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 #include "utilities/resourceHash.hpp"
  35 
  36 // The verifier class
  37 class Verifier : AllStatic {
  38  public:
  39   enum {
  40     STACKMAP_ATTRIBUTE_MAJOR_VERSION    = 50,
  41     INVOKEDYNAMIC_MAJOR_VERSION         = 51,
  42     NO_RELAX_ACCESS_CTRL_CHECK_VERSION  = 52,
  43     DYNAMICCONSTANT_MAJOR_VERSION       = 55
  44   };
  45 
  46   // Verify the bytecodes for a class.
  47   static bool verify(InstanceKlass* klass, bool should_verify_class, TRAPS);
  48 
  49   static void log_end_verification(outputStream* st, const char* klassName, Symbol* exception_name, TRAPS);
  50 
  51   // Return false if the class is loaded by the bootstrap loader,
  52   // or if defineClass was called requesting skipping verification
  53   // -Xverify:all overrides this value
  54   static bool should_verify_for(oop class_loader, bool should_verify_class);
  55 
  56   // Relax certain access checks to enable some broken 1.1 apps to run on 1.2.
  57   static bool relax_access_for(oop class_loader);
  58 
  59   // Print output for class+resolve
  60   static void trace_class_resolution(Klass* resolve_class, InstanceKlass* verify_class);
  61 
  62  private:
  63   static bool is_eligible_for_verification(InstanceKlass* klass, bool should_verify_class);
  64   static Symbol* inference_verify(
  65     InstanceKlass* klass, char* msg, size_t msg_len, TRAPS);
  66 };
  67 
  68 class RawBytecodeStream;
  69 class StackMapFrame;
  70 class StackMapTable;
  71 
  72 // Summary of verifier's memory usage:
  73 // StackMapTable is stack allocated.
  74 // StackMapFrame are resource allocated. There is only one ResourceMark
  75 // for each class verification, which is created at the top level.
  76 // There is one mutable StackMapFrame (current_frame) which is updated
  77 // by abstract bytecode interpretation. frame_in_exception_handler() returns
  78 // a frame that has a mutable one-item stack (ready for pushing the
  79 // catch type exception object). All the other StackMapFrame's
  80 // are immutable (including their locals and stack arrays) after
  81 // their constructions.
  82 // locals/stack arrays in StackMapFrame are resource allocated.
  83 // locals/stack arrays can be shared between StackMapFrame's, except
  84 // the mutable StackMapFrame (current_frame).
  85 
  86 // These macros are used similarly to CHECK macros but also check
  87 // the status of the verifier and return if that has an error.
  88 #define CHECK_VERIFY(verifier) \
  89   CHECK); if ((verifier)->has_error()) return; ((void)0
  90 #define CHECK_VERIFY_(verifier, result) \
  91   CHECK_(result)); if ((verifier)->has_error()) return (result); ((void)0
  92 
  93 class TypeOrigin {
  94  private:
  95   typedef enum {
  96     CF_LOCALS,  // Comes from the current frame locals
  97     CF_STACK,   // Comes from the current frame expression stack
  98     SM_LOCALS,  // Comes from stackmap locals
  99     SM_STACK,   // Comes from stackmap expression stack
 100     CONST_POOL, // Comes from the constant pool
 101     SIG,        // Comes from method signature
 102     IMPLICIT,   // Comes implicitly from code or context
 103     BAD_INDEX,  // No type, but the index is bad
 104     FRAME_ONLY, // No type, context just contains the frame
 105     NONE
 106   } Origin;
 107 
 108   Origin _origin;
 109   u2 _index;              // local, stack, or constant pool index
 110   StackMapFrame* _frame;  // source frame if CF or SM
 111   VerificationType _type; // The actual type
 112 
 113   TypeOrigin(
 114       Origin origin, u2 index, StackMapFrame* frame, VerificationType type)
 115       : _origin(origin), _index(index), _frame(frame), _type(type) {}
 116 
 117  public:
 118   TypeOrigin() : _origin(NONE), _index(0), _frame(NULL) {}
 119 
 120   static TypeOrigin null();
 121   static TypeOrigin local(u2 index, StackMapFrame* frame);
 122   static TypeOrigin stack(u2 index, StackMapFrame* frame);
 123   static TypeOrigin sm_local(u2 index, StackMapFrame* frame);
 124   static TypeOrigin sm_stack(u2 index, StackMapFrame* frame);
 125   static TypeOrigin cp(u2 index, VerificationType vt);
 126   static TypeOrigin signature(VerificationType vt);
 127   static TypeOrigin bad_index(u2 index);
 128   static TypeOrigin implicit(VerificationType t);
 129   static TypeOrigin frame(StackMapFrame* frame);
