1 /* 2 * Copyright (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 // no precompiled headers 26 #include "assembler_x86.inline.hpp" 27 #include "classfile/classLoader.hpp" 28 #include "classfile/systemDictionary.hpp" 29 #include "classfile/vmSymbols.hpp" 30 #include "code/icBuffer.hpp" 31 #include "code/vtableStubs.hpp" 32 #include "interpreter/interpreter.hpp" 33 #include "jvm_bsd.h" 34 #include "memory/allocation.inline.hpp" 35 #include "mutex_bsd.inline.hpp" 36 #include "nativeInst_x86.hpp" 37 #include "os_share_bsd.hpp" 38 #include "prims/jniFastGetField.hpp" 39 #include "prims/jvm.h" 40 #include "prims/jvm_misc.hpp" 41 #include "runtime/arguments.hpp" 42 #include "runtime/extendedPC.hpp" 43 #include "runtime/frame.inline.hpp" 44 #include "runtime/interfaceSupport.hpp" 45 #include "runtime/java.hpp" 46 #include "runtime/javaCalls.hpp" 47 #include "runtime/mutexLocker.hpp" 48 #include "runtime/osThread.hpp" 49 #include "runtime/sharedRuntime.hpp" 50 #include "runtime/stubRoutines.hpp" 51 #include "runtime/timer.hpp" 52 #include "thread_bsd.inline.hpp" 53 #include "utilities/events.hpp" 54 #include "utilities/vmError.hpp" 55 #ifdef COMPILER1 56 #include "c1/c1_Runtime1.hpp" 57 #endif 58 #ifdef COMPILER2 59 #include "opto/runtime.hpp" 60 #endif 61 62 // put OS-includes here 63 # include <sys/types.h> 64 # include <sys/mman.h> 65 # include <pthread.h> 66 # include <signal.h> 67 # include <errno.h> 68 # include <dlfcn.h> 69 # include <stdlib.h> 70 # include <stdio.h> 71 # include <unistd.h> 72 # include <sys/resource.h> 73 # include <pthread.h> 74 # include <sys/stat.h> 75 # include <sys/time.h> 76 # include <sys/utsname.h> 77 # include <sys/socket.h> 78 # include <sys/wait.h> 79 # include <pwd.h> 80 # include <poll.h> 81 #ifndef __OpenBSD__ 82 # include <ucontext.h> 83 #endif 84 85 #if defined(_ALLBSD_SOURCE) && !defined(__APPLE__) && !defined(__NetBSD__) 86 # include <pthread_np.h> 87 #endif 88 89 #ifdef AMD64 90 #define SPELL_REG_SP "rsp" 91 #define SPELL_REG_FP "rbp" 92 #else 93 #define SPELL_REG_SP "esp" 94 #define SPELL_REG_FP "ebp" 95 #endif // AMD64 96 97 #ifdef __FreeBSD__ 98 # define context_trapno uc_mcontext.mc_trapno 99 # ifdef AMD64 100 # define context_pc uc_mcontext.mc_rip 101 # define context_sp uc_mcontext.mc_rsp 102 # define context_fp uc_mcontext.mc_rbp 103 # define context_rip uc_mcontext.mc_rip 104 # define context_rsp uc_mcontext.mc_rsp 105 # define context_rbp uc_mcontext.mc_rbp 106 # define context_rax uc_mcontext.mc_rax 107 # define context_rbx uc_mcontext.mc_rbx 108 # define context_rcx uc_mcontext.mc_rcx 109 # define context_rdx uc_mcontext.mc_rdx 110 # define context_rsi uc_mcontext.mc_rsi 111 # define context_rdi uc_mcontext.mc_rdi 112 # define context_r8 uc_mcontext.mc_r8 113 # define context_r9 uc_mcontext.mc_r9 114 # define context_r10 uc_mcontext.mc_r10 115 # define context_r11 uc_mcontext.mc_r11 116 # define context_r12 uc_mcontext.mc_r12 117 # define context_r13 uc_mcontext.mc_r13 118 # define context_r14 uc_mcontext.mc_r14 119 # define context_r15 uc_mcontext.mc_r15 120 # define context_flags uc_mcontext.mc_flags 121 # define context_err uc_mcontext.mc_err 122 # else 123 # define context_pc uc_mcontext.mc_eip 124 # define context_sp uc_mcontext.mc_esp 125 # define context_fp uc_mcontext.mc_ebp 126 # define context_eip uc_mcontext.mc_eip 127 # define context_esp uc_mcontext.mc_esp 128 # define context_eax uc_mcontext.mc_eax 129 # define context_ebx uc_mcontext.mc_ebx 130 # define context_ecx uc_mcontext.mc_ecx 131 # define context_edx uc_mcontext.mc_edx 132 # define context_ebp uc_mcontext.mc_ebp 133 # define context_esi uc_mcontext.mc_esi 134 # define context_edi uc_mcontext.mc_edi 135 # define context_eflags uc_mcontext.mc_eflags 136 # define context_trapno uc_mcontext.mc_trapno 137 # endif 138 #endif 139 140 #ifdef __APPLE__ 141 # if __DARWIN_UNIX03 && (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5) 142 // 10.5 UNIX03 member name prefixes 143 #define DU3_PREFIX(s, m) __ ## s.__ ## m 144 # else 145 #define DU3_PREFIX(s, m) s ## . ## m 146 # endif 147 148 # ifdef AMD64 149 # define context_pc context_rip 150 # define context_sp context_rsp 151 # define context_fp context_rbp 152 # define context_rip uc_mcontext->DU3_PREFIX(ss,rip) 153 # define context_rsp uc_mcontext->DU3_PREFIX(ss,rsp) 154 # define context_rax uc_mcontext->DU3_PREFIX(ss,rax) 155 # define context_rbx uc_mcontext->DU3_PREFIX(ss,rbx) 156 # define context_rcx uc_mcontext->DU3_PREFIX(ss,rcx) 157 # define context_rdx uc_mcontext->DU3_PREFIX(ss,rdx) 158 # define context_rbp uc_mcontext->DU3_PREFIX(ss,rbp) 159 # define context_rsi uc_mcontext->DU3_PREFIX(ss,rsi) 160 # define context_rdi uc_mcontext->DU3_PREFIX(ss,rdi) 161 # define context_r8 uc_mcontext->DU3_PREFIX(ss,r8) 162 # define context_r9 uc_mcontext->DU3_PREFIX(ss,r9) 163 # define context_r10 