1 /*
2 * Copyright (c) 1998, 2024, 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.
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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);
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 Symbol* inference_verify(
65 InstanceKlass* klass, char* msg, size_t msg_len, TRAPS);
66 };
67
68 class RawBytecodeStream;
69 class StackMapFrame;
70 class StackMapTable;
71
72 // Summary of verifier's memory usage:
73 // StackMapTable is stack allocated.
74 // StackMapFrame are resource allocated. There is only one ResourceMark
75 // for each class verification, which is created at the top level.
76 // There is one mutable StackMapFrame (current_frame) which is updated
77 // by abstract bytecode interpretation. frame_in_exception_handler() returns
78 // a frame that has a mutable one-item stack (ready for pushing the
79 // catch type exception object). All the other StackMapFrame's
80 // are immutable (including their locals and stack arrays) after
81 // their constructions.
82 // locals/stack arrays in StackMapFrame are resource allocated.
83 // locals/stack arrays can be shared between StackMapFrame's, except
84 // the mutable StackMapFrame (current_frame).
85
86 // These macros are used similarly to CHECK macros but also check
87 // the status of the verifier and return if that has an error.
88 #define CHECK_VERIFY(verifier) \
89 CHECK); if ((verifier)->has_error()) return; ((void)0
90 #define CHECK_VERIFY_(verifier, result) \
91 CHECK_(result)); if ((verifier)->has_error()) return (result); ((void)0
92
93 class TypeOrigin {
94 private:
95 typedef enum {
96 CF_LOCALS, // Comes from the current frame locals
97 CF_STACK, // Comes from the current frame expression stack
98 SM_LOCALS, // Comes from stackmap locals
99 SM_STACK, // Comes from stackmap expression stack
100 CONST_POOL, // Comes from the constant pool
101 SIG, // Comes from method signature
102 IMPLICIT, // Comes implicitly from code or context
103 BAD_INDEX, // No type, but the index is bad
104 FRAME_ONLY, // No type, context just contains the frame
105 NONE
106 } Origin;
107
108 Origin _origin;
109 int _index; // local, stack, or constant pool index
110 StackMapFrame* _frame; // source frame if CF or SM
111 VerificationType _type; // The actual type
112
113 TypeOrigin(
114 Origin origin, int index, StackMapFrame* frame, VerificationType type)
115 : _origin(origin), _index(index), _frame(frame), _type(type) {}
116
117 public:
118 TypeOrigin() : _origin(NONE), _index(0), _frame(nullptr) {}
119
120 static TypeOrigin null();
121 static TypeOrigin local(int index, StackMapFrame* frame);
122 static TypeOrigin stack(int index, StackMapFrame* frame);
123 static TypeOrigin sm_local(int index, StackMapFrame* frame);
124 static TypeOrigin sm_stack(int index, StackMapFrame* frame);
125 static TypeOrigin cp(int index, VerificationType vt);
126 static TypeOrigin signature(VerificationType vt);
127 static TypeOrigin bad_index(int index);
128 static TypeOrigin implicit(VerificationType t);
129 static TypeOrigin frame(StackMapFrame* frame);
130
131 void reset_frame();
132 void details(outputStream* ss) const;
133 void print_frame(outputStream* ss) const;
134 const StackMapFrame* frame() const { return _frame; }
135 bool is_valid() const { return _origin != NONE; }
136 int index() const { return _index; }
137
138 #ifdef ASSERT
139 void print_on(outputStream* str) const;
140 #endif
141 };
142
143 class ErrorContext {
144 private:
145 typedef enum {
146 INVALID_BYTECODE, // There was a problem with the bytecode
147 WRONG_TYPE, // Type value was not as expected
148 FLAGS_MISMATCH, // Frame flags are not assignable
149 BAD_CP_INDEX, // Invalid constant pool index
150 BAD_LOCAL_INDEX, // Invalid local index
151 LOCALS_SIZE_MISMATCH, // Frames have differing local counts
