1 /* 2 * Copyright (c) 1999, 2014, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 // no precompiled headers 26 #include "asm/macroAssembler.hpp" 27 #include "classfile/classLoader.hpp" 28 #include "classfile/systemDictionary.hpp" 29 #include "classfile/vmSymbols.hpp" 30 #include "code/icBuffer.hpp" 31 #include "code/vtableStubs.hpp" 32 #include "interpreter/interpreter.hpp" 33 #include "jvm_bsd.h" 34 #include "memory/allocation.inline.hpp" 35 #include "mutex_bsd.inline.hpp" 36 #include "os_share_bsd.hpp" 37 #include "prims/jniFastGetField.hpp" 38 #include "prims/jvm.h" 39 #include "prims/jvm_misc.hpp" 40 #include "runtime/arguments.hpp" 41 #include "runtime/extendedPC.hpp" 42 #include "runtime/frame.inline.hpp" 43 #include "runtime/interfaceSupport.hpp" 44 #include "runtime/java.hpp" 45 #include "runtime/javaCalls.hpp" 46 #include "runtime/mutexLocker.hpp" 47 #include "runtime/osThread.hpp" 48 #include "runtime/sharedRuntime.hpp" 49 #include "runtime/stubRoutines.hpp" 50 #include "runtime/thread.inline.hpp" 51 #include "runtime/timer.hpp" 52 #include "utilities/events.hpp" 53 #include "utilities/vmError.hpp" 54 55 // put OS-includes here 56 # include <sys/types.h> 57 # include <sys/mman.h> 58 # include <pthread.h> 59 # include <signal.h> 60 # include <errno.h> 61 # include <dlfcn.h> 62 # include <stdlib.h> 63 # include <stdio.h> 64 # include <unistd.h> 65 # include <sys/resource.h> 66 # include <pthread.h> 67 # include <sys/stat.h> 68 # include <sys/time.h> 69 # include <sys/utsname.h> 70 # include <sys/socket.h> 71 # include <sys/wait.h> 72 # include <pwd.h> 73 # include <poll.h> 74 #ifndef __OpenBSD__ 75 # include <ucontext.h> 76 #endif 77 78 #if !defined(__APPLE__) && !defined(__NetBSD__) 79 # include <pthread_np.h> 80 #endif 81 82 // needed by current_stack_region() workaround for Mavericks 83 #if defined(__APPLE__) 84 # include <errno.h> 85 # include <sys/types.h> 86 # include <sys/sysctl.h> 87 # define DEFAULT_MAIN_THREAD_STACK_PAGES 2048 88 # define OS_X_10_9_0_KERNEL_MAJOR_VERSION 13 89 #endif 90 91 #ifdef AMD64 92 #define SPELL_REG_SP "rsp" 93 #define SPELL_REG_FP "rbp" 94 #else 95 #define SPELL_REG_SP "esp" 96 #define SPELL_REG_FP "ebp" 97 #endif // AMD64 98 99 #ifdef __FreeBSD__ 100 # define context_trapno uc_mcontext.mc_trapno 101 # ifdef AMD64 102 # define context_pc uc_mcontext.mc_rip 103 # define context_sp uc_mcontext.mc_rsp 104 # define context_fp uc_mcontext.mc_rbp 105 # define context_rip uc_mcontext.mc_rip 106 # define context_rsp uc_mcontext.mc_rsp 107 # define context_rbp uc_mcontext.mc_rbp 108 # define context_rax uc_mcontext.mc_rax 109 # define context_rbx uc_mcontext.mc_rbx 110 # define context_rcx uc_mcontext.mc_rcx 111 # define context_rdx uc_mcontext.mc_rdx 112 # define context_rsi uc_mcontext.mc_rsi 113 # define context_rdi uc_mcontext.mc_rdi 114 # define context_r8 uc_mcontext.mc_r8 115 # define context_r9 uc_mcontext.mc_r9 116 # define context_r10 uc_mcontext.mc_r10 117 # define context_r11 uc_mcontext.mc_r11 118 # define context_r12 uc_mcontext.mc_r12 119 # define context_r13 uc_mcontext.mc_r13 120 # define context_r14 uc_mcontext.mc_r14 121 # define context_r15 uc_mcontext.mc_r15 122 # define context_flags uc_mcontext.mc_flags 123 # define context_err uc_mcontext.mc_err 124 # else 125 # define context_pc uc_mcontext.mc_eip 126 # define context_sp uc_mcontext.mc_esp 127 # define context_fp uc_mcontext.mc_ebp 128 # define context_eip uc_mcontext.mc_eip 129 # define context_esp uc_mcontext.mc_esp 130 # define context_eax uc_mcontext.mc_eax 131 # define context_ebx uc_mcontext.mc_ebx 132 # define context_ecx uc_mcontext.mc_ecx 133 # define context_edx uc_mcontext.mc_edx 134 # define context_ebp uc_mcontext.mc_ebp 135 # define context_esi uc_mcontext.mc_esi 136 # define context_edi uc_mcontext.mc_edi 137 # define context_eflags uc_mcontext.mc_eflags 138 # define context_trapno uc_mcontext.mc_trapno 139 # endif 140 #endif 141 142 #ifdef __APPLE__ 143 # if __DARWIN_UNIX03 && (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5) 144 // 10.5 UNIX03 member name prefixes 145 #define DU3_PREFIX(s, m) __ ## s.