/*
* Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2014, Red Hat Inc. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
// no precompiled headers
#include "jvm.h"
#include "asm/macroAssembler.hpp"
#include "classfile/classLoader.hpp"
#include "classfile/systemDictionary.hpp"
#include "classfile/vmSymbols.hpp"
#include "code/codeCache.hpp"
#include "code/icBuffer.hpp"
#include "code/vtableStubs.hpp"
#include "code/nativeInst.hpp"
#include "interpreter/interpreter.hpp"
#include "memory/allocation.inline.hpp"
#include "os_share_linux.hpp"
#include "prims/jniFastGetField.hpp"
#include "prims/jvm_misc.hpp"
#include "runtime/arguments.hpp"
#include "runtime/extendedPC.hpp"
#include "runtime/frame.inline.hpp"
#include "runtime/interfaceSupport.inline.hpp"
#include "runtime/java.hpp"
#include "runtime/javaCalls.hpp"
#include "runtime/mutexLocker.hpp"
#include "runtime/osThread.hpp"
#include "runtime/sharedRuntime.hpp"
#include "runtime/stubRoutines.hpp"
#include "runtime/thread.inline.hpp"
#include "runtime/timer.hpp"
#include "utilities/debug.hpp"
#include "utilities/events.hpp"
#include "utilities/vmError.hpp"
#ifdef BUILTIN_SIM
#include "../../../../../../simulator/simulator.hpp"
#endif
// put OS-includes here
# include <sys/types.h>
# include <sys/mman.h>
# include <pthread.h>
# include <signal.h>
# include <errno.h>
# include <dlfcn.h>
# include <stdlib.h>
# include <stdio.h>
# include <unistd.h>
# include <sys/resource.h>
# include <pthread.h>
# include <sys/stat.h>
# include <sys/time.h>
# include <sys/utsname.h>
# include <sys/socket.h>
# include <sys/wait.h>
# include <pwd.h>
# include <poll.h>
# include <ucontext.h>
# include <fpu_control.h>
#ifdef BUILTIN_SIM
#define REG_SP REG_RSP
#define REG_PC REG_RIP
#define REG_FP REG_RBP
#define SPELL_REG_SP "rsp"
#define SPELL_REG_FP "rbp"
#else
#define REG_FP 29
#define REG_LR 30
#define SPELL_REG_SP "sp"
#define SPELL_REG_FP "x29"
#endif
address os::current_stack_pointer() {
register void *esp __asm__ (SPELL_REG_SP);
return (address) esp;
}
char* os::non_memory_address_word() {
// Must never look like an address returned by reserve_memory,
// even in its subfields (as defined by the CPU immediate fields,
// if the CPU splits constants across multiple instructions).
return (char*) 0xffffffffffff;
}
address os::Linux::ucontext_get_pc(const ucontext_t * uc) {
#ifdef BUILTIN_SIM
return (address)uc->uc_mcontext.gregs[REG_PC];
#else
return (address)uc->uc_mcontext.pc;
#endif
}
void os::Linux::ucontext_set_pc(ucontext_t * uc, address pc) {
#ifdef BUILTIN_SIM
uc->uc_mcontext.gregs[REG_PC] = (intptr_t)pc;
#else
uc->uc_mcontext.pc = (intptr_t)pc;
#endif
}
intptr_t* os::Linux::ucontext_get_sp(const ucontext_t * uc) {
#ifdef BUILTIN_SIM
return (intptr_t*)uc->uc_mcontext.gregs[REG_SP];
#else
return (intptr_t*)uc->uc_mcontext.sp;
#endif
}
intptr_t* os::Linux::ucontext_get_fp(const ucontext_t * uc) {
#ifdef BUILTIN_SIM
return (intptr_t*)uc->uc_mcontext.gregs[REG_FP];
#else
return (intptr_t*)uc->uc_mcontext.regs[REG_FP];
#endif
}
// For Forte Analyzer AsyncGetCallTrace profiling support - thread
// is currently interrupted by SIGPROF.
// os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal
// frames. Currently we don't do that on Linux, so it's the same as
// os::fetch_frame_from_context().