152 STACK_SIZE_MISMATCH, // Frames have different stack sizes
153 STACK_OVERFLOW, // Attempt to push onto a full expression stack
154 STACK_UNDERFLOW, // Attempt to pop and empty expression stack
155 MISSING_STACKMAP, // No stackmap for this location and there should be
156 BAD_STACKMAP, // Format error in stackmap
157 NO_FAULT, // No error
158 UNKNOWN
159 } FaultType;
160
161 int _bci;
162 FaultType _fault;
163 TypeOrigin _type;
164 TypeOrigin _expected;
165
166 ErrorContext(int bci, FaultType fault) :
167 _bci(bci), _fault(fault) {}
168 ErrorContext(int bci, FaultType fault, TypeOrigin type) :
169 _bci(bci), _fault(fault), _type(type) {}
170 ErrorContext(int bci, FaultType fault, TypeOrigin type, TypeOrigin exp) :
171 _bci(bci), _fault(fault), _type(type), _expected(exp) {}
172
173 public:
174 ErrorContext() : _bci(-1), _fault(NO_FAULT) {}
175
176 static ErrorContext bad_code(int bci) {
177 return ErrorContext(bci, INVALID_BYTECODE);
178 }
179 static ErrorContext bad_type(int bci, TypeOrigin type) {
180 return ErrorContext(bci, WRONG_TYPE, type);
181 }
182 static ErrorContext bad_type(int bci, TypeOrigin type, TypeOrigin exp) {
183 return ErrorContext(bci, WRONG_TYPE, type, exp);
184 }
185 static ErrorContext bad_flags(int bci, StackMapFrame* frame) {
186 return ErrorContext(bci, FLAGS_MISMATCH, TypeOrigin::frame(frame));
187 }
188 static ErrorContext bad_flags(int bci, StackMapFrame* cur, StackMapFrame* sm) {
189 return ErrorContext(bci, FLAGS_MISMATCH,
190 TypeOrigin::frame(cur), TypeOrigin::frame(sm));
191 }
192 static ErrorContext bad_cp_index(int bci, int index) {
193 return ErrorContext(bci, BAD_CP_INDEX, TypeOrigin::bad_index(index));
194 }
195 static ErrorContext bad_local_index(int bci, int index) {
196 return ErrorContext(bci, BAD_LOCAL_INDEX, TypeOrigin::bad_index(index));
197 }
198 static ErrorContext locals_size_mismatch(
199 int bci, StackMapFrame* frame0, StackMapFrame* frame1) {
200 return ErrorContext(bci, LOCALS_SIZE_MISMATCH,
201 TypeOrigin::frame(frame0), TypeOrigin::frame(frame1));
202 }
203 static ErrorContext stack_size_mismatch(
204 int bci, StackMapFrame* frame0, StackMapFrame* frame1) {
205 return ErrorContext(bci, STACK_SIZE_MISMATCH,
206 TypeOrigin::frame(frame0), TypeOrigin::frame(frame1));
207 }
208 static ErrorContext stack_overflow(int bci, StackMapFrame* frame) {
209 return ErrorContext(bci, STACK_OVERFLOW, TypeOrigin::frame(frame));
210 }
211 static ErrorContext stack_underflow(int bci, StackMapFrame* frame) {
212 return ErrorContext(bci, STACK_UNDERFLOW, TypeOrigin::frame(frame));
213 }
214 static ErrorContext missing_stackmap(int bci) {
215 return ErrorContext(bci, MISSING_STACKMAP);
216 }
217 static ErrorContext bad_stackmap(int index, StackMapFrame* frame) {
218 return ErrorContext(0, BAD_STACKMAP, TypeOrigin::frame(frame));
219 }
220
221 bool is_valid() const { return _fault != NO_FAULT; }
222 int bci() const { return _bci; }
223
224 void reset_frames() {
225 _type.reset_frame();
226 _expected.reset_frame();
227 }
228
229 void details(outputStream* ss, const Method* method) const;
230
231 #ifdef ASSERT
232 void print_on(outputStream* str) const {
233 str->print("error_context(%d, %d,", _bci, _fault);
234 _type.print_on(str);
235 str->print(",");
236 _expected.print_on(str);
237 str->print(")");
238 }
239 #endif
240
241 private:
242 void location_details(outputStream* ss, const Method* method) const;
243 void reason_details(outputStream* ss) const;
244 void frame_details(outputStream* ss) const;
245 void bytecode_details(outputStream* ss, const Method* method) const;
246 void handler_details(outputStream* ss, const Method* method) const;
247 void stackmap_details(outputStream* ss, const Method* method) const;
248 };
249
250 class sig_as_verification_types : public ResourceObj {
251 private:
252 int _num_args; // Number of arguments, not including return type.
