1 /* 2 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved. 3 * Copyright (c) 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 // This file is organized as os_linux_x86.cpp. 27 28 // no precompiled headers 29 #include "asm/assembler.inline.hpp" 30 #include "classfile/classLoader.hpp" 31 #include "classfile/systemDictionary.hpp" 32 #include "classfile/vmSymbols.hpp" 33 #include "code/icBuffer.hpp" 34 #include "code/nativeInst.hpp" 35 #include "code/vtableStubs.hpp" 36 #include "compiler/disassembler.hpp" 37 #include "interpreter/interpreter.hpp" 38 #include "jvm_linux.h" 39 #include "memory/allocation.inline.hpp" 40 #include "nativeInst_s390.hpp" 41 #include "os_share_linux.hpp" 42 #include "prims/jniFastGetField.hpp" 43 #include "prims/jvm.h" 44 #include "prims/jvm_misc.hpp" 45 #include "runtime/arguments.hpp" 46 #include "runtime/extendedPC.hpp" 47 #include "runtime/frame.inline.hpp" 48 #include "runtime/interfaceSupport.hpp" 49 #include "runtime/java.hpp" 50 #include "runtime/javaCalls.hpp" 51 #include "runtime/mutexLocker.hpp" 52 #include "runtime/osThread.hpp" 53 #include "runtime/sharedRuntime.hpp" 54 #include "runtime/stubRoutines.hpp" 55 #include "runtime/thread.inline.hpp" 56 #include "runtime/timer.hpp" 57 #include "utilities/events.hpp" 58 #include "utilities/vmError.hpp" 59 60 // put OS-includes here 61 # include <sys/types.h> 62 # include <sys/mman.h> 63 # include <pthread.h> 64 # include <signal.h> 65 # include <errno.h> 66 # include <dlfcn.h> 67 # include <stdlib.h> 68 # include <stdio.h> 69 # include <unistd.h> 70 # include <sys/resource.h> 71 # include <pthread.h> 72 # include <sys/stat.h> 73 # include <sys/time.h> 74 # include <sys/utsname.h> 75 # include <sys/socket.h> 76 # include <sys/wait.h> 77 # include <pwd.h> 78 # include <poll.h> 79 # include <ucontext.h> 80 81 address os::current_stack_pointer() { 82 intptr_t* csp; 83 84 // Inline assembly for `z_lgr regno(csp), Z_SP' (Z_SP = Z_R15): 85 __asm__ __volatile__ ("lgr %0, 15":"=r"(csp):); 86 87 assert(((uint64_t)csp & (frame::alignment_in_bytes-1)) == 0, "SP must be aligned"); 88 return (address) csp; 89 } 90 91 char* os::non_memory_address_word() { 92 // Must never look like an address returned by reserve_memory, 93 // even in its subfields (as defined by the CPU immediate fields, 94 // if the CPU splits constants across multiple instructions). 95 return (char*) -1; 96 } 97 98 // OS specific thread initialization. 99 void os::initialize_thread(Thread* thread) { } 100 101 // Frame information (pc, sp, fp) retrieved via ucontext 102 // always looks like a C-frame according to the frame 103 // conventions in frame_s390.hpp. 104 address os::Linux::ucontext_get_pc(const ucontext_t * uc) { 105 return (address)uc->uc_mcontext.psw.addr; 106 } 107 108 void os::Linux::ucontext_set_pc(ucontext_t * uc, address pc) { 109 uc->uc_mcontext.psw.addr = (unsigned long)pc; 110 } 111 112 intptr_t* os::Linux::ucontext_get_sp(const ucontext_t * uc) { 113 return (intptr_t*)uc->uc_mcontext.gregs[15/*REG_SP*/]; 114 } 115 116 intptr_t* os::Linux::ucontext_get_fp(const ucontext_t * uc) { 117 return NULL; 118 } 119 120 ExtendedPC os::fetch_frame_from_context(const void* ucVoid, 121 intptr_t** ret_sp, intptr_t** ret_fp) { 122 123 ExtendedPC epc; 124 const ucontext_t* uc = (const ucontext_t*)ucVoid; 125 126 if (uc != NULL) { 127 epc = ExtendedPC(os::Linux::ucontext_get_pc(uc)); 128 if (ret_sp) { *ret_sp = os::Linux::ucontext_get_sp(uc); } 129 if (ret_fp) { *ret_fp = os::Linux::ucontext_get_fp(uc); } 130 } else { 131 // Construct empty ExtendedPC for return value checking. 132 epc = ExtendedPC(NULL); 133 if (ret_sp) { *ret_sp = (intptr_t *)NULL; } 134 if (ret_fp) { *ret_fp = (intptr_t *)NULL; } 135 } 136 137 return epc; 138 } 139 140 frame os::fetch_frame_from_context(const void* ucVoid) { 141 intptr_t* sp; 142 intptr_t* fp; 143 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp); 144 return frame(sp, epc.pc()); 145 } 146 147 frame os::get_sender_for_C_frame(frame* fr) { 148 if (*fr->sp() == 0) { 149 // fr is the last C frame. 