uc_mcontext->DU3_PREFIX(ss,r10) 164 # define context_r11 uc_mcontext->DU3_PREFIX(ss,r11) 165 # define context_r12 uc_mcontext->DU3_PREFIX(ss,r12) 166 # define context_r13 uc_mcontext->DU3_PREFIX(ss,r13) 167 # define context_r14 uc_mcontext->DU3_PREFIX(ss,r14) 168 # define context_r15 uc_mcontext->DU3_PREFIX(ss,r15) 169 # define context_flags uc_mcontext->DU3_PREFIX(ss,rflags) 170 # define context_trapno uc_mcontext->DU3_PREFIX(es,trapno) 171 # define context_err uc_mcontext->DU3_PREFIX(es,err) 172 # else 173 # define context_pc context_eip 174 # define context_sp context_esp 175 # define context_fp context_ebp 176 # define context_eip uc_mcontext->DU3_PREFIX(ss,eip) 177 # define context_esp uc_mcontext->DU3_PREFIX(ss,esp) 178 # define context_eax uc_mcontext->DU3_PREFIX(ss,eax) 179 # define context_ebx uc_mcontext->DU3_PREFIX(ss,ebx) 180 # define context_ecx uc_mcontext->DU3_PREFIX(ss,ecx) 181 # define context_edx uc_mcontext->DU3_PREFIX(ss,edx) 182 # define context_ebp uc_mcontext->DU3_PREFIX(ss,ebp) 183 # define context_esi uc_mcontext->DU3_PREFIX(ss,esi) 184 # define context_edi uc_mcontext->DU3_PREFIX(ss,edi) 185 # define context_eflags uc_mcontext->DU3_PREFIX(ss,eflags) 186 # define context_trapno uc_mcontext->DU3_PREFIX(es,trapno) 187 # endif 188 #endif 189 190 #ifdef __OpenBSD__ 191 # define context_trapno sc_trapno 192 # ifdef AMD64 193 # define context_pc sc_rip 194 # define context_sp sc_rsp 195 # define context_fp sc_rbp 196 # define context_rip sc_rip 197 # define context_rsp sc_rsp 198 # define context_rbp sc_rbp 199 # define context_rax sc_rax 200 # define context_rbx sc_rbx 201 # define context_rcx sc_rcx 202 # define context_rdx sc_rdx 203 # define context_rsi sc_rsi 204 # define context_rdi sc_rdi 205 # define context_r8 sc_r8 206 # define context_r9 sc_r9 207 # define context_r10 sc_r10 208 # define context_r11 sc_r11 209 # define context_r12 sc_r12 210 # define context_r13 sc_r13 211 # define context_r14 sc_r14 212 # define context_r15 sc_r15 213 # define context_flags sc_rflags 214 # define context_err sc_err 215 # else 216 # define context_pc sc_eip 217 # define context_sp sc_esp 218 # define context_fp sc_ebp 219 # define context_eip sc_eip 220 # define context_esp sc_esp 221 # define context_eax sc_eax 222 # define context_ebx sc_ebx 223 # define context_ecx sc_ecx 224 # define context_edx sc_edx 225 # define context_ebp sc_ebp 226 # define context_esi sc_esi 227 # define context_edi sc_edi 228 # define context_eflags sc_eflags 229 # define context_trapno sc_trapno 230 # endif 231 #endif 232 233 #ifdef __NetBSD__ 234 # define context_trapno uc_mcontext.__gregs[_REG_TRAPNO] 235 # ifdef AMD64 236 # define __register_t __greg_t 237 # define context_pc uc_mcontext.__gregs[_REG_RIP] 238 # define context_sp uc_mcontext.__gregs[_REG_URSP] 239 # define context_fp uc_mcontext.__gregs[_REG_RBP] 240 # define context_rip uc_mcontext.__gregs[_REG_RIP] 241 # define context_rsp uc_mcontext.__gregs[_REG_URSP] 242 # define context_rax uc_mcontext.__gregs[_REG_RAX] 243 # define context_rbx uc_mcontext.__gregs[_REG_RBX] 244 # define context_rcx uc_mcontext.__gregs[_REG_RCX] 245 # define context_rdx uc_mcontext.__gregs[_REG_RDX] 246 # define context_rbp uc_mcontext.__gregs[_REG_RBP] 247 # define context_rsi uc_mcontext.__gregs[_REG_RSI] 248 # define context_rdi uc_mcontext.__gregs[_REG_RDI] 249 # define context_r8 uc_mcontext.__gregs[_REG_R8] 250 # define context_r9 uc_mcontext.__gregs[_REG_R9] 251 # define context_r10 uc_mcontext.__gregs[_REG_R10] 252 # define context_r11 uc_mcontext.__gregs[_REG_R11] 253 # define context_r12 uc_mcontext.__gregs[_REG_R12] 254 # define context_r13 uc_mcontext.__gregs[_REG_R13] 255 # define context_r14 uc_mcontext.__gregs[_REG_R14] 256 # define context_r15 uc_mcontext.__gregs[_REG_R15] 257 # define context_flags uc_mcontext.__gregs[_REG_RFL] 258 # define context_err uc_mcontext.__gregs[_REG_ERR] 259 # else 260 # define context_pc uc_mcontext.__gregs[_REG_EIP] 261 # define context_sp uc_mcontext.__gregs[_REG_UESP] 262 # define context_fp uc_mcontext.__gregs[_REG_EBP] 263 # define context_eip uc_mcontext.__gregs[_REG_EIP] 264 # define context_esp uc_mcontext.__gregs[_REG_UESP] 265 # define context_eax uc_mcontext.__gregs[_REG_EAX] 266 # define context_ebx uc_mcontext.__gregs[_REG_EBX] 267 # define context_ecx uc_mcontext.__gregs[_REG_ECX] 268 # define context_edx uc_mcontext.__gregs[_REG_EDX] 269 # define context_ebp uc_mcontext.__gregs[_REG_EBP] 270 # define context_esi uc_mcontext.__gregs[_REG_ESI] 271 # define context_edi uc_mcontext.__gregs[_REG_EDI] 272 # define context_eflags uc_mcontext.__gregs[_REG_EFL] 273 # define context_trapno uc_mcontext.