1 /*
2 * Copyright (c) 1998, 2018, 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_VM_CLASSFILE_VERIFIER_HPP
26 #define SHARE_VM_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/none override 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
TypeOrigin(Origin origin,u2 index,StackMapFrame * frame,VerificationType type)112 TypeOrigin(
113 Origin origin, u2 index, StackMapFrame* frame, VerificationType type)
114 : _origin(origin), _index(index), _frame(frame), _type(type) {}
115
116 public:
TypeOrigin()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;
frame() const133 const StackMapFrame* frame() const { return _frame; }
is_valid() const134 bool is_valid() const { return _origin != NONE; }
index() const135 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
ErrorContext(int bci,FaultType fault)165 ErrorContext(int bci, FaultType fault) :
166 _bci(bci), _fault(fault) {}
ErrorContext(int bci,FaultType fault,TypeOrigin type)167 ErrorContext(int bci, FaultType fault, TypeOrigin type) :
168 _bci(bci), _fault(fault), _type(type) {}
ErrorContext(int bci,FaultType fault,TypeOrigin type,TypeOrigin exp)169 ErrorContext(int bci, FaultType fault, TypeOrigin type, TypeOrigin exp) :
170 _bci(bci), _fault(fault), _type(type), _expected(exp) {}
171
172 public:
ErrorContext()173 ErrorContext() : _bci(-1), _fault(NO_FAULT) {}
174
bad_code(u2 bci)175 static ErrorContext bad_code(u2 bci) {
176 return ErrorContext(bci, INVALID_BYTECODE);
177 }
bad_type(u2 bci,TypeOrigin type)178 static ErrorContext bad_type(u2 bci, TypeOrigin type) {
179 return ErrorContext(bci, WRONG_TYPE, type);
180 }
bad_type(u2 bci,TypeOrigin type,TypeOrigin exp)181 static ErrorContext bad_type(u2 bci, TypeOrigin type, TypeOrigin exp) {
182 return ErrorContext(bci, WRONG_TYPE, type, exp);
183 }
bad_flags(u2 bci,StackMapFrame * frame)184 static ErrorContext bad_flags(u2 bci, StackMapFrame* frame) {
185 return ErrorContext(bci, FLAGS_MISMATCH, TypeOrigin::frame(frame));
186 }
bad_flags(u2 bci,StackMapFrame * cur,StackMapFrame * sm)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 }
bad_cp_index(u2 bci,u2 index)191 static ErrorContext bad_cp_index(u2 bci, u2 index) {
192 return ErrorContext(bci, BAD_CP_INDEX, TypeOrigin::bad_index(index));
193 }
bad_local_index(u2 bci,u2 index)194 static ErrorContext bad_local_index(u2 bci, u2 index) {
195 return ErrorContext(bci, BAD_LOCAL_INDEX, TypeOrigin::bad_index(index));
196 }
locals_size_mismatch(u2 bci,StackMapFrame * frame0,StackMapFrame * frame1)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 }
stack_size_mismatch(u2 bci,StackMapFrame * frame0,StackMapFrame * frame1)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 }
stack_overflow(u2 bci,StackMapFrame * frame)207 static ErrorContext stack_overflow(u2 bci, StackMapFrame* frame) {
208 return ErrorContext(bci, STACK_OVERFLOW, TypeOrigin::frame(frame));
209 }
stack_underflow(u2 bci,StackMapFrame * frame)210 static ErrorContext stack_underflow(u2 bci, StackMapFrame* frame) {
211 return ErrorContext(bci, STACK_UNDERFLOW, TypeOrigin::frame(frame));
212 }
missing_stackmap(u2 bci)213 static ErrorContext missing_stackmap(u2 bci) {
214 return ErrorContext(bci, MISSING_STACKMAP);
215 }
bad_stackmap(int index,StackMapFrame * frame)216 static ErrorContext bad_stackmap(int index, StackMapFrame* frame) {
217 return ErrorContext(0, BAD_STACKMAP, TypeOrigin::frame(frame));
218 }
219
is_valid() const220 bool is_valid() const { return _fault != NO_FAULT; }
bci() const221 int bci() const { return _bci; }
222
reset_frames()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
print_on(outputStream * str) const231 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 GrowableArray<Symbol*>* _symbols; // keep a list of symbols created
254
255 Symbol* _exception_type;
256 char* _message;
257
258 ErrorContext _error_context; // contains information about an error
259
260 void verify_method(const methodHandle& method, TRAPS);
261 char* generate_code_data(const methodHandle& m, u4 code_length, TRAPS);
262 void verify_exception_handler_table(u4 code_length, char* code_data,
