1 /* 2 * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved. 3 * Copyright (c) 2012, 2016 SAP SE. All rights reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 * 24 */ 25 26 // no precompiled headers 27 #include "asm/assembler.inline.hpp" 28 #include "classfile/classLoader.hpp" 29 #include "classfile/systemDictionary.hpp" 30 #include "classfile/vmSymbols.hpp" 31 #include "code/codeCache.hpp" 32 #include "code/icBuffer.hpp" 33 #include "code/vtableStubs.hpp" 34 #include "interpreter/interpreter.hpp" 35 #include "jvm_linux.h" 36 #include "memory/allocation.inline.hpp" 37 #include "nativeInst_ppc.hpp" 38 #include "os_share_linux.hpp" 39 #include "prims/jniFastGetField.hpp" 40 #include "prims/jvm.h" 41 #include "prims/jvm_misc.hpp" 42 #include "runtime/arguments.hpp" 43 #include "runtime/extendedPC.hpp" 44 #include "runtime/frame.inline.hpp" 45 #include "runtime/interfaceSupport.hpp" 46 #include "runtime/java.hpp" 47 #include "runtime/javaCalls.hpp" 48 #include "runtime/mutexLocker.hpp" 49 #include "runtime/osThread.hpp" 50 #include "runtime/sharedRuntime.hpp" 51 #include "runtime/stubRoutines.hpp" 52 #include "runtime/thread.inline.hpp" 53 #include "runtime/timer.hpp" 54 #include "utilities/events.hpp" 55 #include "utilities/vmError.hpp" 56 57 // put OS-includes here 58 # include <sys/types.h> 59 # include <sys/mman.h> 60 # include <pthread.h> 61 # include <signal.h> 62 # include <errno.h> 63 # include <dlfcn.h> 64 # include <stdlib.h> 65 # include <stdio.h> 66 # include <unistd.h> 67 # include <sys/resource.h> 68 # include <pthread.h> 69 # include <sys/stat.h> 70 # include <sys/time.h> 71 # include <sys/utsname.h> 72 # include <sys/socket.h> 73 # include <sys/wait.h> 74 # include <pwd.h> 75 # include <poll.h> 76 # include <ucontext.h> 77 78 79 address os::current_stack_pointer() { 80 intptr_t* csp; 81 82 // inline assembly `mr regno(csp), R1_SP': 83 __asm__ __volatile__ ("mr %0, 1":"=r"(csp):); 84 85 return (address) csp; 86 } 87 88 char* os::non_memory_address_word() { 89 // Must never look like an address returned by reserve_memory, 90 // even in its subfields (as defined by the CPU immediate fields, 91 // if the CPU splits constants across multiple instructions). 92 93 return (char*) -1; 94 } 95 96 void os::initialize_thread(Thread *thread) { } 97 98 // Frame information (pc, sp, fp) retrieved via ucontext 99 // always looks like a C-frame according to the frame 100 // conventions in frame_ppc64.hpp. 101 address os::Linux::ucontext_get_pc(const ucontext_t * uc) { 102 // On powerpc64, ucontext_t is not selfcontained but contains 103 // a pointer to an optional substructure (mcontext_t.regs) containing the volatile 104 // registers - NIP, among others. 105 // This substructure may or may not be there depending where uc came from: 106 // - if uc was handed over as the argument to a sigaction handler, a pointer to the 107 // substructure was provided by the kernel when calling the signal handler, and 108 // regs->nip can be accessed. 109 // - if uc was filled by getcontext(), it is undefined - getcontext() does not fill 110 // it because the volatile registers are not needed to make setcontext() work. 111 // Hopefully it was zero'd out beforehand. 112 guarantee(uc->uc_mcontext.regs != NULL, "only use ucontext_get_pc in sigaction context"); 113 return (address)uc->uc_mcontext.regs->nip; 114 } 115 116 // modify PC in ucontext. 