os_linux_x86.cpp revision 3864:f34d701e952e
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_linux.h" 34#include "memory/allocation.inline.hpp" 35#include "mutex_linux.inline.hpp" 36#include "nativeInst_x86.hpp" 37#include "os_share_linux.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/thread.inline.hpp" 52#include "runtime/timer.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# include <ucontext.h> 76# include <fpu_control.h> 77 78#ifdef AMD64 79#define REG_SP REG_RSP 80#define REG_PC REG_RIP 81#define REG_FP REG_RBP 82#define SPELL_REG_SP "rsp" 83#define SPELL_REG_FP "rbp" 84#else 85#define REG_SP REG_UESP 86#define REG_PC REG_EIP 87#define REG_FP REG_EBP 88#define SPELL_REG_SP "esp" 89#define SPELL_REG_FP "ebp" 90#endif // AMD64 91 92address os::current_stack_pointer() { 93#ifdef SPARC_WORKS 94 register void *esp; 95 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp)); 96 return (address) ((char*)esp + sizeof(long)*2); 97#else 98 register void *esp __asm__ (SPELL_REG_SP); 99 return (address) esp; 100#endif 101} 102 103char* os::non_memory_address_word() { 104 // Must never look like an address returned by reserve_memory, 105 // even in its subfields (as defined by the CPU immediate fields, 106 // if the CPU splits constants across multiple instructions). 107 108 return (char*) -1; 109} 110 111void os::initialize_thread(Thread* thr) { 112// Nothing to do. 113} 114 115address os::Linux::ucontext_get_pc(ucontext_t * uc) { 116 return (address)uc->uc_mcontext.gregs[REG_PC]; 117} 118 119intptr_t* os::Linux::ucontext_get_sp(ucontext_t * uc) { 120 return (intptr_t*)uc->uc_mcontext.gregs[REG_SP]; 121} 122 123intptr_t* os::Linux::ucontext_get_fp(ucontext_t * uc) { 124 return (intptr_t*)uc->uc_mcontext.gregs[REG_FP]; 125} 126 127// For Forte Analyzer AsyncGetCallTrace profiling support - thread 128// is currently interrupted by SIGPROF. 129// os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal 130// frames. Currently we don't do that on Linux, so it's the same as 131// os::fetch_frame_from_context(). 132ExtendedPC os::Linux::fetch_frame_from_ucontext(Thread* thread, 133 ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) { 134 135 assert(thread != NULL, "just checking"); 136 assert(ret_sp != NULL, "just checking"); 137 assert(ret_fp != NULL, "just checking"); 138 139 return os::fetch_frame_from_context(uc, ret_sp, ret_fp); 140} 141 142ExtendedPC os::fetch_frame_from_context(void* ucVoid, 143 intptr_t** ret_sp, intptr_t** ret_fp) { 144 145 ExtendedPC epc; 146 ucontext_t* uc = (ucontext_t*)ucVoid; 147 148 if (uc != NULL) { 149 epc = ExtendedPC(os::Linux::ucontext_get_pc(uc)); 150 if (ret_sp) *ret_sp = os::Linux::ucontext_get_sp(uc); 151 if (ret_fp) *ret_fp = os::Linux::ucontext_get_fp(uc); 152 } else { 153 // construct empty ExtendedPC for return value checking 154 epc = ExtendedPC(NULL); 155 if (ret_sp) *ret_sp = (intptr_t *)NULL; 156 if (ret_fp) *ret_fp = (intptr_t *)NULL; 157 } 158 159 return epc; 160} 161 162frame os::fetch_frame_from_context(void* ucVoid) { 163 intptr_t* sp; 164 intptr_t* fp; 165 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp); 166 return frame(sp, fp, epc.pc()); 167} 168 169// By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get 170// turned off by -fomit-frame-pointer, 171frame os::get_sender_for_C_frame(frame* fr) { 172 return frame(fr->sender_sp(), fr->link(), fr->sender_pc()); 173} 174 175intptr_t* _get_previous_fp() { 176#ifdef SPARC_WORKS 177 register intptr_t **ebp; 178 __asm__("mov %%"SPELL_REG_FP", %0":"=r"(ebp)); 179#else 180 register intptr_t **ebp __asm__ (SPELL_REG_FP); 181#endif 182 return (intptr_t*) *ebp; // we want what it points to. 183} 184 185 186frame os::current_frame() { 187 intptr_t* fp = _get_previous_fp(); 188 frame myframe((intptr_t*)os::current_stack_pointer(), 189 (intptr_t*)fp, 190 CAST_FROM_FN_PTR(address, os::current_frame)); 191 if (os::is_first_C_frame(&myframe)) { 192 // stack is not walkable 193 return frame(NULL, NULL, NULL); 194 } else { 195 return os::get_sender_for_C_frame(&myframe); 