1 /*
   2  * Copyright (c) 1998, 2019, 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 #ifndef SHARE_CLASSFILE_VERIFIER_HPP
  26 #define SHARE_CLASSFILE_VERIFIER_HPP
  27 
  28 #include "classfile/verificationType.hpp"
  29 #include "oops/klass.hpp"
  30 #include "oops/method.hpp"
  31 #include "runtime/handles.hpp"
  32 #include "utilities/exceptions.hpp"
  33 #include "utilities/growableArray.hpp"

  34 
  35 // The verifier class
  36 class Verifier : AllStatic {
  37  public:
  38   enum {
  39     STACKMAP_ATTRIBUTE_MAJOR_VERSION    = 50,
  40     INVOKEDYNAMIC_MAJOR_VERSION         = 51,
  41     NO_RELAX_ACCESS_CTRL_CHECK_VERSION  = 52,
  42     DYNAMICCONSTANT_MAJOR_VERSION       = 55
  43   };
  44 
  45   // Verify the bytecodes for a class.
  46   static bool verify(InstanceKlass* klass, bool should_verify_class, TRAPS);
  47 
  48   static void log_end_verification(outputStream* st, const char* klassName, Symbol* exception_name, TRAPS);
  49 
  50   // Return false if the class is loaded by the bootstrap loader,
  51   // or if defineClass was called requesting skipping verification
  52   // -Xverify:all overrides this value
  53   static bool should_verify_for(oop class_loader, bool should_verify_class);
  54 
  55   // Relax certain access checks to enable some broken 1.1 apps to run on 1.2.
  56   static bool relax_access_for(oop class_loader);
  57 
  58   // Print output for class+resolve
  59   static void trace_class_resolution(Klass* resolve_class, InstanceKlass* verify_class);
  60 
  61  private:
  62   static bool is_eligible_for_verification(InstanceKlass* klass, bool should_verify_class);
  63   static Symbol* inference_verify(
  64     InstanceKlass* klass, char* msg, size_t msg_len, TRAPS);
  65 };
  66 
  67 class RawBytecodeStream;
  68 class StackMapFrame;
  69 class StackMapTable;
  70 
  71 // Summary of verifier's memory usage:
  72 // StackMapTable is stack allocated.
  73 // StackMapFrame are resource allocated. There is only one ResourceMark
  74 // for each class verification, which is created at the top level.
  75 // There is one mutable StackMapFrame (current_frame) which is updated
  76 // by abstract bytecode interpretation. frame_in_exception_handler() returns
  77 // a frame that has a mutable one-item stack (ready for pushing the
  78 // catch type exception object). All the other StackMapFrame's
  79 // are immutable (including their locals and stack arrays) after
  80 // their constructions.
  81 // locals/stack arrays in StackMapFrame are resource allocated.
  82 // locals/stack arrays can be shared between StackMapFrame's, except
  83 // the mutable StackMapFrame (current_frame).
  84 
  85 // These macros are used similarly to CHECK macros but also check
  86 // the status of the verifier and return if that has an error.
  87 #define CHECK_VERIFY(verifier) \
  88   CHECK); if ((verifier)->has_error()) return; ((void)0
  89 #define CHECK_VERIFY_(verifier, result) \
  90   CHECK_(result)); if ((verifier)->has_error()) return (result); ((void)0
  91 
  92 class TypeOrigin {
  93  private:
  94   typedef enum {
  95     CF_LOCALS,  // Comes from the current frame locals
  96     CF_STACK,   // Comes from the current frame expression stack
  97     SM_LOCALS,  // Comes from stackmap locals
  98     SM_STACK,   // Comes from stackmap expression stack
  99     CONST_POOL, // Comes from the constant pool
 100     SIG,        // Comes from method signature
 101     IMPLICIT,   // Comes implicitly from code or context
 102     BAD_INDEX,  // No type, but the index is bad
 103     FRAME_ONLY, // No type, context just contains the frame
 104     NONE
 105   } Origin;
 106 
 107   Origin _origin;
 108   u2 _index;              // local, stack, or constant pool index
 109   StackMapFrame* _frame;  // source frame if CF or SM
 110   VerificationType _type; // The actual type
 111 
 112   TypeOrigin(
 113       Origin origin, u2 index, StackMapFrame* frame, VerificationType type)
 114       : _origin(origin), _index(index), _frame(frame), _type(type) {}
 115 
 116  public:
 117   TypeOrigin() : _origin(NONE), _index(0), _frame(NULL) {}
 118 
 119   static TypeOrigin null();
