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