196 } 197} 198 199// Utility functions 200 201// From IA32 System Programming Guide 202enum { 203 trap_page_fault = 0xE 204}; 205 206extern "C" void Fetch32PFI () ; 207extern "C" void Fetch32Resume () ; 208#ifdef AMD64 209extern "C" void FetchNPFI () ; 210extern "C" void FetchNResume () ; 211#endif // AMD64 212 213extern "C" JNIEXPORT int 214JVM_handle_linux_signal(int sig, 215 siginfo_t* info, 216 void* ucVoid, 217 int abort_if_unrecognized) { 218 ucontext_t* uc = (ucontext_t*) ucVoid; 219 220 Thread* t = ThreadLocalStorage::get_thread_slow(); 221 222 SignalHandlerMark shm(t); 223 224 // Note: it's not uncommon that JNI code uses signal/sigset to install 225 // then restore certain signal handler (e.g. to temporarily block SIGPIPE, 226 // or have a SIGILL handler when detecting CPU type). When that happens, 227 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To 228 // avoid unnecessary crash when libjsig is not preloaded, try handle signals 229 // that do not require siginfo/ucontext first. 230 231 if (sig == SIGPIPE || sig == SIGXFSZ) { 232 // allow chained handler to go first 233 if (os::Linux::chained_handler(sig, info, ucVoid)) { 234 return true; 235 } else { 236 if (PrintMiscellaneous && (WizardMode || Verbose)) { 237 char buf[64]; 238 warning("Ignoring %s - see bugs 4229104 or 646499219", 239 os::exception_name(sig, buf, sizeof(buf))); 240 } 241 return true; 242 } 243 } 244 245 JavaThread* thread = NULL; 246 VMThread* vmthread = NULL; 247 if (os::Linux::signal_handlers_are_installed) { 248 if (t != NULL ){ 249 if(t->is_Java_thread()) { 250 thread = (JavaThread*)t; 251 } 252 else if(t->is_VM_thread()){ 253 vmthread = (VMThread *)t; 254 } 255 } 256 } 257/* 258 NOTE: does not seem to work on linux. 259 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) { 260 // can't decode this kind of signal 261 info = NULL; 262 } else { 263 assert(sig == info->si_signo, "bad siginfo"); 264 } 265*/ 266 // decide if this trap can be handled by a stub 267 address stub = NULL; 268 269 address pc = NULL; 270 271 //%note os_trap_1 272 if (info != NULL && uc != NULL && thread != NULL) { 273 pc = (address) os::Linux::ucontext_get_pc(uc); 274 275 if (pc == (address) Fetch32PFI) { 276 uc->uc_mcontext.gregs[REG_PC] = intptr_t(Fetch32Resume) ; 277 return 1 ; 278 } 279#ifdef AMD64 280 if (pc == (address) FetchNPFI) { 281 uc->uc_mcontext.gregs[REG_PC] = intptr_t (FetchNResume) ; 282 return 1 ; 283 } 284#endif // AMD64 285 286 // Handle ALL stack overflow variations here 287 if (sig == SIGSEGV) { 288 address addr = (address) info->si_addr; 289 290 // check if fault address is within thread stack 291 if (addr < thread->stack_base() && 292 addr >= thread->stack_base() - thread->stack_size()) { 293 // stack overflow 294 if (thread->in_stack_yellow_zone(addr)) { 295 thread->disable_stack_yellow_zone(); 296 if (thread->thread_state() == _thread_in_Java) { 297 // Throw a stack overflow exception. Guard pages will be reenabled 298 // while unwinding the stack. 299 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); 300 } else { 301 // Thread was in the vm or native code. Return and try to finish. 302 return 1; 303 } 304 } else if (thread->in_stack_red_zone(addr)) { 305 // Fatal red zone violation. Disable the guard pages and fall through 306 // to handle_unexpected_exception way down below. 307 thread->disable_stack_red_zone(); 308 tty->print_raw_cr("An irrecoverable stack overflow has occurred."); 309 } else { 310 // Accessing stack address below sp may cause SEGV if current 311 // thread has MAP_GROWSDOWN stack. This should only happen when 312 // current thread was created by user code with MAP_GROWSDOWN flag 313 // and then attached to VM. See notes in os_linux.cpp. 314 if (thread->osthread()->expanding_stack() == 0) { 315 thread->osthread()->set_expanding_stack(); 316 if (os::Linux::manually_expand_stack(thread, addr)) { 317 thread->osthread()->clear_expanding_stack(); 318 return 1; 319 } 320 thread->osthread()->clear_expanding_stack(); 321 } else { 322 fatal("recursive segv. expanding stack."); 323 } 324 } 325 } 326 } 327 328 if (thread->thread_state() == _thread_in_Java) { 329 // Java thread running in Java code => find exception handler if any 330 // a fault inside compiled code, the interpreter, or a stub 331 332 if (sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) { 333 stub = SharedRuntime::get_poll_stub(pc); 334 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) { 335 // BugId 4454115: A read from a MappedByteBuffer can fault 336 // here if the underlying file has been truncated. 