1 /* 2 * Copyright (c) 1997, 2024, 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 "precompiled.hpp" 26 #include "code/debugInfo.hpp" 27 #include "oops/access.hpp" 28 #include "oops/compressedOops.inline.hpp" 29 #include "oops/oop.hpp" 30 #include "runtime/frame.inline.hpp" 31 #include "runtime/globals.hpp" 32 #include "runtime/handles.inline.hpp" 33 #include "runtime/stackValue.hpp" 34 #if INCLUDE_ZGC 35 #include "gc/z/zBarrier.inline.hpp" 36 #endif 37 #if INCLUDE_SHENANDOAHGC 38 #include "gc/shenandoah/shenandoahBarrierSet.inline.hpp" 39 #endif 40 41 class RegisterMap; 42 class SmallRegisterMap; 43 44 template StackValue* StackValue::create_stack_value(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv); 45 template StackValue* StackValue::create_stack_value(const frame* fr, const SmallRegisterMap* reg_map, ScopeValue* sv); 46 47 template<typename RegisterMapT> 48 StackValue* StackValue::create_stack_value(const frame* fr, const RegisterMapT* reg_map, ScopeValue* sv) { 49 return create_stack_value(sv, stack_value_address(fr, reg_map, sv), reg_map); 50 } 51 52 static oop oop_from_oop_location(stackChunkOop chunk, void* addr) { 53 if (addr == nullptr) { 54 return nullptr; 55 } 56 57 if (UseCompressedOops) { 58 // When compressed oops is enabled, an oop location may 59 // contain narrow oop values - we deal with that here 60 61 if (chunk != nullptr && chunk->has_bitmap()) { 62 // Transformed stack chunk with narrow oops 63 return chunk->load_oop((narrowOop*)addr); 64 } 65 66 #ifdef _LP64 67 if (CompressedOops::is_base(*(void**)addr)) { 68 // Compiled code may produce decoded oop = narrow_oop_base 69 // when a narrow oop implicit null check is used. 70 // The narrow_oop_base could be null or be the address 71 // of the page below heap. Use null value for both cases. 72 return nullptr; 73 } 74 #endif 75 } 76 77 if (chunk != nullptr) { 78 // Load oop from chunk 79 return chunk->load_oop((oop*)addr); 80 } 81 82 // Load oop from stack 83 oop val = *(oop*)addr; 84 85 #if INCLUDE_SHENANDOAHGC 86 if (UseShenandoahGC) { 87 // Pass the value through the barrier to avoid capturing bad oops as 88 // stack values. Note: do not heal the location, to avoid accidentally 89 // corrupting the stack. Stack watermark barriers are supposed to handle 90 // the healing. 91 val = ShenandoahBarrierSet::barrier_set()->load_reference_barrier(val); 92 } 93 #endif 94 95 return val; 96 } 97 98 static oop oop_from_narrowOop_location(stackChunkOop chunk, void* addr, bool is_register) { 99 assert(UseCompressedOops, "Narrow oops should not exist"); 100 assert(addr != nullptr, "Not expecting null address"); 101 narrowOop* narrow_addr; 102 if (is_register) { 103 // The callee has no clue whether the register holds an int, 104 // long or is unused. He always saves a long. Here we know 105 // a long was saved, but we only want an int back. Narrow the 106 // saved long to the int that the JVM wants. We can't just 107 // use narrow_oop_cast directly, because we don't know what 108 // the high bits of the value might be. 109 narrow_addr = ((narrowOop*)addr) BIG_ENDIAN_ONLY(+ 1); 110 } else { 111 narrow_addr = (narrowOop*)addr; 112 } 113 114 if (chunk != nullptr) { 115 // Load oop from chunk 116 return chunk->load_oop(narrow_addr); 117 } 118 119 // Load oop from stack 120 oop val = CompressedOops::decode(*narrow_addr); 121 122 #if INCLUDE_SHENANDOAHGC 123 if (UseShenandoahGC) { 124 // Pass the value through the barrier to avoid capturing bad oops as 125 // stack values. Note: do not heal the location, to avoid accidentally 126 // corrupting the stack. Stack watermark barriers are supposed to handle 127 // the healing. 