1 /*
   2  * Copyright (c) 1999, 2016, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2014, 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 // no precompiled headers
  27 #include "asm/macroAssembler.hpp"
  28 #include "classfile/classLoader.hpp"
  29 #include "classfile/systemDictionary.hpp"
  30 #include "classfile/vmSymbols.hpp"
  31 #include "code/codeCache.hpp"
  32 #include "code/icBuffer.hpp"
  33 #include "code/vtableStubs.hpp"
  34 #include "code/nativeInst.hpp"
  35 #include "interpreter/interpreter.hpp"
  36 #include "jvm_linux.h"
  37 #include "memory/allocation.inline.hpp"
  38 #include "os_share_linux.hpp"
  39 #include "prims/jniFastGetField.hpp"
  40 #include "prims/jvm.h"
  41 #include "prims/jvm_misc.hpp"
  42 #include "runtime/arguments.hpp"
  43 #include "runtime/extendedPC.hpp"
  44 #include "runtime/frame.inline.hpp"
  45 #include "runtime/interfaceSupport.hpp"
  46 #include "runtime/java.hpp"
  47 #include "runtime/javaCalls.hpp"
  48 #include "runtime/mutexLocker.hpp"
  49 #include "runtime/osThread.hpp"
  50 #include "runtime/sharedRuntime.hpp"
  51 #include "runtime/stubRoutines.hpp"
  52 #include "runtime/thread.inline.hpp"
  53 #include "runtime/timer.hpp"
  54 #include "utilities/events.hpp"
  55 #include "utilities/vmError.hpp"
  56 #ifdef BUILTIN_SIM
  57 #include "../../../../../../simulator/simulator.hpp"
  58 #endif
  59 
  60 // put OS-includes here
  61 # include <sys/types.h>
  62 # include <sys/mman.h>
  63 # include <pthread.h>
  64 # include <signal.h>
  65 # include <errno.h>
  66 # include <dlfcn.h>
  67 # include <stdlib.h>
  68 # include <stdio.h>
  69 # include <unistd.h>
  70 # include <sys/resource.h>
  71 # include <pthread.h>
  72 # include <sys/stat.h>
  73 # include <sys/time.h>
  74 # include <sys/utsname.h>
  75 # include <sys/socket.h>
  76 # include <sys/wait.h>
  77 # include <pwd.h>
  78 # include <poll.h>
  79 # include <ucontext.h>
  80 # include <fpu_control.h>
  81 
  82 #ifdef BUILTIN_SIM
  83 #define REG_SP REG_RSP
  84 #define REG_PC REG_RIP
  85 #define REG_FP REG_RBP
  86 #define SPELL_REG_SP "rsp"
  87 #define SPELL_REG_FP "rbp"
  88 #else
  89 #define REG_FP 29
  90 
  91 #define SPELL_REG_SP "sp"
  92 #define SPELL_REG_FP "x29"
  93 #endif
  94 
  95 address os::current_stack_pointer() {
  96   register void *esp __asm__ (SPELL_REG_SP);
  97   return (address) esp;
  98 }
  99 
 100 char* os::non_memory_address_word() {
 101   // Must never look like an address returned by reserve_memory,
 102   // even in its subfields (as defined by the CPU immediate fields,
 103   // if the CPU splits constants across multiple instructions).
 104 
 105   return (char*) 0xffffffffffff;
 106 }
 107 
 108 void os::initialize_thread(Thread *thr) {
 109 }
 110 
 111 address os::Linux::ucontext_get_pc(const ucontext_t * uc) {
 112 #ifdef BUILTIN_SIM
 113   return (address)uc->uc_mcontext.gregs[REG_PC];
 114 #else
 115   return (address)uc->uc_mcontext.pc;
 116 #endif
 117 }
 118 
 119 void os::Linux::ucontext_set_pc(ucontext_t * uc, address pc) {
 120 #ifdef BUILTIN_SIM
 121   uc->uc_mcontext.gregs[REG_PC] = (intptr_t)pc;
 122 #else
 123   uc->uc_mcontext.pc = (intptr_t)pc;
 124 #endif
 125 }
 126 
 127 intptr_t* os::Linux::ucontext_get_sp(const ucontext_t * uc) {
 128 #ifdef BUILTIN_SIM
 129   return (intptr_t*)uc->uc_mcontext.gregs[REG_SP];
 130 #else
 131   return (intptr_t*)uc->uc_mcontext.sp;
 132 #endif
 133 }
 134 
 135 intptr_t* os::Linux::ucontext_get_fp(const ucontext_t * uc) {
 136 #ifdef BUILTIN_SIM
 137   return (intptr_t*)uc->uc_mcontext.gregs[REG_FP];
 138 #else
 139   return (intptr_t*)uc->uc_mcontext.regs[REG_FP];
 140 #endif
 141 }
 142 
 143 // For Forte Analyzer AsyncGetCallTrace profiling support - thread
 144 // is currently interrupted by SIGPROF.
