1 /* 2 * Copyright (c) 2004, 2023, Oracle and/or its affiliates. All rights reserved. 3 * Copyright (c) 2014, 2020, Red Hat Inc. All rights reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 * 24 */ 25 26 #include "precompiled.hpp" 27 #include "asm/macroAssembler.hpp" 28 #include "gc/shared/barrierSet.hpp" 29 #include "gc/shared/barrierSetAssembler.hpp" 30 #include "memory/resourceArea.hpp" 31 #include "prims/jniFastGetField.hpp" 32 #include "prims/jvm_misc.hpp" 33 #include "prims/jvmtiExport.hpp" 34 #include "runtime/javaThread.inline.hpp" 35 #include "runtime/safepoint.hpp" 36 #include "runtime/threadWXSetters.inline.hpp" 37 38 #define __ masm-> 39 40 #define BUFFER_SIZE 30*wordSize 41 42 // Instead of issuing a LoadLoad barrier we create an address 43 // dependency between loads; this might be more efficient. 44 45 // Common register usage: 46 // r0/v0: result 47 // c_rarg0: jni env 48 // c_rarg1: obj 49 // c_rarg2: jfield id 50 51 static const Register robj = r3; 52 static const Register rcounter = r4; 53 static const Register roffset = r5; 54 static const Register rcounter_addr = r6; 55 static const Register result = r7; 56 57 // On macos/aarch64 we need to ensure WXExec mode when running generated 58 // FastGetXXXField, as these functions can be called from WXWrite context 59 // (8262896). So each FastGetXXXField is wrapped into a C++ statically 60 // compiled template function that optionally switches to WXExec if necessary. 61 62 #ifdef __APPLE__ 63 64 static address generated_fast_get_field[T_LONG + 1 - T_BOOLEAN]; 65 66 template<int BType> struct BasicTypeToJni {}; 67 template<> struct BasicTypeToJni<T_BOOLEAN> { static const jboolean jni_type; }; 68 template<> struct BasicTypeToJni<T_BYTE> { static const jbyte jni_type; }; 69 template<> struct BasicTypeToJni<T_CHAR> { static const jchar jni_type; }; 70 template<> struct BasicTypeToJni<T_SHORT> { static const jshort jni_type; }; 71 template<> struct BasicTypeToJni<T_INT> { static const jint jni_type; }; 72 template<> struct BasicTypeToJni<T_LONG> { static const jlong jni_type; }; 73 template<> struct BasicTypeToJni<T_FLOAT> { static const jfloat jni_type; }; 74 template<> struct BasicTypeToJni<T_DOUBLE> { static const jdouble jni_type; }; 75 76 template<int BType, typename JniType = decltype(BasicTypeToJni<BType>::jni_type)> 77 JniType static_fast_get_field_wrapper(JNIEnv *env, jobject obj, jfieldID fieldID) { 78 JavaThread* thread = JavaThread::thread_from_jni_environment(env); 79 ThreadWXEnable wx(WXExec, thread); 80 address get_field_addr = generated_fast_get_field[BType - T_BOOLEAN]; 81 return ((JniType(*)(JNIEnv *env, jobject obj, jfieldID fieldID))get_field_addr)(env, obj, fieldID); 82 } 83 84 template<int BType> 85 address JNI_FastGetField::generate_fast_get_int_field1() { 86 generated_fast_get_field[BType - T_BOOLEAN] = generate_fast_get_int_field0((BasicType)BType); 87 return (address)static_fast_get_field_wrapper<BType>; 88 } 89 90 #else // __APPLE__ 91 92 template<int BType> 93 address JNI_FastGetField::generate_fast_get_int_field1() { 94 return generate_fast_get_int_field0((BasicType)BType); 95 } 96 97 #endif // __APPLE__ 98 99 address JNI_FastGetField::generate_fast_get_int_field0(BasicType type) { 100 const char *name; 101 switch (type) { 102 case T_BOOLEAN: name = "jni_fast_GetBooleanField"; break; 103 case T_BYTE: name = "jni_fast_GetByteField"; break; 104 case T_CHAR: name = "jni_fast_GetCharField"; break; 105 case T_SHORT: name = "jni_fast_GetShortField"; break; 106 case T_INT: name = "jni_fast_GetIntField"; break; 107 case T_LONG: name = "jni_fast_GetLongField"; break; 108 case T_FLOAT: name = "jni_fast_GetFloatField"; break; 109 case T_DOUBLE: name = "jni_fast_GetDoubleField"; break; 110 default: ShouldNotReachHere(); 111 name = nullptr; // unreachable 112 } 113 ResourceMark rm; 114 BufferBlob* blob = BufferBlob::create(name, BUFFER_SIZE); 115 CodeBuffer cbuf(blob); 116 MacroAssembler* masm = new MacroAssembler(&cbuf); 117 address fast_entry = __ pc(); 118 119 Label slow; 120 121 uint64_t offset; 122 __ adrp(rcounter_addr, 123 SafepointSynchronize::safepoint_counter_addr(), offset); 124 Address safepoint_counter_addr(rcounter_addr, offset); 125 __ ldrw(rcounter, safepoint_counter_addr); 126 __ tbnz(rcounter, 0, slow); 127 128 // It doesn't need to issue a full barrier here even if the field 129 // is volatile, since it has already used "ldar" for it. 130 if (JvmtiExport::can_post_field_access()) { 131 // Using barrier to order wrt. JVMTI check and load of result. 