os_bsd_x86.cpp revision 13249:a2753984d2c1
1/* 2 * Copyright (c) 1999, 2016, 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/codeCache.hpp" 31#include "code/icBuffer.hpp" 32#include "code/vtableStubs.hpp" 33#include "interpreter/interpreter.hpp" 34#include "jvm_bsd.h" 35#include "memory/allocation.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/align.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// needed by current_stack_region() workaround for Mavericks 84#if defined(__APPLE__) 85# include <errno.h> 86# include <sys/types.h> 87# include <sys/sysctl.h> 88# define DEFAULT_MAIN_THREAD_STACK_PAGES 2048 89# define OS_X_10_9_0_KERNEL_MAJOR_VERSION 13 90#endif 91 92#ifdef AMD64 93#define SPELL_REG_SP "rsp" 94#define SPELL_REG_FP "rbp" 95#else 96#define SPELL_REG_SP "esp" 97#define SPELL_REG_FP "ebp" 98#endif // AMD64 99 100#ifdef __FreeBSD__ 101# define context_trapno uc_mcontext.mc_trapno 102# ifdef AMD64 103# define context_pc uc_mcontext.mc_rip 104# define context_sp uc_mcontext.mc_rsp 105# define context_fp uc_mcontext.mc_rbp 106# define context_rip uc_mcontext.mc_rip 107# define context_rsp uc_mcontext.mc_rsp 108# define context_rbp uc_mcontext.mc_rbp 109# define context_rax uc_mcontext.mc_rax 110# define context_rbx uc_mcontext.mc_rbx 111# define context_rcx uc_mcontext.mc_rcx 112# define context_rdx uc_mcontext.mc_rdx 113# define context_rsi uc_mcontext.mc_rsi 114# define context_rdi uc_mcontext.mc_rdi 115# define context_r8 uc_mcontext.mc_r8 116# define context_r9 uc_mcontext.mc_r9 117# define context_r10 uc_mcontext.mc_r10 118# define context_r11 uc_mcontext.mc_r11 119# define context_r12 uc_mcontext.mc_r12 120# define context_r13 uc_mcontext.mc_r13 121# define context_r14 uc_mcontext.mc_r14 122# define context_r15 uc_mcontext.mc_r15 123# define context_flags uc_mcontext.mc_flags 124# define context_err uc_mcontext.mc_err 125# else 126# define context_pc uc_mcontext.mc_eip 127# define context_sp uc_mcontext.mc_esp 128# define context_fp uc_mcontext.mc_ebp 129# define context_eip uc_mcontext.mc_eip 130# define context_esp uc_mcontext.mc_esp 131# define context_eax uc_mcontext.mc_eax 132# define context_ebx uc_mcontext.mc_ebx 133# define context_ecx uc_mcontext.mc_ecx 134# define context_edx uc_mcontext.mc_edx 135# define context_ebp uc_mcontext.mc_ebp 136# define context_esi uc_mcontext.mc_esi 137# define context_edi uc_mcontext.mc_edi 138# define context_eflags uc_mcontext.mc_eflags 139# define context_trapno uc_mcontext.mc_trapno 140# endif 141#endif 142 143#ifdef __APPLE__ 144# if __DARWIN_UNIX03 && (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5) 145 // 10.5 UNIX03 member name prefixes 146 #define DU3_PREFIX(s, m) __ ## s.__ ## m 147# else 148 #define DU3_PREFIX(s, m) s ## . ## m 149# endif 150 151# ifdef AMD64 152# define context_pc context_rip 153# define context_sp context_rsp 154# define context_fp context_rbp 155# define context_rip uc_mcontext->DU3_PREFIX(ss,rip) 156# define context_rsp uc_mcontext->DU3_PREFIX(ss,rsp) 157# define context_rax uc_mcontext->DU3_PREFIX(ss,rax) 158# define context_rbx uc_mcontext->DU3_PREFIX(ss,rbx) 159# define context_rcx uc_mcontext->DU3_PREFIX(ss,rcx) 160# define context_rdx uc_mcontext->DU3_PREFIX(ss,rdx) 161# define context_rbp uc_mcontext->DU3_PREFIX(ss,rbp) 162# define context_rsi uc_mcontext->DU3_PREFIX(ss,rsi) 163# define context_rdi uc_mcontext->DU3_PREFIX(ss,rdi) 164# define context_r8 uc_mcontext->DU3_PREFIX(ss,r8) 165# define context_r9 uc_mcontext->DU3_PREFIX(ss,r9) 166# define context_r10 uc_mcontext->DU3_PREFIX(ss,r10) 167# define context_r11 uc_mcontext->DU3_PREFIX(ss,r11) 168# define context_r12 uc_mcontext->DU3_PREFIX(ss,r12) 169# define context_r13 uc_mcontext->DU3_PREFIX(ss,r13) 170# define context_r14 uc_mcontext->DU3_PREFIX(ss,r14) 171# define context_r15 uc_mcontext->DU3_PREFIX(ss,r15) 172# define context_flags uc_mcontext->DU3_PREFIX(ss,rflags) 173# define context_trapno uc_mcontext->DU3_PREFIX(es,trapno) 174# define context_err uc_mcontext->DU3_PREFIX(es,err) 175# else 176# define context_pc context_eip 177# define context_sp context_esp 178# define context_fp context_ebp 179# define context_eip uc_mcontext->DU3_PREFIX(ss,eip) 180# define context_esp uc_mcontext->DU3_PREFIX(ss,esp) 181# define context_eax uc_mcontext->DU3_PREFIX(ss,eax) 182# define context_ebx uc_mcontext->DU3_PREFIX(ss,ebx) 183# define context_ecx uc_mcontext->DU3_PREFIX(ss,ecx) 184# define context_edx uc_mcontext->DU3_PREFIX(ss,edx) 185# define context_ebp uc_mcontext->DU3_PREFIX(ss,ebp) 186# define context_esi uc_mcontext->DU3_PREFIX(ss,esi) 187# define context_edi uc_mcontext->DU3_PREFIX(ss,edi) 188# define