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 "sanitizers/ub.hpp"
59 #include "services/threadService.hpp"
60 #include "utilities/align.hpp"
61 #include "utilities/copy.hpp"
62 #include "utilities/dtrace.hpp"
63 #include "utilities/macros.hpp"
64
65 /**
152 }
153 #endif
154 }
155
156 static inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
157 assert_field_offset_sane(p, field_offset);
158 uintptr_t base_address = cast_from_oop<uintptr_t>(p);
159 uintptr_t byte_offset = (uintptr_t)field_offset_to_byte_offset(field_offset);
160 return (void*)(base_address + byte_offset);
161 }
162
163 // Externally callable versions:
164 // (Use these in compiler intrinsics which emulate unsafe primitives.)
165 jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) {
166 return field_offset;
167 }
168 jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
169 return byte_offset;
170 }
171
172
173 ///// Data read/writes on the Java heap and in native (off-heap) memory
174
175 /**
176 * Helper class to wrap memory accesses in JavaThread::doing_unsafe_access()
177 */
178 class GuardUnsafeAccess {
179 JavaThread* _thread;
180
181 public:
182 GuardUnsafeAccess(JavaThread* thread) : _thread(thread) {
183 // native/off-heap access which may raise SIGBUS if accessing
184 // memory mapped file data in a region of the file which has
185 // been truncated and is now invalid.
186 _thread->set_doing_unsafe_access(true);
187 }
188
189 ~GuardUnsafeAccess() {
190 _thread->set_doing_unsafe_access(false);
191 }
192 };
231 jboolean normalize_for_read(jboolean x) {
232 return x != 0;
233 }
234
235 public:
236 MemoryAccess(JavaThread* thread, jobject obj, jlong offset)
237 : _thread(thread), _obj(JNIHandles::resolve(obj)), _offset((ptrdiff_t)offset) {
238 assert_field_offset_sane(_obj, offset);
239 }
240
241 T get() {
242 GuardUnsafeAccess guard(_thread);
243 return normalize_for_read(*addr());
244 }
245
246 // we use this method at some places for writing to 0 e.g. to cause a crash;
247 // ubsan does not know that this is the desired behavior
248 ATTRIBUTE_NO_UBSAN
249 void put(T x) {
250 GuardUnsafeAccess guard(_thread);
251 *addr() = normalize_for_write(x);
252 }
253
254
255 T get_volatile() {
256 GuardUnsafeAccess guard(_thread);
257 volatile T ret = RawAccess<MO_SEQ_CST>::load(addr());
258 return normalize_for_read(ret);
259 }
260
261 void put_volatile(T x) {
262 GuardUnsafeAccess guard(_thread);
263 RawAccess<MO_SEQ_CST>::store(addr(), normalize_for_write(x));
264 }
265 };
266
267 // These functions allow a null base pointer with an arbitrary address.
268 // But if the base pointer is non-null, the offset should make some sense.
269 // That is, it should be in the range [0, MAX_OBJECT_SIZE].
270 UNSAFE_ENTRY(jobject, Unsafe_GetReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
271 oop p = JNIHandles::resolve(obj);
272 assert_field_offset_sane(p, offset);
273 oop v = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset);
274 return JNIHandles::make_local(THREAD, v);
275 } UNSAFE_END
276
277 UNSAFE_ENTRY(void, Unsafe_PutReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
278 oop x = JNIHandles::resolve(x_h);
279 oop p = JNIHandles::resolve(obj);
280 assert_field_offset_sane(p, offset);
281 HeapAccess<ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x);
282 } UNSAFE_END
283
284 UNSAFE_ENTRY(jobject, Unsafe_GetReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
285 oop p = JNIHandles::resolve(obj);
286 assert_field_offset_sane(p, offset);
287 oop v = HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset);
288 return JNIHandles::make_local(THREAD, v);
289 } UNSAFE_END
290
291 UNSAFE_ENTRY(void, Unsafe_PutReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
292 oop x = JNIHandles::resolve(x_h);
293 oop p = JNIHandles::resolve(obj);
294 assert_field_offset_sane(p, offset);
