os_solaris_x86.cpp revision 4989:5e3b6f79d280
1/* 2 * Copyright (c) 1999, 2013, 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_solaris.h" 34#include "memory/allocation.inline.hpp" 35#include "mutex_solaris.inline.hpp" 36#include "os_share_solaris.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 <setjmp.h> 61# include <errno.h> 62# include <dlfcn.h> 63# include <stdio.h> 64# include <unistd.h> 65# include <sys/resource.h> 66# include <thread.h> 67# include <sys/stat.h> 68# include <sys/time.h> 69# include <sys/filio.h> 70# include <sys/utsname.h> 71# include <sys/systeminfo.h> 72# include <sys/socket.h> 73# include <sys/trap.h> 74# include <sys/lwp.h> 75# include <pwd.h> 76# include <poll.h> 77# include <sys/lwp.h> 78# include <procfs.h> // see comment in <sys/procfs.h> 79 80#ifndef AMD64 81// QQQ seems useless at this point 82# define _STRUCTURED_PROC 1 // this gets us the new structured proc interfaces of 5.6 & later 83#endif // AMD64 84# include <sys/procfs.h> // see comment in <sys/procfs.h> 85 86 87#define MAX_PATH (2 * K) 88 89// Minimum stack size for the VM. It's easier to document a constant value 90// but it's different for x86 and sparc because the page sizes are different. 91#ifdef AMD64 92size_t os::Solaris::min_stack_allowed = 224*K; 93#define REG_SP REG_RSP 94#define REG_PC REG_RIP 95#define REG_FP REG_RBP 96#else 97size_t os::Solaris::min_stack_allowed = 64*K; 98#define REG_SP UESP 99#define REG_PC EIP 100#define REG_FP EBP 101// 4900493 counter to prevent runaway LDTR refresh attempt 102 103static volatile int ldtr_refresh = 0; 104// the libthread instruction that faults because of the stale LDTR 105 106static const unsigned char movlfs[] = { 0x8e, 0xe0 // movl %eax,%fs 107 }; 108#endif // AMD64 109 110char* os::non_memory_address_word() { 111 // Must never look like an address returned by reserve_memory, 112 // even in its subfields (as defined by the CPU immediate fields, 113 // if the CPU splits constants across multiple instructions). 114 return (char*) -1; 115} 116 117// 118// Validate a ucontext retrieved from walking a uc_link of a ucontext. 119// There are issues with libthread giving out uc_links for different threads 120// on the same uc_link chain and bad or circular links. 121// 122bool os::Solaris::valid_ucontext(Thread* thread, ucontext_t* valid, ucontext_t* suspect) { 123 if (valid >= suspect || 124 valid->uc_stack.ss_flags != suspect->uc_stack.ss_flags || 125 valid->uc_stack.ss_sp != suspect->uc_stack.ss_sp || 126 valid->uc_stack.ss_size != suspect->uc_stack.ss_size) { 127 DEBUG_ONLY(tty->print_cr("valid_ucontext: failed test 1");) 128 return false; 129 } 130 131 if (thread->is_Java_thread()) { 132 if (!valid_stack_address(thread, (address)suspect)) { 133 DEBUG_ONLY(tty->print_cr("valid_ucontext: uc_link not in thread stack");) 134 return false; 135 } 136 if (!valid_stack_address(thread, (address) suspect->uc_mcontext.gregs[REG_SP])) { 137 DEBUG_ONLY(tty->print_cr("valid_ucontext: stackpointer not in thread stack");) 138 return false; 139 } 140 } 141 return true; 142} 143 144// We will only follow one level of uc_link since there are libthread 145// issues with ucontext linking and it is better to be safe and just 146// let caller retry later. 147ucontext_t* os::Solaris::get_valid_uc_in_signal_handler(Thread *thread, 148 ucontext_t *uc) { 149 150 ucontext_t *retuc = NULL; 151 152 if (uc != NULL) { 153 if (uc->uc_link == NULL) { 154 // cannot validate without uc_link so accept current ucontext 155 retuc = uc; 156 } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) { 157 // first ucontext is valid so try the next one 158 uc = uc->uc_link; 159 if (uc->uc_link == NULL) { 160 // cannot validate without uc_link so accept current ucontext 161 retuc = uc; 162 } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) { 163 // the ucontext one level down is also valid so return it 164 retuc = uc; 165 } 166 } 167 } 168 return retuc; 169} 170 171// Assumes ucontext is valid 