os_solaris_x86.cpp revision 9867:3125c4a60cc9
1/* 2 * Copyright (c) 1999, 2015, 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/codeCache.hpp" 31#include "code/icBuffer.hpp" 32#include "code/vtableStubs.hpp" 33#include "interpreter/interpreter.hpp" 34#include "jvm_solaris.h" 35#include "memory/allocation.inline.hpp" 36#include "mutex_solaris.inline.hpp" 37#include "os_share_solaris.hpp" 38#include "prims/jniFastGetField.hpp" 39#include "prims/jvm.h" 40#include "prims/jvm_misc.hpp" 41#include "runtime/arguments.hpp" 42#include "runtime/atomic.inline.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 <setjmp.h> 63# include <errno.h> 64# include <dlfcn.h> 65# include <stdio.h> 66# include <unistd.h> 67# include <sys/resource.h> 68# include <thread.h> 69# include <sys/stat.h> 70# include <sys/time.h> 71# include <sys/filio.h> 72# include <sys/utsname.h> 73# include <sys/systeminfo.h> 74# include <sys/socket.h> 75# include <sys/trap.h> 76# include <sys/lwp.h> 77# include <pwd.h> 78# include <poll.h> 79# include <sys/lwp.h> 80# include <procfs.h> // see comment in <sys/procfs.h> 81 82#ifndef AMD64 83// QQQ seems useless at this point 84# define _STRUCTURED_PROC 1 // this gets us the new structured proc interfaces of 5.6 & later 85#endif // AMD64 86# include <sys/procfs.h> // see comment in <sys/procfs.h> 87 88 89#define MAX_PATH (2 * K) 90 91// Minimum stack size for the VM. It's easier to document a constant value 92// but it's different for x86 and sparc because the page sizes are different. 93#ifdef AMD64 94size_t os::Solaris::min_stack_allowed = 224*K; 95#define REG_SP REG_RSP 96#define REG_PC REG_RIP 97#define REG_FP REG_RBP 98#else 99size_t os::Solaris::min_stack_allowed = 64*K; 100#define REG_SP UESP 101#define REG_PC EIP 102#define REG_FP EBP 103// 4900493 counter to prevent runaway LDTR refresh attempt 104 105static volatile int ldtr_refresh = 0; 106// the libthread instruction that faults because of the stale LDTR 107 108static const unsigned char movlfs[] = { 0x8e, 0xe0 // movl %eax,%fs 109 }; 110#endif // AMD64 111 112char* os::non_memory_address_word() { 113 // Must never look like an address returned by reserve_memory, 114 // even in its subfields (as defined by the CPU immediate fields, 115 // if the CPU splits constants across multiple instructions). 116 return (char*) -1; 117} 118 119// 120// Validate a ucontext retrieved from walking a uc_link of a ucontext. 121// There are issues with libthread giving out uc_links for different threads 122// on the same uc_link chain and bad or circular links. 123// 124bool os::Solaris::valid_ucontext(Thread* thread, const ucontext_t* valid, const ucontext_t* suspect) { 125 if (valid >= suspect || 126 valid->uc_stack.ss_flags != suspect->uc_stack.ss_flags || 127 valid->uc_stack.ss_sp != suspect->uc_stack.ss_sp || 128 valid->uc_stack.ss_size != suspect->uc_stack.ss_size) { 129 DEBUG_ONLY(tty->print_cr("valid_ucontext: failed test 1");) 130 return false; 131 } 132 133 if (thread->is_Java_thread()) { 134 if (!valid_stack_address(thread, (address)suspect)) { 135 DEBUG_ONLY(tty->print_cr("valid_ucontext: uc_link not in thread stack");) 136 return false; 137 } 138 if (!valid_stack_address(thread, (address) suspect->uc_mcontext.gregs[REG_SP])) { 139 DEBUG_ONLY(tty->print_cr("valid_ucontext: stackpointer not in thread stack");) 140 return false; 141 } 142 } 143 return true; 144} 145 146// We will only follow one level of uc_link since there are libthread 147// issues with ucontext linking and it is better to be safe and just 148// let caller retry later. 149const ucontext_t* os::Solaris::get_valid_uc_in_signal_handler(Thread *thread, 150 const ucontext_t *uc) { 151 152 const ucontext_t *retuc = NULL; 153 154 if (uc != NULL) { 155 if (uc->uc_link == NULL) { 156 // cannot validate without uc_link so accept current ucontext 157 retuc = uc; 158 } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) { 159 // first ucontext is valid so try the next one 160 uc = uc->uc_link; 161 if (uc->uc_link == NULL) { 162 // cannot validate without uc_link so accept current ucontext 163 retuc = uc; 164 } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) { 165 // the ucontext one level down is also valid so return it 166 retuc = uc; 167 } 168 } 169 } 170 return retuc; 171} 172 173// Assumes ucontext is valid 174ExtendedPC os::Solaris::ucontext_get_ExtendedPC(const ucontext_t *uc) { 175 return ExtendedPC((address)uc->uc_mcontext.gregs[REG_PC]); 176} 177 178void os::Solaris::ucontext_set_pc(ucontext_t* uc, address pc) { 179 uc->uc_mcontext.gregs [REG_PC] = (greg_t) pc; 180} 181 182// Assumes ucontext is valid 183intptr_t* os::Solaris::ucontext_get_sp(const ucontext_t *uc) { 184 return (intptr_t*)uc->uc_mcontext.gregs[REG_SP]; 185} 186 187// Assumes ucontext is valid 188intptr_t* os::Solaris::ucontext_get_fp(const ucontext_t *uc) { 189 return (intptr_t*)uc->uc_mcontext.gregs[REG_FP]; 190} 191 192address os::Solaris::ucontext_get_pc(const ucontext_t *uc) { 193 return (address) uc->uc_mcontext.gregs[REG_PC]; 194} 195 196// For Forte Analyzer AsyncGetCallTrace profiling support - thread 197// is currently interrupted by SIGPROF. 198// 199// The difference between this and os::fetch_frame_from_context() is that 200// here we try to skip nested signal frames. 201// This method is also used for stack overflow signal handling. 202ExtendedPC os::Solaris::fetch_frame_from_ucontext(Thread* thread, 203 const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) { 204 205 assert(thread != NULL, "just checking"); 206 assert(ret_sp != NULL, "just checking"); 207 assert(ret_fp != NULL, "just checking"); 208 209 const ucontext_t *luc = os::Solaris::get_valid_uc_in_signal_handler(thread, uc); 210 return os::fetch_frame_from_context(luc, ret_sp, ret_fp); 211} 212 213ExtendedPC os::fetch_frame_from_context(const void* ucVoid, 214 intptr_t** ret_sp, intptr_t** ret_fp) { 215 216 ExtendedPC epc; 217 const ucontext_t *uc = (const ucontext_t*)ucVoid; 218 219 if (uc != NULL) { 220 epc = os::Solaris::ucontext_get_ExtendedPC(uc); 221 if (ret_sp) *ret_sp = os::Solaris::ucontext_get_sp(uc); 222 if (ret_fp) *ret_fp = os::Solaris::ucontext_get_fp(uc); 223 } else { 224 // construct empty ExtendedPC for return value checking 225 epc = ExtendedPC(NULL); 226 if (ret_sp) *ret_sp = (intptr_t *)NULL; 227 if (ret_fp) *ret_fp = (intptr_t *)NULL; 228 } 229 230 return epc; 231} 232 233frame os::fetch_frame_from_context(const void* ucVoid) { 234 intptr_t* sp; 235 intptr_t* fp; 236 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp); 237 return frame(sp, fp, epc.pc()); 238} 239 240frame os::fetch_frame_from_ucontext(Thread* thread, void* ucVoid) { 241 intptr_t* sp; 242 intptr_t* fp; 243 ExtendedPC epc = os::Solaris::fetch_frame_from_ucontext(thread, (ucontext_t*)ucVoid, &sp, &fp); 244 return frame(sp, fp, epc.pc()); 245} 246 247bool os::Solaris::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) { 248 address pc = (address) os::Solaris::ucontext_get_pc(uc); 249 if (Interpreter::contains(pc)) { 250 // interpreter performs stack banging after the fixed frame header has 251 // been generated while the compilers perform it before. To maintain 252 // semantic consistency between interpreted and compiled frames, the 253 // method returns the Java sender of the current frame. 254 *fr = os::fetch_frame_from_ucontext(thread, uc); 255 if (!fr->is_first_java_frame()) { 256 assert(fr->safe_for_sender(thread), "Safety check"); 257 *fr = fr->java_sender(); 258 } 259 } else { 260 // more complex code with compiled code 261 assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above"); 262 CodeBlob* cb = CodeCache::find_blob(pc); 263 if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) { 264 // Not sure where the pc points to, fallback to default 265 // stack overflow handling 266 return false; 267 } else { 268 // in compiled code, the stack banging is performed just after the return pc 269 // has been pushed on the stack 270 intptr_t* fp = os::Solaris::ucontext_get_fp(uc); 271 intptr_t* sp = os::Solaris::ucontext_get_sp(uc); 272 *fr = frame(sp + 1, fp, (address)*sp); 273 if (!fr->is_java_frame()) { 274 assert(fr->safe_for_sender(thread), "Safety check"); 275 *fr = fr->java_sender(); 276 } 277 } 278 } 279 assert(fr->is_java_frame(), "Safety check"); 280 return true; 281} 282 283frame os::get_sender_for_C_frame(frame* fr) { 284 return frame(fr->sender_sp(), fr->link(), fr->sender_pc()); 285} 286 287extern "C" intptr_t *_get_current_sp(); // in .il