 145 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal
 146 // frames. Currently we don't do that on Linux, so it's the same as
 147 // os::fetch_frame_from_context().
 148 ExtendedPC os::Linux::fetch_frame_from_ucontext(Thread* thread,
 149   const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
 150 
 151   assert(thread != NULL, "just checking");
 152   assert(ret_sp != NULL, "just checking");
 153   assert(ret_fp != NULL, "just checking");
 154 
 155   return os::fetch_frame_from_context(uc, ret_sp, ret_fp);
 156 }
 157 
 158 ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
 159                     intptr_t** ret_sp, intptr_t** ret_fp) {
 160 
 161   ExtendedPC  epc;
 162   const ucontext_t* uc = (const ucontext_t*)ucVoid;
 163 
 164   if (uc != NULL) {
 165     epc = ExtendedPC(os::Linux::ucontext_get_pc(uc));
 166     if (ret_sp) *ret_sp = os::Linux::ucontext_get_sp(uc);
 167     if (ret_fp) *ret_fp = os::Linux::ucontext_get_fp(uc);
 168   } else {
 169     // construct empty ExtendedPC for return value checking
 170     epc = ExtendedPC(NULL);
 171     if (ret_sp) *ret_sp = (intptr_t *)NULL;
 172     if (ret_fp) *ret_fp = (intptr_t *)NULL;
 173   }
 174 
 175   return epc;
 176 }
 177 
 178 frame os::fetch_frame_from_context(const void* ucVoid) {
 179   intptr_t* sp;
 180   intptr_t* fp;
 181   ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
 182   return frame(sp, fp, epc.pc());
 183 }
 184 
 185 // By default, gcc always saves frame pointer rfp on this stack. This
 186 // may get turned off by -fomit-frame-pointer.
 187 frame os::get_sender_for_C_frame(frame* fr) {
 188 #ifdef BUILTIN_SIM
 189   return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
 190 #else
 191   return frame(fr->link(), fr->link(), fr->sender_pc());
 192 #endif
 193 }
 194 
 195 intptr_t* _get_previous_fp() {
 196   register intptr_t **ebp __asm__ (SPELL_REG_FP);
 197   return (intptr_t*) *ebp;   // we want what it points to.
 198 }
 199 
 200 
 201 frame os::current_frame() {
 202   intptr_t* fp = _get_previous_fp();
 203   frame myframe((intptr_t*)os::current_stack_pointer(),
 204                 (intptr_t*)fp,
 205                 CAST_FROM_FN_PTR(address, os::current_frame));
 206   if (os::is_first_C_frame(&myframe)) {
 207     // stack is not walkable
 208     return frame();
 209   } else {
 210     return os::get_sender_for_C_frame(&myframe);
 211   }
 212 }
 213 
 214 // Utility functions
 215 
 216 // From IA32 System Programming Guide
 217 enum {
 218   trap_page_fault = 0xE
 219 };
 220 
 221 #ifdef BUILTIN_SIM
 222 extern "C" void Fetch32PFI () ;
 223 extern "C" void Fetch32Resume () ;
 224 extern "C" void FetchNPFI () ;
 225 extern "C" void FetchNResume () ;
 226 #endif
 227 
 228 extern "C" JNIEXPORT int
 229 JVM_handle_linux_signal(int sig,
 230                         siginfo_t* info,
 231                         void* ucVoid,
 232                         int abort_if_unrecognized) {
 233   ucontext_t* uc = (ucontext_t*) ucVoid;
 234 
 235   Thread* t = Thread::current_or_null_safe();
 236 
 237   // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away
 238   // (no destructors can be run)
 239   os::WatcherThreadCrashProtection::check_crash_protection(sig, t);
 240 
 241   SignalHandlerMark shm(t);
 242 
 243   // Note: it's not uncommon that JNI code uses signal/sigset to install
 244   // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
 245   // or have a SIGILL handler when detecting CPU type). When that happens,
 246   // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To
 247   // avoid unnecessary crash when libjsig is not preloaded, try handle signals
 248   // that do not require siginfo/ucontext first.
