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 NO_FAULT, // No error
159 UNKNOWN
160 } FaultType;
161
162 int _bci;
163 FaultType _fault;
164 TypeOrigin _type;
165 TypeOrigin _expected;
166
167 ErrorContext(int bci, FaultType fault) :
168 _bci(bci), _fault(fault) {}
169 ErrorContext(int bci, FaultType fault, TypeOrigin type) :
170 _bci(bci), _fault(fault), _type(type) {}
171 ErrorContext(int bci, FaultType fault, TypeOrigin type, TypeOrigin exp) :
172 _bci(bci), _fault(fault), _type(type), _expected(exp) {}
173
174 public:
175 ErrorContext() : _bci(-1), _fault(NO_FAULT) {}
176
177 static ErrorContext bad_code(int bci) {
178 return ErrorContext(bci, INVALID_BYTECODE);
179 }
180 static ErrorContext bad_type(int bci, TypeOrigin type) {
181 return ErrorContext(bci, WRONG_TYPE, type);
182 }
183 static ErrorContext bad_type(int bci, TypeOrigin type, TypeOrigin exp) {
184 return ErrorContext(bci, WRONG_TYPE, type, exp);
185 }
186 static ErrorContext bad_flags(int bci, StackMapFrame* frame) {
187 return ErrorContext(bci, FLAGS_MISMATCH, TypeOrigin::frame(frame));
188 }
189 static ErrorContext bad_flags(int bci, StackMapFrame* cur, StackMapFrame* sm) {
190 return ErrorContext(bci, FLAGS_MISMATCH,
191 TypeOrigin::frame(cur), TypeOrigin::frame(sm));
192 }
193 static ErrorContext bad_cp_index(int bci, int index) {
194 return ErrorContext(bci, BAD_CP_INDEX, TypeOrigin::bad_index(index));
195 }
196 static ErrorContext bad_local_index(int bci, int index) {
197 return ErrorContext(bci, BAD_LOCAL_INDEX, TypeOrigin::bad_index(index));
198 }
199 static ErrorContext locals_size_mismatch(
200 int bci, StackMapFrame* frame0, StackMapFrame* frame1) {
201 return ErrorContext(bci, LOCALS_SIZE_MISMATCH,
202 TypeOrigin::frame(frame0), TypeOrigin::frame(frame1));
203 }
204 static ErrorContext stack_size_mismatch(
205 int bci, StackMapFrame* frame0, StackMapFrame* frame1) {
206 return ErrorContext(bci, STACK_SIZE_MISMATCH,
207 TypeOrigin::frame(frame0), TypeOrigin::frame(frame1));
208 }
209 static ErrorContext stack_overflow(int bci, StackMapFrame* frame) {
210 return ErrorContext(bci, STACK_OVERFLOW, TypeOrigin::frame(frame));
211 }
212 static ErrorContext stack_underflow(int bci, StackMapFrame* frame) {
213 return ErrorContext(bci, STACK_UNDERFLOW, TypeOrigin::frame(frame));
214 }
215 static ErrorContext missing_stackmap(int bci) {
216 return ErrorContext(bci, MISSING_STACKMAP);
217 }
218 static ErrorContext bad_stackmap(int index, StackMapFrame* frame) {
219 return ErrorContext(0, BAD_STACKMAP, TypeOrigin::frame(frame));
220 }
221
222 bool is_valid() const { return _fault != NO_FAULT; }
223 int bci() const { return _bci; }
224
225 void reset_frames() {
226 _type.reset_frame();
227 _expected.reset_frame();
228 }
229
230 void details(outputStream* ss, const Method* method) const;
231
232 #ifdef ASSERT
233 void print_on(outputStream* str) const {
234 str->print("error_context(%d, %d,", _bci, _fault);
235 _type.print_on(str);
236 str->print(",");
237 _expected.print_on(str);
238 str->print(")");
239 }
240 #endif
241
242 private:
243 void location_details(outputStream* ss, const Method* method) const;
244 void reason_details(outputStream* ss) const;
245 void frame_details(outputStream* ss) const;
246 void bytecode_details(outputStream* ss, const Method* method) const;
247 void handler_details(outputStream* ss, const Method* method) const;
248 void stackmap_details(outputStream* ss, const Method* method) const;
249 };
250
251 class sig_as_verification_types : public ResourceObj {
252 private:
253 int _num_args; // Number of arguments, not including return type.
254 GrowableArray<VerificationType>* _sig_verif_types;
255
256 public:
257
258 sig_as_verification_types(GrowableArray<VerificationType>* sig_verif_types) :
259 _num_args(0), _sig_verif_types(sig_verif_types) {
260 }
261
262 int num_args() const { return _num_args; }
263 void set_num_args(int num_args) { _num_args = num_args; }
264
265 GrowableArray<VerificationType>* sig_verif_types() { return _sig_verif_types; }
266 void set_sig_verif_types(GrowableArray<VerificationType>* sig_verif_types) {
267 _sig_verif_types = sig_verif_types;
268 }
269
270 };
271
272 // This hashtable is indexed by the Utf8 constant pool indexes pointed to
273 // by constant pool (Interface)Method_refs' NameAndType signature entries.