file 288 289address os::current_stack_pointer() { 290 return (address)_get_current_sp(); 291} 292 293extern "C" intptr_t *_get_current_fp(); // in .il file 294 295frame os::current_frame() { 296 intptr_t* fp = _get_current_fp(); // it's inlined so want current fp 297 frame myframe((intptr_t*)os::current_stack_pointer(), 298 (intptr_t*)fp, 299 CAST_FROM_FN_PTR(address, os::current_frame)); 300 if (os::is_first_C_frame(&myframe)) { 301 // stack is not walkable 302 frame ret; // This will be a null useless frame 303 return ret; 304 } else { 305 return os::get_sender_for_C_frame(&myframe); 306 } 307} 308 309#ifndef AMD64 310 311// Detecting SSE support by OS 312// From solaris_i486.s 313extern "C" bool sse_check(); 314extern "C" bool sse_unavailable(); 315 316enum { SSE_UNKNOWN, SSE_NOT_SUPPORTED, SSE_SUPPORTED}; 317static int sse_status = SSE_UNKNOWN; 318 319 320static void check_for_sse_support() { 321 if (!VM_Version::supports_sse()) { 322 sse_status = SSE_NOT_SUPPORTED; 323 return; 324 } 325 // looking for _sse_hw in libc.so, if it does not exist or 326 // the value (int) is 0, OS has no support for SSE 327 int *sse_hwp; 328 void *h; 329 330 if ((h=dlopen("/usr/lib/libc.so", RTLD_LAZY)) == NULL) { 331 //open failed, presume no support for SSE 332 sse_status = SSE_NOT_SUPPORTED; 333 return; 334 } 335 if ((sse_hwp = (int *)dlsym(h, "_sse_hw")) == NULL) { 336 sse_status = SSE_NOT_SUPPORTED; 337 } else if (*sse_hwp == 0) { 338 sse_status = SSE_NOT_SUPPORTED; 339 } 340 dlclose(h); 341 342 if (sse_status == SSE_UNKNOWN) { 343 bool (*try_sse)() = (bool (*)())sse_check; 344 sse_status = (*try_sse)() ? SSE_SUPPORTED : SSE_NOT_SUPPORTED; 345 } 346 347} 348 349#endif // AMD64 350 351bool os::supports_sse() { 352#ifdef AMD64 353 return true; 354#else 355 if (sse_status == SSE_UNKNOWN) 356 check_for_sse_support(); 357 return sse_status == SSE_SUPPORTED; 358#endif // AMD64 359} 360 361bool os::is_allocatable(size_t bytes) { 362#ifdef AMD64 363 return true; 364#else 365 366 if (bytes < 2 * G) { 367 return true; 368 } 369 370 char* addr = reserve_memory(bytes, NULL); 371 372 if (addr != NULL) { 373 release_memory(addr, bytes); 374 } 375 376 return addr != NULL; 377#endif // AMD64 378 379} 380 381extern "C" JNIEXPORT int 382JVM_handle_solaris_signal(int sig, siginfo_t* info, void* ucVoid, 383 int abort_if_unrecognized) { 384 ucontext_t* uc = (ucontext_t*) ucVoid; 385 386#ifndef AMD64 387 if (sig == SIGILL && info->si_addr == (caddr_t)sse_check) { 388 // the SSE instruction faulted. supports_sse() need return false. 389 uc->uc_mcontext.gregs[EIP] = (greg_t)sse_unavailable; 390 return true; 391 } 392#endif // !AMD64 393 394 Thread* t = Thread::current_or_null_safe(); 395 396 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away 397 // (no destructors can be run) 398 os::WatcherThreadCrashProtection::check_crash_protection(sig, t); 399 400 SignalHandlerMark shm(t); 401 402 if(sig == SIGPIPE || sig == SIGXFSZ) { 403 if (os::Solaris::chained_handler(sig, info, ucVoid)) { 404 return true; 405 } else { 406 if (PrintMiscellaneous && (WizardMode || Verbose)) { 407 char buf[64]; 408 warning("Ignoring %s - see 4229104 or 6499219", 409 os::exception_name(sig, buf, sizeof(buf))); 410 411 } 412 return true; 413 } 414 } 415 416 JavaThread* thread = NULL; 417 VMThread* vmthread = NULL; 418 419 if (os::Solaris::signal_handlers_are_installed) { 420 if (t != NULL ){ 421 if(t->is_Java_thread()) { 422 thread = (JavaThread*)t; 423 } 424 else if(t->is_VM_thread()){ 425 vmthread = (VMThread *)t; 426 } 427 } 428 } 429 430 if (sig == os::Solaris::SIGasync()) { 431 if(thread || vmthread){ 432 OSThread::SR_handler(t, uc); 433 return true; 434 } else if (os::Solaris::chained_handler(sig, info, ucVoid)) { 435 return true; 436 } else { 437 // If os::Solaris::SIGasync not chained, and this is a non-vm and 438 // non-java thread 439 return true; 440 } 441 } 442 443 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) { 444 // can't decode this kind of signal 445 info = NULL; 446 } else { 447 assert(sig == info->si_signo, "bad siginfo"); 448 } 449 450 // decide if this trap can be handled by a stub 451 address stub = NULL; 452 453 address pc = NULL; 454 455 //%note os_trap_1 456 if (info != NULL && uc != NULL && thread != NULL) { 457 // factor me: getPCfromContext 458 pc = (address) uc->uc_mcontext.gregs[REG_PC]; 459 460 if (StubRoutines::is_safefetch_fault(pc)) { 461 os::Solaris::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc)); 462 return true; 463 } 464 465 // Handle ALL stack overflow variations here 466 if (sig == SIGSEGV && info->si_code == SEGV_ACCERR) { 467 address addr = (address) info->si_addr; 468 if (thread->in_stack_yellow_reserved_zone(addr)) { 469 if (thread->thread_state() == _thread_in_Java) { 470 if (thread->in_stack_reserved_zone(addr)) { 471 frame fr; 472 if (os::Solaris::get_frame_at_stack_banging_point(thread, uc, &fr)) { 473 assert(fr.is_java_frame(), "Must be Java frame"); 474 frame activation = SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr); 475 if (activation.sp() != NULL) { 476 thread->disable_stack_reserved_zone(); 477 if (activation.is_interpreted_frame()) { 478 thread->set_reserved_stack_activation((address)( 479 activation.fp() + frame::interpreter_frame_initial_sp_offset)); 480 } else { 481 thread->set_reserved_stack_activation((address)activation.unextended_sp()); 482 } 483 return true; 484 } 485 } 486 } 487 // Throw a stack overflow exception. Guard pages will be reenabled 488 // while unwinding the stack. 489 thread->disable_stack_yellow_reserved_zone(); 490 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); 491 } else { 492 // Thread was in the vm or native code. Return and try to finish. 493 thread->disable_stack_yellow_reserved_zone(); 494 return true; 495 } 496 } else if (thread->in_stack_red_zone(addr)) { 497 // Fatal red zone violation. Disable the guard pages and fall through 498 // to handle_unexpected_exception way down below. 499 thread->disable_stack_red_zone(); 500 tty->print_raw_cr("An irrecoverable stack overflow has occurred."); 501 } 502 } 503 504 if ((sig == SIGSEGV) && VM_Version::is_cpuinfo_segv_addr(pc)) { 505 // Verify that OS save/restore AVX registers. 506 stub = VM_Version::cpuinfo_cont_addr(); 507 } 508 509 if (thread->thread_state() == _thread_in_vm) { 510 if (sig == SIGBUS && info->si_code == BUS_OBJERR && thread->doing_unsafe_access()) { 511 stub = StubRoutines::handler_for_unsafe_access(); 512 } 513 } 514 515 if (thread->thread_state() == _thread_in_Java) { 516 // Support Safepoint Polling 517 if ( sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) { 518 stub = SharedRuntime::get_poll_stub(pc); 519 } 520 else if (sig == SIGBUS && info->si_code == BUS_OBJERR) { 521 // BugId 4454115: A read from a MappedByteBuffer can fault 522 // here if the underlying file has been truncated. 523 // Do not crash the VM in such a case. 524 CodeBlob* cb = CodeCache::find_blob_unsafe(pc); 525 if (cb != NULL) { 526 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL; 527 if (nm != NULL && nm->has_unsafe_access()) { 528 stub = StubRoutines::handler_for_unsafe_access(); 529 } 530 } 531 } 532 else 533 if (sig == SIGFPE && info->si_code == FPE_INTDIV) { 534 // integer divide by zero 535 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); 536 } 537#ifndef AMD64 538 else if (sig == SIGFPE && info->si_code == FPE_FLTDIV) { 539 // floating-point divide by zero 540 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); 541 } 542 else if (sig == SIGFPE && info->si_code == FPE_FLTINV) { 543 // The encoding of D2I in i486.ad can cause an exception prior 544 // to the fist instruction if there was an invalid operation 545 // pending. We want to dismiss that exception. From the win_32 546 // side it also seems that if it really was the fist causing 547 // the exception that we do the d2i by hand with different 548 // rounding. Seems kind of weird. QQQ TODO 549 // Note that we take the exception at the NEXT floating point instruction. 550 if (pc[0] == 0xDB) { 551 assert(pc[0] == 0xDB, "not a FIST opcode"); 552 assert(pc[1] == 0x14, "not a FIST opcode"); 553 assert(pc[2] == 0x24, "not a FIST opcode"); 554 return true; 555 } else { 556 assert(pc[-3] == 0xDB, "not an flt invalid opcode"); 557 assert(pc[-2] == 0x14, "not an flt invalid opcode"); 558 assert(pc[-1] == 0x24, "not an flt invalid opcode"); 559 } 560 } 561 else if (sig == SIGFPE ) { 562 tty->print_cr("caught SIGFPE, info 0x%x.", info->si_code); 563 } 564#endif // !AMD64 565 566 // QQQ It doesn't seem that we need to do this on x86 because we should be able 567 // to return properly from the handler without this extra stuff on the back side. 568 569 else if (sig == SIGSEGV && info->si_code > 0 && !