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 "classfile/classFileStream.hpp"
27 #include "classfile/classLoader.hpp"
28 #include "classfile/classLoadInfo.hpp"
29 #include "classfile/javaClasses.inline.hpp"
30 #include "classfile/systemDictionary.hpp"
31 #include "classfile/vmSymbols.hpp"
32 #include "jfr/jfrEvents.hpp"
33 #include "jni.h"
34 #include "jvm.h"
35 #include "memory/allocation.inline.hpp"
36 #include "memory/resourceArea.hpp"
37 #include "oops/access.inline.hpp"
38 #include "oops/fieldStreams.inline.hpp"
39 #include "oops/instanceKlass.inline.hpp"
40 #include "oops/klass.inline.hpp"
41 #include "oops/objArrayOop.inline.hpp"
42 #include "oops/oop.inline.hpp"
43 #include "oops/typeArrayOop.inline.hpp"
44 #include "prims/jvmtiExport.hpp"
45 #include "prims/unsafe.hpp"
46 #include "runtime/globals.hpp"
47 #include "runtime/handles.inline.hpp"
48 #include "runtime/interfaceSupport.inline.hpp"
49 #include "runtime/javaThread.inline.hpp"
50 #include "runtime/jniHandles.inline.hpp"
51 #include "runtime/orderAccess.hpp"
52 #include "runtime/reflection.hpp"
53 #include "runtime/sharedRuntime.hpp"
54 #include "runtime/stubRoutines.hpp"
55 #include "runtime/threadSMR.hpp"
56 #include "runtime/vmOperations.hpp"
57 #include "runtime/vm_version.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 /**
65 * Implementation of the jdk.internal.misc.Unsafe class
154 static inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
155 assert_field_offset_sane(p, field_offset);
156 jlong byte_offset = field_offset_to_byte_offset(field_offset);
157
158 if (sizeof(char*) == sizeof(jint)) { // (this constant folds!)
159 return cast_from_oop<address>(p) + (jint) byte_offset;
160 } else {
161 return cast_from_oop<address>(p) + byte_offset;
162 }
163 }
164
165 // Externally callable versions:
166 // (Use these in compiler intrinsics which emulate unsafe primitives.)
167 jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) {
168 return field_offset;
169 }
170 jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
171 return byte_offset;
172 }
173
174
175 ///// Data read/writes on the Java heap and in native (off-heap) memory
176
177 /**
178 * Helper class to wrap memory accesses in JavaThread::doing_unsafe_access()
179 */
180 class GuardUnsafeAccess {
181 JavaThread* _thread;
182
183 public:
184 GuardUnsafeAccess(JavaThread* thread) : _thread(thread) {
185 // native/off-heap access which may raise SIGBUS if accessing
186 // memory mapped file data in a region of the file which has
187 // been truncated and is now invalid.
188 _thread->set_doing_unsafe_access(true);
189 }
190
191 ~GuardUnsafeAccess() {
192 _thread->set_doing_unsafe_access(false);
193 }
194 };
230 return x;
231 }
232
233 jboolean normalize_for_read(jboolean x) {
234 return x != 0;
235 }
236
237 public:
238 MemoryAccess(JavaThread* thread, jobject obj, jlong offset)
239 : _thread(thread), _obj(JNIHandles::resolve(obj)), _offset((ptrdiff_t)offset) {
240 assert_field_offset_sane(_obj, offset);
241 }
242
243 T get() {
244 GuardUnsafeAccess guard(_thread);
245 return normalize_for_read(*addr());
246 }
247
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) \
575 return false;
576 }
577 UNSAFE_END
578
579 static void getBaseAndScale(int& base, int& scale, jclass clazz, TRAPS) {
580 assert(clazz != nullptr, "clazz must not be null");
581
582 oop mirror = JNIHandles::resolve_non_null(clazz);
583 Klass* k = java_lang_Class::as_Klass(mirror);
584
585 if (k == nullptr || !k->is_array_klass()) {
586 THROW(vmSymbols::java_lang_InvalidClassException());
587 } else if (k->is_objArray_klass()) {
588 base = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
589 scale = heapOopSize;
590 } else if (k->is_typeArray_klass()) {
591 TypeArrayKlass* tak = TypeArrayKlass::cast(k);
592 base = tak->array_header_in_bytes();
593 assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
594 scale = (1 << tak->log2_element_size());
595 } else {
596 ShouldNotReachHere();
597 }
598 }
599
600 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset0(JNIEnv *env, jobject unsafe, jclass clazz)) {
601 int base = 0, scale = 0;
602 getBaseAndScale(base, scale, clazz, CHECK_0);
603
604 return field_offset_from_byte_offset(base);
605 } UNSAFE_END
606
607
608 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale0(JNIEnv *env, jobject unsafe, jclass clazz)) {
609 int base = 0, scale = 0;
610 getBaseAndScale(base, scale, clazz, CHECK_0);
611
612 // This VM packs both fields and array elements down to the byte.
