src/os_cpu/linux_x86/vm/os_linux_x86.cpp

Tue, 30 Apr 2013 11:56:52 -0700

author
ccheung
date
Tue, 30 Apr 2013 11:56:52 -0700
changeset 4993
746b070f5022
parent 4763
9ef47379df20
child 5230
2cb5d5f6d5e5
permissions
-rw-r--r--

8011661: Insufficient memory message says "malloc" when sometimes it should say "mmap"
Reviewed-by: coleenp, zgu, hseigel

duke@435 1 /*
mikael@4153 2 * Copyright (c) 1999, 2012, Oracle and/or its affiliates. All rights reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
trims@1907 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907 20 * or visit www.oracle.com if you need additional information or have any
trims@1907 21 * questions.
duke@435 22 *
duke@435 23 */
duke@435 24
stefank@2314 25 // no precompiled headers
twisti@4318 26 #include "asm/macroAssembler.hpp"
stefank@2314 27 #include "classfile/classLoader.hpp"
stefank@2314 28 #include "classfile/systemDictionary.hpp"
stefank@2314 29 #include "classfile/vmSymbols.hpp"
stefank@2314 30 #include "code/icBuffer.hpp"
stefank@2314 31 #include "code/vtableStubs.hpp"
stefank@2314 32 #include "interpreter/interpreter.hpp"
stefank@2314 33 #include "jvm_linux.h"
stefank@2314 34 #include "memory/allocation.inline.hpp"
stefank@2314 35 #include "mutex_linux.inline.hpp"
stefank@2314 36 #include "os_share_linux.hpp"
stefank@2314 37 #include "prims/jniFastGetField.hpp"
stefank@2314 38 #include "prims/jvm.h"
stefank@2314 39 #include "prims/jvm_misc.hpp"
stefank@2314 40 #include "runtime/arguments.hpp"
stefank@2314 41 #include "runtime/extendedPC.hpp"
stefank@2314 42 #include "runtime/frame.inline.hpp"
stefank@2314 43 #include "runtime/interfaceSupport.hpp"
stefank@2314 44 #include "runtime/java.hpp"
stefank@2314 45 #include "runtime/javaCalls.hpp"
stefank@2314 46 #include "runtime/mutexLocker.hpp"
stefank@2314 47 #include "runtime/osThread.hpp"
stefank@2314 48 #include "runtime/sharedRuntime.hpp"
stefank@2314 49 #include "runtime/stubRoutines.hpp"
stefank@4299 50 #include "runtime/thread.inline.hpp"
stefank@2314 51 #include "runtime/timer.hpp"
stefank@2314 52 #include "utilities/events.hpp"
stefank@2314 53 #include "utilities/vmError.hpp"
duke@435 54
duke@435 55 // put OS-includes here
duke@435 56 # include <sys/types.h>
duke@435 57 # include <sys/mman.h>
duke@435 58 # include <pthread.h>
duke@435 59 # include <signal.h>
duke@435 60 # include <errno.h>
duke@435 61 # include <dlfcn.h>
duke@435 62 # include <stdlib.h>
duke@435 63 # include <stdio.h>
duke@435 64 # include <unistd.h>
duke@435 65 # include <sys/resource.h>
duke@435 66 # include <pthread.h>
duke@435 67 # include <sys/stat.h>
duke@435 68 # include <sys/time.h>
duke@435 69 # include <sys/utsname.h>
duke@435 70 # include <sys/socket.h>
duke@435 71 # include <sys/wait.h>
duke@435 72 # include <pwd.h>
duke@435 73 # include <poll.h>
duke@435 74 # include <ucontext.h>
duke@435 75 # include <fpu_control.h>
duke@435 76
duke@435 77 #ifdef AMD64
duke@435 78 #define REG_SP REG_RSP
duke@435 79 #define REG_PC REG_RIP
duke@435 80 #define REG_FP REG_RBP
duke@435 81 #define SPELL_REG_SP "rsp"
duke@435 82 #define SPELL_REG_FP "rbp"
duke@435 83 #else
duke@435 84 #define REG_SP REG_UESP
duke@435 85 #define REG_PC REG_EIP
duke@435 86 #define REG_FP REG_EBP
duke@435 87 #define SPELL_REG_SP "esp"
duke@435 88 #define SPELL_REG_FP "ebp"
duke@435 89 #endif // AMD64
duke@435 90
duke@435 91 address os::current_stack_pointer() {
dcubed@485 92 #ifdef SPARC_WORKS
dcubed@485 93 register void *esp;
dcubed@485 94 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp));
dcubed@485 95 return (address) ((char*)esp + sizeof(long)*2);
dcubed@485 96 #else
duke@435 97 register void *esp __asm__ (SPELL_REG_SP);
duke@435 98 return (address) esp;
dcubed@485 99 #endif
duke@435 100 }
duke@435 101
duke@435 102 char* os::non_memory_address_word() {
duke@435 103 // Must never look like an address returned by reserve_memory,
duke@435 104 // even in its subfields (as defined by the CPU immediate fields,
duke@435 105 // if the CPU splits constants across multiple instructions).
duke@435 106
duke@435 107 return (char*) -1;
duke@435 108 }
duke@435 109
zgu@4079 110 void os::initialize_thread(Thread* thr) {
duke@435 111 // Nothing to do.