 120   static TypeOrigin local(u2 index, StackMapFrame* frame);
 121   static TypeOrigin stack(u2 index, StackMapFrame* frame);
 122   static TypeOrigin sm_local(u2 index, StackMapFrame* frame);
 123   static TypeOrigin sm_stack(u2 index, StackMapFrame* frame);
 124   static TypeOrigin cp(u2 index, VerificationType vt);
 125   static TypeOrigin signature(VerificationType vt);
 126   static TypeOrigin bad_index(u2 index);
 127   static TypeOrigin implicit(VerificationType t);
 128   static TypeOrigin frame(StackMapFrame* frame);
 129 
 130   void reset_frame();
 131   void details(outputStream* ss) const;
 132   void print_frame(outputStream* ss) const;
 133   const StackMapFrame* frame() const { return _frame; }
 134   bool is_valid() const { return _origin != NONE; }
 135   u2 index() const { return _index; }
 136 
 137 #ifdef ASSERT
 138   void print_on(outputStream* str) const;
 139 #endif
 140 };
 141 
 142 class ErrorContext {
 143  private:
 144   typedef enum {
 145     INVALID_BYTECODE,     // There was a problem with the bytecode
 146     WRONG_TYPE,           // Type value was not as expected
 147     FLAGS_MISMATCH,       // Frame flags are not assignable
 148     BAD_CP_INDEX,         // Invalid constant pool index
 149     BAD_LOCAL_INDEX,      // Invalid local index
 150     LOCALS_SIZE_MISMATCH, // Frames have differing local counts
 151     STACK_SIZE_MISMATCH,  // Frames have different stack sizes
 152     STACK_OVERFLOW,       // Attempt to push onto a full expression stack
 153     STACK_UNDERFLOW,      // Attempt to pop and empty expression stack
 154     MISSING_STACKMAP,     // No stackmap for this location and there should be
 155     BAD_STACKMAP,         // Format error in stackmap
 156     NO_FAULT,             // No error
 157     UNKNOWN
 158   } FaultType;
 159 
 160   int _bci;
 161   FaultType _fault;
 162   TypeOrigin _type;
 163   TypeOrigin _expected;
 164 
 165   ErrorContext(int bci, FaultType fault) :
 166       _bci(bci), _fault(fault)  {}
 167   ErrorContext(int bci, FaultType fault, TypeOrigin type) :
 168       _bci(bci), _fault(fault), _type(type)  {}
 169   ErrorContext(int bci, FaultType fault, TypeOrigin type, TypeOrigin exp) :
 170       _bci(bci), _fault(fault), _type(type), _expected(exp)  {}
 171 
 172  public:
 173   ErrorContext() : _bci(-1), _fault(NO_FAULT) {}
 174 
 175   static ErrorContext bad_code(u2 bci) {
 176     return ErrorContext(bci, INVALID_BYTECODE);
 177   }
 178   static ErrorContext bad_type(u2 bci, TypeOrigin type) {
 179     return ErrorContext(bci, WRONG_TYPE, type);
 180   }
 181   static ErrorContext bad_type(u2 bci, TypeOrigin type, TypeOrigin exp) {
 182     return ErrorContext(bci, WRONG_TYPE, type, exp);
 183   }
 184   static ErrorContext bad_flags(u2 bci, StackMapFrame* frame) {
 185     return ErrorContext(bci, FLAGS_MISMATCH, TypeOrigin::frame(frame));
 186   }
 187   static ErrorContext bad_flags(u2 bci, StackMapFrame* cur, StackMapFrame* sm) {
 188     return ErrorContext(bci, FLAGS_MISMATCH,
 189                         TypeOrigin::frame(cur), TypeOrigin::frame(sm));
 190   }
 191   static ErrorContext bad_cp_index(u2 bci, u2 index) {
 192     return ErrorContext(bci, BAD_CP_INDEX, TypeOrigin::bad_index(index));
 193   }
 194   static ErrorContext bad_local_index(u2 bci, u2 index) {
 195     return ErrorContext(bci, BAD_LOCAL_INDEX, TypeOrigin::bad_index(index));
 196   }
 197   static ErrorContext locals_size_mismatch(
 198       u2 bci, StackMapFrame* frame0, StackMapFrame* frame1) {
 199     return ErrorContext(bci, LOCALS_SIZE_MISMATCH,
 200         TypeOrigin::frame(frame0), TypeOrigin::frame(frame1));
 201   }
 202   static ErrorContext stack_size_mismatch(
 203       u2 bci, StackMapFrame* frame0, StackMapFrame* frame1) {
 204     return ErrorContext(bci, STACK_SIZE_MISMATCH,
 205         TypeOrigin::frame(frame0), TypeOrigin::frame(frame1));
 206   }
 207   static ErrorContext stack_overflow(u2 bci, StackMapFrame* frame) {
 208     return ErrorContext(bci, STACK_OVERFLOW, TypeOrigin::frame(frame));
 209   }
 210   static ErrorContext stack_underflow(u2 bci, StackMapFrame* frame) {
