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