os_bsd_x86.cpp revision 3171:da4be62fb889
1/* 2 * Copyright (c) 1999, 2012, 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// no precompiled headers 26#include "assembler_x86.inline.hpp" 27#include "classfile/classLoader.hpp" 28#include "classfile/systemDictionary.hpp" 29#include "classfile/vmSymbols.hpp" 30#include "code/icBuffer.hpp" 31#include "code/vtableStubs.hpp" 32#include "interpreter/interpreter.hpp" 33#include "jvm_bsd.h" 34#include "memory/allocation.inline.hpp" 35#include "mutex_bsd.inline.hpp" 36#include "nativeInst_x86.hpp" 37#include "os_share_bsd.hpp" 38#include "prims/jniFastGetField.hpp" 39#include "prims/jvm.h" 40#include "prims/jvm_misc.hpp" 41#include "runtime/arguments.hpp" 42#include "runtime/extendedPC.hpp" 43#include "runtime/frame.inline.hpp" 44#include "runtime/interfaceSupport.hpp" 45#include "runtime/java.hpp" 46#include "runtime/javaCalls.hpp" 47#include "runtime/mutexLocker.hpp" 48#include "runtime/osThread.hpp" 49#include "runtime/sharedRuntime.hpp" 50#include "runtime/stubRoutines.hpp" 51#include "runtime/timer.hpp" 52#include "thread_bsd.inline.hpp" 53#include "utilities/events.hpp" 54#include "utilities/vmError.hpp" 55#ifdef COMPILER1 56#include "c1/c1_Runtime1.hpp" 57#endif 58#ifdef COMPILER2 59#include "opto/runtime.hpp" 60#endif 61 62// put OS-includes here 63# include <sys/types.h> 64# include <sys/mman.h> 65# include <pthread.h> 66# include <signal.h> 67# include <errno.h> 68# include <dlfcn.h> 69# include <stdlib.h> 70# include <stdio.h> 71# include <unistd.h> 72# include <sys/resource.h> 73# include <pthread.h> 74# include <sys/stat.h> 75# include <sys/time.h> 76# include <sys/utsname.h> 77# include <sys/socket.h> 78# include <sys/wait.h> 79# include <pwd.h> 80# include <poll.h> 81#ifndef __OpenBSD__ 82# include <ucontext.h> 83#endif 84 85#if defined(_ALLBSD_SOURCE) && !defined(__APPLE__) && !defined(__NetBSD__) 86# include <pthread_np.h> 87#endif 88 89#ifdef AMD64 90#define SPELL_REG_SP "rsp" 91#define SPELL_REG_FP "rbp" 92#else 93#define SPELL_REG_SP "esp" 94#define SPELL_REG_FP "ebp" 95#endif // AMD64 96 97#ifdef __FreeBSD__ 98# define context_trapno uc_mcontext.mc_trapno 99# ifdef AMD64 100# define context_pc uc_mcontext.mc_rip 101# define context_sp uc_mcontext.mc_rsp 102# define context_fp uc_mcontext.mc_rbp 103# define context_rip uc_mcontext.mc_rip 104# define context_rsp uc_mcontext.mc_rsp 105# define context_rbp uc_mcontext.mc_rbp 106# define context_rax uc_mcontext.mc_rax 107# define context_rbx uc_mcontext.mc_rbx 108# define context_rcx uc_mcontext.mc_rcx 109# define context_rdx uc_mcontext.mc_rdx 110# define context_rsi uc_mcontext.mc_rsi 111# define context_rdi uc_mcontext.mc_rdi 112# define context_r8 uc_mcontext.mc_r8 113# define context_r9 uc_mcontext.mc_r9 114# define context_r10 uc_mcontext.mc_r10 115# define context_r11 uc_mcontext.mc_r11 116# define context_r12 uc_mcontext.mc_r12 117# define context_r13 uc_mcontext.mc_r13 118# define context_r14 uc_mcontext.mc_r14 119# define context_r15 uc_mcontext.mc_r15 120# define context_flags uc_mcontext.mc_flags 121# define context_err uc_mcontext.mc_err 122# else 123# define context_pc uc_mcontext.mc_eip 124# define context_sp uc_mcontext.mc_esp 125# define context_fp uc_mcontext.mc_ebp 126# define context_eip uc_mcontext.mc_eip 127# define context_esp uc_mcontext.mc_esp 128# define context_eax uc_mcontext.mc_eax 129# define context_ebx uc_mcontext.mc_ebx 130# define context_ecx uc_mcontext.mc_ecx 131# define context_edx uc_mcontext.mc_edx 132# define context_ebp uc_mcontext.mc_ebp 133# define context_esi uc_mcontext.mc_esi 134# define context_edi uc_mcontext.mc_edi 135# define context_eflags uc_mcontext.mc_eflags 136# define context_trapno uc_mcontext.mc_trapno 137# endif 138#endif 139 140#ifdef __APPLE__ 141# if __DARWIN_UNIX03 && (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5) 142 // 10.5 UNIX03 member name prefixes 143 #define DU3_PREFIX(s, m) __ ## s.__ ## m 144# else 145 #define DU3_PREFIX(s, m) s ## . ## m 146# endif 147 148# ifdef AMD64 149# define context_pc context_rip 150# define context_sp context_rsp 151# define context_fp context_rbp 152# define context_rip uc_mcontext->DU3_PREFIX(ss,rip) 153# define context_rsp uc_mcontext->DU3_PREFIX(ss,rsp) 154# define context_rax uc_mcontext->DU3_PREFIX(ss,rax) 155# define context_rbx uc_mcontext->DU3_PREFIX(ss,rbx) 156# define context_rcx uc_mcontext->DU3_PREFIX(ss,rcx) 157# define context_rdx uc_mcontext->DU3_PREFIX(ss,rdx) 158# define context_rbp uc_mcontext->DU3_PREFIX(ss,rbp) 159# define context_rsi uc_mcontext->DU3_PREFIX(ss,rsi) 160# define context_rdi uc_mcontext->DU3_PREFIX(ss,rdi) 161# define context_r8 uc_mcontext->DU3_PREFIX(ss,r8) 162# define context_r9 uc_mcontext->DU3_PREFIX(ss,r9) 163# define context_r10 uc_mcontext->DU3_PREFIX(ss,r10) 164# define context_r11 uc_mcontext->DU3_PREFIX(ss,r11) 