1 /*

     2  * Copyright (c) 1998, 2017, 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 "gc/shared/gcLocker.hpp"

    30 #include "oops/klass.hpp"

    31 #include "oops/method.hpp"

    32 #include "runtime/handles.hpp"

    33 #include "utilities/exceptions.hpp"

    34 #include "utilities/growableArray.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 void log_end_verification(outputStream* st, const char* klassName, Symbol* exception_name, TRAPS);

    54   static bool verify(InstanceKlass* klass, Mode mode, bool should_verify_class, TRAPS);

    55 

    56   // Return false if the class is loaded by the bootstrap loader,

    57   // or if defineClass was called requesting skipping verification

    58   // -Xverify:all/none override this value

    59   static bool should_verify_for(oop class_loader, bool should_verify_class);

    60 

    61   // Relax certain access checks to enable some broken 1.1 apps to run on 1.2.

    62   static bool relax_access_for(oop class_loader);

    63 

    64   // Print output for class+resolve

    65   static void trace_class_resolution(Klass* resolve_class, InstanceKlass* verify_class);

    66 

    67  private:

    68   static bool is_eligible_for_verification(InstanceKlass* klass, bool should_verify_class);

    69   static Symbol* inference_verify(

    70     InstanceKlass* klass, char* msg, size_t msg_len, TRAPS);

    71 };

    72 

    73 class RawBytecodeStream;

    74 class StackMapFrame;

    75 class StackMapTable;

    76 

    77 // Summary of verifier's memory usage:

    78 // StackMapTable is stack allocated.

    79 // StackMapFrame are resource allocated. There is only one ResourceMark

    80 // for each class verification, which is created at the top level.

    81 // There is one mutable StackMapFrame (current_frame) which is updated

    82 // by abstract bytecode interpretation. frame_in_exception_handler() returns

    83 // a frame that has a mutable one-item stack (ready for pushing the

    84 // catch type exception object). All the other StackMapFrame's

    85 // are immutable (including their locals and stack arrays) after

    86 // their constructions.

    87 // locals/stack arrays in StackMapFrame are resource allocated.

    88 // locals/stack arrays can be shared between StackMapFrame's, except

    89 // the mutable StackMapFrame (current_frame).

    90 

    91 // These macros are used similarly to CHECK macros but also check

    92 // the status of the verifier and return if that has an error.

    93 #define CHECK_VERIFY(verifier) \

    94   CHECK); if ((verifier)->has_error()) return; ((void)0

    95 #define CHECK_VERIFY_(verifier, result) \

    96   CHECK_(result)); if ((verifier)->has_error()) return (result); ((void)0

    97 

    98 class TypeOrigin VALUE_OBJ_CLASS_SPEC {

    99  private:

   100   typedef enum {

   101     CF_LOCALS,  // Comes from the current frame locals

   102     CF_STACK,   // Comes from the current frame expression stack

   103     SM_LOCALS,  // Comes from stackmap locals

   104     SM_STACK,   // Comes from stackmap expression stack

   105     CONST_POOL, // Comes from the constant pool

   106     SIG,        // Comes from method signature

   107     IMPLICIT,   // Comes implicitly from code or context

   108     BAD_INDEX,  // No type, but the index is bad

   109     FRAME_ONLY, // No type, context just contains the frame

   110     NONE

   111   } Origin;

   112 

   113   Origin _origin;

   114   u2 _index;              // local, stack, or constant pool index

   115   StackMapFrame* _frame;  // source frame if CF or SM

   116   VerificationType _type; // The actual type

   117 

   118   TypeOrigin(

   119       Origin origin, u2 index, StackMapFrame* frame, VerificationType type)

   120       : _origin(origin), _index(index), _frame(frame), _type(type) {}

   121 

   122  public:

   123   TypeOrigin() : _origin(NONE), _index(0), _frame(NULL) {}

   124 

   125   static TypeOrigin null();

   126   static TypeOrigin local(u2 index, StackMapFrame* frame);

   127   static TypeOrigin stack(u2 index, StackMapFrame* frame);

   128   static TypeOrigin sm_local(u2 index, StackMapFrame* frame);