context_eflags uc_mcontext->DU3_PREFIX(ss,eflags) 189# define context_trapno uc_mcontext->DU3_PREFIX(es,trapno) 190# endif 191#endif 192 193#ifdef __OpenBSD__ 194# define context_trapno sc_trapno 195# ifdef AMD64 196# define context_pc sc_rip 197# define context_sp sc_rsp 198# define context_fp sc_rbp 199# define context_rip sc_rip 200# define context_rsp sc_rsp 201# define context_rbp sc_rbp 202# define context_rax sc_rax 203# define context_rbx sc_rbx 204# define context_rcx sc_rcx 205# define context_rdx sc_rdx 206# define context_rsi sc_rsi 207# define context_rdi sc_rdi 208# define context_r8 sc_r8 209# define context_r9 sc_r9 210# define context_r10 sc_r10 211# define context_r11 sc_r11 212# define context_r12 sc_r12 213# define context_r13 sc_r13 214# define context_r14 sc_r14 215# define context_r15 sc_r15 216# define context_flags sc_rflags 217# define context_err sc_err 218# else 219# define context_pc sc_eip 220# define context_sp sc_esp 221# define context_fp sc_ebp 222# define context_eip sc_eip 223# define context_esp sc_esp 224# define context_eax sc_eax 225# define context_ebx sc_ebx 226# define context_ecx sc_ecx 227# define context_edx sc_edx 228# define context_ebp sc_ebp 229# define context_esi sc_esi 230# define context_edi sc_edi 231# define context_eflags sc_eflags 232# define context_trapno sc_trapno 233# endif 234#endif 235 236#ifdef __NetBSD__ 237# define context_trapno uc_mcontext.__gregs[_REG_TRAPNO] 238# ifdef AMD64 239# define __register_t __greg_t 240# define context_pc uc_mcontext.__gregs[_REG_RIP] 241# define context_sp uc_mcontext.__gregs[_REG_URSP] 242# define context_fp uc_mcontext.__gregs[_REG_RBP] 243# define context_rip uc_mcontext.__gregs[_REG_RIP] 244# define context_rsp uc_mcontext.__gregs[_REG_URSP] 245# define context_rax uc_mcontext.__gregs[_REG_RAX] 246# define context_rbx uc_mcontext.__gregs[_REG_RBX] 247# define context_rcx uc_mcontext.__gregs[_REG_RCX] 248# define context_rdx uc_mcontext.__gregs[_REG_RDX] 249# define context_rbp uc_mcontext.__gregs[_REG_RBP] 250# define context_rsi uc_mcontext.__gregs[_REG_RSI] 251# define context_rdi uc_mcontext.__gregs[_REG_RDI] 252# define context_r8 uc_mcontext.__gregs[_REG_R8] 253# define context_r9 uc_mcontext.__gregs[_REG_R9] 254# define context_r10 uc_mcontext.__gregs[_REG_R10] 255# define context_r11 uc_mcontext.__gregs[_REG_R11] 256# define context_r12 uc_mcontext.__gregs[_REG_R12] 257# define context_r13 uc_mcontext.__gregs[_REG_R13] 258# define context_r14 uc_mcontext.__gregs[_REG_R14] 259# define context_r15 uc_mcontext.__gregs[_REG_R15] 260# define context_flags uc_mcontext.__gregs[_REG_RFL] 261# define context_err uc_mcontext.__gregs[_REG_ERR] 262# else 263# define context_pc uc_mcontext.__gregs[_REG_EIP] 264# define context_sp uc_mcontext.__gregs[_REG_UESP] 265# define context_fp uc_mcontext.__gregs[_REG_EBP] 266# define context_eip uc_mcontext.__gregs[_REG_EIP] 267# define context_esp uc_mcontext.__gregs[_REG_UESP] 268# define context_eax uc_mcontext.__gregs[_REG_EAX] 269# define context_ebx uc_mcontext.__gregs[_REG_EBX] 270# define context_ecx uc_mcontext.__gregs[_REG_ECX] 271# define context_edx uc_mcontext.__gregs[_REG_EDX] 272# define context_ebp uc_mcontext.__gregs[_REG_EBP] 273# define context_esi uc_mcontext.__gregs[_REG_ESI] 274# define context_edi uc_mcontext.__gregs[_REG_EDI] 275# define context_eflags uc_mcontext.__gregs[_REG_EFL] 276# define context_trapno uc_mcontext.__gregs[_REG_TRAPNO] 277# endif 278#endif 279 280address os::current_stack_pointer() { 281#if defined(__clang__) || defined(__llvm__) 282 register void *esp; 283 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp)); 284 return (address) esp; 285#elif defined(SPARC_WORKS) 286 register void *esp; 287 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp)); 288 return (address) ((char*)esp + sizeof(long)*2); 289#else 290 register void *esp __asm__ (SPELL_REG_SP); 291 return (address) esp; 292#endif 293} 294 295char* os::non_memory_address_word() { 296 // Must never look like an address returned by reserve_memory, 297 // even in its subfields (as defined by the CPU immediate fields, 298 // if the CPU splits constants across multiple instructions). 299 300 return (char*) -1; 301} 302 303void os::initialize_thread(Thread* thr) { 304// Nothing to do. 305} 306 307address os::Bsd::ucontext_get_pc(const ucontext_t * uc) { 308 return (address)uc->context_pc; 309} 310 311void os::Bsd::ucontext_set_pc(ucontext_t * uc, address pc) { 312 uc->context_pc = (intptr_t)pc ; 313} 314 315intptr_t* os::Bsd::ucontext_get_sp(const ucontext_t * uc) { 316 return (intptr_t*)uc->context_sp; 317} 318 319intptr_t* os::Bsd::ucontext_get_fp(const ucontext_t * uc) { 320 return (intptr_t*)uc->context_fp; 321} 322 323// For Forte Analyzer AsyncGetCallTrace profiling support - thread 324// is currently interrupted by SIGPROF. 