263 int& min, int& max, TRAPS);
264 void verify_local_variable_table(u4 code_length, char* code_data, TRAPS);
265
cp_ref_index_to_type(int index,const constantPoolHandle & cp,TRAPS)266 VerificationType cp_ref_index_to_type(
267 int index, const constantPoolHandle& cp, TRAPS) {
268 return cp_index_to_type(cp->klass_ref_index_at(index), cp, THREAD);
269 }
270
271 bool is_protected_access(
272 InstanceKlass* this_class, Klass* target_class,
273 Symbol* field_name, Symbol* field_sig, bool is_method);
274
275 void verify_cp_index(u2 bci, const constantPoolHandle& cp, int index, TRAPS);
276 void verify_cp_type(u2 bci, int index, const constantPoolHandle& cp,
277 unsigned int types, TRAPS);
278 void verify_cp_class_type(u2 bci, int index, const constantPoolHandle& cp, TRAPS);
279
280 u2 verify_stackmap_table(
281 u2 stackmap_index, u2 bci, StackMapFrame* current_frame,
282 StackMapTable* stackmap_table, bool no_control_flow, TRAPS);
283
284 void verify_exception_handler_targets(
285 u2 bci, bool this_uninit, StackMapFrame* current_frame,
286 StackMapTable* stackmap_table, TRAPS);
287
288 void verify_ldc(
289 int opcode, u2 index, StackMapFrame *current_frame,
290 const constantPoolHandle& cp, u2 bci, TRAPS);
291
292 void verify_switch(
293 RawBytecodeStream* bcs, u4 code_length, char* code_data,
294 StackMapFrame* current_frame, StackMapTable* stackmap_table, TRAPS);
295
296 void verify_field_instructions(
297 RawBytecodeStream* bcs, StackMapFrame* current_frame,
298 const constantPoolHandle& cp, bool allow_arrays, TRAPS);
299
300 void verify_invoke_init(
301 RawBytecodeStream* bcs, u2 ref_index, VerificationType ref_class_type,
302 StackMapFrame* current_frame, u4 code_length, bool in_try_block,
303 bool* this_uninit, const constantPoolHandle& cp, StackMapTable* stackmap_table,
304 TRAPS);
305
306 // Used by ends_in_athrow() to push all handlers that contain bci onto the
307 // handler_stack, if the handler has not already been pushed on the stack.
308 void push_handlers(ExceptionTable* exhandlers,
309 GrowableArray<u4>* handler_list,
310 GrowableArray<u4>* handler_stack,
311 u4 bci);
312
313 // Returns true if all paths starting with start_bc_offset end in athrow
314 // bytecode or loop.
315 bool ends_in_athrow(u4 start_bc_offset);
316
317 void verify_invoke_instructions(
318 RawBytecodeStream* bcs, u4 code_length, StackMapFrame* current_frame,
319 bool in_try_block, bool* this_uninit, VerificationType return_type,
320 const constantPoolHandle& cp, StackMapTable* stackmap_table, TRAPS);
321
322 VerificationType get_newarray_type(u2 index, u2 bci, TRAPS);
323 void verify_anewarray(u2 bci, u2 index, const constantPoolHandle& cp,
324 StackMapFrame* current_frame, TRAPS);
325 void verify_return_value(
326 VerificationType return_type, VerificationType type, u2 offset,
327 StackMapFrame* current_frame, TRAPS);
328
329 void verify_iload (u2 index, StackMapFrame* current_frame, TRAPS);
330 void verify_lload (u2 index, StackMapFrame* current_frame, TRAPS);
331 void verify_fload (u2 index, StackMapFrame* current_frame, TRAPS);
332 void verify_dload (u2 index, StackMapFrame* current_frame, TRAPS);
333 void verify_aload (u2 index, StackMapFrame* current_frame, TRAPS);
334 void verify_istore(u2 index, StackMapFrame* current_frame, TRAPS);
335 void verify_lstore(u2 index, StackMapFrame* current_frame, TRAPS);
336 void verify_fstore(u2 index, StackMapFrame* current_frame, TRAPS);
337 void verify_dstore(u2 index, StackMapFrame* current_frame, TRAPS);
338 void verify_astore(u2 index, StackMapFrame* current_frame, TRAPS);
339 void verify_iinc (u2 index, StackMapFrame* current_frame, TRAPS);
340
341 bool name_in_supers(Symbol* ref_name, InstanceKlass* current);
342
343 VerificationType object_type() const;
344
345 InstanceKlass* _klass; // the class being verified
346 methodHandle _method; // current method being verified
347 VerificationType _this_type; // the verification type of the current class
348
349 // Some recursive calls from the verifier to the name resolver
350 // can cause the current class to be re-verified and rewritten.
