* sig = ss.as_symbol();
146       if (!sig->is_permanent()) {
147         // Create another symbol to save as signature stream unreferences
148         // this symbol.
149         Symbol *sig_copy =
150           verifier()->create_temporary_symbol(sig);
151         assert(sig_copy == sig, "symbols don't match");
152         sig = sig_copy;
153       }
154       return VerificationType::reference_type(sig);
155     }
156     case T_INT:     return VerificationType::integer_type();
157     case T_BYTE:    return VerificationType::byte_type();
158     case T_CHAR:    return VerificationType::char_type();
159     case T_SHORT:   return VerificationType::short_type();
160     case T_BOOLEAN: return VerificationType::boolean_type();
161     case T_FLOAT:   return VerificationType::float_type();
162     case T_DOUBLE:  return VerificationType::double_type();
163     case T_LONG:    return VerificationType::long_type();
164     case T_VOID:    return VerificationType::bogus_type();
165     default:
166       ShouldNotReachHere();
167   }
168   return VerificationType::bogus_type();
169 }
170 
171 void StackMapFrame::copy_locals(const StackMapFrame* src) {
172   int32_t len = src->locals_size() < _locals_size ?
173     src->locals_size() : _locals_size;
174   for (int32_t i = 0; i < len; i++) {
175     _locals[i] = src->locals()[i];
176   }
177 }
178 
179 void StackMapFrame::copy_stack(const StackMapFrame* src) {
180   int32_t len = src->stack_size() < _stack_size ?
181     src->stack_size() : _stack_size;
182   for (int32_t i = 0; i < len; i++) {
183     _stack[i] = src->stack()[i];
184   }
185 }
186 
187 // Returns the location of the first mismatch, or 'len' if there are no
188 // mismatches
189 int StackMapFrame::is_assignable_to(
190     VerificationType* from, VerificationType* to, int32_t len, TRAPS) const {
191   int32_t i = 0;
192   for (i = 0; i < len; i++) {
193     if (!to[i].is_assignable_from(from[i], verifier(), false, THREAD)) {
194       break;
195     }
196   }
197   return i;
198 }
199 
200 bool StackMapFrame::is_assignable_to(
201     const StackMapFrame* target, ErrorContext* ctx, TRAPS) const {
202   if (_max_locals != target->max_locals()) {
203     *ctx = ErrorContext::locals_size_mismatch(
204         _offset, (StackMapFrame*)this, (StackMapFrame*)target);
205     return false;
206   }
207   if (_stack_size != target->stack_size()) {
208     *ctx = ErrorContext::stack_size_mismatch(
209         _offset, (StackMapFrame*)this, (StackMapFrame*)target);
210     return false;
211   }
212   // Only need to compare type elements up to target->locals() or target->stack().
213   // The remaining type elements in this state can be ignored because they are
214   // assignable to bogus type.
215   int mismatch_loc;
216   mismatch_loc = is_assignable_to(
217     _locals, target->locals(), target->locals_size(), THREAD);
218   if (mismatch_loc != target->locals_size()) {
219     *ctx = ErrorContext::bad_type(target->offset(),
220         TypeOrigin::local(mismatch_loc, (StackMapFrame*)this),
221         TypeOrigin::sm_local(mismatch_loc, (StackMapFrame*)target));
222     return false;
223   }
224   mismatch_loc = is_assignable_to(_stack, target->stack(), _stack_size, THREAD);
225   if (mismatch_loc != _stack_size) {
226     *ctx = ErrorContext::bad_type(target->offset(),
227         TypeOrigin::stack(mismatch_loc, (StackMapFrame*)this),
228         TypeOrigin::sm_stack(mismatch_loc, (StackMapFrame*)target));
229     return false;
230   }
231 
232   // Check that assert unset fields are compatible
233   bool compatible = verify_unset_fields_compatibility(target->assert_unset_fields());
234   if (!compatible) {
235     print_strict_fields(assert_unset_fields());
236     print_strict_fields(target->assert_unset_fields());
237     *ctx = ErrorContext::strict_fields_mismatch(target->offset(),
238         (StackMapFrame*)this, (StackMapFrame*)target);
239     return false;
240   }
241 
242   if ((_flags | target->flags()) == target->flags()) {
243     return true;
244   } else {
245     *ctx = ErrorContext::bad_flags(target->offset(),
246         (StackMapFrame*)this, (StackMapFrame*)target);
247     return false;
248   }
249 }
250 
251 VerificationType StackMapFrame::pop_stack_ex(VerificationType type, TRAPS) {
252   if (_stack_size <= 0) {
253     verifier()->verify_error(
254         ErrorContext::stack_underflow(_offset, this),
255         "Operand stack underflow");
256     return VerificationType::bogus_type();
257   }
258   VerificationType top = _stack[--_stack_size];
259   bool subtype = type.is_assignable_from(
260     top, verifier(), false, CHECK_(VerificationType::bogus_type()));
261   if (!subtype) {
262     verifier()->verify_error(
263         ErrorContext::bad_type(_offset, stack_top_ctx(),
264             TypeOrigin::implicit(type)),
265         "Bad type on operand stack");
266     return VerificationType::bogus_type();
267   }
268   return top;
269 }
270 
271 VerificationType StackMapFrame::get_local(
272     int32_t index, VerificationType type, TRAPS) {
273   if (index >= _max_locals) {
274     verifier()->verify_error(
275         ErrorContext::bad_local_index(_offset, index),
276         "Local variable table overflow");
277     return VerificationType::bogus_type();
278   }
