1 /* 2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved. 3 * Copyright 2012, 2014 SAP AG. 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 hat 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 "assembler_ppc.inline.hpp" 28 #include "classfile/classLoader.hpp" 29 #include "classfile/systemDictionary.hpp" 30 #include "classfile/vmSymbols.hpp" 31 #include "code/icBuffer.hpp" 32 #include "code/vtableStubs.hpp" 33 #include "interpreter/interpreter.hpp" 34 #include "jvm_linux.h" 35 #include "memory/allocation.inline.hpp" 36 #include "mutex_linux.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(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(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(ucontext_t * uc) { 129 return NULL; 130 } 131 132 ExtendedPC os::fetch_frame_from_context(void* ucVoid, 133 intptr_t** ret_sp, intptr_t** ret_fp) { 134 135 ExtendedPC epc; 136 ucontext_t* uc = (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(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 frame os::get_sender_for_C_frame(frame* fr) { 160 if (*fr->sp() == 0) { 161 // fr is the last C frame 162 return frame(NULL, NULL); 163 } 164 return frame(fr->sender_sp(), fr->sender_pc()); 165 } 166 167 168 frame os::current_frame() { 169 intptr_t* csp = (intptr_t*) *((intptr_t*) os::current_stack_pointer()); 170 // hack. 171 frame topframe(csp, (address)0x8); 172 // return sender of current topframe which hopefully has pc != NULL. 173 return os::get_sender_for_C_frame(&topframe); 174 } 175 176 // Utility functions 177 178 extern "C" JNIEXPORT int 179 JVM_handle_linux_signal(int sig, 180 siginfo_t* info, 181 void* ucVoid, 182 int abort_if_unrecognized) { 183 ucontext_t* uc = (ucontext_t*) ucVoid; 184 185 Thread* t = ThreadLocalStorage::get_thread_slow(); 186 187 SignalHandlerMark shm(t); 188 189 // Note: it's not uncommon that JNI code uses signal/sigset to install 190 // then restore certain signal handler (e.g. to temporarily block SIGPIPE, 191 // or have a SIGILL handler when detecting CPU type). When that happens, 192 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To 193 // avoid unnecessary crash when libjsig is not preloaded, try handle signals 194 // that do not require siginfo/ucontext first. 195 196 if (sig == SIGPIPE) { 197 if (os::Linux::chained_handler(sig, info, ucVoid)) { 198 return true; 199 } else { 200 if (PrintMiscellaneous && (WizardMode || Verbose)) { 201 warning("Ignoring SIGPIPE - see bug 4229104"); 202 } 203 return true; 204 } 205 } 206 207 JavaThread* thread = NULL; 208 VMThread* vmthread = NULL; 209 if (os::Linux::signal_handlers_are_installed) { 210 if (t != NULL) { 211 if(t->is_Java_thread()) { 212 thread = (JavaThread*)t; 213 } else if(t->is_VM_thread()) { 214 vmthread = (VMThread *)t; 215 } 216 } 217 } 218 219 // Moved SafeFetch32 handling outside thread!=NULL conditional block to make 220 // it work if no associated JavaThread object exists. 221 if (uc) { 222 address const pc = os::Linux::ucontext_get_pc(uc); 223 if (pc && StubRoutines::is_safefetch_fault(pc)) { 224 os::Linux::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc)); 225 return true; 226 } 227 } 228 229 // decide if this trap can be handled by a stub 230 address stub = NULL; 231 address pc = NULL; 232 233 //%note os_trap_1 234 if (info != NULL && uc != NULL && thread != NULL) { 235 pc = (address) os::Linux::ucontext_get_pc(uc); 236 237 // Handle ALL stack overflow variations here 238 if (sig == SIGSEGV) { 239 // Si_addr may not be valid due to a bug in the linux-ppc64 kernel (see 240 // comment below). Use get_stack_bang_address instead of si_addr. 241 address addr = ((NativeInstruction*)pc)->get_stack_bang_address(uc); 242 243 // Check if fault address is within thread stack. 244 if (addr < thread->stack_base() && 245 addr >= thread->stack_base() - thread->stack_size()) { 246 // stack overflow 247 if (thread->in_stack_yellow_zone(addr)) { 248 thread->disable_stack_yellow_zone(); 249 if (thread->thread_state() == _thread_in_Java) { 250 // Throw a stack overflow exception. 251 // Guard pages will be reenabled while unwinding the stack. 252 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); 253 } else { 254 // Thread was in the vm or native code. Return and try to finish. 255 return 1; 256 } 257 } else if (thread->in_stack_red_zone(addr)) { 258 // Fatal red zone violation. Disable the guard pages and fall through 259 // to handle_unexpected_exception way down below. 