1 /* 2 * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 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 "code/debugInfo.hpp" 26 #include "oops/access.hpp" 27 #include "oops/compressedOops.inline.hpp" 28 #include "oops/oop.hpp" 29 #include "runtime/frame.inline.hpp" 30 #include "runtime/globals.hpp" 31 #include "runtime/handles.inline.hpp" 32 #include "runtime/stackValue.hpp" 33 #if INCLUDE_SHENANDOAHGC 34 #include "gc/shenandoah/shenandoahBarrierSet.inline.hpp" 35 #endif 36 37 class RegisterMap; 38 class SmallRegisterMap; 39 40 template StackValue* StackValue::create_stack_value(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv); 41 template StackValue* StackValue::create_stack_value(const frame* fr, const SmallRegisterMap* reg_map, ScopeValue* sv); 42 43 template<typename RegisterMapT> 44 StackValue* StackValue::create_stack_value(const frame* fr, const RegisterMapT* reg_map, ScopeValue* sv) { 45 return create_stack_value(sv, stack_value_address(fr, reg_map, sv), reg_map); 46 } 47 48 static oop oop_from_oop_location(stackChunkOop chunk, void* addr) { 49 if (addr == nullptr) { 50 return nullptr; 51 } 52 53 if (UseCompressedOops) { 54 // When compressed oops is enabled, an oop location may 55 // contain narrow oop values - we deal with that here 56 57 if (chunk != nullptr && chunk->has_bitmap()) { 58 // Transformed stack chunk with narrow oops 59 return chunk->load_oop((narrowOop*)addr); 60 } 61 62 #ifdef _LP64 63 if (CompressedOops::is_base(*(void**)addr)) { 64 // Compiled code may produce decoded oop = narrow_oop_base 65 // when a narrow oop implicit null check is used. 66 // The narrow_oop_base could be null or be the address 67 // of the page below heap. Use null value for both cases. 68 return nullptr; 69 } 70 #endif 71 } 72 73 if (chunk != nullptr) { 74 // Load oop from chunk 75 return chunk->load_oop((oop*)addr); 76 } 77 78 // Load oop from stack 79 oop val = *(oop*)addr; 80 81 #if INCLUDE_SHENANDOAHGC 82 if (UseShenandoahGC) { 83 // Pass the value through the barrier to avoid capturing bad oops as 84 // stack values. Note: do not heal the location, to avoid accidentally 85 // corrupting the stack. Stack watermark barriers are supposed to handle 86 // the healing. 87 val = ShenandoahBarrierSet::barrier_set()->load_reference_barrier(val); 88 } 89 #endif 90 91 return val; 92 } 93 94 static oop oop_from_narrowOop_location(stackChunkOop chunk, void* addr, bool is_register) { 95 assert(UseCompressedOops, "Narrow oops should not exist"); 96 assert(addr != nullptr, "Not expecting null address"); 97 narrowOop* narrow_addr; 98 if (is_register) { 99 // The callee has no clue whether the register holds an int, 100 // long or is unused. He always saves a long. Here we know 101 // a long was saved, but we only want an int back. Narrow the 102 // saved long to the int that the JVM wants. We can't just 103 // use narrow_oop_cast directly, because we don't know what 104 // the high bits of the value might be. 105 narrow_addr = ((narrowOop*)addr) BIG_ENDIAN_ONLY(+ 1); 106 } else { 107 narrow_addr = (narrowOop*)addr; 108 } 109 110 if (chunk != nullptr) { 111 // Load oop from chunk 112 return chunk->load_oop(narrow_addr); 113 } 114 115 // Load oop from stack 116 oop val = CompressedOops::decode(*narrow_addr); 117 118 #if INCLUDE_SHENANDOAHGC 119 if (UseShenandoahGC) { 120 // Pass the value through the barrier to avoid capturing bad oops as 121 // stack values. Note: do not heal the location, to avoid accidentally 122 // corrupting the stack. Stack watermark barriers are supposed to handle 123 // the healing. 