__ ## m 146 # else 147 #define DU3_PREFIX(s, m) s ## . ## m 148 # endif 149 150 # ifdef AMD64 151 # define context_pc context_rip 152 # define context_sp context_rsp 153 # define context_fp context_rbp 154 # define context_rip uc_mcontext->DU3_PREFIX(ss,rip) 155 # define context_rsp uc_mcontext->DU3_PREFIX(ss,rsp) 156 # define context_rax uc_mcontext->DU3_PREFIX(ss,rax) 157 # define context_rbx uc_mcontext->DU3_PREFIX(ss,rbx) 158 # define context_rcx uc_mcontext->DU3_PREFIX(ss,rcx) 159 # define context_rdx uc_mcontext->DU3_PREFIX(ss,rdx) 160 # define context_rbp uc_mcontext->DU3_PREFIX(ss,rbp) 161 # define context_rsi uc_mcontext->DU3_PREFIX(ss,rsi) 162 # define context_rdi uc_mcontext->DU3_PREFIX(ss,rdi) 163 # define context_r8 uc_mcontext->DU3_PREFIX(ss,r8) 164 # define context_r9 uc_mcontext->DU3_PREFIX(ss,r9) 165 # define context_r10 uc_mcontext->DU3_PREFIX(ss,r10) 166 # define context_r11 uc_mcontext->DU3_PREFIX(ss,r11) 167 # define context_r12 uc_mcontext->DU3_PREFIX(ss,r12) 168 # define context_r13 uc_mcontext->DU3_PREFIX(ss,r13) 169 # define context_r14 uc_mcontext->DU3_PREFIX(ss,r14) 170 # define context_r15 uc_mcontext->DU3_PREFIX(ss,r15) 171 # define context_flags uc_mcontext->DU3_PREFIX(ss,rflags) 172 # define context_trapno uc_mcontext->DU3_PREFIX(es,trapno) 173 # define context_err uc_mcontext->DU3_PREFIX(es,err) 174 # else 175 # define context_pc context_eip 176 # define context_sp context_esp 177 # define context_fp context_ebp 178 # define context_eip uc_mcontext->DU3_PREFIX(ss,eip) 179 # define context_esp uc_mcontext->DU3_PREFIX(ss,esp) 180 # define context_eax uc_mcontext->DU3_PREFIX(ss,eax) 181 # define context_ebx uc_mcontext->DU3_PREFIX(ss,ebx) 182 # define context_ecx uc_mcontext->DU3_PREFIX(ss,ecx) 183 # define context_edx uc_mcontext->DU3_PREFIX(ss,edx) 184 # define context_ebp uc_mcontext->DU3_PREFIX(ss,ebp) 185 # define context_esi uc_mcontext->DU3_PREFIX(ss,esi) 186 # define context_edi uc_mcontext->DU3_PREFIX(ss,edi) 187 # define context_eflags uc_mcontext->DU3_PREFIX(ss,eflags) 188 # define context_trapno uc_mcontext->DU3_PREFIX(es,trapno) 189 # endif 190 #endif 191 192 #ifdef __OpenBSD__ 193 # define context_trapno sc_trapno 194 # ifdef AMD64 195 # define context_pc sc_rip 196 # define context_sp sc_rsp 197 # define context_fp sc_rbp 198 # define context_rip sc_rip 199 # define context_rsp sc_rsp 200 # define context_rbp sc_rbp 201 # define context_rax sc_rax 202 # define context_rbx sc_rbx 203 # define context_rcx sc_rcx 204 # define context_rdx sc_rdx 205 # define context_rsi sc_rsi 206 # define context_rdi sc_rdi 207 # define context_r8 sc_r8 208 # define context_r9 sc_r9 209 # define context_r10 sc_r10 210 # define context_r11 sc_r11 211 # define context_r12 sc_r12 212 # define context_r13 sc_r13 213 # define context_r14 sc_r14 214 # define context_r15 sc_r15 215 # define context_flags sc_rflags 216 # define context_err sc_err 217 # else 218 # define context_pc sc_eip 219 # define context_sp sc_esp 220 # define context_fp sc_ebp 221 # define context_eip sc_eip 222 # define context_esp sc_esp 223 # define context_eax sc_eax 224 # define context_ebx sc_ebx 225 # define context_ecx sc_ecx 226 # define context_edx sc_edx 227 # define context_ebp sc_ebp 228 # define context_esi sc_esi 229 # define context_edi sc_edi 230 # define context_eflags sc_eflags 231 # define context_trapno sc_trapno 232 # endif 233 #endif 234 235 #ifdef __NetBSD__ 236 # define context_trapno uc_mcontext.__gregs[_REG_TRAPNO] 237 # ifdef AMD64 238 # define __register_t __greg_t 239 # define context_pc uc_mcontext.__gregs[_REG_RIP] 240 # define context_sp uc_mcontext.__gregs[_REG_URSP] 241 # define context_fp uc_mcontext.__gregs[_REG_RBP] 242 # define context_rip uc_mcontext.__gregs[_REG_RIP] 243 # define context_rsp uc_mcontext.__gregs[_REG_URSP] 244 # define context_rax uc_mcontext.__gregs[_REG_RAX] 245 # define context_rbx uc_mcontext.__gregs[_REG_RBX] 246 # define context_rcx uc_mcontext.__gregs[_REG_RCX] 247 # define context_rdx uc_mcontext.__gregs[_REG_RDX] 248 # define context_rbp uc_mcontext.__gregs[_REG_RBP] 249 # define context_rsi uc_mcontext.__gregs[_REG_RSI] 250 # define context_rdi uc_mcontext.__gregs[_REG_RDI] 251 # define context_r8 uc_mcontext.__gregs[_REG_R8] 252 # define context_r9 uc_mcontext.__gregs[_REG_R9] 253 # define context_r10 uc_mcontext.__gregs[_REG_R10] 254 # define context_r11 uc_mcontext.__gregs[_REG_R11] 255 # define context_r12 uc_mcontext.__gregs[_REG_R12] 256 # define context_r13 uc_mcontext.__gregs[_REG_R13] 257 # define context_r14 uc_mcontext.__gregs[_REG_R14] 258 # define context_r15 uc_mcontext.__gregs[_REG_R15] 259 # define context_flags uc_mcontext.__gregs[_REG_RFL] 260 # define context_err uc_mcontext.__gregs[_REG_ERR] 261 # else 262 # define context_pc uc_mcontext.