 130 
 131   void reset_frame();
 132   void details(outputStream* ss) const;
 133   void print_frame(outputStream* ss) const;
 134   const StackMapFrame* frame() const { return _frame; }
 135   bool is_valid() const { return _origin != NONE; }
 136   u2 index() const { return _index; }
 137 
 138 #ifdef ASSERT
 139   void print_on(outputStream* str) const;
 140 #endif
 141 };
 142 
 143 class ErrorContext {
 144  private:
 145   typedef enum {
 146     INVALID_BYTECODE,     // There was a problem with the bytecode
 147     WRONG_TYPE,           // Type value was not as expected
 148     FLAGS_MISMATCH,       // Frame flags are not assignable
 149     BAD_CP_INDEX,         // Invalid constant pool index
 150     BAD_LOCAL_INDEX,      // Invalid local index
 151     LOCALS_SIZE_MISMATCH, // Frames have differing local counts
 152     STACK_SIZE_MISMATCH,  // Frames have different stack sizes
 153     STACK_OVERFLOW,       // Attempt to push onto a full expression stack
 154     STACK_UNDERFLOW,      // Attempt to pop and empty expression stack
 155     MISSING_STACKMAP,     // No stackmap for this location and there should be
 156     BAD_STACKMAP,         // Format error in stackmap
 157     NO_FAULT,             // No error
 158     UNKNOWN
 159   } FaultType;
 160 
 161   int _bci;
 162   FaultType _fault;
 163   TypeOrigin _type;
 164   TypeOrigin _expected;
 165 
 166   ErrorContext(int bci, FaultType fault) :
 167       _bci(bci), _fault(fault)  {}
 168   ErrorContext(int bci, FaultType fault, TypeOrigin type) :
 169       _bci(bci), _fault(fault), _type(type)  {}
 170   ErrorContext(int bci, FaultType fault, TypeOrigin type, TypeOrigin exp) :
 171       _bci(bci), _fault(fault), _type(type), _expected(exp)  {}
 172 
 173  public:
 174   ErrorContext() : _bci(-1), _fault(NO_FAULT) {}
 175 
 176   static ErrorContext bad_code(u2 bci) {
 177     return ErrorContext(bci, INVALID_BYTECODE);
 178   }
 179   static ErrorContext bad_type(u2 bci, TypeOrigin type) {
 180     return ErrorContext(bci, WRONG_TYPE, type);
 181   }
 182   static ErrorContext bad_type(u2 bci, TypeOrigin type, TypeOrigin exp) {
 183     return ErrorContext(bci, WRONG_TYPE, type, exp);
 184   }
 185   static ErrorContext bad_flags(u2 bci, StackMapFrame* frame) {
 186     return ErrorContext(bci, FLAGS_MISMATCH, TypeOrigin::frame(frame));
 187   }
 188   static ErrorContext bad_flags(u2 bci, StackMapFrame* cur, StackMapFrame* sm) {
 189     return ErrorContext(bci, FLAGS_MISMATCH,
 190                         TypeOrigin::frame(cur), TypeOrigin::frame(sm));
 191   }
 192   static ErrorContext bad_cp_index(u2 bci, u2 index) {
 193     return ErrorContext(bci, BAD_CP_INDEX, TypeOrigin::bad_index(index));
 194   }
 195   static ErrorContext bad_local_index(u2 bci, u2 index) {
 196     return ErrorContext(bci, BAD_LOCAL_INDEX, TypeOrigin::bad_index(index));
 197   }
 198   static ErrorContext locals_size_mismatch(
 199       u2 bci, StackMapFrame* frame0, StackMapFrame* frame1) {
 200     return ErrorContext(bci, LOCALS_SIZE_MISMATCH,
 201         TypeOrigin::frame(frame0), TypeOrigin::frame(frame1));
 202   }
 203   static ErrorContext stack_size_mismatch(
 204       u2 bci, StackMapFrame* frame0, StackMapFrame* frame1) {
 205     return ErrorContext(bci, STACK_SIZE_MISMATCH,
 206         TypeOrigin::frame(frame0), TypeOrigin::frame(frame1));
 207   }
 208   static ErrorContext stack_overflow(u2 bci, StackMapFrame* frame) {
 209     return ErrorContext(bci, STACK_OVERFLOW, TypeOrigin::frame(frame));
 210   }
 211   static ErrorContext stack_underflow(u2 bci, StackMapFrame* frame) {
 212     return ErrorContext(bci, STACK_UNDERFLOW, TypeOrigin::frame(frame));
 213   }
 214   static ErrorContext missing_stackmap(u2 bci) {
 215     return ErrorContext(bci, MISSING_STACKMAP);
 216   }
 217   static ErrorContext bad_stackmap(int index, StackMapFrame* frame) {
 218     return ErrorContext(0, BAD_STACKMAP, TypeOrigin::frame(frame));
 219   }
 220 
 221   bool is_valid() const { return _fault != NO_FAULT; }
 222   int bci() const { return _bci; }
 223 
 224   void reset_frames() {
 225     _type.reset_frame();
 226     _expected.reset_frame();
 227   }
 228 
 229   void details(outputStream* ss, const Method* method) const;
 230 
 231 #ifdef ASSERT
 232   void print_on(outputStream* str) const {
 233     str->print("error_context(%d, %d,", _bci, _fault);
 234     _type.print_on(str);