613 // But watch out: If this changes, so that array references for
614 // a given primitive type (say, T_BOOLEAN) use different memory units
615 // than fields, this method MUST return zero for such arrays.
616 // For example, the VM used to store sub-word sized fields in full
617 // words in the object layout, so that accessors like getByte(Object,int)
618 // did not really do what one might expect for arrays. Therefore,
619 // this function used to report a zero scale factor, so that the user
620 // would know not to attempt to access sub-word array elements.
621 // // Code for unpacked fields:
622 // if (scale < wordSize) return 0;
623
624 // The following allows for a pretty general fieldOffset cookie scheme,
625 // but requires it to be linear in byte offset.
626 return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
627 } UNSAFE_END
628
629
630 static inline void throw_new(JNIEnv *env, const char *ename) {
631 jclass cls = env->FindClass(ename);
632 if (env->ExceptionCheck()) {
633 env->ExceptionClear();
634 tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", ename);
635 return;
636 }
637
638 env->ThrowNew(cls, nullptr);
639 }
640
641 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
642 // Code lifted from JDK 1.3 ClassLoader.c
643
644 jbyte *body;
645 char *utfName = nullptr;
646 jclass result = 0;
647 char buf[128];
648
649 assert(data != nullptr, "Class bytes must not be null");
829
830
831 /// JVM_RegisterUnsafeMethods
832
833 #define ADR "J"
834
835 #define LANG "Ljava/lang/"
836
837 #define OBJ LANG "Object;"
838 #define CLS LANG "Class;"
839 #define FLD LANG "reflect/Field;"
840 #define THR LANG "Throwable;"
841
842 #define DC_Args LANG "String;[BII" LANG "ClassLoader;" "Ljava/security/ProtectionDomain;"
843 #define DAC_Args CLS "[B[" OBJ
844
845 #define CC (char*) /*cast a literal from (const char*)*/
846 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
847
848 #define DECLARE_GETPUTOOP(Type, Desc) \
849 {CC "get" #Type, CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type)}, \
850 {CC "put" #Type, CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type)}, \
851 {CC "get" #Type "Volatile", CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type##Volatile)}, \
852 {CC "put" #Type "Volatile", CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type##Volatile)}
853
854
855 static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = {
856 {CC "getReference", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetReference)},
857 {CC "putReference", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReference)},
858 {CC "getReferenceVolatile", CC "(" OBJ "J)" OBJ, FN_PTR(Unsafe_GetReferenceVolatile)},
859 {CC "putReferenceVolatile", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReferenceVolatile)},
860
861 {CC "getUncompressedObject", CC "(" ADR ")" OBJ, FN_PTR(Unsafe_GetUncompressedObject)},
862
863 DECLARE_GETPUTOOP(Boolean, Z),
864 DECLARE_GETPUTOOP(Byte, B),
865 DECLARE_GETPUTOOP(Short, S),
866 DECLARE_GETPUTOOP(Char, C),
867 DECLARE_GETPUTOOP(Int, I),
868 DECLARE_GETPUTOOP(Long, J),
869 DECLARE_GETPUTOOP(Float, F),
870 DECLARE_GETPUTOOP(Double, D),
871
872 {CC "allocateMemory0", CC "(J)" ADR, FN_PTR(Unsafe_AllocateMemory0)},
873 {CC "reallocateMemory0", CC "(" ADR "J)" ADR, FN_PTR(Unsafe_ReallocateMemory0)},
874 {CC "freeMemory0", CC "(" ADR ")V", FN_PTR(Unsafe_FreeMemory0)},
875