duke@435 112 }
duke@435 113
duke@435 114 address os::Linux::ucontext_get_pc(ucontext_t * uc) {
duke@435 115 return (address)uc->uc_mcontext.gregs[REG_PC];
duke@435 116 }
duke@435 117
duke@435 118 intptr_t* os::Linux::ucontext_get_sp(ucontext_t * uc) {
duke@435 119 return (intptr_t*)uc->uc_mcontext.gregs[REG_SP];
duke@435 120 }
duke@435 121
duke@435 122 intptr_t* os::Linux::ucontext_get_fp(ucontext_t * uc) {
duke@435 123 return (intptr_t*)uc->uc_mcontext.gregs[REG_FP];
duke@435 124 }
duke@435 125
duke@435 126 // For Forte Analyzer AsyncGetCallTrace profiling support - thread
duke@435 127 // is currently interrupted by SIGPROF.
duke@435 128 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal
duke@435 129 // frames. Currently we don't do that on Linux, so it's the same as
duke@435 130 // os::fetch_frame_from_context().
duke@435 131 ExtendedPC os::Linux::fetch_frame_from_ucontext(Thread* thread,
duke@435 132 ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
duke@435 133
duke@435 134 assert(thread != NULL, "just checking");
duke@435 135 assert(ret_sp != NULL, "just checking");
duke@435 136 assert(ret_fp != NULL, "just checking");
duke@435 137
duke@435 138 return os::fetch_frame_from_context(uc, ret_sp, ret_fp);
duke@435 139 }
duke@435 140
duke@435 141 ExtendedPC os::fetch_frame_from_context(void* ucVoid,
duke@435 142 intptr_t** ret_sp, intptr_t** ret_fp) {
duke@435 143
duke@435 144 ExtendedPC epc;
duke@435 145 ucontext_t* uc = (ucontext_t*)ucVoid;
duke@435 146
duke@435 147 if (uc != NULL) {
duke@435 148 epc = ExtendedPC(os::Linux::ucontext_get_pc(uc));
duke@435 149 if (ret_sp) *ret_sp = os::Linux::ucontext_get_sp(uc);
duke@435 150 if (ret_fp) *ret_fp = os::Linux::ucontext_get_fp(uc);
duke@435 151 } else {
duke@435 152 // construct empty ExtendedPC for return value checking
duke@435 153 epc = ExtendedPC(NULL);
duke@435 154 if (ret_sp) *ret_sp = (intptr_t *)NULL;
duke@435 155 if (ret_fp) *ret_fp = (intptr_t *)NULL;
duke@435 156 }
duke@435 157
duke@435 158 return epc;
duke@435 159 }
duke@435 160
duke@435 161 frame os::fetch_frame_from_context(void* ucVoid) {
duke@435 162 intptr_t* sp;
duke@435 163 intptr_t* fp;
duke@435 164 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
duke@435 165 return frame(sp, fp, epc.pc());
duke@435 166 }
duke@435 167
duke@435 168 // By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get
duke@435 169 // turned off by -fomit-frame-pointer,
duke@435 170 frame os::get_sender_for_C_frame(frame* fr) {
duke@435 171 return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
duke@435 172 }
duke@435 173
duke@435 174 intptr_t* _get_previous_fp() {
dcubed@485 175 #ifdef SPARC_WORKS
dcubed@485 176 register intptr_t **ebp;
dcubed@485 177 __asm__("mov %%"SPELL_REG_FP", %0":"=r"(ebp));
dcubed@485 178 #else
duke@435 179 register intptr_t **ebp __asm__ (SPELL_REG_FP);
dcubed@485 180 #endif
duke@435 181 return (intptr_t*) *ebp; // we want what it points to.
duke@435 182 }
duke@435 183
duke@435 184
duke@435 185 frame os::current_frame() {
duke@435 186 intptr_t* fp = _get_previous_fp();
duke@435 187 frame myframe((intptr_t*)os::current_stack_pointer(),
duke@435 188 (intptr_t*)fp,
duke@435 189 CAST_FROM_FN_PTR(address, os::current_frame));
duke@435 190 if (os::is_first_C_frame(&myframe)) {
duke@435 191 // stack is not walkable
dholmes@4528 192 return frame();
duke@435 193 } else {
duke@435 194 return os::get_sender_for_C_frame(&myframe);
duke@435 195 }
duke@435 196 }
duke@435 197
duke@435 198 // Utility functions
duke@435 199
duke@435 200 // From IA32 System Programming Guide
duke@435 201 enum {
duke@435 202 trap_page_fault = 0xE
duke@435 203 };
duke@435 204
duke@435 205 extern "C" void Fetch32PFI () ;
duke@435 206 extern "C" void Fetch32Resume () ;
duke@435 207 #ifdef AMD64
duke@435 208 extern "C" void FetchNPFI () ;
duke@435 209 extern "C" void FetchNResume () ;
duke@435 210 #endif // AMD64
duke@435 211
coleenp@2507 212 extern "C" JNIEXPORT int
duke@435 213 JVM_handle_linux_signal(int sig,
duke@435 214 siginfo_t* info,
duke@435 215 void* ucVoid,
duke@435 216 int abort_if_unrecognized) {
duke@435 217 ucontext_t* uc = (ucontext_t*) ucVoid;
duke@435 218
duke@435 219 Thread* t = ThreadLocalStorage::get_thread_slow();
duke@435 220
duke@435 221 SignalHandlerMark shm(t);
duke@435 222
duke@435 223 // Note: it's not uncommon that JNI code uses signal/sigset to install
duke@435 224 // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
duke@435 225 // or have a SIGILL handler when detecting CPU type). When that happens,
duke@435 226 // JVM_handle_linux_signal() might be invoked with junk info/ucVoid. To
duke@435 227 // avoid unnecessary crash when libjsig is not preloaded, try handle signals
duke@435 228 // that do not require siginfo/ucontext first.