 235     str->print(",");
 236     _expected.print_on(str);
 237     str->print(")");
 238   }
 239 #endif
 240 
 241  private:
 242   void location_details(outputStream* ss, const Method* method) const;
 243   void reason_details(outputStream* ss) const;
 244   void frame_details(outputStream* ss) const;
 245   void bytecode_details(outputStream* ss, const Method* method) const;
 246   void handler_details(outputStream* ss, const Method* method) const;
 247   void stackmap_details(outputStream* ss, const Method* method) const;
 248 };
 249 
 250 class sig_as_verification_types : public ResourceObj {
 251  private:
 252   int _num_args;  // Number of arguments, not including return type.
 253   GrowableArray<VerificationType>* _sig_verif_types;
 254 
 255  public:
 256 
 257   sig_as_verification_types(GrowableArray<VerificationType>* sig_verif_types) :
 258     _num_args(0), _sig_verif_types(sig_verif_types) {
 259   }
 260 
 261   int num_args() const { return _num_args; }
 262   void set_num_args(int num_args) { _num_args = num_args; }
 263 
 264   GrowableArray<VerificationType>* sig_verif_types() { return _sig_verif_types; }
 265   void set_sig_verif_types(GrowableArray<VerificationType>* sig_verif_types) {
 266     _sig_verif_types = sig_verif_types;
 267   }
 268 
 269 };
 270 
 271 typedef ResourceHashtable<int, sig_as_verification_types*,
 272                           primitive_hash<int>, primitive_equals<int>, 1007>
 273                           method_signatures_table_type;
 274 
 275 // A new instance of this class is created for each class being verified
 276 class ClassVerifier : public StackObj {
 277  private:
 278   Thread* _thread;
 279 
 280   Symbol* _previous_symbol;          // cache of the previously looked up symbol
 281   GrowableArray<Symbol*>* _symbols;  // keep a list of symbols created
 282 
 283   Symbol* _exception_type;
 284   char* _message;
 285 
 286   method_signatures_table_type* _method_signatures_table;
 287 
 288   ErrorContext _error_context;  // contains information about an error
 289 
 290   void verify_method(const methodHandle& method, TRAPS);
 291   char* generate_code_data(const methodHandle& m, u4 code_length, TRAPS);
 292   void verify_exception_handler_table(u4 code_length, char* code_data,
 293                                       int& min, int& max, TRAPS);
 294   void verify_local_variable_table(u4 code_length, char* code_data, TRAPS);
 295 
 296   VerificationType cp_ref_index_to_type(
 297       int index, const constantPoolHandle& cp, TRAPS) {
 298     return cp_index_to_type(cp->klass_ref_index_at(index), cp, THREAD);
 299   }
 300 
 301   bool is_protected_access(
 302     InstanceKlass* this_class, Klass* target_class,
 303     Symbol* field_name, Symbol* field_sig, bool is_method);
 304 
 305   void verify_cp_index(u2 bci, const constantPoolHandle& cp, int index, TRAPS);
 306   void verify_cp_type(u2 bci, int index, const constantPoolHandle& cp,
 307       unsigned int types, TRAPS);
 308   void verify_cp_class_type(u2 bci, int index, const constantPoolHandle& cp, TRAPS);
 309 
 310   u2 verify_stackmap_table(
 311     u2 stackmap_index, u2 bci, StackMapFrame* current_frame,
 312     StackMapTable* stackmap_table, bool no_control_flow, TRAPS);
 313 
 314   void verify_exception_handler_targets(
 315     u2 bci, bool this_uninit, StackMapFrame* current_frame,
 316     StackMapTable* stackmap_table, TRAPS);
 317 
 318   void verify_ldc(
 319     int opcode, u2 index, StackMapFrame *current_frame,
 320     const constantPoolHandle& cp, u2 bci, TRAPS);
 321 
 322   void verify_switch(
 323     RawBytecodeStream* bcs, u4 code_length, char* code_data,
 324     StackMapFrame* current_frame, StackMapTable* stackmap_table, TRAPS);
 325 
 326   void verify_field_instructions(
 327     RawBytecodeStream* bcs, StackMapFrame* current_frame,
 328     const constantPoolHandle& cp, bool allow_arrays, TRAPS);
 329 
 330   void verify_invoke_init(
 331     RawBytecodeStream* bcs, u2 ref_index, VerificationType ref_class_type,
 332     StackMapFrame* current_frame, u4 code_length, bool in_try_block,
 333     bool* this_uninit, const constantPoolHandle& cp, StackMapTable* stackmap_table,
 334     TRAPS);
 335 
 336   // Used by ends_in_athrow() to push all handlers that contain bci onto the
 337   // handler_stack, if the handler has not already been pushed on the stack.