 249 
 250   if (sig == SIGPIPE || sig == SIGXFSZ) {
 251     // allow chained handler to go first
 252     if (os::Linux::chained_handler(sig, info, ucVoid)) {
 253       return true;
 254     } else {
 255       // Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219
 256       return true;
 257     }
 258   }
 259 
 260   JavaThread* thread = NULL;
 261   VMThread* vmthread = NULL;
 262   if (os::Linux::signal_handlers_are_installed) {
 263     if (t != NULL ){
 264       if(t->is_Java_thread()) {
 265         thread = (JavaThread*)t;
 266       }
 267       else if(t->is_VM_thread()){
 268         vmthread = (VMThread *)t;
 269       }
 270     }
 271   }
 272 /*
 273   NOTE: does not seem to work on linux.
 274   if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
 275     // can't decode this kind of signal
 276     info = NULL;
 277   } else {
 278     assert(sig == info->si_signo, "bad siginfo");
 279   }
 280 */
 281   // decide if this trap can be handled by a stub
 282   address stub = NULL;
 283 
 284   address pc          = NULL;
 285 
 286   //%note os_trap_1
 287   if (info != NULL && uc != NULL && thread != NULL) {
 288     pc = (address) os::Linux::ucontext_get_pc(uc);
 289 
 290 #ifdef BUILTIN_SIM
 291     if (pc == (address) Fetch32PFI) {
 292        uc->uc_mcontext.gregs[REG_PC] = intptr_t(Fetch32Resume) ;
 293        return 1 ;
 294     }
 295     if (pc == (address) FetchNPFI) {
 296        uc->uc_mcontext.gregs[REG_PC] = intptr_t (FetchNResume) ;
 297        return 1 ;
 298     }
 299 #else
 300     if (StubRoutines::is_safefetch_fault(pc)) {
 301       os::Linux::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
 302       return 1;
 303     }
 304 #endif
 305 
 306     // Handle ALL stack overflow variations here
 307     if (sig == SIGSEGV) {
 308       address addr = (address) info->si_addr;
 309 
 310       // check if fault address is within thread stack
 311       if (thread->on_local_stack(addr)) {
 312         // stack overflow
 313         if (thread->in_stack_yellow_reserved_zone(addr)) {
 314           thread->disable_stack_yellow_reserved_zone();
 315           if (thread->thread_state() == _thread_in_Java) {
 316             // Throw a stack overflow exception.  Guard pages will be reenabled
 317             // while unwinding the stack.
 318             stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
 319           } else {
 320             // Thread was in the vm or native code.  Return and try to finish.
 321             return 1;
 322           }
 323         } else if (thread->in_stack_red_zone(addr)) {
 324           // Fatal red zone violation.  Disable the guard pages and fall through
 325           // to handle_unexpected_exception way down below.
 326           thread->disable_stack_red_zone();
 327           tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
 328 
 329           // This is a likely cause, but hard to verify. Let's just print
 330           // it as a hint.
 331           tty->print_raw_cr("Please check if any of your loaded .so files has "
 332                             "enabled executable stack (see man page execstack(8))");
 333         } else {
 334           // Accessing stack address below sp may cause SEGV if current
 335           // thread has MAP_GROWSDOWN stack. This should only happen when
 336           // current thread was created by user code with MAP_GROWSDOWN flag
 337           // and then attached to VM. See notes in os_linux.cpp.