ExtendedPC os::Linux::fetch_frame_from_ucontext(Thread* thread,
const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
assert(thread != NULL, "just checking");
assert(ret_sp != NULL, "just checking");
assert(ret_fp != NULL, "just checking");
return os::fetch_frame_from_context(uc, ret_sp, ret_fp);
}
ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
intptr_t** ret_sp, intptr_t** ret_fp) {
ExtendedPC epc;
const ucontext_t* uc = (const ucontext_t*)ucVoid;
if (uc != NULL) {
epc = ExtendedPC(os::Linux::ucontext_get_pc(uc));
if (ret_sp) *ret_sp = os::Linux::ucontext_get_sp(uc);
if (ret_fp) *ret_fp = os::Linux::ucontext_get_fp(uc);
} else {
// construct empty ExtendedPC for return value checking
epc = ExtendedPC(NULL);
if (ret_sp) *ret_sp = (intptr_t *)NULL;
if (ret_fp) *ret_fp = (intptr_t *)NULL;
}
return epc;
}
frame os::fetch_frame_from_context(const void* ucVoid) {
intptr_t* sp;
intptr_t* fp;
ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
return frame(sp, fp, epc.pc());
}
bool os::Linux::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) {
address pc = (address) os::Linux::ucontext_get_pc(uc);
if (Interpreter::contains(pc)) {
// interpreter performs stack banging after the fixed frame header has
// been generated while the compilers perform it before. To maintain
// semantic consistency between interpreted and compiled frames, the
// method returns the Java sender of the current frame.
*fr = os::fetch_frame_from_context(uc);
if (!fr->is_first_java_frame()) {
assert(fr->safe_for_sender(thread), "Safety check");
*fr = fr->java_sender();
}
} else {
// more complex code with compiled code
assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above");
CodeBlob* cb = CodeCache::find_blob(pc);
if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) {
// Not sure where the pc points to, fallback to default
// stack overflow handling
return false;
} else {
// In compiled code, the stack banging is performed before LR
// has been saved in the frame. LR is live, and SP and FP
// belong to the caller.
intptr_t* fp = os::Linux::ucontext_get_fp(uc);
intptr_t* sp = os::Linux::ucontext_get_sp(uc);
address pc = (address)(uc->uc_mcontext.regs[REG_LR]
- NativeInstruction::instruction_size);
*fr = frame(sp, fp, pc);
if (!fr->is_java_frame()) {
assert(fr->safe_for_sender(thread), "Safety check");
assert(!fr->is_first_frame(), "Safety check");
*fr = fr->java_sender();
}
}
}
assert(fr->is_java_frame(), "Safety check");
return true;
}
// By default, gcc always saves frame pointer rfp on this stack. This
// may get turned off by -fomit-frame-pointer.
frame os::get_sender_for_C_frame(frame* fr) {
#ifdef BUILTIN_SIM
return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
#else
return frame(fr->link(), fr->link(), fr->sender_pc());
#endif
}
intptr_t* _get_previous_fp() {
register intptr_t **fp __asm__ (SPELL_REG_FP);
// fp is for this frame (_get_previous_fp). We want the fp for the
// caller of os::current_frame*(), so go up two frames. However, for
// optimized builds, _get_previous_fp() will be inlined, so only go
// up 1 frame in that case.
#ifdef _NMT_NOINLINE_
return **(intptr_t***)fp;
#else
return *fp;
#endif
}
frame os::current_frame() {
intptr_t* fp = _get_previous_fp();
frame myframe((intptr_t*)os::current_stack_pointer(),
(intptr_t*)fp,
CAST_FROM_FN_PTR(address, os::current_frame));
if (os::is_first_C_frame(&myframe)) {
// stack is not walkable
return frame();
} else {
return os::get_sender_for_C_frame(&myframe);
}
}
// Utility functions
// From IA32 System Programming Guide
enum {
trap_page_fault = 0xE
};
#ifdef BUILTIN_SIM
extern "C" void Fetch32PFI () ;
extern "C" void Fetch32Resume () ;
extern "C" void FetchNPFI () ;
extern "C" void FetchNResume () ;
#endif
extern "C" JNIEXPORT int
JVM_handle_linux_signal(int sig,
siginfo_t* info,
void* ucVoid,
int abort_if_unrecognized) {
ucontext_t* uc = (ucontext_t*) ucVoid;
Thread* t = Thread::current_or_null_safe();
// Must do this before SignalHandlerMark, if crash protection installed we will longjmp away
// (no destructors can be run)
os::ThreadCrashProtection::check_crash_protection(sig, t);
SignalHandlerMark shm(t);
// Note: it's not uncommon that JNI code uses signal/sigset to install
// then restore certain signal handler (e.g. to temporarily block SIGPIPE,
// or have a SIGILL handler when detecting CPU type). When that happens,
// JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To
// avoid unnecessary crash when libjsig is not preloaded, try handle signals
// that do not require siginfo/ucontext first.