117 // Note: Only use this for an ucontext handed down to a signal handler. See comment 118 // in ucontext_get_pc. 119 void os::Linux::ucontext_set_pc(ucontext_t * uc, address pc) { 120 guarantee(uc->uc_mcontext.regs != NULL, "only use ucontext_set_pc in sigaction context"); 121 uc->uc_mcontext.regs->nip = (unsigned long)pc; 122 } 123 124 intptr_t* os::Linux::ucontext_get_sp(const ucontext_t * uc) { 125 return (intptr_t*)uc->uc_mcontext.regs->gpr[1/*REG_SP*/]; 126 } 127 128 intptr_t* os::Linux::ucontext_get_fp(const ucontext_t * uc) { 129 return NULL; 130 } 131 132 ExtendedPC os::fetch_frame_from_context(const void* ucVoid, 133 intptr_t** ret_sp, intptr_t** ret_fp) { 134 135 ExtendedPC epc; 136 const ucontext_t* uc = (const ucontext_t*)ucVoid; 137 138 if (uc != NULL) { 139 epc = ExtendedPC(os::Linux::ucontext_get_pc(uc)); 140 if (ret_sp) *ret_sp = os::Linux::ucontext_get_sp(uc); 141 if (ret_fp) *ret_fp = os::Linux::ucontext_get_fp(uc); 142 } else { 143 // construct empty ExtendedPC for return value checking 144 epc = ExtendedPC(NULL); 145 if (ret_sp) *ret_sp = (intptr_t *)NULL; 146 if (ret_fp) *ret_fp = (intptr_t *)NULL; 147 } 148 149 return epc; 150 } 151 152 frame os::fetch_frame_from_context(const void* ucVoid) { 153 intptr_t* sp; 154 intptr_t* fp; 155 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp); 156 return frame(sp, epc.pc()); 157 } 158 159 bool os::Linux::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) { 160 address pc = (address) os::Linux::ucontext_get_pc(uc); 161 if (Interpreter::contains(pc)) { 162 // Interpreter performs stack banging after the fixed frame header has 163 // been generated while the compilers perform it before. To maintain 164 // semantic consistency between interpreted and compiled frames, the 165 // method returns the Java sender of the current frame. 166 *fr = os::fetch_frame_from_context(uc); 167 if (!fr->is_first_java_frame()) { 168 assert(fr->safe_for_sender(thread), "Safety check"); 169 *fr = fr->java_sender(); 170 } 171 } else { 172 // More complex code with compiled code. 173 assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above"); 174 CodeBlob* cb = CodeCache::find_blob(pc); 175 if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) { 176 // Not sure where the pc points to, fallback to default 177 // stack overflow handling. In compiled code, we bang before 178 // the frame is complete. 179 return false; 180 } else { 181 intptr_t* fp = os::Linux::ucontext_get_fp(uc); 182 intptr_t* sp = os::Linux::ucontext_get_sp(uc); 183 *fr = frame(sp, (address)*sp); 184 if (!fr->is_java_frame()) { 185 assert(fr->safe_for_sender(thread), "Safety check"); 186 assert(!fr->is_first_frame(), "Safety check"); 187 *fr = fr->java_sender(); 188 } 189 } 190 } 191 assert(fr->is_java_frame(), "Safety check"); 192 return true; 193 } 194 195 frame os::get_sender_for_C_frame(frame* fr) { 196 if (*fr->sp() == 0) { 197 // fr is the last C frame 198 return frame(NULL, NULL); 199 } 200 return frame(fr->sender_sp(), fr->sender_pc()); 201 } 202 203 204 frame os::current_frame() { 205 intptr_t* csp = (intptr_t*) *((intptr_t*) os::current_stack_pointer()); 206 // hack. 207 frame topframe(csp, (address)0x8); 208 // return sender of current topframe which hopefully has pc != NULL. 209 return os::get_sender_for_C_frame(&topframe); 210 } 211 212 // Utility functions 213 214 extern "C" JNIEXPORT int 215 JVM_handle_linux_signal(int sig, 216 siginfo_t* info, 217 void* ucVoid, 218 int abort_if_unrecognized) { 219 ucontext_t* uc = (ucontext_t*) ucVoid; 220 221 Thread* t = Thread::current_or_null_safe(); 222 223 SignalHandlerMark shm(t); 224 225 // Note: it's not uncommon that JNI code uses signal/sigset to install 226 // then restore certain signal handler (e.g. to temporarily block SIGPIPE, 227 // or have a SIGILL handler when detecting CPU type). When that happens, 228 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To 229 // avoid unnecessary crash when libjsig is not preloaded, try handle signals 230 // that do not require siginfo/ucontext first. 231 232 if (sig == SIGPIPE) { 233 if (os::Linux::chained_handler(sig, info, ucVoid)) { 234 return true; 235 } else { 236 // Ignoring SIGPIPE - see bugs 4229104 237 return true; 238 } 239 } 240 241 // Make the signal handler transaction-aware by checking the existence of a 242 // second (transactional) context with MSR TS bits active. If the signal is 243 // caught during a transaction, then just return to the HTM abort handler. 244 // Please refer to Linux kernel document powerpc/transactional_memory.txt, 245 // section "Signals". 