172ExtendedPC os::Solaris::ucontext_get_ExtendedPC(ucontext_t *uc) { 173 return ExtendedPC((address)uc->uc_mcontext.gregs[REG_PC]); 174} 175 176// Assumes ucontext is valid 177intptr_t* os::Solaris::ucontext_get_sp(ucontext_t *uc) { 178 return (intptr_t*)uc->uc_mcontext.gregs[REG_SP]; 179} 180 181// Assumes ucontext is valid 182intptr_t* os::Solaris::ucontext_get_fp(ucontext_t *uc) { 183 return (intptr_t*)uc->uc_mcontext.gregs[REG_FP]; 184} 185 186address os::Solaris::ucontext_get_pc(ucontext_t *uc) { 187 return (address) uc->uc_mcontext.gregs[REG_PC]; 188} 189 190// For Forte Analyzer AsyncGetCallTrace profiling support - thread 191// is currently interrupted by SIGPROF. 192// 193// The difference between this and os::fetch_frame_from_context() is that 194// here we try to skip nested signal frames. 195ExtendedPC os::Solaris::fetch_frame_from_ucontext(Thread* thread, 196 ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) { 197 198 assert(thread != NULL, "just checking"); 199 assert(ret_sp != NULL, "just checking"); 200 assert(ret_fp != NULL, "just checking"); 201 202 ucontext_t *luc = os::Solaris::get_valid_uc_in_signal_handler(thread, uc); 203 return os::fetch_frame_from_context(luc, ret_sp, ret_fp); 204} 205 206ExtendedPC os::fetch_frame_from_context(void* ucVoid, 207 intptr_t** ret_sp, intptr_t** ret_fp) { 208 209 ExtendedPC epc; 210 ucontext_t *uc = (ucontext_t*)ucVoid; 211 212 if (uc != NULL) { 213 epc = os::Solaris::ucontext_get_ExtendedPC(uc); 214 if (ret_sp) *ret_sp = os::Solaris::ucontext_get_sp(uc); 215 if (ret_fp) *ret_fp = os::Solaris::ucontext_get_fp(uc); 216 } else { 217 // construct empty ExtendedPC for return value checking 218 epc = ExtendedPC(NULL); 219 if (ret_sp) *ret_sp = (intptr_t *)NULL; 220 if (ret_fp) *ret_fp = (intptr_t *)NULL; 221 } 222 223 return epc; 224} 225 226frame os::fetch_frame_from_context(void* ucVoid) { 227 intptr_t* sp; 228 intptr_t* fp; 229 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp); 230 return frame(sp, fp, epc.pc()); 231} 232 233frame os::get_sender_for_C_frame(frame* fr) { 234 return frame(fr->sender_sp(), fr->link(), fr->sender_pc()); 235} 236 237extern "C" intptr_t *_get_current_sp(); // in .il file 238 239address os::current_stack_pointer() { 240 return (address)_get_current_sp(); 241} 242 243extern "C" intptr_t *_get_current_fp(); // in .il file 244 245frame os::current_frame() { 246 intptr_t* fp = _get_current_fp(); // it's inlined so want current fp 247 frame myframe((intptr_t*)os::current_stack_pointer(), 248 (intptr_t*)fp, 249 CAST_FROM_FN_PTR(address, os::current_frame)); 250 if (os::is_first_C_frame(&myframe)) { 251 // stack is not walkable 252 frame ret; // This will be a null useless frame 253 return ret; 254 } else { 255 return os::get_sender_for_C_frame(&myframe); 256 } 257} 258 259static int threadgetstate(thread_t tid, int *flags, lwpid_t *lwp, stack_t *ss, gregset_t rs, lwpstatus_t *lwpstatus) { 260 char lwpstatusfile[PROCFILE_LENGTH]; 261 int lwpfd, err; 262 263 if (err = os::Solaris::thr_getstate(tid, flags, lwp, ss, rs)) 264 return (err); 265 if (*flags == TRS_LWPID) { 266 sprintf(lwpstatusfile, "/proc/%d/lwp/%d/lwpstatus", getpid(), 267 *lwp); 268 if ((lwpfd = open(lwpstatusfile, O_RDONLY)) < 0) { 269 perror("thr_mutator_status: open lwpstatus"); 270 return (EINVAL); 271 } 272 if (pread(lwpfd, lwpstatus, sizeof (lwpstatus_t), (off_t)0) != 273 sizeof (lwpstatus_t)) { 274 perror("thr_mutator_status: read lwpstatus"); 275 (void) close(lwpfd); 276 return (EINVAL); 277 } 278 (void) close(lwpfd); 279 } 280 return (0); 281} 282 283#ifndef AMD64 284 285// Detecting SSE support by OS 286// From solaris_i486.s 287extern "C" bool sse_check(); 288extern "C" bool sse_unavailable(); 289 290enum { SSE_UNKNOWN, SSE_NOT_SUPPORTED, SSE_SUPPORTED}; 291static int sse_status = SSE_UNKNOWN; 292 293 294static void check_for_sse_support() { 295 if (!VM_Version::supports_sse()) { 296 sse_status = SSE_NOT_SUPPORTED; 297 return; 298 } 299 // looking