if (sig == SIGPIPE || sig == SIGXFSZ) {
// allow chained handler to go first
if (os::Linux::chained_handler(sig, info, ucVoid)) {
return true;
} else {
// Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219
return true;
}
}
#ifdef CAN_SHOW_REGISTERS_ON_ASSERT
if ((sig == SIGSEGV || sig == SIGBUS) && info != NULL && info->si_addr == g_assert_poison) {
handle_assert_poison_fault(ucVoid, info->si_addr);
return 1;
}
#endif
JavaThread* thread = NULL;
VMThread* vmthread = NULL;
if (os::Linux::signal_handlers_are_installed) {
if (t != NULL ){
if(t->is_Java_thread()) {
thread = (JavaThread*)t;
}
else if(t->is_VM_thread()){
vmthread = (VMThread *)t;
}
}
}
/*
NOTE: does not seem to work on linux.
if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
// can't decode this kind of signal
info = NULL;
} else {
assert(sig == info->si_signo, "bad siginfo");
}
*/
// decide if this trap can be handled by a stub
address stub = NULL;
address pc = NULL;
//%note os_trap_1
if (info != NULL && uc != NULL && thread != NULL) {
pc = (address) os::Linux::ucontext_get_pc(uc);
#ifdef BUILTIN_SIM
if (pc == (address) Fetch32PFI) {
uc->uc_mcontext.gregs[REG_PC] = intptr_t(Fetch32Resume) ;
return 1 ;
}
if (pc == (address) FetchNPFI) {
uc->uc_mcontext.gregs[REG_PC] = intptr_t (FetchNResume) ;
return 1 ;
}
#else
if (StubRoutines::is_safefetch_fault(pc)) {
os::Linux::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
return 1;
}
#endif
// Handle ALL stack overflow variations here
if (sig == SIGSEGV) {
address addr = (address) info->si_addr;
// check if fault address is within thread stack
if (thread->on_local_stack(addr)) {
// stack overflow
if (thread->in_stack_yellow_reserved_zone(addr)) {
thread->disable_stack_yellow_reserved_zone();
if (thread->thread_state() == _thread_in_Java) {
if (thread->in_stack_reserved_zone(addr)) {
frame fr;
if (os::Linux::get_frame_at_stack_banging_point(thread, uc, &fr)) {
assert(fr.is_java_frame(), "Must be a Java frame");
frame activation =
SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr);
if (activation.sp() != NULL) {
thread->disable_stack_reserved_zone();
if (activation.is_interpreted_frame()) {
thread->set_reserved_stack_activation((address)(
activation.fp() + frame::interpreter_frame_initial_sp_offset));
} else {
thread->set_reserved_stack_activation((address)activation.unextended_sp());
}
return 1;
}
}
}
// Throw a stack overflow exception. Guard pages will be reenabled
// while unwinding the stack.
stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
} else {
// Thread was in the vm or native code. Return and try to finish.
return 1;
}
} else if (thread->in_stack_red_zone(addr)) {
// Fatal red zone violation. Disable the guard pages and fall through
// to handle_unexpected_exception way down below.
thread->disable_stack_red_zone();
tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
// This is a likely cause, but hard to verify. Let's just print
// it as a hint.
tty->print_raw_cr("Please check if any of your loaded .so files has "
"enabled executable stack (see man page execstack(8))");
} else {
// Accessing stack address below sp may cause SEGV if current
// thread has MAP_GROWSDOWN stack. This should only happen when
// current thread was created by user code with MAP_GROWSDOWN flag
// and then attached to VM. See notes in os_linux.cpp.
if (thread->osthread()->expanding_stack() == 0) {
thread->osthread()->set_expanding_stack();
if (os::Linux::manually_expand_stack(thread, addr)) {
thread->osthread()->clear_expanding_stack();
return 1;
}
thread->osthread()->clear_expanding_stack();
} else {
fatal("recursive segv. expanding stack.");
}
}
}
}
if (thread->thread_state() == _thread_in_Java) {
// Java thread running in Java code => find exception handler if any
// a fault inside compiled code, the interpreter, or a stub
// Handle signal from NativeJump::patch_verified_entry().
if ((sig == SIGILL || sig == SIGTRAP)
&& nativeInstruction_at(pc)->is_sigill_zombie_not_entrant()) {
if (TraceTraps) {
tty->print_cr("trap: zombie_not_entrant (%s)", (sig == SIGTRAP) ? "SIGTRAP" : "SIGILL");
}
stub = SharedRuntime::get_handle_wrong_method_stub();
} else if (sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) {
stub = SharedRuntime::get_poll_stub(pc);
} else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) {
// BugId 4454115: A read from a MappedByteBuffer can fault
// here if the underlying file has been truncated.