325// os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal 326// frames. Currently we don't do that on Bsd, so it's the same as 327// os::fetch_frame_from_context(). 328// This method is also used for stack overflow signal handling. 329ExtendedPC os::Bsd::fetch_frame_from_ucontext(Thread* thread, 330 const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) { 331 332 assert(thread != NULL, "just checking"); 333 assert(ret_sp != NULL, "just checking"); 334 assert(ret_fp != NULL, "just checking"); 335 336 return os::fetch_frame_from_context(uc, ret_sp, ret_fp); 337} 338 339ExtendedPC os::fetch_frame_from_context(const void* ucVoid, 340 intptr_t** ret_sp, intptr_t** ret_fp) { 341 342 ExtendedPC epc; 343 const ucontext_t* uc = (const ucontext_t*)ucVoid; 344 345 if (uc != NULL) { 346 epc = ExtendedPC(os::Bsd::ucontext_get_pc(uc)); 347 if (ret_sp) *ret_sp = os::Bsd::ucontext_get_sp(uc); 348 if (ret_fp) *ret_fp = os::Bsd::ucontext_get_fp(uc); 349 } else { 350 // construct empty ExtendedPC for return value checking 351 epc = ExtendedPC(NULL); 352 if (ret_sp) *ret_sp = (intptr_t *)NULL; 353 if (ret_fp) *ret_fp = (intptr_t *)NULL; 354 } 355 356 return epc; 357} 358 359frame os::fetch_frame_from_context(const void* ucVoid) { 360 intptr_t* sp; 361 intptr_t* fp; 362 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp); 363 return frame(sp, fp, epc.pc()); 364} 365 366frame os::fetch_frame_from_ucontext(Thread* thread, void* ucVoid) { 367 intptr_t* sp; 368 intptr_t* fp; 369 ExtendedPC epc = os::Bsd::fetch_frame_from_ucontext(thread, (ucontext_t*)ucVoid, &sp, &fp); 370 return frame(sp, fp, epc.pc()); 371} 372 373bool os::Bsd::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) { 374 address pc = (address) os::Bsd::ucontext_get_pc(uc); 375 if (Interpreter::contains(pc)) { 376 // interpreter performs stack banging after the fixed frame header has 377 // been generated while the compilers perform it before. To maintain 378 // semantic consistency between interpreted and compiled frames, the 379 // method returns the Java sender of the current frame. 380 *fr = os::fetch_frame_from_ucontext(thread, uc); 381 if (!fr->is_first_java_frame()) { 382 // get_frame_at_stack_banging_point() is only called when we 383 // have well defined stacks so java_sender() calls do not need 384 // to assert safe_for_sender() first. 385 *fr = fr->java_sender(); 386 } 387 } else { 388 // more complex code with compiled code 389 assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above"); 390 CodeBlob* cb = CodeCache::find_blob(pc); 391 if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) { 392 // Not sure where the pc points to, fallback to default 393 // stack overflow handling 394 return false; 395 } else { 396 *fr = os::fetch_frame_from_ucontext(thread, uc); 397 // in compiled code, the stack banging is performed just after the return pc 398 // has been pushed on the stack 399 *fr = frame(fr->sp() + 1, fr->fp(), (address)*(fr->sp())); 400 if (!fr->is_java_frame()) { 401 // See java_sender() comment above. 402 *fr = fr->java_sender(); 403 } 404 } 405 } 406 assert(fr->is_java_frame(), "Safety check"); 407 return true; 408} 409 410// By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get 411// turned off by -fomit-frame-pointer, 412frame os::get_sender_for_C_frame(frame* fr) { 413 return frame(fr->sender_sp(), fr->link(), fr->sender_pc()); 414} 415 416intptr_t* _get_previous_fp() { 417#if defined(SPARC_WORKS) || defined(__clang__) || defined(__llvm__) 418 register intptr_t **ebp; 419 __asm__("mov %%"SPELL_REG_FP", %0":"=r"(ebp)); 420#else 421 register intptr_t **ebp __asm__ (SPELL_REG_FP); 422#endif 423 // ebp is for this frame (_get_previous_fp). We want the ebp for the 424 // caller of os::current_frame*(), so go up two frames. However, for 425 // optimized builds, _get_previous_fp() will be inlined, so only go 426 // up 1 frame in that case. 427#ifdef _NMT_NOINLINE_ 428 return **(intptr_t***)ebp; 429#else 430 return *ebp; 431#endif 432} 433 434 435frame os::current_frame() { 436 intptr_t* fp = _get_previous_fp(); 437 frame myframe((intptr_t*)os::current_stack_pointer(), 438 (intptr_t*)fp, 439 CAST_FROM_FN_PTR(address, os::current_frame)); 440 if (os::is_first_C_frame(&myframe)) { 441 // stack is not walkable 442 return frame(); 443 } else { 444 return os::get_sender_for_C_frame(&myframe); 445 } 446} 447 448// Utility functions 449 450// From IA32 System Programming Guide 451enum { 452 trap_page_fault = 