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 "classfile/classFileStream.hpp"
26 #include "classfile/classLoader.hpp"
27 #include "classfile/classLoadInfo.hpp"
28 #include "classfile/javaClasses.inline.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "classfile/vmSymbols.hpp"
31 #include "jfr/jfrEvents.hpp"
32 #include "jni.h"
33 #include "jvm.h"
34 #include "memory/allocation.inline.hpp"
35 #include "memory/resourceArea.hpp"
36 #include "oops/access.inline.hpp"
37 #include "oops/fieldStreams.inline.hpp"
38 #include "oops/instanceKlass.inline.hpp"
39 #include "oops/klass.inline.hpp"
40 #include "oops/objArrayOop.inline.hpp"
41 #include "oops/oop.inline.hpp"
42 #include "oops/typeArrayOop.inline.hpp"
43 #include "prims/jvmtiExport.hpp"
44 #include "prims/unsafe.hpp"
45 #include "runtime/globals.hpp"
46 #include "runtime/handles.inline.hpp"
47 #include "runtime/interfaceSupport.inline.hpp"
48 #include "runtime/javaThread.inline.hpp"
49 #include "runtime/jniHandles.inline.hpp"
50 #include "runtime/orderAccess.hpp"
51 #include "runtime/reflection.hpp"
52 #include "runtime/sharedRuntime.hpp"
53 #include "runtime/stubRoutines.hpp"
54 #include "runtime/threadSMR.hpp"
55 #include "runtime/vmOperations.hpp"
56 #include "runtime/vm_version.hpp"
57 #include "sanitizers/ub.hpp"
58 #include "services/threadService.hpp"
59 #include "utilities/align.hpp"
60 #include "utilities/copy.hpp"
61 #include "utilities/dtrace.hpp"
62 #include "utilities/macros.hpp"
63
64 /**
151 }
152 #endif
153 }
154
155 static inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
156 assert_field_offset_sane(p, field_offset);
157 uintptr_t base_address = cast_from_oop<uintptr_t>(p);
158 uintptr_t byte_offset = (uintptr_t)field_offset_to_byte_offset(field_offset);
159 return (void*)(base_address + byte_offset);
160 }
161
162 // Externally callable versions:
163 // (Use these in compiler intrinsics which emulate unsafe primitives.)
164 jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) {
165 return field_offset;
166 }
167 jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
168 return byte_offset;
169 }
170
171
172 ///// Data read/writes on the Java heap and in native (off-heap) memory
173
174 /**
175 * Helper class to wrap memory accesses in JavaThread::doing_unsafe_access()
176 */
177 class GuardUnsafeAccess {
178 JavaThread* _thread;
179
180 public:
181 GuardUnsafeAccess(JavaThread* thread) : _thread(thread) {
182 // native/off-heap access which may raise SIGBUS if accessing
183 // memory mapped file data in a region of the file which has
184 // been truncated and is now invalid.
185 _thread->set_doing_unsafe_access(true);
186 }
187
188 ~GuardUnsafeAccess() {
189 _thread->set_doing_unsafe_access(false);
190 }
191 };
230 jboolean normalize_for_read(jboolean x) {
231 return x != 0;
232 }
233
234 public:
235 MemoryAccess(JavaThread* thread, jobject obj, jlong offset)
236 : _thread(thread), _obj(JNIHandles::resolve(obj)), _offset((ptrdiff_t)offset) {
237 assert_field_offset_sane(_obj, offset);
238 }
239
240 T get() {
241 GuardUnsafeAccess guard(_thread);
242 return normalize_for_read(*addr());
243 }
244
245 // we use this method at some places for writing to 0 e.g. to cause a crash;
246 // ubsan does not know that this is the desired behavior
247 ATTRIBUTE_NO_UBSAN
248 void put(T x) {
249 GuardUnsafeAccess guard(_thread);
250 *addr() = normalize_for_write(x);
251 }
252
253
254 T get_volatile() {
255 GuardUnsafeAccess guard(_thread);
256 volatile T ret = RawAccess<MO_SEQ_CST>::load(addr());
257 return normalize_for_read(ret);
258 }
259
260 void put_volatile(T x) {
261 GuardUnsafeAccess guard(_thread);
262 RawAccess<MO_SEQ_CST>::store(addr(), normalize_for_write(x));
263 }
264 };
265
266 // These functions allow a null base pointer with an arbitrary address.
267 // But if the base pointer is non-null, the offset should make some sense.
268 // That is, it should be in the range [0, MAX_OBJECT_SIZE].