duke@435 229
duke@435 230 if (sig == SIGPIPE || sig == SIGXFSZ) {
duke@435 231 // allow chained handler to go first
duke@435 232 if (os::Linux::chained_handler(sig, info, ucVoid)) {
duke@435 233 return true;
duke@435 234 } else {
duke@435 235 if (PrintMiscellaneous && (WizardMode || Verbose)) {
duke@435 236 char buf[64];
duke@435 237 warning("Ignoring %s - see bugs 4229104 or 646499219",
duke@435 238 os::exception_name(sig, buf, sizeof(buf)));
duke@435 239 }
duke@435 240 return true;
duke@435 241 }
duke@435 242 }
duke@435 243
duke@435 244 JavaThread* thread = NULL;
duke@435 245 VMThread* vmthread = NULL;
duke@435 246 if (os::Linux::signal_handlers_are_installed) {
duke@435 247 if (t != NULL ){
duke@435 248 if(t->is_Java_thread()) {
duke@435 249 thread = (JavaThread*)t;
duke@435 250 }
duke@435 251 else if(t->is_VM_thread()){
duke@435 252 vmthread = (VMThread *)t;
duke@435 253 }
duke@435 254 }
duke@435 255 }
duke@435 256 /*
duke@435 257 NOTE: does not seem to work on linux.
duke@435 258 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
duke@435 259 // can't decode this kind of signal
duke@435 260 info = NULL;
duke@435 261 } else {
duke@435 262 assert(sig == info->si_signo, "bad siginfo");
duke@435 263 }
duke@435 264 */
duke@435 265 // decide if this trap can be handled by a stub
duke@435 266 address stub = NULL;
duke@435 267
duke@435 268 address pc = NULL;
duke@435 269
duke@435 270 //%note os_trap_1
duke@435 271 if (info != NULL && uc != NULL && thread != NULL) {
duke@435 272 pc = (address) os::Linux::ucontext_get_pc(uc);
duke@435 273
duke@435 274 if (pc == (address) Fetch32PFI) {
duke@435 275 uc->uc_mcontext.gregs[REG_PC] = intptr_t(Fetch32Resume) ;
duke@435 276 return 1 ;
duke@435 277 }
duke@435 278 #ifdef AMD64
duke@435 279 if (pc == (address) FetchNPFI) {
duke@435 280 uc->uc_mcontext.gregs[REG_PC] = intptr_t (FetchNResume) ;
duke@435 281 return 1 ;
duke@435 282 }
duke@435 283 #endif // AMD64
duke@435 284
duke@435 285 // Handle ALL stack overflow variations here
duke@435 286 if (sig == SIGSEGV) {
duke@435 287 address addr = (address) info->si_addr;
duke@435 288
duke@435 289 // check if fault address is within thread stack
duke@435 290 if (addr < thread->stack_base() &&
duke@435 291 addr >= thread->stack_base() - thread->stack_size()) {
duke@435 292 // stack overflow
duke@435 293 if (thread->in_stack_yellow_zone(addr)) {
duke@435 294 thread->disable_stack_yellow_zone();
duke@435 295 if (thread->thread_state() == _thread_in_Java) {
duke@435 296 // Throw a stack overflow exception. Guard pages will be reenabled
duke@435 297 // while unwinding the stack.
duke@435 298 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
duke@435 299 } else {
duke@435 300 // Thread was in the vm or native code. Return and try to finish.
duke@435 301 return 1;
duke@435 302 }
duke@435 303 } else if (thread->in_stack_red_zone(addr)) {
duke@435 304 // Fatal red zone violation. Disable the guard pages and fall through
duke@435 305 // to handle_unexpected_exception way down below.
duke@435 306 thread->disable_stack_red_zone();
duke@435 307 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
iklam@4710 308
iklam@4710 309 // This is a likely cause, but hard to verify. Let's just print
iklam@4710 310 // it as a hint.
iklam@4710 311 tty->print_raw_cr("Please check if any of your loaded .so files has "
iklam@4710 312 "enabled executable stack (see man page execstack(8))");
duke@435 313 } else {
duke@435 314 // Accessing stack address below sp may cause SEGV if current
duke@435 315 // thread has MAP_GROWSDOWN stack. This should only happen when
duke@435 316 // current thread was created by user code with MAP_GROWSDOWN flag
duke@435 317 // and then attached to VM. See notes in os_linux.cpp.