   129   static TypeOrigin sm_stack(u2 index, StackMapFrame* frame);

   130   static TypeOrigin cp(u2 index, VerificationType vt);

   131   static TypeOrigin signature(VerificationType vt);

   132   static TypeOrigin bad_index(u2 index);

   133   static TypeOrigin implicit(VerificationType t);

   134   static TypeOrigin frame(StackMapFrame* frame);

   135 

   136   void reset_frame();

   137   void details(outputStream* ss) const;

   138   void print_frame(outputStream* ss) const;

   139   const StackMapFrame* frame() const { return _frame; }

   140   bool is_valid() const { return _origin != NONE; }

   141   u2 index() const { return _index; }

   142 

   143 #ifdef ASSERT

   144   void print_on(outputStream* str) const;

   145 #endif

   146 };

   147 

   148 class ErrorContext VALUE_OBJ_CLASS_SPEC {

   149  private:

   150   typedef enum {

   151     INVALID_BYTECODE,     // There was a problem with the bytecode

   152     WRONG_TYPE,           // Type value was not as expected

   153     FLAGS_MISMATCH,       // Frame flags are not assignable

   154     BAD_CP_INDEX,         // Invalid constant pool index

   155     BAD_LOCAL_INDEX,      // Invalid local index

   156     LOCALS_SIZE_MISMATCH, // Frames have differing local counts

   157     STACK_SIZE_MISMATCH,  // Frames have different stack sizes

   158     STACK_OVERFLOW,       // Attempt to push onto a full expression stack

   159     STACK_UNDERFLOW,      // Attempt to pop and empty expression stack

   160     MISSING_STACKMAP,     // No stackmap for this location and there should be

   161     BAD_STACKMAP,         // Format error in stackmap

   162     NO_FAULT,             // No error

   163     UNKNOWN

   164   } FaultType;

   165 

   166   int _bci;

   167   FaultType _fault;

   168   TypeOrigin _type;

   169   TypeOrigin _expected;

   170 

   171   ErrorContext(int bci, FaultType fault) :

   172       _bci(bci), _fault(fault)  {}

   173   ErrorContext(int bci, FaultType fault, TypeOrigin type) :

   174       _bci(bci), _fault(fault), _type(type)  {}

   175   ErrorContext(int bci, FaultType fault, TypeOrigin type, TypeOrigin exp) :

   176       _bci(bci), _fault(fault), _type(type), _expected(exp)  {}

   177 

   178  public:

   179   ErrorContext() : _bci(-1), _fault(NO_FAULT) {}

   180 

   181   static ErrorContext bad_code(u2 bci) {

   182     return ErrorContext(bci, INVALID_BYTECODE);

   183   }

   184   static ErrorContext bad_type(u2 bci, TypeOrigin type) {

   185     return ErrorContext(bci, WRONG_TYPE, type);

   186   }

   187   static ErrorContext bad_type(u2 bci, TypeOrigin type, TypeOrigin exp) {

   188     return ErrorContext(bci, WRONG_TYPE, type, exp);

   189   }

   190   static ErrorContext bad_flags(u2 bci, StackMapFrame* frame) {

   191     return ErrorContext(bci, FLAGS_MISMATCH, TypeOrigin::frame(frame));

   192   }

   193   static ErrorContext bad_flags(u2 bci, StackMapFrame* cur, StackMapFrame* sm) {

   194     return ErrorContext(bci, FLAGS_MISMATCH,

   195                         TypeOrigin::frame(cur), TypeOrigin::frame(sm));

   196   }

   197   static ErrorContext bad_cp_index(u2 bci, u2 index) {

   198     return ErrorContext(bci, BAD_CP_INDEX, TypeOrigin::bad_index(index));

   199   }

   200   static ErrorContext bad_local_index(u2 bci, u2 index) {

   201     return ErrorContext(bci, BAD_LOCAL_INDEX, TypeOrigin::bad_index(index));

