os_bsd_x86.cpp revision 4093:12285410684f
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 "asm/macroAssembler.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 "os_share_bsd.hpp" 37#include "prims/jniFastGetField.hpp" 38#include "prims/jvm.h" 39#include "prims/jvm_misc.hpp" 40#include "runtime/arguments.hpp" 41#include "runtime/extendedPC.hpp" 42#include "runtime/frame.inline.hpp" 43#include "runtime/interfaceSupport.hpp" 44#include "runtime/java.hpp" 45#include "runtime/javaCalls.hpp" 46#include "runtime/mutexLocker.hpp" 47#include "runtime/osThread.hpp" 48#include "runtime/sharedRuntime.hpp" 49#include "runtime/stubRoutines.hpp" 50#include "runtime/thread.inline.hpp" 51#include "runtime/timer.hpp" 52#include "utilities/events.hpp" 53#include "utilities/vmError.hpp" 54 55// put OS-includes here 56# include <sys/types.h> 57# include <sys/mman.h> 58# include <pthread.h> 59# include <signal.h> 60# include <errno.h> 61# include <dlfcn.h> 62# include <stdlib.h> 63# include <stdio.h> 64# include <unistd.h> 65# include <sys/resource.h> 66# include <pthread.h> 67# include <sys/stat.h> 68# include <sys/time.h> 69# include <sys/utsname.h> 70# include <sys/socket.h> 71# include <sys/wait.h> 72# include <pwd.h> 73# include <poll.h> 74#ifndef __OpenBSD__ 75# include <ucontext.h> 76#endif 77 78#if !defined(__APPLE__) && !defined(__NetBSD__) 79# include <pthread_np.h> 80#endif 81 82#ifdef AMD64 83#define SPELL_REG_SP "rsp" 84#define SPELL_REG_FP "rbp" 85#else 86#define SPELL_REG_SP "esp" 87#define SPELL_REG_FP "ebp" 88#endif // AMD64 89 90#ifdef __FreeBSD__ 91# define context_trapno uc_mcontext.mc_trapno 92# ifdef AMD64 93# define context_pc uc_mcontext.mc_rip 94# define context_sp uc_mcontext.mc_rsp 95# define context_fp uc_mcontext.mc_rbp 96# define context_rip uc_mcontext.mc_rip 97# define context_rsp uc_mcontext.mc_rsp 98# define context_rbp uc_mcontext.mc_rbp 99# define context_rax uc_mcontext.mc_rax 100# define context_rbx uc_mcontext.mc_rbx 101# define context_rcx uc_mcontext.mc_rcx 102# define context_rdx uc_mcontext.mc_rdx 103# define context_rsi uc_mcontext.mc_rsi 104# define context_rdi uc_mcontext.mc_rdi 105# define context_r8 uc_mcontext.mc_r8 106# define context_r9 uc_mcontext.mc_r9 107# define context_r10 uc_mcontext.mc_r10 108# define context_r11 uc_mcontext.mc_r11 109# define context_r12 uc_mcontext.mc_r12 110# define context_r13 uc_mcontext.mc_r13 111# define context_r14 uc_mcontext.mc_r14 112# define context_r15 uc_mcontext.mc_r15 113# define context_flags uc_mcontext.mc_flags 114# define context_err uc_mcontext.mc_err 115# else 116# define context_pc uc_mcontext.mc_eip 117# define context_sp uc_mcontext.mc_esp 118# define context_fp uc_mcontext.mc_ebp 119# define context_eip uc_mcontext.mc_eip 120# define context_esp uc_mcontext.mc_esp 121# define context_eax uc_mcontext.mc_eax 122# define context_ebx uc_mcontext.mc_ebx 123# define context_ecx uc_mcontext.mc_ecx 124# define context_edx uc_mcontext.mc_edx 125# define context_ebp uc_mcontext.mc_ebp 126# define context_esi uc_mcontext.mc_esi 127# define context_edi uc_mcontext.mc_edi 128# define context_eflags uc_mcontext.mc_eflags 129# define context_trapno uc_mcontext.mc_trapno 130# endif 131#endif 132 133#ifdef __APPLE__ 134# if __DARWIN_UNIX03 && (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5) 135 // 10.5 UNIX03 member name prefixes 136 #define DU3_PREFIX(s, m) __ ## s.__ ## m 137# else 138 #define DU3_PREFIX(s, m) s ## . ## m 139# endif 140 141# ifdef AMD64 142# define context_pc context_rip 143# define context_sp context_rsp 144# define context_fp context_rbp 145# define context_rip uc_mcontext->DU3_PREFIX(ss,rip) 146# define context_rsp uc_mcontext->DU3_PREFIX(ss,rsp) 147# define context_rax uc_mcontext->DU3_PREFIX(ss,rax) 148# define context_rbx uc_mcontext->DU3_PREFIX(ss,rbx) 149# define context_rcx uc_mcontext->DU3_PREFIX(ss,rcx) 150# define context_rdx uc_mcontext->DU3_PREFIX(ss,rdx) 151# define context_rbp uc_mcontext->DU3_PREFIX(ss,rbp) 152# define context_rsi uc_mcontext->DU3_PREFIX(ss,rsi) 153# define context_rdi uc_mcontext->DU3_PREFIX(ss,rdi) 154# define context_r8 uc_mcontext->DU3_PREFIX(ss,r8) 155# define context_r9 uc_mcontext->DU3_PREFIX(ss,r9) 156# define context_r10 uc_mcontext->DU3_PREFIX(ss,r10) 157# define