for _sse_hw in libc.so, if it does not exist or 300 // the value (int) is 0, OS has no support for SSE 301 int *sse_hwp; 302 void *h; 303 304 if ((h=dlopen("/usr/lib/libc.so", RTLD_LAZY)) == NULL) { 305 //open failed, presume no support for SSE 306 sse_status = SSE_NOT_SUPPORTED; 307 return; 308 } 309 if ((sse_hwp = (int *)dlsym(h, "_sse_hw")) == NULL) { 310 sse_status = SSE_NOT_SUPPORTED; 311 } else if (*sse_hwp == 0) { 312 sse_status = SSE_NOT_SUPPORTED; 313 } 314 dlclose(h); 315 316 if (sse_status == SSE_UNKNOWN) { 317 bool (*try_sse)() = (bool (*)())sse_check; 318 sse_status = (*try_sse)() ? SSE_SUPPORTED : SSE_NOT_SUPPORTED; 319 } 320 321} 322 323#endif // AMD64 324 325bool os::supports_sse() { 326#ifdef AMD64 327 return true; 328#else 329 if (sse_status == SSE_UNKNOWN) 330 check_for_sse_support(); 331 return sse_status == SSE_SUPPORTED; 332#endif // AMD64 333} 334 335bool os::is_allocatable(size_t bytes) { 336#ifdef AMD64 337 return true; 338#else 339 340 if (bytes < 2 * G) { 341 return true; 342 } 343 344 char* addr = reserve_memory(bytes, NULL); 345 346 if (addr != NULL) { 347 release_memory(addr, bytes); 348 } 349 350 return addr != NULL; 351#endif // AMD64 352 353} 354 355extern "C" void Fetch32PFI () ; 356extern "C" void Fetch32Resume () ; 357#ifdef AMD64 358extern "C" void FetchNPFI () ; 359extern "C" void FetchNResume () ; 360#endif // AMD64 361 362extern "C" JNIEXPORT int 363JVM_handle_solaris_signal(int sig, siginfo_t* info, void* ucVoid, 364 int abort_if_unrecognized) { 365 ucontext_t* uc = (ucontext_t*) ucVoid; 366 367#ifndef AMD64 368 if (sig == SIGILL && info->si_addr == (caddr_t)sse_check) { 369 // the SSE instruction faulted. supports_sse() need return false. 370 uc->uc_mcontext.gregs[EIP] = (greg_t)sse_unavailable; 371 return true; 372 } 373#endif // !AMD64 374 375 Thread* t = ThreadLocalStorage::get_thread_slow(); // slow & steady 376 377 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away 378 // (no destructors can be run) 379 os::WatcherThreadCrashProtection::check_crash_protection(sig, t); 380 381 SignalHandlerMark shm(t); 382 383 if(sig == SIGPIPE || sig == SIGXFSZ) { 384 if (os::Solaris::chained_handler(sig, info, ucVoid)) { 385 return true; 386 } else { 387 if (PrintMiscellaneous && (WizardMode || Verbose)) { 388 char buf[64]; 389 warning("Ignoring %s - see 4229104 or 6499219", 390 os::exception_name(sig, buf, sizeof(buf))); 391 392 } 393 return true; 394 } 395 } 396 397 JavaThread* thread = NULL; 398 VMThread* vmthread = NULL; 399 400 if (os::Solaris::signal_handlers_are_installed) { 401 if (t != NULL ){ 402 if(t->is_Java_thread()) { 403 thread = (JavaThread*)t; 404 } 405 else if(t->is_VM_thread()){ 406 vmthread = (VMThread *)t; 407 } 408 } 409 } 410 411 guarantee(sig != os::Solaris::SIGinterrupt(), "Can not chain VM interrupt signal, try -XX:+UseAltSigs"); 412 413 if (sig == os::Solaris::SIGasync()) { 414 if(thread || vmthread){ 415 OSThread::SR_handler(t, uc); 416 return true; 417 } else if (os::Solaris::chained_handler(sig, info, ucVoid)) { 418 return true; 419 } else { 420 // If os::Solaris::SIGasync not chained, and this is a non-vm and 421 // non-java thread 422 return true; 423 } 424 } 425 426 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) { 427 // can't decode this kind of signal 428 info = NULL; 429 } else { 430 assert(sig == info->si_signo, "bad siginfo"); 431 } 432 433 // decide if this trap can be handled by a stub 434 address stub = NULL; 435 436 address pc = NULL; 437 438 //%note os_trap_1 439 if (info != NULL && uc != NULL && thread != NULL) { 440 // factor me: getPCfromContext 441 pc = (address) uc->uc_mcontext.gregs[REG_PC]; 442 443 // SafeFetch32() support 444 if (pc == (address) Fetch32PFI) { 445 uc->uc_mcontext.gregs[REG_PC] = intptr_t(Fetch32Resume) ; 446 return true ; 447 } 448#ifdef AMD64 449 if (pc == (address) FetchNPFI) { 450 uc->uc_mcontext.gregs [REG_PC] = intptr_t(FetchNResume) ; 451 return true ; 452 } 453#endif // AMD64 454 455 // Handle ALL stack overflow variations here 456 if (sig == SIGSEGV && info->si_code == SEGV_ACCERR) { 457 address addr = (address) info->si_addr; 458 if (thread->in_stack_yellow_zone(addr)) { 459 thread->disable_stack_yellow_zone(); 460 if (thread->thread_state() == _thread_in_Java) { 461 // Throw a stack overflow exception. Guard pages will be reenabled 462 // while unwinding the stack. 