os_bsd_x86.cpp revision 3794:0af5da0c9d9d
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 56// put OS-includes here 57# include <sys/types.h> 58# include <sys/mman.h> 59# include <pthread.h> 60# include <signal.h> 61# include <errno.h> 62# include <dlfcn.h> 63# include <stdlib.h> 64# include <stdio.h> 65# include <unistd.h> 66# include <sys/resource.h> 67# include <pthread.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#ifdef AMD64 84#define SPELL_REG_SP "rsp" 85#define SPELL_REG_FP "rbp" 86#else 87#define SPELL_REG_SP "esp" 88#define SPELL_REG_FP "ebp" 89#endif // AMD64 90 91#ifdef __FreeBSD__ 92# define context_trapno uc_mcontext.mc_trapno 93# ifdef AMD64 94# define context_pc uc_mcontext.mc_rip 95# define context_sp uc_mcontext.mc_rsp 96# define context_fp uc_mcontext.mc_rbp 97# define context_rip uc_mcontext.mc_rip 98# define context_rsp uc_mcontext.mc_rsp 99# define context_rbp uc_mcontext.mc_rbp 100# define context_rax uc_mcontext.mc_rax 101# define context_rbx uc_mcontext.mc_rbx 102# define context_rcx uc_mcontext.mc_rcx 103# define context_rdx uc_mcontext.mc_rdx 104# define context_rsi uc_mcontext.mc_rsi 105# define context_rdi uc_mcontext.mc_rdi 106# define context_r8 uc_mcontext.mc_r8 107# define context_r9 uc_mcontext.mc_r9 108# define context_r10 uc_mcontext.mc_r10 109# define context_r11 uc_mcontext.mc_r11 110# define context_r12 uc_mcontext.mc_r12 111# define context_r13 uc_mcontext.mc_r13 112# define context_r14 uc_mcontext.mc_r14 113# define context_r15 uc_mcontext.mc_r15 114# define context_flags uc_mcontext.mc_flags 115# define context_err uc_mcontext.mc_err 116# else 117# define context_pc uc_mcontext.mc_eip 118# define context_sp uc_mcontext.mc_esp 119# define context_fp uc_mcontext.mc_ebp 120# define context_eip uc_mcontext.mc_eip 121# define context_esp uc_mcontext.mc_esp 122# define context_eax uc_mcontext.mc_eax 123# define context_ebx uc_mcontext.mc_ebx 124# define context_ecx uc_mcontext.mc_ecx 125# define context_edx uc_mcontext.mc_edx 126# define context_ebp uc_mcontext.mc_ebp 127# define context_esi uc_mcontext.mc_esi 128# define context_edi uc_mcontext.mc_edi 129# define context_eflags uc_mcontext.mc_eflags 130# define context_trapno uc_mcontext.mc_trapno 131# endif 132#endif 133 134#ifdef __APPLE__ 135# if __DARWIN_UNIX03 && (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5) 136 // 10.5 UNIX03 member name prefixes 137 #define DU3_PREFIX(s, m) __ ## s.__ ## m 138# else 139 #define DU3_PREFIX(s, m) s ## . ## m 140# endif 141 142# ifdef AMD64 143# define context_pc context_rip 144# define context_sp context_rsp 145# define context_fp context_rbp 146# define context_rip uc_mcontext->DU3_PREFIX(ss,rip) 147# define context_rsp uc_mcontext->DU3_PREFIX(ss,rsp) 148# define context_rax uc_mcontext->DU3_PREFIX(ss,rax) 149# define context_rbx uc_mcontext->DU3_PREFIX(ss,rbx) 150# define context_rcx uc_mcontext->DU3_PREFIX(ss,rcx) 151# define context_rdx uc_mcontext->DU3_PREFIX(ss,rdx) 152# define context_rbp uc_mcontext->DU3_PREFIX(ss,rbp) 153# define context_rsi uc_mcontext->DU3_PREFIX(ss,rsi) 154# define context_rdi uc_mcontext->DU3_PREFIX(ss,rdi) 155# define context_r8 uc_mcontext->DU3_PREFIX(ss,r8) 156# define context_r9 uc_mcontext->DU3_PREFIX(ss,r9) 157# define context_r10 uc_mcontext->DU3_PREFIX(ss,r10) 158# define context_r11 uc_mcontext->DU3_PREFIX(ss,r11) 159# define context_r12 uc_mcontext->DU3_PREFIX(ss,r12) 160# define context_r13 uc_mcontext->DU3_PREFIX(ss,r13) 161# define context_r14 uc_mcontext->DU3_PREFIX(ss,r14) 162# define context_r15 uc_mcontext->DU3_PREFIX(ss,r15) 163# define context_flags uc_mcontext->DU3_PREFIX(ss,rflags) 164# define context_trapno uc_mcontext->DU3_PREFIX(es,trapno) 165# define context_err uc_mcontext->DU3_PREFIX(es,err) 166# else 167# define context_pc context_eip 168# define context_sp context_esp 169# define context_fp context_ebp 170# define context_eip uc_mcontext->DU3_PREFIX(ss,eip) 171# define context_esp uc_mcontext->DU3_PREFIX(ss,esp) 172# define context_eax uc_mcontext->DU3_PREFIX(ss,eax) 173# define context_ebx uc_mcontext->DU3_PREFIX(ss,ebx) 174# define context_ecx uc_mcontext->DU3_PREFIX(ss,ecx) 175# define