246 if (uc && uc->uc_link) { 247 ucontext_t* second_uc = uc->uc_link; 248 249 // MSR TS bits are 29 and 30 (Power ISA, v2.07B, Book III-S, pp. 857-858, 250 // 3.2.1 "Machine State Register"), however note that ISA notation for bit 251 // numbering is MSB 0, so for normal bit numbering (LSB 0) they come to be 252 // bits 33 and 34. It's not related to endianness, just a notation matter. 253 if (second_uc->uc_mcontext.regs->msr & 0x600000000) { 254 if (TraceTraps) { 255 tty->print_cr("caught signal in transaction, " 256 "ignoring to jump to abort handler"); 257 } 258 // Return control to the HTM abort handler. 259 return true; 260 } 261 } 262 263 JavaThread* thread = NULL; 264 VMThread* vmthread = NULL; 265 if (os::Linux::signal_handlers_are_installed) { 266 if (t != NULL) { 267 if(t->is_Java_thread()) { 268 thread = (JavaThread*)t; 269 } else if(t->is_VM_thread()) { 270 vmthread = (VMThread *)t; 271 } 272 } 273 } 274 275 // Moved SafeFetch32 handling outside thread!=NULL conditional block to make 276 // it work if no associated JavaThread object exists. 277 if (uc) { 278 address const pc = os::Linux::ucontext_get_pc(uc); 279 if (pc && StubRoutines::is_safefetch_fault(pc)) { 280 os::Linux::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc)); 281 return true; 282 } 283 } 284 285 // decide if this trap can be handled by a stub 286 address stub = NULL; 287 address pc = NULL; 288 289 //%note os_trap_1 290 if (info != NULL && uc != NULL && thread != NULL) { 291 pc = (address) os::Linux::ucontext_get_pc(uc); 292 293 // Handle ALL stack overflow variations here 294 if (sig == SIGSEGV) { 295 // Si_addr may not be valid due to a bug in the linux-ppc64 kernel (see 296 // comment below). Use get_stack_bang_address instead of si_addr. 297 address addr = ((NativeInstruction*)pc)->get_stack_bang_address(uc); 298 299 // Check if fault address is within thread stack. 300 if (thread->on_local_stack(addr)) { 301 // stack overflow 302 if (thread->in_stack_yellow_reserved_zone(addr)) { 303 if (thread->thread_state() == _thread_in_Java) { 304 if (thread->in_stack_reserved_zone(addr)) { 305 frame fr; 306 if (os::Linux::get_frame_at_stack_banging_point(thread, uc, &fr)) { 307 assert(fr.is_java_frame(), "Must be a Javac frame"); 308 frame activation = 309 SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr); 310 if (activation.sp() != NULL) { 311 thread->disable_stack_reserved_zone(); 312 if (activation.is_interpreted_frame()) { 313 thread->set_reserved_stack_activation((address)activation.fp()); 314 } else { 315 thread->set_reserved_stack_activation((address)activation.unextended_sp()); 316 } 317 return 1; 318 } 319 } 320 } 321 // Throw a stack overflow exception. 322 // Guard pages will be reenabled while unwinding the stack. 323 thread->disable_stack_yellow_reserved_zone(); 324 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); 325 } else { 326 // Thread was in the vm or native code. Return and try to finish. 327 thread->disable_stack_yellow_reserved_zone(); 328 return 1; 329 } 330 } else if (thread->in_stack_red_zone(addr)) { 331 // Fatal red zone violation. Disable the guard pages and fall through 332 // to handle_unexpected_exception way down below. 333 thread->disable_stack_red_zone(); 334 tty->print_raw_cr("An irrecoverable stack overflow has occurred."); 335 336 // This is a likely cause, but hard to verify. Let's just print 337 // it as a hint. 338 tty->print_raw_cr("Please check if any of your loaded .so files has " 339 "enabled executable stack (see man page execstack(8))"); 340 } else { 341 // Accessing stack address below sp may cause SEGV if current 342 // thread has MAP_GROWSDOWN stack. This should only happen when 343 // current thread was created by user code with MAP_GROWSDOWN flag 344 // and then attached to VM. See notes in os_linux.cpp. 345 if (thread->osthread()->expanding_stack() == 0) { 346 thread->osthread()->set_expanding_stack(); 347 if (os::Linux::manually_expand_stack(thread, addr)) { 348 thread->osthread()->clear_expanding_stack(); 349 return 1; 350 } 351 thread->osthread()->clear_expanding_stack(); 352 } else { 353 fatal("recursive segv. expanding stack."); 354 } 355 } 356 } 357 } 358 359 if (thread->thread_state() == _thread_in_Java) { 360 // Java thread running in Java code => find exception handler if any 361 // a fault inside compiled code, the interpreter, or a stub 362 363 // A VM-related SIGILL may only occur if we are not in the zero page. 364 // On AIX, we get a SIGILL if we jump to 0x0 or to somewhere else 365 // in the zero page, because it is filled with 0x0. We ignore 366 // explicit SIGILLs in the zero page. 367 if (sig == SIGILL && (pc < (address) 0x200)) { 368 if (TraceTraps) { 369 tty->print_raw_cr("SIGILL happened inside zero page."); 370 } 371 goto report_and_die; 372 } 373 374 CodeBlob *cb = NULL; 375 // Handle signal from NativeJump::patch_verified_entry(). 376 if (( TrapBasedNotEntrantChecks && sig == SIGTRAP && nativeInstruction_at(pc)->is_sigtrap_zombie_not_entrant()) || 377 (!TrapBasedNotEntrantChecks && sig == SIGILL && nativeInstruction_at(pc)->is_sigill_zombie_not_entrant())) { 378 if (TraceTraps) { 379 tty->print_cr("trap: zombie_not_entrant (%s)", (sig == SIGTRAP) ? "SIGTRAP" : "SIGILL"); 380 } 381 stub = SharedRuntime::get_handle_wrong_method_stub(); 382 } 383 384 else if (sig == SIGSEGV && 385 // A linux-ppc64 kernel before 2.6.6 doesn't set si_addr on some segfaults 386 // in 64bit mode (cf. http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.6), 387 // especially when we try to read from the safepoint polling page. So the check 388 // (address)info->si_addr == os::get_standard_polling_page() 389 // doesn't work for us. We use: 390 ((NativeInstruction*)pc)->is_safepoint_poll() && 391 CodeCache::contains((void*) pc) && 392 ((cb = CodeCache::find_blob(pc)) != NULL) && 393 cb->is_compiled()) { 394 if (TraceTraps) { 395 tty->print_cr("trap: safepoint_poll at " INTPTR_FORMAT " (SIGSEGV)", p2i(pc)); 396 } 397 stub = SharedRuntime::get_poll_stub(pc); 398 } 399 400 // SIGTRAP-based ic miss check in compiled code. 401 else if (sig == SIGTRAP && TrapBasedICMissChecks && 402 nativeInstruction_at(pc)->is_sigtrap_ic_miss_check()) { 403 if (TraceTraps) { 404 tty->print_cr("trap: ic_miss_check at " INTPTR_FORMAT " (SIGTRAP)", p2i(pc)); 405 } 406 stub = SharedRuntime::get_ic_miss_stub(); 407 } 408 409 // SIGTRAP-based implicit null check in compiled code. 410 else if (sig == SIGTRAP && TrapBasedNullChecks && 411 nativeInstruction_at(pc)->is_sigtrap_null_check()) { 412 if (TraceTraps) { 413 tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGTRAP)", p2i(pc)); 414 } 415 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 416 } 417 418 // SIGSEGV-based implicit null check in compiled code. 419 else if (sig == SIGSEGV && ImplicitNullChecks && 420 CodeCache::contains((void*) pc) && 421 !MacroAssembler::needs_explicit_null_check((intptr_t) info->si_addr)) { 422 if (TraceTraps) { 423 tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGSEGV)", p2i(pc)); 424 } 425 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 426 } 427 428 #ifdef COMPILER2 429 // SIGTRAP-based implicit range check in compiled code. 430 else if (sig == SIGTRAP && TrapBasedRangeChecks && 431 nativeInstruction_at(pc)->is_sigtrap_range_check()) { 432 if (TraceTraps) { 433 tty->print_cr("trap: range_check at " INTPTR_FORMAT " (SIGTRAP)", p2i(pc)); 434 } 435 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 436 } 437 #endif 438 else if (sig == SIGBUS) { 439 // BugId 4454115: A read from a MappedByteBuffer can fault here if the 440 // underlying file has been truncated. Do not crash the VM in such a case. 441 CodeBlob* cb = CodeCache::find_blob_unsafe(pc); 442 CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL; 443 if (nm != NULL && nm->has_unsafe_access()) { 444 address next_pc = pc + 4; 445 next_pc = SharedRuntime::handle_unsafe_access(thread, next_pc); 446 os::Linux::ucontext_set_pc(uc, next_pc); 447 return true; 448 } 449 } 450 } 451 452 else { // thread->thread_state() != _thread_in_Java 453 if (sig == SIGILL && VM_Version::is_determine_features_test_running()) { 454 // SIGILL must be caused by VM_Version::determine_features(). 