463 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); 464 } else { 465 // Thread was in the vm or native code. Return and try to finish. 466 return true; 467 } 468 } else if (thread->in_stack_red_zone(addr)) { 469 // Fatal red zone violation. Disable the guard pages and fall through 470 // to handle_unexpected_exception way down below. 471 thread->disable_stack_red_zone(); 472 tty->print_raw_cr("An irrecoverable stack overflow has occurred."); 473 } 474 } 475 476 if (thread->thread_state() == _thread_in_vm) { 477 if (sig == SIGBUS && info->si_code == BUS_OBJERR && thread->doing_unsafe_access()) { 478 stub = StubRoutines::handler_for_unsafe_access(); 479 } 480 } 481 482 if (thread->thread_state() == _thread_in_Java) { 483 // Support Safepoint Polling 484 if ( sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) { 485 stub = SharedRuntime::get_poll_stub(pc); 486 } 487 else if (sig == SIGBUS && info->si_code == BUS_OBJERR) { 488 // BugId 4454115: A read from a MappedByteBuffer can fault 489 // here if the underlying file has been truncated. 490 // Do not crash the VM in such a case. 491 CodeBlob* cb = CodeCache::find_blob_unsafe(pc); 492 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL; 493 if (nm != NULL && nm->has_unsafe_access()) { 494 stub = StubRoutines::handler_for_unsafe_access(); 495 } 496 } 497 else 498 if (sig == SIGFPE && info->si_code == FPE_INTDIV) { 499 // integer divide by zero 500 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); 501 } 502#ifndef AMD64 503 else if (sig == SIGFPE && info->si_code == FPE_FLTDIV) { 504 // floating-point divide by zero 505 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); 506 } 507 else if (sig == SIGFPE && info->si_code == FPE_FLTINV) { 508 // The encoding of D2I in i486.ad can cause an exception prior 509 // to the fist instruction if there was an invalid operation 510 // pending. We want to dismiss that exception. From the win_32 511 // side it also seems that if it really was the fist causing 512 // the exception that we do the d2i by hand with different 513 // rounding. Seems kind of weird. QQQ TODO 514 // Note that we take the exception at the NEXT floating point instruction. 515 if (pc[0] == 0xDB) { 516 assert(pc[0] == 0xDB, "not a FIST opcode"); 517 assert(pc[1] == 0x14, "not a FIST opcode"); 518 assert(pc[2] == 0x24, "not a FIST opcode"); 519 return true; 520 } else { 521 assert(pc[-3] == 0xDB, "not an flt invalid opcode"); 522 assert(pc[-2] == 0x14, "not an flt invalid opcode"); 523 assert(pc[-1] == 0x24, "not an flt invalid opcode"); 524 } 525 } 526 else if (sig == SIGFPE ) { 527 tty->print_cr("caught SIGFPE, info 0x%x.", info->si_code); 528 } 529#endif // !AMD64 530 531 // QQQ It doesn't seem that we need to do this on x86 because we should be able 532 // to return properly from the handler without this extra stuff on the back side. 533 534 else if (sig == SIGSEGV && info->si_code > 0 && !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { 535 // Determination of interpreter/vtable stub/compiled code null exception 536 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 537 } 538 } 539 540 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in 541 // and the heap gets shrunk before the field access. 542 if ((sig == SIGSEGV) || (sig == SIGBUS)) { 543 address addr = JNI_FastGetField::find_slowcase_pc(pc); 544 if (addr != (address)-1) { 545 stub = addr; 546 } 547 } 548 549 // Check to see if we caught the safepoint code in the 550 // process of write protecting the memory serialization page. 551 // It write enables the page immediately after protecting it 552 // so we can just return to retry the write. 