1 /*
2 * Copyright (c) 1999, 2025, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2014, Red Hat Inc. All rights reserved.
4 * Copyright (c) 2021, Azul Systems, Inc. All rights reserved.
5 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 *
7 * This code is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 only, as
9 * published by the Free Software Foundation.
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
27 #include "asm/macroAssembler.hpp"
28 #include "classfile/classLoader.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "code/codeCache.hpp"
31 #include "code/vtableStubs.hpp"
32 #include "interpreter/interpreter.hpp"
33 #include "jvm.h"
34 #include "logging/log.hpp"
35 #include "memory/allocation.inline.hpp"
36 #include "os_bsd.hpp"
37 #include "os_posix.hpp"
38 #include "prims/jniFastGetField.hpp"
39 #include "prims/jvm_misc.hpp"
40 #include "runtime/arguments.hpp"
41 #include "runtime/frame.inline.hpp"
42 #include "runtime/interfaceSupport.inline.hpp"
43 #include "runtime/java.hpp"
44 #include "runtime/javaCalls.hpp"
45 #include "runtime/javaThread.hpp"
46 #include "runtime/mutexLocker.hpp"
47 #include "runtime/osThread.hpp"
48 #include "runtime/safepointMechanism.hpp"
49 #include "runtime/sharedRuntime.hpp"
50 #include "runtime/stubRoutines.hpp"
51 #include "runtime/timer.hpp"
52 #include "signals_posix.hpp"
53 #include "utilities/align.hpp"
54 #include "utilities/events.hpp"
55 #include "utilities/vmError.hpp"
56
57 // put OS-includes here
58 # include <sys/types.h>
59 # include <sys/mman.h>
60 # include <pthread.h>
61 # include <signal.h>
62 # include <errno.h>
63 # include <dlfcn.h>
64 # include <stdlib.h>
65 # include <stdio.h>
66 # include <unistd.h>
67 # include <sys/resource.h>
68 # include <sys/stat.h>
69 # include <sys/time.h>
70 # include <sys/utsname.h>
71 # include <sys/socket.h>
72 # include <sys/wait.h>
73 # include <pwd.h>
74 # include <poll.h>
75 #ifndef __OpenBSD__
76 # include <ucontext.h>
77 #endif
78
79 #if !defined(__APPLE__) && !defined(__NetBSD__)
80 # include <pthread_np.h>
81 #endif
82
83 #define SPELL_REG_SP "sp"
84 #define SPELL_REG_FP "fp"
85
86 #ifdef __APPLE__
87 // see darwin-xnu/osfmk/mach/arm/_structs.h
88
89 // 10.5 UNIX03 member name prefixes
90 #define DU3_PREFIX(s, m) __ ## s.__ ## m
91 #endif
92
93 #define context_x uc_mcontext->DU3_PREFIX(ss,x)
94 #define context_fp uc_mcontext->DU3_PREFIX(ss,fp)
95 #define context_lr uc_mcontext->DU3_PREFIX(ss,lr)
96 #define context_sp uc_mcontext->DU3_PREFIX(ss,sp)
97 #define context_pc uc_mcontext->DU3_PREFIX(ss,pc)
98 #define context_cpsr uc_mcontext->DU3_PREFIX(ss,cpsr)
99 #define context_esr uc_mcontext->DU3_PREFIX(es,esr)
100
101 #define REG_BCP context_x[22]
102
103 address os::current_stack_pointer() {
104 #if defined(__clang__) || defined(__llvm__)
105 void *sp;
106 __asm__("mov %0, " SPELL_REG_SP : "=r"(sp));
107 return (address) sp;
108 #else
109 register void *sp __asm__ (SPELL_REG_SP);
110 return (address) sp;
111 #endif
112 }
113
114 char* os::non_memory_address_word() {
115 // Must never look like an address returned by reserve_memory,
116 // even in its subfields (as defined by the CPU immediate fields,
117 // if the CPU splits constants across multiple instructions).