__gregs[_REG_TRAPNO] 274 # endif 275 #endif 276 277 address os::current_stack_pointer() { 278 #ifdef SPARC_WORKS 279 register void *esp; 280 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp)); 281 return (address) ((char*)esp + sizeof(long)*2); 282 #else 283 register void *esp __asm__ (SPELL_REG_SP); 284 return (address) esp; 285 #endif 286 } 287 288 char* os::non_memory_address_word() { 289 // Must never look like an address returned by reserve_memory, 290 // even in its subfields (as defined by the CPU immediate fields, 291 // if the CPU splits constants across multiple instructions). 292 293 return (char*) -1; 294 } 295 296 void os::initialize_thread() { 297 // Nothing to do. 298 } 299 300 address os::Bsd::ucontext_get_pc(ucontext_t * uc) { 301 return (address)uc->context_pc; 302 } 303 304 intptr_t* os::Bsd::ucontext_get_sp(ucontext_t * uc) { 305 return (intptr_t*)uc->context_sp; 306 } 307 308 intptr_t* os::Bsd::ucontext_get_fp(ucontext_t * uc) { 309 return (intptr_t*)uc->context_fp; 310 } 311 312 // For Forte Analyzer AsyncGetCallTrace profiling support - thread 313 // is currently interrupted by SIGPROF. 314 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal 315 // frames. Currently we don't do that on Bsd, so it's the same as 316 // os::fetch_frame_from_context(). 317 ExtendedPC os::Bsd::fetch_frame_from_ucontext(Thread* thread, 318 ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) { 319 320 assert(thread != NULL, "just checking"); 321 assert(ret_sp != NULL, "just checking"); 322 assert(ret_fp != NULL, "just checking"); 323 324 return os::fetch_frame_from_context(uc, ret_sp, ret_fp); 325 } 326 327 ExtendedPC os::fetch_frame_from_context(void* ucVoid, 328 intptr_t** ret_sp, intptr_t** ret_fp) { 329 330 ExtendedPC epc; 331 ucontext_t* uc = (ucontext_t*)ucVoid; 332 333 if (uc != NULL) { 334 epc = ExtendedPC(os::Bsd::ucontext_get_pc(uc)); 335 if (ret_sp) *ret_sp = os::Bsd::ucontext_get_sp(uc); 336 if (ret_fp) *ret_fp = os::Bsd::ucontext_get_fp(uc); 337 } else { 338 // construct empty ExtendedPC for return value checking 339 epc = ExtendedPC(NULL); 340 if (ret_sp) *ret_sp = (intptr_t *)NULL; 341 if (ret_fp) *ret_fp = (intptr_t *)NULL; 342 } 343 344 return epc; 345 } 346 347 frame os::fetch_frame_from_context(void* ucVoid) { 348 intptr_t* sp; 349 intptr_t* fp; 350 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp); 351 return frame(sp, fp, epc.pc()); 352 } 353 354 // By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get 355 // turned off by -fomit-frame-pointer, 356 frame os::get_sender_for_C_frame(frame* fr) { 357 return frame(fr->sender_sp(), fr->link(), fr->sender_pc()); 358 } 359 360 intptr_t* _get_previous_fp() { 361 #ifdef SPARC_WORKS 362 register intptr_t **ebp; 363 __asm__("mov %%"SPELL_REG_FP", %0":"=r"(ebp)); 364 #else 365 register intptr_t **ebp __asm__ (SPELL_REG_FP); 366 #endif 367 return (intptr_t*) *ebp; // we want what it points to. 368 } 369 370 371 frame os::current_frame() { 372 intptr_t* fp = _get_previous_fp(); 373 frame myframe((intptr_t*)os::current_stack_pointer(), 374 (intptr_t*)fp, 375 CAST_FROM_FN_PTR(address, os::current_frame)); 376 if (os::is_first_C_frame(&myframe)) { 377 // stack is not walkable 378 return frame(NULL, NULL, NULL); 379 } else { 380 return os::get_sender_for_C_frame(&myframe); 381 } 382 } 383 384 // Utility functions 385 386 // From IA32 System Programming Guide 387 enum { 388 trap_page_fault = 0xE 389 }; 390 391 extern "C" void Fetch32PFI () ; 392 extern "C" void Fetch32Resume () ; 393 #ifdef AMD64 394 extern "C" void FetchNPFI () ; 395 extern "C" void FetchNResume () ; 396 #endif // AMD64 397 398 extern "C" JNIEXPORT int 399 JVM_handle_bsd_signal(int sig, 400 siginfo_t* info, 401 void* ucVoid, 402 int abort_if_unrecognized) { 403 ucontext_t* uc = (ucontext_t*) ucVoid; 404 405 Thread* t = ThreadLocalStorage::get_thread_slow(); 406 407 SignalHandlerMark shm(t); 408 409 // Note: it's not uncommon that JNI code uses signal/sigset to install 410 // then restore certain signal handler (e.g. to temporarily block SIGPIPE, 411 // or have a SIGILL handler when detecting CPU type). When that happens, 412 // JVM_handle_bsd_signal() might be invoked with junk info/ucVoid. To 413 // avoid unnecessary crash when libjsig is not preloaded, try handle signals 414 // that do not require siginfo/ucontext first. 