__gregs[_REG_EIP] 263 # define context_sp uc_mcontext.__gregs[_REG_UESP] 264 # define context_fp uc_mcontext.__gregs[_REG_EBP] 265 # define context_eip uc_mcontext.__gregs[_REG_EIP] 266 # define context_esp uc_mcontext.__gregs[_REG_UESP] 267 # define context_eax uc_mcontext.__gregs[_REG_EAX] 268 # define context_ebx uc_mcontext.__gregs[_REG_EBX] 269 # define context_ecx uc_mcontext.__gregs[_REG_ECX] 270 # define context_edx uc_mcontext.__gregs[_REG_EDX] 271 # define context_ebp uc_mcontext.__gregs[_REG_EBP] 272 # define context_esi uc_mcontext.__gregs[_REG_ESI] 273 # define context_edi uc_mcontext.__gregs[_REG_EDI] 274 # define context_eflags uc_mcontext.__gregs[_REG_EFL] 275 # define context_trapno uc_mcontext.__gregs[_REG_TRAPNO] 276 # endif 277 #endif 278 279 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 280 281 address os::current_stack_pointer() { 282 #if defined(__clang__) || defined(__llvm__) 283 register void *esp; 284 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp)); 285 return (address) esp; 286 #elif defined(SPARC_WORKS) 287 register void *esp; 288 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp)); 289 return (address) ((char*)esp + sizeof(long)*2); 290 #else 291 register void *esp __asm__ (SPELL_REG_SP); 292 return (address) esp; 293 #endif 294 } 295 296 char* os::non_memory_address_word() { 297 // Must never look like an address returned by reserve_memory, 298 // even in its subfields (as defined by the CPU immediate fields, 299 // if the CPU splits constants across multiple instructions). 300 301 return (char*) -1; 302 } 303 304 void os::initialize_thread(Thread* thr) { 305 // Nothing to do. 306 } 307 308 address os::Bsd::ucontext_get_pc(ucontext_t * uc) { 309 return (address)uc->context_pc; 310 } 311 312 void os::Bsd::ucontext_set_pc(ucontext_t * uc, address pc) { 313 uc->context_pc = (intptr_t)pc ; 314 } 315 316 intptr_t* os::Bsd::ucontext_get_sp(ucontext_t * uc) { 317 return (intptr_t*)uc->context_sp; 318 } 319 320 intptr_t* os::Bsd::ucontext_get_fp(ucontext_t * uc) { 321 return (intptr_t*)uc->context_fp; 322 } 323 324 // For Forte Analyzer AsyncGetCallTrace profiling support - thread 325 // is currently interrupted by SIGPROF. 326 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal 327 // frames. Currently we don't do that on Bsd, so it's the same as 328 // os::fetch_frame_from_context(). 329 ExtendedPC os::Bsd::fetch_frame_from_ucontext(Thread* thread, 330 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 } 338 339 ExtendedPC os::fetch_frame_from_context(void* ucVoid, 340 intptr_t** ret_sp, intptr_t** ret_fp) { 341 342 ExtendedPC epc; 343 ucontext_t* uc = (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 } 358 359 frame os::fetch_frame_from_context(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 } 365 366 // By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get 367 // turned off by -fomit-frame-pointer, 368 frame os::get_sender_for_C_frame(frame* fr) { 369 return frame(fr->sender_sp(), fr->link(), fr->sender_pc()); 370 } 371 372 intptr_t* _get_previous_fp() { 373 #if defined(SPARC_WORKS) || defined(__clang__) || defined(__llvm__) 374 register intptr_t **ebp; 375 __asm__("mov %%"SPELL_REG_FP", %0":"=r"(ebp)); 376 #else 377 register intptr_t **ebp __asm__ (SPELL_REG_FP); 378 #endif 379 return (intptr_t*) *ebp; // we want what it points to. 380 } 381 382 383 frame os::current_frame() { 384 intptr_t* fp = _get_previous_fp(); 385 frame myframe((intptr_t*)os::current_stack_pointer(), 386 (intptr_t*)fp, 387 CAST_FROM_FN_PTR(address, os::current_frame)); 388 if (os::is_first_C_frame(&myframe)) { 389 // stack is not walkable 390 return frame(); 391 } else { 392 return os::get_sender_for_C_frame(&myframe); 393 } 394 } 395 396 // Utility functions 397 398 // From IA32 System Programming Guide 399 enum { 400 trap_page_fault = 0xE 401 }; 402 403 extern "C" JNIEXPORT int 404 JVM_handle_bsd_signal(int sig, 405 siginfo_t* info, 406 void* ucVoid, 407 int abort_if_unrecognized) { 408 ucontext_t* uc = (ucontext_t*) ucVoid; 409 410 Thread* t = ThreadLocalStorage::get_thread_slow(); 411 412 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away 413 // (no destructors can be run) 414 os::WatcherThreadCrashProtection::check_crash_protection(sig, t); 415 416 SignalHandlerMark shm(t); 417 418 // Note: it's not uncommon that JNI code uses signal/sigset to install 419 // then restore certain signal handler (e.g. to temporarily block SIGPIPE, 420 // or have a SIGILL handler when detecting CPU type). When that happens, 421 // JVM_handle_bsd_signal() might be invoked with junk info/ucVoid. To 422 // avoid unnecessary crash when libjsig is not preloaded, try handle signals 423 // that do not require siginfo/ucontext first. 