1 /* 2 * Copyright (c) 2020, 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. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 * 25 */ 26 package jdk.internal.foreign.abi.x64.sysv; 27 28 import jdk.incubator.foreign.CSupport; 29 import jdk.incubator.foreign.GroupLayout; 30 import jdk.incubator.foreign.MemoryAddress; 31 import jdk.incubator.foreign.MemoryHandles; 32 import jdk.incubator.foreign.MemoryLayout; 33 import jdk.incubator.foreign.MemorySegment; 34 import jdk.internal.foreign.NativeMemorySegmentImpl; 35 import jdk.internal.foreign.Utils; 36 import jdk.internal.foreign.abi.SharedUtils; 37 import jdk.internal.misc.Unsafe; 38 39 import java.lang.invoke.VarHandle; 40 import java.lang.ref.Cleaner; 41 import java.nio.ByteOrder; 42 import java.util.ArrayList; 43 import java.util.List; 44 45 import static jdk.incubator.foreign.CSupport.SysV; 46 import static jdk.incubator.foreign.CSupport.VaList; 47 import static jdk.incubator.foreign.MemoryLayout.PathElement.groupElement; 48 import static jdk.internal.foreign.abi.SharedUtils.SimpleVaArg; 49 import static jdk.internal.foreign.abi.SharedUtils.checkCompatibleType; 50 import static jdk.internal.foreign.abi.SharedUtils.vhPrimitiveOrAddress; 51 52 // See https://software.intel.com/sites/default/files/article/402129/mpx-linux64-abi.pdf "3.5.7 Variable Argument Lists" 53 public class SysVVaList implements VaList { 54 private static final Unsafe U = Unsafe.getUnsafe(); 55 56 static final Class<?> CARRIER = MemoryAddress.class; 57 58 // struct typedef __va_list_tag __va_list_tag { 59 // unsigned int gp_offset; /* 0 4 */ 60 // unsigned int fp_offset; /* 4 4 */ 61 // void * overflow_arg_area; /* 8 8 */ 62 // void * reg_save_area; /* 16 8 */ 63 // 64 // /* size: 24, cachelines: 1, members: 4 */ 65 // /* last cacheline: 24 bytes */ 66 // }; 67 static final GroupLayout LAYOUT = MemoryLayout.ofStruct( 68 SysV.C_INT.withName("gp_offset"), 69 SysV.C_INT.withName("fp_offset"), 70 SysV.C_POINTER.withName("overflow_arg_area"), 71 SysV.C_POINTER.withName("reg_save_area") 72 ).withName("__va_list_tag"); 73 74 private static final MemoryLayout GP_REG = MemoryLayout.ofValueBits(64, ByteOrder.nativeOrder()); 75 private static final MemoryLayout FP_REG = MemoryLayout.ofValueBits(128, ByteOrder.nativeOrder()); 76 77 private static final GroupLayout LAYOUT_REG_SAVE_AREA = MemoryLayout.ofStruct( 78 GP_REG.withName("%rdi"), 79 GP_REG.withName("%rsi"), 80 GP_REG.withName("%rdx"), 81 GP_REG.withName("%rcx"), 82 GP_REG.withName("%r8"), 83 GP_REG.withName("%r9"), 84 FP_REG.withName("%xmm0"), 85 FP_REG.withName("%xmm1"), 86 FP_REG.withName("%xmm2"), 87 FP_REG.withName("%xmm3"), 88 FP_REG.withName("%xmm4"), 89 FP_REG.withName("%xmm5"), 90 FP_REG.withName("%xmm6"), 91 FP_REG.withName("%xmm7") 92 // specification and implementation differ as to whether the following are part of a reg save area 93 // Let's go with the implementation, since then it actually works :) 94 // FP_REG.withName("%xmm8"), 95 // FP_REG.withName("%xmm9"), 96 // FP_REG.withName("%xmm10"), 97 // FP_REG.withName("%xmm11"), 98 // FP_REG.withName("%xmm12"), 99 // FP_REG.withName("%xmm13"), 100 // FP_REG.withName("%xmm14"), 101 // FP_REG.withName("%xmm15") 102 ); 103 104 private static final long FP_OFFSET = LAYOUT_REG_SAVE_AREA.byteOffset(groupElement("%xmm0")); 105 106 private static final int GP_SLOT_SIZE = (int) GP_REG.byteSize(); 107 private static final int FP_SLOT_SIZE = (int) FP_REG.byteSize(); 108 109 private static final int MAX_GP_OFFSET = (int) FP_OFFSET; // 6 regs used 110 private static final int MAX_FP_OFFSET = (int) LAYOUT_REG_SAVE_AREA.byteSize(); // 8 16 byte regs 111 112 private static final VarHandle VH_fp_offset = LAYOUT.varHandle(int.class, groupElement("fp_offset")); 113 private static final VarHandle VH_gp_offset = LAYOUT.varHandle(int.class, groupElement("gp_offset")); 114 private static final VarHandle VH_overflow_arg_area 115 = MemoryHandles.asAddressVarHandle(LAYOUT.varHandle(long.class, groupElement("overflow_arg_area"))); 116 private static final VarHandle VH_reg_save_area 117 = MemoryHandles.asAddressVarHandle(LAYOUT.varHandle(long.class, groupElement("reg_save_area"))); 118 119 private static final Cleaner cleaner = Cleaner.create(); 120 private static final CSupport.VaList EMPTY = new SharedUtils.EmptyVaList(emptyListAddress()); 121 122 private final MemorySegment segment; 123 private final List<MemorySegment> slices = new ArrayList<>(); 124 private final MemorySegment regSaveArea; 125 126 SysVVaList(MemorySegment segment) { 127 this.segment = segment; 128 regSaveArea = regSaveArea(); 129 slices.add(regSaveArea); 130 } 131 132 private static MemoryAddress emptyListAddress() { 133 long ptr = U.allocateMemory(LAYOUT.byteSize()); 134 MemorySegment ms = NativeMemorySegmentImpl.makeNativeSegmentUnchecked( 135 MemoryAddress.ofLong(ptr), LAYOUT.byteSize(), null, () -> U.freeMemory(ptr), null); 136 cleaner.register(SysVVaList.class, ms::close); 137 MemoryAddress base = ms.baseAddress(); 138 VH_gp_offset.set(base, MAX_GP_OFFSET); 139 VH_fp_offset.set(base, MAX_FP_OFFSET); 140 VH_overflow_arg_area.set(base, MemoryAddress.NULL); 141 VH_reg_save_area.set(base, MemoryAddress.NULL); 142 MemorySegment unconfined = NativeMemorySegmentImpl.makeNativeSegmentUnchecked( 143 base, ms.byteSize(), null, null, null).withAccessModes(0); 144 return unconfined.baseAddress(); 145 } 146 147 public static CSupport.VaList empty() { 148 return EMPTY; 149 } 150 151 private int currentGPOffset() { 152 return (int) VH_gp_offset.get(segment.baseAddress()); 153 } 154 155 private void currentGPOffset(int i) { 156 VH_gp_offset.set(segment.baseAddress(), i); 157 } 158 159 private int currentFPOffset() { 160 return (int) VH_fp_offset.get(segment.baseAddress()); 161 } 162 163 private void currentFPOffset(int i) { 164 VH_fp_offset.set(segment.baseAddress(), i); 165 } 166 167 private MemoryAddress stackPtr() { 168 return (MemoryAddress) VH_overflow_arg_area.get(segment.baseAddress()); 169 } 170 171 private void stackPtr(MemoryAddress ptr) { 172 VH_overflow_arg_area.set(segment.baseAddress(), ptr); 173 } 174 175 private MemorySegment regSaveArea() { 176 