duke@435 318 if (thread->osthread()->expanding_stack() == 0) {
duke@435 319 thread->osthread()->set_expanding_stack();
duke@435 320 if (os::Linux::manually_expand_stack(thread, addr)) {
duke@435 321 thread->osthread()->clear_expanding_stack();
duke@435 322 return 1;
duke@435 323 }
duke@435 324 thread->osthread()->clear_expanding_stack();
duke@435 325 } else {
duke@435 326 fatal("recursive segv. expanding stack.");
duke@435 327 }
duke@435 328 }
duke@435 329 }
duke@435 330 }
duke@435 331
duke@435 332 if (thread->thread_state() == _thread_in_Java) {
duke@435 333 // Java thread running in Java code => find exception handler if any
duke@435 334 // a fault inside compiled code, the interpreter, or a stub
duke@435 335
duke@435 336 if (sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) {
duke@435 337 stub = SharedRuntime::get_poll_stub(pc);
duke@435 338 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) {
duke@435 339 // BugId 4454115: A read from a MappedByteBuffer can fault
duke@435 340 // here if the underlying file has been truncated.
duke@435 341 // Do not crash the VM in such a case.
duke@435 342 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
morris@4763 343 nmethod* nm = (cb != NULL && cb->is_nmethod()) ? (nmethod*)cb : NULL;
duke@435 344 if (nm != NULL && nm->has_unsafe_access()) {
duke@435 345 stub = StubRoutines::handler_for_unsafe_access();
duke@435 346 }
duke@435 347 }
duke@435 348 else
duke@435 349
duke@435 350 #ifdef AMD64
duke@435 351 if (sig == SIGFPE &&
duke@435 352 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) {
duke@435 353 stub =
duke@435 354 SharedRuntime::
duke@435 355 continuation_for_implicit_exception(thread,
duke@435 356 pc,
duke@435 357 SharedRuntime::
duke@435 358 IMPLICIT_DIVIDE_BY_ZERO);
duke@435 359 #else
duke@435 360 if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) {
duke@435 361 // HACK: si_code does not work on linux 2.2.12-20!!!
duke@435 362 int op = pc[0];
duke@435 363 if (op == 0xDB) {
duke@435 364 // FIST
duke@435 365 // TODO: The encoding of D2I in i486.ad can cause an exception
duke@435 366 // prior to the fist instruction if there was an invalid operation
duke@435 367 // pending. We want to dismiss that exception. From the win_32
duke@435 368 // side it also seems that if it really was the fist causing
duke@435 369 // the exception that we do the d2i by hand with different
duke@435 370 // rounding. Seems kind of weird.
duke@435 371 // NOTE: that we take the exception at the NEXT floating point instruction.
duke@435 372 assert(pc[0] == 0xDB, "not a FIST opcode");
duke@435 373 assert(pc[1] == 0x14, "not a FIST opcode");
duke@435 374 assert(pc[2] == 0x24, "not a FIST opcode");
duke@435 375 return true;
duke@435 376 } else if (op == 0xF7) {
duke@435 377 // IDIV
duke@435 378 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
duke@435 379 } else {
duke@435 380 // TODO: handle more cases if we are using other x86 instructions
duke@435 381 // that can generate SIGFPE signal on linux.
duke@435 382 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op);
duke@435 383 fatal("please update this code.");
duke@435 384 }
duke@435 385 #endif // AMD64
duke@435 386 } else if (sig == SIGSEGV &&
duke@435 387 !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
duke@435 388 // Determination of interpreter/vtable stub/compiled code null exception
duke@435 389 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
duke@435 390 }
duke@435 391 } else if (thread->thread_state() == _thread_in_vm &&
duke@435 392 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */
duke@435 393 thread->doing_unsafe_access()) {
duke@435 394 stub = StubRoutines::handler_for_unsafe_access();
duke@435 395 }
duke@435 396
duke@435 397 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
duke@435 398 // and the heap gets shrunk before the field access.
duke@435 399 if ((sig == SIGSEGV) || (sig == SIGBUS)) {
duke@435 400 address addr = JNI_FastGetField::find_slowcase_pc(pc);
duke@435 401 if (addr != (address)-1) {
duke@435 402 stub = addr;
duke@435 403 }
duke@435 404 }
duke@435 405
duke@435 406 // Check to see if we caught the safepoint code in the
duke@435 407 // process of write protecting the memory serialization page.
duke@435 408 // It write enables the page immediately after protecting it
duke@435 409 // so we can just return to retry the write.
duke@435 410 if ((sig == SIGSEGV) &&
duke@435 411 os::is_memory_serialize_page(thread, (address) info->si_addr)) {
duke@435 412 // Block current thread until the memory serialize page permission restored.
duke@435 413 os::block_on_serialize_page_trap();
duke@435 414 return true;
duke@435 415 }
duke@435 416 }
duke@435 417
duke@435 418 #ifndef AMD64
duke@435 419 // Execution protection violation
duke@435 420 //
duke@435 421 // This should be kept as the last step in the triage. We don't
duke@435 422 // have a dedicated trap number for a no-execute fault, so be
duke@435 423 // conservative and allow other handlers the first shot.
duke@435 424 //
duke@435 425 // Note: We don't test that info->si_code == SEGV_ACCERR here.
duke@435 426 // this si_code is so generic that it is almost meaningless; and
duke@435 427 // the si_code for this condition may change in the future.
duke@435 428 // Furthermore, a false-positive should be harmless.