295 HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x);
296 } UNSAFE_END
297
298 UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr)) {
299 oop v = *(oop*) (address) addr;
300 return JNIHandles::make_local(THREAD, v);
301 } UNSAFE_END
302
303 #define DEFINE_GETSETOOP(java_type, Type) \
584 return false;
585 }
586 UNSAFE_END
587
588 static void getBaseAndScale(int& base, int& scale, jclass clazz, TRAPS) {
589 assert(clazz != nullptr, "clazz must not be null");
590
591 oop mirror = JNIHandles::resolve_non_null(clazz);
592 Klass* k = java_lang_Class::as_Klass(mirror);
593
594 if (k == nullptr || !k->is_array_klass()) {
595 THROW(vmSymbols::java_lang_InvalidClassException());
596 } else if (k->is_objArray_klass()) {
597 base = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
598 scale = heapOopSize;
599 } else if (k->is_typeArray_klass()) {
600 TypeArrayKlass* tak = TypeArrayKlass::cast(k);
601 base = tak->array_header_in_bytes();
602 assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
603 scale = (1 << tak->log2_element_size());
604 } else {
605 ShouldNotReachHere();
606 }
607 }
608
609 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset0(JNIEnv *env, jobject unsafe, jclass clazz)) {
610 int base = 0, scale = 0;
611 getBaseAndScale(base, scale, clazz, CHECK_0);
612
613 return field_offset_from_byte_offset(base);
614 } UNSAFE_END
615
616
617 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale0(JNIEnv *env, jobject unsafe, jclass clazz)) {
618 int base = 0, scale = 0;
619 getBaseAndScale(base, scale, clazz, CHECK_0);
620
621 // This VM packs both fields and array elements down to the byte.
622 // But watch out: If this changes, so that array references for
623 // a given primitive type (say, T_BOOLEAN) use different memory units
624 // than fields, this method MUST return zero for such arrays.
625 // For example, the VM used to store sub-word sized fields in full
626 // words in the object layout, so that accessors like getByte(Object,int)
627 // did not really do what one might expect for arrays. Therefore,
628 // this function used to report a zero scale factor, so that the user
629 // would know not to attempt to access sub-word array elements.
630 // // Code for unpacked fields:
631 // if (scale < wordSize) return 0;
632
633 // The following allows for a pretty general fieldOffset cookie scheme,
634 // but requires it to be linear in byte offset.
635 return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
636 } UNSAFE_END
637
638
639 static inline void throw_new(JNIEnv *env, const char *ename) {
640 jclass cls = env->FindClass(ename);
641 if (env->ExceptionCheck()) {
642 env->ExceptionClear();
643 tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", ename);
644 return;
645 }
646
647 env->ThrowNew(cls, nullptr);
648 }
649
650 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
651 // Code lifted from JDK 1.3 ClassLoader.c
652
653 jbyte *body;
654 char *utfName = nullptr;
655 jclass result = nullptr;
656 char buf[128];
657
658 assert(data != nullptr, "Class bytes must not be null");
838
839
840 /// JVM_RegisterUnsafeMethods
841
842 #define ADR "J"
843
844 #define LANG "Ljava/lang/"
845
846 #define OBJ LANG "Object;"
847 #define CLS LANG "Class;"
848 #define FLD LANG "reflect/Field;"
849 #define THR LANG "Throwable;"
850
851 #define DC_Args LANG "String;[BII" LANG "ClassLoader;" "Ljava/security/ProtectionDomain;"
852 #define DAC_Args CLS "[B[" OBJ
853
854 #define CC (char*) /*cast a literal from (const char*)*/
855 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
856
857 #define DECLARE_GETPUTOOP(Type, Desc) \
858 {CC "get" #Type, CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type)}, \
859 {CC "put" #Type, CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type)}, \
860 {CC "get" #Type "Volatile", CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type##Volatile)}, \
