1 /* 2 * Copyright (c) 1997, 2015, 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 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 "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_aix.h" 35 #include "memory/allocation.inline.hpp" 36 #include "mutex_aix.inline.hpp" 37 #include "nativeInst_ppc.hpp" 38 #include "os_share_aix.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 #ifdef COMPILER1 57 #include "c1/c1_Runtime1.hpp" 58 #endif 59 #ifdef COMPILER2 60 #include "opto/runtime.hpp" 61 #endif 62 63 // put OS-includes here 64 # include <ucontext.h> 65 66 address os::current_stack_pointer() { 67 address csp; 68 69 #if !defined(USE_XLC_BUILTINS) 70 // inline assembly for `mr regno(csp), R1_SP': 71 __asm__ __volatile__ ("mr %0, 1":"=r"(csp):); 72 #else 73 csp = (address) __builtin_frame_address(0); 74 #endif 75 76 return csp; 77 } 78 79 char* os::non_memory_address_word() { 80 // Must never look like an address returned by reserve_memory, 81 // even in its subfields (as defined by the CPU immediate fields, 82 // if the CPU splits constants across multiple instructions). 83 84 return (char*) -1; 85 } 86 87 // OS specific thread initialization 88 // 89 // Calculate and store the limits of the memory stack. 90 void os::initialize_thread(Thread *thread) { } 91 92 // Frame information (pc, sp, fp) retrieved via ucontext 93 // always looks like a C-frame according to the frame 94 // conventions in frame_ppc.hpp. 95 96 address os::Aix::ucontext_get_pc(const ucontext_t * uc) { 97 return (address)uc->uc_mcontext.jmp_context.iar; 98 } 99 100 intptr_t* os::Aix::ucontext_get_sp(ucontext_t * uc) { 101 // gpr1 holds the stack pointer on aix 102 return (intptr_t*)uc->uc_mcontext.jmp_context.gpr[1/*REG_SP*/]; 103 } 104 105 intptr_t* os::Aix::ucontext_get_fp(ucontext_t * uc) { 106 return NULL; 107 } 108 109 void os::Aix::ucontext_set_pc(ucontext_t* uc, address new_pc) { 110 uc->uc_mcontext.jmp_context.iar = (uint64_t) new_pc; 111 } 112 113 ExtendedPC os::fetch_frame_from_context(void* ucVoid, 114 intptr_t** ret_sp, intptr_t** ret_fp) { 115 116 ExtendedPC epc; 117 ucontext_t* uc = (ucontext_t*)ucVoid; 118 119 if (uc != NULL) { 120 epc = ExtendedPC(os::Aix::ucontext_get_pc(uc)); 121 if (ret_sp) *ret_sp = os::Aix::ucontext_get_sp(uc); 122 if (ret_fp) *ret_fp = os::Aix::ucontext_get_fp(uc); 123 } else { 124 // construct empty ExtendedPC for return value checking 125 epc = ExtendedPC(NULL); 126 if (ret_sp) *ret_sp = (intptr_t *)NULL; 127 if (ret_fp) *ret_fp = (intptr_t *)NULL; 128 } 129 130 return epc; 131 } 132 133 frame os::fetch_frame_from_context(void* ucVoid) { 134 intptr_t* sp; 135 intptr_t* fp; 136 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp); 137 // Avoid crash during crash if pc broken. 138 if (epc.pc()) { 139 frame fr(sp, epc.pc()); 140 return fr; 141 } 142 frame fr(sp); 143 return fr; 144 } 145 146 frame os::get_sender_for_C_frame(frame* fr) { 147 if (*fr->sp() == NULL) { 148 // fr is the last C frame 149 return frame(NULL, NULL); 150 } 151 return frame(fr->sender_sp(), fr->sender_pc()); 152 } 153 154 155 frame os::current_frame() { 156 intptr_t* csp = (intptr_t*) *((intptr_t*) os::current_stack_pointer()); 157 // hack. 158 frame topframe(csp, (address)0x8); 159 // return sender of current topframe which hopefully has pc != NULL. 160 return os::get_sender_for_C_frame(&topframe); 161 } 162 163 // Utility functions 164 165 extern "C" JNIEXPORT int 166 JVM_handle_aix_signal(int sig, siginfo_t* info, void* ucVoid, int abort_if_unrecognized) { 167 168 ucontext_t* uc = (ucontext_t*) ucVoid; 169 170 Thread* t = Thread::current_or_null_safe(); 171 172 SignalHandlerMark shm(t); 173 174 // Note: it's not uncommon that JNI code uses signal/sigset to install 175 // then restore certain signal handler (e.g. to temporarily block SIGPIPE, 176 // or have a SIGILL handler when detecting CPU type). When that happens, 177 // JVM_handle_aix_signal() might be invoked with junk info/ucVoid. To 178 // avoid unnecessary crash when libjsig is not preloaded, try handle signals 179 // that do not require siginfo/ucontext first. 