274 typedef ResourceHashtable<int, sig_as_verification_types*, 1007>
275 method_signatures_table_type;
276
277 // A new instance of this class is created for each class being verified
278 class ClassVerifier : public StackObj {
279 private:
280 Thread* _thread;
281
282 Symbol* _previous_symbol; // cache of the previously looked up symbol
283 GrowableArray<Symbol*>* _symbols; // keep a list of symbols created
284
285 Symbol* _exception_type;
286 char* _message;
287
288 method_signatures_table_type _method_signatures_table;
289
290 ErrorContext _error_context; // contains information about an error
291
292 void verify_method(const methodHandle& method, TRAPS);
293 char* generate_code_data(const methodHandle& m, u4 code_length, TRAPS);
294 void verify_exception_handler_table(u4 code_length, char* code_data,
295 int& min, int& max, TRAPS);
296 void verify_local_variable_table(u4 code_length, char* code_data, TRAPS);
297
298 VerificationType cp_ref_index_to_type(
299 int index, const constantPoolHandle& cp, TRAPS) {
300 return cp_index_to_type(cp->uncached_klass_ref_index_at(index), cp, THREAD);
301 }
302
303 bool is_protected_access(
304 InstanceKlass* this_class, Klass* target_class,
305 Symbol* field_name, Symbol* field_sig, bool is_method);
306
307 void verify_cp_index(int bci, const constantPoolHandle& cp, u2 index, TRAPS);
308 void verify_cp_type(int bci, u2 index, const constantPoolHandle& cp,
309 unsigned int types, TRAPS);
310 void verify_cp_class_type(int bci, u2 index, const constantPoolHandle& cp, TRAPS);
311
312 u2 verify_stackmap_table(
313 u2 stackmap_index, int bci, StackMapFrame* current_frame,
314 StackMapTable* stackmap_table, bool no_control_flow, TRAPS);
315
316 void verify_exception_handler_targets(
317 int bci, bool this_uninit, StackMapFrame* current_frame,
318 StackMapTable* stackmap_table, TRAPS);
319
320 void verify_ldc(
321 int opcode, u2 index, StackMapFrame *current_frame,
322 const constantPoolHandle& cp, int bci, TRAPS);
323
324 void verify_switch(
325 RawBytecodeStream* bcs, u4 code_length, char* code_data,
326 StackMapFrame* current_frame, StackMapTable* stackmap_table, TRAPS);
327
328 void verify_field_instructions(
329 RawBytecodeStream* bcs, StackMapFrame* current_frame,
330 const constantPoolHandle& cp, bool allow_arrays, TRAPS);
331
332 void verify_invoke_init(
333 RawBytecodeStream* bcs, u2 ref_index, VerificationType ref_class_type,
334 StackMapFrame* current_frame, u4 code_length, bool in_try_block,
335 bool* this_uninit, const constantPoolHandle& cp, StackMapTable* stackmap_table,
336 TRAPS);
337
338 // Used by ends_in_athrow() to push all handlers that contain bci onto the
339 // handler_stack, if the handler has not already been pushed on the stack.
340 void push_handlers(ExceptionTable* exhandlers,
341 GrowableArray<u4>* handler_list,
342 GrowableArray<u4>* handler_stack,
343 u4 bci);
344
345 // Returns true if all paths starting with start_bc_offset end in athrow
346 // bytecode or loop.
347 bool ends_in_athrow(u4 start_bc_offset);
348
349 void verify_invoke_instructions(
350 RawBytecodeStream* bcs, u4 code_length, StackMapFrame* current_frame,
351 bool in_try_block, bool* this_uninit, VerificationType return_type,
352 const constantPoolHandle& cp, StackMapTable* stackmap_table, TRAPS);
353
354 VerificationType get_newarray_type(u2 index, int bci, TRAPS);
355 void verify_anewarray(int bci, u2 index, const constantPoolHandle& cp,
356 StackMapFrame* current_frame, TRAPS);
357 void verify_return_value(
358 VerificationType return_type, VerificationType type, int bci,
359 StackMapFrame* current_frame, TRAPS);
360
361 void verify_iload (int index, StackMapFrame* current_frame, TRAPS);
362 void verify_lload (int index, StackMapFrame* current_frame, TRAPS);
363 void verify_fload (int index, StackMapFrame* current_frame, TRAPS);
364 void verify_dload (int index, StackMapFrame* current_frame, TRAPS);
365 void verify_aload (int index, StackMapFrame* current_frame, TRAPS);
366 void verify_istore(int index, StackMapFrame* current_frame, TRAPS);
367 void verify_lstore(int index, StackMapFrame* current_frame, TRAPS);
368 void verify_fstore(int index, StackMapFrame* current_frame, TRAPS);
369 void verify_dstore(int index, StackMapFrame* current_frame, TRAPS);
370 void verify_astore(int index, StackMapFrame* current_frame, TRAPS);
371 void verify_iinc (int index, StackMapFrame* current_frame, TRAPS);
372
373 bool name_in_supers(Symbol* ref_name, InstanceKlass* current);
374
375 VerificationType object_type() const;
376
377 InstanceKlass* _klass; // the class being verified
378 methodHandle _method; // current method being verified
379 VerificationType _this_type; // the verification type of the current class
380
381 // Some recursive calls from the verifier to the name resolver
382 // can cause the current class to be re-verified and rewritten.