context_r11 uc_mcontext->DU3_PREFIX(ss,r11) 158# define context_r12 uc_mcontext->DU3_PREFIX(ss,r12) 159# define context_r13 uc_mcontext->DU3_PREFIX(ss,r13) 160# define context_r14 uc_mcontext->DU3_PREFIX(ss,r14) 161# define context_r15 uc_mcontext->DU3_PREFIX(ss,r15) 162# define context_flags uc_mcontext->DU3_PREFIX(ss,rflags) 163# define context_trapno uc_mcontext->DU3_PREFIX(es,trapno) 164# define context_err uc_mcontext->DU3_PREFIX(es,err) 165# else 166# define context_pc context_eip 167# define context_sp context_esp 168# define context_fp context_ebp 169# define context_eip uc_mcontext->DU3_PREFIX(ss,eip) 170# define context_esp uc_mcontext->DU3_PREFIX(ss,esp) 171# define context_eax uc_mcontext->DU3_PREFIX(ss,eax) 172# define context_ebx uc_mcontext->DU3_PREFIX(ss,ebx) 173# define context_ecx uc_mcontext->DU3_PREFIX(ss,ecx) 174# define context_edx uc_mcontext->DU3_PREFIX(ss,edx) 175# define context_ebp uc_mcontext->DU3_PREFIX(ss,ebp) 176# define context_esi uc_mcontext->DU3_PREFIX(ss,esi) 177# define context_edi uc_mcontext->DU3_PREFIX(ss,edi) 178# define context_eflags uc_mcontext->DU3_PREFIX(ss,eflags) 179# define context_trapno uc_mcontext->DU3_PREFIX(es,trapno) 180# endif 181#endif 182 183#ifdef __OpenBSD__ 184# define context_trapno sc_trapno 185# ifdef AMD64 186# define context_pc sc_rip 187# define context_sp sc_rsp 188# define context_fp sc_rbp 189# define context_rip sc_rip 190# define context_rsp sc_rsp 191# define context_rbp sc_rbp 192# define context_rax sc_rax 193# define context_rbx sc_rbx 194# define context_rcx sc_rcx 195# define context_rdx sc_rdx 196# define context_rsi sc_rsi 197# define context_rdi sc_rdi 198# define context_r8 sc_r8 199# define context_r9 sc_r9 200# define context_r10 sc_r10 201# define context_r11 sc_r11 202# define context_r12 sc_r12 203# define context_r13 sc_r13 204# define context_r14 sc_r14 205# define context_r15 sc_r15 206# define context_flags sc_rflags 207# define context_err sc_err 208# else 209# define context_pc sc_eip 210# define context_sp sc_esp 211# define context_fp sc_ebp 212# define context_eip sc_eip 213# define context_esp sc_esp 214# define context_eax sc_eax 215# define context_ebx sc_ebx 216# define context_ecx sc_ecx 217# define context_edx sc_edx 218# define context_ebp sc_ebp 219# define context_esi sc_esi 220# define context_edi sc_edi 221# define context_eflags sc_eflags 222# define context_trapno sc_trapno 223# endif 224#endif 225 226#ifdef __NetBSD__ 227# define context_trapno uc_mcontext.__gregs[_REG_TRAPNO] 228# ifdef AMD64 229# define __register_t __greg_t 230# define context_pc uc_mcontext.__gregs[_REG_RIP] 231# define context_sp uc_mcontext.__gregs[_REG_URSP] 232# define context_fp uc_mcontext.__gregs[_REG_RBP] 233# define context_rip uc_mcontext.__gregs[_REG_RIP] 234# define context_rsp uc_mcontext.__gregs[_REG_URSP] 235# define context_rax uc_mcontext.__gregs[_REG_RAX] 236# define context_rbx uc_mcontext.__gregs[_REG_RBX] 237# define context_rcx uc_mcontext.__gregs[_REG_RCX] 238# define context_rdx uc_mcontext.__gregs[_REG_RDX] 239# define context_rbp uc_mcontext.__gregs[_REG_RBP] 240# define context_rsi uc_mcontext.__gregs[_REG_RSI] 241# define context_rdi uc_mcontext.__gregs[_REG_RDI] 242# define context_r8 uc_mcontext.__gregs[_REG_R8] 243# define context_r9 uc_mcontext.__gregs[_REG_R9] 244# define context_r10 uc_mcontext.__gregs[_REG_R10] 245# define context_r11 uc_mcontext.__gregs[_REG_R11] 246# define context_r12 uc_mcontext.__gregs[_REG_R12] 247# define context_r13 uc_mcontext.__gregs[_REG_R13] 248# define context_r14 uc_mcontext.__gregs[_REG_R14] 249# define context_r15 uc_mcontext.__gregs[_REG_R15] 250# define context_flags uc_mcontext.__gregs[_REG_RFL] 251# define context_err uc_mcontext.__gregs[_REG_ERR] 252# else 253# define context_pc uc_mcontext.__gregs[_REG_EIP] 254# define context_sp uc_mcontext.__gregs[_REG_UESP] 255# define context_fp uc_mcontext.__gregs[_REG_EBP] 256# define context_eip uc_mcontext.__gregs[_REG_EIP] 257# define context_esp uc_mcontext.__gregs[_REG_UESP] 258# define context_eax uc_mcontext.__gregs[_REG_EAX] 259# define context_ebx uc_mcontext.__gregs[_REG_EBX] 260# define context_ecx uc_mcontext.__gregs[_REG_ECX] 261# define context_edx uc_mcontext.__gregs[_REG_EDX] 262# define context_ebp uc_mcontext.