118
119 // the return value used in computation of Universe::non_oop_word(), which
120 // is loaded by cpu/aarch64 by MacroAssembler::movptr(Register, uintptr_t)
121 return (char*) 0xffffffffffff;
122 }
123
124 address os::Posix::ucontext_get_pc(const ucontext_t * uc) {
125 return (address)uc->context_pc;
126 }
127
128 void os::Posix::ucontext_set_pc(ucontext_t * uc, address pc) {
129 uc->context_pc = (intptr_t)pc ;
130 }
131
132 intptr_t* os::Bsd::ucontext_get_sp(const ucontext_t * uc) {
133 return (intptr_t*)uc->context_sp;
134 }
135
136 intptr_t* os::Bsd::ucontext_get_fp(const ucontext_t * uc) {
137 return (intptr_t*)uc->context_fp;
138 }
139
140 address os::fetch_frame_from_context(const void* ucVoid,
141 intptr_t** ret_sp, intptr_t** ret_fp) {
142
143 address epc;
144 const ucontext_t* uc = (const ucontext_t*)ucVoid;
145
146 if (uc != nullptr) {
147 epc = os::Posix::ucontext_get_pc(uc);
148 if (ret_sp) *ret_sp = os::Bsd::ucontext_get_sp(uc);
149 if (ret_fp) *ret_fp = os::Bsd::ucontext_get_fp(uc);
150 } else {
151 epc = nullptr;
152 if (ret_sp) *ret_sp = (intptr_t *)nullptr;
153 if (ret_fp) *ret_fp = (intptr_t *)nullptr;
154 }
155
156 return epc;
157 }
158
159 frame os::fetch_frame_from_context(const void* ucVoid) {
160 intptr_t* sp;
161 intptr_t* fp;
162 address epc = fetch_frame_from_context(ucVoid, &sp, &fp);
163 if (!is_readable_pointer(epc)) {
164 // Try to recover from calling into bad memory
165 // Assume new frame has not been set up, the same as
166 // compiled frame stack bang
167 return fetch_compiled_frame_from_context(ucVoid);
168 }
169 return frame(sp, fp, epc);
170 }
171
172 frame os::fetch_compiled_frame_from_context(const void* ucVoid) {
173 const ucontext_t* uc = (const ucontext_t*)ucVoid;
174 // In compiled code, the stack banging is performed before LR
175 // has been saved in the frame. LR is live, and SP and FP
176 // belong to the caller.
177 intptr_t* fp = os::Bsd::ucontext_get_fp(uc);
178 intptr_t* sp = os::Bsd::ucontext_get_sp(uc);
179 address pc = (address)(uc->context_lr
180 - NativeInstruction::instruction_size);
181 return frame(sp, fp, pc);
182 }
183
184 intptr_t* os::fetch_bcp_from_context(const void* ucVoid) {
185 assert(ucVoid != nullptr, "invariant");
186 const ucontext_t* uc = (const ucontext_t*)ucVoid;
187 assert(os::Posix::ucontext_is_interpreter(uc), "invariant");
188 return reinterpret_cast<intptr_t*>(uc->REG_BCP);
189 }
190
191 // JVM compiled with -fno-omit-frame-pointer, so RFP is saved on the stack.
192 frame os::get_sender_for_C_frame(frame* fr) {
193 return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
194 }
195
196 NOINLINE frame os::current_frame() {
197 intptr_t *fp = *(intptr_t **)__builtin_frame_address(0);
198 frame myframe((intptr_t*)os::current_stack_pointer(),
199 (intptr_t*)fp,
200 CAST_FROM_FN_PTR(address, os::current_frame));
201 if (os::is_first_C_frame(&myframe)) {
202 // stack is not walkable
203 return frame();
204 } else {
205 return os::get_sender_for_C_frame(&myframe);
206 }
207 }
208
209 bool PosixSignals::pd_hotspot_signal_handler(int sig, siginfo_t* info,
210 ucontext_t* uc, JavaThread* thread) {
211 // Enable WXWrite: this function is called by the signal handler at arbitrary
212 // point of execution.
213 ThreadWXEnable wx(WXWrite, thread);
214
215 // decide if this trap can be handled by a stub
216 address stub = nullptr;
217
218 address pc = nullptr;
219
220 //%note os_trap_1
221 if (info != nullptr && uc != nullptr && thread != nullptr) {
222 pc = (address) os::Posix::ucontext_get_pc(uc);
223
224 // Handle ALL stack overflow variations here
225 if (sig == SIGSEGV || sig == SIGBUS) {
226 address addr = (address) info->si_addr;
227
228 // Make sure the high order byte is sign extended, as it may be masked away by the hardware.