253 GrowableArray<VerificationType>* _sig_verif_types;
254
255 public:
256
257 sig_as_verification_types(GrowableArray<VerificationType>* sig_verif_types) :
258 _num_args(0), _sig_verif_types(sig_verif_types) {
259 }
260
261 int num_args() const { return _num_args; }
262 void set_num_args(int num_args) { _num_args = num_args; }
263
264 GrowableArray<VerificationType>* sig_verif_types() { return _sig_verif_types; }
265 void set_sig_verif_types(GrowableArray<VerificationType>* sig_verif_types) {
266 _sig_verif_types = sig_verif_types;
267 }
268
269 };
270
271 // This hashtable is indexed by the Utf8 constant pool indexes pointed to
272 // by constant pool (Interface)Method_refs' NameAndType signature entries.
273 typedef ResourceHashtable<int, sig_as_verification_types*, 1007>
274 method_signatures_table_type;
275
276 // A new instance of this class is created for each class being verified
277 class ClassVerifier : public StackObj {
278 private:
279 Thread* _thread;
280
281 Symbol* _previous_symbol; // cache of the previously looked up symbol
282 GrowableArray<Symbol*>* _symbols; // keep a list of symbols created
283
284 Symbol* _exception_type;
285 char* _message;
286
287 method_signatures_table_type _method_signatures_table;
288
289 ErrorContext _error_context; // contains information about an error
290
291 void verify_method(const methodHandle& method, TRAPS);
292 char* generate_code_data(const methodHandle& m, u4 code_length, TRAPS);
293 void verify_exception_handler_table(u4 code_length, char* code_data,
294 int& min, int& max, TRAPS);
295 void verify_local_variable_table(u4 code_length, char* code_data, TRAPS);
296
297 VerificationType cp_ref_index_to_type(
298 int index, const constantPoolHandle& cp, TRAPS) {
299 return cp_index_to_type(cp->uncached_klass_ref_index_at(index), cp, THREAD);
300 }
301
302 bool is_protected_access(
303 InstanceKlass* this_class, Klass* target_class,
304 Symbol* field_name, Symbol* field_sig, bool is_method);
305
306 void verify_cp_index(int bci, const constantPoolHandle& cp, u2 index, TRAPS);
307 void verify_cp_type(int bci, u2 index, const constantPoolHandle& cp,
308 unsigned int types, TRAPS);
309 void verify_cp_class_type(int bci, u2 index, const constantPoolHandle& cp, TRAPS);
310
311 u2 verify_stackmap_table(
312 u2 stackmap_index, int bci, StackMapFrame* current_frame,
313 StackMapTable* stackmap_table, bool no_control_flow, TRAPS);
314
315 void verify_exception_handler_targets(
316 int bci, bool this_uninit, StackMapFrame* current_frame,
317 StackMapTable* stackmap_table, TRAPS);
318
319 void verify_ldc(
320 int opcode, u2 index, StackMapFrame *current_frame,
321 const constantPoolHandle& cp, int bci, TRAPS);
322
323 void verify_switch(
324 RawBytecodeStream* bcs, u4 code_length, char* code_data,
325 StackMapFrame* current_frame, StackMapTable* stackmap_table, TRAPS);
326
327 void verify_field_instructions(
328 RawBytecodeStream* bcs, StackMapFrame* current_frame,
329 const constantPoolHandle& cp, bool allow_arrays, TRAPS);
330
331 void verify_invoke_init(
332 RawBytecodeStream* bcs, u2 ref_index, VerificationType ref_class_type,
333 StackMapFrame* current_frame, u4 code_length, bool in_try_block,
334 bool* this_uninit, const constantPoolHandle& cp, StackMapTable* stackmap_table,
335 TRAPS);
336
337 // Used by ends_in_athrow() to push all handlers that contain bci onto the
338 // handler_stack, if the handler has not already been pushed on the stack.