   202   }

   203   static ErrorContext locals_size_mismatch(

   204       u2 bci, StackMapFrame* frame0, StackMapFrame* frame1) {

   205     return ErrorContext(bci, LOCALS_SIZE_MISMATCH,

   206         TypeOrigin::frame(frame0), TypeOrigin::frame(frame1));

   207   }

   208   static ErrorContext stack_size_mismatch(

   209       u2 bci, StackMapFrame* frame0, StackMapFrame* frame1) {

   210     return ErrorContext(bci, STACK_SIZE_MISMATCH,

   211         TypeOrigin::frame(frame0), TypeOrigin::frame(frame1));

   212   }

   213   static ErrorContext stack_overflow(u2 bci, StackMapFrame* frame) {

   214     return ErrorContext(bci, STACK_OVERFLOW, TypeOrigin::frame(frame));

   215   }

   216   static ErrorContext stack_underflow(u2 bci, StackMapFrame* frame) {

   217     return ErrorContext(bci, STACK_UNDERFLOW, TypeOrigin::frame(frame));

   218   }

   219   static ErrorContext missing_stackmap(u2 bci) {

   220     return ErrorContext(bci, MISSING_STACKMAP);

   221   }

   222   static ErrorContext bad_stackmap(int index, StackMapFrame* frame) {

   223     return ErrorContext(0, BAD_STACKMAP, TypeOrigin::frame(frame));

   224   }

   225 

   226   bool is_valid() const { return _fault != NO_FAULT; }

   227   int bci() const { return _bci; }

   228 

   229   void reset_frames() {

   230     _type.reset_frame();

   231     _expected.reset_frame();

   232   }

   233 

   234   void details(outputStream* ss, const Method* method) const;

   235 

   236 #ifdef ASSERT

   237   void print_on(outputStream* str) const {

   238     str->print("error_context(%d, %d,", _bci, _fault);

   239     _type.print_on(str);

   240     str->print(",");

   241     _expected.print_on(str);

   242     str->print(")");

   243   }

   244 #endif

   245 

   246  private:

   247   void location_details(outputStream* ss, const Method* method) const;

   248   void reason_details(outputStream* ss) const;

   249   void frame_details(outputStream* ss) const;

   250   void bytecode_details(outputStream* ss, const Method* method) const;

   251   void handler_details(outputStream* ss, const Method* method) const;

   252   void stackmap_details(outputStream* ss, const Method* method) const;

   253 };

   254 

   255 // A new instance of this class is created for each class being verified

   256 class ClassVerifier : public StackObj {

   257  private:

   258   Thread* _thread;

   259   GrowableArray<Symbol*>* _symbols;  // keep a list of symbols created

   260 

   261   Symbol* _exception_type;

   262   char* _message;

   263 

   264   ErrorContext _error_context;  // contains information about an error

   265 

   266   void verify_method(const methodHandle& method, TRAPS);

   267   char* generate_code_data(const methodHandle& m, u4 code_length, TRAPS);

   268   void verify_exception_handler_table(u4 code_length, char* code_data,

   269                                       int& min, int& max, TRAPS);

   270   void verify_local_variable_table(u4 code_length, char* code_data, TRAPS);

   271 

   272   VerificationType cp_ref_index_to_type(

   273       int index, const constantPoolHandle& cp, TRAPS) {

   274     return cp_index_to_type(cp->klass_ref_index_at(index), cp, THREAD);

   275   }

   276 

   277   bool is_protected_access(

   278     InstanceKlass* this_class, Klass* target_class,

   279     Symbol* field_name, Symbol* field_sig, bool is_method);

   280 

   281   void verify_cp_index(u2 bci, const constantPoolHandle& cp, int index, TRAPS);

   282   void verify_cp_type(u2 bci, int index, const constantPoolHandle& cp,

   283       unsigned int types, TRAPS);

   284   void verify_cp_class_type(u2 bci, int index, const constantPoolHandle& cp, TRAPS);

   285 

   286   u2 verify_stackmap_table(

   287     u2 stackmap_index, u2 bci, StackMapFrame* current_frame,

   288     StackMapTable* stackmap_table, bool no_control_flow, TRAPS);

   289 

   290   void verify_exception_handler_targets(

   291     u2 bci, bool this_uninit, StackMapFrame* current_frame,

   292     StackMapTable* stackmap_table, TRAPS);

   293 

   294   void verify_ldc(

   295     int opcode, u2 index, StackMapFrame *current_frame,

   296     const constantPoolHandle& cp, u2 bci, TRAPS);