165# define context_r12 uc_mcontext->DU3_PREFIX(ss,r12) 166# define context_r13 uc_mcontext->DU3_PREFIX(ss,r13) 167# define context_r14 uc_mcontext->DU3_PREFIX(ss,r14) 168# define context_r15 uc_mcontext->DU3_PREFIX(ss,r15) 169# define context_flags uc_mcontext->DU3_PREFIX(ss,rflags) 170# define context_trapno uc_mcontext->DU3_PREFIX(es,trapno) 171# define context_err uc_mcontext->DU3_PREFIX(es,err) 172# else 173# define context_pc context_eip 174# define context_sp context_esp 175# define context_fp context_ebp 176# define context_eip uc_mcontext->DU3_PREFIX(ss,eip) 177# define context_esp uc_mcontext->DU3_PREFIX(ss,esp) 178# define context_eax uc_mcontext->DU3_PREFIX(ss,eax) 179# define context_ebx uc_mcontext->DU3_PREFIX(ss,ebx) 180# define context_ecx uc_mcontext->DU3_PREFIX(ss,ecx) 181# define context_edx uc_mcontext->DU3_PREFIX(ss,edx) 182# define context_ebp uc_mcontext->DU3_PREFIX(ss,ebp) 183# define context_esi uc_mcontext->DU3_PREFIX(ss,esi) 184# define context_edi uc_mcontext->DU3_PREFIX(ss,edi) 185# define context_eflags uc_mcontext->DU3_PREFIX(ss,eflags) 186# define context_trapno uc_mcontext->DU3_PREFIX(es,trapno) 187# endif 188#endif 189 190#ifdef __OpenBSD__ 191# define context_trapno sc_trapno 192# ifdef AMD64 193# define context_pc sc_rip 194# define context_sp sc_rsp 195# define context_fp sc_rbp 196# define context_rip sc_rip 197# define context_rsp sc_rsp 198# define context_rbp sc_rbp 199# define context_rax sc_rax 200# define context_rbx sc_rbx 201# define context_rcx sc_rcx 202# define context_rdx sc_rdx 203# define context_rsi sc_rsi 204# define context_rdi sc_rdi 205# define context_r8 sc_r8 206# define context_r9 sc_r9 207# define context_r10 sc_r10 208# define context_r11 sc_r11 209# define context_r12 sc_r12 210# define context_r13 sc_r13 211# define context_r14 sc_r14 212# define context_r15 sc_r15 213# define context_flags sc_rflags 214# define context_err sc_err 215# else 216# define context_pc sc_eip 217# define context_sp sc_esp 218# define context_fp sc_ebp 219# define context_eip sc_eip 220# define context_esp sc_esp 221# define context_eax sc_eax 222# define context_ebx sc_ebx 223# define context_ecx sc_ecx 224# define context_edx sc_edx 225# define context_ebp sc_ebp 226# define context_esi sc_esi 227# define context_edi sc_edi 228# define context_eflags sc_eflags 229# define context_trapno sc_trapno 230# endif 231#endif 232 233#ifdef __NetBSD__ 234# define context_trapno uc_mcontext.__gregs[_REG_TRAPNO] 235# ifdef AMD64 236# define __register_t __greg_t 237# define context_pc uc_mcontext.__gregs[_REG_RIP] 238# define context_sp uc_mcontext.__gregs[_REG_URSP] 239# define context_fp uc_mcontext.__gregs[_REG_RBP] 240# define context_rip uc_mcontext.__gregs[_REG_RIP] 241# define context_rsp uc_mcontext.__gregs[_REG_URSP] 242# define context_rax uc_mcontext.__gregs[_REG_RAX] 243# define context_rbx uc_mcontext.__gregs[_REG_RBX] 244# define context_rcx uc_mcontext.__gregs[_REG_RCX] 245# define context_rdx uc_mcontext.__gregs[_REG_RDX] 246# define context_rbp uc_mcontext.__gregs[_REG_RBP] 247# define context_rsi uc_mcontext.__gregs[_REG_RSI] 248# define context_rdi uc_mcontext.__gregs[_REG_RDI] 249# define context_r8 uc_mcontext.__gregs[_REG_R8] 250# define context_r9 uc_mcontext.__gregs[_REG_R9] 251# define context_r10 uc_mcontext.__gregs[_REG_R10] 252# define context_r11 uc_mcontext.__gregs[_REG_R11] 253# define context_r12 uc_mcontext.__gregs[_REG_R12] 254# define context_r13 uc_mcontext.__gregs[_REG_R13] 255# define context_r14 uc_mcontext.__gregs[_REG_R14] 256# define context_r15 uc_mcontext.__gregs[_REG_R15] 257# define context_flags uc_mcontext.__gregs[_REG_RFL] 258# define context_err uc_mcontext.__gregs[_REG_ERR] 259# else 260# define context_pc uc_mcontext.__gregs[_REG_EIP] 261# define context_sp uc_mcontext.__gregs[_REG_UESP] 262# define context_fp uc_mcontext.__gregs[_REG_EBP] 263# define context_eip uc_mcontext.__gregs[_REG_EIP] 264# define context_esp uc_mcontext.__gregs[_REG_UESP] 265# define context_eax uc_mcontext.__gregs[_REG_EAX] 266# define context_ebx uc_mcontext.__gregs[_REG_EBX] 267# define context_ecx uc_mcontext.__gregs[_REG_ECX] 268# define context_edx uc_mcontext.__gregs[_REG_EDX] 269# define context_ebp uc_mcontext.__gregs[_REG_EBP] 270# define context_esi uc_mcontext.__gregs[_REG_ESI] 271# define context_edi uc_mcontext.__gregs[_REG_EDI] 272# define context_eflags uc_mcontext.__gregs[_REG_EFL] 273# define context_trapno uc_mcontext.