339 void push_handlers(ExceptionTable* exhandlers,
340 GrowableArray<u4>* handler_list,
341 GrowableArray<u4>* handler_stack,
342 u4 bci);
343
344 // Returns true if all paths starting with start_bc_offset end in athrow
345 // bytecode or loop.
346 bool ends_in_athrow(u4 start_bc_offset);
347
348 void verify_invoke_instructions(
349 RawBytecodeStream* bcs, u4 code_length, StackMapFrame* current_frame,
350 bool in_try_block, bool* this_uninit, VerificationType return_type,
351 const constantPoolHandle& cp, StackMapTable* stackmap_table, TRAPS);
352
353 VerificationType get_newarray_type(u2 index, int bci, TRAPS);
354 void verify_anewarray(int bci, u2 index, const constantPoolHandle& cp,
355 StackMapFrame* current_frame, TRAPS);
356 void verify_return_value(
357 VerificationType return_type, VerificationType type, int bci,
358 StackMapFrame* current_frame, TRAPS);
359
360 void verify_iload (int index, StackMapFrame* current_frame, TRAPS);
361 void verify_lload (int index, StackMapFrame* current_frame, TRAPS);
362 void verify_fload (int index, StackMapFrame* current_frame, TRAPS);
363 void verify_dload (int index, StackMapFrame* current_frame, TRAPS);
364 void verify_aload (int index, StackMapFrame* current_frame, TRAPS);
365 void verify_istore(int index, StackMapFrame* current_frame, TRAPS);
366 void verify_lstore(int index, StackMapFrame* current_frame, TRAPS);
367 void verify_fstore(int index, StackMapFrame* current_frame, TRAPS);
368 void verify_dstore(int index, StackMapFrame* current_frame, TRAPS);
369 void verify_astore(int index, StackMapFrame* current_frame, TRAPS);
370 void verify_iinc (int index, StackMapFrame* current_frame, TRAPS);
371
372 bool name_in_supers(Symbol* ref_name, InstanceKlass* current);
373
374 VerificationType object_type() const;
375
376 InstanceKlass* _klass; // the class being verified
377 methodHandle _method; // current method being verified
378 VerificationType _this_type; // the verification type of the current class
379
380 // Some recursive calls from the verifier to the name resolver
381 // can cause the current class to be re-verified and rewritten.
382 // If this happens, the original verification should not continue,
383 // because constant pool indexes will have changed.
384 // The rewriter is preceded by the verifier. If the verifier throws
385 // an error, rewriting is prevented. Also, rewriting always precedes
386 // bytecode execution or compilation. Thus, is_rewritten implies
387 // that a class has been verified and prepared for execution.
388 bool was_recursively_verified() { return _klass->is_rewritten(); }
389
390 bool is_same_or_direct_interface(InstanceKlass* klass,
391 VerificationType klass_type, VerificationType ref_class_type);
392
393 public:
394 enum {
395 BYTECODE_OFFSET = 1,
396 NEW_OFFSET = 2
397 };
398
399 // constructor
400 ClassVerifier(JavaThread* current, InstanceKlass* klass);
401
402 // destructor
403 ~ClassVerifier();
404
405 Thread* thread() { return _thread; }
406 const methodHandle& method() { return _method; }
407 InstanceKlass* current_class() const { return _klass; }
408 VerificationType current_type() const { return _this_type; }
409
410 // Verifies the class. If a verify or class file format error occurs,
411 // the '_exception_name' symbols will set to the exception name and
412 // the message_buffer will be filled in with the exception message.