0xE 453}; 454 455extern "C" JNIEXPORT int 456JVM_handle_bsd_signal(int sig, 457 siginfo_t* info, 458 void* ucVoid, 459 int abort_if_unrecognized) { 460 ucontext_t* uc = (ucontext_t*) ucVoid; 461 462 Thread* t = Thread::current_or_null_safe(); 463 464 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away 465 // (no destructors can be run) 466 os::WatcherThreadCrashProtection::check_crash_protection(sig, t); 467 468 SignalHandlerMark shm(t); 469 470 // Note: it's not uncommon that JNI code uses signal/sigset to install 471 // then restore certain signal handler (e.g. to temporarily block SIGPIPE, 472 // or have a SIGILL handler when detecting CPU type). When that happens, 473 // JVM_handle_bsd_signal() might be invoked with junk info/ucVoid. To 474 // avoid unnecessary crash when libjsig is not preloaded, try handle signals 475 // that do not require siginfo/ucontext first. 476 477 if (sig == SIGPIPE || sig == SIGXFSZ) { 478 // allow chained handler to go first 479 if (os::Bsd::chained_handler(sig, info, ucVoid)) { 480 return true; 481 } else { 482 // Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219 483 return true; 484 } 485 } 486 487 JavaThread* thread = NULL; 488 VMThread* vmthread = NULL; 489 if (os::Bsd::signal_handlers_are_installed) { 490 if (t != NULL ){ 491 if(t->is_Java_thread()) { 492 thread = (JavaThread*)t; 493 } 494 else if(t->is_VM_thread()){ 495 vmthread = (VMThread *)t; 496 } 497 } 498 } 499/* 500 NOTE: does not seem to work on bsd. 501 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) { 502 // can't decode this kind of signal 503 info = NULL; 504 } else { 505 assert(sig == info->si_signo, "bad siginfo"); 506 } 507*/ 508 // decide if this trap can be handled by a stub 509 address stub = NULL; 510 511 address pc = NULL; 512 513 //%note os_trap_1 514 if (info != NULL && uc != NULL && thread != NULL) { 515 pc = (address) os::Bsd::ucontext_get_pc(uc); 516 517 if (StubRoutines::is_safefetch_fault(pc)) { 518 os::Bsd::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc)); 519 return 1; 520 } 521 522 // Handle ALL stack overflow variations here 523 if (sig == SIGSEGV || sig == SIGBUS) { 524 address addr = (address) info->si_addr; 525 526 // check if fault address is within thread stack 527 if (thread->on_local_stack(addr)) { 528 // stack overflow 529 if (thread->in_stack_yellow_reserved_zone(addr)) { 530 if (thread->thread_state() == _thread_in_Java) { 531 if (thread->in_stack_reserved_zone(addr)) { 532 frame fr; 533 if (os::Bsd::get_frame_at_stack_banging_point(thread, uc, &fr)) { 534 assert(fr.is_java_frame(), "Must be a Java frame"); 535 frame activation = SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr); 536 if (activation.sp() != NULL) { 537 thread->disable_stack_reserved_zone(); 538 if (activation.is_interpreted_frame()) { 539 thread->set_reserved_stack_activation((address)( 540 activation.fp() + frame::interpreter_frame_initial_sp_offset)); 541 } else { 542 thread->set_reserved_stack_activation((address)activation.unextended_sp()); 543 } 544 return 1; 545 } 546 } 547 } 548 // Throw a stack overflow exception. Guard pages will be reenabled 549 // while unwinding the stack. 550 thread->disable_stack_yellow_reserved_zone(); 551 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); 552 } else { 553 // Thread was in the vm or native code. Return and try to finish. 554 thread->disable_stack_yellow_reserved_zone(); 555 return 1; 556 } 557 } else if (thread->in_stack_red_zone(addr)) { 558 // Fatal red zone violation. Disable the guard pages and fall through 559 // to handle_unexpected_exception way down below. 560 thread->disable_stack_red_zone(); 561 tty->print_raw_cr("An irrecoverable stack overflow has occurred."); 562 } 563 } 564 } 565 566 if ((sig == SIGSEGV || sig == SIGBUS) && VM_Version::is_cpuinfo_segv_addr(pc)) { 567 // Verify that OS save/restore AVX registers. 568 stub = VM_Version::cpuinfo_cont_addr(); 569 } 570 571 // We test if stub is already set (by the stack overflow code 572 // above) so it is not overwritten by the code that follows. This 573 // check is not required on other platforms, because on other 574 // platforms we check for SIGSEGV only or SIGBUS only, where here 575 // we have to check for both SIGSEGV and SIGBUS. 576 if (thread->thread_state() == _thread_in_Java && stub == NULL) { 577 // Java thread running in Java code => find exception handler if any 578 // a fault inside compiled code, the interpreter, or a stub 579 580 if ((sig == SIGSEGV || sig == SIGBUS) && os::is_poll_address((address)info->si_addr)) { 581 stub = SharedRuntime::get_poll_stub(pc); 582#if defined(__APPLE__) 583 // 32-bit Darwin reports a SIGBUS for nearly all memory access exceptions. 