424 425 if (sig == SIGPIPE || sig == SIGXFSZ) { 426 // allow chained handler to go first 427 if (os::Bsd::chained_handler(sig, info, ucVoid)) { 428 return true; 429 } else { 430 if (PrintMiscellaneous && (WizardMode || Verbose)) { 431 char buf[64]; 432 warning("Ignoring %s - see bugs 4229104 or 646499219", 433 os::exception_name(sig, buf, sizeof(buf))); 434 } 435 return true; 436 } 437 } 438 439 JavaThread* thread = NULL; 440 VMThread* vmthread = NULL; 441 if (os::Bsd::signal_handlers_are_installed) { 442 if (t != NULL ){ 443 if(t->is_Java_thread()) { 444 thread = (JavaThread*)t; 445 } 446 else if(t->is_VM_thread()){ 447 vmthread = (VMThread *)t; 448 } 449 } 450 } 451 /* 452 NOTE: does not seem to work on bsd. 453 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) { 454 // can't decode this kind of signal 455 info = NULL; 456 } else { 457 assert(sig == info->si_signo, "bad siginfo"); 458 } 459 */ 460 // decide if this trap can be handled by a stub 461 address stub = NULL; 462 463 address pc = NULL; 464 465 //%note os_trap_1 466 if (info != NULL && uc != NULL && thread != NULL) { 467 pc = (address) os::Bsd::ucontext_get_pc(uc); 468 469 if (StubRoutines::is_safefetch_fault(pc)) { 470 os::Bsd::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc)); 471 return 1; 472 } 473 474 // Handle ALL stack overflow variations here 475 if (sig == SIGSEGV || sig == SIGBUS) { 476 address addr = (address) info->si_addr; 477 478 // check if fault address is within thread stack 479 if (addr < thread->stack_base() && 480 addr >= thread->stack_base() - thread->stack_size()) { 481 // stack overflow 482 if (thread->in_stack_yellow_zone(addr)) { 483 thread->disable_stack_yellow_zone(); 484 if (thread->thread_state() == _thread_in_Java) { 485 // Throw a stack overflow exception. Guard pages will be reenabled 486 // while unwinding the stack. 487 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); 488 } else { 489 // Thread was in the vm or native code. Return and try to finish. 490 return 1; 491 } 492 } else if (thread->in_stack_red_zone(addr)) { 493 // Fatal red zone violation. Disable the guard pages and fall through 494 // to handle_unexpected_exception way down below. 495 thread->disable_stack_red_zone(); 496 tty->print_raw_cr("An irrecoverable stack overflow has occurred."); 497 } 498 } 499 } 500 501 if ((sig == SIGSEGV || sig == SIGBUS) && VM_Version::is_cpuinfo_segv_addr(pc)) { 502 // Verify that OS save/restore AVX registers. 503 stub = VM_Version::cpuinfo_cont_addr(); 504 } 505 506 // We test if stub is already set (by the stack overflow code 507 // above) so it is not overwritten by the code that follows. This 508 // check is not required on other platforms, because on other 509 // platforms we check for SIGSEGV only or SIGBUS only, where here 510 // we have to check for both SIGSEGV and SIGBUS. 511 if (thread->thread_state() == _thread_in_Java && stub == NULL) { 512 // Java thread running in Java code => find exception handler if any 513 // a fault inside compiled code, the interpreter, or a stub 514 515 if ((sig == SIGSEGV || sig == SIGBUS) && os::is_poll_address((address)info->si_addr)) { 516 stub = SharedRuntime::get_poll_stub(pc); 517 #if defined(__APPLE__) 518 // 32-bit Darwin reports a SIGBUS for nearly all memory access exceptions. 519 // 64-bit Darwin may also use a SIGBUS (seen with compressed oops). 520 // Catching SIGBUS here prevents the implicit SIGBUS NULL check below from 521 // being called, so only do so if the implicit NULL check is not necessary. 522 } else if (sig == SIGBUS && MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { 523 #else 524 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) { 525 #endif 526 // BugId 4454115: A read from a MappedByteBuffer can fault 527 // here if the underlying file has been truncated. 