229 if ((uintptr_t(addr) & (uintptr_t(1) << 55)) != 0) {
230 addr = address(uintptr_t(addr) | (uintptr_t(0xFF) << 56));
231 }
232
233 // check if fault address is within thread stack
234 if (thread->is_in_full_stack(addr)) {
235 // stack overflow
236 if (os::Posix::handle_stack_overflow(thread, addr, pc, uc, &stub)) {
237 return true; // continue
238 }
239 }
240 }
241
242 // We test if stub is already set (by the stack overflow code
243 // above) so it is not overwritten by the code that follows. This
244 // check is not required on other platforms, because on other
245 // platforms we check for SIGSEGV only or SIGBUS only, where here
246 // we have to check for both SIGSEGV and SIGBUS.
247 if (thread->thread_state() == _thread_in_Java && stub == nullptr) {
248 // Java thread running in Java code => find exception handler if any
249 // a fault inside compiled code, the interpreter, or a stub
250
251 // Handle signal from NativeJump::patch_verified_entry().
252 if ((sig == SIGILL)
253 && nativeInstruction_at(pc)->is_sigill_not_entrant()) {
254 if (TraceTraps) {
255 tty->print_cr("trap: not_entrant");
256 }
257 stub = SharedRuntime::get_handle_wrong_method_stub();
258 } else if ((sig == SIGSEGV || sig == SIGBUS) && SafepointMechanism::is_poll_address((address)info->si_addr)) {
259 stub = SharedRuntime::get_poll_stub(pc);
260 #if defined(__APPLE__)
261 // 32-bit Darwin reports a SIGBUS for nearly all memory access exceptions.
262 // 64-bit Darwin may also use a SIGBUS (seen with compressed oops).
263 // Catching SIGBUS here prevents the implicit SIGBUS null check below from
264 // being called, so only do so if the implicit null check is not necessary.
265 } else if (sig == SIGBUS && !MacroAssembler::uses_implicit_null_check(info->si_addr)) {
266 #else
267 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) {
268 #endif
269 // BugId 4454115: A read from a MappedByteBuffer can fault
270 // here if the underlying file has been truncated.
271 // Do not crash the VM in such a case.
272 CodeBlob* cb = CodeCache::find_blob(pc);
273 nmethod* nm = (cb != nullptr) ? cb->as_nmethod_or_null() : nullptr;
274 bool is_unsafe_memory_access = (thread->doing_unsafe_access() && UnsafeMemoryAccess::contains_pc(pc));
275 if ((nm != nullptr && nm->has_unsafe_access()) || is_unsafe_memory_access) {
276 address next_pc = pc + NativeCall::instruction_size;
277 if (is_unsafe_memory_access) {
278 next_pc = UnsafeMemoryAccess::page_error_continue_pc(pc);
279 }
280 stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
281 }
282 } else if (sig == SIGILL && nativeInstruction_at(pc)->is_stop()) {
283 // A pointer to the message will have been placed in r0
284 const char *detail_msg = (const char *)(uc->uc_mcontext->DU3_PREFIX(ss,x[0]));
285 const char *msg = "stop";
286 if (TraceTraps) {
287 tty->print_cr("trap: %s: (SIGILL)", msg);
288 }
289
290 // End life with a fatal error, message and detail message and the context.
291 // Note: no need to do any post-processing here (e.g. signal chaining)
292 VMError::report_and_die(thread, uc, nullptr, 0, msg, "%s", detail_msg);
293 ShouldNotReachHere();
294
295 } else if (sig == SIGFPE &&
296 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) {
297 stub =
298 SharedRuntime::
299 continuation_for_implicit_exception(thread,
300 pc,
301 SharedRuntime::
302 IMPLICIT_DIVIDE_BY_ZERO);
303 } else if ((sig == SIGSEGV || sig == SIGBUS) &&
304 MacroAssembler::uses_implicit_null_check(info->si_addr)) {
305 // Determination of interpreter/vtable stub/compiled code null exception
306 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
307 }
308 } else if ((thread->thread_state() == _thread_in_vm ||
309 thread->thread_state() == _thread_in_native) &&
310 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */
311 thread->doing_unsafe_access()) {
312 address next_pc = pc + NativeCall::instruction_size;
313 if (UnsafeMemoryAccess::contains_pc(pc)) {
314 next_pc = UnsafeMemoryAccess::page_error_continue_pc(pc);
315 }
316 stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
317 }
318
319 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
320 // and the heap gets shrunk before the field access.