__gregs[_REG_TRAPNO] 274# endif 275#endif 276 277address os::current_stack_pointer() { 278#if defined(__clang__) || defined(__llvm__) 279 register void *esp; 280 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp)); 281 return (address) esp; 282#elif defined(SPARC_WORKS) 283 register void *esp; 284 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp)); 285 return (address) ((char*)esp + sizeof(long)*2); 286#else 287 register void *esp __asm__ (SPELL_REG_SP); 288 return (address) esp; 289#endif 290} 291 292char* os::non_memory_address_word() { 293 // Must never look like an address returned by reserve_memory, 294 // even in its subfields (as defined by the CPU immediate fields, 295 // if the CPU splits constants across multiple instructions). 296 297 return (char*) -1; 298} 299 300void os::initialize_thread() { 301// Nothing to do. 302} 303 304address os::Bsd::ucontext_get_pc(ucontext_t * uc) { 305 return (address)uc->context_pc; 306} 307 308intptr_t* os::Bsd::ucontext_get_sp(ucontext_t * uc) { 309 return (intptr_t*)uc->context_sp; 310} 311 312intptr_t* os::Bsd::ucontext_get_fp(ucontext_t * uc) { 313 return (intptr_t*)uc->context_fp; 314} 315 316// For Forte Analyzer AsyncGetCallTrace profiling support - thread 317// is currently interrupted by SIGPROF. 318// os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal 319// frames. Currently we don't do that on Bsd, so it's the same as 320// os::fetch_frame_from_context(). 321ExtendedPC os::Bsd::fetch_frame_from_ucontext(Thread* thread, 322 ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) { 323 324 assert(thread != NULL, "just checking"); 325 assert(ret_sp != NULL, "just checking"); 326 assert(ret_fp != NULL, "just checking"); 327 328 return os::fetch_frame_from_context(uc, ret_sp, ret_fp); 329} 330 331ExtendedPC os::fetch_frame_from_context(void* ucVoid, 332 intptr_t** ret_sp, intptr_t** ret_fp) { 333 334 ExtendedPC epc; 335 ucontext_t* uc = (ucontext_t*)ucVoid; 336 337 if (uc != NULL) { 338 epc = ExtendedPC(os::Bsd::ucontext_get_pc(uc)); 339 if (ret_sp) *ret_sp = os::Bsd::ucontext_get_sp(uc); 340 if (ret_fp) *ret_fp = os::Bsd::ucontext_get_fp(uc); 341 } else { 342 // construct empty ExtendedPC for return value checking 343 epc = ExtendedPC(NULL); 344 if (ret_sp) *ret_sp = (intptr_t *)NULL; 345 if (ret_fp) *ret_fp = (intptr_t *)NULL; 346 } 347 348 return epc; 349} 350 351frame os::fetch_frame_from_context(void* ucVoid) { 352 intptr_t* sp; 353 intptr_t* fp; 354 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp); 355 return frame(sp, fp, epc.pc()); 356} 357 358// By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get 359// turned off by -fomit-frame-pointer, 360frame os::get_sender_for_C_frame(frame* fr) { 361 return frame(fr->sender_sp(), fr->link(), fr->sender_pc()); 362} 363 364intptr_t* _get_previous_fp() { 365#if defined(SPARC_WORKS) || defined(__clang__) || defined(__llvm__) 366 register intptr_t **ebp; 367 __asm__("mov %%"SPELL_REG_FP", %0":"=r"(ebp)); 368#else 369 register intptr_t **ebp __asm__ (SPELL_REG_FP); 370#endif 371 return (intptr_t*) *ebp; // we want what it points to. 372} 373 374 375frame os::current_frame() { 376 intptr_t* fp = _get_previous_fp(); 377 frame myframe((intptr_t*)os::current_stack_pointer(), 378 (intptr_t*)fp, 379 CAST_FROM_FN_PTR(address, os::current_frame)); 380 if (os::is_first_C_frame(&myframe)) { 381 // stack is not walkable 382 return frame(NULL, NULL, NULL); 383 } else { 384 return os::get_sender_for_C_frame(&myframe); 385 } 386} 387 388// Utility functions 389 390// From IA32 System Programming Guide 391enum { 392 trap_page_fault = 0xE 393}; 394 395extern "C" void Fetch32PFI () ; 396extern "C" void Fetch32Resume () ; 397#ifdef AMD64 398extern "C" void FetchNPFI () ; 399extern "C" void FetchNResume () ; 400#endif // AMD64 401 402extern "C" JNIEXPORT int 403JVM_handle_bsd_signal(int sig, 404 siginfo_t* info, 405 void* ucVoid, 406 int abort_if_unrecognized) { 407 ucontext_t* uc = (ucontext_t*) ucVoid; 408 409 Thread* t = ThreadLocalStorage::get_thread_slow(); 410 411 SignalHandlerMark shm(t); 412 413 // Note: it's not uncommon that JNI code uses signal/sigset to install 414 // then restore certain signal handler (e.g. to temporarily block SIGPIPE, 415 // or have a SIGILL handler when detecting CPU type). When that happens, 416 // JVM_handle_bsd_signal() might be invoked with junk info/ucVoid. To 417 // avoid unnecessary crash when libjsig is not preloaded, try handle signals 418 // that do not require siginfo/ucontext first. 