861 {CC "put" #Type "Volatile", CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type##Volatile)}
862
863
864 static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = {
865 {CC "getReference", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetReference)},
866 {CC "putReference", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReference)},
867 {CC "getReferenceVolatile", CC "(" OBJ "J)" OBJ, FN_PTR(Unsafe_GetReferenceVolatile)},
868 {CC "putReferenceVolatile", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReferenceVolatile)},
869
870 {CC "getUncompressedObject", CC "(" ADR ")" OBJ, FN_PTR(Unsafe_GetUncompressedObject)},
871
872 DECLARE_GETPUTOOP(Boolean, Z),
873 DECLARE_GETPUTOOP(Byte, B),
874 DECLARE_GETPUTOOP(Short, S),
875 DECLARE_GETPUTOOP(Char, C),
876 DECLARE_GETPUTOOP(Int, I),
877 DECLARE_GETPUTOOP(Long, J),
878 DECLARE_GETPUTOOP(Float, F),
879 DECLARE_GETPUTOOP(Double, D),
880
881 {CC "allocateMemory0", CC "(J)" ADR, FN_PTR(Unsafe_AllocateMemory0)},
882 {CC "reallocateMemory0", CC "(" ADR "J)" ADR, FN_PTR(Unsafe_ReallocateMemory0)},
883 {CC "freeMemory0", CC "(" ADR ")V", FN_PTR(Unsafe_FreeMemory0)},
884
885 {CC "objectFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_ObjectFieldOffset0)},
886 {CC "objectFieldOffset1", CC "(" CLS LANG "String;)J", FN_PTR(Unsafe_ObjectFieldOffset1)},
887 {CC "staticFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_StaticFieldOffset0)},
888 {CC "staticFieldBase0", CC "(" FLD ")" OBJ, FN_PTR(Unsafe_StaticFieldBase0)},
889 {CC "ensureClassInitialized0", CC "(" CLS ")V", FN_PTR(Unsafe_EnsureClassInitialized0)},
890 {CC "arrayBaseOffset0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayBaseOffset0)},
891 {CC "arrayIndexScale0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayIndexScale0)},
892
893 {CC "defineClass0", CC "(" DC_Args ")" CLS, FN_PTR(Unsafe_DefineClass0)},
894 {CC "allocateInstance", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_AllocateInstance)},
895 {CC "throwException", CC "(" THR ")V", FN_PTR(Unsafe_ThrowException)},
896 {CC "compareAndSetReference",CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSetReference)},
897 {CC "compareAndSetInt", CC "(" OBJ "J""I""I"")Z", FN_PTR(Unsafe_CompareAndSetInt)},
898 {CC "compareAndSetLong", CC "(" OBJ "J""J""J"")Z", FN_PTR(Unsafe_CompareAndSetLong)},
899 {CC "compareAndExchangeReference", CC "(" OBJ "J" OBJ "" OBJ ")" OBJ, FN_PTR(Unsafe_CompareAndExchangeReference)},
900 {CC "compareAndExchangeInt", CC "(" OBJ "J""I""I"")I", FN_PTR(Unsafe_CompareAndExchangeInt)},
901 {CC "compareAndExchangeLong", CC "(" OBJ "J""J""J"")J", FN_PTR(Unsafe_CompareAndExchangeLong)},
902
903 {CC "park", CC "(ZJ)V", FN_PTR(Unsafe_Park)},
904 {CC "unpark", CC "(" OBJ ")V", FN_PTR(Unsafe_Unpark)},
905
906 {CC "getLoadAverage0", CC "([DI)I", FN_PTR(Unsafe_GetLoadAverage0)},
907
908 {CC "copyMemory0", CC "(" OBJ "J" OBJ "JJ)V", FN_PTR(Unsafe_CopyMemory0)},
909 {CC "copySwapMemory0", CC "(" OBJ "J" OBJ "JJJ)V", FN_PTR(Unsafe_CopySwapMemory0)},
910 {CC "writeback0", CC "(" "J" ")V", FN_PTR(Unsafe_WriteBack0)},
911 {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 "sanitizers/ub.hpp"
65 #include "services/threadService.hpp"
66 #include "utilities/align.hpp"
67 #include "utilities/copy.hpp"
68 #include "utilities/dtrace.hpp"
69 #include "utilities/macros.hpp"
70
71 /**
158 }
159 #endif
160 }
161
162 static inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
163 assert_field_offset_sane(p, field_offset);
164 uintptr_t base_address = cast_from_oop<uintptr_t>(p);
165 uintptr_t byte_offset = (uintptr_t)field_offset_to_byte_offset(field_offset);
166 return (void*)(base_address + byte_offset);
167 }
168
169 // Externally callable versions:
170 // (Use these in compiler intrinsics which emulate unsafe primitives.)