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { 570 // Determination of interpreter/vtable stub/compiled code null exception 571 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 572 } 573 } 574 575 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in 576 // and the heap gets shrunk before the field access. 577 if ((sig == SIGSEGV) || (sig == SIGBUS)) { 578 address addr = JNI_FastGetField::find_slowcase_pc(pc); 579 if (addr != (address)-1) { 580 stub = addr; 581 } 582 } 583 584 // Check to see if we caught the safepoint code in the 585 // process of write protecting the memory serialization page. 586 // It write enables the page immediately after protecting it 587 // so we can just return to retry the write. 588 if ((sig == SIGSEGV) && 589 os::is_memory_serialize_page(thread, (address)info->si_addr)) { 590 // Block current thread until the memory serialize page permission restored. 591 os::block_on_serialize_page_trap(); 592 return true; 593 } 594 } 595 596 // Execution protection violation 597 // 598 // Preventative code for future versions of Solaris which may 599 // enable execution protection when running the 32-bit VM on AMD64. 600 // 601 // This should be kept as the last step in the triage. We don't 602 // have a dedicated trap number for a no-execute fault, so be 603 // conservative and allow other handlers the first shot. 604 // 605 // Note: We don't test that info->si_code == SEGV_ACCERR here. 606 // this si_code is so generic that it is almost meaningless; and 607 // the si_code for this condition may change in the future. 608 // Furthermore, a false-positive should be harmless. 609 if (UnguardOnExecutionViolation > 0 && 610 (sig == SIGSEGV || sig == SIGBUS) && 611 uc->uc_mcontext.gregs[TRAPNO] == T_PGFLT) { // page fault 612 int page_size = os::vm_page_size(); 613 address addr = (address) info->si_addr; 614 address pc = (address) uc->uc_mcontext.gregs[REG_PC]; 615 // Make sure the pc and the faulting address are sane. 616 // 617 // If an instruction spans a page boundary, and the page containing 618 // the beginning of the instruction is executable but the following 619 // page is not, the pc and the faulting address might be slightly 620 // different - we still want to unguard the 2nd page in this case. 621 // 622 // 15 bytes seems to be a (very) safe value for max instruction size. 623 bool pc_is_near_addr = 624 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15); 625 bool instr_spans_page_boundary = 626 (align_size_down((intptr_t) pc ^ (intptr_t) addr, 627 (intptr_t) page_size) > 0); 628 629 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) { 630 static volatile address last_addr = 631 (address) os::non_memory_address_word(); 632 633 // In conservative mode, don't unguard unless the address is in the VM 634 if (addr != last_addr && 635 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) { 636 637 // Make memory rwx and retry 638 address page_start = 639 (address) align_size_down((intptr_t) addr, (intptr_t) page_size); 640 bool res = os::protect_memory((char*) page_start, page_size, 641 os::MEM_PROT_RWX); 642 643 if (PrintMiscellaneous && Verbose) { 644 char buf[256]; 645 jio_snprintf(buf, sizeof(buf), "Execution protection violation " 646 "at " INTPTR_FORMAT 647 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr, 648 page_start, (res ? "success" : "failed"), errno); 649 tty->print_raw_cr(buf); 650 } 651 stub = pc; 652 653 // Set last_addr so if we fault again at the same address, we don't end 654 // up in an endless loop. 655 // 656 // There are two potential complications here. Two threads trapping at 657 // the same address at the same time could cause one of the threads to 658 // think it already unguarded, and abort the VM. Likely very rare. 659 // 660 // The other race involves two threads alternately trapping at 661 // different addresses and failing to unguard the page, resulting in 662 // an endless loop. This condition is probably even more unlikely than 663 // the first. 