876 {CC "objectFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_ObjectFieldOffset0)},
877 {CC "objectFieldOffset1", CC "(" CLS LANG "String;)J", FN_PTR(Unsafe_ObjectFieldOffset1)},
878 {CC "staticFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_StaticFieldOffset0)},
879 {CC "staticFieldBase0", CC "(" FLD ")" OBJ, FN_PTR(Unsafe_StaticFieldBase0)},
880 {CC "ensureClassInitialized0", CC "(" CLS ")V", FN_PTR(Unsafe_EnsureClassInitialized0)},
881 {CC "arrayBaseOffset0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayBaseOffset0)},
882 {CC "arrayIndexScale0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayIndexScale0)},
883
884 {CC "defineClass0", CC "(" DC_Args ")" CLS, FN_PTR(Unsafe_DefineClass0)},
885 {CC "allocateInstance", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_AllocateInstance)},
886 {CC "throwException", CC "(" THR ")V", FN_PTR(Unsafe_ThrowException)},
887 {CC "compareAndSetReference",CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSetReference)},
888 {CC "compareAndSetInt", CC "(" OBJ "J""I""I"")Z", FN_PTR(Unsafe_CompareAndSetInt)},
889 {CC "compareAndSetLong", CC "(" OBJ "J""J""J"")Z", FN_PTR(Unsafe_CompareAndSetLong)},
890 {CC "compareAndExchangeReference", CC "(" OBJ "J" OBJ "" OBJ ")" OBJ, FN_PTR(Unsafe_CompareAndExchangeReference)},
891 {CC "compareAndExchangeInt", CC "(" OBJ "J""I""I"")I", FN_PTR(Unsafe_CompareAndExchangeInt)},
892 {CC "compareAndExchangeLong", CC "(" OBJ "J""J""J"")J", FN_PTR(Unsafe_CompareAndExchangeLong)},
893
894 {CC "park", CC "(ZJ)V", FN_PTR(Unsafe_Park)},
895 {CC "unpark", CC "(" OBJ ")V", FN_PTR(Unsafe_Unpark)},
896
897 {CC "getLoadAverage0", CC "([DI)I", FN_PTR(Unsafe_GetLoadAverage0)},
898
899 {CC "copyMemory0", CC "(" OBJ "J" OBJ "JJ)V", FN_PTR(Unsafe_CopyMemory0)},
900 {CC "copySwapMemory0", CC "(" OBJ "J" OBJ "JJJ)V", FN_PTR(Unsafe_CopySwapMemory0)},
901 {CC "writeback0", CC "(" "J" ")V", FN_PTR(Unsafe_WriteBack0)},
902 {CC "writebackPreSync0", CC "()V", FN_PTR(Unsafe_WriteBackPreSync0)},
|
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 "classfile/classFileStream.hpp"
27 #include "classfile/classLoader.hpp"
28 #include "classfile/classLoadInfo.hpp"
29 #include "classfile/javaClasses.inline.hpp"
30 #include "classfile/systemDictionary.hpp"
31 #include "classfile/vmSymbols.hpp"
32 #include "jfr/jfrEvents.hpp"
33 #include "jni.h"
34 #include "jvm.h"
35 #include "memory/allocation.inline.hpp"
36 #include "memory/resourceArea.hpp"
37 #include "logging/log.hpp"
38 #include "logging/logStream.hpp"
39 #include "oops/access.inline.hpp"
40 #include "oops/fieldStreams.inline.hpp"
41 #include "oops/flatArrayKlass.hpp"
42 #include "oops/flatArrayOop.inline.hpp"
43 #include "oops/inlineKlass.inline.hpp"
44 #include "oops/instanceKlass.inline.hpp"
45 #include "oops/klass.inline.hpp"
46 #include "oops/objArrayOop.inline.hpp"
47 #include "oops/oop.inline.hpp"
48 #include "oops/typeArrayOop.inline.hpp"
49 #include "prims/jvmtiExport.hpp"
50 #include "prims/unsafe.hpp"
51 #include "runtime/fieldDescriptor.inline.hpp"
52 #include "runtime/globals.hpp"
53 #include "runtime/handles.inline.hpp"
54 #include "runtime/interfaceSupport.inline.hpp"
55 #include "runtime/javaThread.inline.hpp"
56 #include "runtime/jniHandles.inline.hpp"
57 #include "runtime/orderAccess.hpp"
58 #include "runtime/reflection.hpp"
59 #include "runtime/sharedRuntime.hpp"
60 #include "runtime/stubRoutines.hpp"
61 #include "runtime/threadSMR.hpp"