321 if ((sig == SIGSEGV) || (sig == SIGBUS)) {
322 address addr = JNI_FastGetField::find_slowcase_pc(pc);
323 if (addr != (address)-1) {
324 stub = addr;
325 }
326 }
327 }
328
329 if (stub != nullptr) {
330 // save all thread context in case we need to restore it
331 if (thread != nullptr) thread->set_saved_exception_pc(pc);
332
333 os::Posix::ucontext_set_pc(uc, stub);
334 return true;
335 }
336
337 return false; // Mute compiler
338 }
339
340 void os::Bsd::init_thread_fpu_state(void) {
341 }
342
343 ////////////////////////////////////////////////////////////////////////////////
344 // thread stack
345
346 // Minimum usable stack sizes required to get to user code. Space for
347 // HotSpot guard pages is added later.
348 size_t os::_compiler_thread_min_stack_allowed = 72 * K;
349 size_t os::_java_thread_min_stack_allowed = 72 * K;
350 size_t os::_vm_internal_thread_min_stack_allowed = 72 * K;
351
352 // return default stack size for thr_type
353 size_t os::Posix::default_stack_size(os::ThreadType thr_type) {
354 // default stack size (compiler thread needs larger stack)
355 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
356 return s;
357 }
358 void os::current_stack_base_and_size(address* base, size_t* size) {
359 address bottom;
360 #ifdef __APPLE__
361 pthread_t self = pthread_self();
362 *base = (address) pthread_get_stackaddr_np(self);
363 *size = pthread_get_stacksize_np(self);
364 bottom = *base - *size;
365 #elif defined(__OpenBSD__)
366 stack_t ss;
367 int rslt = pthread_stackseg_np(pthread_self(), &ss);
368
369 if (rslt != 0)
370 fatal("pthread_stackseg_np failed with error = %d", rslt);
371
372 *base = (address) ss.ss_sp;
373 *size = ss.ss_size;
374 bottom = *base - *size;
375 #else
376 pthread_attr_t attr;
377
378 int rslt = pthread_attr_init(&attr);
379
380 // JVM needs to know exact stack location, abort if it fails
381 if (rslt != 0)
382 fatal("pthread_attr_init failed with error = %d", rslt);
383
384 rslt = pthread_attr_get_np(pthread_self(), &attr);
385
386 if (rslt != 0)
387 fatal("pthread_attr_get_np failed with error = %d", rslt);
388
389 if (pthread_attr_getstackaddr(&attr, (void **)&bottom) != 0 ||
390 pthread_attr_getstacksize(&attr, size) != 0) {
391 fatal("Can not locate current stack attributes!");
392 }
393
394 *base = bottom + *size;
395
396 pthread_attr_destroy(&attr);
397 #endif
398 assert(os::current_stack_pointer() >= bottom &&
399 os::current_stack_pointer() < *base, "just checking");
400 }
401
402 /////////////////////////////////////////////////////////////////////////////
403 // helper functions for fatal error handler
404
405 void os::print_context(outputStream *st, const void *context) {
406 if (context == nullptr) return;
407
408 const ucontext_t *uc = (const ucontext_t*)context;
409
410 st->print_cr("Registers:");
411 st->print( " x0=" INTPTR_FORMAT, (intptr_t)uc->context_x[ 0]);
412 st->print(" x1=" INTPTR_FORMAT, (intptr_t)uc->context_x[ 1]);
413 st->print(" x2=" INTPTR_FORMAT, (intptr_t)uc->context_x[ 2]);
414 st->print(" x3=" INTPTR_FORMAT, (intptr_t)uc->context_x[ 3]);
415 st->cr();
416 st->print( " x4=" INTPTR_FORMAT, (intptr_t)uc->context_x[ 4]);
417 st->print(" x5=" INTPTR_FORMAT, (intptr_t)uc->context_x[ 5]);