124 val = ShenandoahBarrierSet::barrier_set()->load_reference_barrier(val); 125 } 126 #endif 127 128 return val; 129 } 130 131 StackValue* StackValue::create_stack_value_from_oop_location(stackChunkOop chunk, void* addr) { 132 oop val = oop_from_oop_location(chunk, addr); 133 assert(oopDesc::is_oop_or_null(val), "bad oop found at " INTPTR_FORMAT " in_cont: %d compressed: %d", 134 p2i(addr), chunk != nullptr, chunk != nullptr && chunk->has_bitmap() && UseCompressedOops); 135 Handle h(Thread::current(), val); // Wrap a handle around the oop 136 return new StackValue(h); 137 } 138 139 StackValue* StackValue::create_stack_value_from_narrowOop_location(stackChunkOop chunk, void* addr, bool is_register) { 140 oop val = oop_from_narrowOop_location(chunk, addr, is_register); 141 assert(oopDesc::is_oop_or_null(val), "bad oop found at " INTPTR_FORMAT " in_cont: %d compressed: %d", 142 p2i(addr), chunk != nullptr, chunk != nullptr && chunk->has_bitmap() && UseCompressedOops); 143 Handle h(Thread::current(), val); // Wrap a handle around the oop 144 return new StackValue(h); 145 } 146 147 template<typename RegisterMapT> 148 StackValue* StackValue::create_stack_value(ScopeValue* sv, address value_addr, const RegisterMapT* reg_map) { 149 stackChunkOop chunk = reg_map->stack_chunk()(); 150 if (sv->is_location()) { 151 // Stack or register value 152 Location loc = ((LocationValue *)sv)->location(); 153 154 // Then package it right depending on type 155 // Note: the transfer of the data is thru a union that contains 156 // an intptr_t. This is because an interpreter stack slot is 157 // really an intptr_t. The use of a union containing an intptr_t 158 // ensures that on a 64 bit platform we have proper alignment 159 // and that we store the value where the interpreter will expect 160 // to find it (i.e. proper endian). Similarly on a 32bit platform 161 // using the intptr_t ensures that when a value is larger than 162 // a stack slot (jlong/jdouble) that we capture the proper part 163 // of the value for the stack slot in question. 164 // 165 switch( loc.type() ) { 166 case Location::float_in_dbl: { // Holds a float in a double register? 167 // The callee has no clue whether the register holds a float, 168 // double or is unused. He always saves a double. Here we know 169 // a double was saved, but we only want a float back. Narrow the 170 // saved double to the float that the JVM wants. 171 assert( loc.is_register(), "floats always saved to stack in 1 word" ); 172 union { intptr_t p; jfloat jf; } value; 173 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF); 174 value.jf = (jfloat) *(jdouble*) value_addr; 175 return new StackValue(value.p); // 64-bit high half is stack junk 176 } 177 case Location::int_in_long: { // Holds an int in a long register? 178 // The callee has no clue whether the register holds an int, 179 // long or is unused. He always saves a long. Here we know 180 // a long was saved, but we only want an int back. Narrow the 181 // saved long to the int that the JVM wants. 182 assert( loc.is_register(), "ints always saved to stack in 1 word" ); 183 union { intptr_t p; jint ji;} value; 184 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF); 185 value.ji = (jint) *(jlong*) value_addr; 186 return new StackValue(value.p); // 64-bit high half is stack junk 187 } 188 #ifdef _LP64 189 case Location::dbl: 190 // Double value in an aligned adjacent pair 191 return new StackValue(*(intptr_t*)value_addr); 192 case Location::lng: 193 // Long value in an aligned adjacent pair 194 return new StackValue(*(intptr_t*)value_addr); 195 case Location::narrowoop: 196 return create_stack_value_from_narrowOop_location(reg_map->stack_chunk()(), (void*)value_addr, loc.is_register()); 197 #endif 198 case Location::oop: 199 return create_stack_value_from_oop_location(reg_map->stack_chunk()(), (void*)value_addr); 200 case Location::addr: { 201 loc.print_on(tty); 202 ShouldNotReachHere(); // both C1 and C2 now inline jsrs 203 } 204 case Location::normal: { 205 // Just copy all other bits straight through 206 union { intptr_t p; jint ji;} value; 207 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF); 208 value.ji = *(jint*)value_addr; 209 return new StackValue(value.p); 210 } 211 case Location::invalid: { 212 return new StackValue(); 213 } 214 case Location::vector: { 215 loc.print_on(tty); 216 ShouldNotReachHere(); // should be handled by VectorSupport::allocate_vector() 217 } 218 default: 219 loc.print_on(tty); 220 ShouldNotReachHere(); 221 } 222 223 } else if (sv->is_constant_int()) { 224 // Constant int: treat same as register int. 225 union { intptr_t p; jint ji;} value; 226 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF); 227 value.ji = (jint)((ConstantIntValue*)sv)->value(); 