62 #include "runtime/vmOperations.hpp"
63 #include "runtime/vm_version.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 /**
71 * Implementation of the jdk.internal.misc.Unsafe class
160 static inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
161 assert_field_offset_sane(p, field_offset);
162 jlong byte_offset = field_offset_to_byte_offset(field_offset);
163
164 if (sizeof(char*) == sizeof(jint)) { // (this constant folds!)
165 return cast_from_oop<address>(p) + (jint) byte_offset;
166 } else {
167 return cast_from_oop<address>(p) + byte_offset;
168 }
169 }
170
171 // Externally callable versions:
172 // (Use these in compiler intrinsics which emulate unsafe primitives.)
173 jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) {
174 return field_offset;
175 }
176 jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
177 return byte_offset;
178 }
179
180 ///// Data read/writes on the Java heap and in native (off-heap) memory
181
182 /**
183 * Helper class to wrap memory accesses in JavaThread::doing_unsafe_access()
184 */
185 class GuardUnsafeAccess {
186 JavaThread* _thread;
187
188 public:
189 GuardUnsafeAccess(JavaThread* thread) : _thread(thread) {
190 // native/off-heap access which may raise SIGBUS if accessing
191 // memory mapped file data in a region of the file which has
192 // been truncated and is now invalid.
193 _thread->set_doing_unsafe_access(true);
194 }
195
196 ~GuardUnsafeAccess() {
197 _thread->set_doing_unsafe_access(false);
198 }
199 };
235 return x;
236 }
237
238 jboolean normalize_for_read(jboolean x) {
239 return x != 0;
240 }
241
242 public:
243 MemoryAccess(JavaThread* thread, jobject obj, jlong offset)
244 : _thread(thread), _obj(JNIHandles::resolve(obj)), _offset((ptrdiff_t)offset) {
245 assert_field_offset_sane(_obj, offset);
246 }
247
248 T get() {
249 GuardUnsafeAccess guard(_thread);
250 return normalize_for_read(*addr());
251 }
252
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->first_field_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_IsFlatArray(JNIEnv *env, jobject unsafe, jclass c)) {
365 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(c));
366 return k->is_flatArray_klass();
367 } UNSAFE_END
368
369 UNSAFE_ENTRY(jobject, Unsafe_UninitializedDefaultValue(JNIEnv *env, jobject unsafe, jclass vc)) {
370 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(vc));
371 InlineKlass* vk = InlineKlass::cast(k);
372 oop v = vk->default_value();
373 return JNIHandles::make_local(THREAD, v);
374 } UNSAFE_END
375
376 UNSAFE_ENTRY(jobject, Unsafe_GetValue(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jclass vc)) {
377 oop base = JNIHandles::resolve(obj);
378 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(vc));
379 InlineKlass* vk = InlineKlass::cast(k);
380 assert_and_log_unsafe_value_access(base, offset, vk);
381 Handle base_h(THREAD, base);
382 oop v = vk->read_flat_field(base_h(), offset, CHECK_NULL);
383 return JNIHandles::make_local(THREAD, v);
384 } UNSAFE_END
385
386 UNSAFE_ENTRY(void, Unsafe_PutValue(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jclass vc, jobject value)) {
387 oop base = JNIHandles::resolve(obj);
388 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(vc));
389 InlineKlass* vk = InlineKlass::cast(k);
390 assert(!base->is_inline_type() || base->mark().is_larval_state(), "must be an object instance or a larval inline type");
391 assert_and_log_unsafe_value_access(base, offset, vk);