279   bool subtype = type.is_assignable_from(_locals[index],
280     verifier(), false, CHECK_(VerificationType::bogus_type()));
281   if (!subtype) {
282     verifier()->verify_error(
283         ErrorContext::bad_type(_offset,
284           TypeOrigin::local(index, this),
285           TypeOrigin::implicit(type)),
286         "Bad local variable type");
287     return VerificationType::bogus_type();
288   }
289   if(index >= _locals_size) { _locals_size = index + 1; }
290   return _locals[index];
291 }
292 
293 void StackMapFrame::get_local_2(
294     int32_t index, VerificationType type1, VerificationType type2, TRAPS) {
295   assert(type1.is_long() || type1.is_double(), "must be long/double");
296   assert(type2.is_long2() || type2.is_double2(), "must be long/double_2");
297   if (index >= _locals_size - 1) {
298     verifier()->verify_error(
299         ErrorContext::bad_local_index(_offset, index),
300         "get long/double overflows locals");
301     return;
302   }
303   bool subtype = type1.is_assignable_from(_locals[index], verifier(), false, CHECK);
304   if (!subtype) {
305     verifier()->verify_error(
306         ErrorContext::bad_type(_offset,
307             TypeOrigin::local(index, this), TypeOrigin::implicit(type1)),
308         "Bad local variable type");
309   } else {
310     subtype = type2.is_assignable_from(_locals[index + 1], verifier(), false, CHECK);
311     if (!subtype) {
312       /* Unreachable? All local store routines convert a split long or double
313        * into a TOP during the store.  So we should never end up seeing an
314        * orphaned half.  */
315       verifier()->verify_error(
316           ErrorContext::bad_type(_offset,
317               TypeOrigin::local(index + 1, this), TypeOrigin::implicit(type2)),
318           "Bad local variable type");
319     }
320   }
321 }
322 
323 void StackMapFrame::set_local(int32_t index, VerificationType type, TRAPS) {
324   assert(!type.is_check(), "Must be a real type");
325   if (index >= _max_locals) {
326     verifier()->verify_error(
327         ErrorContext::bad_local_index(_offset, index),
328         "Local variable table overflow");
329     return;
330   }
331   // If type at index is double or long, set the next location to be unusable
332   if (_locals[index].is_double() || _locals[index].is_long()) {
333     assert((index + 1) < _locals_size, "Local variable table overflow");
334     _locals[index + 1] = VerificationType::bogus_type();
335   }
336   // If type at index is double_2 or long_2, set the previous location to be unusable
337   if (_locals[index].is_double2() || _locals[index].is_long2()) {
338     assert(index >= 1, "Local variable table underflow");
339     _locals[index - 1] = VerificationType::bogus_type();
340   }
341   _locals[index] = type;
342   if (index >= _locals_size) {
343 #ifdef ASSERT
344     for (int i=_locals_size; i<index; i++) {
345       assert(_locals[i] == VerificationType::bogus_type(),
346              "holes must be bogus type");
347     }
348 #endif
349     _locals_size = index + 1;
350   }
351 }
352 
353 void StackMapFrame::set_local_2(
354     int32_t index, VerificationType type1, VerificationType type2, TRAPS) {
355   assert(type1.is_long() || type1.is_double(), "must be long/double");
356   assert(type2.is_long2() || type2.is_double2(), "must be long/double_2");
357   if (index >= _max_locals - 1) {
358     verifier()->verify_error(
359         ErrorContext::bad_local_index(_offset, index),
360         "Local variable table overflow");
361     return;
362   }
363   // If type at index+1 is double or long, set the next location to be unusable
364   if (_locals[index+1].is_double() || _locals[index+1].is_long()) {
365     assert((index + 2) < _locals_size, "Local variable table overflow");
366     _locals[index + 2] = VerificationType::bogus_type();
367   }
368   // If type at index is double_2 or long_2, set the previous location to be unusable
369   if (_locals[index].is_double2() || _locals[index].is_long2()) {
370     assert(index >= 1, "Local variable table underflow");
371     _locals[index - 1] = VerificationType::bogus_type();
372   }
373   _locals[index] = type1;
374   _locals[index+1] = type2;
375   if (index >= _locals_size - 1) {
376 #ifdef ASSERT
377     for (int i=_locals_size; i<index; i++) {
378       assert(_locals[i] == VerificationType::bogus_type(),
379              "holes must be bogus type");
380     }
381 #endif
382     _locals_size = index + 2;
383   }
384 }
385 
386 TypeOrigin StackMapFrame::stack_top_ctx() {
387   return TypeOrigin::stack(_stack_size, this);
388 }
389 
390 void StackMapFrame::print_on(outputStream* str) const {
391   str->print_cr("bci: @%d", _offset);
392   str->print_cr("flags: {%s }",
393       flag_this_uninit() ? " flagThisUninit" : "");
394   str->print("locals: {");
395   for (int32_t i = 0; i < _locals_size; ++i) {
396     str->print(" ");
397     _locals[i].print_on(str);
398     if (i != _locals_size - 1) {
399       str->print(",");
400     }
401   }
402   str->print_cr(" }");
403   str->print("stack: {");
404   for (int32_t j = 0; j < _stack_size; ++j) {
405     str->print(" ");
406     _stack[j].print_on(str);
407     if (j != _stack_size - 1) {
408       str->print(",");
409     }
410   }
411   str->print_cr(" }");
412 }
--- EOF ---