419 420 if (sig == SIGPIPE || sig == SIGXFSZ) { 421 // allow chained handler to go first 422 if (os::Bsd::chained_handler(sig, info, ucVoid)) { 423 return true; 424 } else { 425 if (PrintMiscellaneous && (WizardMode || Verbose)) { 426 char buf[64]; 427 warning("Ignoring %s - see bugs 4229104 or 646499219", 428 os::exception_name(sig, buf, sizeof(buf))); 429 } 430 return true; 431 } 432 } 433 434 JavaThread* thread = NULL; 435 VMThread* vmthread = NULL; 436 if (os::Bsd::signal_handlers_are_installed) { 437 if (t != NULL ){ 438 if(t->is_Java_thread()) { 439 thread = (JavaThread*)t; 440 } 441 else if(t->is_VM_thread()){ 442 vmthread = (VMThread *)t; 443 } 444 } 445 } 446/* 447 NOTE: does not seem to work on bsd. 448 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) { 449 // can't decode this kind of signal 450 info = NULL; 451 } else { 452 assert(sig == info->si_signo, "bad siginfo"); 453 } 454*/ 455 // decide if this trap can be handled by a stub 456 address stub = NULL; 457 458 address pc = NULL; 459 460 //%note os_trap_1 461 if (info != NULL && uc != NULL && thread != NULL) { 462 pc = (address) os::Bsd::ucontext_get_pc(uc); 463 464 if (pc == (address) Fetch32PFI) { 465 uc->context_pc = intptr_t(Fetch32Resume) ; 466 return 1 ; 467 } 468#ifdef AMD64 469 if (pc == (address) FetchNPFI) { 470 uc->context_pc = intptr_t (FetchNResume) ; 471 return 1 ; 472 } 473#endif // AMD64 474 475 // Handle ALL stack overflow variations here 476 if (sig == SIGSEGV || sig == SIGBUS) { 477 address addr = (address) info->si_addr; 478 479 // check if fault address is within thread stack 480 if (addr < thread->stack_base() && 481 addr >= thread->stack_base() - thread->stack_size()) { 482 // stack overflow 483 if (thread->in_stack_yellow_zone(addr)) { 484 thread->disable_stack_yellow_zone(); 485 if (thread->thread_state() == _thread_in_Java) { 486 // Throw a stack overflow exception. Guard pages will be reenabled 487 // while unwinding the stack. 488 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); 489 } else { 490 // Thread was in the vm or native code. Return and try to finish. 491 return 1; 492 } 493 } else if (thread->in_stack_red_zone(addr)) { 494 // Fatal red zone violation. Disable the guard pages and fall through 495 // to handle_unexpected_exception way down below. 496 thread->disable_stack_red_zone(); 497 tty->print_raw_cr("An irrecoverable stack overflow has occurred."); 498#ifndef _ALLBSD_SOURCE 499 } else { 500 // Accessing stack address below sp may cause SEGV if current 501 // thread has MAP_GROWSDOWN stack. This should only happen when 502 // current thread was created by user code with MAP_GROWSDOWN flag 503 // and then attached to VM. See notes in os_bsd.cpp. 504 if (thread->osthread()->expanding_stack() == 0) { 505 thread->osthread()->set_expanding_stack(); 506 if (os::Bsd::manually_expand_stack(thread, addr)) { 507 thread->osthread()->clear_expanding_stack(); 508 return 1; 509 } 510 thread->osthread()->clear_expanding_stack(); 511 } else { 512 fatal("recursive segv. expanding stack."); 513 } 514#endif 515 } 516 } 517 } 518 519 if (thread->thread_state() == _thread_in_Java) { 520 // Java thread running in Java code => find exception handler if any 521 // a fault inside compiled code, the interpreter, or a stub 522 523 if ((sig == SIGSEGV || sig == SIGBUS) && os::is_poll_address((address)info->si_addr)) { 524 stub = SharedRuntime::get_poll_stub(pc); 525#if defined(__APPLE__) && !defined(AMD64) 526 // 32-bit Darwin reports a SIGBUS for nearly all memory access exceptions. 527 // Catching SIGBUS here prevents the implicit SIGBUS NULL check below from 528 // being called, so only do so if the implicit NULL check is not necessary. 529 } else if (sig == SIGBUS && MacroAssembler::needs_explicit_null_check((int)info->si_addr)) { 530#else 531 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) { 532#endif 533 // BugId 4454115: A read from a MappedByteBuffer can fault 534 // here if the underlying file has been truncated. 535 // Do not crash the VM in such a case. 536 CodeBlob* cb = CodeCache::find_blob_unsafe(pc); 537 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL; 538 if (nm != NULL && nm->has_unsafe_access()) { 539 stub = StubRoutines::handler_for_unsafe_access(); 540 } 541 } 542 else 543 544#ifdef AMD64 545 if (sig == SIGFPE && 546 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) { 547 stub = 548 SharedRuntime:: 549 continuation_for_implicit_exception(thread, 550 pc, 551 SharedRuntime:: 552 IMPLICIT_DIVIDE_BY_ZERO); 553#ifdef __APPLE__ 554 } else if (sig == SIGFPE && info->si_code == FPE_NOOP) { 555 int op = pc[0]; 556 557 // Skip REX 558 if ((pc[0] & 0xf0) == 0x40) { 559 op = pc[1]; 560 } else { 561 op = pc[0]; 562 } 563 564 // Check for IDIV 565 if (op == 0xF7) { 566 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime:: IMPLICIT_DIVIDE_BY_ZERO); 567 } else { 568 // TODO: handle more cases if we are using other x86 instructions 569 // that can generate SIGFPE signal. 570 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); 571 fatal("please update this code."); 572 } 573#endif /* __APPLE__ */ 574 575#else 576 if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) { 577 // HACK: si_code does not work on bsd 2.2.12-20!!! 578 int op = pc[0]; 579 if (op == 0xDB) { 580 // FIST 581 // TODO: The encoding of D2I in i486.ad can cause an exception 582 // prior to the fist instruction if there was an invalid operation 583 // pending. We want to dismiss that exception. From the win_32 584 // side it also seems that if it really was the fist causing 585 // the exception that we do the d2i by hand with different 586 // rounding. Seems kind of weird. 