415 416 if (sig == SIGPIPE || sig == SIGXFSZ) { 417 // allow chained handler to go first 418 if (os::Bsd::chained_handler(sig, info, ucVoid)) { 419 return true; 420 } else { 421 if (PrintMiscellaneous && (WizardMode || Verbose)) { 422 char buf[64]; 423 warning("Ignoring %s - see bugs 4229104 or 646499219", 424 os::exception_name(sig, buf, sizeof(buf))); 425 } 426 return true; 427 } 428 } 429 430 JavaThread* thread = NULL; 431 VMThread* vmthread = NULL; 432 if (os::Bsd::signal_handlers_are_installed) { 433 if (t != NULL ){ 434 if(t->is_Java_thread()) { 435 thread = (JavaThread*)t; 436 } 437 else if(t->is_VM_thread()){ 438 vmthread = (VMThread *)t; 439 } 440 } 441 } 442 /* 443 NOTE: does not seem to work on bsd. 444 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) { 445 // can't decode this kind of signal 446 info = NULL; 447 } else { 448 assert(sig == info->si_signo, "bad siginfo"); 449 } 450 */ 451 // decide if this trap can be handled by a stub 452 address stub = NULL; 453 454 address pc = NULL; 455 456 //%note os_trap_1 457 if (info != NULL && uc != NULL && thread != NULL) { 458 pc = (address) os::Bsd::ucontext_get_pc(uc); 459 460 if (pc == (address) Fetch32PFI) { 461 uc->context_pc = intptr_t(Fetch32Resume) ; 462 return 1 ; 463 } 464 #ifdef AMD64 465 if (pc == (address) FetchNPFI) { 466 uc->context_pc = intptr_t (FetchNResume) ; 467 return 1 ; 468 } 469 #endif // AMD64 470 471 // Handle ALL stack overflow variations here 472 if (sig == SIGSEGV || sig == SIGBUS) { 473 address addr = (address) info->si_addr; 474 475 // check if fault address is within thread stack 476 if (addr < thread->stack_base() && 477 addr >= thread->stack_base() - thread->stack_size()) { 478 // stack overflow 479 if (thread->in_stack_yellow_zone(addr)) { 480 thread->disable_stack_yellow_zone(); 481 if (thread->thread_state() == _thread_in_Java) { 482 // Throw a stack overflow exception. Guard pages will be reenabled 483 // while unwinding the stack. 484 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); 485 } else { 486 // Thread was in the vm or native code. Return and try to finish. 487 return 1; 488 } 489 } else if (thread->in_stack_red_zone(addr)) { 490 // Fatal red zone violation. Disable the guard pages and fall through 491 // to handle_unexpected_exception way down below. 492 thread->disable_stack_red_zone(); 493 tty->print_raw_cr("An irrecoverable stack overflow has occurred."); 494 #ifndef _ALLBSD_SOURCE 495 } else { 496 // Accessing stack address below sp may cause SEGV if current 497 // thread has MAP_GROWSDOWN stack. This should only happen when 498 // current thread was created by user code with MAP_GROWSDOWN flag 499 // and then attached to VM. See notes in os_bsd.cpp. 500 if (thread->osthread()->expanding_stack() == 0) { 501 thread->osthread()->set_expanding_stack(); 502 if (os::Bsd::manually_expand_stack(thread, addr)) { 503 thread->osthread()->clear_expanding_stack(); 504 return 1; 505 } 506 thread->osthread()->clear_expanding_stack(); 507 } else { 508 fatal("recursive segv. expanding stack."); 509 } 510 #endif 511 } 512 } 513 } 514 515 if (thread->thread_state() == _thread_in_Java) { 516 // Java thread running in Java code => find exception handler if any 517 // a fault inside compiled code, the interpreter, or a stub 518 519 if ((sig == SIGSEGV || sig == SIGBUS) && os::is_poll_address((address)info->si_addr)) { 520 stub = SharedRuntime::get_poll_stub(pc); 521 #if defined(__APPLE__) && !defined(AMD64) 522 // 32-bit Darwin reports a SIGBUS for nearly all memory access exceptions. 523 // Catching SIGBUS here prevents the implicit SIGBUS NULL check below from 524 // being called, so only do so if the implicit NULL check is not necessary. 525 } else if (sig == SIGBUS && MacroAssembler::needs_explicit_null_check((int)info->si_addr)) { 526 #else 527 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) { 528 #endif 529 // BugId 4454115: A read from a MappedByteBuffer can fault 530 // here if the underlying file has been truncated. 531 // Do not crash the VM in such a case. 532 CodeBlob* cb = CodeCache::find_blob_unsafe(pc); 533 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL; 534 if (nm != NULL && nm->has_unsafe_access()) { 535 stub = StubRoutines::handler_for_unsafe_access(); 536 } 537 } 538 else 539 540 #ifdef AMD64 541 if (sig == SIGFPE && 542 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) { 543 stub = 544 SharedRuntime:: 545 continuation_for_implicit_exception(thread, 546 pc, 547 SharedRuntime:: 548 IMPLICIT_DIVIDE_BY_ZERO); 549 #ifdef __APPLE__ 550 } else if (sig == SIGFPE && info->si_code == FPE_NOOP) { 551 int op = pc[0]; 552 553 // Skip REX 554 if ((pc[0] & 0xf0) == 0x40) { 555 op = pc[1]; 556 } else { 557 op = pc[0]; 558 } 559 560 // Check for IDIV 561 if (op == 0xF7) { 562 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime:: IMPLICIT_DIVIDE_BY_ZERO); 563 } else { 564 // TODO: handle more cases if we are using other x86 instructions 565 // that can generate SIGFPE signal. 566 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); 567 fatal("please update this code."); 568 } 569 #endif /* __APPLE__ */ 570 571 #else 572 if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) { 573 // HACK: si_code does not work on bsd 2.2.12-20!!! 574 int op = pc[0]; 575 if (op == 0xDB) { 576 // FIST 577 // TODO: The encoding of D2I in i486.ad can cause an exception 578 // prior to the fist instruction if there was an invalid operation 579 // pending. We want to dismiss that exception. From the win_32 580 // side it also seems that if it really was the fist causing 581 // the exception that we do the d2i by hand with different 582 // rounding. Seems kind of weird. 