269 UNSAFE_ENTRY(jobject, Unsafe_GetReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
270 oop p = JNIHandles::resolve(obj);
271 assert_field_offset_sane(p, offset);
272 oop v = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset);
273 return JNIHandles::make_local(THREAD, v);
274 } UNSAFE_END
275
276 UNSAFE_ENTRY(void, Unsafe_PutReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
277 oop x = JNIHandles::resolve(x_h);
278 oop p = JNIHandles::resolve(obj);
279 assert_field_offset_sane(p, offset);
280 HeapAccess<ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x);
281 } UNSAFE_END
282
283 UNSAFE_ENTRY(jobject, Unsafe_GetReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
284 oop p = JNIHandles::resolve(obj);
285 assert_field_offset_sane(p, offset);
286 oop v = HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset);
287 return JNIHandles::make_local(THREAD, v);
288 } UNSAFE_END
289
290 UNSAFE_ENTRY(void, Unsafe_PutReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
291 oop x = JNIHandles::resolve(x_h);
292 oop p = JNIHandles::resolve(obj);
293 assert_field_offset_sane(p, offset);
294 HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x);
295 } UNSAFE_END
296
297 UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr)) {
298 oop v = *(oop*) (address) addr;
299 return JNIHandles::make_local(THREAD, v);
300 } UNSAFE_END
301
302 #define DEFINE_GETSETOOP(java_type, Type) \
583 return false;
584 }
585 UNSAFE_END
586
587 static void getBaseAndScale(int& base, int& scale, jclass clazz, TRAPS) {
588 assert(clazz != nullptr, "clazz must not be null");
589
590 oop mirror = JNIHandles::resolve_non_null(clazz);
591 Klass* k = java_lang_Class::as_Klass(mirror);
592
593 if (k == nullptr || !k->is_array_klass()) {
594 THROW(vmSymbols::java_lang_InvalidClassException());
595 } else if (k->is_objArray_klass()) {
596 base = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
597 scale = heapOopSize;
598 } else if (k->is_typeArray_klass()) {
599 TypeArrayKlass* tak = TypeArrayKlass::cast(k);
600 base = tak->array_header_in_bytes();
601 assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
602 scale = (1 << tak->log2_element_size());
603 } else {
604 ShouldNotReachHere();
605 }
606 }
607
608 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset0(JNIEnv *env, jobject unsafe, jclass clazz)) {
609 int base = 0, scale = 0;
610 getBaseAndScale(base, scale, clazz, CHECK_0);
611
612 return field_offset_from_byte_offset(base);
613 } UNSAFE_END
614
615
616 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale0(JNIEnv *env, jobject unsafe, jclass clazz)) {
617 int base = 0, scale = 0;
618 getBaseAndScale(base, scale, clazz, CHECK_0);
619
620 // This VM packs both fields and array elements down to the byte.
621 // But watch out: If this changes, so that array references for
622 // a given primitive type (say, T_BOOLEAN) use different memory units
623 // than fields, this method MUST return zero for such arrays.
624 // For example, the VM used to store sub-word sized fields in full
625 // words in the object layout, so that accessors like getByte(Object,int)
626 // did not really do what one might expect for arrays. Therefore,
627 // this function used to report a zero scale factor, so that the user
628 // would know not to attempt to access sub-word array elements.
629 // // Code for unpacked fields:
630 // if (scale < wordSize) return 0;
631
632 // The following allows for a pretty general fieldOffset cookie scheme,
633 // but requires it to be linear in byte offset.
634 return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
635 } UNSAFE_END
636
637
638 static inline void throw_new(JNIEnv *env, const char *ename) {
639 jclass cls = env->FindClass(ename);
640 if (env->ExceptionCheck()) {
641 env->ExceptionClear();
642 tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", ename);
643 return;
644 }
645
646 env->ThrowNew(cls, nullptr);
647 }
648
649 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
650 // Code lifted from JDK 1.3 ClassLoader.c
651
652 jbyte *body;
653 char *utfName = nullptr;
654 jclass result = nullptr;
655 char buf[128];
656
657 assert(data != nullptr, "Class bytes must not be null");
837
838
839 /// JVM_RegisterUnsafeMethods
840
841 #define ADR "J"
842
843 #define LANG "Ljava/lang/"
844
845 #define OBJ LANG "Object;"
846 #define CLS LANG "Class;"
847 #define FLD LANG "reflect/Field;"
848 #define THR LANG "Throwable;"
849
850 #define DC_Args LANG "String;[BII" LANG "ClassLoader;" "Ljava/security/ProtectionDomain;"
851 #define DAC_Args CLS "[B[" OBJ
852
853 #define CC (char*) /*cast a literal from (const char*)*/
854 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
855
856 #define DECLARE_GETPUTOOP(Type, Desc) \
857 {CC "get" #Type, CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type)}, \
858 {CC "put" #Type, CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type)}, \
859 {CC "get" #Type "Volatile", CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type##Volatile)}, \
860 {CC "put" #Type "Volatile", CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type##Volatile)}
861
862
863 static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = {
864 {CC "getReference", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetReference)},
865 {CC "putReference", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReference)},
866 {CC "getReferenceVolatile", CC "(" OBJ "J)" OBJ, FN_PTR(Unsafe_GetReferenceVolatile)},
867 {CC "putReferenceVolatile", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReferenceVolatile)},
868
869 {CC "getUncompressedObject", CC "(" ADR ")" OBJ, FN_PTR(Unsafe_GetUncompressedObject)},
870
871 DECLARE_GETPUTOOP(Boolean, Z),
872 DECLARE_GETPUTOOP(Byte, B),
873 DECLARE_GETPUTOOP(Short, S),
874 DECLARE_GETPUTOOP(Char, C),
875 DECLARE_GETPUTOOP(Int, I),
876 DECLARE_GETPUTOOP(Long, J),
877 DECLARE_GETPUTOOP(Float, F),
878 DECLARE_GETPUTOOP(Double, D),
879
880 {CC "allocateMemory0", CC "(J)" ADR, FN_PTR(Unsafe_AllocateMemory0)},
881 {CC "reallocateMemory0", CC "(" ADR "J)" ADR, FN_PTR(Unsafe_ReallocateMemory0)},
882 {CC "freeMemory0", CC "(" ADR ")V", FN_PTR(Unsafe_FreeMemory0)},
883
884 {CC "objectFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_ObjectFieldOffset0)},
885 {CC "objectFieldOffset1", CC "(" CLS LANG "String;)J", FN_PTR(Unsafe_ObjectFieldOffset1)},
886 {CC "staticFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_StaticFieldOffset0)},
887 {CC "staticFieldBase0", CC "(" FLD ")" OBJ, FN_PTR(Unsafe_StaticFieldBase0)},
888 {CC "ensureClassInitialized0", CC "(" CLS ")V", FN_PTR(Unsafe_EnsureClassInitialized0)},
889 {CC "arrayBaseOffset0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayBaseOffset0)},
890 {CC "arrayIndexScale0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayIndexScale0)},
891
892 {CC "defineClass0", CC "(" DC_Args ")" CLS, FN_PTR(Unsafe_DefineClass0)},
893 {CC "allocateInstance", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_AllocateInstance)},
894 {CC "throwException", CC "(" THR ")V", FN_PTR(Unsafe_ThrowException)},
895 {CC "compareAndSetReference",CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSetReference)},
896 {CC "compareAndSetInt", CC "(" OBJ "J""I""I"")Z", FN_PTR(Unsafe_CompareAndSetInt)},
897 {CC "compareAndSetLong", CC "(" OBJ "J""J""J"")Z", FN_PTR(Unsafe_CompareAndSetLong)},
898 {CC "compareAndExchangeReference", CC "(" OBJ "J" OBJ "" OBJ ")" OBJ, FN_PTR(Unsafe_CompareAndExchangeReference)},
899 {CC "compareAndExchangeInt", CC "(" OBJ "J""I""I"")I", FN_PTR(Unsafe_CompareAndExchangeInt)},
900 {CC "compareAndExchangeLong", CC "(" OBJ "J""J""J"")J", FN_PTR(Unsafe_CompareAndExchangeLong)},
901
902 {CC "park", CC "(ZJ)V", FN_PTR(Unsafe_Park)},
903 {CC "unpark", CC "(" OBJ ")V", FN_PTR(Unsafe_Unpark)},
904
905 {CC "getLoadAverage0", CC "([DI)I", FN_PTR(Unsafe_GetLoadAverage0)},
906
907 {CC "copyMemory0", CC "(" OBJ "J" OBJ "JJ)V", FN_PTR(Unsafe_CopyMemory0)},
908 {CC "copySwapMemory0", CC "(" OBJ "J" OBJ "JJJ)V", FN_PTR(Unsafe_CopySwapMemory0)},
909 {CC "writeback0", CC "(" "J" ")V", FN_PTR(Unsafe_WriteBack0)},
910 {CC "writebackPreSync0", CC "()V", FN_PTR(Unsafe_WriteBackPreSync0)},
|
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 "classfile/classFileStream.hpp"
26 #include "classfile/classLoader.hpp"
27 #include "classfile/classLoadInfo.hpp"
28 #include "classfile/javaClasses.inline.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "classfile/vmSymbols.hpp"
31 #include "jfr/jfrEvents.hpp"
32 #include "jni.h"
33 #include "jvm.h"
34 #include "memory/allocation.inline.hpp"
35 #include "memory/resourceArea.hpp"
36 #include "logging/log.hpp"
37 #include "logging/logStream.hpp"
38 #include "oops/access.inline.hpp"
39 #include "oops/fieldStreams.inline.hpp"
40 #include "oops/flatArrayKlass.hpp"
41 #include "oops/flatArrayOop.inline.hpp"
42 #include "oops/inlineKlass.inline.hpp"
43 #include "oops/instanceKlass.inline.hpp"
44 #include "oops/klass.inline.hpp"
45 #include "oops/objArrayOop.inline.hpp"
46 #include "oops/oop.inline.hpp"
47 #include "oops/typeArrayOop.inline.hpp"
48 #include "prims/jvmtiExport.hpp"
49 #include "prims/unsafe.hpp"
50 #include "runtime/fieldDescriptor.inline.hpp"
51 #include "runtime/globals.hpp"
52 #include "runtime/handles.inline.hpp"
53 #include "runtime/interfaceSupport.inline.hpp"
54 #include "runtime/javaThread.inline.hpp"
55 #include "runtime/jniHandles.inline.hpp"
56 #include "runtime/orderAccess.hpp"
57 #include "runtime/reflection.hpp"
58 #include "runtime/sharedRuntime.hpp"
59 #include "runtime/stubRoutines.hpp"
60 #include "runtime/threadSMR.hpp"
61 #include "runtime/vmOperations.hpp"
62 #include "runtime/vm_version.hpp"
63 #include "sanitizers/ub.hpp"
64 #include "services/threadService.hpp"
65 #include "utilities/align.hpp"
66 #include "utilities/copy.hpp"
67 #include "utilities/dtrace.hpp"
68 #include "utilities/macros.hpp"
69
70 /**
157 }
158 #endif
159 }
160
161 static inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
162 assert_field_offset_sane(p, field_offset);
163 uintptr_t base_address = cast_from_oop<uintptr_t>(p);
164 uintptr_t byte_offset = (uintptr_t)field_offset_to_byte_offset(field_offset);
165 return (void*)(base_address + byte_offset);
166 }
167
168 // Externally callable versions:
169 // (Use these in compiler intrinsics which emulate unsafe primitives.)