392 oop v = JNIHandles::resolve(value);
393 vk->write_flat_field(base, offset, v, CHECK);
394 } UNSAFE_END
395
396 UNSAFE_ENTRY(jobject, Unsafe_MakePrivateBuffer(JNIEnv *env, jobject unsafe, jobject value)) {
397 oop v = JNIHandles::resolve_non_null(value);
398 assert(v->is_inline_type(), "must be an inline type instance");
399 Handle vh(THREAD, v);
400 InlineKlass* vk = InlineKlass::cast(v->klass());
401 instanceOop new_value = vk->allocate_instance_buffer(CHECK_NULL);
402 vk->inline_copy_oop_to_new_oop(vh(), new_value);
403 markWord mark = new_value->mark();
404 new_value->set_mark(mark.enter_larval_state());
405 return JNIHandles::make_local(THREAD, new_value);
406 } UNSAFE_END
407
408 UNSAFE_ENTRY(jobject, Unsafe_FinishPrivateBuffer(JNIEnv *env, jobject unsafe, jobject value)) {
409 oop v = JNIHandles::resolve(value);
410 assert(v->mark().is_larval_state(), "must be a larval value");
411 markWord mark = v->mark();
412 v->set_mark(mark.exit_larval_state());
413 return JNIHandles::make_local(THREAD, v);
414 } UNSAFE_END
415
416 UNSAFE_ENTRY(jobject, Unsafe_GetReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
417 oop p = JNIHandles::resolve(obj);
418 assert_field_offset_sane(p, offset);
419 oop v = HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset);
420 return JNIHandles::make_local(THREAD, v);
421 } UNSAFE_END
422
423 UNSAFE_ENTRY(void, Unsafe_PutReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
424 oop x = JNIHandles::resolve(x_h);
425 oop p = JNIHandles::resolve(obj);
426 assert_field_offset_sane(p, offset);
427 HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x);
428 } UNSAFE_END
429
430 UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr)) {
431 oop v = *(oop*) (address) addr;
432 return JNIHandles::make_local(THREAD, v);
433 } UNSAFE_END
434
435 #define DEFINE_GETSETOOP(java_type, Type) \
708 return false;
709 }
710 UNSAFE_END
711
712 static void getBaseAndScale(int& base, int& scale, jclass clazz, TRAPS) {
713 assert(clazz != nullptr, "clazz must not be null");
714
715 oop mirror = JNIHandles::resolve_non_null(clazz);
716 Klass* k = java_lang_Class::as_Klass(mirror);
717
718 if (k == nullptr || !k->is_array_klass()) {
719 THROW(vmSymbols::java_lang_InvalidClassException());
720 } else if (k->is_objArray_klass()) {
721 base = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
722 scale = heapOopSize;
723 } else if (k->is_typeArray_klass()) {
724 TypeArrayKlass* tak = TypeArrayKlass::cast(k);
725 base = tak->array_header_in_bytes();
726 assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
727 scale = (1 << tak->log2_element_size());
728 } else if (k->is_flatArray_klass()) {
729 FlatArrayKlass* vak = FlatArrayKlass::cast(k);
730 InlineKlass* vklass = vak->element_klass();
731 base = vak->array_header_in_bytes();
732 scale = vak->element_byte_size();
733 } else {
734 ShouldNotReachHere();
735 }
736 }
737
738 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset0(JNIEnv *env, jobject unsafe, jclass clazz)) {
739 int base = 0, scale = 0;
740 getBaseAndScale(base, scale, clazz, CHECK_0);
741
742 return field_offset_from_byte_offset(base);
743 } UNSAFE_END
744
745
746 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale0(JNIEnv *env, jobject unsafe, jclass clazz)) {
747 int base = 0, scale = 0;
748 getBaseAndScale(base, scale, clazz, CHECK_0);
749
750 // This VM packs both fields and array elements down to the byte.
