1 /*
2 * Copyright (c) 1998, 2011, 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 "memory/gcLocker.hpp"
30 #include "oops/klass.hpp"
31 #include "oops/methodOop.hpp"
32 #include "runtime/handles.hpp"
33 #include "utilities/exceptions.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 };
42 typedef enum { ThrowException, NoException } Mode;
43
44 /**
45 * Verify the bytecodes for a class. If 'throw_exception' is true
46 * then the appropriate VerifyError or ClassFormatError will be thrown.
47 * Otherwise, no exception is thrown and the return indicates the
48 * error.
49 */
50 static bool verify(instanceKlassHandle klass, Mode mode, bool should_verify_class, TRAPS);
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/none override this value
55 static bool should_verify_for(oop class_loader, bool should_verify_class);
56
57 // Relax certain verifier checks to enable some broken 1.1 apps to run on 1.2.
58 static bool relax_verify_for(oop class_loader);
59
60 private:
61 static bool is_eligible_for_verification(instanceKlassHandle klass, bool should_verify_class);
62 static Symbol* inference_verify(
63 instanceKlassHandle klass, char* msg, size_t msg_len, TRAPS);
64 };
65
66 class RawBytecodeStream;
67 class StackMapFrame;
68 class StackMapTable;
69
70 // Summary of verifier's memory usage:
71 // StackMapTable is stack allocated.
72 // StackMapFrame are resource allocated. There is only one ResourceMark
73 // for each class verification, which is created at the top level.
74 // There is one mutable StackMapFrame (current_frame) which is updated
75 // by abstract bytecode interpretation. frame_in_exception_handler() returns
76 // a frame that has a mutable one-item stack (ready for pushing the
77 // catch type exception object). All the other StackMapFrame's
78 // are immutable (including their locals and stack arrays) after
79 // their constructions.
80 // locals/stack arrays in StackMapFrame are resource allocated.
81 // locals/stack arrays can be shared between StackMapFrame's, except
82 // the mutable StackMapFrame (current_frame).
83
84 // These macros are used similarly to CHECK macros but also check
85 // the status of the verifier and return if that has an error.
86 #define CHECK_VERIFY(verifier) \
87 CHECK); if ((verifier)->has_error()) return; (0
88 #define CHECK_VERIFY_(verifier, result) \
89 CHECK_(result)); if ((verifier)->has_error()) return (result); (0
90
91 class TypeOrigin VALUE_OBJ_CLASS_SPEC {
92 private:
93 typedef enum {
94 CF_LOCALS, // Comes from the current frame locals
95 CF_STACK, // Comes from the current frame expression stack
96 SM_LOCALS, // Comes from stackmap locals
97 SM_STACK, // Comes from stackmap exporession stack
98 CONST_POOL, // Comes from the constant pool
99 SIG, // Comes from method signature
100 IMPLICIT, // Comes implicitly from code or context
101 BAD_INDEX, // No type, but the index is bad
102 FRAME_ONLY, // No type, context just contains the frame
103 NONE
104 } Origin;
105
106 Origin _origin;
107 u2 _index; // local, stack, or constant pool index
108 StackMapFrame* _frame; // source frame if CF or SM
109 VerificationType _type; // The actual type
110
111 TypeOrigin(
112 Origin origin, u2 index, StackMapFrame* frame, VerificationType type)
113 : _origin(origin), _index(index), _frame(frame), _type(type) {}
114
115 public:
116 TypeOrigin() : _origin(NONE), _index(0), _frame(NULL) {}
117
118 static TypeOrigin null();
119 static TypeOrigin local(u2 index, StackMapFrame* frame);
120 static TypeOrigin stack(u2 index, StackMapFrame* frame);
121 static TypeOrigin sm_local(u2 index, StackMapFrame* frame);
122 static TypeOrigin sm_stack(u2 index, StackMapFrame* frame);
123 static TypeOrigin cp(u2 index, VerificationType vt);
124 static TypeOrigin signature(VerificationType vt);
125 static TypeOrigin bad_index(u2 index);
126 static TypeOrigin implicit(VerificationType t);
127 static TypeOrigin frame(StackMapFrame* frame);
128
129 void reset_frame();
130 void details(outputStream* ss);
131 void print_frame(outputStream* ss);
132 StackMapFrame* frame() { return _frame; }