 338   void push_handlers(ExceptionTable* exhandlers,
 339                      GrowableArray<u4>* handler_list,
 340                      GrowableArray<u4>* handler_stack,
 341                      u4 bci);
 342 
 343   // Returns true if all paths starting with start_bc_offset end in athrow
 344   // bytecode or loop.
 345   bool ends_in_athrow(u4 start_bc_offset);
 346 
 347   void verify_invoke_instructions(
 348     RawBytecodeStream* bcs, u4 code_length, StackMapFrame* current_frame,
 349     bool in_try_block, bool* this_uninit, VerificationType return_type,
 350     const constantPoolHandle& cp, StackMapTable* stackmap_table, TRAPS);
 351 
 352   VerificationType get_newarray_type(u2 index, u2 bci, TRAPS);
 353   void verify_anewarray(u2 bci, u2 index, const constantPoolHandle& cp,
 354       StackMapFrame* current_frame, TRAPS);
 355   void verify_return_value(
 356       VerificationType return_type, VerificationType type, u2 offset,
 357       StackMapFrame* current_frame, TRAPS);
 358 
 359   void verify_iload (u2 index, StackMapFrame* current_frame, TRAPS);
 360   void verify_lload (u2 index, StackMapFrame* current_frame, TRAPS);
 361   void verify_fload (u2 index, StackMapFrame* current_frame, TRAPS);
 362   void verify_dload (u2 index, StackMapFrame* current_frame, TRAPS);
 363   void verify_aload (u2 index, StackMapFrame* current_frame, TRAPS);
 364   void verify_istore(u2 index, StackMapFrame* current_frame, TRAPS);
 365   void verify_lstore(u2 index, StackMapFrame* current_frame, TRAPS);
 366   void verify_fstore(u2 index, StackMapFrame* current_frame, TRAPS);
 367   void verify_dstore(u2 index, StackMapFrame* current_frame, TRAPS);
 368   void verify_astore(u2 index, StackMapFrame* current_frame, TRAPS);
 369   void verify_iinc  (u2 index, StackMapFrame* current_frame, TRAPS);
 370 
 371   bool name_in_supers(Symbol* ref_name, InstanceKlass* current);
 372 
 373   VerificationType object_type() const;
 374 
 375   InstanceKlass*      _klass;  // the class being verified
 376   methodHandle        _method; // current method being verified
 377   VerificationType    _this_type; // the verification type of the current class
 378 
 379   // Some recursive calls from the verifier to the name resolver
 380   // can cause the current class to be re-verified and rewritten.
 381   // If this happens, the original verification should not continue,
 382   // because constant pool indexes will have changed.
 383   // The rewriter is preceded by the verifier.  If the verifier throws
 384   // an error, rewriting is prevented.  Also, rewriting always precedes
 385   // bytecode execution or compilation.  Thus, is_rewritten implies
 386   // that a class has been verified and prepared for execution.
 387   bool was_recursively_verified() { return _klass->is_rewritten(); }
 388 
 389   bool is_same_or_direct_interface(InstanceKlass* klass,
 390     VerificationType klass_type, VerificationType ref_class_type);
 391 
 392  public:
 393   enum {
 394     BYTECODE_OFFSET = 1,
 395     NEW_OFFSET = 2
 396   };
 397 
 398   // constructor
 399   ClassVerifier(InstanceKlass* klass, TRAPS);
 400 
 401   // destructor
 402   ~ClassVerifier();
 403 
 404   Thread* thread()             { return _thread; }
 405   const methodHandle& method() { return _method; }
 406   InstanceKlass* current_class() const { return _klass; }
 407   VerificationType current_type() const { return _this_type; }
 408 
 409   // Verifies the class.  If a verify or class file format error occurs,
 410   // the '_exception_name' symbols will set to the exception name and
 411   // the message_buffer will be filled in with the exception message.
