1 /*
   2  * Copyright (c) 1998, 2014, 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_VM_CLASSFILE_VERIFIER_HPP
  26 #define SHARE_VM_CLASSFILE_VERIFIER_HPP
  27 
  28 #include "classfile/verificationType.hpp"
  29 #include "memory/gcLocker.hpp"
  30 #include "oops/klass.hpp"
  31 #include "oops/method.hpp"
  32 #include "runtime/handles.hpp"
  33 #include "utilities/growableArray.hpp"
  34 #include "utilities/exceptions.hpp"
  35 
  36 // The verifier class
  37 class Verifier : AllStatic {
  38  public:
  39   enum {
  40     STRICTER_ACCESS_CTRL_CHECK_VERSION  = 49,
  41     STACKMAP_ATTRIBUTE_MAJOR_VERSION    = 50,
  42     INVOKEDYNAMIC_MAJOR_VERSION         = 51,
  43     NO_RELAX_ACCESS_CTRL_CHECK_VERSION  = 52
  44   };
  45   typedef enum { ThrowException, NoException } Mode;
  46 
  47   /**
  48    * Verify the bytecodes for a class.  If 'throw_exception' is true
  49    * then the appropriate VerifyError or ClassFormatError will be thrown.
  50    * Otherwise, no exception is thrown and the return indicates the
  51    * error.
  52    */
  53   static bool verify(instanceKlassHandle klass, Mode mode, bool should_verify_class, TRAPS);
  54 
  55   // Return false if the class is loaded by the bootstrap loader,
  56   // or if defineClass was called requesting skipping verification
  57   // -Xverify:all/none override this value
  58   static bool should_verify_for(oop class_loader, bool should_verify_class);
  59 
  60   // Relax certain verifier checks to enable some broken 1.1 apps to run on 1.2.
  61   static bool relax_verify_for(oop class_loader);
  62 
  63  private:
  64   static bool is_eligible_for_verification(instanceKlassHandle klass, bool should_verify_class);
  65   static Symbol* inference_verify(
  66     instanceKlassHandle klass, char* msg, size_t msg_len, TRAPS);
  67 };
  68 
  69 class RawBytecodeStream;
  70 class StackMapFrame;
  71 class StackMapTable;
  72 
  73 // Summary of verifier's memory usage:
  74 // StackMapTable is stack allocated.
  75 // StackMapFrame are resource allocated. There is only one ResourceMark
  76 // for each class verification, which is created at the top level.
  77 // There is one mutable StackMapFrame (current_frame) which is updated
  78 // by abstract bytecode interpretation. frame_in_exception_handler() returns
  79 // a frame that has a mutable one-item stack (ready for pushing the
  80 // catch type exception object). All the other StackMapFrame's
  81 // are immutable (including their locals and stack arrays) after
  82 // their constructions.
  83 // locals/stack arrays in StackMapFrame are resource allocated.
  84 // locals/stack arrays can be shared between StackMapFrame's, except
  85 // the mutable StackMapFrame (current_frame).
  86 
  87 // These macros are used similarly to CHECK macros but also check
  88 // the status of the verifier and return if that has an error.
  89 #define CHECK_VERIFY(verifier) \
  90   CHECK); if ((verifier)->has_error()) return; ((void)0
  91 #define CHECK_VERIFY_(verifier, result) \
  92   CHECK_(result)); if ((verifier)->has_error()) return (result); ((void)0
  93 
  94 class TypeOrigin VALUE_OBJ_CLASS_SPEC {
  95  private:
  96   typedef enum {
  97     CF_LOCALS,  // Comes from the current frame locals
  98     CF_STACK,   // Comes from the current frame expression stack
  99     SM_LOCALS,  // Comes from stackmap locals
 100     SM_STACK,   // Comes from stackmap expression stack
 101     CONST_POOL, // Comes from the constant pool
 102     SIG,        // Comes from method signature
 103     IMPLICIT,   // Comes implicitly from code or context
 104     BAD_INDEX,  // No type, but the index is bad
 105     FRAME_ONLY, // No type, context just contains the frame
 106     NONE
 107   } Origin;
 108 
 109   Origin _origin;
 110   u2 _index;              // local, stack, or constant pool index
 111   StackMapFrame* _frame;  // source frame if CF or SM
 112   VerificationType _type; // The actual type
 113 
 114   TypeOrigin(
 115       Origin origin, u2 index, StackMapFrame* frame, VerificationType type)
 116       : _origin(origin), _index(index), _frame(frame), _type(type) {}
 117 
 118  public:
 119   TypeOrigin() : _origin(NONE), _index(0), _frame(NULL) {}
 120 
 121   static TypeOrigin null();
 122   static TypeOrigin local(u2 index, StackMapFrame* frame);
 123   static TypeOrigin stack(u2 index, StackMapFrame* frame);