260 thread->disable_stack_red_zone(); 261 tty->print_raw_cr("An irrecoverable stack overflow has occurred."); 262 263 // This is a likely cause, but hard to verify. Let's just print 264 // it as a hint. 265 tty->print_raw_cr("Please check if any of your loaded .so files has " 266 "enabled executable stack (see man page execstack(8))"); 267 } else { 268 // Accessing stack address below sp may cause SEGV if current 269 // thread has MAP_GROWSDOWN stack. This should only happen when 270 // current thread was created by user code with MAP_GROWSDOWN flag 271 // and then attached to VM. See notes in os_linux.cpp. 272 if (thread->osthread()->expanding_stack() == 0) { 273 thread->osthread()->set_expanding_stack(); 274 if (os::Linux::manually_expand_stack(thread, addr)) { 275 thread->osthread()->clear_expanding_stack(); 276 return 1; 277 } 278 thread->osthread()->clear_expanding_stack(); 279 } else { 280 fatal("recursive segv. expanding stack."); 281 } 282 } 283 } 284 } 285 286 if (thread->thread_state() == _thread_in_Java) { 287 // Java thread running in Java code => find exception handler if any 288 // a fault inside compiled code, the interpreter, or a stub 289 290 // A VM-related SIGILL may only occur if we are not in the zero page. 291 // On AIX, we get a SIGILL if we jump to 0x0 or to somewhere else 292 // in the zero page, because it is filled with 0x0. We ignore 293 // explicit SIGILLs in the zero page. 294 if (sig == SIGILL && (pc < (address) 0x200)) { 295 if (TraceTraps) { 296 tty->print_raw_cr("SIGILL happened inside zero page."); 297 } 298 goto report_and_die; 299 } 300 301 // Handle signal from NativeJump::patch_verified_entry(). 302 if (( TrapBasedNotEntrantChecks && sig == SIGTRAP && nativeInstruction_at(pc)->is_sigtrap_zombie_not_entrant()) || 303 (!TrapBasedNotEntrantChecks && sig == SIGILL && nativeInstruction_at(pc)->is_sigill_zombie_not_entrant())) { 304 if (TraceTraps) { 305 tty->print_cr("trap: zombie_not_entrant (%s)", (sig == SIGTRAP) ? "SIGTRAP" : "SIGILL"); 306 } 307 stub = SharedRuntime::get_handle_wrong_method_stub(); 308 } 309 310 else if (sig == SIGSEGV && 311 // A linux-ppc64 kernel before 2.6.6 doesn't set si_addr on some segfaults 312 // in 64bit mode (cf. http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.6), 313 // especially when we try to read from the safepoint polling page. So the check 314 // (address)info->si_addr == os::get_standard_polling_page() 315 // doesn't work for us. We use: 316 ((NativeInstruction*)pc)->is_safepoint_poll()) { 317 if (TraceTraps) { 318 tty->print_cr("trap: safepoint_poll at " INTPTR_FORMAT " (SIGSEGV)", p2i(pc)); 319 } 320 stub = SharedRuntime::get_poll_stub(pc); 321 } 322 323 // SIGTRAP-based ic miss check in compiled code. 324 else if (sig == SIGTRAP && TrapBasedICMissChecks && 325 nativeInstruction_at(pc)->is_sigtrap_ic_miss_check()) { 326 if (TraceTraps) { 327 tty->print_cr("trap: ic_miss_check at " INTPTR_FORMAT " (SIGTRAP)", p2i(pc)); 328 } 329 stub = SharedRuntime::get_ic_miss_stub(); 330 } 331 332 // SIGTRAP-based implicit null check in compiled code. 333 else if (sig == SIGTRAP && TrapBasedNullChecks && 334 nativeInstruction_at(pc)->is_sigtrap_null_check()) { 335 if (TraceTraps) { 336 tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGTRAP)", p2i(pc)); 337 } 338 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 339 } 340 341 // SIGSEGV-based implicit null check in compiled code. 342 else if (sig == SIGSEGV && ImplicitNullChecks && 343 CodeCache::contains((void*) pc) && 344 !MacroAssembler::needs_explicit_null_check((intptr_t) info->si_addr)) { 345 if (TraceTraps) { 346 tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGSEGV)", p2i(pc)); 347 } 348 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 349 } 350 351 #ifdef COMPILER2 352 // SIGTRAP-based implicit range check in compiled code. 353 else if (sig == SIGTRAP && TrapBasedRangeChecks && 354 nativeInstruction_at(pc)->is_sigtrap_range_check()) { 355 if (TraceTraps) { 356 tty->print_cr("trap: range_check at " INTPTR_FORMAT " (SIGTRAP)", p2i(pc)); 357 } 358 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 359 } 360 #endif 361 else if (sig == SIGBUS) { 362 // BugId 4454115: A read from a MappedByteBuffer can fault here if the 363 // underlying file has