return MemorySegment.ofNativeRestricted((MemoryAddress) VH_reg_save_area.get(segment.baseAddress()), 177 LAYOUT_REG_SAVE_AREA.byteSize(), segment.ownerThread(), null, null); 178 } 179 180 private void preAlignStack(MemoryLayout layout) { 181 if (layout.byteAlignment() > 8) { 182 stackPtr(Utils.alignUp(stackPtr(), 16)); 183 } 184 } 185 186 private void postAlignStack(MemoryLayout layout) { 187 stackPtr(Utils.alignUp(stackPtr().addOffset(layout.byteSize()), 8)); 188 } 189 190 @Override 191 public int vargAsInt(MemoryLayout layout) { 192 return (int) read(int.class, layout); 193 } 194 195 @Override 196 public long vargAsLong(MemoryLayout layout) { 197 return (long) read(long.class, layout); 198 } 199 200 @Override 201 public double vargAsDouble(MemoryLayout layout) { 202 return (double) read(double.class, layout); 203 } 204 205 @Override 206 public MemoryAddress vargAsAddress(MemoryLayout layout) { 207 return (MemoryAddress) read(MemoryAddress.class, layout); 208 } 209 210 @Override 211 public MemorySegment vargAsSegment(MemoryLayout layout) { 212 return (MemorySegment) read(MemorySegment.class, layout); 213 } 214 215 private Object read(Class<?> carrier, MemoryLayout layout) { 216 checkCompatibleType(carrier, layout, SysVx64Linker.ADDRESS_SIZE); 217 TypeClass typeClass = TypeClass.classifyLayout(layout); 218 if (isRegOverflow(currentGPOffset(), currentFPOffset(), typeClass)) { 219 preAlignStack(layout); 220 return switch (typeClass.kind()) { 221 case STRUCT -> { 222 try (MemorySegment slice = MemorySegment.ofNativeRestricted(stackPtr(), layout.byteSize(), 223 segment.ownerThread(), null, null)) { 224 MemorySegment seg = MemorySegment.allocateNative(layout); 225 seg.copyFrom(slice); 226 postAlignStack(layout); 227 yield seg; 228 } 229 } 230 case POINTER, INTEGER, FLOAT -> { 231 VarHandle reader = vhPrimitiveOrAddress(carrier, layout); 232 try (MemorySegment slice = MemorySegment.ofNativeRestricted(stackPtr(), layout.byteSize(), 233 segment.ownerThread(), null, null)) { 234 Object res = reader.get(slice.baseAddress()); 235 postAlignStack(layout); 236 yield res; 237 } 238 } 239 }; 240 } else { 241 return switch (typeClass.kind()) { 242 case STRUCT -> { 243 MemorySegment value = MemorySegment.allocateNative(layout); 244 int classIdx = 0; 245 long offset = 0; 246 while (offset < layout.byteSize()) { 247 final long copy = Math.min(layout.byteSize() - offset, 8); 248 boolean isSSE = typeClass.classes.get(classIdx++) == ArgumentClassImpl.SSE; 249 MemorySegment slice = value.asSlice(offset, copy); 250 if (isSSE) { 251 slice.copyFrom(regSaveArea.asSlice(currentFPOffset(), copy)); 252 currentFPOffset(currentFPOffset() + FP_SLOT_SIZE); 253 } else { 254 slice.copyFrom(regSaveArea.asSlice(currentGPOffset(), copy)); 255 currentGPOffset(currentGPOffset() + GP_SLOT_SIZE); 256 } 257 offset += copy; 258 } 259 yield value; 260 } 261 case POINTER, INTEGER -> { 262 VarHandle reader = SharedUtils.vhPrimitiveOrAddress(carrier, layout); 263 Object res = reader.get(regSaveArea.baseAddress().addOffset(currentGPOffset())); 264 