__gregs[_REG_EBP] 263# define context_esi uc_mcontext.__gregs[_REG_ESI] 264# define context_edi uc_mcontext.__gregs[_REG_EDI] 265# define context_eflags uc_mcontext.__gregs[_REG_EFL] 266# define context_trapno uc_mcontext.__gregs[_REG_TRAPNO] 267# endif 268#endif 269 270address os::current_stack_pointer() { 271#if defined(__clang__) || defined(__llvm__) 272 register void *esp; 273 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp)); 274 return (address) esp; 275#elif defined(SPARC_WORKS) 276 register void *esp; 277 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp)); 278 return (address) ((char*)esp + sizeof(long)*2); 279#else 280 register void *esp __asm__ (SPELL_REG_SP); 281 return (address) esp; 282#endif 283} 284 285char* os::non_memory_address_word() { 286 // Must never look like an address returned by reserve_memory, 287 // even in its subfields (as defined by the CPU immediate fields, 288 // if the CPU splits constants across multiple instructions). 289 290 return (char*) -1; 291} 292 293void os::initialize_thread(Thread* thr) { 294// Nothing to do. 295} 296 297address os::Bsd::ucontext_get_pc(ucontext_t * uc) { 298 return (address)uc->context_pc; 299} 300 301intptr_t* os::Bsd::ucontext_get_sp(ucontext_t * uc) { 302 return (intptr_t*)uc->context_sp; 303} 304 305intptr_t* os::Bsd::ucontext_get_fp(ucontext_t * uc) { 306 return (intptr_t*)uc->context_fp; 307} 308 309// For Forte Analyzer AsyncGetCallTrace profiling support - thread 310// is currently interrupted by SIGPROF. 311// os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal 312// frames. Currently we don't do that on Bsd, so it's the same as 313// os::fetch_frame_from_context(). 314ExtendedPC os::Bsd::fetch_frame_from_ucontext(Thread* thread, 315 ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) { 316 317 assert(thread != NULL, "just checking"); 318 assert(ret_sp != NULL, "just checking"); 319 assert(ret_fp != NULL, "just checking"); 320 321 return os::fetch_frame_from_context(uc, ret_sp, ret_fp); 322} 323 324ExtendedPC os::fetch_frame_from_context(void* ucVoid, 325 intptr_t** ret_sp, intptr_t** ret_fp) { 326 327 ExtendedPC epc; 328 ucontext_t* uc = (ucontext_t*)ucVoid; 329 330 if (uc != NULL) { 331 epc = ExtendedPC(os::Bsd::ucontext_get_pc(uc)); 332 if (ret_sp) *ret_sp = os::Bsd::ucontext_get_sp(uc); 333 if (ret_fp) *ret_fp = os::Bsd::ucontext_get_fp(uc); 334 } else { 335 // construct empty ExtendedPC for return value checking 336 epc = ExtendedPC(NULL); 337 if (ret_sp) *ret_sp = (intptr_t *)NULL; 338 if (ret_fp) *ret_fp = (intptr_t *)NULL; 339 } 340 341 return epc; 342} 343 344frame os::fetch_frame_from_context(void* ucVoid) { 345 intptr_t* sp; 346 intptr_t* fp; 347 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp); 348 return frame(sp, fp, epc.pc()); 349} 350 351// By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get 352// turned off by -fomit-frame-pointer, 353frame os::get_sender_for_C_frame(frame* fr) { 354 return frame(fr->sender_sp(), fr->link(), fr->sender_pc()); 355} 356 357intptr_t* _get_previous_fp() { 358#if defined(SPARC_WORKS) || defined(__clang__) || defined(__llvm__) 359 register intptr_t **ebp; 360 __asm__("mov %%"SPELL_REG_FP", %0":"=r"(ebp)); 361#else 362 register intptr_t **ebp __asm__ (SPELL_REG_FP); 363#endif 364 return (intptr_t*) *ebp; // we want what it points to. 365} 366 367 368frame os::current_frame() { 369 intptr_t* fp = _get_previous_fp(); 370 frame myframe((intptr_t*)os::current_stack_pointer(), 371 (intptr_t*)fp, 372 CAST_FROM_FN_PTR(address, os::current_frame)); 373 if (os::is_first_C_frame(&myframe)) { 374 // stack is not walkable 375 return frame(); 376 } else { 377 return os::get_sender_for_C_frame(&myframe); 378 } 379} 380 381// Utility functions 382 383// From IA32 System Programming Guide 384enum { 385 trap_page_fault = 0xE 386}; 387 388extern "C" void Fetch32PFI () ; 389extern "C" void Fetch32Resume () ; 390#ifdef AMD64 391extern "C" void FetchNPFI () ; 392extern "C" void FetchNResume () ; 393#endif // AMD64 394 395extern "C" JNIEXPORT int 396JVM_handle_bsd_signal(int sig, 397 siginfo_t* info, 398 void* ucVoid, 399 int abort_if_unrecognized) { 400 ucontext_t* uc = (ucontext_t*) ucVoid; 401 402 Thread* t = ThreadLocalStorage::get_thread_slow(); 403 404 SignalHandlerMark shm(t); 405 406 // Note: it's not uncommon that JNI code uses signal/sigset to install 407 // then restore certain signal handler (e.g. to temporarily block SIGPIPE, 408 // or have a SIGILL handler when detecting CPU type). When that happens, 409 // JVM_handle_bsd_signal() might be invoked with junk info/ucVoid. To 410 // avoid unnecessary crash when libjsig is not preloaded, try handle signals 411 // that do not require siginfo/ucontext first. 