been truncated. Do not crash the VM in such a case. 364 CodeBlob* cb = CodeCache::find_blob_unsafe(pc); 365 nmethod* nm = (cb != NULL && cb->is_nmethod()) ? (nmethod*)cb : NULL; 366 if (nm != NULL && nm->has_unsafe_access()) { 367 // We don't really need a stub here! Just set the pending exeption and 368 // continue at the next instruction after the faulting read. Returning 369 // garbage from this read is ok. 370 thread->set_pending_unsafe_access_error(); 371 os::Linux::ucontext_set_pc(uc, pc + 4); 372 return true; 373 } 374 } 375 } 376 377 else { // thread->thread_state() != _thread_in_Java 378 if (sig == SIGILL && VM_Version::is_determine_features_test_running()) { 379 // SIGILL must be caused by VM_Version::determine_features(). 380 *(int *)pc = 0; // patch instruction to 0 to indicate that it causes a SIGILL, 381 // flushing of icache is not necessary. 382 stub = pc + 4; // continue with next instruction. 383 } 384 else if (thread->thread_state() == _thread_in_vm && 385 sig == SIGBUS && thread->doing_unsafe_access()) { 386 // We don't really need a stub here! Just set the pending exeption and 387 // continue at the next instruction after the faulting read. Returning 388 // garbage from this read is ok. 389 thread->set_pending_unsafe_access_error(); 390 os::Linux::ucontext_set_pc(uc, pc + 4); 391 return true; 392 } 393 } 394 395 // Check to see if we caught the safepoint code in the 396 // process of write protecting the memory serialization page. 397 // It write enables the page immediately after protecting it 398 // so we can just return to retry the write. 399 if ((sig == SIGSEGV) && 400 // Si_addr may not be valid due to a bug in the linux-ppc64 kernel (see comment above). 401 // Use is_memory_serialization instead of si_addr. 402 ((NativeInstruction*)pc)->is_memory_serialization(thread, ucVoid)) { 403 // Synchronization problem in the pseudo memory barrier code (bug id 6546278) 404 // Block current thread until the memory serialize page permission restored. 405 os::block_on_serialize_page_trap(); 406 return true; 407 } 408 } 409 410 if (stub != NULL) { 411 // Save all thread context in case we need to restore it. 412 if (thread != NULL) thread->set_saved_exception_pc(pc); 413 os::Linux::ucontext_set_pc(uc, stub); 414 return true; 415 } 416 417 // signal-chaining 418 if (os::Linux::chained_handler(sig, info, ucVoid)) { 419 return true; 420 } 421 422 if (!abort_if_unrecognized) { 423 // caller wants another chance, so give it to him 424 return false; 425 } 426 427 if (pc == NULL && uc != NULL) { 428 pc = os::Linux::ucontext_get_pc(uc); 429 } 430 431 report_and_die: 432 // unmask current signal 433 sigset_t newset; 434 sigemptyset(&newset); 435 sigaddset(&newset, sig); 436 sigprocmask(SIG_UNBLOCK, &newset, NULL); 437 438 VMError err(t, sig, pc, info, ucVoid); 439 err.report_and_die(); 440 441 ShouldNotReachHere(); 442 return false; 443 } 444 445 void os::Linux::init_thread_fpu_state(void) { 446 // Disable FP exceptions. 447 __asm__ __volatile__ ("mtfsfi 6,0"); 448 } 449 450 int os::Linux::get_fpu_control_word(void) { 451 // x86 has problems with FPU precision after pthread_cond_timedwait(). 452 // nothing to do on ppc64. 453 return 0; 454 } 455 456 void os::Linux::set_fpu_control_word(int fpu_control) { 457 // x86 has problems with FPU precision after pthread_cond_timedwait(). 458 // nothing to do on ppc64. 459 } 460 461 //////////////////////////////////////////////////////////////////////////////// 462 // thread stack 463 464 size_t os::Linux::min_stack_allowed = 128*K; 465 466 bool os::Linux::supports_variable_stack_size() { return true; } 467 468 // return default stack size for thr_type 469 size_t os::Linux::default_stack_size(os::ThreadType thr_type) { 470 // default stack size (compiler thread needs larger stack) 471 // Notice that the setting for compiler threads here have no impact 472 // because of the strange 'fallback logic' in os::create_thread(). 473 // Better set CompilerThreadStackSize in globals_<os_cpu>.hpp if you want to 474 // specify a different stack size for compiler threads! 475 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1024 * K); 476 return s; 477 } 478 479 size_t os::Linux::default_guard_size(os::ThreadType thr_type) { 480 return 2 * page_size(); 481 } 482 483 // Java thread: 484 // 485 // Low memory addresses 486 // +------------------------+ 487 // | |\ JavaThread created by VM does not have glibc 488 // | glibc guard page | - guard, attached Java thread usually has 489 // | |/ 1 page glibc guard. 