751 // But watch out: If this changes, so that array references for
752 // a given primitive type (say, T_BOOLEAN) use different memory units
753 // than fields, this method MUST return zero for such arrays.
754 // For example, the VM used to store sub-word sized fields in full
755 // words in the object layout, so that accessors like getByte(Object,int)
756 // did not really do what one might expect for arrays. Therefore,
757 // this function used to report a zero scale factor, so that the user
758 // would know not to attempt to access sub-word array elements.
759 // // Code for unpacked fields:
760 // if (scale < wordSize) return 0;
761
762 // The following allows for a pretty general fieldOffset cookie scheme,
763 // but requires it to be linear in byte offset.
764 return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
765 } UNSAFE_END
766
767
768 UNSAFE_ENTRY(jlong, Unsafe_GetObjectSize0(JNIEnv* env, jobject o, jobject obj))
769 oop p = JNIHandles::resolve(obj);
770 return p->size() * HeapWordSize;
771 UNSAFE_END
772
773
774 static inline void throw_new(JNIEnv *env, const char *ename) {
775 jclass cls = env->FindClass(ename);
776 if (env->ExceptionCheck()) {
777 env->ExceptionClear();
778 tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", ename);
779 return;
780 }
781
782 env->ThrowNew(cls, nullptr);
783 }
784
785 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
786 // Code lifted from JDK 1.3 ClassLoader.c
787
788 jbyte *body;
789 char *utfName = nullptr;
790 jclass result = 0;
791 char buf[128];
792
793 assert(data != nullptr, "Class bytes must not be null");
973
974
975 /// JVM_RegisterUnsafeMethods
976
977 #define ADR "J"
978
979 #define LANG "Ljava/lang/"
980
981 #define OBJ LANG "Object;"
982 #define CLS LANG "Class;"
983 #define FLD LANG "reflect/Field;"
984 #define THR LANG "Throwable;"
985
986 #define DC_Args LANG "String;[BII" LANG "ClassLoader;" "Ljava/security/ProtectionDomain;"
987 #define DAC_Args CLS "[B[" OBJ
988
989 #define CC (char*) /*cast a literal from (const char*)*/
990 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
991
992 #define DECLARE_GETPUTOOP(Type, Desc) \
993 {CC "get" #Type, CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type)}, \
994 {CC "put" #Type, CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type)}, \
995 {CC "get" #Type "Volatile", CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type##Volatile)}, \
996 {CC "put" #Type "Volatile", CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type##Volatile)}
997
998
999 static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = {
1000 {CC "getReference", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetReference)},
1001 {CC "putReference", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReference)},
1002 {CC "getReferenceVolatile", CC "(" OBJ "J)" OBJ, FN_PTR(Unsafe_GetReferenceVolatile)},
1003 {CC "putReferenceVolatile", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReferenceVolatile)},
1004
1005 {CC "isFlatArray", CC "(" CLS ")Z", FN_PTR(Unsafe_IsFlatArray)},
1006 {CC "isFlatField0", CC "(" OBJ ")Z", FN_PTR(Unsafe_IsFlatField)},
1007 {CC "getValue", CC "(" OBJ "J" CLS ")" OBJ, FN_PTR(Unsafe_GetValue)},