412 413 if (sig == SIGPIPE || sig == SIGXFSZ) { 414 // allow chained handler to go first 415 if (os::Bsd::chained_handler(sig, info, ucVoid)) { 416 return true; 417 } else { 418 if (PrintMiscellaneous && (WizardMode || Verbose)) { 419 char buf[64]; 420 warning("Ignoring %s - see bugs 4229104 or 646499219", 421 os::exception_name(sig, buf, sizeof(buf))); 422 } 423 return true; 424 } 425 } 426 427 JavaThread* thread = NULL; 428 VMThread* vmthread = NULL; 429 if (os::Bsd::signal_handlers_are_installed) { 430 if (t != NULL ){ 431 if(t->is_Java_thread()) { 432 thread = (JavaThread*)t; 433 } 434 else if(t->is_VM_thread()){ 435 vmthread = (VMThread *)t; 436 } 437 } 438 } 439/* 440 NOTE: does not seem to work on bsd. 441 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) { 442 // can't decode this kind of signal 443 info = NULL; 444 } else { 445 assert(sig == info->si_signo, "bad siginfo"); 446 } 447*/ 448 // decide if this trap can be handled by a stub 449 address stub = NULL; 450 451 address pc = NULL; 452 453 //%note os_trap_1 454 if (info != NULL && uc != NULL && thread != NULL) { 455 pc = (address) os::Bsd::ucontext_get_pc(uc); 456 457 if (pc == (address) Fetch32PFI) { 458 uc->context_pc = intptr_t(Fetch32Resume) ; 459 return 1 ; 460 } 461#ifdef AMD64 462 if (pc == (address) FetchNPFI) { 463 uc->context_pc = intptr_t (FetchNResume) ; 464 return 1 ; 465 } 466#endif // AMD64 467 468 // Handle ALL stack overflow variations here 469 if (sig == SIGSEGV || sig == SIGBUS) { 470 address addr = (address) info->si_addr; 471 472 // check if fault address is within thread stack 473 if (addr < thread->stack_base() && 474 addr >= thread->stack_base() - thread->stack_size()) { 475 // stack overflow 476 if (thread->in_stack_yellow_zone(addr)) { 477 thread->disable_stack_yellow_zone(); 478 if (thread->thread_state() == _thread_in_Java) { 479 // Throw a stack overflow exception. Guard pages will be reenabled 480 // while unwinding the stack. 481 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); 482 } else { 483 // Thread was in the vm or native code. Return and try to finish. 484 return 1; 485 } 486 } else if (thread->in_stack_red_zone(addr)) { 487 // Fatal red zone violation. Disable the guard pages and fall through 488 // to handle_unexpected_exception way down below. 489 thread->disable_stack_red_zone(); 490 tty->print_raw_cr("An irrecoverable stack overflow has occurred."); 491 } 492 } 493 } 494 495 // We test if stub is already set (by the stack overflow code 496 // above) so it is not overwritten by the code that follows. This 497 // check is not required on other platforms, because on other 498 // platforms we check for SIGSEGV only or SIGBUS only, where here 499 // we have to check for both SIGSEGV and SIGBUS. 500 if (thread->thread_state() == _thread_in_Java && stub == NULL) { 501 // Java thread running in Java code => find exception handler if any 502 // a fault inside compiled code, the interpreter, or a stub 503 504 if ((sig == SIGSEGV || sig == SIGBUS) && os::is_poll_address((address)info->si_addr)) { 505 stub = SharedRuntime::get_poll_stub(pc); 506#if defined(__APPLE__) 507 // 32-bit Darwin reports a SIGBUS for nearly all memory access exceptions. 508 // 64-bit Darwin may also use a SIGBUS (seen with compressed oops). 509 // Catching SIGBUS here prevents the implicit SIGBUS NULL check below from 510 // being called, so only do so if the implicit NULL check is not necessary. 511 } else if (sig == SIGBUS && MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { 512#else 513 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) { 514#endif 515 // BugId 4454115: A read from a MappedByteBuffer can fault 516 // here if the underlying file has been truncated. 