133 bool is_valid() const { return _origin != NONE; }
134 u2 index() const { return _index; }
135
136 #ifdef ASSERT
137 void print(outputStream* str);
138 #endif
139 };
140
141 class ErrorContext VALUE_OBJ_CLASS_SPEC {
142 private:
143 typedef enum {
144 INVALID_BYTECODE, // there was a problem with the bytecode
145 WRONG_TYPE, // Type value was not as expected
146 FLAGS_MISMATCH, // Frame flags are not assignable
147 BAD_CP_INDEX, // Invalid constant pool index
148 BAD_LOCAL_INDEX, // Invalid local index
149 LOCALS_SIZE_MISMATCH, // Frames have differing local counts
150 STACK_SIZE_MISMATCH, // Frames have different stack sizes
151 STACK_OVERFLOW, // Attempt to push onto a full expression stack
152 STACK_UNDERFLOW, // Attempt to pop and empty expression stack
153 MISSING_STACKMAP, // No stackmap for this location and there should be
154 BAD_STACKMAP, // Format error in stackmap
155 NO_ERROR, // No error
156 UNKNOWN
157 } FaultType;
158
159 int _bci;
160 FaultType _fault;
161 TypeOrigin _type;
162 TypeOrigin _expected;
163
164 ErrorContext(int bci, FaultType fault) :
165 _bci(bci), _fault(fault) {}
166 ErrorContext(int bci, FaultType fault, TypeOrigin type) :
167 _bci(bci), _fault(fault), _type(type) {}
168 ErrorContext(int bci, FaultType fault, TypeOrigin type, TypeOrigin exp) :
169 _bci(bci), _fault(fault), _type(type), _expected(exp) {}
170
171 public:
172 ErrorContext() : _bci(-1), _fault(NO_ERROR) {}
173
174 static ErrorContext bad_code(u2 bci) {
175 return ErrorContext(bci, INVALID_BYTECODE);
176 }
177 static ErrorContext bad_type(u2 bci, TypeOrigin type) {
178 return ErrorContext(bci, WRONG_TYPE, type);
179 }
180 static ErrorContext bad_type(u2 bci, TypeOrigin type, TypeOrigin exp) {
181 return ErrorContext(bci, WRONG_TYPE, type, exp);
182 }
183 static ErrorContext bad_flags(u2 bci, StackMapFrame* frame) {
184 return ErrorContext(bci, FLAGS_MISMATCH, TypeOrigin::frame(frame));
185 }
186 static ErrorContext bad_flags(u2 bci, StackMapFrame* cur, StackMapFrame* sm) {
187 return ErrorContext(bci, FLAGS_MISMATCH,
188 TypeOrigin::frame(cur), TypeOrigin::frame(sm));
189 }
190 static ErrorContext bad_cp_index(u2 bci, u2 index) {
191 return ErrorContext(bci, BAD_CP_INDEX, TypeOrigin::bad_index(index));
192 }
193 static ErrorContext bad_local_index(u2 bci, u2 index) {
194 return ErrorContext(bci, BAD_LOCAL_INDEX, TypeOrigin::bad_index(index));
195 }
196 static ErrorContext locals_size_mismatch(
197 u2 bci, StackMapFrame* frame0, StackMapFrame* frame1) {
198 return ErrorContext(bci, LOCALS_SIZE_MISMATCH,
199 TypeOrigin::frame(frame0), TypeOrigin::frame(frame1));
200 }
201 static ErrorContext stack_size_mismatch(
202 u2 bci, StackMapFrame* frame0, StackMapFrame* frame1) {
203 return ErrorContext(bci, STACK_SIZE_MISMATCH,
204 TypeOrigin::frame(frame0), TypeOrigin::frame(frame1));
205 }
206 static ErrorContext stack_overflow(u2 bci, StackMapFrame* frame) {
207 return ErrorContext(bci, STACK_OVERFLOW, TypeOrigin::frame(frame));
208 }
209 static ErrorContext stack_underflow(u2 bci, StackMapFrame* frame) {
210 return ErrorContext(bci, STACK_UNDERFLOW, TypeOrigin::frame(frame));
211 }
212 static ErrorContext missing_stackmap(u2 bci) {
213 return ErrorContext(bci, MISSING_STACKMAP);
214 }
215 static ErrorContext bad_stackmap(int index, StackMapFrame* frame) {
216 return ErrorContext(0, BAD_STACKMAP, TypeOrigin::frame(frame));
217 }
218
219 bool is_valid() { return _fault != NO_ERROR; }
220 int bci() const { return _bci; }
221
222 void reset_frames() {
223 _type.reset_frame();
224 _expected.reset_frame();
225 }
226
227 void details(outputStream* ss, methodOop method);
228
229 #ifdef ASSERT
230 void print(outputStream* str) {
231 str->print("error_context(%d, %d,", _bci, _fault);
232 _type.print(str);
233 str->print(",");
234 _expected.print(str);
235 str->print(")");
236 }
237 #endif
238
239 private:
240 void location_details(outputStream* ss, methodOop method);
241 void reason_details(outputStream* ss);
242 void frame_details(outputStream* ss);
243 void bytecode_details(outputStream* ss, methodOop method);