584 // 64-bit Darwin may also use a SIGBUS (seen with compressed oops). 585 // Catching SIGBUS here prevents the implicit SIGBUS NULL check below from 586 // being called, so only do so if the implicit NULL check is not necessary. 587 } else if (sig == SIGBUS && MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { 588#else 589 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) { 590#endif 591 // BugId 4454115: A read from a MappedByteBuffer can fault 592 // here if the underlying file has been truncated. 593 // Do not crash the VM in such a case. 594 CodeBlob* cb = CodeCache::find_blob_unsafe(pc); 595 CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL; 596 if (nm != NULL && nm->has_unsafe_access()) { 597 address next_pc = Assembler::locate_next_instruction(pc); 598 stub = SharedRuntime::handle_unsafe_access(thread, next_pc); 599 } 600 } 601 else 602 603#ifdef AMD64 604 if (sig == SIGFPE && 605 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) { 606 stub = 607 SharedRuntime:: 608 continuation_for_implicit_exception(thread, 609 pc, 610 SharedRuntime:: 611 IMPLICIT_DIVIDE_BY_ZERO); 612#ifdef __APPLE__ 613 } else if (sig == SIGFPE && info->si_code == FPE_NOOP) { 614 int op = pc[0]; 615 616 // Skip REX 617 if ((pc[0] & 0xf0) == 0x40) { 618 op = pc[1]; 619 } else { 620 op = pc[0]; 621 } 622 623 // Check for IDIV 624 if (op == 0xF7) { 625 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime:: IMPLICIT_DIVIDE_BY_ZERO); 626 } else { 627 // TODO: handle more cases if we are using other x86 instructions 628 // that can generate SIGFPE signal. 629 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); 630 fatal("please update this code."); 631 } 632#endif /* __APPLE__ */ 633 634#else 635 if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) { 636 // HACK: si_code does not work on bsd 2.2.12-20!!! 637 int op = pc[0]; 638 if (op == 0xDB) { 639 // FIST 640 // TODO: The encoding of D2I in i486.ad can cause an exception 641 // prior to the fist instruction if there was an invalid operation 642 // pending. We want to dismiss that exception. From the win_32 643 // side it also seems that if it really was the fist causing 644 // the exception that we do the d2i by hand with different 645 // rounding. Seems kind of weird. 646 // NOTE: that we take the exception at the NEXT floating point instruction. 647 assert(pc[0] == 0xDB, "not a FIST opcode"); 648 assert(pc[1] == 0x14, "not a FIST opcode"); 649 assert(pc[2] == 0x24, "not a FIST opcode"); 650 return true; 651 } else if (op == 0xF7) { 652 // IDIV 653 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); 654 } else { 655 // TODO: handle more cases if we are using other x86 instructions 656 // that can generate SIGFPE signal on bsd. 657 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); 658 fatal("please update this code."); 659 } 660#endif // AMD64 661 } else if ((sig == SIGSEGV || sig == SIGBUS) && 662 !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { 663 // Determination of interpreter/vtable stub/compiled code null exception 664 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 665 } 666 } else if (thread->thread_state() == _thread_in_vm && 667 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */ 668 thread->doing_unsafe_access()) { 669 address next_pc = Assembler::locate_next_instruction(pc); 670 stub = SharedRuntime::handle_unsafe_access(thread, next_pc); 671 } 672 673 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in 674 // and the heap gets shrunk before the field access. 675 if ((sig == SIGSEGV) || (sig == SIGBUS)) { 676 address addr = JNI_FastGetField::find_slowcase_pc(pc); 677 if (addr != (address)-1) { 678 stub = addr; 679 } 680 } 681 682 // Check to see if we caught the safepoint code in the 683 // process of write protecting the memory serialization page. 684 // It write enables the page immediately after protecting it 685 // so we can just return to retry the write. 686 if ((sig == SIGSEGV || sig == SIGBUS) && 687 os::is_memory_serialize_page(thread, (address) info->si_addr)) { 688 // Block current thread until the memory serialize page permission restored. 689 os::block_on_serialize_page_trap(); 690 return true; 691 } 692 } 693 694#ifndef AMD64 695 // Execution protection violation 696 // 697 // This should be kept as the last step in the triage. We don't 698 // have a dedicated trap number for a no-execute fault, so be 699 // conservative and allow other handlers the first shot. 700 // 701 // Note: We don't test that info->si_code == SEGV_ACCERR here. 702 // this si_code is so generic that it is almost meaningless; and 703 // the si_code for this condition may change in the future. 