583 // NOTE: that we take the exception at the NEXT floating point instruction. 584 assert(pc[0] == 0xDB, "not a FIST opcode"); 585 assert(pc[1] == 0x14, "not a FIST opcode"); 586 assert(pc[2] == 0x24, "not a FIST opcode"); 587 return true; 588 } else if (op == 0xF7) { 589 // IDIV 590 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); 591 } else { 592 // TODO: handle more cases if we are using other x86 instructions 593 // that can generate SIGFPE signal on bsd. 594 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); 595 fatal("please update this code."); 596 } 597 #endif // AMD64 598 } else if ((sig == SIGSEGV || sig == SIGBUS) && 599 !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { 600 // Determination of interpreter/vtable stub/compiled code null exception 601 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 602 } 603 } else if (thread->thread_state() == _thread_in_vm && 604 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */ 605 thread->doing_unsafe_access()) { 606 stub = StubRoutines::handler_for_unsafe_access(); 607 } 608 609 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in 610 // and the heap gets shrunk before the field access. 611 if ((sig == SIGSEGV) || (sig == SIGBUS)) { 612 address addr = JNI_FastGetField::find_slowcase_pc(pc); 613 if (addr != (address)-1) { 614 stub = addr; 615 } 616 } 617 618 // Check to see if we caught the safepoint code in the 619 // process of write protecting the memory serialization page. 620 // It write enables the page immediately after protecting it 621 // so we can just return to retry the write. 622 if ((sig == SIGSEGV || sig == SIGBUS) && 623 os::is_memory_serialize_page(thread, (address) info->si_addr)) { 624 // Block current thread until the memory serialize page permission restored. 625 os::block_on_serialize_page_trap(); 626 return true; 627 } 628 } 629 630 #ifndef AMD64 631 // Execution protection violation 632 // 633 // This should be kept as the last step in the triage. We don't 634 // have a dedicated trap number for a no-execute fault, so be 635 // conservative and allow other handlers the first shot. 636 // 637 // Note: We don't test that info->si_code == SEGV_ACCERR here. 638 // this si_code is so generic that it is almost meaningless; and 639 // the si_code for this condition may change in the future. 640 // Furthermore, a false-positive should be harmless. 641 if (UnguardOnExecutionViolation > 0 && 642 (sig == SIGSEGV || sig == SIGBUS) && 643 uc->context_trapno == trap_page_fault) { 644 int page_size = os::vm_page_size(); 645 address addr = (address) info->si_addr; 646 address pc = os::Bsd::ucontext_get_pc(uc); 647 // Make sure the pc and the faulting address are sane. 648 // 649 // If an instruction spans a page boundary, and the page containing 650 // the beginning of the instruction is executable but the following 651 // page is not, the pc and the faulting address might be slightly 652 // different - we still want to unguard the 2nd page in this case. 653 // 654 // 15 bytes seems to be a (very) safe value for max instruction size. 655 bool pc_is_near_addr = 656 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15); 657 bool instr_spans_page_boundary = 658 (align_size_down((intptr_t) pc ^ (intptr_t) addr, 659 (intptr_t) page_size) > 0); 660 661 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) { 662 static volatile address last_addr = 663 (address) os::non_memory_address_word(); 664 665 // In conservative mode, don't unguard unless the address is in the VM 666 if (addr != last_addr && 667 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) { 668 669 // Set memory to RWX and retry 670 address page_start = 671 (address) align_size_down((intptr_t) addr, (intptr_t) page_size); 672 bool res = os::protect_memory((char*) page_start, page_size, 673 os::MEM_PROT_RWX); 674 675 if (PrintMiscellaneous && Verbose) { 676 char buf[256]; 677 jio_snprintf(buf, sizeof(buf), "Execution protection violation " 678 "at " INTPTR_FORMAT 679 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr, 680 page_start, (res ? "success" : "failed"), errno); 681 tty->print_raw_cr(buf); 682 } 683 stub = pc; 684 685 // Set last_addr so if we fault again at the same address, we don't end 686 // up in an endless loop. 687 // 688 // There are two potential complications here. Two threads trapping at 689 // the same address at the same time could cause one of the threads to 690 // think it already unguarded, and abort the VM. Likely very rare. 691 // 692 // The other race involves two threads alternately trapping at 693 // different addresses and failing to unguard the page, resulting in 694 // an endless loop. This condition is probably even more unlikely than 695 // the first. 