244 void handler_details(outputStream* ss, methodOop method);
245 void stackmap_details(outputStream* ss, methodOop method);
246 };
247
248 // A new instance of this class is created for each class being verified
249 class ClassVerifier : public StackObj {
250 private:
251 Thread* _thread;
252 GrowableArray<Symbol*>* _symbols; // keep a list of symbols created
253
254 Symbol* _exception_type;
255 char* _message;
256
257 ErrorContext _error_context; // contains information about an error
258
259 void verify_method(methodHandle method, TRAPS);
260 char* generate_code_data(methodHandle m, u4 code_length, TRAPS);
261 void verify_exception_handler_table(u4 code_length, char* code_data,
262 int& min, int& max, TRAPS);
263 void verify_local_variable_table(u4 code_length, char* code_data, TRAPS);
264
265 VerificationType cp_ref_index_to_type(
266 int index, constantPoolHandle cp, TRAPS) {
267 return cp_index_to_type(cp->klass_ref_index_at(index), cp, THREAD);
268 }
269
270 bool is_protected_access(
271 instanceKlassHandle this_class, klassOop target_class,
272 Symbol* field_name, Symbol* field_sig, bool is_method);
273
274 void verify_cp_index(u2 bci, constantPoolHandle cp, int index, TRAPS);
275 void verify_cp_type(u2 bci, int index, constantPoolHandle cp,
276 unsigned int types, TRAPS);
277 void verify_cp_class_type(u2 bci, int index, constantPoolHandle cp, TRAPS);
278
279 u2 verify_stackmap_table(
280 u2 stackmap_index, u2 bci, StackMapFrame* current_frame,
281 StackMapTable* stackmap_table, bool no_control_flow, TRAPS);
282
283 void verify_exception_handler_targets(
284 u2 bci, bool this_uninit, StackMapFrame* current_frame,
285 StackMapTable* stackmap_table, TRAPS);
286
287 void verify_ldc(
288 int opcode, u2 index, StackMapFrame *current_frame,
289 constantPoolHandle cp, u2 bci, TRAPS);
290
291 void verify_switch(
292 RawBytecodeStream* bcs, u4 code_length, char* code_data,
293 StackMapFrame* current_frame, StackMapTable* stackmap_table, TRAPS);
294
295 void verify_field_instructions(
296 RawBytecodeStream* bcs, StackMapFrame* current_frame,
297 constantPoolHandle cp, TRAPS);
298
299 void verify_invoke_init(
300 RawBytecodeStream* bcs, u2 ref_index, VerificationType ref_class_type,
301 StackMapFrame* current_frame, u4 code_length, bool* this_uninit,
302 constantPoolHandle cp, TRAPS);
303
304 void verify_invoke_instructions(
305 RawBytecodeStream* bcs, u4 code_length, StackMapFrame* current_frame,
306 bool* this_uninit, VerificationType return_type,
307 constantPoolHandle cp, TRAPS);
308
309 VerificationType get_newarray_type(u2 index, u2 bci, TRAPS);
310 void verify_anewarray(u2 bci, u2 index, constantPoolHandle cp,
311 StackMapFrame* current_frame, TRAPS);
312 void verify_return_value(
313 VerificationType return_type, VerificationType type, u2 offset,
314 StackMapFrame* current_frame, TRAPS);
315
316 void verify_iload (u2 index, StackMapFrame* current_frame, TRAPS);
317 void verify_lload (u2 index, StackMapFrame* current_frame, TRAPS);
318 void verify_fload (u2 index, StackMapFrame* current_frame, TRAPS);
319 void verify_dload (u2 index, StackMapFrame* current_frame, TRAPS);
320 void verify_aload (u2 index, StackMapFrame* current_frame, TRAPS);
321 void verify_istore(u2 index, StackMapFrame* current_frame, TRAPS);
322 void verify_lstore(u2 index, StackMapFrame* current_frame, TRAPS);
323 void verify_fstore(u2 index, StackMapFrame* current_frame, TRAPS);
324 void verify_dstore(u2 index, StackMapFrame* current_frame, TRAPS);
325 void verify_astore(u2 index, StackMapFrame* current_frame, TRAPS);
326 void verify_iinc (u2 index, StackMapFrame* current_frame, TRAPS);
327
328 bool name_in_supers(Symbol* ref_name, instanceKlassHandle current);
329
330 VerificationType object_type() const;
331
332 instanceKlassHandle _klass; // the class being verified
333 methodHandle _method; // current method being verified
334 VerificationType _this_type; // the verification type of the current class
335
336 // Some recursive calls from the verifier to the name resolver
337 // can cause the current class to be re-verified and rewritten.