587 // NOTE: that we take the exception at the NEXT floating point instruction. 588 assert(pc[0] == 0xDB, "not a FIST opcode"); 589 assert(pc[1] == 0x14, "not a FIST opcode"); 590 assert(pc[2] == 0x24, "not a FIST opcode"); 591 return true; 592 } else if (op == 0xF7) { 593 // IDIV 594 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); 595 } else { 596 // TODO: handle more cases if we are using other x86 instructions 597 // that can generate SIGFPE signal on bsd. 598 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); 599 fatal("please update this code."); 600 } 601#endif // AMD64 602 } else if ((sig == SIGSEGV || sig == SIGBUS) && 603 !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { 604 // Determination of interpreter/vtable stub/compiled code null exception 605 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 606 } 607 } else if (thread->thread_state() == _thread_in_vm && 608 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */ 609 thread->doing_unsafe_access()) { 610 stub = StubRoutines::handler_for_unsafe_access(); 611 } 612 613 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in 614 // and the heap gets shrunk before the field access. 615 if ((sig == SIGSEGV) || (sig == SIGBUS)) { 616 address addr = JNI_FastGetField::find_slowcase_pc(pc); 617 if (addr != (address)-1) { 618 stub = addr; 619 } 620 } 621 622 // Check to see if we caught the safepoint code in the 623 // process of write protecting the memory serialization page. 624 // It write enables the page immediately after protecting it 625 // so we can just return to retry the write. 626 if ((sig == SIGSEGV || sig == SIGBUS) && 627 os::is_memory_serialize_page(thread, (address) info->si_addr)) { 628 // Block current thread until the memory serialize page permission restored. 629 os::block_on_serialize_page_trap(); 630 return true; 631 } 632 } 633 634#ifndef AMD64 635 // Execution protection violation 636 // 637 // This should be kept as the last step in the triage. We don't 638 // have a dedicated trap number for a no-execute fault, so be 639 // conservative and allow other handlers the first shot. 640 // 641 // Note: We don't test that info->si_code == SEGV_ACCERR here. 642 // this si_code is so generic that it is almost meaningless; and 643 // the si_code for this condition may change in the future. 644 // Furthermore, a false-positive should be harmless. 645 if (UnguardOnExecutionViolation > 0 && 646 (sig == SIGSEGV || sig == SIGBUS) && 647 uc->context_trapno == trap_page_fault) { 648 int page_size = os::vm_page_size(); 649 address addr = (address) info->si_addr; 650 address pc = os::Bsd::ucontext_get_pc(uc); 651 // Make sure the pc and the faulting address are sane. 652 // 653 // If an instruction spans a page boundary, and the page containing 654 // the beginning of the instruction is executable but the following 655 // page is not, the pc and the faulting address might be slightly 656 // different - we still want to unguard the 2nd page in this case. 657 // 658 // 15 bytes seems to be a (very) safe value for max instruction size. 659 bool pc_is_near_addr = 660 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15); 661 bool instr_spans_page_boundary = 662 (align_size_down((intptr_t) pc ^ (intptr_t) addr, 663 (intptr_t) page_size) > 0); 664 665 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) { 666 static volatile address last_addr = 667 (address) os::non_memory_address_word(); 668 669 // In conservative mode, don't unguard unless the address is in the VM 670 if (addr != last_addr && 671 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) { 672 673 // Set memory to RWX and retry 674 address page_start = 675 (address) align_size_down((intptr_t) addr, (intptr_t) page_size); 676 bool res = os::protect_memory((char*) page_start, page_size, 677 os::MEM_PROT_RWX); 678 679 if (PrintMiscellaneous && Verbose) { 680 char buf[256]; 681 jio_snprintf(buf, sizeof(buf), "Execution protection violation " 682 "at " INTPTR_FORMAT 683 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr, 684 page_start, (res ? "success" : "failed"), errno); 685 tty->print_raw_cr(buf); 686 } 687 stub = pc; 688 689 // Set last_addr so if we fault again at the same address, we don't end 690 // up in an endless loop. 691 // 692 // There are two potential complications here. Two threads trapping at 693 // the same address at the same time could cause one of the threads to 694 // think it already unguarded, and abort the VM. Likely very rare. 695 // 696 // The other race involves two threads alternately trapping at 697 // different addresses and failing to unguard the page, resulting in 698 // an endless loop. This condition is probably even more unlikely than 699 // the first. 