170 jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) {
171 return field_offset;
172 }
173 jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
174 return byte_offset;
175 }
176
177 ///// Data read/writes on the Java heap and in native (off-heap) memory
178
179 /**
180 * Helper class to wrap memory accesses in JavaThread::doing_unsafe_access()
181 */
182 class GuardUnsafeAccess {
183 JavaThread* _thread;
184
185 public:
186 GuardUnsafeAccess(JavaThread* thread) : _thread(thread) {
187 // native/off-heap access which may raise SIGBUS if accessing
188 // memory mapped file data in a region of the file which has
189 // been truncated and is now invalid.
190 _thread->set_doing_unsafe_access(true);
191 }
192
193 ~GuardUnsafeAccess() {
194 _thread->set_doing_unsafe_access(false);
195 }
196 };
235 jboolean normalize_for_read(jboolean x) {
236 return x != 0;
237 }
238
239 public:
240 MemoryAccess(JavaThread* thread, jobject obj, jlong offset)
241 : _thread(thread), _obj(JNIHandles::resolve(obj)), _offset((ptrdiff_t)offset) {
242 assert_field_offset_sane(_obj, offset);
243 }
244
245 T get() {
246 GuardUnsafeAccess guard(_thread);
247 return normalize_for_read(*addr());
248 }
249
250 // we use this method at some places for writing to 0 e.g. to cause a crash;
251 // ubsan does not know that this is the desired behavior
252 ATTRIBUTE_NO_UBSAN
253 void put(T x) {
254 GuardUnsafeAccess guard(_thread);
255 assert(_obj == nullptr || !_obj->is_inline_type() || _obj->mark().is_larval_state(), "must be an object instance or a larval inline type");
256 *addr() = normalize_for_write(x);
257 }
258
259 T get_volatile() {
260 GuardUnsafeAccess guard(_thread);
261 volatile T ret = RawAccess<MO_SEQ_CST>::load(addr());
262 return normalize_for_read(ret);
263 }
264
265 void put_volatile(T x) {
266 GuardUnsafeAccess guard(_thread);
267 RawAccess<MO_SEQ_CST>::store(addr(), normalize_for_write(x));
268 }
269 };
270
271 #ifdef ASSERT
272 /*
273 * Get the field descriptor of the field of the given object at the given offset.
274 */
275 static bool get_field_descriptor(oop p, jlong offset, fieldDescriptor* fd) {
276 bool found = false;
277 Klass* k = p->klass();
278 if (k->is_instance_klass()) {
279 InstanceKlass* ik = InstanceKlass::cast(k);
280 found = ik->find_field_from_offset((int)offset, false, fd);
281 if (!found && ik->is_mirror_instance_klass()) {
282 Klass* k2 = java_lang_Class::as_Klass(p);
283 if (k2->is_instance_klass()) {
284 ik = InstanceKlass::cast(k2);
285 found = ik->find_field_from_offset((int)offset, true, fd);
286 }
287 }
288 }
289 return found;
290 }
291 #endif // ASSERT
292
293 static void assert_and_log_unsafe_value_access(oop p, jlong offset, InlineKlass* vk) {
294 Klass* k = p->klass();
295 #ifdef ASSERT
296 if (k->is_instance_klass()) {
297 assert_field_offset_sane(p, offset);
298 fieldDescriptor fd;
299 bool found = get_field_descriptor(p, offset, &fd);
300 if (found) {
301 assert(found, "value field not found");
302 assert(fd.is_flat(), "field not flat");
303 } else {
304 if (log_is_enabled(Trace, valuetypes)) {
305 log_trace(valuetypes)("not a field in %s at offset " UINT64_FORMAT_X,
306 p->klass()->external_name(), (uint64_t)offset);
307 }
308 }
309 } else if (k->is_flatArray_klass()) {
310 FlatArrayKlass* vak = FlatArrayKlass::cast(k);
311 int index = (offset - vak->array_header_in_bytes()) / vak->element_byte_size();
312 address dest = (address)((flatArrayOop)p)->value_at_addr(index, vak->layout_helper());
313 assert(dest == (cast_from_oop<address>(p) + offset), "invalid offset");
314 } else {
315 ShouldNotReachHere();
316 }
317 #endif // ASSERT
318 if (log_is_enabled(Trace, valuetypes)) {
319 if (k->is_flatArray_klass()) {
320 FlatArrayKlass* vak = FlatArrayKlass::cast(k);
321 int index = (offset - vak->array_header_in_bytes()) / vak->element_byte_size();
322 address dest = (address)((flatArrayOop)p)->value_at_addr(index, vak->layout_helper());
323 log_trace(valuetypes)("%s array type %s index %d element size %d offset " UINT64_FORMAT_X " at " INTPTR_FORMAT,
324 p->klass()->external_name(), vak->external_name(),
325 index, vak->element_byte_size(), (uint64_t)offset, p2i(dest));
326 } else {
327 log_trace(valuetypes)("%s field type %s at offset " UINT64_FORMAT_X,
328 p->klass()->external_name(), vk->external_name(), (uint64_t)offset);
329 }
330 }
331 }
332
333 // These functions allow a null base pointer with an arbitrary address.