 338           if (thread->osthread()->expanding_stack() == 0) {
 339              thread->osthread()->set_expanding_stack();
 340              if (os::Linux::manually_expand_stack(thread, addr)) {
 341                thread->osthread()->clear_expanding_stack();
 342                return 1;
 343              }
 344              thread->osthread()->clear_expanding_stack();
 345           } else {
 346              fatal("recursive segv. expanding stack.");
 347           }
 348         }
 349       }
 350     }
 351 
 352     if (thread->thread_state() == _thread_in_Java) {
 353       // Java thread running in Java code => find exception handler if any
 354       // a fault inside compiled code, the interpreter, or a stub
 355 
 356       // Handle signal from NativeJump::patch_verified_entry().
 357       if ((sig == SIGILL || sig == SIGTRAP)
 358           && nativeInstruction_at(pc)->is_sigill_zombie_not_entrant()) {
 359         if (TraceTraps) {
 360           tty->print_cr("trap: zombie_not_entrant (%s)", (sig == SIGTRAP) ? "SIGTRAP" : "SIGILL");
 361         }
 362         stub = SharedRuntime::get_handle_wrong_method_stub();
 363       } else if (sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) {
 364         stub = SharedRuntime::get_poll_stub(pc);
 365       } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) {
 366         // BugId 4454115: A read from a MappedByteBuffer can fault
 367         // here if the underlying file has been truncated.
 368         // Do not crash the VM in such a case.
 369         CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
 370         CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
 371         if (nm != NULL && nm->has_unsafe_access()) {
 372           address next_pc = pc + NativeCall::instruction_size;
 373           stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
 374         }
 375       }
 376       else
 377 
 378       if (sig == SIGFPE  &&
 379           (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) {
 380         stub =
 381           SharedRuntime::
 382           continuation_for_implicit_exception(thread,
 383                                               pc,
 384                                               SharedRuntime::
 385                                               IMPLICIT_DIVIDE_BY_ZERO);
 386       } else if (sig == SIGSEGV &&
 387                !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
 388           // Determination of interpreter/vtable stub/compiled code null exception
 389           stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
 390       }
 391     } else if (thread->thread_state() == _thread_in_vm &&
 392                sig == SIGBUS && /* info->si_code == BUS_OBJERR && */
 393                thread->doing_unsafe_access()) {
 394       address next_pc = pc + NativeCall::instruction_size;
 395       stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
 396     }
 397 
 398     // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
 399     // and the heap gets shrunk before the field access.
 400     if ((sig == SIGSEGV) || (sig == SIGBUS)) {
 401       address addr = JNI_FastGetField::find_slowcase_pc(pc);
 402       if (addr != (address)-1) {
 403         stub = addr;
 404       }
 405     }
 406 
 407     // Check to see if we caught the safepoint code in the
 408     // process of write protecting the memory serialization page.
 409     // It write enables the page immediately after protecting it
 410     // so we can just return to retry the write.
 411     if ((sig == SIGSEGV) &&
 412         os::is_memory_serialize_page(thread, (address) info->si_addr)) {
 413       // Block current thread until the memory serialize page permission restored.
 414       os::block_on_serialize_page_trap();
 415       return true;
 416     }
 417   }
 418 
 419   if (stub != NULL) {
 420     // save all thread context in case we need to restore it
 421     if (thread != NULL) thread->set_saved_exception_pc(pc);
 422 
 423     os::Linux::ucontext_set_pc(uc, stub);
 424     return true;
 425   }
 426 
 427   // signal-chaining
 428   if (os::Linux::chained_handler(sig, info, ucVoid)) {
 429      return true;
 430   }
 431 
 432   if (!abort_if_unrecognized) {
 433     // caller wants another chance, so give it to him
 434     return false;
 435   }
 436 
 437   if (pc == NULL && uc != NULL) {
 438     pc = os::Linux::ucontext_get_pc(uc);
 439   }
 440 
 441   // unmask current signal
 442   sigset_t newset;
 443   sigemptyset(&newset);
 444   sigaddset(&newset, sig);
 445   sigprocmask(SIG_UNBLOCK, &newset, NULL);
 446 
 447   VMError::report_and_die(t, sig, pc, info, ucVoid);
 448 
 449   ShouldNotReachHere();
 450   return true; // Mute compiler
 451 }
 452 
 453 void os::Linux::init_thread_fpu_state(void) {
 454 }
 455 
 456 int os::Linux::get_fpu_control_word(void) {
 457   return 0;
 458 }
 459 
 460 void os::Linux::set_fpu_control_word(int fpu_control) {
 461 }
 462 
 463 // Check that the linux kernel version is 2.4 or higher since earlier
 464 // versions do not support SSE without patches.