528 // Do not crash the VM in such a case. 529 CodeBlob* cb = CodeCache::find_blob_unsafe(pc); 530 nmethod* nm = (cb != NULL && cb->is_nmethod()) ? (nmethod*)cb : NULL; 531 if (nm != NULL && nm->has_unsafe_access()) { 532 stub = StubRoutines::handler_for_unsafe_access(); 533 } 534 } 535 else 536 537 #ifdef AMD64 538 if (sig == SIGFPE && 539 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) { 540 stub = 541 SharedRuntime:: 542 continuation_for_implicit_exception(thread, 543 pc, 544 SharedRuntime:: 545 IMPLICIT_DIVIDE_BY_ZERO); 546 #ifdef __APPLE__ 547 } else if (sig == SIGFPE && info->si_code == FPE_NOOP) { 548 int op = pc[0]; 549 550 // Skip REX 551 if ((pc[0] & 0xf0) == 0x40) { 552 op = pc[1]; 553 } else { 554 op = pc[0]; 555 } 556 557 // Check for IDIV 558 if (op == 0xF7) { 559 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime:: IMPLICIT_DIVIDE_BY_ZERO); 560 } else { 561 // TODO: handle more cases if we are using other x86 instructions 562 // that can generate SIGFPE signal. 563 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); 564 fatal("please update this code."); 565 } 566 #endif /* __APPLE__ */ 567 568 #else 569 if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) { 570 // HACK: si_code does not work on bsd 2.2.12-20!!! 571 int op = pc[0]; 572 if (op == 0xDB) { 573 // FIST 574 // TODO: The encoding of D2I in i486.ad can cause an exception 575 // prior to the fist instruction if there was an invalid operation 576 // pending. We want to dismiss that exception. From the win_32 577 // side it also seems that if it really was the fist causing 578 // the exception that we do the d2i by hand with different 579 // rounding. Seems kind of weird. 580 // NOTE: that we take the exception at the NEXT floating point instruction. 581 assert(pc[0] == 0xDB, "not a FIST opcode"); 582 assert(pc[1] == 0x14, "not a FIST opcode"); 583 assert(pc[2] == 0x24, "not a FIST opcode"); 584 return true; 585 } else if (op == 0xF7) { 586 // IDIV 587 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); 588 } else { 589 // TODO: handle more cases if we are using other x86 instructions 590 // that can generate SIGFPE signal on bsd. 591 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); 592 fatal("please update this code."); 593 } 594 #endif // AMD64 595 } else if ((sig == SIGSEGV || sig == SIGBUS) && 596 !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { 597 // Determination of interpreter/vtable stub/compiled code null exception 598 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 599 } 600 } else if (thread->thread_state() == _thread_in_vm && 601 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */ 602 thread->doing_unsafe_access()) { 603 stub = StubRoutines::handler_for_unsafe_access(); 604 } 605 606 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in 607 // and the heap gets shrunk before the field access. 608 if ((sig == SIGSEGV) || (sig == SIGBUS)) { 609 address addr = JNI_FastGetField::find_slowcase_pc(pc); 610 if (addr != (address)-1) { 611 stub = addr; 612 } 613 } 614 615 // Check to see if we caught the safepoint code in the 616 // process of write protecting the memory serialization page. 617 // It write enables the page immediately after protecting it 618 // so we can just return to retry the write. 619 if ((sig == SIGSEGV || sig == SIGBUS) && 620 os::is_memory_serialize_page(thread, (address) info->si_addr)) { 621 // Block current thread until the memory serialize page permission restored. 622 os::block_on_serialize_page_trap(); 623 return true; 624 } 625 } 626 627 #ifndef AMD64 628 // Execution protection violation 629 // 630 // This should be kept as the last step in the triage. We don't 631 // have a dedicated trap number for a no-execute fault, so be 632 // conservative and allow other handlers the first shot. 633 // 634 // Note: We don't test that info->si_code == SEGV_ACCERR here. 635 // this si_code is so generic that it is almost meaningless; and 636 // the si_code for this condition may change in the future. 637 // Furthermore, a false-positive should be harmless. 638 if (UnguardOnExecutionViolation > 0 && 639 (sig == SIGSEGV || sig == SIGBUS) && 640 uc->context_trapno == trap_page_fault) { 641 int page_size = os::vm_page_size(); 642 address addr = (address) info->si_addr; 643 address pc = os::Bsd::ucontext_get_pc(uc); 644 // Make sure the pc and the faulting address are sane. 645 // 646 // If an instruction spans a page boundary, and the page containing 647 // the beginning of the instruction is executable but the following 648 // page is not, the pc and the faulting address might be slightly 649 // different - we still want to unguard the 2nd page in this case. 650 // 651 // 15 bytes seems to be a (very) safe value for max instruction size. 652 bool pc_is_near_addr = 653 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15); 