553 if ((sig == SIGSEGV) && 554 os::is_memory_serialize_page(thread, (address)info->si_addr)) { 555 // Block current thread until the memory serialize page permission restored. 556 os::block_on_serialize_page_trap(); 557 return true; 558 } 559 } 560 561 // Execution protection violation 562 // 563 // Preventative code for future versions of Solaris which may 564 // enable execution protection when running the 32-bit VM on AMD64. 565 // 566 // This should be kept as the last step in the triage. We don't 567 // have a dedicated trap number for a no-execute fault, so be 568 // conservative and allow other handlers the first shot. 569 // 570 // Note: We don't test that info->si_code == SEGV_ACCERR here. 571 // this si_code is so generic that it is almost meaningless; and 572 // the si_code for this condition may change in the future. 573 // Furthermore, a false-positive should be harmless. 574 if (UnguardOnExecutionViolation > 0 && 575 (sig == SIGSEGV || sig == SIGBUS) && 576 uc->uc_mcontext.gregs[TRAPNO] == T_PGFLT) { // page fault 577 int page_size = os::vm_page_size(); 578 address addr = (address) info->si_addr; 579 address pc = (address) uc->uc_mcontext.gregs[REG_PC]; 580 // Make sure the pc and the faulting address are sane. 581 // 582 // If an instruction spans a page boundary, and the page containing 583 // the beginning of the instruction is executable but the following 584 // page is not, the pc and the faulting address might be slightly 585 // different - we still want to unguard the 2nd page in this case. 586 // 587 // 15 bytes seems to be a (very) safe value for max instruction size. 588 bool pc_is_near_addr = 589 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15); 590 bool instr_spans_page_boundary = 591 (align_size_down((intptr_t) pc ^ (intptr_t) addr, 592 (intptr_t) page_size) > 0); 593 594 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) { 595 static volatile address last_addr = 596 (address) os::non_memory_address_word(); 597 598 // In conservative mode, don't unguard unless the address is in the VM 599 if (addr != last_addr && 600 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) { 601 602 // Make memory rwx and retry 603 address page_start = 604 (address) align_size_down((intptr_t) addr, (intptr_t) page_size); 605 bool res = os::protect_memory((char*) page_start, page_size, 606 os::MEM_PROT_RWX); 607 608 if (PrintMiscellaneous && Verbose) { 609 char buf[256]; 610 jio_snprintf(buf, sizeof(buf), "Execution protection violation " 611 "at " INTPTR_FORMAT 612 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr, 613 page_start, (res ? "success" : "failed"), errno); 614 tty->print_raw_cr(buf); 615 } 616 stub = pc; 617 618 // Set last_addr so if we fault again at the same address, we don't end 619 // up in an endless loop. 620 // 621 // There are two potential complications here. Two threads trapping at 622 // the same address at the same time could cause one of the threads to 623 // think it already unguarded, and abort the VM. Likely very rare. 624 // 625 // The other race involves two threads alternately trapping at 626 // different addresses and failing to unguard the page, resulting in 627 // an endless loop. This condition is probably even more unlikely than 628 // the first. 629 // 630 // Although both cases could be avoided by using locks or thread local 631 // last_addr, these solutions are unnecessary complication: this 632 // handler is a best-effort safety net, not a complete solution. It is 633 // disabled by default and should only be used as a workaround in case 634 // we missed any no-execute-unsafe VM code. 635 636 last_addr = addr; 637 } 638 } 639 } 640 641 if (stub != NULL) { 642 // save all thread context in case we need to restore it 643 644 if (thread != NULL) thread->set_saved_exception_pc(pc); 645 // 12/02/99: On Sparc it appears that the full context is also saved 646 // but as yet, no one looks at or restores that saved context 647 // factor me: setPC 648 uc->uc_mcontext.gregs[REG_PC] = (greg_t)stub; 649 return true; 650 } 651 652 // signal-chaining 653 if (os::Solaris::chained_handler(sig, info, ucVoid)) { 654 return true; 655 } 656 657#ifndef AMD64 658 // Workaround (bug 4900493) for Solaris kernel bug 4966651. 