context_edx uc_mcontext->DU3_PREFIX(ss,edx) 176# define context_ebp uc_mcontext->DU3_PREFIX(ss,ebp) 177# define context_esi uc_mcontext->DU3_PREFIX(ss,esi) 178# define context_edi uc_mcontext->DU3_PREFIX(ss,edi) 179# define context_eflags uc_mcontext->DU3_PREFIX(ss,eflags) 180# define context_trapno uc_mcontext->DU3_PREFIX(es,trapno) 181# endif 182#endif 183 184#ifdef __OpenBSD__ 185# define context_trapno sc_trapno 186# ifdef AMD64 187# define context_pc sc_rip 188# define context_sp sc_rsp 189# define context_fp sc_rbp 190# define context_rip sc_rip 191# define context_rsp sc_rsp 192# define context_rbp sc_rbp 193# define context_rax sc_rax 194# define context_rbx sc_rbx 195# define context_rcx sc_rcx 196# define context_rdx sc_rdx 197# define context_rsi sc_rsi 198# define context_rdi sc_rdi 199# define context_r8 sc_r8 200# define context_r9 sc_r9 201# define context_r10 sc_r10 202# define context_r11 sc_r11 203# define context_r12 sc_r12 204# define context_r13 sc_r13 205# define context_r14 sc_r14 206# define context_r15 sc_r15 207# define context_flags sc_rflags 208# define context_err sc_err 209# else 210# define context_pc sc_eip 211# define context_sp sc_esp 212# define context_fp sc_ebp 213# define context_eip sc_eip 214# define context_esp sc_esp 215# define context_eax sc_eax 216# define context_ebx sc_ebx 217# define context_ecx sc_ecx 218# define context_edx sc_edx 219# define context_ebp sc_ebp 220# define context_esi sc_esi 221# define context_edi sc_edi 222# define context_eflags sc_eflags 223# define context_trapno sc_trapno 224# endif 225#endif 226 227#ifdef __NetBSD__ 228# define context_trapno uc_mcontext.__gregs[_REG_TRAPNO] 229# ifdef AMD64 230# define __register_t __greg_t 231# define context_pc uc_mcontext.__gregs[_REG_RIP] 232# define context_sp uc_mcontext.__gregs[_REG_URSP] 233# define context_fp uc_mcontext.__gregs[_REG_RBP] 234# define context_rip uc_mcontext.__gregs[_REG_RIP] 235# define context_rsp uc_mcontext.__gregs[_REG_URSP] 236# define context_rax uc_mcontext.__gregs[_REG_RAX] 237# define context_rbx uc_mcontext.__gregs[_REG_RBX] 238# define context_rcx uc_mcontext.__gregs[_REG_RCX] 239# define context_rdx uc_mcontext.__gregs[_REG_RDX] 240# define context_rbp uc_mcontext.__gregs[_REG_RBP] 241# define context_rsi uc_mcontext.__gregs[_REG_RSI] 242# define context_rdi uc_mcontext.__gregs[_REG_RDI] 243# define context_r8 uc_mcontext.__gregs[_REG_R8] 244# define context_r9 uc_mcontext.__gregs[_REG_R9] 245# define context_r10 uc_mcontext.__gregs[_REG_R10] 246# define context_r11 uc_mcontext.__gregs[_REG_R11] 247# define context_r12 uc_mcontext.__gregs[_REG_R12] 248# define context_r13 uc_mcontext.__gregs[_REG_R13] 249# define context_r14 uc_mcontext.__gregs[_REG_R14] 250# define context_r15 uc_mcontext.__gregs[_REG_R15] 251# define context_flags uc_mcontext.__gregs[_REG_RFL] 252# define context_err uc_mcontext.__gregs[_REG_ERR] 253# else 254# define context_pc uc_mcontext.__gregs[_REG_EIP] 255# define context_sp uc_mcontext.__gregs[_REG_UESP] 256# define context_fp uc_mcontext.__gregs[_REG_EBP] 257# define context_eip uc_mcontext.__gregs[_REG_EIP] 258# define context_esp uc_mcontext.__gregs[_REG_UESP] 259# define context_eax uc_mcontext.__gregs[_REG_EAX] 260# define context_ebx uc_mcontext.__gregs[_REG_EBX] 261# define context_ecx uc_mcontext.__gregs[_REG_ECX] 262# define context_edx uc_mcontext.__gregs[_REG_EDX] 263# define context_ebp uc_mcontext.__gregs[_REG_EBP] 264# define context_esi uc_mcontext.__gregs[_REG_ESI] 265# define context_edi uc_mcontext.__gregs[_REG_EDI] 266# define context_eflags uc_mcontext.__gregs[_REG_EFL] 267# define context_trapno uc_mcontext.__gregs[_REG_TRAPNO] 268# endif 269#endif 270 271address os::current_stack_pointer() { 272#if defined(__clang__) || defined(__llvm__) 273 register void *esp; 274 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp)); 275 return (address) esp; 276#elif defined(SPARC_WORKS) 277 register void *esp; 278 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp)); 279 return (address) ((char*)esp + sizeof(long)*2); 280#else 281 register void *esp __asm__ (SPELL_REG_SP); 282 return (address) esp; 283#endif 284} 285 286char* os::non_memory_address_word() { 287 // Must never look like an address returned by reserve_memory, 288 // even in its subfields (as defined by the CPU immediate fields, 289 // if the CPU splits constants across multiple instructions). 