180 181 if (sig == SIGPIPE) { 182 if (os::Aix::chained_handler(sig, info, ucVoid)) { 183 return 1; 184 } else { 185 if (PrintMiscellaneous && (WizardMode || Verbose)) { 186 warning("Ignoring SIGPIPE - see bug 4229104"); 187 } 188 return 1; 189 } 190 } 191 192 JavaThread* thread = NULL; 193 VMThread* vmthread = NULL; 194 if (os::Aix::signal_handlers_are_installed) { 195 if (t != NULL) { 196 if(t->is_Java_thread()) { 197 thread = (JavaThread*)t; 198 } 199 else if(t->is_VM_thread()) { 200 vmthread = (VMThread *)t; 201 } 202 } 203 } 204 205 // Decide if this trap can be handled by a stub. 206 address stub = NULL; 207 208 // retrieve program counter 209 address const pc = uc ? os::Aix::ucontext_get_pc(uc) : NULL; 210 211 // retrieve crash address 212 address const addr = info ? (const address) info->si_addr : NULL; 213 214 // SafeFetch 32 handling: 215 // - make it work if _thread is null 216 // - make it use the standard os::...::ucontext_get/set_pc APIs 217 if (uc) { 218 address const pc = os::Aix::ucontext_get_pc(uc); 219 if (pc && StubRoutines::is_safefetch_fault(pc)) { 220 os::Aix::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc)); 221 return true; 222 } 223 } 224 225 // Handle SIGDANGER right away. AIX would raise SIGDANGER whenever available swap 226 // space falls below 30%. This is only a chance for the process to gracefully abort. 227 // We can't hope to proceed after SIGDANGER since SIGKILL tailgates. 228 if (sig == SIGDANGER) { 229 goto report_and_die; 230 } 231 232 if (info == NULL || uc == NULL || thread == NULL && vmthread == NULL) { 233 goto run_chained_handler; 234 } 235 236 // If we are a java thread... 237 if (thread != NULL) { 238 239 // Handle ALL stack overflow variations here 240 if (sig == SIGSEGV && (addr < thread->stack_base() && 241 addr >= thread->stack_base() - thread->stack_size())) { 242 // stack overflow 243 // 244 // If we are in a yellow zone and we are inside java, we disable the yellow zone and 245 // throw a stack overflow exception. 246 // If we are in native code or VM C code, we report-and-die. The original coding tried 247 // to continue with yellow zone disabled, but that doesn't buy us much and prevents 248 // hs_err_pid files. 249 if (thread->in_stack_yellow_zone(addr)) { 250 thread->disable_stack_yellow_zone(); 251 if (thread->thread_state() == _thread_in_Java) { 252 // Throw a stack overflow exception. 253 // Guard pages will be reenabled while unwinding the stack. 254 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); 255 goto run_stub; 256 } else { 257 // Thread was in the vm or native code. Return and try to finish. 258 return 1; 259 } 260 } else if (thread->in_stack_red_zone(addr)) { 261 // Fatal red zone violation. Disable the guard pages and fall through 262 // to handle_unexpected_exception way down below. 