654 bool instr_spans_page_boundary = 655 (align_size_down((intptr_t) pc ^ (intptr_t) addr, 656 (intptr_t) page_size) > 0); 657 658 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) { 659 static volatile address last_addr = 660 (address) os::non_memory_address_word(); 661 662 // In conservative mode, don't unguard unless the address is in the VM 663 if (addr != last_addr && 664 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) { 665 666 // Set memory to RWX and retry 667 address page_start = 668 (address) align_size_down((intptr_t) addr, (intptr_t) page_size); 669 bool res = os::protect_memory((char*) page_start, page_size, 670 os::MEM_PROT_RWX); 671 672 if (PrintMiscellaneous && Verbose) { 673 char buf[256]; 674 jio_snprintf(buf, sizeof(buf), "Execution protection violation " 675 "at " INTPTR_FORMAT 676 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr, 677 page_start, (res ? "success" : "failed"), errno); 678 tty->print_raw_cr(buf); 679 } 680 stub = pc; 681 682 // Set last_addr so if we fault again at the same address, we don't end 683 // up in an endless loop. 684 // 685 // There are two potential complications here. Two threads trapping at 686 // the same address at the same time could cause one of the threads to 687 // think it already unguarded, and abort the VM. Likely very rare. 688 // 689 // The other race involves two threads alternately trapping at 690 // different addresses and failing to unguard the page, resulting in 691 // an endless loop. This condition is probably even more unlikely than 692 // the first. 693 // 694 // Although both cases could be avoided by using locks or thread local 695 // last_addr, these solutions are unnecessary complication: this 696 // handler is a best-effort safety net, not a complete solution. It is 697 // disabled by default and should only be used as a workaround in case 698 // we missed any no-execute-unsafe VM code. 699 700 last_addr = addr; 701 } 702 } 703 } 704 #endif // !AMD64 705 706 if (stub != NULL) { 707 // save all thread context in case we need to restore it 708 if (thread != NULL) thread->set_saved_exception_pc(pc); 709 710 os::Bsd::ucontext_set_pc(uc, stub); 711 return true; 712 } 713 714 // signal-chaining 715 if (os::Bsd::chained_handler(sig, info, ucVoid)) { 716 return true; 717 } 718 719 if (!abort_if_unrecognized) { 720 // caller wants another chance, so give it to him 721 return false; 722 } 723 724 if (pc == NULL && uc != NULL) { 725 pc = os::Bsd::ucontext_get_pc(uc); 726 } 727 728 // unmask current signal 729 sigset_t newset; 730 sigemptyset(&newset); 731 sigaddset(&newset, sig); 732 sigprocmask(SIG_UNBLOCK, &newset, NULL); 733 734 VMError err(t, sig, pc, info, ucVoid); 735 err.report_and_die(); 736 737 ShouldNotReachHere(); 738 return false; 739 } 740 741 // From solaris_i486.s ported to bsd_i486.s 742 extern "C" void fixcw(); 743 744 void os::Bsd::init_thread_fpu_state(void) { 745 #ifndef AMD64 746 // Set fpu to 53 bit precision. This happens too early to use a stub. 747 fixcw(); 748 #endif // !AMD64 749 } 750 751 752 // Check that the bsd kernel version is 2.4 or higher since earlier 753 // versions do not support SSE without patches. 754 bool os::supports_sse() { 755 return true; 756 } 757 758 bool os::is_allocatable(size_t bytes) { 759 #ifdef AMD64 760 // unused on amd64? 761 return true; 762 #else 763 764 if (bytes < 2 * G) { 765 return true; 766 } 767 768 char* addr = reserve_memory(bytes, NULL); 769 770 if (addr != NULL) { 771 release_memory(addr, bytes); 772 } 773 774 return addr != NULL; 775 #endif // AMD64 776 } 777 778 //////////////////////////////////////////////////////////////////////////////// 779 // thread stack 780 781 #ifdef AMD64 782 size_t os::Bsd::min_stack_allowed = 64 * K; 783 784 // amd64: pthread on amd64 is always in floating stack mode 785 bool os::Bsd::supports_variable_stack_size() { return true; } 786 #else 787 size_t os::Bsd::min_stack_allowed = (48 DEBUG_ONLY(+4))*K; 788 789 #ifdef __GNUC__ 790 #define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;}) 791 #endif 792 793 bool os::Bsd::supports_variable_stack_size() { return true; } 794 #endif // AMD64 795 796 // return default stack size for thr_type 797 size_t os::Bsd::default_stack_size(os::ThreadType thr_type) { 798 // default stack size (compiler thread needs larger stack) 799 #ifdef AMD64 800 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M); 801 #else 802 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K); 803 #endif // AMD64 804 return s; 805 } 806 807 size_t os::Bsd::default_guard_size(os::ThreadType thr_type) { 808 // Creating guard page is very expensive. Java thread has HotSpot 809 // guard page, only enable glibc guard page for non-Java threads. 