171 jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) {
172 return field_offset;
173 }
174 jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
175 return byte_offset;
176 }
177
178 ///// Data read/writes on the Java heap and in native (off-heap) memory
179
180 /**
181 * Helper class to wrap memory accesses in JavaThread::doing_unsafe_access()
182 */
183 class GuardUnsafeAccess {
184 JavaThread* _thread;
185
186 public:
187 GuardUnsafeAccess(JavaThread* thread) : _thread(thread) {
188 // native/off-heap access which may raise SIGBUS if accessing
189 // memory mapped file data in a region of the file which has
190 // been truncated and is now invalid.
191 _thread->set_doing_unsafe_access(true);
192 }
193
194 ~GuardUnsafeAccess() {
195 _thread->set_doing_unsafe_access(false);
196 }
197 };
236 jboolean normalize_for_read(jboolean x) {
237 return x != 0;
238 }
239
240 public:
241 MemoryAccess(JavaThread* thread, jobject obj, jlong offset)
242 : _thread(thread), _obj(JNIHandles::resolve(obj)), _offset((ptrdiff_t)offset) {
243 assert_field_offset_sane(_obj, offset);
244 }
245
246 T get() {
247 GuardUnsafeAccess guard(_thread);
248 return normalize_for_read(*addr());
249 }
250
251 // we use this method at some places for writing to 0 e.g. to cause a crash;
252 // ubsan does not know that this is the desired behavior
253 ATTRIBUTE_NO_UBSAN
254 void put(T x) {
255 GuardUnsafeAccess guard(_thread);
256 assert(_obj == nullptr || !_obj->is_inline_type() || _obj->mark().is_larval_state(), "must be an object instance or a larval inline type");
257 *addr() = normalize_for_write(x);
258 }
259
260 T get_volatile() {
261 GuardUnsafeAccess guard(_thread);
262 volatile T ret = RawAccess<MO_SEQ_CST>::load(addr());
263 return normalize_for_read(ret);
264 }
265
266 void put_volatile(T x) {
267 GuardUnsafeAccess guard(_thread);
268 RawAccess<MO_SEQ_CST>::store(addr(), normalize_for_write(x));
269 }
270 };
271
272 #ifdef ASSERT
273 /*
274 * Get the field descriptor of the field of the given object at the given offset.
275 */
276 static bool get_field_descriptor(oop p, jlong offset, fieldDescriptor* fd) {
277 bool found = false;
278 Klass* k = p->klass();
279 if (k->is_instance_klass()) {
280 InstanceKlass* ik = InstanceKlass::cast(k);
281 found = ik->find_field_from_offset((int)offset, false, fd);
282 if (!found && ik->is_mirror_instance_klass()) {
283 Klass* k2 = java_lang_Class::as_Klass(p);
284 if (k2->is_instance_klass()) {
285 ik = InstanceKlass::cast(k2);
286 found = ik->find_field_from_offset((int)offset, true, fd);
287 }
288 }
289 }
290 return found;
291 }
292 #endif // ASSERT
293
294 static void assert_and_log_unsafe_value_access(oop p, jlong offset, InlineKlass* vk) {
295 Klass* k = p->klass();
296 #ifdef ASSERT
297 if (k->is_instance_klass()) {
298 assert_field_offset_sane(p, offset);
299 fieldDescriptor fd;
300 bool found = get_field_descriptor(p, offset, &fd);
301 if (found) {
302 assert(found, "value field not found");
303 assert(fd.is_flat(), "field not flat");
304 } else {
305 if (log_is_enabled(Trace, valuetypes)) {
306 log_trace(valuetypes)("not a field in %s at offset " UINT64_FORMAT_X,
307 p->klass()->external_name(), (uint64_t)offset);
308 }
309 }
310 } else if (k->is_flatArray_klass()) {
311 FlatArrayKlass* vak = FlatArrayKlass::cast(k);
312 int index = (offset - vak->array_header_in_bytes()) / vak->element_byte_size();
313 address dest = (address)((flatArrayOop)p)->value_at_addr(index, vak->layout_helper());
314 assert(dest == (cast_from_oop<address>(p) + offset), "invalid offset");
315 } else {
316 ShouldNotReachHere();
317 }
318 #endif // ASSERT
319 if (log_is_enabled(Trace, valuetypes)) {
320 if (k->is_flatArray_klass()) {
321 FlatArrayKlass* vak = FlatArrayKlass::cast(k);
322 int index = (offset - vak->array_header_in_bytes()) / vak->element_byte_size();
323 address dest = (address)((flatArrayOop)p)->value_at_addr(index, vak->layout_helper());
324 log_trace(valuetypes)("%s array type %s index %d element size %d offset " UINT64_FORMAT_X " at " INTPTR_FORMAT,
325 p->klass()->external_name(), vak->external_name(),
326 index, vak->element_byte_size(), (uint64_t)offset, p2i(dest));
327 } else {
328 log_trace(valuetypes)("%s field type %s at offset " UINT64_FORMAT_X,
329 p->klass()->external_name(), vk->external_name(), (uint64_t)offset);
330 }
331 }
332 }
333
334 // These functions allow a null base pointer with an arbitrary address.