duke@435 429 if (UnguardOnExecutionViolation > 0 &&
duke@435 430 (sig == SIGSEGV || sig == SIGBUS) &&
duke@435 431 uc->uc_mcontext.gregs[REG_TRAPNO] == trap_page_fault) {
duke@435 432 int page_size = os::vm_page_size();
duke@435 433 address addr = (address) info->si_addr;
duke@435 434 address pc = os::Linux::ucontext_get_pc(uc);
duke@435 435 // Make sure the pc and the faulting address are sane.
duke@435 436 //
duke@435 437 // If an instruction spans a page boundary, and the page containing
duke@435 438 // the beginning of the instruction is executable but the following
duke@435 439 // page is not, the pc and the faulting address might be slightly
duke@435 440 // different - we still want to unguard the 2nd page in this case.
duke@435 441 //
duke@435 442 // 15 bytes seems to be a (very) safe value for max instruction size.
duke@435 443 bool pc_is_near_addr =
duke@435 444 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
duke@435 445 bool instr_spans_page_boundary =
duke@435 446 (align_size_down((intptr_t) pc ^ (intptr_t) addr,
duke@435 447 (intptr_t) page_size) > 0);
duke@435 448
duke@435 449 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
duke@435 450 static volatile address last_addr =
duke@435 451 (address) os::non_memory_address_word();
duke@435 452
duke@435 453 // In conservative mode, don't unguard unless the address is in the VM
duke@435 454 if (addr != last_addr &&
duke@435 455 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
duke@435 456
coleenp@912 457 // Set memory to RWX and retry
duke@435 458 address page_start =
duke@435 459 (address) align_size_down((intptr_t) addr, (intptr_t) page_size);
coleenp@912 460 bool res = os::protect_memory((char*) page_start, page_size,
coleenp@912 461 os::MEM_PROT_RWX);
duke@435 462
duke@435 463 if (PrintMiscellaneous && Verbose) {
duke@435 464 char buf[256];
duke@435 465 jio_snprintf(buf, sizeof(buf), "Execution protection violation "
duke@435 466 "at " INTPTR_FORMAT
duke@435 467 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr,
duke@435 468 page_start, (res ? "success" : "failed"), errno);
duke@435 469 tty->print_raw_cr(buf);
duke@435 470 }
duke@435 471 stub = pc;
duke@435 472
duke@435 473 // Set last_addr so if we fault again at the same address, we don't end
duke@435 474 // up in an endless loop.
duke@435 475 //
duke@435 476 // There are two potential complications here. Two threads trapping at
duke@435 477 // the same address at the same time could cause one of the threads to
duke@435 478 // think it already unguarded, and abort the VM. Likely very rare.
duke@435 479 //
duke@435 480 // The other race involves two threads alternately trapping at
duke@435 481 // different addresses and failing to unguard the page, resulting in
duke@435 482 // an endless loop. This condition is probably even more unlikely than
duke@435 483 // the first.
duke@435 484 //
duke@435 485 // Although both cases could be avoided by using locks or thread local
duke@435 486 // last_addr, these solutions are unnecessary complication: this
duke@435 487 // handler is a best-effort safety net, not a complete solution. It is
duke@435 488 // disabled by default and should only be used as a workaround in case
duke@435 489 // we missed any no-execute-unsafe VM code.
duke@435 490
duke@435 491 last_addr = addr;
duke@435 492 }
duke@435 493 }
duke@435 494 }
duke@435 495 #endif // !AMD64
duke@435 496
duke@435 497 if (stub != NULL) {
duke@435 498 // save all thread context in case we need to restore it
duke@435 499 if (thread != NULL) thread->set_saved_exception_pc(pc);
duke@435 500
duke@435 501 uc->uc_mcontext.gregs[REG_PC] = (greg_t)stub;
duke@435 502 return true;
duke@435 503 }
duke@435 504
duke@435 505 // signal-chaining
duke@435 506 if (os::Linux::chained_handler(sig, info, ucVoid)) {
duke@435 507 return true;
duke@435 508 }
duke@435 509
duke@435 510 if (!abort_if_unrecognized) {
duke@435 511 // caller wants another chance, so give it to him
duke@435 512 return false;
duke@435 513 }
duke@435 514
duke@435 515 if (pc == NULL && uc != NULL) {
duke@435 516 pc = os::Linux::ucontext_get_pc(uc);
duke@435 517 }
duke@435 518
duke@435 519 // unmask current signal
duke@435 520 sigset_t newset;
duke@435 521 sigemptyset(&newset);
duke@435 522 sigaddset(&newset, sig);
duke@435 523 sigprocmask(SIG_UNBLOCK, &newset, NULL);
duke@435 524
duke@435 525 VMError err(t, sig, pc, info, ucVoid);
duke@435 526 err.report_and_die();
duke@435 527
duke@435 528 ShouldNotReachHere();
duke@435 529 }
duke@435 530
duke@435 531 void os::Linux::init_thread_fpu_state(void) {
duke@435 532 #ifndef AMD64
duke@435 533 // set fpu to 53 bit precision
duke@435 534 set_fpu_control_word(0x27f);
duke@435 535 #endif // !AMD64
duke@435 536 }
duke@435 537
duke@435 538 int os::Linux::get_fpu_control_word(void) {
duke@435 539 #ifdef AMD64
duke@435 540 return 0;
duke@435 541 #else
duke@435 542 int fpu_control;
duke@435 543 _FPU_GETCW(fpu_control);
duke@435 544 return fpu_control & 0xffff;
duke@435 545 #endif // AMD64
duke@435 546 }
duke@435 547
duke@435 548 void os::Linux::set_fpu_control_word(int fpu_control) {
duke@435 549 #ifndef AMD64
duke@435 550 _FPU_SETCW(fpu_control);
duke@435 551 #endif // !AMD64
duke@435 552 }
duke@435 553
duke@435 554 // Check that the linux kernel version is 2.4 or higher since earlier
duke@435 555 // versions do not support SSE without patches.