334 // But if the base pointer is non-null, the offset should make some sense.
335 // That is, it should be in the range [0, MAX_OBJECT_SIZE].
336 UNSAFE_ENTRY(jobject, Unsafe_GetReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
337 oop p = JNIHandles::resolve(obj);
338 assert_field_offset_sane(p, offset);
339 oop v = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset);
340 return JNIHandles::make_local(THREAD, v);
341 } UNSAFE_END
342
343 UNSAFE_ENTRY(void, Unsafe_PutReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
344 oop x = JNIHandles::resolve(x_h);
345 oop p = JNIHandles::resolve(obj);
346 assert_field_offset_sane(p, offset);
347 assert(!p->is_inline_type() || p->mark().is_larval_state(), "must be an object instance or a larval inline type");
348 HeapAccess<ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x);
349 } UNSAFE_END
350
351 UNSAFE_ENTRY(jlong, Unsafe_ValueHeaderSize(JNIEnv *env, jobject unsafe, jclass c)) {
352 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(c));
353 InlineKlass* vk = InlineKlass::cast(k);
354 return vk->payload_offset();
355 } UNSAFE_END
356
357 UNSAFE_ENTRY(jboolean, Unsafe_IsFlatField(JNIEnv *env, jobject unsafe, jobject o)) {
358 oop f = JNIHandles::resolve_non_null(o);
359 Klass* k = java_lang_Class::as_Klass(java_lang_reflect_Field::clazz(f));
360 int slot = java_lang_reflect_Field::slot(f);
361 return InstanceKlass::cast(k)->field_is_flat(slot);
362 } UNSAFE_END
363
364 UNSAFE_ENTRY(jboolean, Unsafe_HasNullMarker(JNIEnv *env, jobject unsafe, jobject o)) {
365 oop f = JNIHandles::resolve_non_null(o);
366 Klass* k = java_lang_Class::as_Klass(java_lang_reflect_Field::clazz(f));
367 int slot = java_lang_reflect_Field::slot(f);
368 return InstanceKlass::cast(k)->field_has_null_marker(slot);
369 } UNSAFE_END
370
371 UNSAFE_ENTRY(jint, Unsafe_NullMarkerOffset(JNIEnv *env, jobject unsafe, jobject o)) {
372 oop f = JNIHandles::resolve_non_null(o);
373 Klass* k = java_lang_Class::as_Klass(java_lang_reflect_Field::clazz(f));
374 int slot = java_lang_reflect_Field::slot(f);
375 return InstanceKlass::cast(k)->null_marker_offset(slot);
376 } UNSAFE_END
377
378 UNSAFE_ENTRY(jint, Unsafe_ArrayLayout(JNIEnv *env, jobject unsafe, jclass c)) {
379 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(c));
380 if (!k->is_flatArray_klass()) {
381 return (jint)LayoutKind::REFERENCE;
382 } else {
383 return (jint)FlatArrayKlass::cast(k)->layout_kind();
384 }
385 } UNSAFE_END
386
387 UNSAFE_ENTRY(jint, Unsafe_FieldLayout(JNIEnv *env, jobject unsafe, jobject field)) {
388 assert(field != nullptr, "field must not be null");
389
390 oop reflected = JNIHandles::resolve_non_null(field);
391 oop mirror = java_lang_reflect_Field::clazz(reflected);
392 Klass* k = java_lang_Class::as_Klass(mirror);
393 int slot = java_lang_reflect_Field::slot(reflected);
394 int modifiers = java_lang_reflect_Field::modifiers(reflected);
395
396 if ((modifiers & JVM_ACC_STATIC) != 0) {
397 return (jint)LayoutKind::REFERENCE; // static fields are never flat
398 } else {
399 InstanceKlass* ik = InstanceKlass::cast(k);
400 if (ik->field_is_flat(slot)) {
401 return (jint)ik->inline_layout_info(slot).kind();
402 } else {
403 return (jint)LayoutKind::REFERENCE;
404 }
405 }
406 } UNSAFE_END
407
408 UNSAFE_ENTRY(jboolean, Unsafe_IsFlatArray(JNIEnv *env, jobject unsafe, jclass c)) {
409 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(c));
410 return k->is_flatArray_klass();
411 } UNSAFE_END
412
413 UNSAFE_ENTRY(jobject, Unsafe_UninitializedDefaultValue(JNIEnv *env, jobject unsafe, jclass vc)) {
414 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(vc));
415 InlineKlass* vk = InlineKlass::cast(k);
416 oop v = vk->default_value();
417 return JNIHandles::make_local(THREAD, v);
418 } UNSAFE_END
419
420 UNSAFE_ENTRY(jobject, Unsafe_GetValue(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jclass vc)) {
421 oop base = JNIHandles::resolve(obj);
422 if (base == nullptr) {
423 THROW_NULL(vmSymbols::java_lang_NullPointerException());
424 }
425 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(vc));
426 InlineKlass* vk = InlineKlass::cast(k);
427 assert_and_log_unsafe_value_access(base, offset, vk);
428 LayoutKind lk = LayoutKind::UNKNOWN;
429 if (base->is_array()) {
430 FlatArrayKlass* fak = FlatArrayKlass::cast(base->klass());
431 lk = fak->layout_kind();
432 } else {
433 fieldDescriptor fd;