1008 {CC "putValue", CC "(" OBJ "J" CLS OBJ ")V", FN_PTR(Unsafe_PutValue)},
1009 {CC "uninitializedDefaultValue", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_UninitializedDefaultValue)},
1010 {CC "makePrivateBuffer", CC "(" OBJ ")" OBJ, FN_PTR(Unsafe_MakePrivateBuffer)},
1011 {CC "finishPrivateBuffer", CC "(" OBJ ")" OBJ, FN_PTR(Unsafe_FinishPrivateBuffer)},
1012 {CC "valueHeaderSize", CC "(" CLS ")J", FN_PTR(Unsafe_ValueHeaderSize)},
1013
1014 {CC "getUncompressedObject", CC "(" ADR ")" OBJ, FN_PTR(Unsafe_GetUncompressedObject)},
1015
1016 DECLARE_GETPUTOOP(Boolean, Z),
1017 DECLARE_GETPUTOOP(Byte, B),
1018 DECLARE_GETPUTOOP(Short, S),
1019 DECLARE_GETPUTOOP(Char, C),
1020 DECLARE_GETPUTOOP(Int, I),
1021 DECLARE_GETPUTOOP(Long, J),
1022 DECLARE_GETPUTOOP(Float, F),
1023 DECLARE_GETPUTOOP(Double, D),
1024
1025 {CC "allocateMemory0", CC "(J)" ADR, FN_PTR(Unsafe_AllocateMemory0)},
1026 {CC "reallocateMemory0", CC "(" ADR "J)" ADR, FN_PTR(Unsafe_ReallocateMemory0)},
1027 {CC "freeMemory0", CC "(" ADR ")V", FN_PTR(Unsafe_FreeMemory0)},
1028
1029 {CC "objectFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_ObjectFieldOffset0)},
1030 {CC "objectFieldOffset1", CC "(" CLS LANG "String;)J", FN_PTR(Unsafe_ObjectFieldOffset1)},
1031 {CC "staticFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_StaticFieldOffset0)},
1032 {CC "staticFieldBase0", CC "(" FLD ")" OBJ, FN_PTR(Unsafe_StaticFieldBase0)},
1033 {CC "ensureClassInitialized0", CC "(" CLS ")V", FN_PTR(Unsafe_EnsureClassInitialized0)},
1034 {CC "arrayBaseOffset0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayBaseOffset0)},
1035 {CC "arrayIndexScale0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayIndexScale0)},
1036 {CC "getObjectSize0", CC "(Ljava/lang/Object;)J", FN_PTR(Unsafe_GetObjectSize0)},
1037
1038 {CC "defineClass0", CC "(" DC_Args ")" CLS, FN_PTR(Unsafe_DefineClass0)},
1039 {CC "allocateInstance", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_AllocateInstance)},
1040 {CC "throwException", CC "(" THR ")V", FN_PTR(Unsafe_ThrowException)},
1041 {CC "compareAndSetReference",CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSetReference)},
1042 {CC "compareAndSetInt", CC "(" OBJ "J""I""I"")Z", FN_PTR(Unsafe_CompareAndSetInt)},
1043 {CC "compareAndSetLong", CC "(" OBJ "J""J""J"")Z", FN_PTR(Unsafe_CompareAndSetLong)},
1044 {CC "compareAndExchangeReference", CC "(" OBJ "J" OBJ "" OBJ ")" OBJ, FN_PTR(Unsafe_CompareAndExchangeReference)},
1045 {CC "compareAndExchangeInt", CC "(" OBJ "J""I""I"")I", FN_PTR(Unsafe_CompareAndExchangeInt)},
1046 {CC "compareAndExchangeLong", CC "(" OBJ "J""J""J"")J", FN_PTR(Unsafe_CompareAndExchangeLong)},
1047
1048 {CC "park", CC "(ZJ)V", FN_PTR(Unsafe_Park)},
1049 {CC "unpark", CC "(" OBJ ")V", FN_PTR(Unsafe_Unpark)},
1050
1051 {CC "getLoadAverage0", CC "([DI)I", FN_PTR(Unsafe_GetLoadAverage0)},
1052
1053 {CC "copyMemory0", CC "(" OBJ "J" OBJ "JJ)V", FN_PTR(Unsafe_CopyMemory0)},
1054 {CC "copySwapMemory0", CC "(" OBJ "J" OBJ "JJJ)V", FN_PTR(Unsafe_CopySwapMemory0)},
1055 {CC "writeback0", CC "(" "J" ")V", FN_PTR(Unsafe_WriteBack0)},
1056 {CC "writebackPreSync0", CC "()V", FN_PTR(Unsafe_WriteBackPreSync0)},
|