263 thread->disable_stack_red_zone(); 264 tty->print_raw_cr("An irrecoverable stack overflow has occurred."); 265 goto report_and_die; 266 } else { 267 // This means a segv happened inside our stack, but not in 268 // the guarded zone. I'd like to know when this happens, 269 tty->print_raw_cr("SIGSEGV happened inside stack but outside yellow and red zone."); 270 goto report_and_die; 271 } 272 273 } // end handle SIGSEGV inside stack boundaries 274 275 if (thread->thread_state() == _thread_in_Java) { 276 // Java thread running in Java code 277 278 // The following signals are used for communicating VM events: 279 // 280 // SIGILL: the compiler generates illegal opcodes 281 // at places where it wishes to interrupt the VM: 282 // Safepoints, Unreachable Code, Entry points of Zombie methods, 283 // This results in a SIGILL with (*pc) == inserted illegal instruction. 284 // 285 // (so, SIGILLs with a pc inside the zero page are real errors) 286 // 287 // SIGTRAP: 288 // The ppc trap instruction raises a SIGTRAP and is very efficient if it 289 // does not trap. It is used for conditional branches that are expected 290 // to be never taken. These are: 291 // - zombie methods 292 // - IC (inline cache) misses. 293 // - null checks leading to UncommonTraps. 294 // - range checks leading to Uncommon Traps. 295 // On Aix, these are especially null checks, as the ImplicitNullCheck 296 // optimization works only in rare cases, as the page at address 0 is only 297 // write protected. // 298 // Note: !UseSIGTRAP is used to prevent SIGTRAPS altogether, to facilitate debugging. 299 // 300 // SIGSEGV: 301 // used for safe point polling: 302 // To notify all threads that they have to reach a safe point, safe point polling is used: 303 // All threads poll a certain mapped memory page. Normally, this page has read access. 304 // If the VM wants to inform the threads about impending safe points, it puts this 305 // page to read only ("poisens" the page), and the threads then reach a safe point. 306 // used for null checks: 307 // If the compiler finds a store it uses it for a null check. Unfortunately this 308 // happens rarely. In heap based and disjoint base compressd oop modes also loads 309 // are used for null checks. 310 311 // A VM-related SIGILL may only occur if we are not in the zero page. 312 // On AIX, we get a SIGILL if we jump to 0x0 or to somewhere else 313 // in the zero page, because it is filled with 0x0. We ignore 314 // explicit SIGILLs in the zero page. 315 if (sig == SIGILL && (pc < (address) 0x200)) { 316 if (TraceTraps) { 317 tty->print_raw_cr("SIGILL happened inside zero page."); 318 } 319 goto report_and_die; 320 } 321 322 // Handle signal from NativeJump::patch_verified_entry(). 323 if (( TrapBasedNotEntrantChecks && sig == SIGTRAP && nativeInstruction_at(pc)->is_sigtrap_zombie_not_entrant()) || 324 (!TrapBasedNotEntrantChecks && sig == SIGILL && nativeInstruction_at(pc)->is_sigill_zombie_not_entrant())) { 325 if (TraceTraps) { 326 tty->print_cr("trap: zombie_not_entrant (%s)", (sig == SIGTRAP) ? "SIGTRAP" : "SIGILL"); 327 } 328 stub = SharedRuntime::get_handle_wrong_method_stub(); 329 goto run_stub; 330 } 331 332 else if (sig == SIGSEGV && os::is_poll_address(addr)) { 333 if (TraceTraps) { 334 tty->print_cr("trap: safepoint_poll at " INTPTR_FORMAT " (SIGSEGV)", pc); 335 } 336 stub = SharedRuntime::get_poll_stub(pc); 337 goto run_stub; 338 } 339 340 // SIGTRAP-based ic miss check in compiled code. 341 else if (sig == SIGTRAP && TrapBasedICMissChecks && 342 nativeInstruction_at(pc)->is_sigtrap_ic_miss_check()) { 343 if (TraceTraps) { 344 tty->print_cr("trap: ic_miss_check at " INTPTR_FORMAT " (SIGTRAP)", pc); 345 } 346 stub = SharedRuntime::get_ic_miss_stub(); 347 goto run_stub; 348 } 349 350 // SIGTRAP-based implicit null check in compiled code. 351 else if (sig == SIGTRAP && TrapBasedNullChecks && 352 nativeInstruction_at(pc)->is_sigtrap_null_check()) { 353 if (TraceTraps) { 354 tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGTRAP)", pc); 355 } 356 