150 return frame(); 151 } 152 153 // If its not one of our frames, the return pc is saved at gpr14 154 // stack slot. The call_stub stores the return_pc to the stack slot 155 // of gpr10. 156 if ((Interpreter::code() != NULL && Interpreter::contains(fr->pc())) || 157 (CodeCache::contains(fr->pc()) && !StubRoutines::contains(fr->pc()))) { 158 return frame(fr->sender_sp(), fr->sender_pc()); 159 } else { 160 if (StubRoutines::contains(fr->pc())) { 161 StubCodeDesc* desc = StubCodeDesc::desc_for(fr->pc()); 162 if (desc && !strcmp(desc->name(),"call_stub")) { 163 return frame(fr->sender_sp(), fr->callstub_sender_pc()); 164 } else { 165 return frame(fr->sender_sp(), fr->sender_pc()); 166 } 167 } else { 168 return frame(fr->sender_sp(), fr->native_sender_pc()); 169 } 170 } 171 } 172 173 frame os::current_frame() { 174 // Expected to return the stack pointer of this method. 175 // But if inlined, returns the stack pointer of our caller! 176 intptr_t* csp = (intptr_t*) *((intptr_t*) os::current_stack_pointer()); 177 assert (csp != NULL, "sp should not be NULL"); 178 // Pass a dummy pc. This way we don't have to load it from the 179 // stack, since we don't know in which slot we can find it. 180 frame topframe(csp, (address)0x8); 181 if (os::is_first_C_frame(&topframe)) { 182 // Stack is not walkable. 183 return frame(); 184 } else { 185 frame senderFrame = os::get_sender_for_C_frame(&topframe); 186 assert(senderFrame.pc() != NULL, "Sender pc should not be NULL"); 187 // Return sender of sender of current topframe which hopefully 188 // both have pc != NULL. 189 #ifdef _NMT_NOINLINE_ // Is set in slowdebug builds. 190 // Current_stack_pointer is not inlined, we must pop one more frame. 191 frame tmp = os::get_sender_for_C_frame(&topframe); 192 return os::get_sender_for_C_frame(&tmp); 193 #else 194 return os::get_sender_for_C_frame(&topframe); 195 #endif 196 } 197 } 198 199 // Utility functions 200 201 extern "C" JNIEXPORT int 202 JVM_handle_linux_signal(int sig, 203 siginfo_t* info, 204 void* ucVoid, 205 int abort_if_unrecognized) { 206 ucontext_t* uc = (ucontext_t*) ucVoid; 207 208 Thread* t = Thread::current_or_null_safe(); 209 210 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away 211 // (no destructors can be run). 212 os::WatcherThreadCrashProtection::check_crash_protection(sig, t); 213 214 SignalHandlerMark shm(t); 215 216 // Note: it's not uncommon that JNI code uses signal/sigset to install 217 // then restore certain signal handler (e.g. to temporarily block SIGPIPE, 218 // or have a SIGILL handler when detecting CPU type). When that happens, 219 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To 220 // avoid unnecessary crash when libjsig is not preloaded, try handle signals 221 // that do not require siginfo/ucontext first. 222 223 if (sig == SIGPIPE) { 224 if (os::Linux::chained_handler(sig, info, ucVoid)) { 225 return true; 226 } else { 227 if (PrintMiscellaneous && (WizardMode || Verbose)) { 228 warning("Ignoring SIGPIPE - see bug 4229104"); 229 } 230 return true; 231 } 232 } 233 234 JavaThread* thread = NULL; 235 VMThread* vmthread = NULL; 236 if (os::Linux::signal_handlers_are_installed) { 237 if (t != NULL) { 238 if(t->is_Java_thread()) { 239 thread = (JavaThread*)t; 240 } else if(t->is_VM_thread()) { 241 vmthread = (VMThread *)t; 242 } 243 } 244 } 245 246 // Moved SafeFetch32 handling outside thread!=NULL conditional block to make 247 // it work if no associated JavaThread object exists. 248 if (uc) { 249 address const pc = os::Linux::ucontext_get_pc(uc); 250 if (pc && StubRoutines::is_safefetch_fault(pc)) { 251 os::Linux::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc)); 252 return true; 253 } 254 } 255 256 // Decide if this trap can be handled by a stub. 257 address stub = NULL; 258 address pc = NULL; // Pc as retrieved from PSW. Usually points past failing instruction. 