335 // But if the base pointer is non-null, the offset should make some sense.
336 // That is, it should be in the range [0, MAX_OBJECT_SIZE].
337 UNSAFE_ENTRY(jobject, Unsafe_GetReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
338 oop p = JNIHandles::resolve(obj);
339 assert_field_offset_sane(p, offset);
340 oop v = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset);
341 return JNIHandles::make_local(THREAD, v);
342 } UNSAFE_END
343
344 UNSAFE_ENTRY(void, Unsafe_PutReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
345 oop x = JNIHandles::resolve(x_h);
346 oop p = JNIHandles::resolve(obj);
347 assert_field_offset_sane(p, offset);
348 assert(!p->is_inline_type() || p->mark().is_larval_state(), "must be an object instance or a larval inline type");
349 HeapAccess<ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x);
350 } UNSAFE_END
351
352 UNSAFE_ENTRY(jlong, Unsafe_ValueHeaderSize(JNIEnv *env, jobject unsafe, jclass c)) {
353 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(c));
354 InlineKlass* vk = InlineKlass::cast(k);
355 return vk->first_field_offset();
356 } UNSAFE_END
357
358 UNSAFE_ENTRY(jboolean, Unsafe_IsFlatField(JNIEnv *env, jobject unsafe, jobject o)) {
359 oop f = JNIHandles::resolve_non_null(o);
360 Klass* k = java_lang_Class::as_Klass(java_lang_reflect_Field::clazz(f));
361 int slot = java_lang_reflect_Field::slot(f);
362 return InstanceKlass::cast(k)->field_is_flat(slot);
363 } UNSAFE_END
364
365 UNSAFE_ENTRY(jboolean, Unsafe_HasNullMarker(JNIEnv *env, jobject unsage, jobject o)) {
366 oop f = JNIHandles::resolve_non_null(o);
367 Klass* k = java_lang_Class::as_Klass(java_lang_reflect_Field::clazz(f));
368 int slot = java_lang_reflect_Field::slot(f);
369 return InstanceKlass::cast(k)->field_has_null_marker(slot);
370 } UNSAFE_END
371
372 UNSAFE_ENTRY(jint, Unsafe_NullMarkerOffset(JNIEnv *env, jobject unsage, jobject o)) {
373 oop f = JNIHandles::resolve_non_null(o);
374 Klass* k = java_lang_Class::as_Klass(java_lang_reflect_Field::clazz(f));
375 int slot = java_lang_reflect_Field::slot(f);
376 return InstanceKlass::cast(k)->null_marker_offsets_array()->at(slot);
377 } UNSAFE_END
378
379 UNSAFE_ENTRY(jboolean, Unsafe_IsFlatArray(JNIEnv *env, jobject unsafe, jclass c)) {
380 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(c));
381 return k->is_flatArray_klass();
382 } UNSAFE_END
383
384 UNSAFE_ENTRY(jobject, Unsafe_UninitializedDefaultValue(JNIEnv *env, jobject unsafe, jclass vc)) {
385 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(vc));
386 InlineKlass* vk = InlineKlass::cast(k);
387 oop v = vk->default_value();
388 return JNIHandles::make_local(THREAD, v);
389 } UNSAFE_END
390
391 UNSAFE_ENTRY(jobject, Unsafe_GetValue(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jclass vc)) {
392 oop base = JNIHandles::resolve(obj);
393 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(vc));
394 InlineKlass* vk = InlineKlass::cast(k);
395 assert_and_log_unsafe_value_access(base, offset, vk);
396 Handle base_h(THREAD, base);
397 oop v = vk->read_flat_field(base_h(), offset, CHECK_NULL);
398 return JNIHandles::make_local(THREAD, v);
399 } UNSAFE_END
400
401 UNSAFE_ENTRY(void, Unsafe_PutValue(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jclass vc, jobject value)) {
402 oop base = JNIHandles::resolve(obj);
403 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(vc));
404 InlineKlass* vk = InlineKlass::cast(k);
405 assert(!base->is_inline_type() || base->mark().is_larval_state(), "must be an object instance or a larval inline type");