duke@435 556 bool os::supports_sse() {
duke@435 557 #ifdef AMD64
duke@435 558 return true;
duke@435 559 #else
duke@435 560 struct utsname uts;
duke@435 561 if( uname(&uts) != 0 ) return false; // uname fails?
duke@435 562 char *minor_string;
duke@435 563 int major = strtol(uts.release,&minor_string,10);
duke@435 564 int minor = strtol(minor_string+1,NULL,10);
duke@435 565 bool result = (major > 2 || (major==2 && minor >= 4));
duke@435 566 #ifndef PRODUCT
duke@435 567 if (PrintMiscellaneous && Verbose) {
duke@435 568 tty->print("OS version is %d.%d, which %s support SSE/SSE2\n",
duke@435 569 major,minor, result ? "DOES" : "does NOT");
duke@435 570 }
duke@435 571 #endif
duke@435 572 return result;
duke@435 573 #endif // AMD64
duke@435 574 }
duke@435 575
duke@435 576 bool os::is_allocatable(size_t bytes) {
duke@435 577 #ifdef AMD64
duke@435 578 // unused on amd64?
duke@435 579 return true;
duke@435 580 #else
duke@435 581
duke@435 582 if (bytes < 2 * G) {
duke@435 583 return true;
duke@435 584 }
duke@435 585
duke@435 586 char* addr = reserve_memory(bytes, NULL);
duke@435 587
duke@435 588 if (addr != NULL) {
duke@435 589 release_memory(addr, bytes);
duke@435 590 }
duke@435 591
duke@435 592 return addr != NULL;
duke@435 593 #endif // AMD64
duke@435 594 }
duke@435 595
duke@435 596 ////////////////////////////////////////////////////////////////////////////////
duke@435 597 // thread stack
duke@435 598
duke@435 599 #ifdef AMD64
duke@435 600 size_t os::Linux::min_stack_allowed = 64 * K;
duke@435 601
duke@435 602 // amd64: pthread on amd64 is always in floating stack mode
duke@435 603 bool os::Linux::supports_variable_stack_size() { return true; }
duke@435 604 #else
duke@435 605 size_t os::Linux::min_stack_allowed = (48 DEBUG_ONLY(+4))*K;
duke@435 606
dcubed@485 607 #ifdef __GNUC__
duke@435 608 #define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;})
dcubed@485 609 #endif
duke@435 610
duke@435 611 // Test if pthread library can support variable thread stack size. LinuxThreads
duke@435 612 // in fixed stack mode allocates 2M fixed slot for each thread. LinuxThreads
duke@435 613 // in floating stack mode and NPTL support variable stack size.
duke@435 614 bool os::Linux::supports_variable_stack_size() {
duke@435 615 if (os::Linux::is_NPTL()) {
duke@435 616 // NPTL, yes
duke@435 617 return true;
duke@435 618
duke@435 619 } else {
duke@435 620 // Note: We can't control default stack size when creating a thread.
duke@435 621 // If we use non-default stack size (pthread_attr_setstacksize), both
duke@435 622 // floating stack and non-floating stack LinuxThreads will return the
duke@435 623 // same value. This makes it impossible to implement this function by
duke@435 624 // detecting thread stack size directly.
duke@435 625 //
duke@435 626 // An alternative approach is to check %gs. Fixed-stack LinuxThreads
duke@435 627 // do not use %gs, so its value is 0. Floating-stack LinuxThreads use
duke@435 628 // %gs (either as LDT selector or GDT selector, depending on kernel)
duke@435 629 // to access thread specific data.
duke@435 630 //
duke@435 631 // Note that %gs is a reserved glibc register since early 2001, so
duke@435 632 // applications are not allowed to change its value (Ulrich Drepper from
duke@435 633 // Redhat confirmed that all known offenders have been modified to use
duke@435 634 // either %fs or TSD). In the worst case scenario, when VM is embedded in
duke@435 635 // a native application that plays with %gs, we might see non-zero %gs
duke@435 636 // even LinuxThreads is running in fixed stack mode. As the result, we'll
duke@435 637 // return true and skip _thread_safety_check(), so we may not be able to
duke@435 638 // detect stack-heap collisions. But otherwise it's harmless.
duke@435 639 //
dcubed@485 640 #ifdef __GNUC__
duke@435 641 return (GET_GS() != 0);
dcubed@485 642 #else
dcubed@485 643 return false;
dcubed@485 644 #endif
duke@435 645 }
duke@435 646 }
duke@435 647 #endif // AMD64
duke@435 648
duke@435 649 // return default stack size for thr_type
duke@435 650 size_t os::Linux::default_stack_size(os::ThreadType thr_type) {
duke@435 651 // default stack size (compiler thread needs larger stack)
duke@435 652 #ifdef AMD64
duke@435 653 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
duke@435 654 #else
duke@435 655 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K);
duke@435 656 #endif // AMD64
duke@435 657 return s;
duke@435 658 }
duke@435 659
duke@435 660 size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
duke@435 661 // Creating guard page is very expensive. Java thread has HotSpot
duke@435 662 // guard page, only enable glibc guard page for non-Java threads.