132 __ membar(Assembler::LoadLoad); 133 134 // Check to see if a field access watch has been set before we 135 // take the fast path. 136 uint64_t offset2; 137 __ adrp(result, 138 ExternalAddress((address) JvmtiExport::get_field_access_count_addr()), 139 offset2); 140 __ ldrw(result, Address(result, offset2)); 141 __ cbnzw(result, slow); 142 143 __ mov(robj, c_rarg1); 144 } else { 145 // Using address dependency to order wrt. load of result. 146 __ eor(robj, c_rarg1, rcounter); 147 __ eor(robj, robj, rcounter); // obj, since 148 // robj ^ rcounter ^ rcounter == robj 149 // robj is address dependent on rcounter. 150 } 151 152 // Both robj and rscratch1 are clobbered by try_resolve_jobject_in_native. 153 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler(); 154 bs->try_resolve_jobject_in_native(masm, c_rarg0, robj, rscratch1, slow); 155 156 __ lsr(roffset, c_rarg2, 2); // offset 157 __ add(result, robj, roffset); 158 159 assert(count < LIST_CAPACITY, "LIST_CAPACITY too small"); 160 speculative_load_pclist[count] = __ pc(); // Used by the segfault handler 161 // Using acquire: Order JVMTI check and load of result wrt. succeeding check 162 // (LoadStore for volatile field). 163 switch (type) { 164 case T_BOOLEAN: __ ldarb(result, result); break; 165 case T_BYTE: __ ldarb(result, result); __ sxtb(result, result); break; 166 case T_CHAR: __ ldarh(result, result); break; 167 case T_SHORT: __ ldarh(result, result); __ sxth(result, result); break; 168 case T_FLOAT: __ ldarw(result, result); break; 169 case T_INT: __ ldarw(result, result); __ sxtw(result, result); break; 170 case T_DOUBLE: 171 case T_LONG: __ ldar (result, result); break; 172 default: ShouldNotReachHere(); 173 } 174 175 __ ldrw(rscratch1, safepoint_counter_addr); 176 __ cmpw(rcounter, rscratch1); 177 __ br (Assembler::NE, slow); 178 179 switch (type) { 180 case T_FLOAT: __ fmovs(v0, result); break; 181 case T_DOUBLE: __ fmovd(v0, result); break; 182 default: __ mov(r0, result); break; 183 } 184 __ ret(lr); 185 186 slowcase_entry_pclist[count++] = __ pc(); 187 __ bind(slow); 188 address slow_case_addr; 189 switch (type) { 190 case T_BOOLEAN: slow_case_addr = jni_GetBooleanField_addr(); break; 191 case T_BYTE: slow_case_addr = jni_GetByteField_addr(); break; 192 case T_CHAR: slow_case_addr = jni_GetCharField_addr(); break; 193 case T_SHORT: slow_case_addr = jni_GetShortField_addr(); break; 194 case T_INT: slow_case_addr = jni_GetIntField_addr(); break; 195 case T_LONG: slow_case_addr = jni_GetLongField_addr(); break; 196 case T_FLOAT: slow_case_addr = jni_GetFloatField_addr(); break; 197 case T_DOUBLE: slow_case_addr = jni_GetDoubleField_addr(); break; 198 default: ShouldNotReachHere(); 199 slow_case_addr = nullptr; // unreachable 200 } 201 202 { 203 __ enter(); 204 __ lea(rscratch1, ExternalAddress(slow_case_addr)); 205 __ blr(rscratch1); 206 __ leave(); 207 __ ret(lr); 208 } 209 __ flush (); 210 211 return fast_entry; 212 } 213 214 address JNI_FastGetField::generate_fast_get_boolean_field() { 215 return generate_fast_get_int_field1<T_BOOLEAN>(); 216 } 217 218 address JNI_FastGetField::generate_fast_get_byte_field() { 219 return generate_fast_get_int_field1<T_BYTE>(); 220 } 221 222 address JNI_FastGetField::generate_fast_get_char_field() { 223 return generate_fast_get_int_field1<T_CHAR>(); 224 } 225 226 address JNI_FastGetField::generate_fast_get_short_field() { 227 return generate_fast_get_int_field1<T_SHORT>(); 228 } 229 230 address JNI_FastGetField::generate_fast_get_int_field() { 231 return generate_fast_get_int_field1<T_INT>(); 232 } 233 234 address JNI_FastGetField::generate_fast_get_long_field() { 235 return generate_fast_get_int_field1<T_LONG>(); 236 } 237 238 address JNI_FastGetField::generate_fast_get_float_field() { 239 return generate_fast_get_int_field1<T_FLOAT>(); 240 } 241 242 address JNI_FastGetField::generate_fast_get_double_field() { 243 return generate_fast_get_int_field1<T_DOUBLE>(); 244 }