517 // Do not crash the VM in such a case. 518 CodeBlob* cb = CodeCache::find_blob_unsafe(pc); 519 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL; 520 if (nm != NULL && nm->has_unsafe_access()) { 521 stub = StubRoutines::handler_for_unsafe_access(); 522 } 523 } 524 else 525 526#ifdef AMD64 527 if (sig == SIGFPE && 528 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) { 529 stub = 530 SharedRuntime:: 531 continuation_for_implicit_exception(thread, 532 pc, 533 SharedRuntime:: 534 IMPLICIT_DIVIDE_BY_ZERO); 535#ifdef __APPLE__ 536 } else if (sig == SIGFPE && info->si_code == FPE_NOOP) { 537 int op = pc[0]; 538 539 // Skip REX 540 if ((pc[0] & 0xf0) == 0x40) { 541 op = pc[1]; 542 } else { 543 op = pc[0]; 544 } 545 546 // Check for IDIV 547 if (op == 0xF7) { 548 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime:: IMPLICIT_DIVIDE_BY_ZERO); 549 } else { 550 // TODO: handle more cases if we are using other x86 instructions 551 // that can generate SIGFPE signal. 552 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); 553 fatal("please update this code."); 554 } 555#endif /* __APPLE__ */ 556 557#else 558 if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) { 559 // HACK: si_code does not work on bsd 2.2.12-20!!! 560 int op = pc[0]; 561 if (op == 0xDB) { 562 // FIST 563 // TODO: The encoding of D2I in i486.ad can cause an exception 564 // prior to the fist instruction if there was an invalid operation 565 // pending. We want to dismiss that exception. From the win_32 566 // side it also seems that if it really was the fist causing 567 // the exception that we do the d2i by hand with different 568 // rounding. Seems kind of weird. 569 // NOTE: that we take the exception at the NEXT floating point instruction. 570 assert(pc[0] == 0xDB, "not a FIST opcode"); 571 assert(pc[1] == 0x14, "not a FIST opcode"); 572 assert(pc[2] == 0x24, "not a FIST opcode"); 573 return true; 574 } else if (op == 0xF7) { 575 // IDIV 576 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); 577 } else { 578 // TODO: handle more cases if we are using other x86 instructions 579 // that can generate SIGFPE signal on bsd. 580 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); 581 fatal("please update this code."); 582 } 583#endif // AMD64 584 } else if ((sig == SIGSEGV || sig == SIGBUS) && 585 !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { 586 // Determination of interpreter/vtable stub/compiled code null exception 587 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 588 } 589 } else if (thread->thread_state() == _thread_in_vm && 590 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */ 591 thread->doing_unsafe_access()) { 592 stub = StubRoutines::handler_for_unsafe_access(); 593 } 594 595 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in 596 // and the heap gets shrunk before the field access. 597 if ((sig == SIGSEGV) || (sig == SIGBUS)) { 598 address addr = JNI_FastGetField::find_slowcase_pc(pc); 599 if (addr != (address)-1) { 600 stub = addr; 601 } 602 } 603 604 // Check to see if we caught the safepoint code in the 605 // process of write protecting the memory serialization page. 606 // It write enables the page immediately after protecting it 607 // so we can just return to retry the write. 608 if ((sig == SIGSEGV || sig == SIGBUS) && 609 os::is_memory_serialize_page(thread, (address) info->si_addr)) { 610 // Block current thread until the memory serialize page permission restored. 611 os::block_on_serialize_page_trap(); 612 return true; 613 } 614 } 615 616#ifndef AMD64 617 // Execution protection violation 618 // 619 // This should be kept as the last step in the triage. We don't 620 // have a dedicated trap number for a no-execute fault, so be 621 // conservative and allow other handlers the first shot. 622 // 623 // Note: We don't test that info->si_code == SEGV_ACCERR here. 624 // this si_code is so generic that it is almost meaningless; and 625 // the si_code for this condition may change in the future. 626 // Furthermore, a false-positive should be harmless. 