700 // 701 // Although both cases could be avoided by using locks or thread local 702 // last_addr, these solutions are unnecessary complication: this 703 // handler is a best-effort safety net, not a complete solution. It is 704 // disabled by default and should only be used as a workaround in case 705 // we missed any no-execute-unsafe VM code. 706 707 last_addr = addr; 708 } 709 } 710 } 711#endif // !AMD64 712 713 if (stub != NULL) { 714 // save all thread context in case we need to restore it 715 if (thread != NULL) thread->set_saved_exception_pc(pc); 716 717 uc->context_pc = (intptr_t)stub; 718 return true; 719 } 720 721 // signal-chaining 722 if (os::Bsd::chained_handler(sig, info, ucVoid)) { 723 return true; 724 } 725 726 if (!abort_if_unrecognized) { 727 // caller wants another chance, so give it to him 728 return false; 729 } 730 731 if (pc == NULL && uc != NULL) { 732 pc = os::Bsd::ucontext_get_pc(uc); 733 } 734 735 // unmask current signal 736 sigset_t newset; 737 sigemptyset(&newset); 738 sigaddset(&newset, sig); 739 sigprocmask(SIG_UNBLOCK, &newset, NULL); 740 741 VMError err(t, sig, pc, info, ucVoid); 742 err.report_and_die(); 743 744 ShouldNotReachHere(); 745} 746 747#ifdef _ALLBSD_SOURCE 748// From solaris_i486.s ported to bsd_i486.s 749extern "C" void fixcw(); 750#endif 751 752void os::Bsd::init_thread_fpu_state(void) { 753#ifndef AMD64 754# ifdef _ALLBSD_SOURCE 755 // Set fpu to 53 bit precision. This happens too early to use a stub. 756 fixcw(); 757# else 758 // set fpu to 53 bit precision 759 set_fpu_control_word(0x27f); 760# endif 761#endif // !AMD64 762} 763 764#ifndef _ALLBSD_SOURCE 765int os::Bsd::get_fpu_control_word(void) { 766#ifdef AMD64 767 return 0; 768#else 769 int fpu_control; 770 _FPU_GETCW(fpu_control); 771 return fpu_control & 0xffff; 772#endif // AMD64 773} 774 775void os::Bsd::set_fpu_control_word(int fpu_control) { 776#ifndef AMD64 777 _FPU_SETCW(fpu_control); 778#endif // !AMD64 779} 780#endif 781 782// Check that the bsd kernel version is 2.4 or higher since earlier 783// versions do not support SSE without patches. 784bool os::supports_sse() { 785#if defined(AMD64) || defined(_ALLBSD_SOURCE) 786 return true; 787#else 788 struct utsname uts; 789 if( uname(&uts) != 0 ) return false; // uname fails? 790 char *minor_string; 791 int major = strtol(uts.release,&minor_string,10); 792 int minor = strtol(minor_string+1,NULL,10); 793 bool result = (major > 2 || (major==2 && minor >= 4)); 794#ifndef PRODUCT 795 if (PrintMiscellaneous && Verbose) { 796 tty->print("OS version is %d.%d, which %s support SSE/SSE2\n", 797 major,minor, result ? "DOES" : "does NOT"); 798 } 799#endif 800 return result; 801#endif // AMD64 802} 803 804bool os::is_allocatable(size_t bytes) { 805#ifdef AMD64 806 // unused on amd64? 807 return true; 808#else 809 810 if (bytes < 2 * G) { 811 return true; 812 } 813 814 char* addr = reserve_memory(bytes, NULL); 815 816 if (addr != NULL) { 817 release_memory(addr, bytes); 818 } 819 820 return addr != NULL; 821#endif // AMD64 822} 823 824//////////////////////////////////////////////////////////////////////////////// 825// thread stack 826 827#ifdef AMD64 828size_t os::Bsd::min_stack_allowed = 64 * K; 829 830// amd64: pthread on amd64 is always in floating stack mode 831bool os::Bsd::supports_variable_stack_size() { return true; } 832#else 833size_t os::Bsd::min_stack_allowed = (48 DEBUG_ONLY(+4))*K; 834 835#ifdef __GNUC__ 836#define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;}) 837#endif 838 839#ifdef _ALLBSD_SOURCE 840bool os::Bsd::supports_variable_stack_size() { return true; } 841#else 842// Test if pthread library can support variable thread stack size. BsdThreads 843// in fixed stack mode allocates 2M fixed slot for each thread. BsdThreads 844// in floating stack mode and NPTL support variable stack size. 845bool os::Bsd::supports_variable_stack_size() { 846 if (os::Bsd::is_NPTL()) { 847 // NPTL, yes 848 return true; 849 850 } else { 851 // Note: We can't control default stack size when creating a thread. 852 // If we use non-default stack size (pthread_attr_setstacksize), both 853 // floating stack and non-floating stack BsdThreads will return the 854 // same value. This makes it impossible to implement this function by 855 // detecting thread stack size directly. 856 // 857 // An alternative approach is to check %gs. Fixed-stack BsdThreads 858 // do not use %gs, so its value is 0. Floating-stack BsdThreads use 859 // %gs (either as LDT selector or GDT selector, depending on kernel) 860 // to access thread specific data. 861 // 862 // Note that %gs is a reserved glibc register since early 2001, so 863 // applications are not allowed to change its value (Ulrich Drepper from 864 // Redhat confirmed that all known offenders have been modified to use 865 // either %fs or TSD). In the worst case scenario, when VM is embedded in 866 // a native application that plays with %gs, we might see non-zero %gs 867 // even BsdThreads is running in fixed stack mode. As the result, we'll 868 // return true and skip _thread_safety_check(), so we may not be able to 869 // detect stack-heap collisions. But otherwise it's harmless. 