290 291 return (char*) -1; 292} 293 294void os::initialize_thread(Thread* thr) { 295// Nothing to do. 296} 297 298address os::Bsd::ucontext_get_pc(ucontext_t * uc) { 299 return (address)uc->context_pc; 300} 301 302intptr_t* os::Bsd::ucontext_get_sp(ucontext_t * uc) { 303 return (intptr_t*)uc->context_sp; 304} 305 306intptr_t* os::Bsd::ucontext_get_fp(ucontext_t * uc) { 307 return (intptr_t*)uc->context_fp; 308} 309 310// For Forte Analyzer AsyncGetCallTrace profiling support - thread 311// is currently interrupted by SIGPROF. 312// os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal 313// frames. Currently we don't do that on Bsd, so it's the same as 314// os::fetch_frame_from_context(). 315ExtendedPC os::Bsd::fetch_frame_from_ucontext(Thread* thread, 316 ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) { 317 318 assert(thread != NULL, "just checking"); 319 assert(ret_sp != NULL, "just checking"); 320 assert(ret_fp != NULL, "just checking"); 321 322 return os::fetch_frame_from_context(uc, ret_sp, ret_fp); 323} 324 325ExtendedPC os::fetch_frame_from_context(void* ucVoid, 326 intptr_t** ret_sp, intptr_t** ret_fp) { 327 328 ExtendedPC epc; 329 ucontext_t* uc = (ucontext_t*)ucVoid; 330 331 if (uc != NULL) { 332 epc = ExtendedPC(os::Bsd::ucontext_get_pc(uc)); 333 if (ret_sp) *ret_sp = os::Bsd::ucontext_get_sp(uc); 334 if (ret_fp) *ret_fp = os::Bsd::ucontext_get_fp(uc); 335 } else { 336 // construct empty ExtendedPC for return value checking 337 epc = ExtendedPC(NULL); 338 if (ret_sp) *ret_sp = (intptr_t *)NULL; 339 if (ret_fp) *ret_fp = (intptr_t *)NULL; 340 } 341 342 return epc; 343} 344 345frame os::fetch_frame_from_context(void* ucVoid) { 346 intptr_t* sp; 347 intptr_t* fp; 348 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp); 349 return frame(sp, fp, epc.pc()); 350} 351 352// By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get 353// turned off by -fomit-frame-pointer, 354frame os::get_sender_for_C_frame(frame* fr) { 355 return frame(fr->sender_sp(), fr->link(), fr->sender_pc()); 356} 357 358intptr_t* _get_previous_fp() { 359#if defined(SPARC_WORKS) || defined(__clang__) || defined(__llvm__) 360 register intptr_t **ebp; 361 __asm__("mov %%"SPELL_REG_FP", %0":"=r"(ebp)); 362#else 363 register intptr_t **ebp __asm__ (SPELL_REG_FP); 364#endif 365 return (intptr_t*) *ebp; // we want what it points to. 366} 367 368 369frame os::current_frame() { 370 intptr_t* fp = _get_previous_fp(); 371 frame myframe((intptr_t*)os::current_stack_pointer(), 372 (intptr_t*)fp, 373 CAST_FROM_FN_PTR(address, os::current_frame)); 374 if (os::is_first_C_frame(&myframe)) { 375 // stack is not walkable 376 return frame(NULL, NULL, NULL); 377 } else { 378 return os::get_sender_for_C_frame(&myframe); 379 } 380} 381 382// Utility functions 383 384// From IA32 System Programming Guide 385enum { 386 trap_page_fault = 0xE 387}; 388 389extern "C" void Fetch32PFI () ; 390extern "C" void Fetch32Resume () ; 391#ifdef AMD64 392extern "C" void FetchNPFI () ; 393extern "C" void FetchNResume () ; 394#endif // AMD64 395 396extern "C" JNIEXPORT int 397JVM_handle_bsd_signal(int sig, 398 siginfo_t* info, 399 void* ucVoid, 400 int abort_if_unrecognized) { 401 ucontext_t* uc = (ucontext_t*) ucVoid; 402 403 Thread* t = ThreadLocalStorage::get_thread_slow(); 404 405 SignalHandlerMark shm(t); 406 407 // Note: it's not uncommon that JNI code uses signal/sigset to install 408 // then restore certain signal handler (e.g. to temporarily block SIGPIPE, 409 // or have a SIGILL handler when detecting CPU type). When that happens, 410 // JVM_handle_bsd_signal() might be invoked with junk info/ucVoid. To 411 // avoid unnecessary crash when libjsig is not preloaded, try handle signals 412 // that do not require siginfo/ucontext first. 