627 if (UnguardOnExecutionViolation > 0 && 628 (sig == SIGSEGV || sig == SIGBUS) && 629 uc->context_trapno == trap_page_fault) { 630 int page_size = os::vm_page_size(); 631 address addr = (address) info->si_addr; 632 address pc = os::Bsd::ucontext_get_pc(uc); 633 // Make sure the pc and the faulting address are sane. 634 // 635 // If an instruction spans a page boundary, and the page containing 636 // the beginning of the instruction is executable but the following 637 // page is not, the pc and the faulting address might be slightly 638 // different - we still want to unguard the 2nd page in this case. 639 // 640 // 15 bytes seems to be a (very) safe value for max instruction size. 641 bool pc_is_near_addr = 642 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15); 643 bool instr_spans_page_boundary = 644 (align_size_down((intptr_t) pc ^ (intptr_t) addr, 645 (intptr_t) page_size) > 0); 646 647 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) { 648 static volatile address last_addr = 649 (address) os::non_memory_address_word(); 650 651 // In conservative mode, don't unguard unless the address is in the VM 652 if (addr != last_addr && 653 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) { 654 655 // Set memory to RWX and retry 656 address page_start = 657 (address) align_size_down((intptr_t) addr, (intptr_t) page_size); 658 bool res = os::protect_memory((char*) page_start, page_size, 659 os::MEM_PROT_RWX); 660 661 if (PrintMiscellaneous && Verbose) { 662 char buf[256]; 663 jio_snprintf(buf, sizeof(buf), "Execution protection violation " 664 "at " INTPTR_FORMAT 665 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr, 666 page_start, (res ? "success" : "failed"), errno); 667 tty->print_raw_cr(buf); 668 } 669 stub = pc; 670 671 // Set last_addr so if we fault again at the same address, we don't end 672 // up in an endless loop. 673 // 674 // There are two potential complications here. Two threads trapping at 675 // the same address at the same time could cause one of the threads to 676 // think it already unguarded, and abort the VM. Likely very rare. 677 // 678 // The other race involves two threads alternately trapping at 679 // different addresses and failing to unguard the page, resulting in 680 // an endless loop. This condition is probably even more unlikely than 681 // the first. 682 // 683 // Although both cases could be avoided by using locks or thread local 684 // last_addr, these solutions are unnecessary complication: this 685 // handler is a best-effort safety net, not a complete solution. It is 686 // disabled by default and should only be used as a workaround in case 687 // we missed any no-execute-unsafe VM code. 688 689 last_addr = addr; 690 } 691 } 692 } 693#endif // !AMD64 694 695 if (stub != NULL) { 696 // save all thread context in case we need to restore it 697 if (thread != NULL) thread->set_saved_exception_pc(pc); 698 699 uc->context_pc = (intptr_t)stub; 700 return true; 701 } 702 703 // signal-chaining 704 if (os::Bsd::chained_handler(sig, info, ucVoid)) { 705 return true; 706 } 707 708 if (!abort_if_unrecognized) { 709 // caller wants another chance, so give it to him 710 return false; 711 } 712 713 if (pc == NULL && uc != NULL) { 714 pc = os::Bsd::ucontext_get_pc(uc); 715 } 716 717 // unmask current signal 718 sigset_t newset; 719 sigemptyset(&newset); 720 sigaddset(&newset, sig); 721 sigprocmask(SIG_UNBLOCK, &newset, NULL); 722 723 VMError err(t, sig, pc, info, ucVoid); 724 err.report_and_die(); 725 726 ShouldNotReachHere(); 727} 728 729// From solaris_i486.s ported to bsd_i486.s 730extern "C" void fixcw(); 731 732void os::Bsd::init_thread_fpu_state(void) { 733#ifndef AMD64 734 // Set fpu to 53 bit precision. This happens too early to use a stub. 735 fixcw(); 736#endif // !AMD64 737} 738 739 740// Check that the bsd kernel version is 2.4 or higher since earlier 741// versions do not support SSE without patches. 742bool os::supports_sse() { 743 return true; 744} 745 746bool os::is_allocatable(size_t bytes) { 747#ifdef AMD64 748 // unused on amd64? 