337 // Do not crash the VM in such a case. 338 CodeBlob* cb = CodeCache::find_blob_unsafe(pc); 339 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL; 340 if (nm != NULL && nm->has_unsafe_access()) { 341 stub = StubRoutines::handler_for_unsafe_access(); 342 } 343 } 344 else 345 346#ifdef AMD64 347 if (sig == SIGFPE && 348 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) { 349 stub = 350 SharedRuntime:: 351 continuation_for_implicit_exception(thread, 352 pc, 353 SharedRuntime:: 354 IMPLICIT_DIVIDE_BY_ZERO); 355#else 356 if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) { 357 // HACK: si_code does not work on linux 2.2.12-20!!! 358 int op = pc[0]; 359 if (op == 0xDB) { 360 // FIST 361 // TODO: The encoding of D2I in i486.ad can cause an exception 362 // prior to the fist instruction if there was an invalid operation 363 // pending. We want to dismiss that exception. From the win_32 364 // side it also seems that if it really was the fist causing 365 // the exception that we do the d2i by hand with different 366 // rounding. Seems kind of weird. 367 // NOTE: that we take the exception at the NEXT floating point instruction. 368 assert(pc[0] == 0xDB, "not a FIST opcode"); 369 assert(pc[1] == 0x14, "not a FIST opcode"); 370 assert(pc[2] == 0x24, "not a FIST opcode"); 371 return true; 372 } else if (op == 0xF7) { 373 // IDIV 374 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); 375 } else { 376 // TODO: handle more cases if we are using other x86 instructions 377 // that can generate SIGFPE signal on linux. 378 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); 379 fatal("please update this code."); 380 } 381#endif // AMD64 382 } else if (sig == SIGSEGV && 383 !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { 384 // Determination of interpreter/vtable stub/compiled code null exception 385 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 386 } 387 } else if (thread->thread_state() == _thread_in_vm && 388 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */ 389 thread->doing_unsafe_access()) { 390 stub = StubRoutines::handler_for_unsafe_access(); 391 } 392 393 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in 394 // and the heap gets shrunk before the field access. 395 if ((sig == SIGSEGV) || (sig == SIGBUS)) { 396 address addr = JNI_FastGetField::find_slowcase_pc(pc); 397 if (addr != (address)-1) { 398 stub = addr; 399 } 400 } 401 402 // Check to see if we caught the safepoint code in the 403 // process of write protecting the memory serialization page. 404 // It write enables the page immediately after protecting it 405 // so we can just return to retry the write. 406 if ((sig == SIGSEGV) && 407 os::is_memory_serialize_page(thread, (address) info->si_addr)) { 408 // Block current thread until the memory serialize page permission restored. 409 os::block_on_serialize_page_trap(); 410 return true; 411 } 412 } 413 414#ifndef AMD64 415 // Execution protection violation 416 // 417 // This should be kept as the last step in the triage. We don't 418 // have a dedicated trap number for a no-execute fault, so be 419 // conservative and allow other handlers the first shot. 420 // 421 // Note: We don't test that info->si_code == SEGV_ACCERR here. 422 // this si_code is so generic that it is almost meaningless; and 423 // the si_code for this condition may change in the future. 424 // Furthermore, a false-positive should be harmless. 