406 assert_and_log_unsafe_value_access(base, offset, vk);
407 oop v = JNIHandles::resolve(value);
408 vk->write_flat_field(base, offset, v, CHECK);
409 } UNSAFE_END
410
411 UNSAFE_ENTRY(jobject, Unsafe_MakePrivateBuffer(JNIEnv *env, jobject unsafe, jobject value)) {
412 oop v = JNIHandles::resolve_non_null(value);
413 assert(v->is_inline_type(), "must be an inline type instance");
414 Handle vh(THREAD, v);
415 InlineKlass* vk = InlineKlass::cast(v->klass());
416 instanceOop new_value = vk->allocate_instance_buffer(CHECK_NULL);
417 vk->inline_copy_oop_to_new_oop(vh(), new_value);
418 markWord mark = new_value->mark();
419 new_value->set_mark(mark.enter_larval_state());
420 return JNIHandles::make_local(THREAD, new_value);
421 } UNSAFE_END
422
423 UNSAFE_ENTRY(jobject, Unsafe_FinishPrivateBuffer(JNIEnv *env, jobject unsafe, jobject value)) {
424 oop v = JNIHandles::resolve(value);
425 assert(v->mark().is_larval_state(), "must be a larval value");
426 markWord mark = v->mark();
427 v->set_mark(mark.exit_larval_state());
428 return JNIHandles::make_local(THREAD, v);
429 } UNSAFE_END
430
431 UNSAFE_ENTRY(jobject, Unsafe_GetReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
432 oop p = JNIHandles::resolve(obj);
433 assert_field_offset_sane(p, offset);
434 oop v = HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset);
435 return JNIHandles::make_local(THREAD, v);
436 } UNSAFE_END
437
438 UNSAFE_ENTRY(void, Unsafe_PutReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
439 oop x = JNIHandles::resolve(x_h);
440 oop p = JNIHandles::resolve(obj);
441 assert_field_offset_sane(p, offset);
442 HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x);
443 } UNSAFE_END
444
445 UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr)) {
446 oop v = *(oop*) (address) addr;
447 return JNIHandles::make_local(THREAD, v);
448 } UNSAFE_END
449
450 #define DEFINE_GETSETOOP(java_type, Type) \
731 return false;
732 }
733 UNSAFE_END
734
735 static void getBaseAndScale(int& base, int& scale, jclass clazz, TRAPS) {
736 assert(clazz != nullptr, "clazz must not be null");
737
738 oop mirror = JNIHandles::resolve_non_null(clazz);
739 Klass* k = java_lang_Class::as_Klass(mirror);
740
741 if (k == nullptr || !k->is_array_klass()) {
742 THROW(vmSymbols::java_lang_InvalidClassException());
743 } else if (k->is_objArray_klass()) {
744 base = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
745 scale = heapOopSize;
746 } else if (k->is_typeArray_klass()) {
747 TypeArrayKlass* tak = TypeArrayKlass::cast(k);
748 base = tak->array_header_in_bytes();
749 assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
750 scale = (1 << tak->log2_element_size());
751 } else if (k->is_flatArray_klass()) {
752 FlatArrayKlass* vak = FlatArrayKlass::cast(k);
753 InlineKlass* vklass = vak->element_klass();
754 base = vak->array_header_in_bytes();
755 scale = vak->element_byte_size();
756 } else {
757 ShouldNotReachHere();
758 }
759 }
760
761 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset0(JNIEnv *env, jobject unsafe, jclass clazz)) {
762 int base = 0, scale = 0;
763 getBaseAndScale(base, scale, clazz, CHECK_0);
764
765 return field_offset_from_byte_offset(base);
766 } UNSAFE_END
767
768
769 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale0(JNIEnv *env, jobject unsafe, jclass clazz)) {
770 int base = 0, scale = 0;
771 getBaseAndScale(base, scale, clazz, CHECK_0);
772
773 // This VM packs both fields and array elements down to the byte.