 412   void verify_class(TRAPS);
 413 
 414   // Translates method signature entries into verificationTypes and saves them
 415   // in the growable array.
 416   void translate_signature(Symbol* const method_sig, sig_as_verification_types* sig_verif_types, TRAPS);
 417 
 418   // Initializes a sig_as_verification_types entry and puts it in the hash table.
 419   void create_method_sig_entry(sig_as_verification_types* sig_verif_types, int sig_index, TRAPS);
 420 
 421   // Return status modes
 422   Symbol* result() const { return _exception_type; }
 423   bool has_error() const { return result() != NULL; }
 424   char* exception_message() {
 425     stringStream ss;
 426     ss.print("%s", _message);
 427     _error_context.details(&ss, _method());
 428     return ss.as_string();
 429   }
 430 
 431   // Called when verify or class format errors are encountered.
 432   // May throw an exception based upon the mode.
 433   void verify_error(ErrorContext ctx, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4);
 434   void class_format_error(const char* fmt, ...) ATTRIBUTE_PRINTF(2, 3);
 435 
 436   Klass* load_class(Symbol* name, TRAPS);
 437 
 438   method_signatures_table_type* method_signatures_table() const {
 439     return _method_signatures_table;
 440   }
 441 
 442   void set_method_signatures_table(method_signatures_table_type* method_signatures_table) {
 443     _method_signatures_table = method_signatures_table;
 444   }
 445 
 446   int change_sig_to_verificationType(
 447     SignatureStream* sig_type, VerificationType* inference_type, TRAPS);
 448 
 449   VerificationType cp_index_to_type(int index, const constantPoolHandle& cp, TRAPS) {
 450     return VerificationType::reference_type(cp->klass_name_at(index));
 451   }
 452 
 453   // Keep a list of temporary symbols created during verification because
 454   // their reference counts need to be decremented when the verifier object
 455   // goes out of scope.  Since these symbols escape the scope in which they're
 456   // created, we can't use a TempNewSymbol.
 457   Symbol* create_temporary_symbol(const Symbol* s, int begin, int end, TRAPS);
 458   Symbol* create_temporary_symbol(const char *s, int length, TRAPS);
 459   Symbol* create_temporary_symbol(Symbol* s) {
 460     if (s == _previous_symbol) {
 461       return s;
 462     }
 463     if (!s->is_permanent()) {
 464       s->increment_refcount();
 465       if (_symbols == NULL) {
 466         _symbols = new GrowableArray<Symbol*>(50, 0, NULL);
 467       }
 468       _symbols->push(s);
 469     }
 470     _previous_symbol = s;
 471     return s;
 472   }
 473 
 474   TypeOrigin ref_ctx(const char* str, TRAPS);
 475 
 476 };
 477 
 478 inline int ClassVerifier::change_sig_to_verificationType(
 479     SignatureStream* sig_type, VerificationType* inference_type, TRAPS) {
 480   BasicType bt = sig_type->type();
 481   switch (bt) {
 482     case T_OBJECT:
 483     case T_ARRAY:
 484       {
 485         Symbol* name = sig_type->as_symbol(CHECK_0);
 486         // Create another symbol to save as signature stream unreferences this symbol.
 487         Symbol* name_copy = create_temporary_symbol(name);
 488         assert(name_copy == name, "symbols don't match");
 489         *inference_type =
 490           VerificationType::reference_type(name_copy);
 491         return 1;
 492       }
 493     case T_LONG:
 494       *inference_type = VerificationType::long_type();
 495       *++inference_type = VerificationType::long2_type();
 496       return 2;
 497     case T_DOUBLE:
 498       *inference_type = VerificationType::double_type();
 499       *++inference_type = VerificationType::double2_type();
 500       return 2;
 501     case T_INT:
 502     case T_BOOLEAN:
 503     case T_BYTE:
 504     case T_CHAR:
 505     case T_SHORT:
 506       *inference_type = VerificationType::integer_type();
 507       return 1;
 508     case T_FLOAT:
 509       *inference_type = VerificationType::float_type();
 510       return 1;
 511     default:
 512       ShouldNotReachHere();
 513       return 1;
 514   }
 515 }
 516 
 517 #endif // SHARE_CLASSFILE_VERIFIER_HPP