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src/hotspot/share/cds/cppVtables.cpp

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 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 #include "precompiled.hpp"
 26 #include "cds/archiveUtils.hpp"
 27 #include "cds/archiveBuilder.hpp"
 28 #include "cds/cdsConfig.hpp"
 29 #include "cds/cppVtables.hpp"
 30 #include "cds/metaspaceShared.hpp"
 31 #include "logging/log.hpp"
 32 #include "oops/instanceClassLoaderKlass.hpp"
 33 #include "oops/instanceMirrorKlass.hpp"
 34 #include "oops/instanceRefKlass.hpp"
 35 #include "oops/instanceStackChunkKlass.hpp"

 36 #include "oops/methodData.hpp"

 37 #include "oops/objArrayKlass.hpp"
 38 #include "oops/typeArrayKlass.hpp"
 39 #include "runtime/arguments.hpp"
 40 #include "utilities/globalDefinitions.hpp"
 41 
 42 // Objects of the Metadata types (such as Klass and ConstantPool) have C++ vtables.
 43 // (In GCC this is the field <Type>::_vptr, i.e., first word in the object.)
 44 //
 45 // Addresses of the vtables and the methods may be different across JVM runs,
 46 // if libjvm.so is dynamically loaded at a different base address.
 47 //
 48 // To ensure that the Metadata objects in the CDS archive always have the correct vtable:
 49 //
 50 // + at dump time:  we redirect the _vptr to point to our own vtables inside
 51 //                  the CDS image
 52 // + at run time:   we clone the actual contents of the vtables from libjvm.so
 53 //                  into our own tables.
 54 
 55 // Currently, the archive contains ONLY the following types of objects that have C++ vtables.
 56 #define CPP_VTABLE_TYPES_DO(f) \
 57   f(ConstantPool) \
 58   f(InstanceKlass) \
 59   f(InstanceClassLoaderKlass) \
 60   f(InstanceMirrorKlass) \
 61   f(InstanceRefKlass) \
 62   f(InstanceStackChunkKlass) \
 63   f(Method) \


 64   f(ObjArrayKlass) \
 65   f(TypeArrayKlass)



 66 
 67 class CppVtableInfo {
 68   intptr_t _vtable_size;
 69   intptr_t _cloned_vtable[1]; // Pseudo flexible array member.
 70   static size_t cloned_vtable_offset() { return offset_of(CppVtableInfo, _cloned_vtable); }
 71 public:
 72   int vtable_size()           { return int(uintx(_vtable_size)); }
 73   void set_vtable_size(int n) { _vtable_size = intptr_t(n); }
 74   // Using _cloned_vtable[i] for i > 0 causes undefined behavior. We use address calculation instead.
 75   intptr_t* cloned_vtable()   { return (intptr_t*)((char*)this + cloned_vtable_offset()); }
 76   void zero()                 { memset(cloned_vtable(), 0, sizeof(intptr_t) * vtable_size()); }
 77   // Returns the address of the next CppVtableInfo that can be placed immediately after this CppVtableInfo
 78   static size_t byte_size(int vtable_size) {
 79     return cloned_vtable_offset() + (sizeof(intptr_t) * vtable_size);
 80   }
 81 };
 82 
 83 static inline intptr_t* vtable_of(const Metadata* m) {
 84   return *((intptr_t**)m);
 85 }