338 // If this happens, the original verification should not continue,
339 // because constant pool indexes will have changed.
340 // The rewriter is preceded by the verifier. If the verifier throws
341 // an error, rewriting is prevented. Also, rewriting always precedes
342 // bytecode execution or compilation. Thus, is_rewritten implies
343 // that a class has been verified and prepared for execution.
344 bool was_recursively_verified() { return _klass->is_rewritten(); }
345
346 public:
347 enum {
348 BYTECODE_OFFSET = 1,
349 NEW_OFFSET = 2
350 };
351
352 // constructor
353 ClassVerifier(instanceKlassHandle klass, TRAPS);
354
355 // destructor
356 ~ClassVerifier();
357
358 Thread* thread() { return _thread; }
359 methodHandle method() { return _method; }
360 instanceKlassHandle current_class() const { return _klass; }
361 VerificationType current_type() const { return _this_type; }
362
363 // Verifies the class. If a verify or class file format error occurs,
364 // the '_exception_name' symbols will set to the exception name and
365 // the message_buffer will be filled in with the exception message.
366 void verify_class(TRAPS);
367
368 // Return status modes
369 Symbol* result() const { return _exception_type; }
370 bool has_error() const { return result() != NULL; }
371 char* exception_message() {
372 stringStream ss;
373 ss.print(_message);
374 _error_context.details(&ss, _method());
375 return ss.as_string();
376 }
377
378 // Called when verify or class format errors are encountered.
379 // May throw an exception based upon the mode.
380 void verify_error(ErrorContext ctx, const char* fmt, ...);
381 void class_format_error(const char* fmt, ...);
382
383 klassOop load_class(Symbol* name, TRAPS);
384
385 int change_sig_to_verificationType(
386 SignatureStream* sig_type, VerificationType* inference_type, TRAPS);
387
388 VerificationType cp_index_to_type(int index, constantPoolHandle cp, TRAPS) {
389 return VerificationType::reference_type(cp->klass_name_at(index));
390 }
391
392 // Keep a list of temporary symbols created during verification because
393 // their reference counts need to be decrememented when the verifier object
394 // goes out of scope. Since these symbols escape the scope in which they're
395 // created, we can't use a TempNewSymbol.
396 Symbol* create_temporary_symbol(
397 const Symbol* s, int begin, int end, TRAPS);
398 Symbol* create_temporary_symbol(const char *s, int length, TRAPS);
399
400 TypeOrigin ref_ctx(const char* str, TRAPS);
401 };
402
403 inline int ClassVerifier::change_sig_to_verificationType(
404 SignatureStream* sig_type, VerificationType* inference_type, TRAPS) {
405 BasicType bt = sig_type->type();
406 switch (bt) {
407 case T_OBJECT:
408 case T_ARRAY:
409 {
410 Symbol* name = sig_type->as_symbol(CHECK_0);
411 // Create another symbol to save as signature stream unreferences
412 // this symbol.
413 Symbol* name_copy =
414 create_temporary_symbol(name, 0, name->utf8_length(), CHECK_0);
415 assert(name_copy == name, "symbols don't match");
416 *inference_type =
417 VerificationType::reference_type(name_copy);
418 return 1;
419 }
420 case T_LONG:
421 *inference_type = VerificationType::long_type();
422 *++inference_type = VerificationType::long2_type();
423 return 2;
424 case T_DOUBLE:
425 *inference_type = VerificationType::double_type();
426 *++inference_type = VerificationType::double2_type();
427 return 2;
428 case T_INT:
429 case T_BOOLEAN:
430 case T_BYTE:
431 case T_CHAR:
432 case T_SHORT:
433 *inference_type = VerificationType::integer_type();
434 return 1;
435 case T_FLOAT:
436 *inference_type = VerificationType::float_type();
437 return 1;
438 default:
439 ShouldNotReachHere();
440 return 1;
441 }
442 }
443
444 #endif // SHARE_VM_CLASSFILE_VERIFIER_HPP