810 return (thr_type == java_thread ? 0 : page_size()); 811 } 812 813 // Java thread: 814 // 815 // Low memory addresses 816 // +------------------------+ 817 // | |\ JavaThread created by VM does not have glibc 818 // | glibc guard page | - guard, attached Java thread usually has 819 // | |/ 1 page glibc guard. 820 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 821 // | |\ 822 // | HotSpot Guard Pages | - red and yellow pages 823 // | |/ 824 // +------------------------+ JavaThread::stack_yellow_zone_base() 825 // | |\ 826 // | Normal Stack | - 827 // | |/ 828 // P2 +------------------------+ Thread::stack_base() 829 // 830 // Non-Java thread: 831 // 832 // Low memory addresses 833 // +------------------------+ 834 // | |\ 835 // | glibc guard page | - usually 1 page 836 // | |/ 837 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 838 // | |\ 839 // | Normal Stack | - 840 // | |/ 841 // P2 +------------------------+ Thread::stack_base() 842 // 843 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from 844 // pthread_attr_getstack() 845 846 static void current_stack_region(address * bottom, size_t * size) { 847 #ifdef __APPLE__ 848 pthread_t self = pthread_self(); 849 void *stacktop = pthread_get_stackaddr_np(self); 850 *size = pthread_get_stacksize_np(self); 851 // workaround for OS X 10.9.0 (Mavericks) 852 // pthread_get_stacksize_np returns 128 pages even though the actual size is 2048 pages 853 if (pthread_main_np() == 1) { 854 if ((*size) < (DEFAULT_MAIN_THREAD_STACK_PAGES * (size_t)getpagesize())) { 855 char kern_osrelease[256]; 856 size_t kern_osrelease_size = sizeof(kern_osrelease); 857 int ret = sysctlbyname("kern.osrelease", kern_osrelease, &kern_osrelease_size, NULL, 0); 858 if (ret == 0) { 859 // get the major number, atoi will ignore the minor amd micro portions of the version string 860 if (atoi(kern_osrelease) >= OS_X_10_9_0_KERNEL_MAJOR_VERSION) { 861 *size = (DEFAULT_MAIN_THREAD_STACK_PAGES*getpagesize()); 862 } 863 } 864 } 865 } 866 *bottom = (address) stacktop - *size; 867 #elif defined(__OpenBSD__) 868 stack_t ss; 869 int rslt = pthread_stackseg_np(pthread_self(), &ss); 870 871 if (rslt != 0) 872 fatal(err_msg("pthread_stackseg_np failed with err = %d", rslt)); 873 874 *bottom = (address)((char *)ss.ss_sp - ss.ss_size); 875 *size = ss.ss_size; 876 #else 877 pthread_attr_t attr; 878 879 int rslt = pthread_attr_init(&attr); 880 881 // JVM needs to know exact stack location, abort if it fails 882 if (rslt != 0) 883 fatal(err_msg("pthread_attr_init failed with err = %d", rslt)); 884 885 rslt = pthread_attr_get_np(pthread_self(), &attr); 886 887 if (rslt != 0) 888 fatal(err_msg("pthread_attr_get_np failed with err = %d", rslt)); 889 890 if (pthread_attr_getstackaddr(&attr, (void **)bottom) != 0 || 891 pthread_attr_getstacksize(&attr, size) != 0) { 892 fatal("Can not locate current stack attributes!"); 893 } 894 895 pthread_attr_destroy(&attr); 896 #endif 897 assert(os::current_stack_pointer() >= *bottom && 898 os::current_stack_pointer() < *bottom + *size, "just checking"); 899 } 900 901 address os::current_stack_base() { 902 address bottom; 903 size_t size; 904 current_stack_region(&bottom, &size); 905 return (bottom + size); 906 } 907 908 size_t os::current_stack_size() { 909 // stack size includes normal stack and HotSpot guard pages 910 address bottom; 911 size_t size; 912 current_stack_region(&bottom, &size); 913 return size; 914 } 915 916 ///////////////////////////////////////////////////////////////////////////// 917 // helper functions for fatal error handler 918 919 void os::print_context(outputStream *st, void *context) { 920 if (context == NULL) return; 921 922 ucontext_t *uc = (ucontext_t*)context; 923 st->print_cr("Registers:"); 924 #ifdef AMD64 925 st->print( "RAX=" INTPTR_FORMAT, uc->context_rax); 926 st->print(", RBX=" INTPTR_FORMAT, uc->context_rbx); 927 st->print(", RCX=" INTPTR_FORMAT, uc->context_rcx); 928 st->print(", RDX=" INTPTR_FORMAT, uc->context_rdx); 929 st->cr(); 930 st->print( "RSP=" INTPTR_FORMAT, uc->context_rsp); 931 st->print(", RBP=" INTPTR_FORMAT, uc->context_rbp); 932 st->print(", RSI=" INTPTR_FORMAT, uc->context_rsi); 933 st->print(", RDI=" INTPTR_FORMAT, uc->context_rdi); 