1 /*
2 * Copyright (c) 1998, 2023, 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.
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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 #include "utilities/resourceHash.hpp"
35
36 // The verifier class
37 class Verifier : AllStatic {
38 public:
39 enum {
40 STACKMAP_ATTRIBUTE_MAJOR_VERSION = 50,
41 INVOKEDYNAMIC_MAJOR_VERSION = 51,
42 NO_RELAX_ACCESS_CTRL_CHECK_VERSION = 52,
43 DYNAMICCONSTANT_MAJOR_VERSION = 55,
44 };
45
46 // Verify the bytecodes for a class.
47 static bool verify(InstanceKlass* klass, bool should_verify_class, TRAPS);
48
49 static void log_end_verification(outputStream* st, const char* klassName, Symbol* exception_name,
50 oop pending_exception);
51
52 // Return false if the class is loaded by the bootstrap loader,
53 // or if defineClass was called requesting skipping verification
54 // -Xverify:all overrides this value
55 static bool should_verify_for(oop class_loader, bool should_verify_class);
56
57 // Relax certain access checks to enable some broken 1.1 apps to run on 1.2.
58 static bool relax_access_for(oop class_loader);
59
60 // Print output for class+resolve
61 static void trace_class_resolution(Klass* resolve_class, InstanceKlass* verify_class);
62
63 private:
64 static bool is_eligible_for_verification(InstanceKlass* klass, bool should_verify_class);
65 static Symbol* inference_verify(
66 InstanceKlass* 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 {
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 int _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, int index, StackMapFrame* frame, VerificationType type)
116 : _origin(origin), _index(index), _frame(frame), _type(type) {}
117
118 public:
119 TypeOrigin() : _origin(NONE), _index(0), _frame(nullptr) {}
120
121 static TypeOrigin null();
122 static TypeOrigin local(int index, StackMapFrame* frame);
123 static TypeOrigin stack(int index, StackMapFrame* frame);
124 static TypeOrigin sm_local(int index, StackMapFrame* frame);
125 static TypeOrigin sm_stack(int index, StackMapFrame* frame);
126 static TypeOrigin cp(int index, VerificationType vt);
127 static TypeOrigin signature(VerificationType vt);
128 static TypeOrigin bad_index(int 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 int index() const { return _index; }
138
139 #ifdef ASSERT
140 void print_on(outputStream* str) const;
141 #endif
142 };
143
144 class ErrorContext {
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 WRONG_INLINE_TYPE, // Mismatched inline type
159 NO_FAULT, // No error
160 UNKNOWN
161 } FaultType;
162
163 int _bci;
164 FaultType _fault;
165 TypeOrigin _type;
166 TypeOrigin _expected;
167
168 ErrorContext(int bci, FaultType fault) :
169 _bci(bci), _fault(fault) {}
170 ErrorContext(int bci, FaultType fault, TypeOrigin type) :
171 _bci(bci), _fault(fault), _type(type) {}
172 ErrorContext(int bci, FaultType fault, TypeOrigin type, TypeOrigin exp) :
173 _bci(bci), _fault(fault), _type(type), _expected(exp) {}
174
175 public:
176 ErrorContext() : _bci(-1), _fault(NO_FAULT) {}
177
178 static ErrorContext bad_code(int bci) {
179 return ErrorContext(bci, INVALID_BYTECODE);
180 }
181 static ErrorContext bad_type(int bci, TypeOrigin type) {
182 return ErrorContext(bci, WRONG_TYPE, type);
183 }
184 static ErrorContext bad_type(int bci, TypeOrigin type, TypeOrigin exp) {
185 return ErrorContext(bci, WRONG_TYPE, type, exp);
186 }
187 static ErrorContext bad_flags(int bci, StackMapFrame* frame) {
188 return ErrorContext(bci, FLAGS_MISMATCH, TypeOrigin::frame(frame));
189 }
190 static ErrorContext bad_flags(int bci, StackMapFrame* cur, StackMapFrame* sm) {
191 return ErrorContext(bci, FLAGS_MISMATCH,
192 TypeOrigin::frame(cur), TypeOrigin::frame(sm));
193 }