425 if (UnguardOnExecutionViolation > 0 && 426 (sig == SIGSEGV || sig == SIGBUS) && 427 uc->uc_mcontext.gregs[REG_TRAPNO] == trap_page_fault) { 428 int page_size = os::vm_page_size(); 429 address addr = (address) info->si_addr; 430 address pc = os::Linux::ucontext_get_pc(uc); 431 // Make sure the pc and the faulting address are sane. 432 // 433 // If an instruction spans a page boundary, and the page containing 434 // the beginning of the instruction is executable but the following 435 // page is not, the pc and the faulting address might be slightly 436 // different - we still want to unguard the 2nd page in this case. 437 // 438 // 15 bytes seems to be a (very) safe value for max instruction size. 439 bool pc_is_near_addr = 440 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15); 441 bool instr_spans_page_boundary = 442 (align_size_down((intptr_t) pc ^ (intptr_t) addr, 443 (intptr_t) page_size) > 0); 444 445 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) { 446 static volatile address last_addr = 447 (address) os::non_memory_address_word(); 448 449 // In conservative mode, don't unguard unless the address is in the VM 450 if (addr != last_addr && 451 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) { 452 453 // Set memory to RWX and retry 454 address page_start = 455 (address) align_size_down((intptr_t) addr, (intptr_t) page_size); 456 bool res = os::protect_memory((char*) page_start, page_size, 457 os::MEM_PROT_RWX); 458 459 if (PrintMiscellaneous && Verbose) { 460 char buf[256]; 461 jio_snprintf(buf, sizeof(buf), "Execution protection violation " 462 "at " INTPTR_FORMAT 463 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr, 464 page_start, (res ? "success" : "failed"), errno); 465 tty->print_raw_cr(buf); 466 } 467 stub = pc; 468 469 // Set last_addr so if we fault again at the same address, we don't end 470 // up in an endless loop. 471 // 472 // There are two potential complications here. Two threads trapping at 473 // the same address at the same time could cause one of the threads to 474 // think it already unguarded, and abort the VM. Likely very rare. 475 // 476 // The other race involves two threads alternately trapping at 477 // different addresses and failing to unguard the page, resulting in 478 // an endless loop. This condition is probably even more unlikely than 479 // the first. 480 // 481 // Although both cases could be avoided by using locks or thread local 482 // last_addr, these solutions are unnecessary complication: this 483 // handler is a best-effort safety net, not a complete solution. It is 484 // disabled by default and should only be used as a workaround in case 485 // we missed any no-execute-unsafe VM code. 486 487 last_addr = addr; 488 } 489 } 490 } 491#endif // !AMD64 492 493 if (stub != NULL) { 494 // save all thread context in case we need to restore it 495 if (thread != NULL) thread->set_saved_exception_pc(pc); 496 497 uc->uc_mcontext.gregs[REG_PC] = (greg_t)stub; 498 return true; 499 } 500 501 // signal-chaining 502 if (os::Linux::chained_handler(sig, info, ucVoid)) { 503 return true; 504 } 505 506 if (!abort_if_unrecognized) { 507 // caller wants another chance, so give it to him 508 return false; 509 } 510 511 if (pc == NULL && uc != NULL) { 512 pc = os::Linux::ucontext_get_pc(uc); 513 } 514 515 // unmask current signal 516 sigset_t newset; 517 sigemptyset(&newset); 518 sigaddset(&newset, sig); 519 sigprocmask(SIG_UNBLOCK, &newset, NULL); 520 521 VMError err(t, sig, pc, info, ucVoid); 522 err.report_and_die(); 523 524 ShouldNotReachHere(); 525} 526 527void os::Linux::init_thread_fpu_state(void) { 528#ifndef AMD64 529 // set fpu to 53 bit precision 530 set_fpu_control_word(0x27f); 531#endif // !AMD64 532} 533 534int os::Linux::get_fpu_control_word(void) { 535#ifdef AMD64 536 return 0; 537#else 538 int fpu_control; 539 _FPU_GETCW(fpu_control); 540 return fpu_control & 0xffff; 541#endif // AMD64 542} 543 544void os::Linux::set_fpu_control_word(int fpu_control) { 545#ifndef AMD64 546 _FPU_SETCW(fpu_control); 547#endif // !AMD64 548} 549 550// Check that the linux kernel version is 2.4 or higher since earlier 551// versions do not support SSE without patches. 