774 // But watch out: If this changes, so that array references for
775 // a given primitive type (say, T_BOOLEAN) use different memory units
776 // than fields, this method MUST return zero for such arrays.
777 // For example, the VM used to store sub-word sized fields in full
778 // words in the object layout, so that accessors like getByte(Object,int)
779 // did not really do what one might expect for arrays. Therefore,
780 // this function used to report a zero scale factor, so that the user
781 // would know not to attempt to access sub-word array elements.
782 // // Code for unpacked fields:
783 // if (scale < wordSize) return 0;
784
785 // The following allows for a pretty general fieldOffset cookie scheme,
786 // but requires it to be linear in byte offset.
787 return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
788 } UNSAFE_END
789
790
791 UNSAFE_ENTRY(jlong, Unsafe_GetObjectSize0(JNIEnv* env, jobject o, jobject obj))
792 oop p = JNIHandles::resolve(obj);
793 return p->size() * HeapWordSize;
794 UNSAFE_END
795
796
797 static inline void throw_new(JNIEnv *env, const char *ename) {
798 jclass cls = env->FindClass(ename);
799 if (env->ExceptionCheck()) {
800 env->ExceptionClear();
801 tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", ename);
802 return;
803 }
804
805 env->ThrowNew(cls, nullptr);
806 }
807
808 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
809 // Code lifted from JDK 1.3 ClassLoader.c
810
811 jbyte *body;
812 char *utfName = nullptr;
813 jclass result = nullptr;
814 char buf[128];
815
816 assert(data != nullptr, "Class bytes must not be null");
996
997
998 /// JVM_RegisterUnsafeMethods
999
1000 #define ADR "J"
1001
1002 #define LANG "Ljava/lang/"
1003
1004 #define OBJ LANG "Object;"
1005 #define CLS LANG "Class;"
1006 #define FLD LANG "reflect/Field;"
1007 #define THR LANG "Throwable;"
1008
1009 #define DC_Args LANG "String;[BII" LANG "ClassLoader;" "Ljava/security/ProtectionDomain;"
1010 #define DAC_Args CLS "[B[" OBJ
1011
1012 #define CC (char*) /*cast a literal from (const char*)*/
1013 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1014
1015 #define DECLARE_GETPUTOOP(Type, Desc) \
1016 {CC "get" #Type, CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type)}, \
1017 {CC "put" #Type, CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type)}, \
1018 {CC "get" #Type "Volatile", CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type##Volatile)}, \
1019 {CC "put" #Type "Volatile", CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type##Volatile)}
1020
1021
1022 static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = {
1023 {CC "getReference", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetReference)},
1024 {CC "putReference", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReference)},
1025 {CC "getReferenceVolatile", CC "(" OBJ "J)" OBJ, FN_PTR(Unsafe_GetReferenceVolatile)},
1026 {CC "putReferenceVolatile", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReferenceVolatile)},
1027
1028 {CC "isFlatArray", CC "(" CLS ")Z", FN_PTR(Unsafe_IsFlatArray)},
1029 {CC "isFlatField0", CC "(" OBJ ")Z", FN_PTR(Unsafe_IsFlatField)},
1030 {CC "hasNullMarker0" , CC "(" OBJ ")Z", FN_PTR(Unsafe_HasNullMarker)},
1031 {CC "nullMarkerOffset0", CC "(" OBJ ")I", FN_PTR(Unsafe_NullMarkerOffset)},