259 address trap_pc = NULL; // Pc of the instruction causing the trap. 260 261 //%note os_trap_1 262 if (info != NULL && uc != NULL && thread != NULL) { 263 pc = os::Linux::ucontext_get_pc(uc); 264 if (TraceTraps) { 265 tty->print_cr(" pc at " INTPTR_FORMAT, p2i(pc)); 266 } 267 if ((unsigned long)(pc - (address)info->si_addr) <= (unsigned long)Assembler::instr_maxlen() ) { 268 trap_pc = (address)info->si_addr; 269 if (TraceTraps) { 270 tty->print_cr("trap_pc at " INTPTR_FORMAT, p2i(trap_pc)); 271 } 272 } 273 274 // Handle ALL stack overflow variations here 275 if (sig == SIGSEGV) { 276 address addr = (address)info->si_addr; // Address causing SIGSEGV, usually mem ref target. 277 278 // Check if fault address is within thread stack. 279 if (thread->on_local_stack(addr)) { 280 // stack overflow 281 if (thread->in_stack_yellow_reserved_zone(addr)) { 282 thread->disable_stack_yellow_reserved_zone(); 283 if (thread->thread_state() == _thread_in_Java) { 284 // Throw a stack overflow exception. 285 // Guard pages will be reenabled while unwinding the stack. 286 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); 287 } else { 288 // Thread was in the vm or native code. Return and try to finish. 289 return 1; 290 } 291 } else if (thread->in_stack_red_zone(addr)) { 292 // Fatal red zone violation. Disable the guard pages and fall through 293 // to handle_unexpected_exception way down below. 294 thread->disable_stack_red_zone(); 295 tty->print_raw_cr("An irrecoverable stack overflow has occurred."); 296 297 // This is a likely cause, but hard to verify. Let's just print 298 // it as a hint. 299 tty->print_raw_cr("Please check if any of your loaded .so files has " 300 "enabled executable stack (see man page execstack(8))"); 301 } else { 302 // Accessing stack address below sp may cause SEGV if current 303 // thread has MAP_GROWSDOWN stack. This should only happen when 304 // current thread was created by user code with MAP_GROWSDOWN flag 305 // and then attached to VM. See notes in os_linux.cpp. 306 if (thread->osthread()->expanding_stack() == 0) { 307 thread->osthread()->set_expanding_stack(); 308 if (os::Linux::manually_expand_stack(thread, addr)) { 309 thread->osthread()->clear_expanding_stack(); 310 return 1; 311 } 312 thread->osthread()->clear_expanding_stack(); 313 } else { 314 fatal("recursive segv. expanding stack."); 315 } 316 } 317 } 318 } 319 320 if (thread->thread_state() == _thread_in_Java) { 321 // Java thread running in Java code => find exception handler if any 322 // a fault inside compiled code, the interpreter, or a stub 323 324 // Handle signal from NativeJump::patch_verified_entry(). 325 if (sig == SIGILL && nativeInstruction_at(pc)->is_sigill_zombie_not_entrant()) { 326 if (TraceTraps) { 327 tty->print_cr("trap: zombie_not_entrant (SIGILL)"); 328 } 329 stub = SharedRuntime::get_handle_wrong_method_stub(); 330 } 331 332 else if (sig == SIGSEGV && 333 os::is_poll_address((address)info->si_addr)) { 334 if (TraceTraps) { 335 tty->print_cr("trap: safepoint_poll at " INTPTR_FORMAT " (SIGSEGV)", p2i(pc)); 336 } 337 stub = SharedRuntime::get_poll_stub(pc); 338 339 // Info->si_addr only points to the page base address, so we 340 // must extract the real si_addr from the instruction and the 341 // ucontext. 