177   ArchivePtrMarker::mark_pointer(&_index[c##_Kind]);
178 
179 #define INITIALIZE_VTABLE(c) \
180   CppVtableCloner<c>::initialize(#c, _index[c##_Kind]);
181 
182 #define INIT_ORIG_CPP_VTPTRS(c) \
183   CppVtableCloner<c>::init_orig_cpp_vtptr(c##_Kind);
184 
185 #define DECLARE_CLONED_VTABLE_KIND(c) c ## _Kind,
186 
187 enum ClonedVtableKind {
188   // E.g., ConstantPool_Kind == 0, InstanceKlass_Kind == 1, etc.
189   CPP_VTABLE_TYPES_DO(DECLARE_CLONED_VTABLE_KIND)
190   _num_cloned_vtable_kinds
191 };
192 
193 // This is a map of all the original vtptrs. E.g., for
194 //     ConstantPool *cp = new (...) ConstantPool(...) ; // a dynamically allocated constant pool
195 // the following holds true:
196 //     _orig_cpp_vtptrs[ConstantPool_Kind] ==  ((intptr_t**)cp)[0]
197 static intptr_t* _orig_cpp_vtptrs[_num_cloned_vtable_kinds];

198 static bool _orig_cpp_vtptrs_inited = false;
199 
200 template <class T>
201 void CppVtableCloner<T>::init_orig_cpp_vtptr(int kind) {
202   assert(kind < _num_cloned_vtable_kinds, "sanity");
203   T tmp; // Allocate temporary dummy metadata object to get to the original vtable.
204   intptr_t* srcvtable = vtable_of(&tmp);
205   _orig_cpp_vtptrs[kind] = srcvtable;
206 }
207 
208 // This is the index of all the cloned vtables. E.g., for
209 //     ConstantPool* cp = ....; // an archived constant pool
210 //     InstanceKlass* ik = ....;// an archived class
211 // the following holds true:
212 //     _index[ConstantPool_Kind]->cloned_vtable()  == ((intptr_t**)cp)[0]
213 //     _index[InstanceKlass_Kind]->cloned_vtable() == ((intptr_t**)ik)[0]
214 static CppVtableInfo* _index[_num_cloned_vtable_kinds];
215 
216 // Vtables are all fixed offsets from ArchiveBuilder::current()->mapped_base()
217 // E.g. ConstantPool is at offset 0x58. We can archive these offsets in the
218 // RO region and use them to alculate their location at runtime without storing
219 // the pointers in the RW region
220 char* CppVtables::_vtables_serialized_base = nullptr;
221 
222 void CppVtables::dumptime_init(ArchiveBuilder* builder) {
223   assert(CDSConfig::is_dumping_static_archive(), "cpp tables are only dumped into static archive");
224 
225   CPP_VTABLE_TYPES_DO(ALLOCATE_AND_INITIALIZE_VTABLE);
226 






227   size_t cpp_tables_size = builder->rw_region()->top() - builder->rw_region()->base();
228   builder->alloc_stats()->record_cpp_vtables((int)cpp_tables_size);
229 }
230 
231 void CppVtables::serialize(SerializeClosure* soc) {
232   if (!soc->reading()) {
233     _vtables_serialized_base = (char*)ArchiveBuilder::current()->buffer_top();
234   }
235   for (int i = 0; i < _num_cloned_vtable_kinds; i++) {
236     soc->do_ptr(&_index[i]);
237   }
238   if (soc->reading()) {
239     CPP_VTABLE_TYPES_DO(INITIALIZE_VTABLE);
240   }








241 }
242 
243 intptr_t* CppVtables::get_archived_vtable(MetaspaceObj::Type msotype, address obj) {
244   if (!_orig_cpp_vtptrs_inited) {
245     CPP_VTABLE_TYPES_DO(INIT_ORIG_CPP_VTPTRS);
246     _orig_cpp_vtptrs_inited = true;
247   }
248 
249   assert(CDSConfig::is_dumping_archive(), "sanity");
250   int kind = -1;
251   switch (msotype) {
252   case MetaspaceObj::SymbolType:
253   case MetaspaceObj::TypeArrayU1Type:
254   case MetaspaceObj::TypeArrayU2Type:
255   case MetaspaceObj::TypeArrayU4Type:
256   case MetaspaceObj::TypeArrayU8Type:
257   case MetaspaceObj::TypeArrayOtherType:
258   case MetaspaceObj::ConstMethodType:
259   case MetaspaceObj::ConstantPoolCacheType:
260   case MetaspaceObj::AnnotationsType:
261   case MetaspaceObj::MethodCountersType:
262   case MetaspaceObj::SharedClassPathEntryType:
263   case MetaspaceObj::RecordComponentType:
264     // These have no vtables.
265     break;
266   case MetaspaceObj::MethodDataType:
267     // We don't archive MethodData <-- should have been removed in removed_unsharable_info
268     ShouldNotReachHere();
269     break;
270   default:
271     for (kind = 0; kind < _num_cloned_vtable_kinds; kind ++) {
272       if (vtable_of((Metadata*)obj) == _orig_cpp_vtptrs[kind]) {