413 414 if (sig == SIGPIPE || sig == SIGXFSZ) { 415 // allow chained handler to go first 416 if (os::Bsd::chained_handler(sig, info, ucVoid)) { 417 return true; 418 } else { 419 if (PrintMiscellaneous && (WizardMode || Verbose)) { 420 char buf[64]; 421 warning("Ignoring %s - see bugs 4229104 or 646499219", 422 os::exception_name(sig, buf, sizeof(buf))); 423 } 424 return true; 425 } 426 } 427 428 JavaThread* thread = NULL; 429 VMThread* vmthread = NULL; 430 if (os::Bsd::signal_handlers_are_installed) { 431 if (t != NULL ){ 432 if(t->is_Java_thread()) { 433 thread = (JavaThread*)t; 434 } 435 else if(t->is_VM_thread()){ 436 vmthread = (VMThread *)t; 437 } 438 } 439 } 440/* 441 NOTE: does not seem to work on bsd. 442 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) { 443 // can't decode this kind of signal 444 info = NULL; 445 } else { 446 assert(sig == info->si_signo, "bad siginfo"); 447 } 448*/ 449 // decide if this trap can be handled by a stub 450 address stub = NULL; 451 452 address pc = NULL; 453 454 //%note os_trap_1 455 if (info != NULL && uc != NULL && thread != NULL) { 456 pc = (address) os::Bsd::ucontext_get_pc(uc); 457 458 if (pc == (address) Fetch32PFI) { 459 uc->context_pc = intptr_t(Fetch32Resume) ; 460 return 1 ; 461 } 462#ifdef AMD64 463 if (pc == (address) FetchNPFI) { 464 uc->context_pc = intptr_t (FetchNResume) ; 465 return 1 ; 466 } 467#endif // AMD64 468 469 // Handle ALL stack overflow variations here 470 if (sig == SIGSEGV || sig == SIGBUS) { 471 address addr = (address) info->si_addr; 472 473 // check if fault address is within thread stack 474 if (addr < thread->stack_base() && 475 addr >= thread->stack_base() - thread->stack_size()) { 476 // stack overflow 477 if (thread->in_stack_yellow_zone(addr)) { 478 thread->disable_stack_yellow_zone(); 479 if (thread->thread_state() == _thread_in_Java) { 480 // Throw a stack overflow exception. Guard pages will be reenabled 481 // while unwinding the stack. 482 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); 483 } else { 484 // Thread was in the vm or native code. Return and try to finish. 485 return 1; 486 } 487 } else if (thread->in_stack_red_zone(addr)) { 488 // Fatal red zone violation. Disable the guard pages and fall through 489 // to handle_unexpected_exception way down below. 490 thread->disable_stack_red_zone(); 491 tty->print_raw_cr("An irrecoverable stack overflow has occurred."); 492 } 493 } 494 } 495 496 // We test if stub is already set (by the stack overflow code 497 // above) so it is not overwritten by the code that follows. This 498 // check is not required on other platforms, because on other 499 // platforms we check for SIGSEGV only or SIGBUS only, where here 500 // we have to check for both SIGSEGV and SIGBUS. 501 if (thread->thread_state() == _thread_in_Java && stub == NULL) { 502 // Java thread running in Java code => find exception handler if any 503 // a fault inside compiled code, the interpreter, or a stub 504 505 if ((sig == SIGSEGV || sig == SIGBUS) && os::is_poll_address((address)info->si_addr)) { 506 stub = SharedRuntime::get_poll_stub(pc); 507#if defined(__APPLE__) 508 // 32-bit Darwin reports a SIGBUS for nearly all memory access exceptions. 509 // 64-bit Darwin may also use a SIGBUS (seen with compressed oops). 510 // Catching SIGBUS here prevents the implicit SIGBUS NULL check below from 511 // being called, so only do so if the implicit NULL check is not necessary. 512 } else if (sig == SIGBUS && MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { 513#else 514 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) { 515#endif 516 // BugId 4454115: A read from a MappedByteBuffer can fault 517 // here if the underlying file has been truncated. 518 // Do not crash the VM in such a case. 519 CodeBlob* cb = CodeCache::find_blob_unsafe(pc); 520 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL; 521 if (nm != NULL && nm->has_unsafe_access()) { 522 stub = StubRoutines::handler_for_unsafe_access(); 523 } 524 } 525 else 526 527#ifdef AMD64 528 if (sig == SIGFPE && 529 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) { 530 stub = 531 SharedRuntime:: 532 continuation_for_implicit_exception(thread, 533 pc, 534 SharedRuntime:: 535 IMPLICIT_DIVIDE_BY_ZERO); 536#ifdef __APPLE__ 537 } else if (sig == SIGFPE && info->si_code == FPE_NOOP) { 538 int op = pc[0]; 539 540 // Skip REX 541 if ((pc[0] & 0xf0) == 0x40) { 542 op = pc[1]; 543 } else { 544 op = pc[0]; 545 } 546 547 // Check for IDIV 548 if (op == 0xF7) { 549 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime:: IMPLICIT_DIVIDE_BY_ZERO); 550 } else { 551 // TODO: handle more cases if we are using other x86 instructions 552 // that can generate SIGFPE signal. 