 465 bool os::supports_sse() {
 466   return true;
 467 }
 468 
 469 bool os::is_allocatable(size_t bytes) {
 470   return true;
 471 }
 472 
 473 ////////////////////////////////////////////////////////////////////////////////
 474 // thread stack
 475 
 476 size_t os::Posix::_compiler_thread_min_stack_allowed = 64 * K;
 477 size_t os::Posix::_java_thread_min_stack_allowed = 64 * K;
 478 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 64 * K;
 479 
 480 // return default stack size for thr_type
 481 size_t os::Posix::default_stack_size(os::ThreadType thr_type) {
 482   // default stack size (compiler thread needs larger stack)
 483   size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
 484   return s;
 485 }
 486 
 487 /////////////////////////////////////////////////////////////////////////////
 488 // helper functions for fatal error handler
 489 
 490 void os::print_context(outputStream *st, const void *context) {
 491   if (context == NULL) return;
 492 
 493   const ucontext_t *uc = (const ucontext_t*)context;
 494   st->print_cr("Registers:");
 495 #ifdef BUILTIN_SIM
 496   st->print(  "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]);
 497   st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]);
 498   st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]);
 499   st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]);
 500   st->cr();
 501   st->print(  "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]);
 502   st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]);
 503   st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]);
 504   st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]);
 505   st->cr();
 506   st->print(  "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]);
 507   st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]);
 508   st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]);
 509   st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]);
 510   st->cr();
 511   st->print(  "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]);
 512   st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]);
 513   st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]);
 514   st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]);
 515   st->cr();
 516   st->print(  "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]);
 517   st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EFL]);
 518   st->print(", CSGSFS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_CSGSFS]);
 519   st->print(", ERR=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ERR]);
 520   st->cr();
 521   st->print("  TRAPNO=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_TRAPNO]);
 522   st->cr();
 523 #else
 524   for (int r = 0; r < 31; r++)
 525     st->print_cr(  "R%d=" INTPTR_FORMAT, r, (size_t)uc->uc_mcontext.regs[r]);
 526 #endif
 527   st->cr();
 528 
 529   intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
 530   st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", p2i(sp));
 531   print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
 532   st->cr();
 533 
 534   // Note: it may be unsafe to inspect memory near pc. For example, pc may
 535   // point to garbage if entry point in an nmethod is corrupted. Leave
 536   // this at the end, and hope for the best.