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 357 goto run_stub; 358 } 359 360 // SIGSEGV-based implicit null check in compiled code. 361 else if (sig == SIGSEGV && ImplicitNullChecks && 362 CodeCache::contains((void*) pc) && 363 !MacroAssembler::needs_explicit_null_check((intptr_t) info->si_addr)) { 364 if (TraceTraps) { 365 tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGSEGV)", pc); 366 } 367 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 368 } 369 370 #ifdef COMPILER2 371 // SIGTRAP-based implicit range check in compiled code. 372 else if (sig == SIGTRAP && TrapBasedRangeChecks && 373 nativeInstruction_at(pc)->is_sigtrap_range_check()) { 374 if (TraceTraps) { 375 tty->print_cr("trap: range_check at " INTPTR_FORMAT " (SIGTRAP)", pc); 376 } 377 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 378 goto run_stub; 379 } 380 #endif 381 382 else if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) { 383 if (TraceTraps) { 384 tty->print_raw_cr("Fix SIGFPE handler, trying divide by zero handler."); 385 } 386 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); 387 goto run_stub; 388 } 389 390 else if (sig == SIGBUS) { 391 // BugId 4454115: A read from a MappedByteBuffer can fault here if the 392 // underlying file has been truncated. Do not crash the VM in such a case. 393 CodeBlob* cb = CodeCache::find_blob_unsafe(pc); 394 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL; 395 if (nm != NULL && nm->has_unsafe_access()) { 396 // We don't really need a stub here! Just set the pending exeption and 397 // continue at the next instruction after the faulting read. Returning 398 // garbage from this read is ok. 399 thread->set_pending_unsafe_access_error(); 400 os::Aix::ucontext_set_pc(uc, pc + 4); 401 return 1; 402 } 403 } 404 } 405 406 else { // thread->thread_state() != _thread_in_Java 407 // Detect CPU features. This is only done at the very start of the VM. Later, the 408 // VM_Version::is_determine_features_test_running() flag should be false. 409 410 if (sig == SIGILL && VM_Version::is_determine_features_test_running()) { 411 // SIGILL must be caused by VM_Version::determine_features(). 412 *(int *)pc = 0; // patch instruction to 0 to indicate that it causes a SIGILL, 413 // flushing of icache is not necessary. 414 stub = pc + 4; // continue with next instruction. 415 goto run_stub; 416 } 417 else if (thread->thread_state() == _thread_in_vm && 418 sig == SIGBUS && thread->doing_unsafe_access()) { 419 // We don't really need a stub here! Just set the pending exeption and 420 // continue at the next instruction after the faulting read. Returning 421 // garbage from this read is ok. 422 thread->set_pending_unsafe_access_error(); 423 os::Aix::ucontext_set_pc(uc, pc + 4); 424 return 1; 425 } 426 } 427 428 // Check to see if we caught the safepoint code in the 429 // process of write protecting the memory serialization page. 430 // It write enables the page immediately after protecting it 431 // so we can just return to retry the write. 432 if ((sig == SIGSEGV) && 433 os::is_memory_serialize_page(thread, addr)) { 434 // Synchronization problem in the pseudo memory barrier code (bug id 6546278) 435 // Block current thread until the memory serialize page permission restored. 436 os::block_on_serialize_page_trap(); 437 return true; 438 } 439 } 440 441 run_stub: 442 443 // One of the above code blocks ininitalized the stub, so we want to 444 // delegate control to that stub. 445 if (stub != NULL) { 446 // Save all thread context in case we need to restore it. 447 if (thread != NULL) thread->set_saved_exception_pc(pc); 448 os::Aix::ucontext_set_pc(uc, stub); 449 return 1; 450 } 451 452 run_chained_handler: 453 454 // signal-chaining 455 if (os::Aix::chained_handler(sig, info, ucVoid)) { 456 return 1; 457 } 458 if (!abort_if_unrecognized) { 459 // caller wants another chance, so give it to him 460 return 0; 461 } 462 463 report_and_die: 464 465 // Use sigthreadmask instead of sigprocmask on AIX and unmask current signal. 