870 // 871#ifdef __GNUC__ 872 return (GET_GS() != 0); 873#else 874 return false; 875#endif 876 } 877} 878#endif 879#endif // AMD64 880 881// return default stack size for thr_type 882size_t os::Bsd::default_stack_size(os::ThreadType thr_type) { 883 // default stack size (compiler thread needs larger stack) 884#ifdef AMD64 885 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M); 886#else 887 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K); 888#endif // AMD64 889 return s; 890} 891 892size_t os::Bsd::default_guard_size(os::ThreadType thr_type) { 893 // Creating guard page is very expensive. Java thread has HotSpot 894 // guard page, only enable glibc guard page for non-Java threads. 895 return (thr_type == java_thread ? 0 : page_size()); 896} 897 898// Java thread: 899// 900// Low memory addresses 901// +------------------------+ 902// | |\ JavaThread created by VM does not have glibc 903// | glibc guard page | - guard, attached Java thread usually has 904// | |/ 1 page glibc guard. 905// P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 906// | |\ 907// | HotSpot Guard Pages | - red and yellow pages 908// | |/ 909// +------------------------+ JavaThread::stack_yellow_zone_base() 910// | |\ 911// | Normal Stack | - 912// | |/ 913// P2 +------------------------+ Thread::stack_base() 914// 915// Non-Java thread: 916// 917// Low memory addresses 918// +------------------------+ 919// | |\ 920// | glibc guard page | - usually 1 page 921// | |/ 922// P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 923// | |\ 924// | Normal Stack | - 925// | |/ 926// P2 +------------------------+ Thread::stack_base() 927// 928// ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from 929// pthread_attr_getstack() 930 931static void current_stack_region(address * bottom, size_t * size) { 932#ifdef __APPLE__ 933 pthread_t self = pthread_self(); 934 void *stacktop = pthread_get_stackaddr_np(self); 935 *size = pthread_get_stacksize_np(self); 936 *bottom = (address) stacktop - *size; 937#elif defined(__OpenBSD__) 938 stack_t ss; 939 int rslt = pthread_stackseg_np(pthread_self(), &ss); 940 941 if (rslt != 0) 942 fatal(err_msg("pthread_stackseg_np failed with err = %d", rslt)); 943 944 *bottom = (address)((char *)ss.ss_sp - ss.ss_size); 945 *size = ss.ss_size; 946#elif defined(_ALLBSD_SOURCE) 947 pthread_attr_t attr; 948 949 int rslt = pthread_attr_init(&attr); 950 951 // JVM needs to know exact stack location, abort if it fails 952 if (rslt != 0) 953 fatal(err_msg("pthread_attr_init failed with err = %d", rslt)); 954 955 rslt = pthread_attr_get_np(pthread_self(), &attr); 956 957 if (rslt != 0) 958 fatal(err_msg("pthread_attr_get_np failed with err = %d", rslt)); 959 960 if (pthread_attr_getstackaddr(&attr, (void **)bottom) != 0 || 961 pthread_attr_getstacksize(&attr, size) != 0) { 962 fatal("Can not locate current stack attributes!"); 963 } 964 965 pthread_attr_destroy(&attr); 966#else 967 if (os::Bsd::is_initial_thread()) { 968 // initial thread needs special handling because pthread_getattr_np() 969 // may return bogus value. 970 *bottom = os::Bsd::initial_thread_stack_bottom(); 971 *size = os::Bsd::initial_thread_stack_size(); 972 } else { 973 pthread_attr_t attr; 974 975 int rslt = pthread_getattr_np(pthread_self(), &attr); 976 977 // JVM needs to know exact stack location, abort if it fails 978 if (rslt != 0) { 979 if (rslt == ENOMEM) { 980 vm_exit_out_of_memory(0, "pthread_getattr_np"); 981 } else { 982 fatal(err_msg("pthread_getattr_np failed with errno = %d", rslt)); 983 } 984 } 985 986 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) { 987 fatal("Can not locate current stack attributes!"); 988 } 989 990 pthread_attr_destroy(&attr); 991 992 } 993#endif 994 assert(os::current_stack_pointer() >= *bottom && 995 os::current_stack_pointer() < *bottom + *size, "just checking"); 996} 997 998address os::current_stack_base() { 999 address bottom; 1000 size_t size; 1001 current_stack_region(&bottom, &size); 1002 return (bottom + size); 1003} 1004 1005size_t os::current_stack_size() { 1006 // stack size includes normal stack and HotSpot guard pages 1007 address bottom; 1008 size_t size; 1009 current_stack_region(&bottom, &size); 1010 return size; 1011} 1012 1013///////////////////////////////////////////////////////////////////////////// 1014// helper functions for fatal error handler 1015 1016void os::print_context(outputStream *st, void *context) { 1017 if (context == NULL) return; 1018 1019 ucontext_t *uc = (ucontext_t*)context; 1020 