418 st->print(" x6=" INTPTR_FORMAT, (intptr_t)uc->context_x[ 6]);
419 st->print(" x7=" INTPTR_FORMAT, (intptr_t)uc->context_x[ 7]);
420 st->cr();
421 st->print( " x8=" INTPTR_FORMAT, (intptr_t)uc->context_x[ 8]);
422 st->print(" x9=" INTPTR_FORMAT, (intptr_t)uc->context_x[ 9]);
423 st->print(" x10=" INTPTR_FORMAT, (intptr_t)uc->context_x[10]);
424 st->print(" x11=" INTPTR_FORMAT, (intptr_t)uc->context_x[11]);
425 st->cr();
426 st->print( "x12=" INTPTR_FORMAT, (intptr_t)uc->context_x[12]);
427 st->print(" x13=" INTPTR_FORMAT, (intptr_t)uc->context_x[13]);
428 st->print(" x14=" INTPTR_FORMAT, (intptr_t)uc->context_x[14]);
429 st->print(" x15=" INTPTR_FORMAT, (intptr_t)uc->context_x[15]);
430 st->cr();
431 st->print( "x16=" INTPTR_FORMAT, (intptr_t)uc->context_x[16]);
432 st->print(" x17=" INTPTR_FORMAT, (intptr_t)uc->context_x[17]);
433 st->print(" x18=" INTPTR_FORMAT, (intptr_t)uc->context_x[18]);
434 st->print(" x19=" INTPTR_FORMAT, (intptr_t)uc->context_x[19]);
435 st->cr();
436 st->print( "x20=" INTPTR_FORMAT, (intptr_t)uc->context_x[20]);
437 st->print(" x21=" INTPTR_FORMAT, (intptr_t)uc->context_x[21]);
438 st->print(" x22=" INTPTR_FORMAT, (intptr_t)uc->context_x[22]);
439 st->print(" x23=" INTPTR_FORMAT, (intptr_t)uc->context_x[23]);
440 st->cr();
441 st->print( "x24=" INTPTR_FORMAT, (intptr_t)uc->context_x[24]);
442 st->print(" x25=" INTPTR_FORMAT, (intptr_t)uc->context_x[25]);
443 st->print(" x26=" INTPTR_FORMAT, (intptr_t)uc->context_x[26]);
444 st->print(" x27=" INTPTR_FORMAT, (intptr_t)uc->context_x[27]);
445 st->cr();
446 st->print( "x28=" INTPTR_FORMAT, (intptr_t)uc->context_x[28]);
447 st->print(" fp=" INTPTR_FORMAT, (intptr_t)uc->context_fp);
448 st->print(" lr=" INTPTR_FORMAT, (intptr_t)uc->context_lr);
449 st->print(" sp=" INTPTR_FORMAT, (intptr_t)uc->context_sp);
450 st->cr();
451 st->print( "pc=" INTPTR_FORMAT, (intptr_t)uc->context_pc);
452 st->print(" cpsr=" INTPTR_FORMAT, (intptr_t)uc->context_cpsr);
453 st->cr();
454 }
455
456 void os::print_register_info(outputStream *st, const void *context, int& continuation) {
457 const int register_count = 29 /* x0-x28 */ + 3 /* fp, lr, sp */;
458 int n = continuation;
459 assert(n >= 0 && n <= register_count, "Invalid continuation value");
460 if (context == nullptr || n == register_count) {
461 return;
462 }
463
464 const ucontext_t *uc = (const ucontext_t*)context;
465 while (n < register_count) {
466 // Update continuation with next index before printing location
467 continuation = n + 1;
468 switch (n) {
469 case 29:
470 st->print(" fp="); print_location(st, uc->context_fp);
471 break;
472 case 30:
473 st->print(" lr="); print_location(st, uc->context_lr);
474 break;
475 case 31:
476 st->print(" sp="); print_location(st, uc->context_sp);
477 break;
478 default:
479 st->print("x%-2d=",n); print_location(st, uc->context_x[n]);
480 break;
481 }
482 ++n;
483 }
484 }
485
486 void os::setup_fpu() {
487 }
488
489 #ifndef PRODUCT
490 void os::verify_stack_alignment() {
491 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
492 }
493 #endif
494
495 int os::extra_bang_size_in_bytes() {
496 // AArch64 does not require the additional stack bang.