934 st->cr(); 935 st->print( "R8 =" INTPTR_FORMAT, uc->context_r8); 936 st->print(", R9 =" INTPTR_FORMAT, uc->context_r9); 937 st->print(", R10=" INTPTR_FORMAT, uc->context_r10); 938 st->print(", R11=" INTPTR_FORMAT, uc->context_r11); 939 st->cr(); 940 st->print( "R12=" INTPTR_FORMAT, uc->context_r12); 941 st->print(", R13=" INTPTR_FORMAT, uc->context_r13); 942 st->print(", R14=" INTPTR_FORMAT, uc->context_r14); 943 st->print(", R15=" INTPTR_FORMAT, uc->context_r15); 944 st->cr(); 945 st->print( "RIP=" INTPTR_FORMAT, uc->context_rip); 946 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_flags); 947 st->print(", ERR=" INTPTR_FORMAT, uc->context_err); 948 st->cr(); 949 st->print(" TRAPNO=" INTPTR_FORMAT, uc->context_trapno); 950 #else 951 st->print( "EAX=" INTPTR_FORMAT, uc->context_eax); 952 st->print(", EBX=" INTPTR_FORMAT, uc->context_ebx); 953 st->print(", ECX=" INTPTR_FORMAT, uc->context_ecx); 954 st->print(", EDX=" INTPTR_FORMAT, uc->context_edx); 955 st->cr(); 956 st->print( "ESP=" INTPTR_FORMAT, uc->context_esp); 957 st->print(", EBP=" INTPTR_FORMAT, uc->context_ebp); 958 st->print(", ESI=" INTPTR_FORMAT, uc->context_esi); 959 st->print(", EDI=" INTPTR_FORMAT, uc->context_edi); 960 st->cr(); 961 st->print( "EIP=" INTPTR_FORMAT, uc->context_eip); 962 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_eflags); 963 #endif // AMD64 964 st->cr(); 965 st->cr(); 966 967 intptr_t *sp = (intptr_t *)os::Bsd::ucontext_get_sp(uc); 968 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp); 969 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t)); 970 st->cr(); 971 972 // Note: it may be unsafe to inspect memory near pc. For example, pc may 973 // point to garbage if entry point in an nmethod is corrupted. Leave 974 // this at the end, and hope for the best. 975 address pc = os::Bsd::ucontext_get_pc(uc); 976 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc); 977 print_hex_dump(st, pc - 32, pc + 32, sizeof(char)); 978 } 979 980 void os::print_register_info(outputStream *st, void *context) { 981 if (context == NULL) return; 982 983 ucontext_t *uc = (ucontext_t*)context; 984 985 st->print_cr("Register to memory mapping:"); 986 st->cr(); 987 988 // this is horrendously verbose but the layout of the registers in the 989 // context does not match how we defined our abstract Register set, so 990 // we can't just iterate through the gregs area 991 992 // this is only for the "general purpose" registers 993 994 #ifdef AMD64 995 st->print("RAX="); print_location(st, uc->context_rax); 996 st->print("RBX="); print_location(st, uc->context_rbx); 997 st->print("RCX="); print_location(st, uc->context_rcx); 998 st->print("RDX="); print_location(st, uc->context_rdx); 999 st->print("RSP="); print_location(st, uc->context_rsp); 1000 st->print("RBP="); print_location(st, uc->context_rbp); 1001 st->print("RSI="); print_location(st, uc->context_rsi); 1002 st->print("RDI="); print_location(st, uc->context_rdi); 1003 st->print("R8 ="); print_location(st, uc->context_r8); 1004 st->print("R9 ="); print_location(st, uc->context_r9); 1005 st->print("R10="); print_location(st, uc->context_r10); 1006 st->print("R11="); print_location(st, uc->context_r11); 1007 st->print("R12="); print_location(st, uc->context_r12); 1008 st->print("R13="); print_location(st, uc->context_r13); 1009 st->print("R14="); print_location(st, uc->context_r14); 1010 st->print("R15="); print_location(st, uc->context_r15); 1011 #else 1012 st->print("EAX="); print_location(st, uc->context_eax); 1013 st->print("EBX="); print_location(st, uc->context_ebx); 1014 st->print("ECX="); print_location(st, uc->context_ecx); 1015 st->print("EDX="); print_location(st, uc->context_edx); 1016 st->print("ESP="); print_location(st, uc->context_esp); 1017 st->print("EBP="); print_location(st, uc->context_ebp); 1018 st->print("ESI="); print_location(st, uc->context_esi); 1019 st->print("EDI="); print_location(st, uc->context_edi); 1020 #endif // AMD64 1021 1022 st->cr(); 1023 } 1024 1025 void os::setup_fpu() { 1026 #ifndef AMD64 1027 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std(); 1028 __asm__ volatile ( "fldcw (%0)" : 1029 : "r" (fpu_cntrl) : "memory"); 1030 #endif // !AMD64 1031 } 1032 1033 #ifndef PRODUCT 1034 void os::verify_stack_alignment() { 1035 } 1036 #endif 1037 1038 int os::extra_bang_size_in_bytes() { 1039 // JDK-8050147 requires the full cache line bang for x86. 1040 return VM_Version::L1_line_size(); 1041 }