 211     return ErrorContext(bci, STACK_UNDERFLOW, TypeOrigin::frame(frame));
 212   }
 213   static ErrorContext missing_stackmap(u2 bci) {
 214     return ErrorContext(bci, MISSING_STACKMAP);
 215   }
 216   static ErrorContext bad_stackmap(int index, StackMapFrame* frame) {
 217     return ErrorContext(0, BAD_STACKMAP, TypeOrigin::frame(frame));
 218   }
 219 
 220   bool is_valid() const { return _fault != NO_FAULT; }
 221   int bci() const { return _bci; }
 222 
 223   void reset_frames() {
 224     _type.reset_frame();
 225     _expected.reset_frame();
 226   }
 227 
 228   void details(outputStream* ss, const Method* method) const;
 229 
 230 #ifdef ASSERT
 231   void print_on(outputStream* str) const {
 232     str->print("error_context(%d, %d,", _bci, _fault);
 233     _type.print_on(str);
 234     str->print(",");
 235     _expected.print_on(str);
 236     str->print(")");
 237   }
 238 #endif
 239 
 240  private:
 241   void location_details(outputStream* ss, const Method* method) const;
 242   void reason_details(outputStream* ss) const;
 243   void frame_details(outputStream* ss) const;
 244   void bytecode_details(outputStream* ss, const Method* method) const;
 245   void handler_details(outputStream* ss, const Method* method) const;
 246   void stackmap_details(outputStream* ss, const Method* method) const;
 247 };
 248 

























 249 // A new instance of this class is created for each class being verified
 250 class ClassVerifier : public StackObj {
 251  private:
 252   Thread* _thread;
 253 
 254   Symbol* _previous_symbol;          // cache of the previously looked up symbol
 255   GrowableArray<Symbol*>* _symbols;  // keep a list of symbols created
 256 
 257   Symbol* _exception_type;
 258   char* _message;
 259 


 260   ErrorContext _error_context;  // contains information about an error
 261 
 262   void verify_method(const methodHandle& method, TRAPS);
 263   char* generate_code_data(const methodHandle& m, u4 code_length, TRAPS);
 264   void verify_exception_handler_table(u4 code_length, char* code_data,
 265                                       int& min, int& max, TRAPS);
 266   void verify_local_variable_table(u4 code_length, char* code_data, TRAPS);
 267 
 268   VerificationType cp_ref_index_to_type(
 269       int index, const constantPoolHandle& cp, TRAPS) {
 270     return cp_index_to_type(cp->klass_ref_index_at(index), cp, THREAD);
 271   }
 272 
 273   bool is_protected_access(
 274     InstanceKlass* this_class, Klass* target_class,
 275     Symbol* field_name, Symbol* field_sig, bool is_method);
 276 
 277   void verify_cp_index(u2 bci, const constantPoolHandle& cp, int index, TRAPS);
 278   void verify_cp_type(u2 bci, int index, const constantPoolHandle& cp,
 279       unsigned int types, TRAPS);
 280   void verify_cp_class_type(u2 bci, int index, const constantPoolHandle& cp, TRAPS);
 281 
 282   u2 verify_stackmap_table(
 283     u2 stackmap_index, u2 bci, StackMapFrame* current_frame,
 284     StackMapTable* stackmap_table, bool no_control_flow, TRAPS);
 285 
 286   void verify_exception_handler_targets(
 287     u2 bci, bool this_uninit, StackMapFrame* current_frame,
 288     StackMapTable* stackmap_table, TRAPS);
 289 
 290   void verify_ldc(
 291     int opcode, u2 index, StackMapFrame *current_frame,
 292     const constantPoolHandle& cp, u2 bci, TRAPS);
 293 
 294   void verify_switch(
 295     RawBytecodeStream* bcs, u4 code_length, char* code_data,
 296     StackMapFrame* current_frame, StackMapTable* stackmap_table, TRAPS);
 297 
 298   void verify_field_instructions(
 299     RawBytecodeStream* bcs, StackMapFrame* current_frame,
 300     const constantPoolHandle& cp, bool allow_arrays, TRAPS);
 301 
 302   void verify_invoke_init(
 303     RawBytecodeStream* bcs, u2 ref_index, VerificationType ref_class_type,
 304     StackMapFrame* current_frame, u4 code_length, bool in_try_block,
 305     bool* this_uninit, const constantPoolHandle& cp, StackMapTable* stackmap_table,
 306     TRAPS);
 307 
 308   // Used by ends_in_athrow() to push all handlers that contain bci onto the
 309   // handler_stack, if the handler has not already been pushed on the stack.