749 return true; 750#else 751 752 if (bytes < 2 * G) { 753 return true; 754 } 755 756 char* addr = reserve_memory(bytes, NULL); 757 758 if (addr != NULL) { 759 release_memory(addr, bytes); 760 } 761 762 return addr != NULL; 763#endif // AMD64 764} 765 766//////////////////////////////////////////////////////////////////////////////// 767// thread stack 768 769#ifdef AMD64 770size_t os::Bsd::min_stack_allowed = 64 * K; 771 772// amd64: pthread on amd64 is always in floating stack mode 773bool os::Bsd::supports_variable_stack_size() { return true; } 774#else 775size_t os::Bsd::min_stack_allowed = (48 DEBUG_ONLY(+4))*K; 776 777#ifdef __GNUC__ 778#define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;}) 779#endif 780 781bool os::Bsd::supports_variable_stack_size() { return true; } 782#endif // AMD64 783 784// return default stack size for thr_type 785size_t os::Bsd::default_stack_size(os::ThreadType thr_type) { 786 // default stack size (compiler thread needs larger stack) 787#ifdef AMD64 788 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M); 789#else 790 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K); 791#endif // AMD64 792 return s; 793} 794 795size_t os::Bsd::default_guard_size(os::ThreadType thr_type) { 796 // Creating guard page is very expensive. Java thread has HotSpot 797 // guard page, only enable glibc guard page for non-Java threads. 798 return (thr_type == java_thread ? 0 : page_size()); 799} 800 801// Java thread: 802// 803// Low memory addresses 804// +------------------------+ 805// | |\ JavaThread created by VM does not have glibc 806// | glibc guard page | - guard, attached Java thread usually has 807// | |/ 1 page glibc guard. 808// P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 809// | |\ 810// | HotSpot Guard Pages | - red and yellow pages 811// | |/ 812// +------------------------+ JavaThread::stack_yellow_zone_base() 813// | |\ 814// | Normal Stack | - 815// | |/ 816// P2 +------------------------+ Thread::stack_base() 817// 818// Non-Java thread: 819// 820// Low memory addresses 821// +------------------------+ 822// | |\ 823// | glibc guard page | - usually 1 page 824// | |/ 825// P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 826// | |\ 827// | Normal Stack | - 828// | |/ 829// P2 +------------------------+ Thread::stack_base() 830// 831// ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from 832// pthread_attr_getstack() 833 834static void current_stack_region(address * bottom, size_t * size) { 835#ifdef __APPLE__ 836 pthread_t self = pthread_self(); 837 void *stacktop = pthread_get_stackaddr_np(self); 838 *size = pthread_get_stacksize_np(self); 839 *bottom = (address) stacktop - *size; 840#elif defined(__OpenBSD__) 841 stack_t ss; 842 int rslt = pthread_stackseg_np(pthread_self(), &ss); 843 844 if (rslt != 0) 845 fatal(err_msg("pthread_stackseg_np failed with err = %d", rslt)); 846 847 *bottom = (address)((char *)ss.ss_sp - ss.ss_size); 848 *size = ss.ss_size; 849#else 850 pthread_attr_t attr; 851 852 int rslt = pthread_attr_init(&attr); 853 854 // JVM needs to know exact stack location, abort if it fails 855 if (rslt != 0) 856 fatal(err_msg("pthread_attr_init failed with err = %d", rslt)); 857 858 rslt = pthread_attr_get_np(pthread_self(), &attr); 859 860 if (rslt != 0) 861 fatal(err_msg("pthread_attr_get_np failed with err = %d", rslt)); 862 863 if (pthread_attr_getstackaddr(&attr, (void **)bottom) != 0 || 864 pthread_attr_getstacksize(&attr, size) != 0) { 865 fatal("Can not locate current stack attributes!"); 866 } 867 868 pthread_attr_destroy(&attr); 869#endif 870 assert(os::current_stack_pointer() >= *bottom && 871 os::current_stack_pointer() < *bottom + *size, "just checking"); 872} 873 874address os::current_stack_base() { 875 address bottom; 876 size_t size; 877 current_stack_region(&bottom, &size); 878 return (bottom + size); 879} 880 881size_t os::current_stack_size() { 882 // stack size includes normal stack and HotSpot guard pages 883 address bottom; 884 size_t size; 885 current_stack_region(&bottom, &size); 886 return size; 887} 888 889///////////////////////////////////////////////////////////////////////////// 890// helper functions for fatal error handler 891 892void os::print_context(outputStream *st, void *context) { 893 if (context == NULL) return; 894 895 ucontext_t *uc = (ucontext_t*)context; 896 st->print_cr("Registers:"); 897#ifdef AMD64 898 st->print( "RAX=" INTPTR_FORMAT, uc->context_rax); 899 st->print(", RBX=" INTPTR_FORMAT, uc->context_rbx); 900 st->print(", RCX=" INTPTR_FORMAT, uc->context_rcx); 901 st->print(", RDX=" INTPTR_FORMAT, uc->context_rdx); 902 st->cr(); 903 st->print( "RSP=" INTPTR_FORMAT, uc->context_rsp); 904 st->print(", RBP=" INTPTR_FORMAT, uc->context_rbp); 905 st->print(", RSI=" INTPTR_FORMAT, uc->context_rsi); 906 