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