194 static ErrorContext bad_cp_index(int bci, int index) {
195 return ErrorContext(bci, BAD_CP_INDEX, TypeOrigin::bad_index(index));
196 }
197 static ErrorContext bad_local_index(int bci, int index) {
198 return ErrorContext(bci, BAD_LOCAL_INDEX, TypeOrigin::bad_index(index));
199 }
200 static ErrorContext locals_size_mismatch(
201 int bci, StackMapFrame* frame0, StackMapFrame* frame1) {
202 return ErrorContext(bci, LOCALS_SIZE_MISMATCH,
203 TypeOrigin::frame(frame0), TypeOrigin::frame(frame1));
204 }
205 static ErrorContext stack_size_mismatch(
206 int bci, StackMapFrame* frame0, StackMapFrame* frame1) {
207 return ErrorContext(bci, STACK_SIZE_MISMATCH,
208 TypeOrigin::frame(frame0), TypeOrigin::frame(frame1));
209 }
210 static ErrorContext stack_overflow(int bci, StackMapFrame* frame) {
211 return ErrorContext(bci, STACK_OVERFLOW, TypeOrigin::frame(frame));
212 }
213 static ErrorContext stack_underflow(int bci, StackMapFrame* frame) {
214 return ErrorContext(bci, STACK_UNDERFLOW, TypeOrigin::frame(frame));
215 }
216 static ErrorContext missing_stackmap(int bci) {
217 return ErrorContext(bci, MISSING_STACKMAP);
218 }
219 static ErrorContext bad_stackmap(int index, StackMapFrame* frame) {
220 return ErrorContext(0, BAD_STACKMAP, TypeOrigin::frame(frame));
221 }
222 static ErrorContext bad_inline_type(int bci, TypeOrigin type, TypeOrigin exp) {
223 return ErrorContext(bci, WRONG_INLINE_TYPE, type, exp);
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 class sig_as_verification_types : public ResourceObj {
256 private:
257 int _num_args; // Number of arguments, not including return type.
258 GrowableArray<VerificationType>* _sig_verif_types;
259
260 public:
261
262 sig_as_verification_types(GrowableArray<VerificationType>* sig_verif_types) :
263 _num_args(0), _sig_verif_types(sig_verif_types) {
264 }
265
266 int num_args() const { return _num_args; }
267 void set_num_args(int num_args) { _num_args = num_args; }
268
269 GrowableArray<VerificationType>* sig_verif_types() { return _sig_verif_types; }
270 void set_sig_verif_types(GrowableArray<VerificationType>* sig_verif_types) {
271 _sig_verif_types = sig_verif_types;
272 }
273
274 };
275
276 // This hashtable is indexed by the Utf8 constant pool indexes pointed to
277 // by constant pool (Interface)Method_refs' NameAndType signature entries.
278 typedef ResourceHashtable<int, sig_as_verification_types*, 1007>
279 method_signatures_table_type;
280
281 // A new instance of this class is created for each class being verified
282 class ClassVerifier : public StackObj {
283 private:
284 Thread* _thread;
285
286 Symbol* _previous_symbol; // cache of the previously looked up symbol
287 GrowableArray<Symbol*>* _symbols; // keep a list of symbols created
288
289 Symbol* _exception_type;
290 char* _message;
291
292 method_signatures_table_type _method_signatures_table;
293
294 ErrorContext _error_context; // contains information about an error
295
296 void verify_method(const methodHandle& method, TRAPS);
297 char* generate_code_data(const methodHandle& m, u4 code_length, TRAPS);
298 void verify_exception_handler_table(u4 code_length, char* code_data,
299 int& min, int& max, TRAPS);
300 void verify_local_variable_table(u4 code_length, char* code_data, TRAPS);
301
302 VerificationType cp_ref_index_to_type(
303 int index, const constantPoolHandle& cp, TRAPS) {
304 return cp_index_to_type(cp->uncached_klass_ref_index_at(index), cp, THREAD);
305 }
306
307 bool is_protected_access(
308 InstanceKlass* this_class, Klass* target_class,
309 Symbol* field_name, Symbol* field_sig, bool is_method);
310
311 void verify_cp_index(int bci, const constantPoolHandle& cp, u2 index, TRAPS);
312 void verify_cp_type(int bci, u2 index, const constantPoolHandle& cp,
313 unsigned int types, TRAPS);