553 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); 554 fatal("please update this code."); 555 } 556#endif /* __APPLE__ */ 557 558#else 559 if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) { 560 // HACK: si_code does not work on bsd 2.2.12-20!!! 561 int op = pc[0]; 562 if (op == 0xDB) { 563 // FIST 564 // TODO: The encoding of D2I in i486.ad can cause an exception 565 // prior to the fist instruction if there was an invalid operation 566 // pending. We want to dismiss that exception. From the win_32 567 // side it also seems that if it really was the fist causing 568 // the exception that we do the d2i by hand with different 569 // rounding. Seems kind of weird. 570 // NOTE: that we take the exception at the NEXT floating point instruction. 571 assert(pc[0] == 0xDB, "not a FIST opcode"); 572 assert(pc[1] == 0x14, "not a FIST opcode"); 573 assert(pc[2] == 0x24, "not a FIST opcode"); 574 return true; 575 } else if (op == 0xF7) { 576 // IDIV 577 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); 578 } else { 579 // TODO: handle more cases if we are using other x86 instructions 580 // that can generate SIGFPE signal on bsd. 581 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); 582 fatal("please update this code."); 583 } 584#endif // AMD64 585 } else if ((sig == SIGSEGV || sig == SIGBUS) && 586 !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { 587 // Determination of interpreter/vtable stub/compiled code null exception 588 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 589 } 590 } else if (thread->thread_state() == _thread_in_vm && 591 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */ 592 thread->doing_unsafe_access()) { 593 stub = StubRoutines::handler_for_unsafe_access(); 594 } 595 596 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in 597 // and the heap gets shrunk before the field access. 598 if ((sig == SIGSEGV) || (sig == SIGBUS)) { 599 address addr = JNI_FastGetField::find_slowcase_pc(pc); 600 if (addr != (address)-1) { 601 stub = addr; 602 } 603 } 604 605 // Check to see if we caught the safepoint code in the 606 // process of write protecting the memory serialization page. 607 // It write enables the page immediately after protecting it 608 // so we can just return to retry the write. 609 if ((sig == SIGSEGV || sig == SIGBUS) && 610 os::is_memory_serialize_page(thread, (address) info->si_addr)) { 611 // Block current thread until the memory serialize page permission restored. 612 os::block_on_serialize_page_trap(); 613 return true; 614 } 615 } 616 617#ifndef AMD64 618 // Execution protection violation 619 // 620 // This should be kept as the last step in the triage. We don't 621 // have a dedicated trap number for a no-execute fault, so be 622 // conservative and allow other handlers the first shot. 623 // 624 // Note: We don't test that info->si_code == SEGV_ACCERR here. 625 // this si_code is so generic that it is almost meaningless; and 626 // the si_code for this condition may change in the future. 627 // Furthermore, a false-positive should be harmless. 628 if (UnguardOnExecutionViolation > 0 && 629 (sig == SIGSEGV || sig == SIGBUS) && 630 uc->context_trapno == trap_page_fault) { 631 int page_size = os::vm_page_size(); 632 address addr = (address) info->si_addr; 633 address pc = os::Bsd::ucontext_get_pc(uc); 634 // Make sure the pc and the faulting address are sane. 635 // 636 // If an instruction spans a page boundary, and the page containing 637 // the beginning of the instruction is executable but the following 638 // page is not, the pc and the faulting address might be slightly 639 // different - we still want to unguard the 2nd page in this case. 640 // 641 // 15 bytes seems to be a (very) safe value for max instruction