342 assert(((NativeInstruction*)pc)->is_safepoint_poll(), "must be safepoint poll"); 343 const address real_si_addr = ((NativeInstruction*)pc)->get_poll_address(uc); 344 } 345 346 // SIGTRAP-based implicit null check in compiled code. 347 else if ((sig == SIGFPE) && 348 TrapBasedNullChecks && 349 (trap_pc != NULL) && 350 Assembler::is_sigtrap_zero_check(trap_pc)) { 351 if (TraceTraps) { 352 tty->print_cr("trap: NULL_CHECK at " INTPTR_FORMAT " (SIGFPE)", p2i(trap_pc)); 353 } 354 stub = SharedRuntime::continuation_for_implicit_exception(thread, trap_pc, SharedRuntime::IMPLICIT_NULL); 355 } 356 357 else if (sig == SIGSEGV && ImplicitNullChecks && 358 CodeCache::contains((void*) pc) && 359 !MacroAssembler::needs_explicit_null_check((intptr_t) info->si_addr)) { 360 if (TraceTraps) { 361 tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGSEGV)", p2i(pc)); 362 } 363 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 364 } 365 366 // SIGTRAP-based implicit range check in compiled code. 367 else if (sig == SIGFPE && TrapBasedRangeChecks && 368 (trap_pc != NULL) && 369 Assembler::is_sigtrap_range_check(trap_pc)) { 370 if (TraceTraps) { 371 tty->print_cr("trap: RANGE_CHECK at " INTPTR_FORMAT " (SIGFPE)", p2i(trap_pc)); 372 } 373 stub = SharedRuntime::continuation_for_implicit_exception(thread, trap_pc, SharedRuntime::IMPLICIT_NULL); 374 } 375 376 else if (sig == SIGFPE && info->si_code == FPE_INTDIV) { 377 stub = SharedRuntime::continuation_for_implicit_exception(thread, trap_pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); 378 } 379 380 else if (sig == SIGBUS) { 381 // BugId 4454115: A read from a MappedByteBuffer can fault here if the 382 // underlying file has been truncated. Do not crash the VM in such a case. 383 CodeBlob* cb = CodeCache::find_blob_unsafe(pc); 384 CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL; 385 if (nm != NULL && nm->has_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 uc->uc_mcontext.psw.addr = ((unsigned long)pc) + Assembler::instr_len(pc); 391 return true; 392 } 393 } 394 } 395 396 else { // thread->thread_state() != _thread_in_Java 397 if (sig == SIGILL && VM_Version::is_determine_features_test_running()) { 398 // SIGILL must be caused by VM_Version::determine_features(). 399 //*(int *) (pc-6)=0; // Patch instruction to 0 to indicate that it causes a SIGILL. 400 // Flushing of icache is not necessary. 401 stub = pc; // Continue with next instruction. 402 } else if (thread->thread_state() == _thread_in_vm && 403 sig == SIGBUS && thread->doing_unsafe_access()) { 404 // We don't really need a stub here! Just set the pending exeption and 405 // continue at the next instruction after the faulting read. Returning 406 // garbage from this read is ok. 407 thread->set_pending_unsafe_access_error(); 408 os::Linux::ucontext_set_pc(uc, pc + Assembler::instr_len(pc)); 409 return true; 410 } 411 } 412 413 // Check to see if we caught the safepoint code in the 414 // process of write protecting the memory serialization page. 415 // It write enables the page immediately after protecting it 416 // so we can just return to retry the write. 417 // Info->si_addr need not be the exact address, it is only 418 // guaranteed to be on the same page as the address that caused 419 // the SIGSEGV. 420 if ((sig == SIGSEGV) && 421 (os::get_memory_serialize_page() == 422 (address)((uintptr_t)info->si_addr & ~(os::vm_page_size()-1)))) { 423 return true; 424 } 425 } 426 427 if (stub != NULL) { 428 // Save all thread context in case we need to restore it. 429 if (thread != NULL) thread->set_saved_exception_pc(pc); 430 os::Linux::ucontext_set_pc(uc, stub); 431 return true; 432 } 433 434 // signal-chaining 435 if (os::Linux::chained_handler(sig, info, ucVoid)) { 436 return true; 437 } 438 439 if (!abort_if_unrecognized) { 440 // caller wants another chance, so give it to him 441 return false; 442 } 443 444 if (pc == NULL && uc != NULL) { 445 pc = os::Linux::ucontext_get_pc(uc); 446 } 447 448 // unmask current signal 449 sigset_t newset; 450 sigemptyset(&newset); 451 sigaddset(&newset, sig); 452 sigprocmask(SIG_UNBLOCK, &newset, NULL); 453 454 VMError::report_and_die(t, sig, pc, info, ucVoid); 455 456 ShouldNotReachHere(); 457 return false; 458 } 459 460 void os::Linux::init_thread_fpu_state(void) { 461 // Nothing to do on z/Architecture. 