 310   void push_handlers(ExceptionTable* exhandlers,
 311                      GrowableArray<u4>* handler_list,
 312                      GrowableArray<u4>* handler_stack,
 313                      u4 bci);
 314 
 315   // Returns true if all paths starting with start_bc_offset end in athrow
 316   // bytecode or loop.
 317   bool ends_in_athrow(u4 start_bc_offset);
 318 
 319   void verify_invoke_instructions(
 320     RawBytecodeStream* bcs, u4 code_length, StackMapFrame* current_frame,
 321     bool in_try_block, bool* this_uninit, VerificationType return_type,
 322     const constantPoolHandle& cp, StackMapTable* stackmap_table, TRAPS);
 323 
 324   VerificationType get_newarray_type(u2 index, u2 bci, TRAPS);
 325   void verify_anewarray(u2 bci, u2 index, const constantPoolHandle& cp,
 326       StackMapFrame* current_frame, TRAPS);
 327   void verify_return_value(
 328       VerificationType return_type, VerificationType type, u2 offset,
 329       StackMapFrame* current_frame, TRAPS);
 330 
 331   void verify_iload (u2 index, StackMapFrame* current_frame, TRAPS);
 332   void verify_lload (u2 index, StackMapFrame* current_frame, TRAPS);
 333   void verify_fload (u2 index, StackMapFrame* current_frame, TRAPS);
 334   void verify_dload (u2 index, StackMapFrame* current_frame, TRAPS);
 335   void verify_aload (u2 index, StackMapFrame* current_frame, TRAPS);
 336   void verify_istore(u2 index, StackMapFrame* current_frame, TRAPS);
 337   void verify_lstore(u2 index, StackMapFrame* current_frame, TRAPS);
 338   void verify_fstore(u2 index, StackMapFrame* current_frame, TRAPS);
 339   void verify_dstore(u2 index, StackMapFrame* current_frame, TRAPS);
 340   void verify_astore(u2 index, StackMapFrame* current_frame, TRAPS);
 341   void verify_iinc  (u2 index, StackMapFrame* current_frame, TRAPS);
 342 
 343   bool name_in_supers(Symbol* ref_name, InstanceKlass* current);
 344 
 345   VerificationType object_type() const;
 346 
 347   InstanceKlass*      _klass;  // the class being verified
 348   methodHandle        _method; // current method being verified
 349   VerificationType    _this_type; // the verification type of the current class
 350 
 351   // Some recursive calls from the verifier to the name resolver
 352   // can cause the current class to be re-verified and rewritten.
 353   // If this happens, the original verification should not continue,
 354   // because constant pool indexes will have changed.
 355   // The rewriter is preceded by the verifier.  If the verifier throws
 356   // an error, rewriting is prevented.  Also, rewriting always precedes
 357   // bytecode execution or compilation.  Thus, is_rewritten implies
 358   // that a class has been verified and prepared for execution.