455 *(int *)pc = 0; // patch instruction to 0 to indicate that it causes a SIGILL, 456 // flushing of icache is not necessary. 457 stub = pc + 4; // continue with next instruction. 458 } 459 else if (thread->thread_state() == _thread_in_vm && 460 sig == SIGBUS && thread->doing_unsafe_access()) { 461 address next_pc = pc + 4; 462 next_pc = SharedRuntime::handle_unsafe_access(thread, next_pc); 463 os::Linux::ucontext_set_pc(uc, pc + 4); 464 return true; 465 } 466 } 467 468 // Check to see if we caught the safepoint code in the 469 // process of write protecting the memory serialization page. 470 // It write enables the page immediately after protecting it 471 // so we can just return to retry the write. 472 if ((sig == SIGSEGV) && 473 // Si_addr may not be valid due to a bug in the linux-ppc64 kernel (see comment above). 474 // Use is_memory_serialization instead of si_addr. 475 ((NativeInstruction*)pc)->is_memory_serialization(thread, ucVoid)) { 476 // Synchronization problem in the pseudo memory barrier code (bug id 6546278) 477 // Block current thread until the memory serialize page permission restored. 478 os::block_on_serialize_page_trap(); 479 return true; 480 } 481 } 482 483 if (stub != NULL) { 484 // Save all thread context in case we need to restore it. 485 if (thread != NULL) thread->set_saved_exception_pc(pc); 486 os::Linux::ucontext_set_pc(uc, stub); 487 return true; 488 } 489 490 // signal-chaining 491 if (os::Linux::chained_handler(sig, info, ucVoid)) { 492 return true; 493 } 494 495 if (!abort_if_unrecognized) { 496 // caller wants another chance, so give it to him 497 return false; 498 } 499 500 if (pc == NULL && uc != NULL) { 501 pc = os::Linux::ucontext_get_pc(uc); 502 } 503 504 report_and_die: 505 // unmask current signal 506 sigset_t newset; 507 sigemptyset(&newset); 508 sigaddset(&newset, sig); 509 sigprocmask(SIG_UNBLOCK, &newset, NULL); 510 511 VMError::report_and_die(t, sig, pc, info, ucVoid); 512 513 ShouldNotReachHere(); 514 return false; 515 } 516 517 void os::Linux::init_thread_fpu_state(void) { 518 // Disable FP exceptions. 519 __asm__ __volatile__ ("mtfsfi 6,0"); 520 } 521 522 int os::Linux::get_fpu_control_word(void) { 523 // x86 has problems with FPU precision after pthread_cond_timedwait(). 524 // nothing to do on ppc64. 525 return 0; 526 } 527 528 void os::Linux::set_fpu_control_word(int fpu_control) { 529 // x86 has problems with FPU precision after pthread_cond_timedwait(). 530 // nothing to do on ppc64. 531 } 532 533 //////////////////////////////////////////////////////////////////////////////// 534 // thread stack 535 536 size_t os::Posix::_compiler_thread_min_stack_allowed = 128 * K; 537 size_t os::Posix::_java_thread_min_stack_allowed = 128 * K; 538 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 128 * K; 539 540 // return default stack size for thr_type 541 size_t os::Posix::default_stack_size(os::ThreadType thr_type) { 542 // default stack size (compiler thread needs larger stack) 543 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1024 * K); 544 return s; 545 } 546 547 size_t os::Linux::default_guard_size(os::ThreadType thr_type) { 548 return 2 * page_size(); 549 } 550 551 // Java thread: 552 // 553 // Low memory addresses 554 // +------------------------+ 555 // | |\ JavaThread created by VM does not have glibc 556 // | glibc guard page | - guard, attached Java thread usually has 557 // | |/ 1 page glibc guard. 