351 // If this happens, the original verification should not continue,
352 // because constant pool indexes will have changed.
353 // The rewriter is preceded by the verifier. If the verifier throws
354 // an error, rewriting is prevented. Also, rewriting always precedes
355 // bytecode execution or compilation. Thus, is_rewritten implies
356 // that a class has been verified and prepared for execution.
was_recursively_verified()357 bool was_recursively_verified() { return _klass->is_rewritten(); }
358
359 bool is_same_or_direct_interface(InstanceKlass* klass,
360 VerificationType klass_type, VerificationType ref_class_type);
361
362 public:
363 enum {
364 BYTECODE_OFFSET = 1,
365 NEW_OFFSET = 2
366 };
367
368 // constructor
369 ClassVerifier(InstanceKlass* klass, TRAPS);
370
371 // destructor
372 ~ClassVerifier();
373
thread()374 Thread* thread() { return _thread; }
method()375 const methodHandle& method() { return _method; }
current_class() const376 InstanceKlass* current_class() const { return _klass; }
current_type() const377 VerificationType current_type() const { return _this_type; }
378
379 // Verifies the class. If a verify or class file format error occurs,
380 // the '_exception_name' symbols will set to the exception name and
381 // the message_buffer will be filled in with the exception message.
382 void verify_class(TRAPS);
383
384 // Return status modes
result() const385 Symbol* result() const { return _exception_type; }
has_error() const386 bool has_error() const { return result() != NULL; }
exception_message()387 char* exception_message() {
388 stringStream ss;
389 ss.print("%s", _message);
390 _error_context.details(&ss, _method());
391 return ss.as_string();
392 }
393
394 // Called when verify or class format errors are encountered.
395 // May throw an exception based upon the mode.
396 void verify_error(ErrorContext ctx, const char* fmt, ...) ATTRIBUTE_PRINTF(3, 4);
397 void class_format_error(const char* fmt, ...) ATTRIBUTE_PRINTF(2, 3);
398
399 Klass* load_class(Symbol* name, TRAPS);
400
401 int change_sig_to_verificationType(
402 SignatureStream* sig_type, VerificationType* inference_type, TRAPS);
403
cp_index_to_type(int index,const constantPoolHandle & cp,TRAPS)404 VerificationType cp_index_to_type(int index, const constantPoolHandle& cp, TRAPS) {
405 return VerificationType::reference_type(cp->klass_name_at(index));
406 }
407
408 // Keep a list of temporary symbols created during verification because
409 // their reference counts need to be decremented when the verifier object
410 // goes out of scope. Since these symbols escape the scope in which they're
411 // created, we can't use a TempNewSymbol.
412 Symbol* create_temporary_symbol(const Symbol* s, int begin, int end, TRAPS);
413 Symbol* create_temporary_symbol(const char *s, int length, TRAPS);
414
create_temporary_symbol(Symbol * s)415 Symbol* create_temporary_symbol(Symbol* s) {
416 // This version just updates the reference count and saves the symbol to be
417 // dereferenced later.
418 s->increment_refcount();
419 _symbols->push(s);
420 return s;
421 }
422
423 TypeOrigin ref_ctx(const char* str, TRAPS);
424
425 };
426
change_sig_to_verificationType(SignatureStream * sig_type,VerificationType * inference_type,TRAPS)427 inline int ClassVerifier::change_sig_to_verificationType(
428 SignatureStream* sig_type, VerificationType* inference_type, TRAPS) {
429 BasicType bt = sig_type->type();
430 switch (bt) {
431 case T_OBJECT:
432 case T_ARRAY:
433 {
434 Symbol* name = sig_type->as_symbol(CHECK_0);
435 // Create another symbol to save as signature stream unreferences this symbol.
436 Symbol* name_copy = create_temporary_symbol(name);
437 assert(name_copy == name, "symbols don't match");
438 *inference_type =
439 VerificationType::reference_type(name_copy);
440 return 1;
441 }
442 case T_LONG:
443 *inference_type = VerificationType::long_type();
444 *++inference_type = VerificationType::long2_type();
445 return 2;
446 case T_DOUBLE:
447 *inference_type = VerificationType::double_type();
448 *++inference_type = VerificationType::double2_type();
449 return 2;
450 case T_INT:
451 case T_BOOLEAN:
452 case T_BYTE:
453 case T_CHAR:
454 case T_SHORT:
455 *inference_type = VerificationType::integer_type();
456 return 1;
457 case T_FLOAT:
458 *inference_type = VerificationType::float_type();
459 return 1;
460 default:
461 ShouldNotReachHere();
462 return 1;
463 }
464 }
465
466 #endif // SHARE_VM_CLASSFILE_VERIFIER_HPP
467