 124   static TypeOrigin sm_local(u2 index, StackMapFrame* frame);
 125   static TypeOrigin sm_stack(u2 index, StackMapFrame* frame);
 126   static TypeOrigin cp(u2 index, VerificationType vt);
 127   static TypeOrigin signature(VerificationType vt);
 128   static TypeOrigin bad_index(u2 index);
 129   static TypeOrigin implicit(VerificationType t);
 130   static TypeOrigin frame(StackMapFrame* frame);
 131 
 132   void reset_frame();
 133   void details(outputStream* ss) const;
 134   void print_frame(outputStream* ss) const;
 135   const StackMapFrame* frame() const { return _frame; }
 136   bool is_valid() const { return _origin != NONE; }
 137   u2 index() const { return _index; }
 138 
 139 #ifdef ASSERT
 140   void print_on(outputStream* str) const;
 141 #endif
 142 };
 143 
 144 class ErrorContext VALUE_OBJ_CLASS_SPEC {
 145  private:
 146   typedef enum {
 147     INVALID_BYTECODE,     // There was a problem with the bytecode
 148     WRONG_TYPE,           // Type value was not as expected
 149     FLAGS_MISMATCH,       // Frame flags are not assignable
 150     BAD_CP_INDEX,         // Invalid constant pool index
 151     BAD_LOCAL_INDEX,      // Invalid local index
 152     LOCALS_SIZE_MISMATCH, // Frames have differing local counts
 153     STACK_SIZE_MISMATCH,  // Frames have different stack sizes
 154     STACK_OVERFLOW,       // Attempt to push onto a full expression stack
 155     STACK_UNDERFLOW,      // Attempt to pop and empty expression stack
 156     MISSING_STACKMAP,     // No stackmap for this location and there should be
 157     BAD_STACKMAP,         // Format error in stackmap
 158     NO_FAULT,             // No error
 159     UNKNOWN
 160   } FaultType;
 161 
 162   int _bci;
 163   FaultType _fault;
 164   TypeOrigin _type;
 165   TypeOrigin _expected;
 166 
 167   ErrorContext(int bci, FaultType fault) :
 168       _bci(bci), _fault(fault)  {}
 169   ErrorContext(int bci, FaultType fault, TypeOrigin type) :
 170       _bci(bci), _fault(fault), _type(type)  {}
 171   ErrorContext(int bci, FaultType fault, TypeOrigin type, TypeOrigin exp) :
 172       _bci(bci), _fault(fault), _type(type), _expected(exp)  {}
 173 
 174  public:
 175   ErrorContext() : _bci(-1), _fault(NO_FAULT) {}
 176 
 177   static ErrorContext bad_code(u2 bci) {
 178     return ErrorContext(bci, INVALID_BYTECODE);
 179   }
 180   static ErrorContext bad_type(u2 bci, TypeOrigin type) {
 181     return ErrorContext(bci, WRONG_TYPE, type);
 182   }
 183   static ErrorContext bad_type(u2 bci, TypeOrigin type, TypeOrigin exp) {
 184     return ErrorContext(bci, WRONG_TYPE, type, exp);
 185   }
 186   static ErrorContext bad_flags(u2 bci, StackMapFrame* frame) {
 187     return ErrorContext(bci, FLAGS_MISMATCH, TypeOrigin::frame(frame));
 188   }
 189   static ErrorContext bad_flags(u2 bci, StackMapFrame* cur, StackMapFrame* sm) {
 190     return ErrorContext(bci, FLAGS_MISMATCH,
 191                         TypeOrigin::frame(cur), TypeOrigin::frame(sm));
 192   }
 193   static ErrorContext bad_cp_index(u2 bci, u2 index) {
 194     return ErrorContext(bci, BAD_CP_INDEX, TypeOrigin::bad_index(index));
 195   }
 196   static ErrorContext bad_local_index(u2 bci, u2 index) {
 197     return ErrorContext(bci, BAD_LOCAL_INDEX, TypeOrigin::bad_index(index));
 198   }
 199   static ErrorContext locals_size_mismatch(
 200       u2 bci, StackMapFrame* frame0, StackMapFrame* frame1) {
 201     return ErrorContext(bci, LOCALS_SIZE_MISMATCH,
 202         TypeOrigin::frame(frame0), TypeOrigin::frame(frame1));
 203   }
 204   static ErrorContext stack_size_mismatch(
 205       u2 bci, StackMapFrame* frame0, StackMapFrame* frame1) {
 206     return ErrorContext(bci, STACK_SIZE_MISMATCH,
 207         TypeOrigin::frame(frame0), TypeOrigin::frame(frame1));
 208   }
 209   static ErrorContext stack_overflow(u2 bci, StackMapFrame* frame) {
 210     return ErrorContext(bci, STACK_OVERFLOW, TypeOrigin::frame(frame));
 211   }
 212   static ErrorContext stack_underflow(u2 bci, StackMapFrame* frame) {
 213     return ErrorContext(bci, STACK_UNDERFLOW, TypeOrigin::frame(frame));
 214   }
 215   static ErrorContext missing_stackmap(u2 bci) {
 216     return ErrorContext(bci, MISSING_STACKMAP);
 217   }
 218   static ErrorContext bad_stackmap(int index, StackMapFrame* frame) {
 219     return ErrorContext(0, BAD_STACKMAP, TypeOrigin::frame(frame));