704 // Furthermore, a false-positive should be harmless. 705 if (UnguardOnExecutionViolation > 0 && 706 (sig == SIGSEGV || sig == SIGBUS) && 707 uc->context_trapno == trap_page_fault) { 708 int page_size = os::vm_page_size(); 709 address addr = (address) info->si_addr; 710 address pc = os::Bsd::ucontext_get_pc(uc); 711 // Make sure the pc and the faulting address are sane. 712 // 713 // If an instruction spans a page boundary, and the page containing 714 // the beginning of the instruction is executable but the following 715 // page is not, the pc and the faulting address might be slightly 716 // different - we still want to unguard the 2nd page in this case. 717 // 718 // 15 bytes seems to be a (very) safe value for max instruction size. 719 bool pc_is_near_addr = 720 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15); 721 bool instr_spans_page_boundary = 722 (align_down((intptr_t) pc ^ (intptr_t) addr, 723 (intptr_t) page_size) > 0); 724 725 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) { 726 static volatile address last_addr = 727 (address) os::non_memory_address_word(); 728 729 // In conservative mode, don't unguard unless the address is in the VM 730 if (addr != last_addr && 731 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) { 732 733 // Set memory to RWX and retry 734 address page_start = align_down(addr, page_size); 735 bool res = os::protect_memory((char*) page_start, page_size, 736 os::MEM_PROT_RWX); 737 738 log_debug(os)("Execution protection violation " 739 "at " INTPTR_FORMAT 740 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", p2i(addr), 741 p2i(page_start), (res ? "success" : "failed"), errno); 742 stub = pc; 743 744 // Set last_addr so if we fault again at the same address, we don't end 745 // up in an endless loop. 746 // 747 // There are two potential complications here. Two threads trapping at 748 // the same address at the same time could cause one of the threads to 749 // think it already unguarded, and abort the VM. Likely very rare. 750 // 751 // The other race involves two threads alternately trapping at 752 // different addresses and failing to unguard the page, resulting in 753 // an endless loop. This condition is probably even more unlikely than 754 // the first. 755 // 756 // Although both cases could be avoided by using locks or thread local 757 // last_addr, these solutions are unnecessary complication: this 758 // handler is a best-effort safety net, not a complete solution. It is 759 // disabled by default and should only be used as a workaround in case 760 // we missed any no-execute-unsafe VM code. 761 762 last_addr = addr; 763 } 764 } 765 } 766#endif // !AMD64 767 768 if (stub != NULL) { 769 // save all thread context in case we need to restore it 770 if (thread != NULL) thread->set_saved_exception_pc(pc); 771 772 os::Bsd::ucontext_set_pc(uc, stub); 773 return true; 774 } 775 776 // signal-chaining 777 if (os::Bsd::chained_handler(sig, info, ucVoid)) { 778 return true; 779 } 780 781 if (!abort_if_unrecognized) { 782 // caller wants another chance, so give it to him 783 return false; 784 } 785 786 if (pc == NULL && uc != NULL) { 787 pc = os::Bsd::ucontext_get_pc(uc); 788 } 789 790 // unmask current signal 791 sigset_t newset; 792 sigemptyset(&newset); 793 sigaddset(&newset, sig); 794 sigprocmask(SIG_UNBLOCK, &newset, NULL); 795 796 VMError::report_and_die(t, sig, pc, info, ucVoid); 797 798 ShouldNotReachHere(); 799 return false; 800} 801 802// From solaris_i486.s ported to bsd_i486.s 803extern "C" void fixcw(); 804 805void os::Bsd::init_thread_fpu_state(void) { 806#ifndef AMD64 807 // Set fpu to 53 bit precision. This happens too early to use a stub. 808 fixcw(); 809#endif // !AMD64 810} 811 812 813// Check that the bsd kernel version is 2.4 or higher since earlier 814// versions do not support SSE without patches. 815bool os::supports_sse() { 816 return true; 817} 818 819bool os::is_allocatable(size_t bytes) { 820#ifdef AMD64 821 // unused on amd64? 822 return true; 823#else 824 825 if (bytes < 2 * G) { 826 return true; 827 } 828 829 char* addr = reserve_memory(bytes, NULL); 830 831 if (addr != NULL) { 832 release_memory(addr, bytes); 833 } 834 835 return addr != NULL; 836#endif // AMD64 837} 838 839//////////////////////////////////////////////////////////////////////////////// 840// thread stack 841 842// Minimum usable stack sizes required to get to user code. Space for 843// HotSpot guard pages is added later. 