128 val = ShenandoahBarrierSet::barrier_set()->load_reference_barrier(val); 129 } 130 #endif 131 132 return val; 133 } 134 135 StackValue* StackValue::create_stack_value_from_oop_location(stackChunkOop chunk, void* addr) { 136 oop val = oop_from_oop_location(chunk, addr); 137 assert(oopDesc::is_oop_or_null(val), "bad oop found at " INTPTR_FORMAT " in_cont: %d compressed: %d", 138 p2i(addr), chunk != nullptr, chunk != nullptr && chunk->has_bitmap() && UseCompressedOops); 139 Handle h(Thread::current(), val); // Wrap a handle around the oop 140 return new StackValue(h); 141 } 142 143 StackValue* StackValue::create_stack_value_from_narrowOop_location(stackChunkOop chunk, void* addr, bool is_register) { 144 oop val = oop_from_narrowOop_location(chunk, addr, is_register); 145 assert(oopDesc::is_oop_or_null(val), "bad oop found at " INTPTR_FORMAT " in_cont: %d compressed: %d", 146 p2i(addr), chunk != nullptr, chunk != nullptr && chunk->has_bitmap() && UseCompressedOops); 147 Handle h(Thread::current(), val); // Wrap a handle around the oop 148 return new StackValue(h); 149 } 150 151 template<typename RegisterMapT> 152 StackValue* StackValue::create_stack_value(ScopeValue* sv, address value_addr, const RegisterMapT* reg_map) { 153 stackChunkOop chunk = reg_map->stack_chunk()(); 154 if (sv->is_location()) { 155 // Stack or register value 156 Location loc = ((LocationValue *)sv)->location(); 157 158 // Then package it right depending on type 159 // Note: the transfer of the data is thru a union that contains 160 // an intptr_t. This is because an interpreter stack slot is 161 // really an intptr_t. The use of a union containing an intptr_t 162 // ensures that on a 64 bit platform we have proper alignment 163 // and that we store the value where the interpreter will expect 164 // to find it (i.e. proper endian). Similarly on a 32bit platform 165 // using the intptr_t ensures that when a value is larger than 166 // a stack slot (jlong/jdouble) that we capture the proper part 167 // of the value for the stack slot in question. 168 // 169 switch( loc.type() ) { 170 case Location::float_in_dbl: { // Holds a float in a double register? 171 // The callee has no clue whether the register holds a float, 172 // double or is unused. He always saves a double. Here we know 173 // a double was saved, but we only want a float back. Narrow the 174 // saved double to the float that the JVM wants. 175 assert( loc.is_register(), "floats always saved to stack in 1 word" ); 176 union { intptr_t p; jfloat jf; } value; 177 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF); 178 value.jf = (jfloat) *(jdouble*) value_addr; 179 return new StackValue(value.p); // 64-bit high half is stack junk 180 } 181 case Location::int_in_long: { // Holds an int in a long register? 182 // The callee has no clue whether the register holds an int, 183 // long or is unused. He always saves a long. Here we know 184 // a long was saved, but we only want an int back. Narrow the 185 // saved long to the int that the JVM wants. 186 assert( loc.is_register(), "ints always saved to stack in 1 word" ); 187 union { intptr_t p; jint ji;} value; 188 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF); 189 value.ji = (jint) *(jlong*) value_addr; 190 return new StackValue(value.p); // 64-bit high half is stack junk 191 } 192 #ifdef _LP64 193 case Location::dbl: 194 // Double value in an aligned adjacent pair 195 return new StackValue(*(intptr_t*)value_addr); 196 case Location::lng: 197 // Long value in an aligned adjacent pair 198 return new StackValue(*(intptr_t*)value_addr); 199 case Location::narrowoop: 200 return create_stack_value_from_narrowOop_location(reg_map->stack_chunk()(), (void*)value_addr, loc.is_register()); 201 #endif 202 case Location::oop: 203 return create_stack_value_from_oop_location(reg_map->stack_chunk()(), (void*)value_addr); 204 case Location::addr: { 205 loc.print_on(tty); 206 ShouldNotReachHere(); // both C1 and C2 now inline jsrs 207 } 208 case Location::normal: { 209 // Just copy all other bits straight through 210 union { intptr_t p; jint ji;} value; 211 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF); 212 value.ji = *(jint*)value_addr; 213 return new StackValue(value.p); 214 } 215 case Location::invalid: { 216 return new StackValue(); 217 } 218 case Location::vector: { 219 loc.print_on(tty); 220 ShouldNotReachHere(); // should be handled by VectorSupport::allocate_vector() 221 } 222 default: 223 loc.print_on(tty); 224 ShouldNotReachHere(); 225 } 226 227 } else if (sv->is_constant_int()) { 228 // Constant int: treat same as register int. 229 union { intptr_t p; jint ji;} value; 230 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF); 231 value.ji = (jint)((ConstantIntValue*)sv)->value(); 232 return new StackValue(value.p); 233 } else if (sv->is_constant_oop()) { 234 // constant oop 235 return new StackValue(sv->as_ConstantOopReadValue()->value()); 236 #ifdef _LP64 237 } else if (sv->is_constant_double()) { 238 // Constant double in a single stack slot 239 union { intptr_t p; double d; } value; 240 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF); 241 value.d = ((ConstantDoubleValue *)sv)->value(); 242 return new StackValue(value.p); 243 } else if (sv->is_constant_long()) { 244 // Constant long in a single stack slot 245 union { intptr_t p; jlong jl; } value; 246 value.p = (intptr_t) CONST64(0xDEADDEAFDEADDEAF); 247 value.jl = ((ConstantLongValue *)sv)->value(); 248 return new StackValue(value.p); 249 #endif 250 } else if (sv->is_object()) { // Scalar replaced object in compiled frame 251 ObjectValue* ov = (ObjectValue *)sv; 252 Handle hdl = ov->value(); 253 return new StackValue(hdl, hdl.is_null() && ov->is_scalar_replaced() ? 1 : 0); 254 } else if (sv->is_marker()) { 255 // Should never need to directly construct a marker. 256 ShouldNotReachHere(); 257 } 258 // Unknown ScopeValue type 259 ShouldNotReachHere(); 260 return new StackValue((intptr_t) 0); // dummy 261 } 262 263 template address StackValue::stack_value_address(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv); 264 template address StackValue::stack_value_address(const frame* fr, const SmallRegisterMap* reg_map, ScopeValue* sv); 265 266 template<typename RegisterMapT> 267 address StackValue::stack_value_address(const frame* fr, const RegisterMapT* reg_map, ScopeValue* sv) { 268 if (!sv->is_location()) { 269 return nullptr; 270 } 271 Location loc = ((LocationValue *)sv)->location(); 272 if (loc.type() == Location::invalid) { 273 return nullptr; 274 } 275 276 if (!reg_map->in_cont()) { 277 address value_addr = loc.is_register() 278 // Value was in a callee-save register 279 ? reg_map->location(VMRegImpl::as_VMReg(loc.register_number()), fr->sp()) 280 // Else value was directly saved on the stack. The frame's original stack pointer, 281 // before any extension by its callee (due to Compiler1 linkage on SPARC), must be used. 282 : ((address)fr->unextended_sp()) + loc.stack_offset(); 283 284 assert(value_addr == nullptr || reg_map->thread() == nullptr || reg_map->thread()->is_in_usable_stack(value_addr), INTPTR_FORMAT, p2i(value_addr)); 285 return value_addr; 286 } 287 288 address value_addr = loc.is_register() 289 ? reg_map->as_RegisterMap()->stack_chunk()->reg_to_location(*fr, reg_map->as_RegisterMap(), VMRegImpl::as_VMReg(loc.register_number())) 290 : reg_map->as_RegisterMap()->stack_chunk()->usp_offset_to_location(*fr, loc.stack_offset()); 291 292 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)); 293 return value_addr; 294 } 295 296 BasicLock* StackValue::resolve_monitor_lock(const frame& fr, Location location) { 297 assert(location.is_stack(), "for now we only look at the stack"); 298 int word_offset = location.stack_offset() / wordSize; 299 // (stack picture) 300 // high: [ ] word_offset + 1 301 // low [ ] word_offset 302 // 303 // sp-> [ ] 0 304 // the word_offset is the distance from the stack pointer to the lowest address 305 // The frame's original stack pointer, before any extension by its callee 306 // (due to Compiler1 linkage on SPARC), must be used. 307 return (BasicLock*) (fr.unextended_sp() + word_offset); 308 } 309 310 311 #ifndef PRODUCT 312 313 void StackValue::print_on(outputStream* st) const { 314 switch(_type) { 315 case T_INT: 316 st->print("%d (int) %f (float) %x (hex)", *(int *)&_integer_value, *(float *)&_integer_value, *(int *)&_integer_value); 317 break; 318 319 case T_OBJECT: 320 if (_handle_value() != nullptr) { 321 _handle_value()->print_value_on(st); 322 } else { 323 st->print("null"); 324 } 325 st->print(" <" INTPTR_FORMAT ">", p2i(_handle_value())); 326 break; 327 328 case T_CONFLICT: 329 st->print("conflict"); 330 break; 331 332 default: 333 ShouldNotReachHere(); 334 } 335 } 336 337 #endif