st->print(", RDI=" INTPTR_FORMAT, uc->context_rdi); 907 st->cr(); 908 st->print( "R8 =" INTPTR_FORMAT, uc->context_r8); 909 st->print(", R9 =" INTPTR_FORMAT, uc->context_r9); 910 st->print(", R10=" INTPTR_FORMAT, uc->context_r10); 911 st->print(", R11=" INTPTR_FORMAT, uc->context_r11); 912 st->cr(); 913 st->print( "R12=" INTPTR_FORMAT, uc->context_r12); 914 st->print(", R13=" INTPTR_FORMAT, uc->context_r13); 915 st->print(", R14=" INTPTR_FORMAT, uc->context_r14); 916 st->print(", R15=" INTPTR_FORMAT, uc->context_r15); 917 st->cr(); 918 st->print( "RIP=" INTPTR_FORMAT, uc->context_rip); 919 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_flags); 920 st->print(", ERR=" INTPTR_FORMAT, uc->context_err); 921 st->cr(); 922 st->print(" TRAPNO=" INTPTR_FORMAT, uc->context_trapno); 923#else 924 st->print( "EAX=" INTPTR_FORMAT, uc->context_eax); 925 st->print(", EBX=" INTPTR_FORMAT, uc->context_ebx); 926 st->print(", ECX=" INTPTR_FORMAT, uc->context_ecx); 927 st->print(", EDX=" INTPTR_FORMAT, uc->context_edx); 928 st->cr(); 929 st->print( "ESP=" INTPTR_FORMAT, uc->context_esp); 930 st->print(", EBP=" INTPTR_FORMAT, uc->context_ebp); 931 st->print(", ESI=" INTPTR_FORMAT, uc->context_esi); 932 st->print(", EDI=" INTPTR_FORMAT, uc->context_edi); 933 st->cr(); 934 st->print( "EIP=" INTPTR_FORMAT, uc->context_eip); 935 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_eflags); 936#endif // AMD64 937 st->cr(); 938 st->cr(); 939 940 intptr_t *sp = (intptr_t *)os::Bsd::ucontext_get_sp(uc); 941 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp); 942 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t)); 943 st->cr(); 944 945 // Note: it may be unsafe to inspect memory near pc. For example, pc may 946 // point to garbage if entry point in an nmethod is corrupted. Leave 947 // this at the end, and hope for the best. 948 address pc = os::Bsd::ucontext_get_pc(uc); 949 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc); 950 print_hex_dump(st, pc - 32, pc + 32, sizeof(char)); 951} 952 953void os::print_register_info(outputStream *st, void *context) { 954 if (context == NULL) return; 955 956 ucontext_t *uc = (ucontext_t*)context; 957 958 st->print_cr("Register to memory mapping:"); 959 st->cr(); 960 961 // this is horrendously verbose but the layout of the registers in the 962 // context does not match how we defined our abstract Register set, so 963 // we can't just iterate through the gregs area 964 965 // this is only for the "general purpose" registers 966 967#ifdef AMD64 968 st->print("RAX="); print_location(st, uc->context_rax); 969 st->print("RBX="); print_location(st, uc->context_rbx); 970 st->print("RCX="); print_location(st, uc->context_rcx); 971 st->print("RDX="); print_location(st, uc->context_rdx); 972 st->print("RSP="); print_location(st, uc->context_rsp); 973 st->print("RBP="); print_location(st, uc->context_rbp); 974 st->print("RSI="); print_location(st, uc->context_rsi); 975 st->print("RDI="); print_location(st, uc->context_rdi); 976 st->print("R8 ="); print_location(st, uc->context_r8); 977 st->print("R9 ="); print_location(st, uc->context_r9); 978 st->print("R10="); print_location(st, uc->context_r10); 979 st->print("R11="); print_location(st, uc->context_r11); 980 st->print("R12="); print_location(st, uc->context_r12); 981 st->print("R13="); print_location(st, uc->context_r13); 982 st->print("R14="); print_location(st, uc->context_r14); 983 st->print("R15="); print_location(st, uc->context_r15); 984#else 985 st->print("EAX="); print_location(st, uc->context_eax); 986 st->print("EBX="); print_location(st, uc->context_ebx); 987 st->print("ECX="); print_location(st, uc->context_ecx); 988 st->print("EDX="); print_location(st, uc->context_edx); 989 st->print("ESP="); print_location(st, uc->context_esp); 990 st->print("EBP="); print_location(st, uc->context_ebp); 991 st->print("ESI="); print_location(st, uc->context_esi); 992 st->print("EDI="); print_location(st, uc->context_edi); 993#endif // AMD64 994 995 st->cr(); 996} 997 998void os::setup_fpu() { 999#ifndef AMD64 1000 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std(); 1001 __asm__ volatile ( "fldcw (%0)" : 1002 : "r" (fpu_cntrl) : "memory"); 1003#endif // !AMD64 1004} 1005 1006#ifndef PRODUCT 1007void os::verify_stack_alignment() { 1008} 1009#endif 1010