size. 642 bool pc_is_near_addr = 643 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15); 644 bool instr_spans_page_boundary = 645 (align_size_down((intptr_t) pc ^ (intptr_t) addr, 646 (intptr_t) page_size) > 0); 647 648 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) { 649 static volatile address last_addr = 650 (address) os::non_memory_address_word(); 651 652 // In conservative mode, don't unguard unless the address is in the VM 653 if (addr != last_addr && 654 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) { 655 656 // Set memory to RWX and retry 657 address page_start = 658 (address) align_size_down((intptr_t) addr, (intptr_t) page_size); 659 bool res = os::protect_memory((char*) page_start, page_size, 660 os::MEM_PROT_RWX); 661 662 if (PrintMiscellaneous && Verbose) { 663 char buf[256]; 664 jio_snprintf(buf, sizeof(buf), "Execution protection violation " 665 "at " INTPTR_FORMAT 666 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr, 667 page_start, (res ? "success" : "failed"), errno); 668 tty->print_raw_cr(buf); 669 } 670 stub = pc; 671 672 // Set last_addr so if we fault again at the same address, we don't end 673 // up in an endless loop. 674 // 675 // There are two potential complications here. Two threads trapping at 676 // the same address at the same time could cause one of the threads to 677 // think it already unguarded, and abort the VM. Likely very rare. 678 // 679 // The other race involves two threads alternately trapping at 680 // different addresses and failing to unguard the page, resulting in 681 // an endless loop. This condition is probably even more unlikely than 682 // the first. 683 // 684 // Although both cases could be avoided by using locks or thread local 685 // last_addr, these solutions are unnecessary complication: this 686 // handler is a best-effort safety net, not a complete solution. It is 687 // disabled by default and should only be used as a workaround in case 688 // we missed any no-execute-unsafe VM code. 689 690 last_addr = addr; 691 } 692 } 693 } 694#endif // !AMD64 695 696 if (stub != NULL) { 697 // save all thread context in case we need to restore it 698 if (thread != NULL) thread->set_saved_exception_pc(pc); 699 700 uc->context_pc = (intptr_t)stub; 701 return true; 702 } 703 704 // signal-chaining 705 if (os::Bsd::chained_handler(sig, info, ucVoid)) { 706 return true; 707 } 708 709 if (!abort_if_unrecognized) { 710 // caller wants another chance, so give it to him 711 return false; 712 } 713 714 if (pc == NULL && uc != NULL) { 715 pc = os::Bsd::ucontext_get_pc(uc); 716 } 717 718 // unmask current signal 719 sigset_t newset; 720 sigemptyset(&newset); 721 sigaddset(&newset, sig); 722 sigprocmask(SIG_UNBLOCK, &newset, NULL); 723 724 VMError err(t, sig, pc, info, ucVoid); 725 err.report_and_die(); 726 727 ShouldNotReachHere(); 728} 729 730// From solaris_i486.s ported to bsd_i486.s 731extern "C" void fixcw(); 732 733void os::Bsd::init_thread_fpu_state(void) { 734#ifndef AMD64 735 // Set fpu to 53 bit precision. This happens too early to use a stub. 736 fixcw(); 737#endif // !AMD64 738} 739 740 741// Check that the bsd kernel version is 2.4 or higher since earlier 742// versions do not support SSE without patches. 743bool os::supports_sse() { 744 return true; 745} 746 747bool os::is_allocatable(size_t bytes) { 748#ifdef AMD64 749 // unused on amd64? 750 return true; 751#else 752 753 if (bytes < 2 * G) { 754 return true; 755 } 756 757 char* addr = reserve_memory(bytes, NULL); 758 759 if (addr != NULL) { 760 release_memory(addr, bytes); 761 } 762 763 return addr != NULL; 764#endif // AMD64 765} 766 767//////////////////////////////////////////////////////////////////////////////// 768// thread stack 769 770#ifdef AMD64 771size_t os::Bsd::min_stack_allowed = 64 * K; 772 773// amd64: pthread on amd64 is always in floating stack mode 774bool os::Bsd::supports_variable_stack_size() { return true; } 775#else 776size_t os::Bsd::min_stack_allowed = (48 DEBUG_ONLY(+4))*K; 777 778#ifdef __GNUC__ 779#define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;}) 780#endif 781 782bool os::Bsd::supports_variable_stack_size() { return true; } 783#endif // AMD64 784 785// return default stack size for thr_type 786size_t os::Bsd::default_stack_size(os::ThreadType thr_type) { 787 // default stack size (compiler thread needs larger stack) 788#ifdef AMD64 789 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M); 790#else 791 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K); 792#endif // AMD64 793 return s; 794} 795 796size_t os::Bsd::default_guard_size(os::ThreadType thr_type) { 797 // Creating guard page is very expensive. Java thread has HotSpot 798 // guard page, only enable glibc guard page for non-Java threads. 