 220   }
 221 
 222   bool is_valid() const { return _fault != NO_FAULT; }
 223   int bci() const { return _bci; }
 224 
 225   void reset_frames() {
 226     _type.reset_frame();
 227     _expected.reset_frame();
 228   }
 229 
 230   void details(outputStream* ss, const Method* method) const;
 231 
 232 #ifdef ASSERT
 233   void print_on(outputStream* str) const {
 234     str->print("error_context(%d, %d,", _bci, _fault);
 235     _type.print_on(str);
 236     str->print(",");
 237     _expected.print_on(str);
 238     str->print(")");
 239   }
 240 #endif
 241 
 242  private:
 243   void location_details(outputStream* ss, const Method* method) const;
 244   void reason_details(outputStream* ss) const;
 245   void frame_details(outputStream* ss) const;
 246   void bytecode_details(outputStream* ss, const Method* method) const;
 247   void handler_details(outputStream* ss, const Method* method) const;
 248   void stackmap_details(outputStream* ss, const Method* method) const;
 249 };
 250 
 251 // A new instance of this class is created for each class being verified
 252 class ClassVerifier : public StackObj {
 253  private:
 254   Thread* _thread;
 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(methodHandle method, TRAPS);
 263   char* generate_code_data(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, 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     instanceKlassHandle this_class, Klass* target_class,
 275     Symbol* field_name, Symbol* field_sig, bool is_method);
 276 
 277   void verify_cp_index(u2 bci, constantPoolHandle cp, int index, TRAPS);
 278   void verify_cp_type(u2 bci, int index, constantPoolHandle cp,
 279       unsigned int types, TRAPS);
 280   void verify_cp_class_type(u2 bci, int index, 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     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     constantPoolHandle cp, 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* this_uninit,
 305     constantPoolHandle cp, TRAPS);
 306 
 307   // Used by ends_in_athrow() to push all handlers that contain bci onto
 308   // the handler_stack, if the handler is not already on the stack.
 309   void push_handlers(ExceptionTable* exhandlers,
 310                      GrowableArray<u4>* handler_stack,
 311                      u4 bci);
 312 
 313   // Returns true if all paths starting with start_bc_offset end in athrow
 314   // bytecode or loop.
 315   bool ends_in_athrow(u4 start_bc_offset);
 316 
 317   void verify_invoke_instructions(
 318     RawBytecodeStream* bcs, u4 code_length, StackMapFrame* current_frame,
 319     bool* this_uninit, VerificationType return_type,
 320     constantPoolHandle cp, TRAPS);
 321 
 322   VerificationType get_newarray_type(u2 index, u2 bci, TRAPS);
 323   void verify_anewarray(u2 bci, u2 index, constantPoolHandle cp,
 324       StackMapFrame* current_frame, TRAPS);
 325   void verify_return_value(
 326       VerificationType return_type, VerificationType type, u2 offset,
 327       StackMapFrame* current_frame, TRAPS);
 328 
 329   void verify_iload (u2 index, StackMapFrame* current_frame, TRAPS);
 330   void verify_lload (u2 index, StackMapFrame* current_frame, TRAPS);
 331   void verify_fload (u2 index, StackMapFrame* current_frame, TRAPS);
 332   void verify_dload (u2 index, StackMapFrame* current_frame, TRAPS);
 333   void verify_aload (u2 index, StackMapFrame* current_frame, TRAPS);
 334   void verify_istore(u2 index, StackMapFrame* current_frame, TRAPS);
 335   void verify_lstore(u2 index, StackMapFrame* current_frame, TRAPS);
 336   void verify_fstore(u2 index, StackMapFrame* current_frame, TRAPS);
 337   void verify_dstore(u2 index, StackMapFrame* current_frame, TRAPS);
 338   void verify_astore(u2 index, StackMapFrame* current_frame, TRAPS);
 339   void verify_iinc  (u2 index, StackMapFrame* current_frame, TRAPS);
 340 
 341   bool name_in_supers(Symbol* ref_name, instanceKlassHandle current);
 342 
 343   VerificationType object_type() const;
 344 
 345   instanceKlassHandle _klass;  // the class being verified
 346   methodHandle        _method; // current method being verified
 347   VerificationType    _this_type; // the verification type of the current class
 348 
 349   // Some recursive calls from the verifier to the name resolver
 350   // can cause the current class to be re-verified and rewritten.