314 void verify_cp_class_type(int bci, u2 index, const constantPoolHandle& cp, TRAPS);
315
316 u2 verify_stackmap_table(
317 u2 stackmap_index, int bci, StackMapFrame* current_frame,
318 StackMapTable* stackmap_table, bool no_control_flow, TRAPS);
319
320 void verify_exception_handler_targets(
321 int bci, bool this_uninit, StackMapFrame* current_frame,
322 StackMapTable* stackmap_table, TRAPS);
323
324 void verify_ldc(
325 int opcode, u2 index, StackMapFrame *current_frame,
326 const constantPoolHandle& cp, int bci, TRAPS);
327
328 void verify_switch(
329 RawBytecodeStream* bcs, u4 code_length, char* code_data,
330 StackMapFrame* current_frame, StackMapTable* stackmap_table, TRAPS);
331
332 void verify_field_instructions(
333 RawBytecodeStream* bcs, StackMapFrame* current_frame,
334 const constantPoolHandle& cp, bool allow_arrays, TRAPS);
335
336 void verify_invoke_init(
337 RawBytecodeStream* bcs, u2 ref_index, VerificationType ref_class_type,
338 StackMapFrame* current_frame, u4 code_length, bool in_try_block,
339 bool* this_uninit, const constantPoolHandle& cp, StackMapTable* stackmap_table,
340 TRAPS);
341
342 // Used by ends_in_athrow() to push all handlers that contain bci onto the
343 // handler_stack, if the handler has not already been pushed on the stack.
344 void push_handlers(ExceptionTable* exhandlers,
345 GrowableArray<u4>* handler_list,
346 GrowableArray<u4>* handler_stack,
347 u4 bci);
348
349 // Returns true if all paths starting with start_bc_offset end in athrow
350 // bytecode or loop.
351 bool ends_in_athrow(u4 start_bc_offset);
352
353 void verify_invoke_instructions(
354 RawBytecodeStream* bcs, u4 code_length, StackMapFrame* current_frame,
355 bool in_try_block, bool* this_uninit,
356 const constantPoolHandle& cp, StackMapTable* stackmap_table, TRAPS);
357
358 VerificationType get_newarray_type(u2 index, int bci, TRAPS);
359 void verify_anewarray(int bci, u2 index, const constantPoolHandle& cp,
360 StackMapFrame* current_frame, TRAPS);
361 void verify_return_value(
362 VerificationType return_type, VerificationType type, int bci,
363 StackMapFrame* current_frame, TRAPS);
364
365 void verify_iload (int index, StackMapFrame* current_frame, TRAPS);
366 void verify_lload (int index, StackMapFrame* current_frame, TRAPS);
367 void verify_fload (int index, StackMapFrame* current_frame, TRAPS);
368 void verify_dload (int index, StackMapFrame* current_frame, TRAPS);
369 void verify_aload (int index, StackMapFrame* current_frame, TRAPS);
370 void verify_istore(int index, StackMapFrame* current_frame, TRAPS);
371 void verify_lstore(int index, StackMapFrame* current_frame, TRAPS);
372 void verify_fstore(int index, StackMapFrame* current_frame, TRAPS);
373 void verify_dstore(int index, StackMapFrame* current_frame, TRAPS);
374 void verify_astore(int index, StackMapFrame* current_frame, TRAPS);
375 void verify_iinc (int index, StackMapFrame* current_frame, TRAPS);
376
377 bool name_in_supers(Symbol* ref_name, InstanceKlass* current);
378
379 VerificationType object_type() const;
380
381 InstanceKlass* _klass; // the class being verified
382 methodHandle _method; // current method being verified
383 VerificationType _this_type; // the verification type of the current class
384
385 // Some recursive calls from the verifier to the name resolver
386 // can cause the current class to be re-verified and rewritten.
387 // If this happens, the original verification should not continue,
388 // because constant pool indexes will have changed.
389 // The rewriter is preceded by the verifier. If the verifier throws
390 // an error, rewriting is prevented. Also, rewriting always precedes
391 // bytecode execution or compilation. Thus, is_rewritten implies
392 // that a class has been verified and prepared for execution.