664 // 665 // Although both cases could be avoided by using locks or thread local 666 // last_addr, these solutions are unnecessary complication: this 667 // handler is a best-effort safety net, not a complete solution. It is 668 // disabled by default and should only be used as a workaround in case 669 // we missed any no-execute-unsafe VM code. 670 671 last_addr = addr; 672 } 673 } 674 } 675 676 if (stub != NULL) { 677 // save all thread context in case we need to restore it 678 679 if (thread != NULL) thread->set_saved_exception_pc(pc); 680 // 12/02/99: On Sparc it appears that the full context is also saved 681 // but as yet, no one looks at or restores that saved context 682 os::Solaris::ucontext_set_pc(uc, stub); 683 return true; 684 } 685 686 // signal-chaining 687 if (os::Solaris::chained_handler(sig, info, ucVoid)) { 688 return true; 689 } 690 691#ifndef AMD64 692 // Workaround (bug 4900493) for Solaris kernel bug 4966651. 693 // Handle an undefined selector caused by an attempt to assign 694 // fs in libthread getipriptr(). With the current libthread design every 512 695 // thread creations the LDT for a private thread data structure is extended 696 // and thre is a hazard that and another thread attempting a thread creation 697 // will use a stale LDTR that doesn't reflect the structure's growth, 698 // causing a GP fault. 699 // Enforce the probable limit of passes through here to guard against an 700 // infinite loop if some other move to fs caused the GP fault. Note that 701 // this loop counter is ultimately a heuristic as it is possible for 702 // more than one thread to generate this fault at a time in an MP system. 703 // In the case of the loop count being exceeded or if the poll fails 704 // just fall through to a fatal error. 705 // If there is some other source of T_GPFLT traps and the text at EIP is 706 // unreadable this code will loop infinitely until the stack is exausted. 707 // The key to diagnosis in this case is to look for the bottom signal handler 708 // frame. 709 710 if(! IgnoreLibthreadGPFault) { 711 if (sig == SIGSEGV && uc->uc_mcontext.gregs[TRAPNO] == T_GPFLT) { 712 const unsigned char *p = 713 (unsigned const char *) uc->uc_mcontext.gregs[EIP]; 714 715 // Expected instruction? 716 717 if(p[0] == movlfs[0] && p[1] == movlfs[1]) { 718 719 Atomic::inc(&ldtr_refresh); 720 721 // Infinite loop? 722 723 if(ldtr_refresh < ((2 << 16) / PAGESIZE)) { 724 725 // No, force scheduling to get a fresh view of the LDTR 726 727 if(poll(NULL, 0, 10) == 0) { 728 729 // Retry the move 730 731 return false; 732 } 733 } 734 } 735 } 736 } 737#endif // !AMD64 738 739 if (!abort_if_unrecognized) { 740 // caller wants another chance, so give it to him 741 return false; 742 } 743 744 if (!os::Solaris::libjsig_is_loaded) { 745 struct sigaction oldAct; 746 sigaction(sig, (struct sigaction *)0, &oldAct); 747 if (oldAct.sa_sigaction != signalHandler) { 748 void* sighand = oldAct.sa_sigaction ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 749 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 750 warning("Unexpected Signal %d occurred under user-defined signal handler %#lx", sig, (long)sighand); 751 } 752 } 753 754 if (pc == NULL && uc != NULL) { 755 pc = (address) uc->uc_mcontext.gregs[REG_PC]; 756 } 757 758 // unmask current signal 759 sigset_t newset; 760 sigemptyset(&newset); 761 sigaddset(&newset, sig); 762 sigprocmask(SIG_UNBLOCK, &newset, NULL); 763 764 // Determine which sort of error to throw. Out of swap may signal 765 // on the thread stack, which could get a mapping error when touched. 766 address addr = (address) info->si_addr; 767 if (sig == SIGBUS && info->si_code == BUS_OBJERR && info->si_errno == ENOMEM) { 768 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "Out of swap space to map in thread stack."); 769 } 770 771 VMError::report_and_die(t, sig, pc, info, ucVoid); 772 773 ShouldNotReachHere(); 774 return false; 775} 776 777void os::print_context(outputStream *st, const void *context) { 778 if (context == NULL) return; 779 780 const ucontext_t *uc = (const ucontext_t*)context; 781 st->print_cr("Registers:"); 782#ifdef AMD64 783 st->print( "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]); 784 st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]); 