558 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 559 // | |\ 560 // | HotSpot Guard Pages | - red and yellow pages 561 // | |/ 562 // +------------------------+ JavaThread::stack_yellow_zone_base() 563 // | |\ 564 // | Normal Stack | - 565 // | |/ 566 // P2 +------------------------+ Thread::stack_base() 567 // 568 // Non-Java thread: 569 // 570 // Low memory addresses 571 // +------------------------+ 572 // | |\ 573 // | glibc guard page | - usually 1 page 574 // | |/ 575 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 576 // | |\ 577 // | Normal Stack | - 578 // | |/ 579 // P2 +------------------------+ Thread::stack_base() 580 // 581 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from 582 // pthread_attr_getstack() 583 584 static void current_stack_region(address * bottom, size_t * size) { 585 if (os::Linux::is_initial_thread()) { 586 // initial thread needs special handling because pthread_getattr_np() 587 // may return bogus value. 588 *bottom = os::Linux::initial_thread_stack_bottom(); 589 *size = os::Linux::initial_thread_stack_size(); 590 } else { 591 pthread_attr_t attr; 592 593 int rslt = pthread_getattr_np(pthread_self(), &attr); 594 595 // JVM needs to know exact stack location, abort if it fails 596 if (rslt != 0) { 597 if (rslt == ENOMEM) { 598 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np"); 599 } else { 600 fatal("pthread_getattr_np failed with errno = %d", rslt); 601 } 602 } 603 604 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) { 605 fatal("Can not locate current stack attributes!"); 606 } 607 608 pthread_attr_destroy(&attr); 609 610 } 611 assert(os::current_stack_pointer() >= *bottom && 612 os::current_stack_pointer() < *bottom + *size, "just checking"); 613 } 614 615 address os::current_stack_base() { 616 address bottom; 617 size_t size; 618 current_stack_region(&bottom, &size); 619 return (bottom + size); 620 } 621 622 size_t os::current_stack_size() { 623 // stack size includes normal stack and HotSpot guard pages 624 address bottom; 625 size_t size; 626 current_stack_region(&bottom, &size); 627 return size; 628 } 629 630 ///////////////////////////////////////////////////////////////////////////// 631 // helper functions for fatal error handler 632 633 void os::print_context(outputStream *st, const void *context) { 634 if (context == NULL) return; 635 636 const ucontext_t* uc = (const ucontext_t*)context; 637 638 st->print_cr("Registers:"); 639 st->print("pc =" INTPTR_FORMAT " ", uc->uc_mcontext.regs->nip); 640 st->print("lr =" INTPTR_FORMAT " ", uc->uc_mcontext.regs->link); 641 st->print("ctr=" INTPTR_FORMAT " ", uc->uc_mcontext.regs->ctr); 642 st->cr(); 643 for (int i = 0; i < 32; i++) { 644 st->print("r%-2d=" INTPTR_FORMAT " ", i, uc->uc_mcontext.regs->gpr[i]); 645 if (i % 3 == 2) st->cr(); 646 } 647 st->cr(); 648 st->cr(); 649 650 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc); 651 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", p2i(sp)); 652 print_hex_dump(st, (address)sp, (address)(sp + 128), sizeof(intptr_t)); 653 st->cr(); 654 655 // Note: it may be unsafe to inspect memory near pc. For example, pc may 656 // point to garbage if entry point in an nmethod is corrupted. Leave 657 // this at the end, and hope for the best. 658 address pc = os::Linux::ucontext_get_pc(uc); 659 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", p2i(pc)); 660 print_hex_dump(st, pc - 64, pc + 64, /*instrsize=*/4); 661 st->cr(); 662 } 663 664 void os::print_register_info(outputStream *st, const void *context) { 665 if (context == NULL) return; 666 667 const ucontext_t *uc = (const ucontext_t*)context; 668 669 st->print_cr("Register to memory mapping:"); 670 st->cr(); 671 672 // this is only for the "general purpose" registers 673 for (int i = 0; i < 32; i++) { 674 st->print("r%-2d=", i); 675 print_location(st, uc->uc_mcontext.regs->gpr[i]); 676 } 677 st->cr(); 678 } 679 680 extern "C" { 681 int SpinPause() { 682 return 0; 683 } 684 } 685 686 #ifndef PRODUCT 687 void os::verify_stack_alignment() { 688 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment"); 689 } 690 #endif 691 692 int os::extra_bang_size_in_bytes() { 693 // PPC does not require the additional stack bang. 694 return 0; 695 }