552bool os::supports_sse() { 553#ifdef AMD64 554 return true; 555#else 556 struct utsname uts; 557 if( uname(&uts) != 0 ) return false; // uname fails? 558 char *minor_string; 559 int major = strtol(uts.release,&minor_string,10); 560 int minor = strtol(minor_string+1,NULL,10); 561 bool result = (major > 2 || (major==2 && minor >= 4)); 562#ifndef PRODUCT 563 if (PrintMiscellaneous && Verbose) { 564 tty->print("OS version is %d.%d, which %s support SSE/SSE2\n", 565 major,minor, result ? "DOES" : "does NOT"); 566 } 567#endif 568 return result; 569#endif // AMD64 570} 571 572bool os::is_allocatable(size_t bytes) { 573#ifdef AMD64 574 // unused on amd64? 575 return true; 576#else 577 578 if (bytes < 2 * G) { 579 return true; 580 } 581 582 char* addr = reserve_memory(bytes, NULL); 583 584 if (addr != NULL) { 585 release_memory(addr, bytes); 586 } 587 588 return addr != NULL; 589#endif // AMD64 590} 591 592//////////////////////////////////////////////////////////////////////////////// 593// thread stack 594 595#ifdef AMD64 596size_t os::Linux::min_stack_allowed = 64 * K; 597 598// amd64: pthread on amd64 is always in floating stack mode 599bool os::Linux::supports_variable_stack_size() { return true; } 600#else 601size_t os::Linux::min_stack_allowed = (48 DEBUG_ONLY(+4))*K; 602 603#ifdef __GNUC__ 604#define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;}) 605#endif 606 607// Test if pthread library can support variable thread stack size. LinuxThreads 608// in fixed stack mode allocates 2M fixed slot for each thread. LinuxThreads 609// in floating stack mode and NPTL support variable stack size. 610bool os::Linux::supports_variable_stack_size() { 611 if (os::Linux::is_NPTL()) { 612 // NPTL, yes 613 return true; 614 615 } else { 616 // Note: We can't control default stack size when creating a thread. 617 // If we use non-default stack size (pthread_attr_setstacksize), both 618 // floating stack and non-floating stack LinuxThreads will return the 619 // same value. This makes it impossible to implement this function by 620 // detecting thread stack size directly. 621 // 622 // An alternative approach is to check %gs. Fixed-stack LinuxThreads 623 // do not use %gs, so its value is 0. Floating-stack LinuxThreads use 624 // %gs (either as LDT selector or GDT selector, depending on kernel) 625 // to access thread specific data. 626 // 627 // Note that %gs is a reserved glibc register since early 2001, so 628 // applications are not allowed to change its value (Ulrich Drepper from 629 // Redhat confirmed that all known offenders have been modified to use 630 // either %fs or TSD). In the worst case scenario, when VM is embedded in 631 // a native application that plays with %gs, we might see non-zero %gs 632 // even LinuxThreads is running in fixed stack mode. As the result, we'll 633 // return true and skip _thread_safety_check(), so we may not be able to 634 // detect stack-heap collisions. But otherwise it's harmless. 635 // 636#ifdef __GNUC__ 637 return (GET_GS() != 0); 638#else 639 return false; 640#endif 641 } 642} 643#endif // AMD64 644 645// return default stack size for thr_type 646size_t os::Linux::default_stack_size(os::ThreadType thr_type) { 647 // default stack size (compiler thread needs larger stack) 648#ifdef AMD64 649 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M); 650#else 651 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K); 652#endif // AMD64 653 return s; 654} 655 656size_t os::Linux::default_guard_size(os::ThreadType thr_type) { 657 // Creating guard page is very expensive. Java thread has HotSpot 658 // guard page, only enable glibc guard page for non-Java threads. 659 return (thr_type == java_thread ? 0 : page_size()); 660} 661 662// Java thread: 663// 664// Low memory addresses 665// +------------------------+ 666// | |\ JavaThread created by VM does not have glibc 667// | glibc guard page | - guard, attached Java thread usually has 668// | |/ 1 page glibc guard. 