273         break;
274       }
275     }
276     if (kind >= _num_cloned_vtable_kinds) {
277       fatal("Cannot find C++ vtable for " INTPTR_FORMAT " -- you probably added"
278             " a new subtype of Klass or MetaData without updating CPP_VTABLE_TYPES_DO or the cases in this 'switch' statement",
279             p2i(obj));
280     }
281   }
282 
283   if (kind >= 0) {
284     assert(kind < _num_cloned_vtable_kinds, "must be");
285     return _index[kind]->cloned_vtable();
286   } else {
287     return nullptr;
288   }
289 }
290 
291 void CppVtables::zero_archived_vtables() {
292   assert(CDSConfig::is_dumping_static_archive(), "cpp tables are only dumped into static archive");

 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 #include "precompiled.hpp"
 26 #include "cds/archiveUtils.hpp"
 27 #include "cds/archiveBuilder.hpp"
 28 #include "cds/cdsConfig.hpp"
 29 #include "cds/cppVtables.hpp"
 30 #include "cds/metaspaceShared.hpp"
 31 #include "logging/log.hpp"
 32 #include "oops/instanceClassLoaderKlass.hpp"
 33 #include "oops/instanceMirrorKlass.hpp"
 34 #include "oops/instanceRefKlass.hpp"
 35 #include "oops/instanceStackChunkKlass.hpp"
 36 #include "oops/methodCounters.hpp"
 37 #include "oops/methodData.hpp"
 38 #include "oops/trainingData.hpp"
 39 #include "oops/objArrayKlass.hpp"
 40 #include "oops/typeArrayKlass.hpp"
 41 #include "runtime/arguments.hpp"
 42 #include "utilities/globalDefinitions.hpp"
 43 
 44 // Objects of the Metadata types (such as Klass and ConstantPool) have C++ vtables.
 45 // (In GCC this is the field <Type>::_vptr, i.e., first word in the object.)
 46 //
 47 // Addresses of the vtables and the methods may be different across JVM runs,
 48 // if libjvm.so is dynamically loaded at a different base address.
 49 //
 50 // To ensure that the Metadata objects in the CDS archive always have the correct vtable:
 51 //
 52 // + at dump time:  we redirect the _vptr to point to our own vtables inside
 53 //                  the CDS image
 54 // + at run time:   we clone the actual contents of the vtables from libjvm.so
 55 //                  into our own tables.
 56 
 57 // Currently, the archive contains ONLY the following types of objects that have C++ vtables.
 58 #define CPP_VTABLE_TYPES_DO(f) \
 59   f(ConstantPool) \
 60   f(InstanceKlass) \
 61   f(InstanceClassLoaderKlass) \
 62   f(InstanceMirrorKlass) \
 63   f(InstanceRefKlass) \
 64   f(InstanceStackChunkKlass) \
 65   f(Method) \
 66   f(MethodData)                \
 67   f(MethodCounters)            \
 68   f(ObjArrayKlass) \
 69   f(TypeArrayKlass)            \
 70   f(KlassTrainingData)         \
 71   f(MethodTrainingData)        \
 72   f(CompileTrainingData)
 73 
 74 class CppVtableInfo {
 75   intptr_t _vtable_size;
 76   intptr_t _cloned_vtable[1]; // Pseudo flexible array member.
 77   static size_t cloned_vtable_offset() { return offset_of(CppVtableInfo, _cloned_vtable); }
 78 public:
 79   int vtable_size()           { return int(uintx(_vtable_size)); }
 80   void set_vtable_size(int n) { _vtable_size = intptr_t(n); }
 81   // Using _cloned_vtable[i] for i > 0 causes undefined behavior. We use address calculation instead.
 82   intptr_t* cloned_vtable()   { return (intptr_t*)((char*)this + cloned_vtable_offset()); }
 83   void zero()                 { memset(cloned_vtable(), 0, sizeof(intptr_t) * vtable_size()); }
 84   // Returns the address of the next CppVtableInfo that can be placed immediately after this CppVtableInfo
 85   static size_t byte_size(int vtable_size) {
 86     return cloned_vtable_offset() + (sizeof(intptr_t) * vtable_size);
 87   }
 88 };
 89 
 90 static inline intptr_t* vtable_of(const Metadata* m) {
 91   return *((intptr_t**)m);
 92 }