799 return (thr_type == java_thread ? 0 : page_size()); 800} 801 802// Java thread: 803// 804// Low memory addresses 805// +------------------------+ 806// | |\ JavaThread created by VM does not have glibc 807// | glibc guard page | - guard, attached Java thread usually has 808// | |/ 1 page glibc guard. 809// P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 810// | |\ 811// | HotSpot Guard Pages | - red and yellow pages 812// | |/ 813// +------------------------+ JavaThread::stack_yellow_zone_base() 814// | |\ 815// | Normal Stack | - 816// | |/ 817// P2 +------------------------+ Thread::stack_base() 818// 819// Non-Java thread: 820// 821// Low memory addresses 822// +------------------------+ 823// | |\ 824// | glibc guard page | - usually 1 page 825// | |/ 826// P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 827// | |\ 828// | Normal Stack | - 829// | |/ 830// P2 +------------------------+ Thread::stack_base() 831// 832// ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from 833// pthread_attr_getstack() 834 835static void current_stack_region(address * bottom, size_t * size) { 836#ifdef __APPLE__ 837 pthread_t self = pthread_self(); 838 void *stacktop = pthread_get_stackaddr_np(self); 839 *size = pthread_get_stacksize_np(self); 840 *bottom = (address) stacktop - *size; 841#elif defined(__OpenBSD__) 842 stack_t ss; 843 int rslt = pthread_stackseg_np(pthread_self(), &ss); 844 845 if (rslt != 0) 846 fatal(err_msg("pthread_stackseg_np failed with err = %d", rslt)); 847 848 *bottom = (address)((char *)ss.ss_sp - ss.ss_size); 849 *size = ss.ss_size; 850#else 851 pthread_attr_t attr; 852 853 int rslt = pthread_attr_init(&attr); 854 855 // JVM needs to know exact stack location, abort if it fails 856 if (rslt != 0) 857 fatal(err_msg("pthread_attr_init failed with err = %d", rslt)); 858 859 rslt = pthread_attr_get_np(pthread_self(), &attr); 860 861 if (rslt != 0) 862 fatal(err_msg("pthread_attr_get_np failed with err = %d", rslt)); 863 864 if (pthread_attr_getstackaddr(&attr, (void **)bottom) != 0 || 865 pthread_attr_getstacksize(&attr, size) != 0) { 866 fatal("Can not locate current stack attributes!"); 867 } 868 869 pthread_attr_destroy(&attr); 870#endif 871 assert(os::current_stack_pointer() >= *bottom && 872 os::current_stack_pointer() < *bottom + *size, "just checking"); 873} 874 875address os::current_stack_base() { 876 address bottom; 877 size_t size; 878 current_stack_region(&bottom, &size); 879 return (bottom + size); 880} 881 882size_t os::current_stack_size() { 883 // stack size includes normal stack and HotSpot guard pages 884 address bottom; 885 size_t size; 886 current_stack_region(&bottom, &size); 887 return size; 888} 889 890///////////////////////////////////////////////////////////////////////////// 891// helper functions for fatal error handler 892 893void os::print_context(outputStream *st, void *context) { 894 if (context == NULL) return; 895 896 ucontext_t *uc = (ucontext_t*)context; 897 st->print_cr("Registers:"); 898#ifdef AMD64 899 st->print( "RAX=" INTPTR_FORMAT, uc->context_rax); 900 st->print(", RBX=" INTPTR_FORMAT, uc->context_rbx); 901 st->print(", RCX=" INTPTR_FORMAT, uc->context_rcx); 902 st->print(", RDX=" INTPTR_FORMAT, uc->context_rdx); 903 st->cr(); 904 st->print( "RSP=" INTPTR_FORMAT, uc->context_rsp); 905 st->print(", RBP=" INTPTR_FORMAT, uc->context_rbp); 906 st->print(", RSI=" INTPTR_FORMAT, uc->context_rsi); 907 st->print(", RDI=" INTPTR_FORMAT, uc->context_rdi); 908 st->cr(); 909 st->print( "R8 =" INTPTR_FORMAT, uc->context_r8); 910 st->print(", R9 =" INTPTR_FORMAT, uc->context_r9); 911 st->print(", R10=" INTPTR_FORMAT, uc->context_r10); 912 st->print(", R11=" INTPTR_FORMAT, uc->context_r11); 913 st->cr(); 914 st->print( "R12=" INTPTR_FORMAT, uc->context_r12); 915 st->print(", R13=" INTPTR_FORMAT, uc->context_r13); 916 st->print(", R14=" INTPTR_FORMAT, uc->context_r14); 917 st->print(", R15=" INTPTR_FORMAT, uc->context_r15); 918 st->cr(); 919 st->print( "RIP=" INTPTR_FORMAT, uc->context_rip); 920 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_flags); 921 st->print(", ERR=" INTPTR_FORMAT, uc->context_err); 922 st->cr(); 923 st->print(" TRAPNO=" INTPTR_FORMAT, uc->context_trapno); 924#else 925 st->print( "EAX=" INTPTR_FORMAT, uc->context_eax); 926 st->print(", EBX=" INTPTR_FORMAT, uc->context_ebx); 927 st->print(", ECX=" INTPTR_FORMAT, uc->context_ecx); 928 st->print(", EDX=" INTPTR_FORMAT, uc->context_edx); 929 st->cr(); 930 st->print( "ESP=" INTPTR_FORMAT, uc->context_esp); 931 st->print(", EBP=" INTPTR_FORMAT, uc->context_ebp); 932 st->print(", ESI=" INTPTR_FORMAT, uc->context_esi); 933 st->print(", EDI=" INTPTR_FORMAT, uc->context_edi); 934 st->cr(); 935 st->print( "EIP=" INTPTR_FORMAT, uc->context_eip); 936 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_eflags); 937#endif // AMD64 938 st->cr(); 939 st->cr(); 940 941 intptr_t *sp = (intptr_t *)os::Bsd::ucontext_get_sp(uc); 942 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp); 943 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t)); 944 st->cr(); 945 946 // Note: it may be unsafe to inspect memory near pc. For example, pc may 947 // point to garbage if entry point in an nmethod is corrupted. Leave 948 // this at the end, and hope for the best. 949 address pc = os::Bsd::ucontext_get_pc(uc); 950 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc); 951 print_hex_dump(st, pc - 32, pc + 32, sizeof(char)); 952} 953 954void os::print_register_info(outputStream *st, void *context) { 955 if (context == NULL) return; 956 957 ucontext_t *uc = (ucontext_t*)context; 958 959 st->print_cr("Register to memory mapping:"); 960 st->cr(); 961 962 // this is horrendously verbose but the layout of the registers in the 963 // context does not match how we defined our abstract Register set, so 964 // we can't just iterate through the gregs area 965 966 // this is only for the "general purpose" registers 967 968#ifdef AMD64 969 st->print("RAX="); print_location(st, uc->context_rax); 970 st->print("RBX="); print_location(st, uc->context_rbx); 971 st->print("RCX="); print_location(st, uc->context_rcx); 972 st->print("RDX="); print_location(st, uc->context_rdx); 973 st->print("RSP="); print_location(st, uc->context_rsp); 974 st->print("RBP="); print_location(st, uc->context_rbp); 975 st->print("RSI="); print_location(st, uc->context_rsi); 976 st->print("RDI="); print_location(st, uc->context_rdi); 977 st->print("R8 ="); print_location(st, uc->context_r8); 978 st->print("R9 ="); print_location(st, uc->context_r9); 979 st->print("R10="); print_location(st, uc->context_r10); 980 st->print("R11="); print_location(st, uc->context_r11); 981 st->print("R12="); print_location(st, uc->context_r12); 982 st->print("R13="); print_location(st, uc->context_r13); 983 st->print("R14="); print_location(st, uc->context_r14); 984 st->print("R15="); print_location(st, uc->context_r15); 985#else 986 st->print("EAX="); print_location(st, uc->context_eax); 987 st->print("EBX="); print_location(st, uc->context_ebx); 988 st->print("ECX="); print_location(st, uc->context_ecx); 989 st->print("EDX="); print_location(st, uc->context_edx); 990 st->print("ESP="); print_location(st, uc->context_esp); 991 st->print("EBP="); print_location(st, uc->context_ebp); 992 st->print("ESI="); print_location(st, uc->context_esi); 993 st->print("EDI="); print_location(st, uc->context_edi); 994#endif // AMD64 995 996 st->cr(); 997} 998 999void os::setup_fpu() { 1000#ifndef AMD64 1001 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std(); 1002 __asm__ volatile ( "fldcw (%0)" : 1003 : "r" (fpu_cntrl) : "memory"); 1004#endif // !AMD64 1005} 1006 1007#ifndef PRODUCT 1008void os::verify_stack_alignment() { 1009} 1010#endif 1011