duke@435 663 return (thr_type == java_thread ? 0 : page_size());
duke@435 664 }
duke@435 665
duke@435 666 // Java thread:
duke@435 667 //
duke@435 668 // Low memory addresses
duke@435 669 // +------------------------+
duke@435 670 // | |\ JavaThread created by VM does not have glibc
duke@435 671 // | glibc guard page | - guard, attached Java thread usually has
duke@435 672 // | |/ 1 page glibc guard.
duke@435 673 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
duke@435 674 // | |\
duke@435 675 // | HotSpot Guard Pages | - red and yellow pages
duke@435 676 // | |/
duke@435 677 // +------------------------+ JavaThread::stack_yellow_zone_base()
duke@435 678 // | |\
duke@435 679 // | Normal Stack | -
duke@435 680 // | |/
duke@435 681 // P2 +------------------------+ Thread::stack_base()
duke@435 682 //
duke@435 683 // Non-Java thread:
duke@435 684 //
duke@435 685 // Low memory addresses
duke@435 686 // +------------------------+
duke@435 687 // | |\
duke@435 688 // | glibc guard page | - usually 1 page
duke@435 689 // | |/
duke@435 690 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size()
duke@435 691 // | |\
duke@435 692 // | Normal Stack | -
duke@435 693 // | |/
duke@435 694 // P2 +------------------------+ Thread::stack_base()
duke@435 695 //
duke@435 696 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from
duke@435 697 // pthread_attr_getstack()
duke@435 698
duke@435 699 static void current_stack_region(address * bottom, size_t * size) {
duke@435 700 if (os::Linux::is_initial_thread()) {
duke@435 701 // initial thread needs special handling because pthread_getattr_np()
duke@435 702 // may return bogus value.
duke@435 703 *bottom = os::Linux::initial_thread_stack_bottom();
duke@435 704 *size = os::Linux::initial_thread_stack_size();
duke@435 705 } else {
duke@435 706 pthread_attr_t attr;
duke@435 707
duke@435 708 int rslt = pthread_getattr_np(pthread_self(), &attr);
duke@435 709
duke@435 710 // JVM needs to know exact stack location, abort if it fails
duke@435 711 if (rslt != 0) {
duke@435 712 if (rslt == ENOMEM) {
ccheung@4993 713 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np");
duke@435 714 } else {
jcoomes@1845 715 fatal(err_msg("pthread_getattr_np failed with errno = %d", rslt));
duke@435 716 }
duke@435 717 }
duke@435 718
duke@435 719 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) {
duke@435 720 fatal("Can not locate current stack attributes!");
duke@435 721 }
duke@435 722
duke@435 723 pthread_attr_destroy(&attr);
duke@435 724
duke@435 725 }
duke@435 726 assert(os::current_stack_pointer() >= *bottom &&
duke@435 727 os::current_stack_pointer() < *bottom + *size, "just checking");
duke@435 728 }
duke@435 729
duke@435 730 address os::current_stack_base() {
duke@435 731 address bottom;
duke@435 732 size_t size;
duke@435 733 current_stack_region(&bottom, &size);
duke@435 734 return (bottom + size);
duke@435 735 }
duke@435 736
duke@435 737 size_t os::current_stack_size() {
duke@435 738 // stack size includes normal stack and HotSpot guard pages
duke@435 739 address bottom;
duke@435 740 size_t size;
duke@435 741 current_stack_region(&bottom, &size);
duke@435 742 return size;
duke@435 743 }
duke@435 744
duke@435 745 /////////////////////////////////////////////////////////////////////////////
duke@435 746 // helper functions for fatal error handler
duke@435 747
duke@435 748 void os::print_context(outputStream *st, void *context) {
duke@435 749 if (context == NULL) return;
duke@435 750
duke@435 751 ucontext_t *uc = (ucontext_t*)context;
duke@435 752 st->print_cr("Registers:");
duke@435 753 #ifdef AMD64
duke@435 754 st->print( "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]);
duke@435 755 st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]);
duke@435 756 st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]);
duke@435 757 st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]);
duke@435 758 st->cr();
duke@435 759 st->print( "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]);
duke@435 760 st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]);
duke@435 761 st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]);
duke@435 762 st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]);
duke@435 763 st->cr();
duke@435 764 st->print( "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]);
duke@435 765 st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]);
duke@435 766 st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]);
duke@435 767 st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]);
duke@435 768 st->cr();
duke@435 769 st->print( "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]);
duke@435 770 st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]);
duke@435 771 st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]);
duke@435 772 st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]);
duke@435 773 st->cr();
duke@435 774 st->print( "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]);
never@2262 775 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EFL]);
duke@435 776 st->print(", CSGSFS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_CSGSFS]);
duke@435 777 st->print(", ERR=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ERR]);
duke@435 778 st->cr();
duke@435 779 st->print(" TRAPNO=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_TRAPNO]);
duke@435 780 #else
duke@435 781 st->print( "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EAX]);
duke@435 782 st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBX]);
duke@435 783 st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ECX]);
duke@435 784 st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDX]);
duke@435 785 st->cr();
duke@435 786 st->print( "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_UESP]);
duke@435 787 st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EBP]);
duke@435 788 st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_ESI]);
duke@435 789 st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EDI]);
duke@435 790 st->cr();
duke@435 791 st->print( "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EIP]);
never@2262 792 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_EFL]);
duke@435 793 st->print(", CR2=" INTPTR_FORMAT, uc->uc_mcontext.cr2);
duke@435 794 #endif // AMD64
duke@435 795 st->cr();
duke@435 796 st->cr();
duke@435 797
duke@435 798 intptr_t *sp = (intptr_t *)os::Linux::ucontext_get_sp(uc);
duke@435 799 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
duke@435 800 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
duke@435 801 st->cr();
duke@435 802
duke@435 803 // Note: it may be unsafe to inspect memory near pc. For example, pc may
duke@435 804 // point to garbage if entry point in an nmethod is corrupted. Leave
duke@435 805 // this at the end, and hope for the best.