466 sigset_t newset; 467 sigemptyset(&newset); 468 sigaddset(&newset, sig); 469 sigthreadmask(SIG_UNBLOCK, &newset, NULL); 470 471 VMError::report_and_die(t, sig, pc, info, ucVoid); 472 473 ShouldNotReachHere(); 474 return 0; 475 } 476 477 void os::Aix::init_thread_fpu_state(void) { 478 #if !defined(USE_XLC_BUILTINS) 479 // Disable FP exceptions. 480 __asm__ __volatile__ ("mtfsfi 6,0"); 481 #else 482 __mtfsfi(6, 0); 483 #endif 484 } 485 486 //////////////////////////////////////////////////////////////////////////////// 487 // thread stack 488 489 size_t os::Aix::min_stack_allowed = 128*K; 490 491 // return default stack size for thr_type 492 size_t os::Aix::default_stack_size(os::ThreadType thr_type) { 493 // default stack size (compiler thread needs larger stack) 494 // Notice that the setting for compiler threads here have no impact 495 // because of the strange 'fallback logic' in os::create_thread(). 496 // Better set CompilerThreadStackSize in globals_<os_cpu>.hpp if you want to 497 // specify a different stack size for compiler threads! 498 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M); 499 return s; 500 } 501 502 size_t os::Aix::default_guard_size(os::ThreadType thr_type) { 503 return 2 * page_size(); 504 } 505 506 ///////////////////////////////////////////////////////////////////////////// 507 // helper functions for fatal error handler 508 509 void os::print_context(outputStream *st, void *context) { 510 if (context == NULL) return; 511 512 ucontext_t* uc = (ucontext_t*)context; 513 514 st->print_cr("Registers:"); 515 st->print("pc =" INTPTR_FORMAT " ", uc->uc_mcontext.jmp_context.iar); 516 st->print("lr =" INTPTR_FORMAT " ", uc->uc_mcontext.jmp_context.lr); 517 st->print("ctr=" INTPTR_FORMAT " ", uc->uc_mcontext.jmp_context.ctr); 518 st->cr(); 519 for (int i = 0; i < 32; i++) { 520 st->print("r%-2d=" INTPTR_FORMAT " ", i, uc->uc_mcontext.jmp_context.gpr[i]); 521 if (i % 3 == 2) st->cr(); 522 } 523 st->cr(); 524 st->cr(); 525 526 intptr_t *sp = (intptr_t *)os::Aix::ucontext_get_sp(uc); 527 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp); 528 print_hex_dump(st, (address)sp, (address)(sp + 128), sizeof(intptr_t)); 529 st->cr(); 530 531 // Note: it may be unsafe to inspect memory near pc. For example, pc may 532 // point to garbage if entry point in an nmethod is corrupted. Leave 533 // this at the end, and hope for the best. 534 address pc = os::Aix::ucontext_get_pc(uc); 535 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc); 536 print_hex_dump(st, pc - 64, pc + 64, /*instrsize=*/4); 537 st->cr(); 538 539 // Try to decode the instructions. 540 st->print_cr("Decoded instructions: (pc=" PTR_FORMAT ")", pc); 541 st->print("<TODO: PPC port - print_context>"); 542 // TODO: PPC port Disassembler::decode(pc, 16, 16, st); 543 st->cr(); 544 } 545 546 void os::print_register_info(outputStream *st, void *context) { 547 if (context == NULL) return; 548 st->print("Not ported - print_register_info\n"); 549 } 550 551 extern "C" { 552 int SpinPause() { 553 return 0; 554 } 555 } 556 557 #ifndef PRODUCT 558 void os::verify_stack_alignment() { 559 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment"); 560 } 561 #endif 562 563 int os::extra_bang_size_in_bytes() { 564 // PPC does not require the additional stack bang. 565 return 0; 566 }