659 // Handle an undefined selector caused by an attempt to assign 660 // fs in libthread getipriptr(). With the current libthread design every 512 661 // thread creations the LDT for a private thread data structure is extended 662 // and thre is a hazard that and another thread attempting a thread creation 663 // will use a stale LDTR that doesn't reflect the structure's growth, 664 // causing a GP fault. 665 // Enforce the probable limit of passes through here to guard against an 666 // infinite loop if some other move to fs caused the GP fault. Note that 667 // this loop counter is ultimately a heuristic as it is possible for 668 // more than one thread to generate this fault at a time in an MP system. 669 // In the case of the loop count being exceeded or if the poll fails 670 // just fall through to a fatal error. 671 // If there is some other source of T_GPFLT traps and the text at EIP is 672 // unreadable this code will loop infinitely until the stack is exausted. 673 // The key to diagnosis in this case is to look for the bottom signal handler 674 // frame. 675 676 if(! IgnoreLibthreadGPFault) { 677 if (sig == SIGSEGV && uc->uc_mcontext.gregs[TRAPNO] == T_GPFLT) { 678 const unsigned char *p = 679 (unsigned const char *) uc->uc_mcontext.gregs[EIP]; 680 681 // Expected instruction? 682 683 if(p[0] == movlfs[0] && p[1] == movlfs[1]) { 684 685 Atomic::inc(&ldtr_refresh); 686 687 // Infinite loop? 688 689 if(ldtr_refresh < ((2 << 16) / PAGESIZE)) { 690 691 // No, force scheduling to get a fresh view of the LDTR 692 693 if(poll(NULL, 0, 10) == 0) { 694 695 // Retry the move 696 697 return false; 698 } 699 } 700 } 701 } 702 } 703#endif // !AMD64 704 705 if (!abort_if_unrecognized) { 706 // caller wants another chance, so give it to him 707 return false; 708 } 709 710 if (!os::Solaris::libjsig_is_loaded) { 711 struct sigaction oldAct; 712 sigaction(sig, (struct sigaction *)0, &oldAct); 713 if (oldAct.sa_sigaction != signalHandler) { 714 void* sighand = oldAct.sa_sigaction ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 715 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 716 warning("Unexpected Signal %d occurred under user-defined signal handler %#lx", sig, (long)sighand); 717 } 718 } 719 720 if (pc == NULL && uc != NULL) { 721 pc = (address) uc->uc_mcontext.gregs[REG_PC]; 722 } 723 724 // unmask current signal 725 sigset_t newset; 726 sigemptyset(&newset); 727 sigaddset(&newset, sig); 728 sigprocmask(SIG_UNBLOCK, &newset, NULL); 729 730 // Determine which sort of error to throw. Out of swap may signal 731 // on the thread stack, which could get a mapping error when touched. 732 address addr = (address) info->si_addr; 733 if (sig == SIGBUS && info->si_code == BUS_OBJERR && info->si_errno == ENOMEM) { 734 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "Out of swap space to map in thread stack."); 735 } 736 737 VMError err(t, sig, pc, info, ucVoid); 738 err.report_and_die(); 739 740 ShouldNotReachHere(); 741} 742 743void os::print_context(outputStream *st, void *context) { 744 if (context == NULL) return; 745 746 ucontext_t *uc = (ucontext_t*)context; 747 st->print_cr("Registers:"); 748#ifdef AMD64 749 st->print( "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]); 750 st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]); 751 st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]); 752 st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]); 753 st->cr(); 754 st->print( "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]); 755 st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]); 756 st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]); 757 