 351   // If this happens, the original verification should not continue,
 352   // because constant pool indexes will have changed.
 353   // The rewriter is preceded by the verifier.  If the verifier throws
 354   // an error, rewriting is prevented.  Also, rewriting always precedes
 355   // bytecode execution or compilation.  Thus, is_rewritten implies
 356   // that a class has been verified and prepared for execution.
 357   bool was_recursively_verified() { return _klass->is_rewritten(); }
 358 
 359   bool is_same_or_direct_interface(instanceKlassHandle klass,
 360     VerificationType klass_type, VerificationType ref_class_type);
 361 
 362  public:
 363   enum {
 364     BYTECODE_OFFSET = 1,
 365     NEW_OFFSET = 2
 366   };
 367 
 368   // constructor
 369   ClassVerifier(instanceKlassHandle klass, TRAPS);
 370 
 371   // destructor
 372   ~ClassVerifier();
 373 
 374   Thread* thread()             { return _thread; }
 375   methodHandle method()        { return _method; }
 376   instanceKlassHandle current_class() const { return _klass; }
 377   VerificationType current_type() const { return _this_type; }
 378 
 379   // Verifies the class.  If a verify or class file format error occurs,
 380   // the '_exception_name' symbols will set to the exception name and
 381   // the message_buffer will be filled in with the exception message.
 382   void verify_class(TRAPS);
 383 
 384   // Return status modes
 385   Symbol* result() const { return _exception_type; }
 386   bool has_error() const { return result() != NULL; }
 387   char* exception_message() {
 388     stringStream ss;
 389     ss.print("%s", _message);
 390     _error_context.details(&ss, _method());
 391     return ss.as_string();
 392   }
 393 
 394   // Called when verify or class format errors are encountered.
 395   // May throw an exception based upon the mode.
 396   void verify_error(ErrorContext ctx, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4);
 397   void class_format_error(const char* fmt, ...) ATTRIBUTE_PRINTF(2, 3);
 398 
 399   Klass* load_class(Symbol* name, TRAPS);
 400 
 401   int change_sig_to_verificationType(
 402     SignatureStream* sig_type, VerificationType* inference_type, TRAPS);
 403 
 404   VerificationType cp_index_to_type(int index, constantPoolHandle cp, TRAPS) {
 405     return VerificationType::reference_type(cp->klass_name_at(index));
 406   }
 407 
 408   // Keep a list of temporary symbols created during verification because
 409   // their reference counts need to be decrememented when the verifier object
 410   // goes out of scope.  Since these symbols escape the scope in which they're
 411   // created, we can't use a TempNewSymbol.
 412   Symbol* create_temporary_symbol(
 413       const Symbol* s, int begin, int end, TRAPS);
 414   Symbol* create_temporary_symbol(const char *s, int length, TRAPS);
 415 
 416   TypeOrigin ref_ctx(const char* str, TRAPS);
 417 
 418 };
 419 
 420 inline int ClassVerifier::change_sig_to_verificationType(
 421     SignatureStream* sig_type, VerificationType* inference_type, TRAPS) {
 422   BasicType bt = sig_type->type();
 423   switch (bt) {
 424     case T_OBJECT:
 425     case T_ARRAY:
 426       {
 427         Symbol* name = sig_type->as_symbol(CHECK_0);
 428         // Create another symbol to save as signature stream unreferences
 429         // this symbol.
 430         Symbol* name_copy =
 431           create_temporary_symbol(name, 0, name->utf8_length(), CHECK_0);
 432         assert(name_copy == name, "symbols don't match");
 433         *inference_type =
 434           VerificationType::reference_type(name_copy);
 435         return 1;
 436       }
 437     case T_LONG:
 438       *inference_type = VerificationType::long_type();
 439       *++inference_type = VerificationType::long2_type();
 440       return 2;
 441     case T_DOUBLE:
 442       *inference_type = VerificationType::double_type();
 443       *++inference_type = VerificationType::double2_type();
 444       return 2;
 445     case T_INT:
 446     case T_BOOLEAN:
 447     case T_BYTE:
 448     case T_CHAR:
 449     case T_SHORT:
 450       *inference_type = VerificationType::integer_type();
 451       return 1;
 452     case T_FLOAT:
 453       *inference_type = VerificationType::float_type();
 454       return 1;
 455     default:
 456       ShouldNotReachHere();
 457       return 1;
 458   }
 459 }
 460 
 461 #endif // SHARE_VM_CLASSFILE_VERIFIER_HPP
--- EOF ---