669// P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 670// | |\ 671// | HotSpot Guard Pages | - red and yellow pages 672// | |/ 673// +------------------------+ JavaThread::stack_yellow_zone_base() 674// | |\ 675// | Normal Stack | - 676// | |/ 677// P2 +------------------------+ Thread::stack_base() 678// 679// Non-Java thread: 680// 681// Low memory addresses 682// +------------------------+ 683// | |\ 684// | glibc guard page | - usually 1 page 685// | |/ 686// P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 687// | |\ 688// | Normal Stack | - 689// | |/ 690// P2 +------------------------+ Thread::stack_base() 691// 692// ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from 693// pthread_attr_getstack() 694 695static void current_stack_region(address * bottom, size_t * size) { 696 if (os::Linux::is_initial_thread()) { 697 // initial thread needs special handling because pthread_getattr_np() 698 // may return bogus value. 699 *bottom = os::Linux::initial_thread_stack_bottom(); 700 *size = os::Linux::initial_thread_stack_size(); 701 } else { 702 pthread_attr_t attr; 703 704 int rslt = pthread_getattr_np(pthread_self(), &attr); 705 706 // JVM needs to know exact stack location, abort if it fails 707 if (rslt != 0) { 708 if (rslt == ENOMEM) { 709 vm_exit_out_of_memory(0, "pthread_getattr_np"); 710 } else { 711 fatal(err_msg("pthread_getattr_np failed with errno = %d", rslt)); 712 } 713 } 714 715 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) { 716 fatal("Can not locate current stack attributes!"); 717 } 718 719 pthread_attr_destroy(&attr); 720 721 } 722 assert(os::current_stack_pointer() >= *bottom && 723 os::current_stack_pointer() < *bottom + *size, "just checking"); 724} 725 726address os::current_stack_base() { 727 address bottom; 728 size_t size; 729 current_stack_region(&bottom, &size); 730 return (bottom + size); 731} 732 733size_t os::current_stack_size() { 734 // stack size includes normal stack and HotSpot guard pages 735 address bottom; 736 size_t size; 737 current_stack_region(&bottom, &size); 738 return size; 739} 740 741///////////////////////////////////////////////////////////////////////////// 742// helper functions for fatal error handler 743 744void os::print_context(outputStream *st, void *context) { 745 if (context == NULL) return; 746 747 ucontext_t *uc = (ucontext_t*)context; 748 st->print_cr("Registers:"); 749#ifdef AMD64 750 st->print( "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]); 751 st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]); 752 st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]); 753 st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]); 754 st->cr(); 755 st->print( "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]); 756 st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]); 757 st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]); 758 st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]); 759 st->cr(); 760 st->print( "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]); 761 st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]); 762 st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]); 763 st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]); 764 st->cr(); 765 st->print( "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]); 766 st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]); 767 st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]); 768 st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]); 769 st->cr(); 770 st->print( "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]); 771 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EFL]); 772 st->print(", CSGSFS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_CSGSFS]); 773 st->print(", ERR=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ERR]); 774 st->cr(); 775 st->print(" TRAPNO=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_TRAPNO]); 776#else 777 st->print( "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EAX]); 778 