st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]); 758 st->cr(); 759 st->print( "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]); 760 st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]); 761 st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]); 762 st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]); 763 st->cr(); 764 st->print( "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]); 765 st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]); 766 st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]); 767 st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]); 768 st->cr(); 769 st->print( "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]); 770 st->print(", RFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RFL]); 771#else 772 st->print( "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EAX]); 773 st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBX]); 774 st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ECX]); 775 st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDX]); 776 st->cr(); 777 st->print( "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[UESP]); 778 st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBP]); 779 st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ESI]); 780 st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDI]); 781 st->cr(); 782 st->print( "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EIP]); 783 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EFL]); 784#endif // AMD64 785 st->cr(); 786 st->cr(); 787 788 intptr_t *sp = (intptr_t *)os::Solaris::ucontext_get_sp(uc); 789 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp); 790 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t)); 791 st->cr(); 792 793 // Note: it may be unsafe to inspect memory near pc. For example, pc may 794 // point to garbage if entry point in an nmethod is corrupted. Leave 795 // this at the end, and hope for the best. 796 ExtendedPC epc = os::Solaris::ucontext_get_ExtendedPC(uc); 797 address pc = epc.pc(); 798 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc); 799 print_hex_dump(st, pc - 32, pc + 32, sizeof(char)); 800} 801 802void os::print_register_info(outputStream *st, void *context) { 803 if (context == NULL) return; 804 805 ucontext_t *uc = (ucontext_t*)context; 806 807 st->print_cr("Register to memory mapping:"); 808 st->cr(); 809 810 // this is horrendously verbose but the layout of the registers in the 811 // context does not match how we defined our abstract Register set, so 812 // we can't just iterate through the gregs area 813 814 // this is only for the "general purpose" registers 815 816#ifdef AMD64 817 st->print("RAX="); print_location(st, uc->uc_mcontext.gregs[REG_RAX]); 818 st->print("RBX="); print_location(st, uc->uc_mcontext.gregs[REG_RBX]); 819 st->print("RCX="); print_location(st, uc->uc_mcontext.gregs[REG_RCX]); 820 st->print("RDX="); print_location(st, uc->uc_mcontext.gregs[REG_RDX]); 821 st->print("RSP="); print_location(st, uc->uc_mcontext.gregs[REG_RSP]); 822 st->print("RBP="); print_location(st, uc->uc_mcontext.gregs[REG_RBP]); 823 st->print("RSI="); print_location(st, uc->uc_mcontext.gregs[REG_RSI]); 824 st->print("RDI="); print_location(st, uc->uc_mcontext.gregs[REG_RDI]); 825 st->print("R8 ="); print_location(st, uc->uc_mcontext.gregs[REG_R8]); 826 st->print("R9 ="); print_location(st, uc->uc_mcontext.gregs[REG_R9]); 827 st->print("R10="); print_location(st, uc->uc_mcontext.gregs[REG_R10]); 828 st->print("R11="); print_location(st, uc->uc_mcontext.gregs[REG_R11]); 829 st->print("R12="); print_location(st, uc->uc_mcontext.gregs[REG_R12]); 830 st->print("R13="); print_location(st, uc->uc_mcontext.gregs[REG_R13]); 831 st->print("R14="); print_location(st, uc->uc_mcontext.gregs[REG_R14]); 832 st->print("R15="); print_location(st, uc->uc_mcontext.gregs[REG_R15]); 833#else 834 st->print("EAX="); print_location(st, uc->uc_mcontext.gregs[EAX]); 835 