844size_t os::Posix::_compiler_thread_min_stack_allowed = 48 * K; 845size_t os::Posix::_java_thread_min_stack_allowed = 48 * K; 846#ifdef _LP64 847size_t os::Posix::_vm_internal_thread_min_stack_allowed = 64 * K; 848#else 849size_t os::Posix::_vm_internal_thread_min_stack_allowed = (48 DEBUG_ONLY(+ 4)) * K; 850#endif // _LP64 851 852#ifndef AMD64 853#ifdef __GNUC__ 854#define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;}) 855#endif 856#endif // AMD64 857 858// return default stack size for thr_type 859size_t os::Posix::default_stack_size(os::ThreadType thr_type) { 860 // default stack size (compiler thread needs larger stack) 861#ifdef AMD64 862 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M); 863#else 864 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K); 865#endif // AMD64 866 return s; 867} 868 869 870// Java thread: 871// 872// Low memory addresses 873// +------------------------+ 874// | |\ Java thread created by VM does not have glibc 875// | glibc guard page | - guard, attached Java thread usually has 876// | |/ 1 glibc guard page. 877// P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 878// | |\ 879// | HotSpot Guard Pages | - red, yellow and reserved pages 880// | |/ 881// +------------------------+ JavaThread::stack_reserved_zone_base() 882// | |\ 883// | Normal Stack | - 884// | |/ 885// P2 +------------------------+ Thread::stack_base() 886// 887// Non-Java thread: 888// 889// Low memory addresses 890// +------------------------+ 891// | |\ 892// | glibc guard page | - usually 1 page 893// | |/ 894// P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 895// | |\ 896// | Normal Stack | - 897// | |/ 898// P2 +------------------------+ Thread::stack_base() 899// 900// ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from 901// pthread_attr_getstack() 902 903static void current_stack_region(address * bottom, size_t * size) { 904#ifdef __APPLE__ 905 pthread_t self = pthread_self(); 906 void *stacktop = pthread_get_stackaddr_np(self); 907 *size = pthread_get_stacksize_np(self); 908 // workaround for OS X 10.9.0 (Mavericks) 909 // pthread_get_stacksize_np returns 128 pages even though the actual size is 2048 pages 910 if (pthread_main_np() == 1) { 911 if ((*size) < (DEFAULT_MAIN_THREAD_STACK_PAGES * (size_t)getpagesize())) { 912 char kern_osrelease[256]; 913 size_t kern_osrelease_size = sizeof(kern_osrelease); 914 int ret = sysctlbyname("kern.osrelease", kern_osrelease, &kern_osrelease_size, NULL, 0); 915 if (ret == 0) { 916 // get the major number, atoi will ignore the minor amd micro portions of the version string 917 if (atoi(kern_osrelease) >= OS_X_10_9_0_KERNEL_MAJOR_VERSION) { 918 *size = (DEFAULT_MAIN_THREAD_STACK_PAGES*getpagesize()); 919 } 920 } 921 } 922 } 923 *bottom = (address) stacktop - *size; 924#elif defined(__OpenBSD__) 925 stack_t ss; 926 int rslt = pthread_stackseg_np(pthread_self(), &ss); 927 928 if (rslt != 0) 929 fatal("pthread_stackseg_np failed with error = %d", rslt); 930 931 *bottom = (address)((char *)ss.ss_sp - ss.ss_size); 932 *size = ss.ss_size; 933#else 934 pthread_attr_t attr; 935 936 int rslt = pthread_attr_init(&attr); 937 938 // JVM needs to know exact stack location, abort if it fails 939 if (rslt != 0) 940 fatal("pthread_attr_init failed with error = %d", rslt); 941 942 rslt = pthread_attr_get_np(pthread_self(), &attr); 943 944 if (rslt != 0) 945 fatal("pthread_attr_get_np failed with error = %d", rslt); 946 947 if (pthread_attr_getstackaddr(&attr, (void **)bottom) != 0 || 948 pthread_attr_getstacksize(&attr, size) != 0) { 949 fatal("Can not locate current stack attributes!"); 950 } 951 952 pthread_attr_destroy(&attr); 953#endif 954 assert(os::current_stack_pointer() >= *bottom && 955 os::current_stack_pointer() < *bottom + *size, "just checking"); 956} 957 958address os::current_stack_base() { 959 address bottom; 960 size_t size; 961 current_stack_region(&bottom, &size); 962 return (bottom + size); 963} 964 965size_t os::current_stack_size() { 966 // stack size includes normal stack and HotSpot guard pages 967 address bottom; 968 size_t size; 969 current_stack_region(&bottom, &size); 970 return size; 971} 972 973///////////////////////////////////////////////////////////////////////////// 974// helper functions for fatal error handler 975 976void os::print_context(outputStream *st, const void *context) { 977 if (context == NULL) return; 978 979 const ucontext_t *uc = (const ucontext_t*)context; 980 st->print_cr("Registers:"); 981#ifdef AMD64 982 st->print( "RAX=" INTPTR_FORMAT, uc->context_rax); 983 st->print(", RBX=" INTPTR_FORMAT, uc->context_rbx); 984 st->print(", RCX=" INTPTR_FORMAT, uc->context_rcx); 985 st->print(", RDX=" INTPTR_FORMAT, uc->context_rdx); 986 st->cr(); 987 st->print( "RSP=" INTPTR_FORMAT, uc->context_rsp); 988 