785 st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]); 786 st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]); 787 st->cr(); 788 st->print( "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]); 789 st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]); 790 st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]); 791 st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]); 792 st->cr(); 793 st->print( "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]); 794 st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]); 795 st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]); 796 st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]); 797 st->cr(); 798 st->print( "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]); 799 st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]); 800 st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]); 801 st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]); 802 st->cr(); 803 st->print( "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]); 804 st->print(", RFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RFL]); 805#else 806 st->print( "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EAX]); 807 st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBX]); 808 st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ECX]); 809 st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDX]); 810 st->cr(); 811 st->print( "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[UESP]); 812 st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBP]); 813 st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ESI]); 814 st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDI]); 815 st->cr(); 816 st->print( "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EIP]); 817 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EFL]); 818#endif // AMD64 819 st->cr(); 820 st->cr(); 821 822 intptr_t *sp = (intptr_t *)os::Solaris::ucontext_get_sp(uc); 823 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp); 824 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t)); 825 st->cr(); 826 827 // Note: it may be unsafe to inspect memory near pc. For example, pc may 828 // point to garbage if entry point in an nmethod is corrupted. Leave 829 // this at the end, and hope for the best. 830 ExtendedPC epc = os::Solaris::ucontext_get_ExtendedPC(uc); 831 address pc = epc.pc(); 832 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc); 833 print_hex_dump(st, pc - 32, pc + 32, sizeof(char)); 834} 835 836void os::print_register_info(outputStream *st, const void *context) { 837 if (context == NULL) return; 838 839 const ucontext_t *uc = (const ucontext_t*)context; 840 841 st->print_cr("Register to memory mapping:"); 842 st->cr(); 843 844 // this is horrendously verbose but the layout of the registers in the 845 // context does not match how we defined our abstract Register set, so 846 // we can't just iterate through the gregs area 847 848 // this is only for the "general purpose" registers 849 850#ifdef AMD64 851 st->print("RAX="); print_location(st, uc->uc_mcontext.gregs[REG_RAX]); 852 st->print("RBX="); print_location(st, uc->uc_mcontext.gregs[REG_RBX]); 853 st->print("RCX="); print_location(st, uc->uc_mcontext.gregs[REG_RCX]); 854 st->print("RDX="); print_location(st, uc->uc_mcontext.gregs[REG_RDX]); 855 st->print("RSP="); print_location(st, uc->uc_mcontext.gregs[REG_RSP]); 856 st->print("RBP="); print_location(st, uc->uc_mcontext.gregs[REG_RBP]); 857 st->print("RSI="); print_location(st, uc->uc_mcontext.gregs[REG_RSI]); 858 st->print("RDI="); print_location(st, uc->uc_mcontext.gregs[REG_RDI]); 859 st->print("R8 ="); print_location(st, uc->uc_mcontext.gregs[REG_R8]); 860 st->print("R9 ="); print_location(st, uc->uc_mcontext.gregs[REG_R9]); 861 st->print("R10="); print_location(st, uc->uc_mcontext.gregs[REG_R10]); 862 st->print("R11="); print_location(st, uc->uc_mcontext.gregs[REG_R11]); 863 st->print("R12="); print_location(st, uc->uc_mcontext.gregs[REG_R12]); 864 st->print("R13="); print_location(st, uc->uc_mcontext.gregs[REG_R13]); 865 st->print("R14="); print_location(st, uc->uc_mcontext.gregs[REG_R14]); 866 st->print("R15="); print_location(st, uc->uc_mcontext.gregs[REG_R15]); 