184   ArchivePtrMarker::mark_pointer(&_index[c##_Kind]);
185 
186 #define INITIALIZE_VTABLE(c) \
187   CppVtableCloner<c>::initialize(#c, _index[c##_Kind]);
188 
189 #define INIT_ORIG_CPP_VTPTRS(c) \
190   CppVtableCloner<c>::init_orig_cpp_vtptr(c##_Kind);
191 
192 #define DECLARE_CLONED_VTABLE_KIND(c) c ## _Kind,
193 
194 enum ClonedVtableKind {
195   // E.g., ConstantPool_Kind == 0, InstanceKlass_Kind == 1, etc.
196   CPP_VTABLE_TYPES_DO(DECLARE_CLONED_VTABLE_KIND)
197   _num_cloned_vtable_kinds
198 };
199 
200 // This is a map of all the original vtptrs. E.g., for
201 //     ConstantPool *cp = new (...) ConstantPool(...) ; // a dynamically allocated constant pool
202 // the following holds true:
203 //     _orig_cpp_vtptrs[ConstantPool_Kind] ==  ((intptr_t**)cp)[0]
204 static intptr_t* _orig_cpp_vtptrs[_num_cloned_vtable_kinds];  // vtptrs set by the C++ compiler
205 static intptr_t* _archived_cpp_vtptrs[_num_cloned_vtable_kinds];  // vtptrs used in the static archive
206 static bool _orig_cpp_vtptrs_inited = false;
207 
208 template <class T>
209 void CppVtableCloner<T>::init_orig_cpp_vtptr(int kind) {
210   assert(kind < _num_cloned_vtable_kinds, "sanity");
211   T tmp; // Allocate temporary dummy metadata object to get to the original vtable.
212   intptr_t* srcvtable = vtable_of(&tmp);
213   _orig_cpp_vtptrs[kind] = srcvtable;
214 }
215 
216 // This is the index of all the cloned vtables. E.g., for
217 //     ConstantPool* cp = ....; // an archived constant pool
218 //     InstanceKlass* ik = ....;// an archived class
219 // the following holds true:
220 //     _index[ConstantPool_Kind]->cloned_vtable()  == ((intptr_t**)cp)[0]
221 //     _index[InstanceKlass_Kind]->cloned_vtable() == ((intptr_t**)ik)[0]
222 static CppVtableInfo* _index[_num_cloned_vtable_kinds];
223 
224 // Vtables are all fixed offsets from ArchiveBuilder::current()->mapped_base()
225 // E.g. ConstantPool is at offset 0x58. We can archive these offsets in the
226 // RO region and use them to alculate their location at runtime without storing
227 // the pointers in the RW region
228 char* CppVtables::_vtables_serialized_base = nullptr;
229 
230 void CppVtables::dumptime_init(ArchiveBuilder* builder) {
231   assert(CDSConfig::is_dumping_static_archive(), "cpp tables are only dumped into static archive");
232 
233   CPP_VTABLE_TYPES_DO(ALLOCATE_AND_INITIALIZE_VTABLE);
234 
235   if (!CDSConfig::is_dumping_final_static_archive()) {
236     for (int kind = 0; kind < _num_cloned_vtable_kinds; kind++) {
237       _archived_cpp_vtptrs[kind] = _index[kind]->cloned_vtable();
238     }
239   }
240 