currentGPOffset(currentGPOffset() + GP_SLOT_SIZE); 265 yield res; 266 } 267 case FLOAT -> { 268 VarHandle reader = layout.varHandle(carrier); 269 Object res = reader.get(regSaveArea.baseAddress().addOffset(currentFPOffset())); 270 currentFPOffset(currentFPOffset() + FP_SLOT_SIZE); 271 yield res; 272 } 273 }; 274 } 275 } 276 277 @Override 278 public void skip(MemoryLayout... layouts) { 279 for (MemoryLayout layout : layouts) { 280 TypeClass typeClass = TypeClass.classifyLayout(layout); 281 if (isRegOverflow(currentGPOffset(), currentFPOffset(), typeClass)) { 282 preAlignStack(layout); 283 postAlignStack(layout); 284 } else { 285 currentGPOffset(currentGPOffset() + (((int) typeClass.nIntegerRegs()) * GP_SLOT_SIZE)); 286 currentFPOffset(currentFPOffset() + (((int) typeClass.nVectorRegs()) * FP_SLOT_SIZE)); 287 } 288 } 289 } 290 291 static SysVVaList.Builder builder() { 292 return new SysVVaList.Builder(); 293 } 294 295 public static VaList ofAddress(MemoryAddress ma) { 296 return new SysVVaList(MemorySegment.ofNativeRestricted(ma, LAYOUT.byteSize(), Thread.currentThread(), null, null)); 297 } 298 299 @Override 300 public boolean isAlive() { 301 return segment.isAlive(); 302 } 303 304 @Override 305 public void close() { 306 segment.close(); 307 slices.forEach(MemorySegment::close); 308 } 309 310 @Override 311 public VaList copy() { 312 MemorySegment copy = MemorySegment.allocateNative(LAYOUT.byteSize()); 313 copy.copyFrom(segment); 314 return new SysVVaList(copy); 315 } 316 317 @Override 318 public MemoryAddress address() { 319 return segment.baseAddress(); 320 } 321 322 private static boolean isRegOverflow(long currentGPOffset, long currentFPOffset, TypeClass typeClass) { 323 return currentGPOffset > MAX_GP_OFFSET - typeClass.nIntegerRegs() * GP_SLOT_SIZE 324 || currentFPOffset > MAX_FP_OFFSET - typeClass.nVectorRegs() * FP_SLOT_SIZE; 325 } 326 327 @Override 328 public String toString() { 329 return "SysVVaList{" 330 + "gp_offset=" + currentGPOffset() 331 + ", fp_offset=" + currentFPOffset() 332 + ", overflow_arg_area=" + stackPtr() 333 + ", reg_save_area=" + regSaveArea() 334 + '}'; 335 } 336 337 static class Builder implements CSupport.VaList.Builder { 338 private final MemorySegment reg_save_area = MemorySegment.allocateNative(LAYOUT_REG_SAVE_AREA); 339 private long currentGPOffset = 0; 340 private long currentFPOffset = FP_OFFSET; 341 private final List<SimpleVaArg> stackArgs = new ArrayList<>(); 342 343 @Override 344 public Builder vargFromInt(MemoryLayout layout, int value) { 345 return arg(int.class, layout, value); 346 } 347 348 @Override 349 public Builder vargFromLong(MemoryLayout layout, long value) { 350 return arg(long.class, layout, value); 351 } 352 353 @Override 354 public Builder vargFromDouble(MemoryLayout layout, double value) { 355 return arg(double.class, layout, value); 356 } 357 358 @Override 359 public Builder vargFromAddress(MemoryLayout layout, MemoryAddress value) { 360 return arg(MemoryAddress.class, layout, value); 361 } 362 363 @Override 364 public Builder vargFromSegment(MemoryLayout layout, MemorySegment value) { 365 return arg(MemorySegment.class, layout, value); 366 } 367 368 private Builder arg(Class<?