383 // If this happens, the original verification should not continue,
384 // because constant pool indexes will have changed.
385 // The rewriter is preceded by the verifier. If the verifier throws
386 // an error, rewriting is prevented. Also, rewriting always precedes
387 // bytecode execution or compilation. Thus, is_rewritten implies
388 // that a class has been verified and prepared for execution.
389 bool was_recursively_verified() { return _klass->is_rewritten(); }
390
391 bool is_same_or_direct_interface(InstanceKlass* klass,
392 VerificationType klass_type, VerificationType ref_class_type);
393
394 public:
395 enum {
396 BYTECODE_OFFSET = 1,
397 NEW_OFFSET = 2
398 };
399
400 // constructor
401 ClassVerifier(JavaThread* current, InstanceKlass* klass);
402
403 // destructor
404 ~ClassVerifier();
405
406 Thread* thread() { return _thread; }
407 const methodHandle& method() { return _method; }
408 InstanceKlass* current_class() const { return _klass; }
409 VerificationType current_type() const { return _this_type; }
410
411 // Verifies the class. If a verify or class file format error occurs,
412 // the '_exception_name' symbols will set to the exception name and
413 // the message_buffer will be filled in with the exception message.
414 void verify_class(TRAPS);
415
416 // Translates method signature entries into verificationTypes and saves them
417 // in the growable array.
418 void translate_signature(Symbol* const method_sig, sig_as_verification_types* sig_verif_types);
419
420 // Initializes a sig_as_verification_types entry and puts it in the hash table.
421 void create_method_sig_entry(sig_as_verification_types* sig_verif_types, int sig_index);
422
423 // Return status modes
424 Symbol* result() const { return _exception_type; }
425 bool has_error() const { return result() != nullptr; }
426 char* exception_message() {
427 stringStream ss;
428 ss.print("%s", _message);
429 _error_context.details(&ss, _method());
430 return ss.as_string();
431 }
432
433 // Called when verify or class format errors are encountered.
434 // May throw an exception based upon the mode.
435 void verify_error(ErrorContext ctx, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4);
436 void class_format_error(const char* fmt, ...) ATTRIBUTE_PRINTF(2, 3);
437
438 Klass* load_class(Symbol* name, TRAPS);
439
440 method_signatures_table_type* method_signatures_table() {
441 return &_method_signatures_table;
442 }
443
444 int change_sig_to_verificationType(
445 SignatureStream* sig_type, VerificationType* inference_type);
446
447 VerificationType cp_index_to_type(int index, const constantPoolHandle& cp, TRAPS) {
448 return VerificationType::reference_type(cp->klass_name_at(index));
449 }
450
451 // Keep a list of temporary symbols created during verification because
452 // their reference counts need to be decremented when the verifier object
453 // goes out of scope. Since these symbols escape the scope in which they're
454 // created, we can't use a TempNewSymbol.
455 Symbol* create_temporary_symbol(const char *s, int length);
456 Symbol* create_temporary_symbol(Symbol* s) {
457 if (s == _previous_symbol) {
458 return s;
459 }
460 if (!s->is_permanent()) {
461 s->increment_refcount();
462 if (_symbols == nullptr) {
463 _symbols = new GrowableArray<Symbol*>(50, 0, nullptr);
464 }
465 _symbols->push(s);
466 }
467 _previous_symbol = s;
468 return s;
469 }
470
471 TypeOrigin ref_ctx(const char* str);
472
473 };
474
475 inline int ClassVerifier::change_sig_to_verificationType(
476 SignatureStream* sig_type, VerificationType* inference_type) {
477 BasicType bt = sig_type->type();
478 switch (bt) {
479 case T_OBJECT:
480 case T_ARRAY:
481 {
482 Symbol* name = sig_type->as_symbol();
483 // Create another symbol to save as signature stream unreferences this symbol.
484 Symbol* name_copy = create_temporary_symbol(name);
485 assert(name_copy == name, "symbols don't match");
486 *inference_type =
487 VerificationType::reference_type(name_copy);
488 return 1;
489 }
490 case T_LONG:
491 *inference_type = VerificationType::long_type();
492 *++inference_type = VerificationType::long2_type();
493 return 2;
494 case T_DOUBLE:
495 *inference_type = VerificationType::double_type();
496 *++inference_type = VerificationType::double2_type();
497 return 2;
498 case T_INT:
499 case T_BOOLEAN:
500 case T_BYTE:
501 case T_CHAR:
502 case T_SHORT:
503 *inference_type = VerificationType::integer_type();
504 return 1;
505 case T_FLOAT:
506 *inference_type = VerificationType::float_type();
507 return 1;
508 default:
509 ShouldNotReachHere();
510 return 1;
511 }
512 }
513
514 #endif // SHARE_CLASSFILE_VERIFIER_HPP