st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBX]); 779 st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ECX]); 780 st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDX]); 781 st->cr(); 782 st->print( "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_UESP]); 783 st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBP]); 784 st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ESI]); 785 st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDI]); 786 st->cr(); 787 st->print( "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EIP]); 788 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EFL]); 789 st->print(", CR2=" INTPTR_FORMAT, uc->uc_mcontext.cr2); 790#endif // AMD64 791 st->cr(); 792 st->cr(); 793 794 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc); 795 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp); 796 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t)); 797 st->cr(); 798 799 // Note: it may be unsafe to inspect memory near pc. For example, pc may 800 // point to garbage if entry point in an nmethod is corrupted. Leave 801 // this at the end, and hope for the best. 802 address pc = os::Linux::ucontext_get_pc(uc); 803 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc); 804 print_hex_dump(st, pc - 32, pc + 32, sizeof(char)); 805} 806 807void os::print_register_info(outputStream *st, void *context) { 808 if (context == NULL) return; 809 810 ucontext_t *uc = (ucontext_t*)context; 811 812 st->print_cr("Register to memory mapping:"); 813 st->cr(); 814 815 // this is horrendously verbose but the layout of the registers in the 816 // context does not match how we defined our abstract Register set, so 817 // we can't just iterate through the gregs area 818 819 // this is only for the "general purpose" registers 820 821#ifdef AMD64 822 st->print("RAX="); print_location(st, uc->uc_mcontext.gregs[REG_RAX]); 823 st->print("RBX="); print_location(st, uc->uc_mcontext.gregs[REG_RBX]); 824 st->print("RCX="); print_location(st, uc->uc_mcontext.gregs[REG_RCX]); 825 st->print("RDX="); print_location(st, uc->uc_mcontext.gregs[REG_RDX]); 826 st->print("RSP="); print_location(st, uc->uc_mcontext.gregs[REG_RSP]); 827 st->print("RBP="); print_location(st, uc->uc_mcontext.gregs[REG_RBP]); 828 st->print("RSI="); print_location(st, uc->uc_mcontext.gregs[REG_RSI]); 829 st->print("RDI="); print_location(st, uc->uc_mcontext.gregs[REG_RDI]); 830 st->print("R8 ="); print_location(st, uc->uc_mcontext.gregs[REG_R8]); 831 st->print("R9 ="); print_location(st, uc->uc_mcontext.gregs[REG_R9]); 832 st->print("R10="); print_location(st, uc->uc_mcontext.gregs[REG_R10]); 833 st->print("R11="); print_location(st, uc->uc_mcontext.gregs[REG_R11]); 834 st->print("R12="); print_location(st, uc->uc_mcontext.gregs[REG_R12]); 835 st->print("R13="); print_location(st, uc->uc_mcontext.gregs[REG_R13]); 836 st->print("R14="); print_location(st, uc->uc_mcontext.gregs[REG_R14]); 837 st->print("R15="); print_location(st, uc->uc_mcontext.gregs[REG_R15]); 838#else 839 st->print("EAX="); print_location(st, uc->uc_mcontext.gregs[REG_EAX]); 840 st->print("EBX="); print_location(st, uc->uc_mcontext.gregs[REG_EBX]); 841 st->print("ECX="); print_location(st, uc->uc_mcontext.gregs[REG_ECX]); 842 st->print("EDX="); print_location(st, uc->uc_mcontext.gregs[REG_EDX]); 843 st->print("ESP="); print_location(st, uc->uc_mcontext.gregs[REG_ESP]); 844 st->print("EBP="); print_location(st, uc->uc_mcontext.gregs[REG_EBP]); 845 st->print("ESI="); print_location(st, uc->uc_mcontext.gregs[REG_ESI]); 846 st->print("EDI="); print_location(st, uc->uc_mcontext.gregs[REG_EDI]); 847#endif // AMD64 848 849 st->cr(); 850} 851 852void os::setup_fpu() { 853#ifndef AMD64 854 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std(); 855 __asm__ volatile ( "fldcw (%0)" : 856 : "r" (fpu_cntrl) : "memory"); 857#endif // !AMD64 858} 859 860#ifndef PRODUCT 861void os::verify_stack_alignment() { 862#ifdef AMD64 863 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment"); 864#endif 865} 866#endif 867