434 InstanceKlass::cast(base->klass())->find_field_from_offset(offset, false, &fd);
435 lk = fd.field_holder()->inline_layout_info(fd.index()).kind();
436 }
437 Handle base_h(THREAD, base);
438 oop v = vk->read_payload_from_addr(base_h(), offset, lk, CHECK_NULL);
439 return JNIHandles::make_local(THREAD, v);
440 } UNSAFE_END
441
442 UNSAFE_ENTRY(jobject, Unsafe_GetFlatValue(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint layoutKind, jclass vc)) {
443 assert(layoutKind != (int)LayoutKind::REFERENCE, "This method handles only flat layouts");
444 oop base = JNIHandles::resolve(obj);
445 if (base == nullptr) {
446 THROW_NULL(vmSymbols::java_lang_NullPointerException());
447 }
448 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(vc));
449 InlineKlass* vk = InlineKlass::cast(k);
450 assert_and_log_unsafe_value_access(base, offset, vk);
451 LayoutKind lk = (LayoutKind)layoutKind;
452 Handle base_h(THREAD, base);
453 oop v = vk->read_payload_from_addr(base_h(), offset, lk, CHECK_NULL);
454 return JNIHandles::make_local(THREAD, v);
455 } UNSAFE_END
456
457 UNSAFE_ENTRY(void, Unsafe_PutValue(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jclass vc, jobject value)) {
458 oop base = JNIHandles::resolve(obj);
459 if (base == nullptr) {
460 THROW(vmSymbols::java_lang_NullPointerException());
461 }
462 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(vc));
463 InlineKlass* vk = InlineKlass::cast(k);
464 assert(!base->is_inline_type() || base->mark().is_larval_state(), "must be an object instance or a larval inline type");
465 assert_and_log_unsafe_value_access(base, offset, vk);
466 LayoutKind lk = LayoutKind::UNKNOWN;
467 if (base->is_array()) {
468 FlatArrayKlass* fak = FlatArrayKlass::cast(base->klass());
469 lk = fak->layout_kind();
470 } else {
471 fieldDescriptor fd;
472 InstanceKlass::cast(base->klass())->find_field_from_offset(offset, false, &fd);
473 lk = fd.field_holder()->inline_layout_info(fd.index()).kind();
474 }
475 oop v = JNIHandles::resolve(value);
476 vk->write_value_to_addr(v, ((char*)(oopDesc*)base) + offset, lk, true, CHECK);
477 } UNSAFE_END
478
479 UNSAFE_ENTRY(void, Unsafe_PutFlatValue(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint layoutKind, jclass vc, jobject value)) {
480 assert(layoutKind != (int)LayoutKind::REFERENCE, "This method handles only flat layouts");
481 oop base = JNIHandles::resolve(obj);
482 if (base == nullptr) {
483 THROW(vmSymbols::java_lang_NullPointerException());
484 }
485 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(vc));
486 InlineKlass* vk = InlineKlass::cast(k);
487 assert(!base->is_inline_type() || base->mark().is_larval_state(), "must be an object instance or a larval inline type");
488 assert_and_log_unsafe_value_access(base, offset, vk);
489 LayoutKind lk = (LayoutKind)layoutKind;
490 oop v = JNIHandles::resolve(value);
491 vk->write_value_to_addr(v, ((char*)(oopDesc*)base) + offset, lk, true, CHECK);
492 } UNSAFE_END
493
494 UNSAFE_ENTRY(jobject, Unsafe_MakePrivateBuffer(JNIEnv *env, jobject unsafe, jobject value)) {
495 oop v = JNIHandles::resolve_non_null(value);
496 assert(v->is_inline_type(), "must be an inline type instance");
497 Handle vh(THREAD, v);
498 InlineKlass* vk = InlineKlass::cast(v->klass());
499 instanceOop new_value = vk->allocate_instance_buffer(CHECK_NULL);
500 vk->copy_payload_to_addr(vk->payload_addr(vh()), vk->payload_addr(new_value), LayoutKind::BUFFERED, false);
501 markWord mark = new_value->mark();
502 new_value->set_mark(mark.enter_larval_state());
503 return JNIHandles::make_local(THREAD, new_value);
504 } UNSAFE_END
505
506 UNSAFE_ENTRY(jobject, Unsafe_FinishPrivateBuffer(JNIEnv *env, jobject unsafe, jobject value)) {
507 oop v = JNIHandles::resolve(value);
508 assert(v->mark().is_larval_state(), "must be a larval value");
509 markWord mark = v->mark();
510 v->set_mark(mark.exit_larval_state());
511 return JNIHandles::make_local(THREAD, v);
512 } UNSAFE_END
513
514 UNSAFE_ENTRY(jobject, Unsafe_GetReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
515 oop p = JNIHandles::resolve(obj);
516 assert_field_offset_sane(p, offset);
517 oop v = HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset);
518 return JNIHandles::make_local(THREAD, v);
519 } UNSAFE_END
520
521 UNSAFE_ENTRY(void, Unsafe_PutReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
522 oop x = JNIHandles::resolve(x_h);
523 oop p = JNIHandles::resolve(obj);