st->print("EBX="); print_location(st, uc->uc_mcontext.gregs[EBX]); 836 st->print("ECX="); print_location(st, uc->uc_mcontext.gregs[ECX]); 837 st->print("EDX="); print_location(st, uc->uc_mcontext.gregs[EDX]); 838 st->print("ESP="); print_location(st, uc->uc_mcontext.gregs[UESP]); 839 st->print("EBP="); print_location(st, uc->uc_mcontext.gregs[EBP]); 840 st->print("ESI="); print_location(st, uc->uc_mcontext.gregs[ESI]); 841 st->print("EDI="); print_location(st, uc->uc_mcontext.gregs[EDI]); 842#endif 843 844 st->cr(); 845} 846 847 848#ifdef AMD64 849void os::Solaris::init_thread_fpu_state(void) { 850 // Nothing to do 851} 852#else 853// From solaris_i486.s 854extern "C" void fixcw(); 855 856void os::Solaris::init_thread_fpu_state(void) { 857 // Set fpu to 53 bit precision. This happens too early to use a stub. 858 fixcw(); 859} 860 861// These routines are the initial value of atomic_xchg_entry(), 862// atomic_cmpxchg_entry(), atomic_inc_entry() and fence_entry() 863// until initialization is complete. 864// TODO - replace with .il implementation when compiler supports it. 865 866typedef jint xchg_func_t (jint, volatile jint*); 867typedef jint cmpxchg_func_t (jint, volatile jint*, jint); 868typedef jlong cmpxchg_long_func_t(jlong, volatile jlong*, jlong); 869typedef jint add_func_t (jint, volatile jint*); 870 871jint os::atomic_xchg_bootstrap(jint exchange_value, volatile jint* dest) { 872 // try to use the stub: 873 xchg_func_t* func = CAST_TO_FN_PTR(xchg_func_t*, StubRoutines::atomic_xchg_entry()); 874 875 if (func != NULL) { 876 os::atomic_xchg_func = func; 877 return (*func)(exchange_value, dest); 878 } 879 assert(Threads::number_of_threads() == 0, "for bootstrap only"); 880 881 jint old_value = *dest; 882 *dest = exchange_value; 883 return old_value; 884} 885 886jint os::atomic_cmpxchg_bootstrap(jint exchange_value, volatile jint* dest, jint compare_value) { 887 // try to use the stub: 888 cmpxchg_func_t* func = CAST_TO_FN_PTR(cmpxchg_func_t*, StubRoutines::atomic_cmpxchg_entry()); 889 890 if (func != NULL) { 891 os::atomic_cmpxchg_func = func; 892 return (*func)(exchange_value, dest, compare_value); 893 } 894 assert(Threads::number_of_threads() == 0, "for bootstrap only"); 895 896 jint old_value = *dest; 897 if (old_value == compare_value) 898 *dest = exchange_value; 899 return old_value; 900} 901 902jlong os::atomic_cmpxchg_long_bootstrap(jlong exchange_value, volatile jlong* dest, jlong compare_value) { 903 // try to use the stub: 904 cmpxchg_long_func_t* func = CAST_TO_FN_PTR(cmpxchg_long_func_t*, StubRoutines::atomic_cmpxchg_long_entry()); 905 906 if (func != NULL) { 907 os::atomic_cmpxchg_long_func = func; 908 return (*func)(exchange_value, dest, compare_value); 909 } 910 assert(Threads::number_of_threads() == 0, "for bootstrap only"); 911 912 jlong old_value = *dest; 913 if (old_value == compare_value) 914 *dest = exchange_value; 915 return old_value; 916} 917 918jint os::atomic_add_bootstrap(jint add_value, volatile jint* dest) { 919 // try to use the stub: 920 add_func_t* func = CAST_TO_FN_PTR(add_func_t*, StubRoutines::atomic_add_entry()); 921 922 if (func != NULL) { 923 os::atomic_add_func = func; 924 return (*func)(add_value, dest); 925 } 926 assert(Threads::number_of_threads() == 0, "for bootstrap only"); 927 928 return (*dest) += add_value; 929} 930 931xchg_func_t* os::atomic_xchg_func = os::atomic_xchg_bootstrap; 932cmpxchg_func_t* os::atomic_cmpxchg_func = os::atomic_cmpxchg_bootstrap; 933cmpxchg_long_func_t* os::atomic_cmpxchg_long_func = os::atomic_cmpxchg_long_bootstrap; 934add_func_t* os::atomic_add_func = os::atomic_add_bootstrap; 935 936extern "C" void _solaris_raw_setup_fpu(address ptr); 937void os::setup_fpu() { 938 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std(); 939 _solaris_raw_setup_fpu(fpu_cntrl); 940} 941#endif // AMD64 942 943#ifndef PRODUCT 944void os::verify_stack_alignment() { 945#ifdef AMD64 946 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment"); 947#endif 948} 949#endif 950