413 void verify_class(TRAPS);
414
415 // Translates method signature entries into verificationTypes and saves them
416 // in the growable array.
417 void translate_signature(Symbol* const method_sig, sig_as_verification_types* sig_verif_types);
418
419 // Initializes a sig_as_verification_types entry and puts it in the hash table.
420 void create_method_sig_entry(sig_as_verification_types* sig_verif_types, int sig_index);
421
422 // Return status modes
423 Symbol* result() const { return _exception_type; }
424 bool has_error() const { return result() != nullptr; }
425 char* exception_message() {
426 stringStream ss;
427 ss.print("%s", _message);
428 _error_context.details(&ss, _method());
429 return ss.as_string();
430 }
431
432 // Called when verify or class format errors are encountered.
433 // May throw an exception based upon the mode.
434 void verify_error(ErrorContext ctx, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4);
435 void class_format_error(const char* fmt, ...) ATTRIBUTE_PRINTF(2, 3);
436
437 Klass* load_class(Symbol* name, TRAPS);
438
439 method_signatures_table_type* method_signatures_table() {
440 return &_method_signatures_table;
441 }
442
443 int change_sig_to_verificationType(
444 SignatureStream* sig_type, VerificationType* inference_type);
445
446 VerificationType cp_index_to_type(int index, const constantPoolHandle& cp, TRAPS) {
447 return VerificationType::reference_type(cp->klass_name_at(index));
448 }
449
450 // Keep a list of temporary symbols created during verification because
451 // their reference counts need to be decremented when the verifier object
452 // goes out of scope. Since these symbols escape the scope in which they're
453 // created, we can't use a TempNewSymbol.
454 Symbol* create_temporary_symbol(const char *s, int length);
455 Symbol* create_temporary_symbol(Symbol* s) {
456 if (s == _previous_symbol) {
457 return s;
458 }
459 if (!s->is_permanent()) {
460 s->increment_refcount();
461 if (_symbols == nullptr) {
462 _symbols = new GrowableArray<Symbol*>(50, 0, nullptr);
463 }
464 _symbols->push(s);
465 }
466 _previous_symbol = s;
467 return s;
468 }
469
470 TypeOrigin ref_ctx(const char* str);
471
472 };
473
474 inline int ClassVerifier::change_sig_to_verificationType(
475 SignatureStream* sig_type, VerificationType* inference_type) {
476 BasicType bt = sig_type->type();
477 switch (bt) {
478 case T_OBJECT:
479 case T_ARRAY:
480 {
481 Symbol* name = sig_type->as_symbol();
482 // Create another symbol to save as signature stream unreferences this symbol.
483 Symbol* name_copy = create_temporary_symbol(name);
484 assert(name_copy == name, "symbols don't match");
485 *inference_type =
486 VerificationType::reference_type(name_copy);
487 return 1;
488 }
489 case T_LONG:
490 *inference_type = VerificationType::long_type();
491 *++inference_type = VerificationType::long2_type();
492 return 2;
493 case T_DOUBLE:
494 *inference_type = VerificationType::double_type();
495 *++inference_type = VerificationType::double2_type();
496 return 2;
497 case T_INT:
498 case T_BOOLEAN:
499 case T_BYTE:
500 case T_CHAR:
501 case T_SHORT:
502 *inference_type = VerificationType::integer_type();
503 return 1;
504 case T_FLOAT:
505 *inference_type = VerificationType::float_type();
506 return 1;
507 default:
508 ShouldNotReachHere();
509 return 1;
510 }
511 }
512
513 #endif // SHARE_CLASSFILE_VERIFIER_HPP