524 assert_field_offset_sane(p, offset);
525 HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x);
526 } UNSAFE_END
527
528 UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr)) {
529 oop v = *(oop*) (address) addr;
530 return JNIHandles::make_local(THREAD, v);
531 } UNSAFE_END
532
533 #define DEFINE_GETSETOOP(java_type, Type) \
814 return false;
815 }
816 UNSAFE_END
817
818 static void getBaseAndScale(int& base, int& scale, jclass clazz, TRAPS) {
819 assert(clazz != nullptr, "clazz must not be null");
820
821 oop mirror = JNIHandles::resolve_non_null(clazz);
822 Klass* k = java_lang_Class::as_Klass(mirror);
823
824 if (k == nullptr || !k->is_array_klass()) {
825 THROW(vmSymbols::java_lang_InvalidClassException());
826 } else if (k->is_objArray_klass()) {
827 base = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
828 scale = heapOopSize;
829 } else if (k->is_typeArray_klass()) {
830 TypeArrayKlass* tak = TypeArrayKlass::cast(k);
831 base = tak->array_header_in_bytes();
832 assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
833 scale = (1 << tak->log2_element_size());
834 } else if (k->is_flatArray_klass()) {
835 FlatArrayKlass* vak = FlatArrayKlass::cast(k);
836 InlineKlass* vklass = vak->element_klass();
837 base = vak->array_header_in_bytes();
838 scale = vak->element_byte_size();
839 } else {
840 ShouldNotReachHere();
841 }
842 }
843
844 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset0(JNIEnv *env, jobject unsafe, jclass clazz)) {
845 int base = 0, scale = 0;
846 getBaseAndScale(base, scale, clazz, CHECK_0);
847
848 return field_offset_from_byte_offset(base);
849 } UNSAFE_END
850
851
852 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale0(JNIEnv *env, jobject unsafe, jclass clazz)) {
853 int base = 0, scale = 0;
854 getBaseAndScale(base, scale, clazz, CHECK_0);
855
856 // This VM packs both fields and array elements down to the byte.
857 // But watch out: If this changes, so that array references for
858 // a given primitive type (say, T_BOOLEAN) use different memory units
859 // than fields, this method MUST return zero for such arrays.
860 // For example, the VM used to store sub-word sized fields in full
861 // words in the object layout, so that accessors like getByte(Object,int)
862 // did not really do what one might expect for arrays. Therefore,
863 // this function used to report a zero scale factor, so that the user
864 // would know not to attempt to access sub-word array elements.
865 // // Code for unpacked fields:
866 // if (scale < wordSize) return 0;
867
868 // The following allows for a pretty general fieldOffset cookie scheme,
869 // but requires it to be linear in byte offset.
870 return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
871 } UNSAFE_END
872
873
874 UNSAFE_ENTRY(jlong, Unsafe_GetObjectSize0(JNIEnv* env, jobject o, jobject obj))
875 oop p = JNIHandles::resolve(obj);
876 return p->size() * HeapWordSize;
877 UNSAFE_END
878
879
880 static inline void throw_new(JNIEnv *env, const char *ename) {
881 jclass cls = env->FindClass(ename);
882 if (env->ExceptionCheck()) {
883 env->ExceptionClear();
884 tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", ename);
885 return;
886 }
887
888 env->ThrowNew(cls, nullptr);
889 }
890
891 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
892 // Code lifted from JDK 1.3 ClassLoader.c
893
894 jbyte *body;
895 char *utfName = nullptr;
896 jclass result = nullptr;
897 char buf[128];
898
899 assert(data != nullptr, "Class bytes must not be null");
1079
1080
1081 /// JVM_RegisterUnsafeMethods
1082
1083 #define ADR "J"
1084
1085 #define LANG "Ljava/lang/"
1086
1087 #define OBJ LANG "Object;"
1088 #define CLS LANG "Class;"
1089 #define FLD LANG "reflect/Field;"
1090 #define THR LANG "Throwable;"
1091
1092 #define DC_Args LANG "String;[BII" LANG "ClassLoader;" "Ljava/security/ProtectionDomain;"
1093 #define DAC_Args CLS "[B[" OBJ
1094
1095 #define CC (char*) /*cast a literal from (const char*)*/
1096 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1097
1098 #define DECLARE_GETPUTOOP(Type, Desc) \
1099 {CC "get" #Type, CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type)}, \
1100 {CC "put" #Type, CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type)}, \
1101 {CC "get" #Type "Volatile", CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type##Volatile)}, \
1102 {CC "put" #Type "Volatile", CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type##Volatile)}