   297 

   298   void verify_switch(

   299     RawBytecodeStream* bcs, u4 code_length, char* code_data,

   300     StackMapFrame* current_frame, StackMapTable* stackmap_table, TRAPS);

   301 

   302   void verify_field_instructions(

   303     RawBytecodeStream* bcs, StackMapFrame* current_frame,

   304     const constantPoolHandle& cp, bool allow_arrays, TRAPS);

   305 

   306   void verify_invoke_init(

   307     RawBytecodeStream* bcs, u2 ref_index, VerificationType ref_class_type,

   308     StackMapFrame* current_frame, u4 code_length, bool in_try_block,

   309     bool* this_uninit, const constantPoolHandle& cp, StackMapTable* stackmap_table,

   310     TRAPS);

   311 

   312   // Used by ends_in_athrow() to push all handlers that contain bci onto the

   313   // handler_stack, if the handler has not already been pushed on the stack.

   314   void push_handlers(ExceptionTable* exhandlers,

   315                      GrowableArray<u4>* handler_list,

   316                      GrowableArray<u4>* handler_stack,

   317                      u4 bci);

   318 

   319   // Returns true if all paths starting with start_bc_offset end in athrow

   320   // bytecode or loop.

   321   bool ends_in_athrow(u4 start_bc_offset);

   322 

   323   void verify_invoke_instructions(

   324     RawBytecodeStream* bcs, u4 code_length, StackMapFrame* current_frame,

   325     bool in_try_block, bool* this_uninit, VerificationType return_type,

   326     const constantPoolHandle& cp, StackMapTable* stackmap_table, TRAPS);

   327 

   328   VerificationType get_newarray_type(u2 index, u2 bci, TRAPS);

   329   void verify_anewarray(u2 bci, u2 index, const constantPoolHandle& cp,

   330       StackMapFrame* current_frame, TRAPS);

   331   void verify_return_value(

   332       VerificationType return_type, VerificationType type, u2 offset,

   333       StackMapFrame* current_frame, TRAPS);

   334 

   335   void verify_iload (u2 index, StackMapFrame* current_frame, TRAPS);

   336   void verify_lload (u2 index, StackMapFrame* current_frame, TRAPS);

   337   void verify_fload (u2 index, StackMapFrame* current_frame, TRAPS);

   338   void verify_dload (u2 index, StackMapFrame* current_frame, TRAPS);

   339   void verify_aload (u2 index, StackMapFrame* current_frame, TRAPS);

   340   void verify_istore(u2 index, StackMapFrame* current_frame, TRAPS);

   341   void verify_lstore(u2 index, StackMapFrame* current_frame, TRAPS);

   342   void verify_fstore(u2 index, StackMapFrame* current_frame, TRAPS);

   343   void verify_dstore(u2 index, StackMapFrame* current_frame, TRAPS);

   344   void verify_astore(u2 index, StackMapFrame* current_frame, TRAPS);

   345   void verify_iinc  (u2 index, StackMapFrame* current_frame, TRAPS);

   346 

   347   bool name_in_supers(Symbol* ref_name, InstanceKlass* current);

   348 

   349   VerificationType object_type() const;

   350 

   351   InstanceKlass*      _klass;  // the class being verified

   352   methodHandle        _method; // current method being verified

   353   VerificationType    _this_type; // the verification type of the current class

   354 

   355   // Some recursive calls from the verifier to the name resolver

   356   // can cause the current class to be re-verified and rewritten.

   357   // If this happens, the original verification should not continue,

   358   // because constant pool indexes will have changed.

   359   // The rewriter is preceded by the verifier.  If the verifier throws

   360   // an error, rewriting is prevented.  Also, rewriting always precedes

   361   // bytecode execution or compilation.  Thus, is_rewritten implies

   362   // that a class has been verified and prepared for execution.