462 } 463 464 int os::Linux::get_fpu_control_word(void) { 465 // Nothing to do on z/Architecture. 466 return 0; 467 } 468 469 void os::Linux::set_fpu_control_word(int fpu_control) { 470 // Nothing to do on z/Architecture. 471 } 472 473 //////////////////////////////////////////////////////////////////////////////// 474 // thread stack 475 476 // These sizes exclude OS stack guard pages, but include 477 // the VM guard pages. 478 size_t os::Posix::_compiler_thread_min_stack_allowed = 128 * K; 479 size_t os::Posix::_java_thread_min_stack_allowed = 236 * K; 480 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 128 * K; 481 482 // Return default stack size for thr_type. 483 size_t os::Posix::default_stack_size(os::ThreadType thr_type) { 484 // Default stack size (compiler thread needs larger stack). 485 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1024 * K); 486 return s; 487 } 488 489 ///////////////////////////////////////////////////////////////////////////// 490 // helper functions for fatal error handler 491 492 void os::print_context(outputStream *st, const void *context) { 493 if (context == NULL) return; 494 495 const ucontext_t* uc = (const ucontext_t*)context; 496 497 st->print_cr("Processor state:"); 498 st->print_cr("----------------"); 499 st->print_cr(" ip = " INTPTR_FORMAT " ", uc->uc_mcontext.psw.addr); 500 st->print_cr(" proc mask = " INTPTR_FORMAT " ", uc->uc_mcontext.psw.mask); 501 st->print_cr(" fpc reg = 0x%8.8x " , uc->uc_mcontext.fpregs.fpc); 502 st->cr(); 503 504 st->print_cr("General Purpose Registers:"); 505 st->print_cr("--------------------------"); 506 for( int i = 0; i < 16; i+=2 ) { 507 st->print(" r%-2d = " INTPTR_FORMAT " " , i, uc->uc_mcontext.gregs[i]); 508 st->print(" r%-2d = " INTPTR_FORMAT " |", i+1, uc->uc_mcontext.gregs[i+1]); 509 st->print(" r%-2d = %23.1ld " , i, uc->uc_mcontext.gregs[i]); 510 st->print(" r%-2d = %23.1ld " , i+1, uc->uc_mcontext.gregs[i+1]); 511 st->cr(); 512 } 513 st->cr(); 514 515 st->print_cr("Access Registers:"); 516 st->print_cr("-----------------"); 517 for( int i = 0; i < 16; i+=2 ) { 518 st->print(" ar%-2d = 0x%8.8x ", i, uc->uc_mcontext.aregs[i]); 519 st->print(" ar%-2d = 0x%8.8x ", i+1, uc->uc_mcontext.aregs[i+1]); 520 st->cr(); 521 } 522 st->cr(); 523 524 st->print_cr("Float Registers:"); 525 st->print_cr("----------------"); 526 for (int i = 0; i < 16; i += 2) { 527 st->print(" fr%-2d = " INTPTR_FORMAT " " , i, (int64_t)(uc->uc_mcontext.fpregs.fprs[i].d)); 528 st->print(" fr%-2d = " INTPTR_FORMAT " |", i+1, (int64_t)(uc->uc_mcontext.fpregs.fprs[i+1].d)); 529 st->print(" fr%-2d = %23.15e " , i, (uc->uc_mcontext.fpregs.fprs[i].d)); 530 st->print(" fr%-2d = %23.15e " , i+1, (uc->uc_mcontext.fpregs.fprs[i+1].d)); 531 st->cr(); 532 } 533 st->cr(); 534 st->cr(); 535 536 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc); 537 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", p2i(sp)); 538 print_hex_dump(st, (address)sp, (address)(sp + 128), sizeof(intptr_t)); 539 st->cr(); 540 541 // Note: it may be unsafe to inspect memory near pc. For example, pc may 542 // point to garbage if entry point in an nmethod is corrupted. Leave 543 // this at the end, and hope for the best. 544 address pc = os::Linux::ucontext_get_pc(uc); 545 if (Verbose) { st->print_cr("pc at " PTR_FORMAT, p2i(pc)); } 546 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", p2i(pc)); 547 print_hex_dump(st, pc-64, pc+64, /*intrsize=*/4); 548 st->cr(); 549 } 550 551 void os::print_register_info(outputStream *st, const void *context) { 552 st->print("Not ported\n"); 553 } 554 555 #ifndef PRODUCT 556 void os::verify_stack_alignment() { 557 } 558 #endif 559 560 int os::extra_bang_size_in_bytes() { 561 // z/Architecture does not require the additional stack bang. 562 return 0; 563 }