1103
1104
1105 static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = {
1106 {CC "getReference", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetReference)},
1107 {CC "putReference", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReference)},
1108 {CC "getReferenceVolatile", CC "(" OBJ "J)" OBJ, FN_PTR(Unsafe_GetReferenceVolatile)},
1109 {CC "putReferenceVolatile", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReferenceVolatile)},
1110
1111 {CC "isFlatArray", CC "(" CLS ")Z", FN_PTR(Unsafe_IsFlatArray)},
1112 {CC "isFlatField0", CC "(" OBJ ")Z", FN_PTR(Unsafe_IsFlatField)},
1113 {CC "hasNullMarker0", CC "(" OBJ ")Z", FN_PTR(Unsafe_HasNullMarker)},
1114 {CC "nullMarkerOffset0", CC "(" OBJ ")I", FN_PTR(Unsafe_NullMarkerOffset)},
1115 {CC "arrayLayout0", CC "(" OBJ ")I", FN_PTR(Unsafe_ArrayLayout)},
1116 {CC "fieldLayout0", CC "(" OBJ ")I", FN_PTR(Unsafe_FieldLayout)},
1117 {CC "getValue", CC "(" OBJ "J" CLS ")" OBJ, FN_PTR(Unsafe_GetValue)},
1118 {CC "getFlatValue", CC "(" OBJ "JI" CLS ")" OBJ, FN_PTR(Unsafe_GetFlatValue)},
1119 {CC "putValue", CC "(" OBJ "J" CLS OBJ ")V", FN_PTR(Unsafe_PutValue)},
1120 {CC "putFlatValue", CC "(" OBJ "JI" CLS OBJ ")V", FN_PTR(Unsafe_PutFlatValue)},
1121 {CC "uninitializedDefaultValue", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_UninitializedDefaultValue)},
1122 {CC "makePrivateBuffer", CC "(" OBJ ")" OBJ, FN_PTR(Unsafe_MakePrivateBuffer)},
1123 {CC "finishPrivateBuffer", CC "(" OBJ ")" OBJ, FN_PTR(Unsafe_FinishPrivateBuffer)},
1124 {CC "valueHeaderSize", CC "(" CLS ")J", FN_PTR(Unsafe_ValueHeaderSize)},
1125
1126 {CC "getUncompressedObject", CC "(" ADR ")" OBJ, FN_PTR(Unsafe_GetUncompressedObject)},
1127
1128 DECLARE_GETPUTOOP(Boolean, Z),
1129 DECLARE_GETPUTOOP(Byte, B),
1130 DECLARE_GETPUTOOP(Short, S),
1131 DECLARE_GETPUTOOP(Char, C),
1132 DECLARE_GETPUTOOP(Int, I),
1133 DECLARE_GETPUTOOP(Long, J),
1134 DECLARE_GETPUTOOP(Float, F),
1135 DECLARE_GETPUTOOP(Double, D),
1136
1137 {CC "allocateMemory0", CC "(J)" ADR, FN_PTR(Unsafe_AllocateMemory0)},
1138 {CC "reallocateMemory0", CC "(" ADR "J)" ADR, FN_PTR(Unsafe_ReallocateMemory0)},
1139 {CC "freeMemory0", CC "(" ADR ")V", FN_PTR(Unsafe_FreeMemory0)},
1140
1141 {CC "objectFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_ObjectFieldOffset0)},
1142 {CC "objectFieldOffset1", CC "(" CLS LANG "String;)J", FN_PTR(Unsafe_ObjectFieldOffset1)},
1143 {CC "staticFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_StaticFieldOffset0)},
1144 {CC "staticFieldBase0", CC "(" FLD ")" OBJ, FN_PTR(Unsafe_StaticFieldBase0)},
1145 {CC "ensureClassInitialized0", CC "(" CLS ")V", FN_PTR(Unsafe_EnsureClassInitialized0)},
1146 {CC "arrayBaseOffset0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayBaseOffset0)},
1147 {CC "arrayIndexScale0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayIndexScale0)},
1148 {CC "getObjectSize0", CC "(Ljava/lang/Object;)J", FN_PTR(Unsafe_GetObjectSize0)},
1149
1150 {CC "defineClass0", CC "(" DC_Args ")" CLS, FN_PTR(Unsafe_DefineClass0)},
1151 {CC "allocateInstance", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_AllocateInstance)},
1152 {CC "throwException", CC "(" THR ")V", FN_PTR(Unsafe_ThrowException)},
1153 {CC "compareAndSetReference",CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSetReference)},
1154 {CC "compareAndSetInt", CC "(" OBJ "J""I""I"")Z", FN_PTR(Unsafe_CompareAndSetInt)},
1155 {CC "compareAndSetLong", CC "(" OBJ "J""J""J"")Z", FN_PTR(Unsafe_CompareAndSetLong)},
1156 {CC "compareAndExchangeReference", CC "(" OBJ "J" OBJ "" OBJ ")" OBJ, FN_PTR(Unsafe_CompareAndExchangeReference)},
1157 {CC "compareAndExchangeInt", CC "(" OBJ "J""I""I"")I", FN_PTR(Unsafe_CompareAndExchangeInt)},
1158 {CC "compareAndExchangeLong", CC "(" OBJ "J""J""J"")J", FN_PTR(Unsafe_CompareAndExchangeLong)},
1159
1160 {CC "park", CC "(ZJ)V", FN_PTR(Unsafe_Park)},
1161 {CC "unpark", CC "(" OBJ ")V", FN_PTR(Unsafe_Unpark)},
1162
1163 {CC "getLoadAverage0", CC "([DI)I", FN_PTR(Unsafe_GetLoadAverage0)},
1164
1165 {CC "copyMemory0", CC "(" OBJ "J" OBJ "JJ)V", FN_PTR(Unsafe_CopyMemory0)},
1166 {CC "copySwapMemory0", CC "(" OBJ "J" OBJ "JJJ)V", FN_PTR(Unsafe_CopySwapMemory0)},
1167 {CC "writeback0", CC "(" "J" ")V", FN_PTR(Unsafe_WriteBack0)},
1168 {CC "writebackPreSync0", CC "()V", FN_PTR(Unsafe_WriteBackPreSync0)},
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