867#else 868 st->print("EAX="); print_location(st, uc->uc_mcontext.gregs[EAX]); 869 st->print("EBX="); print_location(st, uc->uc_mcontext.gregs[EBX]); 870 st->print("ECX="); print_location(st, uc->uc_mcontext.gregs[ECX]); 871 st->print("EDX="); print_location(st, uc->uc_mcontext.gregs[EDX]); 872 st->print("ESP="); print_location(st, uc->uc_mcontext.gregs[UESP]); 873 st->print("EBP="); print_location(st, uc->uc_mcontext.gregs[EBP]); 874 st->print("ESI="); print_location(st, uc->uc_mcontext.gregs[ESI]); 875 st->print("EDI="); print_location(st, uc->uc_mcontext.gregs[EDI]); 876#endif 877 878 st->cr(); 879} 880 881 882#ifdef AMD64 883void os::Solaris::init_thread_fpu_state(void) { 884 // Nothing to do 885} 886#else 887// From solaris_i486.s 888extern "C" void fixcw(); 889 890void os::Solaris::init_thread_fpu_state(void) { 891 // Set fpu to 53 bit precision. This happens too early to use a stub. 892 fixcw(); 893} 894 895// These routines are the initial value of atomic_xchg_entry(), 896// atomic_cmpxchg_entry(), atomic_inc_entry() and fence_entry() 897// until initialization is complete. 898// TODO - replace with .il implementation when compiler supports it. 899 900typedef jint xchg_func_t (jint, volatile jint*); 901typedef jint cmpxchg_func_t (jint, volatile jint*, jint); 902typedef jlong cmpxchg_long_func_t(jlong, volatile jlong*, jlong); 903typedef jint add_func_t (jint, volatile jint*); 904 905jint os::atomic_xchg_bootstrap(jint exchange_value, volatile jint* dest) { 906 // try to use the stub: 907 xchg_func_t* func = CAST_TO_FN_PTR(xchg_func_t*, StubRoutines::atomic_xchg_entry()); 908 909 if (func != NULL) { 910 os::atomic_xchg_func = func; 911 return (*func)(exchange_value, dest); 912 } 913 assert(Threads::number_of_threads() == 0, "for bootstrap only"); 914 915 jint old_value = *dest; 916 *dest = exchange_value; 917 return old_value; 918} 919 920jint os::atomic_cmpxchg_bootstrap(jint exchange_value, volatile jint* dest, jint compare_value) { 921 // try to use the stub: 922 cmpxchg_func_t* func = CAST_TO_FN_PTR(cmpxchg_func_t*, StubRoutines::atomic_cmpxchg_entry()); 923 924 if (func != NULL) { 925 os::atomic_cmpxchg_func = func; 926 return (*func)(exchange_value, dest, compare_value); 927 } 928 assert(Threads::number_of_threads() == 0, "for bootstrap only"); 929 930 jint old_value = *dest; 931 if (old_value == compare_value) 932 *dest = exchange_value; 933 return old_value; 934} 935 936jlong os::atomic_cmpxchg_long_bootstrap(jlong exchange_value, volatile jlong* dest, jlong compare_value) { 937 // try to use the stub: 938 cmpxchg_long_func_t* func = CAST_TO_FN_PTR(cmpxchg_long_func_t*, StubRoutines::atomic_cmpxchg_long_entry()); 939 940 if (func != NULL) { 941 os::atomic_cmpxchg_long_func = func; 942 return (*func)(exchange_value, dest, compare_value); 943 } 944 assert(Threads::number_of_threads() == 0, "for bootstrap only"); 945 946 jlong old_value = *dest; 947 if (old_value == compare_value) 948 *dest = exchange_value; 949 return old_value; 950} 951 952jint os::atomic_add_bootstrap(jint add_value, volatile jint* dest) { 953 // try to use the stub: 954 add_func_t* func = CAST_TO_FN_PTR(add_func_t*, StubRoutines::atomic_add_entry()); 955 956 if (func != NULL) { 957 os::atomic_add_func = func; 958 return (*func)(add_value, dest); 959 } 960 assert(Threads::number_of_threads() == 0, "for bootstrap only"); 961 962 return (*dest) += add_value; 963} 964 965xchg_func_t* os::atomic_xchg_func = os::atomic_xchg_bootstrap; 966cmpxchg_func_t* os::atomic_cmpxchg_func = os::atomic_cmpxchg_bootstrap; 967cmpxchg_long_func_t* os::atomic_cmpxchg_long_func = os::atomic_cmpxchg_long_bootstrap; 968add_func_t* os::atomic_add_func = os::atomic_add_bootstrap; 969 970extern "C" void _solaris_raw_setup_fpu(address ptr); 971void os::setup_fpu() { 972 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std(); 973 _solaris_raw_setup_fpu(fpu_cntrl); 974} 975#endif // AMD64 976 977#ifndef PRODUCT 978void os::verify_stack_alignment() { 979#ifdef AMD64 980 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment"); 981#endif 982} 983#endif 984 985int os::extra_bang_size_in_bytes() { 986 // JDK-8050147 requires the full cache line bang for x86. 987 return VM_Version::L1_line_size(); 988} 989