 537   address pc = os::Linux::ucontext_get_pc(uc);
 538   st->print_cr("Instructions: (pc=" PTR_FORMAT ")", p2i(pc));
 539   print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
 540 }
 541 
 542 void os::print_register_info(outputStream *st, const void *context) {
 543   if (context == NULL) return;
 544 
 545   const ucontext_t *uc = (const ucontext_t*)context;
 546 
 547   st->print_cr("Register to memory mapping:");
 548   st->cr();
 549 
 550   // this is horrendously verbose but the layout of the registers in the
 551   // context does not match how we defined our abstract Register set, so
 552   // we can't just iterate through the gregs area
 553 
 554   // this is only for the "general purpose" registers
 555 
 556 #ifdef BUILTIN_SIM
 557   st->print("RAX="); print_location(st, uc->uc_mcontext.gregs[REG_RAX]);
 558   st->print("RBX="); print_location(st, uc->uc_mcontext.gregs[REG_RBX]);
 559   st->print("RCX="); print_location(st, uc->uc_mcontext.gregs[REG_RCX]);
 560   st->print("RDX="); print_location(st, uc->uc_mcontext.gregs[REG_RDX]);
 561   st->print("RSP="); print_location(st, uc->uc_mcontext.gregs[REG_RSP]);
 562   st->print("RBP="); print_location(st, uc->uc_mcontext.gregs[REG_RBP]);
 563   st->print("RSI="); print_location(st, uc->uc_mcontext.gregs[REG_RSI]);
 564   st->print("RDI="); print_location(st, uc->uc_mcontext.gregs[REG_RDI]);
 565   st->print("R8 ="); print_location(st, uc->uc_mcontext.gregs[REG_R8]);
 566   st->print("R9 ="); print_location(st, uc->uc_mcontext.gregs[REG_R9]);
 567   st->print("R10="); print_location(st, uc->uc_mcontext.gregs[REG_R10]);
 568   st->print("R11="); print_location(st, uc->uc_mcontext.gregs[REG_R11]);
 569   st->print("R12="); print_location(st, uc->uc_mcontext.gregs[REG_R12]);
 570   st->print("R13="); print_location(st, uc->uc_mcontext.gregs[REG_R13]);
 571   st->print("R14="); print_location(st, uc->uc_mcontext.gregs[REG_R14]);
 572   st->print("R15="); print_location(st, uc->uc_mcontext.gregs[REG_R15]);
 573 #else
 574   for (int r = 0; r < 31; r++)
 575     st->print_cr(  "R%d=" INTPTR_FORMAT, r, (uintptr_t)uc->uc_mcontext.regs[r]);
 576 #endif
 577   st->cr();
 578 }
 579 
 580 void os::setup_fpu() {
 581 }
 582 
 583 #ifndef PRODUCT
 584 void os::verify_stack_alignment() {
 585   assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
 586 }
 587 #endif
 588 
 589 int os::extra_bang_size_in_bytes() {
 590   // AArch64 does not require the additional stack bang.
 591   return 0;
 592 }
 593 
 594 extern "C" {
 595   int SpinPause() {
 596     return 0;
 597   }
 598 
 599   void _Copy_conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count) {
 600     if (from > to) {
 601       jshort *end = from + count;
 602       while (from < end)
 603         *(to++) = *(from++);
 604     }
 605     else if (from < to) {
 606       jshort *end = from;
 607       from += count - 1;
 608       to   += count - 1;
 609       while (from >= end)
 610         *(to--) = *(from--);
 611     }
 612   }
 613   void _Copy_conjoint_jints_atomic(jint* from, jint* to, size_t count) {
 614     if (from > to) {
 615       jint *end = from + count;
 616       while (from < end)
 617         *(to++) = *(from++);
 618     }
 619     else if (from < to) {
 620       jint *end = from;
 621       from += count - 1;
 622       to   += count - 1;
 623       while (from >= end)
 624         *(to--) = *(from--);
 625     }
 626   }
 627   void _Copy_conjoint_jlongs_atomic(jlong* from, jlong* to, size_t count) {
 628     if (from > to) {
 629       jlong *end = from + count;
 630       while (from < end)
 631         os::atomic_copy64(from++, to++);
 632     }
 633     else if (from < to) {
 634       jlong *end = from;
 635       from += count - 1;
 636       to   += count - 1;
 637       while (from >= end)
 638         os::atomic_copy64(from--, to--);
 639     }
 640   }
 641 
 642   void _Copy_arrayof_conjoint_bytes(HeapWord* from,
 643                                     HeapWord* to,
 644                                     size_t    count) {
 645     memmove(to, from, count);
 646   }
 647   void _Copy_arrayof_conjoint_jshorts(HeapWord* from,
 648                                       HeapWord* to,
 649                                       size_t    count) {
 650     memmove(to, from, count * 2);
 651   }
 652   void _Copy_arrayof_conjoint_jints(HeapWord* from,
 653                                     HeapWord* to,
 654                                     size_t    count) {
 655     memmove(to, from, count * 4);
 656   }
 657   void _Copy_arrayof_conjoint_jlongs(HeapWord* from,
 658                                      HeapWord* to,
 659                                      size_t    count) {
 660     memmove(to, from, count * 8);
 661   }
 662 };