497 return 0;
498 }
499
500 void os::current_thread_enable_wx(WXMode mode) {
501 pthread_jit_write_protect_np(mode == WXExec);
502 }
503
504 static inline void atomic_copy64(const volatile void *src, volatile void *dst) {
505 *(jlong *) dst = *(const jlong *) src;
506 }
507
508 extern "C" {
509 // needs local assembler label '1:' to avoid trouble when using linktime optimization
510 int SpinPause() {
511 // We don't use StubRoutines::aarch64::spin_wait stub in order to
512 // avoid a costly call to os::current_thread_enable_wx() on MacOS.
513 // We should return 1 if SpinPause is implemented, and since there
514 // will be a sequence of 11 instructions for NONE and YIELD and 12
515 // instructions for NOP and ISB, SpinPause will always return 1.
516 uint64_t br_dst;
517 const int instructions_per_case = 2;
518 int64_t off = VM_Version::spin_wait_desc().inst() * instructions_per_case * Assembler::instruction_size;
519
520 assert(VM_Version::spin_wait_desc().inst() >= SpinWait::NONE &&
521 VM_Version::spin_wait_desc().inst() <= SpinWait::YIELD, "must be");
522 assert(-1 == SpinWait::NONE, "must be");
523 assert( 0 == SpinWait::NOP, "must be");
524 assert( 1 == SpinWait::ISB, "must be");
525 assert( 2 == SpinWait::YIELD, "must be");
526
527 asm volatile(
528 " adr %[d], 20 \n" // 20 == PC here + 5 instructions => address
529 // to entry for case SpinWait::NOP
530 " add %[d], %[d], %[o] \n"
531 " br %[d] \n"
532 " b 1f \n" // case SpinWait::NONE (-1)
533 " nop \n" // padding
534 " nop \n" // case SpinWait::NOP ( 0)
535 " b 1f \n"
536 " isb \n" // case SpinWait::ISB ( 1)
537 " b 1f \n"
538 " yield \n" // case SpinWait::YIELD ( 2)
539 "1: \n"
540 : [d]"=&r"(br_dst)
541 : [o]"r"(off)
542 : "memory");
543 return 1;
544 }
545
546 void _Copy_conjoint_jshorts_atomic(const jshort* from, jshort* to, size_t count) {
547 if (from > to) {
548 const jshort *end = from + count;
549 while (from < end)
550 *(to++) = *(from++);
551 }
552 else if (from < to) {
553 const jshort *end = from;
554 from += count - 1;
555 to += count - 1;
556 while (from >= end)
557 *(to--) = *(from--);
558 }
559 }
560 void _Copy_conjoint_jints_atomic(const jint* from, jint* to, size_t count) {
561 if (from > to) {
562 const jint *end = from + count;
563 while (from < end)
564 *(to++) = *(from++);
565 }
566 else if (from < to) {
567 const jint *end = from;
568 from += count - 1;
569 to += count - 1;
570 while (from >= end)
571 *(to--) = *(from--);
572 }
573 }
574
575 void _Copy_conjoint_jlongs_atomic(const jlong* from, jlong* to, size_t count) {
576 if (from > to) {
577 const jlong *end = from + count;
578 while (from < end)
579 atomic_copy64(from++, to++);
580 }
581 else if (from < to) {
582 const jlong *end = from;
583 from += count - 1;
584 to += count - 1;
585 while (from >= end)
586 atomic_copy64(from--, to--);
587 }
588 }
589
590 void _Copy_arrayof_conjoint_bytes(const HeapWord* from,
591 HeapWord* to,
592 size_t count) {
593 memmove(to, from, count);
594 }
595 void _Copy_arrayof_conjoint_jshorts(const HeapWord* from,
596 HeapWord* to,
597 size_t count) {
598 memmove(to, from, count * 2);
599 }
600 void _Copy_arrayof_conjoint_jints(const HeapWord* from,
601 HeapWord* to,
602 size_t count) {
603 memmove(to, from, count * 4);
604 }
605 void _Copy_arrayof_conjoint_jlongs(const HeapWord* from,
606 HeapWord* to,
607 size_t count) {
608 memmove(to, from, count * 8);
609 }
610 };