// Do not crash the VM in such a case.
CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
if (nm != NULL && nm->has_unsafe_access()) {
address next_pc = pc + NativeCall::instruction_size;
stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
}
}
else
if (sig == SIGFPE &&
(info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) {
stub =
SharedRuntime::
continuation_for_implicit_exception(thread,
pc,
SharedRuntime::
IMPLICIT_DIVIDE_BY_ZERO);
} else if (sig == SIGSEGV &&
!MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
// Determination of interpreter/vtable stub/compiled code null exception
stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
}
} else if (thread->thread_state() == _thread_in_vm &&
sig == SIGBUS && /* info->si_code == BUS_OBJERR && */
thread->doing_unsafe_access()) {
address next_pc = pc + NativeCall::instruction_size;
stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
}
// jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
// and the heap gets shrunk before the field access.
if ((sig == SIGSEGV) || (sig == SIGBUS)) {
address addr = JNI_FastGetField::find_slowcase_pc(pc);
if (addr != (address)-1) {
stub = addr;
}
}
}
if (stub != NULL) {
// save all thread context in case we need to restore it
if (thread != NULL) thread->set_saved_exception_pc(pc);
os::Linux::ucontext_set_pc(uc, stub);
return true;
}
// signal-chaining
if (os::Linux::chained_handler(sig, info, ucVoid)) {
return true;
}
if (!abort_if_unrecognized) {
// caller wants another chance, so give it to him
return false;
}
if (pc == NULL && uc != NULL) {
pc = os::Linux::ucontext_get_pc(uc);
}
// unmask current signal
sigset_t newset;
sigemptyset(&newset);
sigaddset(&newset, sig);
sigprocmask(SIG_UNBLOCK, &newset, NULL);
VMError::report_and_die(t, sig, pc, info, ucVoid);
ShouldNotReachHere();
return true; // Mute compiler
}
void os::Linux::init_thread_fpu_state(void) {
}
int os::Linux::get_fpu_control_word(void) {
return 0;
}
void os::Linux::set_fpu_control_word(int fpu_control) {
}
// Check that the linux kernel version is 2.4 or higher since earlier
// versions do not support SSE without patches.
bool os::supports_sse() {
return true;
}
bool os::is_allocatable(size_t bytes) {
return true;
}
////////////////////////////////////////////////////////////////////////////////
// thread stack
// Minimum usable stack sizes required to get to user code. Space for
// HotSpot guard pages is added later.
size_t os::Posix::_compiler_thread_min_stack_allowed = 72 * K;
size_t os::Posix::_java_thread_min_stack_allowed = 72 * K;
size_t os::Posix::_vm_internal_thread_min_stack_allowed = 72 * K;
// return default stack size for thr_type
size_t os::Posix::default_stack_size(os::ThreadType thr_type) {
// default stack size (compiler thread needs larger stack)
size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
return s;
}
/////////////////////////////////////////////////////////////////////////////
// helper functions for fatal error handler
void os::print_context(outputStream *st, const void *context) {
if (context == NULL) return;
const ucontext_t *uc = (const ucontext_t*)context;
st->print_cr("Registers:");
#ifdef BUILTIN_SIM
st->print( "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]);
st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]);
st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]);
st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]);
st->cr();
st->print( "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]);
st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]);
st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]);
st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]);
st->cr();
st->print( "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]);
st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]);
st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]);
st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]);
st->cr();
st->print( "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]);
st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]);
st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]);
st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]);
st->cr();
st->print( "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]);
st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EFL]);
st->print(", CSGSFS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_CSGSFS]);
st->print(", ERR=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ERR]);
st->cr();
st->print(" TRAPNO=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_TRAPNO]);
st->cr();
#else
for (int r = 0; r < 31; r++) {
st->print("R%-2d=", r);
print_location(st, uc->uc_mcontext.regs[r]);
}
#endif
st->cr();
intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", p2i(sp));
print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
st->cr();
// Note: it may be unsafe to inspect memory near pc. For example, pc may
// point to garbage if entry point in an nmethod is corrupted. Leave
// this at the end, and hope for the best.