696 // 697 // Although both cases could be avoided by using locks or thread local 698 // last_addr, these solutions are unnecessary complication: this 699 // handler is a best-effort safety net, not a complete solution. It is 700 // disabled by default and should only be used as a workaround in case 701 // we missed any no-execute-unsafe VM code. 702 703 last_addr = addr; 704 } 705 } 706 } 707 #endif // !AMD64 708 709 if (stub != NULL) { 710 // save all thread context in case we need to restore it 711 if (thread != NULL) thread->set_saved_exception_pc(pc); 712 713 uc->context_pc = (intptr_t)stub; 714 return true; 715 } 716 717 // signal-chaining 718 if (os::Bsd::chained_handler(sig, info, ucVoid)) { 719 return true; 720 } 721 722 if (!abort_if_unrecognized) { 723 // caller wants another chance, so give it to him 724 return false; 725 } 726 727 if (pc == NULL && uc != NULL) { 728 pc = os::Bsd::ucontext_get_pc(uc); 729 } 730 731 // unmask current signal 732 sigset_t newset; 733 sigemptyset(&newset); 734 sigaddset(&newset, sig); 735 sigprocmask(SIG_UNBLOCK, &newset, NULL); 736 737 VMError err(t, sig, pc, info, ucVoid); 738 err.report_and_die(); 739 740 ShouldNotReachHere(); 741 } 742 743 #ifdef _ALLBSD_SOURCE 744 // From solaris_i486.s ported to bsd_i486.s 745 extern "C" void fixcw(); 746 #endif 747 748 void os::Bsd::init_thread_fpu_state(void) { 749 #ifndef AMD64 750 # ifdef _ALLBSD_SOURCE 751 // Set fpu to 53 bit precision. This happens too early to use a stub. 752 fixcw(); 753 # else 754 // set fpu to 53 bit precision 755 set_fpu_control_word(0x27f); 756 # endif 757 #endif // !AMD64 758 } 759 760 #ifndef _ALLBSD_SOURCE 761 int os::Bsd::get_fpu_control_word(void) { 762 #ifdef AMD64 763 return 0; 764 #else 765 int fpu_control; 766 _FPU_GETCW(fpu_control); 767 return fpu_control & 0xffff; 768 #endif // AMD64 769 } 770 771 void os::Bsd::set_fpu_control_word(int fpu_control) { 772 #ifndef AMD64 773 _FPU_SETCW(fpu_control); 774 #endif // !AMD64 775 } 776 #endif 777 778 // Check that the bsd kernel version is 2.4 or higher since earlier 779 // versions do not support SSE without patches. 780 bool os::supports_sse() { 781 #if defined(AMD64) || defined(_ALLBSD_SOURCE) 782 return true; 783 #else 784 struct utsname uts; 785 if( uname(&uts) != 0 ) return false; // uname fails? 786 char *minor_string; 787 int major = strtol(uts.release,&minor_string,10); 788 int minor = strtol(minor_string+1,NULL,10); 789 bool result = (major > 2 || (major==2 && minor >= 4)); 790 #ifndef PRODUCT 791 if (PrintMiscellaneous && Verbose) { 792 tty->print("OS version is %d.%d, which %s support SSE/SSE2\n", 793 major,minor, result ? "DOES" : "does NOT"); 794 } 795 #endif 796 return result; 797 #endif // AMD64 798 } 799 800 bool os::is_allocatable(size_t bytes) { 801 #ifdef AMD64 802 // unused on amd64? 803 return true; 804 #else 805 806 if (bytes < 2 * G) { 807 return true; 808 } 809 810 char* addr = reserve_memory(bytes, NULL); 811 812 if (addr != NULL) { 813 release_memory(addr, bytes); 814 } 815 816 return addr != NULL; 817 #endif // AMD64 818 } 819 820 //////////////////////////////////////////////////////////////////////////////// 821 // thread stack 822 823 #ifdef AMD64 824 size_t os::Bsd::min_stack_allowed = 64 * K; 825 826 // amd64: pthread on amd64 is always in floating stack mode 827 bool os::Bsd::supports_variable_stack_size() { return true; } 828 #else 829 size_t os::Bsd::min_stack_allowed = (48 DEBUG_ONLY(+4))*K; 830 831 #ifdef __GNUC__ 832 #define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;}) 833 #endif 834 835 #ifdef _ALLBSD_SOURCE 836 bool os::Bsd::supports_variable_stack_size() { return true; } 837 #else 838 // Test if pthread library can support variable thread stack size. BsdThreads 839 // in fixed stack mode allocates 2M fixed slot for each thread. BsdThreads 840 // in floating stack mode and NPTL support variable stack size. 841 bool os::Bsd::supports_variable_stack_size() { 842 if (os::Bsd::is_NPTL()) { 843 // NPTL, yes 844 return true; 845 846 } else { 847 // Note: We can't control default stack size when creating a thread. 848 // If we use non-default stack size (pthread_attr_setstacksize), both 849 // floating stack and non-floating stack BsdThreads will return the 850 // same value. This makes it impossible to implement this function by 851 // detecting thread stack size directly. 852 // 853 // An alternative approach is to check %gs. Fixed-stack BsdThreads 854 // do not use %gs, so its value is 0. Floating-stack BsdThreads use 855 // %gs (either as LDT selector or GDT selector, depending on kernel) 856 // to access thread specific data. 857 // 858 // Note that %gs is a reserved glibc register since early 2001, so 859 // applications are not allowed to change its value (Ulrich Drepper from 860 // Redhat confirmed that all known offenders have been modified to use 861 // either %fs or TSD). In the worst case scenario, when VM is embedded in 862 // a native application that plays with %gs, we might see non-zero %gs 863 // even BsdThreads is running in fixed stack mode. As the result, we'll 864 // return true and skip _thread_safety_check(), so we may not be able to 865 // detect stack-heap collisions. But otherwise it's harmless. 