> carrier, MemoryLayout layout, Object value) { 369 checkCompatibleType(carrier, layout, SysVx64Linker.ADDRESS_SIZE); 370 TypeClass typeClass = TypeClass.classifyLayout(layout); 371 if (isRegOverflow(currentGPOffset, currentFPOffset, typeClass)) { 372 // stack it! 373 stackArgs.add(new SimpleVaArg(carrier, layout, value)); 374 } else { 375 switch (typeClass.kind()) { 376 case STRUCT -> { 377 MemorySegment valueSegment = (MemorySegment) value; 378 int classIdx = 0; 379 long offset = 0; 380 while (offset < layout.byteSize()) { 381 final long copy = Math.min(layout.byteSize() - offset, 8); 382 boolean isSSE = typeClass.classes.get(classIdx++) == ArgumentClassImpl.SSE; 383 MemorySegment slice = valueSegment.asSlice(offset, copy); 384 if (isSSE) { 385 reg_save_area.asSlice(currentFPOffset, copy).copyFrom(slice); 386 currentFPOffset += FP_SLOT_SIZE; 387 } else { 388 reg_save_area.asSlice(currentGPOffset, copy).copyFrom(slice); 389 currentGPOffset += GP_SLOT_SIZE; 390 } 391 offset += copy; 392 } 393 } 394 case POINTER, INTEGER -> { 395 VarHandle writer = SharedUtils.vhPrimitiveOrAddress(carrier, layout); 396 writer.set(reg_save_area.baseAddress().addOffset(currentGPOffset), value); 397 currentGPOffset += GP_SLOT_SIZE; 398 } 399 case FLOAT -> { 400 VarHandle writer = layout.varHandle(carrier); 401 writer.set(reg_save_area.baseAddress().addOffset(currentFPOffset), value); 402 currentFPOffset += FP_SLOT_SIZE; 403 } 404 } 405 } 406 return this; 407 } 408 409 private boolean isEmpty() { 410 return currentGPOffset == 0 && currentFPOffset == FP_OFFSET && stackArgs.isEmpty(); 411 } 412 413 public VaList build() { 414 if (isEmpty()) { 415 return EMPTY; 416 } 417 418 MemorySegment vaListSegment = MemorySegment.allocateNative(LAYOUT.byteSize()); 419 SysVVaList res = new SysVVaList(vaListSegment); 420 MemoryAddress stackArgsPtr = MemoryAddress.NULL; 421 if (!stackArgs.isEmpty()) { 422 long stackArgsSize = stackArgs.stream().reduce(0L, (acc, e) -> acc + e.layout.byteSize(), Long::sum); 423 MemorySegment stackArgsSegment = MemorySegment.allocateNative(stackArgsSize, 16); 424 MemoryAddress maOverflowArgArea = stackArgsSegment.baseAddress(); 425 for (SimpleVaArg arg : stackArgs) { 426 if (arg.layout.byteSize() > 8) { 427 maOverflowArgArea = Utils.alignUp(maOverflowArgArea, Math.min(16, arg.layout.byteSize())); 428 } 429 VarHandle writer = arg.varHandle(); 430 writer.set(maOverflowArgArea, arg.value); 431 maOverflowArgArea = maOverflowArgArea.addOffset(arg.layout.byteSize()); 432 } 433 stackArgsPtr = stackArgsSegment.baseAddress(); 434 res.slices.add(stackArgsSegment); 435 } 436 437 MemoryAddress vaListAddr = vaListSegment.baseAddress(); 438 VH_fp_offset.set(vaListAddr, (int) FP_OFFSET); 439 VH_overflow_arg_area.set(vaListAddr, stackArgsPtr); 440 VH_reg_save_area.set(vaListAddr, reg_save_area.baseAddress()); 441 res.slices.add(reg_save_area); 442 assert reg_save_area.ownerThread() == vaListSegment.ownerThread(); 443 return res; 444 } 445 } 446 }