393 bool was_recursively_verified() { return _klass->is_rewritten(); }
394
395 bool is_same_or_direct_interface(InstanceKlass* klass,
396 VerificationType klass_type, VerificationType ref_class_type);
397
398 public:
399 enum {
400 BYTECODE_OFFSET = 1,
401 NEW_OFFSET = 2
402 };
403
404 // constructor
405 ClassVerifier(JavaThread* current, InstanceKlass* klass);
406
407 // destructor
408 ~ClassVerifier();
409
410 Thread* thread() { return _thread; }
411 const methodHandle& method() { return _method; }
412 InstanceKlass* current_class() const { return _klass; }
413 VerificationType current_type() const { return _this_type; }
414
415 // Verifies the class. If a verify or class file format error occurs,
416 // the '_exception_name' symbols will set to the exception name and
417 // the message_buffer will be filled in with the exception message.
418 void verify_class(TRAPS);
419
420 // Translates method signature entries into verificationTypes and saves them
421 // in the growable array.
422 void translate_signature(Symbol* const method_sig, sig_as_verification_types* sig_verif_types);
423
424 // Initializes a sig_as_verification_types entry and puts it in the hash table.
425 void create_method_sig_entry(sig_as_verification_types* sig_verif_types, int sig_index);
426
427 // Return status modes
428 Symbol* result() const { return _exception_type; }
429 bool has_error() const { return result() != nullptr; }
430 char* exception_message() {
431 stringStream ss;
432 ss.print("%s", _message);
433 _error_context.details(&ss, _method());
434 return ss.as_string();
435 }
436
437 // Called when verify or class format errors are encountered.
438 // May throw an exception based upon the mode.
439 void verify_error(ErrorContext ctx, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4);
440 void class_format_error(const char* fmt, ...) ATTRIBUTE_PRINTF(2, 3);
441
442 Klass* load_class(Symbol* name, TRAPS);
443
444 method_signatures_table_type* method_signatures_table() {
445 return &_method_signatures_table;
446 }
447
448 int change_sig_to_verificationType(
449 SignatureStream* sig_type, VerificationType* inference_type);
450
451 VerificationType cp_index_to_type(int index, const constantPoolHandle& cp, TRAPS) {
452 Symbol* name = cp->klass_name_at(index);
453 return VerificationType::reference_type(name);
454 }
455
456 // Keep a list of temporary symbols created during verification because
457 // their reference counts need to be decremented when the verifier object
458 // goes out of scope. Since these symbols escape the scope in which they're
459 // created, we can't use a TempNewSymbol.
460 Symbol* create_temporary_symbol(const char *s, int length);
461 Symbol* create_temporary_symbol(Symbol* s) {
462 if (s == _previous_symbol) {
463 return s;
464 }
465 if (!s->is_permanent()) {
466 s->increment_refcount();
467 if (_symbols == nullptr) {
468 _symbols = new GrowableArray<Symbol*>(50, 0, nullptr);
469 }
470 _symbols->push(s);
471 }
472 _previous_symbol = s;
473 return s;
474 }
475
476 TypeOrigin ref_ctx(const char* str);
477
478 };
479
480 inline int ClassVerifier::change_sig_to_verificationType(
481 SignatureStream* sig_type, VerificationType* inference_type) {
482 BasicType bt = sig_type->type();
483 switch (bt) {
484 case T_OBJECT:
485 case T_ARRAY:
486 {
487 Symbol* name = sig_type->as_symbol();
488 // Create another symbol to save as signature stream unreferences this symbol.
489 Symbol* name_copy = create_temporary_symbol(name);
490 assert(name_copy == name, "symbols don't match");
491 *inference_type = VerificationType::reference_type(name_copy);
492 return 1;
493 }
494 case T_LONG:
495 *inference_type = VerificationType::long_type();
496 *++inference_type = VerificationType::long2_type();
497 return 2;
498 case T_DOUBLE:
499 *inference_type = VerificationType::double_type();
500 *++inference_type = VerificationType::double2_type();
501 return 2;
502 case T_INT:
503 case T_BOOLEAN:
504 case T_BYTE:
505 case T_CHAR:
506 case T_SHORT:
507 *inference_type = VerificationType::integer_type();
508 return 1;
509 case T_FLOAT:
510 *inference_type = VerificationType::float_type();
511 return 1;
512 default:
513 ShouldNotReachHere();
514 return 1;
515 }
516 }
517
518 #endif // SHARE_CLASSFILE_VERIFIER_HPP