490 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 491 // | |\ 492 // | HotSpot Guard Pages | - red and yellow pages 493 // | |/ 494 // +------------------------+ JavaThread::stack_yellow_zone_base() 495 // | |\ 496 // | Normal Stack | - 497 // | |/ 498 // P2 +------------------------+ Thread::stack_base() 499 // 500 // Non-Java thread: 501 // 502 // Low memory addresses 503 // +------------------------+ 504 // | |\ 505 // | glibc guard page | - usually 1 page 506 // | |/ 507 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 508 // | |\ 509 // | Normal Stack | - 510 // | |/ 511 // P2 +------------------------+ Thread::stack_base() 512 // 513 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from 514 // pthread_attr_getstack() 515 516 static void current_stack_region(address * bottom, size_t * size) { 517 if (os::Linux::is_initial_thread()) { 518 // initial thread needs special handling because pthread_getattr_np() 519 // may return bogus value. 520 *bottom = os::Linux::initial_thread_stack_bottom(); 521 *size = os::Linux::initial_thread_stack_size(); 522 } else { 523 pthread_attr_t attr; 524 525 int rslt = pthread_getattr_np(pthread_self(), &attr); 526 527 // JVM needs to know exact stack location, abort if it fails 528 if (rslt != 0) { 529 if (rslt == ENOMEM) { 530 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np"); 531 } else { 532 fatal(err_msg("pthread_getattr_np failed with errno = %d", rslt)); 533 } 534 } 535 536 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) { 537 fatal("Can not locate current stack attributes!"); 538 } 539 540 pthread_attr_destroy(&attr); 541 542 } 543 assert(os::current_stack_pointer() >= *bottom && 544 os::current_stack_pointer() < *bottom + *size, "just checking"); 545 } 546 547 address os::current_stack_base() { 548 address bottom; 549 size_t size; 550 current_stack_region(&bottom, &size); 551 return (bottom + size); 552 } 553 554 size_t os::current_stack_size() { 555 // stack size includes normal stack and HotSpot guard pages 556 address bottom; 557 size_t size; 558 current_stack_region(&bottom, &size); 559 return size; 560 } 561 562 ///////////////////////////////////////////////////////////////////////////// 563 // helper functions for fatal error handler 564 565 void os::print_context(outputStream *st, void *context) { 566 if (context == NULL) return; 567 568 ucontext_t* uc = (ucontext_t*)context; 569 570 st->print_cr("Registers:"); 571 st->print("pc =" INTPTR_FORMAT " ", uc->uc_mcontext.regs->nip); 572 st->print("lr =" INTPTR_FORMAT " ", uc->uc_mcontext.regs->link); 573 st->print("ctr=" INTPTR_FORMAT " ", uc->uc_mcontext.regs->ctr); 574 st->cr(); 575 for (int i = 0; i < 32; i++) { 576 st->print("r%-2d=" INTPTR_FORMAT " ", i, uc->uc_mcontext.regs->gpr[i]); 577 if (i % 3 == 2) st->cr(); 578 } 579 st->cr(); 580 st->cr(); 581 582 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc); 583 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", p2i(sp)); 584 print_hex_dump(st, (address)sp, (address)(sp + 128), sizeof(intptr_t)); 585 st->cr(); 586 587 // Note: it may be unsafe to inspect memory near pc. For example, pc may 588 // point to garbage if entry point in an nmethod is corrupted. Leave 589 // this at the end, and hope for the best. 590 address pc = os::Linux::ucontext_get_pc(uc); 591 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", p2i(pc)); 592 print_hex_dump(st, pc - 64, pc + 64, /*instrsize=*/4); 593 st->cr(); 594 } 595 596 void os::print_register_info(outputStream *st, void *context) { 597 if (context == NULL) return; 598 599 ucontext_t *uc = (ucontext_t*)context; 600 601 st->print_cr("Register to memory mapping:"); 602 st->cr(); 603 604 // this is only for the "general purpose" registers 605 for (int i = 0; i < 32; i++) { 606 st->print("r%-2d=", i); 607 print_location(st, uc->uc_mcontext.regs->gpr[i]); 608 } 609 st->cr(); 610 } 611 612 extern "C" { 613 int SpinPause() { 614 return 0; 615 } 616 } 617 618 #ifndef PRODUCT 619 void os::verify_stack_alignment() { 620 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment"); 621 } 622 #endif 623 624 int os::extra_bang_size_in_bytes() { 625 // PPC does not require the additional stack bang. 626 return 0; 627 }