228 return new StackValue(value.p); 229 } else if (sv->is_constant_oop()) { 230 // constant oop 231 return new StackValue(sv->as_ConstantOopReadValue()->value()); 232 #ifdef _LP64 233 } else if (sv->is_constant_double()) { 234 // Constant double in a single stack slot 235 union { intptr_t p; double d; } value; 236 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF); 237 value.d = ((ConstantDoubleValue *)sv)->value(); 238 return new StackValue(value.p); 239 } else if (sv->is_constant_long()) { 240 // Constant long in a single stack slot 241 union { intptr_t p; jlong jl; } value; 242 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF); 243 value.jl = ((ConstantLongValue *)sv)->value(); 244 return new StackValue(value.p); 245 #endif 246 } else if (sv->is_object()) { // Scalar replaced object in compiled frame 247 ObjectValue* ov = (ObjectValue *)sv; 248 Handle hdl = ov->value(); 249 return new StackValue(hdl, hdl.is_null() && ov->is_scalar_replaced() ? 1 : 0); 250 } else if (sv->is_marker()) { 251 // Should never need to directly construct a marker. 252 ShouldNotReachHere(); 253 } 254 // Unknown ScopeValue type 255 ShouldNotReachHere(); 256 return new StackValue((intptr_t) 0); // dummy 257 } 258 259 template address StackValue::stack_value_address(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv); 260 template address StackValue::stack_value_address(const frame* fr, const SmallRegisterMap* reg_map, ScopeValue* sv); 261 262 template<typename RegisterMapT> 263 address StackValue::stack_value_address(const frame* fr, const RegisterMapT* reg_map, ScopeValue* sv) { 264 if (!sv->is_location()) { 265 return nullptr; 266 } 267 Location loc = ((LocationValue *)sv)->location(); 268 if (loc.type() == Location::invalid) { 269 return nullptr; 270 } 271 272 if (!reg_map->in_cont()) { 273 address value_addr = loc.is_register() 274 // Value was in a callee-save register 275 ? reg_map->location(VMRegImpl::as_VMReg(loc.register_number()), fr->sp()) 276 // Else value was directly saved on the stack. The frame's original stack pointer, 277 // before any extension by its callee (due to Compiler1 linkage on SPARC), must be used. 278 : ((address)fr->unextended_sp()) + loc.stack_offset(); 279 280 assert(value_addr == nullptr || reg_map->thread() == nullptr || reg_map->thread()->is_in_usable_stack(value_addr), INTPTR_FORMAT, p2i(value_addr)); 281 return value_addr; 282 } 283 284 address value_addr = loc.is_register() 285 ? reg_map->as_RegisterMap()->stack_chunk()->reg_to_location(*fr, reg_map->as_RegisterMap(), VMRegImpl::as_VMReg(loc.register_number())) 286 : reg_map->as_RegisterMap()->stack_chunk()->usp_offset_to_location(*fr, loc.stack_offset()); 287 288 assert(value_addr == nullptr || Continuation::is_in_usable_stack(value_addr, reg_map->as_RegisterMap()) || (reg_map->thread() != nullptr && reg_map->thread()->is_in_usable_stack(value_addr)), INTPTR_FORMAT, p2i(value_addr)); 289 return value_addr; 290 } 291 292 BasicLock* StackValue::resolve_monitor_lock(const frame& fr, Location location) { 293 assert(location.is_stack(), "for now we only look at the stack"); 294 int word_offset = location.stack_offset() / wordSize; 295 // (stack picture) 296 // high: [ ] word_offset + 1 297 // low [ ] word_offset 298 // 299 // sp-> [ ] 0 300 // the word_offset is the distance from the stack pointer to the lowest address 301 // The frame's original stack pointer, before any extension by its callee 302 // (due to Compiler1 linkage on SPARC), must be used. 303 return (BasicLock*) (fr.unextended_sp() + word_offset); 304 } 305 306 307 #ifndef PRODUCT 308 309 void StackValue::print_on(outputStream* st) const { 310 switch(_type) { 311 case T_INT: 312 st->print("%d (int) %f (float) %x (hex)", *(int *)&_integer_value, *(float *)&_integer_value, *(int *)&_integer_value); 313 break; 314 315 case T_OBJECT: 316 if (_handle_value() != nullptr) { 317 _handle_value()->print_value_on(st); 318 } else { 319 st->print("null"); 320 } 321 st->print(" <" INTPTR_FORMAT ">", p2i(_handle_value())); 322 break; 323 324 case T_CONFLICT: 325 st->print("conflict"); 326 break; 327 328 default: 329 ShouldNotReachHere(); 330 } 331 } 332 333 #endif