st->print(", RBP=" INTPTR_FORMAT, uc->context_rbp); 989 st->print(", RSI=" INTPTR_FORMAT, uc->context_rsi); 990 st->print(", RDI=" INTPTR_FORMAT, uc->context_rdi); 991 st->cr(); 992 st->print( "R8 =" INTPTR_FORMAT, uc->context_r8); 993 st->print(", R9 =" INTPTR_FORMAT, uc->context_r9); 994 st->print(", R10=" INTPTR_FORMAT, uc->context_r10); 995 st->print(", R11=" INTPTR_FORMAT, uc->context_r11); 996 st->cr(); 997 st->print( "R12=" INTPTR_FORMAT, uc->context_r12); 998 st->print(", R13=" INTPTR_FORMAT, uc->context_r13); 999 st->print(", R14=" INTPTR_FORMAT, uc->context_r14); 1000 st->print(", R15=" INTPTR_FORMAT, uc->context_r15); 1001 st->cr(); 1002 st->print( "RIP=" INTPTR_FORMAT, uc->context_rip); 1003 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_flags); 1004 st->print(", ERR=" INTPTR_FORMAT, uc->context_err); 1005 st->cr(); 1006 st->print(" TRAPNO=" INTPTR_FORMAT, uc->context_trapno); 1007#else 1008 st->print( "EAX=" INTPTR_FORMAT, uc->context_eax); 1009 st->print(", EBX=" INTPTR_FORMAT, uc->context_ebx); 1010 st->print(", ECX=" INTPTR_FORMAT, uc->context_ecx); 1011 st->print(", EDX=" INTPTR_FORMAT, uc->context_edx); 1012 st->cr(); 1013 st->print( "ESP=" INTPTR_FORMAT, uc->context_esp); 1014 st->print(", EBP=" INTPTR_FORMAT, uc->context_ebp); 1015 st->print(", ESI=" INTPTR_FORMAT, uc->context_esi); 1016 st->print(", EDI=" INTPTR_FORMAT, uc->context_edi); 1017 st->cr(); 1018 st->print( "EIP=" INTPTR_FORMAT, uc->context_eip); 1019 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_eflags); 1020#endif // AMD64 1021 st->cr(); 1022 st->cr(); 1023 1024 intptr_t *sp = (intptr_t *)os::Bsd::ucontext_get_sp(uc); 1025 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp); 1026 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t)); 1027 st->cr(); 1028 1029 // Note: it may be unsafe to inspect memory near pc. For example, pc may 1030 // point to garbage if entry point in an nmethod is corrupted. Leave 1031 // this at the end, and hope for the best. 1032 address pc = os::Bsd::ucontext_get_pc(uc); 1033 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc); 1034 print_hex_dump(st, pc - 32, pc + 32, sizeof(char)); 1035} 1036 1037void os::print_register_info(outputStream *st, const void *context) { 1038 if (context == NULL) return; 1039 1040 const ucontext_t *uc = (const ucontext_t*)context; 1041 1042 st->print_cr("Register to memory mapping:"); 1043 st->cr(); 1044 1045 // this is horrendously verbose but the layout of the registers in the 1046 // context does not match how we defined our abstract Register set, so 1047 // we can't just iterate through the gregs area 1048 1049 // this is only for the "general purpose" registers 1050 1051#ifdef AMD64 1052 st->print("RAX="); print_location(st, uc->context_rax); 1053 st->print("RBX="); print_location(st, uc->context_rbx); 1054 st->print("RCX="); print_location(st, uc->context_rcx); 1055 st->print("RDX="); print_location(st, uc->context_rdx); 1056 st->print("RSP="); print_location(st, uc->context_rsp); 1057 st->print("RBP="); print_location(st, uc->context_rbp); 1058 st->print("RSI="); print_location(st, uc->context_rsi); 1059 st->print("RDI="); print_location(st, uc->context_rdi); 1060 st->print("R8 ="); print_location(st, uc->context_r8); 1061 st->print("R9 ="); print_location(st, uc->context_r9); 1062 st->print("R10="); print_location(st, uc->context_r10); 1063 st->print("R11="); print_location(st, uc->context_r11); 1064 st->print("R12="); print_location(st, uc->context_r12); 1065 st->print("R13="); print_location(st, uc->context_r13); 1066 st->print("R14="); print_location(st, uc->context_r14); 1067 st->print("R15="); print_location(st, uc->context_r15); 1068#else 1069 st->print("EAX="); print_location(st, uc->context_eax); 1070 st->print("EBX="); print_location(st, uc->context_ebx); 1071 st->print("ECX="); print_location(st, uc->context_ecx); 1072 st->print("EDX="); print_location(st, uc->context_edx); 1073 st->print("ESP="); print_location(st, uc->context_esp); 1074 st->print("EBP="); print_location(st, uc->context_ebp); 1075 st->print("ESI="); print_location(st, uc->context_esi); 1076 st->print("EDI="); print_location(st, uc->context_edi); 1077#endif // AMD64 1078 1079 st->cr(); 1080} 1081 1082void os::setup_fpu() { 1083#ifndef AMD64 1084 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std(); 1085 __asm__ volatile ( "fldcw (%0)" : 1086 : "r" (fpu_cntrl) : "memory"); 1087#endif // !AMD64 1088} 1089 1090#ifndef PRODUCT 1091void os::verify_stack_alignment() { 1092} 1093#endif 1094 1095int os::extra_bang_size_in_bytes() { 1096 // JDK-8050147 requires the full cache line bang for x86. 1097 return VM_Version::L1_line_size(); 1098} 1099