866 // 867 #ifdef __GNUC__ 868 return (GET_GS() != 0); 869 #else 870 return false; 871 #endif 872 } 873 } 874 #endif 875 #endif // AMD64 876 877 // return default stack size for thr_type 878 size_t os::Bsd::default_stack_size(os::ThreadType thr_type) { 879 // default stack size (compiler thread needs larger stack) 880 #ifdef AMD64 881 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M); 882 #else 883 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K); 884 #endif // AMD64 885 return s; 886 } 887 888 size_t os::Bsd::default_guard_size(os::ThreadType thr_type) { 889 // Creating guard page is very expensive. Java thread has HotSpot 890 // guard page, only enable glibc guard page for non-Java threads. 891 return (thr_type == java_thread ? 0 : page_size()); 892 } 893 894 // Java thread: 895 // 896 // Low memory addresses 897 // +------------------------+ 898 // | |\ JavaThread created by VM does not have glibc 899 // | glibc guard page | - guard, attached Java thread usually has 900 // | |/ 1 page glibc guard. 901 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 902 // | |\ 903 // | HotSpot Guard Pages | - red and yellow pages 904 // | |/ 905 // +------------------------+ JavaThread::stack_yellow_zone_base() 906 // | |\ 907 // | Normal Stack | - 908 // | |/ 909 // P2 +------------------------+ Thread::stack_base() 910 // 911 // Non-Java thread: 912 // 913 // Low memory addresses 914 // +------------------------+ 915 // | |\ 916 // | glibc guard page | - usually 1 page 917 // | |/ 918 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 919 // | |\ 920 // | Normal Stack | - 921 // | |/ 922 // P2 +------------------------+ Thread::stack_base() 923 // 924 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from 925 // pthread_attr_getstack() 926 927 static void current_stack_region(address * bottom, size_t * size) { 928 #ifdef __APPLE__ 929 pthread_t self = pthread_self(); 930 void *stacktop = pthread_get_stackaddr_np(self); 931 *size = pthread_get_stacksize_np(self); 932 *bottom = (address) stacktop - *size; 933 #elif defined(__OpenBSD__) 934 stack_t ss; 935 int rslt = pthread_stackseg_np(pthread_self(), &ss); 936 937 if (rslt != 0) 938 fatal(err_msg("pthread_stackseg_np failed with err = %d", rslt)); 939 940 *bottom = (address)((char *)ss.ss_sp - ss.ss_size); 941 *size = ss.ss_size; 942 #elif defined(_ALLBSD_SOURCE) 943 pthread_attr_t attr; 944 945 int rslt = pthread_attr_init(&attr); 946 947 // JVM needs to know exact stack location, abort if it fails 948 if (rslt != 0) 949 fatal(err_msg("pthread_attr_init failed with err = %d", rslt)); 950 951 rslt = pthread_attr_get_np(pthread_self(), &attr); 952 953 if (rslt != 0) 954 fatal(err_msg("pthread_attr_get_np failed with err = %d", rslt)); 955 956 if (pthread_attr_getstackaddr(&attr, (void **)bottom) != 0 || 957 pthread_attr_getstacksize(&attr, size) != 0) { 958 fatal("Can not locate current stack attributes!"); 959 } 960 961 pthread_attr_destroy(&attr); 962 #else 963 if (os::Bsd::is_initial_thread()) { 964 // initial thread needs special handling because pthread_getattr_np() 965 // may return bogus value. 966 *bottom = os::Bsd::initial_thread_stack_bottom(); 967 *size = os::Bsd::initial_thread_stack_size(); 968 } else { 969 pthread_attr_t attr; 970 971 int rslt = pthread_getattr_np(pthread_self(), &attr); 972 973 // JVM needs to know exact stack location, abort if it fails 974 if (rslt != 0) { 975 if (rslt == ENOMEM) { 976 vm_exit_out_of_memory(0, "pthread_getattr_np"); 977 } else { 978 fatal(err_msg("pthread_getattr_np failed with errno = %d", rslt)); 979 } 980 } 981 982 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) { 983 fatal("Can not locate current stack attributes!"); 984 } 985 986 pthread_attr_destroy(&attr); 987 988 } 989 #endif 990 assert(os::current_stack_pointer() >= *bottom && 991 os::current_stack_pointer() < *bottom + *size, "just checking"); 992 } 993 994 address os::current_stack_base() { 995 address bottom; 996 size_t size; 997 current_stack_region(&bottom, &size); 998 return (bottom + size); 999 } 1000 1001 size_t os::current_stack_size() { 1002 // stack size includes normal stack and HotSpot guard pages 1003 address bottom; 1004 size_t size; 1005 current_stack_region(&bottom, &size); 1006 return size; 1007 } 1008 1009 ///////////////////////////////////////////////////////////////////////////// 1010 // helper functions for fatal error handler 1011 1012 void os::print_context(outputStream *st, void *context) { 1013 if (context == NULL) return; 1014 1015 ucontext_t *uc = (ucontext_t*)context; 1016 st->print_cr("Registers:"); 1017 #ifdef AMD64 1018 st->print( "RAX=" INTPTR_FORMAT, uc->context_rax); 1019 st->print(", RBX=" INTPTR_FORMAT, uc->context_rbx); 1020 st->print(", RCX=" INTPTR_FORMAT, uc->context_rcx); 1021 st->print(", RDX=" INTPTR_FORMAT, uc->context_rdx); 1022 st->cr(); 1023 st->print( "RSP=" INTPTR_FORMAT, uc->context_rsp); 1024 st->print(", RBP=" INTPTR_FORMAT, uc->context_rbp); 1025 st->print(", RSI=" INTPTR_FORMAT, uc->context_rsi); 1026 st->print(", RDI=" INTPTR_FORMAT, uc->context_rdi); 1027 st->cr(); 1028 st->print( "R8 =" INTPTR_FORMAT, uc->context_r8); 1029 st->print(", R9 =" INTPTR_FORMAT, uc->context_r9); 1030 st->print(", R10=" INTPTR_FORMAT, uc->context_r10); 1031 st->print(", R11=" INTPTR_FORMAT, uc->context_r11); 1032 st->cr(); 1033 st->print( "R12=" INTPTR_FORMAT, uc->context_r12); 1034 st->print(", R13=" INTPTR_FORMAT, uc->context_r13); 1035 st->print(", R14=" INTPTR_FORMAT, uc->context_r14); 1036 st->print(", R15=" INTPTR_FORMAT, uc->context_r15); 1037 st->cr(); 1038 st->print( "RIP=" INTPTR_FORMAT, uc->context_rip); 1039 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_flags); 1040 st->print(", ERR=" INTPTR_FORMAT, uc->context_err); 1041 st->cr(); 1042 st->print(" TRAPNO=" INTPTR_FORMAT, uc->context_trapno); 1043 #else 1044 st->print( "EAX=" INTPTR_FORMAT, uc->context_eax); 1045 st->print(", EBX=" INTPTR_FORMAT, uc->context_ebx); 1046 st->print(", ECX=" INTPTR_FORMAT, uc->context_ecx); 1047 st->print(", EDX=" INTPTR_FORMAT, uc->context_edx); 1048 st->cr(); 1049 st->print( "ESP=" INTPTR_FORMAT, uc->context_esp); 1050 st->print(", EBP=" INTPTR_FORMAT, uc->context_ebp); 1051 st->print(", ESI=" INTPTR_FORMAT, uc->context_esi); 1052 st->print(", EDI=" INTPTR_FORMAT, uc->context_edi); 1053 st->cr(); 1054 st->print( "EIP=" INTPTR_FORMAT, uc->context_eip); 1055 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_eflags); 1056 #endif // AMD64 1057 st->cr(); 1058 st->cr(); 1059 1060 intptr_t *sp = (intptr_t *)os::Bsd::ucontext_get_sp(uc); 1061 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp); 1062 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t)); 1063 st->cr(); 1064 1065 // Note: it may be unsafe to inspect memory near pc. For example, pc may 1066 // point to garbage if entry point in an nmethod is corrupted. Leave 1067 // this at the end, and hope for the best. 1068 address pc = os::Bsd::ucontext_get_pc(uc); 1069 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc); 1070 print_hex_dump(st, pc - 32, pc + 32, sizeof(char)); 1071 } 1072 1073 void os::print_register_info(outputStream *st, void *context) { 1074 if (context == NULL) return; 1075 1076 ucontext_t *uc = (ucontext_t*)context; 1077 1078 st->print_cr("Register to memory mapping:"); 1079 st->cr(); 1080 1081 // this is horrendously verbose but the layout of the registers in the 1082 // context does not match how we defined our abstract Register set, so 1083 // we can't just iterate through the gregs area 1084 1085 // this is only for the "general purpose" registers 1086 1087 #ifdef AMD64 1088 st->print("RAX="); print_location(st, uc->context_rax); 1089 st->print("RBX="); print_location(st, uc->context_rbx); 1090 st->print("RCX="); print_location(st, uc->context_rcx); 1091 st->print("RDX="); print_location(st, uc->context_rdx); 1092 st->print("RSP="); print_location(st, uc->context_rsp); 1093 st->print("RBP="); print_location(st, uc->context_rbp); 1094 st->print("RSI="); print_location(st, uc->context_rsi); 1095 st->print("RDI="); print_location(st, uc->context_rdi); 1096 st->print("R8 ="); print_location(st, uc->context_r8); 1097 st->print("R9 ="); print_location(st, uc->context_r9); 1098 st->print("R10="); print_location(st, uc->context_r10); 1099 st->print("R11="); print_location(st, uc->context_r11); 1100 st->print("R12="); print_location(st, uc->context_r12); 1101 st->print("R13="); print_location(st, uc->context_r13); 1102 st->print("R14="); print_location(st, uc->context_r14); 1103 st->print("R15="); print_location(st, uc->context_r15); 1104 #else 1105 st->print("EAX="); print_location(st, uc->context_eax); 1106 st->print("EBX="); print_location(st, uc->context_ebx); 1107 st->print("ECX="); print_location(st, uc->context_ecx); 1108 st->print("EDX="); print_location(st, uc->context_edx); 1109 st->print("ESP="); print_location(st, uc->context_esp); 1110 st->print("EBP="); print_location(st, uc->context_ebp); 1111 st->print("ESI="); print_location(st, uc->context_esi); 1112 st->print("EDI="); print_location(st, uc->context_edi); 1113 #endif // AMD64 1114 1115 st->cr(); 1116 } 1117 1118 void os::setup_fpu() { 1119 #ifndef AMD64 1120 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std(); 1121 __asm__ volatile ( "fldcw (%0)" : 1122 : "r" (fpu_cntrl) : "memory"); 1123 #endif // !AMD64 1124 }