 359   bool was_recursively_verified() { return _klass->is_rewritten(); }
 360 
 361   bool is_same_or_direct_interface(InstanceKlass* klass,
 362     VerificationType klass_type, VerificationType ref_class_type);
 363 
 364  public:
 365   enum {
 366     BYTECODE_OFFSET = 1,
 367     NEW_OFFSET = 2
 368   };
 369 
 370   // constructor
 371   ClassVerifier(InstanceKlass* klass, TRAPS);
 372 
 373   // destructor
 374   ~ClassVerifier();
 375 
 376   Thread* thread()             { return _thread; }
 377   const methodHandle& method() { return _method; }
 378   InstanceKlass* current_class() const { return _klass; }
 379   VerificationType current_type() const { return _this_type; }
 380 
 381   // Verifies the class.  If a verify or class file format error occurs,
 382   // the '_exception_name' symbols will set to the exception name and
 383   // the message_buffer will be filled in with the exception message.
 384   void verify_class(TRAPS);
 385 







 386   // Return status modes
 387   Symbol* result() const { return _exception_type; }
 388   bool has_error() const { return result() != NULL; }
 389   char* exception_message() {
 390     stringStream ss;
 391     ss.print("%s", _message);
 392     _error_context.details(&ss, _method());
 393     return ss.as_string();
 394   }
 395 
 396   // Called when verify or class format errors are encountered.
 397   // May throw an exception based upon the mode.
 398   void verify_error(ErrorContext ctx, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4);
 399   void class_format_error(const char* fmt, ...) ATTRIBUTE_PRINTF(2, 3);
 400 
 401   Klass* load_class(Symbol* name, TRAPS);








 402 
 403   int change_sig_to_verificationType(
 404     SignatureStream* sig_type, VerificationType* inference_type, TRAPS);
 405 
 406   VerificationType cp_index_to_type(int index, const constantPoolHandle& cp, TRAPS) {
 407     return VerificationType::reference_type(cp->klass_name_at(index));
 408   }
 409 
 410   // Keep a list of temporary symbols created during verification because
 411   // their reference counts need to be decremented when the verifier object
 412   // goes out of scope.  Since these symbols escape the scope in which they're
 413   // created, we can't use a TempNewSymbol.
 414   Symbol* create_temporary_symbol(const Symbol* s, int begin, int end, TRAPS);
 415   Symbol* create_temporary_symbol(const char *s, int length, TRAPS);
 416   Symbol* create_temporary_symbol(Symbol* s) {
 417     if (s == _previous_symbol) {
 418       return s;
 419     }
 420     if (!s->is_permanent()) {
 421       s->increment_refcount();
 422       if (_symbols == NULL) {
 423         _symbols = new GrowableArray<Symbol*>(50, 0, NULL);
 424       }
 425       _symbols->push(s);
 426     }
 427     _previous_symbol = s;
 428     return s;
 429   }
 430 
 431   TypeOrigin ref_ctx(const char* str, TRAPS);
 432 
 433 };
 434 
 435 inline int ClassVerifier::change_sig_to_verificationType(
 436     SignatureStream* sig_type, VerificationType* inference_type, TRAPS) {
 437   BasicType bt = sig_type->type();
 438   switch (bt) {
 439     case T_OBJECT:
 440     case T_ARRAY:
 441       {
 442         Symbol* name = sig_type->as_symbol(CHECK_0);
 443         // Create another symbol to save as signature stream unreferences this symbol.
 444         Symbol* name_copy = create_temporary_symbol(name);
 445         assert(name_copy == name, "symbols don't match");
 446         *inference_type =
 447           VerificationType::reference_type(name_copy);
 448         return 1;
 449       }
 450     case T_LONG:
 451       *inference_type = VerificationType::long_type();
 452       *++inference_type = VerificationType::long2_type();
 453       return 2;
 454     case T_DOUBLE:
 455       *inference_type = VerificationType::double_type();
 456       *++inference_type = VerificationType::double2_type();
 457       return 2;
 458     case T_INT:
 459     case T_BOOLEAN:
 460     case T_BYTE:
 461     case T_CHAR:
 462     case T_SHORT:
 463       *inference_type = VerificationType::integer_type();
 464       return 1;
 465     case T_FLOAT:
 466       *inference_type = VerificationType::float_type();
 467       return 1;
 468     default:
 469       ShouldNotReachHere();
 470       return 1;
 471   }
 472 }
 473 
 474 #endif // SHARE_CLASSFILE_VERIFIER_HPP
--- EOF ---