241   size_t cpp_tables_size = builder->rw_region()->top() - builder->rw_region()->base();
242   builder->alloc_stats()->record_cpp_vtables((int)cpp_tables_size);
243 }
244 
245 void CppVtables::serialize(SerializeClosure* soc) {
246   if (!soc->reading()) {
247     _vtables_serialized_base = (char*)ArchiveBuilder::current()->buffer_top();
248   }
249   for (int i = 0; i < _num_cloned_vtable_kinds; i++) {
250     soc->do_ptr(&_index[i]);
251   }
252   if (soc->reading()) {
253     CPP_VTABLE_TYPES_DO(INITIALIZE_VTABLE);
254   }
255 
256   if (soc->writing() && CDSConfig::is_dumping_final_static_archive()) {
257     memset(_archived_cpp_vtptrs, 0, sizeof(_archived_cpp_vtptrs));
258   }
259 
260   for (int kind = 0; kind < _num_cloned_vtable_kinds; kind++) {
261     soc->do_ptr(&_archived_cpp_vtptrs[kind]);
262   }
263 }
264 
265 intptr_t* CppVtables::get_archived_vtable(MetaspaceObj::Type msotype, address obj) {
266   if (!_orig_cpp_vtptrs_inited) {
267     CPP_VTABLE_TYPES_DO(INIT_ORIG_CPP_VTPTRS);
268     _orig_cpp_vtptrs_inited = true;
269   }
270 
271   assert(CDSConfig::is_dumping_archive(), "sanity");
272   int kind = -1;
273   switch (msotype) {
274   case MetaspaceObj::SymbolType:
275   case MetaspaceObj::TypeArrayU1Type:
276   case MetaspaceObj::TypeArrayU2Type:
277   case MetaspaceObj::TypeArrayU4Type:
278   case MetaspaceObj::TypeArrayU8Type:
279   case MetaspaceObj::TypeArrayOtherType:
280   case MetaspaceObj::ConstMethodType:
281   case MetaspaceObj::ConstantPoolCacheType:
282   case MetaspaceObj::AnnotationsType:

283   case MetaspaceObj::SharedClassPathEntryType:
284   case MetaspaceObj::RecordComponentType:
285     // These have no vtables.
286     break;




287   default:
288     for (kind = 0; kind < _num_cloned_vtable_kinds; kind ++) {
289       if (vtable_of((Metadata*)obj) == _orig_cpp_vtptrs[kind] ||
290           vtable_of((Metadata*)obj) == _archived_cpp_vtptrs[kind]) {
291         break;
292       }
293     }
294     if (kind >= _num_cloned_vtable_kinds) {
295       fatal("Cannot find C++ vtable for " INTPTR_FORMAT " -- you probably added"
296             " a new subtype of Klass or MetaData without updating CPP_VTABLE_TYPES_DO or the cases in this 'switch' statement",
297             p2i(obj));
298     }
299   }
300 
301   if (kind >= 0) {
302     assert(kind < _num_cloned_vtable_kinds, "must be");
303     return _index[kind]->cloned_vtable();
304   } else {
305     return nullptr;
306   }
307 }
308 
309 void CppVtables::zero_archived_vtables() {
310   assert(CDSConfig::is_dumping_static_archive(), "cpp tables are only dumped into static archive");
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