1032 {CC "getValue", CC "(" OBJ "J" CLS ")" OBJ, FN_PTR(Unsafe_GetValue)},
1033 {CC "putValue", CC "(" OBJ "J" CLS OBJ ")V", FN_PTR(Unsafe_PutValue)},
1034 {CC "uninitializedDefaultValue", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_UninitializedDefaultValue)},
1035 {CC "makePrivateBuffer", CC "(" OBJ ")" OBJ, FN_PTR(Unsafe_MakePrivateBuffer)},
1036 {CC "finishPrivateBuffer", CC "(" OBJ ")" OBJ, FN_PTR(Unsafe_FinishPrivateBuffer)},
1037 {CC "valueHeaderSize", CC "(" CLS ")J", FN_PTR(Unsafe_ValueHeaderSize)},
1038
1039 {CC "getUncompressedObject", CC "(" ADR ")" OBJ, FN_PTR(Unsafe_GetUncompressedObject)},
1040
1041 DECLARE_GETPUTOOP(Boolean, Z),
1042 DECLARE_GETPUTOOP(Byte, B),
1043 DECLARE_GETPUTOOP(Short, S),
1044 DECLARE_GETPUTOOP(Char, C),
1045 DECLARE_GETPUTOOP(Int, I),
1046 DECLARE_GETPUTOOP(Long, J),
1047 DECLARE_GETPUTOOP(Float, F),
1048 DECLARE_GETPUTOOP(Double, D),
1049
1050 {CC "allocateMemory0", CC "(J)" ADR, FN_PTR(Unsafe_AllocateMemory0)},
1051 {CC "reallocateMemory0", CC "(" ADR "J)" ADR, FN_PTR(Unsafe_ReallocateMemory0)},
1052 {CC "freeMemory0", CC "(" ADR ")V", FN_PTR(Unsafe_FreeMemory0)},
1053
1054 {CC "objectFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_ObjectFieldOffset0)},
1055 {CC "objectFieldOffset1", CC "(" CLS LANG "String;)J", FN_PTR(Unsafe_ObjectFieldOffset1)},
1056 {CC "staticFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_StaticFieldOffset0)},
1057 {CC "staticFieldBase0", CC "(" FLD ")" OBJ, FN_PTR(Unsafe_StaticFieldBase0)},
1058 {CC "ensureClassInitialized0", CC "(" CLS ")V", FN_PTR(Unsafe_EnsureClassInitialized0)},
1059 {CC "arrayBaseOffset0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayBaseOffset0)},
1060 {CC "arrayIndexScale0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayIndexScale0)},
1061 {CC "getObjectSize0", CC "(Ljava/lang/Object;)J", FN_PTR(Unsafe_GetObjectSize0)},
1062
1063 {CC "defineClass0", CC "(" DC_Args ")" CLS, FN_PTR(Unsafe_DefineClass0)},
1064 {CC "allocateInstance", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_AllocateInstance)},
1065 {CC "throwException", CC "(" THR ")V", FN_PTR(Unsafe_ThrowException)},
1066 {CC "compareAndSetReference",CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSetReference)},
1067 {CC "compareAndSetInt", CC "(" OBJ "J""I""I"")Z", FN_PTR(Unsafe_CompareAndSetInt)},
1068 {CC "compareAndSetLong", CC "(" OBJ "J""J""J"")Z", FN_PTR(Unsafe_CompareAndSetLong)},
1069 {CC "compareAndExchangeReference", CC "(" OBJ "J" OBJ "" OBJ ")" OBJ, FN_PTR(Unsafe_CompareAndExchangeReference)},
1070 {CC "compareAndExchangeInt", CC "(" OBJ "J""I""I"")I", FN_PTR(Unsafe_CompareAndExchangeInt)},
1071 {CC "compareAndExchangeLong", CC "(" OBJ "J""J""J"")J", FN_PTR(Unsafe_CompareAndExchangeLong)},
1072
1073 {CC "park", CC "(ZJ)V", FN_PTR(Unsafe_Park)},
1074 {CC "unpark", CC "(" OBJ ")V", FN_PTR(Unsafe_Unpark)},
1075
1076 {CC "getLoadAverage0", CC "([DI)I", FN_PTR(Unsafe_GetLoadAverage0)},
1077
1078 {CC "copyMemory0", CC "(" OBJ "J" OBJ "JJ)V", FN_PTR(Unsafe_CopyMemory0)},
1079 {CC "copySwapMemory0", CC "(" OBJ "J" OBJ "JJJ)V", FN_PTR(Unsafe_CopySwapMemory0)},
1080 {CC "writeback0", CC "(" "J" ")V", FN_PTR(Unsafe_WriteBack0)},
1081 {CC "writebackPreSync0", CC "()V", FN_PTR(Unsafe_WriteBackPreSync0)},
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