duke@435 806 address pc = os::Linux::ucontext_get_pc(uc);
duke@435 807 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
never@2262 808 print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
never@2262 809 }
never@2262 810
never@2262 811 void os::print_register_info(outputStream *st, void *context) {
never@2262 812 if (context == NULL) return;
never@2262 813
never@2262 814 ucontext_t *uc = (ucontext_t*)context;
never@2262 815
never@2262 816 st->print_cr("Register to memory mapping:");
never@2262 817 st->cr();
never@2262 818
never@2262 819 // this is horrendously verbose but the layout of the registers in the
never@2262 820 // context does not match how we defined our abstract Register set, so
never@2262 821 // we can't just iterate through the gregs area
never@2262 822
never@2262 823 // this is only for the "general purpose" registers
never@2262 824
never@2262 825 #ifdef AMD64
never@2262 826 st->print("RAX="); print_location(st, uc->uc_mcontext.gregs[REG_RAX]);
never@2262 827 st->print("RBX="); print_location(st, uc->uc_mcontext.gregs[REG_RBX]);
never@2262 828 st->print("RCX="); print_location(st, uc->uc_mcontext.gregs[REG_RCX]);
never@2262 829 st->print("RDX="); print_location(st, uc->uc_mcontext.gregs[REG_RDX]);
never@2262 830 st->print("RSP="); print_location(st, uc->uc_mcontext.gregs[REG_RSP]);
never@2262 831 st->print("RBP="); print_location(st, uc->uc_mcontext.gregs[REG_RBP]);
never@2262 832 st->print("RSI="); print_location(st, uc->uc_mcontext.gregs[REG_RSI]);
never@2262 833 st->print("RDI="); print_location(st, uc->uc_mcontext.gregs[REG_RDI]);
never@2262 834 st->print("R8 ="); print_location(st, uc->uc_mcontext.gregs[REG_R8]);
never@2262 835 st->print("R9 ="); print_location(st, uc->uc_mcontext.gregs[REG_R9]);
never@2262 836 st->print("R10="); print_location(st, uc->uc_mcontext.gregs[REG_R10]);
never@2262 837 st->print("R11="); print_location(st, uc->uc_mcontext.gregs[REG_R11]);
never@2262 838 st->print("R12="); print_location(st, uc->uc_mcontext.gregs[REG_R12]);
never@2262 839 st->print("R13="); print_location(st, uc->uc_mcontext.gregs[REG_R13]);
never@2262 840 st->print("R14="); print_location(st, uc->uc_mcontext.gregs[REG_R14]);
never@2262 841 st->print("R15="); print_location(st, uc->uc_mcontext.gregs[REG_R15]);
never@2262 842 #else
never@2262 843 st->print("EAX="); print_location(st, uc->uc_mcontext.gregs[REG_EAX]);
never@2262 844 st->print("EBX="); print_location(st, uc->uc_mcontext.gregs[REG_EBX]);
never@2262 845 st->print("ECX="); print_location(st, uc->uc_mcontext.gregs[REG_ECX]);
never@2262 846 st->print("EDX="); print_location(st, uc->uc_mcontext.gregs[REG_EDX]);
never@2262 847 st->print("ESP="); print_location(st, uc->uc_mcontext.gregs[REG_ESP]);
never@2262 848 st->print("EBP="); print_location(st, uc->uc_mcontext.gregs[REG_EBP]);
never@2262 849 st->print("ESI="); print_location(st, uc->uc_mcontext.gregs[REG_ESI]);
never@2262 850 st->print("EDI="); print_location(st, uc->uc_mcontext.gregs[REG_EDI]);
never@2262 851 #endif // AMD64
never@2262 852
never@2262 853 st->cr();
duke@435 854 }
duke@435 855
duke@435 856 void os::setup_fpu() {
duke@435 857 #ifndef AMD64
duke@435 858 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std();
duke@435 859 __asm__ volatile ( "fldcw (%0)" :
duke@435 860 : "r" (fpu_cntrl) : "memory");
duke@435 861 #endif // !AMD64
duke@435 862 }
roland@3606 863
roland@3606 864 #ifndef PRODUCT
roland@3606 865 void os::verify_stack_alignment() {
roland@3606 866 #ifdef AMD64
roland@3606 867 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
roland@3606 868 #endif
roland@3606 869 }
roland@3606 870 #endif

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