address pc = os::Linux::ucontext_get_pc(uc);
st->print_cr("Instructions: (pc=" PTR_FORMAT ")", p2i(pc));
print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
}
void os::print_register_info(outputStream *st, const void *context) {
if (context == NULL) return;
const ucontext_t *uc = (const ucontext_t*)context;
st->print_cr("Register to memory mapping:");
st->cr();
// this is horrendously verbose but the layout of the registers in the
// context does not match how we defined our abstract Register set, so
// we can't just iterate through the gregs area
// this is only for the "general purpose" registers
#ifdef BUILTIN_SIM
st->print("RAX="); print_location(st, uc->uc_mcontext.gregs[REG_RAX]);
st->print("RBX="); print_location(st, uc->uc_mcontext.gregs[REG_RBX]);
st->print("RCX="); print_location(st, uc->uc_mcontext.gregs[REG_RCX]);
st->print("RDX="); print_location(st, uc->uc_mcontext.gregs[REG_RDX]);
st->print("RSP="); print_location(st, uc->uc_mcontext.gregs[REG_RSP]);
st->print("RBP="); print_location(st, uc->uc_mcontext.gregs[REG_RBP]);
st->print("RSI="); print_location(st, uc->uc_mcontext.gregs[REG_RSI]);
st->print("RDI="); print_location(st, uc->uc_mcontext.gregs[REG_RDI]);
st->print("R8 ="); print_location(st, uc->uc_mcontext.gregs[REG_R8]);
st->print("R9 ="); print_location(st, uc->uc_mcontext.gregs[REG_R9]);
st->print("R10="); print_location(st, uc->uc_mcontext.gregs[REG_R10]);
st->print("R11="); print_location(st, uc->uc_mcontext.gregs[REG_R11]);
st->print("R12="); print_location(st, uc->uc_mcontext.gregs[REG_R12]);
st->print("R13="); print_location(st, uc->uc_mcontext.gregs[REG_R13]);
st->print("R14="); print_location(st, uc->uc_mcontext.gregs[REG_R14]);
st->print("R15="); print_location(st, uc->uc_mcontext.gregs[REG_R15]);
#else
for (int r = 0; r < 31; r++)
st->print_cr( "R%d=" INTPTR_FORMAT, r, (uintptr_t)uc->uc_mcontext.regs[r]);
#endif
st->cr();
}
void os::setup_fpu() {
}
#ifndef PRODUCT
void os::verify_stack_alignment() {
assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
}
#endif
int os::extra_bang_size_in_bytes() {
// AArch64 does not require the additional stack bang.
return 0;
}
extern "C" {
int SpinPause() {
return 0;
}
void _Copy_conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count) {
if (from > to) {
jshort *end = from + count;
while (from < end)
*(to++) = *(from++);
}
else if (from < to) {
jshort *end = from;
from += count - 1;
to += count - 1;
while (from >= end)
*(to--) = *(from--);
}
}
void _Copy_conjoint_jints_atomic(jint* from, jint* to, size_t count) {
if (from > to) {
jint *end = from + count;
while (from < end)
*(to++) = *(from++);
}
else if (from < to) {
jint *end = from;
from += count - 1;
to += count - 1;
while (from >= end)
*(to--) = *(from--);
}
}
void _Copy_conjoint_jlongs_atomic(jlong* from, jlong* to, size_t count) {
if (from > to) {
jlong *end = from + count;
while (from < end)
os::atomic_copy64(from++, to++);
}
else if (from < to) {
jlong *end = from;
from += count - 1;
to += count - 1;
while (from >= end)
os::atomic_copy64(from--, to--);
}
}
void _Copy_arrayof_conjoint_bytes(HeapWord* from,
HeapWord* to,
size_t count) {
memmove(to, from, count);
}
void _Copy_arrayof_conjoint_jshorts(HeapWord* from,
HeapWord* to,
size_t count) {
memmove(to, from, count * 2);
}
void _Copy_arrayof_conjoint_jints(HeapWord* from,
HeapWord* to,
size_t count) {
memmove(to, from, count * 4);
}
void _Copy_arrayof_conjoint_jlongs(HeapWord* from,
HeapWord* to,
size_t count) {
memmove(to, from, count * 8);
}
};