st->print_cr("Registers:"); 1021#ifdef AMD64 1022 st->print( "RAX=" INTPTR_FORMAT, uc->context_rax); 1023 st->print(", RBX=" INTPTR_FORMAT, uc->context_rbx); 1024 st->print(", RCX=" INTPTR_FORMAT, uc->context_rcx); 1025 st->print(", RDX=" INTPTR_FORMAT, uc->context_rdx); 1026 st->cr(); 1027 st->print( "RSP=" INTPTR_FORMAT, uc->context_rsp); 1028 st->print(", RBP=" INTPTR_FORMAT, uc->context_rbp); 1029 st->print(", RSI=" INTPTR_FORMAT, uc->context_rsi); 1030 st->print(", RDI=" INTPTR_FORMAT, uc->context_rdi); 1031 st->cr(); 1032 st->print( "R8 =" INTPTR_FORMAT, uc->context_r8); 1033 st->print(", R9 =" INTPTR_FORMAT, uc->context_r9); 1034 st->print(", R10=" INTPTR_FORMAT, uc->context_r10); 1035 st->print(", R11=" INTPTR_FORMAT, uc->context_r11); 1036 st->cr(); 1037 st->print( "R12=" INTPTR_FORMAT, uc->context_r12); 1038 st->print(", R13=" INTPTR_FORMAT, uc->context_r13); 1039 st->print(", R14=" INTPTR_FORMAT, uc->context_r14); 1040 st->print(", R15=" INTPTR_FORMAT, uc->context_r15); 1041 st->cr(); 1042 st->print( "RIP=" INTPTR_FORMAT, uc->context_rip); 1043 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_flags); 1044 st->print(", ERR=" INTPTR_FORMAT, uc->context_err); 1045 st->cr(); 1046 st->print(" TRAPNO=" INTPTR_FORMAT, uc->context_trapno); 1047#else 1048 st->print( "EAX=" INTPTR_FORMAT, uc->context_eax); 1049 st->print(", EBX=" INTPTR_FORMAT, uc->context_ebx); 1050 st->print(", ECX=" INTPTR_FORMAT, uc->context_ecx); 1051 st->print(", EDX=" INTPTR_FORMAT, uc->context_edx); 1052 st->cr(); 1053 st->print( "ESP=" INTPTR_FORMAT, uc->context_esp); 1054 st->print(", EBP=" INTPTR_FORMAT, uc->context_ebp); 1055 st->print(", ESI=" INTPTR_FORMAT, uc->context_esi); 1056 st->print(", EDI=" INTPTR_FORMAT, uc->context_edi); 1057 st->cr(); 1058 st->print( "EIP=" INTPTR_FORMAT, uc->context_eip); 1059 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_eflags); 1060#endif // AMD64 1061 st->cr(); 1062 st->cr(); 1063 1064 intptr_t *sp = (intptr_t *)os::Bsd::ucontext_get_sp(uc); 1065 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp); 1066 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t)); 1067 st->cr(); 1068 1069 // Note: it may be unsafe to inspect memory near pc. For example, pc may 1070 // point to garbage if entry point in an nmethod is corrupted. Leave 1071 // this at the end, and hope for the best. 1072 address pc = os::Bsd::ucontext_get_pc(uc); 1073 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc); 1074 print_hex_dump(st, pc - 32, pc + 32, sizeof(char)); 1075} 1076 1077void os::print_register_info(outputStream *st, void *context) { 1078 if (context == NULL) return; 1079 1080 ucontext_t *uc = (ucontext_t*)context; 1081 1082 st->print_cr("Register to memory mapping:"); 1083 st->cr(); 1084 1085 // this is horrendously verbose but the layout of the registers in the 1086 // context does not match how we defined our abstract Register set, so 1087 // we can't just iterate through the gregs area 1088 1089 // this is only for the "general purpose" registers 1090 1091#ifdef AMD64 1092 st->print("RAX="); print_location(st, uc->context_rax); 1093 st->print("RBX="); print_location(st, uc->context_rbx); 1094 st->print("RCX="); print_location(st, uc->context_rcx); 1095 st->print("RDX="); print_location(st, uc->context_rdx); 1096 st->print("RSP="); print_location(st, uc->context_rsp); 1097 st->print("RBP="); print_location(st, uc->context_rbp); 1098 st->print("RSI="); print_location(st, uc->context_rsi); 1099 st->print("RDI="); print_location(st, uc->context_rdi); 1100 st->print("R8 ="); print_location(st, uc->context_r8); 1101 st->print("R9 ="); print_location(st, uc->context_r9); 1102 st->print("R10="); print_location(st, uc->context_r10); 1103 st->print("R11="); print_location(st, uc->context_r11); 1104 st->print("R12="); print_location(st, uc->context_r12); 1105 st->print("R13="); print_location(st, uc->context_r13); 1106 st->print("R14="); print_location(st, uc->context_r14); 1107 st->print("R15="); print_location(st, uc->context_r15); 1108#else 1109 st->print("EAX="); print_location(st, uc->context_eax); 1110 st->print("EBX="); print_location(st, uc->context_ebx); 1111 st->print("ECX="); print_location(st, uc->context_ecx); 1112 st->print("EDX="); print_location(st, uc->context_edx); 1113 st->print("ESP="); print_location(st, uc->context_esp); 1114 st->print("EBP="); print_location(st, uc->context_ebp); 1115 st->print("ESI="); print_location(st, uc->context_esi); 1116 st->print("EDI="); print_location(st, uc->context_edi); 1117#endif // AMD64 1118 1119 st->cr(); 1120} 1121 1122void os::setup_fpu() { 1123#ifndef AMD64 1124 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std(); 1125 __asm__ volatile ( "fldcw (%0)" : 1126 : "r" (fpu_cntrl) : "memory"); 1127#endif // !AMD64 1128} 1129 1130#ifndef PRODUCT 1131void os::verify_stack_alignment() { 1132} 1133#endif 1134