   363   bool was_recursively_verified() { return _klass->is_rewritten(); }

   364 

   365   bool is_same_or_direct_interface(InstanceKlass* klass,

   366     VerificationType klass_type, VerificationType ref_class_type);

   367 

   368  public:

   369   enum {

   370     BYTECODE_OFFSET = 1,

   371     NEW_OFFSET = 2

   372   };

   373 

   374   // constructor

   375   ClassVerifier(InstanceKlass* klass, TRAPS);

   376 

   377   // destructor

   378   ~ClassVerifier();

   379 

   380   Thread* thread()             { return _thread; }

   381   const methodHandle& method() { return _method; }

   382   InstanceKlass* current_class() const { return _klass; }

   383   VerificationType current_type() const { return _this_type; }

   384 

   385   // Verifies the class.  If a verify or class file format error occurs,

   386   // the '_exception_name' symbols will set to the exception name and

   387   // the message_buffer will be filled in with the exception message.

   388   void verify_class(TRAPS);

   389 

   390   // Return status modes

   391   Symbol* result() const { return _exception_type; }

   392   bool has_error() const { return result() != NULL; }

   393   char* exception_message() {

   394     stringStream ss;

   395     ss.print("%s", _message);

   396     _error_context.details(&ss, _method());

   397     return ss.as_string();

   398   }

   399 

   400   // Called when verify or class format errors are encountered.

   401   // May throw an exception based upon the mode.

   402   void verify_error(ErrorContext ctx, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4);

   403   void class_format_error(const char* fmt, ...) ATTRIBUTE_PRINTF(2, 3);

   404 

   405   Klass* load_class(Symbol* name, TRAPS);

   406 

   407   int change_sig_to_verificationType(

   408     SignatureStream* sig_type, VerificationType* inference_type, TRAPS);

   409 

   410   VerificationType cp_index_to_type(int index, const constantPoolHandle& cp, TRAPS) {

   411     return VerificationType::reference_type(cp->klass_name_at(index));

   412   }

   413 

   414   // Keep a list of temporary symbols created during verification because

   415   // their reference counts need to be decremented when the verifier object

   416   // goes out of scope.  Since these symbols escape the scope in which they're

   417   // created, we can't use a TempNewSymbol.

   418   Symbol* create_temporary_symbol(const Symbol* s, int begin, int end, TRAPS);

   419   Symbol* create_temporary_symbol(const char *s, int length, TRAPS);

   420 

   421   Symbol* create_temporary_symbol(Symbol* s) {

   422     // This version just updates the reference count and saves the symbol to be

   423     // dereferenced later.

   424     s->increment_refcount();

   425     _symbols->push(s);

   426     return s;

   427   }

   428 

   429   TypeOrigin ref_ctx(const char* str, TRAPS);

   430 

   431 };

   432 

   433 inline int ClassVerifier::change_sig_to_verificationType(

   434     SignatureStream* sig_type, VerificationType* inference_type, TRAPS) {

   435   BasicType bt = sig_type->type();

   436   switch (bt) {

   437     case T_OBJECT:

   438     case T_ARRAY:

   439       {

   440         Symbol* name = sig_type->as_symbol(CHECK_0);

   441         // Create another symbol to save as signature stream unreferences this symbol.

   442         Symbol* name_copy = create_temporary_symbol(name);

   443         assert(name_copy == name, "symbols don't match");

   444         *inference_type =

   445           VerificationType::reference_type(name_copy);

   446         return 1;

   447       }

   448     case T_LONG:

   449       *inference_type = VerificationType::long_type();

   450       *++inference_type = VerificationType::long2_type();

   451       return 2;

   452     case T_DOUBLE:

   453       *inference_type = VerificationType::double_type();

   454       *++inference_type = VerificationType::double2_type();

   455       return 2;

   456     case T_INT:

   457     case T_BOOLEAN:

   458     case T_BYTE:

   459     case T_CHAR:

   460     case T_SHORT:

   461       *inference_type = VerificationType::integer_type();

   462       return 1;

   463     case T_FLOAT:

   464       *inference_type = VerificationType::float_type();

   465       return 1;

   466     default:

   467       ShouldNotReachHere();

   468       return 1;

   469   }

   470 }

   471 

   472 #endif // SHARE_VM_CLASSFILE_VERIFIER_HPP